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Sample records for accumulated residues resulting

  1. Glove accumulation of pesticide residues for strawberry harvester exposure assessment.

    PubMed

    Li, Yanhong; Chen, Li; Chen, Zhenshan; Coehlo, Joe; Cui, Li; Liu, Yu; Lopez, Terry; Sankaran, Gayatri; Vega, Helen; Krieger, Robert

    2011-06-01

    We investigated the accumulation of pesticide residues on rubber latex gloves that are used by strawberry harvesters to protect their skin, reduce pesticide exposure and promote food safety. Gloves accumulated residues of 16 active ingredients including azoxystrobin, bifenthrin, boscalid, captan, cyprodinil, fenhexamid, fenpropathrin, fludioxonil, hexythiazox, malathion, methomyl, naled, propiconazole, pyraclostrobin, quinoline, and quinoxyfen at different times. Glove residue accumulation (t(½) 2.8-3.7 d) was very similar to the dissipation of DFRs (t(½) 2.1-3.0 d) during the first 3 weeks after malathion applications. Dermal malathion dose was 0.2 mg/kg at the preharvest interval and declined to trace levels during the following 3 months. Glove accumulation of malathion indicated trace surface residue availability and was used to assess the relationship between dislodgable foliar residues and potential hand exposure.

  2. Incorporating rice residues into paddy soils affects methylmercury accumulation in rice.

    PubMed

    Zhu, Huike; Zhong, Huan; Wu, Jialu

    2016-06-01

    Paddy fields are characterized by frequent organic input (e.g., fertilization and rice residue amendment), which may affect mercury biogeochemistry and bioaccumulation. To explore potential effects of rice residue amendment on methylmercury (MMHg) accumulation in rice, a mercury-contaminated paddy soil was amended with rice root (RR), rice straw (RS) or composted rice straw (CS), and planted with rice. Incorporating RS or CS increased grain MMHg concentration by 14% or 11%. The observed increases could be attributed to the elevated porewater MMHg levels and thus enhanced MMHg uptake by plants, as well as increased MMHg translocation to grain within plants. Our results indicated for the first time that rice residue amendment could significantly affect MMHg accumulation in rice grain, which should be considered in risk assessment of MMHg in contaminated areas.

  3. Accumulation of lead and organochlorine residues in captive American kestrels fed pine voles from apple orchards

    USGS Publications Warehouse

    Stendell, R.C.; Beyer, W.N.; Stehn, R.A.

    1989-01-01

    Pine voles (Microtus pinetorum) were collected from pesticide-treated orchards in New York and fed to 3 captive American kestrels (Falco sparverius) for 60 days to evaluate potential hazards from soil-borne persistent insecticides. Three control kestrels were fed uncontaminated laboratory mice (Mus musculus). The pine voles contained an average of 38 ppm lead, 48 ppm DDE and 1.2 ppm dieldrin (dry weight). The kestrels accumulated sublethal amounts of lead (1 ppm lead wet weight) in their livers. In contrast, DDE and dieldrin accumulated in the tissues and brains of kestrels to toxicologically significant concentrations. Control kestrels remained healthy and accumulated insignificant concentrations of the contaminants. The results indicated raptors may not be significantly at risk from lead residues in soil and biota following field applications of lead arsenate. However, sublethal effects may be expected from the level of contamination by organochlorine pesticides. raptors may not be significantly at risk from lead residues in soil and biota following field applications of lead arsenate. However, sublethal effects may be expected from the level of contamination byorganochlorine pesticides. lead wet weight) in their livers.

  4. Accumulation and residue of napropamide in alfalfa (Medicago sativa) and soil involved in toxic response.

    PubMed

    Cui, Li E; Yang, Hong

    2011-06-15

    Napropamide belongs to the amide herbicide family and widely used to control weeds in farmland. Intensive use of the herbicide has resulted in widespread contamination to ecosystems. The present study demonstrated an analysis on accumulation of the toxic pesticide napropamide in six genotypes of alfalfa (Medicago sativa), along with biological parameters and its residues in soils. Soil was treated with napropamide at 3 mg kg(-1) dry soil and alfalfa plants were cultured for 10 or 30 d, respectively. The maximum value for napropamide accumulation is 0.426 mg kg(-1) in shoots and 2.444 mg kg(-1) in roots. The napropamide-contaminated soil with alfalfa cultivation had much lower napropamide concentrations than the control (soil without alfalfa cultivation). Also, the content of napropamide residue in the rhizosphere was significantly lower than that in the non-rhizosphere soil. M. sativa exposed to 3 mg kg(-1) napropamide showed inhibited growth. Further analysis revealed that plants treated with napropamide accumulated more reactive oxygen species (O(2)(-) and H(2)O(2)) and less amounts of chlorophyll. However, not all cultivars showed oxidative injury, suggesting that the alfalfa cultivars display different tolerance to napropamide.

  5. Accumulation of clenbuterol residues in the hair of Chinese Simmental beef cattle during and after treatment.

    PubMed

    Li, Lijun; Zhang, Junmin; Tang, Chaohua; Zhao, Qingyu

    2014-01-01

    The aim of this study was to evaluate the concentrations of clenbuterol residues in the red hair of Chinese Simmental beef cattle following exposure to two doses of clenbuterol for 21 days. This experiment was conducted in six male red pied Chinese Simmental beef cattle which were randomly divided into two groups (n = 3). Groups 1 and 2 were administered clenbuterol at a dose of 16 and 48 μg/kg body weight (BW)/day, respectively. Hair samples were collected on Days 7, 14 and 21 during treatment, and on Days 0, 14, 28, 42 and 70 after discontinuation of medication, using liquid chromatography tandem mass spectrometry (LC-MS-MS) method. About 500 mg hair samples spiked with 50 pg/mg D9-clenbuterol internal standard were analyzed with which the method recovery was from 88.6 to 116.9%. The results showed that clenbuterol was significantly accumulated in hair, with a concentration of 0.98 ± 0.56 pg/mg in Group 1 and 6.34 ± 3.21 pg/mg in Group 2 on Day 7 of treatment, and the residue concentrations increased as treatment proceeded. During the early withdrawal period, the residues increased from 13.52 ± 8.69 to 17.96 ± 6.94 pg/mg in Group 1 and from 55.15 ± 4.04 to 147.79 ± 15.35 pg/mg in Group 2. No significant differences were found in the later withdrawal period in both treatment groups. The results of the present study indicated that the red hair of Chinese Simmental beef cattle has high accumulation potential for clenbuterol residues. Hair, as a target matrix, even light-pigmented hair, can be used to monitor clenbuterol abuse over a long period.

  6. Evaluation of nutritive value and in vitro rumen fermentation gas accumulation of de-oiled algal residues

    PubMed Central

    2014-01-01

    Background Algae are widely recognized for their high oil content and for exponentially accumulating biomass with particular potential to provide single cell protein for human consumption or animal feed. It is believed that along with biodiesel from algae, the high protein de-oiled algal residue may become an alternative feed supplement option in the future. This study was conducted to investigate de-oiled algal residue obtained from the common Chlorella species, Thalassiosira weissflogii, Selenarstrum capricornutum, Scenedesmus sp., and Scenedesmus dimorphus for assessment as potential feed supplements for ruminants by comparing with soybean (Glycine max) meal and alfalfa (Medicago sativa) hay. Results With the exception of T. weissflogii, algal residue had higher concentrations of Cu, Zn, and Mn and lower concentration of Ca, Mg, and K than soybean meal and alfalfa hay. The algal residue CP (crude protein) concentrations ranged from 140 to 445 g/kg DM and varied among the de-oiled residues. In vitro rumen fermentation gas accumulation curves indicated that algal biomass degradation potential was less than that of soybean meal or alfalfa hay by up to 41.7%. The gas production curve, interpreted with a dual pool logistic model, confirmed that the fraction sizes for fast fermenting and slow fermenting of de-oiled algal residues were smaller than those in soybean meal and alfalfa hay, and the fermenting rate of the fractions was also low. Conclusions Inferior in vitro rumen gas accumulation from the five de-oiled algal residues suggests that these algal byproducts are less degradable in the rumen. PMID:25093078

  7. Numerical Results of Earth's Core Accumulation 3-D Modelling

    NASA Astrophysics Data System (ADS)

    Khachay, Yurie; Anfilogov, Vsevolod

    2013-04-01

    For a long time as a most convenient had been the model of mega impact in which the early forming of the Earth's core and mantle had been the consequence of formed protoplanet collision with the body of Mercurial mass. But all dynamical models of the Earth's accumulation and the estimations after the Pb-Pb system, lead to the conclusion that the duration of the planet accumulation was about 1 milliard years. But isotopic results after the W-Hf system testify about a very early (5-10) million years, dividing of the geochemical reservoirs of the core and mantle. In [1,3] it is shown, that the account of energy dissipating by the decay of short living radioactive elements and first of all Al,it is sufficient for heating even small bodies with dimensions about (50-100) km up to the iron melting temperature and can be realized a principal new differentiation mechanism. The inner parts of the melted preplanets can join and they are mainly of iron content, but the cold silicate fragments return to the supply zone. Only after the increasing of the gravitational radius, the growing area of the future core can save also the silicate envelope fragments. All existing dynamical accumulation models are constructed by using a spherical-symmetrical model. Hence for understanding the further planet evolution it is significant to trace the origin and evolution of heterogeneities, which occur on the planet accumulation stage. In that paper we are modeling distributions of temperature, pressure, velocity of matter flowing in a block of 3D- spherical body with a growing radius. The boundary problem is solved by the finite-difference method for the system of equations, which include equations which describe the process of accumulation, the Safronov equation, the equation of impulse balance, equation Navier-Stocks, equation for above litho static pressure and heat conductivity in velocity-pressure variables using the Businesque approach. The numerical algorithm of the problem solution in

  8. Numerical Results of 3-D Modeling of Moon Accumulation

    NASA Astrophysics Data System (ADS)

    Khachay, Yurie; Anfilogov, Vsevolod; Antipin, Alexandr

    2014-05-01

    For the last time for the model of the Moon usually had been used the model of mega impact in which the forming of the Earth and its sputnik had been the consequence of the Earth's collision with the body of Mercurial mass. But all dynamical models of the Earth's accumulation and the estimations after the Pb-Pb system, lead to the conclusion that the duration of the planet accumulation was about 1 milliard years. But isotopic results after the W-Hf system testify about a very early (5-10) million years, dividing of the geochemical reservoirs of the core and mantle. In [1,2] it is shown, that the account of energy dissipating by the decay of short living radioactive elements and first of all Al26,it is sufficient for heating even small bodies with dimensions about (50-100) km up to the iron melting temperature and can be realized a principal new differentiation mechanism. The inner parts of the melted preplanets can join and they are mainly of iron content, but the cold silicate fragments return to the supply zone and additionally change the content of Moon forming to silicates. Only after the increasing of the gravitational radius of the Earth, the growing area of the future Earth's core can save also the silicate envelope fragments [3]. For understanding the further system Earth-Moon evolution it is significant to trace the origin and evolution of heterogeneities, which occur on its accumulation stage.In that paper we are modeling the changing of temperature,pressure,velocity of matter flowing in a block of 3d spherical body with a growing radius. The boundary problem is solved by the finite-difference method for the system of equations, which include equations which describe the process of accumulation, the Safronov equation, the equation of impulse balance, equation Navier-Stocks, equation for above litho static pressure and heat conductivity in velocity-pressure variables using the Businesque approach.The numerical algorithm of the problem solution in velocity

  9. Three-Fingered RAVERs: Rapid Accumulation of Variations in Exposed Residues of Snake Venom Toxins

    PubMed Central

    Sunagar, Kartik; Jackson, Timothy N. W.; Undheim, Eivind A. B.; Ali, Syed. A.; Antunes, Agostinho; Fry, Bryan G.

    2013-01-01

    Rapid Accumulation of Variations in Exposed Residues (RAVER) to illustrate the significance of point mutations, guided by focal mutagenesis and positive selection in the evolution and diversification of 3FTx. PMID:24253238

  10. Three-fingered RAVERs: Rapid Accumulation of Variations in Exposed Residues of snake venom toxins.

    PubMed

    Sunagar, Kartik; Jackson, Timothy N W; Undheim, Eivind A B; Ali, Syed A; Antunes, Agostinho; Fry, Bryan G

    2013-11-18

    Rapid Accumulation of Variations in Exposed Residues (RAVER) to illustrate the significance of point mutations, guided by focal mutagenesis and positive selection in the evolution and diversification of 3FTx.

  11. Use of Combined Uncertainty of Pesticide Residue Results for Testing Compliance with Maximum Residue Limits (MRLs).

    PubMed

    Farkas, Zsuzsa; Slate, Andrew; Whitaker, Thomas B; Suszter, Gabriella; Ambrus, Árpád

    2015-05-13

    The uncertainty of pesticide residue levels in crops due to sampling, estimated for 106 individual crops and 24 crop groups from residue data obtained from supervised trials, was adjusted with a factor of 1.3 to accommodate the larger variability of residues under normal field conditions. Further adjustment may be necessary in the case of mixed lots. The combined uncertainty of residue data including the contribution of sampling is used for calculation of an action limit, which should not be exceeded when compliance with maximum residue limits is certified as part of premarketing self-control programs. On the contrary, for testing compliance of marketed commodities the residues measured in composite samples should be greater than or equal to the decision limit calculated only from the combined uncertainty of the laboratory phase of the residue determination. The options of minimizing the combined uncertainty of measured residues are discussed. The principles described are also applicable to other chemical contaminants.

  12. Results from the first Waste and Residue NDA Measurements School

    SciTech Connect

    Ensslin, N.; Abhold, M.; Coop, K.; Prettyman, T.; Rinard, P.; Sheppard, G.; Smith, H.A.

    1996-09-01

    The first Waste and Residue Nondestructive Assay (NDA) Measurements School was given at Los Alamos on June 3--7, 1996. This school is a new part of the DOE Office of Safeguards and Security, Safeguards Training Program, with additional instructor support from the National Transuranic Waste Program, Idaho National Engineering Laboratory, Oak Ridge National Laboratory, Portsmouth Gaseous Diffusion Plant, Westinghouse savannah River Company, Pajarito Scientific Corporation, and Canberra Industries. The school was attended by 22 safeguards and waste measurement personnel from DOE facilities, and included lectures on waste characterization requirements, the WIPP Performance Demonstration Program, waste and residue NDA techniques, and a workshop discussion on waste assay issues. Hands-on training modules with 55-gallon-drum waste assay systems were held using a Segmented Gamma-ray Scanner, a Tomographic Gamma-ray Scanner, two Add-a-Source Waste-Drum Assay Systems, a Californium Shuffler, and a Differential Die-away system that included Combined Thermal-Epithermal Neutron Interrogation (CTEN). This paper will describe the new school and report on the measurement results obtained during the school with the above-mentioned waste-drum assay systems.

  13. Wildlife in some areas of New Mexico and Texas accumulate elevated DDE residues, 1983

    USGS Publications Warehouse

    White, D.H.; Krynitsky, A.J.

    1986-01-01

    Over the last decade, data gathered by the U.S. Fish & Wildlife Service's National Contaminant Biomonitoring Program have identified an area of elevated DDE contamination in portions of New Mexico and Texas. Extensive wildlife sampling in 1983 confirmed that DDE, the major metabolite of the insecticide DDT, was present at high concentrations in wildlife at selected sites in the Rio Grande and Pecos River drainages. DDE in carcasses ranged up to 47 ppm (wet weight) in western kingbirds (Tyrannus verticalis), 35 ppm in house sparrows (Passer domesticus), 46 ppm in Brazilian free-tailed bats (Tadarida brasiliensis), and 104 ppm in whiptail lizards (Cnemidophorus spp.) DDE was also detected in gut contents from western kingbirds at some of the highest concentrations ever reported, ranging up to 21 ppm in proventricular samples. An average of 40% of the eggs of black-crowned night-herons (Nycticorax nycticorax) from two sites along the Pecos River in New Mexico had DDE levels ( gtoreq 8 ppm) that have been associated in other studies with impaired reproduction. In contrast, wintering mallards (Anas platyrhynchos) and American coots (Fulica americana) from the study area did not accumulate elevated DDE levels. DDE in wildlife samples at control sites (non-agricultural areas) was either absent or averaged less than 0.35 ppm. Collectively, these data provide evidence that there is major DDE contamination of several vertebrate species in portions of the Rio Grande and Pecos River drainages, but whether the contamination is recent or residual was not determined. Apparently, the source was not DDE contamination present in dicofol (4-chloro-a-(4-chlorophenyl)-a- (trichloromethyl) benzenemethanol); neither dicofol nor its metabolite, p,p'-dichlorobenzophenone, were detected in wildlife carcasses (0.1 ppm detection limit) or proventricular contents (0.01 ppm detection limit) of western kingbirds.

  14. Accumulator

    NASA Technical Reports Server (NTRS)

    Fenwick, J. R.; Karigan, G. H. (Inventor)

    1977-01-01

    An accumulator particularly adapted for use in controlling the pressure of a stream of fluid in its liquid phase utilizing the fluid in its gaseous phase was designed. The accumulator is characterized by a shell defining a pressure chamber having an entry throat for a liquid and adapted to be connected in contiguous relation with a selected conduit having a stream of fluid flowing through the conduit in its liquid phase. A pressure and volume stabilization tube, including an array of pressure relief perforations is projected into the chamber with the perforations disposed adjacent to the entry throat for accommodating a discharge of the fluid in either gaseous or liquid phases, while a gas inlet and liquid to gas conversion system is provided, the chamber is connected with a source of the fluid for continuously pressuring the chamber for controlling the pressure of the stream of liquid.

  15. XAFS SPECTROSCOPY RESULTS FOR PM SAMPLES FROM RESIDUAL FUEL OIL

    EPA Science Inventory

    X-ray absorption fine structure (XAFS spectroscopy data were obtained from particulate samples produced by the combustion of residual fuel oil in a 732-kW fire-tube boiler at EPA's National Risk Management Research Laboratory in North Carolina. Residual oil flyash (ROFA) from fo...

  16. Toxicity of solid residues resulting from wastewater treatment with nanomaterials.

    PubMed

    Nogueira, Verónica; Lopes, Isabel; Rocha-Santos, Teresa; Gonçalves, Fernando; Pereira, Ruth

    2015-08-01

    Nanomaterials (NMs) are widely recommended for wastewater treatments due to their unique properties. Several studies report the different advantages of nanotechnology in the remediation of wastewaters, but limited research has been directed toward the fate and potential impacts of the solid residues (SRs) produced after the application of such technologies. The present work aimed at investigating the ecotoxicity of SRs resulting from the treatment of three effluents (OOMW, kraft pulp mill, and mining drainage) with two NMs (TiO2 and Fe2O3). The invertebrate Chironomus riparius was selected as test organism and exposed to the residues. The effect on percentage of survival and growth was assessed. Results showed that the SRs from the treatments nano-TiO2(1.0gL(-1))/H2O2(0.5M) and nano-Fe2O3(1.0gL(-1))/H2O2(1.0M) from OOMW and nano-Fe2O3(0.75gL(-1))/H2O2(0.01M) from kraft pulp mill effluent exhibited lethal toxicity to C. riparius. Only the exposure to SRs resulting from the treatment with nano-Fe2O3(0.75gL(-1))/H2O2(0.01M) applied to the kraft pulp mill effluent significantly affected the growth rate based on the head capsule width. In terms of growth rate, based on the body length, it decreased significantly after exposure to the SRs from the treatments nano-TiO2 (1.0gL(-1)) and nano-Fe2O3(0.75gL(-1))/H2O2(0.01M) of kraft paper mill effluent and nano-Fe2O3(1.0gL(-1))/H2O2(1.0M) of OOMW. According to our study the SRs can promote negative effects on C. riparius. However, the effects are dependent on the type of effluent treated as well as on the organic and inorganic compounds attached to the NMs.

  17. Metals accumulations during thermal processing of sewage sludge - characterization of bottom ash and air pollution control (APC) residues

    NASA Astrophysics Data System (ADS)

    Kasina, Monika; Kowalski, Piotr R.; Michalik, Marek

    2016-04-01

    Due to increasing mass of sewage sludge, problems in its management have appeared. Over years sewage sludge was landfilled, however due to EU directives concerning environmental issues this option is no longer possible. This type of material is considered hazardous due to highly concentrated metals and harmful elements, toxic organic substances and biological components (e.g. parasites, microbes). Currently in Europe, incineration is considered to be the most reasonable method for sewage sludge treatment. As a result of sludge incineration significant amount of energy is recovered due to high calorific value of sewage sludge but bottom ash and APC residues are being produced. In this study we show the preliminary results of chemical and mineral analyses of both bottom ash and APC residues produced in fluidized bed boiler in sewage sludge incineration plant in Poland, with a special emphasis on metals which, as a part of incombustible fraction can accumulate in the residual materials after thermal processing. The bottom ash was a SiO2-P2O5-Fe2O3-CaO-Al2O3 dominated material. Main mineral phases identified in X-ray diffraction patterns were: quartz, feldspar, hematite, and phosphates (apatite and scholzite). The bottom ash was characterized by high content of Zn - 4472 mg kg-1, Cu - 665.5 mg kg-1, Pb - 138 mg kg-1, Ni - 119.5 mg kg-1, and interestingly high content of Au - 0.858 mg kg-1 The APC residues composition was dominated by soluble phases which represent more than 90% of the material. The XRD patterns indicated thenardite, halite, anhydrite, calcite and apatite as main mineral phases. The removal of soluble phases by dissolution in deionised water caused a significant mass reduction (ca. 3% of material remained on the filters). Calcite, apatite and quartz were main identified phases. The content of metals in insoluble material is relatively high: Zn - 6326 mg kg-1, Pb - 514.3 mg kg-1, Cu - 476.6 mg kg-1, Ni - 43.3 mg kg-1. The content of Cd, As, Se and Hg was

  18. Residual strain change resulting from stress corrosion in Carrara marble

    NASA Astrophysics Data System (ADS)

    Voigtlaender, Anne; Leith, Kerry; Krautblatter, Michael

    2016-04-01

    Residual stresses and strains have been shown to play a fundamental role in determining the elastic behavior of engineering materials, yet the effect of these strains on brittle and elastic behavior of rocks remains unclear. In order to evaluate the impact of stored elastic strains on fracture propagation in rock, we undertook a four-month-long three-point bending test on three large 1100 x 100 x 100 mm Carrara Marble samples. This test induced stable low stress conditions in which strains were concentrated at the tip of a saw cut and pre-cracked notch. A corrosive environment was created at the tip of the notch on two samples (M2 and M4) by dripping calcite saturated water (pH ~ 7.5-8). Sample M5 was loaded in the same way, but kept dry. Samples were unloaded prior to failure, and along with an additional non-loaded reference sample (M0), cored into cylindrical subsamples (ø = 50 mm, h = 100 mm) before being tested for changes in residual elastic strains at the SALSA neutron diffractometer at the Institute Laue-Langevin (ILL), Grenoble, France. Three diffraction peaks corresponding to crystallographic planes hkl (110), (104) and (006) were measured in all three spatial directions relative to the notch. Shifts in the diffraction peak position (d) with respect to a strain free state are indicative of intergranular strain, while changes in the width of the peak (FWHM) reflect changes in intragranular strain. We observe distinctly different patterns in residual and volumetric strains in hkℓ (104) and (006) for the dry M5 and wet tested samples (M2 and M4) indicating the presence of water changes the deformation mechanism, while (110) is strained in compression around 200 μstrain in all samples. A broadening of the diffraction peaks (006) and (110) in front of the crack tip is observed in M2 and M4, while M5 shows no changes in the peak width throughout the depth of the sample. We suggest water present at the crack tip increased the rate of corrosion, allowing a

  19. Mutagenesis of conserved active site residues of dihydrolipoamide succinyltransferase enhances the accumulation of α-ketoglutarate in Yarrowia lipolytica.

    PubMed

    Guo, Hongwei; Madzak, Catherine; Du, Guocheng; Zhou, Jingwen

    2016-01-01

    α-Ketoglutarate (α-KG) is an important intermediate in the tricarboxylic acid cycle and has broad applications. The mitochondrial ketoglutarate dehydrogenase (KGDH) complex catalyzes the oxidation of α-KG to succinyl-CoA. Disruption of KGDH, which may enhance the accumulation of α-KG theoretically, was found to be lethal to obligate aerobic cells. In this study, individual overexpression of dihydrolipoamide succinyltransferase (DLST), which serves as the inner core of KGDH, decreased overall activity of the enzyme complex. Furthermore, two conserved active site residues of DLST, His419, and Asp423 were identified. In order to determine whether these residues are engaged in enzyme reaction or not, these two conserved residues were individually mutated. Analysis of the kinetic parameters of the enzyme variants provided evidence that the catalytic reaction of DLST depended on residues His419 and Asp423. Overexpression of mutated DLST not only impaired balanced assembly of KGDH, but also disrupted the catalytic integrity of the enzyme complex. Replacement of the Asp423 residue by glutamate increased extracellular α-KG by 40 % to 50 g L(-1) in mutant strain. These observations uncovered catalytic roles of two conserved active site residues of DLST and provided clues for effective metabolic strategies for rational carbon flux control for the enhanced production of α-KG and related bioproducts.

  20. Ames test results on shot-tank residues

    SciTech Connect

    Bloom, G.H.

    1990-09-21

    In August 1987, a routine Ames test on soot from the Lawrence Livermore National Laboratory (LLNL) 4-in. gun showed that the soot was mutagenic to Salmonella bacteria. Subsequent liquid chromatography on the soot showed that, out of hundreds of ultravoilet-absorbing compounds found in the residue, only three or four were mutagenic. When a sample large enough to weigh was collected, it was found that No environmentally identified complex mixture has ever been reported with as much Ames/Salmonella activity per gram as the gun residues.'' Since then, Ames tests of hundreds of samples have verified that the residues from our gun tanks may be hazardous to health. The actual degree of the hazard and the identity of the offending chemicals are still unknown. 2 refs.

  1. Processing constraints resulting from heat accumulation during pulsed and repetitive laser materials processing.

    PubMed

    Weber, Rudolf; Graf, Thomas; Freitag, Christian; Feuer, Anne; Kononenko, Taras; Konov, Vitaly I

    2017-02-20

    In any pulsed and repetitive laser process a part of the absorbed laser energy is thermalized and stays in the material as residual heat. This residual heat is accumulating from pulse to pulse, continuously increasing the temperature, if the time between two pulses does not allow the material to sufficiently cool down. Controlling this so-called heat accumulation is one of the major challenges for materials processing with high average power pulsed lasers and repetitive processing. Heat accumulation caused by subsequent pulses (HAP) on the same spot and heat accumulation caused by subsequent scans (HAS) over the same spot can significantly reduce process quality, e.g., when the temperature increase caused by heat accumulation exceeds the melting temperature. In both cases, HAS and HAP, it is of particular interest to know the limiting number of pulses or scans after which the heat accumulation temperature exceeds a critical temperature and a pause has to be introduced. Approximation formulas for the case, where the duration of the heat input is short compared to the time between two subsequent heat inputs are derived in this paper, providing analytical scaling laws for the heat accumulation as a function of the processing parameters. The validity of these approximations is confirmed for HAP with an example of surface ablation of CrNi-steel and for HAS with multi-scan cutting of carbon fiber reinforced plastics (CFRP), both with a picosecond laser at an average power of up to 1.1 kW. It is shown that for the important case of 1-dimensional heat flow the limiting number of heat inputs decreases with the inverse of the square of the average laser power.

  2. Phosphorous acid residues in apples after foliar fertilization: results of field trials.

    PubMed

    Malusà, E; Tosi, L

    2005-06-01

    The levels of phosphorous acid residues in apples after foliar fertilization with P fertilizers and after treatment with a phosphonate fungicide (Fosetyl-Al) were determined and compared. Two field trials and a glasshouse experiment, using different genotypes and plants of different age, were carried out and monitored over a three-year period. Phosphorous acid residues were found in apples after application of foliar P fertilizers. Concentrations of the residues ranged between 0.02 and 14 mg kg(-1) depending on the phosphorous acid content in the fertilizer used and the plant size and yield. The treatments induced an accumulation of the residue in the course of the experiments, which in some cases reached a level exceeding the maximum limit set by EU legislation. Residues were also detected in other plant organs, i.e., roots and buds. Plants treated with Fosetyl-Al contained phosphorous acid residues in their fruits and buds two years after the suspension of the treatment, suggesting a long-term persistence of the substance in plant storage organs. A second experiment, involving treatment of trees with seven foliar fertilizers of different composition, also induced accumulation of phosphorous acid residues in fruits. It is concluded that a wide array of foliar products containing phosphorous acid, even as a minor component, could mimic the residue effect of phosphonate fungicide treatments.

  3. Critical tissue residue approach linking accumulated metals in aquatic insects to population and community-level effects

    USGS Publications Warehouse

    Schmidt, Travis S.; Clements, William H.; Zuellig, Robert E.; Mitchell, Katharine A.; Church, Stanley E.; Wanty, Richard B.; San Juan, Carma A.; Adams, Monique; Lamothe, Paul J.

    2011-01-01

    Whole body Zn concentrations in individuals (n = 825) from three aquatic insect taxa (mayflies Rhithrogena spp. and Drunella spp. and the caddisfly Arctopsyche grandis) were used to predict effects on populations and communities (n = 149 samples). Both mayflies accumulated significantly more Zn than the caddisfly. The presence/absence of Drunella spp. most reliably distinguished sites with low and high Zn concentrations; however, population densities of mayflies were more sensitive to increases in accumulated Zn. Critical tissue residues (634 (mu or u)g/g Zn for Drunella spp. and 267 (mu or u)g/g Zn for Rhithrogena spp.) caused a 20% reduction in maximum (90th quantile) mayfly densities. These critical tissue residues were associated with exposure to 7.0 and 3.9 (mu or u)g/L dissolved Zn for Drunella spp. and Rhithrogena spp., respectively. A threshold in a measure of taxonomic completeness (observed/expected) was observed at 5.4 (mu or u)g/L dissolved Zn. Dissolved Zn concentrations associated with critical tissue residues in mayflies were also associated with adverse effects in the aquatic community as a whole. These effects on populations and communities occurred at Zn concentrations below the U.S. EPA hardness-adjusted continuous chronic criterion.

  4. Availability of Biota-sediment Accumulation Factor Data Set and PCB Residue Effects Database

    EPA Science Inventory

    At contaminated sites, EPA’s Superfund program must decide how best to protect public health and the environment. This research was undertaken to better inform decision making and reduce uncertainties related to risk assessments at Superfund sites. A residue-effects database (PCB...

  5. Quantifying non-indigenous species in accumulated ballast slurry residuals (swish) arriving at Vancouver, British Columbia

    NASA Astrophysics Data System (ADS)

    Sutherland, T. F.; Levings, C. D.

    2013-08-01

    Ballast tank “swish” samples were collected from ships following their arrival at Vancouver (British Columbia, Canada) after undergoing either a trans-oceanic or a Pacific-coastal voyage. The ballast swish consisted of a residual slurry mixture of sediment and water that remained trapped in ballast tanks following water discharge at port. The ballast tanks of 27 ships were sampled and ballast swish was found on 19 of the 27 ships. These ships were categorized according to ballast water management type: (1) Trans-oceanic = 7 trans-oceanic ships undergoing ballast water exchange (BWE) > 200 nm from shore; (2) Coastal-exchange = 7 Pacific-coastal ships traveling from ports south of Cape Blanco, Oregon undergoing coastal exchange > 50 nm from shore south of Cape Blanco; and (3) Coastal-no-exchange = 5 Pacific-coastal ships traveling from ports north of Cape Blanco, Oregon, without undergoing BWE. Invertebrate abundance and taxa richness were directly correlated with ballast-swish turbidity suggesting that highly-productive coastal source waters and ballast tank retention processes contributed to this trend. In turn, invertebrate taxa diversity increased with increasing invertebrate abundance. A Principal Component Analysis of the trans-oceanic data revealed that length of voyage showed a strong inverse relationship with invertebrate abundance for this category. Within the coastal-exchange voyage category, voyage length and ballast water age tended to be of the same magnitude and were directly correlated with both crustacean and nematode taxa. Finally, the coastal-no-exchange PCA results revealed that voyage length and salinity were inversely related due to the high number of river ports located at the southern border of the regulatory BWE exemption zone. Coastal voyages not undergoing BWE and undertaking a direct river-to-river route should be considered risky for the introduction of non-indigenous species, if the source waters contain potentially invasive species

  6. Transformation and accumulation of PAH and bound residues in soil under extreme conditions - a risk assessment approach

    NASA Astrophysics Data System (ADS)

    Eschenbach, Annette

    2010-05-01

    The degradation of PAH in contaminated soil does not proceed completely in the majority of cases. However microorganisms which are able to degrade PAH are present in PAH-contaminated soils normally. A total degradation of PAH in contaminated soils is often limited by a lack of bioavailability, which results from a lack of mass transfer. The analytical depletion of contaminants in soil is not only based on degradation processes but also on a fixation or immobilization of the xenobiotic substances as stronger adsorbed to or bound residues in the soil matrix. These bound residues were verified by using 14C-labelled PAH in different soil samples. To evaluate the long term fate of theses PAH-residues the stability and transformation of 14C-labelled non-extractable PAH-residues was investigated in detail under different extreme ecological and climate conditions such as biological stress, freezing and thawing cycles, and chemical worst case conditions. The transformation and remobilization of non-extractable PAH-residues was observed in long-time experiments and was very limited in general (Eschenbach et al. 2001). Only small amounts of non extractable residues were transformed and converted to CO2 and thereby detoxified. However the treatment with a complexing agent led to an increase of extractable 14C-activity. In a further set of experiments the long term risk of a groundwater contamination was assessed. Therefore the elution rate of 14C-PAH was investigated by a routinely usable column test system. It was found that the PAH elution was not solely controlled by desorption processes. The extractable PAH concentrations and elution rates were affected by the mineralization and formation of bound residues as well. For the assessment of the maximum PAH release rate the soil material was treated by extreme and worst case conditions as well. The impact of the elution of bidestillated water, of repeated freeze-thaw cycles and a simulation of acidic rain was investigated. The

  7. Partial melting and recrystallization of Archeaan komatiites by residual heat from rapidly accumulated flows

    NASA Astrophysics Data System (ADS)

    Gole, Martin J.; Barnes, Stephen J.; Hill, Robin E. T.

    1990-11-01

    Spinifex-textured komatiites at Honeymoon Well, Western Australia, show evidence of partial melting and recrystallization of original igneous textures. Their textures and mineral compositions differ markedly from those typical of komatiites. Spinifex olivine plates are bent and broken, while interstitial space between spinifex and cumulus olivine is occupied by polygonal aggregates of clinopyroxene, orthopyroxene, minor olivine and plagioclase. Similar granular pyroxene-plagioclase aggregates occur as diffuse veins cutting spinifex zones and cumulate zones of the flows and, in places, form the matrix to a breccia containing corroded fragments of spinifex rock. Thermometry based on the two pyroxene assemblages yields temperatures of 1055° to 1141° C, just below the low-pressure komatiite solidus. Mineral compositions are different from those of typical komatiites: clinopyroxenes are Al-poor and Cr-rich, olivines are unusually iron-rich and depleted in Cr and Ca, and the low-Ca pyroxene is bronzite rather than the more typical pigeonite. We interpret these observations as the results of thermal metamorphism, partial remelting and subsequent slow crystallization of originally normal spinifex-textured komatiite flows. The rocks in question occupy a 40 70 m interval sandwiched between two olivine-rich units: an underlying 90 m-thick olivine adcumulate layer, forming part of the cumulate zone of a basal 160 m-thick flow, and an overlying 1 km-thick extrusive body composed mostly of olivine mesocumulate and adcumulate and capped in turn by spinifex-textured flows. Thermal modelling shows that a sinusoidal temperature profile of cool flow tops and hot flow centres would exist within this sequence shortly after eruption. Conductive thermal relaxation of this profile could reheat spinifex zones to the extent of inducing partial melting and textural reconstitution. Such reheating is largely dependent on the time interval between the emplacement of successive flows

  8. Utilization of agricultural residues of pineapple peels and sugarcane bagasse as cost-saving raw materials in Scenedesmus acutus for lipid accumulation and biodiesel production.

    PubMed

    Rattanapoltee, Panida; Kaewkannetra, Pakawadee

    2014-07-01

    The aim of this study is to optimize the lipid accumulation in microalgae by using two agricultural residues of pineapple peels and sugarcane bagasse as low-cost organic carbon sources. Green microalgae Scenedesmus acutus was isolated and selected for cultivation. Effects of three initial sugar concentrations and the stage for adding sugar during cultivation on biomass and lipid production were investigated. The results clearly showed that two-stage cultivation is more suitable than one-stage. The maximum biomass concentration and productivity were obtained at 3.85 g/L and 160.42 mg/L/day when sugarcane bagasse was used. The highest lipid content and lipid yield was reached at 28.05 % and 0.93 g/L when pineapple peels were used, while in the case of sugarcane bagasse, 40.89 % and 1.24 g/L lipid content and yield were obtained. Lipid content was found in normal condition (autotrophic) at 17.71 % which was approximately 2.13-fold lower than when sugarcane bagasse was used (40.89 %). Biodiesel production via in situ transesterification was also investigated; the main fatty acids of palmitic acid and oleic acid were found. This work indicates that using agricultural residues as organic carbon sources could be able to increase lipid content and reduce the cost of biofuel production.

  9. DNA Repair Decline During Mouse Spermiogenesis Results in the Accumulation of Heritable DNA Damage

    SciTech Connect

    Marchetti, Francesco; Marchetti, Francesco; Wyrobek, Andrew J.

    2007-12-01

    The post-meiotic phase of mouse spermatogenesis (spermiogenesis) is very sensitive to the genomic effects of environmental mutagens because as male germ cells form mature sperm they progressively lose the ability to repair DNA damage. We hypothesized that repeated exposures to mutagens during this repair-deficient phase result in the accumulation of heritable genomic damage in mouse sperm that leads to chromosomal aberrations in zygotes after fertilization. We used a combination of single or fractionated exposures to diepoxybutane (DEB), a component of tobacco smoke, to investigate how differential DNA repair efficiencies during the three weeks of spermiogenesis affected the accumulation of DEB-induced heritable damage in early spermatids (21-15 days before fertilization, dbf), late spermatids (14-8 dbf) and sperm (7-1 dbf). Analysis of chromosomal aberrations in zygotic metaphases using PAINT/DAPI showed that late spermatids and sperm are unable to repair DEB-induced DNA damage as demonstrated by significant increases (P<0.001) in the frequencies of zygotes with chromosomal aberrations. Comparisons between single and fractionated exposures suggested that the DNA repair-deficient window during late spermiogenesis may be less than two weeks in the mouse and that during this repair-deficient window there is accumulation of DNA damage in sperm. Finally, the dose-response study in sperm indicated a linear response for both single and repeated exposures. These findings show that the differential DNA repair capacity of post-meioitic male germ cells has a major impact on the risk of paternally transmitted heritable damage and suggest that chronic exposures that may occur in the weeks prior to fertilization because of occupational or lifestyle factors (i.e, smoking) can lead to an accumulation of genetic damage in sperm and result in heritable chromosomal aberrations of paternal origin.

  10. DNA repair decline during mouse spermiogenesis results in the accumulation of heritable DNA damage

    SciTech Connect

    Marchetti, Francesco; Marchetti, Francesco; Wryobek, Andrew J

    2008-02-21

    The post-meiotic phase of mouse spermatogenesis (spermiogenesis) is very sensitive to the genomic effects of environmental mutagens because as male germ cells form mature sperm they progressively lose the ability to repair DNA damage. We hypothesized that repeated exposures to mutagens during this repair-deficient phase result in the accumulation of heritable genomic damage in mouse sperm that leads to chromosomal aberrations in zygotes after fertilization. We used a combination of single or fractionated exposures to diepoxybutane (DEB), a component of tobacco smoke, to investigate how differential DNA repair efficiencies during the three weeks of spermiogenesis affected the accumulation of DEB-induced heritable damage in early spermatids (21-15 days before fertilization, dbf), late spermatids (14-8 dbf) and sperm (7- 1 dbf). Analysis of chromosomalaberrations in zygotic metaphases using PAINT/DAPI showed that late spermatids and sperm are unable to repair DEB-induced DNA damage as demonstrated by significant increases (P<0.001) in the frequencies of zygotes with chromosomal aberrations. Comparisons between single and fractionated exposures suggested that the DNA repair-deficient window during late spermiogenesis may be less than two weeks in the mouse and that during this repair-deficient window there is accumulation of DNA damage in sperm. Finally, the dose-response study in sperm indicated a linear response for both single and repeated exposures. These findings show that the differential DNA repair capacity of post-meioitic male germ cells has a major impact on the risk of paternally transmitted heritable damage and suggest that chronic exposures that may occur in the weeks prior to fertilization because of occupational or lifestyle factors (i.e, smoking) can lead to an accumulation of genetic damage in sperm and result in heritable chromosomal aberrations of paternal origin.

  11. Effects of residual coronary artery disease on results of coronary artery bypass grafting.

    PubMed

    Iskandrian, A S; Hakki, A H; Nestico, P F; DePace, N L; Goel, I P; Kane, S

    1984-10-01

    To assess the effects of residual coronary artery disease (non-revascularized coronary vessels) after coronary artery bypass grafting on symptoms and exercise left ventricular function, we categorized 77 patients into 3 groups according to the extent of residual coronary artery disease: group I (n = 17) had no residual coronary artery disease (residual score = 0); group II (n = 30) had light residual coronary artery disease (score of 1 to 9, mean 4.7); and group III (n = 30) had moderate residual coronary artery disease (score greater than or equal to 10, mean 23). Sixty patients were asymptomatic after coronary artery bypass grafting (14 in group I, 24 in group II, and 22 in group III), but the remaining patients had occasional angina pectoris. The resting left ventricular ejection fraction was significantly higher in group I than in the remaining 2 groups (56 +/- 18% in group I, 47 +/- 19% in group II, and 43 +/- 16% in group III, P less than 0.05). The exercise left ventricular ejection fraction was also significantly higher in group I (61 +/- 16% in group I, 51 +/- 18% in group II and 45 +/- 18% in group III, P less than 0.01). The ejection fraction response to exercise was abnormal in 5 patients in group I, 15 patients in group II, and 19 patients in group III. Thus, coronary artery bypass grafting results in symptomatic improvement, even in patients with residual coronary artery disease. The presence of residual coronary artery disease, however, may be a determinant of exercise left ventricular function in these patients.

  12. Free-Suspension Residual Flexibility Testing of Space Station Pathfinder: Comparison to Fixed-Base Results

    NASA Technical Reports Server (NTRS)

    Tinker, Michael L.

    1998-01-01

    Application of the free-suspension residual flexibility modal test method to the International Space Station Pathfinder structure is described. The Pathfinder, a large structure of the general size and weight of Space Station module elements, was also tested in a large fixed-base fixture to simulate Shuttle Orbiter payload constraints. After correlation of the Pathfinder finite element model to residual flexibility test data, the model was coupled to a fixture model, and constrained modes and frequencies were compared to fixed-base test. modes. The residual flexibility model compared very favorably to results of the fixed-base test. This is the first known direct comparison of free-suspension residual flexibility and fixed-base test results for a large structure. The model correlation approach used by the author for residual flexibility data is presented. Frequency response functions (FRF) for the regions of the structure that interface with the environment (a test fixture or another structure) are shown to be the primary tools for model correlation that distinguish or characterize the residual flexibility approach. A number of critical issues related to use of the structure interface FRF for correlating the model are then identified and discussed, including (1) the requirement of prominent stiffness lines, (2) overcoming problems with measurement noise which makes the antiresonances or minima in the functions difficult to identify, and (3) the use of interface stiffness and lumped mass perturbations to bring the analytical responses into agreement with test data. It is shown that good comparison of analytical-to-experimental FRF is the key to obtaining good agreement of the residual flexibility values.

  13. Rapid Sediment Accumulation Results in High Methane Effluxes from Coastal Sediments

    PubMed Central

    Lenstra, Wytze; Jong, Dirk; Meysman, Filip J. R.; Sapart, Célia J.; van der Veen, Carina; Röckmann, Thomas; Gonzalez, Santiago; Slomp, Caroline P.

    2016-01-01

    Globally, the methane (CH4) efflux from the ocean to the atmosphere is small, despite high rates of CH4 production in continental shelf and slope environments. This low efflux results from the biological removal of CH4 through anaerobic oxidation with sulfate in marine sediments. In some settings, however, pore water CH4 is found throughout the sulfate-bearing zone, indicating an apparently inefficient oxidation barrier for CH4. Here we demonstrate that rapid sediment accumulation can explain this limited capacity for CH4 removal in coastal sediments. In a saline coastal reservoir (Lake Grevelingen, The Netherlands), we observed high diffusive CH4 effluxes from the sediment into the overlying water column (0.2–0.8 mol m-2 yr-1) during multiple years. Linear pore water CH4 profiles and the absence of an isotopic enrichment commonly associated with CH4 oxidation in a zone with high rates of sulfate reduction (50–170 nmol cm-3 d-1) both suggest that CH4 is bypassing the zone of sulfate reduction. We propose that the rapid sediment accumulation at this site (~ 13 cm yr-1) reduces the residence time of the CH4 oxidizing microorganisms in the sulfate/methane transition zone (< 5 years), thus making it difficult for these slow growing methanotrophic communities to build-up sufficient biomass to efficiently remove pore water CH4. In addition, our results indicate that the high input of organic matter (~ 91 mol C m-2 yr-1) allows for the co-occurrence of different dissimilatory respiration processes, such as (acetotrophic) methanogenesis and sulfate reduction in the surface sediments by providing abundant substrate. We conclude that anthropogenic eutrophication and rapid sediment accumulation likely increase the release of CH4 from coastal sediments. PMID:27560511

  14. Natural Gamma Emitters after a Selective Chemical Separation of a TENORM residue: Preliminary Results

    SciTech Connect

    Alves de Freitas, Antonio; Abrao, Alcidio; Godoy dos Santos, Adir Janete; Pecequilo, Brigitte Roxana Soreanu

    2008-08-07

    An analytical procedure was established in order to obtain selective fractions containing radium isotopes ({sup 228}Ra), thorium ({sup 232}Th), and rare earths from RETOTER (REsiduo de TOrio e TErras Raras), a solid residue rich in rare earth elements, thorium isotopes and small amount of natural uranium generated from the operation of a thorium pilot plant for purification and production of pure thorium nitrate at IPEN -CNEN/SP. The paper presents preliminary results of {sup 228}Ra, {sup 226}Ra, {sup 238}U, {sup 210}Pb, and {sup 40}K concentrations in the selective fractions and total residue determined by high-resolution gamma spectroscopy, considering radioactive equilibrium of the samples.

  15. Electrochemical antimony removal from accumulator acid: results from removal trials in laboratory cells.

    PubMed

    Bergmann, M E Henry; Koparal, A Savas

    2011-11-30

    Regeneration of spent accumulator acid could be an alternative process for crystallization, neutralisation and disposal. Therefore, for the first time in a study of the possibilities of electrochemical removal of antimony and accumulator acid regeneration on a laboratory scale, two synthetic and several real systems containing sulfuric acid of concentrations ranging between 28% and 36%, and antimony species were tested. Discontinuous electrochemical reactors with anion exchange membranes were successfully used in these experiments, which were conducted at a temperature of 35°C. Removal of antimony using cells that were not divided by a separator, however, was not possible. In selected experiments, by varying the electrode material, type of electrolyte, and cell current, the concentration of antimony could be reduced from the range of 5 ppm to 0.15 ppm. This resulted in current efficiencies between 0.00002% and 0.001%, and in specific electroenergy demands between 100 Wh L(-1) and 2000 Wh L(-1). In other experiments on substances with antimony contents up to 3500 mg L(-1), the current efficiencies obtained were more than a thousandfold higher. In contrast to the formally high relative energy consumption parameters absolute demand parameters are relatively small and favour the electrochemical method in small scale application. Besides plate electrodes, 3D-cathodes were used. Copper- and graphite cathodes produced the best results.

  16. Accumulation of phosphorylated sphingoid long chain bases results in cell growth inhibition in Saccharomyces cerevisiae.

    PubMed Central

    Kim, S; Fyrst, H; Saba, J

    2000-01-01

    Sphingolipid metabolites in mammals can function as signaling molecules with cell-specific functions. In Saccharomyces cerevisiae, phosphorylated long chain bases, such as dihydrosphingosine 1-phosphate and phytosphingosine 1-phosphate, have also been implicated in stress responses. To further explore the biological roles of these molecules, we created disruption mutants for LCB4, LCB5, DPL1, YSR2, YSR3, and SUR2. LCB4 and LCB5 encode kinases that phosphorylate long chain bases. DPL1 and YSR2/YSR3 are involved in degradation of the phosphorylated long chain bases. SUR2 catalyzes conversion of dihydrosphingosine to phytosphingosine. We adapted an HPLC method to measure intracellular concentrations of the phosphorylated long chain bases. Double mutants of dpl1 and ysr2 were inviable, whereas dpl1 ysr2 lcb4 triple mutants were viable. Further, growth inhibition associated with accumulated phosphorylated long chain bases was observed in the triple mutant dpl1 ysr2 lcb4 overexpressing LCB4 or LCB5. These results indicate that phosphorylated long chain bases can inhibit cell growth. Mutants defective in both YSR2 and SUR2, which accumulated dihydrosphingosine 1-phosphate only, grew poorly. The phenotypes of the ysr2 sur2 mutants were suppressed by overexpression of DPL1. Our results clearly show that elevated levels of phosphorylated long chain bases have an antiproliferative effect in yeast. PMID:11102354

  17. Sorghum mutant RG displays antithetic leaf shoot lignin accumulation resulting in improved stem saccharification properties

    PubMed Central

    2013-01-01

    Background Improving saccharification efficiency in bioenergy crop species remains an important challenge. Here, we report the characterization of a Sorghum (Sorghum bicolor L.) mutant, named REDforGREEN (RG), as a bioenergy feedstock. Results It was found that RG displayed increased accumulation of lignin in leaves and depletion in the stems, antithetic to the trend observed in wild type. Consistent with these measurements, the RG leaf tissue displayed reduced saccharification efficiency whereas the stem saccharification efficiency increased relative to wild type. Reduced lignin was linked to improved saccharification in RG stems, but a chemical shift to greater S:G ratios in RG stem lignin was also observed. Similarities in cellulose content and structure by XRD-analysis support the correlation between increased saccharification properties and reduced lignin instead of changes in the cellulose composition and/or structure. Conclusion Antithetic lignin accumulation was observed in the RG mutant leaf-and stem-tissue, which resulted in greater saccharification efficiency in the RG stem and differential thermochemical product yield in high lignin leaves. Thus, the red leaf coloration of the RG mutant represents a potential marker for improved conversion of stem cellulose to fermentable sugars in the C4 grass Sorghum. PMID:24103129

  18. Accumulation of human immunodeficiency virus type 1 DNA in T cells: results of multiple infection events.

    PubMed Central

    Robinson, H L; Zinkus, D M

    1990-01-01

    Human immunodeficiency virus type 1 DNA synthesis was followed in a CD4+ line of T cells (C8166) grown in the presence or absence of a monoclonal antibody to CD4 that blocks infection By 48 h after infection, cultures grown in the presence of the antibody contained approximately 4 copies of human immunodeficiency virus type 1 DNA per cell, whereas those grown in the absence of the antibody contained approximately 80 copies of viral DNA per cell. Most of the viral DNA in cultures grown in the absence of the antibody was present in a broad smear of apparently incomplete viral sequences. In cultures grown in the presence or absence of the antibody, the 9.6-kilobase linear duplex of viral DNA appeared to undergo integration within 24 h of its appearance. These results demonstrate that T cells accumulate unintegrated human immunodeficiency virus type 1 DNA as a result of multiple virions entering cells. Images PMID:2398529

  19. Determination of residual monomers resulting from the chemical polymerization process of dental materials

    SciTech Connect

    Boboia, S.; Moldovan, M.; Ardelean, I.

    2013-11-13

    The residual monomer present in post-polymerized dental materials encourages premature degradation of the reconstructed tooth. That is why the residual monomer should be quantified in a simple, fast, accurate and reproducible manner. In our work we propose such an approach for accurate determination of the residual monomer in dental materials which is based on low-field nuclear magnetic resonance (NMR) relaxometry. The results of the NMR approach are compared with those of the high performance liquid chromatography (HPLC) technique. The samples under study contain the main monomers (2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)phenyl]propane and triethylene glycol dimethacrylate) constituting the liquid phase of most dental materials and an initiator. Two samples were analyzed with different ratios of chemical initiation systems: N,N-dimethyl-p-toluide: benzoyl peroxide (1:2 and 0.7:1.2). The results obtained by both techniques highlight that by reducing the initiator the polymerization process slows down and the amount of residual monomer reduces. This prevents the premature degradation of the dental fillings and consequently the reduction of the biomaterial resistance.

  20. Determination of residual monomers resulting from the chemical polymerization process of dental materials

    NASA Astrophysics Data System (ADS)

    Boboia, S.; Moldovan, M.; Ardelean, I.

    2013-11-01

    The residual monomer present in post-polymerized dental materials encourages premature degradation of the reconstructed tooth. That is why the residual monomer should be quantified in a simple, fast, accurate and reproducible manner. In our work we propose such an approach for accurate determination of the residual monomer in dental materials which is based on low-field nuclear magnetic resonance (NMR) relaxometry. The results of the NMR approach are compared with those of the high performance liquid chromatography (HPLC) technique. The samples under study contain the main monomers (2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)phenyl]propane and triethylene glycol dimethacrylate) constituting the liquid phase of most dental materials and an initiator. Two samples were analyzed with different ratios of chemical initiation systems: N,N-dimethyl-p-toluide: benzoyl peroxide (1:2 and 0.7:1.2). The results obtained by both techniques highlight that by reducing the initiator the polymerization process slows down and the amount of residual monomer reduces. This prevents the premature degradation of the dental fillings and consequently the reduction of the biomaterial resistance.

  1. Thiostrepton Variants Containing a Contracted Quinaldic Acid Macrocycle Result from Mutagenesis of the Second Residue

    PubMed Central

    Zhang, Feifei; Li, Chaoxuan

    2016-01-01

    The thiopeptides are a family of ribosomally synthesized and posttranslationally modified peptide metabolites, and the vast majority of thiopeptides characterized to date possess one highly modified macrocycle. A few members, including thiostrepton A, harbor a second macrocycle that incorporates a quinaldic acid moiety and the four N-terminal residues of the peptide. The antibacterial properties of thiostrepton A are well established, and its recently discovered ability to inhibit the proteasome has additional implications for the development of antimalarial and anticancer therapeutics. We have conducted the saturation mutagenesis of Ala2 in the precursor peptide, TsrA, to examine which variants can be transformed into a mature thiostrepton analogue. Although the thiostrepton biosynthetic system is somewhat restrictive towards substitutions at the second residue, eight thiostrepton Ala2 analogues were isolated. The TsrA Ala2Ile and Ala2Val variants were largely channeled through an alternate processing pathway wherein the first residue of the core peptide, Ile1, is removed and the resulting thiostrepton analogues bear quinaldic acid macrocycles abridged by one residue. This is the first report revealing that quinaldic acid loop size is amenable to alteration during the course of thiostrepton biosynthesis. Both the antibacterial and proteasome inhibitory properties of the thiostrepton Ala2 analogues were examined. While the identity of the residue at the second position of the core peptide influences thiostrepton biosynthesis, our report suggests it may not be crucial for antibacterial and proteasome inhibitory properties of the full-length variants. In contrast, the contracted quinaldic acid loop can, to differing degrees, affect both types of biological activity. PMID:26630475

  2. A disrupted transsulphuration pathway results in accumulation of redox metabolites and induction of gametocytogenesis in malaria

    PubMed Central

    Beri, Divya; Balan, Balu; Chaubey, Shweta; Subramaniam, Suraj; Surendra, Bachu; Tatu, Utpal

    2017-01-01

    Intra-erythrocytic growth of malaria parasite is known to induce redox stress. In addition to haem degradation which generates reactive oxygen species (ROS), the parasite is also thought to efflux redox active homocysteine. To understand the basis underlying accumulation of homocysteine, we have examined the transsulphuration (TS) pathway in the parasite, which is known to convert homocysteine to cysteine in higher eukaryotes. Our bioinformatic analysis revealed absence of key enzymes in the biosynthesis of cysteine namely cystathionine-β-synthase and cystathionine-γ-lyase in the parasite. Using mass spectrometry, we confirmed the absence of cystathionine, which is formed by enzymatic conversion of homocysteine thereby confirming truncation of TS pathway. We also quantitated levels of glutathione and homocysteine in infected erythrocytes and its spent medium. Our results showed increase in levels of these metabolites intracellularly and in culture supernatants. Our results provide a mechanistic basis for the long-known occurrence of hyperhomocysteinemia in malaria. Most importantly we find that homocysteine induces the transcription factor implicated in gametocytogenesis namely AP2-G and consequently triggers sexual stage conversion. We confirmed this observation both in vitro using Plasmodium falciparum cultures, and in vivo in the mouse model of malaria. Our study implicates homocysteine as a potential physiological trigger of gametocytogenesis. PMID:28091526

  3. Percutaneous Partial Medial Collateral Ligament Release (PPMCLR) Does Not Result in Residual Medial Collateral Laxity (MCL)

    PubMed Central

    Hinton, M. Alan

    2015-01-01

    Objectives: The intra-articular posterior medial knee can be difficult to approach during arthroscopy. This is especially true for medial meniscal tears, medial meniscal repairs or medial meniscal transplantation. Various methods and instruments have been proposed to help with this approach. PPMCLR is one of these methods. This study found that this is a safe technique and does not result in measurable laxity of the MCL. Methods: 50 consecutive patients took part in the study. The patients were then randomized into a control or partial percutaneous release group (25 in each group). Prior to arthroscopy each patient had standardized 30 degree valgus stress radiograph performed. The MCL was stressed with the Telos Stress Device GA/III at 30 degrees of flexion; utilizing 150 Newton's of stress. The stress radiographs were measured independently for the maximal separation at the medial compartment. At six weeks the stress radiographs were repeated and the results again recorded. The postoperative care for each group was the same. Results: The results were then statistically evaluated using the, finding no radiographic evidence of residual laxity P<.005. There was also no difference in the control and PPMCLR group p<.0005. No patient complained of residual laxity. Patient follow up will be discussed. Conclusion: PPMCLR is an effective and safe method to reach the intra-articular posterior aspect of the knee during arthroscopy. PPMCLR does not result in measurable laxity of the MCL.

  4. Further studies on the use of enzyme profiles to monitor residue accumulation in wildlife: Plasma enzymes in starlings fed graded concentrations of morsodren, DDE, Aroclor 1254, and malathion

    USGS Publications Warehouse

    Dieter, M.P.

    1975-01-01

    Wild-trapped starlings (Sturnus vulgaris) were fed concentrations of Morsodren (2, 4, and 8 ppm), DDE or Aroclor 1254 (5, 25, and 100 ppm), or malathion (8, 35, and 160 ppm) that were found to be sublethal in pen-reared Coturnix quail fed these amounts for 12 weeks. Plasma enzymes had to be measured earlier than planned in starlings fed Morsodren (at three weeks) or the organochlorine compounds (at seven weeks) because of unexpected, subsequent mortality. Variations in enzyme response were greater in wild than in pen-reared birds, but not enough to mask the toxicant-induced changes in enzyme activity. Cholinesterase activities decreased in birds fed Morsodren or malathion, and increased in those fed the organochlorine compounds. Lactate dehydrogenase activities increased two-fold in starlings fed Morsodren and two- to four-fold in those fed the organochlorine compounds, but only 50% in those fed malathion. Further examination of enzyme profiles showed that creatine kinase and aspartate aminotransferase activities increased two-to four-fold in birds fed Morsodren or the organochlorine compounds but not at all in those fed malathion. Thus the classes of environmental contaminants fed to starlings could be easily distinguished by these enzymatic parameters. Evaluation of enzymatic profiles appears to be a potentially valuable technique to monitor the presence of toxicants in wild populations, especially if used to complement standard chemical residue analyses. Here the residue analyses showed, after three weeks feeding, that mercury in the carcasses reflected the concentrations fed daily, whereas accumulation in the livers was two- to four-fold greater. After seven weeks feeding, liver residues of either organochlorine compound were about three-fold higher than the concentrations fed daily. However, four times as much DDE as Aroclor 1254 had accumulated in the carcasses.

  5. Long-term tillage and crop rotation effects on residual nitrate in the crop root zone and nitrate accumulation in the intermediate vadose zone

    USGS Publications Warehouse

    Katupitiya, A.; Eisenhauer, D.E.; Ferguson, R.B.; Spalding, R.F.; Roeth, F.W.; Bobier, M.W.

    1997-01-01

    Tillage influences the physical and biological environment of soil. Rotation of crops with a legume affects the soil N status. A furrow irrigated site was investigated for long-term tillage and crop rotation effects on leaching of nitrate from the root zone and accumulation in the intermediate vadose zone (IVZ). The investigated tillage systems were disk-plant (DP), ridge-till (RT) and slot-plant (SP). These tillage treatments have been maintained on the Hastings silt loam (Udic Argiustoll) and Crete silt loam (Pachic Argiustoll) soils since 1976. Continuous corn (CC) and corn soybean (CS) rotations were the subtreatments. Since 1984, soybeans have been grown in CS plots in even calendar years. All tillage treatments received the same N rate. The N rate varied annually depending on the root zone residual N. Soybeans were not fertilized with N-fertilizer. Samples for residual nitrate in the root zone were taken in 8 of the 15 year study while the IVZ was only sampled at the end of the study. In seven of eight years, root zone residual soil nitrate-N levels were greater with DP than RT and SP. Residual nitrate-N amounts were similar in RT and SP in all years. Despite high residual nitrate-N with DP and the same N application rate, crop yields were higher in RT and SP except when DP had an extremely high root zone nitrate level. By applying the same N rates on all tillage treatments, DP may have been fertilized in excess of crop need. Higher residual nitrate-N in DP was most likely due to a combination of increased mineralization with tillage and lower yield compared to RT and SP. Because of higher nitrate availability with DP, the potential for nitrate leaching from the root zone was greater with DP as compared to the RT and SP tillage systems. Spring residual nitrate-N contents of DP were larger than RT and SP in both crop rotations. Ridge till and SP systems had greater nitrate-N with CS than CC rotations. Nitrate accumulation in IVZ at the upstream end of the

  6. Probative value of gunshot residue on victims of shootings and comparison of gunshot residue results with modern technology versus older testing of samples

    NASA Astrophysics Data System (ADS)

    White, Robert S.; Mershon, William J.

    2011-06-01

    Some government agencies take the position that the results of gunshot residue from the hands of victims of shootings are not probative and meaningless. It is my opinion from experience in many cases that this is not the case and the results can mean life or death in some cases. Actual individual cases are described. The results of samples examined years ago with a small number of gunshot residue particles and reexamined recently shows the number and quality of particles that can be located and identified with modern equipment.

  7. Enhanced carotenoid accumulation as a result of alteration of metabolic sinks in transgenic plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carotenoids are highly beneficial for human nutrition and health because they provide important nutrients and antioxidants in our diets. We have isolated a novel gene, the Or gene, from an orange cauliflower mutant that confers high levels of B-carotene accumulation (Lu et al., Plant Cell 2006 18:3...

  8. Appendix to the report from the low-residue soldering task force: Phase 2 results

    SciTech Connect

    Iman, R.L.; Anderson, D.J.; Huffman, D.D.

    1995-12-01

    The LRSTF report for Phase I of its evaluation of low-residue soldering was issued in June 1995. This Appendix summarizes the results of follow-on testing performed in Phase II and compares electrical test results for both phases. Deliberate decisions were made by the LRSTF in Phase I to challenge the design guideline limits in MILSTD-275, Printed Wiring for Electronic Equipment The LRSTF considered this approach to produce a ``worst case`` design and provide useful information about the robustness of LR soldering processes. As such, good design practices were sometimes deliberately violated in designing the LRSTF board. This approach created some anomalies for both LR boards and RMA/cleaned controls. Phase II testing verified that problems that affected both RMA/cleaned and LR boards in Phase I were design related.

  9. Alcaligenes faecalis subsp. parafaecalis subsp. nov., a bacterium accumulating poly-beta-hydroxybutyrate from acetone-butanol bioprocess residues.

    PubMed

    Schroll, G; Busse, H J; Parrer, G; Rölleke, S; Lubitz, W; Denner, E B

    2001-04-01

    The authors have previously isolated a solvent tolerant bacterium, strain G(T), (T = type strain) capable to convert acetone-butanol bioprocess residues into poly-beta-hydroxybutyrate. Strain G(T) was initially identified as Alcaligenes spp by standard bacteriological tests. In this study the taxonomic position of the bacterium was investigated in detail. The 165 rDNA sequence analysis, the G + C content of DNA (56 mol%) and the presence of ubiquinone Q-8 confirmed strain G(T) as a representative of the genus Alcaligenes. In the polyamine pattern of the bacterium putrescine and cadaverine were detected, but only trace amounts of 2-hydroxyputrescine. The extremely low content of 2-hydroxyputrescine is remarkable, since this unique diamine is a common marker for beta-proteobacteria. Phylogenetic analyses of 16S rDNA demonstrated that Alcaligenes sp. G(T) is most closely related to the species Alcaligenes faecalis (99.6% sequence similarity to A. faecalis HR4 and 98.7% sequence similarity to A. faecalis [ATCC 8750T = DSM 30030T]. On the basis of DNA-DNA relatedness (56% similarity), the unique polyamine pattern, the physiological and biochemical differences strain G(T) could be distinguished from the species A. faecalis. Therefore, a new subspecies for the species Alcaligenes faecalis is proposed; Alcaligenes faecalis subsp. parafaecalis subsp. nov.

  10. Osmium isotope anomalies in chondrites: Results for acid residues and related leachates

    NASA Astrophysics Data System (ADS)

    Yokoyama, Tetsuya; O'D. Alexander, Conel M.; Walker, Richard J.

    2010-03-01

    We have investigated Os isotope anomalies in acid residues enriched in insoluble organic matter (IOM) extracted from ten primitive chondrites, acid leachates and residues of these fractions, as well as acid leachates of bulk chondrites. Osmium isotopic compositions of bulk carbonaceous, ordinary and enstatite chondrites are also reported. Consistent with prior results, bulk chondrites have homogeneous Os isotope compositions for s-, r-, and p-process nuclides that are indistinguishable from terrestrial, at the current level of resolution. In contrast, nearly all the IOM-rich residues are enriched in s-process Os, evidently due to the preferential incorporation of s-process enriched presolar grains (most likely presolar SiC). Presolar silicate grains that formed in red giant branch (RGB) or asymptotic giant branch (AGB) stars are also likely hosts of additional s-process Os in chondrites. Consistent with one prior study, Os released by weak acid leaching of bulk chondrites is slightly to strongly enriched in r-process nuclides, of which the carrier may be fine-grained presolar silicates formed in supernovae or unidentified solar phases. Collectively, the different, chemically concentrated components in these meteorites are variably enriched in s-, r-, and possibly p-process Os, of which the individual carriers must have been produced in multiple stellar environments. The lack of evidence for Os isotopic heterogeneity among bulk chondrites contrasts with evidence for isotopic heterogeneities for various other elements at approximately the same levels of resolution (e.g., Cr, Mo, Ru, Ba, Sm, and Nd). One possible explanation for this is that the heterogeneities for some elements in bulk materials reflect selective removal of some types of presolar grains as a result of nebular processes, and that because of the strong chemical differences between Os and the other elements, the Os was not significantly affected. Another possible explanation is that late-stage injection

  11. Quasi-kernel polynomials and convergence results for quasi-minimal residual iterations

    NASA Technical Reports Server (NTRS)

    Freund, Roland W.

    1992-01-01

    Recently, Freund and Nachtigal have proposed a novel polynominal-based iteration, the quasi-minimal residual algorithm (QMR), for solving general nonsingular non-Hermitian linear systems. Motivated by the QMR method, we have introduced the general concept of quasi-kernel polynomials, and we have shown that the QMR algorithm is based on a particular instance of quasi-kernel polynomials. In this paper, we continue our study of quasi-kernel polynomials. In particular, we derive bounds for the norms of quasi-kernel polynomials. These results are then applied to obtain convergence theorems both for the QMR method and for a transpose-free variant of QMR, the TFQMR algorithm.

  12. 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.

  13. Loss of Clcc1 Results in ER Stress, Misfolded Protein Accumulation, and Neurodegeneration

    PubMed Central

    Jia, Yichang; Jucius, Thomas J.; Cook, Susan A.

    2015-01-01

    Folding of transmembrane and secretory proteins occurs in the lumen of the endoplasmic reticulum (ER) before transportation to the cell surface and is monitored by the unfolded protein response (UPR) signaling pathway. The accumulation of unfolded proteins in the ER activates the UPR that restores ER homeostasis by regulating gene expression that leads to an increase in the protein-folding capacity of the ER and a decrease in the ER protein-folding load. However, prolonged UPR activity has been associated with cell death in multiple pathological conditions, including neurodegeneration. Here, we report a spontaneous recessive mouse mutation that causes progressive cerebellar granule cell death and peripheral motor axon degeneration. By positional cloning, we identify the mutation in this strain as a retrotransposon insertion in the Clcc1 gene, which encodes a putative chloride channel localized to the ER. Furthermore, we demonstrate that the C3H/HeSnJ inbred strain has late onset cerebellar degeneration due to this mutation. Interestingly, acute knockdown of Clcc1 expression in cultured cells increases sensitivity to ER stress. In agreement, GRP78, the major HSP70 family chaperone in the ER, is upregulated in Clcc1-deficient granule cells in vivo, and ubiquitinated proteins accumulate in these neurons before their degeneration. These data suggest that disruption of chloride homeostasis in the ER disrupts the protein-folding capacity of the ER, leading to eventual neuron death. PMID:25698737

  14. Disruption of the human CGI-58 homologue in Arabidopsis results in lipid droplet accumulation in the cytosol of plant cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CGI-58 has been identified as the causative gene in the human neutral lipid storage disease called Chanarin-Dorfman Syndrome. This disorder results in accumulation of intracellular lipid droplets in non-adipose tissues. Here we show that disruption of the homologous CGI-58 gene in Arabidopsis thal...

  15. Results of minimal residual disease (MRD) evaluation and MRD-based treatment stratification in childhood ALL.

    PubMed

    Cazzaniga, Giovanni; d'Aniello, Elisabetta; Corral, Lilia; Biondi, Andrea

    2002-12-01

    The study of minimal residual disease (MRD) as a 'surrogate' marker of molecular response to treatment has drawn great interest because of the potential of tailoring treatment and the possibility of gaining insight into the nature of a cure. Polymerase chain reaction-based (PCR-based) detection of MRD by immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangements can be applied in more than 90-95% of cases of childhood acute lymphoblastic leukaemia (ALL). Accordingly, several retrospective studies of MRD in childhood ALL have used one of the different PCR approaches for the detection of antigen-receptor gene rearrangements. The promising results on the predictivity of MRD evaluation at the end of induction treatment has raised the need of a new definition of remission. Until now, most PCR-based MRD studies have used semiquantitative methods for the detection of Ig and TCR gene rearrangements. The introduction of real-time quantitative PCR (RQ-PCR) has resulted in the improvement of sensitivity and specificity and has given better quality control of the MRD data. There is an urgent need to incorporate MRD data in clinical studies, properly designed to address treatment questions. In this context several ongoing co-operative study groups have adopted an MRD-based risk group classification to explore whether a better tailored treatment would result in further improvement in cure rates for children with ALL.

  16. Recent Results in ICESat Geolocation Parameter Calibration from Range Residual Analysis

    NASA Technical Reports Server (NTRS)

    Luthcke, Scott B.; Rowlands, David D.; Carabajal, Claudia C.; Williams, Terry A.

    2004-01-01

    The Ice, Cloud and land Elevation Satellite (ICESat), launched on January 12, 2003, carries the Geoscience Laser Altimeter System (GLAS), which has a primary measurement of short-pulse laser-ranging to the Earths surface at 1064 nm wavelength at a rate of 40 pulses per second. The instrument has collected (at the time of this writing) over 540 million observations of the Earth's surface including precise elevation measurements of the ice sheets, sea ice roughness and thickness, ocean and land surface elevations and surface reflectivity. The accurate geolocation of GLASs surface returns, the spots from which the laser energy reflects on the Earths surface, is a critical issue in the scientific application of these data. Pointing, ranging, timing and orbit errors must be compensated to accurately geolocate the laser altimeter surface returns. Towards this end, the laser range observations can be fully exploited in an integrated residual analysis to accurately calibrate these geolocation/instrument parameters. The ICESat laser altimeter data have been simultaneously processed as direct altimetry from ocean sweeps and around-the-world scans along with dynamic crossovers in order to calibrate pointing ranging and timing. The analysis has resolved complex time varying signal resulting from thermal variations of instrument pointing and boresite shadowing. The calibration methodology and current calibration results are discussed along with future efforts and current geolocation accuracies.

