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Sample records for accumulated high concentrations

  1. Inhibition of Coenzyme Qs Accumulation in Engineered Escherichia coli by High Concentration of Farnesyl Diphosphate

    PubMed Central

    Samoudi, Mojtaba; Omid Yeganeh, Negar; Shahbani Zahiri, Hossein; Shariati, Parvin; Hajhosseini, Reza

    2015-01-01

    Background: Coenzyme Q 10 (CoQ 10 ) is an isoprenoid component used widely in nutraceutical industries. Farnesyl diphosphate synthase (FPPS) is a responsible enzyme for biosynthesis of farnesyl diphosphate (FPP), a key precursor for CoQs production. This research involved investigating the effect of FPPS over-expression on CoQs production in engineered CoQ 10 -producing Escherichia coli (E. coli). Methods: Two CoQ 10 -producing strains, as referred to E. coli Ba and E. coli Br, were transformed by the encoding gene for FPPS (ispA) under the control of either the trc or P BAD promoters. Results: Over-expression of ispA under the control of P BAD promoter led to a relative increase in CoQ 10 production only in recombinant E. coli Br although induction by arabinose resulted in partial reduction of CoQ 10 production in both recombinant E. coli Ba and E. coli Br strains. Over-expression of ispA under the control of stronger trc promoter, however, led to a severe decrease in CoQ 10 production in both recombinant E. coli Ba and E. coli Br strains, as reflected by reductions from 629±40 to 30±13 and 564±28 to 80±14 μg/g Dried Cell Weight (DCW), respectively. The results showed high level of FPP reduces endogenous CoQ 8 production as well and that CoQs are produced in a complimentary manner, as the increase in production of one decreases the production of the other. Conclusion: The reduction in CoQ 10 production can be a result of Dds inhibition by high FPP concentration. Therefore, more effort is needed to verify the role of intermediate metabolite concentration and to optimize production of CoQ 10 . PMID:26306151

  2. Observations of accumulation mode aerosol composition and soot carbon concentrations by means of a high-temperature volatility technique

    NASA Astrophysics Data System (ADS)

    Smith, Michael H.; O'Dowd, Colin D.

    1996-08-01

    A high-temperature volatility system has been deployed for the measurement of the composition and concentration of the accumulation mode aerosol (0.05 μm < r < 1 μm) within the atmospheric boundary layer. This instrumentation comprises a volatility system based around a Particle Measuring Systems ASASP-X optical particle counter, which was operated together with an aethalometer for the direct observation of soot carbon concentrations. By cycling the heater tube through a range of temperatures from near ambient to over 1000°C, size-differentiated information upon aerosol composition may be obtained. Furthermore, by careful selection of analysis temperatures, discrimination is possible between elemental carbon and the more volatile fractions of the soot carbon aerosol. Observations made over the North Sea near the Dutch coast and in the central United Kingdom are presented for differing environmental conditions with soot carbon concentrations ranging from about 100 to over 6000 ng m-3. For polluted conditions over the North Sea the volatility technique clearly showed the dominance of soot carbon particles over other aerosol components with a narrow carbon particle distribution of mode radius around 0.06 μm accounting for about 80% of all particles with radii below 0.1 μm. Under polluted conditions, only about 25% of the total soot carbon aerosol comprised elemental carbon (with the remainder consisting of more volatile material), whereas this proportion rose to around 50% in the lower carbon loadings found in a cleaner maritime air mass. The use of soot carbon loadings as a tracer of anthropogenic aerosol inputs to oceanic regions is explored on the basis of measurements from a NE Atlantic cruise.

  3. 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.

  4. Effects of high Zn and Pb concentrations on Phragmites australis (Cav.) Trin. Ex. Steudel: Photosynthetic performance and metal accumulation capacity under controlled conditions.

    PubMed

    Bernardini, A; Salvatori, E; Guerrini, V; Fusaro, L; Canepari, S; Manes, F

    2016-01-01

    The response of Phragmites australis (Cav.) Trin. Ex. Steudel to zinc (Zn) and lead (Pb) was studied separately in two hydroponic tests, during a three weeks experiment. The effects on ecophysiology and biomass partitioning were evaluated during the metal treatments and at the recovery, and total metal content and accumulation capacity in different plant organs were assessed. Zn and Pb had different effects on the overall measured parameters, highlighting different mechanism of action. In particular, Zn concentration was higher in roots and, being a micronutrient, it was translocated into leaves, producing a reduction of assimilation rate, stomatal conductance (-71.9 and -81.3% respect to the control plant respectively), and a strong down regulation of photosystems functionality both at PSII and PSI level. Otherwise, Pb was accumulated mainly in the more lignified tissue such as rhizomes, with slightly effect on gas exchange. Chlorophyll a fluorescence highlighted that Pb inhibits the electron transfer process at the PSI donor side, without recovery after the removal of the metal stress. Despite these physiological limitations, P. australis showed a high capacity to accumulate both metals, and only slight reduction of biomass, being therefore a suitable species for phytoremediation interventions.

  5. Influence of high concentrations of mineral salts on production process and NaCl accumulation by Salicornia europaea plants as a constituent of the LSS phototroph link

    NASA Astrophysics Data System (ADS)

    Tikhomirova, N. A.; Ushakova, S. A.; Kovaleva, N. P.; Gribovskaya, I. V.; Tikhomirov, A. A.

    Use of halophytes (salt-tolerant vegetation), in a particular vegetable Salicornia europaea plants which are capable of utilizing NaCl in rather high concentrations, is one of possible means of NaCl incorporation into mass exchange of bioregenerative life support systems. In preliminary experiments it was shown that S. europaea plants, basically, could grow on urine pretreated with physicochemical processing and urease-enzyme decomposing of urea with the subsequent ammonia distillation. But at the same time inhibition of the growth process of the plants was observed. The purpose of the given work was to find out the influence of excessive quantities of some mineral elements contained in products of physicochemical processing of urine on the production process and NaCl accumulation by S. europaea plants. As the content of mineral salts in the human liquid wastes (urine) changed within certain limits, two variants of experimental solutions were examined. In the first variant, the concentration of mineral salts was equivalent to the minimum salt content in the urine and was: K - 1.5 g/l, P - 0.5 g/l, S - 0.5 g/l, Mg - 0.07 g/l, Ca - 0.2 g/l. In the second experimental variant, the content of mineral salts corresponded to the maximum salt content in urine and was the following: K - 3.0 g/l, P - 0.7 g/l, S - 1.2 g/l, Mg - 0.2 g/l, Ca - 0.97 g/l. As the control, the Tokarev nutrient solution containing nitrogen in the form of a urea, and the Knop nutrient solution with nitrogen in the nitrate form were used. N quantity in all four variants made up 177 mg/l. Air temperature was 24 °C, illumination was continuous. Light intensity was 690 μmol/m 2s of photosynthetically active radiation. NaCl concentration in solutions was 1%. Our researches showed that the dry aboveground biomass of an average plant of the first variant practically did not differ from the control and totaled 11 g. In the second variant, S. europaea productivity decreased and the dry aboveground biomass

  6. Influence of high concentrations of mineral salts on production process and NaCl accumulation by Salicornia europaea plants as a constituent of the LSS phototroph link.

    PubMed

    Tikhomirova, N A; Ushakova, S A; Kovaleva, N P; Gribovskaya, I V; Tikhomirov, A A

    2005-01-01

    Use of halophytes (salt-tolerant vegetation), in a particular vegetable Salicornia europaea plants which are capable of utilizing NaCl in rather high concentrations, is one of possible means of NaCl incorporation into mass exchange of bioregenerative life support systems. In preliminary experiments it was shown that S. europaea plants, basically, could grow on urine pretreated with physicochemical processing and urease-enzyme decomposing of urea with the subsequent ammonia distillation. But at the same time inhibition of the growth process of the plants was observed. The purpose of the given work was to find out the influence of excessive quantities of some mineral elements contained in products of physicochemical processing of urine on the production process and NaCl accumulation by S. europaea plants. As the content of mineral salts in the human liquid wastes (urine) changed within certain limits, two variants of experimental solutions were examined. In the first variant, the concentration of mineral salts was equivalent to the minimum salt content in the urine and was: K - 1.5 g/l, P - 0.5 g/l, S - 0.5 g/l, Mg - 0.07 g/l, Ca - 0.2 g/l. In the second experimental variant, the content of mineral salts corresponded to the maximum salt content in urine and was the following: K - 3.0 g/l, P - 0.7 g/l, S - 1.2 g/l, Mg - 0.2 g/l, Ca - 0.97 g/l. As the control, the Tokarev nutrient solution containing nitrogen in the form of a urea, and the Knop nutrient solution with nitrogen in the nitrate form were used. N quantity in all four variants made up 177 mg/l. Air temperature was 24 degrees C, illumination was continuous. Light intensity was 690 micromoles/m2s of photosynthetically active radiation. NaCl concentration in solutions was 1%. Our researches showed that the dry aboveground biomass of an average plant of the first variant practically did not differ from the control and totaled 11 g. In the second variant, S. europaea productivity decreased and the dry aboveground

  7. Amazonian mid- to high-latitude glaciation on Mars: Supply-limited ice sources, ice accumulation patterns, and concentric crater fill glacial flow and ice sequestration

    NASA Astrophysics Data System (ADS)

    Fastook, James L.; Head, James W.

    2014-02-01

    Concentric crater fill (CCF) occurs in the interior of impact craters in mid- to high latitudes on Mars and is interpreted to have formed by glacial ice flow and debris covering. We use the characteristics and orientation of deposits comprising CCF, the thickness of pedestal deposits in mid- to high-latitude pedestal craters (Pd), the volumes of the current polar caps, and information about regional slopes and ice rheology to address questions about (1) the maximum thickness of regional ice deposits during the Late Amazonian, (2) the likelihood that these deposits flowed regionally, (3) the geological regions and features most likely to induce ice-flow, and (4) the locations and environments in which ice is likely to have been sequestered up to the present. We find that regional ice flow under Late Amazonian climate conditions requires ice thicknesses exceeding many hundreds of meters for slopes typical of the vast majority of the surface of Mars, a thickness for the mid-latitudes that is well in excess of the total volume available from polar ice reservoirs. This indicates that although conditions for mid- to high-latitude glaciation may have persisted for tens to hundreds of millions of years, the process is “supply limited”, with a steady state reached when the polar ice cap water ice supply becomes exhausted. Impact craters are by far the most abundant landform with associated slopes (interior wall and exterior rim) sufficiently high to induce glacial ice flow under Late Amazonian climate conditions, and topographic slope data show that Amazonian impact craters have been clearly modified, undergoing crater interior slope reduction and floor shallowing. We show that these trends are the predictable response of ice deposition and preferential accumulation and retention in mid- to high-latitude crater interiors during episodes of enhanced spin-axis obliquity. We demonstrate that flow from a single episode of an inter-crater terrain layer comparable to Pedestal

  8. Flat high concentration devices

    SciTech Connect

    Minano, J.C.; Gonzalez, J.C.; Zanesco, I.

    1994-12-31

    During the last five years new concentrators achieving the theoretical maximum acceptance-angle-concentration product have appeared. In addition, some of these concentrators are very compact (concentrator depth/aperture diameter smaller than 1/3). The feasibility of these concentrators for photovoltaic applications is studied. It is concluded that these concentrators may be useful for high concentration cells (irradiance for maximum efficiency greater than 800 suns) if these cells have a small size (diameter smaller than 5 mm). The concentrators may provide for this case an acceptance angle of {approx} {+-}2.7 degrees with concentration factor around 1,000x and a concentrator depth 10 times the cell diameter. Instantaneous direct insolation and ambient temperature measurements of Madrid and a thermal model of the heat sink is used to calculate the annual electric energy output with which different concentration factors are compared. Concentration of 1,000x is close to the one giving the maximum annual electrical output.

  9. Effect of light intensity on algal biomass accumulation and biodiesel production for mixotrophic strains Chlorella kessleri and Chlorella protothecoide cultivated in highly concentrated municipal wastewater.

    PubMed

    Li, Yecong; Zhou, Wenguang; Hu, Bing; Min, Min; Chen, Paul; Ruan, Roger R

    2012-09-01

    In this research, the effect of light intensity on biomass accumulation, wastewater nutrient removal through algae cultivation, and biodiesel productivity was investigated with algae species Chlorella kessleri and Chlorella protothecoide. The light intensities studied were 0, 15, 30, 60, 120, and 200 µmol m(-2) s(-1). The results showed that light intensity had profound impact on tested responses for both strains, and the dependence of these responses on light intensity varied with different algae strains. For C. kessleri, the optimum light intensity was 120 µmol m(-2) S(-1) for all responses except for COD removal. For C. protothecoide, the optimum light intensity was 30 µmol m(-2) S(-1). The major components of the biodiesel produced from algae biomass were 16-C and 18-C FAME, and the highest biodiesel contents were 24.19% and 19.48% of dried biomass for C. kessleri and C. protothecoide, respectively. Both species were capable of wastewater nutrients removal under all lighting conditions with high removal efficiencies.

  10. High concentration dust monitor

    NASA Astrophysics Data System (ADS)

    Lilienfeld, P.

    1981-06-01

    The development, design, fabrication, and testing of a portable, self-contained prototype monitoring instrument capable of detecting and measuring airborne coal dust levels as concentrations in the range of 20 to 500 g/cu m is described. The output of the high concentration dust monitor is essentially independent of particle size and composition, with a response time of 10 seconds. Direct concentration readout as well as internal memory or recording capabilities are incorporated in the device. The operation of the instrument is based on direct sensing of the mass concentration of airborne dust by air-path beta radiation attenuation. The monitor is battery operated and incorporates a microprocessor that controls periodic automatic zero referencing, executes the mass computations, records the data for subsequent playback, and performs internal diagnostic checks.

  11. Intracellular accumulation of boceprevir according to plasma concentrations and pharmacogenetics.

    PubMed

    Cusato, Jessica; Allegra, Sarah; De Nicolò, Amedeo; Boglione, Lucio; Fatiguso, Giovanna; Abdi, Adnan Mohamed; Cariti, Giuseppe; Di Perri, Giovanni; D'Avolio, Antonio

    2015-06-01

    Boceprevir (BOC) is a directly-acting antiviral agent for the treatment of hepatitis C virus genotype 1 (HCV-1) infection. It is a mixture of two stereoisomers, the inactive R and the active S isomers. No data have previously been published on BOC intracellular accumulation. In this study, BOC isomer concentrations in peripheral blood mononuclear cells (PBMCs) and plasma were determined. The influence of various single nucleotide polymorphisms (SNPs) on plasma and intracellular drug exposure at Week 4 of triple therapy were also evaluated. Plasma and intracellular BOC concentrations were determined at the end of the dosing interval (C(trough)) using a UPLC-MS/MS validated method. Allelic discrimination was performed through real-time PCR. Median plasma concentrations were 65.97 ng/mL for the S isomer and 36.31 ng/mL for the R isomer; the median S/R plasma concentration ratio was 1.66. The median PBMC concentration was 2285.88 ng/mL for the S isomer; the R isomer was undetectable within PBMCs. The median S isomer PBMC/plasma concentration ratio was 28.59. A significant positive correlation was found between plasma and PBMC S isomer concentrations. ABCB1 1236, SLC28A2 124 and IL28B rs12979860 SNPs were associated with the S isomer PBMC/plasma concentration ratio. In regression models, S isomer plasma levels and FokI polymorphism were able to predict S isomer intracellular exposure, whereas SNPs in AKR1, BCRP1 and SLC28A2 predicted the S isomer PBMC/plasma concentration ratio. No similar data regarding BOC pharmacogenetics and pharmacokinetics have been published previously. This study adds a novel and useful overview of the pharmacological properties of this drug.

  12. Thin solar concentrator with high concentration ratio

    NASA Astrophysics Data System (ADS)

    Lin, Jhe-Syuan; Liang, Chao-Wen

    2013-09-01

    Solar concentrators are often used in conjunction with III-V multi-junction solar cells for cost reduction and efficiency improvement purposes. High flux concentration ratio, high optical efficiency and high manufacture tolerance are the key features required for a successful solar concentrator design. This paper describes a novel solar concentrator that combines the concepts, and thus the advantages, of both the refractive type ad reflective type. The proposed concentrator design adopts the Etendue-cascading concept that allows the light beams from all the concentric annular entrance pupils to be collected and transferred to the solar cell with minimal loss. This concept enables the system to perform near its Etendue-Limit and have a high concentration ratio simultaneously. Thereby reducing the costs of solar cells and therefor achieves a better the per watts cost. The concentrator demonstrated has a thing aspect ratio of 0.19 with a zero back focal distance. The numerical aperture at the solar cell immersed inside the dielectric concentrator is as high as 1.33 achieving a unprecedented high optical concentration ratio design.

  13. A new insight to adsorption and accumulation of high lead concentration by exopolymer and whole cells of lead-resistant bacterium Acinetobacter junii L. Pb1 isolated from coal mine dump.

    PubMed

    Kushwaha, Anamika; Rani, Radha; Kumar, Sanjay; Thomas, Tarence; David, Arun Alfred; Ahmed, Meraz

    2017-03-11

    A lead-resistant bacterial strain was isolated from coal mine dump and identified as Acinetobacter junii Pb1 on basis of 16S rRNA (ribosomal ribonucleic acid) gene sequencing. The minimum inhibitory concentration of lead for the strain was 16,000 mg l(-1) and it showed antibiotic and multi metal resistance. In aqueous culture, at an initial lead (Pb(II)) concentration of 100 and 500 mg l(-1), lead adsorption and accumulation by the isolate was 100 and 60%, at pH 7 at 30 °C after 48 and 120 h, respectively. The two fractions of exopolysaccharide (EPS), loosely associated EPS (laEPS) and bound EPS (bEPS), and whole cells (devoid of EPS) showed high binding affinity towards Pb(II). The binding affinity of laEPS towards Pb(II) (1071 mg Pb g(-1)) was three times higher than that of bEPS (321.5 mg Pb g(-1)) and 6.5 times higher than that of whole cells (165 mg Pb g(-1)). The binding affinity of EPS and whole cells with Pb(II), reported in the current study, is considerably higher as compared to that reported in the literature, till date. SEM analysis, showed an increase in thickness of cells on exposure to Pb(II) and TEM analysis, revealed its accumulation (interior of cell) and its adsorption (with the external cell surface). The isolate was also found to be positive for indole acetic acid (IAA) and 1-aminocyclopropane-1-carboxylate (ACC) deaminase production which helps in promoting plant growth. Thus, this study provides a new understanding towards Pb(II) uptake by A. junii Pb1, highlighting its potential on the restoration of Pb(II) contaminated repositories.

  14. Low acetate concentrations favor polyphosphate-accumulating organisms over glycogen-accumulating organisms in enhanced biological phosphorus removal from wastewater.

    PubMed

    Tu, Yunjie; Schuler, Andrew J

    2013-04-16

    Glycogen-accumulating organisms (GAOs) are thought to compete with polyphosphate-accumulating organisms (PAOs) in enhanced biological phosphorus removal (EBPR) wastewater treatment systems. A laboratory sequencing batch reactor (SBR) was operated for one year to test the hypothesis that PAOs have a competitive advantage at low acetate concentrations, with a focus on low pH conditions previously shown to favor GAOs. PAOs dominated the system under conventional SBR operation with rapid acetate addition (producing high in-reactor concentrations) and pH values of 7.4-8.4. GAOs dominated when the pH was decreased (6.4-7.0). Decreasing the acetate addition rate led to very low reactor acetate concentrations, and PAOs recovered, supporting the study hypothesis. When the acetate feed rate was increased, EBPR failed again. Dominant PAOs and GAOs were Candidatus Accumulibacter phosphatis and Defluviicoccus Cluster 2, respectively, according to fluorescent in situ hybridization and 454 pyrosequencing. Surprisingly, GAOs were not the immediate causes of PAO failures, based on functional and population measurements. Pyrosequencing results suggested Dechloromonas and Tetrasphaera spp. may have also been PAOs, and additional potential GAOs were also identified. Full-scale systems typically have lower in-reactor acetate concentrations than laboratory SBRs, and so, previous laboratory studies may have overestimated the practical importance of GAOs as causes of EBPR failure.

  15. Concentration is not enough to evaluate accumulation of heavy metals and nutrients in plants.

    PubMed

    Vymazal, Jan

    2016-02-15

    Wetland plants produce high aboveground biomass and possess the ability to accumulate heavy metals and nutrients. This ability is used for phytoremediation purposes including removal of nutrients and heavy metals from polluted waters. The concentrations of heavy metals are usually much higher in the belowground then in aboveground biomass, especially in roots which are primary sites of uptake. This may lead to the conclusion that accumulation of heavy metals is higher in the belowground biomass. However, in case the aboveground is much higher than belowground biomass the accumulation could be higher in the aboveground biomass. Concentration of nitrogen and phosphorus is always higher in leaves than in stems. However, the stem biomass is often much higher in robust emergent species such as Phragmites australis and therefore, more nutrients can be stored in stems. The examples shown in this communication clearly reveal that to evaluate properly the accumulation of heavy metals and nutrients in particular plant compartment biomass amount must be taken into consideration. In the first study, concentrations of Cd, Cr and Hg in Phalaris arundinacea belowground/aboveground biomass were 150/80 μg/kg, 5420/228 μg/kg and 38/18 μg/kg. The high aboveground biomass (1196 g/m(2)) and low belowground biomass (244 g/(2)) resulted in much higher accumulation of Cd and Hg in aboveground biomass (96 μg/m(2) and 21.2 μg/m(2), respectively) than in belowground biomass (36 μg/m(2) and 9.3 μg/m(2), respectively). Only for chromium, belowground accumulation (1312 μg/m(2)) was higher than aboveground accumulation (272 μg/m(2)). In the second study, both nitrogen and phosphorus concentrations were higher (26.7 mg/g and 749 mg/kg, respectively) in leaves than in stems (8.2mg/g and 534 mg/kg, respectively) of P. australis. The higher biomass of stems (1835 g/m(2)) than leaves (967 g/m(2)) resulted in higher accumulation of nitrogen but lower accumulation of phosphorus in leaves as

  16. Impacts of CO2 concentration on growth, lipid accumulation, and carbon-concentrating-mechanism-related gene expression in oleaginous Chlorella.

    PubMed

    Fan, Jianhua; Xu, Hui; Luo, Yuanchan; Wan, Minxi; Huang, Jianke; Wang, Weiliang; Li, Yuanguang

    2015-03-01

    Biodiesel production by microalgae with photosynthetic CO2 biofixation is thought to be a feasible way in the field of bioenergy and carbon emission reduction. Knowledge of the carbon-concentrating mechanism plays an important role in improving microalgae carbon fixation efficiency. However, little information is available regarding the dramatic changes of cells suffered upon different environmental factors, such as CO2 concentration. The aim of this study was to investigate the growth, lipid accumulation, carbon fixation rate, and carbon metabolism gene expression under different CO2 concentrations in oleaginous Chlorella. It was found that Chlorella pyrenoidosa grew well under CO2 concentrations ranging from 1 to 20 %. The highest biomass and lipid productivity were 4.3 g/L and 107 mg/L/day under 5 % CO2 condition. Switch from high (5 %) to low (0.03 %, air) CO2 concentration showed significant inhibitory effect on growth and CO2 fixation rate. The amount of the saturated fatty acids was increased obviously along with the transition. Low CO2 concentration (0.03 %) was suitable for the accumulation of saturated fatty acids. Reducing the CO2 concentration could significantly decrease the polyunsaturated degree in fatty acids. Moreover, the carbon-concentrating mechanism-related gene expression revealed that most of them, especially CAH2, LCIB, and HLA3, had remarkable change after 1, 4, and 24 h of the transition, which suggests that Chlorella has similar carbon-concentrating mechanism with Chlamydomonas reinhardtii. The findings of the present study revealed that C. pyrenoidosa is an ideal candidate for mitigating CO2 and biodiesel production and is appropriate as a model for mechanism research of carbon sequestration.

  17. High concentration plasma-reduced plateletapheresis concentrates.

    PubMed

    Perseghin, Paolo

    2011-06-01

    Single-donor hyperconcentrated plateletapheresis (dry-platelets) collection has been introduced in the 90's as a part of the newly developed multi-component collection strategy. This approach allowed to safely collect multiple components from a single apheresis donation, i.e. RBC, FFP and/or plateletpheresis units. Dry-platelets are usually resuspended in additive solution to maintain an adequate pH during the storage period until use. Some concern existed about possible higher degrees of platelet activation in dry-platelets units when compared to standard concentration (1.0-1.6 × 10(6)/μL platelets) units and its possible correlation with lower in vivo efficiency and/or survival of the former units. Several authors investigated this specific issue, and dry-platelets units proved to be equally effective than standard concentration plateletpheresis units in recipients. The use of dry-platelets units may reduce (i) the risk of passive infusion of naturally occurring ABO-related hemolytic antibodies when donor O platelets are given to group A, B, or AB recipient, (ii) the risk of TRALI when multiparous donors undergo plateletpheresis. Furthermore, dry-platelet collection may allow for an increased amount of FFP sent to industry. Finally, hyperconcentrated platelet units may be used for "niche" indications, such as intrauterine platelet transfusion or, in case of autologous dry-platelet collection, for further freezing for long term storage in selected patients within onco-hematological settings.

  18. Unusually high indoor radon concentrations

    NASA Astrophysics Data System (ADS)

    Ennemoser, O.; Ambach, W.; Brunner, P.; Schneider, P.; Oberaigner, W.; Purtscheller, F.; Stingl, V.

    Measurements of indoor radon concentrations in the village Umhausen (2600 inhabitants, Ötztal valley, Tyrol, Austria) revealed unusually high indoor radon concentrations up to 274,000 Bq m -3. The medians measured on the basements were 3750 Bq m -3 in winter and 361 Bq m -3 in summer, those on the ground floors were 1180 Bq m -3 and 210 Bq m -3, respectively. Seventy-one per cent of the houses showed basement radon concentrations above the Austrian action level of 400 Bq m -3 in winter, 33% in summer. There are indications that the high radon concentrations are due to a giant rock slide about 8700 years ago. The unusually high radon concentrations in Umhausen coincide with a statistically significant increase in lung cancer mortality. For the period 1970-1991 the age and sex standardized mortality rate is 3.85 (95% confidence interval: 2.9 to 5.1). The control population is the total population of Tyrol (630,000 inhabitants).

  19. Anaerobic biodegradability and digestion in accumulation systems for concentrated black water and kitchen organic-wastes.

    PubMed

    Elmitwalli, T A; van Leeuwen, M; Kujawa-Roeleveld, K; Sanders, W; Zeeman, G

    2006-01-01

    The feasibility of two accumulation-systems (AC) for anaerobic digestion and storage of concentrated black water with (AC1) or without (AC2) urine + kitchen organic-wastes was investigated. The waste(water) was collected by two vacuum toilet/transport systems. The influent-total COD of the AC2 (53,000 mg/L) was more concentrated by four times than that of the AC1. The suspended COD represented the major part (71-73%) of influent total COD of the two systems. The batch-experiments results showed a high anaerobic biodegradability of the waste(water) (> 85%). The AC systems demonstrated stable performance. There was no inhibition effect of NH4 and VFA concentration decreased in time. Total COD removal of 58% was achieved in both systems, after 105 days at 20 degrees C. Moreover, if only the supernatant in AC1 is withdrawn and the settled sludge stays for the next runs, only 20% of the influent total COD will be in the supernatant. In AC2, 74% of influent ortho-P was removed by precipitation. Therefore, the settled sludge in the AC2 had a high total-P concentration of 1,300 mg/L. The C:N:P ratios of the supernatant and the sludge were 26:13:1 and 35:4.5:1, respectively, in the AC1, and were 28:14:1 and 32:2.4:1, respectively, in AC2.

  20. Reverse osmosis concentrate treatment via a PAC-MF accumulative countercurrent adsorption process.

    PubMed

    Zhao, Chunxia; Gu, Ping; Cui, Hangyu; Zhang, Guanghui

    2012-01-01

    Organic pollutants in reverse osmosis (RO) concentrates from wastewater reclamation are mainly comprised of low molecular weight biorefractory compounds. Generally, advanced oxidation methods for oxidizing these organics require a relatively high level of energy consumption. In addition, conventional adsorption removal methods require a large dose of activated carbon. However, the dose can be reduced if its full adsorption capacity can be used. Therefore, the combined technology of powdered activated carbon (PAC) adsorption and microfiltration (MF) membrane filtration was studied to develop a countercurrent two-stage adsorption process. A PAC accumulative adsorption prediction method was proposed based on the verification of a PAC multi-stage adsorption capacity equation. Moreover, the prediction method was amended for a more accurate prediction of the effluent quality because adsorption isotherm constants were affected by the initial adsorbate concentration. The required PAC dose for the accumulative countercurrent two-stage adsorption system was 0.6 g/L, whereas that of the conventional adsorption process was 1.05 g/L when the dilution factor(F) was 0.1 and the COD and DOC removal rates were set to 70% and 68.1%, respectively. Organic pollutants were satisfactorily removed with less consumption of PAC. Effluent from this combined technology can be further reclaimed by an RO process to improve the overall recovery rate to between 91.0% and 93.8% with both economic and environmental benefits.

  1. Advanced high efficiency concentrator cells

    SciTech Connect

    Gale, R. . Varian Research Center)

    1992-06-01

    This report describes research to develop the technology needed to demonstrate a monolithic, multijunction, two-terminal, concentrator solar cell with a terrestrial power conversion efficiency greater than 35%. Under three previous subcontracts, Varian developed many of the aspects of a technology needed to fabricate very high efficiency concentrator cells. The current project was aimed at exploiting the new understanding of high efficiency solar cells. Key results covered in this report are as follows. (1) A 1.93-eV AlGaAs/1.42-eV GaAs metal-interconnected cascade cell was manufactured with a one-sun efficiency at 27.6% at air mass 1.5 (AM1.5) global. (2) A 1.0eV InGaAs cell was fabricated on the reverse'' side of a low-doped GaAs substrate with a one-sun efficiency of 2.5% AM1.5 diffuse and a short-circuit current of 14.4 mA/cm{sup 2}. (3) Small-scale manufacturing of GaAs p/n concentrator cells was attempted and obtained an excellent yield of high-efficiency cells. (4) Grown-in tunnel junction cell interconnects that are transparent and thermally stable using C and Si dopants were developed. 10 refs.

  2. Kale carotenoids are unaffected by, whereas biomass production, elemental concentrations, and selenium accumulation respond to, changes in selenium fertility.

    PubMed

    Lefsrud, Mark G; Kopsell, Dean A; Kopsell, David E; Randle, William M

    2006-03-08

    Selenium (Se) is a micronutrient in mammalian nutrition and is accumulated in kale (Brassica oleracea L. var. acephala), which has high levels of lutein and beta-carotene. Selenium, lutein, and beta-carotene have important human health benefits and possess strong antioxidant properties. The objectives of this study were to determine the influence of different Se [as sodium selenate (Na(2)SeO(4)) and sodium selenite (Na(2)SeO(3))] fertility levels on (1) biomass accumulation, (2) the accumulation patterns of carotenoid pigments, and (3) elemental accumulation in the leaves of kale. Winterbor kale was greenhouse-grown using nutrient solution culture with Se treatment concentrations of 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, and 3.5 mg Se/L as Na(2)SeO(4) and 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mg Se/L as Na(2)SeO(3). Increases in either selenate (SeO(4)(-)(2)) or selenite (SeO(3)(-)(2)) resulted in decreases in kale leaf tissue biomass. Neither of the Se treatments had an effect on the accumulation of lutein or beta-carotene in leaf tissues. Increasing SeO(4)(-)(2) significantly increased the accumulation of kale leaf Se; however, leaf tissue Se did not significantly change over the SeO(3)(-)(2) treatments. Increases in SeO(4)(-)(2) affected the leaf tissue concentrations of P, K, Ca, Mg, S, B, Cu, Mn, and Mo, whereas SeO(3)(-)(2) only affected B and S. Growing kale in the presence of SeO(4)(-)(2) would result in the accumulation of high levels of tissue Se without affecting carotenoid concentrations.

  3. Soybean Ferritin Expression in Saccharomyces cerevisiae Modulates Iron Accumulation and Resistance to Elevated Iron Concentrations

    PubMed Central

    de Llanos, Rosa; Martínez-Garay, Carlos Andrés; Fita-Torró, Josep; Romero, Antonia María; Martínez-Pastor, María Teresa

    2016-01-01

    ABSTRACT Fungi, including the yeast Saccharomyces cerevisiae, lack ferritin and use vacuoles as iron storage organelles. This work explored how plant ferritin expression influenced baker's yeast iron metabolism. Soybean seed ferritin H1 (SFerH1) and SFerH2 genes were cloned and expressed in yeast cells. Both soybean ferritins assembled as multimeric complexes, which bound yeast intracellular iron in vivo and, consequently, induced the activation of the genes expressed during iron scarcity. Soybean ferritin protected yeast cells that lacked the Ccc1 vacuolar iron detoxification transporter from toxic iron levels by reducing cellular oxidation, thus allowing growth at high iron concentrations. Interestingly, when simultaneously expressed in ccc1Δ cells, SFerH1 and SFerH2 assembled as heteropolymers, which further increased iron resistance and reduced the oxidative stress produced by excess iron compared to ferritin homopolymer complexes. Finally, soybean ferritin expression led to increased iron accumulation in both wild-type and ccc1Δ yeast cells at certain environmental iron concentrations. IMPORTANCE Iron deficiency is a worldwide nutritional disorder to which women and children are especially vulnerable. A common strategy to combat iron deficiency consists of dietary supplementation with inorganic iron salts, whose bioavailability is very low. Iron-enriched yeasts and cereals are alternative strategies to diminish iron deficiency. Animals and plants possess large ferritin complexes that accumulate, detoxify, or buffer excess cellular iron. However, the yeast Saccharomyces cerevisiae lacks ferritin and uses vacuoles as iron storage organelles. Here, we explored how soybean ferritin expression influenced yeast iron metabolism, confirming that yeasts that express soybean seed ferritin could be explored as a novel strategy to increase dietary iron absorption. PMID:26969708

  4. Non-tracking solar concentrator with a high concentration ratio

    DOEpatents

    Hinterberger, Henry

    1977-01-01

    A nontracking solar concentrator with a high concentration ratio is provided. The concentrator includes a plurality of energy absorbers which communicate with a main header by which absorbed heat is removed. Undesired heat flow of those absorbers not being heated by radiant energy at a particular instant is impeded, improving the efficiency of the concentrator.

  5. 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.

  6. Damage accumulation in ion-irradiated Ni-based concentrated solid-solution alloys

    DOE PAGES

    Ullah, Mohammad W.; Aidhy, Dilpuneet S.; Zhang, Yanwen; ...

    2016-01-01

    We investigate Irradiation-induced damage accumulation in Ni0.8Fe0.2 and Ni0.8Cr0.2 alloys by using molecular dynamics simulations to assess possible enhanced radiation-resistance in these face-centered cubic (fcc), single-phase, concentrated solid-solution alloys, as compared with pure fcc Ni.

  7. Effects of environmental and physiological variables on the accumulated concentrations of trace metals in the New Zealand cockle Austrovenus stutchburyi.

    PubMed

    Marsden, Islay D; Smith, Brian D; Rainbow, Phillip S

    2014-02-01

    We examined potential causes of variation in trace element accumulation in an estuarine bivalve Austrovenus stutchburyi from two estuarine systems in South Island, New Zealand which differed in their metal contamination and salinity regimes. Concentrations of Ag, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Ti, V and Zn were measured (ICP-OES) in whole body tissues of bivalves collected from 10 sites, seston collected at high tide (a potential food resource) and in the sediment at the sites. All 13 elements showed a relationship between log bioaccumulated trace element concentration (mgkg(-1) dry weight tissue) and log shell length (mm), either in the whole data set or at least one site (ANCOVA). Growth rates of cockles varied significantly amongst sites. Accumulated soft tissue concentrations of Ag, As, Co and Cr increased with age of cockle, those of Pb and Zn decreased, with no clear age-related trend for the remaining metals (ANCOVA). Shell length was generally a good proxy for age when allowing for any size effect in metal accumulation by the cockle. There was no consistent pattern between the estuarine systems, probably reflecting unidentified contaminant inputs. Following depuration, tissue concentrations decreased significantly for some elements (Fe, Mn, Ti and V), indicating high concentrations of these metals in the gut contents. Trace element concentrations in the seston generally did not correlate with the bivalve tissue concentrations. There were few (Spearman's Rank) correlations between environmental variables at the time of sampling and cockle tissue trace element concentrations. The main sources of variation in bioaccumulated trace metal concentrations in the whole tissues of the cockle are location, shell length and age.

  8. High-efficiency solar concentrator

    NASA Technical Reports Server (NTRS)

    Lansing, F. L.; Dorman, J.

    1976-01-01

    A new type of solar concentrator is presented using liquid lenses and simple translational tracking mechanism. The concentrator achieves a 100:1 nominal concentration ratio and is compared in performance with a flat-plate collector having two sheets of glazing and non-selective coating. The results of the thermal analysis show that higher temperatures can be obtained with the concentrator than is possible with the non-concentrator flat-plate type. Furthermore, the thermal efficiency far exceeds that of the comparative flat-plate type for all operating conditions.

  9. High-efficiency solar concentrator

    NASA Technical Reports Server (NTRS)

    Lansing, F. L.; Dorman, J.

    1980-01-01

    A new type of solar concentrator is presented using liquid lenses and simple translational tracking mechanism. The concentrator achieves a 100:1 nominal concentration ratio and is compared in performance with a flat-plate collector having two sheets of glazing and non-selective coating. The results of the thermal analysis show that higher temperatures can be obtained with the concentrator than is possible with the non-concentrator flat-plate type. Furthermore, the thermal efficiency far exceeds that of the comparative flat-plate type for all operating conditions.

  10. Metal accumulation and metallothionein concentrations in tree swallow nestlings near acidified lakes

    SciTech Connect

    St. Louis, V.; Breebaart, L. . Dept. of Zoology); Barlow, J.C. . Dept. of Zoology Royal Ontario Museum, Toronto, Ontario . Dept. of Ornithology); Klaverkamp, J.F. . Dept. of Fisheries and Oceans)

    1993-07-01

    The authors studied metal accumulation in hepatic and renal tissues of tree swallow (Tachycineta bicolor) nestlings at acidified and nonacid reference lakes in northwestern Ontario. Hepatic concentrations of metallothionein (metal-binding proteins, MT) in tree swallow nestlings were negatively correlated with pH of the nest-site lake. Combined concentrations of Cu and Zn in the liver were correlated with liver MT concentrations, but Cd was not. Although no overt signs of metal toxicity were observed in nestlings near acid lakes, the results clearly provided evidence that metals are transferred from acid lakes to birds and that these metals are correlated with increases in hepatic MT production.

  11. Peatlands as Dynamic Biogeochemical Ecotones: Elemental Concentrations, Stoichiometries and Accumulation in Peatland Soils of Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Moore, T. R.; Wang, M.; Talbot, J.; Riley, J. L.

    2015-12-01

    Peatlands act as biogeochemical interfaces between terrestrial and aquatic systems and are 'hotspots', particularly for carbon cycling and the accumulation of nutrients and other elements within the peat profile. This results in storage of substantial amounts of carbon, nutrients and metals, particularly in northern peatlands. Using a data base of over 400 peat profiles and 1700 individual peat samples from bog, fen and swamp sites in Ontario, Canada, we examine the profile concentrations of C, N, P, Ca, Mg, K, Hg, Pb, As, Cu, Mn, Zn, Fe and Al, and estimate the storage and accumulation of these elements. We show how these profiles, spatial patterns, stoichiometries and accumulation rates are controlled by biogeochemical processes and influenced by geochemical setting, hydrology, atmospheric input and pollution, and ecological and microbial transformations.

  12. Dry matter and nitrogen accumulation are not affected by superoptimal concentration of ammonium in flowing solution culture with pH control

    NASA Technical Reports Server (NTRS)

    Rideout, J. W.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

    1994-01-01

    While it is known that superoptimal concentrations of the nitrate (NO3-) ion in solution culture do not increase NO3- uptake or dry matter accumulation, the same is not known for the ammonium (NH4+) ion. An experiment was conducted utilizing flowing solution culture with pH control to investigate the influence of superoptimal NH4+ concentrations on dry matter, nitrogen (N), potassium (K), calcium (Ca), and magnesium (Mg) accumulation by nonnodulated soybean plants. Increasing the NH4+ concentration in solution from 1 to 10 mM did not affect dry matter or N accumulation. Accumulations of K, Ca, and Mg were slightly decreased with increased NH4+ concentration. The NH4+ uptake system, which is saturated at less than 1mM NH4+, is able to regulate uptake of NH4+ at concentrations as high as 10 mM.

  13. Damage accumulation in ion-irradiated Ni-based concentrated solid-solution alloys

    SciTech Connect

    Ullah, Mohammad W.; Aidhy, Dilpuneet S.; Zhang, Yanwen; Weber, William J.

    2016-01-01

    We investigate Irradiation-induced damage accumulation in Ni0.8Fe0.2 and Ni0.8Cr0.2 alloys by using molecular dynamics simulations to assess possible enhanced radiation-resistance in these face-centered cubic (fcc), single-phase, concentrated solid-solution alloys, as compared with pure fcc Ni.

  14. Effects of high ammonium level on biomass accumulation of common duckweed Lemna minor L.

    PubMed

    Wang, Wenguo; Yang, Chuang; Tang, Xiaoyu; Gu, Xinjiao; Zhu, Qili; Pan, Ke; Hu, Qichun; Ma, Danwei

    2014-12-01

    Growing common duckweed Lemna minor L. in diluted livestock wastewater is an alternative option for pollutants removal and consequently the accumulated duckweed biomass can be used for bioenergy production. However, the biomass accumulation can be inhibited by high level of ammonium (NH4 (+)) in non-diluted livestock wastewater and the mechanism of ammonium inhibition is not fully understood. In this study, the effect of high concentration of NH4 (+) on L. minor biomass accumulation was investigated using NH4 (+) as sole source of nitrogen (N). NH4 (+)-induced toxicity symptoms were observed when L. minor was exposed to high concentrations of ammonium nitrogen (NH4 (+)-N) after a 7-day cultivation. L. minor exposed to the NH4 (+)-N concentration of 840 mg l(-1) exhibited reduced relative growth rate, contents of carbon (C) and photosynthetic pigments, and C/N ratio. Ammonium irons were inhibitory to the synthesis of photosynthetic pigments and caused C/N imbalance in L. minor. These symptoms could further cause premature senescence of the fronds, and restrain their reproduction, growth and biomass accumulation. L. minor could grow at NH4 (+)-N concentrations of 7-84 mg l(-1) and the optimal NH4 (+)-N concentration was 28 mg l(-1).

  15. The effect of low fluoride concentrations on microdamage accumulation in mouse tibias under impact loading

    NASA Astrophysics Data System (ADS)

    Luo, Qing; Chen, Nan; Zhou, Yan-Heng; Rong, Qi-Guo

    2015-12-01

    Microdamage accumulation in bone is one of the mechanisms for energy dissipation during the fracture process. Changes in the ultrastructure and composition of bone constituents due to aging or diseases could affect microdamage accumulation. Low concentration (1 mM) of sodium fluoride (NaF) has been used in this study to investigate the effect of ultrastructural changes on microdamage accumulation in mouse tibias following free-fall impact loadings. Twenty-two tibias were divided randomly into control and NaF-treated groups. Free-fall impact loading was conducted twice on each tibia to produce microdamage. The elastic modulus of NaF-treated tibias decreased significantly after the impact loadings, while there was no significant difference in the modulus of untreated samples between pre- and post-damage loadings. Microdamage morphology analysis showed that less and shorter microcracks existed in NaF-treated tibias compared with control bones. Meanwhile, more and longer microcracks were observed in tensile regions in untreated samples compared with that in compressive regions, whereas no significant difference was observed between tensile and compressive regions in NaF-treated bones. The results of this study indicate that more energy is required to generate microcracks in NaF-treated bone than in normal bone. A low concentration of fluoride treatment may increase the toughness of bone under impact loading.

  16. Growth, carbon dioxide exchange and mineral accumulation in potatoes grown at different magnesium concentrations

    NASA Technical Reports Server (NTRS)

    Cao, W.; Tibbitts, T. W.

    1992-01-01

    Plants of Norland potatoes (Solanum tuberosum L.) were maintained for 42 days at Mg concentrations of 0.05, 0.125, 0.25, 1, 2, and 4 mM in a nonrecirculating nutrient film system under controlled environment. With the increased Mg supply from 0.05 to 4 mM, Mg concentrations in the leaves of the 42-day old plants increased significantly from 1.1 to 11.2 mg g-1 dry weight. Plant leaf area and plant and tuber dry weights increased with increased Mg concentrations up to 1 mM in solution or 6.7 mg g-1 in leaves, and then decreased with further increases in Mg concentrations. Rates of CO2 assimilation measured on leaflets in situ at ambient and various intercellular CO2 concentrations were consistently lower at 0.05 and 4 mM Mg than at other Mg treatments, which may indicate decreased photosynthetic activity in mesophyll tissues at the lowest and highest Mg concentrations. Dark respiration rates in leaves were highest at 0.05 and 4 mM Mg, lowest at 0.25 and 1 mM Mg, and intermediate at 0.125 and 2 mM Mg. The different Mg treatments also influenced accumulation of other minerals in leaves. Leaf concentrations of Ca and Mn decreased with increased Mg supply except that Ca and Mn were lower at 0.05 mM than at 0.125 mM Mg. Leaf K concentrations were lower at 1, 2 and 4 mM Mg than at other Mg treatments. Foliar concentrations of P, Fe, Zn, and Cu had small but inconsistent variation with different Mg concentrations. Leaf concentrations of N, S, and B were similar at different Mg concentrations. This study demonstrates that various Mg nutrition, along with altered accumulation of other nutrients, could regulate dry matter production in potatoes by affecting not only leaf area but also leaf carbon dioxide assimilation and respiration.

  17. Predicting the minimal inhibitory concentration of fluoroquinolones for Escherichia coli using an accumulation model.

    PubMed

    Zhang, Wen; Wang, Chenyin; Tam, Kin Y

    2014-01-01

    The objective of this study is to evaluate whether the accumulation model developed by Zarfl et al. (2008) could be used to predict the minimal inhibitory concentration (MIC) of a group of antibacterial fluoroquinolones (FQs) for Escherichia coli (E. coli). Our model, which is based on the "Fick-Nernst-Planck" equation and the permeability of the neutral and charged species as well as the physicochemical parameters of the FQs, could predict 1/MIC90 using a linear function. It is envisaged that in the drug development projects of new FQs, the accumulation model described in this study could be utilized as an effective tool to enable early assessment of MIC value using physiochemical parameters.

  18. Persistent high temperature and low precipitation reduce peat carbon accumulation.

    PubMed

    Bragazza, Luca; Buttler, Alexandre; Robroek, Bjorn J M; Albrecht, Remy; Zaccone, Claudio; Jassey, Vincent E J; Signarbieux, Constant

    2016-12-01

    Extreme climate events are predicted to become more frequent and intense. Their ecological impacts, particularly on carbon cycling, can differ in relation to ecosystem sensitivity. Peatlands, being characterized by peat accumulation under waterlogged conditions, can be particularly sensitive to climate extremes if the climate event increases soil oxygenation. However, a mechanistic understanding of peatland responses to persistent climate extremes is still lacking, particularly in terms of aboveground-belowground feedback. Here, we present the results of a transplantation experiment of peat mesocosms from high to low altitude in order to simulate, during 3 years, a mean annual temperature c. 5 °C higher and a mean annual precipitation c. 60% lower. Specifically, we aim at understanding the intensity of changes for a set of biogeochemical processes and their feedback on carbon accumulation. In the transplanted mesocosms, plant productivity showed a species-specific response depending on plant growth forms, with a significant decrease (c. 60%) in peat moss productivity. Soil respiration almost doubled and Q10 halved in the transplanted mesocosms in combination with an increase in activity of soil enzymes. Spectroscopic characterization of peat chemistry in the transplanted mesocosms confirmed the deepening of soil oxygenation which, in turn, stimulated microbial decomposition. After 3 years, soil carbon stock increased only in the control mesocosms whereas a reduction in mean annual carbon accumulation of c. 30% was observed in the transplanted mesocosms. Based on the above information, a structural equation model was built to provide a mechanistic understanding of the causal connections between peat moisture, vegetation response, soil respiration and carbon accumulation. This study identifies, in the feedback between plant and microbial responses, the primary pathways explaining the reduction in carbon accumulation in response to recurring climate extremes in

  19. Potassium concentration effect on growth, gas exchange and mineral accumulation in potatoes

    NASA Technical Reports Server (NTRS)

    Cao, W.; Tibbitts, T. W.

    1991-01-01

    This study was conducted to evaluate the responses of potatoes to six K solution concentrations maintained with a flow-through nutrient film system. Potato plants were grown for 42 days in sloping shallow trays containing a 1 cm layer of quartz gravel with a continuous flow of 4 ml min-1 of nutrient solutions having K concentrations of 0.10, 0.55, 1.59, 3.16, 6.44, 9.77 meq L-1. Plant leaf area, total and tuber dry weights were reduced over 25% at 0.10 meq L-1 of K and over 17% at 9.77 meq L-1 of K compared to concentrations of 0.55, 1.59, 3.16 and 6.44 meq L-1 of K. Gas exchange measurements on leaflets in situ after 39 days of growth demonstrated no significant differences among different K treatments in CO2 assimilation rate, stomatal conductance, intercellular CO2 concentration, and transpiration. Further measurements made only on plants grown at 0.10, 1.59, 6.44 meq L-1 of K showed similar responses of CO2 assimilation rate to different intercellular CO2 concentrations. This suggested that the photosynthetic systems were not affected by different K nutrition. The leaves of plants accumulated about 60% less K at 0.10 meq L-1 of K than at higher K concentrations. However, Ca and Mg levels in the leaves were higher at 0.10 meq L-1 of K than at higher K concentrations. This indicates that low K nutrition not only reduced plant growth, but also affected nutrient balance between major cations.

  20. Potassium concentration effect on growth, gas exchange and mineral accumulation in potatoes.

    PubMed

    Cao, W; Tibbitts, T W

    1991-01-01

    This study was conducted to evaluate the responses of potatoes to six K solution concentrations maintained with a flow-through nutrient film system. Potato plants were grown for 42 days in sloping shallow trays containing a 1 cm layer of quartz gravel with a continuous flow of 4 ml min-1 of nutrient solutions having K concentrations of 0.10, 0.55, 1.59, 3.16, 6.44, 9.77 meq L-1. Plant leaf area, total and tuber dry weights were reduced over 25% at 0.10 meq L-1 of K and over 17% at 9.77 meq L-1 of K compared to concentrations of 0.55, 1.59, 3.16 and 6.44 meq L-1 of K. Gas exchange measurements on leaflets in situ after 39 days of growth demonstrated no significant differences among different K treatments in CO2 assimilation rate, stomatal conductance, intercellular CO2 concentration, and transpiration. Further measurements made only on plants grown at 0.10, 1.59, 6.44 meq L-1 of K showed similar responses of CO2 assimilation rate to different intercellular CO2 concentrations. This suggested that the photosynthetic systems were not affected by different K nutrition. The leaves of plants accumulated about 60% less K at 0.10 meq L-1 of K than at higher K concentrations. However, Ca and Mg levels in the leaves were higher at 0.10 meq L-1 of K than at higher K concentrations. This indicates that low K nutrition not only reduced plant growth, but also affected nutrient balance between major cations.

  1. Design and development of a high-concentration photovoltaic concentrator

    SciTech Connect

    Hodge, R C

    1982-04-01

    The design and development of a high concentration photovoltaic concentrator module is discussed. The design concept described herein incorporates a curved groove domed Fresnel lens, a high concentration etched multiple vertical junction (EMVJ) solar cell and a passively cooled direct-bonded copper cell mount all packaged in a plastic module. Two seven inch diameter 1200x domed Fresnel lenses were fabricated using single point diamond turning technology. Testing at both GE and Sandia confirmed optical transmission efficiencies of over 83%. Samples of the latest available EMVJ cells were mounted and installed, with a domed Fresnel lens, into a prototype module. Subsequent testing demonstrated net lens-cell efficiencies of 10 to 13%. As a result of this program, salient conclusions have been formulated as to this technology.

  2. Shallow Sediment Trace Metal Concentrations and Short-Term Accumulation Rates in the Neponset River Estuary, Massachusetts, USA

    NASA Astrophysics Data System (ADS)

    Spencer, J. R.; Zhu, J.; Olsen, C. R.

    2010-12-01

    The Neponset River estuary is a small estuary that drains into the Boston Harbor on the east coast of the United States. It is also a highly urbanized estuary and has a long history of urban development over 450 years. In July 2006, six sediment cores were collected in the Neponset River estuary to examine particle dynamics and sediment accumulation via radionuclide (Beryllium-7) dating, and to determine sediment metal concentrations (As, Cu, Pb, and Zn) via ED-XRF measurements. Measured sediment Be-7 profiles indicate various sedimentation environments, where sediment accumulation, resuspension or redeposition is likely to occur. High metal concentrations were often corresponding to high Be-7 inventories in sediment cores. Possible sources of trace metal contaminants in the water column include: storm water run-off, Combined Sewer Overflows (CSOs), a well-documented industrial pollution event that occurred upstream in the early to mid twentieth century, and the resuspension of sediment. Existing and future data will provide baseline information for quantifying the effects of the proposed and pending environmental restoration project, which includes the removal of the Baker Dam. The combined pre- and post-Dam removal data may then be used in cost-benefit analyses for other similar estuarine restoration projects.

  3. Nitrite accumulation performance of aerobic MBBR treating Lurgi coal gasification waste water by adjusting pollutant load and DO concentration.

    PubMed

    Li, Hui-Qiang; Han, Hong-Jun

    2015-01-01

    An aerobic moving bed biofilm reactor (MBBR) was adopted to treat Lurgi coal gasification waste water (LCGW) in about 10 months. The pollutant load and dissolve oxygen (DO) concentration were adjusted by trying to maximize the accumulation of [Formula: see text] in the MBBR for LCGW treatment. The highest [Formula: see text] accumulation proportion [Formula: see text] was 73.9%, but was not stable with influent chemical oxygen demand (COD) and DO concentrations of around 1000 and 1.5 mg/L, respectively. Around 1500 mg/L of influent COD concentration and 1.5 mg/L of DO concentration were proper operation conditions for the aerobic MBBR to achieve relatively stable [Formula: see text] accumulation, with [Formula: see text] ratio at 53% and [Formula: see text] ratio at just 4.3% in the effluent. More specifically, free ammonia concentration and DO concentration affected [Formula: see text] accumulation much more obvious than phenols concentration. The activity and quantity of nitrifying bacteria growth in suspended sludge and biofilm of the MBBR were monitored simultaneously to explain the variations of [Formula: see text] accumulation performance under different operation conditions. An aerobic moving bed biofilm reactor (MBBR) was adopted to treat Lurgi coal gasification waste water (LCGW)in about 10 months. The pollutant load and dissolve oxygen (DO) concentration were adjusted by trying to maximize the accumulation of NO(−)(2)−N in the MBBR for LCGW treatment. The highest NO(−)(2)−N accumulation proportion(NO(−)(2)−Neffluent/TN effluent) was 73.9%, but was not stable with influent chemical oxygen demand (COD) and DO concentrations of around 1000 and 1.5 mg/L, respectively. Around 1500 mg/L of influent COD concentration and 1.5 mg/L of DO concentration were proper operation conditions for the aerobic MBBR to achieve relatively stable NO(−)(2)−N accumulation,with NO(−)(2)−N/TN ratio at 53% and NO(-)(3)−N/TN ratio at just 4.3% in the

  4. Relationship of cadmium accumulation to zinc or copper concentration in horse liver and kidney

    SciTech Connect

    Koizumi, Naoko; Ninomiya, Ruriko; Fujita, Daisuke; Tsukamoto, Toshiyuki ); Inoue, Yoshiki )

    1989-06-01

    The concentrations of Cd, Zn, Cu, and metallothionein (MT) in the liver, renal cortex, and renal medulla were determined in 24 male and 15 female younger thoroughbreds (age 27 to 97 months) and two old male horses (age 154 months and 190 months). High correlations were found between Zn and MT in the liver, between Cd and MT in the renal cortex, and between Cd and Zn in the renal cortex, while the correlation between Cd and MT in the liver was low. In the renal medulla, high correlations were found between Cd and Zn, between Zn and Cu, and between Cd and Cu. Therefore, in the liver, the MT concentration is the most highly correlated with the Zn concentration and is not correlated with the Cd concentration unless artificially exposed to Cd. In the renal cortex, the MT and Cd concentrations are very highly correlated with each other. The Zn concentration is about 20 {mu}/g when the Cd concentration in the renal cortex is the lowest.

  5. The HSP terminator of Arabidopsis thaliana induces a high level of miraculin accumulation in transgenic tomatoes.

    PubMed

    Hirai, Tadayoshi; Kurokawa, Natsuko; Duhita, Narendra; Hiwasa-Tanase, Kyoko; Kato, Kazuhisa; Kato, Ko; Ezura, Hiroshi

    2011-09-28

    High-level accumulation of the target recombinant protein is a significant issue in heterologous protein expression using transgenic plants. Miraculin, a taste-modifying protein, was accumulated in transgenic tomatoes using an expression cassette in which the miraculin gene was expressed by the cauliflower mosaic virus (CaMV) 35S promoter and the heat shock protein (HSP) terminator (MIR-HSP). The HSP terminator was derived from heat shock protein 18.2 in Arabidopsis thaliana . Using this HSP-containing cassette, the miraculin concentration in T0 transgenic tomato lines was 1.4-13.9% of the total soluble protein (TSP), and that in the T1 transgenic tomato line homozygous for the miraculin gene reached 17.1% of the TSP. The accumulation level of the target protein was comparable to levels observed with chloroplast transformation. The high-level accumulation of miraculin in T0 transgenic tomato lines achieved by the HSP terminator was maintained in the successive T1 generation, demonstrating the genetic stability of this accumulation system.