  17. Mutation of a Rice Gene Encoding a Phenylalanine Biosynthetic Enzyme Results in Accumulation of Phenylalanine and Tryptophan[W

    PubMed Central

    Yamada, Tetsuya; Matsuda, Fumio; Kasai, Koji; Fukuoka, Shuichi; Kitamura, Keisuke; Tozawa, Yuzuru; Miyagawa, Hisashi; Wakasa, Kyo

    2008-01-01

    Two distinct biosynthetic pathways for Phe in plants have been proposed: conversion of prephenate to Phe via phenylpyruvate or arogenate. The reactions catalyzed by prephenate dehydratase (PDT) and arogenate dehydratase (ADT) contribute to these respective pathways. The Mtr1 mutant of rice (Oryza sativa) manifests accumulation of Phe, Trp, and several phenylpropanoids, suggesting a link between the synthesis of Phe and Trp. Here, we show that the Mtr1 mutant gene (mtr1-D) encodes a form of rice PDT with a point mutation in the putative allosteric regulatory region of the protein. Transformed callus lines expressing mtr1-D exhibited all the characteristics of Mtr1 callus tissue. Biochemical analysis revealed that rice PDT possesses both PDT and ADT activities, with a preference for arogenate as substrate, suggesting that it functions primarily as an ADT. The wild-type enzyme is feedback regulated by Phe, whereas the mutant enzyme showed a reduced feedback sensitivity, resulting in Phe accumulation. In addition, these observations indicate that rice PDT is critical for regulating the size of the Phe pool in plant cells. Feeding external Phe to wild-type callus tissue and seedlings resulted in Trp accumulation, demonstrating a connection between Phe accumulation and Trp pool size. PMID:18487352

  18. The distribution of iron in a soil chronosequence: the result of biological lifting and surficial accumulation

    NASA Astrophysics Data System (ADS)

    Schulz, M. S.; White, A. F.; Fitzpatrick, J.

    2007-12-01

    The abundance of iron increases with soil age in a marine terrace chronosequence (5 terraces aged from 65 to 226 Ka) located northwest of Santa Cruz, California. The iron has two distinct morphologies in the soils. At depths less than 1m on all terraces hard nodules are formed by Fe-oxides cementing and replacing sediment grains. At depths greater than 1m in the youngest terrace (T1), disseminated Fe forms coatings on sediment grains. In terraces 2 through 5 (depths greater than 1m) the disseminated iron becomes increasingly concentrated in mottles within the argillic horizon. Iron nodules do not occur at depths greater than 1m in any of the soils. Iron mineralogy of the nodules is generally goethite with a subset of nodules that are maghemite. Mass change calculations, reveal Fe concentration near the surface and Fe depletion at depth that cannot be accounted for by weathering and compaction of the profile or by the Fe content of eolian additions to the soils. The terrace regoliths are generally unsaturated and aerobic; thus lateral movement of large amounts of reduced Fe is unlikely. Iron as a plant nutrient, unlike other mineral nutrients, is relatively insoluble in aerobic soil solutions. We propose that plant roots and symbiotic fungi (mycorrhizae) transport Fe from deeper in the regolith through the process of biolifting. When released through plant decay, the Fe forms immobile oxides at shallow depths. Iron content of the current grassland vegetation was measured and yearly biomass input of Fe was calculated. The above ground cycling of plant iron when multiplied by the age of the terrace can account for the shallow Fe accumulation in these soils.

  19. Lineations on the ``White'' Accumulation Areas of the Residual Northern Ice Cap of Mars: Their Relation to the ``Accublation'' and Ice Flow Hypothesis

    NASA Astrophysics Data System (ADS)

    Fisher, David A.; Winebrenner, Dale P.; Stern, Harry

    2002-09-01

    Mars Orbiter Camera (MOC) images of the whiter areas of the residual North Polar Cap (P. C. Thomas et al. 2000, Nature404, 161-164) show a gentle hummocky pitted surface that has been popularly called "cottage cheese" terrain. The pits are 1 or 2 m deep and tens of meters across. They are typically joined in roughly linear strings or long depressions and these features are referred to here as "lineations." The lineations tend to have one or occasionally two preferred directions. We have examined the MOC imagery for the North Cap and using high-resolution images that have good wide-angle context images were able to determine the lineation angles for 31 sites scattered over most of the ice cap. We propose a process that will produce linear features in the white areas, then relate the orientation of the lineations over much of the North Cap to these processes and the inferred ice flow direction. There is first-order agreement between the measured sign of the lineation angles and those predicted assuming ice flow. Higher accumulations and velocities are predicted in the catchment for ice that flows into Chasma Boreale. This comes from the indications that katabatic winds are concentrated in this catchment.

  20. Effects of Different Forms of Selenium Fertilizers on Se Accumulation, Distribution, and Residual Effect in Winter Wheat-Summer Maize Rotation System.

    PubMed

    Wang, Qi; Yu, Yao; Li, Jixiang; Wan, Yanan; Huang, Qingqing; Guo, Yanbin; Li, Huafen

    2017-02-15

    Foliar Se fertilizers were applied to investigate the effects of Se forms on Se accumulation and distribution in the wheat-maize rotation system and residual concentration of Se in subsequent crops. Sodium selenite, sodium selenate, selenomethionine, chemical nano-Se, humic acid + sodium selenite, and compound fertilizer + sodium selenite were applied once at the flowering stage of wheat (30 g ha(-1)) and at the bell stage of maize (60 g ha(-1)). Compared with the control treatment, foliar Se applications significant increased the grain Se concentration of wheat and maize by 0.02-0.31 and 0.07-1.09 mg kg(-1), respectively. Wheat and maize grain Se recoveries were 3.0-10.4 and 4.1-18.5%, respectively. However, Se concentrations in the grain of subsequent wheat and maize significantly decreased by 77.9 and 91.2%, respectively. The change of Se concentration in soil was a dynamic process with Se depletion after harvest of maize.

  1. Accumulate-Repeat-Accumulate-Accumulate-Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Sam; Thorpe, Jeremy

    2004-01-01

    Inspired by recently proposed Accumulate-Repeat-Accumulate (ARA) codes [15], in this paper we propose a channel coding scheme called Accumulate-Repeat-Accumulate-Accumulate (ARAA) codes. These codes can be seen as serial turbo-like codes or as a subclass of Low Density Parity Check (LDPC) codes, and they have a projected graph or protograph representation; this allows for a high-speed iterative decoder implementation using belief propagation. An ARAA code can be viewed as a precoded Repeat-and-Accumulate (RA) code with puncturing in concatenation with another accumulator, where simply an accumulator is chosen as the precoder; thus ARAA codes have a very fast encoder structure. Using density evolution on their associated protographs, we find examples of rate-lJ2 ARAA codes with maximum variable node degree 4 for which a minimum bit-SNR as low as 0.21 dB from the channel capacity limit can be achieved as the block size goes to infinity. Such a low threshold cannot be achieved by RA or Irregular RA (IRA) or unstructured irregular LDPC codes with the same constraint on the maximum variable node degree. Furthermore by puncturing the accumulators we can construct families of higher rate ARAA codes with thresholds that stay close to their respective channel capacity thresholds uniformly. Iterative decoding simulation results show comparable performance with the best-known LDPC codes but with very low error floor even at moderate block sizes.

  2. Renal mass reduction results in accumulation of lipids and dysregulation of lipid regulatory proteins in the remnant kidney.

    PubMed

    Kim, Hyun Ju; Moradi, Hamid; Yuan, Jun; Norris, Keith; Vaziri, Nosratola D

    2009-06-01

    A significant reduction of renal mass results in proteinuria, glomerulosclerosis, and tubulointerstitial injury, culminating in end-stage chronic renal failure (CRF). The accumulation of lipids in the kidney can cause renal disease. Uptake of oxidized lipoproteins via scavenger receptors, reabsorption of filtered protein-bound lipids via the megalin-cubilin complex, and increased glucose load per nephron can promote lipid accumulation in glomerular, tubular, and interstitial cells in CRF. Cellular lipid homeostasis is regulated by lipid influx, synthesis, catabolism, and efflux. We examined lipid-regulatory factors in the remnant kidney of rats 11 wk after nephrectomy (CRF) or sham operation. CRF resulted in azotemia, proteinuria, lipid accumulation in the kidney, upregulation of megalin, cubilin, mediators of lipid influx (scavenger receptor class A and lectin-like oxidized receptor-1), lipid efflux (liver X receptor alpha/beta and ATP-binding cassette transporter), and fatty acid biosynthesis (carbohydrate-response element binding protein, fatty acid synthase, and acetyl-CoA carboxylase). However, factors involved in cholesterol biosynthesis (sterol regulatory element binding protein, 3-hydroxy-3-methylglutaryl coenzyme A reductase, SCAP, Insig-1, and Insig-2) and fatty acid oxidation (peroxisome proliferator-activated receptor, acyl-CoA oxidase, and liver-type fatty acid binding protein) were reduced in the remnant kidney. Thus CRF results in heavy lipid accumulation in the remnant kidney, which is mediated by upregulation of pathways involved in tubular reabsorption of filtered protein-bound lipids, influx of oxidized lipoproteins and synthesis of fatty acids, and downregulation of pathways involved in fatty acid catabolism.

  3. Pesticide residue dynamics in passion fruits: comparing field trial and modelling results.

    PubMed

    Juraske, Ronnie; Fantke, Peter; Ramírez, Ana Cecilia Romero; González, Alonso

    2012-10-01

    We evaluated the exposure to pesticides from the consumption of passion fruits and subsequent human health risks by combining several methods: (i) experimental field studies including the determination of pesticide residues in/on passion fruits, (ii) dynamic plant uptake modelling, and (iii) human health risk assessment concepts. Eight commonly used pesticides were applied onto passion fruits cultivated in Colombia. Pesticide concentrations were measured periodically (between application and harvest) in whole fruits and fruit pulp. Measured concentrations were compared with predicted residues calculated with a dynamic and crop-specific pesticide uptake model, namely dynamiCROP. The model accounts for the time between pesticide application and harvest, the time between harvest and consumption, the amount of spray deposition on plant surfaces, uptake processes, dilution due to crop growth, degradation in plant components, and reduction due to food processing (peeling). Measured and modelled residues correspond well (r(2)=0.88-0.99), with all predictions falling within the 90% confidence interval of the measured values. A mean error of 43% over all studied pesticides was observed between model estimates and measurements. The fraction of pesticide applied during cultivation that is eventually ingested by humans is on average 10(-4)-10(-6), depending on the time period between application and ingestion and the processing step considered. Model calculations and intake fractions via fruit consumption based on experimental data corresponded well for all pesticides with a deviation of less than a factor of 2. Pesticide residues in fruits measured at recommended harvest dates were all below European Maximum Residue Limits (MRLs) and therefore do not indicate any violation of international regulatory thresholds.

  4. Strategies for the enhancement of automobile shredder residues (ASRs) recycling: results and cost assessment.

    PubMed

    Ruffino, Barbara; Fiore, Silvia; Zanetti, Maria Chiara

    2014-01-01

    With reference to the European regulation about the management of End-of-Life Vehicles (ELVs), Directive 2000/53/EC imposes the achievement of a recycling target of 85%, and 95% of total recovery by 2015. Over the last few years many efforts have been made to find solutions to properly manage the waste coming from ELVs with the aim of complying with the targets fixed by the Directive. This paper focuses on the economical evaluation of a treatment process, that includes physical (size and density), magnetic and electrical separations, performed on the light fraction of the automobile shredder residue (ASR) with the aim of reducing the amount of waste to dispose of in a landfill and enhancing the recovery of valuable fractions as stated by the EU Directive. The afore mentioned process is able to enhance the recovery of ferrous and non-ferrous metals of an amount equal to about 1% b.w. (by weight) of the ELV weight, and to separate a high energetic-content product suitable for thermal valorization for an amount close to (but not higher than) 10% b.w. of the ELV weight. The results of the economical assessment led to annual operating costs of the treatment ranging from 300,000 €/y to 350,000 €/y. Since the considered plant treats about 13,500 metrictons of ASR per year, this would correspond to an operating cost of approximately 20-25 €/t. Taking into account the amount and the selling price of the scrap iron and of the non magnetic metal recovered by the process, thus leading to a gain of about 30 €/t per ton of light ASR treated, the cost of the recovery process is balanced by the profit from the selling of the recovered metals. On the other hand, the proposed treatment is able to achieve the fulfillment of the targets stated by Directive 2000/53/EC concerning thermal valorization and reduce the amount of waste generated from ELV shredding to landfill.

  5. Gunshot residue inserted under hair scales as a result of a muzzle blast

    NASA Astrophysics Data System (ADS)

    Burnett, Bryan R.

    2009-05-01

    The victim was alleged to have been shot in the head with a .40 caliber pistol from several feet. The defendant claimed that the shot was on the order of inches. Examination in the scanning electron microscope of the hair from around the victim's wound showed no adherent gunshot residue (GSR). However, when the hair was pulled apart by the adhesive of a standard GSR sampler, GSR was found associated with the exposed inner surfaces of the cuticle and cortex fragments. The pistol was discharged close enough to the victim's head that some of the cuticular scales were lifted in the muzzle blast which allowed GSR to be inserted under those scales. Gunshot residue associated with the surface of the victim's hair had somehow been removed. The defendant's account of the shooting was verified by the presence of under-scale GSR.

  6. Residual Hearing Preservation with the Evo® Cochlear Implant Electrode Array: Preliminary Results.

    PubMed

    Bento, Ricardo Ferreira; Danieli, Fabiana; Magalhães, Ana Tereza de Matos; Gnansia, Dan; Hoen, Michel

    2016-10-01

    Introduction The preservation of residual hearing is currently an important challenge for cochlear implant surgeries. Indeed, if patients exhibit functional hearing after cochlear implantation, they can benefit from the combination of acoustical stimulation, usually in the low-frequencies and electrical stimulation in the high-frequencies. This combined mode of stimulation has proven to be beneficial both in terms of speech perception and of sound quality. Finding the right procedures for conducting soft-surgeries and designing electrode arrays dedicated to hearing preservation is an open issue. Objective The objective of this study is to evaluate the combination of a soft-surgery procedure implicating round-window insertion and the use of dexamethasone and hyaluronic acid during surgery, with the use of a specifically designed straight soft electrode array, on hearing preservation in patients with functional hearing in the low frequencies. Methods This pre-clinical trial was conducted on seven patients with residual hearing in the low frequencies. The surgical method used employed a round window insertion and the use of topical dexamethasone. Results The soft-surgery protocol could be successfully followed in five patients. In this group, the average hearing threshold shift compared with pre-operative values was of 18.7 +/- 16.1 dB HL up to 500 Hz and 15.7 +/- 15.1 up to 1 kHz, demonstrating satisfying levels of hearing preservation. Conclusion We were able to demonstrate the possibility of preserving residual hearing in most of the patients using the EVO electrode. Significant residual hearing preservation levels were was obtained when a soft surgical approach involving round window insertion, dexamethasone and hyaluronic use during the surgery.

  7. Preliminary results of residual deficits observed in athletes with concussion history: combined EEG and cognitive study.

    PubMed

    Munia, Tamanna T K; Gendreau, Jeffrey L; Verma, Ajay K; Johnson, Benjamin D; Romanick, Mark; Tavakolian, Kouhyar; Fazel-Rezai, Reza

    2016-08-01

    Assessment, treatment, and management of sport-related concussions are a widely recognized public health issue. Although several neuropsychological and motor assessment tools have been developed and implemented for sports teams at various levels and ages, the sensitivity of these tests has yet to be validated with more objective measures to make return-to-play (RTP) decisions more confidently. The present study sought to analyze the residual effect of concussions on a sample of adolescent athletes who sustained one or more previous concussions compared to those who had no concussion history. For this purpose, a wide variety of assessment tools containing both neurocognitive and electroencephalogram (EEG) elements were used. All clinical testing and EEG were repeated at 8 months, 10 months, and 12 months post-injury for both healthy and concussed athletes. The concussed athletes performed poorer than healthy athletes on processing speed and impulse control subtest of neurocognitive test on month 8, but no alterations were marked in terms of visual and postural stability. EEG analysis revealed significant differences in brain activities of concussed athletes through all three intervals. These long-term neurocognitive and EEG deficits found from this ongoing sport-related concussion study suggest that the post-concussion physiological deficits may last longer than the observed clinical recovery.

  8. Using noble gas tracers to estimate residual CO2 saturation in the field: results from the CO2CRC Otway residual saturation and dissolution test

    NASA Astrophysics Data System (ADS)

    LaForce, T.; Ennis-King, J.; Paterson, L.

    2013-12-01

    Residual CO2 saturation is a critically important parameter in CO2 storage as it can have a large impact on the available secure storage volume and post-injection CO2 migration. A suite of single-well tests to measure residual trapping was conducted at the Otway test site in Victoria, Australia during 2011. One or more of these tests could be conducted at a prospective CO2 storage site before large-scale injection. The test involved injection of 150 tonnes of pure carbon dioxide followed by 454 tonnes of CO2-saturated formation water to drive the carbon dioxide to residual saturation. This work presents a brief overview of the full test sequence, followed by the analysis and interpretation of the tests using noble gas tracers. Prior to CO2 injection krypton (Kr) and xenon (Xe) tracers were injected and back-produced to characterise the aquifer under single-phase conditions. After CO2 had been driven to residual the two tracers were injected and produced again. The noble gases act as non-partitioning aqueous-phase tracers in the undisturbed aquifer and as partitioning tracers in the presence of residual CO2. To estimate residual saturation from the tracer test data a one-dimensional radial model of the near-well region is used. In the model there are only two independent parameters: the apparent dispersivity of each tracer and the residual CO2 saturation. Independent analysis of the Kr and Xe tracer production curves gives the same estimate of residual saturation to within the accuracy of the method. Furthermore the residual from the noble gas tracer tests is consistent with other measurements in the sequence of tests.

  9. Effects of elevated vacuum on in-socket residual limb fluid volume: Case study results using bioimpedance analysis

    PubMed Central

    Sanders, JE; Harrison, DS; Myers, TR; Allyn, KJ

    2015-01-01

    Bioimpedance analysis was used to measure residual limb fluid volume on seven trans-tibial amputee subjects using elevated vacuum sockets and non-elevated vacuum sockets. Fluid volume changes were assessed during sessions with the subjects sitting, standing, and walking. In general, fluid volume losses during 3 or 5 min walks and losses over the course of the 30-min test session were less for elevated vacuum than for suction. A number of variables including the time of day data were collected, soft tissue consistency, socket-to-limb size differences and shape differences, and subject health may have affected the results and had an equivalent or greater impact on limb fluid volume compared with elevated vacuum. Researchers should well consider these variables in study design of future investigations on the effects of elevated vacuum on residual limb volume. PMID:22234667

  10. CS(2) blinds in Brassica crops: false positive results in the dithiocarbamate residue analysis by the acid digestion method.

    PubMed

    Perz, R C; van Lishaut, H; Schwack, W

    2000-03-01

    Various members of the Brassicaceae family (cauliflower, savoy cabbage, red cabbage, turnip-rooted cabbage) grown without any application of pesticides were analyzed according to the acid digestion method commonly used for the determination of dithiocarbamate fungicide residues. Depending on postharvest treatments, high non-anthropogenic CS(2) values up to 4 mg/kg were found in some cases, especially in frozen raw cabbage samples, exceeding maximum residue limits. To explore phytogenic CS(2) occurrences, two model substances (phenylisothiocyanate and methyl tryptaminedithiocarbamate) representing natural mustard oils and brassinines, respectively, were analyzed for their acid hydrolysis decomposition products. In both cases, COS was found generally, but CS(2) was readily formed during acid digestion, too, when sulfides were present. The results obtained clearly demonstrate that CS(2) values determined by using the acid digestion method of crops rich in secondary metabolism sulfur compounds have to be interpreted carefully.

  11. Do all of the neurologic diseases in patients with DNA repair gene mutations result from the accumulation of DNA damage?

    PubMed

    Brooks, P J; Cheng, Tsu-Fan; Cooper, Lori

    2008-06-01

    The classic model for neurodegeneration due to mutations in DNA repair genes holds that DNA damage accumulates in the absence of repair, resulting in the death of neurons. This model was originally put forth to explain the dramatic loss of neurons observed in patients with xeroderma pigmentosum neurologic disease, and is likely to be valid for other neurodegenerative diseases due to mutations in DNA repair genes. However, in trichiothiodystrophy (TTD), Aicardi-Goutières syndrome (AGS), and Cockayne syndrome (CS), abnormal myelin is the most prominent neuropathological feature. Myelin is synthesized by specific types of glial cells called oligodendrocytes. In this review, we focus on new studies that illustrate two disease mechanisms for myelin defects resulting from mutations in DNA repair genes, both of which are fundamentally different than the classic model described above. First, studies using the TTD mouse model indicate that TFIIH acts as a co-activator for thyroid hormone-dependent gene expression in the brain, and that a causative XPD mutation in TTD results in reduction of this co-activator function and a dysregulation of myelin-related gene expression. Second, in AGS, which is caused by mutations in either TREX1 or RNASEH2, recent evidence indicates that failure to degrade nucleic acids produced during S-phase triggers activation of the innate immune system, resulting in myelin defects and calcification of the brain. Strikingly, both myelin defects and brain calcification are both prominent features of CS neurologic disease. The similar neuropathology in CS and AGS seems unlikely to be due to the loss of a common DNA repair function, and based on the evidence in the literature, we propose that vascular abnormalities may be part of the mechanism that is common to both diseases. In summary, while the classic DNA damage accumulation model is applicable to the neuronal death due to defective DNA repair, the myelination defects and brain calcification seem to

  12. Dietary exposure of Hong Kong adults to pesticide residues: results of the first Hong Kong Total Diet Study.

    PubMed

    Wong, Waiky W K; Yau, Arthur T C; Chung, Stephen W C; Lam, Chi-ho; Ma, Stephanie; Ho, Y Y; Xiao, Ying

    2014-01-01

    The use of pesticides and other chemicals has become a common practice in modern agriculture to enhance and stabilise crop yield, protect the nutritional integrity of food, facilitate food storage to assure year-round supplies, and provide attractive and appealing food products. With the adoption of strict good agricultural practice (GAP), only minimal amounts of pesticide residues should remain on the crops or in connected foods of animal origin up the food chain. To assess their associated health risk to local people, the dietary exposure of Hong Kong adults to residues of four groups of pesticides or their metabolites - organophosphorus pesticides (OPPs), carbamates, pyrethrins and pyrethroids, and dithiocarbamate (DTC) metabolites - is estimated in the first Hong Kong Total Diet Study (TDS). A total of 150 commonly consumed food items were collected and prepared "as consumed". A total of 600 composite food samples were analysed for 85 pesticides or their metabolites by liquid chromatography-tandem mass spectrometry (LC-MS/MS). These pesticides were primarily found at low levels (highest mean = 350 μg kg⁻¹) in food samples of plant origin such as vegetables and fruits. Dietary exposures to pesticide residues were estimated based on the analytical results and the food consumption data of the local residents. The estimated dietary exposures of Hong Kong adults to all individual pesticides were well below their respective acceptable daily intakes (ADIs). The percentage contributions of the estimated mean and 95th percentile dietary exposures to the ADIs of individual pesticides were <6% and <24% for the OPPs, <1% for the carbamates and pyrethrins and pyrethroids, and <1% and <4% for the DTC metabolites, respectively. The findings indicate that dietary exposures to all the pesticide residues analysed in this study were unlikely to pose unacceptable health risks to the Hong Kong population.

  13. Anisotropic stress accumulation in cooling lava flows and resulting fracture patterns: Insights from starch-water desiccation experiments

    NASA Astrophysics Data System (ADS)

    Lodge, Robert W. D.; Lescinsky, David T.

    2009-09-01

    Desiccation of starch-water slurries is a useful analog for the production of polygonal fractures/columnar joints in cooling lava flows. When left to dry completely, a simple mixture of 1:1 starch and water will produce columns that appear remarkably similar to natural columnar joints formed in cooled lava flows. Columns form when the accumulation of isotropic stress exceeds the tensile strength of a material, at which point a fracture forms and advances through the material perpendicular to the desiccating surface. Individual fractures will initially form orthogonal to the desiccation surface but will quickly evolve into a hexagonal fracture network that advances incrementally through the material. However, some fracture patterns found within natural lava flows are not hexagonal ( Lodge and Lescinsky, 2009-this issue), but rather have fracture lengths that are much longer than the distance to adjacent fractures. These fractures are commonly found at lava flows that have interacted with glacial ice during emplacement. The purpose of this study is to utilize starch analog experiments to better understand the formation of these fractures and the stress regimes responsible for their non-hexagonal patterns. To simulate anisotropic conditions during cooling, the starch slurry was poured into a container with a movable wall that was attached to a screw-type jack. The jack was then set to slowly extend or retract while the slurry desiccated. This resulted in either a decrease or increase in the chamber cross-sectional area thus creating compressional or extensional regimes. Decreasing chamber area (DCA) experiments resulted in fractures with larger lengths parallel to the direction of wall movement (also direction of compression). It also caused localized thrust faulting and curved column development. Increasing chamber area (ICA) experiments produced a zone of horizontal column development along the expanding margin (produced when the wall detached from the sample

  14. Envisat derived Elevation Changes of the Greenland Ice Sheet, and a Comparison with ICESat Results in the Accumulation Area.

    NASA Astrophysics Data System (ADS)

    Sandberg Sørensen, L.; Simonsen, S. B.; Meister, R.; Forsberg, R.; Levinsen, J. F.; Flament, T.

    2014-12-01

    We show that an along track method for deriving rates of elevation change can successfully be applied to Envisat radar altimetry data over Greenland (2002-2010). The results provide improved resolution and coverage compared to previous results obtained from cross-over methods. Also, we find that temporal changes in the elevation change rate can be derived from Envisat data, and show clear examples of this by generating five-year running means for selected areas of the Greenland ice sheet. For a period between 2003 and 2009, the elevation of the ice sheets was measured by both the laser altimeter on board ICESat and the radar altimeter on board Envisat. We compare rates of elevation change derived from ICESat and Envisat for this time span in which both sensors were operating. We focus on the area above the equilibrium line altitude, in order to specifically derive information on snow parameters. A comparison of the elevation changes observed by the two sensors shows a complex pattern, which can be explained regionally by model output describing the changes in both firn air content and accumulation rates.

  15. Accumulation of mutant huntingtin fragments in aggresome-like inclusion bodies as a result of insufficient protein degradation.

    PubMed

    Waelter, S; Boeddrich, A; Lurz, R; Scherzinger, E; Lueder, G; Lehrach, H; Wanker, E E

    2001-05-01

    The huntingtin exon 1 proteins with a polyglutamine repeat in the pathological range (51 or 83 glutamines), but not with a polyglutamine tract in the normal range (20 glutamines), form aggresome-like perinuclear inclusions in human 293 Tet-Off cells. These structures contain aggregated, ubiquitinated huntingtin exon 1 protein with a characteristic fibrillar morphology. Inclusion bodies with truncated huntingtin protein are formed at centrosomes and are surrounded by vimentin filaments. Inhibition of proteasome activity resulted in a twofold increase in the amount of ubiquitinated, SDS-resistant aggregates, indicating that inclusion bodies accumulate when the capacity of the ubiquitin-proteasome system to degrade aggregation-prone huntingtin protein is exhausted. Immunofluorescence and electron microscopy with immunogold labeling revealed that the 20S, 19S, and 11S subunits of the 26S proteasome, the molecular chaperones BiP/GRP78, Hsp70, and Hsp40, as well as the RNA-binding protein TIA-1, the potential chaperone 14-3-3, and alpha-synuclein colocalize with the perinuclear inclusions. In 293 Tet-Off cells, inclusion body formation also resulted in cell toxicity and dramatic ultrastructural changes such as indentations and disruption of the nuclear envelope. Concentration of mitochondria around the inclusions and cytoplasmic vacuolation were also observed. Together these findings support the hypothesis that the ATP-dependent ubiquitin-proteasome system is a potential target for therapeutic interventions in glutamine repeat disorders.

  16. Accumulation of nonfunctional S-haplotypes results in the breakdown of gametophytic self-incompatibility in tetraploid Prunus.

    PubMed

    Hauck, Nathanael R; Yamane, Hisayo; Tao, Ryutaro; Iezzoni, Amy F

    2006-02-01

    The transition from self-incompatibility (SI) to self-compatibility (SC) is regarded as one of the most prevalent transitions in Angiosperm evolution, having profound impacts on the genetic structure of populations. Yet, the identity and function of mutations that result in the breakdown of SI in nature are not well understood. This work provides the first detailed genetic description of the breakdown of S-RNase-mediated gametophytic self-incompatibility (GSI) in a polyploid species that exhibits genotype-dependent loss of SI. Genetic analyses of six natural sour cherry (Rosaceae, Prunus cerasus) selections identified seven independent, nonfunctional S-haplotypes with disrupted pistil component (stylar-S) and/or pollen component (pollen-S) function. A genetic model demonstrating that the breakdown of SI in sour cherry is due to the accumulation of a minimum of two nonfunctional S-haplotypes within a single individual is developed and validated. Our finding that sour cherry is SI when only one nonfunctional S-haplotype is present has significant evolutionary implications since nonfunctional S-haplotypes would be maintained in the population without causing an abrupt shift to SC. Furthermore, we demonstrate that heteroallelic sour cherry pollen is self-incompatible, which is counter to the well-documented phenomenon in the Solanaceae where SC accompanying polyploidization is frequently due to the SC of heteroallelic pollen.

  17. Switching to aripiprazole for the treatment of residual mutism resulted in distinct clinical courses in two catatonic schizophrenia cases

    PubMed Central

    Muneoka, Katsumasa; Kanahara, Nobuhisa; Kimura, Shou

    2017-01-01

    Objectives: The efficacy of a partial agonist for the dopamine D2 receptor, aripiprazole, for catatonia in schizophrenia has been reported. Methods: We report distinct clinical courses in challenging aripiprazole to treat residual mutism after severe catatonic symptoms improved. Results: In the first case, mutism was successfully treated when the patient was switched from olanzapine to aripiprazole. In contract, switching to aripiprazole from risperidone aggravated auditory hallucinations in the second case. Conclusions: We will discuss the benefits and risks of using aripiprazole for the treatment of catatonic schizophrenia and the possibility of dopamine supersensitivity psychosis. PMID:28255444

  18. Feasibility analysis and residual evaluation of automated planar segmentation results of large-scale Martian surface structures

    NASA Astrophysics Data System (ADS)

    Székely, B.; Dorninger, P.; Koma, Zs.; Jansa, J.; Kovács, G.; Nothegger, C.

    2012-04-01

    As increasingly larger coverage of DTMs is available for the Martian surface, not only the number of studies on individual specific Martian features increase, but the need for large-scale geomorphometric evaluation is amplified as well. The computer power and the increasingly sophisticated methods are about to allow such extensive studies. Our DTM segmentation method that has been tailored and tested recently for various geoscientific applications, now allows to process large DTMs created within the framework of ESA Mars Express HRSC project. The implementation uses computation parallelization, kd-tree approach for storage and several sophisticated techniques in seeking for seed points to improve performance. Test runs on high-capacity multi-core computers demonstrate that now processing of complete DTMs of an orbit is feasible. The possibility to process large areas also implies that the segmentation results in high number of planar facets, typically several thousand features. Furthermore, the segmentation is often sensitive to the initial parameters (number of points to calculate local normal vectors, point-to-plane distance, angular tolerance, etc.) and also the use of splitting segments parameter has typically a stronger influence on the corresponding segmentation pattern. This complexity may complicate the evaluation of the results. In order to recognize the general behaviour a number of test runs have been carried out. The resulting sets of planar facets were then evaluated whether the segmentation fulfilled the original purpose (e.g., in the case of the modeling of an impact crater, its typical features should be modeled. In case of unsatisfying coverage or residual values those models have been sorted out. Model results considered to be satisfying are then analysed from the point of view of the residual values (the pointwise difference of measured height and modeled height). The distributions of the residuals are sometimes asymmetric, but the results are

  19. Toolkit for Monitoring and Evaluation of Indoor Residual Spraying for Visceral Leishmaniasis Control in the Indian Subcontinent: Application and Results

    PubMed Central

    Huda, M. Mamun; Mondal, Dinesh; Kumar, Vijay; Das, Pradeep; Sharma, S. N.; Das, Murari Lal; Roy, Lolita; Gurung, Chitra Kumar; Banjara, Megha Raj; Akhter, Shireen; Maheswary, Narayan Prosad; Kroeger, Axel; Chowdhury, Rajib

    2011-01-01

    Background. We field tested and validated a newly developed monitoring and evaluation (M&E) toolkit for indoor residual spraying to be used by the supervisors at different levels of the national kala-azar elimination programs in Bangladesh, India and Nepal. Methods. Methods included document analysis, in-depth interviews, direct observation of spraying squads, and entomological-chemical assessments (bioassay, susceptibility test, chemical analysis of insecticide residues on sprayed surfaces, vector density measurements at baseline, and three follow-up surveys). Results. We found that the documentation at district offices was fairly complete; important shortcomings included insufficient training of spraying squads and supervisors, deficient spray equipment, poor spraying performance, lack of protective clothing, limited coverage of houses resulting in low bioavailability of the insecticide on sprayed surfaces, and reduced vector susceptibility to DDT in India, which limited the impact on vector densities. Conclusion. The M&E toolkit is a useful instrument for detecting constraints in IRS operations and to trigger timely response. PMID:21811510

  20. Loss of AP-5 results in accumulation of aberrant endolysosomes: defining a new type of lysosomal storage disease.

    PubMed

    Hirst, Jennifer; Edgar, James R; Esteves, Typhaine; Darios, Frédéric; Madeo, Marianna; Chang, Jaerak; Roda, Ricardo H; Dürr, Alexandra; Anheim, Mathieu; Gellera, Cinzia; Li, Jun; Züchner, Stephan; Mariotti, Caterina; Stevanin, Giovanni; Blackstone, Craig; Kruer, Michael C; Robinson, Margaret S

    2015-09-01

    Adaptor proteins (AP 1-5) are heterotetrameric complexes that facilitate specialized cargo sorting in vesicular-mediated trafficking. Mutations in AP5Z1, encoding a subunit of the AP-5 complex, have been reported to cause hereditary spastic paraplegia (HSP), although their impact at the cellular level has not been assessed. Here we characterize three independent fibroblast lines derived from skin biopsies of patients harbouring nonsense mutations in AP5Z1 and presenting with spastic paraplegia accompanied by neuropathy, parkinsonism and/or cognitive impairment. In all three patient-derived lines, we show that there is complete loss of AP-5 ζ protein and a reduction in the associated AP-5 µ5 protein. Using ultrastructural analysis, we show that these patient-derived lines consistently exhibit abundant multilamellar structures that are positive for markers of endolysosomes and are filled with aberrant storage material organized as exaggerated multilamellar whorls, striated belts and 'fingerprint bodies'. This phenotype can be replicated in a HeLa cell culture model by siRNA knockdown of AP-5 ζ. The cellular phenotype bears striking resemblance to features described in a number of lysosomal storage diseases (LSDs). Collectively, these findings reveal an emerging picture of the role of AP-5 in endosomal and lysosomal homeostasis, illuminates a potential pathomechanism that is relevant to the role of AP-5 in neurons and expands the understanding of recessive HSPs. Moreover, the resulting accumulation of storage material in endolysosomes leads us to propose that AP-5 deficiency represents a new type of LSDs.

  1. Comparison of veterinary drug residue results in animal tissues by ultrahigh-performance liquid chromatography coupled to triple quadrupole ... use of a commercial lipid removal product

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Veterinary drug residues in animal-derived foods must be monitored to ensure food safety, verify proper veterinary practices, enforce legal limits in domestic and imported foods, and other purposes. A common goal in drug residue analysis in foods is to achieve acceptable monitoring results for as m...

  2. Tides, and tidal and residual currents in Suisun and San Pablo bays, California; results of measurements, 1986

    USGS Publications Warehouse

    Gartner, J.W.; Yost, B.T.

    1988-01-01

    Current meter data collected at 11 stations and water level data collected at one station in Suisun and San Pablo Bays, California, in 1986 are compiled in this report. Current-meter measurements include current speed and direction, and water temperature and salinity (computed from temperature and conductivity). For each of the 19 current-meter records, data are presented in two forms. These are: (1) results of harmonic analysis; and (2) plots of tidal current speed and direction versus time and plots of temperature and salinity versus time. Spatial distribution of the properties of tidal currents are given in graphic form. In addition, Eulerian residual currents have been compiled by using a vector-averaging technique. Water level data are presented in the form of a time-series plot and the results of harmonic analysis. (USGS)

  3. Amino acid substitutions in the poliovirus maturation cleavage site affect assembly and result in accumulation of provirions.

    PubMed Central

    Ansardi, D C; Morrow, C D

    1995-01-01

    encapsidated the defective genome RNA. However, the cleavage of VP0 to VP4 and VP2 was delayed, resulting in the accumulation of provirions. The maturation cleavage of the VP0 protein containing the VP4-TS mutation was accelerated by incubation of the provirions at 37 degrees C. The results of these studies demonstrate that mutations in the maturation cleavage site have profound effects on the subsequent capability of the capsid proteins to assemble and provide evidence for the existence of the provirion as an assembly intermediate. PMID:7853487

  4. Melatonin Improved Anthocyanin Accumulation by Regulating Gene Expressions and Resulted in High Reactive Oxygen Species Scavenging Capacity in Cabbage

    PubMed Central

    Zhang, Na; Sun, Qianqian; Li, Hongfei; Li, Xingsheng; Cao, Yunyun; Zhang, Haijun; Li, Shuangtao; Zhang, Lei; Qi, Yan; Ren, Shuxin; Zhao, Bing; Guo, Yang-Dong

    2016-01-01

    In this work, we found, that exogenous melatonin pretreatment improved anthocyanin accumulation (1- to 2-fold) in cabbage. To verify the relationship with melatonin and anthocyanin, an Arabidopsis mutant, snat, which expresses a defective form of the melatonin biosynthesis enzyme SNAT (Serotonin N-acetyl transferase), was employed. Under cold conditions, the foliage of wild-type Arabidopsis exhibited a deeper red color than the snat mutant. This finding further proved, that exogenous melatonin treatment was able to affect anthocyanin accumulation. To gain a better understanding of how exogenous melatonin upregulates anthocyanin, we measured gene expression in cabbage samples treated with melatonin and untreated controls. We found that the transcript levels of anthocyanin biosynthetic genes were upregulated by melatonin treatment. Moreover, melatonin treatment increased the expression levels of the transcription factors MYB, bHLH, and WD40, which constitute the transcriptional activation complex responsible for coordinative regulation of anthocyanin biosynthetic genes. We found, that free radical generation was downregulated, whereas the osmotic adjustment and antioxidant capacities were upregulated in exogenous melatonin-treated cabbage plants. We concluded, that melatonin increases anthocyanin production and benefits cabbage growth. PMID:27047496

  5. ICESat Laser Altimeter Pointing, Ranging and Timing Calibration from Integrated Residual Analysis: A Summary of Early Mission Results

    NASA Technical Reports Server (NTRS)

    Lutchke, Scott B.; Rowlands, David D.; Harding, David J.; Bufton, Jack L.; Carabajal, Claudia C.; Williams, Teresa A.

    2003-01-01

    On January 12, 2003 the Ice, Cloud and land Elevation Satellite (ICESat) was successfUlly placed into orbit. The ICESat mission carries the Geoscience Laser Altimeter System (GLAS), which consists of three near-infrared lasers that operate at 40 short pulses per second. The instrument has collected precise elevation measurements of the ice sheets, sea ice roughness and thickness, ocean and land surface elevations and surface reflectivity. The accurate geolocation of GLAS's surface returns, the spots from which the laser energy reflects on the Earth's surface, is a critical issue in the scientific application of these data Pointing, ranging, timing and orbit errors must be compensated to accurately geolocate the laser altimeter surface returns. Towards this end, the laser range observations can be fully exploited in an integrated residual analysis to accurately calibrate these geolocation/instrument parameters. Early mission ICESat data have been simultaneously processed as direct altimetry from ocean sweeps along with dynamic crossovers resulting in a preliminary calibration of laser pointing, ranging and timing. The calibration methodology and early mission analysis results are summarized in this paper along with future calibration activities

  6. Physiological and biochemical responses resulting from nitrite accumulation in tomato (Lycopersicon esculentum Mill. cv. Ibiza F1).

    PubMed

    Ezzine, Monia; Ghorbel, Mohamed Habib

    2006-10-01

    The sensitivity of hydroponically cultivated tomato (Lycopersicon esculentum Mill. cv. Ibiza F1) submitted to nitrite treatments (0.25-10mM KNO(2)) for 7d was studied. Increasing nitrite levels in the culture medium led to several disruptions of tomato plants, reflected by reductions of both dry matter per plant, chlorophyll concentrations and the appearance of chlorosis symptoms at the leaf surface. This behaviour was accompanied by stimulation of nitrite, nitrate and ammonia ion accumulation, mainly in roots and old leaves. Higher proteolytic and gaiacol peroxidase (GPX, EC. 1.11.1.7) activities and malonyldialdehyde content were also noted. Protein content of the different plant organs was decreased by nitrite treatment. These physiological and biochemical parameters were chosen as they are stress indicators. Taken together, our data partly explain the harmful effects of nitrite ions, when excessive in the culture medium.

  7. Disruption of Mycobacterial AftB Results in Complete Loss of Terminal β(1 → 2) Arabinofuranose Residues of Lipoarabinomannan

    PubMed Central

    2016-01-01

    Lipoarabinomannan (LAM) and arabinogalactan (AG) are the two major mycobacterial cell wall (lipo)polysaccharides, which contain a structurally similar arabinan domain that is highly branched and assembled in a stepwise fashion by variety of arabinofuranosyltransferases (ArafT). In addition to playing an essential role in mycobacterial physiology, LAM and its biochemical precursor lipomannan possess potent immunomodulatory activities that affect the host immune response. In the search of additional mycobacterial ArafTs that participate in the synthesis of the arabinan segment of LAM, we disrupted aftB (MSMEG_6400) in Mycobacterium smegmatis. The deletion of chromosomal aftB locus could only be achieved in the presence of a rescue plasmid carrying a functional copy of aftB, strongly suggesting that it is essential for the viability of M. smegmatis. Isolation and detailed structural characterization of a LAM molecule derived from the conditional mutant deficient in AftB revealed the absence of terminal β(1 → 2)-linked arabinofuranosyl residues. Furthermore, we demonstrated that truncated LAM displays proinflammatory activity, which is due to its ability to activate Toll-like receptor 2. All together, our results indicate that AftB is an essential mycobacterial ArafT that plays a role in the synthesis of the arabinan domain of LAM. PMID:28033704

  8. Distribution and health risk assessment of organochlorine pesticides (OCPs) residue in edible cattle tissues from northeastern part of Egypt: High accumulation level of OCPs in tongue.

    PubMed

    Mahmoud, Abdallah Fikry A; Ikenaka, Yoshinori; Yohannes, Yared B; Darwish, Wageh S; Eldaly, Elsaid A; Morshdy, Alaa Eldin M A; Nakayama, Shouta M M; Mizukawa, Hazuki; Ishizuka, Mayumi

    2016-02-01

    Food consumption is an important route of human exposure to organochlorine pesticides (OCPs). In order to assess the potential human health risks associated with OCPs, edible cattle tissues (liver, kidney and tongue) were collected from three slaughter houses in Mansoura, Zagazig and Ismailia cities, Egypt. Levels of 22 OCPs such as hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), aldrin, dieldrin and endrin (Drins), chlordanes (CHLs), heptachlors (HPTs) and hexachlorobenzene (HCB) residues were investigated. Among the investigated OCPs, HCHs represented the most dominant group with high proportions of γ-HCH isomer (53-91% of total HCHs). Mansoura city had the highest OCPs contamination load ranged from 0.1 to 2827 ng g(-1) lw (lipid weight). Surprisingly, tongue samples collected from Mansoura showed the highest concentration of HCHs (448 ng g(-1) lw) in comparison to liver (152 ng g(-1) lw) and kidney (266 ng g(-1) lw). Generally, contamination pattern of OCPs was in the order of HCHs > Drins > CHLs > DDTs ≅ HCB and HPTs. Estimated daily intakes (EDIs) through dietary consumption of cattle tissues were lower than the recommended acceptable daily intakes (ADIs) established by FAO/WHO. However, the hazard ratios (HRs) based on cancer risk were greater than 1.0 for HCHs based on the average and 95th centile concentrations, indicating carcinogenic effects to consumers through cattle tissues consumption.

  9. The surface chemistry resulting from low-pressure plasma treatment of polystyrene: The effect of residual vessel bound oxygen

    NASA Astrophysics Data System (ADS)

    Dhayal, Marshal; Alexander, Morgan R.; Bradley, James W.

    2006-09-01

    The surface chemistry of plasma treated polystyrene samples has been studied in a specially designed low-pressure argon discharge system incorporating in situ XPS analysis. By using an electrostatic grid biasing technique, the plasma source can also be used in a mode preventing ion interactions with the sample. The system, which utilizes a vacuum transfer chamber between plasma and XPS analysis has allowed us to differentiate between the level of oxygen incorporated at the polystyrene surface from residual gas during treatment and that from the exposure of the treated sample to the laboratory atmosphere. Using typical base pressures of about 5 × 10 -3 Pa (4 × 10 -5 Torr) the XPS results show that significant oxygen surface incorporation resulted from oxygen containing species in the plasma itself (i.e. water vapour with 2 × 10 -3 Pa partial pressure). The surface concentration of O was measured at 7.6 at.%. Subsequent atmospheric exposure of the treated samples resulted in only a small increase (of 0.6 at.%) in oxygen incorporation in the form of acid anhydride functionalities. XPS measurements of PS samples exposed to plasmas with no ion-surface component (i.e. exposure from VUV, UV and excited neutral species only) showed no appreciable change in oxygen incorporation compared to those with low-energy ion bombardment from the plasma (<20 eV). Given the energetics of the remaining bombarding species, it indicates that VUV radiation may be chiefly responsible for the production of free radical sites in this discharge regime.

  10. The effects of biochars from rice residue on the formation of iron plaque and the accumulation of Cd, Zn, Pb, As in rice (Oryza sativa L.) seedlings.

    PubMed

    Zheng, Rui-Lun; Cai, Chao; Liang, Jian-Hong; Huang, Qing; Chen, Zheng; Huang, Yi-Zong; Arp, Hans Peter H; Sun, Guo-Xin

    2012-10-01

    A historically multi-metal contaminated soil was amended with biochars produced from different parts of rice plants (straw, husk and bran) to investigate how biochar can influence the mobility of Cd, Zn, Pb and As in rice seedlings (Oryza sativa L.). Rice shoot concentrations of Cd, Zn and Pb decreased by up to 98%, 83% and 72%, respectively, due to biochar amendment, though that of As increased by up to 327%. Biochar amendments significantly decreased pore water concentrations (C(pw)) of Cd and Zn and increased that of As. For Pb it depended on the amendment. Porewater pH, dissolved organic carbon, dissolved phosphorus, silicon in pore water and iron plaque formation on root surfaces all increased significantly after the amendments. The proportions of Cd and Pb in iron plaque increased by factors 1.8-5.7 and 1.4-2.8, respectively; no increase was observed for As and Zn. Straw-char application significantly and noticeably decreased the plant transfer coefficients of Cd and Pb. This study, the first to investigate changes in metal mobility and iron plaque formation in rice plants due to amending a historically contaminated soil with biochar, indicates that biochar has a potential to decrease Cd, Zn and Pb accumulations in rice shoot but increase that of As. The main cause is likely biochar decreasing the C(pw) of Cd and Zn, increasing the C(pw) of As, and increasing the iron plaque blocking capacity for Cd and Pb.

  11. Intrathoracic impedance vs daily weight monitoring for predicting worsening heart failure events: results of the Fluid Accumulation Status Trial (FAST).

    PubMed

    Abraham, William T; Compton, Steven; Haas, Garrie; Foreman, Blair; Canby, Robert C; Fishel, Robert; McRae, Scott; Toledo, Gloria B; Sarkar, Shantanu; Hettrick, Douglas A

    2011-01-01

    The relative sensitivity and unexplained detection rate of changes in intrathoracic impedance has not been compared with standard heart failure (HF) monitoring using daily weight changes. The Fluid Accumulation Status Trial (FAST) prospectively followed 156 HF patients with implanted cardioverter-defibrillator or cardiac resynchronization therapy defibrillator devices modified to record daily changes in intrathoracic impedance in a blinded fashion for 537±312 days. Daily impedance changes were used to calculate a fluid index that could be compared with a prespecified threshold. True positives were defined as adjudicated episodes of worsening HF occurring within 30 days of a fluid index above threshold or an acute weight gain. Unexplained detections were defined as threshold crossings or acute weight gains not associated with worsening HF. Impedance measurements were performed on >99% of follow-up days, compared with only 76% of days for weight measurements. Sixty-five HF events occurred during follow-up (0.32/patient-year). Forty HF events were detected by impedance but not weight, whereas 5 were detected by weight but not impedance. Sensitivity was greater (76% vs 23%; P<.0001) and unexplained detection rate was lower (1.9 vs 4.3/patient-year; P<.0001) for intrathoracic impedance monitoring at the threshold of 60Ω days compared with acute weight increases of 3 lbs in 1 day or 5 lbs in 3 days and also over a wide range of fluid index and weight thresholds. The sensitivity and unexplained detection rate of intrathoracic impedance monitoring was superior to that seen for acute weight changes. Intrathoracic impedance monitoring represents a useful adjunctive clinical tool for managing HF in patients with implanted devices.

  12. Triosephosphate isomerase: removal of a putatively electrophilic histidine residue results in a subtle change in catalytic mechanism

    SciTech Connect

    Nickbarg, E.B.; Davenport, R.C.; Petsko, G.A.; Knowles, J.R.

    1988-08-09

    An important active-site residue in the glycolytic enzyme triosephosphate isomerase is His-95, which appears to act as an electrophilic component in catalyzing the enolization of the substrates. With the techniques of site-directed mutagenesis, His-95 has been replaced by Gln in the isomerase from Saccharomyces cerevisiae. The mutant isomerase has been expressed in Escherichia coli strain DF502 and purified to homogeneity. The specific catalytic activity of the mutant enzyme is less than that of wild type by a factor of nearly 400. The mutant enzyme can be resolved from the wild-type isomerase on nondenaturing isoelectric focusing gels, and an isomerase activity stain shows that the observed catalytic activity indeed derives from the mutant protein. The mutant enzyme shows the same stereospecificity of proton transfer as the wild type. Tritium exchange experiments similar to those used to define the free energy profile for the wild-type yeast isomerase, together with a new method of analysis involving /sup 14/C and /sup 3/H doubly labeled substrates, have been used to investigate the energetics of the mutant enzyme catalyzed reaction. The deuterium kinetic isotope effects observed with the mutant isomerase using (1(R)-/sup 2/H)dihydroxyacetone phosphate and (2-/sup 2/H)glyceraldehyde 3-phosphate are 2.15 +/- 0.04 and 2.4 +/- 0.1, respectively. These results lead to the conclusion that substitution of Gln for His-95 so impairs the ability of the enzyme to stabilize the reaction intermediate that there is a change in the pathways of proton transfer mediated by the mutant enzyme.

  13. Accumulate-Repeat-Accumulate-Accumulate Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Samuel; Thorpe, Jeremy

    2007-01-01

    Accumulate-repeat-accumulate-accumulate (ARAA) codes have been proposed, inspired by the recently proposed accumulate-repeat-accumulate (ARA) codes. These are error-correcting codes suitable for use in a variety of wireless data-communication systems that include noisy channels. ARAA codes can be regarded as serial turbolike codes or as a subclass of low-density parity-check (LDPC) codes, and, like ARA codes they have projected graph or protograph representations; these characteristics make it possible to design high-speed iterative decoders that utilize belief-propagation algorithms. The objective in proposing ARAA codes as a subclass of ARA codes was to enhance the error-floor performance of ARA codes while maintaining simple encoding structures and low maximum variable node degree.

  14. Increased expression of apolipoprotein E in transgenic rabbits results in reduced levels of very low density lipoproteins and an accumulation of low density lipoproteins in plasma.

    PubMed Central

    Fan, J; Ji, Z S; Huang, Y; de Silva, H; Sanan, D; Mahley, R W; Innerarity, T L; Taylor, J M

    1998-01-01

    Transgenic rabbits expressing human apo E3 were generated to investigate mechanisms by which apo E modulates plasma lipoprotein metabolism. Compared with nontransgenic littermates expressing approximately 3 mg/dl of endogenous rabbit apo E, male transgenic rabbits expressing approximately 13 mg/dl of human apo E had a 35% decrease in total plasma triglycerides that was due to a reduction in VLDL levels and an absence of large VLDL. With its greater content of apo E, transgenic VLDL had an increased binding affinity for the LDL receptor in vitro, and injected chylomicrons were cleared more rapidly by the liver in transgenic rabbits. In contrast to triglyceride changes, transgenic rabbits had a 70% increase in plasma cholesterol levels due to an accumulation of LDL and apo E-rich HDL. Transgenic and control LDL had the same binding affinity for the LDL receptor. Both transgenic and control rabbits had similar LDL receptor levels, but intravenously injected human LDL were cleared more slowly in transgenic rabbits than in controls. Changes in lipoprotein lipolysis did not contribute to the accumulation of LDL or the reduction in VLDL levels. These observations suggest that the increased content of apo E3 on triglyceride-rich remnant lipoproteins in transgenic rabbits confers a greater affinity for cell surface receptors, thereby increasing remnant clearance from plasma. The apo E-rich large remnants appear to compete more effectively than LDL for receptor-mediated binding and clearance, resulting in delayed clearance and the accumulation of LDL in plasma. PMID:9593771

  15. A review of the analysis of vegetable oil residues from fire debris samples: analytical scheme, interpretation of the results, and future needs.

    PubMed

    Stauffer, Eric

    2006-09-01

    This paper reviews the literature on the analysis of vegetable (and animal) oil residues from fire debris samples. The examination sequence starts with the solvent extraction of the residues from the substrate. The extract is then prepared for instrumental analysis by derivatizing fatty acids (FAs) into fatty acid methyl esters. The analysis is then carried out by gas chromatography or gas chromatography-mass spectrometry. The interpretation of the results is a difficult operation seriously limited by a lack of research on the subject. The present data analysis scheme utilizes FA ratios to determine the presence of vegetable oils and their propensity to self-heat and possibly, to spontaneously ignite. Preliminary work has demonstrated that it is possible to detect chemical compounds specific to an oil that underwent spontaneous ignition. Guidelines to conduct future research in the analysis of vegetable oil residues from fire debris samples are also presented.

  16. Biological nitrogen fixation and biomass accumulation within poplar clones as a result of inoculations with diazotrophic endophyte consortia.

    PubMed

    Knoth, Jenny L; Kim, Soo-Hyung; Ettl, Gregory J; Doty, Sharon L

    2014-01-01

    Sustainable production of biomass for bioenergy relies on low-input crop production. Inoculation of bioenergy crops with plant growth-promoting endophytes has the potential to reduce fertilizer inputs through the enhancement of biological nitrogen fixation (BNF). Endophytes isolated from native poplar growing in nutrient-poor conditions were selected for a series of glasshouse and field trials designed to test the overall hypothesis that naturally occurring diazotrophic endophytes impart growth promotion of the host plants. Endophyte inoculations contributed to increased biomass over uninoculated control plants. This growth promotion was more pronounced with multi-strain consortia than with single-strain inocula. Biological nitrogen fixation was estimated through (15)N isotope dilution to be 65% nitrogen derived from air (Ndfa). Phenotypic plasticity in biomass allocation and branch production observed as a result of endophyte inoculations may be useful in bioenergy crop breeding and engineering programs.

  17. Evidence for a palaeo-oil column and alteration of residual oil in a gas-condensate field: Integrated oil inclusion and experimental results

    NASA Astrophysics Data System (ADS)

    Bourdet, Julien; Burruss, Robert C.; Chou, I.-Ming; Kempton, Richard; Liu, Keyu; Hung, Nguyen Viet

    2014-10-01

    displays a similar yellow shift when gas is added. Solid residues rarely form in mixtures with 42 °API oil. FT-IR spectra suggest that the decrease of fluorescence intensity of the original oil at short wavelengths to be due to the partitioning of low molecular weight aromatic molecules into the vapour phase and/or the new immiscible liquid phase. The decrease of fluorescence intensity at long wavelengths appears to be due to loss of high molecular weight aromatics during precipitation of solid residues by desorption of aromatics and resins from asphaltenes. Desorption of low molecular weight aromatics and resins from asphaltenes during precipitation can also increase the fluorescence intensity at short wavelengths of the residual oil. Water clearly affects the precipitation of semi-solid residues from the oil phase of the lowest API gravity oil. The change of hydrocarbon phase(s) in UV-visible fluorescence and FT-IR enclosed within the FSCCs were compared with the fluorescence patterns of natural fluid inclusions at Phuong Dong gas condensate field. The experimental results support the concept of gas-washing of residual oil and are consistent with the oil inclusion attributes from the current gas zone at Phuong Dong field. The hydrocarbon charge history of the fractured granite reservoir is interpreted to result from the trapping of residual oil after drainage of a palaeo-oil column by gas.

  18. Monocrotophpos and dicrotophos residues in birds as a result of misuse of organophosphates in Matagorda County, Texas

    USGS Publications Warehouse

    Flickinger, Edward L.; White, D.H.; Mitchell, C.A.; Lamont, T.G.

    1984-01-01

    About 1100 birds of 12 species died from organophosphate poisoning in Matagorda County on the Texas Gulf Coast in March and May 1982. Birds died from feeding on rice seed that was illegally treated with dicrotophos or monocrotophos and placed near rice fields as bait to attract and kill birds. Brain acetylcholinesterase inhibition of affected birds averaged 87% (range 82-89%), and contents of gastrointestinal tracts contained residues of dicrotophos (5.6-14 ppm) or monocrotophos (2.1-13 ppm). Rice seed collected at mortality sites contained 210 ppm dicrotophos or 950 ppm monocrotophos. Mortality from dicrotophos poisoning continued for almost 3 weeks. The practice of illegally treating rice seed with either of these 2 organophosphates appears to be infrequent but widespread at present.

  19. Cellular change and callose accumulation in zygotic embryos of Eleutherococcus senticosus caused by plasmolyzing pretreatment result in high frequency of single-cell-derived somatic embryogenesis.

    PubMed

    Ling You, Xiang; Seon Yi, Jae; Eui Choi, Yong

    2006-05-01

    Eleutherococcus senticosus zygotic embryos were pretreated with 1.0 M mannitol or sucrose for 3-24 h. This pretreatment resulted in a high frequency of somatic-embryo formation on hormone-free medium. All the somatic embryos developed directly and independently from single epidermal cells on the surface of zygotic embryos after plasmolyzing pretreatment. Scanning electron microscopic observation revealed that the epidermal cells of hypocotyls rapidly became irregular and showed a random orientation before somatic-embryo development commenced. At the same time, the epidermal cells in the untreated control remained regular. Callose concentration determined by fluorometric analysis increased sharply in E. senticosus zygotic embryos after plasmolyzing pretreatment but remained low in the untreated control. Aniline blue fluorescent staining of callose showed that the plasmolyzing pretreatment of zygotic embryos resulted in heavy accumulation of callose between the plasma membrane and cell walls. On the basis of these results, we suggest that plasmolyzing pretreatment of zygotic embryos induces the accumulation of callose, and the interruption of cell-to-cell communication imposed by this might stimulate the reprogramming of epidermal cells into embryogenically competent cells and finally induce somatic-embryo development from single cells.

  20. RNAi based simultaneous silencing of all forms of light-dependent NADPH:protochlorophyllide oxidoreductase genes result in the accumulation of protochlorophyllide in tobacco (Nicotiana tabacum).

    PubMed

    Talaat, Neveen B

    2013-10-01

    Conversion of protochlorophyllide (Pchlide) into chlorophyllide (Chlide), a key step in chlorophyll biosynthesis, is mediated by a light-dependent NADPH:protochlorophyllide oxidoreductase (POR). POR exists in multiple isoforms that share high degree of homology. RNAi-mediated gene silencing approach was used to suppress the expression of POR genes in order to study its role in the Chls biosynthesis in tobacco (Nicotiana tabacum L.). The transgenic plants were devoid of chlorophyll pigments and resembled albino plants. Northern blot analysis confirmed the degradation of POR transcripts into 21-23 bp fragments. Pigment analysis showed the accumulation of various intermediate compounds of Chl biosynthesis pathway including Pchlide. However, no trace of chlorophyll was observed. As compared to wild type, POR-silenced plants accumulated larger (60%) amounts of Pchlide from its endogenous substrate. When leaf discs of WT and POR-silenced plants were treated with exogenous ALA both WT and POR-silenced plants accumulated large amounts of tetrapyrrolic intermediates demonstrating that Pchlide biosynthesis potential was not suppressed in POR-silenced plants. Upon illumination, WT plants photo-transformed large amounts of Pchlide to Chlide. However, POR-silenced plants almost completely failed to do so. Results demonstrate that the antisense approaches to drop expression of individual POR isoforms have provided valuable insights into the role of distinct PORs during greening. Moreover, data illustrate that the POR is the only enzyme that can convert the Pchlide to Chlide and there is no alternate enzyme that can substitute the POR in higher plants. Thus, this investigation describes ideal mechanism for the silencing of POR isozymes in tobacco.

  1. Monocrotophos and dicrotophos residues in birds as a result of misuse of organophosphates in Matagorda county Texas USA

    USGS Publications Warehouse

    Flickinger, Edward L.; White, D.H.; Mitchell, C.A.; Lamont, T.G.

    1984-01-01

    About 1100 birds of 12 spp. [Red-winged blackbird (Agelaius phoeniceus), great-tailed grackle (Quiscalus mexicanus), brown-headed cowbird (Molothrus ater), mourning dove (Zenaida macrours), Eastern meadowlark (Sturnella magna), vesper sparrow (Pooecetes gramineus), common snipe (Gallinago gallinago), blue-winged teal (Anas discors), mottled duck (Anas fulvigula), common moorhen (Gallinula chloropus), redhead (Aythya americana) and ruddy turnstone (Arenaria interpres)] died from organophosphate poisoning in Matagorda County on the Texas Gulf Coast in March and May 1982. Birds died from feeding on rice seed that was illegally treated with dicrotophos or monocrotophos and placed near rice fields as bait to attract and kill birds. Brain acetylcholinesterase inhibition of affected birds averaged 87% (range 82-89%), and contents of gastrointestinal tracts contained residues of dicrotophos (5.6-14 ppm) or monocrotophos (2.1-13 ppm). Rice seed collected at mortality sites contained 210 ppm dicrotophos or 950 ppm monocrotophos. Mortality from dicrotophos poisoning continued for almost 3 wk. The practice of illegally treating rice seed with either of the 2 organophosphates appears to be infrequent but widespread at present.

  2. Effects of coal combustion residues on survival, antioxidant potential, and genotoxicity resulting from full-lifecycle exposure of grass shrimp (Palaemonetes pugio Holthius).

    PubMed

    Kuzmick, Danika M; Mitchelmore, Carys L; Hopkins, William A; Rowe, Christopher L

    2007-02-01

    Coal combustion residues (CCRs), largely derived from coal-fired electrical generation, are rich in numerous trace elements that have the potential to induce sublethal effects including oxidative stress, alterations in antioxidant status and DNA single strand breaks (SSB). CCRs are frequently discharged into natural and man-made aquatic systems. As the effects of CCRs have received relatively little attention in estuarine systems, the estuarine grass shrimp, Palaemonetes pugio, was chosen for this study. Grass shrimp were exposed in the laboratory to CCR-enriched sediments and food over a full life cycle. Survival to metamorphosis was significantly reduced in CCR-exposed larvae (17+/-4 versus 70+/-13% in the controls) but not in the juveniles or adults. The COMET assay, a general but sensitive assay for genotoxicity, was used to quantify DNA SSB in the adults. Total antioxidant potential was examined to assess the overall antioxidant scavenging capacity of CCR-exposed and non-exposed adult grass shrimp. Grass shrimp exposed to CCR significantly accumulated selenium and cadmium compared to unexposed shrimp, although an inverse relationship was seen for mercury accumulation. Chronic CCR exposure caused DNA SSB in hepatopancreas cells, as evidenced by the significantly increased percent tail DNA, tail moment, and tail length as compared to reference shrimp. However, no significant difference was observed in total antioxidant potential. Our findings suggest that genotoxicity may be an important mode of toxicity of CCR, and that DNA SSB may serve as a useful biomarker of exposure and effect of this very common, complex waste stream.

  3. Ephemeral liquid water at the surface of the martian North Polar Residual Cap: Results of numerical modelling

    NASA Astrophysics Data System (ADS)

    Losiak, Anna; Czechowski, Leszek; Velbel, Michael A.

    2015-12-01

    Gypsum, a mineral that requires water to form, is common on the surface of Mars. Most of it originated before 3.5 Gyr when the Red Planet was more humid than now. However, occurrences of gypsum dune deposits around the North Polar Residual Cap (NPRC) seem to be surprisingly young: late Amazonian in age. This shows that liquid water was present on Mars even at times when surface conditions were as cold and dry as the present-day. A recently proposed mechanism for gypsum formation involves weathering of dust within ice (e.g., Niles, P.B., Michalski, J. [2009]. Nat. Geosci. 2, 215-220.). However, none of the previous studies have determined if this process is possible under current martian conditions. Here, we use numerical modelling of heat transfer to show that during the warmest days of the summer, solar irradiation may be sufficient to melt pure water ice located below a layer of dark dust particles (albedo ⩽ 0.13) lying on the steepest sections of the equator-facing slopes of the spiral troughs within martian NPRC. During the times of high irradiance at the north pole (every 51 ka; caused by variation of orbital and rotational parameters of Mars e.g., Laskar, J. et al. [2002]. Nature 419, 375-377.) this process could have taken place over larger parts of the spiral troughs. The existence of small amounts of liquid water close to the surface, even under current martian conditions, fulfils one of the main requirements necessary to explain the formation of the extensive gypsum deposits around the NPRC. It also changes our understanding of the degree of current geological activity on Mars and has important implications for estimating the astrobiological potential of Mars.

  4. Results from the chemical analysis of oily residue samples taken from stranded juvenile sea turtles collected from Padre and Mustang Islands, Texas. Special report (Final)

    SciTech Connect

    Overton, E.B.; Byrne, C.J.; McFall, J.A.; Antoine, S.R.; Laseter, J.L.

    1983-12-01

    Juvenile Kemp's Ridley sea turtles were released June 7, 1983 off the Texas coast by the National Marine Fisheries Service, as part of an U.S. - Mexico cooperative effort to augment the natural breeding stock of the endangered species. Between one and six days later many dead or distressed Kemp's Ridleys were found stranded on Padre and Mustang Islands with oily residues in the mouth and esophagus. Six samples were analyzed for Ni/V content API gravity, stable C, H, and S isotopes, and hydrocarbon composition with high-resolution gas chromatography and HRGC-mass spectrometry. Results were: (1) oils came from multiple sources, (2) composition was predominantly in the n-C20 to n-C32 range (waxy paraffins), (3) residues were most probably from discarded tanker cleaning operations.

  5. Elastic/plastic analyses of advanced composites investigating the use of the compliant layer concept in reducing residual stresses resulting from processing

    NASA Technical Reports Server (NTRS)

    Arnold, Steven M.; Arya, Vinod K.; Melis, Matthew E.

    1990-01-01

    High residual stresses within intermetallic and metal matrix composite systems can develop upon cooling from the processing temperature to room temperature due to the coefficient of thermal expansion (CTE) mismatch between the fiber and matrix. As a result, within certain composite systems, radial, circumferential, and/or longitudinal cracks have been observed to form at the fiber-matrix interface. The compliant layer concept (insertion of a compensating interface material between the fiber and matrix) was proposed to reduce or eliminate the residual stress buildup during cooling and thus minimize cracking. The viability of the proposed compliant layer concept is investigated both elastically and elastoplastically. A detailed parametric study was conducted using a unit cell model consisting of three concentric cylinders to determine the required character (i.e., thickness and material properties) of the compliant layer as well as its applicability. The unknown compliant layer mechanical properties were expressed as ratios of the corresponding temperature dependent Ti-24Al-11Nb (a/o) matrix properties. The fiber properties taken were those corresponding to SCS-6 (SiC). Results indicate that the compliant layer can be used to reduce, if not eliminate, radial and circumferential residual stresses within the fiber and matrix and therefore also reduce or eliminate the radial cracking. However, with this decrease in in-plane stresses, one obtains an increase in longitudinal stress, thus potentially initiating longitudinal cracking. Guidelines are given for the selection of a specific compliant material, given a perfectly bonded system.

  6. Distinct Carotenoid and Flavonoid Accumulation in a Spontaneous Mutant of Ponkan (Citrus reticulata Blanco) Results in Yellowish Fruit and Enhanced Postharvest Resistance.

    PubMed

    Luo, Tao; Xu, Kunyang; Luo, Yi; Chen, Jiajing; Sheng, Ling; Wang, Jinqiu; Han, Jingwen; Zeng, Yunliu; Xu, Juan; Chen, Jianmin; Wu, Qun; Cheng, Yunjiang; Deng, Xiuxin

    2015-09-30

    As the most important fresh fruit worldwide, citrus is often subjected to huge postharvest losses caused by abiotic and biotic stresses. As a promising strategy to reduce postharvest losses, enhancing natural defense by potential metabolism reprogramming in citrus mutants has rarely been reported. The yellowish spontaneous mutant of Ponkan (Citrus reticulata Blanco) (YP) was used to investigate the influence of metabolism reprogramming on postharvest performance. Our results show that reduced xanthophyll accumulation is the cause of yellowish coloring of YP and might be attributed to the reduced carotenoid sequestration capacity and upregulated expression of carotenoid cleavage dioxygenase genes. Constantly higher levels of polymethoxylated flavones (PMFs) during the infection and the storage stage might make significant contribution to the more strongly induced resistance against Penicillium digitatum and lower rotting rate. The present study demonstrates the feasibility of applying bud mutants to improve the postharvest performance of citrus fruits.

  7. Evaluation of the geomorphometric results and residual values of a robust plane fitting method applied to different DTMs of various scales and accuracy

    NASA Astrophysics Data System (ADS)

    Koma, Zsófia; Székely, Balázs; Dorninger, Peter; Kovács, Gábor

    2013-04-01

    Due to the need for quantitative analysis of various geomorphological landforms, the importance of fast and effective automatic processing of the different kind of digital terrain models (DTMs) is increasing. The robust plane fitting (segmentation) method, developed at the Institute of Photogrammetry and Remote Sensing at Vienna University of Technology, allows the processing of large 3D point clouds (containing millions of points), performs automatic detection of the planar elements of the surface via parameter estimation, and provides a considerable data reduction for the modeled area. Its geoscientific application allows the modeling of different landforms with the fitted planes as planar facets. In our study we aim to analyze the accuracy of the resulting set of fitted planes in terms of accuracy, model reliability and dependence on the input parameters. To this end we used DTMs of different scales and accuracy: (1) artificially generated 3D point cloud model with different magnitudes of error; (2) LiDAR data with 0.1 m error; (3) SRTM (Shuttle Radar Topography Mission) DTM database with 5 m accuracy; (4) DTM data from HRSC (High Resolution Stereo Camera) of the planet Mars with 10 m error. The analysis of the simulated 3D point cloud with normally distributed errors comprised different kinds of statistical tests (for example Chi-square and Kolmogorov-Smirnov tests) applied on the residual values and evaluation of dependence of the residual values on the input parameters. These tests have been repeated on the real data supplemented with the categorization of the segmentation result depending on the input parameters, model reliability and the geomorphological meaning of the fitted planes. The simulation results show that for the artificially generated data with normally distributed errors the null hypothesis can be accepted based on the residual value distribution being also normal, but in case of the test on the real data the residual value distribution is

  8. The Partition Intervalometer: A Programmable Underwater Timer for Marking Accumulated Sediment Profiles Collected in Anderson Sediment Traps: Development, Operation, Testing Procedures, and Field Results

    USGS Publications Warehouse

    Rendigs, Richard R.; Anderson, Roger Y.; Xu, Jingping; Davis, Raymond E.; Bergeron, Emile M.

    2009-01-01

    This manual illustrates the development of a programmable instrument designed to deploy a series of wafer-shaped discs (partitions) into the collection tube of a sediment trap in various aquatic environments. These hydrodynamically shaped discs are deployed at discrete time intervals from the Intervalometer and provide markers that delineate time intervals within the sediments that accumulate in the collection tube. The timer and mechanical system are lodged in an air-filled, water-tight pressure housing that is vertically hung within the confines of a cone-shaped sediment trap. The instrumentation has been operationally pressure tested to an equivalent water depth of approximately 1 km. Flaws discovered during extensive laboratory and pressure testing resulted in the implementation of several mechanical modifications (such as a redesign of the rotor and the discs) that improved the operation of the rotor assembly as well as the release of discs through the end cap. These results also identified a preferred azimuth placement of the rotor disc relative to the drop hole of the end cap. In the initial field trial, five sediment traps and coupled Intervalometers were attached to moored arrays and deployed at two sites off the coast of Southern California for approximately 8 months. Each of the instruments released 18 discs at the programmed 10 day intervals, except one unit, which experienced a malfunction after approximately 4 months. Most of the discs oriented in a near-horizontal position upon the surface of the sediment in the collection tubes. Sampling of the sediments for geochemical analyses was improved by these clearly defined markers, which indicated the changes in the flux and nature of sediments accumulated during the deployment period of each sediment trap.

  9. Overexpression of serine hydroxymethyltransferase from halotolerant cyanobacterium in Escherichia coli results in increased accumulation of choline precursors and enhanced salinity tolerance.