  6. Dual Mode NOx Sensor: Measuring Both the Accumulated Amount and Instantaneous Level at Low Concentrations

    PubMed Central

    Groß, Andrea; Beulertz, Gregor; Marr, Isabella; Kubinski, David J.; Visser, Jaco H.; Moos, Ralf

    2012-01-01

    The accumulating-type (or integrating-type) NOx sensor principle offers two operation modes to measure low levels of NOx: The direct signal gives the total amount dosed over a time interval and its derivative the instantaneous concentration. With a linear sensor response, no baseline drift, and both response times and recovery times in the range of the gas exchange time of the test bench (5 to 7 s), the integrating sensor is well suited to reliably detect low levels of NOx. Experimental results are presented demonstrating the sensor’s integrating properties for the total amount detection and its sensitivity to both NO and to NO2. We also show the correlation between the derivative of the sensor signal and the known gas concentration. The long-term detection of NOx in the sub-ppm range (e.g., for air quality measurements) is discussed. Additionally, a self-adaption of the measurement range taking advantage of the temperature dependency of the sensitivity is addressed. PMID:22736980

  7. Highly concentrated foam formulation for blast mitigation

    DOEpatents

    Tucker, Mark D.; Gao, Huizhen

    2010-12-14

    A highly concentrated foam formulation for blast suppression and dispersion mitigation for use in responding to a terrorism incident involving a radiological dispersion device. The foam formulation is more concentrated and more stable than the current blast suppression foam (AFC-380), which reduces the logistics burden on the user.

  8. Achievement of high nitrite accumulation via endogenous partial denitrification (EPD).

    PubMed

    Ji, Jiantao; Peng, Yongzhen; Wang, Bo; Wang, Shuying

    2017-01-01

    This study proposed a novel strategy for achievement of partial denitrification driven by endogenous carbon sources in an anaerobic/anoxic/aerobic activated sludge system. Results showed that in the steady-stage, the nitrate-to-nitrite transformation ratio (NTR) was kept at around 87% without nitrate in the effluent. During the anaerobic period, exogenous carbon sources was completely taken up, accompanied by the consumption of glycogen and production of polyhydroxyalkanoates (PHAs). During the anoxic period, nitrate was reduced to nitrite by using PHAs as carbon sources, followed by the replenishment of glycogen. Thus, the phenotype of denitrifying GAOs was clearly observed and endogenous partial denitrification (EPD) occurred. Furthermore, results showed the nitrate reduction was prior to the nitrite reduction in the presence of nitrate, which led to the high nitrite accumulation.

  9. Massive accumulation of highly polluted sedimentary deposits by river damming.

    PubMed

    Palanques, Albert; Grimalt, Joan; Belzunces, Marc; Estrada, Ferran; Puig, Pere; Guillén, Jorge

    2014-11-01

    Uncontrolled dumping of anthropogenic waste in rivers regulated by dams has created contaminated deposits in reservoirs that have remained unidentified for decades. The Flix Reservoir is located in the Ebro River, the second largest river flowing into the NW Mediterranean, has been affected by residue dumping from a chlor-alkali electrochemical plant for decades. High-resolution seismic profiles, bathymetric data, surficial sediment samples and sediment cores were obtained in the Flix Reservoir to study the characteristics of the deposit accumulated by this dumping. These data were used to reconstruct the waste deposit history. Since the construction of the Flix Dam in 1948, more than 3.6×10(5) t of industrial waste has accumulated in the reservoir generating a delta-like deposit formed by three sediment lobes of fine-grained material highly contaminated by Hg, Cd, Zn and Cr (max: 640, 26, 420 and 750 mg kg(-1), respectively). This contamination was associated with the Hg that was used for the cathode in the electrochemical plant from 1949 and with the production of phosphorite derivatives from 1973. After the construction of two large dams only a few kilometres upstream during the 1960s, the solids discharged from the industrial complex became the main sediment source to the Flix Reservoir. The deposit has remained in the reservoir forming a delta that obstructs about 50% of the river water section. Its stability only depended on the flow retention by the Flix Dam. At present, this contaminated waste deposit is being removed from the water reservoir as it is a cause of concern for the environment and for human health downriver.

  10. High salinity leads to accumulation of soil organic carbon in mangrove soil.

    PubMed

    Kida, Morimaru; Tomotsune, Mitsutoshi; Iimura, Yasuo; Kinjo, Kazutoshi; Ohtsuka, Toshiyuki; Fujitake, Nobuhide

    2017-06-01

    Although mangrove forests are one of the most well-known soil organic carbon (SOC) sinks, the mechanism underlying SOC accumulation is relatively unknown. High net primary production (NPP) along with the typical bottom-heavy biomass allocation and low soil respiration (SR) have been considered to be responsible for SOC accumulation. However, an emerging paradigm postulates that SR is severely underestimated because of the leakage of dissolved inorganic carbon (DIC) in groundwater. Here we propose a simple yet unique mechanism for SOC accumulation in mangrove soils. We conducted sequential extraction of water extractable organic matter (WEOM) from mangrove soils using ultrapure water and artificial seawater, respectively. A sharp increase in humic substances (HS) concentration was observed only in the case of ultrapure water, along with a decline in salinity. Extracted WEOM was colloidal, and ≤70% of it re-precipitated by the addition of artificial seawater. These results strongly suggest that HS is selectively flocculated and maintained in the mangrove soils because of high salinity. Because sea salts are a characteristic of any mangrove forest, high salinity may be one of mechanisms underlying SOC accumulation in mangrove soils.

  11. Uptake, Accumulation and Toxicity of Silver Nanoparticle in Autotrophic Plants, and Heterotrophic Microbes: A Concentric Review.

    PubMed

    Tripathi, Durgesh K; Tripathi, Ashutosh; Shweta; Singh, Swati; Singh, Yashwant; Vishwakarma, Kanchan; Yadav, Gaurav; Sharma, Shivesh; Singh, Vivek K; Mishra, Rohit K; Upadhyay, R G; Dubey, Nawal K; Lee, Yonghoon; Chauhan, Devendra K

    2017-01-01

    Nanotechnology is a cutting-edge field of science with the potential to revolutionize today's technological advances including industrial applications. It is being utilized for the welfare of mankind; but at the same time, the unprecedented use and uncontrolled release of nanomaterials into the environment poses enormous threat to living organisms. Silver nanoparticles (AgNPs) are used in several industries and its continuous release may hamper many physiological and biochemical processes in the living organisms including autotrophs and heterotrophs. The present review gives a concentric know-how of the effects of AgNPs on the lower and higher autotrophic plants as well as on heterotrophic microbes so as to have better understanding of the differences in effects among these two groups. It also focuses on the mechanism of uptake, translocation, accumulation in the plants and microbes, and resulting toxicity as well as tolerance mechanisms by which these microorganisms are able to survive and reduce the effects of AgNPs. This review differentiates the impact of silver nanoparticles at various levels between autotrophs and heterotrophs and signifies the prevailing tolerance mechanisms. With this background, a comprehensive idea can be made with respect to the influence of AgNPs on lower and higher autotrophic plants together with heterotrophic microbes and new insights can be generated for the researchers to understand the toxicity and tolerance mechanisms of AgNPs in plants and microbes.

  12. Uptake, Accumulation and Toxicity of Silver Nanoparticle in Autotrophic Plants, and Heterotrophic Microbes: A Concentric Review

    PubMed Central

    Tripathi, Durgesh K.; Tripathi, Ashutosh; Shweta; Singh, Swati; Singh, Yashwant; Vishwakarma, Kanchan; Yadav, Gaurav; Sharma, Shivesh; Singh, Vivek K.; Mishra, Rohit K.; Upadhyay, R. G.; Dubey, Nawal K.; Lee, Yonghoon; Chauhan, Devendra K.

    2017-01-01

    Nanotechnology is a cutting-edge field of science with the potential to revolutionize today’s technological advances including industrial applications. It is being utilized for the welfare of mankind; but at the same time, the unprecedented use and uncontrolled release of nanomaterials into the environment poses enormous threat to living organisms. Silver nanoparticles (AgNPs) are used in several industries and its continuous release may hamper many physiological and biochemical processes in the living organisms including autotrophs and heterotrophs. The present review gives a concentric know-how of the effects of AgNPs on the lower and higher autotrophic plants as well as on heterotrophic microbes so as to have better understanding of the differences in effects among these two groups. It also focuses on the mechanism of uptake, translocation, accumulation in the plants and microbes, and resulting toxicity as well as tolerance mechanisms by which these microorganisms are able to survive and reduce the effects of AgNPs. This review differentiates the impact of silver nanoparticles at various levels between autotrophs and heterotrophs and signifies the prevailing tolerance mechanisms. With this background, a comprehensive idea can be made with respect to the influence of AgNPs on lower and higher autotrophic plants together with heterotrophic microbes and new insights can be generated for the researchers to understand the toxicity and tolerance mechanisms of AgNPs in plants and microbes. PMID:28184215

  13. Copper uptake by Eichhornia crassipes exposed at high level concentrations.

    PubMed

    Melignani, Eliana; de Cabo, Laura Isabel; Faggi, Ana María

    2015-06-01

    The objective of this study was to assess the growth of water hyacinth (Eichhornia crassipes) and its ability to accumulate Cu from polluted water with high Cu concentrations and a mixture of other contaminants under short-term exposure, in order to use this species for the remediation of highly contaminated sites. Two hydroponic experiments were performed under greenhouse conditions for 7 days. One of them consisted of growing water hyacinth in Hoagland solution supplemented with 15 or 25 mg Cu/L and a control. The other one contained water hyacinth growing in polluted river water supplemented with 15 mg Cu/L and a control. Cu was accumulated principally in roots. The maximum Cu concentration was 23,387.2 mg/kg dw in the treatment of 25 mg Cu/L in Hoagland solution. Cu translocation from roots to leaves was low. The mixture of 15 mg Cu/L with polluted water did not appear to have toxic effects on the water hyacinth. This plant showed a remarkable uptake capacity under elevated Cu concentrations in a mixture of pollutants similar to pure industrial effluents in a short time of exposure. This result has not been reported before, to our knowledge. This species is suitable for phytoremediation of waters subject to discharge of mixed industrial effluents containing elevated Cu concentrations (≥15 mg Cu/L), as well as nutrient-rich domestic wastewaters.

  14. Fluorescence quenching at high quencher concentrations

    NASA Astrophysics Data System (ADS)

    Peak, David; Werner, T. C.; Dennin, Richard M., Jr.; Baird, James K.

    1983-10-01

    Chemical reactions occurring in dense media at high reactant concentrations can be described by rate ``constants'' which are actually functions of concentration. We present a theoretical model in which this so-called rate constant ``renormalization'' occurs for the specific case of fluorescence quenching in solution. We show that both the quenching and the excitation rate constants can become concentration dependent. We fit our theory to several sets of experimental data—our own and some from the literature—and show that excellent agreement is obtained by varying a single free parameter, namely, the efficiency with which a fluorophore-quencher collision leads to a quench of the excited state.

  15. Different palm oil preparations reduce plasma cholesterol concentrations and aortic cholesterol accumulation compared to coconut oil in hypercholesterolemic hamsters.

    PubMed

    Wilson, Thomas A; Nicolosi, Robert J; Kotyla, Timothy; Sundram, Kalyana; Kritchevsky, David

    2005-10-01

    Several studies have reported on the effect of refined, bleached and deodorized palm oil (RBD-PO) incorporation into the diet on blood cholesterol concentrations and on the development of atherosclerosis. However, very little work has been reported on the influence of red palm oil (RPO), which is higher in carotenoid and tocopherol content than RBD-PO. Thus, we studied the influence of RPO, RBD-PO and a RBD-PO plus red palm oil extract (reconstituted RBD-PO) on plasma cholesterol concentrations and aortic accumulation vs. hamsters fed coconut oil. Forty-eight F1B Golden Syrian hamsters (Mesocricetus auratus) (BioBreeders, Watertown, MA) were group housed (three/cage) in hanging polystyrene cages with bedding in an air-conditioned facility maintained on a 12-h light/dark cycle. The hamsters were fed a chow-based hypercholesterolemic diet (HCD) containing 10% coconut oil and 0.1% cholesterol for 2 weeks at which time they were bled after an overnight fast and segregated into four groups of 12 with similar plasma cholesterol concentrations. Group 1 continued on the HCD, Group 2 was fed the HCD containing 10% RPO in place of coconut oil, Group 3 was fed the HCD containing 10% RBD-PO in place of coconut oil and Group 4 was fed the HCD with 10% reconstituted RBD-PO for an additional 10 weeks. Plasma total cholesterol (TC) and non-high-density lipoprotein-cholesterol (HDL-C) (very low- and low-density lipoprotein) concentrations were significantly lower in the hamsters fed the RPO (-42% and -48%), RBD-PO (-32% and -36%) and the reconstituted RBD-PO (-37% and -41%) compared to the coconut oil-fed hamsters. Plasma HDL-C concentrations were significantly higher by 14% and 31% in hamsters fed the RBD-PO and RPO compared to the coconut oil-fed hamsters. Plasma triglyceride (TG) concentrations were significantly lower in hamsters fed RBD-PO (-32%) and the reconstituted RBD-PO (-31%) compared to the coconut oil-fed hamsters. The plasma gamma-tocopherol concentrations were higher

  16. Growth and photosynthetic limitation analysis of the Cd-accumulator Salicornia ramosissima under excessive cadmium concentrations and optimum salinity conditions.

    PubMed

    Pérez-Romero, Jesús Alberto; Redondo-Gómez, Susana; Mateos-Naranjo, Enrique

    2016-12-01

    Cadmium (Cd) is a non-essential element for plants, and its excess impairs plant performance. Physiological impacts of Cd excess are well known in non-tolerant plants, however this information is scarce for Cd-tolerant plants. A glasshouse experiment was designed to investigate the effect of five different Cd levels (0, 0.05, 0.20, 0.65 and 1.35 mM Cd) on the growth, photosynthetic apparatus (PSII chemistry), gas exchange characteristics, photosynthetic pigments profiles, water relations and nutritional balance of the Cd-accumulator Salicornia ramosissima. Ours results confirmed the accumulation capacity of S. ramosissima, as indicated the bioaccumulation factor (BC) greater than 1.0 for all Cd levels. Furthermore, after 21 days of treatment S. ramosissima growth was not highly affected by Cd. Total photosynthetic limitation increased from 38% at 0.05 mM Cd to 70% at 1.35 mM Cd. CO2 diffusion restriction imposed the main contribution to total photosynthetic limitation. Mesophyll conductance reduction was of major importance (with between 69 and 86%), followed by stomatal conductance (with between 9 and 20%). Maximum carboxylation rate (Vc,max), remained stable until 0.2 mM Cd, and chlorophyll fluorescence parameters (Fv/Fm, qP) and pigments concentrations were not significantly decreased by increased Cd supply. Finally, S. ramosissima water relations (intrinsic water use efficiency and relative water content) and nutritional level did not highly vary between Cd treatments. Thus, our finding suggested that Cd tolerance S. ramosissima is in certain degree supported by the tolerance of its carbon assimilation enzyme (RuBisCO) and with the high functionality and integrity of the PSII reaction center under Cd excess.

  17. Different responses of low grain-Cd-accumulating and high grain-Cd-accumulating rice cultivars to Cd stress.

    PubMed

    Wang, Feijuan; Wang, Min; Liu, Zhouping; Shi, Yan; Han, Tiqian; Ye, Yaoyao; Gong, Ning; Sun, Junwei; Zhu, Cheng

    2015-11-01

    Cadmium (Cd) is a major heavy metal pollutant which is highly toxic to plants and animals. The accumulation of Cd in rice grains is a major agricultural problem in regions with Cd pollution. A hydroponics experiment using low grain-Cd-accumulating rice (xiushui 11) and high grain-Cd-accumulating rice (xiushui 110) was carried out to characterize the different responses of rice cultivars to Cd stress. We found that xiushui 11 was more tolerant to Cd than xiushui 110, and xiushui 11 suffered less oxidative damage. Cell walls played an important role in limiting the amount of Cd that entered the protoplast, especially in xiushui 11. Cd stored in organelles as soluble fractions, leading to greater physiological stress of Cd detoxification. We found that Cd can disturb the ion homeostasis in rice roots because Cd(2+) and Ca(2+) may have a similar uptake route. Xiushui 11 had a faster root-to-shoot transport of Cd, and the expression level of OsPCR1 gene which was predicted related with Cd accumulation in rice was consist with the Cd transport of root-to-shoot in rice and maintain the greater Cd tolerance of xiushui 11. These results suggest there are different Cd detoxification and accumulation mechanisms in rice cultivars.

  18. 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).

  19. ELEVATED CO2 AND ELEVATED TEMPERATURE AFFECT CARBON AND NITROGEN CONCENTRATIONS BUT NOT ACCUMULATION IN PSEUDOTSUGA MENZIESII SEEDLINGS

    EPA Science Inventory

    To determine the impact of climate change on concentrations and accumulation of C and N in trees, we grew Pseudotsuga menziesii (Mirb.) Franco (Douglas-fir) seedlings treated with ambient or elevated (+180 mol mol-1) CO2, and with ambient or elevated (+3.5 C) temperature for f...

  20. Estimation of Biota Sediment Accumulation Factor (BSAF) from Paired Observations of Chemical Concentrations in Biota and Sediment (Final Report)

    EPA Science Inventory

    In March 2009, EPA's Ecological Risk Assessment Support Center (ERASC) released the final report entitled, Estimation of Biota Sediment Accumulation Factor (BSAF) from Paired Observations of Chemical Concentrations in Biota and Sediment. This report was written in response...

  1. Organic and inorganic amendments affect soil concentration and accumulation of cadmium and lead in wheat in calcareous alkaline soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigation with untreated effluent in periurban agriculture could result in accumulation and bioconcentrations of cadmium (Cd) and lead (Pb). Different amendments were used to investigate their effect on availability, concentration, and uptake of metals by wheat in texturally different soils. Crop w...

  2. Tolerance of Ricinus communis L. to Cd and screening of high Cd accumulation varieties for remediation of Cd contaminated soils.

    PubMed

    Wu, Shanshan; Shen, Chuang; Yang, Zhongyi; Lin, Biyun; Yuan, Jiangang

    2016-11-01

    Response of castor (Ricinus communis L.) to cadmium (Cd) was assessed by a seed-suspending seedbed approach. Length of total radicle was the most sensitive indicator of Cd tolerance among the tested germination and growth characters. The ED50 value for Cd was 11.87 mg L(-1), indicating high Cd tolerance in castor. A pot experiment was conducted by growing 46 varieties of castor under CK (without Cd) and Cd1 (10 mg kg(-1) of Cd) and Cd2 (50 mg kg(-1) of Cd) treatments to investigate genotype variations in growth response and Cd accumulation of castor under different Cd exposures. Castor possessed high Cd accumulation ability; average shoot and root Cd concentrations of the 46 tested varieties were 21.83 and 185.43 mg kg(-1), and 174.99 and 1181.96 mg kg(-1) under Cd1 and Cd2, respectively. Great variation in Cd accumulation was observed among varieties, and Cd concentration of castor was genotype dependent. The correlation between biomass and Cd accumulation was significantly positive, while no significant correlation was observed between Cd concentration and Cd accumulation, which indicated that biomass performance is the dominant factor in determining Cd accumulation ability.

  3. HvZIP7 mediates zinc accumulation in barley (Hordeum vulgare) at moderately high zinc supply.

    PubMed

    Tiong, Jingwen; McDonald, Glenn K; Genc, Yusuf; Pedas, Pai; Hayes, Julie E; Toubia, John; Langridge, Peter; Huang, Chun Y

    2014-01-01

    High expression of zinc (Zn)-regulated, iron-regulated transporter-like protein (ZIP) genes increases root Zn uptake in dicots, leading to high accumulation of Zn in shoots. However, none of the ZIP genes tested previously in monocots could enhance shoot Zn accumulation. In this report, barley (Hordeum vulgare) HvZIP7 was investigated for its functions in Zn transport. The functions of HvZIP7 in planta were studied using in situ hybridization and transient analysis of subcellular localization with a green fluorescent protein (GFP) reporter. Transgenic barley lines overexpressing HvZIP7 were also generated to further understand the functions of HvZIP7 in metal transport. HvZIP7 is strongly induced by Zn deficiency, primarily in vascular tissues of roots and leaves, and its protein was localized in the plasma membrane. These properties are similar to its closely related homologs in dicots. Overexpression of HvZIP7 in barley plants increased Zn uptake when moderately high concentrations of Zn were supplied. Significantly, there was a specific enhancement of shoot Zn accumulation, with no measurable increase in iron (Fe), manganese (Mn), copper (Cu) or cadmium (Cd). HvZIP7 displays characteristics of low-affinity Zn transport. The unique function of HvZIP7 provides new insights into the role of ZIP genes in Zn homeostasis in monocots, and offers opportunities to develop Zn biofortification strategies in cereals.

  4. High-dimensional entanglement concentration of twisted photon pairs High-dimensional entanglement concentration

    NASA Astrophysics Data System (ADS)

    Chen, L. X.; Wu, Q. P.

    2012-10-01

    Recently, Dada et al. reported on the experimental entanglement concentration and violation of generalized Bell inequalities with orbital angular momentum (OAM) [Nat. Phys. 7, 677 (2011)]. Here we demonstrate that the high-dimensional entanglement concentration can be performed in arbitrary OAM subspaces with selectivity. Instead of violating the generalized Bell inequalities, the working principle of present entanglement concentration is visualized by the biphoton OAM Klyshko picture, and its good performance is confirmed and quantified through the experimental Shannon dimensionalities after concentration.

  5. Highly Concentrated Catalytic Asymmetric Allylation of Ketones

    PubMed Central

    Wooten, Alfred J.; Kim, Jeung Gon; Walsh, Patrick J.

    2008-01-01

    We report the catalytic asymmetric allylation of ketones under highly concentrated reaction conditions with a catalyst generated from titanium tetraisopropoxide and BINOL (1:2 ratio) in the presence of isopropanol. This catalyst promotes the addition of tetraallylstannane to a variety of ketones to produce tertiary homoallylic alcohols in excellent yield (80–99%) with high enantioselectivities (79–95%). The resulting homoallylic alcohols can also be epoxidized in situ using tert-butyl hydroperoxide (TBHP) to afford cyclic epoxy alcohols in high yield (84–87%). PMID:17249767

  6. Highly concentrated catalytic asymmetric allylation of ketones.

    PubMed

    Wooten, Alfred J; Kim, Jeung Gon; Walsh, Patrick J

    2007-02-01

    [reaction: see text] We report the catalytic asymmetric allylation of ketones under highly concentrated reaction conditions with a catalyst generated from titanium tetraisopropoxide and BINOL (1:2 ratio) in the presence of isopropanol. This catalyst promotes the addition of tetraallylstannane to a variety of ketones to produce tertiary homoallylic alcohols in excellent yield (80-99%) with high enantioselectivities (79-95%). The resulting homoallylic alcohols can also be epoxidized in situ using tert-butyl hydroperoxide (TBHP) to afford cyclic epoxy alcohols in high yield (84-87%).

  7. DOE High Performance Concentrator PV Project

    SciTech Connect

    McConnell, R.; Symko-Davies, M.

    2005-08-01

    Much in demand are next-generation photovoltaic (PV) technologies that can be used economically to make a large-scale impact on world electricity production. The U.S. Department of Energy (DOE) initiated the High-Performance Photovoltaic (HiPerf PV) Project to substantially increase the viability of PV for cost-competitive applications so that PV can contribute significantly to both our energy supply and environment. To accomplish such results, the National Center for Photovoltaics (NCPV) directs in-house and subcontracted research in high-performance polycrystalline thin-film and multijunction concentrator devices with the goal of enabling progress of high-efficiency technologies toward commercial-prototype products. We will describe the details of the subcontractor and in-house progress in exploring and accelerating pathways of III-V multijunction concentrator solar cells and systems toward their long-term goals. By 2020, we anticipate that this project will have demonstrated 33% system efficiency and a system price of $1.00/Wp for concentrator PV systems using III-V multijunction solar cells with efficiencies over 41%.

  8. Differences in the accumulated metal concentrations in two epigeic earthworm species (Lumbricus rubellus and Dendrodrilus rubidus) living in contaminated soils

    SciTech Connect

    Morgan, J.E.; Morgan, A.J. )

    1991-08-01

    Lumbricus rubellus and Denrodrilus rubidus are acid-tolerant epigeic species, which are often the only species inhabiting the poorly vegetated and heavily contaminated soils associated with many abandoned mine sites. Although both species probably consume similar food materials, observations on worms collected from acidic and calcareous mine sites indicate that they accumulate significantly different metal concentrations in their tissues: the larger L. rubellus accumulates more Zn and Ca, but less Pb and Cd than D. rubidus. The aim of the present study was to analyze these two epigeic species sampled from ten diverse sites to determine whether the inter-species differences in relative metal accumulation is a general feature of these sympatrics.

  9. High-efficiency silicon concentrator cell commercialization

    SciTech Connect

    Sinton, R.A.; Swanson, R.M.

    1993-05-01

    This report summarizes the first phase of a forty-one month program to develop a commercial, high-efficiency concentrator solar cell and facility for manufacturing it. The period covered is November 1, 1990 to December 31, 1991. This is a joint program between the Electric Power Research Institute (EPRI) and Sandia National Laboratories. (This report is also published by EPRI as EPRI report number TR-102035.) During the first year of the program, SunPower accomplished the following major objectives: (1) a new solar cell fabrication facility, which is called the Cell Pilot Line (CPL), (2) a baseline concentrator cell process has been developed, and (3) a cell testing facility has been completed. Initial cell efficiencies are about 23% for the baseline process. The long-range goal is to improve this efficiency to 27%.

  10. Thin photovoltaic modules at ultra high concentration

    NASA Astrophysics Data System (ADS)

    Pérez-Higueras, Pedro; Ferrer-Rodríguez, Juan Pablo; Shanks, Katie; Almonacid, Florencia; Férnández, Eduardo F.

    2015-09-01

    A new design concept of high concentration photovoltaic (HCPV) module is studied both by ray-tracing simulation and by building a prototype. This set-up is based on the idea of concentrating sunlight from different optical units to a single commercial multi-junction solar cell, which is located in a different plane than that of the primary optics (e.g. Fresnel lenses). A two-optical-unit set-up, as a first approach, is built and measured with the solar simulator "Helios 3198". These results are compared to the measurement results of the single-unit of one Fresnel lens and the same solar cell. The feasibility of this new design has been confirmed theoretically and practically.

  11. High-concentration photovoltaic module design

    SciTech Connect

    Levy, S.L.; Stoddard, L.E.

    1986-08-01

    Over the past 3 years, Black and Veatch has been leading a team in the ongoing design of a high-concentration, high-performance photovoltaic (PV) module for the Electric Power Research Institute (EPRI). The current design consists of a deep-drawn aluminized steel housing containing 48 cell packages in a 4-row by 12-column matrix. Each cell package includes an anodized aluminum secondary optical element, a 27.5% efficient Stanford University/EPRI 500X concentration point contact silicon PV cell, an alumina substrate, and a copper heat spreader. Developmental efforts underway for a comolded glass/polymer Fresnel lens parquet indicate the potential for a substantial decrease in molding time and, thereby, cost, in comparison to more conventional compression molding of acrylic lenses. Further development is necessary to achieve comparable optical performance of the lens. Current activities have included the development of PVOPTICS, a Monte Carlo computer code particularly suited to the module optical design. The module is projected to produce 287 watts at an efficiency of 22%. The module cost, at large production rates, is estimated to be $275 ($0.96 per watt).

  12. Effects of sludge retention time, carbon and initial biomass concentrations on selection process: From activated sludge to polyhydroxyalkanoate accumulating cultures.

    PubMed

    Chen, Zhiqiang; Huang, Long; Wen, Qinxue; Zhang, Huichao; Guo, Zirui

    2017-02-01

    Four sequence batch reactors (SBRs) fed by fermented sugar cane wastewater were continuously operated under the aerobic dynamic feeding (ADF) mode with different configurations of sludge retention time (SRT), carbon and initial biomass concentrations to enrich polyhydroxyalkanoate (PHA) accumulating mixed microbial cultures (MMCs) from municipal activated sludge. The stability of SBRs was investigated besides the enrichment performance. The microbial community structures of the enriched MMCs were analyzed using terminal restriction fragment length polymorphism (T-RFLP). The optimum operating conditions for the enrichment process were: SRT of 5days, carbon concentration of 2.52g COD/L and initial biomass concentration of 3.65g/L. The best enrichment performance in terms of both operating stability and PHA storage ability of enriched cultures (with the maximum PHA content and PHA storage yield (YPHA/S) of 61.26% and 0.68mg COD/mg COD, respectively) was achieved under this condition. Effects of the SRT, carbon concentration and initial biomass concentration on the PHA accumulating MMCs selection process were discussed respectively. A new model including the segmentation of the enrichment process and the effects of SRT on each phase was proposed.

  13. Distribution of the concentration of heavy metals associated with the sediment particles accumulated on road surfaces.

    PubMed

    Zafra, C A; Temprano, J; Tejero, I

    2011-07-01

    The heavy metal pollution caused by road run-off water constitutes a problem in urban areas. The metallic load associated with road sediment must be determined in order to study its impact in drainage systems and receiving waters, and to perfect the design of prevention systems. This paper presents data regarding the sediment collected on road surfaces in the city of Torrelavega (northern Spain) during a period of 65 days (132 samples). Two sample types were collected: vacuum-dried samples and those swept up following vacuuming. The sediment loading (g m(-2)), particle size distribution (63-2800 microm) and heavy metal concentrations were determined. The data showed that the concentration of heavy metals tends to increase with the reduction in the particle diameter (exponential tendency). The concentrations ofPb, Zn, Cu, Cr, Ni, Cd, Fe, Mn and Co in the size fraction <63 microm were 350, 630, 124, 57, 56, 38, 3231, 374 and 51 mg kg(-1), respectively (average traffic density: 3800 vehicles day(-1)). By increasing the residence time of the sediment, the concentration increases, whereas the ratio of the concentration between the different size fractions decreases. The concentration across the road diminishes when the distance between the roadway and the sampling siteincreases; when the distance increases, the ratio between size fractions for heavy metal concentrations increases. Finally, the main sources of heavy metals are the particles detached by braking (brake pads) and tyre wear (rubber), and are associated with particle sizes <125 microm.

  14. Ammonia Solubility in High Concentration Salt Solutions

    SciTech Connect

    HEDENGREN, D.C.

    2000-02-01

    Solubility data for ammonia in water and various dilute solutions are abundant in the literature. However, there is a noticeable lack of ammonia solubility data for high salt, basic solutions of various mixtures of salts including those found in many of the Hanford Washington underground waste tanks. As a result, models based on solubility data for dilute salt solutions have been used to extrapolate to high salt solutions. These significant extrapolations need to be checked against actual laboratory data. Some indirect vapor measurements have been made. A more direct approach is to determine the ratio of solubility of ammonia in water to its solubility in high salt solutions. In various experiments, pairs of solutions, one of which is water and the other a high salt solution, are allowed to come to equilibrium with a common ammonia vapor pressure. The ratio of concentrations of ammonia in the two solutions is equal to the ratio of the respective ammonia solubilities (Henry's Law constants) at a given temperature. This information can then be used to refine the models that predict vapor space compositions of ammonia. Ammonia at Hanford is of concern because of its toxicity in the environment and its contribution to the flammability of vapor space gas mixtures in waste tanks.

  15. Diverse microbial species survive high ammonia concentrations

    NASA Astrophysics Data System (ADS)

    Kelly, Laura C.; Cockell, Charles S.; Summers, Stephen

    2012-04-01

    Planetary protection regulations are in place to control the contamination of planets and moons with terrestrial micro-organisms in order to avoid jeopardizing future scientific investigations relating to the search for life. One environmental chemical factor of relevance in extraterrestrial environments, specifically in the moons of the outer solar system, is ammonia (NH3). Ammonia is known to be highly toxic to micro-organisms and may disrupt proton motive force, interfere with cellular redox reactions or cause an increase of cell pH. To test the survival potential of terrestrial micro-organisms exposed to such cold, ammonia-rich environments, and to judge whether current planetary protection regulations are sufficient, soil samples were exposed to concentrations of NH3 from 5 to 35% (v/v) at -80°C and room temperature for periods up to 11 months. Following exposure to 35% NH3, diverse spore-forming taxa survived, including representatives of the Firmicutes (Bacillus, Sporosarcina, Viridibacillus, Paenibacillus, Staphylococcus and Brevibacillus) and Actinobacteria (Streptomyces). Non-spore forming organisms also survived, including Proteobacteria (Pseudomonas) and Actinobacteria (Arthrobacter) that are known to have environmentally resistant resting states. Clostridium spp. were isolated from the exposed soil under anaerobic culture. High NH3 was shown to cause a reduction in viability of spores over time, but spore morphology was not visibly altered. In addition to its implications for planetary protection, these data show that a large number of bacteria, potentially including spore-forming pathogens, but also environmentally resistant non-spore-formers, can survive high ammonia concentrations.

  16. Refractory dissolved organic nitrogen accumulation in high-elevation lakes.

    PubMed

    Goldberg, S J; Ball, G I; Allen, B C; Schladow, S G; Simpson, A J; Masoom, H; Soong, R; Graven, H D; Aluwihare, L I

    2015-02-23

    The role of dissolved organic matter (DOM) as either a sink for inorganic nutrients or an additional nutrient source is an often-neglected component of nutrient budgets in aquatic environments. Here, we examined the role of DOM in reactive nitrogen (N) storage in Sierra Nevada (California, USA) lakes where atmospheric deposition of N has shifted the lakes toward seasonal phosphorus (P)-limitation. Nuclear magnetic resonance (NMR) spectroscopy and isotope analyses performed on DOM isolated from Lake Tahoe reveal the accumulation of refractory proteinaceous material with a 100-200-year residence time. In contrast, smaller lakes in the same watershed contain DOM with typical terrestrial characteristics, indicating that proteins in Lake Tahoe are autochthonously produced. These data support the role of DOM as a possible sink for reactive N in these lake ecosystems and identify a potential role for DOM in affecting the inorganic nutrient stoichiometry of these environments.

  17. Changes of concentrations and possibility of accumulation of bisphenol A and alkylphenols, depending on biomass and composition, in zooplankton of the Southern Baltic (Gulf of Gdansk).

    PubMed

    Staniszewska, Marta; Nehring, Iga; Mudrak-Cegiołka, Stella

    2016-06-01

    The focus of the present study was to find the relationship between concentrations of bisphenol A (BPA), 4-tert-octylphenol (OP) and 4-nonylphenol (NP) in zooplankton and seasonal changes in the composition and biomass of particular zooplankton taxa in the Gulf of Gdansk (Southern Baltic) in the years 2011-2012. Assays of BPA, OP and NP in water and zooplankton samples were performed using the HPLC/FL system. High mean concentrations of the studied compounds, determined in spring (405.9 (BPA); 25.7 (OP); 111.2 (NP) ng g(-1) dw), can be linked to the high proportion of meroplankton in that season. Rotifera also had an influence on the rise in concentrations of the studied compounds but to a lesser degree, while the lowest concentrations (determined in summer) can be associated with the high participation of Copepoda and Cladocera in zooplankton biomass. It was also observed that juvenile forms can be more susceptible to accumulating endocrine disrupting compounds (EDCs). This is indicated by the positive correlation between BPA concentration in zooplankton and the proportion of Copepoda nauplii biomass in spring (r = 0.90; p < 0.05). In most cases, greater zooplankton biomass accumulated higher concentrations and loads of the studied compounds. With biomass growth (to 123.32 μg m(-3)), the bioconcentration factor also rose (to max 46.1·10(3)), demonstrating that unlike typical hydrophobic compounds the studied EDCs do not become "diluted" in zooplankton biomass. The highest BPA concentrations from all compounds may be connected with anthropogenic sources located in the coastal zone.

  18. Capture and accumulation of perchlorate in lettuce. Effect of genotype, temperature, perchlorate concentration, and competition with anions.

    PubMed

    Calderón, Raúl; Palma, Paulina; Parker, David; Escudey, Mauricio

    2014-09-01

    Various studies have evaluated the accumulation of ClO4(-) in lettuce (Lactuca sativa), but very few have dealt with the variables that can interfere with its capture. The present study evaluates the transfer of ClO4(-) in two L. sativa varieties: butter head (L. sativa var. capitata) and cos lettuce (L. sativa var. crispa) under hydroponic conditions. The ClO4(-) concentrations used correspond to levels (1 and 2mgL(-1)), measured in irrigation water in the Iquique region in the north of Chile. Results indicate that the capture of ClO4(-) is dependent on its concentration, lettuce genotype, and temperature. The butter head variety accumulates the highest perchlorate concentrations. Anion competition involving NO3(-) (16 and 48mM), Cl(-) (23 and 56mM), and SO4(2-) (10 and 20mM) was evaluated, being NO3(-) (48mM), the most significant competition reducing the concentration of ClO4(-) in tissues of L. sativa varieties.

  19. [Effects of elevated CO2 concentration and temperature on nutrient accumulation and allocation in Betula albo-sinensis seedlings].

    PubMed

    Hou, Ying; Wang, Kai-yun; Zhang, Chao

    2008-01-01

    With enclosed chamber system, this paper studied the effects of elevated CO2 concentration (ambient + 350 micromol x mol(-1), E(C)), temperature (ambient + 2 degrees C, E(T)), and their combination (E(CT)) on the nutrient accumulation and allocation in subalpine Betula albo-sinensis seedlings in western Sichuan Province. The results showed that after a growth season, the accumulation amount of N, P and K per plant increased by 44%, 45% and 11% under E(C) (P < 0.05), by 37%, 76% and 9% under E(T) (P < 0.05), and by 24%, 88% and 20% under E(CT) (P < 0.05), respectively. The N allocation to leaves reduced by 11.68% (P < 0.05) under E(C) but increased by 11.09% (P <0.05) under E(T) while that to branches, stems and roots increased by 2.95%, 3.39% and 5.34% under E(C) (P > 0.05), but decreased by 0.69%, 10.35% and 0.05% under E(T) (P > 0.05), respectively. The N allocation pattern under E(CT) was similar to that under E(C). The allocation of P and K had greater differences under E(C), E(T) and E(CT). All of these suggested that elevated CO2 concentration and temperature could promote nutrient accumulation, and change its allocation pattern in plant organs.

  20. Temperature-dependent accumulation mode particle and cloud nuclei concentrations from biogenic sources during WACS 2010

    NASA Astrophysics Data System (ADS)

    Ahlm, L.; Shakya, K. M.; Russell, L. M.; Schroder, J. C.; Wong, J. P. S.; Sjostedt, S. J.; Hayden, K. L.; Liggio, J.; Wentzell, J. J. B.; Wiebe, H. A.; Mihele, C.; Leaitch, W. R.; Macdonald, A. M.

    2013-03-01

    Submicron aerosol particles collected simultaneously at the mountain peak (2182 m a.s.l.) and at a forested mid-mountain site (1300 m a.s.l.) on Whistler Mountain, British Columbia, Canada, during June and July 2010 were analyzed by Fourier transform infrared (FTIR) spectroscopy for quantification of organic functional groups. Positive matrix factorization (PMF) was applied to the FTIR spectra. Three PMF factors associated with (1) combustion, (2) biogenics, and (3) vegetative detritus were identified at both sites. The biogenic factor was correlated with both temperature and several volatile organic compounds (VOCs). The combustion factor dominated the submicron particle mass during the beginning of the campaign, when the temperature was lower and advection was from the Vancouver area, but as the temperature started to rise in early July, the biogenic factor came to dominate as a result of increased emissions of biogenic VOCs, and thereby increased formation of secondary organic aerosol (SOA). On average, the biogenic factor represented 69% and 49% of the submicron organic particle mass at Whistler Peak and at the mid-mountain site, respectively. The lower fraction at the mid-mountain site was a result of more vegetative detritus there, and also higher influence from local combustion sources. The biogenic factor was strongly correlated (r~0.9) to number concentration of particles with diameter (Dp)> 100 nm, whereas the combustion factor was better correlated to number concentration of particles with Dp<100 nm (r~0.4). The number concentration of cloud condensation nuclei (CCN) was correlated (r~0.7) to the biogenic factor for supersaturations (S) of 0.2% or higher, which indicates that particle condensational growth from biogenic vapors was an important factor in controlling the CCN concentration for clouds where S≥0.2%. Both the number concentration of particles with Dp>100 nm and numbers of CCN for S≥0.2% were correlated to temperature. Considering the

  1. Temperature-dependent accumulation mode particle and cloud nuclei concentrations from biogenic sources during WACS 2010

    NASA Astrophysics Data System (ADS)

    Ahlm, L.; Shakya, K. M.; Russel, L. M.; Schroder, J. C.; Wong, J. P. S.; Sjostedt, S. J.; Hayden, K. L.; Liggio, J.; Wentzell, J. J. B.; Wiebe, H. A.; Mihele, C.; Leaitch, W. R.; Macdonald, A. M.

    2012-10-01

    Submicron aerosol particles collected simultaneously at the mountain peak (2182 m a.s.l.) and at a forested mid-mountain site (1300 m a.s.l.) on Whistler Mountain, British Columbia, Canada, during June and July 2010 were analyzed by Fourier transform infrared (FTIR) spectroscopy for quantification of organic functional groups. Positive matrix factorization (PMF) was applied to the FTIR spectra. Three PMF factors associated with (1) combustion, (2) biogenics, and (3) vegetative detritus, were identified at both sites. The biogenic factor was correlated with both temperature and several volatile organic compounds (VOCs). The combustion factor dominated the submicron particle mass during the beginning of the campaign when the temperature was lower and advection was from the Vancouver area, but as the temperature started to rise in early July the biogenic factor came to dominate as a result of increased emissions of biogenic VOCs and thereby increased formation of secondary organic aerosol (SOA). On average, the biogenic factor represented 69% and 49% of the submicron organic particle mass at Whistler Peak and at the mid-mountain site, respectively. The lower fraction at the mid-mountain site was a result of more vegetative detritus there, and also higher influence from local combustion sources. The biogenic factor was strongly correlated (r ~ 0.9) to number concentration of particles with diameter (Dp)> 100 nm, whereas the combustion factor was better correlated to number concentration of particles with Dp < 100 nm (r~ 0.4). The number concentration of cloud condensation nuclei (CCN) was correlated (r ~ 0.7) to the biogenic factor for supersaturations (S) of 0.2% or higher, which indicates that particle condensational growth from biogenic vapors was an important factor in controlling the CCN concentration for clouds where S≥0.2%. Both the number concentration of particles with Dp > 100 nm and numbers of CCN for S≥0.2% were correlated to temperature. Considering

  2. Highly accumulative production of L(+)-lactate from glucose by crystallization fermentation with immobilized Rhizopus oryzae.

    PubMed

    Yamane, Tsuneo; Tanaka, Ryohsuke

    2013-01-01

    In order to produce microbiologically large amount of l(+)-lactic acid (LA) from glucose, batch and fed-batch (intermittent addition of sterilized glucose powder aseptically) cultures of Rhizopus oryzae NBRC 5384 (identical to NRRL 395 and ATCC 9363) whose mycelia were immobilized in situ within sponge-like cubic particles (3.5 mm edge long) were carried out at 37°C in a three baffled shake flask. Appropriately calculated amount of fine powdery calcium carbonate (CaCO(3)) was added initially or intermittently to control pH of the culture liquids. High accumulations of LA (145 g/L and 231 g/L, in reality 176 g/L and 280 g/L as anhydrous calcium lactate) were achieved by a batch (glucose concentration = 150 g/L) and a fed-batch cultures (the initial glucose concentration = 150 g/L and the intermittent addition of glucose equivalent to 100 g/L). In these cultures the yields and productivities of LA were, 95.0%, 1.42 g/L·h and 92.5%, 1.83 g/L·h, respectively. Existence of considerable amounts of calcium lactate (Ca(LA)(2)) as crystals in the culture broth was experimentally proved by two evidences: (i) heating up (70°C) followed by quick low centrifugal force to remove remaining CaCO(3) solids from culture broth and then cooling down (37°C) followed by incubation of the culture supernatant at 37°C to observe recrystallization of Ca(LA)(2), and (ii) the measurement of solubility of Ca(LA)(2) in the culture media. It was conceptually discussed to be able to avoid the product inhibition by means of crystallization fermentation for the high accumulation of LA by R. oryzae.

  3. Acute systemic accumulation of acrolein in mice by inhalation at a concentration similar to that in cigarette smoke

    PubMed Central

    Tully, Melissa; Zheng, Lingxing; Acosta, Glen; Tian, Ran; Shi, Riyi

    2015-01-01

    Cigarette smoke is an important environmental factor associated with a wide array of public health concerns. Acrolein, a component of tobacco smoke and a known toxin to various cell types, may be a key pathological factor mediating the adverse effects linked with tobacco smoke. Although acrolein is known to accumulate in the respiratory system after acute nasal exposure, it is not clear if it accumulates systemically, and less is known in the nervous system. The aim of this study was to assess the degree of acrolein accumulation in the circulation and in the spinal cord following acute acrolein inhalation in mice. Using a laboratory-fabricated inhalation chamber, we found elevated urinary 3-HPMA, an acrolein metabolite, and increased acrolein adducts in the spinal cord after weeks of nasal exposure to acrolein at a concentration similar to that in tobacco smoke. The data indicated that acrolein is absorbed into the circulatory system and some enters the nervous system. It is expected that these findings may facilitate further studies to probe the pathological role of acrolein in the nervous system resulting from smoke and other external sources. PMID:25446876

  4. Lithium Accumulates in Neurogenic Brain Regions as Revealed by High Resolution Ion Imaging

    PubMed Central

    Zanni, Giulia; Michno, Wojciech; Di Martino, Elena; Tjärnlund-Wolf, Anna; Pettersson, Jean; Mason, Charlotte Elizabeth; Hellspong, Gustaf; Blomgren, Klas; Hanrieder, Jörg

    2017-01-01

    Lithium (Li) is a potent mood stabilizer and displays neuroprotective and neurogenic properties. Despite extensive investigations, the mechanisms of action have not been fully elucidated, especially in the juvenile, developing brain. Here we characterized lithium distribution in the juvenile mouse brain during 28 days of continuous treatment that result in clinically relevant serum concentrations. By using Time-of-Flight Secondary Ion Mass Spectrometry- (ToF-SIMS) based imaging we were able to delineate temporospatial lithium profile throughout the brain and concurrent distribution of endogenous lipids with high chemical specificity and spatial resolution. We found that Li accumulated in neurogenic regions and investigated the effects on hippocampal neurogenesis. Lithium increased proliferation, as judged by Ki67-immunoreactivity, but did not alter the number of doublecortin-positive neuroblasts at the end of the treatment period. Moreover, ToF-SIMS revealed a steady depletion of sphingomyelin in white matter regions during 28d Li-treatment, particularly in the olfactory bulb. In contrast, cortical levels of cholesterol and choline increased over time in Li-treated mice. This is the first study describing ToF-SIMS imaging for probing the brain-wide accumulation of supplemented Li in situ. The findings demonstrate that this technique is a powerful approach for investigating the distribution and effects of neuroprotective agents in the brain. PMID:28098178

  5. Lithium Accumulates in Neurogenic Brain Regions as Revealed by High Resolution Ion Imaging.

    PubMed

    Zanni, Giulia; Michno, Wojciech; Di Martino, Elena; Tjärnlund-Wolf, Anna; Pettersson, Jean; Mason, Charlotte Elizabeth; Hellspong, Gustaf; Blomgren, Klas; Hanrieder, Jörg

    2017-01-18

    Lithium (Li) is a potent mood stabilizer and displays neuroprotective and neurogenic properties. Despite extensive investigations, the mechanisms of action have not been fully elucidated, especially in the juvenile, developing brain. Here we characterized lithium distribution in the juvenile mouse brain during 28 days of continuous treatment that result in clinically relevant serum concentrations. By using Time-of-Flight Secondary Ion Mass Spectrometry- (ToF-SIMS) based imaging we were able to delineate temporospatial lithium profile throughout the brain and concurrent distribution of endogenous lipids with high chemical specificity and spatial resolution. We found that Li accumulated in neurogenic regions and investigated the effects on hippocampal neurogenesis. Lithium increased proliferation, as judged by Ki67-immunoreactivity, but did not alter the number of doublecortin-positive neuroblasts at the end of the treatment period. Moreover, ToF-SIMS revealed a steady depletion of sphingomyelin in white matter regions during 28d Li-treatment, particularly in the olfactory bulb. In contrast, cortical levels of cholesterol and choline increased over time in Li-treated mice. This is the first study describing ToF-SIMS imaging for probing the brain-wide accumulation of supplemented Li in situ. The findings demonstrate that this technique is a powerful approach for investigating the distribution and effects of neuroprotective agents in the brain.

  6. Copepods in turbid shallow soda lakes accumulate unexpected high levels of carotenoids.

    PubMed

    Schneider, Tobias; Herzig, Alois; Koinig, Karin A; Sommaruga, Ruben

    2012-01-01

    Carotenoids are protective pigments present in many aquatic organisms that reduce the photooxidative stress induced by short-wavelenght solar radiation, yet increase their susceptibility to predators. Arctodiaptomus spinosus, a calanoid copepod typically found in many fishless shallow soda lakes, shows large between-lake differences in pigmentation. Here, we attribute these differences to the environmental state of these ecosystems, namely, 'dark water' lakes with submersed vegetation and turbid 'white' lakes lacking macrophytes. Copepod carotenoid concentration in the turbid 'white' lakes was significantly (about 20-fold) higher than in the 'dark water' ones, although the latter systems were characterized by higher transparency. In addition, males had on a dry weight basis around three times higher carotenoid concentrations than females. Mycosporine-like amino acids (direct UV screening substances) were found in all cases, but in low concentration. The environmental conditions in these ecosystems were largely shaped by the presence/absence of submersed macrophytes Thus, in the turbid lakes, the strong wind-driven mixis allows for copepods to be brought to the surface and being exposed to solar radiation, whereas in 'dark water' ones, macrophytes reduce water turbulence and additionally provide shelter. Our results explain the counter-intuitive notion of strong red pigmentation in copepods from a turbid ecosystem and suggest that factors other than high UV transparency favor carotenoid accumulation in zooplankton.

  7. Copepods in Turbid Shallow Soda Lakes Accumulate Unexpected High Levels of Carotenoids

    PubMed Central

    Schneider, Tobias; Herzig, Alois; Koinig, Karin A.; Sommaruga, Ruben

    2012-01-01

    Carotenoids are protective pigments present in many aquatic organisms that reduce the photooxidative stress induced by short-wavelenght solar radiation, yet increase their susceptibility to predators. Arctodiaptomus spinosus, a calanoid copepod typically found in many fishless shallow soda lakes, shows large between-lake differences in pigmentation. Here, we attribute these differences to the environmental state of these ecosystems, namely, ‘dark water’ lakes with submersed vegetation and turbid ‘white’ lakes lacking macrophytes. Copepod carotenoid concentration in the turbid ‘white’ lakes was significantly (about 20-fold) higher than in the ‘dark water’ ones, although the latter systems were characterized by higher transparency. In addition, males had on a dry weight basis around three times higher carotenoid concentrations than females. Mycosporine-like amino acids (direct UV screening substances) were found in all cases, but in low concentration. The environmental conditions in these ecosystems were largely shaped by the presence/absence of submersed macrophytes Thus, in the turbid lakes, the strong wind-driven mixis allows for copepods to be brought to the surface and being exposed to solar radiation, whereas in ‘dark water’ ones, macrophytes reduce water turbulence and additionally provide shelter. Our results explain the counter-intuitive notion of strong red pigmentation in copepods from a turbid ecosystem and suggest that factors other than high UV transparency favor carotenoid accumulation in zooplankton. PMID:22916208

  8. High accumulation of soluble sugars in deep supercooling Japanese white birch xylem parenchyma cells.

    PubMed

    Kasuga, Jun; Arakawa, Keita; Fujikawa, Seizo

    2007-01-01

    Seasonal changes in the accumulation of soluble sugars in extracellular freezing cortical parenchyma cells and deep supercooling xylem parenchyma cells in Japanese white birch (Betula platyphylla var. japonica) were compared to identify the effects of soluble sugars on the mechanism of deep supercooling, which keeps the liquid state of water in cells under extremely low temperatures for long periods. Soluble sugars in both tissues were analyzed by high-performance liquid chromatography (HPLC), and the concentrations of sugars in cells were estimated by histological observation of occupancy rates of parenchyma cells in each tissue. Relative and equilibrium melting points of parenchyma cells were measured by differential thermal analysis and cryoscanning electron microscopy, respectively. In both xylem and cortical parenchyma cells, amounts of sucrose, raffinose and stachyose increased in winter, but amounts of fructose and glucose exhibited little change throughout the entire year. In addition, no sugars were found to be specific for either tissue. Combined results of HPLC analyses, histological observation and melting point analyses confirmed that the concentration of sugars was much higher in xylem cells than in cortical cells. It is thought that the higher concentration of soluble sugars in xylem cells may contribute to facilitation of deep supercooling in xylem cells by depressing the nucleation temperature.

  9. Mineral accumulation by perennial grasses in a high rainfall environment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Straw produced as a co-product of perennial ryegrass (Lolium perenne L.), orchardgrass (Dactylis glomerata), tall fescue (Schedonorus phoenix (Scop.) Holub), and Kentucky bluegrass (Poa pratensis L.) seed production in the high rainfall area of western Oregon as well as clippings from urban and recr...

  10. Effects of elevated CO2 concentrations and fly ash amended soils on trace element accumulation and translocation among roots, stems and seeds of Glycine max (L.) Merr.

    PubMed

    Rodriguez, J H; Klumpp, A; Fangmeier, A; Pignata, M L

    2011-03-15

    The carbon dioxide (CO(2)) levels of the global atmosphere and the emissions of heavy metals have risen in recent decades, and these increases are expected to produce an impact on crops and thereby affect yield and food safety. In this study, the effects of elevated CO(2) and fly ash amended soils on trace element accumulation and translocation in the root, stem and seed compartments in soybean [Glycine max (L.) Merr.] were evaluated. Soybean plants grown in fly ash (FA) amended soil (0, 1, 10, 15, and 25% FA) at two CO(2) regimes (400 and 600 ppm) in controlled environmental chambers were analyzed at the maturity stage for their trace element contents. The concentrations of Br, Co, Cu, Fe, Mn, Ni, Pb and Zn in roots, stems and seeds in soybeans were investigated and their potential risk to the health of consumers was estimated. The results showed that high levels of CO(2) and lower concentrations of FA in soils were associated with an increase in biomass. For all the elements analyzed except Pb, their accumulation in soybean plants was higher at elevated CO(2) than at ambient concentrations. In most treatments, the highest concentrations of Br, Co, Cu, Fe, Mn, and Pb were found in the roots, with a strong combined effect of elevated CO(2) and 1% of FA amended soils on Pb accumulation (above maximum permitted levels) and translocation to seeds being observed. In relation to non-carcinogenic risks, target hazard quotients (TQHs) were significant in a Chinese individual for Mn, Fe and Pb. Also, the increased health risk due to the added effects of the trace elements studied was significant for Chinese consumers. According to these results, soybean plants grown for human consumption under future conditions of elevated CO(2) and FA amended soils may represent a toxicological hazard. Therefore, more research should be carried out with respect to food consumption (plants and animals) under these conditions and their consequences for human health.

  11. Molecular basis of high viscosity in concentrated antibody solutions: Strategies for high concentration drug product development

    PubMed Central

    Tomar, Dheeraj S.; Kumar, Sandeep; Singh, Satish K.; Goswami, Sumit; Li, Li

    2016-01-01

    ABSTRACT Effective translation of breakthrough discoveries into innovative products in the clinic requires proactive mitigation or elimination of several drug development challenges. These challenges can vary depending upon the type of drug molecule. In the case of therapeutic antibody candidates, a commonly encountered challenge is high viscosity of the concentrated antibody solutions. Concentration-dependent viscosity behaviors of mAbs and other biologic entities may depend on pairwise and higher-order intermolecular interactions, non-native aggregation, and concentration-dependent fluctuations of various antibody regions. This article reviews our current understanding of molecular origins of viscosity behaviors of antibody solutions. We discuss general strategies and guidelines to select low viscosity candidates or optimize lead candidates for lower viscosity at early drug discovery stages. Moreover, strategies for formulation optimization and excipient design are also presented for candidates already in advanced product development stages. Potential future directions for research in this field are also explored. PMID:26736022

  12. Molecular basis of high viscosity in concentrated antibody solutions: Strategies for high concentration drug product development.

    PubMed

    Tomar, Dheeraj S; Kumar, Sandeep; Singh, Satish K; Goswami, Sumit; Li, Li

    2016-01-01

    Effective translation of breakthrough discoveries into innovative products in the clinic requires proactive mitigation or elimination of several drug development challenges. These challenges can vary depending upon the type of drug molecule. In the case of therapeutic antibody candidates, a commonly encountered challenge is high viscosity of the concentrated antibody solutions. Concentration-dependent viscosity behaviors of mAbs and other biologic entities may depend on pairwise and higher-order intermolecular interactions, non-native aggregation, and concentration-dependent fluctuations of various antibody regions. This article reviews our current understanding of molecular origins of viscosity behaviors of antibody solutions. We discuss general strategies and guidelines to select low viscosity candidates or optimize lead candidates for lower viscosity at early drug discovery stages. Moreover, strategies for formulation optimization and excipient design are also presented for candidates already in advanced product development stages. Potential future directions for research in this field are also explored.

  13. Biological denitrification of high concentration nitrate waste

    DOEpatents

    Francis, Chester W.; Brinkley, Frank S.

    1977-01-01

    Biological denitrification of nitrate solutions at concentrations of greater than one kilogram nitrate per cubic meter is accomplished anaerobically in an upflow column having as a packing material a support for denitrifying bacteria.

  14. Cadmium tolerance and accumulation in cultivars of a high-biomass tropical tree (Averrhoa carambola) and its potential for phytoextraction.