    PubMed

    Waditee-Sirisattha, Rungaroon; Sittipol, Daungjai; Tanaka, Yoshito; Takabe, Teruhiro

    2012-08-01

    Serine hydroxymethyltransferase (SHMT) is a key enzyme in cellular one-carbon pathway and has been studied in many living organisms from bacteria to higher plants and mammals. However, biochemical and molecular characterization of SHMT from photoautotrophic microorganisms remains a challenge. Here, we isolated the SHMT gene from a halotolerant cyanobacterium Aphanothece halophytica (ApSHMT) and expressed it in Escherichia coli. Purified recombinant ApSHMT protein exhibited catalytic reactions for dl-threo-3-phenylserine as well as for l-serine. Catalytic reaction for l-serine was strongly inhibited by NaCl, but not to that level with glycine betaine. Overexpression of ApSHMT in E. coli resulted in the increased accumulation of glycine and serine. Choline and glycine betaine levels were also significantly increased. Under high salinity, the growth rate of ApSHMT-expressing cells was faster compared to its respective control. High salinity also strongly induced the transcript level of ApSHMT in A. halophytica. Our results indicate the importance of a novel pathway; salt-induced ApSHMT increased the level of glycine betaine via serine and choline and conferred the tolerance to salinity stress.

  10. Both overexpression and suppression of an Oryza sativa NB-LRR-like gene OsLSR result in autoactivation of immune response and thiamine accumulation

    PubMed Central

    Wang, Liangchao; Ye; Liu, Huachun; Liu, Xuejiao; Wei, Chuchu; Huang, Yuqing; Liu, Yujun; Tu, Jumin

    2016-01-01

    Tight and accurate regulation of immunity and thiamine biosynthesis is critical for proper defence mechanisms and several primary metabolic cycles in plants. Although thiamine is known to enhance plant defence by priming, the mechanism by which thiamine biosynthesis responds to immune signals remains poorly understood. Here we identified a novel rice (Oryza sativa L.) NB-LRR gene via an insertion mutation, this mutant confesses a low seed setting phenotype and the corresponding genetic locus was named OsLSR (Low seed setting related). Comparing with wildtype plant, both overexpression and suppression of OsLSR lead to the autoactivation of the rice immune system and accumulation of thiamine, which result in a great fitness cost and yield penalty. Moreover, when fused with eGFP at their C terminus, two fragments, OsLSR1-178 and OsLSR464-546, localized to chloroplasts where thiamine is produced. Our result suggests that OsLSR differs from traditional NB-LRR genes. Its expression is closely related to the immune status and thiamine level in plant cells and should be maintained within a narrow range for rice growth. PMID:27052628

  11. Identification of Inhibitors of Triacylglyceride Accumulation in Muscle Cells: Comparing HTS Results from 1536-well Plate-Based and High-Content Platforms

    PubMed Central

    Sugarman, Eliot; Koo, Ada; Suyama, Eigo; Ruidiaz, Manuel E.; Heynen-Genel, Susanne; Nguyen, Kevin H.; Vasile, Stefan; Soundarapandian, Mangala M.; Vega, Rick B.; Kelly, Daniel P.; Smith, Layton H.; Malany, Siobhan

    2014-01-01

    Excess caloric consumption leads to triacylglyceride (TAG) accumulation in tissues that do not typically store fat, such as skeletal muscle. This ectopic accumulation alters cells, contributing to the pathogenesis of metabolic syndrome, a major health problem worldwide. We developed a 1536-well assay to measure intracellular TAG accumulation in differentiating H9c2 myoblasts. For this assay, cells were incubated with oleic acid to stimulate TAG accumulation prior to adding compounds. We used Nile red as a fluorescent dye to quantify TAG content with a microplate-reader. The cell nuclei were counterstained with DAPI nuclear stain to assess cell count and filter cytotoxic compounds. In parallel, we developed an image-based assay in H9c2 cells to measure lipid accumulation levels via high-content analysis, exploiting the dual emission spectra characteristic of Nile red staining of neutral and phospholipids. Using both approaches, we successfully screened ~227,000 compounds from the NIH Library. The screening data from the plate-reader and IC50 values correlated with that from the Opera QEHS cell imager. The 1536-well plate-reader assay is a powerful HTS platform to identify potent inhibitors of TAG accumulation to better understand the molecular pathways involved in lipid metabolism that lead to lipotoxicity. PMID:23989452

  12. Influence of enzyme loading on enzymatic hydrolysis of cardboard waste and size distribution of the resulting fiber residue.

    PubMed

    Kinnarinen, Teemu; Häkkinen, Antti

    2014-05-01

    Enzymatic hydrolysis of lignocellulosic biomass to sugars alters the properties of the cellulosic fibers. Several process variables, including enzyme loading, play an important role in these changes. Many physical properties of fibers are affected: their length and width, porosity, specific surface area, and degree of fibrillation, for instance, may undergo dramatic changes when subjected to enzymatic degradation. In this study, the influence of enzyme loading on the fiber size was investigated using milled cardboard waste as the raw material. The effect of cellulases and hemicellulases on the monosaccharide production and the resulting fiber size was studied using commercial enzyme products. It was shown that the cellulase loading largely determined the amount of sugars produced. The fiber length was reduced during the course of hydrolysis, although the size reduction was not especially dramatic. Based on the SEM images, no significant damage to the fiber surfaces occurred during the process.

  13. Salidroside stimulates the accumulation of HIF-1α protein resulted in the induction of EPO expression: a signaling via blocking the degradation pathway in kidney and liver cells.

    PubMed

    Zheng, Ken Yu-Zhong; Zhang, Zhen-Xia; Guo, Ava Jiang-Yang; Bi, Cathy Wen-Chuang; Zhu, Kevin Yue; Xu, Sherry Li; Zhan, Janis Ya-Xian; Lau, David Tai-Wei; Dong, Tina Ting-Xia; Choi, Roy Chi-Yan; Tsim, Karl Wah-Keung

    2012-03-15

    Rhodiolae Crenulatae Radix et Rhizoma (Rhodiola), the root and rhizome of Rhodiola crenulata (Hook. f. et Thoms.) H. Ohba, has been used as a traditional Chinese medicine (TCM) to increase the body resistance to mountain sickness in preventing hypoxia; however, the functional ingredient responsible for this adaptogenic effect has not been revealed. Here, we have identified salidroside, a glycoside predominantly found in Rhodiola, is the chemical in providing such anti-hypoxia effect. Cultured human embryonic kidney fibroblast (HEK293T) and human hepatocellular carcinoma (HepG2) were used to reveal the mechanism of this hematopoietic function mediated by salidroside. The application of salidroside in cultures induced the expression of erythropoietin (EPO) mRNA from its transcription regulatory element hypoxia response element (HRE), located on EPO gene. The application of salidroside stimulated the accumulation of hypoxia-inducible factor-1α (HIF-1α) protein, but not HIF-2α protein: the salidroside-induced HIF-1α protein was via the reduction of HIF-1α degradation but not the mRNA induction. The increased HIF-1α could account for the activation of EPO gene. These results supported the notion that hematopoietic function of Rhodiola was triggered, at least partially, by salidroside.

  14. Loss of lysosomal membrane protein NCU-G1 in mice results in spontaneous liver fibrosis with accumulation of lipofuscin and iron in Kupffer cells

    PubMed Central

    Kong, Xiang Y.; Nesset, Cecilie Kasi; Damme, Markus; Løberg, Else-Marit; Lübke, Torben; Mæhlen, Jan; Andersson, Kristin B.; Lorenzo, Petra I.; Roos, Norbert; Thoresen, G. Hege; Rustan, Arild C.; Kase, Eili T.; Eskild, Winnie

    2014-01-01

    Human kidney predominant protein, NCU-G1, is a highly conserved protein with an unknown biological function. Initially described as a nuclear protein, it was later shown to be a bona fide lysosomal integral membrane protein. To gain insight into the physiological function of NCU-G1, mice with no detectable expression of this gene were created using a gene-trap strategy, and Ncu-g1gt/gt mice were successfully characterized. Lysosomal disorders are mainly caused by lack of or malfunctioning of proteins in the endosomal-lysosomal pathway. The clinical symptoms vary, but often include liver dysfunction. Persistent liver damage activates fibrogenesis and, if unremedied, eventually leads to liver fibrosis/cirrhosis and death. We demonstrate that the disruption of Ncu-g1 results in spontaneous liver fibrosis in mice as the predominant phenotype. Evidence for an increased rate of hepatic cell death, oxidative stress and active fibrogenesis were detected in Ncu-g1gt/gt liver. In addition to collagen deposition, microscopic examination of liver sections revealed accumulation of autofluorescent lipofuscin and iron in Ncu-g1gt/gt Kupffer cells. Because only a few transgenic mouse models have been identified with chronic liver injury and spontaneous liver fibrosis development, we propose that the Ncu-g1gt/gt mouse could be a valuable new tool in the development of novel treatments for the attenuation of fibrosis due to chronic liver damage. PMID:24487409

  15. Intermolecular 'cross-torque': the N4-cytosine propargyl residue is rotated to the 'CH'-edge as a result of Watson-Crick interaction.

    PubMed

    Domingo, Olwen; Hellmuth, Isabell; Jäschke, Andres; Kreutz, Christoph; Helm, Mark

    2015-06-23

    Propargyl groups are attractive functional groups for labeling purposes, as they allow CuAAC-mediated bioconjugation. Their size minimally exceeds that of a methyl group, the latter being frequent in natural nucleotide modifications. To understand under which circumstances propargyl-containing oligodeoxynucleotides preserve base pairing, we focused on the exocyclic amine of cytidine. Residues attached to the exocyclic N4 may orient away from or toward the Watson-Crick face, ensuing dramatic alteration of base pairing properties. ROESY-NMR experiments suggest a uniform orientation toward the Watson-Crick face of N(4)-propargyl residues in derivatives of both deoxycytidine and 5-methyl-deoxycytidine. In oligodeoxynucleotides, however, UV-melting indicated that N(4)-propargyl-deoxycytidine undergoes standard base pairing. This implies a rotation of the propargyl moiety toward the 'CH'-edge as a result of base pairing on the Watson-Crick face. In oligonucleotides containing the corresponding 5-methyl-deoxycytidine derivative, dramatically reduced melting temperatures indicate impaired Watson-Crick base pairing. This was attributed to a steric clash of the propargyl moiety with the 5-methyl group, which prevents back rotation to the 'CH'-edge, consequently preventing Watson-Crick geometry. Our results emphasize the tendency of an opposing nucleic acid strand to mechanically rotate single N(4)-substituents to make way for Watson-Crick base pairing, providing no steric hindrance is present on the 'CH'-edge.

  16. Accumulate Repeat Accumulate Coded Modulation

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative coded modulation scheme called 'Accumulate Repeat Accumulate Coded Modulation' (ARA coded modulation). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes that are combined with high level modulation. Thus at the decoder belief propagation can be used for iterative decoding of ARA coded modulation on a graph, provided a demapper transforms the received in-phase and quadrature samples to reliability of the bits.

  17. Pesticide residues in birds and mammals

    USGS Publications Warehouse

    Stickel, L.F.; Edwards, C.A.

    1973-01-01

    SUMMARY: Residues of organochlorine pesticides and their breakdown products are present in the tissues of essentially all wild birds throughout the world. These chemicals accumulate in fat from a relatively small environmental exposure. DDE and dieldrin are most prevalent. Others, such as heptachlor epoxide, chlordane, endrin, and benzene hexachloride also occur, the quantities and kinds generally reflecting local or regional use. Accumulation may be sufficient to kill animals following applications for pest control. This has occurred in several large-scale programmes in the United States. Mortality has also resulted from unintentional leakage of chemical from commercial establishments. Residues may persist in the environment for many years, exposing successive generations of animals. In general, birds that eat other birds, or fish, have higher residues than those that eat seeds and vegetation. The kinetic processes of absorption, metabolism, storage, and output differ according to both kind of chemical and species of animal. When exposure is low and continuous, a balance between intake and excretion may be achieved. Residues reach a balance at an approximate animal body equilibrium or plateau; the storage is generally proportional to dose. Experiments with chickens show that dieldrin and heptachlor epoxide have the greatest propensity for storage, endrin next, then DDT, then lindane. The storage of DDT was complicated by its metabolism to DDE and DDD, but other studies show that DDE has a much greater propensity for storage than either DDD or DDT. Methoxychlor has little cumulative capacity in birds. Residues in eggs reflect and parallel those in the parent bird during accumulation, equilibrium, and decline when dosage is discontinued. Residues with the greatest propensity for storage are also lost most slowly. Rate of loss of residues can be modified by dietary components and is speeded by weight loss of the animal. Under sublethal conditions of continuous

  18. Reinfection results in accumulation of unintegrated viral DNA in cytopathic and persistent human immunodeficiency virus type 1 infection of CEM cells

    PubMed Central

    1990-01-01

    High levels of unintegrated viral DNA accumulate during human immunodeficiency virus type 1 (HIV-1) infection of CEM T cells. Reinfection of already infected cells is required to attain these levels and reinfection also promotes the development of HIV-induced cytopathology. Rates of virus production, however, are independent of the accumulation of unintegrated viral DNA. Neutralizing antibody added soon after infection reduced viral DNA levels without appreciably affecting the production of cell-free viral p24 antigen or reverse transcriptase activity. Only 50 pM AZT were required to reduce the accumulation of unintegrated viral DNA by 50% in contrast to the 25 nM required to inhibit virus production by 50%. Cytopathology, as measured by number of syncytia in infected cell cultures, was correlated with highly elevated levels of unintegrated viral DNA. The minimal levels of unintegrated viral DNA present constitutively in the persistently infected HCEM cell line were consonant with the absence of cytopathic effects in these cells. These data demonstrate that inhibiting the reinfection of already infected cells modulates cytopathic HIV-1 infection to a form that is persistent and noncytopathic. PMID:2212939

  19. Accumulation of Krebs cycle intermediates and over-expression of HIF1alpha in tumours which result from germline FH and SDH mutations.

    PubMed

    Pollard, P J; Brière, J J; Alam, N A; Barwell, J; Barclay, E; Wortham, N C; Hunt, T; Mitchell, M; Olpin, S; Moat, S J; Hargreaves, I P; Heales, S J; Chung, Y L; Griffiths, J R; Dalgleish, A; McGrath, J A; Gleeson, M J; Hodgson, S V; Poulsom, R; Rustin, P; Tomlinson, I P M

    2005-08-01

    The nuclear-encoded Krebs cycle enzymes, fumarate hydratase (FH) and succinate dehydrogenase (SDHB, -C and -D), act as tumour suppressors. Germline mutations in FH predispose individuals to leiomyomas and renal cell cancer (HLRCC), whereas mutations in SDH cause paragangliomas and phaeochromocytomas (HPGL). In this study, we have shown that FH-deficient cells and tumours accumulate fumarate and, to a lesser extent, succinate. SDH-deficient tumours principally accumulate succinate. In situ analyses showed that these tumours also have over-expression of hypoxia-inducible factor 1alpha (HIF1alpha), activation of HIF1alphatargets (such as vascular endothelial growth factor) and high microvessel density. We found no evidence of increased reactive oxygen species in our cells. Our data provide in vivo evidence to support the hypothesis that increased succinate and/or fumarate causes stabilization of HIF1alpha a plausible mechanism, inhibition of HIF prolyl hydroxylases, has previously been suggested by in vitro studies. The basic mechanism of tumorigenesis in HPGL and HLRCC is likely to be pseudo-hypoxic drive, just as it is in von Hippel-Lindau syndrome.

  20. Evaluation of the efficacy of bendiocarb in indoor residual spraying against pyrethroid resistant malaria vectors in Benin: results of the third campaign

    PubMed Central

    2012-01-01

    Background Since 2008, the National Malaria Control Program (NMCP) has been engaged in the implementation of indoor residual spraying (IRS) in Benin. The first and second round was a success with a drastic decrease of malaria transmission in areas under IRS. We present here the results of the third round. The purpose of this study was to compare the results of the third round of IRS to those achieved during the first two rounds. A second success of IRS will enable the Government of Benin to extend the strategy to other areas. Methods Mosquito collections were carried out in the department of Ouémé where the homes of four districts were treated with bendiocarb. In these districts, more than 350 000 inhabitants were protected by IRS. A fifth untreated district served as control. In the five districts, mosquito collections were organized to follow the dynamics of malaria transmission and possible changes in the behavior of mosquitoes. Results A significant reduction in human biting rate was recorded after the third round of IRS, specifically in Adjohoun (89.78%), Dangbo (56.8%) and Missérété (93.22%) where an inhabitant received less than 2 bites of An. gambiae per night. During this same time, the entomological inoculation rate (EIR) declined dramatically in all areas under intervention (74.26% reduction). We also noted a significant reduction in longevity, the blood feeding rate of the vectors and an increase in exophily induced by bendiocarb on An. gambiae and Mansonia spp. Conclusion The present study showed, once again, the effectiveness of bendiocarb on anopheles populations resistant to pyrethroids. This product can be recommended in combination with other insecticides for the management of vector resistance to insecticides. PMID:22873930

  1. Results.

    ERIC Educational Resources Information Center

    Zemsky, Robert; Shaman, Susan; Shapiro, Daniel B.

    2001-01-01

    Describes the Collegiate Results Instrument (CRI), which measures a range of collegiate outcomes for alumni 6 years after graduation. The CRI was designed to target alumni from institutions across market segments and assess their values, abilities, work skills, occupations, and pursuit of lifelong learning. (EV)

  2. Null mutation of the murine ATP7B (Wilson disease) gene results in intracellular copper accumulation and late-onset hepatic nodular transformation.

    PubMed

    Buiakova, O I; Xu, J; Lutsenko, S; Zeitlin, S; Das, K; Das, S; Ross, B M; Mekios, C; Scheinberg, I H; Gilliam, T C

    1999-09-01

    The Atp7b protein is a copper-transporting ATPase expressed predominantly in the liver and to a lesser extent in most other tissues. Mutations in the ATP7B gene lead to Wilson disease, a copper toxicity disorder characterized by dramatic build-up of intracellular hepatic copper with subsequent hepatic and neuro-logical abnormalities. Using homologous recombination to disrupt the normal translation of ATP7B, we have generated a strain of mice that are homozygous mutants (null) for the Wilson disease gene. The ATP7B null mice display a gradual accumulation of hepatic copper that increases to a level 60-fold greater than normal by 5 months of age. An increase in copper concentration was also observed in the kidney, brain, placenta and lactating mammary glands of homo-zygous mutants, although milk from the mutant glands was copper deficient. Morphological abnormalities resembling cirrhosis developed in the majority of the livers from homozygous mutants older than 7 months of age. Progeny of the homozygous mutant females demonstrated neurological abnormalities and growth retardation characteristic of copper deficiency. Copper concentration in the livers of the newborn homozygous null mutants was decreased dramatically. In summary, inactivation of the murine ATP7B gene produces a form of cirrhotic liver disease that resembles Wilson disease in humans and the 'toxic milk' phenotype in the mouse.

  3. Retrospective study of triclosan and methyl-triclosan residues in fish and suspended particulate matter: results from the German Environmental Specimen Bank.

    PubMed

    Rüdel, Heinz; Böhmer, Walter; Müller, Martin; Fliedner, Annette; Ricking, Mathias; Teubner, Diana; Schröter-Kermani, Christa

    2013-06-01

    A retrospective monitoring of triclosan (TCS; period 1994-2003 and 2008) and its potential transformation product methyl-triclosan (MTCS; period 1994-2008) was performed using archived fish samples from German rivers (16 sites, including Elbe and Rhine). At four of these sites suspended particulate matter (SPM) was also investigated covering the period 2005-2007. Samples were analyzed by GC/MS, either directly (MTCS) or after derivatization (TCS). TCS burdens of fish muscle tissue ranged from <0.2-3.4 ng g(-1) ww (wet weight; corresponding to <2-69 ng g(-1) lw, lipid weight) without apparent concentration trends over time. MTCS was detected at considerably higher concentrations in fish ranging from 1.0-33 ng g(-1) ww (47-1010 ng g(-1) lw) and increased until about 2003-2005. Thereafter, concentrations generally were lower, although at some sites single higher values were observed in recent years. In SPM, decreasing MTCS concentrations in the range 1-4 ng g(-1) dry weight were detected while TCS was always below the limit of quantification. Assuming that MTCS concentrations are correlated to TCS consumption, the observed decrease in MTCS levels may be partly a result of the voluntary renunciation of TCS use in detergents for, e.g., laundry or dishwashing declared by a manufacturers' association in 2001. Because of a lack of ecotoxicity studies for MTCS, a QSAR-derived predicted no effect concentration (PNEC) was compared to averaged ambient water concentrations of fish which were calculated from maximum tissue residues by applying an appropriate bioconcentration factor from literature. Since these calculated water concentrations were below the PNEC it is assumed that MTCS alone poses no immediate risk to aquatic organism. The conversion to a PNEC for SPM organisms and comparison with detected SPM levels of MTCS also revealed no risk.

  4. Lipid Accumulation in Hypoxic Tissue Culture Cells

    PubMed Central

    Gordon, Gerald B.; Barcza, Maureen A.; Bush, Marilyn E.

    1977-01-01

    Lipid droplets have long been recognized by light microscopy to accumulate in hypoxic cells both in vivo and in vitro. In the present tissue culture experiments, correlative electron microscopic observations and lipid analyses were performed to determine the nature and significance of lipid accumulation in hypoxia. Strain L mouse fibroblasts were grown in suspension culture, both aerobically and under severe oxygen restriction obtained by gassing cultures daily with an 8% CO2-92% nitrogen mixture. After 48 hours, hypoxic cells showed an increase in total lipid/protein ratio of 42% over control cells. Most of this increase was accounted for by an elevation in the level of cellular triglyceride from 12.3 ± 0.9 μg/mg cell protein in aerobic cultures to 41.9 ± 0.7 in the hypoxic cultures, an increase of 240%. Levels of cellular free fatty acids (FFA) were 96% higher in the hypoxic cultures. No significant changes in the levels of cellular phospholipid or cholesterol were noted. Electron microscopic examination revealed the accumulation of homogeneous cytoplasmic droplets. The hypoxic changes were reversible upon transferring the cultures to aerobic atmospheres with disappearance of the lipid. These experiments indicate that hypoxic injury initially results in triglyceride and FFA accumulation from an inability to oxidize fatty acids taken up from the media and not from autophagic processes, as described in other types of cell injury associated with the sequestration of membranous residues and intracellular cholesterol and phospholipid accumulation. ImagesFigure 3Figure 4Figure 5Figure 6Figure 7Figure 1Figure 2 PMID:196505

  5. Chimpanzee accumulative stone throwing.

    PubMed

    Kühl, Hjalmar S; Kalan, Ammie K; Arandjelovic, Mimi; Aubert, Floris; D'Auvergne, Lucy; Goedmakers, Annemarie; Jones, Sorrel; Kehoe, Laura; Regnaut, Sebastien; Tickle, Alexander; Ton, Els; van Schijndel, Joost; Abwe, Ekwoge E; Angedakin, Samuel; Agbor, Anthony; Ayimisin, Emmanuel Ayuk; Bailey, Emma; Bessone, Mattia; Bonnet, Matthieu; Brazolla, Gregory; Buh, Valentine Ebua; Chancellor, Rebecca; Cipoletta, Chloe; Cohen, Heather; Corogenes, Katherine; Coupland, Charlotte; Curran, Bryan; Deschner, Tobias; Dierks, Karsten; Dieguez, Paula; Dilambaka, Emmanuel; Diotoh, Orume; Dowd, Dervla; Dunn, Andrew; Eshuis, Henk; Fernandez, Rumen; Ginath, Yisa; Hart, John; Hedwig, Daniela; Ter Heegde, Martijn; Hicks, Thurston Cleveland; Imong, Inaoyom; Jeffery, Kathryn J; Junker, Jessica; Kadam, Parag; Kambi, Mohamed; Kienast, Ivonne; Kujirakwinja, Deo; Langergraber, Kevin; Lapeyre, Vincent; Lapuente, Juan; Lee, Kevin; Leinert, Vera; Meier, Amelia; Maretti, Giovanna; Marrocoli, Sergio; Mbi, Tanyi Julius; Mihindou, Vianet; Moebius, Yasmin; Morgan, David; Morgan, Bethan; Mulindahabi, Felix; Murai, Mizuki; Niyigabae, Protais; Normand, Emma; Ntare, Nicolas; Ormsby, Lucy Jayne; Piel, Alex; Pruetz, Jill; Rundus, Aaron; Sanz, Crickette; Sommer, Volker; Stewart, Fiona; Tagg, Nikki; Vanleeuwe, Hilde; Vergnes, Virginie; Willie, Jacob; Wittig, Roman M; Zuberbuehler, Klaus; Boesch, Christophe

    2016-02-29

    The study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behaviour leading to artefacts and their assemblages to be incorporated. Here, we describe newly discovered stone tool-use behaviour and stone accumulation sites in wild chimpanzees reminiscent of human cairns. In addition to data from 17 mid- to long-term chimpanzee research sites, we sampled a further 34 Pan troglodytes communities. We found four populations in West Africa where chimpanzees habitually bang and throw rocks against trees, or toss them into tree cavities, resulting in conspicuous stone accumulations at these sites. This represents the first record of repeated observations of individual chimpanzees exhibiting stone tool use for a purpose other than extractive foraging at what appear to be targeted trees. The ritualized behavioural display and collection of artefacts at particular locations observed in chimpanzee accumulative stone throwing may have implications for the inferences that can be drawn from archaeological stone assemblages and the origins of ritual sites.

  6. Chimpanzee accumulative stone throwing

    PubMed Central

    Kühl, Hjalmar S.; Kalan, Ammie K.; Arandjelovic, Mimi; Aubert, Floris; D’Auvergne, Lucy; Goedmakers, Annemarie; Jones, Sorrel; Kehoe, Laura; Regnaut, Sebastien; Tickle, Alexander; Ton, Els; van Schijndel, Joost; Abwe, Ekwoge E.; Angedakin, Samuel; Agbor, Anthony; Ayimisin, Emmanuel Ayuk; Bailey, Emma; Bessone, Mattia; Bonnet, Matthieu; Brazolla, Gregory; Buh, Valentine Ebua; Chancellor, Rebecca; Cipoletta, Chloe; Cohen, Heather; Corogenes, Katherine; Coupland, Charlotte; Curran, Bryan; Deschner, Tobias; Dierks, Karsten; Dieguez, Paula; Dilambaka, Emmanuel; Diotoh, Orume; Dowd, Dervla; Dunn, Andrew; Eshuis, Henk; Fernandez, Rumen; Ginath, Yisa; Hart, John; Hedwig, Daniela; Ter Heegde, Martijn; Hicks, Thurston Cleveland; Imong, Inaoyom; Jeffery, Kathryn J.; Junker, Jessica; Kadam, Parag; Kambi, Mohamed; Kienast, Ivonne; Kujirakwinja, Deo; Langergraber, Kevin; Lapeyre, Vincent; Lapuente, Juan; Lee, Kevin; Leinert, Vera; Meier, Amelia; Maretti, Giovanna; Marrocoli, Sergio; Mbi, Tanyi Julius; Mihindou, Vianet; Moebius, Yasmin; Morgan, David; Morgan, Bethan; Mulindahabi, Felix; Murai, Mizuki; Niyigabae, Protais; Normand, Emma; Ntare, Nicolas; Ormsby, Lucy Jayne; Piel, Alex; Pruetz, Jill; Rundus, Aaron; Sanz, Crickette; Sommer, Volker; Stewart, Fiona; Tagg, Nikki; Vanleeuwe, Hilde; Vergnes, Virginie; Willie, Jacob; Wittig, Roman M.; Zuberbuehler, Klaus; Boesch, Christophe

    2016-01-01

    The study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behaviour leading to artefacts and their assemblages to be incorporated. Here, we describe newly discovered stone tool-use behaviour and stone accumulation sites in wild chimpanzees reminiscent of human cairns. In addition to data from 17 mid- to long-term chimpanzee research sites, we sampled a further 34 Pan troglodytes communities. We found four populations in West Africa where chimpanzees habitually bang and throw rocks against trees, or toss them into tree cavities, resulting in conspicuous stone accumulations at these sites. This represents the first record of repeated observations of individual chimpanzees exhibiting stone tool use for a purpose other than extractive foraging at what appear to be targeted trees. The ritualized behavioural display and collection of artefacts at particular locations observed in chimpanzee accumulative stone throwing may have implications for the inferences that can be drawn from archaeological stone assemblages and the origins of ritual sites. PMID:26923684

  7. Extraction of hemicellulose from ryegrass straw for the production of glucose isomerase and use of the resulting straw residue for animal feed

    SciTech Connect

    Chen, W.P.; Anderson, A.W.

    1980-03-01

    The hemicellulose fraction of ryegrass straw was extracted with NaOH and used for the production of glucose isomerase by Streptomyces flavogriseus. The level of hemicellulose extracted increased proportionately with increasing NaOH concentration up to about 4%, then the rate of increase slowed down. Hemicellulose extraction was facilitated by the combined application of heat and NaOH. Approximately 15% hemicellulose (12% as pentosan) could be obtained by treating straw with 4% NaOH for either 3 hours at 90/sup 0/C or 24 hour at room temperature. The highest level (3.04 units/ml culture) of intracellular glucose isomerase was obtained when the organism was grown at 30 degrees Centigrade for two days on 2% straw hemicellulose. The organism also produced a high yield of glucose isomerase on xylose or xylan. The NaOH treated straw residue, after removal of hemicellulose, had approximately 75% higher digestibility and 20% higher feed efficiency for weanling meadow voles than untreated straw, but almost the equivalent to that obtained by NaOH treatment without removal of the hemicellulose. Thus, the residue could be used as animal feed. A process for the production of glucose isomerase and animal feed from ryegrass straw was also proposed.

  8. Mutation of critical serine residues in HIV-1 matrix result in an envelope incorporation defect which can be rescued by truncation of the gp41 cytoplasmic tail

    SciTech Connect

    Bhatia, Ajay K.; Kaushik, Rajnish; Campbell, Nancy A.; Pontow, Suzanne E.; Ratner, Lee

    2009-02-05

    The human immunodeficiency virus type 1 (HIV-1) matrix (MA) domain is involved in both early and late events of the viral life cycle. Simultaneous mutation of critical serine residues in MA has been shown previously to dramatically reduce phosphorylation of MA. However, the role of phosphorylation in viral replication remains unclear. Viruses harboring serine to alanine substitutions at positions 9, 67, 72, and 77 are severely impaired in their ability to infect target cells. In addition, the serine mutant viruses are defective in their ability to fuse with target cell membranes. Interestingly, both the fusion defect and the infectivity defect can be rescued by truncation of the long cytoplasmic tail of gp41 envelope protein (gp41CT). Sucrose density gradient analysis also reveals that these mutant viruses have reduced levels of gp120 envelope protein incorporated into the virions as compared to wild type virus. Truncation of the gp41CT rescues the envelope incorporation defect. Here we propose a model in which mutation of specific serine residues prevents MA interaction with lipid rafts during HIV-1 assembly and thereby impairs recruitment of envelope to the sites of viral budding.

  9. Changing a conserved amino acid in R2R3-MYB transcription repressors results in cytoplasmic accumulation and abolishes their repressive activity in Arabidopsis.

    PubMed

    Zhou, Meiliang; Sun, Zhanmin; Wang, Chenglong; Zhang, Xinquan; Tang, Yixiong; Zhu, Xuemei; Shao, Jirong; Wu, Yanmin

    2015-10-01

    Sub-group 4 R2R3-type MYB transcription factors, including MYB3, MYB4, MYB7 and MYB32, act as repressors in phenylpropanoid metabolism. These proteins contain the conserved MYB domain and the ethylene-responsive element binding factor-associated amphiphilic repression (EAR) repression domain. Additionally, MYB4, MYB7 and MYB32 possess a putative zinc-finger domain and a conserved GY/FDFLGL motif in their C-termini. The protein 'sensitive to ABA and drought 2' (SAD2) recognizes the nuclear pore complex, which then transports the SAD2-MYB4 complex into the nucleus. Here, we show that the conserved GY/FDFLGL motif contributes to the interaction between MYB factors and SAD2. The Asp → Asn mutation in the GY/FDFLGL motif abolishes the interaction between MYB transcription factors and SAD2, and therefore they cannot be transported into the nucleus and cannot repress their target genes. We found that MYB4(D261N) loses the capacity to repress expression of the cinnamate 4-hydroxylase (C4H) gene and biosynthesis of sinapoyl malate. Our results indicate conservation among MYB transcription factors in terms of their interaction with SAD2. Therefore, the Asp → Asn mutation may be used to engineer transcription factors.

  10. Using Noble Gas Tracers to Estimate CO2 Saturation in the Field: Results from the 2014 CO2CRC Otway Repeat Residual Saturation Test

    NASA Astrophysics Data System (ADS)

    LaForce, T.; Ennis-King, J.; Boreham, C.; Serno, S.; Cook, P. J.; Freifeld, B. M.; Gilfillan, S.; Jarrett, A.; Johnson, G.; Myers, M.; Paterson, L.

    2015-12-01

    Residual trapping efficiency is a critical parameter in the design of secure subsurface CO2 storage. Residual saturation is also a key parameter in oil and gas production when a field is under consideration for enhanced oil recovery. Tracers are an important tool that can be used to estimate saturation in field tests. A series of measurements of CO2 saturation in an aquifer were undertaken as part of the Otway stage 2B extension field project in Dec. 2014. These tests were a repeat of similar tests in the same well in 2011 with improvements to the data collection and handling method. Two single-well tracer tests using noble gas tracers were conducted. In the first test krypton and xenon are injected into the water-saturated formation to establish dispersivity of the tracers in single-phase flow. Near-residual CO2 saturation is then established near the well. In the second test krypton and xenon are injected with CO2-saturated water to measure the final CO2 saturation. The recovery rate of the tracers is similar to predicted rates using recently published partitioning coefficients. Due to technical difficulties, there was mobile CO2 in the reservoir throughout the second tracer test in 2014. As a consequence, it is necessary to use a variation of the previous simulation procedure to interpret the second tracer test. One-dimensional, radial simulations are used to estimate average saturation of CO2 near the well. Estimates of final average CO2 saturation are computed using two relative permeability models, thermal and isothermal simulations, and three sets of coefficients for the partitioning of the tracers between phases. Four of the partitioning coefficients used were not previously available in the literature. The noble gas tracer field test and analysis of the 2011 and 2014 data both give an average CO2 saturation that is consistent with other field measurements. This study has demonstrated the repeatability of the methodology for noble gas tracer tests in the

  11. Acute and residual effects in adolescent rats resulting from exposure to the novel synthetic cannabinoids AB-PINACA and AB-FUBINACA.

    PubMed

    Kevin, Richard C; Wood, Katie E; Stuart, Jordyn; Mitchell, Andrew J; Moir, Michael; Banister, Samuel D; Kassiou, Michael; McGregor, Iain S

    2017-01-01

    Synthetic cannabinoids (SCs) have rapidly proliferated as recreational drugs, and may present a substantial health risk to vulnerable populations. However, information on possible effects of long-term use is sparse. This study compared acute and residual effects of the popular indazole carboxamide SC compounds AB-PINACA and AB-FUBINACA in adolescent rats with ∆(9)-tetrahydrocannabinol (THC) and control treatments. Albino Wistar rats were injected (i.p.) with AB-PINACA or AB-FUBINACA every second day (beginning post-natal day (PND) 31), first at a low dose (0.2 mg/kg on 6 days) followed by a higher dose (1 mg/kg on a further 6 days). THC-treated rats received equivalent doses of 6 × 1 mg/kg and 6 × 5 mg/kg. During drug treatment, THC, AB-PINACA, and AB-FUBINACA decreased locomotor activity at high and low doses, increased anxiety-like behaviours and audible vocalisations, and reduced weight gain. Two weeks after dosing was completed, all cannabinoid pre-treated rats exhibited object recognition memory deficits. These were notably more severe in rats pre-treated with AB-FUBINACA. However, social interaction was reduced in the THC pre-treated group only. Six weeks post-dosing, plasma levels of cytokines interleukin (IL)-1α and IL-12 were reduced by AB-FUBINACA pre-treatment, while cerebellar endocannabinoids were reduced by THC and AB-PINACA pre-treatment. The acute effects of AB-PINACA and AB-FUBINACA were broadly similar to those of THC, suggesting that acute SC toxicity in humans may be modulated by dose factors, including inadvertent overdose and product contamination. However, some lasting residual effects of these different cannabinoid receptor agonists were subtly different, hinting at recruitment of different mechanisms of neuroadaptation.

  12. Structure-activity relationships of oligo-beta-glucoside elicitors of phytoalexin accumulation in soybean.

    PubMed Central

    Cheong, J J; Birberg, W; Fügedi, P; Pilotti, A; Garegg, P J; Hong, N; Ogawa, T; Hahn, M G

    1991-01-01

    The abilities of a family of chemically synthesized oligo-beta-glucosides, ranging in size from hexamer to decamer, to induce phytoalexin accumulation in soybean cotyledons were investigated to determine which structural elements of the oligoglucosides are important for their biological activity. The results of the biological assays established that the following structural motif is necessary for the oligo-beta-glucosides to have high elicitor activity: [formula; see text] The branched trisaccharide at the nonreducing end of the oligoglucosides was found to be essential for maximum elicitor activity. Substitution of either the nonreducing terminal backbone glucosyl residue or the side-chain glucosyl residue closest to the nonreducing end with glucosaminyl or N-acetylglucosaminyl residues reduced the elicitor activity of the oligoglucosides between 10-fold and 10,000-fold. Elicitor activity was also reduced 1000-fold if the two side-chain glucosyl residues were attached to adjacent backbone glucosyl residues rather than to glucosyl residues separated by an unbranched residue. In contrast, modifications of the reducing terminal glucosyl residue of an elicitor-active hepta-beta-glucoside by conjugation with tyramine and subsequent iodination had no significant effect on the elicitor activity of the hepta-beta-glucoside. These results demonstrate that oligo-beta-glucosides must have a specific structure to trigger the signal transduction pathway, which ultimately leads to the de novo synthesis of phytoalexins in soybean. PMID:1840904

  13. Protein repair L-isoaspartyl methyltransferase in plants. Phylogenetic distribution and the accumulation of substrate proteins in aged barley seeds.

    PubMed Central

    Mudgett, M B; Lowenson, J D; Clarke, S

    1997-01-01

    Protein L-isoaspartate (D-aspartate) O-methyltransferases (MTs; EC 2.1.1.77) can initiate the conversion of detrimental L-isoaspartyl residues in spontaneously damaged proteins to normal L-aspartyl residues. We detected this enzyme in 45 species from 23 families representing most of the divisions of the plant kingdom. MT activity is often localized in seeds, suggesting that it has a role in their maturation, quiescence, and germination. The relationship among MT activity, the accumulation of abnormal protein L-isoaspartyl residues, and seed viability was explored in barley (Hordeum vulgare cultivar Himalaya) seeds, which contain high levels of MT. Natural aging of barley seeds for 17 years resulted in a significant reduction in MT activity and in seed viability, coupled with increased levels of "unrepaired" L-isoaspartyl residues. In seeds heated to accelerate aging, we found no reduction of MT activity, but we did observe decreased seed viability and the accumulation of isoaspartyl residues. Among populations of accelerated aged seed, those possessing the highest levels of L-isoaspartyl-containing proteins had the lowest germination percentages. These results suggest that the MT present in seeds cannot efficiently repair all spontaneously damaged proteins containing altered aspartyl residues, and their accumulation during aging may contribute to the loss of seed viability. PMID:9414558

  14. Conversion of citrate synthase into citryl-CoA lyase as a result of mutation of the active-site aspartic acid residue to glutamic acid.

    PubMed Central

    Man, W J; Li, Y; O'Connor, C D; Wilton, D C

    1991-01-01

    The active-site aspartic acid residue, Asp-362, of Escherichia coli citrate synthase was changed by site-directed mutagenesis to Glu-362, Asn-362 or Gly-362. Only very low catalytic activity could be detected with the Asp----Asn and Asp----Gly mutations. The Asp----Glu mutation produced an enzyme that expressed about 0.8% of the overall catalytic rate, and the hydrolysis step in the reaction, monitored as citryl-CoA hydrolysis, was inhibited to a similar extent. However, the condensation reaction, measured in the reverse direction as citryl-CoA cleavage to oxaloacetate and acetyl-CoA, was not affected by the mutation, and this citryl-CoA lyase activity was the major catalytic activity of the mutant enzyme. This high condensation activity in an enzyme in which the subsequent hydrolysis step was about 98% inhibited permitted considerable exchange of the methyl protons of acetyl-CoA during catalysis by the mutant enzyme. The Km for oxaloacetate was not significantly altered in the D362E mutant enzyme, whereas the Km for acetyl-CoA was about 5 times lower. A mechanism is proposed in which Asp-362 is involved in the hydrolysis reaction of this enzyme, and not as a base in the deprotonation of acetyl-CoA as recently suggested by others. [Karpusas, Branchaud & Remington (1990) Biochemistry 29, 2213-2219; Alter, Casazza, Zhi, Nemeth, Srere & Evans, (1990) Biochemistry 29, 7557-7563]. PMID:1684105

  15. Solids Accumulation Scouting Studies

    SciTech Connect

    Duignan, M. R.; Steeper, T. J.; Steimke, J. L.

    2012-09-26

    The objective of Solids Accumulation activities was to perform scaled testing to understand the behavior of remaining solids in a Double Shell Tank (DST), specifically AW-105, at Hanford during multiple fill, mix, and transfer operations. It is important to know if fissionable materials can concentrate when waste is transferred from staging tanks prior to feeding waste treatment plants. Specifically, there is a concern that large, dense particles containing plutonium could accumulate in poorly mixed regions of a blend tank heel for tanks that employ mixing jet pumps. At the request of the DOE Hanford Tank Operations Contractor, Washington River Protection Solutions, the Engineering Development Laboratory of the Savannah River National Laboratory performed a scouting study in a 1/22-scale model of a waste staging tank to investigate this concern and to develop measurement techniques that could be applied in a more extensive study at a larger scale. Simulated waste tank solids: Gibbsite, Zirconia, Sand, and Stainless Steel, with stainless steel particles representing the heavier particles, e.g., plutonium, and supernatant were charged to the test tank and rotating liquid jets were used to mix most of the solids while the simulant was pumped out. Subsequently, the volume and shape of the mounds of residual solids and the spatial concentration profiles for the surrogate for heavier particles were measured. Several techniques were developed and equipment designed to accomplish the measurements needed and they included: 1. Magnetic particle separator to remove simulant stainless steel solids. A device was designed and built to capture these solids, which represent the heavier solids during a waste transfer from a staging tank. 2. Photographic equipment to determine the volume of the solids mounds. The mounds were photographed as they were exposed at different tank waste levels to develop a composite of topographical areas. 3. Laser rangefinders to determine the volume of

  16. RESIDUAL RISK ASSESSMENTS - RESIDUAL RISK ...

    EPA Pesticide Factsheets

    This source category previously subjected to a technology-based standard will be examined to determine if health or ecological risks are significant enough to warrant further regulation for Coke Ovens. These assesments utilize existing models and data bases to examine the multi-media and multi-pollutant impacts of air toxics emissions on human health and the environment. Details on the assessment process and methodologies can be found in EPA's Residual Risk Report to Congress issued in March of 1999 (see web site). To assess the health risks imposed by air toxics emissions from Coke Ovens to determine if control technology standards previously established are adequately protecting public health.

  17. Intracellular accumulation and resistance to degradation of the Alzheimer amyloid A4/beta protein.

    PubMed Central

    Knauer, M F; Soreghan, B; Burdick, D; Kosmoski, J; Glabe, C G

    1992-01-01

    The A4 or beta protein is a peptide that constitutes the major protein component of senile plaques in Alzheimer disease. The A4/beta protein is derived from a larger, transmembrane amyloid precursor protein (APP). The putative abnormal processing events leading to amyloid accumulation are largely unknown. Here we report that a 42-residue synthetic peptide, beta 1-42, corresponding to one of the longer forms of the A4/beta protein, accumulates in cultured human skin fibroblasts and is stable for at least 3 days. The peptide appears to accumulate intracellularly, since it does not accumulate under conditions that prevent endocytosis and accumulation is correlated with the acquisition of resistance to removal by trypsin digestion. This intracellular accumulation is also correlated with the ability of the peptide to aggregate as determined by SDS/polyacrylamide gel electrophoresis. At low concentrations of the beta 1-42 peptide, which favor the nonaggregated state, no accumulation is observed. Shorter peptide analogs (28 or 39 residues) that are truncated at the C terminus, which lack the ability to aggregate in SDS gels, fail to accumulate. The accumulated intracellular beta 1-42 peptide is in an aggregated state and is contained in a dense organellar compartment that overlaps the distribution of late endosomes or secondary lysosomes. Immunofluorescence of the internalized peptide in permeabilized cells reveals that it is contained in granular deposits, consistent with localization in late endosomes or secondary lysosomes. Sequence analysis indicates that some of the internalized peptide is subject to N-terminal trimming. These results suggest that the aggregated A4/beta protein may be resistant to degradation and suggest that the A4/beta protein may arise, at least in part, by endosomal or lysosomal processing of APP. Our results also suggest that relatively nonspecific proteolysis may be sufficient to generate the A4/beta protein if this part of APP is selectively

  18. Residual disease detected by flow cytometry is an independent predictor of survival in childhood acute myeloid leukaemia; results of the NOPHO-AML 2004 study.

    PubMed

    Tierens, Anne; Bjørklund, Elizabeth; Siitonen, Sanna; Marquart, Hanne Vibeke; Wulff-Juergensen, Gitte; Pelliniemi, Tarja-Terttu; Forestier, Erik; Hasle, Henrik; Jahnukainen, Kirsi; Lausen, Birgitte; Jonsson, Olafur G; Palle, Josefine; Zeller, Bem; Fogelstrand, Linda; Abrahamsson, Jonas

    2016-08-01

    Early response after induction is a prognostic factor for disease outcome in childhood acute myeloid leukaemia (AML). Residual disease (RD) detection by multiparameter flow cytometry (MFC) was performed at day 15 and before consolidation therapy in 101 patients enrolled in the Nordic Society of Paediatric Haemato-Oncology AML 2004 study. A multicentre laboratory approach to RD analysis was used. Event-free survival (EFS) and overall survival (OS) was significantly different in patients with and without RD at both time points, using a 0·1% RD cut-off level. RD-negative and -positive patients after first induction showed a 5-year EFS of 65 ± 7% and 22 ± 7%, respectively (P < 0·001) and an OS of 77 ± 6% (P = 0·025) and 51 ± 8%. RD-negative and -positive patients at start of consolidation therapy had a 5-year EFS of 57 ± 7% and 11 ± 7%, respectively (P < 0·001) and an OS of 78 ± 6% and 28 ± 11%) (P < 0·001). In multivariate analysis only RD was significantly correlated with survival. RD before consolidation therapy was the strongest independent prognostic factor for EFS [hazard ratio (HR):5·0; 95% confidence interval (CI):1·9-13·3] and OS (HR:7·0; 95%CI:2·0-24·5). In conclusion, RD before consolidation therapy identifies patients at high risk of relapse in need of intensified treatment. In addition, RD detection can be performed in a multicentre setting and can be implemented in future trials.

  19. Racial Differences in Patterns of Wealth Accumulation

    ERIC Educational Resources Information Center

    Gittleman, Maury; Wolff, Edward N.

    2004-01-01

    The race differences in patterns of asset accumulations were examined using PSD data for 1984, 1989 and 1994. The results indicate that inheritances led to wealth accumulations among whites as compared to the African Americans.

  20. New crystal structures of ColE1 Rom and variants resulting from mutation of a surface exposed residue: Implications for RNA-recognition.

    PubMed

    Struble, E B; Ladner, J E; Brabazon, D M; Marino, J P

    2008-08-01

    the apparent flexibility of this side chain suggests a highly constrained packing of this residue in the RNA-protein complex.

  1. Organochlorine pesticides residue in breast milk: a systematic review

    PubMed Central

    Pirsaheb, Meghdad; Limoee, Mojtaba; Namdari, Farideh; Khamutian, Razieh

    2015-01-01

    Background: Chlorinated pesticides have been used in pest control for several decades in the world. These compounds are still applied in many regions, and their continuous usage has resulted in their bioaccumulation and residue in the food chain. These residues could transfer to food products and accumulate in fat tissues. Undoubtedly, the breast milk could be a significant biomarker for estimation of these residues in the human body. This study was conducted to review and compile the results of the studies undertaken in the world which surveyed the organochlorine pesticides residue in breast milk. Methods: A total of 710 national and international articles and texts related to the focused subject were extracted from the virtual databases using the following key words: Chlorinated pesticides, residue and breast milk. Thirty articles published between 1980 and 2013 were selected and reviewed. Results: The majority of the reviewed articles indicated the presence of two or more organochlorine pesticides in the collected samples of breast milk. Based on the reviewed studies, dichlorodiphenyltrichloroethane (DDT) had the highest level of concentration in the collected samples of breast milk. Moreover, there was a statistically significant positive correlation between mother’s age, her multiparty and concentration of chlorinated pesticides in breast milk. Conclusion: The organochlorine pesticides are still applied in some developing countries including some regions of Iran. Thus, it seems essential to inform the community about the adverse effects of this class of pesticides; and most importantly the governments should also ban the use of such compounds. PMID:26478886

  2. Phytoavailability and mechanism of bound PAH residues in filed contaminated soils.

    PubMed

    Gao, Yanzheng; Hu, Xiaojie; Zhou, Ziyuan; Zhang, Wei; Wang, Yize; Sun, Bingqing

    2017-03-01

    Understanding the phytoavailability of bound residues of polycyclic aromatic hydrocarbons (PAHs) in soils is essential to assessing their environmental fate and risks. This study investigated the release and plant uptake of bound PAH residues (reference to parent compounds) in field contaminated soils after the removal of extractable PAH fractions. Plant pot experiments were performed in a greenhouse using ryegrass (Lolium multiflorum Lam.) to examine the phytoavailablility of bound PAH residues, and microcosm incubation experiments with and without the addition of artificial root exudates (AREs) or oxalic acid were conducted to examine the effect of root exudates on the release of bound PAH residues. PAH accumulation in the ryegrass after a 50-day growth period indicated that bound PAH residues were significantly phytoavailable. The extractable fractions, including the desorbing and non-desorbing fractions, dominated the total PAH concentrations in vegetated soils after 50 days, indicating the transfer of bound PAH residues to the extractable fractions. This transfer was facilitated by root exudates. The addition of AREs and oxalic acid to test soils enhanced the release of bound PAH residues into their extractable fractions, resulting in enhanced phytoavailability of bound PAH residues in soils. This study provided important information regarding environmental fate and risks of bound PAH residues in soils.

  3. Materials recovery from shredder residues

    SciTech Connect

    Daniels, E. J.; Jody, B. J.; Pomykala, J., Jr.

    2000-07-24

    Each year, about five (5) million ton of shredder residues are landfilled in the US. Similar quantities are landfilled in Europe and the Pacific Rim. Landfilling of these residues results in a cost to the existing recycling industry and also represents a loss of material resources that are otherwise recyclable. In this paper, the authors outline the resources recoverable from typical shredder residues and describe technology that they have developed to recover these resources.

  4. Photorefractive Keratectomy with Adjunctive Mitomycin C for Residual Error after Laser-Assisted In Situ Keratomileusis Using the Pulzar 213 nm Solid-State Laser: Early Results.

    PubMed

    Ng-Darjuan, Maya Fe; Evangelista, Raymond P; Agahan, Archimedes Lee D

    2013-01-01

    Purpose. To evaluate the accuracy, efficacy, stability, and safety of photorefractive keratectomy (PRK) enhancement using the Pulzar 213 nm solid-state laser (SSL) with adjunctive Mitomycin C in eyes previously treated with laser assisted in situ keratomileusis (LASIK) with residual error of refraction. Methods. This is a prospective noncomparative case series of 16 eyes of 12 patients who underwent PRK for residual refractive error after primary LASIK. Mitomycin C 0.02% was used after the PRK to prevent haze formation. Outcomes measured were pre- and postoperative manifest refraction spherical equivalent (MRSE), uncorrected (UDVA) and best-corrected distance visual acuity (CDVA), and slit lamp evidence of corneal complications. Results. The mean UDVA improved from 20/70 preoperatively to 20/30 postoperatively. The average gain in lines for the UDVA was 2.38. After six months of followup, the postoperative MRSE within 0.50 D in 56% (9) of eyes and 94% (15) eyes were within 1.0 diopters of the intended correction. No eyes developed haze all throughout the study. Conclusion. PRK enhancement with adjunctive use of Mitomycin C for the correction of residual error of refraction after LASIK using the Pulzar 213 nm solid-state laser is an accurate, effective, and safe procedure.

  5. An EBV recombinant deleted for residues 130-159 in EBNA3C can deregulate p53/Mdm2 and Cyclin D1/CDK6 which results in apoptosis and reduced cell proliferation

    PubMed Central

    El-Naccache, Darine W.; Robertson, Erle S.

    2016-01-01

    Epstein-Barr virus (EBV), a gamma herpes virus is associated with B-cell malignancies. EBNA-3C is critical for in vitro primary B-cell transformation. Interestingly, the N terminal domain of EBNA3C which contains residues 130–159, interacts with various cellular proteins, such as p53, Mdm2, CyclinD1/Cdk6 complex, and E2F1. In the current reverse genetics study, we deleted the residues 130-159 aa within EBNA3C open reading frame (ORF) by BACmid recombinant engineering methodology. Our experiments demonstrated that deletion of the 130-159 aa showed a reduction in cell proliferation. Also, this recombinant virus showed with higher infectivity of human peripheral blood mononuclear cells (PBMCs) compared to wild type EBV. PBMCs- infected with recombinant EBV deleted for 130-159 residues have differential expression patterns for the p53/Mdm2, CyclinD1/Cdk6 and pRb/E2F1 pathways compared to wild type EBV-infected PBMCs. PBMCs infected with recombinant virus showed increased apoptotic cell death which further resulted in activation of polymerase 1 (PARP1), an important contributor to apoptotic signaling. Interestingly, cells infected with this recombinant virus showed a dramatic decrease in chromosomal instability, indicated by the presence of increased multinucleation and micronucleation. In addition infection with recombinant virus have increased cells in G0/G1 phase and decreased cells in S-G2M phase when compared to wild type infected cells. Thus, these differences in signaling activities due to 29 amino acid residues of EBNA3C is of particular significance in deregulation of cell proliferation in EBV-infected cells. PMID:26908453

  6. Glioma residual or recurrence versus radiation necrosis: accuracy of pentavalent technetium-99m-dimercaptosuccinic acid [Tc-99m (V) DMSA] brain SPECT compared to proton magnetic resonance spectroscopy (1H-MRS): initial results.

    PubMed

    Amin, Amr; Moustafa, Hosna; Ahmed, Ebaa; El-Toukhy, Mohamed

    2012-02-01

    We compared pentavalent technetium-99m dimercaptosuccinic acid (Tc-99m (V) DMSA) brain single photon emission computed tomography (SPECT) and proton magnetic resonance spectroscopy ((1)H-MRS) for the detection of residual or recurrent gliomas after surgery and radiotherapy. A total of 24 glioma patients, previously operated upon and treated with radiotherapy, were studied. SPECT was acquired 2-3 h post-administration of 555-740 MBq of Tc-99m (V) DMSA. Lesion to normal (L/N) delayed uptake ratio was calculated as: mean counts of tumor ROI (L)/mean counts of normal mirror symmetric ROI (N). (1)H-MRS was performed using a 1.5-T scanner equipped with a spectroscopy package. SPECT and (1)H-MRS results were compared with pathology or follow-up neuroimaging studies. SPECT and (1)H-MRS showed concordant residue or recurrence in 9/24 (37.5%) patients. Both were true negative in 6/24 (25%) patients. SPECT and (1)H-MRS disagreed in 9 recurrences [7/9 (77.8%) and 2/9 (22.2%) were true positive by SPECT and (1)H-MRS, respectively]. Sensitivity of SPECT and (1)H-MRS in detecting recurrence was 88.8 and 61.1% with accuracies of 91.6 and 70.8%, respectively. A positive association between the delayed L/N ratio and tumor grade was found; the higher the grade, the higher is the L/N ratio (r = 0.62, P = 0.001). Tc-99m (V) DMSA brain SPECT is more accurate compared to (1)H-MRS for the detection of tumor residual tissues or recurrence in glioma patients with previous radiotherapy. It allows early and non-invasive differentiation of residual tumor or recurrence from irradiation necrosis.

  7. Microwave emission and crop residues

    NASA Technical Reports Server (NTRS)

    Jackson, Thomas J.; O'Neill, Peggy E.

    1991-01-01

    A series of controlled experiments were conducted to determine the significance of crop residues or stubble in estimating the emission of the underlying soil. Observations using truck-mounted L and C band passive microwave radiometers showed that for dry wheat and soybeans the dry residue caused negligible attenuation of the background emission. Green residues, with water contents typical of standing crops, did have a significant effect on the background emission. Results for these green residues also indicated that extremes in plant structure, as created using parallel and perpendicular stalk orientations, can cause very large differences in the degree of attenuation.

  8. Changes in the physiological properties and kinetics of citric acid accumulation via carbon ion irradiation mutagenesis of Aspergillus niger *

    PubMed Central

    Hu, Wei; Chen, Ji-hong; Wang, Shu-yang; Liu, Jing; Song, Yuan; Wu, Qing-feng; Li, Wen-jian

    2016-01-01

    The objective of this work was to produce citric acid from corn starch using a newly isolated mutant of Aspergillus niger, and to analyze the relationship between changes in the physiological properties of A. niger induced by carbon ion irradiation and citric acid accumulation. Our results showed that the physiological characteristics of conidia in A. niger were closely related to citric acid accumulation and that lower growth rate and viability of conidia may be beneficial to citric acid accumulation. Using corn starch as a raw material, a high-yielding citric acid mutant, named HW2, was obtained. In a 10-L bioreactor, HW2 can accumulate 118.9 g/L citric acid with a residual total sugar concentration of only 14.4 g/L. This represented an 18% increase in citric acid accumulation and a 12.5% decrease in sugar utilization compared with the original strain.

  9. Estimation of Zn mobility and biological availability in sod-podzolic soil and leached chernozem based on results of soil extraction by various salt solutions and Zn accumulation in barley plants

    NASA Astrophysics Data System (ADS)

    Pivovarova, Y. A.

    2012-04-01

    Extraction of soils by chemical reagents is widely used as a basis for forecasting the stock of the metal in the soil available to the plants. There are some doubts about how heavy metals uptake from specific soil to certain plant species can be adequately modeled on the results of chemical extraction. Problems of regulation of heavy metals in natural objects and risk assessment of soil contamination must be solved as issues of unification and standardization of existing assessment methods and new methods developing for their use in studies of the mobility of metals in soils and their availability to plants. Zn is a priority pollutant of the soil. The availability of Zn compounds to plants in two soils of different genesis was compared on the basis of their extraction by neutral salt solutions Ca(NO3)2, MgCl2, and CH3COONH4 and a pot experiment. It was shown that not only the concentration of contaminant in the extractant, but also the proportion of extractable Zn in its total content in the soil increased with increasing contamination of soil. The difference between the estimates of exchangeable Zn obtained by these methods was ~2.5 times for soddy-podzolic soil and 3-6 times for leached chernozem. The relationship between the accumulation of Zn in 14-day-old barley seedlings and the content of its exchangeable form in the soil was near linear, but the parameters of regression equations for two soils differed significantly. Chemical extraction allowed the differentiation of the mobile Zn fraction, but its accumulation by plants from different soils could not be predicted from the extractability of the element by neutral salt solutions without consideration for other soil properties.

  10. Are diurnal patterns of stomatal movement the result of alternating metabolism of endogenous guard cell ABA and accumulation of ABA delivered to the apoplast around guard cells by transpiration?

    PubMed

    Tallman, Gary

    2004-09-01

    Abscisic acid (ABA) prevents opening of closed stomata and causes open stomata to close. A dual-source model is proposed linking ABA to diurnal stomatal movements. Darkness would favour guard cell biosynthesis of endogenous ABA and disfavour ABA catabolism. At first light, xanthophyll cycling, isomerization of ABA precursors, and activation of a cytochrome P450 mono-oxygenase (CytP450) would deplete endogenous guard cell ABA. The NADPH-requiring CytP450 would be activated by elevated O2 and reduced CO2 concentrations resulting from mesophyll photosynthesis. An increased O2-to-CO2 ratio would limit the Calvin cycle in guard cells, diverting NADPH produced by photosynthetic electron transport to the cytosol where, along with elevated O2, it would activate CytP450. Depletion of endogenous ABA would liberate guard cells to extrude protons and accumulate the ions and water needed to increase guard cell turgor and open stomata. By midday, stomata would be regulated by steady-state concentrations of ABA delivered to the apoplast around guard cells by transpiration. In temperate conditions, ABA would reach concentrations high enough to trigger ion efflux from guard cells, but too low to defeat the accumulation of sugars used to maintain opening. In dry conditions, ABA would reach effective concentrations by midday, high enough to trigger ion efflux and inhibit sugar uptake, reducing apertures for the rest of the day. At sunset, conditions would again favour biosynthesis and disfavour catabolism of endogenous guard cell ABA. The model can be used to reconcile proposed cellular mechanisms for guard cell signal transduction with patterns of stomatal movements in leaves.

  11. Characteristics of discrete and basin-centered parts of the Lower Silurian regional oil and gas accumulation, Appalachian basin; preliminary results from a data set of 25 oil and gas fields

    USGS Publications Warehouse

    Ryder, Robert T.

    1998-01-01

    Oil and gas trapped in Lower Silurian 'Clinton' sands and Medina Group sandstone constitute a regional hydrocarbon accumulation that extends 425 mi in length from Ontario, Canada to northeastern Kentucky. The 125-mi width of the accumulation extends from central Ohio eastward to western Pennsylvania and west-central New York. Lenticular and intertonguing reservoirs, a gradual eastward decrease in reservoir porosity and permeability, and poorly segregated gas, oil, and water in the reservoirs make it very difficult to recognize clear-cut geologic- and production-based subdivisions in the accumulation that are relevant to resource assessment. However, subtle variations are recognizable that permit the regional accumulation to be subdivided into three tentative parts: a western gas-bearing part having more or less discrete fields; an eastern gas-bearing part having many characteristics of a basin-centered accumulation; and a central oil- and gas-bearing part with 'hybrid' fields that share characteristics of both discrete and basin-centered accumulation. A data set of 25 oil and gas fields is used in the report to compare selected attributes of the three parts of the regional accumulation. A fourth part of the regional accumulation, not discussed here, is an eastern extension of basin-centered accumulation having local commercial gas in the Tuscarora Sandstone, a proximal facies of the Lower Silurian depositional system. A basin-centered gas accumulation is a regionally extensive and commonly very thick zone of gas saturation that occurs in low-permeability rocks in the central, deeper part of a sedimentary basin. Another commonly used term for this type of accumulation is deep-basin gas accumulation. Basin-centered accumulation is a variety of continuous-type accumulation. The 'Clinton' sands and Medina Group sandstone part of the basin-centered gas accumulation is characterized by: a) reservoir porosity ranging from about 5 to 10 percent; b) reservoir permeability

  12. Comparison of clenbuterol and salbutamol accumulation in the liver of two different mouse strains.

    PubMed

    Vulić, Ana; Pleadin, Jelka; Durgo, Ksenija; Scortichini, Giampiero; Stojković, Ranko

    2014-06-01

    In the European Union, β(2)-adrenergic agonists like clenbuterol and salbutamol are banned from use as growth promoters. Although clenbuterol and salbutamol both accumulate in the liver, differences in the accumulation rate can be seen among animal species due to different β(2)-adrenoreceptor distributions. The aim of this study was to compare the accumulation of the two in the liver tissue of two different mouse strains. The study included 200 8-week-old BALB/c and C57/BL/6 mice. One group of BALB/c (40) and one group of C57/BL/6 (40) mice were treated with 2.5 mg/kg body mass clenbuterol per os for 28 days. The remaining two animal groups were treated with salbutamol in the same manner. The animals were then randomly sacrificed on day 1, 15 and 30 post treatments. Despite of the same treatment dose, the results revealed clenbuterol to persist in the liver tissue longer than salbutamol. On post treatment day 30, the concentration of clenbuterol residue in C57/BL/6 and BALB/c mice liver tissue were 0.23 ± 0.02 and 0.21 ± 0.03 ng/g, respectively, while residues of salbutamol were not detected. When comparing the accumulation of both compounds between the two mouse strains, it becomes apparent that no significant difference (P > 0.05) in the accumulation rate can be found.

  13. Production and use of DDT containing antifouling paint resulted in high DDTs residue in three paint factory sites and two shipyard sites, China.

    PubMed

    Xin, Jia; Liu, Xiang; Liu, Wei; Jiang, Lu; Wang, Jihua; Niu, Jia

    2011-06-01

    This study provides the first intensive investigation of Dichlorodiphenyltrichloroethanes (DDT) distribution in typical paint factories and shipyards in China where DDT containing antifouling paint were mass produced and used respectively. DDTs were analyzed in soil, sludge and sediment samples collected from three major paint factories and two shipyards. The results showed that the total DDTs concentrations detected in paint factory and shipyard sites ranged from 0.06 to 8387.24 mg kg(-1). In comparison with paint factory sites, the shipyard sites were much more seriously contaminated. However, for both kinds of sites, the DDTs level was found to be largely affected by history and capacity of production and use of DDT containing antifouling paint. (DDE+DDD)/DDT ratios indicated that DDT containing antifouling paint could serve as important fresh input sources for DDTs. It can be seen that most samples in shipyards were in ranges where heavy contamination and potential ecological risk were identified.

  14. Mutation of the aspartic acid residues of the GDD sequence motif of poliovirus RNA-dependent RNA polymerase results in enzymes with altered metal ion requirements for activity.

    PubMed Central

    Jablonski, S A; Morrow, C D

    1995-01-01

    different metal ions. Surprisingly, the transfection of the cDNA containing the 3D-N-329 mutation resulted in the production of virus at a low frequency in the presence of FeSO4 or CoCl2. The virus derived from transfection in the presence of FeSO4 grew slowly, while the viruses recovered from transfection in CoCl2 grew at a rate which was similar to that of the wild-type poliovirus.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:7853486

  15. Representativity of mosses as biomonitor organisms for the accumulation of environmental chemicals in plants and soils

    SciTech Connect

    Thomas, W.

    1986-06-01

    The suitability of mosses for air pollution monitoring of benzohexachloride isomers and polyaromatic hydrocarbons is shown by residue data of different samples from Europe. The interpretation of the results makes it obvious that next to regional pattern analysis, hypotheses for atmospheric transport and deposition processes of different environmental chemicals can also be formed. An evaluation of these kinds of bioindicator methods is presented by a quantitative comparison of air pollution data and accumulated residues in plants. The results indicate a high retention efficiency of mosses for pollutants dominantly adsorbed to particulate matter in the air, like polyaromatic hydrocarbons and heavy metals. The comparison of residue data of trace pollutants in mosses and other plants underlines the indicator functions of lower plants for air monitoring patterns with the exception of chlorinated hydrocarbons. They are more effective enriched by coniferous plants which contain ingredients able to absorb and transport these groups of environmental pollutants in the organism.

  16. PESTICIDE RESIDUE RECOVERIES FROM SURFACE WIPES

    EPA Science Inventory

    Human exposure is a consequence of pesticide use indoors with a primary source resulting from residue deposition on household surfaces. Accurate measurements of surface residues is essential for estimating exposure from different routes. Various procedures have been developed ...

  17. Combination of quercetin and tannic acid in inhibiting 26S proteasome affects S5a and 20S expression, and accumulation of ubiquitin resulted in apoptosis in cancer chemoprevention.

    PubMed

    Chang, Tsui-Ling; Wang, Chi-Hsien

    2013-04-01

    To look for oral proteasome inhibitors, daily injested food is the best source for cancer chemoprevention. A combination of active components from vegetables, coffee, tea, and fruit could be more efficient to inhibit 26S proteasome activities for preventing cancer diseases. Tannic acid and quercetin have been shown to strongly inhibit 26S proteasome activity, but the molecular target involved remains unknown. Overlay assay, peptide assay, Western blot, and 2-D gels were used to assess the combination of quercetin and tannic acid as a potential inhibitor. Here, we demonstrated that the combination of quercetin and tannic acid (1) synergistically suppresses chymotrypsin-, caspase-, and trypsin-like proteolytic activities, (2) are tightly binding substrates, (3) do not perturb the proteasome structure, (4) inhibit the 26S proteasome affected by ubiquitin, ATP, or β-casein, and (5) inhibit β-casein degradation by the 26S proteasome in vitro. Finally, the inhibition of the proteasome by a combination of quercetin plus tannic acid in Hep-2 cells resulted in the induction of S5a at low dose, accumulation of ubiquitin, and the cleavage of pro-caspase-3, followed by the induction of apoptotic cell death. Evaluating the combination of quercetin and tannic acid as an oral drug to prevent cancer may provide a pharmacological rationale to pursue preclinical trials of this combination.

  18. SRC Residual fuel oils

    DOEpatents

    Tewari, Krishna C.; Foster, Edward P.

    1985-01-01

    Coal solids (SRC) and distillate oils are combined to afford single-phase blends of residual oils which have utility as fuel oils substitutes. The components are combined on the basis of their respective polarities, that is, on the basis of their heteroatom content, to assure complete solubilization of SRC. The resulting composition is a fuel oil blend which retains its stability and homogeneity over the long term.

  19. RESIDUAL RISK ASSESSMENT: MAGNETIC TAPE ...

    EPA Pesticide Factsheets

    This document describes the residual risk assessment for the Magnetic Tape Manufacturing source category. For stationary sources, section 112 (f) of the Clean Air Act requires EPA to assess risks to human health and the environment following implementation of technology-based control standards. If these technology-based control standards do not provide an ample margin of safety, then EPA is required to promulgate addtional standards. This document describes the methodology and results of the residual risk assessment performed for the Magnetic Tape Manufacturing source category. The results of this analyiss will assist EPA in determining whether a residual risk rule for this source category is appropriate.

  20. RESIDUAL RISK ASSESSMENT: ETHYLENE OXIDE ...

    EPA Pesticide Factsheets

    This document describes the residual risk assessment for the Ethylene Oxide Commercial Sterilization source category. For stationary sources, section 112 (f) of the Clean Air Act requires EPA to assess risks to human health and the environment following implementation of technology-based control standards. If these technology-based control standards do not provide an ample margin of safety, then EPA is required to promulgate addtional standards. This document describes the methodology and results of the residual risk assessment performed for the Ethylene Oxide Commercial Sterilization source category. The results of this analyiss will assist EPA in determining whether a residual risk rule for this source category is appropriate.

  1. Accumulated Dose in Liver Stereotactic Body Radiotherapy: Positioning, Breathing, and Deformation Effects

    SciTech Connect

    Velec, Michael; Moseley, Joanne L.; Craig, Tim; Dawson, Laura A.; Brock, Kristy K.

    2012-07-15

    Purpose: To investigate the accumulated dose deviations to tumors and normal tissues in liver stereotactic body radiotherapy (SBRT) and investigate their geometric causes. Methods and Materials: Thirty previously treated liver cancer patients were retrospectively evaluated. Stereotactic body radiotherapy was planned on the static exhale CT for 27-60 Gy in 6 fractions, and patients were treated in free-breathing with daily cone-beam CT guidance. Biomechanical model-based deformable image registration accumulated dose over both the planning four-dimensional (4D) CT (predicted breathing dose) and also over each fraction's respiratory-correlated cone-beam CT (accumulated treatment dose). The contribution of different geometric errors to changes between the accumulated and predicted breathing dose were quantified. Results: Twenty-one patients (70%) had accumulated dose deviations relative to the planned static prescription dose >5%, ranging from -15% to 5% in tumors and -42% to 8% in normal tissues. Sixteen patients (53%) still had deviations relative to the 4D CT-predicted dose, which were similar in magnitude. Thirty-two tissues in these 16 patients had deviations >5% relative to the 4D CT-predicted dose, and residual setup errors (n = 17) were most often the largest cause of the deviations, followed by deformations (n = 8) and breathing variations (n = 7). Conclusion: The majority of patients had accumulated dose deviations >5% relative to the static plan. Significant deviations relative to the predicted breathing dose still occurred in more than half the patients, commonly owing to residual setup errors. Accumulated SBRT dose may be warranted to pursue further dose escalation, adaptive SBRT, and aid in correlation with clinical outcomes.

  2. Elucidation of the structures of residual and dissolved pine kraft lignins using an HMQC NMR technique.

    PubMed

    Balakshin, Mikhail Yu; Capanema, Ewellyn A; Chen, Chen-Loung; Gracz, Hanna S

    2003-10-08

    Comparative studies on the structures of residual and dissolved lignins isolated from pine kraft pulp and pulping liquor have been undertaken using the (1)H-(13)C HMQC NMR technique, GPC, and sugar analysis to elucidate the reaction mechanisms in kraft pulping and the lignin reactivity. A modified procedure for the isolation of enzymatic residual lignins has resulted in an appreciable decrease in protein contaminants in the residual lignin preparations (N content < 0.2%). The very high dispersion of HMQC spectra allows identification of different lignin moieties, which signals appear overlapped in 1D (13)C NMR spectra. Elucidation of the role of condensation reactions indicates that an increase in the degree of lignin condensation during pulping results from accumulation of original condensed lignin moieties rather than from the formation of new alkyl-aryl structures. Among aryl-vinyl type moieties, only stilbene structures are accumulated in lignin in appreciable amounts. Benzyl ether lignin-carbohydrate bonds involving primary hydroxyl groups of carbohydrates have been detected in residual and dissolved lignin preparations. Structures of the alpha-hydroxyacid type have been postulated to be among the important lignin degradation products in kraft pulping. The effect of the isolation method on the lignin structure and differences between the residual and dissolved lignins are discussed.

  3. Analysis of Residual DSBs in Ataxia-Telangiectasia Lymphoblast Cells Initiating Apoptosis

    PubMed Central

    Anglada, Teresa; Terradas, Mariona; Hernández, Laia; Genescà, Anna; Martín, Marta

    2016-01-01

    In order to examine the relationship between accumulation of residual DNA double-strand breaks (DSBs) and cell death, we have used a control and an ATM (Ataxia-Telangiectasia Mutated) defective cell line, as Ataxia-Telangiectasia (AT) cells tend to accumulate residual DSBs at long times after damage infliction. After irradiation, AT cells showed checkpoint impairment and a fraction of cells displayed an abnormal centrosome number and tetraploid DNA content, and this fraction increased along with apoptosis rates. At all times analyzed, AT cells displayed a significantly higher rate of radiation-induced apoptosis than normal cells. Besides apoptosis, 70–85% of the AT viable cells (TUNEL-negative) carried ≥10 γH2AX foci/cell, while only 12–27% of normal cells did. The fraction of AT and normal cells undergoing early and late apoptosis were isolated by flow cytometry and residual DSBs were concretely scored in these populations. Half of the γH2AX-positive AT cells undergoing early apoptosis carried ≥10 γH2AX foci/cell and this fraction increased to 75% in late apoptosis. The results suggest that retention of DNA damage-induced γH2AX foci is an indicative of lethal DNA damage, as cells undergoing apoptosis are those accumulating more DSBs. Scoring of residual γH2AX foci might function as a predictive tool to assess radiation-induced apoptosis. PMID:27057549

  4. 40 CFR 180.339 - MCPA; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...; tolerances for residues. (a) General. (1) Tolerances are established for residues of the herbicide MCPA ((4... for residues of the herbicide MCPA ((4-chloro-2-methylphenoxy)acetic acid) resulting from the...

  5. 40 CFR 180.339 - MCPA; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...; tolerances for residues. (a) General. (1) Tolerances are established for residues of the herbicide MCPA ((4... for residues of the herbicide MCPA ((4-chloro-2-methylphenoxy)acetic acid) resulting from the...

  6. 40 CFR 180.339 - MCPA; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...; tolerances for residues. (a) General. (1) Tolerances are established for residues of the herbicide MCPA ((4... for residues of the herbicide MCPA ((4-chloro-2-methylphenoxy)acetic acid) resulting from the...

  7. 40 CFR 180.339 - MCPA; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...; tolerances for residues. (a) General. (1) Tolerances are established for residues of the herbicide MCPA ((4... for residues of the herbicide MCPA ((4-chloro-2-methylphenoxy)acetic acid) resulting from the...

  8. 40 CFR 180.339 - MCPA; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...; tolerances for residues. (a) General. (1) Tolerances are established for residues of the herbicide MCPA ((4... for residues of the herbicide MCPA ((4-chloro-2-methylphenoxy)acetic acid) resulting from the...

  9. Presence of metals in biomass residues after pyrolysis

    NASA Astrophysics Data System (ADS)

    Guehenneux, G.; Varin, S.; Baussand, P.

    2003-05-01

    In contribution to research into renewable energy, pyrolysis tests are run to develop the process of pyrolysis of biomass allowing the production of Hydrogen. Various families of combustibles (oleaginous, lignocellulosics, and seeds) have been tested at different temperatures. The pyrolysis of biomass is hampered by technical problems such as the blockage of the furnace by tars. The residues are collected and treated in a solution of chloric and nitric acid, so that the mineral part is extracted and then analysed by ICP. The first results indicate the presence ofmetals: Ni, Mg, Zn, Mn, Fe... Various proposais for the use of these residues so as to avoid pollution due to their accumulation have been put forward. These ashes can be recombined with fuels, acting as catalysts to reduce the formation of tar and increase the production of hydrogen.

  10. Soil C saturation does not seem to influence short-term decomposition of maize residues

    NASA Astrophysics Data System (ADS)

    Poirier, Vincent; Angers, Denis; Rochette, Philippe; Whalen, Joann

    2010-05-01

    exceeded the amount that would be added to soils under field conditions (e.g., > 20 g C kg-1), whole soil SOC (27.2 g C kg-1 soil) in the subsoil did not reach the theoretical C storage capacity limit. However, the expected C storage capacity was greatly surpassed in the topsoil (50.0 g C kg-1 soil) with the same amount of residue-C added. Results presented here do not support the hypothesis that whole soil C accumulation is limited with respect to residue C inputs, at least in the short-term. Residue-induced cumulative C-CO2 lost was positively correlated with the amount of C added and was greater in topsoil than subsoil within each C input rate. The linear increase in total respiration with application rates implies that for the 51 d of incubation, no limitation or levelling off of soil decomposition activity occurred in the topsoil or the subsoil. Despite differences in C mineralization, similar amounts of residue-C were stabilized in both soils. This suggests that the increased C mineralization observed in the topsoil could be attributable to the mineralization of native SOC and thus that a priming effect could have occurred in our study. However, if a priming effect occurred in the topsoil, its magnitude was small when compared to the high levels of SOC measured at the end of the experiment. Soil C saturation deficit did not influence residue-C stabilization in this study and the linear accumulation of residue-C tends to show that whole soil SOC accumulation is not limited with respect to C inputs in the short term in this heavy clay soil.

  11. Organochlorine insecticide residues in African Fauna: 1971-1995.

    PubMed

    Wiktelius, S; Edwards, C A

    1997-01-01

    Organochlorine insecticides (OCLs), which were introduced in the decade following World War II, were used extensively in Europe, the U.S., and other developed countries into the 1970s. However, data began to accumulate on their persistence in soils and aquatic sediments, their potential to be taken up into animal tissues and to bioconcentrate in birds and mammals in the higher tropic levels of food chains and even in humans. As a result, registration authorities phased out their use progressively, in Europe and the U.S., from 1973 onward. However, the production of OCLs in developed countries and their use in developing countries continued through the 1970s and 1980s into the 1990s because they were, no longer under patent agreement, were inexpensive to manufacture, and were very effective in pest control. In Africa, the use of OCLs continued well into the 1990s for the control of mosquitoes, tsetse flies, and desert locusts as well as to combat various crop, animal, and human pests. Some of these uses involved extensive spraying of large areas of nonagricultural land, thereby exposing many groups and species of wildlife to their residues. Although there is some evidence of a gradual decline in the use of OCLs in Africa, they are still being used in appreciable quantities. During the past 25 yr, there have been 50 published reports of OCL residues in the various groups of invertebrate and vertebrate animals constituting the African fauna. These have been based on a diverse range of surveys, target animals, sampling methods, and analytical techniques. Moreover, they are extremely regionally-biased, the most intense surveys being in Zimbabwe, Kenya, Egypt, and South Africa. DDT was the most commonly used OCL, accounting for about half the total use, followed closely by dieldrin and HCH. Birds and fish have been sampled most intensively, with relatively few studies on other taxa. We reviewed the OCL residue data on African fauna from these reports and summarized the

  12. 46 CFR 58.30-25 - Accumulators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... RELATED SYSTEMS Fluid Power and Control Systems § 58.30-25 Accumulators. (a) An accumulator is an unfired pressure vessel in which energy is stored under high pressure in the form of a gas or a gas and hydraulic... result in contamination of the hydraulic fluid and loss of gas through absorption. (c) Each...

  13. 46 CFR 58.30-25 - Accumulators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... RELATED SYSTEMS Fluid Power and Control Systems § 58.30-25 Accumulators. (a) An accumulator is an unfired pressure vessel in which energy is stored under high pressure in the form of a gas or a gas and hydraulic... result in contamination of the hydraulic fluid and loss of gas through absorption. (c) Each...

  14. Proline accumulation in plants: a review.

    PubMed

    Verbruggen, Nathalie; Hermans, Christian

    2008-11-01

    Proline (Pro) accumulation is a common physiological response in many plants in response to a wide range of biotic and abiotic stresses. Controversy has surrounded the possible role(s) of proline accumulation. In this review, knowledge on the regulation of Pro metabolism during development and stress, results of genetic manipulation of Pro metabolism and current debate on Pro toxicity in plants are presented.

  15. Accumulation of the planets

    NASA Technical Reports Server (NTRS)

    Wetherill, G. W.

    1987-01-01

    In modeling the accumulation of planetesimals into planets, it is appropriate to distinguish between two stages: an early stage, during which approximately 10 km diameter planetesimals accumulate locally to form bodies approximate 10 to the 25th g in mass; and a later stage in which the approximately 10 to the 25th g planetesimals accumulate into the final planets. In the terrestrial planet region, an initial planetesimal swarm corresponding to the critical mass of dust layer gravitational instabilities is considered. In order to better understand the accumulation history of Mercury-sized bodies, 19 Monte-Carlo simulations of terrestrial planet growth were calculated. A Monte Carlo technique was used to investigate the orbital evolution of asteroidal collision debris produced interior to 2.6 AU. It was found that there are two regions primarily responsible for production of Earth-crossing meteoritic material and Apollo objects. The same techniques were extended to include the origin of Earth-approaching asteroidal bodies. It is found that these same two resonant mechanisms predict a steady-state number of Apollo-Amor about 1/2 that estimated based on astronomical observations.

  16. Residual stresses in welded plates

    NASA Technical Reports Server (NTRS)

    Bernstein, Edward L.

    1994-01-01

    The purpose of this project was to develop a simple model which could be used to study residual stress. The mechanism that results in residual stresses in the welding process starts with the deposition of molten weld metal which heats the immediately adjacent material. After solidification of weld material, normal thermal shrinkage is resisted by the adjacent, cooler material. When the thermal strain exceeds the elastic strain corresponding to the yield point stress, the stress level is limited by this value, which decreases with increasing temperature. Cooling then causes elastic unloading which is restrained by the adjoining material. Permanent plastic strain occurs, and tension is caused in the region immediately adjacent to the weld material. Compression arises in the metal farther from the weld in order to maintain overall static equilibrium. Subsequent repair welds may add to the level of residual stresses. The level of residual stress is related to the onset of fracture during welding. Thus, it is of great importance to be able to predict the level of residual stresses remaining after a weld procedure, and to determine the factors, such as weld speed, temperature, direction, and number of passes, which may affect the magnitude of remaining residual stress. It was hoped to use traditional analytical modeling techniques so that it would be easier to comprehend the effect of these variables on the resulting stress. This approach was chosen in place of finite element methods so as to facilitate the understanding of the physical processes. The accuracy of the results was checked with some existing experimental studies giving residual stress levels found from x-ray diffraction measurements.

  17. An essential tyrosine residue of Aspergillus polygalacturonase.

    PubMed

    Stratilová, E; Dzúrová, M; Markovic, O; Jörnvall, H

    1996-03-11

    Based on strict conservation of a tyrosine residue in 24 polygalacturonases, tyrosine modification was assessed in two different forms of the Aspergillus enzyme. The second subform was unknown in structure but submitted to sequence analysis and was found also to have the conserved tyrosine residue. Results of chemical modifications are consistent in showing inactivation of the proteins with all tyrosine-reactive agents tested, acetic anhydride, N-acetyl imidazole, and tetranitromethane. Furthermore, after acetylation, regeneration of enzyme activity was possible with hydroxylamine. Spectrophotometric pH titration showed that one accessible tyrosine residue is ionized at pH 9.3-9.5, whereas the remaining, masked residues are all ionized at pH 10.5. It is concluded that one tyrosine residue is catalytically important, in agreement with the inactivation and reactivation data, that this residue is accessible, and that it is likely to correspond to the strictly conserved residue observed in all forms.

  18. Neutron diffraction investigation of residual stresses in transverse/oblique rail slices subjected to different grinding strategies

    SciTech Connect

    Gnaeupel-Herold, T.; Brand, P.C.; Prask, H.J.

    1999-05-01

    Using the Double Axis system for Residual stress, Texture, and Single crystal analysis (DARTS) at NIST, neutron diffraction residual stress measurements were carried out in the head region of five pairs of transverse and oblique cut slices of railroad track, each having a thickness of 6.35 mm. The slices were taken from a 300 HB rail of CFI 136 RE size. All slices except one unworn reference piece had the same accumulated tonnage but were ground in different intervals. The measurements confirm the results previously found which indicated the existence of high sub-surface residual tensile stresses, while the regional close to the wheel-rail contact line shows high residual compressive stresses.

  19. Residuals and the Residual-Based Statistic for Testing Goodness of Fit of Structural Equation Models

    ERIC Educational Resources Information Center

    Foldnes, Njal; Foss, Tron; Olsson, Ulf Henning

    2012-01-01

    The residuals obtained from fitting a structural equation model are crucial ingredients in obtaining chi-square goodness-of-fit statistics for the model. The authors present a didactic discussion of the residuals, obtaining a geometrical interpretation by recognizing the residuals as the result of oblique projections. This sheds light on the…

  20. NK depletion results in increased CCL22 secretion and Treg levels in Lewis lung carcinoma via the accumulation of CCL22-secreting CD11b+CD11c+ cells.

    PubMed

    Mailloux, Adam W; Clark, Anna-Maria A; Young, M Rita I

    2010-12-01

    Tumor-induced immune suppression involves the accumulation of suppressive infiltrates in the tumor microenvironment such as regulatory T-cells (Tregs). Previous studies demonstrated that NK-dependant increases in CCL22 secretion selectively recruit Tregs toward murine lungs bearing Lewis Lung Carcinoma (LLC). To extend the in vitro studies, the present studies utilized in vivo depletion of NK cells to ascertain the contribution of NK-derived CCL22 toward total CCL22 and subsequent Treg levels in both normal and LLC-bearing lungs. However, NK depletion had the unexpected effect of increasing both CCL22 secretion and Treg levels in the lungs of NK-depleted LLC-bearing mice. This was concurrent with an increase in tumor burden. Flow cytometry and a series of both immunomagnetic and FACS isolations were used to identify the CCL22-producing cellular fractions in LLC-bearing lungs. A novel CD11b(+)CD11c(+) cell population was identified that accumulates in large numbers in NK-depleted LLC-bearing lung tissue. These CD11b(+)CD11c(+) cells secreted large amounts of CCL22 that may overcompensate for the loss of NK-derived CCL22 in the lungs of NK-depleted LLC-bearing mice. Taken together, these data suggest that NK cells play both a positive and negative role in the regulation of CCL22 secretion and, in turn, the recruitment of Tregs toward LLC-bearing lungs.

  1. Control of helium accumulation

    SciTech Connect

    Varadarajan, V.; Miley, G.H.

    1990-01-01

    The fishbone like oscillations in ignited tokamaks are addressed in an exploratory manner. The effects of the strong m = 1 oscillations and the weak high-frequency oscillations are examined in order to explore the feasibility of utilizing these oscillations for alpha accumulation control. The prospects of achieving small scale continuous alpha removal from the plasma center by mild fishbone-like oscillations are examined.

  2. Physiological changes and tissue metal accumulation in rainbow trout exposed to foodborne and waterborne metals

    SciTech Connect

    Farag, A.A.; Boese, C.J.; Bergman, H.L. . Dept. of Zoology and Physiology); Woodward, D.F. )

    1994-12-01

    Sublethal physiological effects and metal residue accumulation in tissues were measured in adult and juvenile rainbow trout fed a metal-contaminated diet and/or exposed to waterborne metals for 21 d. The consumption of metal-contaminated invertebrates from the Clark Fork River, Montana, significantly affected scale loss and metal accumulation in gut tissue of adult trout. Survival, scale loss, and metal accumulation in gill and kidney tissue were affected by exposure to a waterborne mixture of Cd, Cu, and Pb at twice the acceptable levels and Zn at the maximum acceptable level established by the US Environmental Protection Agency for protection of aquatic wildlife. A combination of dietary and waterborne metals also caused lipid peroxidation in the kidney of adult fish and decreased whole-body potassium of juvenile trout. In general, metal accumulation in tissues was higher in gill and kidney with waterborne exposures and was higher in stomach and pyloric caeca with dietary exposure. And metal concentrations in juvenile whole-body tissues accumulated significantly with a combination of waterborne and dietary metals. Although some physiological changes were noted (scale loss, lipid peroxidation of kidney), an exposure time longer than 21 d is probably needed to observe more extensive physiological changes. Regardless, results from this study suggest that a full assessment of metal exposure to fish populations in natural systems must include evaluation of dietary as well as waterborne metal contamination.

  3. Residual contact restraints in cryogenics

    NASA Astrophysics Data System (ADS)

    Cretegny, J. F.; Demonicault, J. M.

    The use of residual stress measurements to evaluate the state of cryogenic turbomachines, whose surfaces are worn by the working conductions in dry contact, is addressed. Their contribution to the understanding of the reasons of possible ruptures is considered. It is stated that residual stress measurements should be used as a complementary tool rather than as input data for models. It is shown, thanks to two examples concerning the ball bearings and splines of the liquid hydrogen turbopump of the Vulcain engine, what can be expected from such techniques. Total exploitation of the results has still to be done, but preliminary results are quite encouraging.

  4. Selenium accumulation by plants

    PubMed Central

    White, Philip J.

    2016-01-01

    Background Selenium (Se) is an essential mineral element for animals and humans, which they acquire largely from plants. The Se concentration in edible plants is determined by the Se phytoavailability in soils. Selenium is not an essential element for plants, but excessive Se can be toxic. Thus, soil Se phytoavailability determines the ecology of plants. Most plants cannot grow on seleniferous soils. Most plants that grow on seleniferous soils accumulate <100 mg Se kg–1 dry matter and cannot tolerate greater tissue Se concentrations. However, some plant species have evolved tolerance to Se, and commonly accumulate tissue Se concentrations >100 mg Se kg–1 dry matter. These plants are considered to be Se accumulators. Some species can even accumulate Se concentrations of 1000–15 000 mg Se kg–1 dry matter and are called Se hyperaccumulators. Scope This article provides an overview of Se uptake, translocation and metabolism in plants and highlights the possible genetic basis of differences in these between and within plant species. The review focuses initially on adaptations allowing plants to tolerate large Se concentrations in their tissues and the evolutionary origin of species that hyperaccumulate Se. It then describes the variation in tissue Se concentrations between and within angiosperm species and identifies genes encoding enzymes limiting the rates of incorporation of Se into organic compounds and chromosomal loci that might enable the development of crops with greater Se concentrations in their edible portions. Finally, it discusses transgenic approaches enabling plants to tolerate greater Se concentrations in the rhizosphere and in their tissues. Conclusions The trait of Se hyperaccumulation has evolved several times in separate angiosperm clades. The ability to tolerate large tissue Se concentrations is primarily related to the ability to divert Se away from the accumulation of selenocysteine and selenomethionine, which might be incorporated

  5. Evaluation of residue-residue contact prediction in CASP10

    PubMed Central

    Monastyrskyy, Bohdan; D’Andrea, Daniel; Fidelis, Krzysztof; Tramontano, Anna; Kryshtafovych, Andriy

    2013-01-01

    We present the results of the assessment of the intra-molecular residue-residue contact predictions from 26 prediction groups participating in the 10th round of the CASP experiment. The most recently developed direct coupling analysis methods did not take part in the experiment likely because they require a very deep sequence alignment not available for any of the 114 CASP10 targets. The performance of contact prediction methods was evaluated with the measures used in previous CASPs (i.e., prediction accuracy and the difference between the distribution of the predicted contacts and that of all pairs of residues in the target protein), as well as new measures, such as the Matthews correlation coefficient, the area under the precision-recall curve and the ranks of the first correctly and incorrectly predicted contact. We also evaluated the ability to detect inter-domain contacts and tested whether the difficulty of predicting contacts depends upon the protein length and the depth of the family sequence alignment. The analyses were carried out on the target domains for which structural homologs did not exist or were difficult to identify. The evaluation was performed for all types of contacts (short, medium, and long-range), with emphasis placed on long-range contacts, i.e. those involving residues separated by at least 24 residues along the sequence. The assessment suggests that the best CASP10 contact prediction methods perform at approximately the same level, and comparably to those participating in CASP9. PMID:23760879

  6. Ractopamine Residues in Beef Cattle Hair During and After Treatment.

    PubMed

    Liang, Xiaowei; Zhang, Kai; Zhang, Junmin; Li, Fadi; Zhao, Qingyu; Tang, Chaohua; Meng, Qingshi

    2016-03-01

    The objective of the present study was to assess the accumulation of ractopamine (RAC) residues in hair of Chinese Simmental beef cattle following exposure to two doses of RAC for 28 days. Six male cattle were orally administered with RAC hydrochloride at a dose of 0.67 mg/kg body weight/day (low-dose group, n = 3) and 2.01 mg/kg body weight/day (high-dose group, n = 3). The results suggested that RAC was obviously accumulated in hair, with a concentration of 5.57 ± 0.66 ng/g (white hair) and 13.67 ± 2.73 ng/g (red hair) in the low-dose group on Day 1 of treatment, respectively. In red hair, the peak concentrations of RAC were 5619.38 ± 2156.84 ng/g (low-dose group) and 6908.3 ± 1177.62 ng/g (high-dose group) on Day 14 of treatment, and then decreased slowly. In white hair, the highest concentrations of RAC were 3387.38 ± 1620.87 ng/g (low-dose group) on Day 14 of withdraw and 9621.72 ± 1497.65 ng/g (high-dose group) on Day 28 of treatment. The concentration of RAC in old hair was higher than that in new hair. No significant differences in RAC concentrations were obtained among dosage, hair color and old versus new hair (P > 0.05). The results indicated that ractopamine is significantly accumulated in red and white hair of Chinese Simmental beef cattle, which can be used as a matrix to assess the presence of RAC residues.

  7. Accumulation of "small dense" low density lipoproteins (LDL) in a homozygous patients with familial defective apolipoprotein B-100 results from heterogenous interaction of LDL subfractions with the LDL receptor.

    PubMed Central

    März, W; Baumstark, M W; Scharnagl, H; Ruzicka, V; Buxbaum, S; Herwig, J; Pohl, T; Russ, A; Schaaf, L; Berg, A

    1993-01-01

    The interaction of LDL and LDL subfractions from a patient homozygous for familial defective apoB-100 (FDB) has been studied. His LDL cholesterol ranged from 2.65 to 3.34 g/liter. In cultured fibroblasts, binding, internalization, and degradation of the patient's LDL was diminished, but not completely abolished. The patient's apolipoprotein E concentration was low, and the amount of apolipoprotein E associated with LDL was not elevated over normal. LDL were separated into six subfractions: LDL-1 (1.019-1.031 kg/liter), LDL-2 (1.031-1.034 kg/liter), LDL-3 (1.034-1.037 kg/liter), LDL-4 (1.037-1.040 kg/liter), LDL-5 (1.040-1.044 kg/liter), and LDL-6 (> 1.044 kg/liter). LDL-5 and LDL-6 selectively accumulated in the patient's plasma. Concentrations of LDL-1 to 3 were normal. The LDL receptor-mediated uptake of LDL-1 and LDL-2 could not be distinguished from normal LDL. LDL-3 and LDL-4 displayed reduced uptake; LDL-5 and LDL-6 were completely defective in binding. When apolipoprotein E-containing particles were removed by immunoabsorption before preparing subfractions, LDL-3 and LDL-4, but not LDL-1 and LDL-2, retained some receptor binding activity. We conclude that in FDB, LDL-1 and LDL-2 contain sufficient apolipoprotein E to warrant normal cellular uptake. In LDL-3 and LDL-4, the defective apoB-100 itself displays some receptor binding; LDL-5 and LDL-6 are inable to interact with LDL receptors and accumulate in plasma. Images PMID:8254047

  8. Influence of laying on lead accumulation in bone of mallard ducks

    USGS Publications Warehouse

    Finley, M.T.; Dieter, M.P.

    1978-01-01

    Paired mallard ducks (Anas platyrhynchos) were given No. 4 lead shot, and bone lead concentrations were compared in drakes and in laying and nonlaying hens. Lead accumulation was significantly greater in bones with a high medullary content (femur and sternum) compared with bones with a lower medullary content (ulna-radius or wingbones). In dosed groups, hens always contained higher bone lead residues than drakes. After dosage with one shot (approximately 200 mg lead), lead in femurs of laying hens averaged 488.4 ppm compared with 113.6 ppm in nonlaying hens. Femurs of drakes averaged 9.4 ppm lead. Dosage with the second lead shot did not result in further accumulation of bone lead in hens, but increased bone lead concentrations threefold in drakes, suggesting that saturation levels for bone lead had already been reached in the hens after ingestion of one shot. There was no demonstrable relationship between egg production and bone lead residues. The high lead residues, found in medullary bones of laying hens indicate that sex and physiological condition are major factors influencing lead absorption by bone.

  9. Magnetic Barkhausen Noise and Neutron Diffraction Techniques for the Study of Intergranular Residual Strains in Mild Steel

    SciTech Connect

    Hutanu, Roxana; Clapham, Lynann; Rogge, Ronald

    2004-02-26

    Intergranular residual stresses (IS) are microscopic residual stresses which have been found to accumulate along the <100> direction in steels. The <100> direction is also the magnetic easy axis direction in steel. This work involved Magnetic Barkhausen Noise (MBN) studies on steel samples, deformed uniaxially to increasing levels of strain. The MBN results indicated that a bulk magnetic easy axis was produced by the deformation process, and neutron diffraction experiments showed that this easy axis was correlated with the tensile strain in grains oriented in the <100> direction.

  10. Hydrothermal carbonization of agricultural residues.

    PubMed

    Oliveira, Ivo; Blöhse, Dennis; Ramke, Hans-Günter

    2013-08-01

    The work presented in this article addresses the application of hydrothermal carbonization (HTC) to produce a solid fuel named HTC-Biochar, whose characteristics are comparable to brown coal. Several batch HTC experiments were performed using agricultural residues (AR) as substrates, commonly treated in farm-based biogas plants in Germany. Different AR were used in different combinations with other biomass residues. The biogas potential from the resulting process water was also determined. The combination of different AR lead to the production of different qualities of HTC-Biochars as well as different mass and energy yields. Using more lignocellulosic residues lead to higher mass and energy yields for the HTC-Biochar produced. Whilst residues rich in carbohydrates of lower molecular weight such as corn silage and dough residues lead to the production of a HTC-Biochar of better quality and more similar to brown coal. Process water achieved a maximum of 16.3 L CH4/kg FM (fresh matter).

  11. Local flexibility facilitates oxidization of buried methionine residues.

    PubMed

    Xu, Kuiran; Uversky, Vladimir N; Xue, Bin

    2012-06-01

    In proteins, all amino acid residues are susceptible to oxidation by various reactive oxygen species (ROS), with methionine and cysteine residues being particularly sensitive to oxidation. Methionine oxidation is known to lead to destabilization and inactivation of proteins, and oxidatively modified proteins can accumulate during aging, oxidative stress, and in various age-related diseases. Although the efficiency of a given methionine oxidation can depend on its solvent accessibility (evaluated from a protein structure as the accessible surface area of the corresponding methionine residue), many experimental results on oxidation rate and oxidation sites cannot be unequivocally explained by the methionine solvent accessible surface area alone. In order to explore other possible mechanisms, we analyzed a set of seventy-one oxidized methionines contained in thirty-one proteins by various bioinformatics tools. In which, 41% of the methionines are exposed, 15% are buried but with various degree of flexibility, and the rest 44% are buried and structured. Buried but highly flexible methionines can be oxidized. Buried and less flexible methionines can acquire additional local structural flexibility from flanking regions to facilitate the oxidation. Oxidation of buried and structured methionine can also be promoted by the oxidation of neighboring methionine that is more exposed and/or flexible. Our data are consistent with the hypothesis that protein structural flexibility represents another important factor favoring the oxidation process.

  12. Bacterial communities established in bauxite residues with different restoration histories.

    PubMed

    Schmalenberger, Achim; O'Sullivan, Orla; Gahan, Jacinta; Cotter, Paul D; Courtney, Ronan

    2013-07-02

    Bauxite residue is the alkaline byproduct generated when alumina is extracted from bauxite ores and is commonly deposited in impoundments. These sites represent hostile environments with increased salinity and alkalinity and little prospect of revegetation when left untreated. This study reports the establishment of bacterial communities in bauxite residues with and without restoration amendments (compost and gypsum addition, revegetation) in samples taken in 2009 and 2011 from 0 to 10 cm depth. DNA fingerprint analysis of bacterial communities based on 16S rRNA gene fragments revealed a significant separation of the untreated site and the amended sites in both sampling years. 16S amplicon analysis (454 FLX pyrosequencing) revealed significantly lower alpha diversities in the unamended in comparison to the amended sites and hierarchical clustering separated the unamended site from the amended sites. The taxonomic analysis revealed that the restoration resulted in the accumulation of bacterial populations typical for soils including Acidobacteriaceae, Nitrosomonadaceae, and Caulobacteraceae. In contrast, the unamended site was dominated by taxonomic groups including Beijerinckiaceae, Xanthomonadaceae, Acetobacteraceae, and Chitinophagaceae, repeatedly associated with alkaline salt lakes and sediments. While bacterial communities developed in the initially sterile bauxite residue, only the restoration treatments created diverse soil-like bacterial communities alongside diverse vegetation on the surface.

  13. 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.

  14. Heat exchanger-accumulator

    DOEpatents

    Ecker, Amir L.

    1980-01-01

    What is disclosed is a heat exchanger-accumulator for vaporizing a refrigerant or the like, characterized by an upright pressure vessel having a top, bottom and side walls; an inlet conduit eccentrically and sealingly penetrating through the top; a tubular overflow chamber disposed within the vessel and sealingly connected with the bottom so as to define an annular outer volumetric chamber for receiving refrigerant; a heat transfer coil disposed in the outer volumetric chamber for vaporizing the liquid refrigerant that accumulates there; the heat transfer coil defining a passageway for circulating an externally supplied heat exchange fluid; transferring heat efficiently from the fluid; and freely allowing vaporized refrigerant to escape upwardly from the liquid refrigerant; and a refrigerant discharge conduit penetrating sealingly through the top and traversing substantially the length of the pressurized vessel downwardly and upwardly such that its inlet is near the top of the pressurized vessel so as to provide a means for transporting refrigerant vapor from the vessel. The refrigerant discharge conduit has metering orifices, or passageways, penetrating laterally through its walls near the bottom, communicating respectively interiorly and exteriorly of the overflow chamber for controllably carrying small amounts of liquid refrigerant and oil to the effluent stream of refrigerant gas.

  15. Chemistry of combined residual chlorination

    SciTech Connect

    Leao, S.F.; Selleck, R.E.

    1982-01-01

    The decay of the combined chlorine residual was investigated in this work. Recent concerns about the formation of undesirable compounds such as chloroform with free residual chlorination have focused attention on the alternative use of combined residual chlorination. This work investigates the applicability of reactions proposed to describe the transformations and decay of the combined residual with time. Sodium hypochlorite was added to buffered solutions of ammonia with the chlorine residual being monitored over periods extending up to 10 days. The reaction was studied at four initial concentrations of hypochlorite of 100, 50, 25 and 10 mg/L as Cl/sub 2/ with molar application ratios of chlorine to ammonia, defined herein as M ratios, of 0.90, 0.50, 0.25 and 0.05 at each hypochlorite dose. Sixty-eight experiments were conducted at the pH of 6.6 and 7.2. The conclusions are: (1) in the absence of free chlorine, the concentration of NH/sub 3/ does not seem to affect the rate of disappearance of the residual other than through the formation of NHCl/sub 2/ by NH/sub 2/Cl hydrolysis; (2) the reaction between NHCl/sub 2/ and NH/sub 4//sup +/ to form NH/sub 2/Cl is either much slower than reported by Gray et. al. or the mechanism is different with a rate limiting step not involving NH/sub 3/ or NH/sub 4//sup +/; (3) a redox reaction in addition to the first-order decomposition of NHCl/sub 2/ appears necessary. Model simulation results indicated that a reaction of the type NH/sub 2/Cl + NHCl/sub 2/ ..-->.. P added to the first-order NHCl/sub 2/ decomposition can explain the results observed except at the higher chlorine doses.

  16. Fate of phenanthrene and mineralization of its non-extractable residues in an oxic soil.

    PubMed

    Wang, Yongfeng; Xu, Jun; Shan, Jun; Ma, Yini; Ji, Rong

    2017-05-01

    The fate of organic pollutants in the environment, especially the formation and stability of non-extractable (i.e., bound) residues (NERs) determines their environmental risk. Using (14)C-tracers, we studied the fate of the carcinogen phenanthrene in active or sterilized oxic loamy soil in the absence and presence of the geophagous earthworm Metaphire guillelmi and characterized the NERs derived from phenanthrene. After incubation of (14)C-phenanthrene in active soil for 28 days, 40 ± 3.1% of the initial amount was mineralized and 70.1 ± 1.9% was converted to NERs. Most of the NERs (>92%) were bound to soil humin. Silylation of the humin-bound residues released 45.3 ± 5.3% of these residues, which indicated that they were physically entrapped, whereas the remainder of the residues were chemically bound or biogenic. By contrast, in sterilized soil, only 43.4 ± 12.6% of the phenanthrene was converted to NERs and all of these residues were completely released upon silylation, which underlines the essential role of microbial activity in NER formation. The presence of M. guillelmi in active soil significantly inhibited phenanthrene mineralization (24.4 ± 2.6% mineralized), but NER formation was not significantly affected. Only a small amount of phenanthrene-derived residues (1.9-5.3% of the initial amount) accumulated in the earthworm body. When humin-bound residues were mixed with fresh soil, 33.9% (humin recovered from active soils) and 12.4% (humin recovered from sterilized soils) of the residues were mineralized after 75 days of incubation, respectively, which indicated a high bioavailability of NERs, albeit lower than the initial addition of phenanthrene. Our results indicated that many phenanthrene-derived NERs, especially those physically entrapped, are still bioavailable and may pose a toxic threat to soil organisms.

  17. Chloroquine accumulation by purified plasma membranes from Plasmodium falciparum.

    PubMed

    Elandaloussi, Laurence M; Smith, Peter J

    2006-01-01

    Resistance of Plasmodium falciparum to chloroquine (CQ) has been associated with a decrease in CQ accumulation by parasitized erythrocytes. This study aimed at investigating the role of parasite plasma membranes (PPM) in the mechanism of CQ accumulation. CQ accumulation capabilities of membranes were determined using tritiated CQ. PPM isolated from chloroquine-sensitive parasites were found to accumulate less CQ than those isolated from chloroquine-resistant parasites. However, CQ accumulation was found to be ATP-independent suggesting that this accumulation results from binding rather than transport.

  18. Expression of a borage desaturase cDNA containing an N-terminal cytochrome b5 domain results in the accumulation of high levels of delta6-desaturated fatty acids in transgenic tobacco.

    PubMed

    Sayanova, O; Smith, M A; Lapinskas, P; Stobart, A K; Dobson, G; Christie, W W; Shewry, P R; Napier, J A

    1997-04-15

    gamma-Linolenic acid (GLA; C18:3 delta(6,9,12)) is a component of the seed oils of evening primrose (Oenothera spp.), borage (Borago officinalis L.), and some other plants. It is widely used as a dietary supplement and for treatment of various medical conditions. GLA is synthesized by a delta6-fatty acid desaturase using linoleic acid (C18:2 delta(9,12)) as a substrate. To enable the production of GLA in conventional oilseeds, we have isolated a cDNA encoding the delta6-fatty acid desaturase from developing seeds of borage and confirmed its function by expression in transgenic tobacco plants. Analysis of leaf lipids from a transformed plant demonstrated the accumulation of GLA and octadecatetraenoic acid (C18:4 delta(6,9,12,15)) to levels of 13.2% and 9.6% of the total fatty acids, respectively. The borage delta6-fatty acid desaturase differs from other desaturase enzymes, characterized from higher plants previously, by the presence of an N-terminal domain related to cytochrome b5.

  19. Processes of contaminant accumulation in an Arctic beluga whale population

    SciTech Connect

    Hickie, B.E.; Muir, D.; Kingsley, M.

    1995-12-31

    As long-lived top predators in marine food chains, marine mammals accumulate high levels of persistent organic contaminants. While arctic marine mammal contaminant concentrations are lower than those from temperate regions, levels are sufficiently high to be a health concern to people who rely on marine mammals as food. Monitoring programs developed to address this problem and to define spatial and temporal trends often are difficult to interpret since tissue contaminant concentrations vary with species, age, sex, reproductive effort, and condition (ie blubber thickness). It can be difficult to relate contaminant concentrations in other environmental compartments to those in marine mammals since their residues reflect exposure over their entire life, often 20 to 30 years. Contaminant accumulation models for marine mammals enable us to better understand the importance of, and interaction between, factors affecting contaminant accumulation, and can provide a dynamic framework for interpreting contaminant monitoring data. The authors developed two models for the beluga whale (Delphinapterus leucas): one provides a detailed view of processes at the individual level, the other examines population-based processes. The models quantify uptake, release and disposition of organic contaminants over their entire lifespan by incorporating all aspects of life-history. These models are used together to examine impact of a variety of factors on patterns and variability of PCBs found in the West Greenland beluga population (sample size: 696, 729). Factors examined include: energetics, growth, birth rate, lactation, contaminant assimilation and clearance rates, and dietary contaminant concentrations. Results are discussed in relation to the use of marine mammals for monitoring contaminant trends.

  20. Prospective long-term minimal residual disease monitoring using RQ-PCR in RUNX1-RUNX1T1-positive acute myeloid leukemia: results of the French CBF-2006 trial

    PubMed Central

    Willekens, Christophe; Blanchet, Odile; Renneville, Aline; Cornillet-Lefebvre, Pascale; Pautas, Cécile; Guieze, Romain; Ifrah, Norbert; Dombret, Hervé; Jourdan, Eric; Preudhomme, Claude; Boissel, Nicolas

    2016-01-01

    In t(8;21)(q22;q22) acute myeloid leukemia, the prognostic value of early minimal residual disease assessed with real-time quantitative polymerase chain reaction is the most important prognostic factor, but how long-term minimal residual disease monitoring may contribute to drive individual patient decisions remains poorly investigated. In the multicenter CBF-2006 study, a prospective monitoring of peripheral blood and bone marrow samples was performed every 3 months and every year, respectively, for 2 years following intensive chemotherapy in 94 patients in first complete remission. A complete molecular remission was defined as a (RUNX1-RUNX1T1/ABL1)×100 ≤ 0.001%. After the completion of consolidation therapy, a bone marrow complete molecular remission was observed in 30% of the patients, but was not predictive of subsequent relapse. Indeed, 8 patients (9%) presented a positive bone marrow minimal residual disease for up to 2 years of follow-up while still remaining in complete remission. Conversely, a peripheral blood complete molecular remission was statistically associated with a lower risk of relapse whatever the time-point considered after the completion of consolidation therapy. During the 2-year follow-up, the persistence of peripheral blood complete molecular remission was associated with a lower risk of relapse (4-year cumulative incidence, 8.2%), while molecular relapse confirmed on a subsequent peripheral blood sample predicted hematological relapse (4-year cumulative incidence, 86.9%) within a median time interval of 3.9 months. In t(8;21)(q22;q22) acute myeloid leukemia, minimal residual disease monitoring on peripheral blood every 3 months allows for the prediction of hematological relapse, and to identify patients who could potentially benefit from intervention therapy. PMID:26635039

  1. Non-local residue-residue contacts in proteins are more conserved than local ones.

    PubMed

    Noivirt-Brik, Orly; Hazan, Gershon; Unger, Ron; Ofran, Yanay

    2013-02-01

    Non-covalent residue-residue contacts drive the folding of proteins and stabilize them. They may be local-i.e. involve residues that are close in sequence, or non-local. It has been suggested that, in most proteins, local contacts drive protein folding by providing crucial constraints of the conformational space, thus allowing proteins to fold. We compared residues that are involved in local contacts to residues that are involved in non-local contacts and found that, in most proteins, residues in non-local contacts are significantly more conserved evolutionarily than residues in local contacts. Moreover, non-local contacts are more structurally conserved: a contact between positions that are distant in sequence is more likely to exist in many structural homologues compared with a contact between positions that are close in sequence. These results provide new insights into the mechanisms of protein folding and may allow for better prediction of critical intra-chain contacts.

  2. Multi-state complex angular momentum residues

    NASA Astrophysics Data System (ADS)

    Thylwe, Karl-Erik

    2006-09-01

    A relation between a multi-state complex angular momentum (CAM) pole residue and the corresponding CAM-state wavefunction is derived for a real symmetric potential matrix. The result generalizes a residue formula available for single-channel atomical collision systems and it is based on a diagonalization of the S matrix together with the use of exact Wronskian relations.

  3. The accumulation and structure of comets

    NASA Technical Reports Server (NTRS)

    Donn, Bertram

    1991-01-01

    The paper reviews evidence for the accumulation of the terrestrial planets and comets from solid grains, with emphasis on the various proposals for the formation of cometary nuclei. With three exceptions, all hypotheses conclude or imply that a single compact object forms. Several hypotheses start with Goldreich-Ward-type gravitational instabilities. The collapse for this case also occurs at low velocities in the cm/s to m/s range. Experiment and theory show that under these conditions, low-density, filamentary clusters form that are fractal aggregates with a fractal dimension approximately equal to 2. In order to form cometary nuclei, the initial temperature must be about 50 K and not undergo a significant temperature rise during the accumulation process. The calculations show that accumulation will occur at low temperatures. Models of cometary nuclei are reviewed, and a simple model of the structure that results fom the accumulation of fluffy aggregates is described.

  4. TENORM: Coal Combustion Residuals

    EPA Pesticide Factsheets

    Burning coal in boilers to create steam for power generation and industrial applications produces a number of combustion residuals. Naturally radioactive materials that were in the coal mostly end up in fly ash, bottom ash and boiler slag.

  5. Accumulation of Polyphosphate in Lactobacillus spp. and Its Involvement in Stress Resistance

    PubMed Central

    Alcántara, Cristina; Blasco, Amalia; Zúñiga, Manuel

    2014-01-01

    Polyphosphate (poly-P) is a polymer of phosphate residues synthesized and in some cases accumulated by microorganisms, where it plays crucial physiological roles such as the participation in the response to nutritional stringencies and environmental stresses. Poly-P metabolism has received little attention in Lactobacillus, a genus of lactic acid bacteria of relevance for food production and health of humans and animals. We show that among 34 strains of Lactobacillus, 18 of them accumulated intracellular poly-P granules, as revealed by specific staining and electron microscopy. Poly-P accumulation was generally dependent on the presence of elevated phosphate concentrations in the culture medium, and it correlated with the presence of polyphosphate kinase (ppk) genes in the genomes. The ppk gene from Lactobacillus displayed a genetic arrangement in which it was flanked by two genes encoding exopolyphosphatases of the Ppx-GppA family. The ppk functionality was corroborated by its disruption (LCABL_27820 gene) in Lactobacillus casei BL23 strain. The constructed ppk mutant showed a lack of intracellular poly-P granules and a drastic reduction in poly-P synthesis. Resistance to several stresses was tested in the ppk-disrupted strain, showing that it presented a diminished growth under high-salt or low-pH conditions and an increased sensitivity to oxidative stress. These results show that poly-P accumulation is a characteristic of some strains of lactobacilli and may thus play important roles in the physiology of these microorganisms. PMID:24375133

  6. Accumulation of polyphosphate in Lactobacillus spp. and its involvement in stress resistance.

    PubMed

    Alcántara, Cristina; Blasco, Amalia; Zúñiga, Manuel; Monedero, Vicente

    2014-03-01

    Polyphosphate (poly-P) is a polymer of phosphate residues synthesized and in some cases accumulated by microorganisms, where it plays crucial physiological roles such as the participation in the response to nutritional stringencies and environmental stresses. Poly-P metabolism has received little attention in Lactobacillus, a genus of lactic acid bacteria of relevance for food production and health of humans and animals. We show that among 34 strains of Lactobacillus, 18 of them accumulated intracellular poly-P granules, as revealed by specific staining and electron microscopy. Poly-P accumulation was generally dependent on the presence of elevated phosphate concentrations in the culture medium, and it correlated with the presence of polyphosphate kinase (ppk) genes in the genomes. The ppk gene from Lactobacillus displayed a genetic arrangement in which it was flanked by two genes encoding exopolyphosphatases of the Ppx-GppA family. The ppk functionality was corroborated by its disruption (LCABL_27820 gene) in Lactobacillus casei BL23 strain. The constructed ppk mutant showed a lack of intracellular poly-P granules and a drastic reduction in poly-P synthesis. Resistance to several stresses was tested in the ppk-disrupted strain, showing that it presented a diminished growth under high-salt or low-pH conditions and an increased sensitivity to oxidative stress. These results show that poly-P accumulation is a characteristic of some strains of lactobacilli and may thus play important roles in the physiology of these microorganisms.

  7. Accumulation of Deleterious Mutations on the Neo-Y Chromosome of Japan Sea Stickleback (Gasterosteus nipponicus).

    PubMed

    Yoshida, Kohta; Makino, Takashi; Kitano, Jun

    2017-01-01

    Degeneration of Y chromosomes is a common evolutionary path of XY sex chromosome systems. Recent genomic studies in flies and plants have revealed that even young neo-sex chromosomes with the age of a few million years show signs of Y degeneration, such as the accumulation of nonsense and frameshift mutations. However, it remains unclear whether neo-Y chromosomes also show rapid degeneration in fishes, which often have homomorphic sex chromosomes. Here, we investigated whether a neo-Y chromosome of Japan Sea stickleback (Gasterosteus nipponicus), which was formed by a Y-autosome fusion within the last 2 million years, accumulates deleterious mutations. Our previous genomic analyses did not detect excess nonsense and frameshift mutations on the Japan Sea stickleback neo-Y. In the present study, we found that the nonrecombining region of the neo-Y near the fusion end has accumulated nonsynonymous mutations altering amino acids of evolutionarily highly conserved residues. Enrichment of gene ontology terms related to protein phosphorylation and cellular protein modification process was found in the genes with potentially deleterious mutations on the neo-Y. These results suggest that the neo-Y of the Japan Sea stickleback has already accumulated mutations that may impair protein functions.

  8. Genetic associations of residual feed intake with serum insulin-like growth factor-I and leptin concentrations, meat quality, and carcass cross sectional fat area ratios in Duroc pigs.

    PubMed

    Hoque, M A; Katoh, K; Suzuki, K

    2009-10-01

    length, and last thoracic vertebra, respectively). Residual feed intake was strongly and positively correlated with all of the fat accumulation traits (ranging from 0.53 to 0.88). The results indicate that reducing residual feed intake (increased efficiency) would lead to increased cooking loss and darkness, and decreased serum leptin concentration, fat accumulations at the different sites, and seam fat at the 6th rib interface of pork carcasses.

  9. TENORM: Wastewater Treatment Residuals

    EPA Pesticide Factsheets

    Water and wastes which have been discharged into a municipal sewers are treated at wastewater treatment plants. These may contain both man-made and naturally occurring radionuclides which can accumulate in the treatment plant.

  10. EXPERIMENTAL METHODS TO ESTIMATE ACCUMULATED SOLIDS IN NUCLEAR WASTE TANKS

    SciTech Connect

    Duignan, M.; Steeper, T.; Steimke, J.

    2012-12-10

    The Department of Energy has a large number of nuclear waste tanks. It is important to know if fissionable materials can concentrate when waste is transferred from staging tanks prior to feeding waste treatment plants. Specifically, there is a concern that large, dense particles, e.g., plutonium containing, could accumulate in poorly mixed regions of a blend tank heel for tanks that employ mixing jet pumps. At the request of the DOE Hanford Tank Operations Contractor, Washington River Protection Solutions, the Engineering Development Laboratory of the Savannah River National Laboratory performed a scouting study in a 1/22-scale model of a waste tank to investigate this concern and to develop measurement techniques that could be applied in a more extensive study at a larger scale. Simulated waste tank solids and supernatant were charged to the test tank and rotating liquid jets were used to remove most of the solids. Then the volume and shape of the residual solids and the spatial concentration profiles for the surrogate for plutonium were measured. This paper discusses the overall test results, which indicated heavy solids only accumulate during the first few transfer cycles, along with the techniques and equipment designed and employed in the test. Those techniques include: Magnetic particle separator to remove stainless steel solids, the plutonium surrogate from a flowing stream; Magnetic wand used to manually remove stainless steel solids from samples and the tank heel; Photographs were used to determine the volume and shape of the solids mounds by developing a composite of topographical areas; Laser rangefinders to determine the volume and shape of the solids mounds; Core sampler to determine the stainless steel solids distribution within the solids mounds; Computer driven positioner that placed the laser rangefinders and the core sampler over solids mounds that accumulated on the bottom of a scaled staging tank in locations where jet velocities were low. These

  11. Geomorphic control of landscape carbon accumulation

    USGS Publications Warehouse

    Rosenbloom, N.A.; Harden, J.W.; Neff, J.C.; Schimel, D.S.

    2006-01-01

    We use the CREEP process-response model to simulate soil organic carbon accumulation in an undisturbed prairie site in Iowa. Our primary objectives are to identify spatial patterns of carbon accumulation, and explore the effect of erosion on basin-scale C accumulation. Our results point to two general findings. First, redistribution of soil carbon by erosion results in a net increase in basin-wide carbon storage relative to a noneroding environment. Landscape-average mean residence times are increased in an eroding landscape owing to the burial/preservation of otherwise labile C. Second, field observations taken along a slope transect may overlook significant intraslope variations in carbon accumulation. Spatial patterns of modeled deep C accumulation are complex. While surface carbon with its relatively short equilibration time is predictable from surface properties, deep carbon is strongly influenced by the landscape's geomorphic and climatic history, resulting in wide spatial variability. Convergence and divergence associated with upland swales and interfluves result in bimodal carbon distributions in upper and mid slopes; variability in carbon storage within modeled mid slopes was as high as simulated differences between erosional shoulders and depositional valley bottoms. The bimodality of mid-slope C variability in the model suggests that a three-dimensional sampling strategy is preferable over the traditional two-dimensional analog or "catena" approach. Copyright 2006 by the American Geophysical Union.

  12. Partitioning Residue-derived and Residue-induced Emissions of N2O Using 15N-labelled Crop Residues

    NASA Astrophysics Data System (ADS)

    Farrell, R. E.; Carverhill, J.; Lemke, R.; Knight, J. D.

    2014-12-01

    Estimates of N2O emissions in Canada indicate that 17% of all agriculture-based emissions are associated with the decomposition of crop residues. However, research specific to the western Canadian prairies (including Saskatchewan) has shown that the N2O emission factor for N sources in this region typically ranges between 0.2 and 0.6%, which is well below the current IPCC default emission factor of 1.0%. Thus, it stands to reason that emissions from crop residues should also be lower than those calculated using the current IPCC emission factor. Current data indicates that residue decomposition, N mineralization and N2O production are affected by a number of factors such as C:N ratio and chemical composition of the residue, soil type, and soil water content; thus, a bench-scale incubation study was conducted to examine the effects of soil type and water content on N2O emissions associated with the decomposition of different crop residues. The study was carried out using soils from the Black, Dark Brown, Brown, and Gray soil zones and was conducted at both 50% and 70% water-filled pore space (WFPS); the soils were amended with 15N-labeled residues of wheat, pea, canola, and flax, or with an equivalent amount of 15N-labeled urea; 15N2O production was monitored using a Picarro G5101-i isotopic N2O analyzer. Crop residue additions to the soils resulted in both direct and indirect emissions of N2O, with residue derived emissions (RDE; measured as 15N2O) generally exceeding residue-induced emissions (RIE) at 50% WFPS—with RDEs ranging from 42% to 88% (mean = 58%) of the total N2O. Conversely, at 70% WFPS, RDEs were generally lower than RIEs—ranging from 21% to 83% (mean = 48%). Whereas both water content and soil type had an impact on N2O production, there was a clear and consistent trend in the emission factors for the residues; i.e., emissions were always greatest for the canola residue and lowest for the wheat residue and urea fertilizer; and intermediate for pea

  13. Mineralogical and geochemical features of human body ash residue of spatially-localized technogenic system (Norilsk city)

    NASA Astrophysics Data System (ADS)

    Rikhvanov, L. P.; Deriglazova, M. A.; Baranovskaya, N. V.; Matveenko, I. A.

    2016-09-01

    The paper presents the information on the element and mineral composition of the human body ash residue of Norilsk residents. The data are obtained by such methods as X-ray analysis, inductively coupled plasma mass spectrometry, and electron microscopy. This research has identified the content of 47 elements, 17 of which have their own mineral phases. Besides, the estimation of average content of chemical elements in terms of sex and correlation analysis of the data was conducted in this research. The final results indicate the influence of Norilsk industry on the element and mineral composition of ash residue. For example, the accumulation of such elements as Zr, Al, Ca, Y, some rare earth, and radioactive elements has been observed in the human body ash residue of Norilsk residents. The presence of Ag, Au, Pt microphases and numerous compounds of Cu, Ni etc. was detected among all mineral phases.

  14. Residual strength and crack propagation tests on C-130 airplane center wings with service-imposed fatigue damage

    NASA Technical Reports Server (NTRS)

    Snider, H. L.; Reeder, F. L.; Dirkin, W. J.

    1972-01-01

    Fourteen C-130 airplane center wings, each containing service-imposed fatigue damage resulting from 4000 to 13,000 accumulated flight hours, were tested to determine their fatigue crack propagation and static residual strength characteristics. Eight wings were subjected to a two-step constant amplitude fatigue test prior to static testing. Cracks up to 30 inches long were generated in these tests. Residual static strengths of these wings ranged from 56 to 87 percent of limit load. The remaining six wings containing cracks up to 4 inches long were statically tested as received from field service. Residual static strengths of these wings ranged from 98 to 117 percent of limit load. Damage-tolerant structural design features such as fastener holes, stringers, doublers around door cutouts, and spanwise panel splices proved to be effective in retarding crack propagation.

  15. Glyphosate fate in soils when arriving in plant residues.

    PubMed

    Mamy, Laure; Barriuso, Enrique; Gabrielle, Benoît

    2016-07-01

    A significant fraction of pesticides sprayed on crops may be returned to soils via plant residues, but its fate has been little documented. The objective of this work was to study the fate of glyphosate associated to plants residues. Oilseed rape was used as model plant using two lines: a glyphosate-tolerant (GT) line and a non-GT one, considered as a crucifer weed. The effects of different fragmentation degrees and placements in soil of plant residues were tested. A control was set up by spraying glyphosate directly on the soil. The mineralization of glyphosate in soil was slower when incorporated into plant residues, and the amounts of extractable and non-extractable glyphosate residues increased. Glyphosate availability for mineralization increased when the size of plant residues decreased, and as the distribution of plant residues in soil was more homogeneous. After 80 days of soil incubation, extractable (14)C-residues mostly involved one metabolite of glyphosate (AMPA) but up to 2.6% of initial (14)C was still extracted from undecayed leaves as glyphosate. Thus, the trapping of herbicides in plant materials provided a protection against degradation, and crops residues returns may increase the persistence of glyphosate in soils. This pattern appeared more pronounced for GT crops, which accumulated more non-degraded glyphosate in their tissues.

  16. Detection of radioactive accumulations within an incinerator

    SciTech Connect

    Schoenig, F.C. Jr.; Grossman, L.N.

    1986-03-25

    This patent describes an incinerator for burning combustible material contaminated by radiation. This incinerator has a combustion chamber having containment walls of high density refractory brick provided with at least one window opening through the high density refractory brick containment walls. The window consists of a low density body of ceramic fibers. Any radiation from residual radioactive ash within the incinerator containment and inhibited by the high density refractory brick can penetrate outward through the window of low density fiber to beyond the incinerator containment walls. A radiation detector is mounted outside the incinerator containment walls adjacent to the window of low density ceramic fiber for measuring any radiation passing out from the combustion chamber through the low density window. The amount of retained radioactive ash accumulated in the incinerator combustion chamber is indicated on the detector.

  17. THE RELATIONSHIP OF BIOACCUMULATIVE CHEMICALS IN WATER AND SEDIMENT TO RESIDUES IN FISH: A VISUALIZATION APPROACH

    EPA Science Inventory

    A visualization approach is developed and presented for depicting and interpreting bioaccumulation relationships and data, i.e., bioaccumulation factors (BAFs), biota-sediment accumulation factors (BSAFs) and chemical residues in fish, using water-sediment chemical concentration ...

  18. Pesticide residue in water--a challenging task in India.

    PubMed

    Agarwal, Akriti; Prajapati, Rajmani; Singh, Om Pal; Raza, S K; Thakur, L K

    2015-02-01

    Modern agriculture practices reveal an increase in use of pesticides to meet the food demand of increasing population which results in contamination of the environment. In India, crop production increased to 100 %, but the cropping area has increased marginally by 20 %. Pesticides have played a major role in achieving the maximum crop production but maximum usage and accumulation of pesticide residues is highly detrimental to aquatic and other ecosystem. Pesticide residues in drinking water have become a major challenge over the last few years. It has been monitored in public water supply resources in National capital territory, i.e., Delhi. Organochlorine pesticides (OCPs), mainly isomers of hexachlorohexane (HCH), dichloro-diphenyl-trichloroethane (DDT), endosulphan, endrin, aldrin, dieldrin, and heptachlore, were identified from potable water samples. Results suggested that continuous consumption of contaminated water can pose severe health threats to local residents of this area. Central Pollution Control Board (CPCB), Delhi, had found α and β isomers of endosulphan residues in the Yamuna river. High concentrations of γ-HCH (0.259 μg/l) and malathion (2.618 μg/l) were detected in the surface water samples collected from the river Ganga in Kanpur, Uttar Pradesh (UP). High concentration of methyl parathion, endosulfan, and DDT were observed in water samples collected from the river at Bhagalpur, Bihar. The Industrial Toxicology Research Centre (ITRC), Lucknow (UP) study also found 0.5671 ppb concentrations of endosulfan in the river at Allahabad, UP. Similar results were found in other water samples in India.

  19. Residues of veterinary drugs at injection sites.

    PubMed

    Reeves, P T

    2007-02-01

    Residues of veterinary drugs have potential implications for human food safety and international trade in animal-derived food commodities. A particular concern is the slow depletion of residues of some injectable formulations from the site of administration. Licensing authorities have adopted different approaches to the human food safety assessment of injection site residues. European agencies apply the maximum residue limit (MRL) for muscle to muscle at the injection site and specify a withdrawal period sufficient to ensure the ingestion of a 300 g portion of muscle, if comprised entirely of injection site tissue, does not exceed the acceptable daily intake. The agencies in Australia, Canada and the USA also exclude injection site residues from the MRL-setting process. These agencies evaluate the risk to consumers posed by potential acute manifestations resulting from the infrequent ingestion of injection site residues based on acute dietary exposure considerations. While all of these approaches protect the safety of consumers, the adoption of different approaches has potential implications for residue surveillance programs in the international trade in meat. In particular, when an exporting country establishes standards for residues at injection sites based on acute dietary exposure considerations and the importing country assesses these residues against the MRL for muscle, the unnecessary condemnation of meat and disruption to market access may result. The latter may represent a potential economical impost to the exporting country. An internationally harmonized approach to the risk analysis of residues of veterinary drugs at injection sites, which protects the safety of consumers and facilitates the international trade in meat, is needed.

  20. Evaluation of resource recovery from waste incineration residues--the case of zinc.

    PubMed

    Fellner, J; Lederer, J; Purgar, A; Winterstetter, A; Rechberger, H; Winter, F; Laner, D

    2015-03-01

    Solid residues generated at European Waste to Energy plants contain altogether about 69,000 t/a of Zn, of which more than 50% accumulates in air pollution control residues, mainly boiler and filter ashes. Intensive research activities aiming at Zn recovery from such residues recently resulted in a technical scale Zn recovery plant at a Swiss waste incinerator. By acidic leaching and subsequent electrolysis this technology (FLUREC) allows generating metallic Zn of purity>99.9%. In the present paper the economic viability of the FLUREC technology with respect to Zn recovery from different solid residues of waste incineration has been investigated and subsequently been categorised according to the mineral resource classification scheme of McKelvey. The results of the analysis demonstrate that recovery costs for Zn are highly dependent on the costs for current fly ash disposal (e.g. cost for subsurface landfilling). Assuming current disposal practice costs of 220€/ton fly ash, resulting recovery costs for Zn are generally higher than its current market price of 1.6€/kg Zn. With respect to the resource classification this outcome indicates that none of the identified Zn resources present in incineration residues can be economically extracted and thus cannot be classified as a reserve. Only for about 4800 t/a of Zn an extraction would be marginally economic, meaning that recovery costs are only slightly (less than 20%) higher than the current market price for Zn. For the remaining Zn resources production costs are between 1.5 and 4 times (7900 t/a Zn) and 10-80 times (55,300 t/a Zn) higher than the current market value. The economic potential for Zn recovery from waste incineration residues is highest for filter ashes generated at grate incinerators equipped with wet air pollution control.

  1. Effects of residual disinfectant on soil and lettuce crop irrigated with chlorinated water.

    PubMed

    Lonigro, A; Montemurro, N; Laera, G

    2017-04-15

    The accidental or continuous release of residual chlorine in water reclaimed for irrigational purposes could compromise the crop yield and increase the load of toxic organo-halogenated compounds, posing additional risks for environment and human health. This study was aimed at assessing the consequences of using chlorinated water for irrigating lettuce crops grown in pots with two different types of soil. The results show that the accumulation of extractable organo-halogenated compounds (EOX) in soil, roots and leaves is directly related to the chlorine concentration in the irrigation water. The accumulation of EOX in sandy soils is not significant, while it reached up to 300% of the control in the silty-clay soil, demonstrating that the phenomenon is linked to the organic matter content in the soil. The accumulation of EOX in the soil appears to play a significant role in subsequent bioaccumulation in cultures irrigated with tap water (long term memory effect). Chloramines also demonstrated to have similar impacts as the free chlorine from hypochlorite. The consistent bioaccumulation of 400-700μgClkg(-1) of EOX in the leaves of crops irrigated with just 0.2mgClL(-1) of residual chlorine, as compared to levels below the detection limit of 75μgClkg(-1) in the control crops, evidences the potential impact on food chain and human health.

  2. Organochlorine and PCB residues in Lake Erie mink populations

    SciTech Connect

    Proulx, G.; Weseloh, D.V.C.; Elliott, J.E.; Teeple, S.; Anghern, P.A.M.; Mineau, P.

    1987-12-01

    PCB poisoning has been found in mink (Mustela vison) fed on Great Lakes fish but is poorly know for wild mink populations. The objective of this study was to determine whether mink from the Lake Erie basin were accumulating levels of PCB and organochlorine residues high enough to cause health effects

  3. Organochlorine residues in northeaster Alberta otters

    SciTech Connect

    Somers, J.D.; Goski, B.C.; Barrett, M.W.

    1987-11-01

    The use of organochlorine pesticides in North America has for the most part been legislatively curtailed during the last decade, and North American production of polychlorinated biphenyls (PCS's) was stopped in the 1970's. However, monitoring of chemical residues in fish and wildlife indicates that these persistent compound are still much in evidence throughout North America. Data on chemical residues in Alberta wildlife, particularly non-migratory species, is for the most part unknown. Otters (Lutra canadensis) are consumers of fish, invertebrates, amphibians and small mammals cohabiting their aquatic habitat. As carnivores at the terminus of their respective food chains, semi-aquatic mammals such as otter and mink (Mustela vison) may be expected to accumulate pesticides, PCBs and heavy metals. Otters are relatively sedentary and monitoring of chemical residues in their tissues might yield a diverse contaminant profile unique to the specific environs from which the animals are collected. The purpose of this report is to present chemical residue data for otters collected from aquatic habitats in northeastern Alberta.

  4. Noise Reduction by Signal Accumulation

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2006-01-01

    The aim of this paper is to show how the noise reduction by signal accumulation can be accomplished with a data acquisition system. This topic can be used for student projects. In many cases, the noise reduction is an unavoidable part of experimentation. Several techniques are known for this purpose, and among them the signal accumulation is the…

  5. Oral inoculation of neonatal Suffolk sheep with the agent of classical scrapie results in PrP(Sc) accumulation in sheep with the PRNP ARQ/ARQ but not the ARQ/ARR genotype.

    PubMed

    Greenlee, Justin J; Smith, Jodi D; Hamir, Amir N

    2016-04-01

    Scrapie is a transmissible spongiform encephalopathy that can be transmitted amongst susceptible sheep. The prion protein gene (PRNP) profoundly influences the susceptibility of sheep to the scrapie agent. This study reports the failure to detect PrP(Sc) in nervous or lymphoid tissues of Suffolk sheep of the PRNP ARQ/ARR genotype after oral inoculation with a U.S. scrapie isolate. Lambs were inoculated within the first 24 h of birth with 1 ml of a 10% (wt./vol.) brain homogenate derived from a clinically affected ARQ/ARQ sheep. The inoculated sheep were observed daily throughout the experiment for clinical signs suggestive of scrapie until they were necropsied at 86 months post inoculation. Tissues were collected for examination by immunohistochemistry and enzyme immunoassay, but all failed to demonstrate evidence of scrapie infection. Neonatal sheep of the ARQ/ARQ genotype receiving the same inoculum developed scrapie within 24 months. Lambs of the ARQ/ARR genotype that received the same inoculum by intracranial inoculation develop scrapie with a prolonged incubation period and with abnormal prion present within the central nervous system, but not peripheral lymphoid tissues. Results of this study suggest that ARQ/ARR sheep are resistant to oral infection with the scrapie isolate used even during the neonatal period.

  6. On the structural context and identification of enzyme catalytic residues.

    PubMed

    Chien, Yu-Tung; Huang, Shao-Wei

    2013-01-01

    Enzymes play important roles in most of the biological processes. Although only a small fraction of residues are directly involved in catalytic reactions, these catalytic residues are the most crucial parts in enzymes. The study of the fundamental and unique features of catalytic residues benefits the understanding of enzyme functions and catalytic mechanisms. In this work, we analyze the structural context of catalytic residues based on theoretical and experimental structure flexibility. The results show that catalytic residues have distinct structural features and context. Their neighboring residues, whether sequence or structure neighbors within specific range, are usually structurally more rigid than those of noncatalytic residues. The structural context feature is combined with support vector machine to identify catalytic residues from enzyme structure. The prediction results are better or comparable to those of recent structure-based prediction methods.

  7. On the Structural Context and Identification of Enzyme Catalytic Residues

    PubMed Central

    Chien, Yu-Tung; Huang, Shao-Wei

    2013-01-01

    Enzymes play important roles in most of the biological processes. Although only a small fraction of residues are directly involved in catalytic reactions, these catalytic residues are the most crucial parts in enzymes. The study of the fundamental and unique features of catalytic residues benefits the understanding of enzyme functions and catalytic mechanisms. In this work, we analyze the structural context of catalytic residues based on theoretical and experimental structure flexibility. The results show that catalytic residues have distinct structural features and context. Their neighboring residues, whether sequence or structure neighbors within specific range, are usually structurally more rigid than those of noncatalytic residues. The structural context feature is combined with support vector machine to identify catalytic residues from enzyme structure. The prediction results are better or comparable to those of recent structure-based prediction methods. PMID:23484160

  8. Resistance to and Accumulation of Heavy Metals by Actinobacteria Isolated from Abandoned Mining Areas

    PubMed Central

    El Baz, Soraia; Baz, Mohamed; El Gharmali, Abdelhay; Imziln, Boujamâa

    2015-01-01

    Accumulation of high concentrations of heavy metals in environments can cause many human health risks and serious ecological problems. Nowadays, bioremediation using microorganisms is receiving much attention due to their good performance. The aim of this work is to investigate heavy metals resistance and bioaccumulation potential of actinobacteria strains isolated from some abandoned mining areas. Analysis of mining residues revealed that high concentration of zinc “Zn” was recorded in Sidi Bouatman, Arbar, and Bir Nhass mining residues. The highest concentration of lead “Pb” was found in Sidi Bouatman. Copper “Cu,” cadmium “Cd,” and chromium “Cr” were found with moderate and low concentrations. The resistance of 59 isolated actinobacteria to the five heavy metals was also determined. Using molecular identification 16S rRNA, these 27 isolates were found to belong to Streptomyces and Amycolatopsis genera. The results showed different levels of heavy metal resistance; the minimum inhibitory concentration (MIC) recorded was 0.55 for Pb, 0.15 for Cr, and 0.10 mg·mL−1 for both Zn and Cu. Chemical precipitation assay of heavy metals using hydrogen sulfide technic (H2S) revealed that only 27 isolates have a strong ability to accumulate Pb (up to 600 mg of Pb per g of biomass for Streptomyces sp. BN3). PMID:25763383

  9. Residue contact-count potentials are as effective as residue-residue contact-type potentials for ranking protein decoys

    PubMed Central

    Bolser, Dan M; Filippis, Ioannis; Stehr, Henning; Duarte, Jose; Lappe, Michael

    2008-01-01

    Background For over 30 years potentials of mean force have been used to evaluate the relative energy of protein structures. The most commonly used potentials define the energy of residue-residue interactions and are derived from the empirical analysis of the known protein structures. However, single-body residue 'environment' potentials, although widely used in protein structure analysis, have not been rigorously compared to these classical two-body residue-residue interaction potentials. Here we do not try to combine the two different types of residue interaction potential, but rather to assess their independent contribution to scoring protein structures. Results A data set of nearly three thousand monomers was used to compare pairwise residue-residue 'contact-type' propensities to single-body residue 'contact-count' propensities. Using a large and standard set of protein decoys we performed an in-depth comparison of these two types of residue interaction propensities. The scores derived from the contact-type and contact-count propensities were assessed using two different performance metrics and were compared using 90 different definitions of residue-residue contact. Our findings show that both types of score perform equally well on the task of discriminating between near-native protein decoys. However, in a statistical sense, the contact-count based scores were found to carry more information than the contact-type based scores. Conclusion Our analysis has shown that the performance of either type of score is very similar on a range of different decoys. This similarity suggests a common underlying biophysical principle for both types of residue interaction propensity. However, several features of the contact-count based propensity suggests that it should be used in preference to the contact-type based propensity. Specifically, it has been shown that contact-counts can be predicted from sequence information alone. In addition, the use of a single-body term allows

  10. Phosphorylation of K+ channels at single residues regulates memory formation

    PubMed Central

    Vernon, Jeffrey; Irvine, Elaine E.; Peters, Marco; Jeyabalan, Jeshmi

    2016-01-01

    Phosphorylation is a ubiquitous post-translational modification of proteins, and a known physiological regulator of K+ channel function. Phosphorylation of K+ channels by kinases has long been presumed to regulate neuronal processing and behavior. Although circumstantial evidence has accumulated from behavioral studies of vertebrates and invertebrates, the contribution to memory of single phosphorylation sites on K+ channels has never been reported. We have used gene targeting in mice to inactivate protein kinase A substrate residues in the fast-inactivating subunit Kv4.2 (T38A mutants), and in the small-conductance Ca2+-activated subunit SK1 (S105A mutants). Both manipulations perturbed a specific form of memory, leaving others intact. T38A mutants had enhanced spatial memory for at least 4 wk after training, whereas performance in three tests of fear memory was unaffected. S105A mutants were impaired in passive avoidance memory, sparing fear, and spatial memory. Together with recent findings that excitability governs the participation of neurons in a memory circuit, this result suggests that the memory type supported by neurons may depend critically on the phosphorylation of specific K+ channels at single residues. PMID:26980786

  11. [Residual risk: The roles of triglycerides and high density lipoproteins].

    PubMed

    Grammer, Tanja; Kleber, Marcus; Silbernagel, Günther; Scharnagl, Hubert; März, Winfried

    2016-06-01

    In clinical trials, the reduction of LDL-cholesterol (LDL-C) with statins reduces the incidence rate of cardiovascular events by approximately one third. This means, that a sizeable "residual risk" remains. Besides high lipoprotein (a), disorders in the metabolism of triglyceride-rich lipoproteins and high density liproteins have been implicated as effectors of the residual risk. Both lipoprotein parameters correlate inversely with each other. Therefore, the etiological contributions of triglycerides and / or of HDL for developing cardiovascular disease can hardly be estimated from either observational studies or from intervention studies. The largely disappointing results of intervention studies with inhibitors of the cholesteryl ester transfer protein and in particular the available set of genetically-epidemiological studies suggest that in the last decade, the importance of HDL cholesterol has been overvalued, while the importance of triglycerides has been underestimated. High triglycerides not always atherogenic, but only if they are associated with the accumulation relatively cholesterol-enriched, incompletely catabolized remnants of chylomicrons and very low density lipoproteins (familial type III hyperlipidemia, metabolic syndrome, diabetes mellitus). The normalization of the concentration of triglycerides and remnants by inhibiting the expression of apolipoprotein C3 is hence a new, promising therapeutic target.