    PubMed

    Li, J T; Liao, B; Lan, C Y; Ye, Z H; Baker, A J M; Shu, W S

    2010-01-01

    Averrhoa carambola is a high-biomass tropical tree that has been identified as a Cd accumulator. In the present study, field survey, pot, and hydroponic experiments were conducted to investigate the variation of Cd tolerance and accumulation in cultivars of A. carambola as well as its potential for phytoextraction. In the field survey, it was found that concentrations of Cd in aerial tissues of A. carambola varied greatly among sites and cultivars. The Cd bioconcentration factors (BCFs) and Cd removals by the field-grown A. carambola differed significantly among sites but not among cultivars. Nonetheless, all four carambola cultivars investigated were able to accumulate considerably high concentrations of Cd in their shoots, which indicated that the 4-yr-old carambola stands could remove 0.3 to 51.8% of the total Cd content in the top 20-cm soil layer. When cultured in Cd-spiked soils, the carambola cultivar Hua-Di always showed higher Cd tolerance than the other cultivars; however, this tendency was not confirmed by hydroponic experiment. The Cd BCFs of cultivar Thailand grown in soils with 6 and 12 mg Cd kg(-1) were highest among cultivars, whereas this trend was reversed at 120 mg Cd kg(-1) treatment. Nevertheless, the pot- and hydroponics-grown carambola cultivars generally showed higher capacities to tolerate and accumulate Cd, compared with the control species. The present results indicate that a strong ability to tolerate and accumulate Cd seems to be a trait at the species level in A. carambola, although some degree of variances in both Cd tolerance and accumulation exists among cultivars.

  15. Horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications.

    PubMed

    Ma, Hongcai; Wu, Lin

    2015-07-10

    We present the design of a horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications. This solar concentrator consists of an array of telecentric primary concentrators, a horizontally staggered lightguide layer, and a vertically tapered lightguide layer. The primary concentrator is realized by two plano-aspheric lenses with lateral movement and maintains a high F-number over an angle range of ±23.5°. The results of the simulations show that the solar concentrator achieves a high concentration ratio of 500× with ±0.5° of acceptance angle by a single-axis tracker and dual lateral translation stages.

  16. Unexpectedly high mercury concentration in commercial fish feed

    SciTech Connect

    Choi, H.; Cech, J. Jr.

    1995-12-31

    Unexpectedly high mercury was found in a commercial fish pellet which has been widely used to feed fish in laboratory and fish farm settings. Researchers working with fish in mercury studies need to know that fish pellets contain mercury and consider the pellets, influence in their results. Mean mercury concentration in the commercial fish pellet was 47.4 ug/g (ranging from 35 to 56 ug Hg/g). Total mercury (T-Hg) in the blood of Sacramento blackfish (orthodon microlepidotus), fed the commercial feed for 8 months, was determined by inductively coupled plasma-mass spectrometry (ICP-MS). Mean blood T-Hg reached a steady state at 41 ug Hg/L (ranging from 34 to 51 ug Hg/L) during 5 months of feeding after capture from Clear Lake in California. The accumulation of mercury in blood followed a monoexponential pattern, in accordance with a one-compartment model. There were great variations in mercury levels in blood between individual fishes. The mercury concentrations in the blood did not tend to increase with the growth of the fish. In summary, feed sources of mercury need to be considered in mercury exposure experiments.

  17. Haematological and biochemical parameters and tissue accumulations of cadmium in Oreochromis niloticus exposed to various concentrations of cadmium chloride.

    PubMed

    Al-Asgah, Nasser A; Abdel-Warith, Abdel-Wahab A; Younis, El-Sayed M; Allam, Hassan Y

    2015-09-01

    Oreochromis niloticus, weighing 36.45 ± 1.12 g were exposed to 10%, 20% and 30% of the LC50 of CdCl2 which represents treatments (T1)1.68, (T2)3.36 and (T3)5.03 mg/l, respectively, for a period of 10, 20 and 30 days. It was found that, compared to a control group reading of 0.19 ± 0.03 μg/g dry weight, accumulation of Cd in the gills was significantly (p < 0.05) increased in samples ranging between 7.64 ± 0.86 and 61.73 ± 0.82 μg/g dry weight from T1 at 10 days to T3 at 30 days. The accumulation of Cd in the liver, meanwhile, was also observed to significantly increase (p < 0.05) with increasing time and concentrations with results ranging between 3.21 ± 0.12 and 181.61 ± 1.32 compared to the control group results of 0.29 ± 0.04 μg/g dry weight. Although muscles exhibited lower levels of accumulation than the gills and liver they still showed the same pattern of increase compared to the control group, with a significant difference ranging between 0.32 ± 0.02 and 2.16 ± 0.08 compared to the control group results of 0.03 ± 0.001 μg/g dry weight. Also, haematological parameters such as red blood cells (RBCs), haemoglobin (Hb) and haematocrit (Hct) were reduced in fish exposed to Cd at all periods, with significant differences (p < 0.05). Plasma glucose concentration showed a significant increase. Total protein levels of fish showed a significant reduction (p > 0.05) for all exposed treatments. Also, the total lipid level increased significantly as fish were exposed to increasing cadmium concentrations, compared to control fish. Finally, the activities of aspartate aminotransferase (AST IU/l) and alanine aminotransferase (ALT IU/l) showed a significant increase (p < 0.05) with increasing time and concentrations.

  18. Haematological and biochemical parameters and tissue accumulations of cadmium in Oreochromis niloticus exposed to various concentrations of cadmium chloride

    PubMed Central

    Al-Asgah, Nasser A.; Abdel-Warith, Abdel-Wahab A.; Younis, El-Sayed M.; Allam, Hassan Y.

    2015-01-01

    Oreochromis niloticus, weighing 36.45 ± 1.12 g were exposed to 10%, 20% and 30% of the LC50 of CdCl2 which represents treatments (T1)1.68, (T2)3.36 and (T3)5.03 mg/l, respectively, for a period of 10, 20 and 30 days. It was found that, compared to a control group reading of 0.19 ± 0.03 μg/g dry weight, accumulation of Cd in the gills was significantly (p < 0.05) increased in samples ranging between 7.64 ± 0.86 and 61.73 ± 0.82 μg/g dry weight from T1 at 10 days to T3 at 30 days. The accumulation of Cd in the liver, meanwhile, was also observed to significantly increase (p < 0.05) with increasing time and concentrations with results ranging between 3.21 ± 0.12 and 181.61 ± 1.32 compared to the control group results of 0.29 ± 0.04 μg/g dry weight. Although muscles exhibited lower levels of accumulation than the gills and liver they still showed the same pattern of increase compared to the control group, with a significant difference ranging between 0.32 ± 0.02 and 2.16 ± 0.08 compared to the control group results of 0.03 ± 0.001 μg/g dry weight. Also, haematological parameters such as red blood cells (RBCs), haemoglobin (Hb) and haematocrit (Hct) were reduced in fish exposed to Cd at all periods, with significant differences (p < 0.05). Plasma glucose concentration showed a significant increase. Total protein levels of fish showed a significant reduction (p > 0.05) for all exposed treatments. Also, the total lipid level increased significantly as fish were exposed to increasing cadmium concentrations, compared to control fish. Finally, the activities of aspartate aminotransferase (AST IU/l) and alanine aminotransferase (ALT IU/l) showed a significant increase (p < 0.05) with increasing time and concentrations. PMID:26288556

  19. HIGH INTENSITY EFFECTS IN THE SNS ACCUMULATOR RING

    SciTech Connect

    Holmes, Jeffrey A; Cousineau, Sarah M; Danilov, Viatcheslav; Plum, Michael A; Shishlo, Andrei P

    2008-01-01

    Currently operating at 0.5 MW beam power on target, the Spallation Neutron Source (SNS) is already the world's most powerful pulsed neutron source. However, we are only one third of the way to full power. As we ramp toward full power, the control of the beam and beam loss in the ring will be critical. In addition to practical considerations, such as choice of operating point, painting scheme, RF bunching, and beam scattering, it may be necessary to understand and mitigate collective effects due to space charge, impedances, and electron clouds. At each stage of the power ramp-up, we use all available resources to understand and to minimize beam losses. From the standpoint of beam dynamics, the losses observed so far under normal operating conditions have not involved collective phenomena. We are now entering the intensity regime in which this may change. In dedicated high intensity beam studies, we have already observed resistive wall, extraction kicker impedance-driven, and electron cloud activities. The analysis and simulation of this data are important ongoing activities at SNS. This paper discusses the status of this work, as well as other considerations necessary to the successful full power operation of SNS.

  20. Elevated rates of organic carbon, nitrogen, and phosphorus accumulation in a highly impacted mangrove wetland

    NASA Astrophysics Data System (ADS)

    Sanders, Christian J.; Eyre, Bradley D.; Santos, Isaac R.; Machado, Wilson; Luiz-Silva, Wanilson; Smoak, Joseph M.; Breithaupt, Joshua L.; Ketterer, Michael E.; Sanders, Luciana; Marotta, Humberto; Silva-Filho, Emmanoel

    2014-04-01

    The effect of nutrient enrichment on mangrove sediment accretion and carbon accumulation rates is poorly understood. Here we quantify sediment accretion through radionuclide tracers to determine organic carbon (OC), total nitrogen (TN), and total phosphorus (TP) accumulation rates during the previous 60 years in both a nutrient-enriched and a pristine mangrove forest within the same geomorphological region of southeastern Brazil. The forest receiving high nutrient loads has accumulated OC, TN, and TP at rates that are fourfold, twofold, and eightfold respectively, higher than those from the undisturbed mangrove. Organic carbon and TN stable isotopes (δ13C and δ15N) reflect an increased presence of organic matter (OM) originating with either phytoplankton, benthic algae, or another allochthonous source within the more rapidly accumulated sediments of the impacted mangrove. This suggests that the accumulation rate of OM in eutrophic mangrove systems may be enhanced through the addition of autochthonous and allochthonous nonmangrove material.

  1. Influence of exogenous CO₂ on biomass and lipid accumulation of microalgae Auxenochlorella protothecoides cultivated in concentrated municipal wastewater.

    PubMed

    Hu, Bing; Min, Min; Zhou, Wenguang; Li, Yecong; Mohr, Michael; Cheng, Yanling; Lei, Hanwu; Liu, Yuhuan; Lin, Xiangyang; Chen, Paul; Ruan, Roger

    2012-04-01

    The effects of exogenous CO₂ on the growth and lipid accumulation of a local screened facultative heterotrophic microalgae strain Auxenochlorella protothecoides (UMN280) as well as nutrient removal from concentrated municipal wastewater stream (centrate) were examined in this study. A 12-day batch experiment was conducted with CO₂ aeration at three levels, namely, 0%, 1%, and 5% (v/v) CO₂ mixed with air, under light intensity of 60 μmol/(m² @@s). A two-stage growth pattern was observed. The first stage (first-fifth day) was dominated by heterotrophic growth in which organic carbon was the main carbon source. The second stage (6th-12th day) was dominated by autotrophic growth in which exogenous CO₂ had a positive effect on algal biomass accumulation. The addition of 5% CO₂ was better than that of 1% CO₂ on the biomass and lipid production. The uptakes of nutrients were similar between injection and no injection of CO₂, except on phosphorus removal which was affected by the acidification of CO₂.

  2. Cell wall targeted in planta iron accumulation enhances biomass conversion and seed iron concentration in Arabidopsis and rice.

    PubMed

    Yang, Haibing; Wei, Hui; Ma, Guojie; Antunes, Mauricio S; Vogt, Stefan; Cox, Joseph; Zhang, Xiao; Liu, Xiping; Bu, Lintao; Gleber, S Charlotte; Carpita, Nicholas C; Makowski, Lee; Himmel, Michael E; Tucker, Melvin P; McCann, Maureen C; Murphy, Angus S; Peer, Wendy A

    2016-10-01

    Conversion of nongrain biomass into liquid fuel is a sustainable approach to energy demands as global population increases. Previously, we showed that iron can act as a catalyst to enhance the degradation of lignocellulosic biomass for biofuel production. However, direct addition of iron catalysts to biomass pretreatment is diffusion-limited, would increase the cost and complexity of biorefinery unit operations and may have deleterious environmental impacts. Here, we show a new strategy for in planta accumulation of iron throughout the volume of the cell wall where iron acts as a catalyst in the deconstruction of lignocellulosic biomass. We engineered CBM-IBP fusion polypeptides composed of a carbohydrate-binding module family 11 (CBM11) and an iron-binding peptide (IBP) for secretion into Arabidopsis and rice cell walls. CBM-IBP transformed Arabidopsis and rice plants show significant increases in iron accumulation and biomass conversion compared to respective controls. Further, CBM-IBP rice shows a 35% increase in seed iron concentration and a 40% increase in seed yield in greenhouse experiments. CBM-IBP rice potentially could be used to address iron deficiency, the most common and widespread nutritional disorder according to the World Health Organization.

  3. 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.

  4. The lead accumulation and hematological findings in juvenile rock fish Sebastes schlegelii exposed to the dietary lead (II) concentrations.

    PubMed

    Kim, Jun-Hwan; Kang, Ju-Chan

    2015-05-01

    Juvenile rockfish (mean length 14.2 ± 1.9 cm, and mean weight 57.3 ± 5.2g) were exposed for 4 weeks with the different levels of dietary lead (Pb(2+)) at 0, 30, 60, 120 and 240 mg/L. The exposure concentration and period of Pb have induced significant amount of it the specific tissues of rockfish. The highest Pb accumulation was observed in the kidney tissue by the dietary lead exposure. The growth rate and hepatosomatic index were considerably inhibited over 120 mg/kg. The hematological parameters such as red blood cell (RBC) counts, hematocrit (Ht) value, and hemoglobin (Hb) concentration were significantly decreased over 60 mg/kg Pb concentration. In the inorganic components, the values of calcium and magnesium in plasma were significantly decreased. The glucose and cholesterol values were notably increased, whereas total protein was decreased. The enzyme components, glutamic oxalate transaminase (GOT) and glutamic pyruvate transaminase (GPT), were significantly elevated by the dietary lead exposure, but no change was observed in alkaline phosphatase (ALP).

  5. High cadmium accumulation among humans and primates: comparison across various mammalian species--a study from Japan.

    PubMed

    Koizumi, Naoru; Murata, Koichi; Hayashi, Chiyo; Nishio, Hisahide; Goji, Junko

    2008-03-01

    The majority of existing literature reports that cadmium (Cd) is toxic to humans and most living organisms. This paper reports the results of our study that measured Cd levels in the livers and kidneys of humans and other 50 mammalian species under normal conditions in Japan. The study tests the differences in the Cd concentrations across different mammalian species and sexes. Our results revealed that (1) there is a strong correlation between the Cd levels in the livers and kidneys across all examined species, (2) humans exhibit the highest Cd accumulation level in both organs, (3) primates also show a high Cd concentration at a level close to humans, (4) mice and rats show low Cd levels in both organs, indicating that humans accumulate about a few thousand times more Cd than mice and rats, and (5) the Cd concentration of female mammals is more than double of males for both organs. Our results indicate that these cross-sex as well as cross-species discrepancies cannot be explained by the difference in daily Cd intake. While further research is necessary to determine any potential role of Cd accumulation, we speculate that Cd plays some physiological function in the renal cortex of humans and primates.

  6. Comparative proteome analysis of high and low cadmium accumulating soybeans under cadmium stress.

    PubMed

    Hossain, Zahed; Hajika, Makita; Komatsu, Setsuko

    2012-12-01

    A comparative proteomic study was performed to unravel the protein networks involved in cadmium stress response in soybean. Ten-day-old seedlings of contrasting cadmium accumulating soybean cultivars-Harosoy (high cadmium accumulator), Fukuyutaka (low cadmium accumulator), and their recombinant inbred line CDH-80 (high cadmium accumulator) were exposed to 100 μM CdCl(2) treatment for 3 days. Root growth was found to be affected under cadmium stress in all. Varietal differences at root protein level were evaluated. NADP-dependent alkenal double bond reductase P1 was found to be more abundant in low cadmium accumulating Fukuyutaka. Leaf proteome analysis revealed that differentially expressed proteins were primarily involved in metabolism and energy production. The results indicate that both high and low cadmium accumulating cultivars and CDH-80 share some common defense strategies to cope with the cadmium stress. High abundance of enzymes involved in glycolysis and TCA cycle might help cadmium challenged cells to produce more energy necessary to meet the high energy demand. Moreover, enhanced expressions of photosynthesis related proteins indicate quick utilization of photoassimilates in energy generation. Increased abundance of glutamine synthetase in all might be involved in phytochelatin mediated detoxification of cadmium ions. In addition, increased abundance of antioxidant enzymes, namely superoxide dismutase, ascorbate peroxidase, catalase, ensures cellular protection from reactive oxygen species mediated damages under cadmium stress. Enhanced expression of molecular chaperones in high cadmium accumulating cultivar might be another additional defense mechanism for refolding of misfolded proteins and to stabilize protein structure and function, thus maintain cellular homeostasis.

  7. Concentration-dependent effects and intracellular accumulation of HIV protease inhibitors in cultured CD4 T cells and primary human lymphocytes

    PubMed Central

    Janneh, Omar; Bray, Patrick G.; Jones, Elizabeth; Wyen, Christoph; Chiba, Peter; Back, David J.; Khoo, Saye H.

    2010-01-01

    Background The intracellular and plasma concentrations of HIV protease inhibitors (HPIs) vary widely in vivo. It is unclear whether there is a concentration-dependent effect of HPIs such that at increasing concentration they may either block their own efflux (leading to ‘autoboosting’) or influx (leading to saturability/decreased intracellular accumulation). Method The effects of various concentrations (0–30 µM) of lopinavir, saquinavir, ritonavir and atazanavir on the accumulation of [14C]lopinavir, [3H]saquinavir, [3H]ritonavir and [3H]atazanavir, respectively, were investigated in CEMparental, CEMVBL [P-glycoprotein (ABCB1) overexpressing], CEME1000 (MRP1 overexpressing) and in peripheral blood mononuclear cells (PBMCs). We also investigated the effects of inhibitors of ABCB1/ABCG2 (tariquidar), ABCC (MK571) and ABCC1/2 (frusemide), singly and in combination with HPIs, on cellular accumulation. Results In all the cell lines, with increasing concentration of lopinavir, saquinavir and ritonavir, there was a significant increase in the cellular accumulation of [14C]lopinavir, [3H]saquinavir and [3H]ritonavir. Tariquidar, MK571 and frusemide (alone and in combination with lopinavir, saquinavir and ritonavir) significantly increased the accumulation of [14C]lopinavir, [3H]saquinavir and [3H]ritonavir. Ritonavir (alone or in combination with tariquidar) decreased the intracellular accumulation of [3H]ritonavir in PBMCs. Atazanavir decreased the accumulation of [3H]atazanavir in a concentration-dependent manner in all of the cells tested. Conclusions There are complex and variable drug-specific rather than class-specific effects of the HPIs on their own accumulation. PMID:20237075

  8. [Concentrations of mercury in ambient air in wastewater irrigated area of Tianjin City and its accumulation in leafy vegetables].

    PubMed

    Zheng, Shun-An; Han, Yun-Lei; Zheng, Xiang-Qun

    2014-11-01

    limit of mercury in food. Spinach appeared to accumulate more mercury than the other four vegetables, in which the median and mean mercury content were both higher than 20 μg x kg(-1). The mercury concentrations in rape, lettuce and allium tuberosum were lower than the standard. Moreover, test results indicated that the Hg content in leafy vegetables was mainly the gaseous mercury through leaf adsorption but not the Hg particulates. This study clearly manifested that there should be a great concern on the pollution risk of both air-and soil borne mercury when cultivating leafy vegetables in long-term wastewater-irrigated area.

  9. Culturable associated-bacteria of the sponge Theonella swinhoei show tolerance to high arsenic concentrations

    PubMed Central

    Keren, Ray; Lavy, Adi; Mayzel, Boaz; Ilan, Micha

    2015-01-01

    Sponges are potent filter feeders and as such are exposed to high fluxes of toxic trace elements, which can accumulate in their body over time. Such is the case of the Red Sea sponge Theonella swinhoei, which has been shown to accumulate up to 8500 mg/Kg of the highly toxicelement arsenic. T. swinhoei is known to harbor a multitude of sponge-associated bacteria, so it is hypothesized that the associated-bacteria will be tolerant to high arsenic concentration. This study also investigates the fate of the arsenic accumulated in the sponge to test if the associated-bacteria have an important role in the arsenic accumulation process of their host, since bacteria are key players in the natural arsenic cycle. Separation of the sponge to sponge cells and bacteria enriched fractions showed that arsenic is accumulated by the bacteria. Sponge-associated, arsenic-tolerant bacteria were cultured in the presence of 5 mM of either arsenate or arsenite (equivalent to 6150 mg/Kg arsenic, dry weight). The 54 isolated bacteria were grouped to 15 operational taxonomic units (OTUs) and isolates belonging to 12 OTUs were assessed for tolerance to arsenate at increased concentrations up to 100 mM. Eight of the 12 OTUs tolerated an order of magnitude increase in the concentration of arsenate, and some exhibited external biomineralization of arsenic–magnesium salts. The biomineralization of this unique mineral was directly observed in bacteria for the first time. These results may provide an explanation for the ability of the sponge to accumulate considerable amounts of arsenic. Furthermore arsenic-mineralizing bacteria can potentially be used for the study of bioremediation, as arsenic toxicity affects millions of people worldwide. PMID:25762993

  10. Influences of different stress media and high light intensities on accumulation of astaxanthin in the green alga Haematococcus pluvialis.

    PubMed

    Imamoglu, Esra; Dalay, Meltem Conk; Sukan, Fazilet Vardar

    2009-10-31

    Haematococcus pluvialis Flotow is used in the aquaculture, pharmaceutical and cosmetic industries. The aim of this study was to compare the effect of various stress media and high light intensities on astaxanthin accumulation. The experimental design was achieved by four different stress media and two different light intensities for 14 days of induction period. The astaxanthin concentrations of 29.62 mg g(-1) and 30.07 mg g(-1) were obtained in distilled water with CO(2) and N-free medium, respectively, with no significant difference between them at 546 micromol photons m(-2)s(-1). Because of the morphological changes of H. pluvialis, microscopic observation was considered during the induction period to facilitate the selection of stress medium. It was clear that the rate of astaxanthin accumulation was much faster in distilled water with the addition of CO(2). The main point is that, this medium is more economical than others, especially for the large-scale productions.

  11. Accumulation of heavy metals in the fish, Oreochromis niloticus and Poecilia latipinna and their concentration in water and sediment of dam lake of Wadi Namar, Saudi Arabia.

    PubMed

    Ahmad, Zubair; Al-Ghanim, Khalid A; Al-Balawi, Hmoud F Al-Kahem; Al-Misned, Fahad; Maboob, Shahid; Suliman, El-Amin M

    2015-01-01

    The present study reports the accumulation of heavy metals like Cu, Hg, Cd, Pb and Cr in different tissues viz. liver, kidney, gills and muscles of Oreochromisniloticus and Poecilia latipinna from two sites in dam lake of Wadi Namar. Water and sediment samples were also collected from two sites for heavy metal analysis. Metal concentration in water and sediment samples of both the sites were observed in the following order: Cu>Cr>Pb>Cd>Hg; however, their concentration was found to be more at site 2 as compared to site 1. The order of metal accumulation in different tissues of O. niloticus and P. latipinna was in the following order: Cu>Cr>Pb>Cd>Hg at both the sites, while liver accumulated maximum amounts of metals followed by kidney, gills and muscles. The results showed the site 2 was more polluted by metals than Site 1 and O. niloticus accumulated greater amount of metals than P. latipinna.

  12. The importance of biological factors affecting trace metal concentration as revealed from accumulation patterns in co-occurring terrestrial invertebrates.

    PubMed

    Hendrickx, Frederik; Maelfait, Jean-Pierre; Bogaert, Nicolas; Tojal, Catarina; Du Laing, Gijs; Tack, Filip M G; Verloo, Marc G

    2004-01-01

    As physicochemical properties of the soil highly influence the bioavailable fraction of a particular trace metal, measured metal body burdens in a particular species are often assumed to be more reliable estimators of the contamination of the biota. To test this we compared the Cd, Cu and Zn content of three spiders (generalist predators) and two amphipods (detritivores), co-occurring in seven tidal marshes along the river Schelde, between each other and with the total metal concentrations and the concentrations of four sequential extractions of the soils. Correlations were significant in only one case and significant site x species interactions for all metals demonstrate that factors affecting metal concentration were species and site specific and not solely determined by site specific characteristics. These results emphasize that site and species specific biological factors might be of the utmost importance in determining the contamination of the biota, at least for higher trophic levels. A hypothetical example clarifies these findings.

  13. Sugar loss and enzyme inhibition due to oligosaccharides accumulation during high solids-loading enzymatic hydrolysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oligosaccharide accumulation occurs during high solid loading enzymatic hydrolysis of corn stover (CS) irrespective of using different pretreated corn stover (dilute acid: DA, ionic liquids: IL, ammonia fiber expansion: AFEX and extractive ammonia: EA). The methodology for large-scale separation of ...

  14. Refractive Secondary Solar Concentrator Demonstrated High-Temperature Operation

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.

    2002-01-01

    Space applications that utilize solar thermal energy--such as electric power conversion systems, thermal propulsion systems, and furnaces--require highly efficient solar concentration systems. The NASA Glenn Research Center is developing the refractive secondary concentrator, which uses refraction and total internal reflection to efficiently concentrate and direct solar energy. When used in combination with advanced lightweight primary concentrators, such as inflatable thin films, the refractive secondary concentrator enables very high system concentration ratios and very high temperatures. Last year, Glenn successfully demonstrated a secondary concentrator throughput efficiency of 87 percent, with a projected efficiency of 93 percent using an antireflective coating. Building on this achievement, Glenn recently successfully demonstrated high-temperature operation of the secondary concentrator when it was used to heat a rhenium receiver to 2330 F. The high-temperature demonstration of the concentrator was conducted in Glenn's 68-ft long Tank 6 thermal vacuum facility equipped with a solar simulator. The facility has a rigid panel primary concentrator that was used to concentrate the light from the solar simulator onto the refractive secondary concentrator. NASA Marshall Space Flight Center provided a rhenium cavity, part of a solar thermal propulsion engine, to serve as the high-temperature receiver. The prototype refractive secondary concentrator, measuring 3.5 in. in diameter and 11.2 in. long, is made of single-crystal sapphire. A water-cooled splash shield absorbs spillage light outside of the 3.5-in. concentrator aperture. Multilayer foil insulation composed of tungsten, molybdenum, and niobium is used to minimize heat loss from the hightemperature receiver. A liquid-cooled canister calorimeter is used to measure the heat loss through the multilayer foil insulation.

  15. Pressure drop increase by biofilm accumulation in spiral wound RO and NF membrane systems: role of substrate concentration, flow velocity, substrate load and flow direction.

    PubMed

    Vrouwenvelder, J S; Hinrichs, C; Van der Meer, W G J; Van Loosdrecht, M C M; Kruithof, J C

    2009-01-01

    In an earlier study, it was shown that biofouling predominantly is a feed spacer channel problem. In this article, pressure drop development and biofilm accumulation in membrane fouling simulators have been studied without permeate production as a function of the process parameters substrate concentration, linear flow velocity, substrate load and flow direction. At the applied substrate concentration range, 100-400 microg l(-1) as acetate carbon, a higher concentration caused a faster and greater pressure drop increase and a greater accumulation of biomass. Within the range of linear flow velocities as applied in practice, a higher linear flow velocity resulted in a higher initial pressure drop in addition to a more rapid and greater pressure drop increase and biomass accumulation. Reduction of the linear flow velocity resulted in an instantaneous reduction of the pressure drop caused by the accumulated biomass, without changing the biofilm concentration. A higher substrate load (product of substrate concentration and flow velocity) was related to biomass accumulation. The effect of the same amount of accumulated biomass on the pressure drop increase was related to the linear flow velocity. A decrease of substrate load caused a gradual decline in time of both biomass concentration and pressure drop increase. It was concluded that the pressure drop increase over spiral wound reverse osmosis (RO) and nanofiltration (NF) membrane systems can be reduced by lowering both substrate load and linear flow velocity. There is a need for RO and NF systems with a low pressure drop increase irrespective of the biomass formation. Current efforts to control biofouling of spiral wound membranes focus in addition to pretreatment on membrane improvement. According to these authors, adaptation of the hydrodynamics, spacers and pressure vessel configuration offer promising alternatives. Additional approaches may be replacing heavily biofouled elements and flow direction reversal.

  16. Anaerobic granule-based biofilms formation reduces propionate accumulation under high H2 partial pressure using conductive carbon felt particles.

    PubMed

    Xu, Heng; Wang, Cuiping; Yan, Kun; Wu, Jing; Zuo, Jiane; Wang, Kaijun

    2016-09-01

    Syngas based co-digestion is not only more economically attractive than separate syngas methanation but also able to upgrade biogas and increase overall CH4 amount simultaneously. However, high H2 concentration in the syngas could inhibit syntrophic degradation of propionate, resulting in propionate accumulation and even failure of the co-digestion system. In an attempt to reduce propionate accumulation via enhancing both H2 interspecies transfer (HIT) and direct interspecies electron transfer (DIET) pathways, layered granule-based biofilms induced by conductive carbon felt particles (CCFP) was employed. The results showed that propionate accumulation was effectively reduced with influent COD load up to 7gL(-1)d(-1). Two types of granule-based biofilms, namely biofilm adhered to CCFP (B-CCFP) and granules formed by self-immobilization (B-SI) were formed in the reactor. Clostridium, Syntrophobacter, Methanospirillum were possibly involved in HIT and Clostridium, Geobacter, Anaerolineaceae, Methanosaeta in DIET, both of which might be responsible for the high-rate propionate degradation.

  17. Phytolacca americana inhibits the high glucose-induced mesangial proliferation via suppressing extracellular matrix accumulation and TGF-beta production.

    PubMed

    Jeong, Seung Il; Kim, Kang Ju; Choo, Yong Kug; Keum, Kyung Soo; Choi, Bong Kyu; Jung, Kyu Yong

    2004-02-01

    This study describes a potential of Phytolaccaceae (Phytolacca americana var.) as an inhibitor of high glucose-stimulated production of extracellular matrix (ECM) proteins and TGF-beta in cultured glomerular mesangial cells (GMCs). Raising the ambient glucose concentration for 24 hrs caused a dose-dependent increase in [3H]thymidine incorporation of GMCs, and the maximal response was achieved at 20 mM. Phytolaccaceae extracts (2.5-20 microg/ml) inhibited the high glucose-induced [3H]thymidine incorporation in a dose-dependent manner, and the concentrations tested here did not affect to the cell viability. Exposure of the GMCs to 20 mM glucose caused both ECM (collagen and fibronectin) accumulation and TGF-beta secretion, and these changes were significantly diminished by treatment of GMCs with Phytolaccaceae (10 microg/ml). Taken together, these results indicate that Phytolaccaceae inhibits the high glucose-induced GMCs proliferation partially through suppressing accumulation of ECM components and TGF-beta production, suggesting that Phytolaccaceae may be a promising agent for treating the development and progression of diabetic glomerulopathy.

  18. 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.

  19. Significance of trophic transfer in predicting the high concentration of zinc in barnacles

    SciTech Connect

    Wang, W.X.; Qui, J.W.; Qian, P.Y.

    1999-09-01

    Barnacles are known to accumulate Zn to a phenomenal concentration, but physiological processes governing Zn accumulation are poorly defined. The authors determined the assimilation efficiency and efflux rate constant of Zn in barnacles (Balanus amphitrite) using radiotracer technique. Assimilation efficiency of Zn from ingested food ranged between 76 and 87% for the diatom diets and between 86 and 98% for the zooplankton preys. These AEs were the highest measured among aquatic invertebrates. Varying distribution in the soft tissues of zooplankton did not account for the variability of Zn AE observed among different zooplankton preys. Most Zn was distributed in the guts of the animals, presumably associated with the numerous granules beneath the gut epithelium. The efflux rate constant was 0.003 d{sup {minus}1}, and the calculated biological retention half-time was about 230 days. Using a simple bioenergetic-based kinetic model, the authors demonstrated that trophic transfer can account for such a high Zn concentration in barnacles. The predicted Zn concentrations in barnacles were directly comparable to the concentrations measured in Hong Kong coastal waters {micro}g. The high Zn concentration is related to its very efficient assimilation in barnacles coupled with a very low efflux rate. Biological variability must be fully appreciated before barnacles can be designated as an appropriate biomonitor of Zn contamination in coastal waters. The authors study suggests that metal concentration in aquatic animals can be predicted only when both physiological and geochemical processes are considered.

  20. Effects of Puerarin on Lipid Accumulation and Metabolism in High-Fat Diet-Fed Mice

    PubMed Central

    Zheng, Guodong; Lin, Lezhen; Zhong, Shusheng; Zhang, Qingfeng; Li, Dongming

    2015-01-01

    In order to investigate the mechanisms by which puerarin from kudzu root extract regulates lipid metabolism, fifty mice were randomly assigned to five groups: normal diet, high-fat diet (HFD), and HFD containing 0.2%, 0.4% or 0.8% puerarin for 12 weeks. Body weight, intraperitioneal adipose tissue (IPAT) weight, serum biochemical parameters, and hepatic and feces lipids were measured. Activity and mRNA and protein expressions of hepatic lipid metabolism-related enzymes were analyzed. Compared with HFD, 0.4% and 0.8% puerarin significantly decreased body and IPAT weight. There was a significant decrease in the serum and hepatic concentrations of total cholesterol, triglycerides and leptin in mice fed the 0.4% and 0.8% puerarin diets compared with HFD. Fatty acid synthase activity was suppressed in mice fed the 0.4% and 0.8% puerarin diets, while the activities of AMP-activated protein kinase (AMPK), carnitine acyltransferase (CAT) and hormone-sensitive lipase (HSL) were increased. mRNA expression of peroxisome proliferator-activated receptor γ 2 (PPARγ 2) was down-regulated in liver of mice fed the 0.8% diet compared with HFD, while mRNA expression of CAT and HSL was considerably up-regulated by 0.4% and 0.8% puerarin diets. The protein expression of PPARγ2 in liver was decreased and those of p-AMPK, HSL and p-HSL were increased in mice fed 0.4% and 0.8% puerarin diets. These results suggest that > 0.4% puerarin influenced the activity, mRNA and protein levels of hepatic lipid metabolism-related enzymes, decreasing serum and liver lipids, body weight gain and fat accumulation. Puerarin might be beneficial to prevent lifestyle-related diseases. PMID:25822741

  1. Effect of Nutrient Starvation under High Irradiance on Lipid and Starch Accumulation in Chlorella fusca (Chlorophyta).

    PubMed

    Jerez, Celia G; Malapascua, José R; Sergejevová, Magda; Figueroa, Félix L; Masojídek

    2016-02-01

    The effect of nitrogen and sulphur limitation under high irradiance (PAR) was studied in the green microalga Chlorella fusca (Chlorophyta) in order to follow lipid and/or starch accumulation. Growth, biomass composition and the changes in photosynthetic activity (in vivo chlorophyll a fluorescence) were followed in the trials. The full nutrient culture showed high biomass production and starch accumulation at Day 1, when photosynthetic activity was high. Gradual deprivation (no nutrients added) became evident when photosynthesis was significantly suppressed (Day 3 onwards), which entailed a decrease of maximum relative electron transport rate (rETRmax) and increase of non-photochemical quenching (NPQ), accompanied by the onset of lipid accumulation and decline in starch content. In N- and S-starved cultures, rETRmax significantly decreased by Day 3, which caused a substantial drop in biomass production, cell number, biovolume and induction of lipid and starch accumulation. High starch content (45-50 % of DW) was found at the initial stage in full nutrient culture and at the stationary phase in nutrient-starved cultures. By the end of the trial, all treatments showed high lipid content (~30 % of DW). The full nutrient culture had higher biomass yield than starved treatments although starch (~0.2 g L(-1) day(-1)) and lipid (~0.15 g L(-1) day(-1) productivities were fairly similar in all the cultures. Our results showed that we could enrich biomass of C. fusca (% DW) in lipids using a two-stage strategy (a nutrient replete stage followed by gradual nutrient limitation) while under either procedure, N- or S-starvation, both high lipid and starch contents could be achieved.

  2. 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.

  3. CONCENTRATION DEPENDENT ACCUMULATION OF [3H]-DELTAMETHRIN IN SODIUM CHANNEL N AV1.2 EXPRESSING XENOPUS LAEVIS OOCYTES.

    EPA Science Inventory

    Disruption of neuronal voltage-sensitive sodium channels (VSSCs) by pyrethroid insecticides such as deltamethrin (DLT) has been widely studied using Xenopus laevis oocytes transfected with VSSC. However, the extent of pyrethroid accumulation in VSSC-expressing oocytes is unknown....

  4. Effects of inorganic carbon concentration on carbon formation, nitrate utilization, biomass and oil accumulation of Nannochloropsis oculata CS 179.

    PubMed

    Lin, Qiang; Gu, Na; Li, Gang; Lin, Junda; Huang, Liangmin; Tan, LingLing

    2012-05-01

    This investigation examined the effects of the inorganic carbon concentration (4, 0.8 and 0 g/L NaHCO(3)) on the carbon formation, nitrate utilization, growth and fatty acids compositions of Nannochloropsis oculata. The dissolved inorganic carbon (DIC) concentration in the three treatments decreased sharply during the first 6 days, and the percentage of dissolved organic carbon (DOC) (% of total organic carbon (TOC)) decreased with the depletion of the DIC. The NO(3)(-) assimilation of the algae was correlated with the DIC concentration. The algae in the highest DIC treatment had the highest specific grow rate (0.0843 d(-1)) (P<0.0001), and their biomass and fatty acid methyl esters (FAME) productivity were 84.00 and 9.69 mg/L/d, respectively (P<0.0001). Contents of C16 and C18 series (% of FAME) were high and the C16:0 increased with the decrease of C18:1 during the cultivation. The iodine value (IV) of the algae was low at the low DIC media.

  5. Hair and toenail arsenic concentrations of residents living in areas with high environmental arsenic concentrations.

    PubMed Central

    Hinwood, Andrea L; Sim, Malcolm R; Jolley, Damien; de Klerk, Nick; Bastone, Elisa B; Gerostamoulos, Jim; Drummer, Olaf H

    2003-01-01

    Surface soil and groundwater in Australia have been found to contain high concentrations of arsenic. The relative importance of long-term human exposure to these sources has not been established. Several studies have investigated long-term exposure to environmental arsenic concentrations using hair and toenails as the measure of exposure. Few have compared the difference in these measures of environmental sources of exposure. In this study we aimed to investigate risk factors for elevated hair and toenail arsenic concentrations in populations exposed to a range of environmental arsenic concentrations in both drinking water and soil as well as in a control population with low arsenic concentrations in both drinking water and soil. In this study, we recruited 153 participants from areas with elevated arsenic concentrations in drinking water and residential soil, as well as a control population with no anticipated arsenic exposures. The median drinking water arsenic concentrations in the exposed population were 43.8 micro g/L (range, 16.0-73 micro g/L) and median soil arsenic concentrations were 92.0 mg/kg (range, 9.1-9,900 mg/kg). In the control group, the median drinking water arsenic concentration was below the limit of detection, and the median soil arsenic concentration was 3.3 mg/kg. Participants were categorized based on household drinking water and residential soil arsenic concentrations. The geometric mean hair arsenic concentrations were 5.52 mg/kg for the drinking water exposure group and 3.31 mg/kg for the soil exposure group. The geometric mean toenail arsenic concentrations were 21.7 mg/kg for the drinking water exposure group and 32.1 mg/kg for the high-soil exposure group. Toenail arsenic concentrations were more strongly correlated with both drinking water and soil arsenic concentrations; however, there is a strong likelihood of significant external contamination. Measures of residential exposure were better predictors of hair and toenail arsenic

  6. The Synthesis and Accumulation of Resveratrol Are Associated with Veraison and Abscisic Acid Concentration in Beihong (Vitis vinifera × Vitis amurensis) Berry Skin

    PubMed Central

    Wang, Junfang; Wang, Shuqin; Liu, Guotian; Edwards, Everard J.; Duan, Wei; Li, Shaohua; Wang, Lijun

    2016-01-01

    Resveratrols are polyphenolic secondary metabolites that can benefit human health, and only occur in a few plant families including Vitaceae. It has been reported that abscisic acid (ABA) can induce veraison (the onset of grape berry ripening) and may induce the accumulation of resveratrol in berry skin. However, the relationships between ABA, veraison, the accumulation of anthocyanins and the accumulation of resveratrol in the berry are poorly understood. This study attempted to answer this question through an investigation of the effect of applied ABA and fluridone (a synthetic inhibitor of ABA) on the biosynthesis and accumulation of ABA, anthocyanin, and resveratrol in Beihong (Vitis vinifera × Vitis amurensis) berry skin. Under natural conditions, resveratrol concentration was very low before 91 DAA (days after anthesis), i.e., 2 weeks after veraison, however, it increased sharply from this point to 126 DAA (maturity). Exogenous ABA applications all resulted in an increase in berry skin ABA and anthocyanin concentration, irrespective of the developmental stage at which the treatment occurred (20 and 10 days pre-veraison, veraison or 7 days post-veraison), thereby advancing veraison. In contrast, resveratrol concentration increased only when ABA was applied at 10 days pre-veraison or at veraison. As a result, the accumulation of resveratrol was associated with veraison in grape berry skin and this accumulation, together with that of anthocyanins, was associated with ABA concentration. The response of resveratrol biosynthesis in the berry skin to manipulation of ABA varied during berry development and was less sensitive to ABA than the response of anthocyanin biosynthesis. PMID:27857716

  7. High Performance Concentrating Photovoltaic Module Designs Employing Reflective Lens Optics

    NASA Astrophysics Data System (ADS)

    Vasylyev, Sergey V.; Vasylyev, Viktor P.

    2011-12-01

    The present study is aimed at advancing the optical component as well as optimizing the design of concentrating photovoltaic (CPV) modules in order to increase the conversion efficiency and improve the utility of CPV while obtaining the prescribed concentration ratio. In this work, we turn to non-traditional concentrating optics, namely Reflective Lenses™ (RL), first introduced in early 2000s. The optical configuration of RLs is unique since it combines the very low F/D number (hence resulting in a very low profile of the unit) of mirrors with a rear-focus of lenses and uses only a single-stage reflection. A liner-focus version of RLs, the Slat-Array Concentrator (SAC), is a capable alternative to the parabolic troughs for mid-concentration CPV. A point-focus version called the Ring-Array Concentrator (RAC) is deemed suitable for high concentration photovoltaics.

  8. Biomass accumulation modelling in a highly loaded biotrickling filter for hydrogen sulphide removal.

    PubMed

    Mannucci, Alberto; Munz, Giulio; Mori, Gualtiero; Lubello, Claudio

    2012-07-01

    A pilot scale test on a biotrickling filter packed with polyurethane foam cubes was carried out for 110 d at high volumetric mass load (up to 280 g m(bed)(-3) h(-1)) with the aim of studying the accumulation of solids in the treatment of H(2)S. Removal rate up to 245 g m(bed)(-3) h(-1) was obtained; however, an accumulation of gypsum, elemental sulphur and, above all, inert biomass was identified as the cause of an increased pressure drop over the long term. A mathematical model was applied and calibrated with the experimental results to describe the accumulation of biomass. The model was capable of describing the accumulation of solids and, corresponding to a solids retention time of 50 d, the observed yield resulted in 0.07 g of solids produced g(-1) H(2)S removed. Respirometric tests showed that heterotrophic activity is inhibited at low pH (pH < 2.3), and the contribution to biomass removal through decay was negligible.

  9. Evaluation of high-concentration photovoltaic power plants

    SciTech Connect

    Stolte, W.J. ); Whisnant, R.A. ); McGowin, C.R. )

    1991-01-01

    This paper describes the conceptual design, and estimated cost and performance of two high-concentration, 50 MW photovoltaic power plants. Both designs are based on a similar advanced back-contact silicon concentrator cell. The first design uses Fresnel lens/glass silo modules mounted on two-axis tracking arrays. The second design has all of the cells mounted on a central receiver on top of a single tower, with heliostats concentrating sunlight onto the receiver.

  10. Multijunction Photovoltaic Technologies for High-Performance Concentrators: Preprint

    SciTech Connect

    McConnell, R.; Symko-Davies, M.

    2006-05-01

    Multijunction solar cells provide high-performance technology pathways leading to potentially low-cost electricity generated from concentrated sunlight. The National Center for Photovoltaics at the National Renewable Energy Laboratory has funded different III-V multijunction solar cell technologies and various solar concentration approaches. Within this group of projects, III-V solar cell efficiencies of 41% are close at hand and will likely be reported in these conference proceedings. Companies with well-developed solar concentrator structures foresee installed system costs of $3/watt--half of today's costs--within the next 2 to 5 years as these high-efficiency photovoltaic technologies are incorporated into their concentrator photovoltaic systems. These technology improvements are timely as new large-scale multi-megawatt markets, appropriate for high performance PV concentrators, open around the world.

  11. Consumption of sucrose from infancy increases the visceral fat accumulation, concentration of triglycerides, insulin and leptin, and generates abnormalities in the adrenal gland.

    PubMed

    Díaz-Aguila, Yadira; Castelán, Francisco; Cuevas, Estela; Zambrano, Elena; Martínez-Gómez, Margarita; Muñoz, Alvaro; Rodríguez-Antolín, Jorge; Nicolás-Toledo, Leticia

    2016-03-01

    Consumption of sugar-sweetened beverages promotes the development of metabolic syndrome (MetS) and type 2 diabetes mellitus in humans. One factor related to the appearance of MetS components is the dysfunction of the adrenal gland. In fact, the experimental generation of hyperglycemia has been associated with morphological and microvascular changes in the adrenal glands of rats. We hypothesized that high sucrose consumption from infancy promotes histological disruption of the adrenal glands associated with the appearance of metabolic syndrome indicators. Male Wistar rats were separated at weaning (21 days old) into two groups: free access to tap water (control group, C) or 30 % sucrose diluted in water (sugar-fed group). After 12 weeks, high sucrose consumption promoted an increase in visceral fat accumulation, adipose cell number, and insulin resistance. Also, a rise in the concentration of triglycerides, very low-density lipoprotein, insulin and leptin was observed. In control rats, a histomorphometric asymmetry between the right and left adrenal glands was found. In the sugar-fed group, sucrose consumption produced a major change in adrenal gland asymmetry. No changes in corticosterone serum level were observed in either group. Our results suggest that a high sucrose liquid-diet from early life alters the morphology of adrenocortical zones, leading to MetS indicators.

  12. Physiological and biochemical responses to high Mn concentrations in two contrasting Populus cathayana populations.

    PubMed

    Lei, Yanbao; Korpelainen, Helena; Li, Chunyang

    2007-06-01

    We exposed the cuttings of Populus cathayana to Hoagland's solution containing four different manganese (Mn) concentrations (0, 0.1, 0.5 and 1mM) in a greenhouse to characterize the physiological and biochemical basis of Mn resistance in woody plants. Two contrasting populations of P. cathayana were used in our study, which were from the wet and dry climate regions in western China, respectively. The results showed that Mn treatments significantly decreased chlorophyll content and growth characteristics, including shoot height, basal diameter, biomass accumulation and total leaf area in the two populations. Mn treatments also significantly increased the levels of abscisic acid (ABA), polyamines and free amino acids especially proline (Pro), histidine (His) and phenylalanine (Phe) available for cellular signaling and heavy metal chelation. In addition, high Mn concentrations also caused oxidative stress indicated as the accumulation of hydrogen peroxide (H(2)O(2)) and malondialdehyde (MDA) contents. On the other hand, there were different responses to Mn stress between the two contrasting populations. Compared with the dry climate population, the wet climate population accumulated more Mn in plant tissues especially in leaves; it showed lower tolerance index and more pronounced decrease in growth and chlorophyll contents. The wet climate population not only accumulated less ABA, putrescine and free amino acids, but also exhibited lower activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX), thus suffering from more serious oxidative damage. Therefore, our results showed that the wet climate population was more susceptible to Mn stress than the dry climate population.

  13. Highly accurate boronimeter assay of concentrated boric acid solutions

    SciTech Connect

    Ball, R.M. )

    1992-01-01

    The Random-Walk Boronimeter has successfully been used as an on-line indicator of boric acid concentration in an operating commercial pressurized water reactor. The principle has been adapted for measurement of discrete samples to high accuracy and to concentrations up to 6000 ppm natural boron in light water. Boric acid concentration in an aqueous solution is a necessary measurement in many nuclear power plants, particularly those that use boric acid dissolved in the reactor coolant as a reactivity control system. Other nuclear plants use a high-concentration boric acid solution as a backup shutdown system. Such a shutdown system depends on rapid injection of the solution and frequent surveillance of the fluid to ensure the presence of the neutron absorber. The two methods typically used to measure boric acid are the chemical and the physical methods. The chemical method uses titration to determine the ionic concentration of the BO[sub 3] ions and infers the boron concentration. The physical method uses the attenuation of neutrons by the solution and infers the boron concentration from the neutron absorption properties. This paper describes the Random-Walk Boronimeter configured to measure discrete samples to high accuracy and high concentration.

  14. Combined effects of water flow and copper concentration on the feeding behavior, growth rate, and accumulation of copper in tissue of the infaunal polychaete Polydora cornuta.

    PubMed

    Colvin, Marienne A; Hentschel, Brian T; Deheyn, Dimitri D

    2016-12-01

    We performed an experiment in a laboratory flume to test the effects of water flow speed and the concentration of aqueaous copper on the feeding behavior, growth rate, and accumulation of copper in the tissues of juvenile polychaetes Polydora cornuta. The experiment included two flow speeds (6 or 15 cm/s) and two concentrations of added copper (0 or 85 μg/L). Worms grew significantly faster in the faster flow and in the lower copper concentration. In the slower flow, the total time worms spent feeding decreased significantly as copper concentration increased, but copper did not significantly affect the time worms spent feeding in the faster flow. Across all treatments, there was a significant, positive relationship between the time individuals spent feeding and their relative growth rate. Worms were observed suspension feeding significantly more often in the faster flow and deposit feeding significantly more often in the slower flow, but copper concentration did not affect the proportion of time spent in either feeding mode. The addition of 85 μg/L copper significantly increased copper accumulation in P. cornuta tissue, but the accumulation did not differ significantly due to flow speed. There was a significant interaction between copper and flow; the magnitude of the difference in copper accumulation between the 0 and 85 μg/L treatments was greater in the faster flow than in the slower flow. In slow flows that favor deposit feeding, worms grow slowly and accumulate less copper in their tissue than in faster flows that favor suspension feeding and faster growth.

  15. Association of a Specific Algal Group with Methylmercury Accumulation in Periphyton of a Tropical High-Altitude Andean Lake.

    PubMed

    Lanza, William G; Achá, Darío; Point, David; Masbou, Jeremy; Alanoca, Lucia; Amouroux, David; Lazzaro, Xavier

    2017-01-01

    Periphyton relevance for methylmercury (MeHg) production and accumulation are now well known in aquatic ecosystems. Sulfate-reducing bacteria and other microbial groups were identified as the main MeHg producers, but the effect of periphyton algae on the accumulation and transfer of MeHg to the food web remains little studied. Here we investigated the role of specific groups of algae on MeHg accumulation in the periphyton of Schoenoplectus californicus ssp. (Totora) and Myriophyllum sp. in Uru Uru, a tropical high-altitude Bolivian lake with substantial fishing and mining activities accruing around it. MeHg concentrations were most strongly related to the cell abundance of the Chlorophyte genus Oedogonium (r (2) = 0.783, p = 0.0126) and to no other specific genus despite the presence of other 34 genera identified. MeHg was also related to total chlorophyll-a (total algae) (r (2) = 0.675, p = 0.0459), but relations were more significant with chlorophyte cell numbers, chlorophyll-b (chlorophytes), and chlorophyll-c (diatoms and dinoflagellates) (r (2) = 0.72, p = 0.028, r (2) = 0.744, p = 0.0214, and r (2) = 0.766, p = 0.0161 respectively). However, Oedogonium explains most variability of chlorophytes and chlorophyll-c (r (2) = 0.856, p = < 0.001 and r (2) = 0.619, p = 0.002, respectively), suggesting it is the most influential group for MeHg accumulation and periphyton algae composition at this particular location and given time.

  16. 9-Fold Fresnel Köhler concentrator for increased uniform irradiance on high concentrations

    NASA Astrophysics Data System (ADS)

    Mendes-Lopes, João; Benítez, Pablo; Zamora, Pablo; Miñano, Carlos

    2013-09-01

    Non-uniform irradiance patterns created by Concentrated Photovoltaics (CPV) concentrators over Multi-Junction Cells (MJC) can originate significant power losses, especially when there are different spectral irradiance distributions over the different MJC junctions. This fact has an increased importance considering the recent advances in 4 and 5 junction cells. The spectral irradiance distributions are especially affected with thermal effects on Silicone-on-Glass (SoG) CPV systems. This work presents a new CPV optical design, the 9-fold Fresnel Köhler concentrator, prepared to overcome these effects at high concentrations while maintaining a large acceptance angle, paving the way for a future generation of high efficiency CPV systems of 4 and 5 junction cells.

  17. Factors impeding enzymatic wheat gluten hydrolysis at high solid concentrations.

    PubMed

    Hardt, N A; Janssen, A E M; Boom, R M; van der Goot, A J

    2014-07-01

    Enzymatic wheat gluten hydrolysis at high solid concentrations is advantageous from an environmental and economic point of view. However, increased wheat gluten concentrations result in a concentration effect with a decreased hydrolysis rate at constant enzyme-to-substrate ratios and a decreased maximum attainable degree of hydrolysis (DH%). We here identified the underlying factors causing the concentration effect. Wheat gluten was hydrolyzed at solid concentrations from 4.4% to 70%. The decreased hydrolysis rate was present at all solid concentrations and at any time of the reaction. Mass transfer limitations, enzyme inhibition and water activity were shown to not cause this hydrolysis rate limitation up to 50% solids. However, the hydrolysis rate limitation can be, at least partly, explained by a second-order enzyme inactivation process. Furthermore, mass transfer impeded the hydrolysis above 60% solids. Addition of enzyme after 24 h at high solid concentrations scarcely increased the DH%, suggesting that the maximum attainable DH% decreases at high solid concentrations. Reduced enzyme activities caused by low water activities can explain this DH% limitation. Finally, a possible influence of the plastein reaction on the DH% limitation is discussed.

  18. Rice bran oil and oryzanol reduce plasma lipid and lipoprotein cholesterol concentrations and aortic cholesterol ester accumulation to a greater extent than ferulic acid in hypercholesterolemic hamsters.

    PubMed

    Wilson, Thomas A; Nicolosi, Robert J; Woolfrey, Benjamin; Kritchevsky, David

    2007-02-01

    Our laboratory has reported that the hypolipidemic effect of rice bran oil (RBO) is not entirely explained by its fatty acid composition. Because RBO has a greater content of the unsaponifiables, which also lower cholesterol compared to most vegetable oils, we wanted to know whether oryzanol or ferulic acid, two major unsaponifiables in RBO, has a greater cholesterol-lowering activity. Forty-eight F(1)B Golden Syrian hamsters (Mesocricetus auratus) (BioBreeders, Watertown, MA) were group housed (three per cage) in cages with bedding in an air-conditioned facility maintained on a 12-h light/dark cycle. The hamsters were fed a chow-based hypercholesterolemic diet (HCD) containing 10% coconut oil and 0.1% cholesterol for 2 weeks, at which time they were bled after an overnight fast (16 h) and segregated into 4 groups of 12 with similar plasma cholesterol concentrations. Group 1 (control) continued on the HCD, group 2 was fed the HCD containing 10% RBO in place of coconut oil, group 3 was fed the HCD plus 0.5% ferulic acid and group 4 was fed the HCD plus 0.5% oryzanol for an additional 10 weeks. After 10 weeks on the diets, plasma total cholesterol (TC) and non-high-density lipoprotein cholesterol (HDL-C) (very low- and low-density lipoprotein) concentrations were significantly lower in the RBO (-64% and -70%, respectively), the ferulic acid (-22% and -24%, respectively) and the oryzanol (-70% and -77%, respectively) diets compared to control. Plasma TC and non-HDL-C concentrations were also significantly lower in the RBO (-53% and -61%, respectively) and oryzanol (-61% and -70%, respectively) diets compared to the ferulic acid. Compared to control and ferulic acid, plasma HDL-C concentrations were significantly higher in the RBO (10% and 20%, respectively) and oryzanol (13% and 24%, respectively) diets. The ferulic acid diet had significantly lower plasma HDL-C concentrations compared to the control (-9%). The RBO and oryzanol diets were significantly lower for

  19. Applications of nonimaging optics for very high solar concentrations

    SciTech Connect

    O`Gallagher, J.; Winston, R.

    1997-12-31

    Using the principles and techniques of nonimaging optics, solar concentrations that approach the theoretical maximum can be achieved. This has applications in solar energy collection wherever concentration is desired. In this paper, we survey recent progress in attaining and using high and ultrahigh solar fluxes. We review a number of potential applications for highly concentrated solar energy and the current status of the associated technology. By making possible new and unique applications for intense solar flux, these techniques have opened a whole new frontier for research and development of potentially economic uses of solar energy.

  20. Optimum Leaf Removal Increases Nitrogen Accumulation in Kernels of Maize Grown at High Density

    PubMed Central

    Liu, Tiening; Huang, Rundong; Cai, Tie; Han, Qingfang; Dong, Shuting

    2017-01-01

    Increasing plant density is one of the main approaches of achieving higher yields for modern maize crop. However, there exists leaf redundancy for high-density maize, and leaves of the upper canopy shade more competent leaves at the middle strata. In a two-year field experiments, Jinhai5, a semi-compact corn cultivar, was grown at a density of 105,000 plants ha−1 grown until 3 days after silking (3DAS), when plants were subjected to removal of the uppermost two leaves (S2), four leaves (S4) or six leaves (S6), with no leaf removal as control (S0). We evaluated the effects of leaf removal on N remobilization, photosynthetic capacity of the remaining leaves for N uptake, and N accumulation in kernels. Our present results concluded that, under high plant density, excising the uppermost two leaves promoted N remobilization from vegetative organs to kernels and enhanced photosynthetic capacity for N uptake, leading to an increased N accumulation in kernels (19.6% higher than control). However, four or six uppermost leaves removal reduced N remobilization from stem and photosynthesis for poor N uptake, resulting in 37.5 and 50.2% significantly reduced N accumulation in kernels, respectively. PMID:28084467

  1. Effects of heavy metal concentrations (Cd, Zn and Pb) in agricultural soils near different emission sources on quality, accumulation and food safety in soybean [Glycine max (L.) Merrill].