  12. Sequential biases in accumulating evidence

    PubMed Central

    Huggins, Richard; Dogo, Samson Henry

    2015-01-01

    Whilst it is common in clinical trials to use the results of tests at one phase to decide whether to continue to the next phase and to subsequently design the next phase, we show that this can lead to biased results in evidence synthesis. Two new kinds of bias associated with accumulating evidence, termed ‘sequential decision bias’ and ‘sequential design bias’, are identified. Both kinds of bias are the result of making decisions on the usefulness of a new study, or its design, based on the previous studies. Sequential decision bias is determined by the correlation between the value of the current estimated effect and the probability of conducting an additional study. Sequential design bias arises from using the estimated value instead of the clinically relevant value of an effect in sample size calculations. We considered both the fixed‐effect and the random‐effects models of meta‐analysis and demonstrated analytically and by simulations that in both settings the problems due to sequential biases are apparent. According to our simulations, the sequential biases increase with increased heterogeneity. Minimisation of sequential biases arises as a new and important research area necessary for successful evidence‐based approaches to the development of science. © 2015 The Authors. Research Synthesis Methods Published by John Wiley & Sons Ltd. PMID:26626562

  13. Simple approach for ranking structure determining residues.

    PubMed

    Luna-Martínez, Oscar D; Vidal-Limón, Abraham; Villalba-Velázquez, Miryam I; Sánchez-Alcalá, Rosalba; Garduño-Juárez, Ramón; Uversky, Vladimir N; Becerril, Baltazar

    2016-01-01

    Mutating residues has been a common task in order to study structural properties of the protein of interest. Here, we propose and validate a simple method that allows the identification of structural determinants; i.e., residues essential for preservation of the stability of global structure, regardless of the protein topology. This method evaluates all of the residues in a 3D structure of a given globular protein by ranking them according to their connectivity and movement restrictions without topology constraints. Our results matched up with sequence-based predictors that look up for intrinsically disordered segments, suggesting that protein disorder can also be described with the proposed methodology.

  14. Simple approach for ranking structure determining residues

    PubMed Central

    Luna-Martínez, Oscar D.; Vidal-Limón, Abraham; Villalba-Velázquez, Miryam I.; Sánchez-Alcalá, Rosalba; Garduño-Juárez, Ramón; Uversky, Vladimir N.

    2016-01-01

    Mutating residues has been a common task in order to study structural properties of the protein of interest. Here, we propose and validate a simple method that allows the identification of structural determinants; i.e., residues essential for preservation of the stability of global structure, regardless of the protein topology. This method evaluates all of the residues in a 3D structure of a given globular protein by ranking them according to their connectivity and movement restrictions without topology constraints. Our results matched up with sequence-based predictors that look up for intrinsically disordered segments, suggesting that protein disorder can also be described with the proposed methodology. PMID:27366642

  15. Geotechnical characteristics of residual soils

    SciTech Connect

    Townsend, F.C.

    1985-01-01

    Residual soils are products of chemical weathering and thus their characteristics are dependent upon environmental factors of climate, parent material, topography and drainage, and age. These conditions are optimized in the tropics where well-drained regions produce reddish lateritic soils rich in iron and aluminum sesquioxides and kaolinitic clays. Conversely, poorly drained areas tend towards montmorillonitic expansive black clays. Andosols develop over volcanic ash and rock regions and are rich in allophane (amorphous silica) and metastable halloysite. The geological origins greatly affect the resulting engineering characteristics. Both lateritic soils and andosols are susceptible to property changes upon drying, and exhibit compaction and strength properties not indicative of their classification limits. Both soils have been used successfully in earth dam construction, but attention must be given to seepage control through the weathered rock. Conversely, black soils are unpopular for embankments. Lateritic soils respond to cement stabilization and, in some cases, lime stabilization. Andosols should also respond to lime treatment and cement treatments if proper mixing can be achieved. Black expansive residual soils respond to lime treatment by demonstrating strength gains and decreased expansiveness. Rainfall induced landslides are typical of residual soil deposits.

  16. Cohabitation history, marriage, and wealth accumulation.

    PubMed

    Vespa, Jonathan; Painter, Matthew A

    2011-08-01

    This study extends research on the relationship between wealth accumulation and union experiences, such as marriage and cohabitation. Using data from the National Longitudinal Survey of Youth 1979, we explore the wealth trajectories of married individuals in light of their premarital cohabitation histories. Over time, marriage positively correlates with wealth accumulation. Most married persons with a premarital cohabitation history have wealth trajectories that are indistinguishable from those without cohabitation experience, with one exception: individuals who marry their one and only cohabiting partner experience a wealth premium that is twice as large as that for married individuals who never cohabited prior to marrying. Results remain robust over time despite cohabiters' selection out of marriage, yet vary by race/ethnicity. We conclude that relationship history may shape long-term wealth accumulation, and contrary to existing literature, individuals who marry their only cohabiting partners experience a beneficial marital outcome. It is therefore important to understand the diversity of cohabitation experiences among the married.

  17. Ordinary differential equation for local accumulation time.

    PubMed

    Berezhkovskii, Alexander M

    2011-08-21

    Cell differentiation in a developing tissue is controlled by the concentration fields of signaling molecules called morphogens. Formation of these concentration fields can be described by the reaction-diffusion mechanism in which locally produced molecules diffuse through the patterned tissue and are degraded. The formation kinetics at a given point of the patterned tissue can be characterized by the local accumulation time, defined in terms of the local relaxation function. Here, we show that this time satisfies an ordinary differential equation. Using this equation one can straightforwardly determine the local accumulation time, i.e., without preliminary calculation of the relaxation function by solving the partial differential equation, as was done in previous studies. We derive this ordinary differential equation together with the accompanying boundary conditions and demonstrate that the earlier obtained results for the local accumulation time can be recovered by solving this equation.

  18. Accumulation of DNA Double-Strand Breaks in Normal Tissues After Fractionated Irradiation

    SciTech Connect

    Ruebe, Claudia E.

    2010-03-15

    Purpose: There is increasing evidence that genetic factors regulating the recognition and/or repair of DNA double-strand breaks (DSBs) are responsible for differences in radiosensitivity among patients. Genetically defined DSB repair capacities are supposed to determine patients' individual susceptibility to develop adverse normal tissue reactions after radiotherapy. In a preclinical murine model, we analyzed the impact of different DSB repair capacities on the cumulative DNA damage in normal tissues during the course of fractionated irradiation. Material and Methods: Different strains of mice with defined genetic backgrounds (SCID{sup -/-} homozygous, ATM{sup -/-} homozygous, ATM{sup +/-}heterozygous, and ATM{sup +/+}wild-type mice) were subjected to single (2 Gy) or fractionated irradiation (5 x 2 Gy). By enumerating gammaH2AX foci, the formation and rejoining of DSBs were analyzed in organs representative of both early-responding (small intestine) and late-responding tissues (lung, kidney, and heart). Results: In repair-deficient SCID{sup -/-} and ATM{sup -/-}homozygous mice, large proportions of radiation-induced DSBs remained unrepaired after each fraction, leading to the pronounced accumulation of residual DNA damage after fractionated irradiation, similarly visible in early- and late-responding tissues. The slight DSB repair impairment of ATM{sup +/-}heterozygous mice was not detectable after single-dose irradiation but resulted in a significant increase in unrepaired DSBs during the fractionated irradiation scheme. Conclusions: Radiation-induced DSBs accumulate similarly in acute- and late-responding tissues during fractionated irradiation, whereas the whole extent of residual DNA damage depends decisively on the underlying genetically defined DSB repair capacity. Moreover, our data indicate that even minor impairments in DSB repair lead to exceeding DNA damage accumulation during fractionated irradiation and thus may have a significant impact on normal

  19. Gypsum accumulation on carbonate stone

    USGS Publications Warehouse

    McGee, E.S.; Mossotti, V.G.

    1992-01-01

    The accumulation of gypsum on carbonate stone has been investigated through exposure of fresh samples of limestone and marble at monitored sites, through examination of alteration crusts from old buildings and through laboratory experiments. Several factors contribute to gypsum accumulation on carbonate stone. Marble or limestone that is sheltered from direct washing by rain in an urban environment with elevated pollution levels is likely to accumulate a gypsum crust. Crust development may be enhanced if the stone is porous or has an irregular surface area. Gypsum crusts are a surficial alteration feature; gypsum crystals form at the pore opening-air interface, where evaporation is greatest.

  20. Strain accumulation in quasicrystalline solids

    NASA Technical Reports Server (NTRS)

    Nori, Franco; Ronchetti, Marco; Elser, Veit

    1988-01-01

    The relaxation of two-dimensional quasicrystalline elastic networks when their constituent bonds are perturbed homogeneously is studied. Whereas ideal, quasi-periodic networks are stable against such perturbations, significant accumulations of strain in a class of disordered networks generated by a growth process are found. The grown networks are characterized by root mean square phason fluctuations which grow linearly with system size. The strain accumulation observed in these networks also grows linearly with system size. Finally, dependence of strain accumulation on cooling rate is found.

  1. [Biosynthesis and accumulation of poly(3-hydroxybutyrate) in Vibrio natriegens].

    PubMed

    Liu, Shuang-Jiang

    2002-09-01

    Accumulation of poly(3-hydroxybutyrate) [poly(3HB)] by V. natriegens was studied. Results indicated that V. natriegens used glucose, gluconate, fructose and molasses as carbon sources for poly(3HB) synthesis. When molasses was used, up to 28.4% of poly(3HB) to cellular dry weight was accumulated. The accumulation of poly(3HB) followed, was not simultaneously to, the cell growth. Analysis of the PHA polymerase, beta-ketothiolase, and acetoacetyl-CoA reductase showed that the poly(3HB) accumulation was correlated to the increase of their activities in cells. Poly(3HB) accumulation was also related to the de novo fatty acid synthesis, as revealed by the results that cerulenin, a specific inhibitor to the de novo fatty acid synthesis, significantly reduced accumulation of poly(3HB). Based on the results from this study, the synthetic pathway of poly(3HB) was proposed.

  2. Accumulating Knowledge: When Are Reading Intervention Results Meaningful?

    ERIC Educational Resources Information Center

    Fletcher, Jack M.; Wagner, Richard K.

    2014-01-01

    The three target articles provide examples of intervention studies that are excellent models for the field. They rely on rigorous and elegant designs, the interventions are motivated by attention to underlying theoretical mechanisms, and longitudinal designs are used to examine the duration of effects of interventions that occur. When studies are…

  3. The ASCE Residuals Transport Manual

    SciTech Connect

    Albertson, O.E.; Bizier, P.A.; Brown, J.; Koch, C.; Sadick, T.

    1999-07-01

    This presentation will highlight the ASCE Residuals Transport Manual, which has been published by ASCE this year. This document, which represents the state of the art in information on residuals transport, is designed to be used by both the active practitioner, as well as for instructional purposes. The authors will present the various chapters which cover the following topics: Conveyance of Water and Wastewater Residuals, Rheology, Sludge Characteristics, Quality and Quantity, Overview of Residuals Conveyance Devices, Pumping of Viscous Sludges and Slurries, Transport of Thickened Residuals, Conveyance of Dewatered Residuals, Transport of Granular and Compactable Residuals, and Case Studies. The Objective of the Transport Monograph is to summarize in one concise volume the general state of knowledge regarding residuals transport from both water and wastewater residuals. The presentation will cover each chapter and will review the pertinent information contained in the manual.

  4. Natural radionuclide accumulation by raindrops

    NASA Astrophysics Data System (ADS)

    Gusev, Anatoly; Martin, Inacio; Shkevov, Rumen; Alves, Mauro

    2016-07-01

    The laboratory of environmental radiation of ITA (São José dos Campos, 23°11'11″S, 45°52'43″W, 650 MAMSL) performs simultaneous monitoring of a natural radiation background and meteorological parameters. A time resolution of up to 1 minute allows a detailed comparison of changes in meteorological parameters with those of a concentration of ambient radon progenies in the atmosphere. Results of a study of variation of a fallout of radon progenies ^{214}Pb and ^{214}Bi concomitanting rainfalls are present. The radionuclide fallout rate is reconstructed from the observed gamma rate through a simulation of the first kind Volterra integral equation with difference kernel, determined by ratio of precipitating rates of 214Pb and 214Bi and their decay half times. An original straightforward step-by-step procedure was used for the numerical solution of the equation. The radionuclide concentration in the rainwater is calculated as a ratio of the reconstructed fallout to the measured rainfall. It was observed that the radionuclide fallout rate increases as the rainfall one in approximately power 0.6, i.e. the same as the mean raindrop volume. The concentration thereafter decreases as the rainfall rate in power 0.4. A numerical simulation of the process of accumulation of the radionuclides during diffusion and coalescence drop growth and aerosol scavenging during a passage from a cloud to the ground was performed. The results of the simulations agree with the experimental data.

  5. Leaching of lead from zinc leach residue in acidic calcium chloride aqueous solution

    NASA Astrophysics Data System (ADS)

    Wang, Le; Mu, Wen-ning; Shen, Hong-tao; Liu, Shao-ming; Zhai, Yu-chun

    2015-05-01

    A process with potentially reduced environmental impacts and occupational hazards of lead-bearing zinc plant residue was studied to achieve a higher recovery of lead via a cost-effective and environmentally friendly process. This paper describes an optimization study on the leaching of lead from zinc leach residue using acidic calcium chloride aqueous solution. Six main process conditions, i.e., the solution pH value, stirring rate, concentration of CaCl2 aqueous solution, liquid-to-solid (L/S) ratio, leaching temperature, and leaching time, were investigated. The microstructure and components of the residue and tailing were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). On the basis of experimental results, the optimum reaction conditions were determined to be a solution pH value of 1, a stirring rate of 500 r·min-1, a CaCl2 aqueous solution concentration of 400 g·L-1, a liquid-to-solid mass ratio of 7:1, a leaching temperature of 80°C, and a leaching time of 45 min. The leaching rate of lead under these conditions reached 93.79%, with an iron dissolution rate of 19.28%. Silica did not take part in the chemical reaction during the leaching process and was accumulated in the residue.

  6. Utilization of phosphorus loaded alkaline residue to immobilize lead in a shooting range soil.

    PubMed

    Yan, Yubo; Qi, Fangjie; Seshadri, Balaji; Xu, Yilu; Hou, Jiexi; Ok, Yong Sik; Dong, Xiaoli; Li, Qiao; Sun, Xiuyun; Wang, Lianjun; Bolan, Nanthi

    2016-11-01

    The alkaline residue generated from the production of soda ash using the ammonia-soda method has been successfully used in removing phosphorus (P) from aqueous solution. But the accumulation of P-containing solid after P removal is an undesirable menace to the environment. To achieve the goal of recycling, this study explored the feasibility of reusing the P loaded alkaline residue as an amendment for immobilization of lead (Pb) in a shooting range soil. The main crystalline phase and micromorphology of amendments were determined using X-ray diffraction (XRD) and scanning electron microscopy-electron dispersion spectroscopy (SEM-EDS) methods. The toxicity characteristic leaching procedure (TCLP), sequential extraction procedure, and physiologically based extraction test (PBET) were employed to evaluate the effectiveness of Pb immobilization in soil after 45 d incubation. Treatment with P loaded alkaline residue was significantly effective in reducing the TCLP and PBET extractable Pb concentrations in contrast to the untreated soil. Moreover, a positive change in the distribution of Pb fractions was observed in the treated soil, i.e., more than 60% of soil-Pb was transformed to the residual fraction compared to the original soil. On the other hand, P loaded amendments also resulted in a drastic reduction in phytoavailable Pb to the winter wheat and a mild release of P as a nutrient in treated soil, which also confirmed the improvement of soil quality.

  7. Manganese As a Metal Accumulator

    EPA Science Inventory

    Manganese deposits in water distribution systems accumulate metals, radionuclides and oxyanions by a combination of surface complexation, adsorption and solid substitution, as well as a combination of oxidation followed by manganese reduction and sorption of the oxidized constitu...

  8. Residual stresses in material processing

    SciTech Connect

    Kozaczek, K.J.; Watkins, T.R.; Hubbard, C.R.; Wang, Xun-Li; Spooner, S.

    1994-09-01

    Material manufacturing processes often introduce residual stresses into the product. The residual stresses affect the properties of the material and often are detrimental. Therefore, the distribution and magnitude of residual stresses in the final product are usually an important factor in manufacturing process optimization or component life prediction. The present paper briefly discusses the causes of residual stresses. It then adresses the direct, nondestructive methods of residual stress measurement by X-ray and neutron diffraction. Examples are presented to demonstrate the importance of residual stress measurement in machining and joining operations.

  9. Copper, nickel and zinc accumulations in lettuce grown in soil amended with contaminated cattle manure vermicompost after sequential cultivations.

    PubMed

    Jordão, Cláudio P; de Andrade, Renato P; Cotta, Aloísio J B; Cecon, Paulo R; Neves, Júlio C L; Fontes, Mauricio P F; Fernandes, Raphael B A

    2013-01-01

    The Cu, Ni and Zn accumulations in leaves and roots of lettuce (Lactuca sativa L) grown in soil amended with natural and contaminated cattle manure vermicompost were evaluated. The vermicompost residues containing relatively high metal concentrations used in this work were obtained from a previous experiment, in which vermicompost was applied to removing metals from electroplating wastes. Sequential lettuce cultivations were conducted in pots containing the residual substrates from the first cultivation by adding metal-enriched vermicompost residues. In general, the Cu, Ni and Zn concentrations in leaves and roots of lettuce plants grown in vermicompost enriched with these metals were higher than in the treatment using the natural vermicompost. The metal concentrations in leaves from treatments with natural vermicompost were below the critical concentrations of toxicity to plants. However, the metal concentrations in leaves of the third cultivation in which metal-enriched vermicompost was applied were greater than the upper limit that causes plant toxicity, but no visual damage was observed in the plants. Treatment with Zn-enriched vermicompost resulted in toxicity symptoms, but plant damage did not result in the death of the plant. The chemical fractionation of Cu, Ni and Zn in residues from lettuce cultivation was evaluated by using a sequential extraction procedure and metal concentrations were increased in the different chemical fractions according to the increase of vermicompost dose.

  10. Metallic elements fractionation in municipal solid waste incineration residues

    NASA Astrophysics Data System (ADS)

    Kowalski, Piotr R.; Kasina, Monika; Michalik, Marek

    2016-04-01

    Municipal solid waste incineration (MSWI) residues are represented by three main materials: bottom ash, fly ash and air pollution control (APC) residues. Among them ˜80 wt% is bottom ash. All of that materials are products of high temperature (>1000° C) treatment of waste. Incineration process allows to obtain significant reduction of waste mass (up to 70%) and volume (up to 90%) what is commonly used in waste management to reduce the amount need to be landfilled or managed in other way. Incineration promote accumulation non-combustible fraction of waste, which part are metallic elements. That type of concentration is object of concerns about the incineration residues impact on the environment and also gives the possibility of attempts to recover them. Metallic elements are not equally distributed among the materials. Several factors influence the process: melting points, volatility and place and forms of metallic occurrence in the incinerated waste. To investigate metallic elements distribution in MSWI residues samples from one of the biggest MSW incineration plant in Poland were collected in 2015. Chemical analysis with emphasis on the metallic elements content were performed using inductively coupled plasma optical emission (ICP-OES) and mass spectrometry (ICP-MS). The bottom ash was a SiO2-CaO-Al2O3-Fe2O3-Na2O rich material, whereas fly ash and APC residues were mostly composed of CaO and SiO2. All of the materials were rich in amorphous phase occurring together with various, mostly silicate crystalline phases. In a mass of bottom ash 11 wt% were metallic elements but also in ashes 8.5 wt% (fly ash) and ˜4.5 wt% (APC residues) of them were present. Among the metallic elements equal distribution between bottom and fly ash was observed for Al (˜3.85 wt%), Mn (770 ppm) and Ni (˜65 ppm). In bottom ash Fe (5.5 wt%), Cr (590 ppm) and Cu (1250 ppm) were concentrated. These values in comparison to fly ash were 5-fold higher for Fe, 3-fold for Cu and 1.5-fold for

  11. Factors affecting polyhydroxybutyrate accumulation in mesophyll cells of sugarcane and switchgrass

    PubMed Central

    2014-01-01

    Background Polyhydroxyalkanoates are linear biodegradable polyesters produced by bacteria as a carbon store and used to produce a range of bioplastics. Widespread polyhydroxyalkanoate production in C4 crops would decrease petroleum dependency by producing a renewable supply of biodegradable plastics along with residual biomass that could be converted into biofuels or energy. Increasing yields to commercial levels in biomass crops however remains a challenge. Previously, lower accumulation levels of the short side chain polyhydroxyalkanoate, polyhydroxybutyrate (PHB), were observed in the chloroplasts of mesophyll (M) cells compared to bundle sheath (BS) cells in transgenic maize (Zea mays), sugarcane (Saccharum sp.), and switchgrass (Panicum virgatum L.) leading to a significant decrease in the theoretical yield potential. Here we explore various factors which might affect polymer accumulation in mesophyll cells, including targeting of the PHB pathway enzymes to the mesophyll plastid and their access to substrate. Results The small subunit of Rubisco from pea effectively targeted the PHB biosynthesis enzymes to both M and BS chloroplasts of sugarcane and switchgrass. PHB enzyme activity was retained following targeting to M plastids and was equivalent to that found in the BS plastids. Leaf total fatty acid content was not affected by PHB production. However, when fatty acid synthesis was chemically inhibited, polymer accumulated in M cells. Conclusions In this study, we provide evidence that access to substrate and neither poor targeting nor insufficient activity of the PHB biosynthetic enzymes may be the limiting factor for polymer production in mesophyll chloroplasts of C4 plants. PMID:25209261

  12. Recovery of transuranics from process residues

    SciTech Connect

    Gray, J.H.; Gray, L.W.

    1987-01-01

    Process residues are generated at both the Rocky Flats Plant (RFP) and the Savannah River Plant (SRP) during aqueous chemical and pyrochemical operations. Frequently, process operations will result in either impure products or produce residues sufficiently contaminated with transuranics to be nondiscardable as waste. Purification and recovery flowsheets for process residues have been developed to generate solutions compatible with subsequent Purex operations and either solid or liquid waste suitable for disposal. The ''scrub alloy'' and the ''anode heel alloy'' are examples of materials generated at RFP which have been processed at SRP using the developed recovery flowsheets. Examples of process residues being generated at SRP for which flowsheets are under development include LECO crucibles and alpha-contaminated hydraulic oil.

  13. Landscape Evolution and the Reincarnation of the Residual CO2 Ice Cap of Mars

    NASA Astrophysics Data System (ADS)

    Byrne, S.; Zuber, M.

    2006-12-01

    Observations of the southern residual CO2 cap of Mars reveal a wide range of landforms including flat-floored quasi-circular pits with steep walls (dubbed Swiss-cheese features). Interannual comparisons show that these depressions are expanding laterally at rates of ~2m/yr to ~4m/yr, prompting suggestions of climate change. The residual CO2 ice cap is up to 10m thick and underlain by an involatile basement, it also contains layers roughly 2m thick representing different accumulation episodes in the recent past. Changes in the appearance of the residual ice between the Mariner 9 and Viking missions indicate that the top-most layer was deposited in that time-frame, soon after the global dust storm of 1971. The spatial density of the Swiss-cheese features, and the rate at which they expand, mean that it is unlikely that any part of the residual ice cap is older than a few centuries. Given this, we may ask: how can there be a residual cap present today for us to observe? To answer this and other questions we have developed a model to examine the evolution of a CO2 ice landscape. This model reproduces the morphologies and expansion rates seen in the actual residual CO2 ice cap. Our model results indicate that the fate of CO2 ice surfaces is controlled by their surface roughness. Surface roughness always increases with time, which results in an unstable situation. When the surface roughness exceeds a critical point small pits can begin to develop. The walls of these pits rapidly steepen and begin retreating which enlarges and deepens the pit. This situation always occurs even if the surface of the CO2 slab has a high enough albedo to have a net mass gain each year. Once these pits begin expanding they quickly erode the entire ice slab. When the underlying non-CO2 material is exposed, it will not frost over again if Mars were to repeat like clockwork every year. We conclude that interannual climatic variability is actually a requirement for the continued existence of a

  14. Late 20th Century increase in South Pole snow accumulation

    USGS Publications Warehouse

    Mosley-Thompson, E.; Paskievitch, J.F.; Gow, A.J.; Thompson, L.G.

    1999-01-01

    A compilation of the 37-year history of net accumulation at the South Pole [Mosley-Thompson et al., 1995] suggests an increase in net annual accumulation since 1965. This record is sporadic and its quality is compromised by spatially restricted observations and nonsystematic measurement procedures. Results from a new, spatially extensive network of 236 accumulation poles document that the current 5-year (1992-1997) average annual net accumulation at the South Pole is 84.5??8.9 mm water equivalent (w.e.). This accumulation rate reflects a 30% increase since the 1960s when the best, although not optimal, records indicate that it was 65 mm w.e. Identification of two prominent beta radioactivity horizons (1954/1955 and 1964/1965) in six firn cores confirms an increase in accumulation since 1965. Viewed from a longer perspective of accumulation provided by ice cores and a snow mine study, the net accumulation of the 30-year period, 1965-1994, is the highest 30-year average of this millennium. Limited data suggest this recent accumulation increase extends beyond the South Pole region and may be characteristic of the high East Antarctic Plateau. Enhanced accumulation over the polar ice sheets has been identified as a potential early indicator of warmer sea surface temperatures and may offset a portion of the current rise in global sea level. Copyright 1999 by the American Geophysical Union.

  15. Method for residual household waste composition studies.

    PubMed

    Sahimaa, Olli; Hupponen, Mari; Horttanainen, Mika; Sorvari, Jaana

    2015-12-01

    The rising awareness of decreasing natural resources has brought forward the idea of a circular economy and resource efficiency in Europe. As a part of this movement, European countries have identified the need to monitor residual waste flows in order to make recycling more efficient. In Finland, studies on the composition of residual household waste have mostly been conducted using different methods, which makes the comparison of the results difficult. The aim of this study was to develop a reliable method for residual household waste composition studies. First, a literature review on European study methods was performed. Also, 19 Finnish waste composition studies were compared in order to identify the shortcomings of the current Finnish residual household waste composition data. Moreover, the information needs of different waste management authorities concerning residual household waste were studied through a survey and personal interviews. Stratification, sampling, the classification of fractions and statistical analysis were identified as the key factors in a residual household waste composition study. The area studied should be divided into non-overlapping strata in order to decrease the heterogeneity of waste and enable comparisons between different waste producers. A minimum of six subsamples, each 100 kg, from each stratum should be sorted. Confidence intervals for each waste category should be determined in order to evaluate the applicability of the results. A new three-level classification system was created based on Finnish stakeholders' information needs and compared to four other European waste composition study classifications.

  16. Measurements of residual stress in fracture mechanics coupons

    SciTech Connect

    Prime, Michael B; Hill, Michael R; Nav Dalen, John E

    2010-01-01

    This paper describes measurements of residual stress in coupons used for fracture mechanics testing. The primary objective of the measurements is to quantify the distribution of residual stress acting to open (and/or close) the crack across the crack plane. The slitting method and the contour method are two destructive residual stress measurement methods particularly capable of addressing that objective, and these were applied to measure residual stress in a set of identically prepared compact tension (C(T)) coupons. Comparison of the results of the two measurement methods provides some useful observations. Results from fracture mechanics tests of residual stress bearing coupons and fracture analysis, based on linear superposition of applied and residual stresses, show consistent behavior of coupons having various levels of residual stress.

  17. DISTRIBUTED AND ACCUMULATED REINFORCEMENT ARRANGEMENTS: EVALUATIONS OF EFFICACY AND PREFERENCE

    PubMed Central

    DELEON, ISER G.; CHASE, JULIE A.; FRANK-CRAWFORD, MICHELLE A.; CARREAU-WEBSTER, ABBEY B.; TRIGGS, MANDY M.; BULLOCK, CHRISTOPHER E.; JENNETT, HEATHER K.

    2015-01-01

    We assessed the efficacy of, and preference for, accumulated access to reinforcers, which allows uninterrupted engagement with the reinforcers but imposes an inherent delay required to first complete the task. Experiment 1 compared rates of task completion in 4 individuals who had been diagnosed with intellectual disabilities when reinforcement was distributed (i.e., 30-s access to the reinforcer delivered immediately after each response) and accumulated (i.e., 5-min access to the reinforcer after completion of multiple consecutive responses). Accumulated reinforcement produced response rates that equaled or exceeded rates during distributed reinforcement for 3 participants. Experiment 2 used a concurrent-chains schedule to examine preferences for each arrangement. All participants preferred delayed, accumulated access when the reinforcer was an activity. Three participants also preferred accumulated access to edible reinforcers. The collective results suggest that, despite the inherent delay, accumulated reinforcement is just as effective and is often preferred by learners over distributed reinforcement. PMID:24782203

  18. Distributed and accumulated reinforcement arrangements: evaluations of efficacy and preference.

    PubMed

    DeLeon, Iser G; Chase, Julie A; Frank-Crawford, Michelle A; Carreau-Webster, Abbey B; Triggs, Mandy M; Bullock, Christopher E; Jennett, Heather K

    2014-01-01

    We assessed the efficacy of, and preference for, accumulated access to reinforcers, which allows uninterrupted engagement with the reinforcers but imposes an inherent delay required to first complete the task. Experiment 1 compared rates of task completion in 4 individuals who had been diagnosed with intellectual disabilities when reinforcement was distributed (i.e., 30-s access to the reinforcer delivered immediately after each response) and accumulated (i.e., 5-min access to the reinforcer after completion of multiple consecutive responses). Accumulated reinforcement produced response rates that equaled or exceeded rates during distributed reinforcement for 3 participants. Experiment 2 used a concurrent-chains schedule to examine preferences for each arrangement. All participants preferred delayed, accumulated access when the reinforcer was an activity. Three participants also preferred accumulated access to edible reinforcers. The collective results suggest that, despite the inherent delay, accumulated reinforcement is just as effective and is often preferred by learners over distributed reinforcement.

  19. Heat accumulation during pulsed laser materials processing.

    PubMed

    Weber, Rudolf; Graf, Thomas; Berger, Peter; Onuseit, Volkher; Wiedenmann, Margit; Freitag, Christian; Feuer, Anne

    2014-05-05

    Laser materials processing with ultra-short pulses allows very precise and high quality results with a minimum extent of the thermally affected zone. However, with increasing average laser power and repetition rates the so-called heat accumulation effect becomes a considerable issue. The following discussion presents a comprehensive analytical treatment of multi-pulse processing and reveals the basic mechanisms of heat accumulation and its consequence for the resulting processing quality. The theoretical findings can explain the experimental results achieved when drilling microholes in CrNi-steel and for cutting of CFRP. As a consequence of the presented considerations, an estimate for the maximum applicable average power for ultra-shorts pulsed laser materials processing for a given pulse repetition rate is derived.

  20. Residual stress characterization of steel TIG welds by neutron diffraction and by residual magnetic stray field mappings

    NASA Astrophysics Data System (ADS)

    Stegemann, Robert; Cabeza, Sandra; Lyamkin, Viktor; Bruno, Giovanni; Pittner, Andreas; Wimpory, Robert; Boin, Mirko; Kreutzbruck, Marc

    2017-03-01

    The residual stress distribution of tungsten inert gas welded S235JRC+C plates was determined by means of neutron diffraction (ND). Large longitudinal residual stresses with maxima around 600 MPa were found. With these results as reference, the evaluation of residual stress with high spatial resolution GMR (giant magneto resistance) sensors was discussed. The experiments performed indicate a correlation between changes in residual stresses (ND) and the normal component of local residual magnetic stray fields (GMR). Spatial variations in the magnetic field strength perpendicular to the welds are in the order of the magnetic field of the earth.

  1. Residues of oxytetracycline in cultured rainbow trout.

    PubMed

    Sharafati-Chaleshtori, R; Mardani, G; Rafieian-Kopaei, M; Sharafati-Chaleshtori, A; Drees, F

    2013-11-01

    Nowadays, antibiotics are widely used in aquatic animals to control and treatment of infections or as food supplement for growth increase and animal output. With increasing use of veterinary drugs in food production, there is global consideration about the consumption of antimicrobial residues in aquatic foods and their effects on human health. This study was aimed to evaluate the Oxytetracycline (OTC) residues in Rainbow trout meat in Shahre-kord (Iran) markets before and after frying. After randomized collection of 50 samples of fish in Shahre-kord markets in a six months period were examined. The prepared samples were examined for OTC residues using HPLC analytical method before and after frying. Results showed that 3 (6%) of the samples before frying and 12 (24%) after frying were having lower than Maximum residual limits (MRLs) in Codex alimentarius. However, mean OTC residues before and after frying samples were above MRLs. The mean amounts of OTC were 2260 +/- 1090 and 1110 +/- 930 ng g(-1) before and after frying, respectively. These findings show that the frying of fish reduces OTC residual. Nevertheless, the usage of OTC should be reduced to an acceptable level in fishery industry.

  2. Maximum likelihood decoding analysis of Accumulate-Repeat-Accumulate Codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    Repeat-Accumulate (RA) codes are the simplest turbo-like codes that achieve good performance. However, they cannot compete with Turbo codes or low-density parity check codes (LDPC) as far as performance is concerned. The Accumulate Repeat Accumulate (ARA) codes, as a subclass of LDPC codes, are obtained by adding a pre-coder in front of RA codes with puncturing where an accumulator is chosen as a precoder. These codes not only are very simple, but also achieve excellent performance with iterative decoding. In this paper, the performance of these codes with (ML) decoding are analyzed and compared to random codes by very tight bounds. The weight distribution of some simple ARA codes is obtained, and through existing tightest bounds we have shown the ML SNR threshold of ARA codes approaches very closely to the performance of random codes. We have shown that the use of precoder improves the SNR threshold but interleaving gain remains unchanged with respect to RA code with puncturing.

  3. Isothermal Fatigue, Damage Accumulation, and Life Prediction of a Woven PMC

    NASA Technical Reports Server (NTRS)

    Gyekenyesi, Andrew L.

    1998-01-01

    This dissertation focuses on the characterization of the fully reversed fatigue behavior exhibited by a carbon fiber/polyimide resin, woven laminate at room and elevated temperatures. Nondestructive video edge view microscopy and destructive sectioning techniques were used to study the microscopic damage mechanisms that evolved. The residual elastic stiffness was monitored and recorded throughout the fatigue life of the coupon. In addition, residual compressive strength tests were conducted on fatigue coupons with various degrees of damage as quantified by stiffness reduction. Experimental results indicated that the monotonic tensile properties were only minimally influenced by temperature, while the monotonic compressive and fully reversed fatigue properties displayed noticeable reductions due to the elevated temperature. The stiffness degradation, as a function of cycles, consisted of three stages; a short-lived high degradation period, a constant degradation rate segment composing the majority of the life, and a final stage demonstrating an increasing rate of degradation up to failure. Concerning the residual compressive strength tests at room and elevated temperatures, the elevated temperature coupons appeared much more sensitive to damage. At elevated temperatures, coupons experienced a much larger loss in compressive strength when compared to room temperature coupons with equivalent damage. The fatigue damage accumulation law proposed for the model incorporates a scalar representation for damage, but admits a multiaxial, anisotropic evolutionary law. The model predicts the current damage (as quantified by residual stiffness) and remnant life of a composite that has undergone a known load at temperature. The damage/life model is dependent on the applied multiaxial stress state as well as temperature. Comparisons between the model and data showed good predictive capabilities concerning stiffness degradation and cycles to failure.

  4. Catalytic combustion with incompletely vaporized residual fuel

    NASA Technical Reports Server (NTRS)

    Rosfjord, T. J.

    1981-01-01

    Catalytic combustion of fuel lean mixtures of incompletely vaporized residual fuel and air was investigated. The 7.6 cm diameter, graded cell reactor was constructed from zirconia spinel substrate and catalyzed with a noble metal catalyst. Streams of luminous particles exited the rector as a result of fuel deposition and carbonization on the substrate. Similar results were obtained with blends of No. 6 and No. 2 oil. Blends of shale residual oil and No. 2 oil resulted in stable operation. In shale oil blends the combustor performance degraded with a reduced degree of fuel vaporization. In tests performed with No. 2 oil a similar effect was observed.

  5. Differential accumulation of lead by soft tissues of rabbit

    SciTech Connect

    Villarreal-Trevino, C.M.; Villegas-Navarro, A.

    1987-08-01

    In studies on retention of lead by soft tissues, it is reported that, in acute and chronic intoxications, the concentration of Pb decrease in the following order: liver, kidney, heart and brain. The liver contains more lead than the other soft tissues; this might be due to the volume of blood that stays within the organ. Several parameters like age, temperature, perfusion, vascularity and residual blood volume could be important factors in the movement and differential accumulation of lead in blood and tissues. However, these parameters do not completely explain the quantitative differences in the retention of Pb between organs, and it is possible that other factors like the dose and the time between the administration of lead and the killing (exposure time), would have considerable importance in this process that so far has not been satisfactorily explained. The relationships between the size of a dose of lead given intravenously and the retention of this metal by some organs, as well as the effect of the duration of exposure of an intravenously administered dose of lead on accumulation were studied in this work. The possible relationships between accumulation and the values reported for perfusion and residual blood volumes were also studied.

  6. Contaminant Accumulation in Many New England Lead Pipe Scales

    EPA Science Inventory

    Previous work has shown that contaminants such as Al, As and Ra can accumulate in drinking water distribution system solids. The release of accumulated contaminants back into the water supply could conceivably result in elevated levels at consumers' taps. The objective of this s...

  7. The Effects of the Capital Accumulation Ratio on Wealth

    ERIC Educational Resources Information Center

    Harness, Nathaniel J.; Finke, Michael S.; Chatterjee, Swarn

    2009-01-01

    The capital accumulation ratio (CAR) is commonly used in academic research as a measure of household portfolio quality. This study tested whether a higher initial CAR impacts change in wealth over a decade among households in the accumulation life cycle stage. Meeting the 25% CAR guideline resulted in a 28.1% increase in net worth between 1994 and…

  8. ACCUMULATION OF PERCHLORATE IN TOBACCO PLANTS AND TOBACCO PRODUCTS

    EPA Science Inventory

    Previous field and laboratory studies with vascular plants have shown that perchlorate is transported from perchlorate fortified soils and is accumulated in the plant tissues and organs. This paper reports results of initial investigations on the accumulation of perchlorate in t...

  9. Isolation and functional characterization of an influx silicon transporter in two pumpkin cultivars contrasting in silicon accumulation.

    PubMed

    Mitani, Namiki; Yamaji, Naoki; Ago, Yukiko; Iwasaki, Kozo; Ma, Jian Feng

    2011-04-01

    A high accumulation of silicon (Si) is required for overcoming abiotic and biotic stresses, but the molecular mechanisms of Si uptake, especially in dicotyledonous species, is poorly understood. Herein, we report the identification of an influx transporter of Si in two Cucurbita moschata (pumpkin) cultivars greatly differing in Si accumulation, which are used for the rootstocks of bloom and bloomless Cucumis sativus (cucumber), respectively. Heterogeneous expression in both Xenopus oocytes and rice mutant defective in Si uptake showed that the influx transporter from the bloom pumpkin rootstock can transport Si, whereas that from the bloomless rootstock cannot. Analysis with site-directed mutagenesis showed that, among the two amino acid residues differing between the two types of rootstocks, only changing a proline to a leucine at position 242 results in the loss of Si transport activity. Furthermore, all pumpkin cultivars for bloomless rootstocks tested have this mutation. The transporter is localized in all cells of the roots, and investigation of the subcellular localization with different approaches consistently showed that the influx Si transporter from the bloom pumpkin rootstock was localized at the plasma membrane, whereas the one from the bloomless rootstock was localized at the endoplasmic reticulum. Taken together, our results indicate that the difference in Si uptake between two pumpkin cultivars is probably the result of allelic variation in one amino acid residue of the Si influx transporter, which affects the subcellular localization and subsequent transport of Si from the external solution to the root cells.

  10. Plaque accumulations caused by interdental stripping.

    PubMed

    Radlanski, R J; Jäger, A; Schwestka, R; Bertzbach, F

    1988-11-01

    Human enamel surfaces were stripped with orthodontic grinding and finishing materials, and evaluated with the scanning electron microscope (SEM). Even under in vitro conditions with the finest finishing strips, it was not possible to produce an enamel surface free of the furrows that result from the initial abrasion caused by the coarse strip. Enamel surfaces stripped gradually from coarse to superfine were left in the mouths of patients for 12 weeks and evaluated with the SEM. The edges of the furrows were found to be smoother but the furrows remained wide and deep enough to facilitate more plaque accumulations than those on untreated surfaces. The use of dental floss did not result in prevention of plaque accumulations along the bottom of the furrows.

  11. Detailed monitoring of two biogas plants and mechanical solid-liquid separation of fermentation residues.

    PubMed

    Bauer, Alexander; Mayr, Herwig; Hopfner-Sixt, Katharina; Amon, Thomas

    2009-06-01

    The Austrian "green electricity act" (Okostromgesetz) has led to an increase in biogas power plant size and consequently to an increased use of biomass. A biogas power plant with a generating capacity of 500 kW(el) consumes up to 38,000 kg of biomass per day. 260 ha of cropland is required to produce this mass. The high water content of biomass necessitates a high transport volume for energy crops and fermentation residues. The transport and application of fermentation residues to farmland is the last step in this logistic chain. The use of fermentation residues as fertilizer closes the nutrient cycle and is a central element in the efficient use of biomass for power production. Treatment of fermentation residues by separation into liquid and solid phases may be a solution to the transport problem. This paper presents detailed results from the monitoring of two biogas plants and from the analysis of the separation of fermentation residues. Furthermore, two different separator technologies for the separation of fermentation residues of biogas plants were analyzed. The examined biogas plants correspond to the current technological state of the art and have designs developed specifically for the utilization of energy crops. The hydraulic retention time ranged between 45.0 and 83.7 days. The specific methane yields were 0.40-0.43 m(3)N CH(4) per kg VS. The volume loads ranged between 3.69 and 4.00 kg VS/m(3). The degree of degradation was between 77.3% and 82.14%. The screw extractor separator was better suited for biogas slurry separation than the rotary screen separator. The screw extractor separator exhibited a high throughput and good separation efficiency. The efficiency of slurry separation depended on the dry matter content of the fermentation residue. The higher the dry matter content, the higher the proportion of solid phase after separation. In this project, we found that the fermentation residues could be divided into 79.2% fluid phase with a dry matter

  12. Ion Trapping in the Accumulator

    SciTech Connect

    Marriner, J.

    1985-02-18

    The beam space charge (- for {bar p}'s) will attract positive ions. In the absence of additional fields (clearing electrodes, e.g.) these ions will be trapped in the beam potential well. The depth of this potential well has been calculated for some geometries relevant for the accumulator.

  13. Effects of oral and parenteral selenium supplements on residues in meat, milk and eggs.

    PubMed

    Beale, A M; Fasulo, D A; Craigmill, A L

    1990-01-01

    Oral and parenteral preparations of Se are used worldwide to prevent and treat nutritional muscular dystrophy and other Se deficiency syndromes. There are extensive published data on the effects of oral supplementation on Se residues in food animal products. Very little published data exist on the effects of parenteral administration on Se residues, even for cattle and swine in which parenteral preparations are used extensively. The distribution of Se into kidney and liver appears to be equivalent for both forms of supplementation. Elimination of Se in milk is greater after parenteral administration and correlates with high plasma Se levels, however the milk excretion drops quickly and after 4 d returns to control levels (Little et al. 1979). Of particular interest is the finding that up to 18% of Se in an oral diet may be excreted in milk (Maus et al. 1980). Use of Se supplements in poultry results in increased levels of Se in liver, kidney, and eggs. Distribution of Se into liver and kidney is much greater than into breast muscle indicating a greater capacity of these organs to accumulate Se. Excretion of Se into eggs results in Se levels equivalent to those in liver and kidney, indicating that eggs are an important route of Se excretion in laying hens (Ort and Latshaw 1978). When Se supplementation stops, the liver, kidney, and egg white and yolk residues decline quickly to control values within 1-2 wk. Breast muscle Se content changes little during supplementation and after withdrawal of supplementation. Oral and parenteral selenium supplementation in swine result in greater accumulation of Se in liver and kidney than in muscle. Oral selenium supplementation also increases the excretion of Se into milk. This method has been used to prevent Se deficiency disease in piglets (Mahan et al. 1975). Oral supplementation with 0.1 ppm Se, as sodium selenate, did not result in levels of Se in blood, meat, or viscera at slaughter (Jenkins and Winter 1973). Despite the

  14. Residual number processing in dyscalculia.

    PubMed

    Cappelletti, Marinella; Price, Cathy J

    2014-01-01

    Developmental dyscalculia - a congenital learning disability in understanding numerical concepts - is typically associated with parietal lobe abnormality. However, people with dyscalculia often retain some residual numerical abilities, reported in studies that otherwise focused on abnormalities in the dyscalculic brain. Here we took a different perspective by focusing on brain regions that support residual number processing in dyscalculia. All participants accurately performed semantic and categorical colour-decision tasks with numerical and non-numerical stimuli, with adults with dyscalculia performing slower than controls in the number semantic tasks only. Structural imaging showed less grey-matter volume in the right parietal cortex in people with dyscalculia relative to controls. Functional MRI showed that accurate number semantic judgements were maintained by parietal and inferior frontal activations that were common to adults with dyscalculia and controls, with higher activation for participants with dyscalculia than controls in the right superior frontal cortex and the left inferior frontal sulcus. Enhanced activation in these frontal areas was driven by people with dyscalculia who made faster rather than slower numerical decisions; however, activation could not be accounted for by response times per se, because it was greater for fast relative to slow dyscalculics but not greater for fast controls relative to slow dyscalculics. In conclusion, our results reveal two frontal brain regions that support efficient number processing in dyscalculia.

  15. Enantioselective accumulation of chiral polychlorinated biphenyls in lotus plant (Nelumbonucifera spp.).

    PubMed

    Dai, Shouhui; Wong, Charles S; Qiu, Jing; Wang, Min; Chai, Tingting; Fan, Li; Yang, Shuming

    2014-09-15

    Enantioselective accumulation of chiral polychlorinated biphenyls (PCBs) 91, 95, 136, 149, 176 and 183 was investigated in lotus plants (Nelumbonucifera spp.) exposed to these chemicals via spiked sediment, to determine uptake and possible biotransformation for aquatic phytoremediation purposes. The concentrations of most PCBs were greatest in roots at 60 d (19.6 ± 1.51-70.6 ± 6.14 μg kg(-1)), but were greatest in stems and leaves at 120 d (25.3 ± 6.14-95.5 ± 19.4 μg kg(-1) and 17.4 ± 4.41-70.4 ± 10.4 μg kg(-1), respectively). Total amounts were greatest at 120 d and significantly higher in roots than those in stems and in leaves (1,457 ± 220-5,852 ± 735 ng, 237 ± 47.1-902 ± 184 ng and 202 ± 60.3-802 ± 90.2 ng, respectively), but represented less than 0.51% of the total mass of PCBs added to sediments, indicating that lotus plants were unlikely to remove appreciable amounts of PCBs from contaminated sediments. Racemic PCB residues in sediment indicate no enantioselective biodegradation by sedimentary microbial consortia over the entire experiment. Preferential accumulation of the (-)-enantiomers of PCBs 91, 95 and 136 were observed in roots, stems and leaves, but non-enantioselective accumulation was observed for PCBs 149, 176 and 183. These results indicate that aquatic plants can accumulate PCBs enantioselectively via root uptake, possibly by biotransformation within plant tissues as observed for terrestrial plants. This is also the first report to identify optical rotation of the atropisomers of PCBs 91 and 95.

  16. Mutagenesis of conserved amino acids of Helicobacter pylori fur reveals residues important for function.

    PubMed

    Carpenter, Beth M; Gancz, Hanan; Benoit, Stéphane L; Evans, Sarah; Olsen, Cara H; Michel, Sarah L J; Maier, Robert J; Merrell, D Scott

    2010-10-01

    The ferric uptake regulator (Fur) of the medically important pathogen Helicobacter pylori is unique in that it has been shown to function as a repressor both in the presence of an Fe2+ cofactor and in its apo (non-Fe2+-bound) form. However, virtually nothing is known concerning the amino acid residues that are important for Fur functioning. Therefore, mutations in six conserved amino acid residues of H. pylori Fur were constructed and analyzed for their impact on both iron-bound and apo repression. In addition, accumulation of the mutant proteins, protein secondary structure, DNA binding ability, iron binding capacity, and the ability to form higher-order structures were also examined for each mutant protein. While none of the mutated residues completely abrogated the function of Fur, we were able to identify residues that were critical for both iron-bound and apo-Fur repression. One mutation, V64A, did not alter regulation of any target genes. However, each of the five remaining mutations showed an effect on either iron-bound or apo regulation. Of these, H96A, E110A, and E117A mutations altered iron-bound Fur regulation and were all shown to influence iron binding to different extents. Additionally, the H96A mutation was shown to alter Fur oligomerization, and the E110A mutation was shown to impact oligomerization and DNA binding. Conversely, the H134A mutant exhibited changes in apo-Fur regulation that were the result of alterations in DNA binding. Although the E90A mutant exhibited alterations in apo-Fur regulation, this mutation did not affect any of the assessed protein functions. This study is the first for H. pylori to analyze the roles of specific amino acid residues of Fur in function and continues to highlight the complexity of Fur regulation in this organism.

  17. Premature chromatin condensation upon accumulation of NIMA.

    PubMed Central

    O'Connell, M J; Norbury, C; Nurse, P

    1994-01-01

    The NIMA protein kinase of Aspergillus nidulans is required for the G2/M transition of the cell cycle. Mutants lacking NIMA arrest without morphological characteristics of mitosis, but they do contain an activated p37nimX kinase (the Aspergillus homologue of p34cdc2). To gain a better understanding of NIMA function we have investigated the effects of expressing various NIMA constructs in Aspergillus, fission yeast and human cells. Our experiments have shown that the instability of the NIMA protein requires sequences in the non-catalytic C-terminus of the protein. Removal of this domain results in a stable protein that, once accumulated, promotes a lethal premature condensation of chromatin without any other aspects of mitosis. Similar effects were also observed in fission yeast and human cells accumulating Aspergillus NIMA. This phenotype is independent of cell cycle progression and does not require p34cdc2 kinase activity. As gain of NIMA function by accumulation results in premature chromatin condensation, and loss of NIMA function results in an inability to enter mitosis, we propose that NIMA functions in G2 to promote the condensation of chromatin normally associated with entry into mitosis. Images PMID:7957060

  18. Extracting sea level residual in tidally dominated estuarine environments

    NASA Astrophysics Data System (ADS)

    Brown, Jennifer M.; Bolaños, Rodolfo; Howarth, Michael J.; Souza, Alejandro J.

    2012-07-01

    Sea level comprises a mean level, tidal elevation and a residual elevation. Knowledge of what causes maximum water levels is often key in coastal management. However, different methods to extract deviations in water level (residuals) from modelled and observed elevation can give different results. The Dee Estuary, northwest England is a macrotidal estuary that undergoes periodic stratification. It is used here to demonstrate methods to extract the residual water level in response to the following interactive processes: tidal, river-induced stratification and flow, meteorology and waves. Using modelling techniques, the interaction and contribution of different physical processes are investigated. Classical harmonic tidal analysis, model simulations and filtering techniques have been used to "de-tide" the total elevation for short-term (approximately month long) records. Each technique gives a different result highlighting the need to select the correct method for a required study. Analysis of the residual components demonstrates that all processes inducing residuals interact with the tide generating a semi-diurnal residual component. It is suggested that modelling methods enable the full effect of tidal interaction to remain in the residual, whilst harmonic tidal analysis (partly) modify and filtering methods (fully) remove this component of the residual. The analysis methods presented and their influences on the resultant residual are applicable to other study sites. However, when applied specifically to the mouth of the Dee Estuary, the external surge is found to be the main contributor to the total residual, whilst local wind and stratification effects are of secondary importance.

  19. Hydroxynonenal inactivates cathepsin B by forming Michael adducts with active site residues.

    PubMed

    Crabb, John W; O'Neil, June; Miyagi, Masaru; West, Karen; Hoff, Henry F

    2002-04-01

    Oxidation of plasma low-density lipoprotein (oxLDL) generates the lipid peroxidation product 4-hydroxy-2 nonenal (HNE) and also reduces proteolytic degradation of oxLDL and other proteins internalized by mouse peritoneal macrophages in culture. This leads to accumulation of undegraded material in lysosomes and formation of ceroid, a component of foam cells in atherosclerotic lesions. To explore the possibility that HNE contributes directly to the inactivation of proteases, structure-function studies of the lysosomal protease cathepsin B have been pursued. We found that treatment of mouse macrophages with HNE reduces degradation of internalized maleyl bovine serine albumin and cathepsin B activity. Purified bovine cathepsin B treated briefly with 15 microM HNE lost approximately 76% of its protease activity and also developed immunoreactivity with antibodies to HNE adducts in Western blot analysis. After stabilization of the potential Michael adducts by sodium borohydride reduction, modified amino acids were localized within the bovine cathepsin B protein structure by mass spectrometric analysis of tryptic peptides. Michael adducts were identified by tandem mass spectrometry at cathepsin B active site residues Cys 29 (mature A chain) and His 150 (mature B chain). Thus, covalent interaction between HNE and critical active site residues inactivates cathepsin B. These results support the hypothesis that the accumulation of undegraded macromolecules in lysosomes after oxidative damage are caused in part by direct protease inactivation by adduct formation with lipid peroxidation products such as HNE.

  20. residue and shunting pinholes

    NASA Astrophysics Data System (ADS)

    Gorji, Nima E.

    2014-09-01

    The present work considers two observable phenomena through the experimental fabrication and electrical characterization of the rf-sputtered CdS/CdTe thin film solar cells that extremely reduce the overall conversion efficiency of the device: CdCl2 residue on the surface of the semiconductor and shunting pinholes. The former happens through nonuniform treatment of the As-deposited solar cells before annealing at high temperature and the latter occurs by shunting pinholes when the cell surface is shunted by defects, wire-like pathways or scratches on the metallic back contact caused from the external contacts. Such physical problems may be quite common in the experimental activities and reduce the performance down to 4-5 % which leads to dismantle the device despite its precise fabrication. We present our electrical characterization on the samples that received wet CdCl2 surface treatment (uniform or nonuniform) and are damaged by the pinholes.

  1. Treatment of vacuum residues in hydroconversion conditions

    NASA Astrophysics Data System (ADS)

    León, A. Y.; Mendoza, D. L.; Espinosa, J. O.; Laverde, D.

    2016-02-01

    In this paper the use of a liquid homogeneous catalyst has been studied in reactivity vacuum residues by hydroconversion under different conditions. To cover a wide range of compositions, six (6) vacuum residues were selected from crude mixtures. Hydroconversion test were performed in batch reactor with hydrogen atmosphere at about 2000psi in a temperature range between 430 and 480°C. The results allowed to establish that the reactivity hydroconversion conditions about coke formation is higher in vacuum residues with higher content of resins and asphaltenes. The reaction conditions promote distillate formation, however, with increasing stringency conditions, the distillate yield decreases due to distillate transformation into temperature range 430 and 460°C compared to the tests performed without catalyst demonstrating that the use of homogeneous catalyst is an alternative to treating vacuum residues and results are satisfactory in the conversion processes. Finally, predictive expressions have been developed in the formation of products depending on the conditions of temperature and physicochemical properties of processed vacuum residue.

  2. Comparison of veterinary drug residue results in animal tissues by ultrahigh-performance liquid chromatography coupled to triple quadrupole or quadrupole-time-of-flight tandem mass spectrometry after different sample preparation methods, including use of a commercial lipid removal product.

    PubMed

    Anumol, Tarun; Lehotay, Steven J; Stevens, Joan; Zweigenbaum, Jerry

    2017-04-01

    Veterinary drug residues in animal-derived foods must be monitored to ensure food safety, verify proper veterinary practices, enforce legal limits in domestic and imported foods, and for other purposes. A common goal in drug residue analysis in foods is to achieve acceptable monitoring results for as many analytes as possible, with higher priority given to the drugs of most concern, in an efficient and robust manner. The U.S. Department of Agriculture has implemented a multiclass, multi-residue method based on sample preparation using dispersive solid phase extraction (d-SPE) for cleanup and ultrahigh-performance liquid chromatography-tandem quadrupole mass spectrometry (UHPLC-QQQ) for analysis of >120 drugs at regulatory levels of concern in animal tissues. Recently, a new cleanup product called "enhanced matrix removal for lipids" (EMR-L) was commercially introduced that used a unique chemical mechanism to remove lipids from extracts. Furthermore, high-resolution quadrupole-time-of-flight (Q/TOF) for (U)HPLC detection often yields higher selectivity than targeted QQQ analyzers while allowing retroactive processing of samples for other contaminants. In this study, the use of both d-SPE and EMR-L sample preparation and UHPLC-QQQ and UHPLC-Q/TOF analysis methods for shared spiked samples of bovine muscle, kidney, and liver was compared. The results showed that the EMR-L method provided cleaner extracts overall and improved results for several anthelmintics and tranquilizers compared to the d-SPE method, but the EMR-L method gave lower recoveries for certain β-lactam antibiotics. QQQ vs. Q/TOF detection showed similar mixed performance advantages depending on analytes and matrix interferences, with an advantage to Q/TOF for greater possible analytical scope and non-targeted data collection. Either combination of approaches may be used to meet monitoring purposes, with an edge in efficiency to d-SPE, but greater instrument robustness and less matrix effects when

  3. A radiographic, morphologic, biochemical and molecular analysis of a case of achondrogenesis type II resulting from substitution for a glycine residue (Gly691-->Arg) in the type II collagen trimer.

    PubMed

    Mortier, G R; Wilkin, D J; Wilcox, W R; Rimoin, D L; Lachman, R S; Eyre, D R; Cohn, D H

    1995-02-01

    The type II collagenopathies form a continuous spectrum of clinical severity, ranging from lethal achondrogenesis type II and hypochondrogenesis, through spondyloepiphyseal dysplasia, spondyloepimetaphyseal dysplasia and Kniest dysplasia to the Stickler syndrome and familial precocious osteoarthropathy at the mildest end of the spectrum. We have carried out a radiographic, morphologic, biochemical and molecular study in a case of achondrogenesis type II. Electron micrographs showed inclusion bodies of dilated rough endoplasmic reticulum in the chondrocytes and the presence of sparse collagen fibers in the cartilage matrix. Protein analysis of collagen from cartilage indicated posttranslational overmodification of the major cyanogen bromide peptides, and suggested a mutation near the carboxyl terminus of the type II collagen molecule. Analysis at the DNA level demonstrated that the phenotype was produced by a single base change (G-->C) that resulted in the substitution of glycine691 by arginine in the type II collagen triple helical domain. We confirm previous observations in three cases of hypochondrogenesis that glycine substitutions in the alpha 1(II) chain can result in a phenotype at the most severe end of the type II collagenopathy spectrum.

  4. Determining Greenland Ice Sheet Accumulation Rates from Radar Remote Sensing

    NASA Technical Reports Server (NTRS)

    Jezek, Kenneth C.

    2002-01-01

    An important component of NASA's Program for Arctic Regional Climate Assessment (PARCA) is a mass balance investigation of the Greenland Ice Sheet. The mass balance is calculated by taking the difference between the areally Integrated snow accumulation and the net ice discharge of the ice sheet. Uncertainties in this calculation Include the snow accumulation rate, which has traditionally been determined by interpolating data from ice core samples taken from isolated spots across the ice sheet. The sparse data associated with ice cores juxtaposed against the high spatial and temporal resolution provided by remote sensing , has motivated scientists to investigate relationships between accumulation rate and microwave observations as an option for obtaining spatially contiguous estimates. The objective of this PARCA continuation proposal was to complete an estimate of surface accumulation rate on the Greenland Ice Sheet derived from C-band radar backscatter data compiled in the ERS-1 SAR mosaic of data acquired during, September-November, 1992. An empirical equation, based on elevation and latitude, is used to determine the mean annual temperature. We examine the influence of accumulation rate, and mean annual temperature on C-band radar backscatter using a forward model, which incorporates snow metamorphosis and radar backscatter components. Our model is run over a range of accumulation and temperature conditions. Based on the model results, we generate a look-up table, which uniquely maps the measured radar backscatter, and mean annual temperature to accumulation rate. Our results compare favorably with in situ accumulation rate measurements falling within our study area.

  5. Accumulative Tritium Transfer from Water into Biosystems

    SciTech Connect

    Baumgaertner, Franz

    2005-07-15

    The energy balance of hydrogen isotopes in H bonds of water and biomolecules results in accumulative tritium transfer from water into biomolecules. Tests of DNA dissolved in tritiated water and of maize or barley hydroponically grown in tritiated water confirm the increase. The primary hydration shell of DNA shows an accumulation factor of {approx}1.4, and the exchangeable hydrogens inside DNA show {approx}2. Logistic growth analyses of maize and barley reveal the intrinsic growth rates of tritium 1.3 and 1.2 times larger than that of hydrogen. The higher rate of tritium than hydrogen incorporation in solid biomatter is caused by the hydration shells, which constitute an intrinsic component of biomolecules.

  6. Sustainable System for Residual Hazards Management

    SciTech Connect

    Kevin M. Kostelnik; James H. Clarke; Jerry L. Harbour

    2004-06-01

    Hazardous, radioactive and other toxic substances have routinely been generated and subsequently disposed of in the shallow subsurface throughout the world. Many of today’s waste management techniques do not eliminate the problem, but rather only concentrate or contain the hazardous contaminants. Residual hazards result from the presence of hazardous and/or contaminated material that remains on-site following active operations or the completion of remedial actions. Residual hazards pose continued risk to humans and the environment and represent a significant and chronic problem that require continuous longterm management (i.e. >1000 years). To protect human health and safeguard the natural environment, a sustainable system is required for the proper management of residual hazards. A sustainable system for the management of residual hazards will require the integration of engineered, institutional and land-use controls to isolate residual contaminants and thus minimize the associated hazards. Engineered controls are physical modifications to the natural setting and ecosystem, including the site, facility, and/or the residual materials themselves, in order to reduce or eliminate the potential for exposure to contaminants of concern (COCs). Institutional controls are processes, instruments, and mechanisms designed to influence human behavior and activity. System failure can involve hazardous material escaping from the confinement because of system degradation (i.e., chronic or acute degradation) or by externalintrusion of the biosphere into the contaminated material because of the loss of institutional control. An ongoing analysis of contemporary and historic sites suggests that the significance of the loss of institutional controls is a critical pathway because decisions made during the operations/remedial action phase, as well as decisions made throughout the residual hazards management period, are key to the longterm success of the prescribed system. In fact

  7. N-Terminal Lipid Modification Is Required for the Stable Accumulation of CyanoQ in Synechocystis sp. PCC 6803

    PubMed Central

    Juneau, Andrea D.; Frankel, Laurie K.; Bricker, Terry M.; Roose, Johnna L.

    2016-01-01

    The CyanoQ protein has been demonstrated to be a component of cyanobacterial Photosystem II (PS II), but there exist a number of outstanding questions concerning its physical association with the complex. CyanoQ is a lipoprotein; upon cleavage of its transit peptide by Signal Peptidase II, which targets delivery of the mature protein to the thylakoid lumenal space, the N-terminal cysteinyl residue is lipid-modified. This modification appears to tether this otherwise soluble component to the thylakoid membrane. To probe the functional significance of the lipid anchor, mutants of the CyanoQ protein have been generated in Synechocystis sp. PCC 6803 to eliminate the N-terminal cysteinyl residue, preventing lipid modification. Substitution of the N-terminal cysteinyl residue with serine (Q-C22S) resulted in a decrease in the amount of detectable CyanoQ protein to 17% that of the wild-type protein. Moreover, the physical properties of the accumulated Q-C22S protein were consistent with altered processing of the CyanoQ precursor. The Q-C22S protein was shifted to a higher apparent molecular mass and partitioned in the hydrophobic phase in TX-114 phase-partitioning experiments. These results suggest that the hydrophobic N-terminal 22 amino acids were not properly cleaved by a signal peptidase. Substitution of the entire CyanoQ transit peptide with the transit peptide of the soluble lumenal protein PsbO yielded the Q-SS mutant and resulted in no detectable accumulation of the modified CyanoQ protein. Finally, the CyanoQ protein was present at normal amounts in the PS II mutant strains ΔpsbB and ΔpsbO, indicating that an association with PS II was not a prerequisite for stable CyanoQ accumulation. Together these results indicate that CyanoQ accumulation in Synechocystis sp. PCC 6803 depends on the presence of the N-terminal lipid anchor, but not on the association of CyanoQ with the PS II complex. PMID:27656895

  8. Expression of the Isoamylase Gene of Flavobacterium odoratum KU in Escherichia coli and Identification of Essential Residues of the Enzyme by Site-Directed Mutagenesis

    PubMed Central

    Abe, Jun-ichi; Ushijima, Chiaki; Hizukuri, Susumu

    1999-01-01

    The isoamylase gene from Flavobacterium odoratum KU was cloned into and expressed in Escherichia coli JM109. The promoter of the gene was successful in E. coli, and the enzyme produced was excreted into the culture medium, depending on the amount of the enzyme expressed. The enzyme found in the culture medium showed almost the same Mr, heat-inactivating constant, and N-terminal sequence as those of the enzyme accumulated in the periplasmic space. This result indicated that the enzyme accumulated in an active form at the periplasm was transported out of the cell. The primary sequence of the enzyme, which was deduced from its nucleotide sequence, showed that the mature enzyme consisted of 741 amino acid residues. By changing five possible residues to Ala independently, it was found that Asp-374, Glu-422, and Asp-497 were essential. The sequences around those residues were highly conserved in isoamylases of different origins and the glycogen operon protein X, GlgX. The comparison of the distance between these essential residues with those of various amylases suggested that the bacterial and plant isoamylase but not GlgX had a longer fourth loop than the other amylases. This longer fourth loop had a possible role in accommodating the long branched chains of native glycogens and starches. PMID:10473430

  9. Multiple anatomy optimization of accumulated dose

    SciTech Connect

    Watkins, W. Tyler Siebers, Jeffrey V.; Moore, Joseph A.; Gordon, James; Hugo, Geoffrey D.

    2014-11-01

    Purpose: To investigate the potential advantages of multiple anatomy optimization (MAO) for lung cancer radiation therapy compared to the internal target volume (ITV) approach. Methods: MAO aims to optimize a single fluence to be delivered under free-breathing conditions such that the accumulated dose meets the plan objectives, where accumulated dose is defined as the sum of deformably mapped doses computed on each phase of a single four dimensional computed tomography (4DCT) dataset. Phantom and patient simulation studies were carried out to investigate potential advantages of MAO compared to ITV planning. Through simulated delivery of the ITV- and MAO-plans, target dose variations were also investigated. Results: By optimizing the accumulated dose, MAO shows the potential to ensure dose to the moving target meets plan objectives while simultaneously reducing dose to organs at risk (OARs) compared with ITV planning. While consistently superior to the ITV approach, MAO resulted in equivalent OAR dosimetry at planning objective dose levels to within 2% volume in 14/30 plans and to within 3% volume in 19/30 plans for each lung V20, esophagus V25, and heart V30. Despite large variations in per-fraction respiratory phase weights in simulated deliveries at high dose rates (e.g., treating 4/10 phases during single fraction beams) the cumulative clinical target volume (CTV) dose after 30 fractions and per-fraction dose were constant independent of planning technique. In one case considered, however, per-phase CTV dose varied from 74% to 117% of prescription implying the level of ITV-dose heterogeneity may not be appropriate with conventional, free-breathing delivery. Conclusions: MAO incorporates 4DCT information in an optimized dose distribution and can achieve a superior plan in terms of accumulated dose to the moving target and OAR sparing compared to ITV-plans. An appropriate level of dose heterogeneity in MAO plans must be further investigated.

  10. H{sup -} charge exchange injection for the NSNS accumulator

    SciTech Connect

    Blumberg, L.N.; Lee, Y.Y.

    1997-08-01

    A scheme for injection into the FODO cell of the National Spallation Neutron Source (NSNS) Accumulator ring is discussed. A 400 {mu}g/cm{sup 2} carbon foil is chosen for a high stripping efficiency and for heating of the foil consideration. Additional schemes to reduce losses due to nuclear and Coulomb scattering at the foil are discussed. Subsequent loss from magnetic field ionization of the residual H{sup 0} component is estimated to be small comparable to nuclear loss. A method for sweeping and collecting the stripped electrons from the foil is presented.

  11. Evaluation of the diffuse contamination of soils caused by residues coming from the large scale production of phosphate fertilisers

    NASA Astrophysics Data System (ADS)

    Martinez, M. J.; Perez-Sirvent, C.; Martinez-Lopez, S.; Bolivar, J. P.; Mosqueda, F.; Vaca, F.; Garcia-Tenorio, R.

    2012-04-01

    The obtaining of phosphate fertilizers results in large amounts of residues that are frequently accumulated in deposits or pools occupying a wide area. These residues are acidic, and contain variable amounts of trace elements and radionuclides. The potentially polluting agents can be leached by rainwater, and so transferred to the surface waters and then to the groundwater after soil infiltration. Since the distribution and thickness of the residue deposits are variable, the contaminants cannot be easily traced back to a single, well defined source, and so a diffuse contamination (nonpoint source pollution) of the surrounding soils and waters occurs. This communication reports the results obtained in the study of soils close to the phosphogypsum deposits placed near Rio Tinto (Huelva, Spain). The zone is affected not only by the mentioned residues but also by the tides due to the vicinity of the sea. The samples studied had a low organic content and a low acidity with average values of 30 mS/cm for the EC. The mineralogical study allowed illite, goethite, quartz, gypsum and kaolinite to be identified as the main mineralogical components. Although the arsenic level was relatively high (about 600 mg/Kg) the data proved that this element is not mobilized into water. Analytical data for 238U , 234U, 235U, 228Th, 230Th, 232Th, 226Ra, 228Ra, 210Po, 40K , 137Cs were also obtained.

  12. Atmospheric mercury accumulation and washoff processes on impervious urban surfaces

    USGS Publications Warehouse

    Eckley, C.S.; Branfireun, B.; Diamond, M.; Van Metre, P.C.; Heitmuller, F.

    2008-01-01

    The deposition and transport of mercury (Hg) has been studied extensively in rural environments but is less understood in urbanized catchments, where elevated atmospheric Hg concentrations and impervious surfaces may efficiently deliver Hg to waterways in stormwater runoff. We determined the rate at which atmospheric Hg accumulates on windows, identified the importance of washoff in removing accumulated Hg, and measured atmospheric Hg concentrations to help understand the relationship between deposition and surface accumulation. The main study location was Toronto, Ontario. Similar samples were also collected from Austin, Texas for comparison of Hg accumulation between cities. Windows provided a good sampling surface because they are ubiquitous in urban environments and are easy to clean/blank allowing the assessment of contemporary Hg accumulation. Hg Accumulation rates were spatially variable ranging from 0.82 to 2.7 ng m-2 d-1 in Toronto and showed similar variability in Austin. The highest accumulation rate in Toronto was at the city center and was 5?? higher than the rural comparison site (0.58 ng m-2 d-1). The atmospheric total gaseous mercury (TGM) concentrations were less than 2?? higher between the rural and urban locations (1.7 ?? 0.3 and 2.7 ?? 1.1 ng m-3, respectively). The atmospheric particulate bound fraction (HgP), however, was more than 3?? higher between the rural and urban sites, which may have contributed to the higher urban Hg accumulation rates. Windows exposed to precipitation had 73 ?? 9% lower accumulation rates than windows sheltered from precipitation. Runoff collected from simulated rain events confirmed that most Hg accumulated on windows was easily removed and that most of the Hg in washoff was HgP. Our results indicate that the Hg flux from urban catchments will respond rapidly to changes in atmospheric concentrations due to the mobilization of the majority of the surface accumulated Hg during precipitation events. ?? 2008 Elsevier

  13. Bacterial accumulation in viscosity gradients

    NASA Astrophysics Data System (ADS)

    Waisbord, Nicolas; Guasto, Jeffrey

    2016-11-01

    Cell motility is greatly modified by fluid rheology. In particular, the physical environments in which cells function, are often characterized by gradients of viscous biopolymers, such as mucus and extracellular matrix, which impact processes ranging from reproduction to digestion to biofilm formation. To understand how spatial heterogeneity of fluid rheology affects the motility and transport of swimming cells, we use hydrogel microfluidic devices to generate viscosity gradients in a simple, polymeric, Newtonian fluid. Using video microscopy, we characterize the random walk motility patterns of model bacteria (Bacillus subtilis), showing that both wild-type ('run-and-tumble') cells and smooth-swimming mutants accumulate in the viscous region of the fluid. Through statistical analysis of individual cell trajectories and body kinematics in both homogeneous and heterogeneous viscous environments, we discriminate passive, physical effects from active sensing processes to explain the observed cell accumulation at the ensemble level.

  14. Metal accumulating plants: Medium's role

    NASA Astrophysics Data System (ADS)

    Rabier, J.; Prudent, P.; Szymanska, B.; Mevy, J.-P.

    2003-05-01

    To evaluate phytoremediation potentialities by metal accumulation in tolerant plants, trials are carried out using in vitro cultures. Organie compounds influence on metal accumulation is studied with metals supplemented media. The tested compounds on zinc and lead absorption by Brassica juncea, are chelating agents (EDTA, citric acid) and soluble organic fractions of compost. EDTA seems to enhance the transfer of lead in plant but it is the opposite in the case of zinc. Citric acid stimulates root absorption for both zinc and lead. For the aqueous extracts of compost, variable effects are obtained according to the origin of compost (green wastes and food wastes). In'all tested conditions of cultures, zinc is mainly exported towards shoot while lead is stored in root.

  15. Mechanisms of intrahepatic triglyceride accumulation

    PubMed Central

    Ress, Claudia; Kaser, Susanne

    2016-01-01

    Hepatic steatosis defined as lipid accumulation in hepatocytes is very frequently found in adults and obese adolescents in the Western World. Etiologically, obesity and associated insulin resistance or excess alcohol intake are the most frequent causes of hepatic steatosis. However, steatosis also often occurs with chronic hepatitis C virus (HCV) infection and is also found in rare but potentially life-threatening liver diseases of pregnancy. Clinical significance and outcome of hepatic triglyceride accumulation are highly dependent on etiology and histological pattern of steatosis. This review summarizes current concepts of pathophysiology of common causes of hepatic steatosis, including non-alcoholic fatty liver disease (NAFLD), alcoholic fatty liver disease, chronic HCV infections, drug-induced forms of hepatic steatosis, and acute fatty liver of pregnancy. Regarding the pathophysiology of NAFLD, this work focuses on the close correlation between insulin resistance and hepatic triglyceride accumulation, highlighting the potential harmful effects of systemic insulin resistance on hepatic metabolism of fatty acids on the one side and the role of lipid intermediates on insulin signalling on the other side. Current studies on lipid droplet morphogenesis have identified novel candidate proteins and enzymes in NAFLD. PMID:26819531

  16. Charge accumulation due to spin transport in magnetic multilayers

    NASA Astrophysics Data System (ADS)

    Zhu, Yao-Hui; Xu, Deng-Hui; Geng, Ai-Cong

    2014-08-01

    Starting with the Valet-Fert theory of the current-perpendicular-to-plane giant magnetoresistance, we studied the charge accumulation due to spin transport in magnetic multilayers by solving Poisson's equation analytically. Our results show that, in ferromagnetic layers, the charge accumulation has two exponential terms with opposite signs and different decaying lengths: the Thomas-Fermi screening length (on the order of angstrom) and the spin diffusion length (tens of nm in 3d ferromagnetic metals). The charge accumulation on the scale of the screening length is spin-unpolarized and also present in spin-independent transport in nonmagnetic multilayers. However, the charge accumulation on the scale of the spin diffusion length is spin-polarized and shows up only in ferromagnetic layers. Our analysis also provides new insights into the widely used quasi-neutrality approximation, which neglects the charge accumulation.

  17. Residual stress characterization for laminated composites

    NASA Astrophysics Data System (ADS)

    Liu, Shao-Chun

    With increasing applications of advanced laminated composites, process-induced residual stress has drawn more and more attention in recent years. Efforts have been devoted to understanding residual stress both quantitatively and qualitatively. In the current study, a novel technique called the Cure Referencing Method was developed which has the capability for measuring the residual stress on the symmetric laminated composite plates. It can also differentiate residual stress into two components: one is due to the mismatch of the coefficient of thermal expansion, the other is caused by the matrix chemical curing shrinkage. The chemical curing shrinkage of the polymer matrix was investigated in further detail. A technique was developed to measure the post-gel chemical curing shrinkage which is the portion of curing shrinkage that really induces the residual stress in the polymer matrix composites. Time-dependent material property is another issue associated with polymer matrix composite materials. The data of several short-term tensile creep tests run at different temperature were used to construct a linear viscoelastic: model for describing the behavior of the composites over a long period of time. It was found that physical aging of the polymer matrix needs to be taken into account in order to have a more accurate representation of the long-term behavior. A fair agreement was obtained between the result of the long-term creep test and the master curve constructed from several momentary creep tests.

  18. Organochlorine residues in human adipose tissue in Spain: Study of an agrarian area

    SciTech Connect

    Camps, M.; Planas, J.; Gomez-Catalan, J.; Sabroso, M.; To-Figueras, J.; Corbella, J.

    1989-02-01

    The environmental pollution by persistent organochlorine residues has received much attention in the last years because of its possible effects on wildlife and human health. These residues - organochlorine insecticides, hexa-chlorobenzene (HCB), polychlorinated biphenyls (PCBs) and, in minor levels, polychlorinated dibenzofurans (PCDFs) and dibenzodioxins (PCDDs) - are accumulated in lipid-rich tissues. Their concentrations in adipose tissues of human populations are the best indices in determining the extent of exposure and in evaluating the hazard. In a previous study on the urban population of Barcelona (Spain) during the years 1982-83, high levels of DDE, DDT, /beta/-HCH and HCB were determined. Recently the incidence of HCB in Barcelona has been confirmed by serum determinations. In the present paper the authors have investigated the levels of organochlorine residues - with special concern on HCB- in human adipose tissues from an agrarian area, located at 130 km from Barcelona, mainly devoted to fruit-trees and cereal culture. Results obtained will form part of an up-to-date report on organochlorine pollution in Spain, including several populations of different geographical and socioeconomic characteristics, that will make it possible to identify the sources and trends of this contamination.

  19. Baseline-free estimation of residual fatigue life using a third order acoustic nonlinear parameter.

    PubMed

    Amura, Mikael; Meo, Michele; Amerini, F

    2011-10-01

    Prediction of crack growth and fatigue life estimation of metals using linear/nonlinear acousto-ultrasound methods is an ongoing issue. It is known that by measuring nonlinear parameters, the relative accumulated fatigue damage can be evaluated. However, there is still a need to measure two crack propagation states to assess the absolute residual fatigue life. A procedure based on the measurement of a third-order acoustic nonlinear parameter is presented to assess the residual fatigue life of a metallic component without the need of a baseline. The analytical evaluation of how the cubic nonlinear-parameter evolves during crack propagation is presented by combining the Paris law to the Nazarov-Sutin crack equation. Unlike other developed models, the proposed model assumes a crack surface topology with variable geometrical parameters. Measurements of the cubic nonlinearity parameter on AA2024-T351 specimens demonstrated high sensitivity to crack propagation and excellent agreement with the predicted theoretical behavior. The advantages of using the cubic nonlinearity parameter for fatigue cracks on metals are discussed by comparing the relevant results of a quadratic nonlinear parameter. Then the methodology to estimate crack size and residual fatigue life without the need of a baseline is presented, and advantages and limitations are discussed.

  20. Inelastic strain analogy for piecewise linear computation of creep residues in built-up structures

    NASA Technical Reports Server (NTRS)

    Jenkins, Jerald M.

    1987-01-01

    An analogy between inelastic strains caused by temperature and those caused by creep is presented in terms of isotropic elasticity. It is shown how the theoretical aspects can be blended with existing finite-element computer programs to exact a piecewise linear solution. The creep effect is determined by using the thermal stress computational approach, if appropriate alterations are made to the thermal expansion of the individual elements. The overall transient solution is achieved by consecutive piecewise linear iterations. The total residue caused by creep is obtained by accumulating creep residues for each iteration and then resubmitting the total residues for each element as an equivalent input. A typical creep law is tested for incremental time convergence. The results indicate that the approach is practical, with a valid indication of the extent of creep after approximately 20 hr of incremental time. The general analogy between body forces and inelastic strain gradients is discussed with respect to how an inelastic problem can be worked as an elastic problem.

  1. Residual images in charged-coupled device detectors

    NASA Astrophysics Data System (ADS)

    Rest, Armin; Mündermann, Lars; Widenhorn, Ralf; Bodegom, Erik; McGlinn, T. C.

    2002-05-01

    We present results of a systematic study of persistent, or residual, images that occur in charged-coupled device (CCD) detectors. A phenomenological model for these residual images, also known as "ghosting," is introduced. This model relates the excess dark current in a CCD after exposure to the number of filled impurity sites which is tested for various temperatures and exposure times. We experimentally derive values for the cross section, density, and characteristic energy of the impurity sites responsible for the residual images.

  2. Choline metabolism in glycinebetaine accumulating and non-accumulating near-isogenic lines of Zea mays and Sorghum bicolor.

    PubMed

    Peel, Gregory J; Mickelbart, Michael V; Rhodes, David

    2010-03-01

    Glycinebetaine (GB) is a compatible solute that is accumulated by some plant species, especially under conditions leading to tissue osmotic stress. Genetic modification for accumulation of GB in an attempt to produce more stress tolerant plants has been a focus for several groups in recent years. However, attempts to increase tissue GB concentrations have been unsuccessful, with many transgenic lines accumulating far lower concentrations than naturally-occurring GB accumulators. A better understanding of the metabolic regulation of GB synthesis is necessary for successful molecular breeding and biotechnology. We utilized previously developed near-isogenic lines for GB accumulation to characterize the biochemical basis for GB deficiency in maize and sorghum. Salinity resulted in increased accumulation of choline in both accumulating and non-accumulating lines. When grown in the presence of NaCl, GB-non-accumulating lines had increased concentrations of choline and phosphocholine, but not GB. Decreased GB synthesis can be explained from the increased concentrations of phosphocholine in planta and the strong inhibition of N-phosphoethanolamine methyltransferase by phosphocholine observed in vitro. The lack of GB accumulation in GB-/- homozygous NILs was not due to the lack of the putative choline monooxygenase (the enzyme responsible for choline oxidation to betaine aldehyde) gene or protein that we describe. The previously identified bet1 locus does not appear to be choline monooxygenase. However, the lack of GB synthesis does affect the synthesis and turnover of choline moieties in GB non-accumulating lines, which may lead to alterations in overall 1-carbon metabolism in plants.

  3. Accumulation of perfluoroalkyl substances in human tissues.

    PubMed

    Pérez, Francisca; Nadal, Martí; Navarro-Ortega, Alícia; Fàbrega, Francesc; Domingo, José L; Barceló, Damià; Farré, Marinella

    2013-09-01

    Perfluoroalkyl substances (PFASs) are environmental pollutants with an important bioaccumulation potential. However, their metabolism and distribution in humans are not well studied. In this study, the concentrations of 21 PFASs were analyzed in 99 samples of autopsy tissues (brain, liver, lung, bone, and kidney) from subjects who had been living in Tarragona (Catalonia, Spain). The samples were analyzed by solvent extraction and online purification by turbulent flow and liquid chromatography coupled to tandem mass spectrometry. The occurrence of PFASs was confirmed in all human tissues. Although PFASs accumulation followed particular trends depending on the specific tissue, some similarities were found. In kidney and lung, perfluorobutanoic acid was the most frequent compound, and at highest concentrations (median values: 263 and 807ng/g in kidney and lung, respectively). In liver and brain, perfluorohexanoic acid showed the maximum levels (median: 68.3 and 141ng/g, respectively), while perfluorooctanoic acid was the most contributively in bone (median: 20.9ng/g). Lung tissues accumulated the highest concentration of PFASs. However, perfluorooctane sulfonic acid and perfluorooctanoic acid were more prevalent in liver and bone, respectively. To the best of our knowledge, the accumulation of different PFASs in samples of various human tissues from the same subjects is here reported for the very first time. The current results may be of high importance for the validation of physiologically based pharmacokinetic models, which are being developed for humans. However, further studies on the distribution of the same compounds in the human body are still required.

  4. Mercury accumulation of three Lactarius mushroom species.

    PubMed

    Falandysz, Jerzy

    2017-01-01

    Accumulation, distribution and potential dietary intake of mercury accumulated by mushrooms of Lactarius species L. delicious, L. volemus and L. deterrimus were studied in the Pomerania region of Poland. In total, 212 fruiting bodies and 106 underlying topsoil samples were analyzed. Analysis indicated that the concentrations of Hg were at low levels both in mushrooms and forest topsoils for a majority of the locations investigated. L. volemus that grew in soils with only a slightly elevated contamination (0.11±0.07mgkg(-1) of dried soil), very efficiently accumulated Hg in fruiting bodies and concentration levels were at 3.7±1.3mgkg(-1) of dry biomass in caps and at 1.9±0.9mgkg(-1) of dry biomass in stipes. Consumption of mushrooms foraged from the Sobowidz forest, which is close to a foundry using ferrous and non-ferrous metals could result in a Hg intake that exceeds the current statutory limits.

  5. [Total amitraz residues in bee honeys].

    PubMed

    Hemmerling, C; Augustyniak, B; Risto, C

    1991-01-01

    A total of 330 bee honey samples was analysed in 1986-1990, and the results are reported. Analysis was performed according to the method for the amitraz total residue determination by hydrolysis and steam distillation as described. 60% of the honeys were practically not contamined (total residue content amounting to 0.01 mg/kg), 8.5% of the honeys contained more than 0.05 mg/kg. Maximal values of 0.2-0.5 mg/kg were stated. 54% of the rape-honeys contained more than 0.01 mg/kg, 19% more than 0.05 mg/kg.

  6. Field Test Kit for Gun Residue Detection

    SciTech Connect

    WALKER, PAMELA K.; RODACY, PHILIP J.

    2002-01-01

    One of the major needs of the law enforcement field is a product that quickly, accurately, and inexpensively identifies whether a person has recently fired a gun--even if the suspect has attempted to wash the traces of gunpowder off. The Field Test Kit for Gunshot Residue Identification based on Sandia National Laboratories technology works with a wide variety of handguns and other weaponry using gunpowder. There are several organic chemicals in small arms propellants such as nitrocellulose, nitroglycerine, dinitrotoluene, and nitrites left behind after the firing of a gun that result from the incomplete combustion of the gunpowder. Sandia has developed a colorimetric shooter identification kit for in situ detection of gunshot residue (GSR) from a suspect. The test kit is the first of its kind and is small, inexpensive, and easily transported by individual law enforcement personnel requiring minimal training for effective use. It will provide immediate information identifying gunshot residue.

  7. Arsenic accumulation by edible aquatic macrophytes.

    PubMed

    Falinski, K A; Yost, R S; Sampaga, E; Peard, J

    2014-01-01

    Edible aquatic macrophytes grown in arsenic (As)-contaminated soil and sediment were investigated to determine the extent of As accumulation and potential risk to humans when consumed. Nasturtium officinale (watercress) and Diplazium esculentum (warabi) are two aquatic macrophytes grown and consumed in Hawaii. Neither has been assessed for potential to accumulate As when grown in As-contaminated soil. Some former sugarcane plantation soils in eastern Hawaii have been shown to have concentrations of total As over 500 mg kg(-1). It was hypothesized that both species will accumulate more As in contaminated soils than in non-contaminated soils. N. officinale and D. esculentum were collected in areas with and without As-contaminated soil and sediment. High soil As concentrations averaged 356 mg kg(-1), while low soil As concentrations were 0.75 mg kg(-1). Average N. officinale and D. esculentum total As concentrations were 0.572 mg kg(-1) and 0.075 mg kg(-1), respectively, corresponding to hazard indices of 0.12 and 0.03 for adults. Unlike previous studies where watercress was grown in As-contaminated water, N. officinale did not show properties of a hyperaccumulator, yet plant concentrations in high As areas were more than double those in low As areas. There was a slight correlation between high total As in sediment and soil and total As concentrations in watercress leaves and stems, resulting in a plant uptake factor of 0.010, an order of magnitude higher than previous studies. D. esculentum did not show signs of accumulating As in the edible fiddleheads. Hawaii is unique in having volcanic ash soils with extremely high sorption characteristics of As and P that limit release into groundwater. This study presents a case where soils and sediments were significantly enriched in total As concentration, but the water As concentration was below detection limits.

  8. Ecotoxicological risk assessment linked to the discharge by hospitals of bio-accumulative pharmaceuticals into aquatic media: The case of mitotane.

    PubMed

    Aurélien, Brackers de Hugo; Sylvie, Bony; Alain, Devaux; Jérôme, Guitton; Yves, Perrodin

    2013-11-01

    The release of hospital wastewater into the urban sewer networks contributes to the general contamination of aquatic media by pharmaceutical residues. These residues include bio-accumulative pharmaceuticals that lead to increased risk for ecosystems because they can concentrate in organisms and food chains, and therefore reach toxic levels. In order to assess the ecotoxicological risks linked to this particular category of residues, we have developed a specific method, by combining a theoretical calculation of pollutant concentrations in organisms to estimate Body Residue (BR), and ecotoxicity biomarkers in fish cell lines, enabling the calculation of a Critical Body Residue (CBR). This method finally results in the calculation of a specific risk quotient (Qb=BR/CBR), characterizing the risk linked to this type of pollutant. This method was applied to mitotane, a bio-accumulative pharmaceutical typically found in hospital wastewater, in the framework of an exposure scenario corresponding to the discharge of all the hospital wastewaters into the Rhone River which flows through the city of Lyon, France. This approach leads to risk quotients (Qb and Qbg) much higher than those found with the classical approach, i.e. Q=PEC/PNEC (Predictive Environmental Concentration/Predictive Non Effect Concentration)=0.0006. This difference in the appreciation of risk is important when using cytotoxicity as the criterion for measuring the toxicity of mitotane (Qb=0.056) and it is even greater when the criterion used is genotoxicity (Qbg=6.8). This study must be now consolidated by taking the biomagnification of the pharmaceuticals into consideration.

  9. On tide-induced lagrangian residual current and residual transport: 1. Lagrangian residual current

    USGS Publications Warehouse

    Feng, Shizuo; Cheng, Ralph T.; Pangen, Xi

    1986-01-01

    Residual currents in tidal estuaries and coastal embayments have been recognized as fundamental factors which affect the long-term transport processes. It has been pointed out by previous studies that it is more relevant to use a Lagrangian mean velocity than an Eulerian mean velocity to determine the movements of water masses. Under weakly nonlinear approximation, the parameter k, which is the ratio of the net displacement of a labeled water mass in one tidal cycle to the tidal excursion, is assumed to be small. Solutions for tides, tidal current, and residual current have been considered for two-dimensional, barotropic estuaries and coastal seas. Particular attention has been paid to the distinction between the Lagrangian and Eulerian residual currents. When k is small, the first-order Lagrangian residual is shown to be the sum of the Eulerian residual current and the Stokes drift. The Lagrangian residual drift velocity or the second-order Lagrangian residual current has been shown to be dependent on the phase of tidal current. The Lagrangian drift velocity is induced by nonlinear interactions between tides, tidal currents, and the first-order residual currents, and it takes the form of an ellipse on a hodograph plane. Several examples are given to further demonstrate the unique properties of the Lagrangian residual current.

  10. Edaphic factors affecting the toxicity and accumulation of arsenate in the earthworm Lumbricus terrestris

    SciTech Connect

    Meharg, A.A.; Shore, R.F.; Broadgate, K.

    1998-06-01

    The toxicity and accumulation of arsenate was determined in the earthworm Lumbricus terrestris in soil from different layers of a forest profile. Toxicity increased fourfold between 2 and 10 d. Edaphic factors (pH, soil organic matter, and depth in soil profile) also affected toxicity with a three fold decrease in the concentration that causes 50% mortality with increasing depth in soil. In a 4-d exposure study, there was no evidence of arsenic bioconcentration in earthworm tissue, although bioaccumulation was occurring. There was a considerable difference in tissue residues between living and dead earthworms, with dead worms having higher concentrations. This difference was dependent on both soil arsenate concentration and on soil type. Over a wide range of soil arsenate concentrations, earthworm arsenic residues are homeostatically maintained in living worms, but this homeostasis breaks down during death. Alternatively, equilibration with soil residues may occur via accumulation after death. In long-term accumulation studies in soils dosed with a sublethal arsenate concentration, bioconcentration of arsenate did not occur until day 12, after which earthworm concentrations rose steadily above the soil concentration, with residues in worms three fold higher than soil concentrations by the termination of the study. This bioconcentration only occurred in depurated worms over the time period of the study. Initially, depurated worms had lower arsenic concentrations than undepurated until tissue concentrations were equivalent to the soil concentration. Once tissue concentration was greater than soil concentration, depurated worms had higher arsenic residues than undepurated.

  11. Transformation of corn plant residues in loamy and sandy substrates

    NASA Astrophysics Data System (ADS)

    Mal'tseva, A. N.; Zolotareva, B. N.; Pinskii, D. L.

    2014-05-01

    The mineralization and humification dynamics of corn plant residues in loamy and sandy substrates have been studied under laboratory conditions. It has been shown that the dynamics are determined by the undulating development laws of the microbial community under constant temperature and moisture conditions. At the same time, the intensity and final results of the processes significantly differ depending on the composition and properties of the mineral substrate. The loss of Corg during the mineralization and the content of newly formed humic substances reached the maximum values a month after the beginning of the experiment. The mineralization is more intensive in sand at the early stages, and the humification is more active in loam throughout the incubation period. The loamy substrate has better protective properties compared to the sand; therefore, it favors the accumulation of significant amounts of fulvic acids (FAs), along with humic acids (HAs), and causes the relative fulvatization of the humic substances. It has been found using densimetric fractionation and Fourier IR spectroscopy that the different mineralogy of the fractions results in differences in the chemical composition of the formed mineral-organic compounds of newly formed humic substances, mainly due to carboxyl and nitrogen-containing groups. The similarity of the humification products in the heavy fractions of the loamy and sandy substrates has been revealed.

  12. Grinding Induced Changes in Residual Stresses of Carburized Gears

    SciTech Connect

    Lemaster, Robert A; Boggs, Bryan L; Bunn, Jeffrey R; Hubbard, Camden R; Watkins, Thomas R

    2009-01-01

    This paper presents the results of a study performed to measure the change in residual stress that results from the finish grinding of carburized gears. Residual stresses were measured in five gears using the x-ray diffraction equipment in the Large Specimen Residual Stress Facility at Oak Ridge National Laboratory. Two of the gears were hobbed, carburized, quenched and tempered, but not finished. The remaining three gears were processed similarly, but were finish ground. The residual stresses were measured at 64 different locations on a tooth from each gear. Residual stresses were also measured at fewer points on other teeth to determine the tooth-to-tooth variation. Tooth profile measurements were made of the finished and unfinished gear samples. The results show a fairly uniform and constant compressive residual field in the nonfinished gears. There was a significant reduction in the average residual stress measured in the finished gears. Additionally, there was a significant increase in the variability of the residual stress that was introduced by the grinding process. Analysis of the data suggests a linear relationship between the change in average residual stress and the amount of material removed by the grinding process.

  13. Use of vacuum residue in thermal cracking

    SciTech Connect

    Mikulla, K.D.; Wernicke, H.J.

    1981-03-24

    Vacuum residue is used for production of olefins by first separating, preferably by solvent extraction, the asphalt therein , blending resultant asphalt depleted fraction with a lighter fraction, E.G., a vacuum gas oil, and then subjecting the blend to a conventional catalytic hydrogenation step prior to thermal cracking. The hydrogenate may be separated into fractions with the heavy fraction only being thermally cracked.

  14. Residue-based scattering factors.

    PubMed

    Xu, Hongliang

    2016-11-01

    A glob is defined as a group of atoms in the crystal which can be chosen in various ways. Globs themselves can be used as scattering elements in the theory of structure determination, just as atoms are used at present. In this paper, amino-acid residues are chosen to form globs and empirical formulas for residue-based scattering factors have been developed.

  15. Mechanically induced residual stresses: Modelling and characterisation

    NASA Astrophysics Data System (ADS)

    Stranart, Jean-Claude E.

    Accurate characterisation of residual stress represents a major challenge to the engineering community. This is because it is difficult to validate the measurement and the accuracy is doubtful. It is with this in mind that the current research program concerning the characterisation of mechanically induced residual stresses was undertaken. Specifically, the cold expansion of fastener holes and the shot peening treatment of aerospace alloys, aluminium 7075 and titanium Ti-6Al-4V, are considered. The objective of this study is to characterise residual stresses resulting from cold working using three powerful techniques. These are: (i) theoretical using three dimensional non-linear finite element modelling, (ii) semi-destructive using a modified incremental hole drilling technique and (iii) nondestructive using a newly developed guided wave method supplemented by traditional C-scan measurements. The three dimensional finite element results of both simultaneous and sequential cold expansion of two fastener holes revealed the importance of the separation distance, the expansion level and the loading history upon the development and growth of the plastic zone and unloading residual stresses. It further showed that the commonly adopted two dimensional finite element models are inaccurate and incapable of predicting these residual stresses. Similarly, the dynamic elasto-plastic finite element studies of shot peening showed that the depth of the compressed layer, surface and sub-surface residual stresses are significantly influenced by the shot characteristics. Furthermore, the results reveal that the separation distance between two simultaneously impacting shots governs the plastic zone development and its growth. In the semi-destructive incremental hole drilling technique, the accuracy of the newly developed calibration coefficients and measurement techniques were verified with a known stress field and the method was used to measure peening residual stresses. Unlike

  16. Capacity of the aquatic fern (Salvinia minima Baker) to accumulate high concentrations of nickel in its tissues, and its effect on plant physiological processes.

    PubMed

    Fuentes, Ignacio I; Espadas-Gil, Francisco; Talavera-May, Carlos; Fuentes, Gabriela; Santamaría, Jorge M

    2014-10-01

    An experiment was designed to assess the capacity of Salvinia minima Baker to uptake and accumulate nickel in its tissues and to evaluate whether or not this uptake can affect its physiology. Our results suggest that S. minima plants are able to take up high amounts of nickel in its tissues, particularly in roots. In fact, our results support the idea that S. minima might be considered a hyper-accumulator of nickel, as it is able to accumulate 16.3 mg g(-1) (whole plant DW basis). Our results also showed a two-steps uptake pattern of nickel, with a fast uptake of nickel at the first 6 to 12h of being expose to the metal, followed by a slow take up phase until the end of the experiment at 144 h. S. minima thus, may be considered as a fern useful in the phytoremediation of residual water bodies contaminated with this metal. Also from our results, S. minima can tolerate fair concentrations of the metal; however, at concentrations higher than 80 μM Ni (1.5 mg g(-1) internal nickel concentration), its physiological performance can be affected. For instance, the integrity of cell membranes was affected as the metal concentration and exposure time increased. The accumulation of high concentrations of internal nickel did also affect photosynthesis, the efficiency of PSII, and the concentration of photosynthetic pigments, although at a lower extent.

  17. Simulating wheat crop residue reflectance with the SAIL model.

    SciTech Connect

    Su, H.; Ransom, M. D.; Kanemasu, E. T.; Environmental Assessment; Kansas State Univ.; Univ. of Georgia

    1997-01-01

    Estimating crop residue is important for soil conservation and tillage management. Remote sensing could provide the potential of estimating amount of crop residue using reflectance measurement and model simulation procedures. The purpose of this study was (1) to use the SAIL (Scattering by Arbitrarily Inclined Leaves) model to simulate crop residue reflectance from wheat, Triticum aestivum (L.), at visible and near-infrared wavelengths; and (2) to compare the simulated reflectance with field-measured reflectance for evaluating the simulation model. Simulated reflectance in visible and near-infrared wavebands was overestimated about 1 to 5 per cent, compared with measured reflectance in the field. However, overestimation was within the experimental errors. Results suggest that the SAIL model can be used to simulate crop residue reflectance in different wheat crop residue covers and that wheat crop residue cover could be estimated by inverting the model.

  18. Determinants of rice residue burning in the field.

    PubMed

    Haider, Mohammed Ziaul

    2013-10-15

    This study determines the factors that influence rice residue burning in the field. We consider the southwest region of Bangladesh as the study site. Our results indicate that while straw length, low-elevation land, and distance of the plot from homestead positively and significantly influence the rice residue burning decision, residue price negatively and significantly influences the residue burning decision of farmers. Our study proposes subsidies for the purchase of new varieties of seeds and/or education in order to persuade farmers to move to short-straw varieties on high/medium-elevation lands as policy interventions for handling the residue burning issue. Another option might be to switch from residue burning to incorporation. Research and development efforts into shortening straw length and shortening the time period between planting and harvesting time are among other options that would mitigate the problem under consideration.

  19. Spontaneous vegetation encroachment upon bauxite residue (red mud) as an indicator and facilitator of in situ remediation processes.

    PubMed

    Santini, Talitha C; Fey, Martin V

    2013-01-01

    The spontaneous colonization of a bauxite residue (alumina refining tailings) deposit by local vegetation in Linden, Guyana, over 30 years, indicates that natural weathering processes can ameliorate tailings to the extent that it can support vegetation. Samples were collected from vegetated and unvegetated areas to investigate the relationships between bauxite residue properties and vegetation cover. Compared to unvegetated areas, bauxite residue in vegetated areas had lower pH (mean pH 7.9 vs 10.9), lower alkalinity (mean titratable alkalinity 0.4 vs 1.4 mol H(+) kg(-1)), lower electrical conductivity (mean EC 0.3 vs 2.1 mS cm(-1)), lower total Al (mean Al2O3 19.8 vs 25.8% wt) and Na (mean Na2O 0.9 vs 3.7% wt), and less sodalite and calcite. Accumulation of N, NH4(+), and organic C occurred under vegetation, demonstrating the capacity for plants to modify residue to suit their requirements as a soil-like growth medium. Aeolian redistribution of coarse grained tailings appeared to support vegetation establishment by providing a thin zone of enhanced drainage at the surface. Natural pedogenic processes may be supplemented by irrigation, enhanced drainage, and incorporation of sand and organic matter at other tailings deposits to accelerate the remediation process and achieve similar results in a shorter time frame.

  20. Trace element accumulation in lotic dragonfly nymphs: Genus matters

    PubMed Central

    Fletcher, Dean E.; Lindell, Angela H.; Stillings, Garrett K.; Blas, Susan A.; McArthur, J. Vaun

    2017-01-01

    between sites. Our results underscore the element and taxa specific nature of trace element accumulation, but we provide evidence of accumulation of some trace elements differing among dragonflies that differ in body form and utilize different sub-habitats within a stream reach. PMID:28207806

  1. Trace element accumulation in lotic dragonfly nymphs: Genus matters.

    PubMed

    Fletcher, Dean E; Lindell, Angela H; Stillings, Garrett K; Blas, Susan A; McArthur, J Vaun

    2017-01-01

    between sites. Our results underscore the element and taxa specific nature of trace element accumulation, but we provide evidence of accumulation of some trace elements differing among dragonflies that differ in body form and utilize different sub-habitats within a stream reach.

  2. Bioavailability and release of nonextractable (bound) residues of chiral cycloxaprid using geophagous earthworm Metaphire guillelmi in rice paddy soil.

    PubMed

    Liu, Xuanqi; Xu, Xiaoyong; Zhang, Hanxue; Li, Chao; Shao, Xusheng; Ye, Qingfu; Li, Zhong

    2015-09-01

    The widespread adoption of neonicotinoids has led to a move away from integrated pest management (IPM) and caused adverse effects on non-target invertebrate species. Due to their living in close contact with and consuming large amounts of soil, earthworms are a model organism used to study bioaccumulation. We investigated the bioaccumulation and release of bound, or non-extractable, residues (BRs) of (14)C labeled racemic cycloxaprid (CYC) and its individual enantiomers by the geophagous earthworm Metaphire guillelmi. In a previous work, the fraction of BRs of (14)C-CYC individual enantiomers reached up to 70-85% of the initially spiked radioactivity after 100 d of treatment. The bulk volume of the soil was then diluted by a factor of 15 with fresh soil. Here we showed that after earthworms lived in the soil-bound residues for 28 d, 11-25% of the previously bound radioactivity in soil was extractable by solvent, mineralized to CO2, and accumulated in earthworm tissues. While earthworms were exposed to (14)C-CYC a two-compartment accumulation model could explain the bio-accumulation as individual enantiomers. At the end of the experiment, the biota-sediment accumulation factors were between 0.59 and 0.82, which suggested CYC immobilization in the soil resulted in its bioavailability being reduced which enhanced its degradation. Additionally, the elimination of CYC individual enantiomers from M. guillelmi was fitted to an availability-adjusted decay model with a half-life of 9 d. Stereoselective release or bioavailability between CYC enantiomers was not observed. These results provide the important data about the release of BRs of CYC and potential transfer in the food chain to support the long-term environmental risk assessment of neonicotinoids.

  3. A blood pressure-associated variant of the SLC39A8 gene influences cellular cadmium accumulation and toxicity

    PubMed Central

    Zhang, Ruoxin; Witkowska, Kate; Afonso Guerra-Assunção, José; Ren, Meixia; Ng, Fu Liang; Mauro, Claudio; Tucker, Arthur T.; Caulfield, Mark J.; Ye, Shu

    2016-01-01

    Genome-wide association studies have revealed a relationship between inter-individual variation in blood pressure and the single nucleotide polymorphism rs13107325 in the SLC39A8 gene. This gene encodes the ZIP8 protein which co-transports divalent metal cations, including heavy metal cadmium, the accumulation of which has been associated with increased blood pressure. The polymorphism results in two variants of ZIP8 with either an alanine (Ala) or a threonine (Thr) at residue 391. We investigated the functional impact of this variant on protein conformation, cadmium transport, activation of signalling pathways and cell viability in relation to blood pressure regulation. Following incubation with cadmium, higher intracellular cadmium was detected in cultured human embryonic kidney cells (HEK293) expressing heterologous ZIP8-Ala391, compared with HEK293 cells expressing heterologous ZIP8-Thr391. This Ala391-associated cadmium accumulation also increased the phosphorylation of the signal transduction molecule ERK2, activation of the transcription factor NFκB, and reduced cell viability. Similarly, vascular endothelial cells with the Ala/Ala genotype had higher intracellular cadmium concentration and lower cell viability than their Ala/Thr counterpart following cadmium exposure. These results indicate that the ZIP8 Ala391-to-Thr391 substitution has an effect on intracellular cadmium accumulation and cell toxicity, providing a potential mechanistic explanation for the association of this genetic variant with blood pressure. PMID:27466201

  4. Differential accumulation of four phaseolin glycoforms in transgenic tobacco.

    PubMed

    Bustos, M M; Kalkan, F A; VandenBosch, K A; Hall, T C

    1991-03-01

    An intron-less phaseolin gene was used to express phaseolin polypeptides in transgenic tobacco plants. The corresponding amounts of phaseolin immunoreactive polypeptides and mRNA were similar to those found in plants transformed with a bean genomic DNA sequence that encodes an identical beta-phaseolin subunit. These results justified the use of the intron-less gene for engineering of the phaseolin protein by oligonucleotide-directed mutagenesis. Each and both of the two Asn residues that serve as glycan acceptors in wild-type phaseolin were modified to prevent N-linked glycosylation. Wild-type (beta wti-) and mutant phaseolin glycoforms (beta dgly1, beta dgly2 and beta dgly1,2) were localized to the protein body matrix by immunogold microscopy. Although quantitative slot-blot hybridization analysis showed similar levels of phaseolin mRNA in transgenic seed derived from all constructs, seed from the beta dgly1 and beta dgly2 mutations contained only 41% and 73% of that expressed from the wild-type control; even less (23%) was present in seed of plants transformed with the phaseolin beta dgly1,2 gene. Additionally, the profile of 25-29 kDa processed peptides was different for each of the glycoforms, indicating that processing of the full-length phaseolin polypeptides was modified. Thus, although targeting of phaseolin to the protein body was not eliminated by removal of the glycan side-chains, decreased accumulation and stability of the full-length phaseolin protein in transgenic tobacco seed were evident.

  5. Salt tectonics and oil accumulation in Campos basin, offshore Brazil

    SciTech Connect

    Figueiredo, A.M.F.; Pereira, M.J.; Mohriak, W.U.; Gaglianone, P.C.; Trinidade, L.A.F.

    1985-02-01

    Salt tectonics were responsible for the development of optimum conditions for accumulation of large hydrocarbon reserves in Campos basin. The salt movements, triggered by basin tilting and differential loading, initially formed low-relief salt pillows that controlled the porous facies of the shallow-water Macae limestones. The continuous evolution of halokinetic processes produced growth faults, rollover crests, and faulted anticlines. Upper Cretaceous turbidite sandstones were channelized in the downthrown blocks of growth faults. Salt-collapse, residual, and relief-inversion features were formed in areas where the salt was sufficiently thick. The oil, generated in the Neocomian shales of Lagoa Feia Formation, migrated to upper formations through normal faults associated with the rift phase, stratigraphic conduits such as porous rocks and regional unconformities, and gaps created by salt flowage in the Aptian evaporite section. Oil migration to the post-salt rocks was favored by active growth faults and by the presence of a regional unconformity developed at the Cretaceous-Tertiary boundary and covered by turbidite sheet sands. The oils underwent progressive alteration along their paths to the post-salt reservoirs. Oil-oil and oil-source rock correlations suggest that the hydrocarbons trapped in many diverse plays, although affected by bacterial degradation and water washing, belong to only one oil family. The oil degradation was probably enhanced by meteoric water invasions during Tertiary low stands of sea level in areas close to the paleocoastline. These phenomena resulted in large amounts of oil becoming heavier and enriched in sulfur, resins, asphaltenes, and cycloparaffins.

  6. Constant-Differential-Pressure Two-Fluid Accumulator

    NASA Technical Reports Server (NTRS)

    Piecuch, Benjamin; Dalton, Luke T.

    2010-01-01

    A two-fluid accumulator has been designed, built, and demonstrated to provide an acceptably close approximation to constant differential static pressure between two fluids over the full ranges of (1) accumulator stroke, (2) rates of flow of the fluids, and (3) common static pressure applied to the fluids. Prior differential- pressure two-fluid accumulators are generally not capable of maintaining acceptably close approximations to constant differential pressures. The inadequacies of a typical prior differential-pressure two-fluid accumulator can be summarized as follows: The static differential pressure is governed by the intrinsic spring rate (essentially, the stiffness) of an accumulator tank. The spring rate can be tailored through selection of the tank-wall thickness, selection of the number and/or shape of accumulator convolutions, and/or selection of accumulator material(s). Reliance on the intrinsic spring rate of the tank results in three severe limitations: (1) The spring rate and the expulsion efficiency tend to be inversely proportional to each other: that is to say, as the stiffness (and thus the differential pressure) is increased, the range of motion of the accumulator is reduced. (2) As the applied common static pressure increases, the differential pressure tends to decrease. An additional disadvantage, which may or may not be considered limiting, depending on the specific application, is that an increase in stiffness entails an increase in weight. (3) The additional weight required by a low expulsion efficiency accumulator eliminates the advantage given to such gas storage systems. The high expulsion efficiency provided by this two-fluid accumulator allows for a lightweight, tightly packaged system, which can be used in conjunction with a fuel cell-based system.

  7. Shallow magma accumulation at Kilauea Volcano, Hawai'i, revealed by microgravity surveys

    USGS Publications Warehouse

    Johnson, David J.; Eggers, Albert A.; Bagnardi, Marco; Battaglia, Maurizio; Poland, Michael P.; Miklius, Asta

    2010-01-01

    Using microgravity data collected at Kilauea Volcano, Hawai'i (United States), between November 1975 and January 2008, we document significant mass increase beneath the east margin of Halema'uma'u Crater, within Kilauea's summit caldera. Surprisingly, there was no sustained uplift accompanying the mass accumulation. We propose that the positive gravity residual in the absence of significant uplift is indicative of magma accumulation in void space (probably a network of interconnected cracks), which may have been created when magma withdrew from the summit in response to the 29 November 1975 M = 7.2 south flank earthquake. Subsequent refilling documented by gravity represents a gradual recovery from that earthquake. A new eruptive vent opened at the summit of Kilauea in 2008 within a few hundred meters of the positive gravity residual maximum, probably tapping the reservoir that had been accumulating magma since the 1975 earthquake.

  8. Shallow magma accumulation at Kīlauea Volcano, Hawai‘i, revealed by microgravity surveys

    USGS Publications Warehouse

    Johnson, Daniel J.; Eggers, Albert A.; Bagnardi, Marco; Battaglia, Maurizio; Poland, Michael P.; Miklius, Asta

    2010-01-01

    Using microgravity data collected at Kīlauea Volcano, Hawai‘i (United States), between November 1975 and January 2008, we document significant mass increase beneath the east margin of Halema‘uma‘u Crater, within Kīlauea's summit caldera. Surprisingly, there was no sustained uplift accompanying the mass accumulation. We propose that the positive gravity residual in the absence of significant uplift is indicative of magma accumulation in void space (probably a network of interconnected cracks), which may have been created when magma withdrew from the summit in response to the 29 November 1975 M = 7.2 south flank earthquake. Subsequent refilling documented by gravity represents a gradual recovery from that earthquake. A new eruptive vent opened at the summit of Kīlauea in 2008 within a few hundred meters of the positive gravity residual maximum, probably tapping the reservoir that had been accumulating magma since the 1975 earthquake.

  9. Time Scale of Gas Accumulation before the 2010 Eyjafjallajökull Eruption (Iceland) from 210Po Radioactive Excess

    NASA Astrophysics Data System (ADS)

    Sigmarsson, O.

    2015-12-01

    The 2010 mildly explosive eruption at Eyjafjallajökull, Iceland, produced mingled tephra of benmoreitic and trachytic composition whereas alkali basalt was emitted during preceding flank eruption. Tephra of the first explosive phase are composed of three glass types, alkaline rhyolite, mixed benmoreite, and basalt. The early formed benmoreitic tephra (erupted on 15 and 17 April 2010) had large 210Po in excess of 210Pb [(210Po/210Pb)0= 1.88)] at the time of eruption, and possibly a small 210Pb excess over its parent 226Ra. In contrast, the preceding flank eruption produced basalt with (210Po)0 = 0, upon eruption, and the final trachyte (end of May 2010) had lost most of its 210Po during open-system degassing. The 210Po excess in the first erupted benmoreites is interpreted to result from 210Po degassing of basaltic magma and the accumulation of 210Po-enriched gas, either in the upper part of the basaltic intrusion, below the rhyolite-basalt interface, on in the pre-existing residual rhyolitic magma chamber. A model of radon and polonium accumulation in the rhyolitic reservoir, allows calculating the ratio of mass of basalt magma degassing over mass of magma accumulating excess gas. This ratio decreased from 20 to 15 over 2 days, implying zoned magma reservoir, with the uppermost and gas-richest part erupted first. The duration of pre-eruptive gas accumulation in this model is approximately one year. This corresponds closely to the initiation of a seismic swarm beneath Eyjafjallajökull, early June 2009, which was the first pre-eruptive signal detected. The coincidence between initiation of gas accumulation at relatively shallow depth and deeper seismicity strongly suggests that the excess gas phase originated from a basalt magma batch intruded at depth, and that this gas phase reached the surface approximately a year later.

  10. Proposal for defining the relevance of drug accumulation derived from single dose study data for modified release dosage forms.

    PubMed

    Scheerans, Christian; Heinig, Roland; Mueck, Wolfgang

    2015-03-01

    Recently, the European Medicines Agency (EMA) published the new draft guideline on the pharmacokinetic and clinical evaluation of modified release (MR) formulations. The draft guideline contains the new requirement of performing multiple dose (MD) bioequivalence studies, in the case when the MR formulation is expected to show 'relevant' drug accumulation at steady state (SS). This new requirement reveals three fundamental issues, which are discussed in the current work: first, measurement for the extent of drug accumulation (MEDA) predicted from single dose (SD) study data; second, its relationship with the percentage residual area under the plasma concentration-time curve (AUC) outside the dosing interval (τ) after SD administration, %AUC(τ-∞)SD ; and third, the rationale for a threshold of %AUC(τ-∞)SD that predicts 'relevant' drug accumulation at SS. This work revealed that the accumulation ratio RA,AUC , derived from the ratio of the time-averaged plasma concentrations during τ at SS and after SD administration, respectively, is the 'preferred' MEDA for MR formulations. A causal relationship was derived between %AUC(τ-∞)SD and RA,AUC , which is valid for any drug (product) that shows (dose- and time-) linear pharmacokinetics regardless of the shape of the plasma concentration-time curve. Considering AUC thresholds from other guidelines together with the causal relationship between %AUC(τ-∞)SD and RA,AUC indicates that values of %AUC(τ-∞)SD ≤ 20%, resulting in RA,AUC ≤ 1.25, can be considered as leading to non-relevant drug accumulation. Hence, the authors suggest that 20% for %AUC(τ-∞)SD is a reasonable threshold and selection criterion between SD or MD study designs for bioequivalence studies of new MR formulations.

  11. MODELING LONG-TERM DYNAMICS OF LITTER ACCUMULATION IN RESPONSE TO STATIC AND VARIABLE HYDROPERIODS

    EPA Science Inventory

    Accumulated litter from emergent species like the cattail hybrid (Typha glauca Godr.) can influence local abiotic conditions, other biota, and ecosystem processes. Litter accumulation results from high production coupled with slow breakdown rates. Wetland managers regularly mani...

  12. Assessing wheat residue cover with hyperspectral remote sensing

    NASA Astrophysics Data System (ADS)

    Tripathy, Rojalin; Manjunath, K. R.

    2016-04-01

    Hyperspectral remote sensing can aid in discriminating crop residue owing to the ability of narrow bands to capture the unique absorption feature of soil and residue. The present study was carried out to find out the suitable narrow spectral bands and hyper-spectral indices for discriminating wheat residue (stubble and burnt). Ground spectra of wheat residue and the adjoining soil were collected using the ASD fieldspec™ spectroradiometer. The best spectral range was derived using the Stepwise Discriminating Analysis (SDA). `F' statistics from one-way ANOVA was used to find out the best index for discriminating wheat residue from soil. EO1-Hyperion data over Anand-Borsad region of Gujarat state in India was acquired free of cost from USGS earth explorer website (http://eo1.usgs.gov/) to apply the field based result over the Hyperion scene. Spectral Angle Mapper (SAM) classification scheme was used to generate the wheat residue cover over the Hyperion scene. Among the hyperspectral indices evaluated for this study the Cellulose Absorption Index (CAI) was found to be the best and hence CAI was used to classify the Hyperion scene for discriminating crop residue in field and also the burnt wheat residue. Results indicated that the wave bands at 10 nm width in the SWIR spectral region specifically from 1500-1700nm and 1900 to 2300nm are most suitable for wheat residue discrimination. The SAM classification technique is suitable for classifying the wheat residues with an overall accuracy of around 80 % whereas classification based on CAI could be used successfully to identify both wheat stubble and the burnt residues. This study concluded that wheat residue can be mapped for a large area with an accuracy of 80% using the space borne hyperspectral data with.

  13. Limitations in the determination of maximum residue limits and highest residues of pesticides: Part I.

    PubMed

    Horváth, Zsuzsanna; Sali, Judit; Zentai, Andrea; Dorogházi, Enikő; Farkas, Zsuzsa; Kerekes, Kata; Ambrus, Árpád

    2014-01-01

    The pesticide usages are controlled by comparing residue concentrations in treated commodities to legally permitted maximum levels (MRLs) determined based on supervised trials designed to reflect likely maximum residues occurring in practice following authorised use. The number of trials available may significantly affect the accuracy of estimated maximum residues. We conducted a study with synthetic lognormal distributions with mean of 1 and standard deviations of 0.8 and 1.0, which reflect the residue distributions observed in practice. The likely residues in samples were modelled by drawing random samples of size 3, 5, 10 and 25 from the synthetic populations. The results indicate that the estimations of highest residues (HR), used for calculation of short-term intake, and the MRLs, serving as legal limits, are very uncertain based on 3-5 trials indicated by the calculated HR0.975/HR0.025 and MRL0.975/MRL0.025 ratios of 12 and 9, and 13 and 10, respectively, which question the suitability of such trials for the intended purpose. As the 95% range of HR and MRL rapidly decreases with number of trials, ideally ≥15 but minimum 6-8 trials should be used for estimation of HR and MRL according to the current typical practice of Codex Alimentarius.

  14. Modeling the Residual Strength of a Fibrous Composite Using the Residual Daniels Function

    NASA Astrophysics Data System (ADS)

    Paramonov, Yu.; Cimanis, V.; Varickis, S.; Kleinhofs, M.

    2016-09-01

    The concept of a residual Daniels function (RDF) is introduced. Together with the concept of Daniels sequence, the RDF is used for estimating the residual (after some preliminary fatigue loading) static strength of a unidirectional fibrous composite (UFC) and its S-N curve on the bases of test data. Usually, the residual strength is analyzed on the basis of a known S-N curve. In our work, an inverse approach is used: the S-N curve is derived from an analysis of the residual strength. This approach gives a good qualitive description of the process of decreasing residual strength and explanes the existence of the fatigue limit. The estimates of parameters of the corresponding regression model can be interpreted as estimates of parameters of the local strength of components of the UFC. In order to approach the quantitative experimental estimates of the fatigue life, some ideas based on the mathematics of the semiMarkovian process are employed. Satisfactory results in processing experimental data on the fatigue life and residual strength of glass/epoxy laminates are obtained.

  15. Accumulation of heavy metals in a long-term poultry waste-amended soil

    SciTech Connect

    Han, F.X.; Kingery, W.L.; Selim, H.M.; Gerard, P.D.

    2000-03-01

    Various metals are added to poultry diets to facilitate weight increase and disease prevention. The large amounts of poultry waste produced annually are dispersed intensively over relatively small areas of land, resulting in accumulations that pose potential environmental risks to the surface and groundwater. The focus of this study was to assess the distribution of heavy metals among various solid-phase fractions in soil profiles from a 25-year poultry waste-amended soil. Copper and Zn accumulated close to the soil surface where the total amounts of Cu and Zn in waste-amended soils were significantly higher than in nonamended soils. The total metal concentrations in amended soils were not critically high. Copper in the amended soil was present mostly in the organic matter (OM) fraction (46.9%), whereas Zn was found in the easily reducible oxide (ERO) fraction (47.3%). This suggests that the Cu and Zn in this long-term amended soil are potentially bioavailable and mobile. The authors observed the mobility of Zn through much of the soil profile of the long-term waste-amended soil. Zinc in this soil profile was found primarily in forms of the residual (RES) and crystalline iron oxide bound (CryFe) fractions, followed by the organic matter-bound and exchangeable (EXC) fractions.

  16. Microstructural examination of fatigue accumulation in critical LWR (light water reactor) components: Final report

    SciTech Connect

    Allen, A.J.; Buttle, D.J.; Coleman, C.F.; Smith, F.A.; Smith, R.L.

    1988-01-01

    This report describes a morphological study of the feasibility of measuring the fatigue damage accumulation state of critical light water reactor (LWR) components by microstructural examination. The changes in microstructure associated with fatigue processes are first discussed so that relevant NDE measurement parameters can be identified. (The creep regime is not considered in this report). The candidate NDE techniques are then reviewed in detail under the following headings: positron annihilation, x-ray diffraction, magnetic techniques, the magnetic Barkhausen effect, the magneto acoustic technique, acoustic emission, ultrasonic techniques and finally other miscellaneous techniques applicable to fatigue damage assessment. All the feasible techniques are summarised and rated in a set of comparison tables. A possible programme for the immediate development of the positron annihilation lineshape technique is proposed. It is concluded that the most successful method of measuring the fatigue accumulation in LWR critical components in a way which relates to the intent of the ASME pressure vessel codes, is likely to be the use of several techniques together and the cross-relation of the results obtained by each. Five techniques are highlighted for immediate possible development: 'etching and surface replication', 'positron annihilation lineshapes', 'x-ray diffraction residual stress', 'acoustic emission' and 'ultrasonic surface acoustic waves'.

  17. Tissue-specific mutation accumulation in human adult stem cells during life

    NASA Astrophysics Data System (ADS)

    Blokzijl, Francis; de Ligt, Joep; Jager, Myrthe; Sasselli, Valentina; Roerink, Sophie; Sasaki, Nobuo; Huch, Meritxell; Boymans, Sander; Kuijk, Ewart; Prins, Pjotr; Nijman, Isaac J.; Martincorena, Inigo; Mokry, Michal; Wiegerinck, Caroline L.; Middendorp, Sabine; Sato, Toshiro; Schwank, Gerald; Nieuwenhuis, Edward E. S.; Verstegen, Monique M. A.; van der Laan, Luc J. W.; de Jonge, Jeroen; Ijzermans, Jan N. M.; Vries, Robert G.; van de Wetering, Marc; Stratton, Michael R.; Clevers, Hans; Cuppen, Edwin; van Boxtel, Ruben

    2016-10-01

    The gradual accumulation of genetic mutations in human adult stem cells (ASCs) during life is associated with various age-related diseases, including cancer. Extreme variation in cancer risk across tissues was recently proposed to depend on the lifetime number of ASC divisions, owing to unavoidable random mutations that arise during DNA replication. However, the rates and patterns of mutations in normal ASCs remain unknown. Here we determine genome-wide mutation patterns in ASCs of the small intestine, colon and liver of human donors with ages ranging from 3 to 87 years by sequencing clonal organoid cultures derived from primary multipotent cells. Our results show that mutations accumulate steadily over time in all of the assessed tissue types, at a rate of approximately 40 novel mutations per year, despite the large variation in cancer incidence among these tissues. Liver ASCs, however, have different mutation spectra compared to those of the colon and small intestine. Mutational signature analysis reveals that this difference can be attributed to spontaneous deamination of methylated cytosine residues in the colon and small intestine, probably reflecting their high ASC division rate. In liver, a signature with an as-yet-unknown underlying mechanism is predominant. Mutation spectra of driver genes in cancer show high similarity to the tissue-specific ASC mutation spectra, suggesting that intrinsic mutational processes in ASCs can initiate tumorigenesis. Notably, the inter-individual variation in mutation rate and spectra are low, suggesting tissue-specific activity of common mutational processes throughout life.

  18. Accumulation and toxicokinetics of fluoranthene in sediment bioassays with freshwater amphipods

    SciTech Connect

    Driscoll, S.K.; Harkey, G.A.; Landrum, P.F.

    1997-04-01

    Two freshwater amphipods, Hyalella azteca and Diporeia sp., were exposed to sediment spiked with radiolabeled fluoranthene at nominal concentrations of 0.1 (trace) to 1,270 nmol fluoranthene/g dry weight. In two experiments, uptake kinetics and mortality were determined over 30-d exposures. Concentrations of fluoranthene in sediment and pore water were also measured. Mean survival of H. azteca was generally high, greater than 90% after 10 or 16 d, and greater than 74% after 30 d. Mean survival was lower for Diporeia, 14% after a 30-d exposure to the highest sediment concentration in experiment 1, and 53% in experiment 2. Tissue concentrations in Diporeia were as high as 2 to 4 {micro}mol/g wet weight, a body burden that could be expected to result in death by narcosis. Hyalella azteca did not typically accumulate more than 1 {micro}mol/g wet weight, which is consistent with the lower observed mortality. Apparent steady-state biota-sediment accumulation factors (BSAFs, lipid- and organic-carbon-normalized) for sediment concentrations other than trace level tended to be higher for Diporeia than for H. azteca. The BSAFs for trace levels tended to be lower for both species in comparison to higher sediment concentrations. For both organisms, the internal concentration based on body residue was a more reliable indicator of toxicity than were equilibrium partitioning predictions.

  19. Thermally induced magnon accumulation in two-sublattice magnets

    NASA Astrophysics Data System (ADS)

    Ritzmann, Ulrike; Hinzke, Denise; Nowak, Ulrich

    2017-02-01

    We present a temperature-dependent study of the thermal excitation of a magnon accumulation in two-sublattice magnetic materials. Using atomistic spin model simulations, we study the local magnetization profiles sublattice-wise in the vicinity of a temperature step in antiferromagnets, as well as in ferrimagnets. It is shown that the strength of the magnon accumulation in these systems scales with the derivative of the magnetization with respect to the temperature. These results give an insight into the complex temperature dependence of the magnon accumulation by making a direct link to the macroscopic behavior of the magnetization.

  20. Design Analysis of the Ares 1 Pogo Accumulator

    NASA Technical Reports Server (NTRS)

    Swanson, Luke A.; Giel, Thomas V.

    2009-01-01

    Several accumulator designs and gas charge systems are considered in order to suppress POGO within the Ares I vehicle Upper Stage Liquid Ox ygen System. The thermodynamic and flow analysis completed to evaluat e candidate designs are presented and the results are used to evaluat e the ability of each concept to meet the levied suppression requirements. One annular accumulator design meets all suppression requirement s while also providing manufacturability and operability advantages. Of the two proposed charge systems to provide and maintain gas within the accumulator, a passive level control design meets the charge req uirements and maximizes reliability.

  1. Critical tissue copper residues for marine bivalve (Mytilus galloprovincialis) and echinoderm (Strongylocentrotus purpuratus) embryonic development: conceptual, regulatory and environmental implications.

    PubMed

    Rosen, Gunther; Rivera-Duarte, Ignacio; Chadwick, D Bart; Ryan, Adam; Santore, Robert C; Paquin, Paul R

    2008-09-01

    Critical tissue copper (Cu) residues associated with adverse effects on embryo-larval development were determined for the Mediterranean mussel (Mytilus galloprovincialis) and purple sea urchin (Strongylocentrotus purpuratus) following laboratory exposure to Cu-spiked seawater collected from San Diego Bay, California, USA. Whole body no-observed-effect-residues (NOER) were similar, with means of 21 and 23 microg g(-1) dw, for M. galloprovincialis and S. purpuratus, respectively. Mean whole body median effect residues (ER50) were 49 and 142 microg g(-1) dw for M. galloprovincialis and S. purpuratus, respectively. The difference in ER50s between species was reduced to a factor of <2 when expressed as soft tissue residues. Coefficients of variation among whole body-ER50s were 3-fold lower than median waterborne effect concentrations (EC50) for both species exposed to samples varying in water quality characteristics. This suggests that tissue concentrations were a better predictor of toxicity than water concentrations. The CBRs described herein do not differentiate between the internal Cu concentrations that are metabolically available and those that are accumulated and then detoxified. They do appear, however, to be well enough related to the level of accumulation at the site of action of toxicity that they serve as useful surrogates for the copper concentration that affects embryonic development of the species tested. Results presented have potentially important implications for a variety of monitoring and assessment strategies. These include regulatory approaches for deriving saltwater ambient water quality criteria for Cu, contributions towards the development of a saltwater biotic ligand model, the conceptual approach of using CBRs, and ecological risk assessment.

  2. Soil sorptivity enhancement with crop residue accumulation in simiarid dryland no-till agroecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water capture and precipitation use efficiency are of great importance in dryland cropping systems because the world’s dependence on food produced in dryland areas continues to increase. Growing season evapotranspiration potential greatly exceeds growing season precipitation rates in dryland areas,...

  3. Stabilized copper plating method by programmed electroplated current: Accumulation of densely packed copper grains in the interconnect

    NASA Astrophysics Data System (ADS)

    Kao, Li-Chi; Hsu, Li-Hsuan; Brahma, Sanjaya; Huang, Bo-Chia; Liu, Chun-Chu; Lo, Kuang-Yao

    2016-12-01

    In this work, we programmed the plating current to stack the different size of copper (Cu) grain and analyzed the relation between the sequence of different Cu grain size and the stability of the residual stress. The residual stress was measured with varying times of annealing process in order to reach the purpose of simulating the actual Cu interconnect process. We found that varied plating strategy will make different stabilization condition of residual stress through the proof of X-ray diffraction (XRD) and optical parallel beams reflection (PBR) method. The accumulation of Cu grains, formed by Cu grain with successive variation in grain size, would enhance the packing density better than only single grain size in the finite space. The high density of the grain boundary in the electroplated Cu film will be eliminated through annealing process and it will help to suppress the void formation in further interconnect process. The electroplated Cu film with the plating current of saw tooth wave can soon reach a stable tensile stress through annealing since the Cu grains with high packing density will be quickly eliminated to approach the minimum of the strain energy which reflects to variation in the texture of Cu (2 0 0). The result of this work illustrates the importance of how to stack different size of Cu grain, for achieving a densely packed Cu film which close to the Cu bulk.

  4. Measuring Residual Stress Using Nonlinear Ultrasound

    NASA Astrophysics Data System (ADS)

    Liu, M.; Kim, J.-Y.; Qu, J.; Jacobs, L. J.

    2010-02-01

    Near-surface compressive residual stresses, which are generated by shot peening, are known to retard crack initiation and thus extend the fatigue life of a metal component. The ability to effectively measure these near-surface residual stresses would greatly help predict the fatigue life of shot-peened components. This research uses the nonlinear surface acoustic wave technique to measure the residual stresses in a shot-peened component. Experiments are conducted on three different aluminum alloy (AA 7075) samples: as-received with no peeing, and shot-peened at the Almen intensities of 8A and 16A. Surface roughness measurements are also carried out for these three samples. The nonlinear ultrasonic results show that the measured acoustic nonlinearity parameter increases by 81% and 115% for the 8A and 16A samples. These large increases in measured acoustic nonlinearity clearly indicate the potential of the nonlinear ultrasonic technique as an NDE tool to measure the near-surface residual stresses. The effects of surface roughness on the ultrasonic measurement are briefly examined. Finally, a preliminary model prediction is presented to interpret the experimental results.

  5. Low-latency digital frequency synthesizer using the residue number system

    NASA Technical Reports Server (NTRS)

    Chren, William A., Jr.

    1993-01-01

    A low-latency frequency synthesizer using the Direct Digital Synthesis (DDS) technique has been designed. Called the Residue Assisted Frequency Synthesizer (RAFS), it exhibits frequency switching times which are reduced by more than 50 percent below previously published designs. The switching speed advantage is made possible by the use of the Residue Number System, which allows the pipeline lengths in the Phase Accumulator and other circuitry to be reduced significantly.

  6. Neurodegeneration with brain iron accumulation (NBIA)

    MedlinePlus

    ... gov/ency/article/001225.htm Neurodegeneration with brain iron accumulation (NBIA) To use the sharing features on this page, please enable JavaScript. Neurodegeneration with brain iron accumulation (NBIA) are a group of rare nervous ...

  7. 40 CFR 180.487 - Pyrithiobac sodium; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Pyrithiobac sodium; tolerances for... § 180.487 Pyrithiobac sodium; tolerances for residues. (a) General. Tolerances are established for residues of the herbicide, pyrithiobac sodium, (sodium 2-chloro-6- benzoate), resulting from...

  8. 40 CFR 180.130 - Hydrogen Cyanide; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Hydrogen Cyanide; tolerances for... § 180.130 Hydrogen Cyanide; tolerances for residues. (a) General. A tolerance for residues of the insecticide hydrogen cyanide from postharvest fumigation as a result of application of sodium cyanide...

  9. 40 CFR 180.130 - Hydrogen Cyanide; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Hydrogen Cyanide; tolerances for... § 180.130 Hydrogen Cyanide; tolerances for residues. (a) General. A tolerance for residues of the insecticide hydrogen cyanide from postharvest fumigation as a result of application of sodium cyanide...

  10. 40 CFR 180.130 - Hydrogen Cyanide; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Hydrogen Cyanide; tolerances for... § 180.130 Hydrogen Cyanide; tolerances for residues. (a) General. A tolerance for residues of the insecticide hydrogen cyanide from postharvest fumigation as a result of application of sodium cyanide...

  11. 40 CFR 180.130 - Hydrogen Cyanide; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Hydrogen Cyanide; tolerances for... § 180.130 Hydrogen Cyanide; tolerances for residues. (a) General. A tolerance for residues of the insecticide hydrogen cyanide from postharvest fumigation as a result of application of sodium cyanide...

  12. 40 CFR 180.130 - Hydrogen Cyanide; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Hydrogen Cyanide; tolerances for... § 180.130 Hydrogen Cyanide; tolerances for residues. (a) General. A tolerance for residues of the insecticide hydrogen cyanide from postharvest fumigation as a result of application of sodium cyanide...

  13. 40 CFR 180.513 - Chlorfenapyr; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances... established for residues of chlorfenapyr in or on all food commodities (other than those covered by a higher tolerance as a result of use on growing crops) in food/feed handling areas where food/feed products...

  14. 40 CFR 180.513 - Chlorfenapyr; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances... established for residues of chlorfenapyr in or on all food commodities (other than those covered by a higher tolerance as a result of use on growing crops) in food/feed handling areas where food/feed products...

  15. 40 CFR 180.513 - Chlorfenapyr; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances... established for residues of chlorfenapyr in or on all food commodities (other than those covered by a higher tolerance as a result of use on growing crops) in food/feed handling areas where food/feed products...

  16. Visual Feedback in Treatment of Residual Phonological Disorders.

    ERIC Educational Resources Information Center

    Ruscello, Dennis M.

    1995-01-01

    The use of visual biofeedback in the treatment of individuals who have residual phonological errors is discussed. Biofeedback is conceptualized as a cognitive treatment that requires the client's analysis of visual information and then use of that information in developing correct productions of residual phonological errors. Results suggest the…

  17. Conversion of direct process high-boiling residue to monosilanes

    DOEpatents

    Brinson, Jonathan Ashley; Crum, Bruce Robert; Jarvis, Jr., Robert Frank

    2000-01-01

    A process for the production of monosilanes from the high-boiling residue resulting from the reaction of hydrogen chloride with silicon metalloid in a process typically referred to as the "direct process." The process comprises contacting a high-boiling residue resulting from the reaction of hydrogen chloride and silicon metalloid, with hydrogen gas in the presence of a catalytic amount of aluminum trichloride effective in promoting conversion of the high-boiling residue to monosilanes. The present process results in conversion of the high-boiling residue to monosilanes. At least a portion of the aluminum trichloride catalyst required for conduct of the process may be formed in situ during conduct of the direct process and isolation of the high-boiling residue.

  18. Effects of Insect-Proof Net Cultivation, Rice-Duck Farming, and Organic Matter Return on Rice Dry Matter Accumulation and Nitrogen Utilization

    PubMed Central

    Liu, Xin; Xu, Guochun; Wang, Qiangsheng; Hang, Yuhao

    2017-01-01

    Insect-proof net cultivation (IPN), rice-duck farming (RD), and organic matter return (OM) are important methods to realize sustainable development of rice production. A split-plot field experiment was performed to study the effects of IPN, RD, and OM on the rice yield, dry matter accumulation and N utilization. Results showed that compared to inorganic N fertilizer (IN), wheat straw return, and biogas residue return increased the rice yield by 2.11–4.28 and 4.78–7.67%, respectively, and also improved dry matter and N accumulation after the elongation stage (EG), dry matter and N translocation, and N recovery efficiency (NRE). These results attributed to an increase in leaf SPAD values and net photosynthetic rate (Pn) after the EG. Compared to conventional rice farming (CR), RD promoted the rice yield by 1.52–3.74%, and contributed to higher the leaf photosynthesis, dry matter and N accumulation, dry matter and N translocation, and NRE. IPN decreased the intensity of sun radiation in the nets due to the coverage of the insect-proof nets, which declined the leaf Pn, dry matter accumulation and translocation, N absorption and translocation, and NRE compared to open field cultivation (OFC). The rice yield of IPN were 2.48–4.98% lower than that of OFC. Compared to the interaction between CR and IN, the interaction between RD and OM improved the rice yield by 5.26–9.33%, and increased dry matter and N accumulation after the EG, dry matter and N translocation, and NRE. These results indicated that OM, RD and the interaction between RD and OM could promote dry matter accumulation and N utilization, which was beneficial to improve the rice yield. PMID:28174589

  19. Effects of Insect-Proof Net Cultivation, Rice-Duck Farming, and Organic Matter Return on Rice Dry Matter Accumulation and Nitrogen Utilization.

    PubMed

    Liu, Xin; Xu, Guochun; Wang, Qiangsheng; Hang, Yuhao

    2017-01-01

    Insect-proof net cultivation (IPN), rice-duck farming (RD), and organic matter return (OM) are important methods to realize sustainable development of rice production. A split-plot field experiment was performed to study the effects of IPN, RD, and OM on the rice yield, dry matter accumulation and N utilization. Results showed that compared to inorganic N fertilizer (IN), wheat straw return, and biogas residue return increased the rice yield by 2.11-4.28 and 4.78-7.67%, respectively, and also improved dry matter and N accumulation after the elongation stage (EG), dry matter and N translocation, and N recovery efficiency (NRE). These results attributed to an increase in leaf SPAD values and net photosynthetic rate (Pn) after the EG. Compared to conventional rice farming (CR), RD promoted the rice yield by 1.52-3.74%, and contributed to higher the leaf photosynthesis, dry matter and N accumulation, dry matter and N translocation, and NRE. IPN decreased the intensity of sun radiation in the nets due to the coverage of the insect-proof nets, which declined the leaf Pn, dry matter accumulation and translocation, N absorption and translocation, and NRE compared to open field cultivation (OFC). The rice yield of IPN were 2.48-4.98% lower than that of OFC. Compared to the interaction between CR and IN, the interaction between RD and OM improved the rice yield by 5.26-9.33%, and increased dry matter and N accumulation after the EG, dry matter and N translocation, and NRE. These results indicated that OM, RD and the interaction between RD and OM could promote dry matter accumulation and N utilization, which was beneficial to improve the rice yield.

  20. The metalloid arsenite induces nuclear export of Id3 possibly via binding to the N-terminal cysteine residues

    SciTech Connect

    Kurooka, Hisanori; Sugai, Manabu; Mori, Kentaro; Yokota, Yoshifumi

    2013-04-19

    Highlights: •Sodium arsenite induces cytoplasmic accumulation of Id3. •Arsenite binds to closely spaced N-terminal cysteine residues of Id3. •N-terminal cysteines are essential for arsenite-induced nuclear export of Id3. •Nuclear export of Id3 counteracts its transcriptional repression activity. -- Abstract: Ids are versatile transcriptional repressors that regulate cell proliferation and differentiation, and appropriate subcellular localization of the Id proteins is important for their functions. We previously identified distinct functional nuclear export signals (NESs) in Id1 and Id2, but no active NES has been reported in Id3. In this study, we found that treatment with the stress-inducing metalloid arsenite led to the accumulation of GFP-tagged Id3 in the cytoplasm. Cytoplasmic accumulation was impaired by a mutation in the Id3 NES-like sequence resembling the Id1 NES, located at the end of the HLH domain. It was also blocked by co-treatment with the CRM1-specific nuclear export inhibitor leptomycin B (LMB), but not with the inhibitors for mitogen-activated protein kinases (MAPKs). Importantly, we showed that the closely spaced N-terminal cysteine residues of Id3 interacted with the arsenic derivative phenylarsine oxide (PAO) and were essential for the arsenite-induced cytoplasmic accumulation, suggesting that arsenite induces the CRM1-dependent nuclear export of Id3 via binding to the N-terminal cysteines. Finally, we demonstrated that Id3 significantly repressed arsenite-stimulated transcription of the immediate-early gene Egr-1 and that this repression activity was inversely correlated with the arsenite-induced nuclear export. Our results imply that Id3 may be involved in the biological action of arsenite.

  1. Pesticide residues in cereal crop grains in Poland in 2013.

    PubMed

    Malinowska, Elżbieta; Jankowski, Kazimierz; Sosnowski, Jacek; Wiśniewska-Kadżajan, Beata

    2015-06-01

    This paper presents the results of the audit on pesticide residues in cereal grains throughout Poland in 2013. The number of all samples of cereal grains was 380. Altogether 292 active substances of plant protection products were checked in the audit. Qualitative and quantative analyses were done according to Polish Standard PN-EN 15562:2008, using the LC-MS/MS technique. The methods (QuEChERS) is based on extraction of residues of plant protection products from a sample using acetonitrile. In the samples analyzed, 62 % of them did not contain any pesticide residues, 34 % of samples of cereal grains contained such residues but below the maximum residue limit, 3 % contained residues over the maximum limit, whereas 1 % of the samples contained illegal substances. The lowest amounts of pesticide residues were found in cereal grains coming from fields with cereal mixtures and in Avena grains, while the highest amounts were in Hordeum and Triticum grains. The substances found most often were fungicide residues. In northern and southern regions of Poland (Silesian, Pomeranian, and Kuyavian-Pomeranian voivodeships), cereal grains with pesticide residues were much more common than in other regions of Poland.

  2. Accelerated mutation accumulation in asexual lineages of a freshwater snail.

    PubMed

    Neiman, Maurine; Hehman, Gery; Miller, Joseph T; Logsdon, John M; Taylor, Douglas R

    2010-04-01

    Sexual reproduction is both extremely costly and widespread relative to asexual reproduction, meaning that it must also confer profound advantages in order to persist. One theorized benefit of sex is that it facilitates the clearance of harmful mutations, which would accumulate more rapidly in the absence of recombination. The extent to which ineffective purifying selection and mutation accumulation are direct consequences of asexuality and whether the accelerated buildup of harmful mutations in asexuals can occur rapidly enough to maintain sex within natural populations, however, remain as open questions. We addressed key components of these questions by estimating the rate of mutation accumulation in the mitochondrial genomes of multiple sexual and asexual representatives of Potamopyrgus antipodarum, a New Zealand snail characterized by mixed sexual/asexual populations. We found that increased mutation accumulation is associated with asexuality and occurs rapidly enough to be detected in recently derived asexual lineages of P. antipodarum. Our results demonstrate that increased mutation accumulation in asexuals can differentially affect coexisting and ecologically similar sexual and asexual lineages. The accelerated rate of mutation accumulation observed in asexual P. antipodarum provides some of the most direct evidence to date for a link between asexuality and mutation accumulation and implies that mutational buildup could be rapid enough to contribute to the short-term evolutionary mechanisms that favor sexual reproduction.

  3. Measurement of residual stresses in deposited films of SOFC component materials

    SciTech Connect

    Kato, T.; Momma, A.; Nagata, S.; Kasuga, Y.