    PubMed

    Salazar, María Julieta; Rodriguez, Judith Hebelen; Leonardo Nieto, Gastón; Pignata, María Luisa

    2012-09-30

    Argentina is one of the major producers of soybean in the world, this generates a high global demand for this crop leading to find it everywhere, even close to human activities involving pollutant emissions. This study evaluated heavy metal content, the transfer of metals and its relation to crop quality, and the toxicological risk of seed consumption, through soil and soybean sampling. The results show that concentrations of Pb and Cd in soils and soybeans at several sites were above the maximum permissible levels. The heavy metal bioaccumulation depending on the rhizosphere soil compartment showed significant and high regression coefficients. In addition, the similar behavior of Cd and Zn accumulation by plants reinforces the theory of other studies indicating that these metals are incorporated into the plant for a common system of transport. On the other hand, the seed quality parameters did not show a clear pattern of response to metal bioacumulation. Taken together, our results show that soybeans grown nearby to anthropic emission sources might represent a toxicological hazard for human consumption in a potential Chinese consumer. Hence, further studies should be carried out taking into account the potential negative health effects from the consumption of soybeans (direct or indirect through consumption of meat from cattle) in these conditions.

  2. The effect of carbohydrate accumulation and nitrogen deficiency on feedback regulation of photosynthesis in beech (Fagus sylvatica) under elevated CO2 concentration

    NASA Astrophysics Data System (ADS)

    Klem, K.; Urban, O.; Holub, P.; Rajsnerova, P.

    2012-04-01

    One of the main manifestations of global change is an increase in atmospheric CO2 concentration. Elevated concentration of CO2 has stimulating effect on plant photosynthesis and consequently also on the productivity. Long-term studies, however, show that this effect is progressively reduced due to feedback regulation of photosynthesis. The main causes of this phenomenon are considered as two factors: i) increased biomass production consumes a larger amount of nitrogen from the soil and this leads to progressive nitrogen limitation of photosynthesis, particularly at the level of the enzyme Rubisco, ii) the sink capacity is genetically limited and elevated CO2 concentration leads to increased accumulation of carbohydtrates (mainly sucrose, which is the main transport form of assimilates) in leaves. Increased concentrations of carbohydrates leads to a feedback regulation of photosynthesis by both, long-term feedback regulation of synthesis of the enzyme Rubisco, and also due to reduced capacity to produce ATP in the chloroplasts. However, mechanisms for interactive effects of nitrogen and accumulation of non-structural carbohydrates are still not well understood. Using 3-year-old Fagus sylvatica seedlings we have explored the interactive effects of nitrogen nutrition and sink capacity manipulation (sucrose feeding) on the dynamics of accumulation of non-structural carbohydrates and changes in photosynthetic parameters under ambient (385 μmol (CO2) mol-1) and elevated (700 μmol(CO2) mol-1) CO2 concentration. Sink manipulation by sucrose feeding led to a continuous increase of non-structural carbohydrates in leaves, which was higher in nitrogen fertilized seedlings. The accumulation of non-structural carbohydrates was also slightly stimulated by elevated CO2 concentration. Exponential decay (p <0.01) was observed in CO2 assimilation rate and stomatal conductance when the content of non-structural carbohydrates increased. However, this relationship was modified by the

  3. Molecular nitrogen in natural gas accumulations: Generation from sedimentary organic matter at high temperatures

    SciTech Connect

    Littke, R.; Krooss, B.; Frielingsdorf, J.; Idiz, E.

    1995-03-01

    The occurrence of natural gas accumulations with high percentages (up to 100%) of molecular nitrogen in various hydrocarbon provinces represents a largely unresolved problem and a serious exploration risk. In this context, a geochemical and basin modeling study was performed to evaluate the potential of sedimentary organic matter to generate molecular nitrogen. The masses of nitrogen present in coals - if converted into molecular nitrogen - are sufficient to fill commercial gas reservoirs. A calculation for gas accumulations in northern Germany, where percentages of molecular nitrogen range from less than 5 to greater than 90%, reveals that the molecular nitrogen generated in underlying coal-bearing strata is sufficient to account for the nitrogen gas even in the largest fields. In addition, much of the total nitrogen in clay-rich rock types, such as shales and mudstones, is fixed in sedimentary organic matter and may add to the nitrogen generation capacity of the coals.

  4. Seasonal accumulation of persistent organic pollutants on a high altitude glacier in the Eastern Alps.

    PubMed

    Kirchgeorg, T; Dreyer, A; Gabrielli, P; Gabrieli, J; Thompson, L G; Barbante, C; Ebinghaus, R

    2016-11-01

    The seasonal accumulations of perfluorinated substances (PFAS), polybrominated diphenyl ethers (PBDE) and polycyclic aromatic hydrocarbons (PAH) were measured in a 10 m shallow firn core from a high altitude glacier at Mt. Ortles (Italy, 3830 m above sea level) in South Tyrol in the Italian Eastern Alps. The most abundant persistent organic pollutants of each group were perfluorobutanoic acid (PFBA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA) (for PFASs); BDE 47, BDE 99, BDE 209 (for PBDEs) and phenanthrene (PHE), fluoranthene (FLA) and pyrene (PYR) (for PAHs). All compounds show different extents of seasonality, with higher accumulation during summer time compared to winter. This seasonal difference mainly reflects meteorological conditions with a low and stable atmospheric boundary layer in winter and strong convective activity in summer, transformation processes during the transport of chemicals and/or post-depositional alterations. Change in the composition of the water-soluble PFCAs demonstrates the influence of meltwater percolation through the firn layers.

  5. High Black Carbon (BC) Concentrations along Indian National Highways

    NASA Astrophysics Data System (ADS)

    Kumar, S.; Singh, A. K.; Singh, R. P.

    2015-12-01

    Abstract:Black carbon (BC), the optically absorbing component of carbonaceous aerosol, has direct influence on radiation budget and global warming. Vehicular pollution is one of the main sources for poor air quality and also atmospheric pollution. The number of diesel vehicles has increased on the Indian National Highways during day and night; these vehicles are used for the transport of goods from one city to another city and also used for public transport. A smoke plume from the vehicles is a common feature on the highways. We have made measurements of BC mass concentrations along the Indian National Highways using a potable Aethalometer installed in a moving car. We have carried out measurements along Varanasi to Kanpur (NH-2), Varanasi to Durgapur (NH-2), Varanasi to Singrauli (SH-5A) and Varanasi to Ghazipur (NH-29). We have found high concentration of BC along highways, the average BC mass concentrations vary in the range 20 - 40 µg/m3 and found high BC mass concentrations up to 600 μg/m3. Along the highways high BC concentrations were characteristics of the presence of industrial area, power plants, brick kilns and slow or standing vehicles. The effect of increasing BC concentrations along the National Highways and its impact on the vegetation and human health will be presented. Key Words: Black Carbon; Aethalometer; mass concentration; Indian National Highways.

  6. Biodegradation of phenol at high initial concentration by Alcaligenes faecalis.

    PubMed

    Jiang, Yan; Wen, Jianping; Bai, Jing; Jia, Xiaoqiang; Hu, Zongding

    2007-08-17

    Strain Alcaligenes faecalis was isolated and identified as a member of the genus Alcaligenes by using BIOLOG and 16S rDNA sequence analysis. The phenol biodegradation tests showed that the phenol-degrading potential of A. faecalis related greatly to the different physiological phases of inoculum. The maximum phenol degradation occurred at the late phase of the exponential growth stages, where 1600 mg L(-1) phenol was completely degraded within 76 h. A. faecalis secreted and accumulated a vast quantity of phenol hydroxylase in this physiological phase, which ensured that the cells could quickly utilize phenol as a sole carbon and energy source. In addition, the kinetic behavior of A. faecalis in batch cultures was also investigated over a wide range of initial phenol concentrations (0-1600 mg L(-1)) by using Haldane model. It was clear that the Haldane kinetic model adequately described the dynamic behavior of the phenol biodegradation by the strain of A. faecalis.

  7. High-speed VLSI concentrators for terabit intelligent optical backplanes

    NASA Astrophysics Data System (ADS)

    Supmonchai, Boonchuay; Szymanski, Ted H.

    1998-05-01

    Self-routing `concentrators' are fundamental building blocks of optical switching systems. An N-to-M concentrator can process and extract data packets from N optical channels and forward the packets to M electrical channels, where typically N M. Terabit Optical Backplanes which exploit free-space optical data links, with bandwidths approaching 1 - 10 Terabits per second will require extremely fast self- routing concentrators which can make routing decisions within a few nanoseconds. In this paper, a VLSI analysis of a new circuit called the `Daisy Chain' concentrator is presented. This concentrator has a regular topology suitable for very efficient VLSI layout, which leads to very high clock rates. The analyses are performed using 0.8 micrometers standard cell CMOS technology with the Synopsys CAD tool. The results shows that the proposed concentrator uses substantially less VLSI area from 20 - 50% less in the control logic and up to 150% less on the switching logic than the previous best known concentrator circuit. It also performs significantly faster, ranging from 20 - 40% faster in the control logic and 150 - 300% faster in the switching logic. Using 0.8 micrometers CMOS technology, the proposed concentrator can be used in smart pixel arrays for optical backplanes with clock rates in the range of 500 Mhz. Using faster CMOS or ECL logic, the concentrator can support clock rates in the several Gigahertz range.

  8. Correlating concentrations of heavy metals in atmospheric deposition with respective accumulation in moss and natural surface soil for ecological land classes in Norway between 1990 and 2010.

    PubMed

    Nickel, Stefan; Hertel, Anne; Pesch, Roland; Schröder, Winfried; Steinnes, Eiliv; Uggerud, Hilde Thelle

    2015-06-01

    This study investigated whether statistical correlation of modeled atmospheric heavy metal deposition and respective accumulation in moss and natural surface soil varies across natural landscapes in Norway. Target metals were cadmium, lead, and mercury, and analyses were run between 1990 and 2010 on a 5-year interval. The landscape information was derived from the Ecological Land Classification of Europe. Correlations between concentration and respective deposition data were computed for each land class. The strongest correlations between heavy metal concentrations in atmospheric deposition and corresponding levels in moss and natural surface soil were observed for lead. Correlations for mercury were weaker compared to those calculated for cadmium and lead, indicating that atmospheric transport of mercury occurs at a larger spatial scale, while accumulation additionally seems to be influenced by factors operating on smaller scales. The correlation between concentrations in atmospheric deposition and moss is landscape-specific and metal-specific. The same holds true for the relations between heavy metal concentration in modeled atmospheric deposition and natural surface soil. The results of this investigation are in line with similar calculations from across Europe. They further confirm previous studies indicating that for Norway atmospheric transport is a main source of lead and cadmium accumulation in moss as well as in natural surface soil.

  9. High concentration low wattage solar arrays and their applications

    NASA Astrophysics Data System (ADS)

    Hoffmann, Robert; O'Gallagher, Joseph; Winston, Roland

    1997-02-01

    Midway Labs currently produces a 335x concentrator module that has reached as high as 19% active area efficiency in production. The current production module uses the single crystal silicon back contact SunPower cell. The National Renewable Energy Lab has developed a multi junction cell using GalnP/GaAs technologies. The high efficiency (>30%) and high cell voltage offer an opportunity for Midway Labs to develop a tracking concentrator module that will provide 24 volts in the 140 to 160 watt range. This voltage and wattage range is applicable to a range of small scale water pumping applications that make up the bulk of water pumping solar panel sales.

  10. Chemicals to enhance microalgal growth and accumulation of high-value bioproducts.

    PubMed

    Yu, Xinheng; Chen, Lei; Zhang, Weiwen

    2015-01-01

    Photosynthetic microalgae have attracted significant attention as they can serve as important sources for cosmetic, food and pharmaceutical products, industrial materials and even biofuel biodiesels. However, current productivity of microalga-based processes is still very low, which has restricted their scale-up application. In addition to various efforts in strain improvement and cultivation optimization, it was proposed that the productivity of microalga-based processes can also be increased using various chemicals to trigger or enhance cell growth and accumulation of bioproducts. Herein, we summarized recent progresses in applying chemical triggers or enhancers to improve cell growth and accumulation of bioproducts in algal cultures. Based on their enhancing mechanisms, these chemicals can be classified into four categories:chemicals regulating biosynthetic pathways, chemicals inducing oxidative stress responses, phytohormones and analogs regulating multiple aspects of microalgal metabolism, and chemicals directly as metabolic precursors. Taken together, the early researches demonstrated that the use of chemical stimulants could be a very effective and economical way to improve cell growth and accumulation of high-value bioproducts in large-scale cultivation of microalgae.

  11. 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

  12. High concentration honey chitosan electrospun nanofibers: biocompatibility and antibacterial effects.

    PubMed

    Sarhan, Wessam A; Azzazy, Hassan M E

    2015-05-20

    Honey nanofibers represent an attractive formulation with unique medicinal and wound healing advantages. Nanofibers with honey concentrations of <10% were prepared, however, there is a need to prepare nanofibers with higher honey concentrations to increase the antibacterial and wound healing effects. In this work, chitosan and honey (H) were cospun with polyvinyl alcohol (P) allowing the fabrication of nanofibers with high honey concentrations up to 40% and high chitosan concentrations up to 5.5% of the total weight of the fibers using biocompatible solvents (1% acetic acid). The fabricated nanofibers were further chemically crosslinked, by exposure to glutaraldehyde vapor, and physically crosslinked by heating and freezing/thawing. The new HP-chitosan nanofibers showed pronounced antibacterial activity against Staphylococcus aureus but weak antibacterial activity against Escherichia coli. The developed HP-chitosan nanofibers revealed no cytotoxicity effects on cultured fibroblasts. In conclusion, biocompatible, antimicrobial crosslinked honey/polyvinyl alcohol/chitosan nanofibers were developed which hold potential as effective wound dressing.

  13. High Accumulation and Subcellular Distribution of Thallium in Green Cabbage (Brassica Oleracea L. Var. Capitata L.).

    PubMed

    Ning, Zengping; He, Libin; Xiao, Tangfu; Márton, László

    2015-01-01

    The accumulation of thallium (Tl) in brassicaceous crops is widely known, but both the uptake extents of Tl by the individual cultivars of green cabbage and the distribution of Tl in the tissues of green cabbage are not well understood. Five commonly available cultivars of green cabbage grown in the Tl-spiked pot-culture trials were studied for the uptake extent and subcellular distribution of Tl. The results showed that all the trial cultivars mainly concentrated Tl in the leaves (101∼192 mg/kg, DW) rather than in the roots or stems, with no significant differences among cultivars (p = 0.455). Tl accumulation in the leaves revealed obvious subcellular fractionation: cell cytosol and vacuole > cell wall > cell organelles. The majority (∼ 88%) of leaf-Tl was found to be in the fraction of cytosol and vacuole, which also served as the major storage site for other major elements such as Ca and Mg. This specific subcellular fractionation of Tl appeared to enable green cabbage to avoid Tl damage to its vital organelles and to help green cabbage tolerate and detoxify Tl. This study demonstrated that all the five green cabbage cultivars show a good application potential in the phytoremediation of Tl-contaminated soils.

  14. Freeform solar concentrator with a highly asymmetric acceptance cone

    NASA Astrophysics Data System (ADS)

    Wheelwright, Brian; Angel, J. Roger P.; Coughenour, Blake; Hammer, Kimberly

    2014-10-01

    A solar concentrator with a highly asymmetric acceptance cone is investigated. Concentrating photovoltaic systems require dual-axis sun tracking to maintain nominal concentration throughout the day. In addition to collecting direct rays from the solar disk, which subtends ~0.53 degrees, concentrating optics must allow for in-field tracking errors due to mechanical misalignment of the module, wind loading, and control loop biases. The angular range over which the concentrator maintains <90% of on-axis throughput is defined as the optical acceptance angle. Concentrators with substantial rotational symmetry likewise exhibit rotationally symmetric acceptance angles. In the field, this is sometimes a poor match with azimuth-elevation trackers, which have inherently asymmetric tracking performance. Pedestal-mounted trackers with low torsional stiffness about the vertical axis have better elevation tracking than azimuthal tracking. Conversely, trackers which rotate on large-footprint circular tracks are often limited by elevation tracking performance. We show that a line-focus concentrator, composed of a parabolic trough primary reflector and freeform refractive secondary, can be tailored to have a highly asymmetric acceptance angle. The design is suitable for a tracker with excellent tracking accuracy in the elevation direction, and poor accuracy in the azimuthal direction. In the 1000X design given, when trough optical errors (2mrad rms slope deviation) are accounted for, the azimuthal acceptance angle is +/- 1.65°, while the elevation acceptance angle is only +/-0.29°. This acceptance angle does not include the angular width of the sun, which consumes nearly all of the elevation tolerance at this concentration level. By decreasing the average concentration, the elevation acceptance angle can be increased. This is well-suited for a pedestal alt-azimuth tracker with a low cost slew bearing (without anti-backlash features).

  15. Sterile Filtration of Highly Concentrated Protein Formulations: Impact of Protein Concentration, Formulation Composition, and Filter Material.

    PubMed

    Allmendinger, Andrea; Mueller, Robert; Huwyler, Joerg; Mahler, Hanns-Christian; Fischer, Stefan

    2015-10-01

    Differences in filtration behavior of concentrated protein formulations were observed during aseptic drug product manufacturing of biologics dependent on formulation composition. The present study investigates filtration forces of monoclonal antibody formulations in a small-scale set-up using polyvinylidene difluoride (PVDF) or polyethersulfone (PES) filters. Different factors like formulation composition and protein concentration related to differences in viscosity, as well as different filtration rates were evaluated. The present study showed that filtration behavior was influenced by the presence or absence of a surfactant in the formulation, which defines the interaction between filter membrane and surface active formulation components. This can lead to a change in filter resistance (PES filter) independent on the buffer system used. Filtration behavior was additionally defined by rheological non-Newtonian flow behavior. The data showed that high shear rates resulting from small pore sizes and filtration pressure up to 1.0 bar led to shear-thinning behavior for highly concentrated protein formulations. Differences in non-Newtonian behavior were attributed to ionic strength related to differences in repulsive and attractive interactions. The present study showed that the interplay of formulation composition, filter material, and filtration rate can explain differences in filtration behavior/filtration flux observed for highly concentrated protein formulations thus guiding filter selection.

  16. Characteristic of nitrous oxide production in partial denitrification process with high nitrite accumulation.

    PubMed

    Du, Rui; Peng, Yongzhen; Cao, Shenbin; Wang, Shuying; Niu, Meng

    2016-03-01

    Nitrous oxide (N2O) production during the partial denitrification process with nitrate (NO3(-)-N) to nitrite (NO2(-)-N) transformation ratio of 80% was investigated in this study. Results showed that N2O was seldom observed before complete depletion of NO3(-)-N, but it was closely related to the reduction of NO2(-)-N rather than NO3(-)-N. High COD/NO3(-)-N was in favor of N2O production in partial denitrification with high NO2(-)-N accumulation. It was seriously enhanced at constant acidic pH due to the free nitrous acid (FNA) inhibition. However, the N2O production was much lower at initial pH of 5.5 and 6.5 due to the pH increase during denitrification process. Significantly, the pH turning point could be chosen as a controlled parameter to denote the end of NO3(-)-N reduction, which could not only achieve high NO2(-)-N accumulation but also decrease the N2O production significantly for practical application.

  17. High Sucrose Intake Ameliorates the Accumulation of Hepatic Triacylglycerol Promoted by Restraint Stress in Young Rats.

    PubMed

    Corona-Pérez, Adriana; Díaz-Muñoz, Mauricio; Rodríguez, Ida Soto; Cuevas, Estela; Martínez-Gómez, Margarita; Castelán, Francisco; Rodríguez-Antolín, Jorge; Nicolás-Toledo, Leticia

    2015-11-01

    Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder. Stress promotes the onset of the NAFLD with a concomitant increment in the activity of the hepatic 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD-1). However, the interaction between the stress and a carbohydrate-enriched diet for the development of NAFLD in young animals is unknown. In the present study, we evaluated the impact of chronic stress on the hepatic triacylglycerol level of young rats fed or not with a high sucrose-diet. For doing this, 21-day old male Wistar rats were allocated into 4 groups: control (C), chronic restraint stress (St), high-sucrose diet (S30), and chronic restraint stress plus a 30 % sucrose diet (St + S30). Chronic restraint stress consisted of 1-hour daily session, 5 days per week and for 4 weeks. Rats were fed with a standard chow and tap water (C group) or 30 % sucrose diluted in water (S30 group). The St + S30 groups consumed less solid food but had an elevated visceral fat accumulation in comparison with the St group. The St group showed a high level of serum corticosterone and a high activity of the hepatic 11β-HSD-1 concomitantly to the augmentation of hepatic steatosis signs, a high hepatic triacylglycerol content, and hepatic oxidative stress. Conversely, the high-sucrose intake in stressed rats (St + S30 group) reduced the hepatic 11β-HSD-1 activity, the level of serum corticosterone, and the hepatic triacylglycerol content. Present findings show that a high-sucrose diet ameliorates the triacylglycerol accumulation in liver promoted by the restraint stress in young male rats.

  18. Calculation of injection forces for highly concentrated protein solutions.

    PubMed

    Fischer, Ingo; Schmidt, Astrid; Bryant, Andrew; Besheer, Ahmed

    2015-09-30

    Protein solutions often manifest a high viscosity at high solution concentrations, thus impairing injectability. Accordingly, accurate prediction of the injection force based on solution viscosity can greatly support protein formulation and device development. In this study, the shear-dependent viscosity of three concentrated protein solutions is reported, and calculated injection forces obtained by two different mathematical models are compared against measured values. The results show that accurate determination of the needle dimensions and the shear-thinning behavior of the protein solutions is vital for injection force prediction. Additionally, one model delivered more accurate results, particularly for solutions with prominent shear-thinning behavior.

  19. Sugar loss and enzyme inhibition due to oligosaccharide accumulation during high solids-loading enzymatic hydrolysis

    DOE PAGES

    Xue, Saisi; Uppugundla, Nirmal; Bowman, Michael J.; ...

    2015-11-26

    Accumulation of recalcitrant oligosaccharides during high-solids loading enzymatic hydrolysis of cellulosic biomass reduces biofuel yields and increases processing costs for a cellulosic biorefinery. Recalcitrant oligosaccharides in AFEX-pretreated corn stover hydrolysate accumulate to the extent of about 18–25 % of the total soluble sugars in the hydrolysate and 12–18 % of the total polysaccharides in the inlet biomass (untreated), equivalent to a yield loss of about 7–9 kg of monomeric sugars per 100 kg of inlet dry biomass (untreated). These oligosaccharides represent a yield loss and also inhibit commercial hydrolytic enzymes, with both being serious bottlenecks for economical biofuel production frommore » cellulosic biomass. Very little is understood about the nature of these oligomers and why they are recalcitrant to commercial enzymes. This work presents a robust method for separating recalcitrant oligosaccharides from high solid loading hydrolysate in gramme quantities. Composition analysis, recalcitrance study and enzyme inhibition study were performed to understand their chemical nature. Results indicate that, oligosaccharide accumulation occurs during high solid loading enzymatic hydrolysis of corn stover (CS) irrespective of using different pretreated corn stover (dilute acid: DA, ionic liquids: IL, and ammonia fibre expansion: AFEX). The methodology for large-scale separation of recalcitrant oligosaccharides from 25 % solids-loading AFEXcorn stover hydrolysate using charcoal fractionation and size exclusion chromatography is reported for the first time. Oligosaccharides with higher degree of polymerization (DP) were recalcitrant towards commercial enzyme mixtures [Ctec2, Htec2 and Multifect pectinase (MP)] compared to lower DP oligosaccharides. Enzyme inhibition studies using processed substrates (Avicel and xylan) showed that low DP oligosaccharides also inhibit commercial enzymes. Addition of monomeric sugars to oligosaccharides increases the

  20. Sugar loss and enzyme inhibition due to oligosaccharide accumulation during high solids-loading enzymatic hydrolysis

    SciTech Connect

    Xue, Saisi; Uppugundla, Nirmal; Bowman, Michael J.; Cavalier, David; Da Costa Sousa, Leonardo; Dale, Bruce E.; Balan, Venkatesh

    2015-11-26

    Accumulation of recalcitrant oligosaccharides during high-solids loading enzymatic hydrolysis of cellulosic biomass reduces biofuel yields and increases processing costs for a cellulosic biorefinery. Recalcitrant oligosaccharides in AFEX-pretreated corn stover hydrolysate accumulate to the extent of about 18–25 % of the total soluble sugars in the hydrolysate and 12–18 % of the total polysaccharides in the inlet biomass (untreated), equivalent to a yield loss of about 7–9 kg of monomeric sugars per 100 kg of inlet dry biomass (untreated). These oligosaccharides represent a yield loss and also inhibit commercial hydrolytic enzymes, with both being serious bottlenecks for economical biofuel production from cellulosic biomass. Very little is understood about the nature of these oligomers and why they are recalcitrant to commercial enzymes. This work presents a robust method for separating recalcitrant oligosaccharides from high solid loading hydrolysate in gramme quantities. Composition analysis, recalcitrance study and enzyme inhibition study were performed to understand their chemical nature. Results indicate that, oligosaccharide accumulation occurs during high solid loading enzymatic hydrolysis of corn stover (CS) irrespective of using different pretreated corn stover (dilute acid: DA, ionic liquids: IL, and ammonia fibre expansion: AFEX). The methodology for large-scale separation of recalcitrant oligosaccharides from 25 % solids-loading AFEXcorn stover hydrolysate using charcoal fractionation and size exclusion chromatography is reported for the first time. Oligosaccharides with higher degree of polymerization (DP) were recalcitrant towards commercial enzyme mixtures [Ctec2, Htec2 and Multifect pectinase (MP)] compared to lower DP oligosaccharides. Enzyme inhibition studies using processed substrates (Avicel and xylan) showed that low DP oligosaccharides also inhibit commercial enzymes. Addition of monomeric sugars to oligosaccharides increases the

  1. High estrogen concentrations in receiving river discharge from a concentrated livestock feedlot.

    PubMed

    Chen, Te-San; Chen, Ting-Chien; Yeh, Kuei-Jyum C; Chao, How-Ran; Liaw, Ean-Tun; Hsieh, Chi-Ying; Chen, Kuan-Chung; Hsieh, Lien-Te; Yeh, Yi-Lung

    2010-07-15

    Environmental estrogenic chemicals interrupt endocrine systems and generate reproductive abnormalities in wildlife, especially natural and synthetic estrogenic steroid hormones such as 17beta-estradiol (E2), estrone (E1), estriol (E3), 17alpha-ethynylestradiol (EE2), and diethylstilbestrol (DES). Concentrated animal feedlot operations (CAFOs) are of particular concern since large amounts of naturally excreted estrogens are discharged into aquatic environments. This study investigated E2, E1, E3, EE2, and DES with high performance liquid chromatography/tandem mass (HPLC-MS/MS) analyses along Wulo Creek in southern Taiwan, near a concentrated livestock feedlot containing 1,030,000 broiler chickens, 934,000 laying hens, 85,000 pigs, and 1500 cattle. Sampling was performed from December 2008 to May 2009, in which 54 samples were collected. Experimental results indicate that concentrations of EE2 were lower than the limit of detection (LOD), and concentrations of DES were only detected twice. Concentrations ranged from 7.4 to 1267 ng/L for E1, from not detected (ND) to 313.6 ng/L for E2, and from ND to 210 ng/L for E3. E1 had the highest average mass fraction (72.2 + or - 3.6%), which was significantly higher than E3 (16.2 + or - 1.7%) and E2 (11.5 + or - 2.6%). Additionally, the mean E2 equivalent quotient (EEQ) ranged from 17.3 to 137.9 ng-E2/L. Despite having a markedly lower concentration than E1, E2 more significantly contributed (52.4 + or - 6.0%) EEQ than E1 (19.7 + or - 3.5%). Moreover, the concentrations of E2, E1, and E3 upstream were significantly higher than concentrations downstream, suggesting a high attenuation effect and fast degradation in the study water. Most concentrations in winter season were higher than those of spring season due to the low dilution effect and low microbial activity in the winter season. Based on the results of this study, we recommend further treatment of the wastewater discharge from the feedlot.

  2. Atmospheric conditions during high ragweed pollen concentrations in Zagreb, Croatia

    NASA Astrophysics Data System (ADS)

    Prtenjak, Maja Telišman; Srnec, Lidija; Peternel, Renata; Madžarević, Valentina; Hrga, Ivana; Stjepanović, Barbara

    2012-11-01

    We examined the atmospheric conditions favourable to the occurrence of maximum concentrations of ragweed pollen with an extremely high risk of producing allergy. Over the 2002-2009 period, daily pollen data collected in Zagreb were used to identify two periods of high pollen concentration (> 600 grains/m3) for our analysis: period A (3-4 September 2002) and period B (6-7 September 2003). Synoptic conditions in both periods were very similar: Croatia was under the influence of a lower sector high pressure system moving slowly eastward over Eastern Europe. During the 2002-2009 period, this type of weather pattern (on ~ 70% of days), in conjunction with almost non-gradient surface pressure conditions in the area (on ~ 30% of days) characterised days when the daily pollen concentrations were higher than 400 grains/m3. Numerical experiments using a mesoscale model at fine resolution showed successful multi-day simulations reproducing the local topographic influence on wind flow and in reasonable agreement with available observations. According to the model, the relatively weak synoptic flow (predominantly from the eastern direction) allowed local thermal circulations to develop over Zagreb during both high pollen episodes. Two-hour pollen concentrations and 48-h back-trajectories indicated that regional-range transport of pollen grains from the central Pannonian Plain was the cause of the high pollen concentrations during period A. During period B, the north-westward regional-range transport in Zagreb was supplemented significantly by pronounced horizontal recirculation of pollen grains. This recirculation happened within the diurnal local circulation over the city, causing a late-evening increase in pollen concentration.

  3. Accumulated source imaging of brain activity with both low and high-frequency neuromagnetic signals

    PubMed Central

    Xiang, Jing; Luo, Qian; Kotecha, Rupesh; Korman, Abraham; Zhang, Fawen; Luo, Huan; Fujiwara, Hisako; Hemasilpin, Nat; Rose, Douglas F.

    2014-01-01

    Recent studies have revealed the importance of high-frequency brain signals (>70 Hz). One challenge of high-frequency signal analysis is that the size of time-frequency representation of high-frequency brain signals could be larger than 1 terabytes (TB), which is beyond the upper limits of a typical computer workstation's memory (<196 GB). The aim of the present study is to develop a new method to provide greater sensitivity in detecting high-frequency magnetoencephalography (MEG) signals in a single automated and versatile interface, rather than the more traditional, time-intensive visual inspection methods, which may take up to several days. To address the aim, we developed a new method, accumulated source imaging, defined as the volumetric summation of source activity over a period of time. This method analyzes signals in both low- (1~70 Hz) and high-frequency (70~200 Hz) ranges at source levels. To extract meaningful information from MEG signals at sensor space, the signals were decomposed to channel-cross-channel matrix (CxC) representing the spatiotemporal patterns of every possible sensor-pair. A new algorithm was developed and tested by calculating the optimal CxC and source location-orientation weights for volumetric source imaging, thereby minimizing multi-source interference and reducing computational cost. The new method was implemented in C/C++ and tested with MEG data recorded from clinical epilepsy patients. The results of experimental data demonstrated that accumulated source imaging could effectively summarize and visualize MEG recordings within 12.7 h by using approximately 10 GB of computer memory. In contrast to the conventional method of visually identifying multi-frequency epileptic activities that traditionally took 2–3 days and used 1–2 TB storage, the new approach can quantify epileptic abnormalities in both low- and high-frequency ranges at source levels, using much less time and computer memory. PMID:24904402

  4. High concentrations of stavudine impair fatty acid oxidation without depleting mitochondrial DNA in cultured rat hepatocytes.

    PubMed

    Igoudjil, Anissa; Massart, Julie; Begriche, Karima; Descatoire, Véronique; Robin, Marie-Anne; Fromenty, Bernard

    2008-06-01

    The antiretroviral nucleoside reverse-transcriptase inhibitor (NRTI) stavudine (d4T) can induce mild to severe liver injuries such as steatosis (i.e. triglyceride accumulation), steatohepatitis and liver failure. NRTI-induced toxicity has been ascribed to the inhibition of mitochondrial DNA (mtDNA) replication causing mtDNA depletion and respiratory chain dysfunction. This can secondarily impair the tricarboxylic acid cycle and fatty acid oxidation (FAO), thus leading to lactic acidosis and hepatic steatosis. However, NRTIs could also impair mitochondrial function and induce hepatic steatosis through other mechanisms. In this study, we sought to determine whether d4T could inhibit mitochondrial FAO and induce triglyceride accumulation through a mtDNA-independent mechanism. Since human tumoral and non-tumoral hepatic cell lines were unable to efficiently oxidize palmitic acid, the effects of d4T on mitochondrial FAO were assessed on cultured rat hepatocytes. Our results showed that 750 microM of d4T significantly inhibited palmitic acid oxidation after 48 or 72 h of culture, without inducing cell death. Importantly, high concentrations of zidovudine and zalcitabine (two other NRTIs that can induce hepatic steatosis), or beta-aminoisobutyric acid (a d4T metabolite), did not impair FAO in rat hepatocytes. D4T-induced FAO inhibition was observed without mtDNA depletion and lactate production, and was fully prevented with l-carnitine or clofibrate coincubation. l-carnitine also prevented the accretion of neutral lipids within rat hepatocytes. High concentrations of d4T were unable to inhibit FAO on freshly isolated liver mitochondria. Moreover, a microarray analysis was performed to clarify the mechanism whereby d4T can inhibit mitochondrial FAO and induce triglyceride accumulation in rat hepatocytes. The microarray data, confirmed by quantitative real-time PCR analysis, showed that d4T increased the expression of sterol regulatory element-binding protein-1c (SREBP1c

  5. Process for producing high-concentration slurry of coal

    SciTech Connect

    Nakaoji, K.; Itoh, H.; Kamao, M.; Takao, Sh.; Tatsumi, Sh.

    1985-02-19

    High concentrated coal-water slurry is produced by coarsely crushing coal, thereafter pulverizing the coarsely crushed coal, together with water and a slurry dispersant, according to necessity, in a wet-type ball mill, and feeding back one portion of the finely pulverized coal slurry thus obtained into the inlet of the wet-type ball mill.

  6. Waste to Energy Potential - A High Concentration Anaerobic Bioreactor

    DTIC Science & Technology

    2012-05-23

    output • Uses the organic portion of solid waste (such as food waste , paper products, and agricultural waste ) to fuel an anaerobic digestion ...Sustainability Symposium & Exhibition Anaerobic Digestion • What does it do? • Offers sustainability by addressing renewable energy, waste ... Waste to Energy Potential – A High Concentration Anaerobic Bioreactor Presenter: Scott Murphy & Rebecca Robbennolt ARCADIS/Malcolm Pirnie Date

  7. On the concentration structure of high-concentration constant-volume fluid mud gravity currents

    NASA Astrophysics Data System (ADS)

    Jacobson, M. R.; Testik, F. Y.

    2013-01-01

    An exhaustive laboratory experimental campaign was undertaken in order to elucidate the concentration structure of two-dimensional constant-volume non-Newtonian fluid mud gravity currents. Two sets of experiments were conducted in a lock-exchange tank. The first set of experiments involved measuring the vertical concentration profiles using a siphoning technique; the second set involved auxiliary visual observations. The first set of experiments consisted of 32 experimental runs for four different experimental conditions, with an array of siphoned samples being withdrawn throughout the head and body of the gravity current. From these samples, vertical concentration profiles occurring in constant-volume fluid mud gravity currents were classified and the underlying physical processes that led to the occurrence of observed profiles were discussed. Furthermore, the functional form of the vertical concentration profiles within the head of relatively low-initial-concentration gravity currents was proposed. The relatively high-initial-concentration gravity currents revealed the presence of a lutocline in the current head and body, the presence of which was observed for constant-flux release gravity currents. To our knowledge, this is the first measurement of a lutocline in constant-volume gravity currents. Abrupt transitions, a phenomenon in which the bulk of the suspended sediment in the propagating gravity current drops out, were observed through the concentration profiles and through 15 auxiliary visual experimental runs. It was found that abrupt transitions were caused by the presence of a lutocline. The entrainment of ambient water resulting in the dilution of the gravity current at different concentration contours has been quantified. In a previous work by the authors of this study, it was shown that the initial reduced gravity is directly proportional to the growth rate of the visual area of the two-dimensional current. The analysis of our experimental observations

  8. Europium doped lanthanum zirconate nanoparticles with high concentration quenching

    SciTech Connect

    Alaparthi, Suresh B.; Lu, Long; Tian, Yue; Mao, Yuanbing

    2014-01-01

    Graphical abstract: - Highlights: • Eu:La{sub 2}Zr{sub 2}O{sub 7} nanoparticles were prepared facilely by a kinetically modified molten salt method. • High color purity and concentration quenching were achieved in these La{sub 2}Zr{sub 2}O{sub 7}:Eu nanoparticles. • Concentration quenching mechanism was discussed for Eu{sup 3+} in these Eu:La{sub 2}Zr{sub 2}O{sub 7} nanoparticles. - Abstract: A series of Eu{sup 3+} doped lanthanum zirconate (La{sub 2}Zr{sub 2}O{sub 7}) nanoparticles (NPs, 20 ± 5 nm in diameter) with cubic fluorite structure were facilely synthesized by a kinetically modified molten salt synthetic (MSS) process and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and photoluminescence spectra (PL). Under the excitation of 405 nm, intense red emission with high color purity can be observed in the Eu{sup 3+} doped La{sub 2}Zr{sub 2}O{sub 7} NPs. Moreover, the as-prepared Eu:La{sub 2}Zr{sub 2}O{sub 7} NPs possess high concentration quenching, which is as high as ∼32.5 mol% of europium dopants in the La{sub 2}Zr{sub 2}O{sub 7} host. The corresponding concentration quenching mechanism was discussed as well. Our results confirm that the kinetically modified MSS process is a promising approach for preparing rare earth (RE) ions doped A{sub 2}B{sub 2}O{sub 7} nanoparticles with uniform RE doping and high concentration quenching.

  9. Different mechanisms of extracellular adenosine accumulation by reduction of the external Ca(2+) concentration and inhibition of adenosine metabolism in spinal astrocytes.

    PubMed

    Eguchi, Ryota; Akao, Sanae; Otsuguro, Ken-ichi; Yamaguchi, Soichiro; Ito, Shigeo

    2015-05-01

    Extracellular adenosine is a neuromodulator in the central nervous system. Astrocytes mainly participate in adenosine production, and extracellular adenosine accumulates under physiological and pathophysiological conditions. Inhibition of intracellular adenosine metabolism and reduction of the external Ca(2+) concentration ([Ca(2+)]e) participate in adenosine accumulation, but the precise mechanisms remain unclear. This study investigated the mechanisms underlying extracellular adenosine accumulation in cultured rat spinal astrocytes. The combination of adenosine kinase and deaminase (ADK/ADA) inhibition and a reduced [Ca(2+)]e increased the extracellular adenosine level. ADK/ADA inhibitors increased the level of extracellular adenosine but not of adenine nucleotides, which was suppressed by inhibition of equilibrative nucleoside transporter (ENT) 2. Unlike ADK/ADA inhibition, a reduced [Ca(2+)]e increased the extracellular level not only of adenosine but also of ATP. This adenosine increase was enhanced by ENT2 inhibition, and suppressed by sodium polyoxotungstate (ecto-nucleoside triphosphate diphosphohydrolase inhibitor). Gap junction inhibitors suppressed the increases in adenosine and adenine nucleotide levels by reduction of [Ca(2+)]e. These results indicate that extracellular adenosine accumulation by ADK/ADA inhibition is due to the adenosine release via ENT2, while that by reduction of [Ca(2+)]e is due to breakdown of ATP released via gap junction hemichannels, after which ENT2 incorporates adenosine into the cells.

  10. [Toxic effects of high concentrations of ammonia on Euglena gracilis].

    PubMed

    Liu, Yan; Shi, Xiao-Rong; Cui, Yi-Bin; Li, Mei

    2013-11-01

    Ammonia is among the common contaminants in aquatic environments. The present study aimed at evaluation of the toxicity of ammonia at high concentration by detecting its effects on the growth, pigment contents, antioxidant enzyme activities, and DNA damage (comet assay) of a unicellular microalga, Euglena gracilis. Ammonia restrained the growth of E. gracilis, while at higher concentrations, ammonia showed notable inhibition effect, the growth at 2 000 mg x L(-1) was restrained to 55.7% compared with that of the control; The contents of photosynthetic pigments and protein went up with increasing ammonia dosage and decreased when the ammonia concentration was above 1000 mg x L(-1); In addition, there was an obvious increase in SOD and POD activities, at higher concentration (2 000 mg x L(-1)), activities of SOD and POD increased by 30.7% and 49.4% compared with those of the control, indicating that ammonia could promote activities of antioxidant enzymes in E. gracilis; The degree of DNA damage observed in the comet assay increased with increasing ammonia concentration, which suggested that high dose of ammonia may have potential mutagenicity on E. gracilis.

  11. Osmotic induction of calcium accumulation in human embryonic kidney cells detected with a high sensitivity FRET calcium sensor.

    PubMed

    Hou, Bi-Huei; Takanaga, Hitomi; Griesbeck, Oliver; Frommer, Wolf B

    2009-08-01

    Calcium serves as a second messenger in glucose-triggered insulin secretion of pancreatic cells. Less is known about sugar signaling in non-excitable cells. Here, the high sensitivity FRET calcium sensor TN-XXL was used to characterize glucose-induced calcium responses in non-excitable human embryonic kidney HEK293T cells. HEK293T cells responded to perfusion with glucose with a sustained and concentration-dependent increase in cytosolic calcium levels. Sucrose and mannitol triggered comparable calcium responses, suggesting that the increase of the calcium concentration was caused by osmotic effects. HEK293T cells are characterized by low endogenous glucose uptake capacity as shown with a high sensitivity glucose sensor. Consistently, when glucose influx was artificially increased by co-expression of GLUT glucose transporters, the glucose-induced calcium increase was significantly reduced. Neither calcium depletion, nor gadolinium or thapsigargin were able to inhibit the calcium accumulation. Taken together, membrane impermeable osmolytes such as sucrose and mannitol lead to an increase in calcium levels, while the effect of glucose depends on the cell's glucose uptake capacity and will thus vary between cell types in the body that differ in their glucose uptake capacity.

  12. Unusually high indoor radon concentrations from a giant rock slide.

    PubMed

    Ennemoser, O; Ambach, W; Brunner, P; Schneider, P; Oberaigner, W; Purtscheller, F; Stingl, V; Keller, G

    1994-07-18

    In a village in western Tyrol, Austria (Umhausen, approximately 2600 inhabitants) unusually high indoor radon concentrations were measured. The medians were found to be 3750 Bq/m3 (basements) and 1160 Bq/m3 (ground floors) in winter, and 361 Bq/m3 (basements) and 210 Bq/m3 (ground floors) in summer. Maximum radon concentrations of up to 274,000 Bq/m3 were registered. The unusually high radon concentrations are due to the geology of the locality. The part of Umhausen with the highest radon concentrations is built on an alluvial fan of a giant rock slide (granitic gneiss). Measurements of the radon exhalation rate from soil showed a median of 0.4 Bq/m2/s, measurements of the radium content of rock samples yielded a median of 125 Bq/kg. The material of the rock slide is heavily fractured so that an elevated emanating power and an increased diffusion coefficient for radon in soil must be assumed. Given a diffusion coefficient of 8 x 10(-6) m2/s and an emanating power of 0.3, the median exhalation rate of 0.4 Bq/m2/s is obtained at a radium concentration of 125 Bq/kg. The rock slide is therefore considered to be the main source of radon. The abnormally high radon concentrations in Umhausen coincide with a statistically significant increase in lung cancer mortality (age and sex standardized mortality rate = 3.9, 95% C.I.: 2.9-5.1); the control population is the population of the entire Tyrol (630,000 inhabitants).

  13. Combined effects of elevated temperature and CO2 concentration on Cd and Zn accumulation dynamics in Triticum aestivum L.

    PubMed

    Wang, Xiaoheng; Li, Yu; Lu, Hong; Wang, Shigong

    2016-09-01

    A simulated climate warming experiment was conducted to evaluate the combined effects of elevated temperature and CO2 concentration on the bioaccumulation, translocation and subcellular distributions of Cd and Zn in wheat seedlings (Triticum aestivum L. cv. Xihan 1.) at Dingxi, Gansu Province, China. The objective was to find evidence that global climate change is affecting the bioaccumulation of Cd and Zn in T. aestivum L. cv. Xihan 1. The results showed that compared to control A, elevated temperature and CO2 increased Cd bioaccumulation in the shoots by 1.4-2.5 times, and increased that in the roots by 1.2-1.5 times, but decreased Zn levels in wheat shoots by 1.4-2.0 times, while decreased that in the roots by 1.6-1.9 times. Moreover, temperature and CO2 concentration increase also led to increased Cd concentration, and decreased Zn concentration in subcellular compartments of wheat seedlings. The largest Cd concentration increase (174.4%) was observed in the cell wall and debris fractions of shoots after they were subjected to the highest CO2 and temperature treatment (TC3). The largest Zn concentration decrease (53.1%) was observed in the soluble (F3) fractions of shoots after they were subjected to the medium CO2 and temperature treatment (TC2). The temperature and CO2 increase had no significant effect on the proportional distribution of Cd and Zn in the subcellular fractions. The root-to-shoot translocation of Cd increased with the increasing temperature and CO2 concentration. However, the Zn distributions only fluctuated within a small range.

  14. High resolution modelling of snow accumulation and ablation in alpine regions

    NASA Astrophysics Data System (ADS)

    Byrne, J.; Kienzle, S.; Duke, G.; Lapp, S.; Taylor, B.; Neilsen, D.

    2005-12-01

    This work is to combine downscaled climate change scenarios with several meso-micro scale climatologic assessments of alpine snow accumulation and ablation over winter to evaluate the impacts of forecast climate change on snowpack conditions in the Oldman watershed in southern Alberta and Okanagan watershed in southern British Columbia. The synoptic analysis was used to generate long term precipitation time series scenarios using the Canadian Centre for Climate Modeling and Analysis (CCCma) CGCM1 and CGCM2 coupled general circulation model runs. Forecast changes in wintertime synoptic conditions over western North America provided estimates of changing precipitation regimes for the historical (1961-90) and future time periods (2021-50). Temperature changes as forecast by the GCCM1 and CGCM2 model runs were applied to both study basins. The historic and future climate scenarios were applied to both watersheds with several novel meso and micro scale alpine hydrometeorology models and a range of spatial analysis techniques. Work in the Okanagan basin used empirical analysis to de-trend the historical meteorological data and interpolation routines were applied to develop daily high resolution gridded surfaces of temperature and precipitation. The analysis reveals that temperature will play a dominant role in future SWE accumulations and related water supplies from these alpine watersheds. Midwinter melting and conversion of snow to rain will reduce snow accumulations over winter, resulting in much lower spring runoff volumes in an average year. The overall decline in spring maximum SWE for the future period relative to the historic data was about 30% in the Okanagan and about 40% for the Oldman River basin. However, in warm dry years, SWE declines much more, indicating there could be dramatic water shortages in future. The alpine hydrometeorological models need more development, evaluation and validation. Our estimates of SWE at high elevations are likely subject to

  15. Betaine alleviates hepatic lipid accumulation via enhancing hepatic lipid export and fatty acid oxidation in rats fed with a high-fat diet.

    PubMed

    Xu, Li; Huang, Danping; Hu, Qiaolin; Wu, Jing; Wang, Yizhen; Feng, Jie

    2015-06-28

    To assess the effects of betaine on hepatic lipid accumulation and investigate the underlying mechanism, thirty-two male Sprague-Dawley rats weighing 100 (sd 2·50) g were divided into four groups, and started on one of four treatments: basal diet, basal diet with betaine administration, high-fat diet and high-fat diet with betaine administration. The results showed that no significant difference of body weight was found among experimental groups. Compared with high-fat diet-fed rats, a betaine supplementation decreased (P< 0·05) hepatic TAG accumulation induced by high-fat diet, which was also supported by hepatic histology results. Additionally, hepatic betaine-homocysteine methyltransferase concentration [corrected] as well as its mRNA abundance and lecithin level were found increased (P< 0·05) by betaine supplementation in both basal diet-fed rats and high-fat diet-fed rats. Betaine administration in high-fat diet-fed rats exhibited a higher (P< 0·05) concentration [corrected] of hepatic carnitine palmitoyltransferase 1 (CPT1) compared with high-fat diet-fed rats. High-fat diet inhibited (P< 0·05) the gene expression of hepatic PPARα and CPT1. However, betaine administration in high-fat diet-fed rats elevated (P< 0·05) the gene expression of PPARα and CPT1. Moreover, concentration, gene and protein expressions of hepatic fibroblast growth factor 21 (FGF21) were increased (P< 0·05) in response to betaine administration in high-fat diet group; meanwhile the gene expression of hepatic AMP-activated protein kinase was increased (P< 0·05) as well. The results suggest that betaine administration enhanced hepatic lipid export and fatty acid oxidation in high-fat diet-fed rats, thus effectively alleviating fat accumulation in the liver.

  16. Manufacture of concentrated, lipid-based oxygen microbubble emulsions by high shear homogenization and serial concentration.

    PubMed

    Thomson, Lindsay M; Polizzotti, Brian D; McGowan, Frances X; Kheir, John N

    2014-05-26

    Gas-filled microbubbles have been developed as ultrasound contrast and drug delivery agents. Microbubbles can be produced by processing surfactants using sonication, mechanical agitation, microfluidic devices, or homogenization. Recently, lipid-based oxygen microbubbles (LOMs) have been designed to deliver oxygen intravenously during medical emergencies, reversing life-threatening hypoxemia, and preventing subsequent organ injury, cardiac arrest, and death. We present methods for scaled-up production of highly oxygenated microbubbles using a closed-loop high-shear homogenizer. The process can produce 2 L of concentrated LOMs (90% by volume) in 90 min. Resulting bubbles have a mean diameter of ~2 μm, and a rheologic profile consistent with that of blood when diluted to 60 volume %. This technique produces LOMs in high capacity and with high oxygen purity, suggesting that this technique may be useful for translational research labs.

  17. Heavy metal accumulation in Diplodus annularis, Liza aurata, and Solea vulgaris relevant to their concentration in water and sediment from the southwestern Mediterranean (coast of Sfax).

    PubMed

    Ben Salem, Zohra; Ayadi, Habib

    2016-07-01

    The concentrations of heavy metals (Cd, Cu, Fe, Pb, Ni, and Zn) were measured in the liver, gills, and muscle of Solea vulgaris, Liza aurata, and Diplodus annularis, collected from the south coast of Sfax (Gabes Gulf, southwestern Mediterranean). The concentrations of heavy metals in water exhibited the following decreasing order (expressed in μg l(-1)): Fe > Ni > Zn > Cu > Pb > Cd whereas the trend is somewhat different in sediments (mg kg(-1) D.W.) Fe > Zn > Pb > Ni > Cu > Cd. The levels of heavy metals varied significantly among fish species and tissues. Heavy metal levels were found generally higher in the liver and gills than the muscle in all species. The liver was the target organ for Cd, Cu, Fe, Ni, and Zn accumulation. Nickel and lead, however, exhibited their highest concentrations in the gills. The three studied fishes showed a difference in metals accumulation decreasing in following order S. vulgaris > D. annularis > L. aurata. Solea vulgaris with the highest TFwater, TFsediment, and metal concentrations in tissues would be considered as a potential bio-indicator in the south coast of Sfax for the assessment of environmental pollution status. Comparative studies with Luza zone indicate considerable bioaccumulation of heavy metals (Pb and Zn) in the various tissues of fish samples of the south coast of Sfax.

  18. Structure and rheology of highly concentrated emulsions: a modern look

    NASA Astrophysics Data System (ADS)

    Malkin, A. Ya; Kulichikhin, V. G.

    2015-08-01

    The review concerns modern physicochemical, chemical and physical approaches to research into structural features that determine the rheological properties of highly concentrated emulsions. The structures and properties of various systems (suspensions, emulsions as well as transient forms including micellar colloidal solutions) are considered. The formation of highly concentrated emulsions is treated as the concentration glass transition leading to suppression of the molecular and supermolecular mobility and, subsequently, to the existence of a solid-like state of the systems in question. The emphasis is placed on analysis of visco-plasticity which manifests itself in the possibility for emulsions (unlike suspensions) to undergo irreversible deformation (to flow) at stresses exceeding some threshold (critical value) called the yield stress. The thixotropic nature of the transition through the yield stress, governed by the kinetics of the breakup/recovery of the inherent structure is considered in detail. It has been shown that structure formation in highly concentrated emulsions can extend to a macroscopic level and result in the onset of heterogeneity of a flow in the form of shear bands. The bibliography includes 202 references.

  19. Intestinal Mucosal Triacylglycerol Accumulation Secondary to Decreased Lipid Secretion in Obese and High Fat Fed Mice

    PubMed Central

    Douglass, John D.; Malik, Nashmia; Chon, Su-Hyoun; Wells, Kevin; Zhou, Yin Xiu; Choi, Andrew S.; Joseph, Laurie B.; Storch, Judith

    2012-01-01

    The ectopic deposition of fat in liver and muscle during obesity is well established, however surprisingly little is known about the intestine. We used the ob/ob mouse and C57BL6/J mice fed a high fat (HF) diet to examine the effects of obesity and the effects of HF feeding, respectively, on intestinal mucosal triacylglycerol (TG) accumulation. Male C57BL6/J (wild-type, WT) mice were fed low fat (LF; 10% kcal as fat) or HF (45%) diets, and ob/ob mice were fed the LF diet, for 3 weeks. In this time frame, the WT–HF mice did not become obese, enabling independent examination of effects of the HF diet and effects of obesity. Analysis of intestinal lipid extracts from fed and fasted animals demonstrated that the mucosa, like other tissues, accumulates excess lipid. In the fed state, mucosal triacylglycerol (TG) levels were threefold and fivefold higher in the WT–HF and ob/ob mice, respectively, relative to the WT–LF mice. In the fasted state, mucosa from ob/ob mice had threefold higher TG levels relative to WT–LF mucosa. q-PCR analysis of mucosal mRNA from fed state mice showed alterations in the expression of several genes related to both anabolic and catabolic lipid metabolism pathways in WT–HF and ob/ob mice relative to WT–LF controls. Fewer changes were found in mucosal samples from the fasted state animals. Remarkably, oral fat tolerance tests showed a striking reduction in the plasma appearance of an oral fat load in the ob/ob and WT–HF mice compared to WT–LF. Overall, the results demonstrate that the intestinal mucosa accumulates excess TG during obesity. Changes in the expression of lipid metabolic and transport genes, as well as reduced secretion of dietary lipid from the mucosal cells into the circulation, may contribute to the TG accumulation in intestinal mucosa during obesity. Moreover, even in the absence of frank obesity, HF feeding leads to a large decrease in the rate of intestinal lipid secretion. PMID:22375121

  20. Review of silicon solar cells for high concentrations

    NASA Astrophysics Data System (ADS)

    Schwartz, R. J.

    1982-06-01

    The factors that limit the performance of high concentration silicon solar cells are reviewed. The design of a conventional high concentration cell is discussed, together with the present state of the art. Unconventional cell designs that have been proposed to overcome the limitations of the conventional design are reviewed and compared. The current status of unconventional cells is reviewed. Among the unconventional cells discussed are the interdigitated back-contact cell, the double-sided cell, the polka dot cell, and the V-groove cell. It is noted that all the designs for unconventional cells require long diffusion lengths for high efficiency operation, even though the demands in this respect are less for those cells with the optical path longer than the diffusion path.

  1. The fate of fertilizer nitrogen in a high nitrate accumulated agricultural soil.

    PubMed

    Quan, Zhi; Huang, Bin; Lu, Caiyan; Shi, Yi; Chen, Xin; Zhang, Haiyang; Fang, Yunting

    2016-02-12

    Well-acclimatized nitrifiers in high-nitrate agricultural soils can quickly nitrify NH4(+) into NO3(-) subject to leaching and denitrifying loss. A 120-day incubation experiment was conducted using a greenhouse soil to explore the fates of applied fertilizer N entering into seven soil N pools and to examine if green manure (as ryegrass) co-application can increase immobilization of the applied N into relatively stable N pools and thereby reduce NO3(-) accumulation and loss. We found that 87-92% of the applied (15)N-labelled NH4(+) was rapidly recovered as NO3(-) since day 3 and only 2-4% as microbial biomass and soil organic matter (SOM), while ryegrass co-application significantly decreased its recovery as NO3(-) but enhanced its recovery as SOM (17%) at the end of incubation. The trade-off relationship between (15)N recoveries in microbial biomass and SOM indicated that ryegrass co-application stabilized newly immobilized N via initial microbial uptake and later breakdown. Nevertheless, ryegrass application didn't decrease soil total NO3(-) accumulation due to its own decay. Our results suggest that green manure co-application can increase immobilization of applied N into stable organic N via microbial turnover, but the quantity and quality of green manure should be well considered to reduce N release from itself.

  2. High-energy carbonate-sand accumulation, the Quicksands, southwest Florida Keys

    USGS Publications Warehouse

    Shinn, Eugene A.; Lidz, Barbara H.; Holmes, Charles W.