    1996-12-31

    The stress induced in Solid oxide fuel cells (SOFC)s has important influence on the lifetime of SOFC. But the data on stress in SOFC and mechanical properties of SOW component materials have not been accumulated enough to manufacture SOFC. Especially, the data of La{sub 1-x}Sr{sub x}MnO{sub 3} cathode and La{sub 1-x}Sr{sub x}CrO{sub 3} interconnection have been extremely limited. We have estimated numerically the dependences of residual stress in SOFC on the material properties, the cell structure and the fabrication temperatures of the components, but these unknown factors have caused obstruction to simulate the accurate behavior of residual stress. Therefore, the residual stresses in deposited La{sub 1-x}Sr{sub x}MnO{sub 3} and La{sub 1-x}Sr{sub x}CrO{sub 3} films are researched by the observation of the bending behavior of the substrate strips. The films of SOFC component materials were prepared by the RF sputtering method, because: (1) It can fabricate dense films of poor sinterable material such as La{sub 1-x}Sr{sub x}CrO{sub 3} compared with sintering or plasma spray method. (2) For the complicated material such as perovskite materials, the difference between the composition of a film and that of a target material is generally small. (3) It can fabricate a thick ceramics film by improving of the deposition rate. For example, Al{sub 2}O{sub 3} thick films of 50{mu}m can be fabricated with the deposition rate of approximately 5{mu}m/h industrially. In this paper, the dependence of residual stress on the deposition conditions is defined and mechanical properties of these materials are estimated from the results of the experiments.

  4. Trace metal residues in soil as markers of ancient site occupance in Greece

    SciTech Connect

    Davies, B.E.; Bintliff, J.L.; Gaffney, C.F.; Waters, A.T.

    1988-01-01

    Modern evidence shows that wherever people work or live the concentrations of heavy metals rise in nearby soils and these residues persist for many years. This paper reports similar accumulations of Cu and Pb in soils at sites of ancient occupation in Greece. It is proposed that such accumulations can act as markers of such occupation and complement evidence derived from other archaeological survey methods.

  5. Organochlorine insecticide residues in the free-tailed bat (Tadarida brasiliensis) at Bracken Cave, Texas

    USGS Publications Warehouse

    Clark, D.R.; Martin, C.O.; Swineford, D.M.

    1975-01-01

    Fifty-nine free-tailed bats (Tadarida brasiliensis mexicana ) were collected at Bracken Cave, Texas, and analyzed for organochlorine insecticides and polychlorinated biphenyls (PCBs). Residues of DDE in the brain were greater in 12 young collected from the floor than in 15 young taken from the ceiling, but food deprivation, not higher residues in the brain, apparently caused young to fall....Among 18 pregnant females, residues of DDE and DDT were highest in yearlings. The first lactation by yearlings caused their residue loads to drop sharply. Thereafter, increasing age was accompanied by increasing residues but amounts generally did not exceed those in yearlings.....Residue levels in embryos were a function both of levels in the female parent and degree of embryonic development. Residues accumulated rapidly in nursing young, and lactating females may excrete from 1.3 to 16.2 (mean = 4.3) micrograms of DDE in milk per day. Maximum individual residue loads may be attained toward the end of nursing, and mobilization of these residues during southward migration may subject Bracken Cave free-tails to maximum lifetime residues in the brain....Comparison of our data with residue data for the free-tail population at Eagle Creek Cave (Arizona) in 1970 produced the following conclusions: ( 1) residues of DDE appeared similar in pregnant females, embryos, lactating females, and fallen young for the two populations; (2) residues of DDT and dieldrin appeared greater in pregnant females at Bracken Cave; (3) DDE and DDT occurred at greater levels in guano samples from Bracken Cave. On this basis, the population decline observed at Eagle Creek Cave between 1963 and 1969 does not appear to be related to the residues observed in the 1970 samples taken from that cave.

  6. Aberrant Accumulation of the Diabetes Autoantigen GAD65 in Golgi Membranes in Conditions of ER Stress and Autoimmunity.

    PubMed

    Phelps, Edward A; Cianciaruso, Chiara; Michael, Iacovos P; Pasquier, Miriella; Kanaani, Jamil; Nano, Rita; Lavallard, Vanessa; Billestrup, Nils; Hubbell, Jeffrey A; Baekkeskov, Steinunn

    2016-09-01

    Pancreatic islet β-cells are particularly susceptible to endoplasmic reticulum (ER) stress, which is implicated in β-cell dysfunction and loss during the pathogenesis of type 1 diabetes (T1D). The peripheral membrane protein GAD65 is an autoantigen in human T1D. GAD65 synthesizes γ-aminobutyric acid, an important autocrine and paracrine signaling molecule and a survival factor in islets. We show that ER stress in primary β-cells perturbs the palmitoylation cycle controlling GAD65 endomembrane distribution, resulting in aberrant accumulation of the palmitoylated form in trans-Golgi membranes. The palmitoylated form has heightened immunogenicity, exhibiting increased uptake by antigen-presenting cells and T-cell stimulation compared with the nonpalmitoylated form. Similar accumulation of GAD65 in Golgi membranes is observed in human β-cells in pancreatic sections from GAD65 autoantibody-positive individuals who have not yet progressed to clinical onset of T1D and from patients with T1D with residual β-cell mass and ongoing T-cell infiltration of islets. We propose that aberrant accumulation of immunogenic GAD65 in Golgi membranes facilitates inappropriate presentation to the immune system after release from stressed and/or damaged β-cells, triggering autoimmunity.

  7. 47 CFR 32.3100 - Accumulated depreciation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Accumulated depreciation. 32.3100 Section 32... Accumulated depreciation. (a) This account shall include the accumulated depreciation associated with the... with depreciation amounts concurrently charged to Account 6561, Depreciation...

  8. Effect of silicate on arsenic fractionation in soils and its accumulation in rice plants.

    PubMed

    Wu, Chuan; Zou, Qi; Xue, Sheng-Guo; Pan, Wei-Song; Yue, Xu; Hartley, William; Huang, Liu; Mo, Jing-Yu

    2016-12-01

    Four rice genotypes, two hybrid and two indica, were selected to investigate the effects of silicate (Si) application on arsenic (As) accumulation and speciation in rice and As fractionation in soil. There were significant differences in root, straw and grain biomass among genotypes (p < 0.05), and Si application significantly increased root (p < 0.05) and grain biomass (p < 0.001). Silicate addition reduced the proportion of As associated with well-crystallized hydrous oxides of Fe and Al and residual phases, whilst increasing the proportions of specifically-sorbed As and As associated with amorphous and poorly-crystalline Fe and Al hydrous oxides. Furthermore, the results indicated that the fraction proportions of non-specifically sorbed, specifically-sorbed, and associated with amorphous and poorly-crystalline hydrous oxides of Fe and Al in rhizosphere soils, were greater than non-rhizosphere soils. Silicate application had a significant effect decreasing total As concentrations in root (p < 0.005), straw (p < 0.05) and husk (p < 0.001) of rice plants. The effect of Si on reducing As accumulation in rice leaves was revealed by SXRF. Indica genotypes transported and accumulated less As than hybrid genotypes. Both percentage and concentration of iAs were lower in indica genotype XFY-9 than in hybrid genotype XWX-12. Silicate reduced iAs and DMA by 21% and 58% in grain (polished) respectively. DMA may have a greater translocation capacity from straw to grain (polished) than inorganic As. The study provides the potential for understanding As uptake mechanisms in rice and mitigating the health risks posed by As contamination in paddy fields.

  9. Transgenic rice seeds accumulating recombinant hypoallergenic birch pollen allergen Bet v 1 generate giant protein bodies.

    PubMed

    Wang, Shuyi; Takahashi, Hideyuki; Kajiura, Hiroyuki; Kawakatsu, Taiji; Fujiyama, Kazuhito; Takaiwa, Fumio

    2013-06-01

    A versatile hypoallergenic allergen derivative against multiple allergens is an ideal tolerogen for allergen-specific immunotherapy. Such a tolerogen should exhibit high efficacy, without side effects, when administered at high doses and should be applicable to several allergens. Tree pollen chimera 7 (TPC7), a hypoallergenic Bet v 1 tolerogen against birch pollen allergy, was previously selected by DNA shuffling of 14 types of Fagales tree pollen allergens. In this study, transgenic rice seed accumulating TPC7 was generated as an oral vaccine against birch pollen allergy by expressing this protein as a secretory protein using the N-terminal signal peptide and the C-terminal KDEL tag under the control of an endosperm-specific glutelin promoter. The highest level of TPC7 accumulation was approximately 207 µg grain(-1). Recombinant TPC7 is a glycoprotein with high mannose-type N-glycan, but without β1,2-xylose or α1,3-fucose, suggesting that TPC7 is retained in the endoplasmic reticulum (ER). TPC7 is deposited as a novel, giant spherical ER-derived protein body, >20 µm in diameter, which is referred to as the TPC7 body. Removal of the KDEL retention signal or mutation of a cysteine residue resulted in an alteration of TPC7 body morphology, and deletion of the signal peptide prevented the accumulation of TPC7 in rice seeds. Therefore, the novel TPC7 bodies may have formed aggregates within the ER lumen, primarily due to the intrinsic physicochemical properties of the protein.

  10. A survey of gunshot residue analysis methods.

    PubMed

    Singer, R L; Davis, D; Houck, M M

    1996-03-01

    A survey was sent to 80 forensic laboratories in 44 States and two Canadian Provinces concerning methodology in analyzing gunshot residue (GSR) and interpreting the results. Of the 80 surveys, 50 (63%) were returned completed. Questions included standard procedures, collection methods, thresholding problems and specificity of data. These results are compared to a previous survey reported in 1990. Implications for the interpretation and future study of these methods are discussed.

  11. Ectoine accumulation in Brevibacterium epidermis.

    PubMed

    Onraedt, Annelies; De Muynck, Cassandra; Walcarius, Bart; Soetaert, Wim; Vandamme, Erick

    2004-10-01

    As a halotolerant bacterial species, Brevibacterium epidermis DSM 20659 can grow at relatively high salinity, tolerating up to 2 M NaCl. It synthesizes ectoine and the intracellular content increases with the medium salinity, with a maximum of 0.14 g ectoine/g CDW at 1 M NaCl. Sugar-stressed cells do not synthesize ectoine. Ectoine synthesis is also affected by the presence of external osmolytes. Added betaine is taken up and completely replaced ectoine, while L-proline is only temporarily accumulated after which ectoine is synthesized. The strain can metabolize ectoine; L-glutamate is a better carbon source for ectoine synthesis than L-aspartate.

  12. OECD Maximum Residue Limit Calculator

    EPA Pesticide Factsheets

    With the goal of harmonizing the calculation of maximum residue limits (MRLs) across the Organisation for Economic Cooperation and Development, the OECD has developed an MRL Calculator. View the calculator.

  13. Distinct relationships of parietal and prefrontal cortices to evidence accumulation

    PubMed Central

    Hanks, Timothy; Kopec, Charles D.; Brunton, Bingni W.; Duan, Chunyu A.; Erlich, Jeffrey C.; Brody, Carlos D.

    2014-01-01

    Gradual accumulation of evidence is thought to be fundamental for decision-making, and its neural correlates have been found in multiple brain regions1–8. Here we develop a generalizable method to measure tuning curves that specify the relationship between neural responses and mentally-accumulated evidence, and apply it to distinguish the encoding of decision variables in posterior parietal cortex (PPC) and prefrontal cortex (frontal orienting fields, FOF). We recorded the firing rates of neurons in PPC and FOF from rats performing a perceptual decision-making task. Classical analyses uncovered correlates of accumulating evidence, similar to previous observations in primates and also similar across the two regions. However, tuning curve assays revealed that while the PPC encodes a graded value of the accumulating evidence, the FOF has a more categorical encoding that indicates, throughout the trial, the decision provisionally favored by the evidence accumulated so far. Contrary to current views3,5,7–9, this suggests that premotor activity in frontal cortex does not play a role in the accumulation process, but instead has a more categorical function, such as transforming accumulated evidence into a discrete choice. To causally probe the role of FOF activity, we optogenetically silenced it during different timepoints of the trial. Consistent with a role in committing to a categorical choice at the end of the evidence accumulation process, but not consistent with a role during the accumulation itself, a behavioral effect was observed only when FOF silencing occurred at the end of the perceptual stimulus. Our results place important constraints on the circuit logic of brain regions involved in decision-making. PMID:25600270

  14. Determination of Pesticides Residues in Cucumbers Grown in Greenhouse and the Effect of Some Procedures on Their Residues

    PubMed Central

    LEILI, Mostafa; PIRMOGHANI, Amin; SAMADI, Mohammad Taghi; SHOKOOHI, Reza; ROSHANAEI, Ghodratollah; POORMOHAMMADI, Ali

    2016-01-01

    Background: The objective of this study was to determine the residual concentrations of ethion and imidacloprid in cucumbers grown in greenhouse. The effect of some simple processing procedures on both ethion and imidacloprid residues were also studied. Methods: Ten active greenhouses that produce cucumber were randomly selected. Ethion and imidacloprid as the most widely used pesticides were measured in cucumber samples of studied greenhouses. Moreover, the effect of storing, washing, and peeling as simple processing procedures on both ethion and imidacloprid residues were investigated. Results: One hour after pesticide application; the maximum residue levels (MRLs) of ethion and imidacloprid were higher than that of Codex standard level. One day after pesticide application, the levels of pesticides were decreased about 35 and 31% for ethion and imidacloprid, respectively, which still were higher than the MRL. Washing procedure led to about 51 and 42.5% loss in ethion and imidacloprid residues, respectively. Peeling procedure also led to highest loss of 93.4 and 63.7% in ethion and imidacloprid residues, respectively. The recovery for both target analytes was in the range between 88 and 102%. Conclusion: The residue values in collected samples one hour after pesticides application were higher than standard value. The storing, washing, and peeling procedures lead to the decrease of pesticide residues in greenhouse cucumbers. Among them, the peeling procedure has the greatest impact on residual reduction. Therefore, these procedures can be used as simple and effective processing techniques for reducing and removing pesticides from greenhouse products before their consumption. PMID:28032066

  15. Americium recovery from reduction residues

    DOEpatents

    Conner, W.V.; Proctor, S.G.

    1973-12-25

    A process for separation and recovery of americium values from container or bomb'' reduction residues comprising dissolving the residues in a suitable acid, adjusting the hydrogen ion concentration to a desired level by adding a base, precipitating the americium as americium oxalate by adding oxalic acid, digesting the solution, separating the precipitate, and thereafter calcining the americium oxalate precipitate to form americium oxide. (Official Gazette)

  16. Chemical Stabilization of Hanford Tank Residual Waste

    SciTech Connect

    Cantrell, Kirk J.; Um, Wooyong; Williams, Benjamin D.; Bowden, Mark E.; Gartman, Brandy N.; Lukens, Wayne W.; Buck, Edgar C.; Mausolf, Edward J.

    2014-03-01

    Three different chemical treatment methods were tested for their ability to stabilize residual waste from Hanford tank C-202 for reducing contaminant release (Tc, Cr, and U in particular). The three treatment methods tested were lime addition [Ca(OH)2], an in-situ Ceramicrete waste form based on chemically bonded phosphate ceramics, and a ferrous iron/goethite treatment. These approaches rely on formation of insoluble forms of the contaminants of concern (lime addition and ceramicrete) and chemical reduction followed by co-precipitation (ferrous iron/goethite incorporation treatment). The results have demonstrated that release of the three most significant mobile contaminants of concern from tank residual wastes can be dramatically reduced after treatment compared to contact with simulated grout porewater without treatment. For uranium, all three treatments methods reduced the leachable uranium concentrations by well over three orders of magnitude. In the case of uranium and technetium, released concentrations were well below their respective MCLs for the wastes tested. For tank C-202 residual waste, chromium release concentrations were above the MCL but were considerably reduced relative to untreated tank waste. This innovative approach has the potential to revolutionize Hanford’s tank retrieval process, by allowing larger volumes of residual waste to be left in tanks while providing an acceptably low level of risk with respect to contaminant release that is protective of the environment and human health. Such an approach could enable DOE to realize significant cost savings through streamlined retrieval and closure operations.

  17. 14C-carbaryl residues in hazelnut.

    PubMed

    Yücel, Ulkü; Ilim, Murat; Aslan, Nazife

    2006-01-01

    A hazelnut ocak (shrub growing form) in the field in Black Sea region of Turkey was treated with commercial carbaryl insecticide spiked with 14C-carbaryl. Three months later, the harvested hazelnuts were separated into husk, shell, and kernel components, then homogenized and analyzed. The total and unextractable (bound) 14C-residues were determined by combustion and the extractable 14C-residues were obtained by extracting the samples with methanol. Concentrated extracts were first analyzed by thin layer chromatography (TLC). The extracts were also subjected to a series of liquid-liquid extraction procedures for clean-up and the final extracts were analyzed by high performance liquid chromatography (HPLC). Crude hazelnut oil was also extracted with hexane and analyzed for total 14C-residue. A total of 1.3% of applied radioactivity was recovered from the total nut harvested, with 0.04%, 0.06%, and 1.2% present in shell, kernel, and husk, respectively. The results show that the inedible husk and shell contained 95.7% 14C, whereas the edible kernel contained 4.3% of the total 14C recovered. The terminal 14C-residue in hazelnut kernel and oil did not contain carbaryl and/or its metabolite naphthol.

  18. Sedentary behavior and residual-specific mortality

    PubMed Central

    Loprinzi, Paul D.; Edwards, Meghan K.; Sng, Eveleen; Addoh, Ovuokerie

    2016-01-01

    Background: The purpose of this study was to examine the association of accelerometer-assessed sedentary behavior and residual-specific mortality. Methods: Data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) were used (N = 5536), with follow-up through 2011. Sedentary behavior was objectively measured over 7 days via accelerometry. Results: When expressing sedentary behavior as a 60 min/day increase, the hazard ratio across the models ranged from 1.07-1.40 (P < 0.05). There was evidence of an interaction effect between sedentary behavior and total physical activity on residual-specific mortality (Hazard ratiointeraction [HR] = 0.9989; 95% CI: 0.9982-0.9997; P = 0.008). Conclusion: Sedentary behavior was independently associated with residual-specific mortality. However, there was evidence to suggest that residual-specific mortality risk was a function of sedentary behavior and total physical activity. These findings highlight the need for future work to not only examine the association between sedentary behavior and health independent of total physical activity, but evaluate whether there is a joint effect of these two parameters on health. PMID:27766237

  19. Selenium speciation in flue desulfurization residues.

    PubMed

    Zhong, Liping; Cao, Yan; Li, Wenying; Xie, Kechang; Pan, Wei-Ping

    2011-01-01

    Flue gas from coal combustion contains significant amounts of volatile selenium (Se). The capture of Se in the flue gas desulfurization (FGD) scrubber unit has resulted in a generation of metal-laden residues. It is important to determine Se speciation to understand the environmental impact of its disposal. A simple method has been developed for selective inorganic Se(IV), Se(VI) and organic Se determination in the liquid-phase FGD residues by hydride generation atomic fluorescence spectrometry (AFS). It has been determined that Se(IV), Se(VI) and organic Se can be accurately determined with detection limits (DL) of 0.05, 0.06 and 0.06 microg/L, respectively. The accuracy of the proposed method was evaluated by analyzing the certified reference material, NIST CRM 1632c, and also by analyzing spiked tap-water samples. Analysis indicates that the concentration of Se is high in FGD liquid residues and primarily exists in a reduced state as selenite (Se(IV)). The toxicity of Se(IV) is the strongest of all Se species. Flue gas desulfurization residues pose a serious environmental risk.

  20. Cadmium uptake and speciation changes in the rhizosphere of cadmium accumulator and non-accumulator oilseed rape varieties.

    PubMed

    Su, Dechun; Xing, Jianping; Jiao, Weiping; Wong, Woonchung

    2009-01-01

    Characteristics of cadmium (Cd) uptake kinetics and distribution of Cd speciation in the rhizosphere for Cd accumulator and non-accumulator oilseed rape varieties were investigated under nutrient solution and rhizobox soil culture conditions. The results showed that the maximal influx (V(max)) for Cd2+ and Km were significantly different for the two oilseed rape varieties. The value of V(max) for Cd accumulator oilseed rape Zhucang Huazi was two-fold greater than that for oilseed rape Chuan you II-93. The exchangeable Cd concentration in the rhizosphere was significantly lower than in non-rhizospheric soils supplemented with CdSO4 for both the varieties. Carbonate-bound Cd in the rhizosphere of Cd accumulator oilseed rape was significantly higher than that in the rhizosphere of non-accumulator oilseed rape and non-rhizospheric soil. Cd accumulator oilseed rape had a higher Cd2+ affinity and more ability to uptake insoluble Cd in the soil than the non-accumulator oilseed rape.

  1. Comparing the mutagenicity of toxaphene after aging in anoxic soils and accumulating in fish.

    PubMed

    Young, James C; Freeman, Anne D; Bruce, Robert M; Williams, Douglas; Maruya, Keith

    2009-01-01

    A test program was conducted to evaluate the mutagenicity of toxaphene residuals extracted from aged soils and from fish collected in creeks near a toxaphene-contaminated site. The ultimate objective was to determine if the residual toxaphene congeners were more or less mutagenic than those in technical-grade toxaphene. The study showed that the mutagenicity of the bioaccumulated toxaphene congeners in fish, expressed as colony revertants per microg of residual toxaphene, was no greater than that of technical-grade toxaphene. The mutagenic impact of the toxaphene residuals in aged soil statistically was less than that for technical-grade toxaphene. Two specific congeners, a hexachlorobornane (labeled Hx-Sd) and a heptachlorobornane (labeled Hp-Sd), were found to accumulate over time in both soil and fish extracts, but did not show increased mutagenic impacts relative to that produced by technical-grade toxaphene.

  2. Heat accumulation during sequential cortical bone drilling.

    PubMed

    Palmisano, Andrew C; Tai, Bruce L; Belmont, Barry; Irwin, Todd A; Shih, Albert; Holmes, James R

    2016-03-01

    Significant research exists regarding heat production during single-hole bone drilling. No published data exist regarding repetitive sequential drilling. This study elucidates the phenomenon of heat accumulation for sequential drilling with both Kirschner wires (K wires) and standard two-flute twist drills. It was hypothesized that cumulative heat would result in a higher temperature with each subsequent drill pass. Nine holes in a 3 × 3 array were drilled sequentially on moistened cadaveric tibia bone kept at body temperature (about 37 °C). Four thermocouples were placed at the center of four adjacent holes and 2 mm below the surface. A battery-driven hand drill guided by a servo-controlled motion system was used. Six samples were drilled with each tool (2.0 mm K wire and 2.0 and 2.5 mm standard drills). K wire drilling increased temperature from 5 °C at the first hole to 20 °C at holes 6 through 9. A similar trend was found in standard drills with less significant increments. The maximum temperatures of both tools increased from <0.5 °C to nearly 13 °C. The difference between drill sizes was found to be insignificant (P > 0.05). In conclusion, heat accumulated during sequential drilling, with size difference being insignificant. K wire produced more heat than its twist-drill counterparts. This study has demonstrated the heat accumulation phenomenon and its significant effect on temperature. Maximizing the drilling field and reducing the number of drill passes may decrease bone injury.

  3. Guidelines for Waste Accumulation Areas (WAAs)

    SciTech Connect

    Not Available

    1991-07-01

    The purpose of this document is to set conditions for establishing and maintaining areas for the accumulation of hazardous waste at LBL. Areas designed for accumulation of these wastes in quantities greater than 100 kg (220 lb) per month of solid waste or 55 gallons per month of liquid waste are called Waste Accumulation Areas (WAAs). Areas designed for accumulation of wastes in smaller amounts are called Satellite Accumulation Areas (SAAs). This document provides guidelines for employee and organizational responsibilities for WAAs; constructing a WAA; storing waste in a WAA; operating and maintaining a WAA, and responding to spills in a WAA. 4 figs.

  4. Statistical Analysis of Tank 5 Floor Sample Results

    SciTech Connect

    Shine, E. P.

    2013-01-31

    Sampling has been completed for the characterization of the residual material on the floor of Tank 5 in the F-Area Tank Farm at the Savannah River Site (SRS), near Aiken, SC. The sampling was performed by Savannah River Remediation (SRR) LLC using a stratified random sampling plan with volume-proportional compositing. The plan consisted of partitioning the residual material on the floor of Tank 5 into three non-overlapping strata: two strata enclosed accumulations, and a third stratum consisted of a thin layer of material outside the regions of the two accumulations. Each of three composite samples was constructed from five primary sample locations of residual material on the floor of Tank 5. Three of the primary samples were obtained from the stratum containing the thin layer of material, and one primary sample was obtained from each of the two strata containing an accumulation. This report documents the statistical analyses of the analytical results for the composite samples. The objective of the analysis is to determine the mean concentrations and upper 95% confidence (UCL95) bounds for the mean concentrations for a set of analytes in the tank residuals. The statistical procedures employed in the analyses were consistent with the Environmental Protection Agency (EPA) technical guidance by Singh and others [2010]. Savannah River National Laboratory (SRNL) measured the sample bulk density, nonvolatile beta, gross alpha, and the radionuclide1, elemental, and chemical concentrations three times for each of the composite samples. The analyte concentration data were partitioned into three separate groups for further analysis: analytes with every measurement above their minimum detectable concentrations (MDCs), analytes with no measurements above their MDCs, and analytes with a mixture of some measurement results above and below their MDCs. The means, standard deviations, and UCL95s were computed for the analytes in the two groups that had at least some measurements

  5. STATISTICAL ANALYSIS OF TANK 5 FLOOR SAMPLE RESULTS

    SciTech Connect

    Shine, E.

    2012-03-14

    Sampling has been completed for the characterization of the residual material on the floor of Tank 5 in the F-Area Tank Farm at the Savannah River Site (SRS), near Aiken, SC. The sampling was performed by Savannah River Remediation (SRR) LLC using a stratified random sampling plan with volume-proportional compositing. The plan consisted of partitioning the residual material on the floor of Tank 5 into three non-overlapping strata: two strata enclosed accumulations, and a third stratum consisted of a thin layer of material outside the regions of the two accumulations. Each of three composite samples was constructed from five primary sample locations of residual material on the floor of Tank 5. Three of the primary samples were obtained from the stratum containing the thin layer of material, and one primary sample was obtained from each of the two strata containing an accumulation. This report documents the statistical analyses of the analytical results for the composite samples. The objective of the analysis is to determine the mean concentrations and upper 95% confidence (UCL95) bounds for the mean concentrations for a set of analytes in the tank residuals. The statistical procedures employed in the analyses were consistent with the Environmental Protection Agency (EPA) technical guidance by Singh and others [2010]. Savannah River National Laboratory (SRNL) measured the sample bulk density, nonvolatile beta, gross alpha, radionuclide, inorganic, and anion concentrations three times for each of the composite samples. The analyte concentration data were partitioned into three separate groups for further analysis: analytes with every measurement above their minimum detectable concentrations (MDCs), analytes with no measurements above their MDCs, and analytes with a mixture of some measurement results above and below their MDCs. The means, standard deviations, and UCL95s were computed for the analytes in the two groups that had at least some measurements above their

  6. Statistical Analysis Of Tank 5 Floor Sample Results

    SciTech Connect

    Shine, E. P.

    2012-08-01

    Sampling has been completed for the characterization of the residual material on the floor of Tank 5 in the F-Area Tank Farm at the Savannah River Site (SRS), near Aiken, SC. The sampling was performed by Savannah River Remediation (SRR) LLC using a stratified random sampling plan with volume-proportional compositing. The plan consisted of partitioning the residual material on the floor of Tank 5 into three non-overlapping strata: two strata enclosed accumulations, and a third stratum consisted of a thin layer of material outside the regions of the two accumulations. Each of three composite samples was constructed from five primary sample locations of residual material on the floor of Tank 5. Three of the primary samples were obtained from the stratum containing the thin layer of material, and one primary sample was obtained from each of the two strata containing an accumulation. This report documents the statistical analyses of the analytical results for the composite samples. The objective of the analysis is to determine the mean concentrations and upper 95% confidence (UCL95) bounds for the mean concentrations for a set of analytes in the tank residuals. The statistical procedures employed in the analyses were consistent with the Environmental Protection Agency (EPA) technical guidance by Singh and others [2010]. Savannah River National Laboratory (SRNL) measured the sample bulk density, nonvolatile beta, gross alpha, and the radionuclide, elemental, and chemical concentrations three times for each of the composite samples. The analyte concentration data were partitioned into three separate groups for further analysis: analytes with every measurement above their minimum detectable concentrations (MDCs), analytes with no measurements above their MDCs, and analytes with a mixture of some measurement results above and below their MDCs. The means, standard deviations, and UCL95s were computed for the analytes in the two groups that had at least some measurements

  7. Pesticide Residues on Three Cut Flower Species and Potential Exposure of Florists in Belgium

    PubMed Central

    Toumi, Khaoula; Vleminckx, Christiane; van Loco, Joris; Schiffers, Bruno

    2016-01-01

    In order to assess the prevalence of pesticide contamination and the risk of florists’ exposure when handling cut flowers, sampling and analysis of 90 bouquets of the most commonly sold cut flowers in Belgium (50 bouquets of roses; 20 of gerberas, and 20 of chrysanthemums) were carried out. The bouquets were collected from 50 florists located in the seven largest cities of Belgium (Antwerp, Brussels, Charleroi, Ghent, Leuven, Liege, and Namur) and from five supermarkets located in the different regions. To have a better understanding of the route of exposure and professional practices a questionnaire was also addressed to a group of 25 florists who volunteered to take part in the survey. All florists were interviewed individually when collecting the questionnaire. The residual pesticide deposit values on cut flowers were determined in an accredited laboratory using a multi-residue (QuEChERS Quick Easy Cheap Effective Rugged Safe) method and a combination of gas chromatography (GC) and liquid chormatograhphy (LC) analysis. A total of 107 active substances were detected from all samples; i.e., an average of about 10 active substances per bouquet. The most severely contaminated bouquet accumulated a total concentration of residues up to 97 mg/kg. Results show that roses are the most contaminated cut flowers; with an average of 14 substances detected per sample and a total concentration per rose sample of 26 mg/kg. Some active substances present an acute toxicity (acephate, methiocarb, monocrotophos, methomyl, deltamethrin, etc.) and exposure can generate a direct effect on the nervous system of florists. Nevertheless, fungicides (dodemorph, propamocarb, and procymidone) were the most frequently detected in samples and had the highest maximum concentrations out of all the active substances analysed. Dodemorph was the most frequently detected substance with the highest maximum concentration (41.9 mg/kg) measured in the rose samples. It appears from the survey that

  8. Pesticide Residues on Three Cut Flower Species and Potential Exposure of Florists in Belgium.

    PubMed

    Toumi, Khaoula; Vleminckx, Christiane; van Loco, Joris; Schiffers, Bruno

    2016-09-23

    In order to assess the prevalence of pesticide contamination and the risk of florists' exposure when handling cut flowers, sampling and analysis of 90 bouquets of the most commonly sold cut flowers in Belgium (50 bouquets of roses; 20 of gerberas, and 20 of chrysanthemums) were carried out. The bouquets were collected from 50 florists located in the seven largest cities of Belgium (Antwerp, Brussels, Charleroi, Ghent, Leuven, Liege, and Namur) and from five supermarkets located in the different regions. To have a better understanding of the route of exposure and professional practices a questionnaire was also addressed to a group of 25 florists who volunteered to take part in the survey. All florists were interviewed individually when collecting the questionnaire. The residual pesticide deposit values on cut flowers were determined in an accredited laboratory using a multi-residue (QuEChERS Quick Easy Cheap Effective Rugged Safe) method and a combination of gas chromatography (GC) and liquid chormatograhphy (LC) analysis. A total of 107 active substances were detected from all samples; i.e., an average of about 10 active substances per bouquet. The most severely contaminated bouquet accumulated a total concentration of residues up to 97 mg/kg. Results show that roses are the most contaminated cut flowers; with an average of 14 substances detected per sample and a total concentration per rose sample of 26 mg/kg. Some active substances present an acute toxicity (acephate, methiocarb, monocrotophos, methomyl, deltamethrin, etc.) and exposure can generate a direct effect on the nervous system of florists. Nevertheless, fungicides (dodemorph, propamocarb, and procymidone) were the most frequently detected in samples and had the highest maximum concentrations out of all the active substances analysed. Dodemorph was the most frequently detected substance with the highest maximum concentration (41.9 mg/kg) measured in the rose samples. It appears from the survey that

  9. Modeling Sustainable Agricultural Residue Removal at the Subfield Scale

    SciTech Connect

    Muth, D.J.; McCorkle, D.S.; Koch, J.B.; Bryden, K.M.

    2012-05-02

    This study developed a computational strategy that utilizes data inputs from multiple spatial scales to investigate how variability within individual fields can impact sustainable residue removal for bioenergy production. Sustainable use of agricultural residues for bioenergy production requires consideration of the important role that residues play in limiting soil erosion and maintaining soil C, health, and productivity. Increased availability of subfield-scale data sets such as grain yield data, high-fidelity digital elevation models, and soil characteristic data provides an opportunity to investigate the impacts of subfield-scale variability on sustainable agricultural residue removal. Using three representative fields in Iowa, this study contrasted the results of current NRCS conservation management planning analysis with subfield-scale analysis for rake-and-bale removal of agricultural residue. The results of the comparison show that the field-average assumptions used in NRCS conservation management planning may lead to unsustainable residue removal decisions for significant portions of some fields. This highlights the need for additional research on subfield-scale sustainable agricultural residue removal including the development of real-time variable removal technologies for agricultural residue.

  10. Control of ash accumulation by induced-fishbones

    SciTech Connect

    Varadarajan, V.; Miley, G.H.

    1989-01-01

    Thermal alphas will accumulate in the ignited long pulse tokamak. Ash accumulation results in fuel dilution, reduced power output, increase in Z{sub eff}, and increased synchrotron losses. Recent Baldur' simulations of the ITER show that the ash accumulation is a distinct possibility for high ash recycling case, inevitably leading to burn quench. So, some means of ash is highly desirable. To this end, several control schemes have been looked at. Given the uncertainty in transport information especially for the ash and other impurity transport, it is desirable to incorporate some explicit ash control features in the tokamak design. Continuing the search for more desirable schemes, in this paper we explore the effectiveness of fishbones' towards controlling the alpha accumulation.

  11. DISSOLUTION OF NEPTUNIUM OXIDE RESIDUES

    SciTech Connect

    Kyser, E

    2009-01-12

    This report describes the development of a dissolution flowsheet for neptunium (Np) oxide (NpO{sub 2}) residues (i.e., various NpO{sub 2} sources, HB-Line glovebox sweepings, and Savannah River National Laboratory (SRNL) thermogravimetric analysis samples). Samples of each type of materials proposed for processing were dissolved in a closed laboratory apparatus and the rate and total quantity of off-gas were measured. Samples of the off-gas were also analyzed. The quantity and type of solids remaining (when visible) were determined after post-dissolution filtration of the solution. Recommended conditions for dissolution of the NpO{sub 2} residues are: Solution Matrix and Loading: {approx}50 g Np/L (750 g Np in 15 L of dissolver solution), using 8 M nitric acid (HNO{sub 3}), 0.025 M potassium fluoride (KF) at greater than 100 C for at least 3 hours. Off-gas: Analysis of the off-gas indicated nitric oxide (NO), nitrogen dioxide (NO{sub 2}) and nitrous oxide (N{sub 2}O) as the only identified components. No hydrogen (H{sub 2}) was detected. The molar ratio of off-gas produced per mole of Np dissolved ranged from 0.25 to 0.4 moles of gas per mole of Np dissolved. A peak off-gas rate of {approx}0.1 scfm/kg bulk oxide was observed. Residual Solids: Pure NpO{sub 2} dissolved with little or no residue with the proposed flowsheet but the NpCo and both sweepings samples left visible solid residue after dissolution. For the NpCo and Part II Sweepings samples the residue amounted to {approx}1% of the initial material, but for the Part I Sweepings sample, the residue amounted to {approx}8 % of the initial material. These residues contained primarily aluminum (Al) and silicon (Si) compounds that did not completely dissolve under the flowsheet conditions. The residues from both sweepings samples contained minor amounts of plutonium (Pu) particles. Overall, the undissolved Np and Pu particles in the residues were a very small fraction of the total solids.

  12. Catalyst deactivation in residue hydrocracking

    SciTech Connect

    Oballa, M.C.; Wong, C.; Krzywicki, A.

    1994-12-31

    The existence of a computer-controlled bench scale hydrocracking units at the authors site has made cheaper the non-stop running of experiments for long periods of time. It was, therefore possible to show, at minimal costs, when three hydrocracking catalysts in service reach their maximum lifetime. Different parameters which are helpful for catalyst life and activity predictions were calculated, e.g., relative catalyst age and the effectiveness factor. Experimental results compared well with model, giving them the minimum and maximum catalyst lifetime, as well as the deactivation profile with regard to sulfur and metals removal. Reaction rate constants for demetallization and desulfurization were also determined. Six commercial catalysts were evaluated at short term runs and the three most active were used for long term runs. Out of three catalysts tested for deactivation at long term runs, it was possible to choose one whose useful life was higher than the others. All runs were carried out in a Robinson-Mahoney continuous flow stirred tank reactor, using 50/50 volumetric mixture of Cold Lake/Lloydminster atmospheric residue and NiMo/Al{sub 2}O{sub 3} catalyst.

  13. Lipid accumulation in prokaryotic microorganisms from arid habitats.

    PubMed

    Hauschild, Philippa; Röttig, Annika; Madkour, Mohamed H; Al-Ansari, Ahmed M; Almakishah, Naief H; Steinbüchel, Alexander

    2017-03-01

    This review shall provide support for the suitability of arid environments as preferred location to search for unknown lipid-accumulative bacteria. Bacterial lipids are attracting more and more attention as sustainable replacement for mineral oil in fuel and plastic production. The development of prokaryotic microorganisms in arid desert habitats is affected by its harsh living conditions. Drought, nutrient limitation, strong radiation, and extreme temperatures necessitate effective adaption mechanisms. Accumulation of storage lipids as energy reserve and source of metabolic water represents a common adaption in desert animals and presumably in desert bacteria and archaea as well. Comparison of corresponding literature resulted in several bacterial species from desert habitats, which had already been described as lipid-accumulative elsewhere. Based on the gathered information, literature on microbial communities in hot desert, cold desert, and humid soil were analyzed on its content of lipid-accumulative bacteria. With more than 50% of the total community size in single studies, hot deserts appear to be more favorable for lipid-accumulative species then humid soil (≤20%) and cold deserts (≤17%). Low bacterial lipid accumulation in cold deserts is assumed to result from the influence of low temperatures on fatty acids and the increased necessity of permanent adaption methods.

  14. Organochlorine residues in bird species collected dead in Ontario 1972-1988

    SciTech Connect

    Frank, R.; Braun, H.E. )

    1990-06-01

    Organochlorine residues have been reported in many species of birds found dead or shot around the Great Lakes Basin. Raptors and fish-eating birds have had very high residues in the past while terrestrial seed- and insect-eaters have had relatively low residues. Most of the organochlorine insecticides like DDT, aldrin, dieldrin, chlordane, endrin and heptachlor have been removed from field use, and controls have been placed on the dispersal of organochlorine industrial chemicals like mirex and PCB. These substances are very persistent. The major sources of contamination now are environmental residues picked up by birds in their normal feeding. These compounds bioaccumulate in bird species, and the highest residues accumulate at the top of the food chain. This paper is a compilation of data obtained from dead birds collected in the Great Lakes Basin over the last 16 years and analyzed for organochlorine contaminants.

  15. Effects of prion protein devoid of the N-terminal residues 25-50 on prion pathogenesis in mice.

    PubMed

    Das, Nandita Rani; Miyata, Hironori; Hara, Hideyuki; Uchiyama, Keiji; Chida, Junji; Yano, Masashi; Watanabe, Hitomi; Kondoh, Gen; Sakaguchi, Suehiro

    2017-03-02

    The N-terminal polybasic region of the normal prion protein, PrP(C), which encompasses residues 23-31, is important for prion pathogenesis by affecting conversion of PrP(C) into the pathogenic isoform, PrP(Sc). We previously reported transgenic mice expressing PrP with residues 25-50 deleted in the PrP-null background, designated as Tg(PrP∆preOR)/Prnp (0/0) mice. Here, we produced two new lines of Tg(PrP∆preOR)/Prnp (0/0) mice, each expressing the mutant protein, PrP∆preOR, 1.1 and 1.6 times more than PrP(C) in wild-type mice, and subsequently intracerebrally inoculated RML and 22L prions into them. The lower expresser showed slightly reduced susceptibility to RML prions but not to 22L prions. The higher expresser exhibited enhanced susceptibility to both prions. No prion transmission barrier was created in Tg(PrP∆preOR)/Prnp (0/0) mice against full-length PrP(Sc). PrP(Sc)∆preOR accumulated in the brains of infected Tg(PrP∆preOR)/Prnp (0/0) mice less than PrP(Sc) in control wild-type mice, although lower in RML-infected Tg(PrP∆preOR)/Prnp (0/0) mice than in 22L-infected mice. Prion infectivity in infected Tg(PrP∆preOR)/Prnp (0/0) mice was also lower than that in wild-type mice. These results indicate that deletion of residues 25-50 only slightly affects prion susceptibility, the conversion of PrP(C) into PrP(Sc), and prion infectivity in a strain-specific way. PrP∆preOR retains residues 23-24 and lacks residues 25-31 in the polybasic region. It is thus conceivable that residues 23-24 rather than 25-31 are important for the polybasic region to support prion pathogenesis. However, other investigators have reported that residues 27-31 not 23-24 are important to support prion pathogenesis. Taken together, the polybasic region might support prion pathogenesis through multiple sites including residues 23-24 and 27-31.

  16. Normative evidence accumulation in unpredictable environments

    PubMed Central

    Glaze, Christopher M; Kable, Joseph W; Gold, Joshua I

    2015-01-01

    In our dynamic world, decisions about noisy stimuli can require temporal accumulation of evidence to identify steady signals, differentiation to detect unpredictable changes in those signals, or both. Normative models can account for learning in these environments but have not yet been applied to faster decision processes. We present a novel, normative formulation of adaptive learning models that forms decisions by acting as a leaky accumulator with non-absorbing bounds. These dynamics, derived for both discrete and continuous cases, depend on the expected rate of change of the statistics of the evidence and balance signal identification and change detection. We found that, for two different tasks, human subjects learned these expectations, albeit imperfectly, then used them to make decisions in accordance with the normative model. The results represent a unified, empirically supported account of decision-making in unpredictable environments that provides new insights into the expectation-driven dynamics of the underlying neural signals. DOI: http://dx.doi.org/10.7554/eLife.08825.001 PMID:26322383

  17. Predicting Accumulations of Ice on Aerodynamic Surfaces

    NASA Technical Reports Server (NTRS)

    Bidwell, Colin; Potapczuk, Mark; Addy, Gene; Wright, William

    2003-01-01

    LEWICE is a computer program that predicts the accumulation of ice on two-dimensional aerodynamic surfaces under conditions representative of the flight of an aircraft through an icing cloud. The software first calculates the airflow surrounding the body of interest, then uses the airflow to compute the trajectories of water droplets that impinge on the surface of the body. The droplet trajectories are also used to compute impingement limits and local collection efficiencies, which are used in subsequent ice-growth calculations and are also useful for designing systems to protect against icing. Next, the software predicts the shape of accumulating ice by modeling transfers of mass and energy in small control volumes. The foregoing computations are repeated over several computational time steps until the total icing exposure time is reached. Results of computations by LEWICE have been compared with an extensive database of measured ice shapes obtained from experiments, and have been shown to closely approximate those shapes under most conditions of interest to the aviation community.

  18. Experiment specific processing of residual acceleration data

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.; Alexander, J. I. D.

    1992-01-01

    To date, most Spacelab residual acceleration data collection projects have resulted in data bases that are overwhelming to the investigator of low-gravity experiments. This paper introduces a simple passive accelerometer system to measure low-frequency accelerations. Model responses for experiments using actual acceleration data are produced and correlations are made between experiment response and the accelerometer time history in order to test the idea that recorded acceleration data and experimental responses can be usefully correlated. Spacelab 3 accelerometer data are used as input to a variety of experiment models, and sensitivity limits are obtained for particular experiment classes. The modeling results are being used to create experiment-specific residual acceleration data processing schemes for interested investigators.

  19. Residual insecticides and the problem of sorption

    PubMed Central

    Bertagna, P.

    1959-01-01

    Whereas laboratory investigations have elucidated the mechanism of sorption of residual insecticides and demonstrated that their persistency is determined by a number of physico-chemical factors and is therefore theoretically calculable, the variables encountered in the field may produce results in apparent conflict with those theoretically expected. Attempts to enhance persistency through the prevention of sorption, although promising, have so far not been fully successful. It is consequently also necessary to assess the residual effectiveness of insecticides, “effectiveness” here being viewed as a biological effect expressed in terms of the mosquito mortality produced. For this purpose bio-assay tests have been used, but with very variable results, and it is suggested that a study of the bio-assay technique itself is needed. This should be conducted in parallel with chemical determinations of the total amount of insecticide present both on and below the sprayed surface. PMID:13799942

  20. CONCEPTUAL MODEL FOR ORIGIN OF ABNORMALLY PRESSURED GAS ACCUMULATIONS IN LOW-PERMEABILITY RESERVOIRS.

    USGS Publications Warehouse

    Law, B.E.; Dickinson, W.W.

    1985-01-01

    The paper suggests that overpressured and underpressured gas accumulations of this type have a common origin. In basins containing overpressured gas accumulations, rates of thermogenic gas accumulation exceed gas loss, causing fluid (gas) pressure to rise above the regional hydrostatic pressure. Free water in the larger pores is forced out of the gas generation zone into overlying and updip, normally pressured, water-bearing rocks. While other diagenetic processes continue, a pore network with very low permeability develops. As a result, gas accumulates in these low-permeability reservoirs at rates higher than it is lost. In basins containing underpressured gas accumulations, rates of gas generation and accumulation are less than gas loss. The basin-center gas accumulation persists, but because of changes in the basin dynamics, the overpressured accumulation evolves into an underpressured system.

  1. Energy release, beam attenuation radiation damage, gas production and accumulation of long-lived activity in Pb, Pb-Bi and Hg targets

    SciTech Connect

    Shubin, Yu.N.

    1996-06-01

    The calculation and analysis of the nuclei concentrations and long-lived residual radioactivity accumulated in Pb, Pb-Bi and Hg targets irradiated by 800 MeV, 30 mA proton beam have been performed. The dominating components to the total radioactivity of radionuclides resulting from fission and spallation reactions and radiative capture by both target nuclei and accumulated radioactive nuclei for various irradiation and cooling times were analyzed. The estimations of spectral component contributions of neutron and proton fluxes to the accumulated activity were carried out. The contributions of fission products to the targets activity and partial activities of main long-lived fission products to the targets activity and partial activities of main long-lived fission products were evaluated. The accumulation of Po isotopes due to reactions induced by secondary alpha-particles were found to be important for the Pb target as compared with two-step radiative capture. The production of Tritium in the targets and its contribution to the total targets activity was considered in detail. It is found that total activities of both targets are close to one another.

  2. Partial connectivity increases cultural accumulation within groups.

    PubMed

    Derex, Maxime; Boyd, Robert

    2016-03-15

    Complex technologies used in most human societies are beyond the inventive capacities of individuals. Instead, they result from a cumulative process in which innovations are gradually added to existing cultural traits across many generations. Recent work suggests that a population's ability to develop complex technologies is positively affected by its size and connectedness. Here, we present a simple computer-based experiment that compares the accumulation of innovations by fully and partially connected groups of the same size in a complex fitness landscape. We find that the propensity to learn from successful individuals drastically reduces cultural diversity within fully connected groups. In comparison, partially connected groups produce more diverse solutions, and this diversity allows them to develop complex solutions that are never produced in fully connected groups. These results suggest that explanations of ancestral patterns of cultural complexity may need to consider levels of population fragmentation and interaction patterns between partially isolated groups.

  3. Partial connectivity increases cultural accumulation within groups

    PubMed Central

    Boyd, Robert

    2016-01-01

    Complex technologies used in most human societies are beyond the inventive capacities of individuals. Instead, they result from a cumulative process in which innovations are gradually added to existing cultural traits across many generations. Recent work suggests that a population’s ability to develop complex technologies is positively affected by its size and connectedness. Here, we present a simple computer-based experiment that compares the accumulation of innovations by fully and partially connected groups of the same size in a complex fitness landscape. We find that the propensity to learn from successful individuals drastically reduces cultural diversity within fully connected groups. In comparison, partially connected groups produce more diverse solutions, and this diversity allows them to develop complex solutions that are never produced in fully connected groups. These results suggest that explanations of ancestral patterns of cultural complexity may need to consider levels of population fragmentation and interaction patterns between partially isolated groups. PMID:26929364

  4. THE CONTOUR METHOD: SIMPLE 2-D MAPPING OF RESIDUAL STRESSES

    SciTech Connect

    M. PRIME; A. GONZALES

    2000-06-01

    We present an entirely new method for measuring residual stress that is extremely simple to apply yet more powerful than existing techniques. In this method, a part is carefully cut in two. The contour of the resulting new surface is measured to determine the displacements normal to the surface caused by the release of the residual stresses. Analytically, the opposite of these measured displacements are applied as boundary conditions to the surface in a finite element model. By Bueckner's superposition principle, this gives the original residual stresses normal to the plane of the cut. Unlike other relaxation methods for measuring residual stress, the measured data can be used to solve directly for the stresses without a tedious inversion technique. At the same time, an arbitrary two-dimensional variation in stresses can be determined. We demonstrate the method on a steel specimen with a known residual stress profile.

  5. Response times from ensembles of accumulators

    PubMed Central

    Zandbelt, Bram; Purcell, Braden A.; Palmeri, Thomas J.; Logan, Gordon D.; Schall, Jeffrey D.

    2014-01-01

    Decision-making is explained by psychologists through stochastic accumulator models and by neurophysiologists through the activity of neurons believed to instantiate these models. We investigated an overlooked scaling problem: How does a response time (RT) that can be explained by a single model accumulator arise from numerous, redundant accumulator neurons, each of which individually appears to explain the variability of RT? We explored this scaling problem by developing a unique ensemble model of RT, called e pluribus unum, which embodies the well-known dictum “out of many, one.” We used the e pluribus unum model to analyze the RTs produced by ensembles of redundant, idiosyncratic stochastic accumulators under various termination mechanisms and accumulation rate correlations in computer simulations of ensembles of varying size. We found that predicted RT distributions are largely invariant to ensemble size if the accumulators share at least modestly correlated accumulation rates and RT is not governed by the most extreme accumulators. Under these regimes the termination times of individual accumulators was predictive of ensemble RT. We also found that the threshold measured on individual accumulators, corresponding to the firing rate of neurons measured at RT, can be invariant with RT but is equivalent to the specified model threshold only when the rate correlation is very high. PMID:24550315

  6. Strain accumulation at Yucca Mountain, Nevada, 1983-1998

    NASA Astrophysics Data System (ADS)

    Savage, J. C.; Svarc, J. L.; Prescott, W. H.

    1999-08-01

    A 14-station, 50-km aperture geodetic array centered on the proposed radioactive waste disposal site at Yucca Mountain, Nevada, was surveyed in 1983, 1984, 1993, and 1998 to determine the rate of strain accumulation there. The coseismic effects of the 1992 (MS=5.4) Little Skull Mountain earthquake, which occurred within the array, were calculated from a dislocation model and removed from the data. The measured principal strain accumulation rates determined over the 1983-1998 interval are ɛ1 = 2±12 nanostrain/yr N87°W±12° and ɛ2 = -22±12 nanostrain/yr N03°E±12° (extension reckoned positive and quoted uncertainties are standard deviations). The N65°W extension rate is -2±12 nanostrain/yr, significantly less than the 1991-1997 N65°W rate of 50±9 nanostrain/yr reported by Wernicke et al. [1998]. The implied maximum right-lateral engineering-shear, strain accumulation rate is γ=ɛ1-ɛ2 = 23±10 nanostrain/yr, a marginally significant rate. Almost half (ɛ1 = 6 nanostrain/yr N90°W, ɛ2 = -6 nanostrain/yr N00°E, and γ = 12 nanostrain/yr ) of the measured strain rate can be attributed to strain accumulation on the Death Valley-Furnace Creek (50 km distant) and Hunter Mountain-Panamint Valley (90 km distant) faults. The residual strain rate after the removal of those fault contributions is not significant at the 95% confidence level.

  7. SVD analysis of Aura TES spectral residuals

    NASA Technical Reports Server (NTRS)

    Beer, Reinhard; Kulawik, Susan S.; Rodgers, Clive D.; Bowman, Kevin W.

    2005-01-01

    Singular Value Decomposition (SVD) analysis is both a powerful diagnostic tool and an effective method of noise filtering. We present the results of an SVD analysis of an ensemble of spectral residuals acquired in September 2004 from a 16-orbit Aura Tropospheric Emission Spectrometer (TES) Global Survey and compare them to alternative methods such as zonal averages. In particular, the technique highlights issues such as the orbital variation of instrument response and incompletely modeled effects of surface emissivity and atmospheric composition.

  8. Herbicide retention in soil as affected by sugarcane mulch residue.

    PubMed

    Selim, H M; Zhou, L; Zhu, H

    2003-01-01

    Reducing surface and subsurface losses of herbicides in the soil and thus their potential contamination of water resources is a national concern. This study evaluated the effectiveness of sugarcane (Saccharum spp.) residue (mulch cover) in reducing nonpoint-source contamination of applied herbicides from sugarcane fields. Specifically, the effect of mulch residue on herbicide retention was quantified. Two main treatments were investigated: a no-till treatment and a no-mulch treatment. The amounts of extractable atrazine [2-chloro-4-(isopropylamino)-6-ethylamino-s-triazine], metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one], and pendimethalin [N-(ethylpropyl)-3,4-dimethyl-2,6-dinitroaniline] from the mulch residue and the surface soil layer were quantified during the 1999 and 2000 growing seasons. Significant amounts of applied herbicides were intercepted by the mulch residue. Extractable concentrations were at least one order of magnitude higher for the mulch residue compared with that retained by the soil. Moreover, the presence of mulch residue on the sugarcane rows was highly beneficial in minimizing runoff losses of the herbicides applied. When the residue was not removed, a reduction in runoff-effluent concentrations, as much as 50%, for atrazine and pendimethalin was realized. Moreover, the presence of mulch residue resulted in consistently lower estimates for rates of decay or disappearance of atrazine and pendimethalin in the surface soil.

  9. Using ASTER image for soybean plant residue coverage estimation

    NASA Astrophysics Data System (ADS)

    Yao, Haibo; Lewis, David; Kincaid, Russell

    2006-10-01

    Soil erosion and its related runoff is a serious problem in U.S. agriculture. USDA has classified 27% of U.S. agricultural land as being highly erodible. Because of the erosion, rivers, lakes, and water table are contaminated due to the agriculture chemicals such as nitrogen, phosphorus, and pesticides contained in the runoff water. This is a serious environmental problem nationwide. It is well recognized that residue coverage on the soil surface can reduce soil erosion. The objective of this paper was to explore the potential of using ASTER data for soybean plant residue cover estimation. In the spring of 2004, personnel from Natural Resource Conservation Service (NRCS) and Institute for Technology Development (ITD) did a traditional windshield survey in three Indiana Counties, Wabash, Huntington, and Grant. Fields with greater than 30% residue cover were classified as conservation tillage (no till); those with 16-30% residue cover as reduced tillage; and those with less than 15% residue cover as traditional tillage. ASTER data was collected over the study sites on April 14, 2004. Spectral information was extracted from the ASTER image for statistical analysis. Field values for various indices were calculated from the reflectance data. Residue coverage estimation from the survey was used as the ground truth for the field. Analysis was performed to determine the capability of ASTER data to identify crop residue coverage. The initial results indicated that ASTER imagery has moderate capability to identify residue coverage - or tillage practice within the soybean fields.

  10. Presence and biomagnification of organochlorine chemical residues in oxbow lakes of northeastern Louisiana

    USGS Publications Warehouse

    Niethammer, K.R.; White, D.H.; Baskett, T.S.; Sayre, M.W.

    1984-01-01

    Samples (98) of 16 spp. of animals were collected at Lake Providence, 88 samples of 15 spp. at Lake Bruin and 21 samples of 5 spp. at Lake St. John, Louisiana, between July 15 and Sept. 25, 1980. Residues of 13 organochlorine compounds were identified in these samples. Substantial concentrations of many compounds throughout the food webs of all 3 lakes showed that the lakes acted as sumps, accumulating residues from nearby agricultural land. DDT and its metabolites (DDE, TDE and DDMU [1-chloro-2,2,-bis(p-chlorophenyl)ethylene]), toxaphene and polychlorobiphenyls (PCB) were the principal organochloride residues detected. With few exceptions, biomagnification of the principal residues was clearly illustrated. Tertiary consumers such as green-backed heron (Butorides striatus), snakes, spotted gar (Lepisosteus oculatus) and largemouth bass (Micropterus salmoides) contained the highest residues. Bluegill (Lepomis macrochirus), blacktail shiner (Notropis venustus), yellow-crowned night heron (Nycticorax violaceus) and other secondary consumers contained lower levels of residues. Primary consumers, crayfish (Orconectes lancifer) and threadfin shad (Dorosoma petenense), contained relatively low residue levels of most compounds. Frogs contained lower residue levels than expected based on their position in the food web. Residue levels in immature green-backed herons and .gtoreq. 1 of the longer-lived predators, e.g., snakes, gars or largemouth bass could be monitored to evaluate levels of organochlorine chemical contaminants in aquatic habitats.

  11. Tipping news in information accumulation system

    NASA Astrophysics Data System (ADS)

    Shin, J. K.

    2010-05-01

    As a continuous opinion dynamics model, the information accumulation system (IAS) includes three basic mechanisms of the news, the inheritance and the diffusion as contributing to the information accumulation process of a system. A system is composed of agents who diffuse information through internal interaction, while each of them has incomplete memory or inheritance rate. The news comes from external sources of information, such as mass media. Previously the model IAS was studied only for the small news problems. In this study, a tipping news problem is considered. A key question of the problem is: what is the minimum strength of advertisement that can tip the minority opinion to a majority one? Dynamics of the IAS is briefly revisited with a special interest on nonlinear behavior of the model. In particular, it is shown that a discrete map of the IAS for a single color problem can be transformed into a logistic map, from which the dynamics of the IAS can be better understood. To show the applicability of the IAS model, the result is applied to explain the concept of the critical population size, which claims that there is a minimum population size for a social knowledge system to be continuously inherited without being lost. And critical size of the tipping news is found analytically in terms of IAS parameters. Some of the key results from the present study are compared in detail with the results from the Brownian particle model, which is believed to be the most similar model to the IAS. The concept of tipping news is used to show that a traditional society can tip at an exceptionally low inter-community exposure. Finally, the result was applied to the language competition problem.

  12. Replication of Aleutian Mink Disease Parvovirus In Vivo Is Influenced by Residues in the VP2 Protein

    PubMed Central

    Fox, James M.; McCrackin Stevenson, Mary A.; Bloom, Marshall E.

    1999-01-01

    Aleutian mink disease parvovirus (ADV) is the etiological agent of Aleutian disease of mink. Several ADV isolates have been identified which vary in the severity of the disease they elicit. The isolate ADV-Utah replicates to high levels in mink, causing severe Aleutian disease that results in death within 6 to 8 weeks, but does not replicate in Crandell feline kidney (CrFK) cells. In contrast, ADV-G replicates in CrFK cells but does not replicate in mink. The ability of the virus to replicate in vivo is determined by virally encoded determinants contained within a defined region of the VP2 gene (M. E. Bloom, J. M. Fox, B. D. Berry, K. L. Oie, and J. B. Wolfinbarger. Virology 251:288–296, 1998). Within this region, ADV-G and ADV-Utah differ at only five amino acid residues. To determine which of these five amino acid residues comprise the in vivo replication determinant, site-directed mutagenesis was performed to individually convert the amino acid residues of ADV-G to those of ADV-Utah. A virus in which the ADV-G VP2 residue at 534, histidine (H), was converted to an aspartic acid (D) of ADV-Utah replicated in CrFK cells as efficiently as ADV-G. H534D also replicated in mink, causing transient viremia at 30 days postinfection and a strong antibody response. Animals infected with this virus developed diffuse hepatocellular microvesicular steatosis, an abnormal accumulation of intracellular fat, but did not develop classical Aleutian disease. Thus, the substitution of an aspartic acid at residue 534 for a histidine allowed replication of ADV-G in mink, but the ability to replicate was not sufficient to cause classical Aleutian disease. PMID:10482625

  13. Accumulation boundaries: codimension-two accumulation of accumulations in phase diagrams of semiconductor lasers, electric circuits, atmospheric and chemical oscillators.

    PubMed

    Bonatto, Cristian; Gallas, Jason Alfredo Carlson

    2008-02-28

    We report high-resolution phase diagrams for several familiar dynamical systems described by sets of ordinary differential equations: semiconductor lasers; electric circuits; Lorenz-84 low-order atmospheric circulation model; and Rössler and chemical oscillators. All these systems contain chaotic phases with highly complicated and interesting accumulation boundaries, curves where networks of stable islands of regular oscillations with ever-increasing periodicities accumulate systematically. The experimental exploration of such codimension-two boundaries characterized by the presence of infinite accumulation of accumulations is feasible with existing technology for some of these systems.

  14. Measurement of Residual Stress in a Welded Branch Connection and Effects on Fracture Behaviour

    NASA Astrophysics Data System (ADS)

    Law, M.; Luzin, V.; Kirstein, O.

    2010-11-01

    The branch analysed in this paper was not post weld heat treated, resulting in significant residual stresses. Assessment codes assume these to be at, or close to, yield. An integrity assessment of a welded branch connection was carried out using these high assumed residual stresses. The weld then had residual stresses determined by neutron diffraction, performed using ANSTO's residual stress diffractometer, Kowari. The maximum measured residual stress (290 MPa or 60% of yield) was much lower than the yield value assumed by assessment codes. Reanalysing with the actual residual stresses almost doubled the critical crack size, increasing the safety of the connection.

  15. Residual Stresses in 21-6-9 Stainless Steel Warm Forgings

    SciTech Connect

    Everhart, Wesley A.; Lee, Jordan D.; Broecker, Daniel J.; Bartow, John P.; McQueen, Jamie M.; Switzner, Nathan T.; Neidt, Tod M.; Sisneros, Thomas A.; Brown, Donald W.

    2012-11-14

    Forging residual stresses are detrimental to the production and performance of derived machined parts due to machining distortions, corrosion drivers and fatigue crack drivers. Residual strains in a 21-6-9 stainless steel warm High Energy Rate Forging (HERF) were measured via neutron diffraction. The finite element analysis (FEA) method was used to predict the residual stresses that occur during forging and water quenching. The experimentally measured residual strains were used to calibrate simulations of the three-dimensional residual stress state of the forging. ABAQUS simulation tools predicted residual strains that tend to match with experimental results when varying yield strength is considered.

  16. Pyrolysis-GC-MS analysis of the formation and degradation stages of charred residues from lignocellulosic biomass.

    PubMed

    González-Vila, F J; Tinoco, P; Almendros, G; Martin, F

    2001-03-01

    The structural transformations undergone by lignocellulosic biomass (freeze-dried rye grass, Lolium rigidum) subjected to progressive isothermal heating (burning at 350 degrees C under oxidizing conditions for 30, 45, 60, 75, and 90 s) have been monitored by Curie-point pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). The pyrograms suggest that even charred residues after severe heating (carbon loss ca. 50%) still contain substantial concentrations of some resistant plant structural components. Several trends were observed when monitoring the relative concentrations of the different groups of pyrolysis compounds released during successive charring stages: (i) the tetrapyrrole moiety of chlorophylls is rapidly destroyed as indicated by the decreasing yields of pyrroles and pyrrolines, whereas the phytol backbone is comparatively more resistant, leading to phytadienes after dehydration and reduction; (ii) the increasing yields of imidazoles from progressively heated samples (maximum at 45 s stage) suggest accumulation of newly formed nitrogen-containing compounds that may survive natural fires; (iii) the lignin backbone shows a relative resistance, the yields of aromatic products pointing to progressive demethoxylation; and, (iv) a selective accumulation of recalcitrant alkyl material occurred, which is interpreted as the result of thermal condensation of hydrocarbons and fatty acids into macromolecular materials in the charred residue. In terms of the intensity of the isothermal heating, the yields of the different classes of alkyl compounds follow the order phytadienes < fatty acids < alkanes < wax esters < sterols.

  17. Experimental Methods to Estimate Accumulated Solids in Nuclear Waste Tanks - 13313

    SciTech Connect

    Duignan, Mark R.; Steeper, Timothy J.; Steimke, John L.

    2013-07-01

    The Department of Energy has a large number of nuclear waste tanks. It is important to know if fissionable materials can concentrate when waste is transferred from staging tanks prior to feeding waste treatment plants. Specifically, there is a concern that large, dense particles, e.g., plutonium containing, could accumulate in poorly mixed regions of a blend tank heel for tanks that employ mixing jet pumps. At the request of the DOE Hanford Tank Operations Contractor, Washington River Protection Solutions, the Engineering Development Laboratory of the Savannah River National Laboratory performed a scouting study in a 1/22-scale model of a waste tank to investigate this concern and to develop measurement techniques that could be applied in a more extensive study at a larger scale. Simulated waste tank solids and supernatant were charged to the test tank and rotating liquid jets were used to remove most of the solids. Then the volume and shape of the residual solids and the spatial concentration profiles for the surrogate for plutonium were measured. This paper discusses the overall test results, which indicated heavy solids only accumulate during the first few transfer cycles, along with the techniques and equipment designed and employed in the test. Those techniques include: - Magnetic particle separator to remove stainless steel solids, the plutonium surrogate from a flowing stream. - Magnetic wand used to manually remove stainless steel solids from samples and the tank heel. - Photographs were used to determine the volume and shape of the solids mounds by developing a composite of topographical areas. - Laser range finders to determine the volume and shape of the solids mounds. - Core sampler to determine the stainless steel solids distribution within the solids mounds. - Computer driven positioner that placed the laser range finders and the core sampler over solids mounds that accumulated on the bottom of a scaled staging tank in locations where jet velocities

  18. Total carbon accumulation in a tropical forest landscape

    PubMed Central

    2012-01-01

    Background Regrowing tropical forests worldwide sequester important amounts of carbon and restore part of the C emissions emitted by deforestation. However, there are large uncertainties concerning the rates of carbon accumulation after the abandonment of agricultural and pasture land. We report here accumulation of total carbon stocks (TCS) in a chronosequence of secondary forests at a mid-elevation landscape (900-1200 m asl) in the Andean mountains of Colombia. Results We found positive accumulation rates for all ecosystem pools except soil carbon, which showed no significant trend of recovery after 36 years of secondary succession. We used these data to develop a simple model to predict accumulation of TCS over time. This model performed remarkably well predicting TCS at other chronosequences in the Americas (Root Mean Square Error < 40 Mg C ha-1), which provided an opportunity to explore different assumptions in the calculation of large-scale carbon budgets. Simulations of TCS with our empirical model were used to test three assumptions often made in carbon budgets: 1) the use of carbon accumulation in tree aboveground biomass as a surrogate for accumulation of TCS, 2) the implicit consideration of carbon legacies from previous land-use, and 3) the omission of landscape age in calculating accumulation rates of TCS. Conclusions Our simulations showed that in many situations carbon can be released from regrowing secondary forests depending on the amount of carbon legacies and the average age of the landscape. In most cases, the rates used to predict carbon accumulation in the Americas were above the rates predicted in our simulations. These biome level rates seemed to be realistic only in landscapes not affected by carbon legacies from previous land-use and mean ages of around 10 years. PMID:23249727

  19. Strain accumulation and rotation in the Eastern California Shear Zone

    USGS Publications Warehouse

    Savage, J.C.; Gan, Weijun; Svarc, J.L.

    2001-01-01

    Although the Eastern California Shear Zone (ECSZ) (strike ???N25??W) does not quite coincide with a small circle drawn about the Pacific-North America pole of rotation, trilateration and GPS measurements demonstrate that the motion within the zone corresponds to right-lateral simple shear across a vertical plane (strike N33??W??5??) roughly parallel to the tangent to that local small circle (strike ???N40??W). If the simple shear is released by slip on faults subparallel to the shear zone, the accumulated rotation is also released, leaving no secular rotation. South of the Garlock fault the principal faults (e.g., Calico-Blackwater fault) strike ???N40??W, close enough to the strike of the vertical plane across which maximum right-lateral shear accumulates to almost wholly accommodate that accumulation of both strain and rotation by right-lateral slip. North of the Garlock fault dip slip as well as strike slip on the principal faults (strike ???N20??W) is required to accommodate the simple shear accumulation. In both cases the accumulated rotation is released with the shear strain. The Garlock fault, which transects the ECSZ, is not offset by north-northwest striking faults nor, despite geological evidence for long-term left-lateral slip, does it appear at the present time to be accumulating left-lateral simple shear strain across the fault due to slip at depth. Rather the motion is explained by right-lateral simple shear across the orthogonal ECSZ. Left-lateral slip on the Garlock fault will release the shear strain accumulating there but would augment the accumulating rotation, resulting in a secular clockwise rotation rate ???80 nrad yr-1 (4.6?? Myr-1).

  20. MYB89 Transcription Factor Represses Seed Oil Accumulation1[OPEN

    PubMed Central

    Li, Dong; Jin, Changyu; Duan, Shaowei; Zhu, Yana; Qi, Shuanghui; Liu, Kaige; Gao, Chenhao; Ma, Haoli; Liao, Yuncheng

    2017-01-01

    In many higher plants, seed oil accumulation is precisely controlled by intricate multilevel regulatory networks, among which transcriptional regulation mainly influences oil biosynthesis. In Arabidopsis (Arabidopsis thaliana), the master positive transcription factors, WRINKLED1 (WRI1) and LEAFY COTYLEDON1-LIKE (L1L), are important for seed oil accumulation. We found that an R2R3-MYB transcription factor, MYB89, was expressed predominantly in developing seeds during maturation. Oil and major fatty acid biosynthesis in seeds was significantly promoted by myb89-1 mutation and MYB89 knockdown; thus, MYB89 was an important repressor during seed oil accumulation. RNA sequencing revealed remarkable up-regulation of numerous genes involved in seed oil accumulation in myb89 seeds at 12 d after pollination. Posttranslational activation of a MYB89-glucocorticoid receptor fusion protein and chromatin immunoprecipitation assays demonstrated that MYB89 inhibited seed oil accumulation by directly repressing WRI1 and five key genes and by indirectly suppressing L1L and 11 key genes involved in oil biosynthesis during seed maturation. These results help us to understand the novel function of MYB89 and provide new insights into the regulatory network of transcriptional factors controlling seed oil accumulation in Arabidopsis. PMID:27932421

  1. High-stage analog accumulator for TDI CMOS image sensors

    NASA Astrophysics Data System (ADS)

    Jianxin, Li; Fujun, Huang; Yong, Zong; Jing, Gao

    2016-02-01

    The impact of the parasitic phenomenon on the performance of the analog accumulator in TDI CMOS image sensor is analyzed and resolved. A 128-stage optimized accumulator based on 0.18-μm one-poly four-metal 3.3 V CMOS technology is designed and simulated. A charge injection effect from the top plate sampling is employed to compensate the un-eliminated parasitics based on the accumulator with a decoupling switch, and then a calibration circuit is designed to restrain the mismatch and Process, Voltage and Temperature (PVT) variations. The post layout simulation indicates that the improved SNR of the accumulator upgrades from 17.835 to 21.067 dB, while an ideal value is 21.072 dB. In addition, the linearity of the accumulator is 99.62%. The simulation results of two extreme cases and Monte Carlo show that the mismatch and PVT variations are restrained by the calibration circuit. Furthermore, it is promising to design a higher stage accumulator based on the proposed structure. Project supported by the National Natural Science Foundation of China (Nos. 61404090, 61434004).

  2. Effects of Pro --> peptoid residue substitution on cell selectivity and mechanism of antibacterial action of tritrpticin-amide antimicrobial peptide.

    PubMed

    Zhu, Wan Long; Lan, Hongliang; Park, Yoonkyung; Yang, Sung-Tae; Kim, Jae Il; Park, Il-Seon; You, Ho Jin; Lee, Jung Sup; Park, Yong Sun; Kim, Yangmee; Hahm, Kyung-Soo; Shin, Song Yub

    2006-10-31

    To investigate the effect of Pro --> peptoid residue substitution on cell selectivity and the mechanism of antibacterial action of Pro-containing beta-turn antimicrobial peptides, we synthesized tritrpticin-amide (TP, VRRFPWWWPFLRR-NH(2)) and its peptoid residue-substituted peptides in which two Pro residues at positions 5 and 9 are replaced with Nleu (Leu peptoid residue), Nphe (Phe peptoid residue), or Nlys (Lys peptoid residue). Peptides with Pro --> Nphe (TPf) or Pro --> Nleu substitution (TPl) retained antibacterial activity but had significantly higher toxicity to mammalian cells. In contrast, Pro --> Nlys substitution (TPk) increased the antibacterial activity but decreased the toxicity to mammalian cells. Tryptophan fluorescence studies indicated that the bacterial cell selectivity of TPk is closely correlated with a preferential interaction with negatively charged phospholipids. Interestingly, TPk was much less effective at depolarizing of the membrane potential of Staphylococus aureus and Escherichia coli spheroplasts and causing the leakage of a fluorescent dye entrapped within negatively charged vesicles. Furthermore, confocal laser-scanning microscopy showed that TPk effectively penetrated the membrane of both E. coli and S. aureus and accumulated in the cytoplasm, whereas TP and TPf did not penetrate the cell membrane but remained outside or on the cell membrane. These results suggest that the bactericidal action of TPk is due to inhibition of the intracellular components after penetration of the bacterial cell membrane. In addition, TPK with Lys substitution effectively depolarized the membrane potential of S. aureus and E. coli spheroplasts. TPK induced rapid and effective dye leakage from bacterial membrane-mimicking liposomes and did not penetrate the bacterial cell membranes. These results suggested that the ability of TPk to penetrate the bacterial cell membranes appears to involve the dual effects that are related to the increase in the

  3. Dry fermentation of agricultural residues

    NASA Astrophysics Data System (ADS)

    Jewell, W. J.; Chandler, J. A.; Dellorto, S.; Fanfoni, K. J.; Fast, S.; Jackson, D.; Kabrick, R. M.

    1981-09-01

    A dry fermentation process is discussed which converts agricultural residues to methane, using the residues in their as produced state. The process appears to simplify and enhance the possibilities for using crop residues as an energy source. The major process variables investigated include temperature, the amount and type of inoculum, buffer requirements, compaction, and pretreatment to control the initial available organic components that create pH problems. A pilot-scale reactor operation on corn stover at a temperature of 550 C, with 25 percent initial total solids, a seed-to-feed ratio of 2.5 percent, and a buffer-to-feed ratio of 8 percent achieved 33 percent total volatile solids destruction in 60 days. Volumetric biogas yields from this unit were greater than 1 vol/vol day for 12 days, and greater than 0.5 vol/vol day for 32 days, at a substrate density of 169 kg/m (3).

  4. 40 CFR 180.182 - Endosulfan; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-dioxide, in or on dried tea (reflecting less than 0.1 ppm residues in beverage tea) resulting from application of the insecticide to growing tea. (b) Section 18 emergency exemptions. (c) Tolerances...

  5. 40 CFR 180.324 - Bromoxynil; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... of the herbicide bromoxynil (3,5-dibromo-4-hydroxybenzonitrile) resulting from application of its...) Tolerances are established for residues of the herbicide bromoxynil (3,5-dibromo-4-hydroxybenzonitrile)...

  6. Pesticide residues in olive oil.

    PubMed

    Lentza-Rizos, C; Avramides, E J

    1995-01-01

    The attacks of pests and diseases and the presence of weeds make it necessary to apply pesticides to olive trees to ensure crop protection. Residues of these compounds may remain and contaminate the oil produced. For the analysis of pesticide residues in olive oil, the most common methods are multiresidue methods for fatty substrates, based on partitioning between hexane or light petroleum and acetonitrile. Recently, other methods have been applied, such as ready-to-use, disposable minicolumns or direct injection of oil into a capillary gas chromatograph equipped with a precolumn with an oil recovery tank. Although several pesticides are registered in oil-producing countries for use on olive trees, available literature on the level and fate of residues is very limited. However, it is clear that fat-soluble pesticides tend to concentrate in the oil, both after full coverage and bait spraying, and their use close to harvest should therefore be avoided. Because it is sometimes necessary to use such pesticides late in autumn because of their effectiveness in cases of severe attack, residue trials should be carried out to determine the residue concentration in oil and to set a reasonable preharvest safety interval. Data produced by such trials would permit the establishment of MRLs (tolerances) in olive oil to cover cases where the residues, although relatively high, are not of toxicological significance for consumers (risk assessment). Such is the case with corn oil and the fat-soluble insecticide methyl pirimiphos, registered in the U.S. for use on corn. The U.S. EPA tolerance for methyl pirimiphos in corn is 8 mg/kg, whereas it is 11 times higher (88 mg/kg) for corn oil because it is known to concentrate in the oil. Similar provisions for olive oil, based on data from residue trials according to Good Agricultural Practice, the long-term toxicity of each pesticide as expressed by its ADI for man, and olive oil consumption patterns, would facilitate international trade

  7. Collection of sugarcane crop residue for energy

    SciTech Connect

    Eiland, B.R.; Clayton, J.E.

    1982-12-01

    Crop residue left after sugarcane harvesting was recovered using a forage harvester and a large round baler. The quantity, bulk density and moisture content of the crop residue was determined in four fields. Crop residue from 7 ha was burned in boilers at a sugar mill. Samples of this residue were tested by a laboratory and compared to sugarcane bagasse.

  8. Alkali activation processes for incinerator residues management.

    PubMed

    Lancellotti, Isabella; Ponzoni, Chiara; Barbieri, Luisa; Leonelli, Cristina

    2013-08-01

    Incinerator bottom ash (BA) is produced in large amount worldwide and in Italy, where 5.1 millionstons of municipal solid residues have been incinerated in 2010, corresponding to 1.2-1.5 millionstons of produced bottom ash. This residue has been used in the present study for producing dense geopolymers containing high percentage (50-70 wt%) of ash. The amount of potentially reactive aluminosilicate fraction in the ash has been determined by means of test in NaOH. The final properties of geopolymers prepared with or without taking into account this reactive fraction have been compared. The results showed that due to the presence of both amorphous and crystalline fractions with a different degree of reactivity, the incinerator BA geopolymers exhibit significant differences in terms of Si/Al ratio and microstructure when reactive fraction is considered.

  9. Geomycology. [fungal biosolubilization and accumulation of metals

    NASA Technical Reports Server (NTRS)

    Puerner, N. J.; Siegel, S. M.

    1976-01-01

    Fungi have long been known to have capabilities for reduction and alkylation of arsenate and selenate but their general capabilities for solubilizing and accumulating metallic substances have been given serious attention only in recent years. Common members of the Aspergillaceae cultured on boron, copper, lead and other metals or oxides can solubilize and concentrate the elements or their compounds. To account for biosolubilization of the metals, we have set up a model study, incubating selected metals, e.g., mercury, in solutions of various metabolites including L-lysine and citric acid. Results of 100-300 days incubation showed that many metals can in fact be readily solubilized, and in some cases more effectively at pH 6-7 than at pH 1.5-2.

  10. Recycling of auto shredder residue.

    PubMed

    Nourreddine, Menad

    2007-01-31

    Currently, about 75% of end-of-life vehicle's (ELV) total weight is recycled in EU countries. The remaining 25%, which is called auto shredder residues (ASR) or auto fluff, is disposed of as landfill because of its complexity. It is a major challenge to reduce this percentage of obsolete cars. The European draft directive states that by the year 2006, only 15% of the vehicle's weight can be disposed of at landfill sites and by 2015, this will be reduced to 5%. The draft directive states that a further 10% can be incinerated. The quantities of shredder fluff are likely to increase in the coming years. This is because of the growing number of cars being scrapped, coupled with the increase in the amount of plastics used in cars. In Sweden, some current projects are focusing on recycling of ASR material. In this paper some different alternatives for using this material are reported. The hypothetical injection of ASR into a blast furnace concentrating on ASR's effect to some blast furnace (BF) parameters has been completed using a blast furnace mass balance model. As a result, in principle, ASR can be used as reducing agent in the BF process if certain conditions are met. The particle size of ASR material must be controlled to ensure optimal gasification of the material in the raceway. Regarding the chemical composition of ASR, the non-ferrous content can affect the pig iron quality, which is difficult to rectify at a later point. The most attractive recycling alternative is to use the products obtained from pyrolysis of ASR in appropriate metallurgical processes.

  11. Conjugated fatty acid synthesis: residues 111 and 115 influence product partitioning of Momordica charantia conjugase.

    PubMed

    Rawat, Richa; Yu, Xiao-Hong; Sweet, Marie; Shanklin, John

    2012-05-11

    Conjugated linolenic acids (CLNs), 18:3 Δ(9,11,13), lack the methylene groups found between the double bonds of linolenic acid (18:3 Δ(9,12,15)). CLNs are produced by conjugase enzymes that are homologs of the oleate desaturases FAD2. The goal of this study was to map the domain(s) within the Momordica charantia conjugase (FADX) responsible for CLN formation. To achieve this, a series of Momordica FADX-Arabidopsis FAD2 chimeras were expressed in the Arabidopsis fad3fae1 mutant, and the transformed seeds were analyzed for the accumulation of CLN. These experiments identified helix 2 and the first histidine box as a determinant of conjugase product partitioning into punicic acid (18:3 Δ(9cis,11trans,13cis)) or α-eleostearic acid (18:3 Δ(9cis,11trans,13trans)). This was confirmed by analysis of a FADX mutant containing six substitutions in which the sequence of helix 2 and first histidine box was converted to that of FAD2. Each of the six FAD2 substitutions was individually converted back to the FADX equivalent identifying residues 111 and 115, adjacent to the first histidine box, as key determinants of conjugase product partitioning. Additionally, expression of FADX G111V and FADX G111V/D115E resulted in an approximate doubling of eleostearic acid accumulation to 20.4% and 21.2%, respectively, compared with 9.9% upon expression of the native Momordica FADX. Like the Momordica conjugase, FADX G111V and FADX D115E produced predominantly α-eleostearic acid and little punicic acid, but the FADX G111V/D115E double mutant produced approximately equal amounts of α-eleostearic acid and its isomer, punicic acid, implicating an interactive effect of residues 111 and 115 in punicic acid formation.

  12. Uranium decay daughters from isolated mines: Accumulation and sources.

    PubMed

    Cuvier, A; Panza, F; Pourcelot, L; Foissard, B; Cagnat, X; Prunier, J; van Beek, P; Souhaut, M; Le Roux, G

    2015-11-01

    This study combines in situ gamma spectrometry performed at different scales, in order to accurately locate the contamination pools, to identify the concerned radionuclides and to determine the distribution of the contaminants from soil to bearing phase scale. The potential mobility of several radionuclides is also evaluated using sequential extraction. Using this procedure, an accumulation area located downstream of a former French uranium mine and concentrating a significant fraction of radioactivity is highlighted. We report disequilibria in the U-decay chains, which are likely related to the processes implemented on the mining area. Coupling of mineralogical analyzes with sequential extraction allow us to highlight the presence of barium sulfate, which may be the carrier of the Ra-226 activities found in the residual phase (Ba(Ra)SO4). In contrast, uranium is essentially in the reducible fraction and potentially trapped in clay-iron coatings located on the surface of minerals.

  13. Evaluation of Surface Residual Stresses in Friction Stir Welds Due to Laser and Shot Peening

    NASA Technical Reports Server (NTRS)

    Hatamleh, Omar; Rivero, Iris V.; Lyons, Jed

    2007-01-01

    The effects of laser, and shot peening on the residual stresses in Friction Stir Welds (FSW) has been investigated. The surface residual stresses were measured at five different locations across the weld in order to produce an adequate residual stress profile. The residual stresses before and after sectioning the coupon from the welded plate were also measured, and the effect of coupon size on the residual stress relaxation was determined and characterized. Measurements indicate that residual stresses were not uniform along the welded plate, and large variation in stress magnitude could be exhibited at various locations along the FSW plate. Sectioning resulted in significant residual stress relaxation in the longitudinal direction attributed to the large change in dimensions in this direction. Overall, Laser and shot peening resulted in a significant reduction in tensile residual stresses at the surface of the specimens.

  14. Selenocystamine improves protein accumulation in chloroplasts of eukaryotic green algae.

    PubMed

    Ferreira-Camargo, Livia S; Tran, Miller; Beld, Joris; Burkart, Michael D; Mayfield, Stephen P

    2015-12-01

    Eukaryotic green algae have become an increasingly popular platform for recombinant proteins production. In particular, Chlamydomonas reinhardtii, has garnered increased attention for having the necessary biochemical machinery to produce vaccines, human antibodies and next generation cancer targeting immunotoxins. While it has been shown that chloroplasts contain chaperones, peptidyl prolylisomerases and protein disulfide isomerases that facilitate these complex proteins folding and assembly, little has been done to determine which processes serve as rate-limiting steps for protein accumulation. In other expression systems, as Escherichia coli, Chinese hamster ovary cells, and insect cells, recombinant protein accumulation can be hampered by cell's inability to fold the target polypeptide into the native state, resulting in aggregation and degradation. To determine if chloroplasts' ability to oxidize proteins that require disulfide bonds into a stable conformation is a rate-limiting step of protein accumulation, three recombinant strains, each expressing a different recombinant protein, were analyzed. These recombinant proteins included fluorescent GFP, a reporter containing no disulfide bonds; Gaussia princeps luciferase, a luminescent reporter containing disulfide bonds; and an immunotoxin, an antibody-fusion protein containing disulfide bonds. Each strain was analyzed for its ability to accumulate proteins when supplemented with selenocystamine, a small molecule capable of catalyzing the formation of disulfide bonds. Selenocystamine supplementation led to an increase in luciferase and immunotoxin but not GFP accumulation. These results demonstrated that selenocystamine can increase the accumulation of proteins containing disulfide bonds and suggests that a rate-limiting step in chloroplast protein accumulation is the disulfide bonds formation in recombinant proteins native structure.

  15. Herpes simplex virus 2 infection impacts stress granule accumulation.

    PubMed

    Finnen, Renée L; Pangka, Kyle R; Banfield, Bruce W

    2012-08-01

    Interference with stress granule (SG) accumulation is gaining increased appreciation as a common strategy used by diverse viruses to facilitate their replication and to cope with translational arrest. Here, we examined the impact of infection by herpes simplex virus 2 (HSV-2) on SG accumulation by monitoring the localization of the SG components T cell internal antigen 1 (TIA-1), Ras-GTPase-activating SH3-domain-binding protein (G3BP), and poly(A)-binding protein (PABP). Our results indicate that SGs do not accumulate in HSV-2-infected cells and that HSV-2 can interfere with arsenite-induced SG accumulation early after infection. Surprisingly, SG accumulation was inhibited despite increased phosphorylation of eukaryotic translation initiation factor 2α (eIF2α), implying that HSV-2 encodes previously unrecognized activities designed to maintain translation initiation downstream of eIF2α. SG accumulation was not inhibited in HSV-2-infected cells treated with pateamine A, an inducer that works independently of eIF2α phosphorylation. The SGs that accumulated following pateamine A treatment of infected cells contained G3BP and PABP but were largely devoid of TIA-1. We also identified novel nuclear structures containing TIA-1 that form late in infection. These structures contain the RNA binding protein 68-kDa Src-associated in mitosis (Sam68) and were noticeably absent in infected cells treated with inhibitors of viral DNA replication, suggesting that they arise as a result of late events in the virus replicative cycle.

  16. Short communication: Macrocyclic lactone residues in butter from Brazilian markets.

    PubMed

    Macedo, Fabio; Marsico, Eliane Teixeira; Conte-Júnior, Carlos Adam; de Almeida Furtado, Leonardo; Brasil, Taila Figueredo; Pereira Netto, Annibal Duarte

    2015-06-01

    Macrocyclic lactones (ML) are commonly used in drug formulations for the treatment of parasites in cattle. In Brazil, except for drugs (or formulations) with long-term (half-life) effects, ML are registered for use in bovines. Indiscriminate use of ML may result in the presence of residues in milk and dairy products due to their lipophilic properties and thermal stability. This study applied a method of liquid chromatography with fluorimetric detection, recently developed and validated for the determination of residues of abamectin, doramectin, ivermectin, and moxidectin in butter. The method was applied to 38 samples of commercial butter purchased in the metropolitan area of Rio de Janeiro, Brazil, between June and September 2013, analyzed in triplicate. Ivermectin was detected in 89.5% of the samples, with concentrations between 0.3 and 119.4 µg/kg; 76.3% of the samples contained doramectin (0.6 to 64.7 µg/kg) and 55.2% contained abamectin (0.7 to 4.5 µg/kg). Most butter samples (76.3%) contained residues of more than 1 ML; however, no residues of moxidectin were detected. The results showed a high incidence of the presence of avermectins in butter samples. Butter is not included in the Brazilian National Plan for Control of Residues and Contaminants in Animal Products. As ML residues concentrate in lipophilic compounds, butter and other fatty dairy products should be screened for the presence of ML residues.

  17. Potential hazards of fumigant residues.

    PubMed Central

    Fishbein, L

    1976-01-01

    A spectrum of fumigants (primarily ethylene dibromide, 1,2-dibromo-3-chloropropane, ethylene oxide, symdibromotetetrachloroethane, 1,3-dichloropropene, dichlorovos, carbon tetrachloride, methyl bromide) as well as their degradation products in foodstuffs and soil have been examined mainly in regard to the potential mutagenicity of their residues. PMID:789068

  18. Residual Stresses in Ground Steels.

    DTIC Science & Technology

    1979-06-13

    stress near the surface can be lower. The level of residual stress is also strongly affected by carbon,’3 which influences the microplastic behaviour of...1966, Vol. 14, 99-104. 14. C. 3. )4cMahon: “ Microplastic Behaviour in Iron” in Mv. in Mater . S d . Res., Vol. 2, 121-140, Interscience, New York

  19. Pyrolytic characteristics of biodiesel prepared from lipids accumulated in diatom cells with growth regulation.

    PubMed

    Cheng, Jun; Feng, Jia; Ge, Tingting; Yang, Weijuan; Zhou, Junhu; Cen, Kefa

    2015-08-01

    Dynamic compositions of lipids accumulated in two diatoms Chaetoceros gracilis and Nitzschia closterium cultured with nitrogen and silicon deprivation were studied. It was found that short-chain fatty acids (C14-C16) content was much higher than long-chain fatty acids (C18-C20) content in lipids of two diatoms. The pyrolytic characteristics of biodiesel made from two diatoms and two plant seeds were compared by thermogravimetric analysis. The highest activation energy of 46.68 kJ mol(-1) and the minimum solid residue of 25.18% were obtained in the pyrolysis of biodiesel made from C. gracilis cells, which were cultured with 0.5 mmol L(-1) of nitrogen (no silicon) and accumulated the minimum polyunsaturated fatty acid (C20:5). The pyrolysis residue percentage of C. gracilis biodiesel was lower than that of N. closterium biodiesel and higher than those of plant (Cormus wilsoniana and Pistacia chinensis) biodiesels.

  20. Environmental assessment, finding of no significant impact, and response to comments. Sold residue treatment, repackaging, and storage

    SciTech Connect

    1996-04-01

    From its founding in 1952 through the cessation of production in 1989, the United States Department of Energy`s (DOE) Rocky Flats Plant (now the Rocky Flats Environmental Technology Site [the Site]) produced components for nuclear weapons. Some of those components were made of plutonium. As a result of the processes used to recover and purify plutonium and manufacture the components, a variety of materials became contaminated with plutonium. If the level of contamination were low, the material was considered waste. However, if the concentration of plutonium in the material exceeded the {open_quotes}economic discard limit,{close_quotes} the materials were classified as {open_quotes}residue{close_quotes} rather than{open_quotes}Waste{close_quotes} and were stored for later recovery of the plutonium. While large quantities of residues were processed, others, primarily those more difficult to process, accumulated at the Site in storage. Two important events regarding residues have occurred at the Site since production activities ceased. One event was the end of the Cold War in 1991, which made the return to production of nuclear weapons, with their Rocky Flats-made components, unnecessary. This event led to DOE`s decision to permanently cease production at the Site, clean up and remove radioactive and chemical contamination at the Site, and find alternative uses for the Site. This document describes methods for processing of the wastes for safe interim storage. Environmental impacts from the processing and storage are discussed.

  1. Oil crop biomass residue-based media for enhanced algal lipid production.

    PubMed

    Wang, Zhen; Ma, Xiaochen; Zhou, Wenguang; Min, Min; Cheng, Yanling; Chen, Paul; Shi, Jian; Wang, Qin; Liu, Yuhuan; Ruan, Roger

    2013-10-01

    The aim of this study was to evaluate the use of hydrolysates from acid hydrolysis of four different oil crop biomass residues (OCBR) as low cost culture media for algae growth. The one-factor-at-a-time method was used to design a series of experiments to optimize the acid hydrolysis conditions through examining the total nitrogen, total phosphorus, chemical oxygen demand, and ammonia nitrogen in the hydrolysates. The optimal conditions were found to be using 3% sulfuric acid and hydrolyzing residues at 90 °C for 20 h. The hydrolysates (OCBR media) produced under the optimal conditions were used to cultivate the two algae strains, namely UM258 and UM268. The results from 5 days of cultivation showed that the OCBR media supported faster algae growth with maximal algal biomass yield of 2.7 and 3 g/L, respectively. Moreover, the total lipids for UM258 and UM268 were 54 and 35%, respectively, after 5 days of cultivation, which suggested that the OCBR media allowed the algae strains to accumulate higher lipids probably due to high C/N ratio. Furthermore, over 3% of omega-3 fatty acid (EPA) was produced for the two algae strains. In conclusion, OCBR media are excellent alternative for algae growth and have a great potential for large-scale production of algae-based ingredients for biodiesel as well as high-value food and pharmaceutical products.

  2. Identification of Catalytic Residues in the As(III) S-Adenosylmethionine Methyltransferase

    PubMed Central

    Marapakala, Kavitha; Qin, Jie; Rosen, Barry P.

    2012-01-01

    The enzyme As(III) S-adenosylmethionine methyltransferase (EC 2.1.1.137) (ArsM or AS3MT) is found in members of every kingdom, from bacteria to humans. In these enzymes, there are three conserved cysteine residues at positions 72, 174, and 224 in the CmArsM orthologue from the thermophilic eukaryotic alga Cyanidioschyzon sp. 5508. Substitution of any of the three led to loss of As(III) methylation. In contrast, a C72A mutant still methylated trivalent methylarsenite [MAs(III)]. Protein fluorescence of a single-tryptophan mutant reported binding of As(III) or MAs(III). As(GS)3 and MAs(GS)2 bound significantly faster than As(III), suggesting that the glutathionylated arsenicals are preferred substrates for the enzyme. Protein fluorescence also reported binding of Sb(III), and the purified enzyme methylated and volatilized Sb(III). The results suggest that all three cysteine residues are necessary for the first step in the reaction, As(III) methylation, but that only Cys174 and Cys224 are required for the second step, methylation of MAs(III) to dimethylarsenite [DMAs(III)]. The rate-limiting step was identified as the conversion of DMAs(III) to trimethylarsine, and DMAs(III) accumulates as the principal product. PMID:22257120

  3. Residual flexibility test method for verification of constrained structural models

    NASA Technical Reports Server (NTRS)

    Admire, John R.; Tinker, Michael L.; Ivey, Edward W.

    1992-01-01

    A method is presented for deriving constrained modes and frequencies from a model correlated to a set of free-free test modes and a set of measured residual flexibilities. The method involves a simple modification of the MacNeal and Rubin component mode representation to allow verification of a constrained structural model. Results for two spaceflight structures show quick convergence of constrained modes using an easily measurable set of free-free modes plus the residual flexibility matrix or its boundary partition. This paper further validates the residual flexibility approach as an alternative test/analysis method when fixed-base testing proves impractical.

  4. Nondestructive Testing Residual Stress Using Ultrasonic Critical Refracted Longitudinal Wave

    NASA Astrophysics Data System (ADS)

    Xu, Chunguang; Song, Wentao; Pan, Qinxue; Li, Huanxin; Liu, Shuai

    Residual stress has significant impacts on the performance of the mechanical components, especially on its strength, fatigue life and corrosion resistance and dimensional stability. Based on theory of acoustoelasticity, the testing principle of ultrasonic LCR wave method is analyzed. The testing system of residual stress is build. The method of calibration of stress coefficient is proposed in order to improve the detection precision. At last, through experiments and applications on residual stress testing of oil pipeline weld joint, vehicle's torsion shaft, glass and ceramics, gear tooth root, and so on, the result show that it deserved to be studied deeply on application and popularization of ultrasonic LCR wave method.

  5. Residual bias in a multiphase flow model calibration and prediction

    USGS Publications Warehouse

    Poeter, E.P.; Johnson, R.H.

    2002-01-01

    When calibrated models produce biased residuals, we assume it is due to an inaccurate conceptual model and revise the model, choosing the most representative model as the one with the best-fit and least biased residuals. However, if the calibration data are biased, we may fail to identify an acceptable model or choose an incorrect model. Conceptual model revision could not eliminate biased residuals during inversion of simulated DNAPL migration under controlled conditions at the Borden Site near Ontario Canada. This paper delineates hypotheses for the source of bias, and explains the evolution of the calibration and resulting model predictions.

  6. Excess 210Po in 2010 Eyjafjallajökull tephra (Iceland): Evidence for pre-eruptive gas accumulation

    NASA Astrophysics Data System (ADS)

    Sigmarsson, Olgeir; Condomines, Michel; Gauthier, Pierre-Jean

    2015-10-01

    Excess gas phase in magmas erupting explosively is well known worldwide. However, the origin of this gas phase, in excess of what can be dissolved in the erupting magma at depth, and the rate of gas accumulation is less well defined. The 2010 mildly explosive eruption at Eyjafjallajökull, Iceland, produced mingled tephra of benmoreitic and trachytic composition whereas alkali basalt was emitted during preceding flank eruption. Tephra of the first explosive phase are composed of three glass types, alkaline rhyolite, mixed benmoreite, and basalt, which suggests that the basaltic magma intruded a pre-existing rhyolitic magma chamber, and ultimately triggered the eruption. The mixed benmoreitic tephra (erupted on 15 and 17 April 2010) had large 210Po in excess of 210Pb [(210Po /210Pb) 0 = 1.88 ] at the time of eruption, and possibly a small 210Pb excess over its parent 226Ra. In contrast, the preceding flank eruption produced basalt with (210Po) 0 = 0, upon eruption, and the final trachyte had lost most of its 210Po during open-system degassing. The 210Po excess in the first erupted benmoreites is interpreted to result from 210Po degassing of basaltic magma and the accumulation of 210Po-enriched gas, either in the upper part of the basaltic intrusion, below the rhyolite-basalt interface, or in the pre-existing residual rhyolitic magma chamber. From a simple model of radon and polonium accumulation in the rhyolitic reservoir, the ratio of the mass of basalt magma degassing over the mass of magma accumulating the excess gas decreased from 20 to 15 over 2 days, implying zoned magma reservoir, with the uppermost and gas-richest part erupting first. The duration of pre-eruptive gas accumulation in this model is approximately one year. This corresponds closely to the initiation of a seismic swarm beneath Eyjafjallajökull, early June 2009, which was the first pre-eruptive signal detected. The coincidence between initiation of gas accumulation at relatively shallow depth and

  7. Engineering the bacterial shapes for enhanced inclusion bodies accumulation.

    PubMed

    Jiang, Xiao-Ran; Wang, Huan; Shen, Rui; Chen, Guo-Qiang

    2015-05-01

    Many bacteria can accumulate inclusion bodies such as sulfur, polyphosphate, glycogen, proteins or polyhydroxyalkanoates. To exploit bacteria as factories for effective production of inclusion bodies, a larger intracellular space is needed for more inclusion body accumulation. In this study, polyhydroxybutyrate (PHB) was investigated as an inclusion bodies representative to be accumulated by Escherichia coli JM109SG. Various approaches were taken to increase the bacterial cell sizes including deletion on actin-like protein gene mreB, weak expression of mreB in mreB deletion mutant, and weak expression of mreB in mreB deletion mutant under inducible expression of SulA, the inhibitor of division ring protein FtsZ. All of the methods resulted in different levels of increases in bacterial sizes and PHB granules accumulation. Remarkably, an increase of over 100% PHB accumulation was observed in recombinant E. coli overexpressing mreB in an mreB deletion mutant under inducible expression of FtsZ inhibiting protein SulA. The molecular mechanism of enlarged bacterial size was found to be directly relate to weakened cytoskeleton which was the result of broken skeleton helix.

  8. N₂O accumulation from denitrification under different temperatures.

    PubMed

    Poh, Leong Soon; Jiang, Xie; Zhang, Zhongbo; Liu, Yu; Ng, Wun Jern; Zhou, Yan

    2015-11-01

    The effects of temperature on nitrous oxide (N2O) accumulation during denitrification and denitritation were investigated. Batch experiments were performed to measure N2O accumulation at 25 and 35 °C. More N2O accumulation was observed during denitritation at the higher temperature as compared with full denitrification and low temperature tests. The highest nitrite concentration tested in this study (25 mg/L NO2 (-)N and pH 8.0) did not show inhibitory effect on N2O reduction. It was found that the major cause of more N2O accumulation during denitrification at higher temperature was due to higher N2O production rate and lower N2O solubility. Specific nitrate, nitrite, and N2O reduction rates increased 62, 61, and 41 %, respectively, when temperature rose from 25 to 35 °C. The decrease of N2O solubility in mixed liquor at 35 °C (when compared to 25 °C) resulted in faster diffusing rate of N2O from liquid to gas phase. It was also more difficult for gas phase N2O to be re-dissolved. The diffused N2O was then accumulated in the headspace, which was not available for denitrification by denitrifiers. The results of this study suggest higher temperature may worsen N2O emission from wastewater treatment plants (WWTPs).

  9. Deleterious mutation accumulation in asexual Timema stick insects.

    PubMed

    Henry, Lee; Schwander, Tanja; Crespi, Bernard J

    2012-01-01

    Sexual reproduction is extremely widespread in spite of its presumed costs relative to asexual reproduction, indicating that it must provide significant advantages. One postulated benefit of sex and recombination is that they facilitate the purging of mildly deleterious mutations, which would accumulate in asexual lineages and contribute to their short evolutionary life span. To test this prediction, we estimated the accumulation rate of coding (nonsynonymous) mutations, which are expected to be deleterious, in parts of one mitochondrial (COI) and two nuclear (Actin and Hsp70) genes in six independently derived asexual lineages and related sexual species of Timema stick insects. We found signatures of increased coding mutation accumulation in all six asexual Timema and for each of the three analyzed genes, with 3.6- to 13.4-fold higher rates in the asexuals as compared with the sexuals. In addition, because coding mutations in the asexuals often resulted in considerable hydrophobicity changes at the concerned amino acid positions, coding mutations in the asexuals are likely associated with more strongly deleterious effects than in the sexuals. Our results demonstrate that deleterious mutation accumulation can differentially affect sexual and asexual lineages and support the idea that deleterious mutation accumulation plays an important role in limiting the long-term persistence of all-female lineages.

  10. Elemental quantification of large gunshot residues

    NASA Astrophysics Data System (ADS)

    Duarte, A.; Silva, L. M.; de Souza, C. T.; Stori, E. M.; Boufleur, L. A.; Amaral, L.; Dias, J. F.

    2015-04-01

    In the present work we embarked on the evaluation of the Sb/Pb, Ba/Pb and Sb/Ba elemental ratios found in relatively large particles (of the order of 50-150 μm across) ejected in the forward direction when a gun is fired. These particles are commonly referred to as gunshot residues (GSR). The aim of this work is to compare the elemental ratios of the GSR with those found in the primer of pristine cartridges in order to check for possible correlations. To that end, the elemental concentration of gunshot residues and the respective ammunition were investigated through PIXE (Particle-Induced X-ray Emission) and micro-PIXE techniques. The ammunition consisted of a .38 SPL caliber (ogival lead type) charged in a Taurus revolver. Pristine cartridges were taken apart for the PIXE measurements. The shooting sessions were carried out in a restricted area at the Forensic Institute at Porto Alegre. Residues ejected at forward directions were collected on a microporous tape. The PIXE experiments were carried out employing 2.0 MeV proton beams with a beam spot size of 1 mm2. For the micro-PIXE experiments, the samples were irradiated with 2.2 MeV proton beams of 2 × 2 μm2. The results found for the ratios of Sb/Pb, Ba/Pb and Sb/Ba do not correlate with those stemming from the analysis of the primer.

  11. Free Energy Landscape - Settlements of Key Residues.

    NASA Astrophysics Data System (ADS)

    Aroutiounian, Svetlana

    2007-03-01

    FEL perspective in studies of protein folding transitions reflects notion that since there are ˜10^N conformations to scan in search of lowest free energy state, random search is beyond biological timescale. Protein folding must follow certain fel pathways and folding kinetics of evolutionary selected proteins dominates kinetic traps. Good model for functional robustness of natural proteins - coarse-grained model protein is not very accurate but affords bringing simulations closer to biological realm; Go-like potential secures the fel funnel shape; biochemical contacts signify the funnel bottleneck. Boltzmann-weighted ensemble of protein conformations and histogram method are used to obtain from MC sampling of protein conformational space the approximate probability distribution. The fel is F(rmsd) = -1/βLn[Hist(rmsd)], β=kBT and rmsd is root-mean-square-deviation from native conformation. The sperm whale myoglobin has rich dynamic behavior, is small and large - on computational scale, has a symmetry in architecture and unusual sextet of residue pairs. Main idea: there is a mathematical relation between protein fel and a key residues set providing stability to folding transition. Is the set evolutionary conserved also for functional reasons? Hypothesis: primary sequence determines the key residues positions conserved as stabilizers and the fel is the battlefield for the folding stability. Preliminary results: primary sequence - not the architecture, is the rule settler, indeed.

  12. Demonstration of catalytic combustion with residual fuel

    NASA Technical Reports Server (NTRS)

    Dodds, W. J.; Ekstedt, E. E.

    1981-01-01

    An experimental program was conducted to demonstrate catalytic combustion of a residual fuel oil. Three catalytic reactors, including a baseline configuration and two backup configurations based on baseline test results, were operated on No. 6 fuel oil. All reactors were multielement configurations consisting of ceramic honeycomb catalyzed with palladium on stabilized alumina. Stable operation on residual oil was demonstrated with the baseline configuration at a reactor inlet temperature of about 825 K (1025 F). At low inlet temperature, operation was precluded by apparent plugging of the catalytic reactor with residual oil. Reduced plugging tendency was demonstrated in the backup reactors by increasing the size of the catalyst channels at the reactor inlet, but plugging still occurred at inlet temperature below 725 K (845 F). Operation at the original design inlet temperature of 589 K (600 F) could not be demonstrated. Combustion efficiency above 99.5% was obtained with less than 5% reactor pressure drop. Thermally formed NO sub x levels were very low (less than 0.5 g NO2/kg fuel) but nearly 100% conversion of fuel-bound nitrogen to NO sub x was observed.

  13. Differential spectroscopic imaging of particulate explosives residue

    NASA Astrophysics Data System (ADS)

    Bernacki, Bruce E.; Hô, Nicolas

    2008-04-01

    We present experimental results showing transmission and reflection imaging of approximately 100 μg quantities of particulate explosives residue using a commercial uncooled microbolometer infrared camera and CO II laser differential wavelength illumination. Fine particulates may be generated during bomb-making activities and these particulates can tenaciously adhere to packing material, as well as to the clothing or skin of the bomb maker and could be detectable during transportation. A rapid screening method that detects this residue can serve as a first-line screening method in conjunction with more sensitive, but invasive, approaches. Explosives exhibit absorption features in the mid-infrared molecular fingerprint region that spans 3 to 15 μm, which can be probed with many high-brightness sources such as fixed wavelength and tunable quantum cascade lasers, CO II, CO, and OPO lasers. Commercial uncooled microbolometer cameras typically have detection sensitivity from 7.5 to 13 μm, spanning an absorption region for explosives detection with adequate signal-to-noise ratio. By illuminating a target on and off its absorption wavelengths, ratio images of suspected residue can be obtained without any sample preparation or cooperation and contact with the target. Our proof-of-principle experiment employed tunable CO II lasers, with a tuning range from 9.2 to 10.6 μm, overlapping minor absorption features of RDX and Tetryl.

  14. Thin layer chromatography residue applicator sampler

    DOEpatents

    Nunes, Peter J.; Kelly, Fredrick R.; Haas, Jeffrey S.; Andresen, Brian D.

    2007-07-24

    A thin layer chromatograph residue applicator sampler. The residue applicator sampler provides for rapid analysis of samples containing high explosives, chemical warfare, and other analyses of interest under field conditions. This satisfied the need for a field-deployable, small, hand-held, all-in-one device for efficient sampling, sample dissolution, and sample application to an analytical technique. The residue applicator sampler includes a sampling sponge that is resistant to most chemicals and is fastened via a plastic handle in a hermetically sealed tube containing a known amount of solvent. Upon use, the wetted sponge is removed from the sealed tube and used as a swiping device across an environmental sample. The sponge is then replaced in the hermetically sealed tube where the sample remains contained and dissolved in the solvent. A small pipette tip is removably contained in the hermetically sealed tube. The sponge is removed and placed into the pipette tip where a squeezing-out of the dissolved sample from the sponge into the pipette tip results in a droplet captured in a vial for later instrumental analysis, or applied directly to a thin layer chromatography plate for immediate analysis.

  15. SWIR hyperspectral imaging detector for surface residues

    NASA Astrophysics Data System (ADS)

    Nelson, Matthew P.; Mangold, Paul; Gomer, Nathaniel; Klueva, Oksana; Treado, Patrick

    2013-05-01

    ChemImage has developed a SWIR Hyperspectral Imaging (HSI) sensor which uses hyperspectral imaging for wide area surveillance and standoff detection of surface residues. Existing detection technologies often require close proximity for sensing or detecting, endangering operators and costly equipment. Furthermore, most of the existing sensors do not support autonomous, real-time, mobile platform based detection of threats. The SWIR HSI sensor provides real-time standoff detection of surface residues. The SWIR HSI sensor provides wide area surveillance and HSI capability enabled by liquid crystal tunable filter technology. Easy-to-use detection software with a simple, intuitive user interface produces automated alarms and real-time display of threat and type. The system has potential to be used for the detection of variety of threats including chemicals and illicit drug substances and allows for easy updates in the field for detection of new hazardous materials. SWIR HSI technology could be used by law enforcement for standoff screening of suspicious locations and vehicles in pursuit of illegal labs or combat engineers to support route-clearance applications- ultimately to save the lives of soldiers and civilians. In this paper, results from a SWIR HSI sensor, which include detection of various materials in bulk form, as well as residue amounts on vehicles, people and other surfaces, will be discussed.

  16. 40 CFR 262.34 - Accumulation time.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) STANDARDS APPLICABLE TO GENERATORS OF HAZARDOUS WASTE Pre-Transport Requirements § 262.34 Accumulation time. (a) Except as provided in paragraphs (d), (e), and (f) of this section, a generator may accumulate...: (1) The waste is placed: (i) In containers and the generator complies with the...

  17. 40 CFR 262.34 - Accumulation time.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) STANDARDS APPLICABLE TO GENERATORS OF HAZARDOUS WASTE Pre-Transport Requirements § 262.34 Accumulation time. (a) Except as provided in paragraphs (d), (e), and (f) of this section, a generator may accumulate...: (1) The waste is placed: (i) In containers and the generator complies with the...

  18. 40 CFR 262.34 - Accumulation time.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) STANDARDS APPLICABLE TO GENERATORS OF HAZARDOUS WASTE Pre-Transport Requirements § 262.34 Accumulation time. (a) Except as provided in paragraphs (d), (e), and (f) of this section, a generator may accumulate...: (1) The waste is placed: (i) In containers and the generator complies with the...

  19. 40 CFR 262.34 - Accumulation time.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) STANDARDS APPLICABLE TO GENERATORS OF HAZARDOUS WASTE Pre-Transport Requirements § 262.34 Accumulation time. (a) Except as provided in paragraphs (d), (e), and (f) of this section, a generator may accumulate...: (1) The waste is placed: (i) In containers and the generator complies with the...

  20. 40 CFR 262.34 - Accumulation time.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) STANDARDS APPLICABLE TO GENERATORS OF HAZARDOUS WASTE Pre-Transport Requirements § 262.34 Accumulation time. (a) Except as provided in paragraphs (d), (e), and (f) of this section, a generator may accumulate...: (1) The waste is placed: (i) In containers and the generator complies with the...

  1. 19 CFR 10.2017 - Accumulation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Accumulation. 10.2017 Section 10.2017 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY... Rules of Origin § 10.2017 Accumulation. (a) Originating materials from the territory of a Party that...

  2. Use of mussels and semipermeable membrane devices to assess bioavailability of residual polynuclear aromatic hydrocarbons three years after the Exxon Valdez oil spill

    SciTech Connect

    Shigenaka, G.; Henry, C.B. Jr.

    1995-12-31

    Mussels (Mytilus cf. trossulus) were transplanted to a heavily oiled and extensively treated site on Smith Island, Prince William Sound, Alaska, in 1992. A new monitoring and assessment tool, the semipermeable membrane device, was also deployed to compare hydrocarbon uptake with mussels and to evaluate the route of exposure to mussels. Both mussels and semipermeable membrane devices accumulated polynuclear aromatic hydrocarbons during 14- and 52-day deployments, particularly at the oiled site. Accumulation levels were similar between mussels and the semipermeable membrane devices, but the distribution of individual hydrocarbons differed. The results permit some inference about route of exposure to mussels. Sheens leaching from subsurface deposits of residual oil, and particulate material with adsorbed hydrocarbons were apparently more important exposure pathways than dissolved hydrocarbons in water. Semipermeable membrane devices show promise as monitoring tools and to provide insights into exposure pathways for biota. 20 refs., 7 figs., 4 tabs.

  3. Residues of chlorantraniliprole in rice field ecosystem.

    PubMed

    Zhang, Jin-Ming; Chai, Wei-Gang; Wu, Yin-Liang

    2012-04-01

    The fate of chlorantraniliprole was studied in rice field ecosystem, and a simple and reliable analytical method was developed for determination of chlorantraniliprole in soil, rice straw, paddy water and brown rice. Chlorantraniliprole residues were extracted from samples with acetonitrile. The extract was cleaned up with QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method, and determined by high-performance liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The average recoveries were 76.9-82.4% from soil, 83.6-89.3% from rice straw, 95.2-103.1% from paddy water and 84.9-87.7% from brown rice. The relative standard deviation was less than 15%. The limits of detection (LODs) of chlorantraniliprole calculated as a sample concentration (S/N ratio of 3) were 0.012 μg L(-1) for paddy water, 0.15 μg kg(-1) for soil, brown rice and rice straw. The results of the kinetics study of chlorantraniliprole residue showed that chlorantraniliprole degradation in soil, water and rice straw coincided with C=0.01939e(-0.0434t), C=0.01425e(-0.8111t), and C=1.171e(-0.198t), respectively; the half-lives were about 16.0 d, 0.85 d and 3.50 d, respectively. The degradation rate of chlorantraniliprole in water was the fastest, followed by rice straw. The final residues of chlorantraniliprole on brown rice were lower than maximum residue limit (MRL) of 0.02 mg kg(-1) after 14 d Pre-Harvest Interval (PHI). Therefore, a dosage of 150 mL a.i.hm(-2) was recommended, which could be considered as safe to human beings and animals.

  4. Food crop accumulation and bioavailability assessment for antimony (Sb) compared with arsenic (As) in contaminated soils.

    PubMed

    Wilson, Susan C; Tighe, Matthew; Paterson, Ewan; Ashley, Paul M

    2014-10-01

    Field samples and a 9-week glasshouse growth trial were used to investigate the accumulation of mining derived arsenic (As) and antimony (Sb) in vegetable crops growing on the Macleay River Floodplain in Northern New South Wales, Australia. The soils were also extracted using EDTA to assess the potential for this extractant to be used as a predictor of As and Sb uptake in vegetables, and a simplified bioaccessibility extraction test (SBET) to understand potential for uptake in the human gut with soil ingestion. Metalloids were not detected in any field vegetables sampled. Antimony was not detected in the growth trial vegetable crops over the 9-week greenhouse trial. Arsenic accumulation in edible vegetable parts was <10 % total soil-borne As with concentrations less than the current Australian maximum residue concentration for cereals. The results indicate that risk of exposure through short-term vegetable crops is low. The data also demonstrate that uptake pathways for Sb and As in the vegetables were different with uptake strongly impacted by soil properties. A fraction of soil-borne metalloid was soluble in the different soils resulting in Sb soil solution concentration (10.75 ± 0.52 μg L(-1)) that could present concern for contamination of water resources. EDTA proved a poor predictor of As and Sb phytoavailability. Oral bioaccessibility, as measured by SBET, was <7 % for total As and <3 % total Sb which is important to consider when estimating the real risk from soil borne As and Sb in the floodplain environment.

  5. Spatial and temporal variation in snow accumulation in the Central Spanish Pyrenees

    NASA Astrophysics Data System (ADS)

    López-Moreno, I.; Beguería, S.; García-Ruiz, J. M.

    2003-04-01

    Water stored in winter snowpack represents a valuable resource in mountainous regions. The distribution of the snow determines the availability of water resources during snowmelt period, as well as the development of the economy based on winter sports. This work analyses the main factors that explain the variation in snow accumulation in the Central Spanish Pyrenees. Data about evolution of snowpack is provided by the measurement of 106 sticks installed in the study area from 1985. The snow depth is measured in two moments of the year, at the beginning of March and at the end of April or beginning of May. Snow depth, of both measurements moments, has been mapped using linear regression between snow depth and different topographic and geographic variables derived from the digital terrain model. In order to improve the estimation interpolated residuals values have been subtracted. The variability of the interannual snow distribution has been analysed with a factorial analysis in order to obtain different annual patterns of snowpack distribution. Relation between the dominant winter weather-type and the different patterns, provided by the factorial analysis, has been studied. The weather-type classification has been obtained using the Jenkinson and Collison system based on daily series of sea level atmospheric pressure measured around the Iberian Peninsula with a 5º x 10º scale. Thus, it is possible to know the influence of the prevailing winter synoptic situations in the snowpack distribution. The results show that topographic and geographic variables have a high capacity to explain the spatial distribution of the average snow cover during the study period. Nevertheless, the annual snow accumulation is the result of the arrival of frontal disturbances that come from different directions. By that, it is complex to relate the different snow distribution patterns to the main winter synoptic conditions of each year.

  6. Migratory peregrine falcons, Falco peregrinus, accumulate pesticides in Latin America during winter

    USGS Publications Warehouse

    Henny, C.J.; Ward, F.P.; Riddle, K.E.; Prouty, R.M.

    1982-01-01

    Blood samples from 433 Peregrine Falcons (Falco peregrinus) during fall and spring migrations, 1976-80, indicated that most of their pesticide burden, primarily DDE, was accumulated on wintering grounds in Latin America. DDE in spring migrants returning from Latin America for the first time declined significantly from 1979 to 1980. Only about 10% of breeding-age females contained organochlorine residues likely to adversely affect reproduction. The organochlorine pesticide threat in Latin America may be diminishing.

  7. Iron-induced turnover of the Arabidopsis IRON-REGULATED TRANSPORTER1 metal transporter requires lysine residues.

    PubMed

    Kerkeb, Loubna; Mukherjee, Indrani; Chatterjee, Iera; Lahner, Brett; Salt, David E; Connolly, Erin L

    2008-04-01

    Iron is an essential micronutrient but is toxic if accumulated at high levels. Thus, iron uptake and distribution in plants are controlled by precise regulatory mechanisms. IRON-REGULATED TRANSPORTER1 (IRT1) is the major high affinity iron transporter responsible for iron uptake from the soil in Arabidopsis (Arabidopsis thaliana). Previously, we showed that IRT1 is subject to posttranscriptional regulation; when expressed from the constitutive cauliflower mosaic virus 35S promoter, IRT1 protein accumulates only in iron-deficient roots. IRT1 contains an intracellular loop that may be critical for posttranslational regulation by metals. Of particular interest are a histidine (His) motif (HGHGHGH) that might bind metals and two lysine residues that could serve as attachment sites for ubiquitin. We constructed a set of mutant IRT1 alleles: IRT1H154Q, IRT1H156Q, IRT1H158Q, IRT1H160Q, IRT14HQ (quadruple His mutant), IRT1K146R, IRT1K171R, and a double mutant (IRT1K146R,K171R). Mutation of the His or lysine residues did not eliminate the ability of IRT1 to transport iron or zinc. Expression of each of the IRT1 variants and an IRT1intact construct in plants from the 35S promoter revealed that either K146 or K171 is required for iron-induced protein turnover, and 35S-IRT1K146R,K171R plants contain higher levels of iron as compared to 35S-IRT1 and wild type. Furthermore, accumulation of metals in 35S-IRT1K146R,K171R plants was not associated with an increase in ferric chelate reductase activity; this result indicates that, at least under conditions when iron is abundant, reduction of ferric iron may not be the rate-limiting step in iron uptake by strategy I plants such as Arabidopsis.

  8. The respective effects of soil heavy metal fractions by sequential extraction procedure and soil properties on the accumulation of heavy metals in rice grains and brassicas.

    PubMed

    Xiao, Ling; Guan, Dongsheng; Peart, M R; Chen, Yujuan; Li, Qiqi

    2017-01-01

    This study was carried out to examine heavy metal accumulation in rice grains and brassicas and to identify the different controls, such as soil properties and soil heavy metal fractions obtained by the Community Bureau of Reference (BCR) sequential extraction, in their accumulation. In Guangdong Province, South China, rice grain and brassica samples, along with their rhizospheric soil, were collected from fields on the basis of distance downstream from electroplating factories, whose wastewater was used for irrigation. The results showed that long-term irrigation using the electroplating effluent has not only enriched the rhizospheric soil with Cd, Cr, Cu, and Zn but has also increased their mobility and bioavailability. The average concentrations of Cd and Cr in rice grains and brassicas from closest to the electroplating factories were significantly higher than those from the control areas. Results from hybrid redundancy analysis (hRDA) and redundancy analysis (RDA) showed that the BCR fractions of soil heavy metals could explain 29.0 and 46.5 % of total eigenvalue for heavy metal concentrations in rice grains and brassicas, respectively, while soil properties could only explain 11.1 and 33.4 %, respectively. This indicated that heavy metal fractions exerted more control upon their concentrations in rice grains and brassicas than soil properties. In terms of metal interaction, an increase of residual Zn in paddy soil or a decrease of acid soluble Cd in the brassica soil could enhance the accumulation of Cd, Cu, Cr, and Pb in both rice grains and brassicas, respectively, while the reducible or oxidizable Cd in soil could enhance the plants' accumulation of Cr and Pb. The RDA showed an inhibition effect of sand content and CFO on the accumulation of heavy metals in rice grains and brassicas. Moreover, multiple stepwise linear regression could offer prediction for Cd, Cu, Cr, and Zn concentrations in the two crops by soil heavy metal fractions and soil properties.

  9. Deciphering the relationship among phosphate dynamics, electron-dense body and lipid accumulation in the green alga Parachlorella kessleri

    PubMed Central

    Ota, Shuhei; Yoshihara, Mai; Yamazaki, Tomokazu; Takeshita, Tsuyoshi; Hirata, Aiko; Konomi, Mami; Oshima, Kenshiro; Hattori, Masahira; Bišová, Kateřina; Zachleder, Vilém; Kawano, Shigeyuki

    2016-01-01

    Phosphorus is an essential element for life on earth and is also important for modern agriculture, which is dependent on inorganic fertilizers from phosphate rock. Polyphosphate is a biological polymer of phosphate residues, which is accumulated in organisms during the biological wastewater treatment process to enhance biological phosphorus removal. Here, we investigated the relationship between polyphosphate accumulation and electron-dense bodies in the green alga Parachlorella kessleri. Under sulfur-depleted conditions, in which some symporter genes were upregulated, while others were downregulated, total phosphate accumulation increased in the early stage of culture compared to that under sulfur-replete conditions. The P signal was detected only in dense bodies by energy dispersive X-ray analysis. Transmission electron microscopy revealed marked ultrastructural variations in dense bodies with and without polyphosphate. Our findings suggest that the dense body is a site of polyphosphate accumulation, and P. kessleri has potential as a phosphate-accumulating organism. PMID:27180903

  10. Thermal Residual Stress in Environmental Barrier Coated Silicon Nitride - Modeled

    NASA Technical Reports Server (NTRS)

    Ali, Abdul-Aziz; Bhatt, Ramakrishna T.

    2009-01-01

    When exposed to combustion environments containing moisture both un-reinforced and fiber reinforced silicon based ceramic materials tend to undergo surface recession. To avoid surface recession environmental barrier coating systems are required. However, due to differences in the elastic and thermal properties of the substrate and the environmental barrier coating, thermal residual stresses can be generated in the coated substrate. Depending on their magnitude and nature thermal residual stresses can have significant influence on the strength and fracture behavior of coated substrates. To determine the maximum residual stresses developed during deposition of the coatings, a finite element model (FEM) was developed. Using this model, the thermal residual stresses were predicted in silicon nitride substrates coated with three environmental coating systems namely barium strontium aluminum silicate (BSAS), rare earth mono silicate (REMS) and earth mono di-silicate (REDS). A parametric study was also conducted to determine the influence of coating layer thickness and material parameters on thermal residual stress. Results indicate that z-direction stresses in all three systems are small and negligible, but maximum in-plane stresses can be significant depending on the composition of the constituent layer and the distance from the substrate. The BSAS and REDS systems show much lower thermal residual stresses than REMS system. Parametric analysis indicates that in each system, the thermal residual stresses can be decreased with decreasing the modulus and thickness of the coating.

  11. Preliminary evaluation of the persistence of organic gunshot residue.

    PubMed

    Arndt, James; Bell, Suzanne; Crookshanks, Lindsey; Lovejoy, Marco; Oleska, Casey; Tulley, Tanya; Wolfe, Drew

    2012-10-10

    The organic components of gunshot residue (OGSR, also called firearms discharge residue (FDR) or cartridge discharge residue (CDR)) have been studied and discussed in the literature. These residues, consisting of particulates such as burned and unburned powder as well as molecular compounds, are rarely used in casework except for purposes such as shooting reconstructions. Molecular compounds that survive the firing event or that are created as a result of the firing event could, with focused research and development, open a new avenue for forensic gunshot residue analysis. In this study, the persistence of organic gunshot residue was evaluated using diphenylamine (DPA) as a target analyte and ion mobility spectrometry (IMS) as the detection system. Samples were collected from hands using a solvent swabbing technique and the swab was analyzed using direct thermal desorption for sample introduction into the IMS. OGSR was found to persist for at least 4 h. Although DPA is a widely used industrial compound, analysis of numerous blank and background samples (n∼100) did not show any significant response for DPA using this detector. Variations were noted among individuals and as such, the data set does not support estimation of a half-life as has been done for traditional primer residues. No secondary transfers were observed, suggesting the possibility of skin adhesion via interactions between the lipophilic organic compounds and skin lipids. IMS proved valuable as a means of generating patterns for forensic pattern matching and shows promise as a screening tool applied to firearms discharge.

  12. Organochlorine Pesticide Residues in Plankton, Rangsit Agricultural Area, Central Thailand

    PubMed Central

    Siriwong, W.; Thirakhupt, K.; Sitticharoenchai, D.; Borjan, M.; Robson, M.

    2014-01-01

    Few studies have investigated organochlorine pesticide residue content in freshwater plankton communities in Thailand. As a result, this study looks to examine the concentration of organochlorine pesticide residues in plankton collected from Khlong 7 (canal) at Rangsit agricultural area, central Thailand from June 2006 to February 2007. The results from this study show that plankton communities were composed of microphytoplankton, microzooplankton, and mesozooplankton. The average method recoveries varied from 84% to 103% with a relative standard deviation between 0.20% and 3.72%. The concentrations of organochlorine pesticide residues during a one-year-period were in the range of 0.10–3.65 ng/g wet wt and contained DDT and derivatives > Σ endosulfan > Σ HCH > Σ heptachlor > aldrin and dieldrin > endrin and endrin aldehyde > methoxychlor, respectively. Moreover, the residues of Σ HCH, DDT and derivatives, and methoxychlor were higher during wet season than dry season (t-test, p ≤ 0.05). PMID:18777151

  13. Dissipation and residue of spinosad in zucchini under field conditions.

    PubMed

    Liu, Yanping; Sun, Haibin; Wang, Siwei

    2013-08-01

    The dissipation and residue of the insecticide spinosad in zucchini were investigated. An ultra-performance liquid chromatography-tandem mass spectrometry analytical method was developed for spinosad analysis. The half-lives of spinosad were 3.5-3.9 days in zucchini and 3.6-4.1 days in soil. The results showed that the dissipation rate of spinosad was fast, and it is suggested that a combination of rapid growth of zucchini, photodecomposition and the activity of soil microorganisms affected the dissipation rate of spinosad. The terminal residues of spinosad in zucchini were all below the quantification limit. No residue limit currently exists for spinosad in zucchini in China and other countries. Thus, the results can be useful in establishing a maximum residue limit.

  14. Direct coevolutionary couplings reflect biophysical residue interactions in proteins

    NASA Astrophysics Data System (ADS)

    Coucke, Alice; Uguzzoni, Guido; Oteri, Francesco; Cocco, Simona; Monasson, Remi; Weigt, Martin

    2016-11-01

    Coevolution of residues in contact imposes strong statistical constraints on the sequence variability between homologous proteins. Direct-Coupling Analysis (DCA), a global statistical inference method, successfully models this variability across homologous protein families to infer structural information about proteins. For each residue pair, DCA infers 21 × 21 matrices describing the coevolutionary coupling for each pair of amino acids (or gaps). To achieve the residue-residue contact prediction, these matrices are mapped onto simple scalar parameters; the full information they contain gets lost. Here, we perform a detailed spectral analysis of the coupling matrices resulting from 70 protein families, to show that they contain quantitative information about the physico-chemical properties of amino-acid interactions. Results for protein families are corroborated by the analysis of synthetic data from lattice-protein models, which emphasizes the critical effect of sampling quality and regularization on the biochemical features of the statistical coupling matrices.

  15. Residual stress measurements of tension leg platform tendon welds

    SciTech Connect

    Kim, D.S.; Smith, J.D.

    1994-12-31

    Results of fatigue test of prototype welded tendons showed that fatigue life was greatly reduced for the weld repaired joint. Since tensile residual stresses near the fusion boundary were suspected to cause the fatigue life reduction, these residual stresses were measured. Residual stresses of girth welded tendon pipes for a tension leg platform (TLP) were obtained for various fabrication conditions. The stresses were measured experimentally using the blind hole drilling (BHD) technique, X-ray diffraction (XRD) technique and Barkhausen Noise (BHN) method. The results of these measurements illustrate the reliability of each measurement technique. Effects of joint configuration, weld repair, weld cap grinding, and pre-fatigue test on residual stresses were discussed.

  16. A review of residual stress analysis using thermoelastic techniques

    NASA Astrophysics Data System (ADS)

    Robinson, A. F.; Dulieu-Barton, J. M.; Quinn, S.; Burguete, R. L.

    2009-08-01

    Thermoelastic Stress Analysis (TSA) is a full-field technique for experimental stress analysis that is based on infra-red thermography. The technique has proved to be extremely effective for studying elastic stress fields and is now well established. It is based on the measurement of the temperature change that occurs as a result of a stress change. As residual stress is essentially a mean stress it is accepted that the linear form of the TSA relationship cannot be used to evaluate residual stresses. However, there are situations where this linear relationship is not valid or departures in material properties due to manufacturing procedures have enabled evaluations of residual stresses. The purpose of this paper is to review the current status of using a TSA based approach for the evaluation of residual stresses and to provide some examples of where promising results have been obtained.

  17. Residual stresses in cross-ply composite tubes

    NASA Technical Reports Server (NTRS)

    Cohen, D.; Hyer, M. W.

    1984-01-01

    The residual thermal stresses in 4-layer cross-ply tubes are studied. The tubes considered has a small radius to wall-thickness ratios and so elasticity solutions were used. The residual thermal stress problem was considered to be axisymmetric and three elasticity solutions were derived and the results compared with the results using classical lamination theory. The comparison illustrates the limitations of classical lamination theory. The three elasticity solutions derived were: plane stress, plane strain, and generalized plane strain, the latter being the most realistic. Residual stresses in both the hoop and axial direction is significant. Stacking arrangement effects the residual stress to some extent, as do the material properties of the individual lamina. The benefits of hybrid construction are briefly discussed.

  18. Direct coevolutionary couplings reflect biophysical residue interactions in proteins.

    PubMed

    Coucke, Alice; Uguzzoni, Guido; Oteri, Francesco; Cocco, Simona; Monasson, Remi; Weigt, Martin

    2016-11-07

    Coevolution of residues in contact imposes strong statistical constraints on the sequence variability between homologous proteins. Direct-Coupling Analysis (DCA), a global statistical inference method, successfully models this variability across homologous protein families to infer structural information about proteins. For each residue pair, DCA infers 21 × 21 matrices describing the coevolutionary coupling for each pair of amino acids (or gaps). To achieve the residue-residue contact prediction, these matrices are mapped onto simple scalar parameters; the full information they contain gets lost. Here, we perform a detailed spectral analysis of the coupling matrices resulting from 70 protein families, to show that they contain quantitative information about the physico-chemical properties of amino-acid interactions. Results for protein families are corroborated by the analysis of synthetic data from lattice-protein models, which emphasizes the critical effect of sampling quality and regularization on the biochemical features of the statistical coupling matrices.

  19. Organochlorine pesticide residues in plankton, Rangsit agricultural area, central Thailand.

    PubMed

    Siriwong, W; Thirakhupt, K; Sitticharoenchai, D; Borjan, M; Robson, M

    2008-12-01

    Few studies have investigated organochlorine pesticide residue content in freshwater plankton communities in Thailand. As a result, this study looks to examine the concentration of organochlorine pesticide residues in plankton collected from Khlong 7 (canal) at Rangsit agricultural area, central Thailand from June 2006 to February 2007. The results from this study show that plankton communities were composed of microphytoplankton, microzooplankton, and mesozooplankton. The average method recoveries varied from 84% to 103% with a relative standard deviation between 0.20% and 3.72%. The concentrations of organochlorine pesticide residues during a one-year-period were in the range of 0.10-3.65 ng/g wet wt and contained DDT and derivatives > Sigma endosulfan > Sigma HCH > Sigma heptachlor > aldrin and dieldrin > endrin and endrin aldehyde > methoxychlor, respectively. Moreover, the residues of Sigma HCH, DDT and derivatives, and methoxychlor were higher during wet season than dry season (t-test, p

  20. Accumulation and source of heavy metals in sediment of a reservoir near an industrial park of northwest China

    NASA Astrophysics Data System (ADS)

    Zhu, Yuanjie; Lu, Xinwei; Yang, Linna; Wang, Lijun

    2016-12-01

    The accumulation and source of heavy metals As, Ba, Co, Cr, Cu, Mn, Ni, Pb, V, and Zn in the surface sediment of a reservoir near an industrial park of northwest China were determined by enrichment factor and multi-variate statistical analysis. Multivariate statistical analyses, i.e., factor analysis, cluster analysis, and correlation coefficient analysis, were used to identify the possible sources of the heavy metals. The results show that the mean concentrations of As, Ba, Co, Cr, Cu, Mn, Ni, Pb, V, and Zn in the reservoir sediment are higher than their corresponding concentrations in the control sample, indicating all analyzed heavy metals accumulated in the surface sediments. The values of the mean concentrations of heavy metals in the surface sediment divided by their corresponding concentrations in the control sample increase in the order of Ba = Crresults of correlation coefficient analysis, factor analysis, and cluster analysis, three main sources of these heavy metals were identified. As, Co, Cu, Mn, Ni, and V have mixed sources of natural and industrial sources and local consumption residues; Pb and Zn mainly originate from industrial activities, while Ba and Cr primarily originate from natural sources.

  1. 3 Surface water accumulation and subsequent drip loss for processed broiler carcasses subjected to a postchill water dip or spray

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To estimate the potential residual carryover of antimicrobials, surface water accumulation and loss was measured for postchill carcasses either dipped or sprayed with water and allowed to drip for up to 5 min. In trials 1 and 2, 10 male broilers were slaughtered, and either soft or hard scalded, and...

  2. Thermogravimetric investigation on co-combustion characteristics of tobacco residue and high-ash anthracite coal.

    PubMed

    Li, X G; Lv, Y; Ma, B G; Jian, S W; Tan, H B

    2011-10-01

    The thermal behavior of high-ash anthracite coal, tobacco residue and their blends during combustion processes was investigated by means of thermogravimetric analysis (20 K min(-1), ranging from ambient temperature to 1273 K). Effects of the mixed proportion between coal and tobacco residue on the combustion process, ignition and burnout characteristics were also studied. The results indicated that the combustion of tobacco residue was controlled by the emission of volatile matter; the regions were more complex for tobacco residue (four peaks) than for coal (two peaks). Also, the blends had integrative thermal profiles that reflected both tobacco residue and coal. The incorporation of tobacco residue could improve the combustion characteristics of high-ash anthracite coal, especially the ignition and burnout characteristics comparing with the separate burning of tobacco residue and coal. It was feasible to use the co-combustion of tobacco residue and high-ash anthracite coal as fuel.

  3. Bioavailability of TNT residues in composts of TNT-contaminated soil

    SciTech Connect

    Palmer, W.G.; Beaman, J.R.; Walters, D.M.; Creasia, D.A.

    1997-10-01

    Composting is being explored as a means to remediate 2,4,6-trinitrotoluene (TNT) contaminated soils. This process appears to modify TNT and to bind it to organic matter. The health hazards associated with dusts generated from such materials cannot be predicted without knowing if the association between TNT residues and compost particulate is stable in biological systems. To address this question, single doses of [{sup 14}C]-TNT, soil spiked with [{sup 14C]-TNT, or compost generated with [{sup 14}C]-TNT-spiked soils were administered to rats by intratracheal instillation. The appearance of {sup 14}C in urine and tissues was taken as an indication of the bioavailability of TNT residues from compost particles. In rats instilled with neat [{sup 14}C]-TNT, about 35% of the {sup 14}C dose appeared in urine within 3 d. The {sup 14}C excreted in urine by these rats decreased rapidly thereafter, and was undetectable by 4 wk after treatment. Similar results were obtained with soil-treated rats. In contrast, after treatment with [{sup 14}C]-TNT-labeled compost, only 2.3% of the total {sup 14}C dose appeared in urine during the first 3 d. Low levels of {sup 14}C continued to be excreted in urine from compost-treated rats for more than 6 mo, and the total amount of {sup 14}C in urine was comparable to that in TNT-treated animals. Determination of the radiolabel in tissues showed that {sup 14}C accumulated in the kidneys of rats treated with labeled compost but not in rats treated with [{sup 14}C]-TNT or [{sup 14}C]-TNT-spiked soil. These results indicate that the association between TNT and particulate matter in compost is not stable when introduced into the lungs. Accumulation of {sup 14}C in kidneys suggests the presence of a unique TNT residue in compost-treated rats. The rate of excretion and tissue disposition of {sup 14}}C in rats treated with TNT-spiked soil indicate that TNT in soil is freely available in the lungs. 12 refs., 4 figs., 1 tab.

  4. Genomics and Transcriptomics Analyses of the Oil-Accumulating Basidiomycete Yeast Trichosporon oleaginosus: Insights into Substrate Utilization and Alternative Evolutionary Trajectories of Fungal Mating Systems

    PubMed Central

    Bracharz, Felix; Lorenzen, Jan; Kracht, Octavia N.; Chovatia, Mansi; Daum, Chris; Deshpande, Shweta; Lipzen, Anna; Nolan, Matt; Ohm, Robin A.; Grigoriev, Igor V.; Sun, Sheng; Heitman, Joseph

    2015-01-01

    ABSTRACT Microbial fermentation of agro-industrial waste holds great potential for reducing the environmental impact associated with the production of lipids for industrial purposes from plant biomass. However, the chemical complexity of many residues currently prevents efficient conversion into lipids, creating a high demand for strains with the ability to utilize all energy-rich components of agricultural residues. Here, we present results of genome and transcriptome analyses of Trichosporon oleaginosus. This oil-accumulating yeast is able to grow on a wide variety of substrates, including pentoses and N-acetylglucosamine, making it an interesting candidate for biotechnological applications. Transcriptomics shows specific changes in gene expression patterns under lipid-accumulating conditions. Furthermore, gene content and expression analyses indicate that T. oleaginosus is well-adapted for the utilization of chitin-rich biomass. We also focused on the T. oleaginosus mating type, because this species is a member of the Tremellomycetes, a group that has been intensively analyzed as a model for the evolution of sexual development, the best-studied member being Cryptococcus neoformans. The structure of the T. oleaginosus mating-type regions differs significantly from that of other Tremellomycetes and reveals a new evolutionary trajectory paradigm. Comparative analysis shows that recruitment of developmental genes to the ancestral tetrapolar mating-type loci occurred independently in the Trichosporon and Cryptococcus lineages, supporting the hypothesis of a trend toward larger mating-type regions in fungi. PMID:26199329

  5. On the relation between residue flexibility and residue interactions in proteins.

    PubMed

    Yin, Hui; Li, Yi-Zhou; Li, Meng-Long

    2011-05-01

    B-factor from X-ray crystal structure can well measure protein structural flexibility, which plays an important role in different biological processes, such as catalysis, binding and molecular recognition. Understanding the essence of flexibility can be helpful for the further study of the protein function. In this study, we attempted to correlate the flexibility of a residue to its interactions with other residues by representing the protein structure as a residue contact network. Here, several well established network topological parameters were employed to feature such interactions. A prediction model was constructed for B-factor of a residue by using support vector regression (SVR). Pearson correlation coefficient (CC) was used as the performance measure. CC values were 0.63 and 0.62 for single amino acid and for the whole sequence, respectively. Our results revealed well correlations between B-factors and network topological parameters. This suggests that the protein structural flexibility could be well characterized by the inter-amino acid interactions in a protein.

  6. Neutron diffractometer RSND for residual stress analysis at CAEP

    NASA Astrophysics Data System (ADS)

    Li, Jian; Wang, Hong; Sun, Guangai; Chen, Bo; Chen, Yanzhou; Pang, Beibei; Zhang, Ying; Wang, Yun; Zhang, Changsheng; Gong, Jian; Liu, Yaoguang

    2015-05-01

    Residual Stress Neutron Diffractometer (RSND) has been built at China Academy of Engineering Physics (CAEP) in Mianyang. Due to its excellent flexibility, the residual stress measurement on different samples, as well as in-situ study for materials science, can be carried out through RSND. The basic tests on its intensity and resolution and some preliminary experimental results under mechanical load, demonstrate the high quality of RSND.

  7. CO2CRC's Otway Residual Saturation and Dissolution Test: Using Reactive Ester Tracers to Determine Residual CO2 Saturation

    NASA Astrophysics Data System (ADS)

    Myers, M.; Stalker, L.; LaForce, T.; Pejcic, B.; Dyt, C.; Ho, K.; Ennis-King, J.

    2013-12-01

    Residual trapping, that is CO2 held in the rock pore space due to capillarity, is an important storage mechanism in geo-sequestration of over the short to medium term (up to 1000 years). As such residual CO2 saturation is a critical reservoir parameter for assessing the storage capacity and security of carbon capture and storage (CCS). As a component of the CO2CRC's Residual Gas Saturation and Dissolution Test at the CO2CRC Otway Project site in Victoria (Australia), we have recently tested a suite of reactive esters (triacetin, tripropionin and propylene glycol diacetate) in a single well chemical tracer test to determine residual CO2 saturation. The goal of this project was to assess and validate a suite of possible tests that could be implemented to determine residual CO2 saturation. For this test, the chemical tracers were injected with a saturated CO2/water mixture into the formation (that is already at residual CO2 saturation) where they were allowed to 'soak' for approximately 10 days allowing for the partial hydrolysis of the esters to their corresponding carboxylic acids and alcohols. Water containing the tracers was then produced from the well resulting in over 600 tracer samples over a period of 12 hours. A selection of these samples were analysed for tracer content and to establish tracer breakthrough curves. To understand the behaviour of these chemical tracers in the downhole environment containing residually trapped supercritical CO2 and formation water, it is necessary to determine the supercritical CO2/water partition coefficients. We have previously determined these in the laboratory (Myers et al., 2012) and they are used here to model the tracer behaviour and provide an estimate of the residual CO2 saturation. Two different computational simulators were used to analyse the tracer breakthrough profiles. The first is based on simple chromatographic retardation and has been used extensively in single well chemical tracer tests to determine residual

  8. Fluorescence of crop residue: postmortem analysis of crop conditions

    NASA Astrophysics Data System (ADS)

    McMurtrey, James E., III; Kim, Moon S.; Daughtry, Craig S. T.; Corp, Lawrence A.; Chappelle, Emmett W.

    1997-07-01

    Fluorescence of crop residues at the end of the growing season may provide an indicator of the past crop's vegetative condition. Different levels of nitrogen (N) fertilization were applied to field grown corn and wheat at Beltsville, Maryland. The N fertilizer treatments produce a range of physiological conditions, pigment concentrations, biomass levels, and grain yields that resulted in varying growth and stress conditions in the living crops. After normal harvesting procedures the crop residues remained. The fluorescence spectral characteristics of the plant residues from crops grown under different levels of N nutrition were analyzed. The blue-green fluorescence response of in-vitro residue biomass of the N treated field corn had different magnitudes. A blue-green- yellow algorithm, (460/525)*600 nm, gave the best separations between prior corn growth conditions at different N fertilization levels. Relationships between total dry biomass, the grain yield, and fluorescence properties in the 400 - 670 nm region of the spectrum were found in both corn and wheat residues. The wheat residue was analyzed to evaluate the constituents responsible for fluorescence. A ratio of the blue-green, 450/550 nm, images gave the best separation among wheat residues at different N fertilization levels. Fluorescence of extracts from wheat residues showed inverse fluorescence intensities as a function of N treatments compared to that of the intact wheat residue or ground residue samples. The extracts also had an additional fluorescence emission peak in the red, 670 nm. Single band fluorescence intensity in corn and wheat residues is due mostly to the quantity of the material on the soil surface. Ratios of fluorescence bands varied as a result of the growth conditions created by the N treatments and are thought to be indicat