    1990-01-01

    High-resolution seismic-reflection profiles of the Quicksands, located along a broad ridge on the platform shelf west of Key West, Florida, indicate a significant deposit of non-oolitic carbonate sand occurs in a belt 47 km long by 28 km wide. The surface of the belt is ornamented by large (5 m), migrating tidal bars, oriented in a north-south direction, on which sand waves, oriented in an east-west direction, are superimposed. Some of the sand waves are awash at low tide. The sand waves are formed by strong reversing tidal currents flowing between the Gulf of Mexico and the Straits of Florida. The waves migrate directly over Pleistocene bedrock to the east, but the deposit thickens to the west and sand waves there overlie non-oolitic Holocene accumulations as thick as 12 m. Westward-dipping accretionary bedding indicates that net migration of the sands is to the west, despite north-south movement of tidal currents. The westward edge of the accumulation has accreted over deeper, muddier deposits. Although tidal currents and resultant bedforms appear identical to those of active ooid deposits in the Bahamas and elsewhere, no oolitically coated grains were found in this study. Thin-section analyses show the principal component (average 48%) of the sands is fragmented plates of species of the green alga Halimeda , followed by particulate coral (average 17%), which increases off the flanks of the main sand body. Short vibracores confirm the presence of cross-bedding.

  3. The fate of fertilizer nitrogen in a high nitrate accumulated agricultural soil

    PubMed Central

    Quan, Zhi; Huang, Bin; Lu, Caiyan; Shi, Yi; Chen, Xin; Zhang, Haiyang; Fang, Yunting

    2016-01-01

    Well-acclimatized nitrifiers in high-nitrate agricultural soils can quickly nitrify NH4+ into NO3− subject to leaching and denitrifying loss. A 120-day incubation experiment was conducted using a greenhouse soil to explore the fates of applied fertilizer N entering into seven soil N pools and to examine if green manure (as ryegrass) co-application can increase immobilization of the applied N into relatively stable N pools and thereby reduce NO3− accumulation and loss. We found that 87–92% of the applied 15N-labelled NH4+ was rapidly recovered as NO3− since day 3 and only 2–4% as microbial biomass and soil organic matter (SOM), while ryegrass co-application significantly decreased its recovery as NO3− but enhanced its recovery as SOM (17%) at the end of incubation. The trade-off relationship between 15N recoveries in microbial biomass and SOM indicated that ryegrass co-application stabilized newly immobilized N via initial microbial uptake and later breakdown. Nevertheless, ryegrass application didn’t decrease soil total NO3− accumulation due to its own decay. Our results suggest that green manure co-application can increase immobilization of applied N into stable organic N via microbial turnover, but the quantity and quality of green manure should be well considered to reduce N release from itself. PMID:26868028

  4. Atmospheric Controls of Snow Accumulation on Glaciers and Ice Caps in High Asia

    NASA Astrophysics Data System (ADS)

    Scherer, D.; Curio, J.

    2015-12-01

    Snowfall is the major contributor to snow accumulation on glaciers and ice caps. Unfortunately, its quantification is rather difficult, both by observations and by numerical modelling. Field measurements of snowfall are generally problematic, and particularly inaccurate in mountainous regions. This holds true also for data from remote sensing systems like the TRMM. Numerical modelling of precipitation in general, and of snowfall in particular, is depending on parameterization of sub-grid processes occurring at a wide range of spatial scales. The scarcity of reliable observational data on snowfall required to test and validate the relevant parameterization schemes is one of the major obstacles for deepening our understanding of atmospheric controls of snow accumulation on glaciers and ice caps. In addition, the often made assumption that easy-to-measure snow accumulation equals snowfall is not valid in areas where other processes like snowdrift or avalanches cause snow deposition or erosion. Besides a general discussion of the above-mentioned problems, the presentation will focus on results obtained from a gridded atmospheric data set, i.e., the so-called High Asia Refined analysis (HAR), covering the study region by two nested domains of 30 km and 10 km grid spacing. Starting from autumn 2000, three-hourly (30 km) and hourly (10 km) data are available for a comprehensive set of atmospheric variables (see www.klima.tu-berlin.de/HAR). HAR data was used to analyse annual and seasonal patterns of precipitation and atmospheric water transport, as well as to drive numerical models for surface mass balance of glaciers and ice sheets. A new study, which is the main subject of this presentation, reveals specific regimes of dynamic controls of precipitation in different regions of High Asia. One of the striking results is that the analysis identified a specific regime that is able to explain some of the atmospheric controls behind the so-called Karakoram anomaly (glaciers in

  5. High Actin Concentrations in Brain Dendritic Spines and Postsynaptic Densities

    NASA Astrophysics Data System (ADS)

    Matus, Andrew; Ackermann, Marcel; Pehling, Gundula; Randolph Byers, H.; Fujiwara, Keigi

    1982-12-01

    Antibodies against actin were used to corroborate the presence of actin as a major component protein of isolated brain postsynaptic densities. The same antibodies also were used as an immunohistochemical stain to study the distribution of actin in sections of intact brain tissue. This showed two major sites where actin is concentrated: smooth muscle cells around blood vessels and postsynaptic sites. In the postsynaptic area the highest concentration of actin occurs in postsynaptic densities and there also is intense staining in the surrounding cytoplasm, especially within dendritic spines. Antiactin staining was much weaker in other parts of neurons and in glial cells. The high concentration of actin in dendritic spines may be related to shape changes that these structures have been found to undergo in response to prolonged afferent stimulation.

  6. Decomposition of high concentration SF6 using an electron beam

    NASA Astrophysics Data System (ADS)

    Son, Youn-Suk; Lee, Sung-Joo; Choi, Chang Yong; Park, Jun-Hyeong; Kim, Tak-Hyun; Jung, In-Ha

    2016-07-01

    In this study, high concentration SF6 (2-10%) was decomposed using an electron beam irradiation. Various influential factors were investigated to improve the destruction and removal efficiency (DRE) of SF6. The initial concentrations of SF6, absorbed doses, SF6/H2 ratios and retention times were the main factors of concern. As a result, the DRE increased as the adsorbed dose and retention time increased. The DRE of SF6 also increased up to 20% approximately when H2 was added to the reaction mixture. On the other hand, the DRE of SF6 decreased as initial concentrations of SF6 increased. Finally, the main by-product formed from SF6 decomposition by the electron beam was HF.

  7. Athletic Activity and Hormone Concentrations in High School Female Athletes

    PubMed Central

    Wojtys, Edward M.; Jannausch, Mary L.; Kreinbrink, Jennifer L.; Harlow, Siobán D.; Sowers, MaryFran R.

    2015-01-01

    Context: Physical activity may affect the concentrations of circulating endogenous hormones in female athletes. Understanding the relationship between athletic and physical activity and circulating female hormone concentrations is critical. Objective: To test the hypotheses that (1) the estradiol-progesterone profile of high school adolescent girls participating in training, conditioning, and competition would differ from that of physically inactive, age-matched adolescent girls throughout a 3-month period; and (2) athletic training and conditioning would alter body composition (muscle, bone), leading to an increasingly greater lean–body-mass to fat–body-mass ratio with accompanying hormonal changes. Design: Cohort study. Settings: Laboratory and participants' homes. Patients or Other Participants: A total of 106 adolescent girls, ages 14–18 years, who had experienced at least 3 menstrual cycles in their lifetime. Main Outcome Measure(s): Participants were prospectively monitored throughout a 13-week period, with weekly physical activity assessments and 15 urine samples for estrogen, luteinizing hormone, creatinine, and progesterone concentrations. Each girl underwent body-composition measurements before and after the study period. Results: Seventy-four of the 98 girls (76%) who completed the study classified themselves as athletes. Body mass index, body mass, and fat measures remained stable, and 17 teenagers had no complete menstrual cycle during the observation period. Mean concentrations of log(estrogen/creatinine) were slightly greater in nonathletes who had cycles of <24 or >35 days. Mean log(progesterone/creatinine) concentrations in nonathletes were less in the first half and greater in the second half of the cycle, but the differences were not statistically significant. Conclusions: A moderate level of athletic or physical activity did not influence urine concentrations of estrogen, progesterone, or luteinizing hormones. However, none of the

  8. Understanding dry matter and nitrogen accumulation with time-course for high-yielding wheat production in China.

    PubMed

    Meng, Qingfeng; Yue, Shanchao; Chen, Xinping; Cui, Zhenling; Ye, Youliang; Ma, Wenqi; Tong, Yanan; Zhang, Fusuo

    2013-01-01

    Understanding the time-course of dry matter (DM) and nitrogen (N) accumulation in terms of yield-trait relationships is essential to simultaneously increase grain yield and synchronize N demand and N supply. We collected 413 data points from 11 field experiments to address patterns of DM and N accumulation with time in relation to grain yield and management of winter wheat in China. Detailed growth analysis was conducted at the Zadok growth stages (GS) 25 (regreening), GS30 (stem elongation), GS60 (anthesis), and GS100 (maturity) in all experiments, including DM and N accumulation. Grain yield averaged 7.3 Mg ha(-1), ranging from 2.1 to 11.2 Mg ha(-1). The percent N accumulation was consistent prior to DM accumulation, while both DM and N accumulation increased continuously with growing time. Both the highest and fastest DM and N accumulations were observed from stem elongation to the anthesis stage. Significant correlations between grain yield and DM and N accumulation were found at each of the four growth stages, although no positive relationship was observed between grain yield and harvest index or N harvest index. The yield increase from 7-9 Mg ha(-1) to >9 Mg ha(-1) was mainly attributed to increased DM and N accumulation from stem elongation to anthesis. Although applying more N fertilizer increased N accumulation during this stage, DM accumulation was not improved, indicating that N fertilizer management and related agronomic management should be intensified synchronously across the wheat growing season to simultaneously achieve high yields and match N demand and N supply.

  9. Acute toxicity of high concentrations of carbon dioxide in rats.

    PubMed

    Muijser, H; van Triel, J J; Duistermaat, E; Bos, P M J

    2014-07-01

    Subterranean storage of carbon dioxide (CO2) has been proposed to diminish atmospheric increases of this greenhouse gas. To contribute to risk assessment of accidental release associated with handling, transport and storage, rats were exposed to high concentrations (targets 40, 43 and 50 volume %) of CO2. The oxygen concentrations dropped as a result, but were not supplemented. For each concentration, pairs of animals were exposed for different exposure durations to derive an exposure concentration-duration relation in which mortality is described as a function of C(n)×t (probit relation). A very high "n" value for the probit function could be derived from the data obtained at 40% and 43% CO2, which indicates that for exposure durations longer than 30 min the LC50 decreases hardly with increasing exposure duration. Below 30 min the LC50 seemed to increase with decreasing exposure durations. The variability in the data of 43% and 50% CO2, however, did not allow to derive a meaningful value of "n".

  10. High-efficiency GaAs concentrator space cells

    NASA Technical Reports Server (NTRS)

    Werthen, J. G.; Virshup, G. F.; Macmillan, H. F.; Ford, C. W.; Hamaker, H. C.

    1987-01-01

    High efficiency Al sub x Ga sub 1-x As/GaAs heteroface solar concentrator cells have been developed for space applications. The cells, which were grown using metalorganic chemical vapor deposition (MOCVD), have been fabricated in both the p-n and n-p configurations. Magnesium and zinc are used as the p-type dopants, and Se is used as the n-type dopant. The space cells, which are designed for use in a Cassegrainian concentrator operating at 100 suns, AMO, have a circular illuminated area 4 mm in diameter on a 5 mm by 5 mm cell. These cells have exhibited flash-tested efficiencies as high as 23.6 percent at 28 C and 21.6 percent at 80 C.

  11. Responses in growth, lipid accumulation, and fatty acid composition of four oleaginous microalgae to different nitrogen sources and concentrations

    NASA Astrophysics Data System (ADS)

    Li, Tao; Wan, Linglin; Li, Aifen; Zhang, Chengwu

    2013-11-01

    Nitrogen deficiency is an effective strategy for enhancing lipid production in microalgae. Close relationships exist among lipid production, microalgal species, and nitrogen sources. We report growth, lipid accumulation, and fatty acid composition in four microalgae ( Chlorococcum ellipsoideum UTEX972, Chlorococcum nivale LB2225, Chlorococcum tatrense UTEX2227, and Scenedesmus deserticola JNU19) under nitrate- and urea-nitrogen deficiencies. We found three patterns of response to nitrogen deficiency: Type-A (decrease in biomass and increase in lipid content), Type-B (reduction in both biomass and lipid content), and Type-C (enhancement of both biomass and lipid content). Type-C microalgae are potential candidates for large-scale oil production. Chlorococcum ellipsoideum, for example, exhibited a neutral lipid production of up to 239.6 mg/(L·d) under urea-nitrogen deficiency. In addition, nitrogen deficiency showed only a slight influence on lipid fractions and fatty acid composition. Our study provides useful information for further screening hyper-lipid microalgal strains for biofuel production.

  12. Mercury concentrations in canned and fresh fish and its accumulation in a population of Port Moresby residents.

    PubMed

    Kyle, J H; Ghani, N

    1983-01-01

    Five varieties of canned fish and hair specimens from 243 subjects in Port Moresby have been analysed for organic and total mercury. The mean concentrations of total mercury in the canned fish were 0.45 mg/kg for tuna, 0.21 mg/kg for salmon, 0.17 mg/kg for mackerel, 0.08 mg/kg for sardines and 0.04 mg/kg for pilchard, based on the weight of the fish. The mean hair concentration was 2.1 mg/kg, the standard deviation 1.8 mg/kg and the range 0.15 to 14.4 mg/kg. The total mercury levels in hair were significantly higher for coastal people than for non-coastals. Although this is probably due to the greater fish intake of the coastal people, no significant correlation was found between fish consumption and hair mercury levels.

  13. The chromium accumulation and its physiological effects in juvenile rockfish, Sebastes schlegelii, exposed to different levels of dietary chromium (Cr(6+)) concentrations.

    PubMed

    Kim, Jun-Hwan; Kang, Ju-Chan

    2016-01-01

    Juvenile rockfish (mean length 13.7±1.7 cm, and mean weight 55.6±4.8 g) were exposed for 4 weeks with the different levels of dietary chromium (Cr(6+)) at 0, 30, 60, 120 and 240 mg/kg. The profile of chromium in the tissues of rockfish is dependent on the exposure periods and chromium concentration. After 4 weeks, the order of chromium accumulation in tissues was liver>kidney>spleen>intestine>gill>muscle. The dietary chromium exposure decreased the growth rate and hepatosomatic index of rockfish. The major hematological findings were significant decrease in the red blood cell (RBC) count, hematocrit (Ht) value, and hemoglobin (Hb) concentration exposed to ≥120 mg/kg chromium concentrations. The dietary chromium exposure (≥120 mg/kg) led to notable increase in glucose, cholesterol, glutamic oxalate transaminase (GOT), and glutamic pyruvate transaminase (GPT) in plasma, whereas there was no considerable change in calcium, magnesium, total protein, and alkaline phosphatase (ALP). The results indicated that the dietary chromium exposure to rockfish can induce significant chromium accumulation in the specific tissues, inhibition of growth, and hematological alterations.

  14. Human Adipose-Derived Stem Cells Expanded Under Ambient Oxygen Concentration Accumulate Oxidative DNA Lesions and Experience Procarcinogenic DNA Replication Stress.

    PubMed

    Bétous, Rémy; Renoud, Marie-Laure; Hoede, Claire; Gonzalez, Ignacio; Jones, Natalie; Longy, Michel; Sensebé, Luc; Cazaux, Christophe; Hoffmann, Jean-Sébastien

    2017-01-01

    Adipose-derived stem cells (ADSCs) have led to growing interest in cell-based therapy because they can be easily harvested from an abundant tissue. ADSCs must be expanded in vitro before transplantation. This essential step causes concerns about the safety of adult stem cells in terms of potential transformation. Tumorigenesis is driven in its earliest step by DNA replication stress, which is characterized by the accumulation of stalled DNA replication forks and activation of the DNA damage response. Thus, to evaluate the safety of ADSCs during ex vivo expansion, we monitored DNA replication under atmospheric (21%) or physiologic (1%) oxygen concentration. Here, by combining immunofluorescence and DNA combing, we show that ADSCs cultured under 21% oxygen accumulate endogenous oxidative DNA lesions, which interfere with DNA replication by increasing fork stalling events, thereby leading to incomplete DNA replication and fork collapse. Moreover, we found by RNA sequencing (RNA-seq) that culture of ADSCs under atmospheric oxygen concentration leads to misexpression of cell cycle and DNA replication genes, which could contribute to DNA replication stress. Finally, analysis of acquired small nucleotide polymorphism shows that expansion of ADSCs under 21% oxygen induces a mutational bias toward deleterious transversions. Overall, our results suggest that expanding ADSCs at a low oxygen concentration could reduce the risk for DNA replication stress-associated transformation, as occurs in neoplastic tissues. Stem Cells Translational Medicine 2017;6:68-76.

  15. Human Adipose-Derived Stem Cells Expanded Under Ambient Oxygen Concentration Accumulate Oxidative DNA Lesions and Experience Procarcinogenic DNA Replication Stress.

    PubMed

    Bétous, Rémy; Renoud, Marie-Laure; Hoede, Claire; Gonzalez, Ignacio; Jones, Natalie; Longy, Michel; Sensebé, Luc; Cazaux, Christophe; Hoffmann, Jean-Sébastien

    2016-08-24

    : Adipose-derived stem cells (ADSCs) have led to growing interest in cell-based therapy because they can be easily harvested from an abundant tissue. ADSCs must be expanded in vitro before transplantation. This essential step causes concerns about the safety of adult stem cells in terms of potential transformation. Tumorigenesis is driven in its earliest step by DNA replication stress, which is characterized by the accumulation of stalled DNA replication forks and activation of the DNA damage response. Thus, to evaluate the safety of ADSCs during ex vivo expansion, we monitored DNA replication under atmospheric (21%) or physiologic (1%) oxygen concentration. Here, by combining immunofluorescence and DNA combing, we show that ADSCs cultured under 21% oxygen accumulate endogenous oxidative DNA lesions, which interfere with DNA replication by increasing fork stalling events, thereby leading to incomplete DNA replication and fork collapse. Moreover, we found by RNA sequencing (RNA-seq) that culture of ADSCs under atmospheric oxygen concentration leads to misexpression of cell cycle and DNA replication genes, which could contribute to DNA replication stress. Finally, analysis of acquired small nucleotide polymorphism shows that expansion of ADSCs under 21% oxygen induces a mutational bias toward deleterious transversions. Overall, our results suggest that expanding ADSCs at a low oxygen concentration could reduce the risk for DNA replication stress-associated transformation, as occurs in neoplastic tissues.

  16. Vertical distribution of trace-element concentrations and occurrence of metallurgical slag particles in accumulated bed sediments of Lake Roosevelt, Washington, September 2002

    USGS Publications Warehouse

    Cox, S.E.; Bell, P.R.; Lowther, J.S.; Van Metre, P.C.

    2005-01-01

    Sediment cores were collected from six locations in Lake Roosevelt to determine the vertical distributions of trace-element concentrations in the accumulated sediments of Lake Roosevelt. Elevated concentrations of arsenic, cadmium, copper, lead, mercury, and zinc occurred throughout much of the accumulated sediments. Concentrations varied greatly within the sediment core profiles, often covering a range of 5 to 10 fold. Trace-element concentrations typically were largest below the surficial sediments in the lower one-half of each profile, with generally decreasing concentrations from the 1964 horizon to the surface of the core. The trace-element profiles reflect changes in historical discharges of trace elements to the Columbia River by an upstream smelter. All samples analyzed exceeded clean-up guidelines adopted by the Confederated Tribes of the Colville Reservation for cadmium, lead, and zinc and more than 70 percent of the samples exceeded cleanup guidelines for mercury, arsenic, and copper. Although 100 percent of the samples exceeded sediment guidelines for cadmium, lead, and zinc, surficial concentrations of arsenic, copper, and mercury in some cores were less than the sediment-quality guidelines. With the exception of copper, the trace-element profiles of the five cores collected along the pre-reservoir Columbia River channel typically showed trends of decreasing concentrations in sediments deposited after the 1964 time horizon. The decreasing concentrations of trace elements in the upper half of cores from along the pre-reservoir Columbia River showed a pattern of decreasing concentrations similar to reductions in trace-element loading in liquid effluent from an upstream smelter. Except for arsenic, trace-element concentrations typically were smaller at downstream reservoir locations along the pre-reservoir Columbia River. Trace-element concentration in sediments from the Spokane Arm of the reservoir showed distinct differences compared to the similarities

  17. Particle sedimentation monitoring in high-concentration slurries

    NASA Astrophysics Data System (ADS)

    Nagasawa, Yoshihiro; Kato, Zenji; Tanaka, Satoshi

    2016-11-01

    In this study, the sedimentation states of particles in high-concentration slurries were elucidated by monitoring their internal states. We prepared transparent high-concentration silica slurries by adjusting the refractive index of the aqueous glycerol liquid in which the particles were dispersed to match that of the silica particles. In addition, a fluorescent dye was dissolved in the liquid. Then, we directly observed the individual and flocculated particles in the slurries during sedimentation by confocal laser scanning fluorescent microscopy. The particles were found to sediment very slowly while exhibiting fluctuating motion. The particle sedimentation rate in the high-concentration slurry with the aqueous glycerol solution (η =0.068 Pa. s ) and a particle volume fraction on the order of 0.3 was determined to be 1.58 ± 0.66 μ m. min-1 on the basis of the obtained image sequences for 24.9 h. In-situ observation provides a large amount of information about the sedimentation behavior of particles in condensed matter.

  18. Study of upconversion in PCFs with high erbium concentration

    NASA Astrophysics Data System (ADS)

    Berdejo, Víctor; Vallés, Juan A.; Rebolledo, Miguel Á.; Diez, Antonio; Martin, Juan C.; Sanchez-Martin, José A.; Álvarez, José M.; Andrés, Miguel V.

    2011-09-01

    We report on a comparison of characterization techniques for high concentration erbium-doped photonic crystal fibres (PCFs). A highly erbium-doped-silica PCF was fabricated and an amplifier based on the PCF was built. Then, measurements on the amplifier output optical powers were carried out. To model the amplifier, three different formalisms were assumed for the Er3+-ion upconversion mechanism and the numerical results were fitted to the experimental ones. The sets of best-fit parameters are compared and the use of these techniques for active PCF characterisation is discussed.

  19. Improved Dispersion of Carbon Nanotubes in Polymers at High Concentrations

    PubMed Central

    Liu, Chao-Xuan; Choi, Jin-Woo

    2012-01-01

    The polymer nanocomposite used in this work comprises elastomer poly(dimethylsiloxane) (PDMS) as a polymer matrix and multi-walled carbon nanotubes (MWCNTs) as a conductive nanofiller. To achieve uniform distribution of carbon nanotubes within the polymer, an optimized dispersion process was developed, featuring a strong organic solvent—chloroform, which dissolved PDMS base polymer easily and allowed high quality dispersion of MWCNTs. At concentrations as high as 9 wt.%, MWCNTs were dispersed uniformly through the polymer matrix, which presented a major improvement over prior techniques. The dispersion procedure was optimized via extended experimentation, which is discussed in detail.

  20. Amino acid accumulation in frog muscle. II. Are cycloleucine fluxes consistent with an adsorption model for concentrative uptake of amino acid?

    PubMed

    Neville, M C

    1975-03-25

    Cycloleucine accumulation by frog muscle was studied at 0 degrees C and 25 degrees C. At external concentrations less than 5 mM the distribution ratio of cycloleucine is higher at 0 degrees C. At concentrations greater than 5 mM the converse is true due to apparent exclusion of cycloleucine from a larger portion of the cell water at 0 degrees C than at 25 degrees C. The steady state data are consistent with an adsorption model for amino acid accumulation. Flux studies provide a means to rule out this model if all the possible rate-limiting steps in the movement of amino acid into and out of the cell are considered. These steps include intra-cytoplasmic diffusion, desorption from cytoplasmic or membrane sites and passage through the cell membrane. The assumption is made that the rate-limiting step for influx and efflux is the same, allowing the use of either influx or efflux data to examine the model. Diffusion-limited flux is ruled out on the basis of "influx profile analysis" of the time course of cycloleucine entry at both 0 degrees C and 25 degrees C. At least 95% of all intracellular cycloleucine leaves frog muscle cells with a single exponential time course at both 0 degrees C and 25 degrees C. The rate constant of efflux does not vary with cellular concentration. These findings are shown to be incompatible with desorption-limited efflux. They are compatible with membrane-limited efflux only if (i) adsorption sites are located on membranes with direct access to the extracellular space and (ii) the rate constant for desorption is equal to the rate constant of membrane-limited efflux of free amino acid. It is considered unlikely that such a coincidence would occur at both 0 degrees C and 25 degrees C. Therefore, an adsorption model for cycloleucine accumulation in frog muscle appears to be untenable.

  1. High concentration biotherapeutic formulation and ultrafiltration: Part 1 pressure limits.

    PubMed

    Lutz, Herb; Arias, Joshua; Zou, Yu

    2017-01-01

    High therapeutic dosage requirements and the desire for ease of administration drive the trend to subcutaneous administration using delivery systems such as subcutaneous pumps and prefilled syringes. Because of dosage volume limits, prefilled syringe administration requires higher concentration liquid formulations, limited to about 30 cP or roughly 100-300 g L(-1) for mAb's. Ultrafiltration (UF) processes are routinely used to formulate biological therapeutics. This article considers pressure constraints on the UF process that may limit its ability to achieve high final product concentrations. A system hardware analysis shows that the ultrafiltration cassette pressure drop is the major factor limiting UF systems. Additional system design recommendations are also provided. The design and performance of a new cassette with a lower feed channel flow resistance is described along with 3D modeling of feed channel pressure drop. The implications of variations in cassette flow channel resistance for scaling up and setting specifications are considered. A recommendation for a maximum pressure specification is provided. A review of viscosity data and theory shows that molecular engineering, temperature, and the use of viscosity modifying excipients including pH adjustment can be used to achieve higher concentrations. The combined use of a low pressure drop cassette with excipients further increased final concentrations by 35%. Guidance is provided on system operation to control hydraulics during final concentration. These recommendations should allow one to design and operate systems to routinely achieve the 30 cP target final viscosity capable of delivery using a pre-filled syringe. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:113-124, 2017.

  2. Spectral phonon mean free path and thermal conductivity accumulation in defected graphene: The effects of defect type and concentration

    NASA Astrophysics Data System (ADS)

    Feng, Tianli; Ruan, Xiulin; Ye, Zhenqiang; Cao, Bingyang

    2015-06-01

    The spectral phonon properties in defected graphene have been unclear due to the lack of advanced techniques for predicting the phonon-defect scattering rate without fitting parameters. Taking advantage of the extended phonon normal mode analysis, we obtained the spectral phonon relaxation time and mean free path (MFP) in defected graphene and studied the impacts of three common types of defects: Stone-Thrower-Wales (STW) defect, double vacancy (DV), and monovacancy (MV). The phonon-STW defect scattering rate is found to have no significant frequency dependence, and as a result, the relative contribution of long-wavelength phonons sharply decreases. In contrast, the phonon scattering by DVs or MVs exhibits a frequency dependence of τp-d -1˜ω1.1 -1.3 except for a few long-wavelength phonons, revisiting the traditionally used ˜ω4 dependence. We note that although MV-defected graphene has the lowest thermal conductivity as compared to the other two defected graphene samples at the same defect concentration, it has a portion of phonons with the longest MFP. The contribution from the long-MFP and long-wavelength phonons does not decrease much as the vacancy concentration increases. STW defect and MV block more out-of-plane modes than in-plane modes, while DV has less bias for which mode to block. As the MV concentration increases from 0 to 1.1%, the relative contribution from out-of-plane modes decreases from 30% to 18%, while that of the transverse acoustic mode remains at around 30%. These findings of spectral phonon properties can provide more insight than the effective properties and benefit the prospective phononic engineering.

  3. Wet oxidation of real coke wastewater containing high thiocyanate concentration.

    PubMed

    Oulego, Paula; Collado, Sergio; Garrido, Laura; Laca, Adriana; Rendueles, Manuel; Díaz, Mario

    2014-01-01

    Coke wastewaters, in particular those with high thiocyanate concentrations, represent an important environmental problem because of their very low biodegradability. In this work, the treatment by wet oxidation of real coke wastewaters containing concentrations of thiocyanate above 17 mM has been studied in a 1-L semi-batch reactor at temperatures between 453 and 493 K, with total oxygen pressures in the range of 2.0-8.0 MPa. A positive effect of the matrix of real coke wastewater was observed, resulting in faster thiocyanate degradation than was obtained with synthetic wastewaters. Besides, the effect of oxygen concentration and temperature on thiocyanate wet oxidation was more noticeable in real effluents than in synthetic wastewaters containing only thiocyanate. It was also observed that the degree of mineralization of the matrix organic compounds was higher when the initial thiocyanate concentration increased. Taking into account the experimental data, kinetic models were obtained, and a mechanism implying free radicals was proposed for thiocyanate oxidation in the matrix considered. In all cases, sulphate, carbonates and ammonium were identified as the main reaction products of thiocyanate wet oxidation.

  4. Intraspecific variation in cadmium tolerance and accumulation of a high-biomass tropical tree Averrhoa carambola L.: implication for phytoextraction.

    PubMed

    Dai, Zi-yun; Shu, Wen-sheng; Liao, Bin; Wan, Cai-yun; Li, Jin-tian

    2011-06-01

    Averrhoa carambola L., a high-biomass tropical tree, has recently been shown to be a strong accumulator of cadmium (Cd) and has great potential for Cd phytoextraction. In the present study, field studies and a controlled-environment experiment were combined to establish the extent of variation in Cd tolerance and accumulation at the cultivar level using 14 to 19 cultivars of A. carambola. The results indicated that all cultivars tested could accumulate Cd at high but different levels, and that Cd tolerance also varied greatly between these cultivars. It is confirmed that the high Cd tolerance and accumulation capacity are species-level and constitutional traits in A. carambola. However, no correlation was detected between tolerance index and accumulation of Cd in different cultivars, suggesting that the two traits are independent in this woody Cd accumulator. More importantly, cultivar Wuchuan Sweet (WCT) was shown to have the highest Cd-extraction potential; it yielded a high shoot biomass of 30 t ha(-1) in 230 d, and extracted 330 g ha(-1) Cd in the aerial tissues grown in Cd-contaminated field soil, which accounted for 12.8% of the total soil Cd in the top 20 cm of the soil profile.

  5. Effect of seasonal variation in seawater dissolved mercury concentrations on mercury accumulation in the muscle of red sea bream (Pagrus major) held in Minamata Bay, Japan.

    PubMed

    Matsuyama, Akito; Yokoyama, Saichiro; Kindaichi, Michiaki; Sonoda, Ikuko; Koyama, Jiro

    2013-09-01

    Japanese stingfish (Sebastiscus marmoratus) and Bambooleaf wrasse (Pseudolabrus japonicas) are monitored annually for mercury pollution in Minamata Bay, Japan. The average total mercury concentration in the muscle of these two species in Minamata Bay was 0.36 mg kg(-1) wet weight and 0.20 kg(-1) wet weigh, respectively, between 2008 and 2010. This is higher than levels elsewhere in Japan (0.125 mg kg(-1) wet weight and 0.038 mg kg(-1) wet weight, respectively). The FDA (2001) and EPA (2004) suggested that a proportion of mercury accumulated in fish is derived from seawater. We reared young red sea bream (Pagrus major) over a 2-year period in Minamata Bay and Nagashima (control) to evaluate the uptake of mercury from seawater and dietary sources. Fish were fed a synthesized diet that did not contain mercury. There was no difference in mercury accumulation in the muscle of red sea bream between Minamata Bay and Nagashima. Thus, our results suggest that the majority of mercury accumulated in fish muscle is not from seawater.

  6. Estradiol prevents fat accumulation and overcomes leptin resistance in female high-fat diet mice.

    PubMed

    Litwak, Sara A; Wilson, Jenny L; Chen, Weiyi; Garcia-Rudaz, Cecilia; Khaksari, Mohammad; Cowley, Michael A; Enriori, Pablo J

    2014-11-01

    In premenopausal and menopausal women in particular, suboptimal estrogens have been linked to the development of the metabolic syndrome as major contributors to fat accumulation. At the same time, estrogens have been described to have a role in regulating body metabolic status. We evaluated how endogenous or administered estrogens impact on the changes associated with high-fat diet (HFD) consumption in 2 different paradigms; ovarian-intact and in ovariectomized mice. When estradiol (E2) was cyclically administered to ovarian-intact HFD-fed mice for 12 weeks, animals gained significantly less weight than ovarian-intact vehicle controls (P < .01). This difference was mainly due to a reduced caloric intake but not to an increase in energy expenditure or locomotor activity. This E2 treatment regime to mice exposed to HFD was overall able to avoid the increase of visceral fat content to levels of those found in mice fed a regular chow diet. In the ovariectomized model, the main body weight and fat content reducing action of E2 was not only through decreasing food intake but also by increasing the whole-body energy expenditure, locomotor activity, and by inducing fat oxidation. Importantly, these animals became responsive to the anorexigenic effects of leptin in contrast to the vehicle-treated and the pair-fed control groups (P < .01). Further, in vitro hypothalamic secretion experiments revealed that treatment of obese mice with E2 is able to modulate the secretion of appetite-regulating neuropeptides; namely, E2 increased the secretion of the anorectic neuropeptide α-melanocyte-stimulating hormone and decreased the secretion of the orexigenic neuropetides neuropeptide Y and Agouti-related peptide. In conclusion, differences in response to E2 treatment of HFD-fed animals depend on their endogenous estrogenic status. Overall, E2 administration overcomes arcuate leptin resistance and partially prevents fat accumulation on these mice.

  7. Peripheral adaptation codes for high odor concentration in glomeruli.

    PubMed

    Lecoq, Jérôme; Tiret, Pascale; Charpak, Serge

    2009-03-11

    Adaptation is a general property of sensory receptor neurons and has been extensively studied in isolated cell preparation of olfactory receptor neurons. In contrast, little is known about the conditions under which peripheral adaptation occurs in the CNS during odorant stimulation. Here, we used two-photon laser-scanning microscopy and targeted extracellular recording in freely breathing anesthetized rats to investigate the correlate of peripheral adaptation at the first synapse of the olfactory pathway in olfactory bulb glomeruli. We find that during sustained stimulation at high concentration, odorants can evoke local field potential (LFP) postsynaptic responses that rapidly adapt with time, some within two inhalations. Simultaneous measurements of LFP and calcium influx at olfactory receptor neuron terminals reveal that postsynaptic adaptation is associated with a decrease in odorant-evoked calcium response, suggesting that it results from a decrease in glutamate release. This glomerular adaptation was concentration-dependent and did not change the glomerular input-output curve. In addition, in situ application of antagonists of either ionotropic glutamate receptors or metabotropic GABA(B) receptors did not affect this adaptation, thus discarding the involvement of local presynaptic inhibition. Glomerular adaptation, therefore, reflects the response decline of olfactory receptor neurons to sustained odorant. We postulate that peripheral fast adaptation is a means by which glomerular output codes for high concentration of odor.

  8. Electromagnetically assisted synthesis of highly concentrated gold nanoparticle colloids

    NASA Astrophysics Data System (ADS)

    Hernandez, Laura; Rosas, Walter; Naranjo, Guillermo; Peralta, Xomalin G.; Vargas, Watson L.

    2015-03-01

    The synthesis of metallic nanoparticles is currently an extremely active area of research due to the multiple potential applications of nanomaterials to areas ranging from nano-medicine to catalysis. Some of the current challenges of nanoparticle synthesis protocols include synthesizing nanoparticles in high concentrations with a small polydispersity. The present study contrasts and compares the synthesis of highly concentrated colloidal gold using three different sources of electromagnetic radiation to assist the reaction. The first source was a Spectra Physics Mai Tai Ti:Sapphire laser made by Sperian, this laser generates 70 fs FWHM pulses with wavelengths in the range of 690-1040 nm. The second source was sun light; this was measured to have a power of 10W. The third source was a lowelDP lamp with a measured intensity of 25W. Both the solar light and the lamp's rays were concentrated using a 28cm x 28cm Fresnel lens. Results will be presented highlighting differences and similarities in size, shape, crystallinity and time of the reaction. We speculate about the role played by variations in wavelength, temporal profile of the electromagnetic source (pulsed vs. continuous), temperature of the reaction and excitation power in the final structure of the nanoparticles generated.

  9. Towards operating direct methanol fuel cells with highly concentrated fuel

    NASA Astrophysics Data System (ADS)

    Zhao, T. S.; Yang, W. W.; Chen, R.; Wu, Q. X.

    A significant advantage of direct methanol fuel cells (DMFCs) is the high specific energy of the liquid fuel, making it particularly suitable for portable and mobile applications. Nevertheless, conventional DMFCs have to be operated with excessively diluted methanol solutions to limit methanol crossover and the detrimental consequences. Operation with diluted methanol solutions significantly reduces the specific energy of the power pack and thereby prevents it from competing with advanced batteries. In view of this fact, there exists a need to improve conventional DMFC system designs, including membrane electrode assemblies and the subsystems for supplying/removing reactants/products, so that both the cell performance and the specific energy can be simultaneously maximized. This article provides a comprehensive review of past efforts on the optimization of DMFC systems that operate with concentrated methanol. Based on the discussion of the key issues associated with transport of the reactants/products, the strategies to manage the supply/removal of the reactants/products in DMFC operating with highly concentrated methanol are identified. With these strategies, the possible approaches to achieving the goal of concentrated fuel operation are then proposed. Past efforts in the management of the reactants/products for implementing each of the approaches are also summarized and reviewed.

  10. Optical design considerations for high-concentration photovoltaics

    NASA Astrophysics Data System (ADS)

    Garboushian, Vahan; Gordon, Robert

    2006-08-01

    Over the past 15 years, major advances in Concentrating Photovoltaics (CPV) have been achieved. Ultra-efficient Si solar cells have produced commercial concentration systems which are being fielded today and are competitively priced. Advanced research has primarily focused on significantly more efficient multi-junction solar cells for tomorrow's systems. This effort has produced sophisticated solar cells that significantly improve power production. Additional performance and cost improvements, especially in the optical system area and system integration, must be made before CPV can realize its ultimate commercial potential. Structural integrity and reliability are vital for commercial success. As incremental technical improvements are made in solar cell technologies, evaluation and 'fine-tuning' of optical systems properly matched to the solar cell are becoming increasingly necessary. As we move forward, it is increasingly important to optimize all of the interrelated elements of a CPV system for high performance without sacrificing the marketable cost and structural requirements of the system. Areas such as wavelength absorption of refractive optics need to be carefully matched to the solar cell technology employed. Reflective optics require advanced engineering models to insure uniform flux distribution without excessive losses. In Situ measurement of the 'fine-grain' improvements are difficult as multiple variables such as solar insolation, temperature, wind, altitude, etc. infringe on analytical data. This paper discusses design considerations based on 10 years of field trials of high concentration systems and their relevance for tomorrow's advanced CPV systems.

  11. Strategies for the production of high concentrations of bioethanol from seaweeds: production of high concentrations of bioethanol from seaweeds.

    PubMed

    Yanagisawa, Mitsunori; Kawai, Shigeyuki; Murata, Kousaku

    2013-01-01

    Bioethanol has attracted attention as an alternative to petroleum-derived fuel. Seaweeds have been proposed as some of the most promising raw materials for bioethanol production because they have several advantages over lignocellulosic biomass. However, because seaweeds contain low contents of glucans, i.e., polysaccharides composed of glucose, the conversion of only the glucans from seaweed is not sufficient to produce high concentrations of ethanol. Therefore, it is also necessary to produce ethanol from other specific carbohydrate components of seaweeds, including sulfated polysaccharides, mannitol, alginate, agar and carrageenan. This review summarizes the current state of research on the production of ethanol from seaweed carbohydrates for which the conversion of carbohydrates to sugars is a key step and makes comparisons with the production of ethanol from lignocellulosic biomass. This review provides valuable information necessary for the production of high concentrations of ethanol from seaweeds.

  12. Ecologically relevant UV-B dose combined with high PAR intensity distinctly affect plant growth and accumulation of secondary metabolites in leaves of Centella asiatica L. Urban.

    PubMed

    Müller, Viola; Albert, Andreas; Barbro Winkler, J; Lankes, Christa; Noga, Georg; Hunsche, Mauricio

    2013-10-05

    We investigated the effects of environmentally relevant dose of ultraviolet (UV)-B and photosynthetic active radiation (PAR) on saponin accumulation in leaves on the example of Centella asiatica L. Urban. For this purpose, plants were exposed to one of four light regimes i.e., two PAR intensities with or without UV-B radiation. The experiment was conducted in technically complex sun simulators under almost natural irradiance and climatic conditions. As observed, UV-B radiation increased herb and leaf production as well as the content of epidermal flavonols, which was monitored by non-destructive fluorescence measurements. Specific fluorescence indices also indicate an increase in the content of anthocyanins under high PAR; this increase was likewise observed for the saponin concentrations. In contrast, UV-B radiation had no distinct effects on saponin and sapogenin concentrations. Our findings suggest that besides flavonoids, also saponins were accumulated under high PAR protecting the plant from oxidative damage. Furthermore, glycosylation of sapogenins seems to be important either for the protective function and/or for compartmentalization of the compounds. Moreover, our study revealed that younger leaves contain higher amounts of saponins, while in older leaves the sapogenins were the most abundant constituents. Concluding, our results proof that ambient dose of UV-B and high PAR intensity distinctly affect the accumulation of flavonoids and saponins, enabling the plant tissue to adapt to the light conditions.

  13. Symmetry-breaking phase transitions in highly concentrated semen

    PubMed Central

    Creppy, Adama; Plouraboué, Franck; Praud, Olivier; Druart, Xavier; Cazin, Sébastien; Yu, Hui

    2016-01-01

    New experimental evidence of self-motion of a confined active suspension is presented. Depositing fresh semen sample in an annular shaped microfluidic chip leads to a spontaneous vortex state of the fluid at sufficiently large sperm concentration. The rotation occurs unpredictably clockwise or counterclockwise and is robust and stable. Furthermore, for highly active and concentrated semen, richer dynamics can occur such as self-sustained or damped rotation oscillations. Experimental results obtained with systematic dilution provide a clear evidence of a phase transition towards collective motion associated with local alignment of spermatozoa akin to the Vicsek model. A macroscopic theory based on previously derived self-organized hydrodynamics models is adapted to this context and provides predictions consistent with the observed stationary motion. PMID:27733694

  14. Symmetry-breaking phase-transitions in highly concentrated semen

    NASA Astrophysics Data System (ADS)

    Plouraboué, Franck; Creppy, Adama; Praud, Olivier; Druart, Xavier; Cazin, Sébastien; Yu, Hui; Degond, Pierre

    2015-11-01

    New experimental evidence of self-motion of a confined active suspension is presented. Depositing fresh semen sample in an annular shaped micro-fluidic chip leads to a spontaneous rotation motion of the fluid at sufficiently large sperm concentration. The rotation occurs unpredictably clockwise or counterclockwise and is robust and stable. Furthermore, for highly active and concentrated semen, richer dynamics can occur such as self-sustained or damped rotation oscillations. Experimental results obtained with systematic dilution provide a clear evidence of a phase transition toward collective motion associated with local alignment of spermatozoa akin to the Vicsek model. A macroscopic theory based on previously derived Self-Organized Hydrodynamics (SOH) models is adapted to this context and provides predictions consistent with the observed stationary motion.

  15. Ignition characteristics of pulverized coal under high oxygen concentrations

    SciTech Connect

    Yue-sheng Fan; Zheng Zou; Zidong Cao; Yingchao Xu; Xiaoke Jiang

    2008-03-15

    In order to reduce overall fuel consumption, or partially substitute a 'valuable' fuel with a poor one, in electric power plant boilers, oxygen enrichment of combustion air can be very effective. Combustion characteristics of three Chinese pulverized coals, Shenmu bituminous, Tianhushan anthracite, and Duolun lignite, and three different particle sizes, under high oxygen concentrations more than 21%, have been investigated using thermogravimetric/differential scanning calorimetry analysis (TG/DSC) and a drop-tube furnace. Results showed that the ignitability, the combustion property, and the burnout were largely improved when added oxygen was used, especially for small particles, the influence of oxygen on the bituminous coal was greater than the lignite and the anthracite, and the suitable O{sub 2} concentration for the ignition of pulverized coal flow should be controlled below 40%. 38 refs., 12 figs., 3 tabs.

  16. Concentrations and environmental fate of Ra in cation-exchange regeneration brine waste disposed to septic tanks and accumulation in sludge, New Jersey Coastal Plain, USA

    USGS Publications Warehouse

    Szabo, Z.; Jacobsen, E.; Kraemer, T.F.; Parsa, B.

    2008-01-01

    Concentrations of Ra in liquid and solid wastes generated from 15 softeners treating domestic well waters from New Jersey Coastal Plain aquifers (where combined Ra (226Ra plus 228Ra) concentrations commonly exceed 0.185 Bq L-1) were determined. Softeners, when maintained, reduced combined Ra about 10-fold (<0.024 Bq L-1). Combined Ra exceeded 0.185 Bq L-1 at 1 non-maintained system. Combined Ra was enriched in regeneration brine waste (maximum, 81.2 Bq L-1), but concentrations in septic-tank effluents receiving brine waste were less than in the untreated ground waters. The maximum combined Ra concentration in aquifer sands (40.7 Bq kg-1 dry weight) was less than that in sludge from the septic tanks (range, 84-363 Bq kg-1), indicating Ra accumulation in sludge from effluent. The combined Ra concentration in sludge from the homeowners' septic systems falls within the range reported for sludge samples from publicly owned treatment works within the region.

  17. Concentration Response Curve for Ozone Realted Mortality at High Concentrations for presentation at International Society for Environmental Epidemiology

    EPA Science Inventory

    Concentration Response Curve for Ozone related Mortality at High Concentrations Ana G. Rappold, James Crooks, Lucas M. Neas Background Rising temperatures and decreased global circulation in the upcoming decades are expected to have a detrimental impact on air quality, particular...

  18. Application of cyclic damage accumulation life prediction model to high temperature components

    NASA Technical Reports Server (NTRS)

    Nelson, Richard S.

    1989-01-01

    A high temperature, low cycle fatigue life prediction method was developed. This method, Cyclic Damage Accumulation (CDA), was developed for use in predicting the crack initiation lifetime of gas turbine engine materials, but it can be applied to other materials as well. The method is designed to account for the effects on creep-fatigue life of complex loading such as thermomechanical fatigue, hold periods, waveshapes, mean stresses, multiaxiality, cumulative damage, coatings, and environmental attack. Several features of this model were developed to make it practical for application to actual component analysis, such as the ability to handle nonisothermal loading (including TMF), arbitrary cycle paths, and multiple damage modes. The CDA life prediction model was derived from extensive specimen tests conducted on cast nickel-base superalloy B1900 + Hf. These included both monotonic tests (tensile and creep) and strain-controlled fatigue experiments (uniaxial, biaxial, TMF, mixed creep-fatigue, and controlled mean stress). Additional specimen tests were conducted on wrought INCO 718 to verify the applicability of the final CDA model to other high-temperature alloys. The model will be available to potential users in the near future in the form of a FORTRAN-77 computer program.

  19. High-cell-density batch fermentation of Rhodococcus opacus PD630 using a high glucose concentration for triacylglycerol production.

    PubMed

    Kurosawa, Kazuhiko; Boccazzi, Paolo; de Almeida, Naomi M; Sinskey, Anthony J

    2010-06-01

    Biodiesel, monoalkyl esters of long-chain fatty acids with short-chain alcohols derived from triacylglycerols (TAGs), can be produced from renewable biomass sources. Recently, there has been interest in producing microbial oils from oleaginous microorganisms. Rhodococcus opacus PD630 is known to accumulate large amounts of TAGs. Following on these earlier works we demonstrate that R. opacus PD630 has the uncommon capacity to grow in defined media supplemented with glucose at a concentration of 300 g l(-1) during batch-culture fermentations. We found that we could significantly increase concentrations of both glucose and (NH4)2SO4 in the production medium resulting in a dramatic increase in fatty acid production when pH was controlled. We describe the experimental design protocol used to achieve the culture conditions necessary to obtain both high-cell-density and TAG accumulation; specifically, we describe the importance of the C/N ratio of the medium composition. Our bioprocess results demonstrate that R. opacus PD630 grown in batch-culture with an optimal production medium containing 240 g l(-1) glucose and 13.45 g l(-1) (NH4)2SO4 (C/N of 17.8) yields 77.6 g l(-1) of cell dry weight composed of approximately 38% TAGs indicating that this strain holds great potential as a future source of industrial biodiesel on starchy cellulosic feedstocks that are glucose polymers.

  20. Particulate Matter Concentrations in East Oakland's High Street Corridor

    NASA Astrophysics Data System (ADS)

    Lei, P.; Jackson, J.; Lewis, R.; Marigny, A.; Mitchell, J. D.; Nguyen, R.; Philips, B.; Randle, D.; Romero, D.; Spears, D.; Telles, C.; Weissman, D.

    2012-12-01

    Particulate matter (PM) is a complex mixture of small solid pieces and/or liquid droplets in the air. High concentrations of PM can pose a serious health hazard because inhalation can result in breathing problems and/or aggravate asthma. Long term exposure can increase the likelihood of respiratory problems like asthma and emphysema as well as cancer. The smaller the particles, the deeper they can get into the respiratory system. For this reason, the smallest particles, those smaller than 2.5 micrometers in diameter (PM2.5), are the most dangerous. PM2.5 is largely emitted from motor vehicles burning fuels that don't break down fully. Our research team investigated the levels of PM2.5 as well as particles smaller than 10 micrometers (PM10) and total suspended particulate (TSP) along the northeast-southwest trending High Street Corridor, near Fremont High School in East Oakland, California. Using the Aerocet 531 mass particle counter, team members walked through neighborhoods and along major roads within a 1 mile radius of Fremont High School. The Aerocet 531 recorded two minute average measurements of all the relevant PM sizes, which are reported in mg/m3. Measurements were consistently taken in the morning, between 8:30 and 11:30 am. Preliminary results indicate maximum readings of all PM sizes at sites that are in close proximity to a major freeway (Interstate-880). These results support our initial hypothesis that proximity to major roads and freeways, especially those with high diesel-fuel burning truck traffic, would be the primary factor affecting PM concentration levels. Preliminary median and maximum readings all suggest particulate matter levels below what the EPA would consider unhealthy or risky.

  1. High performance concentration method for viruses in drinking water.

    PubMed

    Kunze, Andreas; Pei, Lu; Elsässer, Dennis; Niessner, Reinhard; Seidel, Michael

    2015-09-15

    According to the risk assessment of the WHO, highly infectious pathogenic viruses like rotaviruses should not be present in large-volume drinking water samples of up to 90 m(3). On the other hand, quantification methods for viruses are only operable in small volumes, and presently no concentration procedure for processing such large volumes has been reported. Therefore, the aim of this study was to demonstrate a procedure for processing viruses in-line of a drinking water pipeline by ultrafiltration (UF) and consecutive further concentration by monolithic filtration (MF) and centrifugal ultrafiltration (CeUF) of viruses to a final 1-mL sample. For testing this concept, the model virus bacteriophage MS2 was spiked continuously in UF instrumentation. Tap water was processed in volumes between 32.4 m(3) (22 h) and 97.7 m(3) (72 h) continuously either in dead-end (DE) or cross-flow (CF) mode. Best results were found by DE-UF over 22 h. The concentration of MS2 was increased from 4.2×10(4) GU/mL (genomic units per milliliter) to 3.2×10(10) GU/mL and from 71 PFU/mL to 2×10(8) PFU/mL as determined by qRT-PCR and plaque assay, respectively.

  2. Implication of eolian delivery and accumulation of highly reactive iron to the Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Lee, B. K.; Owens, J. D.; Lyons, T. W.

    2014-12-01

    Iron, although abundant in the Earth's crust, is present at low concentrations in sea water and is a limiting nutrient for phytoplankton. Eolian dust (loess) is a major source of this micronutrient, and its deposition has important implications for the global CO2 budget. In this study, we explore distributions of potentially bioreactive Fe, the soluble fraction required by phytoplankton for photosynthesis and nitrogen assimilation, in deep-sea sediments in the North and South Atlantic Oceans. We used a state-of-the-art Fe speciation technique to characterize Fe inputs from different source regions, specifically North Africa and Patagonia to address the patterns and implications across glacial-interglacial time scales. In many open-ocean regions the input of new iron to the surface waters is dominated by the atmospheric deposition of soluble iron in eolian dusts. Multiple records have shown dust accumulation is correlated with glacial-interglacial cycles - glacial periods are substantially dustier. Furthermore, the delivery of eolian dust to the North and South Atlantic Oceans are from two very different source regions and soil types. We analyzed IODP cores from these two regions and our preliminary data shows similar pattern of iron distribution from both the North and South Atlantic Oceans. To date we have found no simple global pattern of bioavailable iron distribution during glacial and interglacial periods. We have analyzed a range of size distributions to isolate the dust-dominated fraction and the data shows no size effects in bioavailable form of iron distribution. We will explore the role of deep-water dust dissolution and sedimentary redox implications and its role on the bioreactive Fe record in marine cores.

  3. A high-frequency response relaxed eddy accumulation flux measurement system for sampling short-lived biogenic volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Arnts, Robert R.; Mowry, Fred L.; Hampton, Gary A.

    2013-05-01

    second-generation relaxed eddy accumulation system was built and tested with the capability to measure vertical biogenic volatile organic compound (VOC) fluxes at levels as low as 10 µg C m-2 hr-1. The system features a continuous, integrated gas-phase ozone removal procedure to allow for the measurement of highly reactive species such as β-caryophyllene and polar terpenoids such as linalool. A two-component internal standard continuously added to the accumulators was used to correct for switching-induced volumetric errors and as a check on VOC losses exceeding accumulator tube adsorption limits. In addition, the internal standards were used to demonstrate that accumulators quickly return to target flow rates at segregation valve switching frequencies up to at least 0.8 Hz. The system was able to measure daytime hourly fluxes of individual biogenic VOC including oxygenated terpenoids, monoterpenes, and sesquiterpenes.

  4. Unexpectedly high ultrafine aerosol concentrations above East Antarctic sea ice

    NASA Astrophysics Data System (ADS)

    Humphries, R. S.; Klekociuk, A. R.; Schofield, R.; Keywood, M.; Ward, J.; Wilson, S. R.

    2016-02-01

    Better characterisation of aerosol processes in pristine, natural environments, such as Antarctica, have recently been shown to lead to the largest reduction in uncertainties in our understanding of radiative forcing. Our understanding of aerosols in the Antarctic region is currently based on measurements that are often limited to boundary layer air masses at spatially sparse coastal and continental research stations, with only a handful of studies in the vast sea-ice region. In this paper, the first observational study of sub-micron aerosols in the East Antarctic sea ice region is presented. Measurements were conducted aboard the icebreaker Aurora Australis in spring 2012 and found that boundary layer condensation nuclei (CN3) concentrations exhibited a five-fold increase moving across the polar front, with mean polar cell concentrations of 1130 cm-3 - higher than any observed elsewhere in the Antarctic and Southern Ocean region. The absence of evidence for aerosol growth suggested that nucleation was unlikely to be local. Air parcel trajectories indicated significant influence from the free troposphere above the Antarctic continent, implicating this as the likely nucleation region for surface aerosol, a similar conclusion to previous Antarctic aerosol studies. The highest aerosol concentrations were found to correlate with low-pressure systems, suggesting that the passage of cyclones provided an accelerated pathway, delivering air masses quickly from the free troposphere to the surface. After descent from the Antarctic free troposphere, trajectories suggest that sea-ice boundary layer air masses travelled equatorward into the low-albedo Southern Ocean region, transporting with them emissions and these aerosol nuclei which, after growth, may potentially impact on the region's radiative balance. The high aerosol concentrations and their transport pathways described here, could help reduce the discrepancy currently present between simulations and observations of

  5. High manganese concentrations in rocks at Gale crater, Mars

    USGS Publications Warehouse

    Lanza, Nina L.; Fischer, Woodward W.; Wiens, Roger C.; Grotzinger, John; Ollila, Ann M.; Anderson, Ryan B.; Clark, Benton C.; Gellert, Ralf; Mangold, Nicolas; Maurice, Sylvestre; Le Mouélic, Stéphane; Nachon, Marion; Schmidt, Mariek E.; Berger, Jeffrey; Clegg, Samuel M.; Forni, Olivier; Hardgrove, Craig; Melikechi, Noureddine; Newsom, Horton E.; Sautter, Violaine

    2014-01-01

    The surface of Mars has long been considered a relatively oxidizing environment, an idea supported by the abundance of ferric iron phases observed there. However, compared to iron, manganese is sensitive only to high redox potential oxidants, and when concentrated in rocks, it provides a more specific redox indicator of aqueous environments. Observations from the ChemCam instrument on the Curiosity rover indicate abundances of manganese in and on some rock targets that are 1–2 orders of magnitude higher than previously observed on Mars, suggesting the presence of an as-yet unidentified manganese-rich phase. These results show that the Martian surface has at some point in time hosted much more highly oxidizing conditions than has previously been recognized.

  6. Shock initiation studies on high concentration hydrogen peroxide

    SciTech Connect

    Sheffield, Stephen A; Dattelbaum, Dana M; Stahl, David B; Gibson, L. Lee; Bartram, Brian D.

    2009-01-01

    Concentrated hydrogen peroxide (H{sub 2}O{sub 2}) has been known to detonate for many years. However, because of its reactivity and the difficulty in handling and confining it, along with the large critical diameter, few studies providing basic information about the initiation and detonation properties have been published. We are conducting a study to understand and quantify the initiation and detonation properties of highly concentrated H{sub 2}O{sub 2} using a gas-driven two-stage gun to produce well defined shock inputs. Multiple magnetic gauges are used to make in-situ measurements of the growth of reaction and subsequent detonation in the liquid. These experiments are designed to be one-dimensional to eliminate any difficulties that might be encountered with large critical diameters. Because of the concern of the reactivity of the H{sub 2}O{sub 2} with the confining materials, a remote loading system has been developed. The gun is pressurized, then the cell is filled and the experiment shot within less than three minutes. TV cameras are attached to the target so the cell filling can be monitored. Several experiments have been completed on {approx}98 wt % H{sub 2}O{sub 2}/H{sub 2}O mixtures; initiation has been observed in some experiments that shows homogeneous shock initiation behavior. The initial shock pressurizes and heats the mixture. After an induction time, a thermal explosion type reaction produces an evolving reactive wave that strengthens and eventually overdrives the first wave producing a detonation. From these measurements, we have determined unreacted Hugoniot information, times (distances) to detonation (Pop-plot points) that indicate low sensitivity, and detonation velocities of high concentration H{sub 2}O{sub 2}/H{sub 2}O solutions that agree with earlier estimates.

  7. Effect of High Temperature on Albumin and Globulin Accumulation in the Endosperm Proteome of the Developing Wheat Grain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of high temperature during grain fill on the accumulation of KCl-soluble/methanol-insoluble albumins and globulins was investigated in the endosperm of developing wheat (Triticum aestivum, L. cv. Butte 86) grain. Plants were grown under a moderate (24°C/17°C, day/night) or a high temperat...

  8. 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.

  9. Ammonia concentrations in different size classes of ovarian follicles of sheep (Ovis aries): Possible mechanisms of accumulation and its effect on oocyte and granulosa cell growth in vitro.

    PubMed

    Nandi, S; Gupta, P S P; Mondal, S

    2016-03-01

    The present study investigated the concentrations and the mechanisms of accumulation of ammonia in different sizes of ovarian follicles and the effect of ammonia on oocyte and granulosa cell growth and functions in vitro with sheep (Ovis aries) as an animal model. The effects of cyclicity, seasonality, phases of the estrous cycle, and seasons (environmental) on ammonia concentrations in follicular fluid were also investigated. The effect of ammonia on in vitro development of oocytes (maturation rate, viability rate, cleavage rate, morulae/blastocysts yield) recovered from different sizes of follicles was examined at the levels of 0, 50, 100, 150, 250, 300, and 500 μM. Same concentrations of ammonia were examined on growth parameters (metabolic activity, viability, cell number increment, monolayer formation, apoptosis rate) and hormone (progesterone, estrogen) secretion activity of granulosa cells in vitro. Results suggested as the follicle size increased, ammonia concentrations decreased. The ammonia concentrations in ovine follicular fluid were found to be 261.5 ± 32.4, 157.7 ± 19.2, and 42.9 ± 8.3 μM, respectively, for small, medium, and large follicles. The corresponding ranges were 290 to 238 μM, 184 to 142 μM, and 70 to 22 μM. The differences were due to more accumulation of fluid, less metabolic activity of granulosa cells, and elevation of protein, potassium, and chloride as the follicle size increased. The seasonality and phases of the estrous cycle did not have any effect on ammonia level in ovarian follicles. Ammonia concentrations in all size classes of follicles examined were significantly reduced in ewes during hot seasons compared to cold seasons and in acyclic animals compared to cyclic ones. Ammonia impaired oocyte development at 300 μM when the oocytes were isolated from small follicles and at 250 μM when the oocytes were isolated from medium and large follicles. In contrast, ammonia caused the negative impact on granulosa cells growth

  10. Design and development of a high-concentration and high-efficiency photovoltaic concentrator using a curved Fresnel lens

    SciTech Connect

    Scharlack, R.S.; Moffat, A.

    1983-08-01

    Thermo Electron has designed a high concentration photovoltaic module that uses a domed, point-focus Fresnel lens. Their design, design optimization process, and results from lens and receiver tests are described in this report. A complete module has not been fabricated and probably will not be fabricated in the future; however, Thermo Electron's optical design, analysis, and testing of both secondary optical units and domed Fresnel lenses have made a significant contribution to our project. Tooling errors prevented the lens from reaching its potential efficiency by the end of the contract, and resolution of these tooling problems is currently being attempted with a follow-on contract, No. 68-9463.

  11. Ionic Behavior in Highly Concentrated Aqueous Solutions Nanoconfined between Discretely Charged Silicon Surfaces.

    PubMed

    Qiu, Yinghua; Ma, Jian; Chen, Yunfei

    2016-05-17

    Through molecular dynamics simulations considering thermal vibration of surface atoms, ionic behaviors in concentrated NaCl solutions confined between discretely charged silicon surfaces have been investigated. The electric double layer structure was found to be sensitive to the density and distribution of surface charges. Due to the discreteness of the surface charge, a slight charge inversion appeared which depended on the surface charge density, bulk concentration, and confinement. In the nanoconfined NaCl solutions concentrated from 0.2 to 4.0 M, the locations of accumulation layers for Na(+) and Cl(-) ions remained stable, but their peak values increased. The higher the concentration was, the more obvious the charge inversion appeared. In 4.0 M NaCl solution, Na(+) and Cl(-) ions show obvious alternating layered distributions which may correspond to the solidification found in experiments. By changing surface separation, the confinement had a large effect on the ionic distribution. As both surfaces approached each other, many ions and water molecules were squeezed out of the confined space. Two adjacent layers in ion or water distribution profiles can be forced closer to each other and merge together. From ionic hydration analysis, the coordination number of Na(+) ions in highly confined space was much lower than that in the bulk.

  12. SU-E-T-315: The Change of Optically Stimulated Luminescent Dosimeters (OSLDs) Sensitivity by Accumulated Dose and High Dose

    SciTech Connect

    Han, S; Jung, H; Kim, M; Ji, Y; Kim, K; Choi, S; Park, S; Yoo, H; Yi, C

    2014-06-01

    Purpose: The objective of this study is to evaluate radiation sensitivity of optical stimulated luminance dosimeters (OSLDs) by accumulated dose and high dose. Methods: This study was carried out in Co-60 unit (Theratron 780, AECL, and Canada) and used InLight MicroStar reader (Landauer, Inc., Glenwood, IL) for reading. We annealed for 30 min using optical annealing system which contained fluorescent lamps (Osram lumilux, 24 W, 280 ∼780 nm). To evaluate change of OSLDs sensitivity by repeated irradiation, the dosimeters were repeatedly irradiated with 1 Gy. And whenever a repeated irradiation, we evaluated OSLDs sensitivity. To evaluate OSLDs sensitivity after accumulated dose with 5 Gy, We irradiated dose accumulatively (from 1 Gy to 5 Gy) without annealing. And OSLDs was also irradiated with 15, 20, 30 Gy to certify change of OSLDs sensitivity after high dose irradiation. After annealing them, they were irradiated with 1Gy, repeatedly. Results: The OSLDs sensitivity increased up to 3% during irradiating seven times and decreased continuously above 8 times. That dropped by about 0.35 Gy per an irradiation. Finally, after 30 times irradiation, OSLDs sensitivity decreased by about 7%. For accumulated dose from 1 Gy to 5 Gy, OSLDs sensitivity about 1 Gy increased until 4.4% after second times accumulated dose compared with before that. OSLDs sensitivity about 1 Gy decreased by 1.6% in five times irradiation. When OSLDs were irradiated ten times with 1Gy after irradiating high dose (10, 15, 20 Gy), OSLDs sensitivity decreased until 6%, 9%, 12% compared with it before high dose irradiation, respectively. Conclusion: This study certified OSLDs sensitivity by accumulated dose and high dose. When irradiated with 1Gy, repeatedly, OSLDs sensitivity decreased linearly and the reduction rate of OSLDs sensitivity after high dose irradiation had dependence on irradiated dose.

  13. Heterogeneous effects of dopamine on highly localized, voltage-induced Ca2+ accumulation in identified motoneurons.

    PubMed

    Kloppenburg, Peter; Zipfel, Warren R; Webb, Watt W; Harris-Warrick, Ronald M

    2007-11-01

    Modulation of synaptic transmission is a major mechanism for the functional reconfiguration of neuronal circuits. Neurotransmitter release and, consequently, synaptic strength are regulated by intracellular Ca(2+) levels in presynaptic terminals. In identified neurons of the lobster pyloric network, we studied localized, voltage-induced Ca(2+) accumulation and its modulation in varicosities on distal neuritic arborizations, which have previously been shown to be sites of synaptic contacts. We previously demonstrated that dopamine (DA) weakens synaptic output from the pyloric dilator (PD) neuron and strengthens synaptic output from the lateral pyloric (LP) and pyloric constrictor (PY) neurons. Here we show that DA modifies voltage-activated Ca(2+) accumulation in many varicosities in ways that are consistent with DA's effects on synaptic transmission: DA elevates Ca(2+) accumulation in LP and PY varicosities and reduces Ca(2+) accumulation in PD varicosities. However, in all three neuron types, we also found varicosities that were unaffected by DA. In the PY neurons, we found that DA can simultaneously increase and decrease voltage-evoked Ca(2+) accumulation at different varicosities, even within the same neuron. These results suggest that regulation of Ca(2+) entry is a common mechanism to regulate synaptic strength in the pyloric network. However, voltage-evoked local Ca(2+) accumulation can be differentially modulated to control Ca(2+)-dependent processes in functionally separate varicosities of a single neuron.

  14. High Concentration of Zinc in Sub-retinal Pigment Epithelial Deposits

    SciTech Connect

    Lengyel,I.; Flinn, J.; Peto, T.; Linkous, D.; Cano, K.; Bird, A.; Lanzirotti, A.; Frederickson, C.; van Kuijk, F.

    2007-01-01

    One of the hallmarks of age-related macular degeneration (AMD), the leading cause of blindness in the elderly in Western societies, is the accumulation of sub-retinal pigment epithelial deposits (sub-RPE deposits), including drusen and basal laminar deposits, in Bruch's membrane (BM). The nature and the underlying mechanisms of this deposit formation are not fully understood. Because we know that zinc contributes to deposit formation in neurodegenerative diseases, we tested the hypothesis that zinc might be involved in deposit formation in AMD. Using zinc specific fluorescent probes and microprobe synchrotron X-ray fluorescence we showed that sub-RPE deposits in post-mortem human tissues contain unexpectedly high concentrations of zinc, including abundant bio-available (ionic and/or loosely protein bound) ions. Zinc accumulation was especially high in the maculae of eyes with AMD. Internal deposit structures are especially enriched in bio-available zinc. Based on the evidence provided here we suggest that zinc plays a role in sub-RPE deposit formation in the aging human eye and possibly also in the development and/or progression of AMD.

  15. Molecular chaperone accumulation as a function of stress evidences adaptation to high hydrostatic pressure in the piezophilic archaeon Thermococcus barophilus

    PubMed Central

    Cario, Anaïs; Jebbar, Mohamed; Thiel, Axel; Kervarec, Nelly; Oger, Phil M.

    2016-01-01

    The accumulation of mannosyl-glycerate (MG), the salinity stress response osmolyte of Thermococcales, was investigated as a function of hydrostatic pressure in Thermococcus barophilus strain MP, a hyperthermophilic, piezophilic archaeon isolated from the Snake Pit site (MAR), which grows optimally at 40 MPa. Strain MP accumulated MG primarily in response to salinity stress, but in contrast to other Thermococcales, MG was also accumulated in response to thermal stress. MG accumulation peaked for combined stresses. The accumulation of MG was drastically increased under sub-optimal hydrostatic pressure conditions, demonstrating that low pressure is perceived as a stress in this piezophile, and that the proteome of T. barophilus is low-pressure sensitive. MG accumulation was strongly reduced under supra-optimal pressure conditions clearly demonstrating the structural adaptation of this proteome to high hydrostatic pressure. The lack of MG synthesis only slightly altered the growth characteristics of two different MG synthesis deletion mutants. No shift to other osmolytes was observed. Altogether our observations suggest that the salinity stress response in T. barophilus is not essential and may be under negative selective pressure, similarly to what has been observed for its thermal stress response. PMID:27378270

  16. The Accumulative Effect of Concentric-Biased and Eccentric-Biased Exercise on Cardiorespiratory and Metabolic Responses to Subsequent Low-Intensity Exercise: A Preliminary Study

    PubMed Central

    Gavin, James Peter; Myers, Stephen; Willems, Mark Elisabeth Theodorus

    2015-01-01

    The study investigated the accumulative effect of concentric-biased and eccentric-biased exercise on cardiorespiratory, metabolic and neuromuscular responses to low-intensity exercise performed hours later. Fourteen young men cycled at low-intensity (~60 rpm at 50% maximal oxygen uptake) for 10 min before, and 12 h after: concentric-biased, single-leg cycling exercise (CON) (performed ~19:30 h) and eccentric-biased, double-leg knee extension exercise (ECC) (~06:30 h the following morning). Respiratory measures were sampled breath-by-breath, with oxidation values derived from stoichiometry equations. Knee extensor neuromuscular function was assessed before and after CON and ECC. Cardiorespiratory responses during low-intensity cycling were unchanged by accumulative CON and ECC. The RER was lower during low-intensity exercise 12 h after CON and ECC (0.88 ± 0.08), when compared to baseline (0.92 ± 0.09; p = 0.02). Fat oxidation increased from baseline (0.24 ± 0.2 g·min−1) to 12 h after CON and ECC (0.39 ± 0.2 g·min−1; p = 0.01). Carbohydrate oxidation decreased from baseline (1.59 ± 0.4 g·min−1) to 12 h after CON and ECC (1.36 ± 0.4 g·min−1; p = 0.03). These were accompanied by knee extensor force loss (right leg: −11.6%, p < 0.001; left leg: −10.6%, p = 0.02) and muscle soreness (right leg: 2.5 ± 0.9, p < 0.0001; left leg: 2.3 ± 1.2, p < 0.01). Subsequent concentric-biased and eccentric-biased exercise led to increased fat oxidation and decreased carbohydrate oxidation, without impairing cardiorespiration, during low-intensity cycling. An accumulation of fatiguing and damaging exercise increases fat utilisation during low intensity exercise performed as little as 12 h later. PMID:26839613

  17. The Accumulative Effect of Concentric-Biased and Eccentric-Biased Exercise on Cardiorespiratory and Metabolic Responses to Subsequent Low-Intensity Exercise: A Preliminary Study.

    PubMed

    Gavin, James Peter; Myers, Stephen; Willems, Mark Elisabeth Theodorus

    2015-12-22

    The study investigated the accumulative effect of concentric-biased and eccentric-biased exercise on cardiorespiratory, metabolic and neuromuscular responses to low-intensity exercise performed hours later. Fourteen young men cycled at low-intensity (~60 rpm at 50% maximal oxygen uptake) for 10 min before, and 12 h after: concentric-biased, single-leg cycling exercise (CON) (performed ~19:30 h) and eccentric-biased, double-leg knee extension exercise (ECC) (~06:30 h the following morning). Respiratory measures were sampled breath-by-breath, with oxidation values derived from stoichiometry equations. Knee extensor neuromuscular function was assessed before and after CON and ECC. Cardiorespiratory responses during low-intensity cycling were unchanged by accumulative CON and ECC. The RER was lower during low-intensity exercise 12 h after CON and ECC (0.88 ± 0.08), when compared to baseline (0.92 ± 0.09; p = 0.02). Fat oxidation increased from baseline (0.24 ± 0.2 g·min(-1)) to 12 h after CON and ECC (0.39 ± 0.2 g·min(-1); p = 0.01). Carbohydrate oxidation decreased from baseline (1.59 ± 0.4 g·min(-1)) to 12 h after CON and ECC (1.36 ± 0.4 g·min(-1); p = 0.03). These were accompanied by knee extensor force loss (right leg: -11.6%, p < 0.001; left leg: -10.6%, p = 0.02) and muscle soreness (right leg: 2.5 ± 0.9, p < 0.0001; left leg: 2.3 ± 1.2, p < 0.01). Subsequent concentric-biased and eccentric-biased exercise led to increased fat oxidation and decreased carbohydrate oxidation, without impairing cardiorespiration, during low-intensity cycling. An accumulation of fatiguing and damaging exercise increases fat utilisation during low intensity exercise performed as little as 12 h later.

  18. 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.

  19. Liquefaction of lignocellulose at high-solids concentrations.

    PubMed

    Jørgensen, Henning; Vibe-Pedersen, Jakob; Larsen, Jan; Felby, Claus

    2007-04-01

    To improve process economics of the lignocellulose to ethanol process a reactor system for enzymatic liquefaction and saccharification at high-solids concentrations was developed. The technology is based on free fall mixing employing a horizontally placed drum with a horizontal rotating shaft mounted with paddlers for mixing. Enzymatic liquefaction and saccharification of pretreated wheat straw was tested with up to 40% (w/w) initial DM. In less than 10 h, the structure of the material was changed from intact straw particles (length 1-5 cm) into a paste/liquid that could be pumped. Tests revealed no significant effect of mixing speed in the range 3.3-11.5 rpm on the glucose conversion after 24 h and ethanol yield after subsequent fermentation for 48 h. Low-power inputs for mixing are therefore possible. Liquefaction and saccharification for 96 h using an enzyme loading of 7 FPU/g.DM and 40% DM resulted in a glucose concentration of 86 g/kg. Experiments conducted at 2%-40% (w/w) initial DM revealed that cellulose and hemicellulose conversion decreased almost linearly with increasing DM. Performing the experiments as simultaneous saccharification and fermentation also revealed a decrease in ethanol yield at increasing initial DM. Saccharomyces cerevisiae was capable of fermenting hydrolysates up to 40% DM. The highest ethanol concentration, 48 g/kg, was obtained using 35% (w/w) DM. Liquefaction of biomass with this reactor system unlocks the possibility of 10% (w/w) ethanol in the fermentation broth in future lignocellulose to ethanol plants.

  20. High-density carrier-accumulated and electrically stable oxide thin-film transistors from ion-gel gate dielectric

    PubMed Central

    Fujii, Mami N.; Ishikawa, Yasuaki; Miwa, Kazumoto; Okada, Hiromi; Uraoka, Yukiharu; Ono, Shimpei

    2015-01-01

    The use of indium–gallium–zinc oxide (IGZO) has paved the way for high-resolution uniform displays or integrated circuits with transparent and flexible devices. However, achieving highly reliable devices that use IGZO for low-temperature processes remains a technological challenge. We propose the use of IGZO thin-film transistors (TFTs) with an ionic-liquid gate dielectric in order to achieve high-density carrier-accumulated IGZO TFTs with high reliability, and we discuss a distinctive mechanism for the degradation of this organic–inorganic hybrid device under long-term electrical stress. Our results demonstrated that an ionic liquid or gel gate dielectric provides highly reliable and low-voltage operation with IGZO TFTs. Furthermore, high-density carrier accumulation helps improve the TFT characteristics and reliability, and it is highly relevant to the electronic phase control of oxide materials and the degradation mechanism for organic–inorganic hybrid devices. PMID:26677773

  1. High-density carrier-accumulated and electrically stable oxide thin-film transistors from ion-gel gate dielectric

    NASA Astrophysics Data System (ADS)

    Fujii, Mami N.; Ishikawa, Yasuaki; Miwa, Kazumoto; Okada, Hiromi; Uraoka, Yukiharu; Ono, Shimpei

    2015-12-01

    The use of indium-gallium-zinc oxide (IGZO) has paved the way for high-resolution uniform displays or integrated circuits with transparent and flexible devices. However, achieving highly reliable devices that use IGZO for low-temperature processes remains a technological challenge. We propose the use of IGZO thin-film transistors (TFTs) with an ionic-liquid gate dielectric in order to achieve high-density carrier-accumulated IGZO TFTs with high reliability, and we discuss a distinctive mechanism for the degradation of this organic-inorganic hybrid device under long-term electrical stress. Our results demonstrated that an ionic liquid or gel gate dielectric provides highly reliable and low-voltage operation with IGZO TFTs. Furthermore, high-density carrier accumulation helps improve the TFT characteristics and reliability, and it is highly relevant to the electronic phase control of oxide materials and the degradation mechanism for organic-inorganic hybrid devices.

  2. Low Viscosity Highly Concentrated Injectable Nonaqueous Suspensions of Lysozyme Microparticles

    PubMed Central

    Miller, Maria A.; Engstrom, Joshua D.; Ludher, Baltej S.; Johnston, Keith P.

    2011-01-01

    Subcutaneous injection of concentrated protein and peptide solutions, in the range of 100–400 mg/mL, is often not possible with a 25- to 27-gauge needle, as the viscosity can be well above 50 cP. Apparent viscosities below this limit are reported for suspensions of milled lysozyme microparticles up to nearly 400 mg/mL in benzyl benzoate or benzyl benzoate mixtures with safflower oils through a syringe with a 25- to 27-gauge needle at room temperature. These apparent viscosities were confirmed using a cone-and-plate rheometer. The intrinsic viscosity regressed from the Kreiger–Dougherty model was only slightly above the Einstein value of 2.5, indicating the increase in viscosity relative to that of the solvent was caused primarily by the excluded volume. Thus, the increases in viscosity from electrical double layer interactions (electroviscous effects), solvation of the particles, or deviations of the particle shape from a spherical geometry were minimal, and much smaller than typically observed for proteins dissolved in aqueous solutions. The small electroviscous effects are expected given the negligible zeta potential and thin double layers in the low dielectric constant organic solvent. The suspensions were resuspendable after a year, with essentially constant particle size after two months as measured by static light scattering. The lower apparent viscosities for highly concentrated protein suspensions relative to protein solutions, coupled with these favorable characteristics upon resuspension, may offer novel opportunities for subcutaneous injection of therapeutic proteins. PMID:19803503

  3. Catalytic wet air oxidation of high concentration pharmaceutical wastewater.

    PubMed

    Zhan, Wei; Wang, Xiaocong; Li, Daosheng; Ren, Yongzheng; Liu, Dongqi; Kang, Jianxiong

    2013-01-01

    In this study, we investigated the pretreatment of a high concentration pharmaceutical wastewater by catalytic wet air oxidation (CWAO) process. Different experiments were conducted to investigate the effects of the catalyst type, operating temperature, initial system pH, and oxygen partial pressure on the oxidation of the wastewater. Results show that the catalysts prepared by the co-precipitation method have better catalytic activity compared to others. Chemical oxygen demand (COD) conversion increased with the increase in temperature from 160 to 220 °C and decreased with the increase in pH. Moreover, the effect of the oxygen partial pressure on the COD conversion was significant only during the first 20 min of the reaction. Furthermore, the biodegradability of the wastewater improved greatly after CWAO, the ratio of BOD5/COD increased less than 0.1-0.75 when treated at 220 °C (BOD: biochemical oxygen demand).

  4. Verification of Fresnel lens in high concentration photovoltaic system

    NASA Astrophysics Data System (ADS)

    Wei, An-Chi; Sze, Jyh-Rou; Chern, Jyh-Long

    2012-10-01

    An approach using micro lens arrays to confine the cone angle of light source in a solar simulator has been proposed to verify the Fresnel lens in a high concentration photovoltaic (HCPV) system. Compared with other three prior arts by the computer simulation, the proposed method had the characteristics of the better approximation to the direct normal insolation and the low cost. Also, to ensure the erection of the evaluation system, the tolerance of lens alignment has been analyzed. The results showed that to maintain at least the 50% of the maximum luminous flux incident on the solar cell, the transverse and longitudinal tolerances of ±1.4 mm and ±4 mm, respectively, were required.

  5. Do high concentrations of microcystin prevent Daphnia control of phytoplankton?

    PubMed

    Chislock, Michael F; Sarnelle, Orlando; Jernigan, Lauren M; Wilson, Alan E

    2013-04-15

    Toxin-producing cyanobacteria have frequently been hypothesized to limit the ability of herbivorous zooplankton (such as Daphnia) to control phytoplankton biomass by inhibiting feeding, and in extreme cases, causing zooplankton mortality. Using limnocorral experiments in hyper-eutrophic ponds located in Alabama and Michigan (U.S.A.), we tested the hypothesis that high levels of cyanobacteria and microcystin, a class of hepatotoxins produced by several cyanobacterial genera, prevent Daphnia from strongly reducing phytoplankton abundance. At the start of the first experiment (Michigan), phytoplankton communities were dominated by toxic Microcystis and Anabaena (∼96% of total phytoplankton biomass), and concentrations of microcystin were ∼3 μg L⁻¹. Two weeks after adding Daphnia pulicaria from a nearby eutrophic lake, microcystin levels increased to ∼6.5 μg L⁻¹, yet Daphnia populations increased exponentially (r = 0.24 day⁻¹). By the third week, Daphnia had suppressed phytoplankton biomass by ∼74% relative to the no Daphnia controls and maintained reduced phytoplankton biomass until the conclusion of the five-week experiment. In the second experiment (Alabama), microcystin concentrations were greater than 100 μg L⁻¹, yet a mixture of three D. pulicaria clones from eutrophic lakes in southern MI increased and again reduced phytoplankton biomass, in this case by over 80%. The ability of Daphnia to increase in abundance and suppress phytoplankton biomass, despite high initial levels of cyanobacteria and microcystin, indicates that the latter does not prevent strong control of phytoplankton biomass by Daphnia genotypes that are adapted to environments with abundant cyanobacteria and associated cyanotoxins.

  6. High temperature helical tubular receiver for concentrating solar power system

    NASA Astrophysics Data System (ADS)

    Hossain, Nazmul

    In the field of conventional cleaner power generation technology, concentrating solar power systems have introduced remarkable opportunity. In a solar power tower, solar energy concentrated by the heliostats at a single point produces very high temperature. Falling solid particles or heat transfer fluid passing through that high temperature region absorbs heat to generate electricity. Increasing the residence time will result in more heat gain and increase efficiency. A novel design of solar receiver for both fluid and solid particle is approached in this paper which can increase residence time resulting in higher temperature gain in one cycle compared to conventional receivers. The helical tubular solar receiver placed at the focused sunlight region meets the higher outlet temperature and efficiency. A vertical tubular receiver is modeled and analyzed for single phase flow with molten salt as heat transfer fluid and alloy625 as heat transfer material. The result is compared to a journal paper of similar numerical and experimental setup for validating our modeling. New types of helical tubular solar receivers are modeled and analyzed with heat transfer fluid turbulent flow in single phase, and granular particle and air plug flow in multiphase to observe the temperature rise in one cyclic operation. The Discrete Ordinate radiation model is used for numerical analysis with simulation software Ansys Fluent 15.0. The Eulerian granular multiphase model is used for multiphase flow. Applying the same modeling parameters and boundary conditions, the results of vertical and helical receivers are compared. With a helical receiver, higher temperature gain of heat transfer fluid is achieved in one cycle for both single phase and multiphase flow compared to the vertical receiver. Performance is also observed by varying dimension of helical receiver.

  7. Bioconversion of High Concentrations of Hydrogen Sulfide to Elemental Sulfur in Airlift Bioreactor

    PubMed Central

    Abdel-Monaem Zytoon, Mohamed; Ahmad AlZahrani, Abdulraheem; Hamed Noweir, Madbuli; Ahmed El-Marakby, Fadia

    2014-01-01

    Several bioreactor systems are used for biological treatment of hydrogen sulfide. Among these, airlift bioreactors are promising for the bioconversion of hydrogen sulfide into elemental sulfur. The performance of airlift bioreactors is not adequately understood, particularly when directly fed with hydrogen sulfide gas. The objective of this paper is to investigate the performance of an airlift bioreactor fed with high concentrations of H2S with special emphasis on the effect of pH in combination with other factors such as H2S loading rate, oxygen availability, and sulfide accumulation. H2S inlet concentrations between 1,008 ppm and 31,215 ppm were applied and elimination capacities up to 113 g H2S m−3 h−1 were achieved in the airlift bioreactor under investigation at a pH range 6.5–8.5. Acidic pH values reduced the elimination capacity. Elemental sulfur recovery up to 95% was achieved under oxygen limited conditions (DO < 0.2 mg/L) and at higher pH values. The sulfur oxidizing bacteria in the bioreactor tolerated accumulated dissolved sulfide concentrations >500 mg/L at pH values 8.0–8.5, and near 100% removal efficiency was achieved. Overall, the resident microorganisms in the studied airlift bioreactor favored pH values in the alkaline range. The bioreactor performance in terms of elimination capacity and sulfur recovery was better at pH range 8–8.5. PMID:25147857

  8. Characterization of personal exposure concentration of fine particles for adults and children exposed to high ambient concentrations in Beijing, China.

    PubMed

    Du, Xuan; Kong, Qian; Ge, Weihua; Zhang, Shaojun; Fu, Lixin

    2010-01-01

    In China, the health risk from overexposure to particles is becoming an important public health concern. To investigate daily exposure characteristics to PM2.5 with high ambient concentration in urban area, a personal exposure study was conducted for school children, and office workers in Beijing, China. For all participants (N = 114), the mean personal 24-hr exposure concentration was 102.5, 14.7, 0.093, 0.528, 0.934, 0.174 and 0.703 microg/m3 for PM2.5, black carbon, Mn, Al, Ca, Pb, and Fe. Children's exposure concentrations of PM2.5 were 4-5 times higher than those in related studies. The ambient concentration of PM2.5 (128.5 microg/m3) was significantly higher than the personal exposure concentration (P < 0.05), and exceed the reference concentration (25 microg/m3) of WHO air quality guideline. Good correlation relationships and significant differences were identified between ambient concentration and personal exposure concentration. The relationships indicate that the ambient concentration is the main factor influencing personal exposure concentration, but is not a good indicator of personal exposure concentration. Outdoor activities (commute mode, exposure to heating, workday or weekend travel) influenced personal exposure concentrations significantly, but the magnitude of the influence from indoor activities (exposure to cooking) was masked by the high ambient concentrations.

  9. Accumulation of trehalose by Escherichia coli K-12 at high osmotic pressure depends on the presence of amber suppressors

    SciTech Connect

    Rod, M.L. Alam, K.Y.; Cunningham, P.R.; Clark, D.P. )

    1988-08-01

    When grown at high osmotic pressure, some strains of Escherichia coli K-12 synthesized substantial levels of free sugar and accumulated proline if it was present in the growth medium. The sugar was identified as trehalose. Strains of E. coli K-12 could be divided into two major classes with respect of osmoregulation. Those of class A showed a large increase in trehalose levels with increasing medium osmolarity and also accumulated proline from the medium, whereas those in class B showed no accumulation of trehalose or proline. Most class A strains carried suppressor mutations which arose during their derivation from the wild type, whereas the osmodefective strains of class B were suppressor free. When amber suppressor mutations at the supD, supE, or supF loci were introduced into such sup{sup o} osmodefective strains, they became osmotolerant and gained the ability to accumulate trehalose in response to elevated medium osmolarity. It appears that the original K-12 strain of E. coli carries an amber mutation in a gene affecting osmoregulation. Mutants lacking ADP-glucose synthetase (glgC) accumulated trehalose normally, whereas mutants lacking UDP-glucose synthetase (galU) did not make trehalose and grew poorly in medium of high osmolarity. Trehalose synthesis was repressed by exogenous glycine betaine but not by proline.

  10. HIV populations are large and accumulate high genetic diversity in a nonlinear fashion.

    PubMed

    Maldarelli, Frank; Kearney, Mary; Palmer, Sarah; Stephens, Robert; Mican, JoAnn; Polis, Michael A; Davey, Richard T; Kovacs, Joseph; Shao, Wei; Rock-Kress, Diane; Metcalf, Julia A; Rehm, Catherine; Greer, Sarah E; Lucey, Daniel L; Danley, Kristen; Alter, Harvey; Mellors, John W; Coffin, John M

    2013-09-01

    HIV infection is characterized by rapid and error-prone viral replication resulting in genetically diverse virus populations. The rate of accumulation of diversity and the mechanisms involved are under intense study to provide useful information to understand immune evasion and the development of drug resistance. To characterize the development of viral diversity after infection, we carried out an in-depth analysis of single genome sequences of HIV pro-pol to assess diversity and divergence and to estimate replicating population sizes in a group of treatment-naive HIV-infected individuals sampled at single (n = 22) or multiple, longitudinal (n = 11) time points. Analysis of single genome sequences revealed nonlinear accumulation of sequence diversity during the course of infection. Diversity accumulated in recently infected individuals at rates 30-fold higher than in patients with chronic infection. Accumulation of synonymous changes accounted for most of the diversity during chronic infection. Accumulation of diversity resulted in population shifts, but the rates of change were low relative to estimated replication cycle times, consistent with relatively large population sizes. Analysis of changes in allele frequencies revealed effective population sizes that are substantially higher than previous estimates of approximately 1,000 infectious particles/infected individual. Taken together, these observations indicate that HIV populations are large, diverse, and slow to change in chronic infection and that the emergence of new mutations, including drug resistance mutations, is governed by both selection forces and drift.

  11. Inhibition by dietary D-psicose of body fat accumulation in adult rats fed a high-sucrose diet.

    PubMed

    Ochiai, Masaru; Nakanishi, Yosuke; Yamada, Takako; Iida, Tetsuo; Matsuo, Tatsuhiro

    2013-01-01

    We investigated the anti-obesity effects of dietary D-psicose on adult rats fed a high-sucrose diet. Wistar rats (16 weeks old) that had previously been fed a high-sucrose diet (HSD) were fed HSD or a high-starch diet (HTD) with or without 5% D-psicose for 8 weeks. The food efficiency, carcass fat percentage, abdominal fat accumulation, and body weight gain were all significantly suppressed by dietary D-psicose.

  12. Multiple liquid crystal phases of DNA at high concentrations.

    PubMed

    Strzelecka, T E; Davidson, M W; Rill, R L

    1988-02-04

    DNA packaging in vivo is very tight, with volume concentrations approaching 70% w/v in sperm heads, virus capsids and bacterial nucleoids. The packaging mechanisms adopted may be related to the natural tendency of semi-rigid polymers to form liquid crystalline phases in concentrated solutions. We find that DNA forms at least three distinct liquid crystalline phases at concentrations comparable to those in vivo, with phase transitions occurring over relatively narrow ranges of DNA concentration. A weakly birefringent, dynamic, 'precholesteric' mesophase with microscopic textures intermediate between those of a nematic and a true cholesteric phase forms at the lowest concentrations required for phase separation. At slightly higher DNA concentrations, a second mesophase forms which is a strongly birefringent, well-ordered cholesteric phase with a concentration-dependent pitch varying from 2 to 10 micron. At the highest DNA concentrations, a phase forms which is two-dimensionally ordered and resembles smectic phases of thermotropic liquid crystals observed with small molecules.

  13. Modelling acceptance of sunlight in high and low photovoltaic concentration

    SciTech Connect

    Leutz, Ralf

    2014-09-26

    A simple model incorporating linear radiation characteristics, along with the optical trains and geometrical concentration ratios of solar concentrators is presented with performance examples for optical trains of HCPV, LCPV and benchmark flat-plate PV.

  14. The impact of high tephra loading on late-Holocene carbon accumulation and vegetation succession in peatland communities

    NASA Astrophysics Data System (ADS)

    Hughes, P. D. M.; Mallon, G.; Brown, A.; Essex, H. J.; Stanford, J. D.; Hotes, S.

    2013-05-01

    Peatlands are major terrestrial stores of carbon (C) of importance to the global climate system. Recent studies have made progress in understanding the climatic controls on the C cycle; however, important interactions between volcanic deposition and peatland C stores remain to be addressed. This study uses a 3000-year peatland record from northern Japan to examine the interactions between carbon accumulation, vegetation community succession and volcanic ash deposition. Plant macrofossil and testate amoebae records are presented alongside records of total organic carbon, nitrogen and phosphorous. Age-depth models are developed using a Bayesian approach, with seven AMS radiocarbon dates and two identified historical tephras from Baitoushan (AD 969 (981 cal. BP)), and Hokkaido-Komagatake (AD 1640 (310 cal. BP)) volcanoes. Results show that moderate to high tephra loading can shift peatland plant communities from Sphagnum to monocotyledon domination. This vegetation change is associated with increased peat humification and reduced carbon accumulation. Where tephra deposition and reworking has occurred, the apparent rate of carbon accumulation can be halved while high tephra loading of the mire surface is sustained. Sphagnum species vary in their tolerance to tephra deposition. After each ash fall Sphagnum magellanicum disappeared from the plant macrofossil record, whereas Sphagnum papillosum showed apparent continuity of development through the 1856 (94 cal. BP) Ko-c1 tephra. High rates of carbon accumulation (peaking at >100 g m-2 yr-1), 2-3 times faster than the average for northern peatlands, were recorded in the Sphagnum communities that established after the cessation of tephra deposition and reworking from the AD 969 Baitoushan ash fall (B-Tm tephra). This peak in C accumulation was coincident with a radical shift in mire nutrient cycling most probably caused by the interaction of S. magellanicum with leachates from the underlying tephras. The phase of high C

  15. High Temperature Concentrated Solar Power Using Liquid Metal

    NASA Astrophysics Data System (ADS)

    Henry, Asegun

    One of the most attractive ways to try and reduce the cost of concentrated solar power (CSP) is to increase the system efficiency and the biggest loss in the system occurs in the conversion of heat to electricity via heat engine. Heat engines that utilize turbomachinery currently operate near their thermodynamic limitations and thus one of the only ways to improve heat engine efficiency is to increase the turbine inlet temperature. Significant effort is being devoted to the development of supercritical CO2 heat engines, but the most efficient heat engines are combined cycles, which reach efficiencies as high as 60%. However, such heat engines require turbine inlet temperatures ~1300-1500C, which is far beyond what is currently feasible with the state of the art molten salt infrastructure. In working towards the development of a system that can operate in the 1300-1500C temperature range, the most significant challenges lie in the materials and forming functional and reliable components out of new materials. One of the most attractive options from a cost and heat transfer perspective is to use liquid metals, such as tin and aluminum-silicon alloys along with a ceramic based infrastructure. This talk will overview ongoing efforts in the Atomistic Simulation and Energy (ASE) research group at Georgia Tech to develop prototype components such as an efficient high temperature cavity receiver, pumps and valves that can make a liquid metal based CSP infrastructure realizable.

  16. High-performance deployable structures for the support of high-concentration ratio solar array modules

    NASA Technical Reports Server (NTRS)

    Mobrem, M.

    1985-01-01

    A study conducted on high-performance deployable structures for the support of high-concentration ratio solar array modules is discussed. Serious consideration is being given to the use of high-concentration ratio solar array modules or applications such as space stations. These concentrator solar array designs offer the potential of reduced cost, reduced electrical complexity, higher power per unit area, and improved survivability. Arrays of concentrators, such as the miniaturized Cassegrainian concentrator modules, present a serious challenge to the structural design because their mass per unit area (5.7 kg/square meters) is higher than that of flexible solar array blankets, and the requirement for accurate orientation towards the Sun (plus or minus 0.5 degree) requires structures with improved accuracy potentials. In addition, use on a space station requires relatively high structural natural frequencies to avoid deleterious interactions with control systems and other large structural components. The objective here is to identify and evaluate conceptual designs of structures suitable for deploying and accurately supporting high-concentration ratio solar array modules.

  17. Crystal accumulation in the Hanford Waste Treatment Plant high level waste melter: Summary of FY2016 experiements

    SciTech Connect

    Fox, K.; Fowley, M.; Miller, D.

    2016-12-01

    Five experiments were completed with the full-scale, room temperature Hanford Waste Treatment and Immobilization Plant (WTP) high-level waste (HLW) melter riser test system to observe particle flow and settling in support of a crystal tolerant approach to melter operation. A prototypic pour rate was maintained based on the volumetric flow rate. Accumulation of particles was observed at the bottom of the riser and along the bottom of the throat after each experiment. Measurements of the accumulated layer thicknesses showed that the settled particles at the bottom of the riser did not vary in thickness during pouring cycles or idle periods. Some of the settled particles at the bottom of the throat were re-suspended during subsequent pouring cycles, and settled back to approximately the same thickness after each idle period. The cause of the consistency of the accumulated layer thicknesses is not year clear, but was hypothesized to be related to particle flow back to the feed tank. Additional experiments reinforced the observation of particle flow along a considerable portion of the throat during idle periods. Limitations of the system are noted in this report and may be addressed via future modifications. Follow-on experiments will be designed to evaluate the impact of pouring rate on particle re-suspension, the influence of feed tank agitation on particle accumulation, and the effect of changes in air lance positioning on the accumulation and re-suspension of particles at the bottom of the riser. A method for sampling the accumulated particles will be developed to support particle size distribution analyses. Thicker accumulated layers will be intentionally formed via direct addition of particles to select areas of the system to better understand the ability to continue pouring and re-suspend particles. Results from the room temperature system will be correlated with observations and data from the Research Scale Melter (RSM) at Pacific Northwest National Laboratory

  18. Effect of high nitrate concentration on PHB storage in sequencing batch reactor under anoxic conditions.

    PubMed

    Ciğgin, Asli S; Karahan, Ozlem; Orhon, Derin

    2009-02-01

    The study investigated effect of high influent nitrate concentration on poly-beta-hydroxybutyrate, (PHB), storage in a sequencing batch reactor, (SBR), under anoxic conditions. Acetate was fed as pulse during anoxic phase, sustained with external nitrate feeding. SBR operation involved three runs at steady state with COD/N ratios of 3.84, 2.93 and 1.54 gCOD/gN, where external nitrate concentrations gradually increased from 50 mg N/l to 114 mg N/l and 226 mg N/l, in 1st, 2nd and 3rd runs, respectively. In 1st run, acetate was fully converted into PHB with the storage yield value of 0.57-0.59 gCOD/gCOD, calculated both in terms of PHB formation and NO(X) utilization, confirming storage was the sole substrate utilization mechanism. In the following runs, PHB formation was reduced and the storage yield based on PHB dropped down to 0.40 and 0.33 gCOD/gCOD with increasing influent nitrate concentrations, indicating that higher portions of acetate were diverted to simultaneous direct growth. The observations suggested that nitrite accumulation detected at low COD/N ratios was responsible for inhibition of PHB storage.

  19. Nitrification of ammonia nitrogen high concentration in membrane assisted bioreactor.

    PubMed

    Zabczyński, S; Surmacz-Górska, J; Miksch, K

    2003-01-01

    Use of the membrane-assisted bioreactors (MBR) in wastewater treatment can bring a lot of advantages. Usually COD removal achieves level 90% and nitrification of ammonia nitrogen concentrations typical for municipal wastewater performs without any disturbances, what was confirmed by large number of experiments. However, inhibition of nitrification of the high ammonia nitrogen concentration was noticed. In this study, the performance of ammonia-rich wastewater nitrification in membrane-assisted bioreactor (MBR) was examined. With SRT of 40, 32, 24 and 16 days any nitrification inhibition effect wasn't noticed. Ammonia nitrogen removal was around 98% and full nitrification was observed. At the sludge age equal to 12 d the first stage of nitrification was full, but the second stage of nitrification was incomplete. The variation in number and presence of the higher organisms were noticed at the all examined sludge ages. With SRT of 40, 32, 24 and 16 days the free ciliates were prominent organisms. At the sludge age of 12 days the domination of flagellates was observed The kinetic constants of the high-ammonia wastewater nitrification were calculated The average value of Vmax at the sludge age 12, 16 and 24 days was constant (4.7 mg NH4(+)-N/g MLSS h, 4.8 mg NH4(+)-N/g MLSS h and 4.8 mg NH4(+)-N/g MLSS, respectively), but the value of Km rose, when the sludge age increased (6.8 mg NH4(+)-N/L for 12 days, 11.3 mg NH4(+)-N/L for 16 days, 21.6 mg NH4(+)-N/L for 24 days). At the sludge age 32 and 40 days the increase of Vmax was observed (7.2 mg NH4(+)-N/g MLSS h and 12.5 mg NH4(+)-N/g MLSS h, respectively) and, also, changes of Km (6.8 mg NH4(+)-N/L and 44 mg NH4(+)-N/L, respectively. Concerning the second stage of nitrification value of Vmax decreased with the increase of the sludge age and the average Km varied from 20.3 to 31.3 mg NO2(-)-N/L.

  20. Identification of oleaginous yeast strains able to accumulate high intracellular lipids when cultivated in alkaline pretreated corn stover

    PubMed Central

    Sitepu, Irnayuli R.; Jin, Mingjie; Fernandez, J. Enrique; da Costa Sousa, Leonardo; Balan, Venkatesh; Boundy-Mills, Kyria L.

    2015-01-01

    Microbial oil is a potential alternative to food/plant-derived biodiesel fuel. Our previous screening studies identified a wide range of oleaginous yeast species, using a defined laboratory medium known to stimulate lipid accumulation. In this study, the ability of these yeasts to grow and accumulate lipids was further investigated in synthetic hydrolysate (SynH) and authentic ammonia fiber expansion (AFEX™)-pretreated corn stover hydrolysate (ACSH). Most yeast strains tested were able to accumulate lipids in SynH, but only a few were able to grow and accumulate lipids in ACSH medium. Cryptococcus humicola UCDFST 10-1004 was able to accumulate as high as 15.5 g/L lipids, out of a total of 36 g/L cellular biomass when grown in ACSH, with a cellular lipid content of 40% of cell dry weight. This lipid production is among the highest reported values for oleaginous yeasts grown in authentic hydrolysate. Pre-culturing in SynH media with xylose as sole carbon source enabled yeasts to assimilate both glucose and xylose more efficiently in the subsequent hydrolysate medium. This study demonstrates that ACSH is a suitable medium for certain oleaginous yeasts to convert lignocellullosic sugars to triacylglycerols for production of biodiesel and other valuable oleochemicals. PMID:25052467

  1. Starch and lipid accumulation in eight strains of six Chlorella species under comparatively high light intensity and aeration culture conditions.

    PubMed

    Takeshita, Tsuyoshi; Ota, Shuhei; Yamazaki, Tomokazu; Hirata, Aiko; Zachleder, Vilém; Kawano, Shigeyuki

    2014-04-01

    The microalgae family Chlorella species are known to accumulate starch and lipids. Although nitrogen or phosphorous deficiencies promote starch and lipids formation in many microalgae, these deficiencies also limit their growth and productivity. Therefore, the Chlorellaceae strains were attempted to increase starch and lipids productivity under high-light-intensity conditions (600-μmol photons m(-2)s(-1)). The 12:12-h light-dark (LD) cycle conditions elicited more stable growth than the continuous light (LL) conditions, whereas the starch and lipids yields increased in LL conditions. The amount of starch and lipids per cell increased in Chlorella viscosa and Chlorella vulgaris in sulfur-deficient medium, and long-chain fatty acids with 20 or more carbon atoms accumulated in cells grown in sulfur-deficient medium. Accumulation of starch and lipids was investigated in eight strains. The accumulation was strain-dependent, and varied according to the medium and light conditions. Five of the eight Chlorella strains exhibited similar accumulation patterns.

  2. 27 CFR 18.52 - Production of high-proof concentrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Production of high-proof... § 18.52 Production of high-proof concentrate. (a) General. High-proof concentrate may be produced in a... whether a particular concentrate is a high-proof concentrate. However, a proprietor may at any time...

  3. Accumulation of NMR signals in a BS-487 high-resolution spectrometer

    SciTech Connect

    Zagitov, G.N.; Zeleev, M.K.; Valiakhmetov, I.A.

    1992-02-01

    A system for accumulation of NMR signals in a BS-487 spectrometer using an Iskra-1256 computer system is described. The spectrometer`s scanning frequency is controlled by a G3-110 precision low-frequency signal generator. 3 refs., 3 figs.

  4. Comparative Polygenic Analysis of Maximal Ethanol Accumulation Capacity and Tolerance to High Ethanol Levels of Cell Proliferation in Yeast

    PubMed Central

    Pais, Thiago M.; Foulquié-Moreno, María R.; Hubmann, Georg; Duitama, Jorge; Swinnen, Steve; Goovaerts, Annelies; Yang, Yudi; Dumortier, Françoise; Thevelein, Johan M.

    2013-01-01

    The yeast Saccharomyces cerevisiae is able to accumulate ≥17% ethanol (v/v) by fermentation in the absence of cell proliferation. The genetic basis of this unique capacity is unknown. Up to now, all research has focused on tolerance of yeast cell proliferation to high ethanol levels. Comparison of maximal ethanol accumulation capacity and ethanol tolerance of cell proliferation in 68 yeast strains showed a poor correlation, but higher ethanol tolerance of cell proliferation clearly increased the likelihood of superior maximal ethanol accumulation capacity. We have applied pooled-segregant whole-genome sequence analysis to identify the polygenic basis of these two complex traits using segregants from a cross of a haploid derivative of the sake strain CBS1585 and the lab strain BY. From a total of 301 segregants, 22 superior segregants accumulating ≥17% ethanol in small-scale fermentations and 32 superior segregants growing in the presence of 18% ethanol, were separately pooled and sequenced. Plotting SNP variant frequency against chromosomal position revealed eleven and eight Quantitative Trait Loci (QTLs) for the two traits, respectively, and showed that the genetic basis of the two traits is partially different. Fine-mapping and Reciprocal Hemizygosity Analysis identified ADE1, URA3, and KIN3, encoding a protein kinase involved in DNA damage repair, as specific causative genes for maximal ethanol accumulation capacity. These genes, as well as the previously identified MKT1 gene, were not linked in this genetic background to tolerance of cell proliferation to high ethanol levels. The superior KIN3 allele contained two SNPs, which are absent in all yeast strains sequenced up to now. This work provides the first insight in the genetic basis of maximal ethanol accumulation capacity in yeast and reveals for the first time the importance of DNA damage repair in yeast ethanol tolerance. PMID:23754966

  5. Si-Accumulation In Artemisia annua Glandular Trichomes Increases Artemisinin Concentration, but Does Not Interfere In the Impairment of Toxoplasma gondii Growth

    PubMed Central

    Rostkowska, Cristina; Mota, Caroline M.; Oliveira, Taísa C.; Santiago, Fernanda M.; Oliveira, Lilian A.; Korndörfer, Gaspar H.; Lana, Regina M. Q.; Rossi, Monica L.; Nogueira, Neusa L.; Simonnet, Xavier; Mineo, Tiago W. P.; Silva, Deise A.O.; Mineo, José R.

    2016-01-01

    Artemisia annua is used as a source of artemisinin, a potent therapeutic agent used for the treatment of infectious diseases, chiefly malaria. However, the low concentration (from 0.01 to 1.4% of dried leaf matter) of artemisinin in the plant obtained with the traditional cropping system makes it a relatively expensive drug, especially in developing countries. Considering that artemisinin and silicon (Si) are both stored in A. annua glandular trichomes, and that Si accumulation has never been investigated, this study aimed to look into Si effects on A. annua trichome artemisinin concentration, and whether leaf infusion from Si-treated A. annua plants is able to control Toxoplasma gondii growth. T. gondii is the etiologic agent of toxoplasmosis, a zoonotic parasitic disease whose traditional treatment shows significant side effects. The experimental design consisted of A. annua seedlings randomly planted in soil treated with different doses of calcium/magnesium silicate (0, 200, 400, 800, and 1600 kg ha-1). Analysis of foliar macronutrients showed significant increases of nitrogen content only at the highest dose of silicate. Foliar micronutrients, Si concentrations, and plant height were not affected by any of the silicate doses. However, the dose of 400 kg ha-1 of silicate increased the trichome size, which in turn raised artemisinin concentration in leaves and the infusion. In contrast, the 800 and 1600 kg ha-1 doses dramatically decreased artemisinin concentration. HeLa cell treatment with the infusion of A. annua grown in soil treated with 400 kg ha-1 of silicate decreased parasite proliferation in a dose-dependent manner when the treatment was carried out after or along with T. gondii infection. However, this effect was similar to A. annua grown in soil without silicate treatment. Thus, it can be concluded that, even though Si applied to the soil at 400 kg ha-1 has a positive effect on the A. annua glandular trichome size and the artemisinin concentration

  6. Denitrification of high nitrate concentration wastewater using alternative carbon sources.

    PubMed

    Fernández-Nava, Y; Marañón, E; Soons, J; Castrillón, L

    2010-01-15

    The use of different organic carbon sources in the denitrification of wastewater containing 2500 mg nitrates/L in a SBR was studied. Three alternative sources of carbon were tested: wastewater from a sweet factory, a residue from a soft drinks factory and a residue from a dairy plant. The first two are sugar-rich, whereas the third presents a high content in lactic acid. Maximum specific denitrification rates of between 42 and 48 mg NO(3)-N/g VSS h were obtained. The effluents were nitrate-free and very low COD concentrations were obtained in 4-6h reaction time, especially with the sugar-rich carbon sources. The values of the denitrifier net yield coefficient were higher than when using methanol (0.93-1.75 g VSS(formed)/g NO(x)-N(reduced)). The lowest value was obtained using the lactic acid-rich residue. The optimum COD/N ratios varied between 4.6 for the lactic acid-rich carbon source and 5.5-6.5 for the sugar-rich carbon sources.

  7. Accumulation of copper in the kidney of pigs fed high dietary zinc is due to metallothionein expression with minor effects on genes involved in copper metabolism.

    PubMed

    Zetzsche, A; Schunter, N; Zentek, J; Pieper, R

    2016-05-01

    A study was conducted to determine the effect of high dietary zinc (Zn) oxide on trace element accumulation in various organs with special emphasis on the kidney. A total of 40 weaned piglets were allocated into two groups with 16 and 24 piglets each receiving a diet containing normal (NZn; 100mg Zn/kg) or high (HZn; 2,100mg Zn/kg) Zn concentration, respectively. After two weeks, eight piglets from each treatment were killed and organ samples were taken. Eight piglets from the remaining 16 pigs fed HZn diets were changed to NZn diets (CZn). All remaining piglets were killed after another two weeks for organ sampling. Trace element concentration was determined in the jejunum, liver, kidney, pancreas, bone (metacarpal IV), spleen, lung, thymus, tonsils and lymph nodes of jejunum, ileum and colon. Kidney mRNA expression of Zn transporter ZnT1 and ZIP4, genes involved in Cu metabolism (Ctr1, Atox1, SOD1, ATP7A, CCS, CP) and divalent metal ion transport (DMT1) and binding (MT-1a, MT-2b, MT-3) were determined. The Zn concentration in jejunum, liver, pancreas tissue and metacarpal IV was higher (P<0.05) in HZn group compared with NZn and CZn groups. Trace element concentration in organs of CZn pigs was similar to those fed NZn diets. Zn concentration in muscle, lung and lymphatic organs as thymus, tonsils, spleen and lymph nodes of jejunum, ileum and colon did not differ between the groups. Zn and Cu were positively correlated (R=0.67; P<0.05) in the kidney. No significant differences for Cu chaperones, Cu transporters and Cu-dependent factors were determined despite decreased expression of Atox1 after two weeks and increased Ctr1 expression over time in the HZn group. Expression of MT-1a, MT-2b and MT-3 were significantly higher in HZn fed pigs with most pronounced effects for MT-1a > MT-2b > MT-3. Gene expression of MTs in pigs fed CZn diets did not differ from pigs fed NZn diets. The data suggest that high dietary Zn feeding in pigs leads to Cu co-accumulation in the

  8. Accumulation of cytoplasmic calcium, but not apamin-sensitive afterhyperpolarization current, during high frequency firing in rat subthalamic nucleus cells

    PubMed Central

    Teagarden, Mark; Atherton, Jeremy F; Bevan, Mark D; Wilson, Charles J

    2008-01-01

    The autonomous firing pattern of neurons in the rat subthalamic nucleus (STN) is shaped by action potential afterhyperpolarization currents. One of these is an apamin-sensitive calcium-dependent potassium current (SK). The duration of SK current is usually considered to be limited by the clearance of calcium from the vicinity of the channel. When the cell is driven to fire faster, calcium is expected to accumulate, and this is expected to result in accumulation of calcium-dependent AHP current. We measured the time course of calcium transients in the soma and proximal dendrites of STN neurons during spontaneous firing and their accumulation during driven firing. We compared these to the time course and accumulation of AHP currents using whole-cell and perforated patch recordings. During spontaneous firing, a rise in free cytoplasmic calcium was seen after each action potential, and decayed with a time constant of about 200 ms in the soma, and 80 ms in the dendrites. At rates higher than 10 Hz, calcium transients accumulated as predicted. In addition, there was a slow calcium transient not predicted by summation of action potentials that became more pronounced at high firing frequency. Spike AHP currents were measured in voltage clamp as tail currents after 2 ms voltage pulses that triggered action currents. Apamin-sensitive AHP (SK) current was measured by subtraction of tail currents obtained before and after treatment with apamin. SK current peaked between 10 and 15 ms after an action potential, had a decay time constant of about 30 ms, and showed no accumulation. At frequencies between 5 and 200 spikes s−1, the maximal SK current remained the same as that evoked by a single action potential. AHP current did not have time to decay between action potentials, so at frequencies above 50 spikes s−1 the apamin-sensitive current was effectively constant. These results are inconsistent with the view that the decay of SK current is governed by calcium dynamics. They

  9. Accumulation of cytoplasmic calcium, but not apamin-sensitive afterhyperpolarization current, during high frequency firing in rat subthalamic nucleus cells.

    PubMed

    Teagarden, Mark; Atherton, Jeremy F; Bevan, Mark D; Wilson, Charles J

    2008-02-01

    The autonomous firing pattern of neurons in the rat subthalamic nucleus (STN) is shaped by action potential afterhyperpolarization currents. One of these is an apamin-sensitive calcium-dependent potassium current (SK). The duration of SK current is usually considered to be limited by the clearance of calcium from the vicinity of the channel. When the cell is driven to fire faster, calcium is expected to accumulate, and this is expected to result in accumulation of calcium-dependent AHP current. We measured the time course of calcium transients in the soma and proximal dendrites of STN neurons during spontaneous firing and their accumulation during driven firing. We compared these to the time course and accumulation of AHP currents using whole-cell and perforated patch recordings. During spontaneous firing, a rise in free cytoplasmic calcium was seen after each action potential, and decayed with a time constant of about 200 ms in the soma, and 80 ms in the dendrites. At rates higher than 10 Hz, calcium transients accumulated as predicted. In addition, there was a slow calcium transient not predicted by summation of action potentials that became more pronounced at high firing frequency. Spike AHP currents were measured in voltage clamp as tail currents after 2 ms voltage pulses that triggered action currents. Apamin-sensitive AHP (SK) current was measured by subtraction of tail currents obtained before and after treatment with apamin. SK current peaked between 10 and 15 ms after an action potential, had a decay time constant of about 30 ms, and showed no accumulation. At frequencies between 5 and 200 spikes s(-1), the maximal SK current remained the same as that evoked by a single action potential. AHP current did not have time to decay between action potentials, so at frequencies above 50 spikes s(-1) the apamin-sensitive current was effectively constant. These results are inconsistent with the view that the decay of SK current is governed by calcium dynamics. They

  10. High-field penning-malmberg trap: confinement properties and use in positron accumulation

    SciTech Connect

    Hartley, J.H.

    1997-09-01

    This dissertation reports on the development of the 60 kG cryogenic positron trap at Lawrence Livermore National Laboratory, and compares the trap`s confinement properties with other nonneutral plasma devices. The device is designed for the accumulation of up to 2{times}10{sup 9} positrons from a linear-accelerator source. This positron plasma could then be used in Bhabha scattering experiments. Initial efforts at time-of-flight accumulation of positrons from the accelerator show rapid ({approximately}100 ms) deconfinement, inconsistent with the long electron lifetimes. Several possible deconfinement mechanisms have been explored, including annihilation on residual gas, injection heating, rf noise from the accelerator, magnet field curvature, and stray fields. Detailed studies of electron confinement demonstrate that the empirical scaling law used to design the trap cannot be extrapolated into the parameter regime of this device. Several possible methods for overcoming these limitations are presented.

  11. Plastic litter accumulation on high-water strandline of urban beaches in Mumbai, India.

    PubMed

    Jayasiri, H B; Purushothaman, C S; Vennila, A

    2013-09-01

    Today, almost every beach on every coastline is threatened by human activities. The inadequate recycling and poor management of waste in developing countries has resulted in considerable quantities of plastic contaminating beaches. Though India has long coastline of 5,420 km along the mainland with 43 % of sandy beaches, data on litter accumulation, particularly the plastics, which are one of the most common and persistent pollutants in marine environment, are scanty. The abundance and distribution of plastic litter was quantitatively assessed in four sandy beaches in Mumbai, India, bimonthly from May 2011 to March 2012. Triplicates of 2 × 2 m (4 m(2)) quadrats were sampled in each beach with a total of 72 quadrats. Overall, average abundance of 11.6 items m(-2) (0.25-282.5 items m(-2)) and 3.24 g m(-2) (0.27-15.53 g m(-2)) plastic litter was recorded in Mumbai beaches. Plastic litter accumulation significantly varied temporally and spatially at p = 0.05. Significantly higher plastic litter accumulation was recorded in Juhu beach. Furthermore, the highest abundance by weight was recorded in November and May numerically. More than 80 % of plastic particles were within the size range of 5-100 mm both by number and weight. Moreover, coloured plastics were predominant with 67 % by number of items and 51 % by weight. Probably, the intense use of beaches for recreation, tourism, and religious activities has increased the potential for plastic contamination in urban beaches in Mumbai.

  12. Growth, morphology, ammonium uptake and nutrient allocation of Myriophyllum brasiliense Cambess. under high NH₄⁺ concentrations.

    PubMed

    Saunkaew, Piyanart; Wangpakapattanawong, Prasit; Jampeetong, Arunothai

    2011-11-01

    The effects of high NH(4)(+) concentration on growth, morphology, NH(4) (+) uptake and nutrient allocation of Myriophyllum brasiliense were investigated in hydroponic culture. The plants were grown under greenhouse conditions for 4 weeks using four levels of NH(4)(+) concentration: 1, 5, 10 and 15 mM. M. brasiliense grew well with a relative growth rate of c.0.03 day(-1) at NH(4)(+) concentration up to 5 mM. At the higher NH(4)(+) concentrations the growth of the plants was stunted and the plants had short roots and few new buds, especially when grown in 15 mM NH(4)(+) where the submerged leaves were lost and there were rotten roots and submerged stems. To avoid NH(4)(+) toxicity, the plants may have a mechanism to prevent cytoplasmic NH(4)(+) accumulation in plant cells. The net uptake of NH(4)(+) significantly decreased and the total N significantly increased in the plants treated with 10 and 15 mM NH(4)(+), respectively. The plant may employ NH(4)(+) assimilation and extrusion as a mechanism to compensate for the high NH(4)(+) concentrations. However, the plants may show nutrient deficiency symptoms, especially K deficiency symptoms, after they were exposed to NH(4)(+) concentration higher than 10 mM. The present study provides a basic ecophysiology of M. brasiliense that it can grow in NH(4)(+) enriched water up to concentrations as high as 5 mM.

  13. Bandgap Engineering in High-Efficiency Multijunction Concentrator Cells

    SciTech Connect

    King, R. R.; Sherif, R. A.; Kinsey, G. S.; Kurtz, S.; Fetzer, C. M.; Edmondson, K. M.; Law, D. C.; Cotal, H. L.; Krut, D. D.; Ermer, J. H.; Karam, N. H.

    2005-08-01

    This paper discusses semiconductor device research paths under investigation with the aim of reaching the milestone efficiency of 40%. A cost analysis shows that achieving very high cell efficiencies is crucial for the realization of cost-effective photovoltaics, because of the strongly leveraging effect of efficiency on module packaging and balance-of systems costs. Lattice-matched (LM) GaInP/ GaInAs/ Ge 3-junction cells have achieved the highest independently confirmed efficiency at 175 suns, 25?C, of 37.3% under the standard AM1.5D, low-AOD terrestrial spectrum. Lattice-mismatched, or metamorphic (MM), materials offer still higher potential efficiencies, if the crystal quality can be maintained. Theoretical efficiencies well over 50% are possible for a MM GaInP/ 1.17-eV GaInAs/ Ge 3-junction cell limited by radiative recombination at 500 suns. The bandgap - open circuit voltage offset, (Eg/q) - Voc, is used as a valuable theoretical and experimental tool to characterize multijunction cells with subcell bandgaps ranging from 0.7 to 2.1 eV. Experimental results are presented for prototype 6-junction cells employing an active {approx}1.1-eV dilute nitride GaInNAs subcell, with active-area efficiency greater than 23% and over 5.3 V open-circuit voltage under the 1-sun AM0 space spectrum. Such cell designs have theoretical efficiencies under the terrestrial spectrum at 500 suns concentration exceeding 55% efficiency, even for lattice-matched designs.

  14. Response of nitrite accumulation and microbial community to free ammonia and dissolved oxygen treatment of high ammonium wastewater.

    PubMed

    Sui, Qianwen; Liu, Chong; Zhang, Junya; Dong, Hongmin; Zhu, Zhiping; Wang, Yi

    2016-05-01

    The effects of free ammonia (FA) and dissolved oxygen (DO) on nitrite accumulation in the treatment of high ammonium wastewater and on the evolution of the microbial community were investigated. Under high DO conditions (3.75 ± 0.49 mg/L), FA as high as 10.61 ± 2.89 mg NH3/L maintained stable nitrite accumulation rate (NAR) of 84 % with NH4 (+)-N load of 2.05 kg N/(m(3) day) at sludge retention time (SRT) of 15-18 days. After 56 days of operation, Proteobacteria and Nitrosomonas were the dominant phylum and genus, respectively; Nitrosomonas increased from 21.14 to 54.57 %. By contrast, under relative low DO and low FA, nitrite-oxidizing bacteria (NOB) were nearly eliminated (NOB/AOB of 0; ammonium-oxidizing bacteria (AOB)), and NAR of 94 % was achieved with lower NH4 (+)-N load of 0.48 kg N/(m(3) day). DO correlated with AOB and NOB abundance, and FA decreased NOB activity and the NOB/AOB ratio. In conclusion, high FA and high DO conditions are optimal for efficient nitrite accumulation.

  15. High lipid accumulation in Yarrowia lipolytica cultivated under double limitation of nitrogen and magnesium.

    PubMed

    Bellou, S; Triantaphyllidou, I-E; Mizerakis, P; Aggelis, G

    2016-09-20

    Yarrowia lipolytica cultivated under double nitrogen and magnesium limitation, but not under single nitrogen or single magnesium limitation, produced 12.2g/l biomass containing 47.5% lipids, which corresponds to a lipid production 5.8g/l. These yields are the higher described in the literature for wild strains of Y. lipolytica. Transcription of ACL1 and ACL2, encoding for ATP-citrate lyase (ATP:CL) was observed even under non-oleaginous conditions but high activity of ATP:CL was only detected under oleaginous conditions induced by low or zero activity of NAD(+) dependent isocitrate dehydrogenase. The low activity of malic enzyme (ME), a NADPH donor in typical oleaginous microorganisms, indicated that ME may not be implicated in lipid biosynthesis in this yeast, and NADPH may be provided by the pentose phosphate pathway (PPP). These findings underline the essential role of magnesium in lipogenesis, which is currently quite unexplored. The presence of organic nitrogen in low concentrations during lipogenesis was also required, and this peculiarity was probably related with the PPP functioning, being the NADPH donor of lipogenic machinery in Y. lipolytica.

  16. Highly anomalous accumulation rates of C and N recorded by a relic, free-floating peatland in Central Italy.

    PubMed

    Zaccone, Claudio; Lobianco, Daniela; Shotyk, William; Ciavatta, Claudio; Appleby, Peter G; Brugiapaglia, Elisabetta; Casella, Laura; Miano, Teodoro M; D'Orazio, Valeria

    2017-02-23

    Floating islands mysteriously moving around on lakes were described by several Latin authors almost two millennia ago. These fascinating ecosystems, known as free-floating mires, have been extensively investigated from ecological, hydrological and management points of view, but there have been no detailed studies of their rates of accumulation of organic matter (OM), organic carbon (OC) and total nitrogen (TN). We have collected a peat core 4 m long from the free-floating island of Posta Fibreno, a relic mire in Central Italy. This is the thickest accumulation of peat ever found in a free-floating mire, yet it has formed during the past seven centuries and represents the greatest accumulation rates, at both decadal and centennial timescale, of OM (0.63 vs. 0.37 kg/m(2)/yr), OC (0.28 vs. 0.18 kg/m(2)/yr) and TN (3.7 vs. 6.1 g/m(2)/yr) ever reported for coeval peatlands. The anomalously high accretion rates, obtained using (14)C age dating, were confirmed using (210)Pb and (137)Cs: these show that the top 2 m of Sphagnum-peat has accumulated in only ~100 years. As an environmental archive, Posta Fibreno offers a temporal resolution which is 10x greater than any terrestrial peat bog, and promises to provide new insight into environmental changes occurring during the Anthropocene.

  17. Highly anomalous accumulation rates of C and N recorded by a relic, free-floating peatland in Central Italy

    PubMed Central

    Zaccone, Claudio; Lobianco, Daniela; Shotyk, William; Ciavatta, Claudio; Appleby, Peter G.; Brugiapaglia, Elisabetta; Casella, Laura; Miano, Teodoro M.; D’Orazio, Valeria

    2017-01-01

    Floating islands mysteriously moving around on lakes were described by several Latin authors almost two millennia ago. These fascinating ecosystems, known as free-floating mires, have been extensively investigated from ecological, hydrological and management points of view, but there have been no detailed studies of their rates of accumulation of organic matter (OM), organic carbon (OC) and total nitrogen (TN). We have collected a peat core 4 m long from the free-floating island of Posta Fibreno, a relic mire in Central Italy. This is the thickest accumulation of peat ever found in a free-floating mire, yet it has formed during the past seven centuries and represents the greatest accumulation rates, at both decadal and centennial timescale, of OM (0.63 vs. 0.37 kg/m2/yr), OC (0.28 vs. 0.18 kg/m2/yr) and TN (3.7 vs. 6.1 g/m2/yr) ever reported for coeval peatlands. The anomalously high accretion rates, obtained using 14C age dating, were confirmed using 210Pb and 137Cs: these show that the top 2 m of Sphagnum-peat has accumulated in only ~100 years. As an environmental archive, Posta Fibreno offers a temporal resolution which is 10x greater than any terrestrial peat bog, and promises to provide new insight into environmental changes occurring during the Anthropocene. PMID:28230066

  18. Crystal accumulation in the Hanford Waste Treatment Plant high level waste melter. Preliminary settling and resuspension testing

    SciTech Connect

    Fox, K. M.; Fowley, M. D.; Miller, D. H.

    2016-05-01

    The full-scale, room-temperature Hanford Tank Waste Treatment and Immobilization Plant (WTP) High-Level Waste (HLW) melter riser test system was successfully operated with silicone oil and magnetite particles at a loading of 0.1 vol %. Design and construction of the system and instrumentation, and the selection and preparation of simulant materials, are briefly reviewed. Three experiments were completed. A prototypic pour rate was maintained, based on the volumetric flow rate. Settling and accumulation of magnetite particles were observed at the bottom of the riser and along the bottom of the throat after each experiment. The height of the accumulated layer at the bottom of the riser, after the first pouring experiment, approximated the expected level given the solids loading of 0.1 vol %. More detailed observations of particle resuspension and settling were made during and after the third pouring experiment. The accumulated layer of particles at the bottom of the riser appeared to be unaffected after a pouring cycle of approximately 15 minutes at the prototypic flow rate. The accumulated layer of particles along the bottom of the throat was somewhat reduced after the same pouring cycle. Review of the time-lapse recording showed that some of the settling particles flow from the riser into the throat. This may result in a thicker than expected settled layer in the throat.

  19. Biodegradation of high concentrations of tetrachloroethene in a continuous flow column system

    SciTech Connect

    Isalou, M; Sleep, B.E.; Liss, S.N.

    1998-11-15

    A long-term (2.5 years) study of the anaerobic biodegradation of high concentrations of perchloroethylene (PCE) was carried out in a continuously operated laboratory column filled with sand which was inoculated with biomass from an anaerobic digester. Concentrations of PCE fed to the column were increased from 12 {micro}M to over 600 {micro}M over 21 months, with methanol added as electron donor. Vinyl chloride (VC) was the terminal product of PCE dechlorination for the first 21 months at which point significant conversion of VC to ethylene (ETH) was detected. The onset of ETH production coincided with acetogenesis becoming the primary pathway for methanol metabolism. ETH production occurred in the column in the presence of PCE and TCE. Varying methanol:PCE molar ratios from 1.4 to 7.5 had little effect on the transformation of PCE and TCE to VC. The degradation of VC to ETH was much more sensitive, and VC accumulated when the methanol:PCE molar ratio dropped below 5.0. Withdrawal of PCE from the system for a 5 month period and maintenance of the column on methanol alone did not result in the loss of PCE degradation capability of the consortium.

  20. [Partial nitrification of digested sludge liquor with low C/N and high-concentration ammonia].

    PubMed

    Zhang, Shu-Jun; Ma, Fu-Guo; Cao, Xiang-Sheng; Gan, Yi-Ping; Meng, Xue-Zheng; Zhou, Jun; Wang, Hong-Chen; Peng, Yong-Zhen

    2009-06-15

    The experimental system consisted of anoxic filter and aerobic suspended carrier biofilm reactor. The partial nitrification was achieved and maintained stably in the aerobic reactor under normal temperature (15-29 degrees C) and high DO (6-9 mg/L). The nitritation with 70%-80% nitrite accumulation efficiency was obtained when FA concentration was in the range of 1.0-10.3 mg/L by controlling influent ammonia loading rate (ALR), ratio of alkalinity and ammonia and HRT in the aerobic reactor. The effluent nitrite/ammonia ratio was about 1.25 when the average influent ammonia, influent ALR and influent ratio of alkalinity and ammonia were 315.80 mg/L, 0.43 kg/(m3 x d) and 5.25, respectively. So the effluent of partial nitrification process provided the influent substrate demand for the following ANAMMOX process. The integrative analysis indicated that the proper FA concentration was the main factor achieving the partial nitrification. The study developed a novel partial nitrification technology adapt to water characteristics of digested sludge liquor.

  1. Accumulation of CD62P during storage of apheresis platelet concentrates and the role of CD62P in transfusion-related acute lung injury.

    PubMed

    Tong, Shan; Wang, Haibao; Zhang, Ting; Chen, Linfeng; Liu, Bowei

    2015-11-01

    Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-associated morbidity and mortality. Activated platelets have important roles in TRALI and CD62P was identified to be an important indicator of platelet activation. However, the precise roles of CD62P in TRALI have remained elusive. The present study assessed CD62P accumulation during storage of apheresis platelet concentrates (A‑Plts) and established a mouse model of TRALI to further investigate the roles of CD62P in TRALI. The results showed that the CD62P concentration in A‑Plts was increased with the storage time. Mice were treated with monoclonal major histocompatibility complex (MHC)‑1 antibody to induce TRALI. The murine model of TRALI was successfully established as evidenced by pulmonary oedema, accompanied by decreased clearance of bronchoalveolar lavage fluid (BALF), increased pulmonary and systemic inflammation, elevated lung myeloperoxidase (MPO) activity as well as increased pulmonary and systemic coagulation in the TRALI group compared with those in the control group. To further determine the role of CD62P in TRALI, mice were treated with anti‑CD62P antibody to knockdown CD62P in vivo. It was found that pulmonary oedema, BALF clearance, pulmonary and systemic inflammation, MPO activity as well as pulmonary and systemic coagulation were decreased in the TRALI + anti‑CD62P antibody group compared with those in the TRALI + isotype antibody group. The present study supported the notion that CD62P is involved in mediating TRALI and may provide an important molecular basis for enhancing the clinical safety and effectiveness of platelet transfusion.

  2. Trehalose accumulation in rice plants confers high tolerance levels to different abiotic stresses

    PubMed Central

    Garg, Ajay K.; Kim, Ju-Kon; Owens, Thomas G.; Ranwala, Anil P.; Choi, Yang Do; Kochian, Leon V.; Wu, Ray J.

    2002-01-01

    Trehalose is a nonreducing disaccharide of glucose that functions as a compatible solute in the stabilization of biological structures under abiotic stress in bacteria, fungi, and invertebrates. With the notable exception of the desiccation-tolerant “resurrection plants,” trehalose is not thought to accumulate to detectable levels in most plants. We report here the regulated overexpression of Escherichia coli trehalose biosynthetic genes (otsA and otsB) as a fusion gene for manipulating abiotic stress tolerance in rice. The fusion gene has the advantages of necessitating only a single transformation event and a higher net catalytic efficiency for trehalose formation. The expression of the transgene was under the control of either tissue-specific or stress-dependent promoters. Compared with nontransgenic rice, several independent transgenic lines exhibited sustained plant growth, less photo-oxidative damage, and more favorable mineral balance under salt, drought, and low-temperature stress conditions. Depending on growth conditions, the transgenic rice plants accumulate trehalose at levels 3–10 times that of the nontransgenic controls. The observation that peak trehalose levels remain well below 1 mg/g fresh weight indicates that the primary effect of trehalose is not as a compatible solute. Rather, increased trehalose accumulation correlates with higher soluble carbohydrate levels and an elevated capacity for photosynthesis under both stress and nonstress conditions, consistent with a suggested role in modulating sugar sensing and carbohydrate metabolism. These findings demonstrate the feasibility of engineering rice for increased tolerance of abiotic stress and enhanced productivity through tissue-specific or stress-dependent overproduction of trehalose. PMID:12456878

  3. Carbon dioxide concentrations are very high in developing oilseeds.

    PubMed

    Goffman, Fernando D; Ruckle, Mike; Ohlrogge, John; Shachar-Hill, Yair

    2004-09-01

    A new method has been developed to rapidly determine the total inorganic carbon concentration (gaseous [CO2] + aqueous [CO(2)] + [HCO3-] + [CO3(2)-]) in developing seeds. Seeds are rapidly dissected and homogenized in 1 N HCl in gas-tight vials. The headspace gas is then analyzed by infrared gas analysis. Developing rapeseed (Brassica napus L.) and soybean [Glycine max (L.) Merr.] seeds were analyzed and found to have up to 40 and 12 mM total inorganic carbon, respectively. These concentrations are ca. 600-2000-fold higher than in ambient air or values reported for leaves. Carbon dioxide concentrations in rapeseed peaked during the stage of maximum oil synthesis and declined as seeds matured. The consequences for seed metabolism, physiology and carbon economy are discussed.

  4. Development of manufacturing capability for high-concentration, high-efficiency silicon solar cells

    SciTech Connect

    Sinton, R.A.; Verlinden, P.J.; Crane, R.A.; Swanson, R.N.

    1996-10-01

    This report presents a summary of the major results from a program to develop a manufacturable, high-efficiency silicon concentrator solar cell and a cost-effective manufacturing facility. The program was jointly funded by the Electric Power Research Institute, Sandia National Laboratories through the Concentrator Initiative, and SunPower Corporation. The key achievements of the program include the demonstration of 26%-efficient silicon concentrator solar cells with design-point (20 W/cm{sup 2}) efficiencies over 25%. High-performance front-surface passivations; that were developed to achieve this result were verified to be absolutely stable against degradation by 475 days of field exposure at twice the design concentration. SunPower demonstrated pilot production of more than 1500 of these cells. This cell technology was also applied to pilot production to supply 7000 17.7-cm{sup 2} one-sun cells (3500 yielded wafers) that demonstrated exceptional quality control. The average efficiency of 21.3% for these cells approaches the peak efficiency ever demonstrated for a single small laboratory cell within 2% (absolute). Extensive cost models were developed through this program and calibrated by the pilot-production project. The production levels achieved indicate that SunPower could produce 7-10 MW of concentrator cells per year in the current facility based upon the cell performance demonstrated during the program.

  5. Micronutrients-fortified rapeseed oil improves hepatic lipid accumulation and oxidative stress in rats fed a high-fat diet.

    PubMed

    Xu, Jiqu; Zhou, Xiaoqi; Gao, Hui; Chen, Chang; Deng, Qianchun; Huang, Qingde; Ma, Jing; Wan, Zhengyang; Yang, Jin'e; Huang, Fenghong

    2013-03-06

    Intake of high-fat diet is associated with increased fatty livers. Hepatic lipid accumulation and oxidative stress are key pathophysiological mechanisms in this disease. Micronutrients polyphenols, tocopherols and phytosterols in rapeseed exert potential benefit to hepatoprotection, but most of these micronutrients are removed by the traditional refining process. The purpose of the present study was to determine whether rapeseed oil fortified with these micronutrients can decrease hepatic lipid accumulation and oxidative stress induced by high-fat diet. Sprague-Dawley rats received rodent diet contained 20% fat whose source was refined rapeseed oil (RRO) or fortified RRO with low, middle and high quantities of these micronutrients for 10 weeks. Intake of RRO caused a remarkable hepatic steatosis. Micronutrients supplementation was effective in reducing steatosis as well as total triglyceride and total cholesterol contents in liver. These micronutrients also significantly increased hepatic antioxidant defense capacities, as evaluated by the significant elevation in the activities of SOD and GPx as well as the level of GSH, and the significant decline in lipid peroxidation. These findings suggest that rapeseed oil fortified with micronutrients polyphenols, tocopherols and phytosterols may contribute to prevent fatty livers such as nonalcoholic fatty liver disease by ameliorating hepatic lipid accumulation and oxidative stress.

  6. Relevance of GaAs(001) surface electronic structure for high frequency dispersion on n-type accumulation capacitance

    NASA Astrophysics Data System (ADS)

    Pi, T. W.; Chen, W. S.; Lin, Y. H.; Cheng, Y. T.; Wei, G. J.; Lin, K. Y.; Cheng, C.-P.; Kwo, J.; Hong, M.

    2017-01-01

    This study investigates the origin of long-puzzled high frequency dispersion on the accumulation region of capacitance-voltage characteristics in an n-type GaAs-based metal-oxide-semiconductor. Probed adatoms with a high Pauling electronegativity, Ag and Au, unexpectedly donate charge to the contacted As/Ga atoms of as-grown α2 GaAs(001)-2 × 4 surfaces. The GaAs surface atoms behave as charge acceptors, and if not properly passivated, they would trap those electrons accumulated at the oxide and semiconductor interface under a positive bias. The exemplified core-level spectra of the Al2O3/n-GaAs(001)-2 × 4 and the Al2O3/n-GaAs(001)-4 × 6 interfaces exhibit remnant of pristine surface As emission, thereby causing high frequency dispersion in the accumulation region. For the p-type GaAs, electrons under a negatively biased condition are expelled from the interface, thereby avoiding becoming trapped.

  7. Methods and devices for high-throughput dielectrophoretic concentration

    DOEpatents

    Simmons, Blake A.; Cummings, Eric B.; Fiechtner, Gregory J.; Fintschenko, Yolanda; McGraw, Gregory J.; Salmi, Allen

    2010-02-23

    Disclosed herein are methods and devices for assaying and concentrating analytes in a fluid sample using dielectrophoresis. As disclosed, the methods and devices utilize substrates having a plurality of pores through which analytes can be selectively prevented from passing, or inhibited, on application of an appropriate electric field waveform. The pores of the substrate produce nonuniform electric field having local extrema located near the pores. These nonuniform fields drive dielectrophoresis, which produces the inhibition. Arrangements of electrodes and porous substrates support continuous, bulk, multi-dimensional, and staged selective concentration.

  8. High spatial resolution shortwave infrared imaging technology based on time delay and digital accumulation method

    NASA Astrophysics Data System (ADS)

    Jia, Jianxin; Wang, Yueming; Zhuang, Xiaoqiong; Yao, Yi; Wang, Shengwei; Zhao, Ding; Shu, Rong; Wang, Jianyu

    2017-03-01

    Shortwave infrared (SWIR) imaging technology attracts more and more attention by its fascinating ability of penetrating haze and smoke. For application of spaceborne remote sensing, spatial resolution of SWIR is lower compared with that of visible light (VIS) wavelength. It is difficult to balance between the spatial resolution and signal to noise ratio (SNR). Some conventional methods, such as enlarging aperture of telescope, image motion compensation, and analog time delay and integration (TDI) technology are used to gain SNR. These techniques bring in higher cost of satellite, complexity of system or other negative factors. In this paper, time delay and digital accumulation (TDDA) method is proposed to achieve higher spatial resolution. The method can enhance the SNR and non-uniformity of system theoretically. A prototype of SWIR imager consists of opto-mechanical, 1024 × 128 InGaAs detector, and electronics is designed and integrated to prove TDDA method. Both of measurements and experimental results indicate TDDA method can promote SNR of system approximated of the square root of accumulative stage. The results exhibit that non-uniformity of system is also improved by this approach to some extent. The experiment results are corresponded with the theoretical analysis. Based on the experiments results, it is proved firstly that the goal of 1 m ground sample distance (GSD) in orbit of 500 km is feasible with the TDDA stage of 30 for SWIR waveband (0.9-1.7 μm).

  9. Carinal and tubular airway particle concentrations in the large airways of non-smokers in the general population: evidence for high particle concentration at airway carinas.

    PubMed Central

    Churg, A; Vedal, S

    1996-01-01

    OBJECTIVE: To evaluate the extent to which human airway carinas accumulate ambient atmospheric particles, a newly developed technique was used to micro-dissect and analyse particle concentration in tubular segments and carinas of the large airways of 10 necropsy lungs from non-smokers from the general population of Vancouver. METHODS: Ratios of the particle concentrations on the carinas to the tubular segment immediately preceding it were measured with analytical electron microscopy for the mainstem bronchus, upper and lower lobe bronchi, and four different segmental or subsegmental bronchi--that is, Weibel generations 1 to about 5. A total of 119 carinal-tubular pairs was evaluated. RESULTS: Over all cases, both carinal and tubular particle concentrations increased with increasing airway generation; the median ratio of carinal to tubular particle concentration was 9:1 and did not show any trend with airway generation. The ratio was > 5 in 71% of carinal-tubular pairs, > 10 in 42% of pairs, > 20 in 31% of pairs, and > 100 in 9% of pairs. Some subjects showed a notable tendency to high ratios, with many ratios > 100, and other subjects had a tendency toward low ratios. The predominant mineral species in both carinas and tubular airway segments was crystalline silica and the relative proportion was similar in both sites; however, mean particle diameter was consistently less in the carinal tissues. CONCLUSIONS: These findings suggest that the ratio of carinal to tubular retained particles in the large airways in non-smokers is higher than might be supposed from data generated in airway casts, and that there is considerable variation in this ratio between subjects. This finding is of potential interest in models of carcinogen, toxin, and dose of fibrogenic agent to the large airways as it suggests high and sometimes extreme concentrations of toxic particles at carinas, and thus reinforces the notion that carinas may be sites of initiation of disease. PMID:8983467

  10. High concentrations of Na+ and Cl- ions in soil solution have simultaneous detrimental effects on growth of faba bean under salinity stress.

    PubMed

    Tavakkoli, Ehsan; Rengasamy, Pichu; McDonald, Glenn K

    2010-10-01

    Despite the fact that most plants accumulate both sodium (Na(+)) and chloride (Cl(-)) ions to high concentration in their shoot tissues when grown in saline soils, most research on salt tolerance in annual plants has focused on the toxic effects of Na(+) accumulation. There have also been some recent concerns about the ability of hydroponic systems to predict the responses of plants to salinity in soil. To address these two issues, an experiment was conducted to compare the responses to Na(+) and to Cl(-) separately in comparison with the response to NaCl in a soil-based system using two varieties of faba bean (Vicia faba), that differed in salinity tolerance. The variety Nura is a salt-sensitive variety that accumulates Na(+) and Cl(-) to high concentrations while the line 1487/7 is salt tolerant which accumulates lower concentrations of Na(+) and Cl(-). Soils were prepared which were treated with Na(+) or Cl(-) by using a combination of different Na(+) salts and Cl(-) salts, respectively, or with NaCl. While this method produced Na(+)-dominant and Cl(-)-dominant soils, it unavoidably led to changes in the availability of other anions and cations, but tissue analysis of the plants did not indicate any nutritional deficiencies or toxicities other than those targeted by the salt treatments. The growth, water use, ionic composition, photosynthesis, and chlorophyll fluorescence were measured. Both high Na(+) and high Cl(-) reduced growth of faba bean but plants were more sensitive to Cl(-) than to Na(+). The reductions in growth and photosynthesis were greater under NaCl stress and the effect was mainly additive. An important difference to previous hydroponic studies was that increasing the concentrations of NaCl in the soil increased the concentration of Cl(-) more than the concentration of Na(+). The data showed that salinity caused by high concentrations of NaCl can reduce growth by the accumulation of high concentrations of both Na(+) and Cl(-) simultaneously, but

  11. Fabricating high-concentration GaAs cell photovoltaic modules

    SciTech Connect

    Kaminar, N.R.; Hamaker, H.C.

    1986-04-01

    This program comprises the design and manufacture of components of a GaAs-cell, passively-cooled concentrator. A Fresnel lens, 5.44-inches square, was used in conjunction with a solid glass, domed-top secondary optical element to concentrate the light on single-junction GaAs cells. The cell had an active area 0.2 inches in diameter and was soldered directly to the copper heatspreader. The heatspreader was bonded with heat-conductive RTV to an aluminum dissipator, which formed the module housing. The module was designed to be attached to a tracker at the center. Obtained were 26% cell efficiency in flash tests and 19.2% combined lens/cell efficiency outdoors. Optical transmission was lower than expected due to higher than expected losses in the secondary. The secondaries were made using a molding technique applicable to mass production.

  12. Effects of salicylic acid on thermotolerance and cardenolide accumulation under high temperature stress in Digitalis trojana Ivanina.

    PubMed

    Cingoz, Gunce Sahin; Gurel, Ekrem

    2016-08-01

    Long periods of high temperature or transitory increased temperature, a widespread agricultural problem, may lead to a drastic reduction in economic yield, affecting plant growth and development in many areas of the world. Heat stress causes many anatomical and physiological changes in plants. Its unfavorable effects can be alleviated by thermotolerance induced by exogenous application of plant growth regulators and osmoprotectants or by gradual application of temperature stress. Digitalis trojana Ivanina is an important medicinal plant species well known mainly for its cardenolides. The production of cardenolides via traditional agriculture is commercially inadequate. In this study, elicitation strategies were employed for improving crop thermotolerance and accumulation of cardenolides. For these purposes, the effects of salicylic acid (SA) and/or high temperature treatments in inducing cardenolide accumulation and thermotolerance were tested in callus cultures of D. trojana. Considerable increases in the production of cardenolides (up to 472.28 μg.g(-1) dry weight, dw) and induction of thermotolerance capacity were observed when callus cultures were exposed to high temperature for 2 h after pretreating with SA. High temperature treatments (2 h and 4 h) caused a marked reduction in superoxide dismutase (SOD; EC 1.15.1.1) and catalase (CAT; EC 1.11.1.6) activities, while SA pretreatment increased their activities. High temperature and/or SA appeared to increase the levels of proline, total phenolic, and flavonoid content. Elevated phenolic accumulation could be associated with increased stress protection. These results indicated that SA treatments induced synthesis of antioxidants and cardenolides, which may play a significant role in resistance to high temperature stress.

  13. Dimerization in Highly Concentrated Solutions of Phosphoimidazolide Activated Monomucleotides

    NASA Astrophysics Data System (ADS)

    Kanavarioti, Anastassia

    1997-08-01

    Phosphoimidazolide activated ribomononucleotides (*pN) are useful substrates for the non-enzymatic synthesis of polynucleotides. However, dilute neutral aqueous solutions of *pN typically yield small amounts of dimers and traces of polymers; most of *pN hydrolyzes to yield nucleoside 5'-monophosphate. Here we report the self-condensation of nucleoside 5'-phosphate 2-methylimidazolide (2-MeImpN with N = cytidine, uridine or guanosine) in the presence of Mg2+ in concentrated solutions, such as might have been found in an evaporating lagoon on prebiotic Earth. The product distribution indicates that oligomerization is favored at the expense of hydrolysis. At 1.0 M, 2-MeImpU and 2-MeImpC produce about 65% of oligomers including 4% of the 3',5'-linked dimer. Examination of the product distribution of the three isomeric dimers in a self-condensation allows identification of reaction pathways that lead to dimer formation. Condensations in a concentrated mixture of all three nucleotides (U,C,G mixtures) is made possible by the enhanced solubility of 2-MeImpG in such mixtures. Although percent yield of internucleotide linked dimers is enhanced as a function of initial monomer concentration, pyrophosphate dimer yields remain practically unchanged at about 20% for 2-MeImpU, 16% for 2-MeImpC and 25% of the total pyrophosphate in the U,C,G mixtures. The efficiency by which oligomers are produced in these concentrated solutions makes the evaporating lagoon scenario a potentially interesting medium for the prebiotic synthesis of dimers and short RNAs.

  14. Asymptotic Expansion in Enzyme Reactions with High Enzyme Concentrations

    NASA Astrophysics Data System (ADS)

    Bersani, Alberto Maria; Dell'Acqua, Guido

    2010-09-01

    In this paper we find a new asymptotic expansion valid in enzymatic reactions where the total amount of enzyme exceeds greatly the total amount of substrate. In such case it is well known that the Michelis-Menten approximation is no longer valid; therefore our asymptotic expansion is a new tool to approximate in a closed form the concentrations of the reactants in presence of an enzyme excess.

  15. Dimerization in Highly Concentrated Solutions of Phosphoimidazolide Activated Mononucleotides

    NASA Technical Reports Server (NTRS)

    Kanavarioti, Anastassia

    1997-01-01

    Phosphoimidazolide activated ribomononucleotides (*pN) are useful substrates for the non-enzymatic synthesis of polynucleotides. However, dilute neutral aqueous solutions of *pN typically yield small amounts of dimers and traces of polymers; most of *pN hydrolyzes to yield nucleoside 5'-monophosphate. Here we report the self-condensation of nucleoside 5'-phosphate 2- methylimidazolide (2-MeImpN with N = cytidine, uridine or guanosine) in the presence of Mg2(+) in concentrated solutions, such as might have been found in an evaporating lagoon on prebiotic Earth. The product distribution indicates that oligomerization is favored at the expense of hydrolysis. At 1.0 M, 2-MelmpU and 2-MelmpC produce about 65% of oligomers including 4% of the 3',5'-Iinked dimer. Examination of the product distribution of the three isomeric dimers in a self-condensation allows identification of reaction pathways that lead to dimer formation. Condensations in a concentrated mixture of all three nucleotides (U,C,G mixtures) is made possible by the enhanced solubility of 2-MeImpG in such mixtures. Although percent yield of intemucleotide linked dimers is enhanced as a function of initial monomer concentration, pyrophosphate dimer yields remain practically unchanged at about 20% for 2-MelmpU, 16% for 2-MeImpC and 25% of the total pyrophosphate in the U,C,G mixtures. The efficiency by which oligomers are produced in these concentrated solutions makes the evaporating lagoon scenario a potentially interesting medium for the prebiotic synthesis of dimers and short RNAs.

  16. Concentration measurement of yeast suspensions using high frequency ultrasound backscattering.

    PubMed

    Elvira, Luis; Vera, Pedro; Cañadas, Francisco Jesús; Shukla, Shiva Kant; Montero, Francisco

    2016-01-01

    This work proposes the use of an ultrasound based technique to measure the concentration of yeasts in liquid suspension. This measurement was achieved by the detection and quantification of ultrasonic echoes backscattered by the cells. More specifically, the technique was applied to the detection and quantification of Saccharomyces cerevisiae. A theoretical approach was proposed to get the average density and sound speed of the yeasts, which were found to be 1116 kg/m(3) and 1679 m/s, respectively. These parameters were needed to model the waves backscattered by each single cell. A pulse-echo arrangement working around 50 MHz, being able to detect echoes from single yeasts was used to characterize experimentally yeast solutions from 10(2) to 10(7)cells/ml. The Non-negative Matrix Factorization denoising technique was applied for data analysis. This technique required a previous learning of the spectral patterns of the echoes reflected from yeasts in solution and the base noise from the liquid medium. Comparison between pulse correlation (without denoising) and theoretical and experimental pattern learning was made to select the best signal processing. A linear relation between ultrasound output and concentration was obtained with correlation coefficient R(2)=0.996 for the experimental learning. Concentrations from 10(4) to 10(7)cells/ml were detected above the base noise. These results show the viability of using the ultrasound backscattering technique to detect yeasts and measure their concentration in liquid cultures, improving the sensitivity obtained using spectrophotometric methods by one order of magnitude.

  17. Serum POP concentrations are highly predictive of inner blubber concentrations at two extremes of body condition in northern elephant seals.

    PubMed

    Peterson, Michael G; Peterson, Sarah H; Debier, Cathy; Covaci, Adrian; Dirtu, Alin C; Malarvannan, Govindan; Crocker, Daniel E; Costa, Daniel P

    2016-11-01

    Long-lived, upper trophic level marine mammals are vulnerable to bioaccumulation of persistent organic pollutants (POPs). Internal tissues may accumulate and mobilize POP compounds at different rates related to the body condition of the animal and the chemical characteristics of individual POP compounds; however, collection of samples from multiple tissues is a major challenge to ecotoxicology studies of free-ranging marine mammals and the ability to predict POP concentrations in one tissue from another tissue remains rare. Northern elephant seals (Mirounga angustirostris) forage on mesopelagic fish and squid for months at a time in the northeastern Pacific Ocean, interspersed with two periods of fasting on land, which results in dramatic seasonal fluctuations in body condition. Using northern elephant seals, we examined commonly studied tissues in mammalian toxicology to describe relationships and determine predictive equations among tissues for a suite of POP compounds, including ΣDDTs, ΣPCBs, Σchlordanes, and ΣPBDEs. We collected paired blubber (inner and outer) and blood serum samples from adult female and male seals in 2012 and 2013 at Año Nuevo State Reserve (California, USA). For females (N = 24), we sampled the same seals before (late in molting fast) and after (early in breeding fast) their approximately seven month foraging trip. For males, we sampled different seals before (N = 14) and after (N = 15) their approximately four month foraging trip. We observed strong relationships among tissues for many, but not all compounds. Serum POP concentrations were strong predictors of inner blubber POP concentrations for both females and males, while serum was a more consistent predictor of outer blubber for males than females. The ability to estimate POP blubber concentrations from serum, or vice versa, has the potential to enhance toxicological assessment and physiological modeling. Furthermore, predictive equations may illuminate commonalities or

  18. Does a high concentration of calcium in the urine cause an important renal concentrating defect in human subjects?

    PubMed

    Lam, G S; Asplin, J R; Halperin, M L

    2000-03-01

    The objective of this study was to evaluate the hypothesis that a high concentration of ionized calcium in the lumen of the medullary collecting duct causes an osmole-free water diuresis. The urine flow rate and osmolality were measured in normal human subjects, as well as in patients with a history of nephrolithiasis who excreted more than 5 mmol of calcium per 24 h. There was an inverse relationship between the concentration of calcium in the urine and the 24 h urine volume both in normal subjects and in patients with a history of nephrolithiasis. When the concentration of calcium in the urine was greater than 5 mmol/l, the urine volume was less than 1 litre per day in the majority of subjects. After 16 h of water deprivation, when the concentration of calcium in the urine was as high as 17 mmol/l (ionized calcium 7.4 mmol/l), urine osmolality was 1258 mOsm/kg of water and the urine flow rate was 0.30 ml/min. We conclude that, although a calcium receptor may be present in the lumen of the medullary collecting duct in human subjects, an extremely high concentration of urinary total and ionized calcium does not cause a clinically important defect in the renal concentrating process.

  19. High glucose concentrations attenuate hypoxia-inducible factor-1{alpha} expression and signaling in non-tumor cells

    SciTech Connect

    Dehne, Nathalie; Bruene, Bernhard

    2010-04-15

    Hypoxia-inducible factor (HIF) is the major transcription factor mediating adaption to hypoxia e.g. by enhancing glycolysis. In tumor cells, high glucose concentrations are known to increase HIF-1{alpha} expression even under normoxia, presumably by enhancing the concentration of tricarboxylic acid cycle intermediates, while reactions of non-tumor cells are not well defined. Therefore, we analyzed cellular responses to different glucose concentrations in respect to HIF activation comparing tumor to non-tumor cells. Using cells derived from non-tumor origin, we show that HIF-1{alpha} accumulation was higher under low compared to high glucose concentrations. Low glucose allowed mRNA expression of HIF-1 target genes like adrenomedullin. Transfection of C{sub 2}C{sub 12} cells with a HIF-1{alpha} oxygen-dependent degradation domaine-GFP fusion protein revealed that prolyl hydroxylase (PHD) activity is impaired at low glucose concentrations, thus stabilizing the fusion protein. Mechanistic considerations suggested that neither O{sub 2} redistribution nor an altered redox state explains impaired PHD activity in the absence of glucose. In order to affect PHD activity, glucose needs to be metabolized. Amino acids present in the medium also diminished HIF-1{alpha} expression, while the addition of fatty acids did not. This suggests that glucose or amino acid metabolism increases oxoglutarate concentrations, which enhances PHD activity in non-tumor cells. Tumor cells deprived of glutamine showed HIF-1{alpha} accumulation in the absence of glucose, proposing that enhanced glutaminolysis observed in many tumors enables these cells to compensate reduced oxoglutarate production in the absence of glucose.

  20. The design and development of a high concentration and high efficiency photovoltaic concentrator utilizing a curved Fresnel lens

    SciTech Connect

    Moffat, A.L.; Scharlack, R.S.

    1982-09-01

    The design and development of an innovative photovoltaic concentrator which utilizes a low cost molded Fresnel lens is described. The lens design and fabrication are discussed, as well as the design of the collector module and tracking structure. A description of instrumentation developed to aid in the testing of lenses and solar cells is presented, and includes the test results.

  1. Excess Thermodynamic Properties of Concentrated Aqueous Solutions at High Temperatures

    SciTech Connect

    Guszkiewicz, M.S.

    2001-06-07

    Measurements of the vapor pressure of the solvent in wide ranges of concentration and temperature provide information on solute solvation and ion pairing--the two phenomena most often invoked for description of dilute solutions. Even in moderately concentrated solutions, as interionic distances become comparable to ionic diameters, these simple concepts gradually lose their meaning and solutions behave like molten salts. The usefulness of experimental vapor pressure results increases rapidly with their accuracy, since derived properties, such as solution enthalpies and heat capacities, can be calculated. Very accurate results can be obtained by the isopiestic method, but primary vapor pressure data for standard solutions are needed. In order to obtain vapor pressures at conditions where accurate isopiestic standards are not available and to establish more accurate standards, the ORNL isopiestic apparatus was modified for simultaneous direct vapor pressure measurements and isopiestic comparisons. There are no comprehensive solution theories derived from molecular level models and able to predict thermodynamic properties of various electrolytes as the composition changes from dilute solutions to molten salts in a wide range of temperatures. Empirical and semi-empirical models are useful for representation of experimental results, interpretation of measurements of other properties such as conductance., solubility or liquid-vapor partitioning of solutes, and for verification of theoretical predictions. Vapor pressures for aqueous CaCl{sub 2}, CaBr{sub 2}, LiCl, LiBr, LiI, NaI were measured at temperatures between 380 and 523 K in the concentration range extended to water activities below 0.2 (over 30 mol/kg for LiCl). General equations based on the modified Pitzer ion-interaction model were used to obtain enthalpy and heat capacity surfaces, which are compared with direct calorimetric measurements.

  2. Unexpectedly high indoor hydroxyl radical concentrations associated with nitrous acid.

    PubMed

    Gómez Alvarez, Elena; Amedro, Damien; Afif, Charbel; Gligorovski, Sasho; Schoemaecker, Coralie; Schoemacker, Coralie; Fittschen, Christa; Doussin, Jean-Francois; Wortham, Henri

    2013-08-13

    The hydroxyl (OH) radical is the most important oxidant in the atmosphere since it controls its self-oxidizing capacity. The main sources of OH radicals are the photolysis of ozone and the photolysis of nitrous acid (HONO). Due to the attenuation of solar radiation in the indoor environment, the possibility of OH formation through photolytic pathways indoors has been ignored up to now. In the indoor air, the ozonolysis of alkenes has been suggested as an alternative route of OH formation. Models and indirect measurements performed up to now according to this hypothesis suggest concentrations of OH radicals on the order of 10(4)-10(5) molecules per cubic centimeter. Here, we present direct measurements of significant amounts of OH radicals of up to 1.8⋅10(6) molecules per cubic centimeter during an experimental campaign carried out in a school classroom in Marseille. This concentration is on the same order of magnitude of outdoor OH levels in the urban scenario. We also show that photolysis of HONO is an important source of OH radicals indoors under certain conditions (i.e., direct solar irradiation inside the room). Additionally, the OH concentrations were found to follow a linear dependence with the product J(HONO)⋅[HONO]. This was also supported by using a simple quasiphotostationary state model on the OH radical budget. These findings force a change in our understanding of indoor air quality because the reactivity linked to OH would involve formation of secondary species through chemical reactions that are potentially more hazardous than the primary pollutants in the indoor air.

  3. Unexpectedly high indoor hydroxyl radical concentrations associated with nitrous acid

    PubMed Central

    Gómez Alvarez, Elena; Amedro, Damien; Afif, Charbel; Gligorovski, Sasho; Schoemaecker, Coralie; Fittschen, Christa; Doussin, Jean-Francois; Wortham, Henri

    2013-01-01

    The hydroxyl (OH) radical is the most important oxidant in the atmosphere since it controls its self-oxidizing capacity. The main sources of OH radicals are the photolysis of ozone and the photolysis of nitrous acid (HONO). Due to the attenuation of solar radiation in the indoor environment, the possibility of OH formation through photolytic pathways indoors has been ignored up to now. In the indoor air, the ozonolysis of alkenes has been suggested as an alternative route of OH formation. Models and indirect measurements performed up to now according to this hypothesis suggest concentrations of OH radicals on the order of 104–105 molecules per cubic centimeter. Here, we present direct measurements of significant amounts of OH radicals of up to 1.8⋅106 molecules per cubic centimeter during an experimental campaign carried out in a school classroom in Marseille. This concentration is on the same order of magnitude of outdoor OH levels in the urban scenario. We also show that photolysis of HONO is an important source of OH radicals indoors under certain conditions (i.e., direct solar irradiation inside the room). Additionally, the OH concentrations were found to follow a linear dependence with the product J(HONO)⋅[HONO]. This was also supported by using a simple quasiphotostationary state model on the OH radical budget. These findings force a change in our understanding of indoor air quality because the reactivity linked to OH would involve formation of secondary species through chemical reactions that are potentially more hazardous than the primary pollutants in the indoor air. PMID:23898188

  4. The anaesthesia of fish by high carbon-dioxide concentrations

    USGS Publications Warehouse

    1942-01-01

    A practical and economical method for anaesthetizing adult salmon and steelhead trout in the fish trucks used in the Grand Coulee fish salvage program is described. The method consists in generating a predetermined carbon-dioxide concentration in the 1000-gallon tanks of the trucks through the successive addition of predissolved sodium bicarbonate and dilute sulphuric acid in proper quantities. Carbon-dioxide anaesthesia effectively solved the acute problem of species segregation in the fish salvage program and, with minor modifications, could be used with equal success in certain hatchery operations necessitating the handling of large fish.

  5. New PSA high concentration solar furnace SF40

    NASA Astrophysics Data System (ADS)

    Rodriguez, Jose; Cañadas, Inmaculada; Zarza, Eduardo

    2016-05-01

    A new solar furnace has been designed and built at Plataforma Solar de Almería. In this work, its main components such as heliostat, concentrator, attenuator and test table, and the method used to align them are described. Other equipment like the auxiliary systems necessary for the solar operation, vacuum chamber and gas system are outlined too. Finally, the thermal characteristics of the focus were measured during a test campaign, where different planes along the optical axis were scanned with a radiometer, and the peak flux was obtained and is presented in the last section of this report.

  6. Reductions in ozone at high concentrations of stratospheric halogens

    NASA Technical Reports Server (NTRS)

    Prather, M. J.; Mcelroy, M. B.; Wofsy, S. C.

    1984-01-01

    An increase in the concentration of inorganic chlorine to levels comparable to that of oxidized reactive nitrogen could cause a significant change in the chemistry of the lower stratosphere leading to a reduction potentially larger than 15 percent in the column density of ozone. This could occur, for example by the middle of the next century, if emissions of man-made chlorocarbons were to grow at a rate of 3 percent per year. Ozone could be further depressed by release of industrial bromocarbon.

  7. High-performance flat-panel solar thermoelectric generators with high thermal concentration.

    PubMed

    Kraemer, Daniel; Poudel, Bed; Feng, Hsien-Ping; Caylor, J Christopher; Yu, Bo; Yan, Xiao; Ma, Yi; Wang, Xiaowei; Wang, Dezhi; Muto, Andrew; McEnaney, Kenneth; Chiesa, Matteo; Ren, Zhifeng; Chen, Gang

    2011-05-01

    The conversion of sunlight into electricity has been dominated by photovoltaic and solar thermal power generation. Photovoltaic cells are deployed widely, mostly as flat panels, whereas solar thermal electricity generation relying on optical concentrators and mechanical heat engines is only seen in large-scale power plants. Here we demonstrate a promising flat-panel solar thermal to electric power conversion technology based on the Seebeck effect and high thermal concentration, thus enabling wider applications. The developed solar thermoelectric generators (STEGs) achieved a peak efficiency of 4.6% under AM1.5G (1 kW m(-2)) conditions. The efficiency is 7-8 times higher than the previously reported best value for a flat-panel STEG, and is enabled by the use of high-performance nanostructured thermoelectric materials and spectrally-selective solar absorbers in an innovative design that exploits high thermal concentration in an evacuated environment. Our work opens up a promising new approach which has the potential to achieve cost-effective conversion of solar energy into electricity.

  8. Massive intoxication involving unusual high concentration of amitriptyline.

    PubMed

    Margalho, Cláudia; Barroso, Mário; Gallardo, Eugenia; Monsanto, Paula; Vieira, Duarte Nuno

    2007-08-01

    Amitriptyline is a tricyclic antidepressant widely used in the treatment of depression. Antidepressant drugs are among the most commonly encountered causes of self-poisoning, as illustrated by several published cases in the literature. This investigation reports a case of massive amitriptyline intoxication, involving a 44-year old female found dead in bed. The presence of this tricyclic antidepressant was revealed by a routine screening procedure. The concentration was calculated by gas chromatography/ electron ionization-mass spectrometry in the selected ion monitoring mode after solid-phase extraction using proadifen as internal standard and was in the post-mortem whole blood sample 85.9 mug/mL. This value was much higher than the reported toxic values ever found in the literature, and may therefore have caused the victim's death. Nortriptyline was also detected in the toxic concentration range, as well as therapeutic levels of diazepam and nor-diazepam. Taking into account both the available circumstantial information and toxicological results, it is very likely that death was caused by self-poisoning. Human & Experimental Toxicology (2007) 26, 667-670.

  9. Effects of the Polysaccharide from the Sporophyll of Brown Alga Undaria Pinnatifida on Serum Lipid Profile and Fat Tissue Accumulation in Rats Fed a High-Fat Diet.

    PubMed

    Kim, Byoung-Mok; Park, Jae-Ho; Kim, Dong-Soo; Kim, Young-Myung; Jun, Joon-Young; Jeong, In-Hak; Chi, Young-Min

    2016-07-01

    We investigated the effects of the polysaccharide from the sporophyll of a selected brown alga Undaria pinnatifida on serum lipid profile, fat tissue accumulation, and gastrointestinal transit time in rats fed a high-fat diet. The algal polysaccharide (AP) was prepared by the treatment of multiple cellulase-producing fungi Trichoderma reesei and obtained from the sporophyll with a yield of 38.7% (dry basis). The AP was mostly composed of alginate and fucoidan (up to 89%) in a ratio of 3.75:1. The AP was added to the high-fat diet in concentrations of 0.6% and 1.7% and was given to male Sprague-Dawley rats (5-wk-old) for 5 wk. The 1.7% AP addition notably reduced body weight gain and fat tissue accumulation, and it improved the serum lipid profile, including triglycerides, total cholesterol, and very low-density lipoprotein-cholesterol. The effects were associated with increased feces weight and shortened gastrointestinal transit time. In addition, the lipid peroxidation of the liver was decreased in both groups.

  10. P accumulation and physiological responses to different high P regimes in Polygonum hydropiper for understanding a P-phytoremediation strategy

    PubMed Central

    Ye, Daihua; Li, Tingxuan; Liu, Dan; Zhang, Xizhou; Zheng, Zicheng

    2015-01-01

    Phosphorus (P) accumulators used for phytoremediation vary in their potential to acquire P from different high P regimes. Growth and P accumulation in Polygonum hydropiper were both dependent on an increasing level of IHP (1–8 mM P) and on a prolonged growth period (3-9 weeks), and those of the mining ecotype (ME) were higher than the non-mining ecotype (NME). Biomass increments in root, stem, and leaf of both ecotypes were significantly greater in IHP relative to other organic P (Po) sources (G1P, AMP, ATP), but lower than those in inorganic P (Pi) treatment (KH2PO4). P accumulation in the ME exceeded the NME from different P regimes. The ME demonstrated higher root activity compared to the NME grown in various P sources. Acid phosphatase (Apase) and phytase activities in root extracts of both ecotypes grown in IHP were comparable to that in Pi, or even higher in IHP. Higher secreted Apase and phytase activities were detected in the ME treated with different P sources relative to the NME. Therefore, the ME demonstrates higher P-uptake efficiency and it is a potential material for phytoextraction from P contaminated areas, irrespective of Pi or Po contamination. PMID:26648137

  11. Dormant cancer cells accumulate high protoporphyrin IX levels and are sensitive to 5-aminolevulinic acid-based photodynamic therapy

    PubMed Central

    Nakayama, Taku; Otsuka, Shimpei; Kobayashi, Tatsuya; Okajima, Hodaka; Matsumoto, Kentaro; Hagiya, Yuichiro; Inoue, Keiji; Shuin, Taro; Nakajima, Motowo; Tanaka, Tohru; Ogura, Shun-ichiro

    2016-01-01

    Photodynamic therapy (PDT) and diagnosis (PDD) using 5-aminolevulinic acid (ALA) to drive the production of an intracellular photosensitizer, protoporphyrin IX (PpIX), are in common clinical use. However, the tendency to accumulate PpIX is not well understood. Patients with cancer can develop recurrent metastatic disease with latency periods. This pause can be explained by cancer dormancy. Here we created uniformly sized PC-3 prostate cancer spheroids using a 3D culture plate (EZSPHERE). We demonstrated that cancer cells exhibited dormancy in a cell density-dependent manner not only in spheroids but also in 2D culture. Dormant cancer cells accumulated high PpIX levels and were sensitive to ALA-PDT. In dormant cancer cells, transporter expressions of PEPT1, ALA importer, and ABCB6, an intermediate porphyrin transporter, were upregulated and that of ABCG2, a PpIX exporter, was downregulated. PpIX accumulation and ALA-PDT cytotoxicity were enhanced by G0/G1-phase arrestors in non-dormant cancer cells. Our results demonstrate that ALA-PDT would be an effective approach for dormant cancer cells and can be enhanced by combining with a cell-growth inhibitor. PMID:27857072

  12. Modeling full-scale osmotic membrane bioreactor systems with high sludge retention and low salt concentration factor for wastewater reclamation.

    PubMed

    Park, Sung Hyuk; Park, Beomseok; Shon, Ho Kyong; Kim, Suhan

    2015-08-01

    A full-scale model was developed to find optimal design parameters for osmotic membrane bioreactor (OMBR) and reverse osmosis (RO) hybrid system for wastewater reclamation. The model simulates salt accumulation, draw solution dilution and water flux in OMBR with sludge concentrator for high retention and low salt concentration factor. The full-scale OMBR simulation results reveal that flat-sheet module with spacers exhibits slightly higher flux than hollow-fiber; forward osmosis (FO) membrane with high water permeability, low salt permeability, and low resistance to salt diffusion shows high water flux; an optimal water recovery around 50% ensures high flux and no adverse effect on microbial activity; and FO membrane cost decreases and RO energy consumption and product water concentration increases at higher DS flow rates and concentrations. The simulated FO water flux and RO energy consumption ranges from 3.03 to 13.76LMH and 0.35 to 1.39kWh/m(3), respectively.

  13. High-quality and high-purity homoepitaxial diamond (100) film growth under high oxygen concentration condition

    SciTech Connect

    Teraji, Tokuyuki

    2015-09-21

    Defect formation during diamond homoepitaxial growth was sufficiently inhibited by adding oxygen simultaneously in the growth ambient with high concentration of 2%. A 30-μm thick diamond films with surface roughness of <2 nm were homoepitaxially deposited on the (100) diamond single crystal substrates with reasonable growth rate of approximately 3 μm h{sup −1} under the conditions of higher methane concentration of 10%, higher substrate temperature of ∼1000 °C, and higher microwave power density condition of >100 W cm{sup −3}. Surface characteristic patterns moved to an identical direction with growth thickness, indicating that lateral growth was dominant growth mode. High chemical purity represented by low nitrogen concentration of less than 1 ppb and the highest {sup 12}C isotopic ratio of 99.998% of the obtained homoepitaxial diamond (100) films suggest that the proposed growth condition has high ability of impurity control.

  14. Determination of water quality variables, endotoxin concentration, and enterobacteriaceae concentration and identification in Southern High Plains dairy lagoons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of this study were to determine the concentration of endotoxin, determine 20 water quality variables, and identify and enumerate fungal and bacterial pathogens from United States southern High Plains dairy lagoons and control lakes during summer and winter. Water samples were collecte...

  15. Preparation of high concentration polyaluminum chloride with high content of Alb or Alc.

    PubMed

    Zhao, Changwei; Zhang, Jingbo; Luan, Zhaokun; Peng, Xianjia; Ren, Xiaojing

    2009-01-01

    A novel membrane distillation concentration method was used to prepare high concentration polyaluminum chloride (PACl) with high content of Alb or Alc. 2.52 mol/L PACl1 with 88% Alb and 2.38 mol/L PACl2 with 61% Alc were successfully prepared. Three coagulants, AlCl3, PACl1 and PACl2 were investigated on their hydrolysis behavior and speciation under different conditions. The effects of pH and dilution ratio on Al species distribution were investigated by ferron assay. Experimental result showed that pH had a significant effect on Al species distribution for the three coagulants. Dilution ratio had little effects on Alb and Alc distribution in whole dilution process except the beginning for PACl1 and PACl2. The results indicated that transformation of Al depends largely on their original composition. AlCl3 was the most unstable coagulant among these three coagulants during hydrolysis process. PACl1 and PACl2 with significant amounts of highly charged and stable polynuclear aluminum hydrolysis products were less affected by the hydrolysis conditions and could maintain high speciation stability under various conditions.

  16. Effect of self-alkalization on nitrite accumulation in a high-rate denitrification system: Performance, microflora and enzymatic activities.

    PubMed

    Li, Wei; Shan, Xiao-Yu; Wang, Zhi-Yao; Lin, Xiao-Yu; Li, Chen-Xu; Cai, Chao-Yang; Abbas, Ghulam; Zhang, Meng; Shen, Li-Dong; Hu, Zhi-Qiang; Zhao, He-Ping; Zheng, Ping

    2016-01-01

    The self-alkalization of denitrifying automatic circulation (DAC) reactor resulted in a large increase of pH up to 9.20 and caused a tremendous accumulation of nitrite up to 451.1 ± 49.0 mgN L(-1) at nitrate loading rate (NLR) from 35 kgN m(-3) d(-1) to 55 kgN m(-3) d(-1). The nitrite accumulation was greatly relieved even at the same NLR once the pH was maintained at 7.6 ± 0.2 in the system. Enzymatic assays indicated that the long-term bacterial exposure to high pH significantly inhibited the activity of copper type nitrite reductase (NirK) rather than the cytochrome cd1 type nitrite reductase (NirS). The terminal restriction fragment length polymorphism (T-RFLP) analysis revealed that the dominant denitrifying bacteria shifted from the NirS-containing Thauear sp. 27 to the NirK-containing Hyphomicrobium nitrativorans strain NL23 during the self-alkalization. The significant nitrite accumulation in the high-rate denitrification system could be therefore, due to the inhibition of Cu-containing NirK by high pH from the self-alkalization. The results suggest that the NirK-containing H. nitrativorans strain NL23 could be an ideal functional bacterium for the conversion of nitrate to nitrite, i.e. denitritation, which could be combined with anaerobic ammonium oxidation (Anammox) to develop a new process for nitrogen removal from wastewater.

  17. Titanium doped silicon layers with very high concentration

    SciTech Connect

    Olea, J.; Toledano-Luque, M.; Pastor, D.; Gonzalez-Diaz, G.; Martil, I.

    2008-07-01

    Ion implantation of Ti into Si at high doses has been performed. After laser annealing the maximum average of substitutional Ti atoms is about 10{sup 18} cm{sup -3}. Hall effect measurements show n-type samples with mobility values of about 400 cm{sup 2}/V s at room temperature. These results clearly indicate that Ti solid solubility limit in Si has been exceeded by far without the formation of a titanium silicide layer. This is a promising result toward obtaining of an intermediate band into Si that allows the design of a new generation of high efficiency solar cell using Ti implanted Si wafers.

  18. Responses of Trapa natans L. floating laminae to high concentrations of manganese.

    PubMed

    Baldisserotto, C; Ferroni, L; Anfuso, E; Pagnoni, A; Fasulo, M P; Pancaldi, S

    2007-01-01

    The present study focuses on the responses of floating laminae of the Mn-tolerant hydrophyte Trapa natans L. to 1 mM Mn and their ability to accumulate the metal. Studies were carried out first on young floating laminae belonging to the second verticil of 30-day-old plants which originated from fruits that had been maintained in a 1 mM Mn-treated environment and again on the young floating laminae after 10 days of further treatment with 1 mM Mn. Mn storing was observed from the first days after germination, but only 10-day-treated laminae showed the capability to hyperaccumulate the element inside specialised cells (>20000 microg/g [dry weight]). Electron microscopy and the Folin-Ciocalteu reaction for phenolics revealed deposits of chelated material inside vacuoles of the first palisade layer and of idioblasts in the spongy tissue. X-ray microanalysis indicated that the deposits were Mn chelated with phenolic compounds. Numerous trichomes were observed at the lower epidermis of 10-day-treated laminae. They were rich in phenolics and characterised by Mn concretions at their base. As they are associated with a high concentration of the metal in culture water and sediments, trichomes may constitute a morphological differentiation for the secretion of Mn-chelating molecules into the culture water, as a probable "avoidance" mechanism. Finally, monitoring of the photosynthetic apparatus showed that photosynthetic function was not impaired, though differences in development occurred.

  19. Reusable chelating resins concentrate metal ions from highly dilute solutions

    NASA Technical Reports Server (NTRS)

    Bauman, A. J.; Weetal, H. H.; Weliky, N.

    1966-01-01

    Column chromatographic method uses new metal chelating resins for recovering heavy-metal ions from highly dilute solutions. The absorbed heavy-metal cations may be removed from the chelating resins by acid or base washes. The resins are reusable after the washes are completed.

  20. Bryant Junior High School Concentrated Education Center Reading Program.

    ERIC Educational Resources Information Center

    Asplund, Bennett; Benolken, David

    This report, included in "Effective Reading Programs...," describes a Title I sequential reading support program for educationally disadvantaged junior high school students and analyzes the vocabulary and reading comprehension test results of this program for the school year 1972-1973. After group and individual pretesting in reading and…

  1. Comparative effects of piperine and simvastatin in fat accumulation and antioxidative status in high fat-induced hyperlipidemic rats.

    PubMed

    Tunsophon, Sakara; Chootip, Krongkarn

    2016-12-01

    The present study investigated the comparative effects of piperine (PIP) - the active ingredient of black and long peppers - and simvastatin (SIM) on hepatic steatosis in hyperlipidemic rats. Male Wistar rats were fed a cholesterol mixture daily by intragastric gavage for 8 weeks. Piperine was given by oral gavage 8 h after cholesterol feeding. The animals were divided into 4 groups: control, high fat (HF), high fat plus 40 mg PIP/kg, and high fat plus 2 mg SIM/kg. At the end of the treatment, liver cholesterol, triglyceride, thiobaribituric reacting substances, superoxide dismutase (SOD), serum aminotransferase (AST), and alanine transferase (ALT) were measured. The result demonstrated that PIP and SIM significantly reduced the accumulation of cholesterol, triglyceride, and lipid peroxidation in the liver, while elevation of SOD was observed. The activities of AST and ALT significantly decreased in PIP when compared with the HF group. Our in vitro study of pancreatic lipase also showed the inhibitory effect of PIP higher than 30% at 5 mmol/L. These results demonstrate that PIP has beneficial effects in the treatment and (or) prevention of fat accumulation in the liver and that this mechanism is due to the inhibition of pancreatic lipase and the improvement of oxidative status.

  2. Sorbitol promotes growth of Zymomonas mobilis in environments with high concentrations of sugar: evidence for a physiological function of glucose-fructose oxidoreductase in osmoprotection.

    PubMed Central

    Loos, H; Krämer, R; Sahm, H; Sprenger, G A

    1994-01-01

    The gram-negative ethanologenic bacterium Zymomonas mobilis is able to grow in media containing high concentrations of glucose or other sugars. A novel compatible solute for bacteria, sorbitol, which enhances growth of Z. mobilis at glucose concentrations exceeding 0.83 M (15%), is described. Added sorbitol was accumulated intracellularly up to 1 M to counteract high external glucose concentrations (up to 1.66 M or 30%). Accumulation of sorbitol was triggered by a glucose upshift (e.g., from 0.33 to 1.27 M or 6 to 23%) and was prevented by the uncoupler CCCP (carbonyl cyanide m-chlorophenylhydrazone; 100 microM). The sorbitol transport system followed Michaelis-Menten kinetics, with an apparent Km of 34 mM and a Vmax of 11.2 nmol.min-1.mg-1 (dry mass). Sorbitol was produced by the cells themselves and was accumulated when growing on sucrose (1 M or 36%) by the action of the periplasmic enzyme glucose-fructose oxidoreductase, which converts glucose and fructose to gluconolactone and sorbitol. Thus, Z. mobilis can form and accumulate the compatible solute sorbitol from a natural carbon source, sucrose, in order to overcome osmotic stress in high-sugar media. No other major compatible solute (betaine, proline, glutamate, or trehalose) was detected. PMID:8002594

  3. Production of Isolated Giant Unilamellar Vesicles under High Salt Concentrations

    PubMed Central

    Stein, Hannah; Spindler, Susann; Bonakdar, Navid; Wang, Chun; Sandoghdar, Vahid

    2017-01-01

    The cell membrane forms a dynamic and complex barrier between the living cell and its environment. However, its in vivo studies are difficult because it consists of a high variety of lipids and proteins and is continuously reorganized by the cell. Therefore, membrane model systems with precisely controlled composition are used to investigate fundamental interactions of membrane components under well-defined conditions. Giant unilamellar vesicles (GUVs) offer a powerful model system for the cell membrane, but many previous studies have been performed in unphysiologically low ionic strength solutions which might lead to altered membrane properties, protein stability and lipid-protein interaction. In the present work, we give an overview of the existing methods for GUV production and present our efforts on forming single, free floating vesicles up to several tens of μm in diameter and at high yield in various buffer solutions with physiological ionic strength and pH. PMID:28243205

  4. High plasma uric acid concentration: causes and consequences

    PubMed Central

    2012-01-01

    High plasma uric acid (UA) is a precipitating factor for gout and renal calculi as well as a strong risk factor for Metabolic Syndrome and cardiovascular disease. The main causes for higher plasma UA are either lower excretion, higher synthesis or both. Higher waist circumference and the BMI are associated with higher insulin resistance and leptin production, and both reduce uric acid excretion. The synthesis of fatty acids (tryglicerides) in the liver is associated with the de novo synthesis of purine, accelerating UA production. The role played by diet on hyperuricemia has not yet been fully clarified, but high intake of fructose-rich industrialized food and high alcohol intake (particularly beer) seem to influence uricemia. It is not known whether UA would be a causal factor or an antioxidant protective response. Most authors do not consider the UA as a risk factor, but presenting antioxidant function. UA contributes to > 50% of the antioxidant capacity of the blood. There is still no consensus if UA is a protective or a risk factor, however, it seems that acute elevation is a protective factor, whereas chronic elevation a risk for disease. PMID:22475652

  5. Deep Sea Memory of High Atmospheric CO2 Concentration

    NASA Astrophysics Data System (ADS)

    Mathesius, Sabine; Hofmann, Matthias; Caldeira, Ken; Schellnhuber, Hans Joachim

    2015-04-01

    Carbon dioxide removal (CDR) from the atmosphere has been proposed as a powerful measure to mitigate global warming and ocean acidification. Planetary-scale interventions of that kind are often portrayed as "last-resort strategies", which need to weigh in if humankind keeps on enhancing the climate-system stock of CO2. Yet even if CDR could restore atmospheric CO2 to substantially lower concentrations, would it really qualify to undo the critical impacts of past emissions? In the study presented here, we employed an Earth System Model of Intermediate Complexity (EMIC) to investigate how CDR might erase the emissions legacy in the marine environment, focusing on pH, temperature and dissolved oxygen. Against a background of a world following the RCP8.5 emissions path ("business-as-usual") for centuries, we simulated the effects of two massive CDR interventions with CO2 extraction rates of 5 GtC yr-1 and 25 GtC yr-1, respectively, starting in 2250. We found that the 5 GtC yr-1 scheme would have only minor ameliorative influence on the oceans, even after several centuries of application. By way of contrast, the extreme 25 GtC yr-1 scheme eventually leads to tangible improvements. However, even with such an aggressive measure, past CO2 emissions leave a substantial legacy in the marine environment within the simulated period (i.e., until 2700). In summary, our study demonstrates that anthropogenic alterations of the oceans, caused by continued business-as-usual emissions, may not be reversed on a multi-centennial time scale by the most aspirational geoengineering measures. We also found that a transition from the RCP8.5 state to the state of a strong mitigation scenario (RCP2.6) is not possible, even under the assumption of extreme extraction rates (25 GtC yr-1). This is explicitly demonstrated by simulating additional scenarios, starting CDR already in 2150 and operating until the atmospheric CO2 concentration reaches 280 ppm and 180 ppm, respectively. The simulated

  6. Intercomparison of high-volume PM10 samplers at a site with high-particulate concentrations

    SciTech Connect

    Purdue, L.J.; Rodes, C.E.; Rehme, K.A.; Holland, D.M.; Bond, A.E.

    1986-01-01

    Commercially available high-volume PM10 samplers were intercompared at a site in Phoenix characterized by high concentrations of coarse particles. Over a 21-day period, Sierra Andersen 321A (SA 321A) samplers gave PM10 measurements 58% higher than the Wedding IP10 (WED) samplers and 16% higher than a SA 321A sampler that had an oil coating on the internal impaction surfaces of the inlet. WED samplers that were subjected to a simple brush-cleaning procedure after each sampling period gave PM10 results 16% higher than the WED samplers not subjected to cleaning. The oiled SA 321A sampler gave PM10 values 15% higher than the cleaned WED samplers. The results demonstrate that the SA 321A overestimates PM10 when sampling in an environment with high coarse-particle concentrations. The over collection results from pass-through of large particles, and can be minimized by oiling the internal impaction surfaces of the inlet. The WED sampler underestimates PM10 after several days of sampling in such an environment.

  7. 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.

  8. Design requirements for high-efficiency high concentration ratio space solar cells

    NASA Technical Reports Server (NTRS)

    Rauschenbach, H.; Patterson, R.

    1980-01-01

    A miniaturized Cassegrainian concentrator system concept was developed for low cost, multikilowatt space solar arrays. The system imposes some requirements on solar cells which are new and different from those imposed for conventional applications. The solar cells require a circular active area of approximately 4 mm in diameter. High reliability contacts are required on both front and back surfaces. The back area must be metallurgically bonded to a heat sink. The cell should be designed to achieve the highest practical efficiency at 100 AMO suns and at 80 C. The cell design must minimize losses due to nonuniform illumination intensity and nonnormal light incidence. The primary radiation concern is the omnidirectional proton environment.

  9. Anthocyanin-rich Phytochemicals from Aronia Fruits Inhibit Visceral Fat Accumulation and Hyperglycemia in High-fat Diet-induced Dietary Obese Rats.

    PubMed

    Takahashi, Azusa; Shimizu, Hisae; Okazaki, Yukako; Sakaguchi, Hirohide; Taira, Toshio; Suzuki, Takashi; Chiji, Hideyuki

    2015-01-01

    Aronia fruits (chokeberry: Aronia melanocarpa E.) containing phenolic phytochemicals, such as cyanidin 3-glycosides and chlorogenic acid, have attracted considerable attention because of their potential human health benefits in humans including antioxidant activities and ability to improved vision. In the present study, the effects of anthocyanin-rich phytochemicals from aronia fruits (aronia phytochemicals) on visceral fat accumulation and fasting hyperglycemia were examined in rats fed a high-fat diet (Experiment 1). Total visceral fat mass was significantly lower in rats fed aronia phytochemicals than that in both the control group and bilberry phytochemicals-supplemented rats (p < 0.05). Moreover, perirenal and epididymal adipose tissue mass in rats fed aronia phytochemicals was significantly lower than that in both the control and bilberry phytochemicals group. Additionally, the mesenteric adipose tissue mass in aronia phytochemicals-fed rats was significantly low (p < 0.05). Furthermore, the fasting blood glucose levels significantly decreased in rats fed aronia phytochemicals for 4 weeks compared to that in the control rats (p < 0.05). Therefore, we investigated the effects of phytochemicals on postprandial hyperlipidemia after corn oil loading in rats, pancreatic lipase activity in vitro, and the plasma glycemic response after sucrose loading in order to elucidate the preventive factor of aronia phytochemical on visceral fat accumulation. In the oral corn oil tolerance tests (Experiment 2), aronia phytochemicals significantly inhibited the increases in plasma triglyceride levels, with a half-maximal inhibitory concentration (IC(50)) of 1.50 mg/mL. However, the inhibitory activity was similar to that of bilberry and tea catechins. In the sucrose tolerance tests (Experiment 3), aronia phytochemicals also significantly inhibited the increases in blood glucose levels that were observed in the control animals (p < 0.05). These results suggest that anthocyanin

  10. View looking northwest toward HIghGrade Ore Bin and Concentrate Bin ...

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

    View looking northwest toward HIgh-Grade Ore Bin and Concentrate Bin - Kennecott Copper Corporation, Concentration Mill, On Copper River & Northwestern Railroad, Kennicott, Valdez-Cordova Census Area, AK

  11. Polyamine accumulation in transgenic tomato enhances the tolerance to high temperature stress.

    PubMed

    Cheng, Lin; Zou, Yijing; Ding, Shuli; Zhang, Jiajing; Yu, Xiaolin; Cao, Jiashu; Lu, Gang

    2009-05-01

    Polyamines play an important role in plant response to abiotic stress. S-adenosyl-l-methionine decarboxylase (SAMDC) is one of the key regulatory enzymes in the biosynthesis of polyamines. In order to better understand the effect of regulation of polyamine biosynthesis on the tolerance of high-temperature stress in tomato, SAMDC cDNA isolated from Saccharomyces cerevisiae was introduced into tomato genome by means of Agrobacterium tumefaciens through leaf disc transformation. Transgene and expression was confirmed by Southern and Northern blot analyses, respectively. Transgenic plants expressing yeast SAMDC produced 1.7- to 2.4-fold higher levels of spermidine and spermine than wild-type plants under high temperature stress, and enhanced antioxidant enzyme activity and the protection of membrane lipid peroxidation was also observed. This subsequently improved the efficiency of CO(2) assimilation and protected the plants from high temperature stress, which indicated that the transgenic tomato presented an enhanced tolerance to high temperature stress (38 degrees C) compared with wild-type plants. Our results demonstrated clearly that increasing polyamine biosynthesis in plants may be a means of creating high temperature-tolerant germplasm.

  12. Constructing the integral concept on the basis of the idea of accumulation: suggestion for a high school curriculum

    NASA Astrophysics Data System (ADS)

    Kouropatov, Anatoli; Dreyfus, Tommy

    2013-07-01

    Students have a tendency to see integral calculus as a series of procedures with associated algorithms and many do not develop a conceptual grasp giving them the desirable versatility of thought. Thus, instead of a proceptual view of the symbols in integration, they have, at best, a process-oriented view. On the other hand, it is not surprising that many students find concepts such as the integral difficult when they are unable to experience these processes directly in the classroom. With a view towards improving this situation, constructing the integral concept on the basis of the idea of accumulation has been proposed (Educ Stud Math. 1994;26:229-274; Integral as accumulation: a didactical perspective for school mathematics; Thessaloniki: PME; 2009. p. 417-424). In this paper, we discuss a curriculum that is based on this idea and a design for curriculum materials that are intended to develop an improved cognitive base for a flexible proceptual understanding of the integral and integration in high school. The main focus is on how we (mathematics teachers and mathematics educators) might teach the integral concept in order to help high school students to construct meaningful knowledge alongside acquiring technical abilities.

  13. Silicic magma accumulation beneath Mount Mazama, Oregon, 71 ka to 24 ka constrained by SHRIMP measurements of dissolved volatile concentrations in melt inclusions

    NASA Astrophysics Data System (ADS)

    Wright, H. M.; Bacon, C. R.; Vazquez, J. A.; Sisson, T. W.

    2010-12-01

    Dissolved volatile contents of melt inclusions trapped in pyroxene and plagioclase crystals from 7 silicic eruptions preceding the climactic ~7.7 ka Mazama eruption were measured by SIMS with the Stanford-USGS SHRIMP-RG. Melt inclusions in crystals were intersected, polished, and crystals were mounted in indium in Al mounts. A 1.2-3.0 nA (depending on the session), O2- primary beam was accelerated and focused to a 15-25 μm spot on the sample surface, which generated positive secondary ions of analyzed Li, Be, B, C, OH, F, Mg, Si, SiH, S, Cl, Ca, AlO, KO, Rb, and Sr. Measurements were made at high mass resolution (6000-7000). Trace element and volatile concentrations were calculated using a best-fit regression to count rate ratios (normalized to 30Si) vs. variable known concentrations in experimental and natural rhyolite glass standards. Pumiceous samples were chosen from dacitic to rhyodacitic eruptive deposits, consisting of the 71ka dacite of Pumice Castle, 70ka dacite below Llao Rock, 50ka dacite of the Watchman, 35ka dacite of Munson Valley, 35ka Williams Crater tephra, 27ka Redcloud Cliff rhyodacite, and 24ka andesite S of Bear Bluff. Melt inclusions are abundant in spongy, mineral-inclusion-rich interiors of pyroxene crystals in early (71-35ka) eruptive deposits and are less abundant throughout pyroxenes from later eruptions (35-24ka) and in plagioclase crystals. Over the entire time interval, most trace element and volatile concentrations remain approximately constant between melt inclusion populations. However, there are some variations in water and carbon dioxide concentration. A large proportion of inclusions in the smaller eruptive deposits (0.003-0.4 km3) of the dacite of the Watchman, dacite of Munson Valley, and Williams Crater tephra have low water contents, ~1 wt% H2O, corresponding to a saturation pressure of 25MPa, or ~1km depth (at 870°, approximate average temperature for these deposits, e.g., Druitt and Bacon, Contrib Mineral Petrol 1989

  14. High-Q ultrasonic determination of the critical nanoaggregate concentration of asphaltenes and the critical micelle concentration of standard surfactants.

    PubMed

    Andreatta, Gaëlle; Bostrom, Neil; Mullins, Oliver C

    2005-03-29

    Asphaltenes are known to be interfacially active in many circumstances such as at toluene-water interfaces. Furthermore, the term micelle has been used to describe the primary aggregation of asphaltenes in good solvents such as toluene. Nevertheless, there has been significant uncertainty regarding the critical micelle concentration (CMC) of asphaltenes and even whether the micelle concept is appropriate for asphaltenes. To avoid semantic debates we introduce the terminology critical nanoaggregate concentration (CNAC) for asphaltenes. In this report, we investigate asphaltenes and standard surfactants using high-Q, ultrasonic spectroscopy in both aqueous and organic solvents. As expected, standard surfactants are shown to exhibit a sharp break in sonic velocity versus concentration at known CMCs. To prove our methods, we measured known surfactants with CMCs in the range from 0.010 g/L to 2.3 g/L in agreement with the literature. Using density determinations, we obtain micelle compressibilities consistent with previous literature reports. Asphaltenes are also shown to exhibit behavior similar to that of ultrasonic velocity versus concentration as standard surfactants; asphaltene CNACs in toluene occur at roughly 0.1 g/L, although the exact concentration depends on the specific (crude oil) asphaltene. Furthermore, using asphaltene solution densities, we show that asphaltene nanoaggregate compressibilities are similar to micellar compressibilities obtained with standard nonionic surfactants in toluene. These results strongly support the contention that asphaltenes in toluene can be treated roughly within the micelle framework, although asphaltenes may exhibit small levels of aggregation (dimers, etc.) below their CNAC. Furthermore, our extensive results on known surfactants agree with the literature while the asphaltene CNACs reported here are one to two orders of magnitude lower than most previously published results. (Previous work utilized the terminology "micelle

  15. Gibberellin-responsive genes: high level of transcript accumulation in leaf sheath meristematic tissue from Zea mays L.

    PubMed

    Ogawa, M; Kusano, T; Koizumi, N; Katsumi, M; Sano, H

    1999-07-01

    In order to identify genes that are related to the gibberellin (GA) response in maize (Zea mays L.), mRNA species from wild-type and single-gene dwarf mutants, d5 and D8, were compared by fluorescent differential display. The d5 mutant is unable to produce biologically active GA, but recovers its tall stature on exogenous application of GA. D8 is insensitive to GA, despite the accumulation of a high level of endogenous GA, suggesting it to be a receptor mutant or a mutant in signal transduction pathway(s). After screening 7000 cDNA populations, one clone was isolated, for which transcripts were rare in d5 shoots but accumulated within 1 h after GA3 application. This clone, designated as ZmGR1a, encodes a polypeptide with a relative molecular mass of ca. 13 kDa, which shows significant homology to proline-rich proteins from several plant species. A similar experiment with D8 identified a clone, ZmGR2a, with low transcript levels, but accumulation within 6 h after GA3 treatment of d5 shoots. ZmGR2a encodes a polypeptide with a relative molecular mass of ca. 19 kDa, which shows no significant homology with any known protein. Southern blot analysis indicated that ZmGR1a and ZmGR2a form a small multigene family within the maize genome. In situ hybridization with wild-type seedlings showed transcripts on both to be abundant in leaf sheath meristematic tissue, in which GA enhances cell elongation and cell division.

  16. Atomic physics and synchrotron radiation: The production and accumulation of highly charged ions

    SciTech Connect

    Johnson, B.M.; Meron, M.; Agagu, A.; Jones, K.W.

    1986-01-01

    Synchrotron radiation can be used to produce highly-charged ions, and to study photoexcitation and photoionization for ions of virtually any element in the periodic table. To date, with few exceptions, atomic physics studies have been limited to rare gases and a few metal vapors, and to photoexcitation energies in the VUV region of the electromagnetic spectrum. These limitations can now be overcome using photons produced by high-brightness synchrotron storage rings, such as the x-ray ring at the National Synchrotron Light Source (NSLS) at Brookhaven. Furthermore, calculations indicate that irradiation of an ion trap with an intense energetic photon beam will result in a viable source of highly-charged ions that can be given the name PHOBIS: the PHOton Beam Ion Source. Promising results, which encourage the wider systematic use of synchrotron radiation in atomic physics research, have been obtained in recent experiments on VUV photoemission and the production and storage of multiply-charged ions. 26 refs., 4 figs., 1 tab.

  17. 1-FFT amino acids involved in high DP inulin accumulation in Viguiera discolor

    PubMed Central

    De Sadeleer, Emerik; Vergauwen, Rudy; Struyf, Tom; Le Roy, Katrien; Van den Ende, Wim

    2015-01-01

    Fructans are important vacuolar reserve carbohydrates with drought, cold, ROS and general abiotic stress mediating properties. They occur in 15% of all flowering plants and are believed to display health benefits as a prebiotic and dietary fiber. Fructans are synthesized by specific fructosyltransferases and classified based on the linkage type between fructosyl units. Inulins, one of these fructan types with β(2-1) linkages, are elongated by fructan:fructan 1-fructosyltransferases (1-FFT) using a fructosyl unit from a donor inulin to elongate the acceptor inulin molecule. The sequence identity of the 1-FFT of Viguiera discolor (Vd) and Helianthus tuberosus (Ht) is 91% although these enzymes produce distinct fructans. The Vd 1-FFT produces high degree of polymerization (DP) inulins by preferring the elongation of long chain inulins, in contrast to the Ht 1-FFT which prefers small molecules (DP3 or 4) as acceptor. Since higher DP inulins have interesting properties for industrial, food and medical applications, we report here on the influence of two amino acids on the high DP inulin production capacity of the Vd 1-FFT. Introducing the M19F and H308T mutations in the active site of the Vd 1-FFT greatly reduces its capacity to produce high DP inulin molecules. Both amino acids can be considered important to this capacity, although the double mutation had a much higher impact than the single mutations. PMID:26322058

  18. 1-FFT amino acids involved in high DP inulin accumulation in Viguiera discolor.

    PubMed

    De Sadeleer, Emerik; Vergauwen, Rudy; Struyf, Tom; Le Roy, Katrien; Van den Ende, Wim

    2015-01-01

    Fructans are important vacuolar reserve carbohydrates with drought, cold, ROS and general abiotic stress mediating properties. They occur in 15% of all flowering plants and are believed to display health benefits as a prebiotic and dietary fiber. Fructans are synthesized by specific fructosyltransferases and classified based on the linkage type between fructosyl units. Inulins, one of these fructan types with β(2-1) linkages, are elongated by fructan:fructan 1-fructosyltransferases (1-FFT) using a fructosyl unit from a donor inulin to elongate the acceptor inulin molecule. The sequence identity of the 1-FFT of Viguiera discolor (Vd) and Helianthus tuberosus (Ht) is 91% although these enzymes produce distinct fructans. The Vd 1-FFT produces high degree of polymerization (DP) inulins by preferring the elongation of long chain inulins, in contrast to the Ht 1-FFT which prefers small molecules (DP3 or 4) as acceptor. Since higher DP inulins have interesting properties for industrial, food and medical applications, we report here on the influence of two amino acids on the high DP inulin production capacity of the Vd 1-FFT. Introducing the M19F and H308T mutations in the active site of the Vd 1-FFT greatly reduces its capacity to produce high DP inulin molecules. Both amino acids can be considered important to this capacity, although the double mutation had a much higher impact than the single mutations.

  19. Effect of concentrate feeder design on performance, eating and animal behavior, welfare, ruminal health, and carcass quality in Holstein bulls fed high-concentrate diets.

    PubMed

    Verdú, M; Bach, A; Devant, M

    2015-06-01

    A total of 240 Holstein bulls (121 ± 2.0 kg initial BW; 99 ± 1.0 d of age), from 2 consecutive fattening cycles, were randomly allocated in 1 of 6 pens and assigned to 1 of the 3 treatments consisting of different concentrate feeder designs: a control feeder with 4 feeding spaces (CF), a feeder with less concentrate capacity (CFL), and a single-space feeder with lateral protections (SF). Each pen had a straw feeder and a drinker. All animals were fed a high-concentrate diet for ad libitum intake. Concentrate consumption was recorded daily using a computerized feeder, straw consumption was recorded weekly, and BW was recorded every 14 d. Animal behavior was registered on d 1, 3, 5, 8, and 14 and every 28 d by scan sampling. Eating behavior at concentrate feeders was filmed on d 12, 125, and 206. On d 7, 120, and 204, samples of rumen contents were collected for measurement of pH and VFA and blood samples were obtained to analyze NEFA, haptoglobin, glucose, and insulin. Animals were slaughtered after 223 d, and HCW and lesions of the rumen wall and liver were recorded. The accumulative concentrate consumption per animal tended (P = 0.09) to be greater with CF than with CFL and SF. Also, CV of concentrate consumption was greater (P < 0.01) for SF than for CF or CFL. However, feeder design did not influence the other performance and carcass data. Also, no differences among treatments in rumen wall evaluation and liver abscesses were observed. At 7 and 204 d of study, SF bulls had greater (P < 0.05) rumen pH compared with CF and CFL bulls. On d 7, the acetate to propionate ratio from SF was greater (P < 0.05) than for CFL or CF. At d 7, NEFA of SF were greater (P < 0.05) compared with CF and CFL. Bulls fed with CF have the greatest (P < 0.01) concentrate disappearance velocity followed by bulls fed with CFL and finally by bulls fed with SF, and this was associated with different feeding behaviors. Bulls on SF spent more time (P < 0.05) eating straw and exhibited fewer

  20. Bacteriological Study on Effects of Beta-Lactam Group Antibiotics in High Concentrations

    PubMed Central

    Nishino, Takeshi; Nakazawa, Shozo

    1976-01-01

    The growth and viability of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa exposed to various concentrations of a number of β-lactam group antibiotics were determined. In S. aureus, the bacteriolytic and bactericidal activity of these drugs was lower at very high drug concentrations than that occurring at low concentrations, but these phenomena were not observed in E. coli and P. aeruginosa. Under phase-contrast and scanning electron microscopy, S. aureus treated with high concentrations of β-lactam group antibiotics revealed a lower frequency of bacteriolysis than at low drug concentrations, and similarly by transmission electron microscopy fewer cells were transformed into spheroplasts at high drug concentrations. However, swelling of the cell wall septum was seen in many cells. Spheroplast formation occurred with the highest frequency at drug levels near the minimum inhibitory concentration and became less frequent as drug concentrations were increased. Images PMID:820242

  1. Nitrogen Accumulation and Partitioning in High Arctic Tundra from Extreme Atmospheric N Deposition Events

    NASA Astrophysics Data System (ADS)

    Phoenix, G. K.; Osborn, A.; Blaud, A.; Press, M. C.; Choudhary, S.

    2013-12-01

    Arctic ecosystems are threatened by pollution from extreme atmospheric nitrogen (N) deposition events. These events occur from the long-range transport of reactive N from pollution sources at lower latitudes and can deposit up to 80% of the annual N deposition in just a few days. To date, the fate and impacts of these extreme pollutant events has remained unknown. Using a field simulation study, we undertook the first assessment of the fate of acutely deposited N on arctic tundra. Extreme N deposition events were simulated on field plots at Ny-Ålesund, Svalbard (79oN) at rates of 0, 0.04, 0.4 and 1.2 g N m-2 yr-1 applied as NH4NO3 solution over 4 days, with 15N tracers used in the second year to quantify the fate of the deposited N in the plant, soil, microbial and leachate pools. Separate applications of 15NO3- and 15NH4+ were also made to determine the importance of N form in the fate of N. Recovery of the 15N tracer at the end of the first growing season approached 100% of the 15N applied irrespective of treatment level, demonstrating the considerable capacity of High Arctic tundra to capture pollutant N from extreme deposition events. Most incorporation of the 15N was found in bryophytes, followed by the dominant vascular plant (Salix polaris) and the microbial biomass of the soil organic layer. Total recovery remained high in the second growing season (average of 90%), indicating highly conservative N retention. Between the two N forms, recovery of 15NO3- and 15NH4+ were equal in the non-vascular plants, whereas in the vascular plants (particularly Salix polaris) recovery of 15NO3- was four times higher than of 15NH4+. Overall, these findings show that High Arctic tundra has considerable capacity to capture and retain the pollutant N deposited in acute extreme deposition events. Given they can represent much of the annual N deposition, extreme deposition events may be more important than increased chronic N deposition as a pollution source. Furthermore

  2. Damage accumulation and annealing behavior in high fluence implanted MgZnO

    NASA Astrophysics Data System (ADS)

    Azarov, A. Yu.; Hallén, A.; Svensson, B. G.; Du, X. L.; Kuznetsov, A. Yu.

    2012-02-01

    Molecular beam epitaxy grown Mg xZn 1-xO ( x ⩽ 0.3) layers were implanted at room temperature with 150 keV 166Er + ions in a fluence range of 5 × 10 15-3 × 10 16 cm -2. Evolution of ion-induced damage and structural changes were studied by a combination of Rutherford backscattering spectrometry, nuclear reaction analysis and time-of-flight elastic recoil detection analysis. Results show that damage production enhances in both Zn- and O-sublattices with increasing the Mg content in the MgZnO. However, MgZnO as well as pure ZnO exhibits a high degree of dynamic annealing and MgZnO can not be amorphized even at the highest ion fluence used. Annealing of heavily damaged ZnO leads to a strong surface erosion and thinning of the film. Increasing the Mg content suppresses the surface evaporation in high fluence implanted MgZnO but leads to a strong surface decomposition accompanied with a Mg-rich surface layer formation during post-implantation annealing.

  3. Thermal insulation and accumulation of heat in the downy inflorescences of Saussurea medusa (Asteraceae) at high elevation in Yunnan, China.

    PubMed

    Tsukaya, Hirokazu; Fujikawa, Kazumi; Wu, Su-Gong

    2002-08-01

    Himalayan snowball plants, which are considered to be an extreme form of downy plants, have very dense trichomes on well-developed bracts that surround the inflorescences. It has been postulated that the downy inflorescences of these plants might serve to keep the interior of inflorescences warmer than the outside and, thus, to protect reproductive cells from low temperatures in their Himalayan habitat. In the present study, we examined the downy inflorescences of Saussurea medusaMaxim. in native habitats in the high alpine zone of the Henduan Mountains in Yunnan, China, and we analyzed the temperature within inflorescences after absorbance of light energy. S. medusais pollinated by bumblebees and we found that its inflorescences accumulated heat not on the inside, but, rather, on the upper surfaces. The thick hollow stems and the overlapping bracts with obvious epinasty might serve not only to retain heat, but also as an insulator to protect the inside against overheating, with apparent local warming of flowers that are located at the tops of plants, which are cone-shaped. We made a model that mimicked the warming of inflorescences, providing support for the hypothesis that the downy bracts of S. medusahave two functions: thermal insulation to protect the inside of flowers and the accumulation of heat on the upper surfaces of the inflorescence. Such a system might be effective in attracting pollinators and also in protecting tissues from extreme variations in temperature.

  4. Overexpression of UV-DAMAGED DNA BINDING PROTEIN 1 links plant development and phytonutrient accumulation in high pigment-1 tomato.

    PubMed

    Azari, Raviv; Reuveni, Moshe; Evenor, Dalia; Nahon, Sahadia; Shlomo, Haviva; Chen, Lea; Levin, Ilan

    2010-08-01

    Fruits of tomato plants carrying the high pigment-1 mutations hp-1 and hp-1(w) are characterized by an increased number of plastids coupled with enhanced levels of functional metabolites. Unfortunately, hp-1 mutant plants are also typified by light-dependent retardation in seedling and whole-plant growth and development, which limits their cultivation. These mutations were mapped to the gene encoding UV-DAMAGED DNA BINDING PROTEIN 1 (DDB1) and, recently, fruit-specific RNA interference studies have demonstrated an increased number of plastids and enhanced carotenoid accumulation in the transgenic tomato fruits. However, whole-plant overexpression of DDB1, required to substantiate its effects on seedling and plant development and to couple them with fruit phenotypes, has heretofore been unsuccessful. In this study, five transgenic lines constitutively overexpressing normal DDB1 in hp-1 mutant plants were analysed. Eleven-day-old seedlings, representing these lines, displayed up to approximately 73- and approximately 221-fold overexpression of the gene in hypocotyls and cotyledons, respectively. This overexpression resulted in statistically significant reversion to the non-mutant developmental phenotypes, including more than a full quantitative reversion. This reversion of phenotypes was generally accompanied by correlated responses in chlorophyll accumulation and altered expression of selected light signalling genes: PHYTOCHROME A, CRYPTOCHROME 1, ELONGATED HYPOCOTYL 5, and the gene encoding CHLOROPHYLL A/B-BINDING PROTEIN 4. Cumulatively, these results provide the missing link between DDB1 and its effects on tomato plant development.

  5. Accumulation of carbon and nitrogen in vegetation and soils of deglaciated area in Ellesmere Island, high-Arctic Canada

    NASA Astrophysics Data System (ADS)

    Osono, Takashi; Mori, Akira S.; Uchida, Masaki; Kanda, Hiroshi

    2016-09-01

    The amount of biomass, carbon (C), and nitrogen (N) in vegetation and soil were measured at two spatial scales in the high Arctic. At the scale of proglacial landscape, the amount of C and N in aboveground and belowground parts of vegetation, surface litter, and soil were significantly affected by the habitat (moraines vs hummocks), the relative age of the terrain after the deglaciation, and/or the vegetation. At another scale, we focused on mudboils as an agent of local disturbance in the vegetation and soil of the glacier foreland. The biomass and the amount of C and N in aboveground vegetation, surface litter, biological soil crust, and soil were generally increased with the stage of mudboils' inactivation. Biomass, C, and N in aboveground vegetation and surface litter were generally greater at moraine than at hummock, whereas those in biological soil crust and soil were greater at hummock. Principal component analysis identified two pathways, xeric and mesic ones on moraines and hummocks, respectively, of C and N accumulation both at the two spatial scales. These results suggested that the C and N accumulation was not linearly related to the time since deglaciation and that moisture condition, vegetation, and mudboil activity were locally important.

  6. Linking environmental heavy metal concentrations and salinity gradients with metal accumulation and their effects: A case study in 3 mussel species of Vitória estuary and Espírito Santo bay, Southeast Brazil.

    PubMed

    Kumar, Vikas; Sinha, Amit Kumar; Rodrigues, Paulo Pinheiro; Mubiana, Valentine K; Blust, Ronny; De Boeck, Gudrun

    2015-08-01

    The present study was conducted to link the heavy metal load in three species of mussels (Perna perna, Mytella falcata and Mytella guyanensis) from the estuaries and bays around Vitória island, south-east of Brazil, with the salinity gradient and the heavy metal levels in the abiotic environment (including water, suspended particulate matter (SPM) and sediment). Primarily based on the salinity gradient, a total of 26 sites around Vitória Island were selected for sampling of water, SPM, sediments and organisms. Besides tissue metal levels, the condition index and energy stores (glycogen, lipid and protein) were quantified as an indicator of fitness in response to metal pollution. Dissolved metals in water indicate that Cd and Mn content was higher along Espírito Santo Bay, while Al, Co, Cu, Cr and Fe were elevated in the sites with low salinity such as river mouths, estuarine and sewage canals. Likewise, suspended matter sampled from low salinity sites showed a higher heavy metal load compared to moderate and high salinity sites. Though mussels were sampled from different sites, the contamination for Cd, Cu, Fe and Mn was higher in mussels inhabiting low salinity sites (M. guyanensis and M. falcata) compared to P. perna, a high saline water inhabitant. However, a higher Zn body burden was observed for P. perna compared to Mytella species. Tissue Fe accumulation (but not Mn and Zn) correlated with heavy metal levels in suspended material for all three species, and for M. falcata this correlation also existed for Cd and Cu. Energy store and condition index in all mussels varied depending on the sampling sites and correlated with salinity gradient rather than tissue metal concentration. Overall, metal concentration in mussels did not exceed the safe levels as per the international standards for metals, and would be of no risk for human consumption.

  7. Rapid transport and high accumulation of amorphous silica in the Congo deep-sea fan: A preliminary budget

    NASA Astrophysics Data System (ADS)

    Raimonet, Mélanie; Ragueneau, Olivier; Jacques, Vincent; Corvaisier, Rudolph; Moriceau, Brivaëla; Khripounoff, Alexis; Pozzato, Lara; Rabouille, Christophe

    2015-01-01

    Mechanisms controlling the transfer and retention of silicon (Si) along continental margins are poorly understood, but play a major role in the functioning of coastal ecosystems and the oceanic biological pump of carbon. Deep-sea fans are well recognized as carbon sink spots, but we lack knowledge about the importance of the fans in the global Si cycle. Here, we provide a first estimate of the role played by the Congo deep-sea fan, one of the biggest in the world, in the Si cycle. Sediment cores sampled in the deep-sea fan were analyzed to build a Si mass balance. An exceptionally high accumulation rate of amorphous silica aSiO2 (2.29 ± 0.58 mol Si m- 2 y- 1) was found, due to a high sedimentation rate and the presence of aluminum in the sediments. Although favored by bioirrigation, recycling fluxes remained low (0.3 mol Si m- 2 y- 1) and reconstructed input fluxes could only be explained by lateral inputs coming from the canyon. Preliminary calculations show that the rapid transport of aSiO2 through the canyon and the excellent preservation efficiency in the sediments imply that 50% of aSiO2 river inputs from the Congo River accumulate annually in the deep-sea fan. Si:C ratios in deep-sea fan sediments were very low (0.2) and only three times as high as those measured in the river itself, which suggests that material from the river and the continental shelf was delivered directly through the canyon, with very little time for Si and C cycle decoupling to take place.

  8. Elevated CO2-mitigation of high temperature stress associated with maintenance of positive carbon balance and carbohydrate accumulation in Kentucky bluegrass.

    PubMed

    Song, Yali; Yu, Jingjin; Huang, Bingru

    2014-01-01

    Elevated CO2 concentration may promote plant growth while high temperature is inhibitory for C3 plant species. The interactive effects of elevated CO2 and high temperatures on C3 perennial grass growth and carbon metabolism are not well documented. Kentucky bluegrass (Poa pratensis) plants were exposed to two CO2 levels (400 and 800 μmol mol-1) and five temperatures (15/12, 20/17, 25/22, 30/27, 35/32°C, day/night) in growth chambers. Increasing temperatures to 25°C and above inhibited leaf photosynthetic rate (Pn) and shoot and root growth, but increased leaf respiration rate (R), leading to a negative carbon balance and a decline in soluble sugar content under ambient CO2. Elevated CO2 did not cause shift of optimal temperatures in Kentucky bluegrass, but promoted Pn, shoot and root growth under all levels of temperature (15, 20, 25, 30, and 35°C) and mitigated the adverse effects of severe high temperatures (30 and 35°C). Elevated CO2-mitigation of adverse effects of high temperatures on Kentucky bluegrass growth could be associated with the maintenance of a positive carbon balance and the accumulation of soluble sugars and total nonstructural carbohydrates through stimulation of Pn and suppression of R and respiratory organic acid metabolism.

  9. Elevated CO2-Mitigation of High Temperature Stress Associated with Maintenance of Positive Carbon Balance and Carbohydrate Accumulation in Kentucky Bluegrass

    PubMed Central

    Huang, Bingru

    2014-01-01

    Elevated CO2 concentration may promote plant growth while high temperature is inhibitory for C3 plant species. The interactive effects of elevated CO2 and high temperatures on C3 perennial grass growth and carbon metabolism are not well documented. Kentucky bluegrass (Poa pratensis) plants were exposed to two CO2 levels (400 and 800 μmol mol−1) and five temperatures (15/12, 20/17, 25/22, 30/27, 35/32°C, day/night) in growth chambers. Increasing temperatures to 25°C and above inhibited leaf photosynthetic rate (Pn) and shoot and root growth, but increased leaf respiration rate (R), leading to a negative carbon balance and a decline in soluble sugar content under ambient CO2. Elevated CO2 did not cause shift of optimal temperatures in Kentucky bluegrass, but promoted Pn, shoot and root growth under all levels of temperature (15, 20, 25, 30, and 35°C) and mitigated the adverse effects of severe high temperatures (30 and 35°C). Elevated CO2-mitigation of adverse effects of high temperatures on Kentucky bluegrass growth could be associated with the maintenance of a positive carbon balance and the accumulation of soluble sugars and total nonstructural carbohydrates through stimulation of Pn and suppression of R and respiratory organic acid metabolism. PMID:24662768

  10. Moderation of neoclassical impurity accumulation in high temperature plasmas of helical devices

    NASA Astrophysics Data System (ADS)

    Velasco, J. L.; Calvo, I.; Satake, S.; Alonso, A.; Nunami, M.; Yokoyama, M.; Sato, M.; Estrada, T.; Fontdecaba, J. M.; Liniers, M.; McCarthy, K. J.; Medina, F.; Van Milligen, B. Ph; Ochando, M.; Parra, F.; Sugama, H.; Zhezhera, A.; The LHD Experimental Team; The TJ-II Team

    2017-01-01

    Achieving impurity and helium ash control is a crucial issue in the path towards fusion-grade magnetic confinement devices, and this is particularly the case of helical reactors, whose low-collisionality ion-root operation scenarios usually display a negative radial electric field which is expected to cause inwards impurity pinch. In this work we discuss, based on experimental measurements and standard predictions of neoclassical theory, how plasmas of very low ion collisionality, similar to those observed in the impurity hole of the large helical device (Yoshinuma et al and The LHD Experimental Group 2009 Nucl. Fusion 49 062002, Ida et al and The LHD Experimental Group 2009 Phys. Plasmas 16 056111 and Yokoyama et al and LHD Experimental Group 2002 Nucl. Fusion 42 143), can be an exception to this general rule, and how a negative radial electric field can coexist with an outward impurity flux. This interpretation is supported by comparison with documented discharges available in the International Stellarator-Heliotron Profile Database, and it can be extrapolated to show that achievement of high ion temperature in the core of helical devices is not fundamentally incompatible with low core impurity content.

  11. Fucoidan prevents high-fat diet-induced obesity in animals by suppression of fat accumulation.

    PubMed

    Kim, Mi-Ja; Jeon, Joseph; Lee, Jin-Sil

    2014-01-01

    This study examines the antiobesity effects of fucoidan in an animal model of diet-induced obesity. Mice were fed a standard diet or high-fat diet (HFD) for 5 weeks. After that, the mice were divided into four experimental groups, with 10 mice per group, including a standard diet group, HFD group, HFD containing 1% fucoidan (HFD + FUCO 1%) group and HFD containing 2% fucoidan (HFD + FUCO 2%) group. The fucoidan supplementation group had significantly decreased body-weight gain, food efficiency ratio and relative liver and epididymal fat mass compared with the HFD group. The mice supplemented with fucoidan showed significantly reduced triglyceride, total cholesterol and low-density lipoprotein levels in the plasma. Liver steatosis induced by the HFD improved in the fucoidan-supplemented group. Furthermore, fucoidan affected the down-regulation expression patterns of epididymal adipose tissue genes such as peroxisome proliferator-activated receptor γ, adipose-specific fatty acid binding protein and acetyl CoA carboxylase. Therefore, fucoidan may be considered for use in improving obesity.

  12. 27 CFR 18.52 - Production of high-proof concentrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Production of high-proof concentrate. 18.52 Section 18.52 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE... concentrate plant. Concentrate having an alcohol content of more than 24 percent by volume that is fit...

  13. Neuroprotective effects of chronic exposure of SH-SY5Y to low lithium concentration involve glycolysis stimulation, extracellular pyruvate accumulation and resistance to oxidative stress.

    PubMed

    Nciri, Riadh; Desmoulin, Frank; Allagui, Mohamed Saleh; Murat, Jean-Claude; Feki, Abdelfattah El; Vincent, Christian; Croute, Françoise

    2013-03-01

    Recent studies suggest that lithium protects neurons from death induced by a wide array of neurotoxic insults, stimulates neurogenesis and could be used to prevent age-related neurodegenerative diseases. In this study, SH-SY5Y human neuronal cells were cultured in the absence (Con) or in the presence (Li+) of a low lithium concentration (0.5 mm Li2CO3, i.e. 1 mm lithium ion) for 25-50 wk. In the course of treatment, growth rate of Con and Li+ cells was regularly analysed using Alamar Blue dye. Resistance to oxidative stress was investigated by evaluating: (1) the adverse effects of high concentrations of lithium (4-8 mm) or glutamate (20-90 mm) on cell growth rate; (2) the levels of lipid peroxidation (TBARS) and total glutathione; (3) the expression levels of the anti-apoptotic Bcl-2 protein. In addition, glucose metabolism was investigated by analysing selected metabolites in culture media and cell extracts by 1H-NMR spectroscopy. As compared to Con, Li+ cells multiplied faster and were more resistant to stress, as evidenced by a lower dose-dependent decrease of Alamar Blue reduction and dose-dependent increase of TBARS levels induced by toxic doses of lithium and glutamate. Total glutathione content and Bcl-2 level were increased in Li+ cells. Glucose consumption and glycolytic activity were enhanced in Li+ cells and an important release of pyruvate was observed. We conclude that chronic exposure to lithium induces adaptive changes in metabolism of SH-SY5Y cells involving a higher cell growth rate and a better resistance to oxidative stress.

  14. Nitrogen accumulation and partitioning in a High Arctic tundra ecosystem from extreme atmospheric N deposition events.

    PubMed

    Choudhary, Sonal; Blaud, Aimeric; Osborn, A Mark; Press, Malcolm C; Phoenix, Gareth K

    2016-06-01

    Arctic ecosystems are threatened by pollution from recently detected extreme atmospheric nitrogen (N) deposition events in which up to 90% of the annual N deposition can occur in just a few days. We undertook the first assessment of the fate of N from extreme deposition in High Arctic tundra and are presenting the results from the whole ecosystem (15)N labelling experiment. In 2010, we simulated N depositions at rates of 0, 0.04, 0.4 and 1.2 g Nm(-2)yr(-1), applied as (15)NH4(15)NO3 in Svalbard (79(°)N), during the summer. Separate applications of (15)NO3(-) and (15)NH4(+) were also made to determine the importance of N form in their retention. More than 95% of the total (15)N applied was recovered after one growing season (~90% after two), demonstrating a considerable capacity of Arctic tundra to retain N from these deposition events. Important sinks for the deposited N, regardless of its application rate or form, were non-vascular plants>vascular plants>organic soil>litter>mineral soil, suggesting that non-vascular plants could be the primary component of this ecosystem to undergo measurable changes due to N enrichment from extreme deposition events. Substantial retention of N by soil microbial biomass (70% and 39% of (15)N in organic and mineral horizon, respectively) during the initial partitioning demonstrated their capacity to act as effective buffers for N leaching. Between the two N forms, vascular plants (Salix polaris) in particular showed difference in their N recovery, incorporating four times greater (15)NO3(-) than (15)NH4(+), suggesting deposition rich in nitrate will impact them more. Overall, these findings show that despite the deposition rates being extreme in statistical terms, biologically they do not exceed the capacity of tundra to sequester pollutant N during the growing season. Therefore, current and future extreme events may represent a major source of eutrophication.

  15. High catechin concentrations detected in Withania somnifera (ashwagandha) by high performance liquid chromatography analysis

    PubMed Central

    2011-01-01

    Background Withania somnifera is an important medicinal plant traditionally used in the treatment of many diseases. The present study was carried out to characterize the phenolic acids, flavonoids and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging activities in methanolic extracts of W. somnifera fruits, roots and leaves (WSFEt, WSREt and WSLEt). Methods WSFEt, WSREt and WSLEt was prepared by using 80% aqueous methanol and total polyphenols, flavonoids as well as DPPH radical scavenging activities were determined by spectrophotometric methods and phenolic acid profiles were determined by HPLC methods. Results High concentrations of both phenolics and flavonoids were detected in all parts of the plant with the former ranging between 17.80 ± 5.80 and 32.58 ± 3.16 mg/g (dry weight) and the latter ranging between 15.49 ± 1.02 and 31.58 ± 5.07 mg/g. All of the three different plant parts showed strong DPPH radical scavenging activities (59.16 ± 1.20 to 91.84 ± 0.38%). Eight polyphenols (gallic, syringic, benzoic, p-coumaric and vanillic acids as well as catechin, kaempferol and naringenin) have been identified by HPLC in parts of the plant as well. Among all the polyphenols, catechin was detected in the highest concentration (13.01 ± 8.93 to 30.61 ± 11.41 mg/g). Conclusion The results indicating that W. somnifera is a plant with strong therapeutic properties thus further supporting its traditional claims. All major parts of W. somnifera such as the roots, fruits and leaves provide potential benefits for human health because of its high content of polyphenols and antioxidant activities with the leaves containing the highest amounts of polyphenols specially catechin with strong antioxidant properties. PMID:21854608

  16. Beta-catenin Forms Protein Aggregation at High Concentrations in HEK293TCells

    PubMed Central

    Jazi, Marie Saghaeian; Najafi, Seyed Mahmoud Arab

    2017-01-01

    Background: The canonical Wnt signal transduction (or the Wnt/β-catenin pathway) plays a crucial role in the development of animals and in carcinogenesis. Beta-catenin is the central component of this signaling pathway. The activation of Wnt/β-catenin signaling results in the cytoplasmic and nuclear accumulation of β-catenin. In the nucleus, β-catenin interacts with the TCF/LEF transcription factors and, therefore, participates in the upregulation or downregulation of some important genes involved in diverse cellular activities. In addition, β-catenin is a critical component of the cadherin-mediated cell adherens junction. We had previously noticed that very high cellular concentrations of β-catenin had a negative effect on the transcriptional activity of this protein and, therefore, the aim of this study was to find a mechanism for this negative interaction. Methods: Cell fractionation, western blotting, and immunofluorescence microscopy experiments were performed to measure β-catenin protein levels and β-catenin cellular localization in HEK293Tcells transfected with various amounts of a β-catenin-encoding plasmid. Also, total RNA was extracted from the cells and used for reverse transcriptase-PCR experiments to measure the expression of the β-catenin target genes. SPSS, version 16, was used to analyze the results statistically. Results: We demonstrated that overexpression of β-catenin led to the formation of rod-shaped protein aggregates. The aggregate structures were mainly formed in the cell nucleus and were heavy enough to be isolated by centrifugation. Beta-catenin aggregate formation was accompanied by a decrease in the expression of the β-catenin target genes used in this study. Conclusion: Since deregulation of β-catenin function occurs in several human diseases, including cancer and neurological disorders, the results of this paper further support the possible biological and clinical significance of β-catenin aggregate formation. PMID

  17. Ultra-low specific on-resistance high-voltage vertical double diffusion metal-oxide-semiconductor field-effect transistor with continuous electron accumulation layer

    NASA Astrophysics Data System (ADS)

    Da, Ma; Xiao-Rong, Luo; Jie, Wei; Qiao, Tan; Kun, Zhou; Jun-Feng, Wu

    2016-04-01

    A new ultra-low specific on-resistance (R on,sp) vertical double diffusion metal-oxide-semiconductor field-effect transistor (VDMOS) with continuous electron accumulation (CEA) layer, denoted as CEA-VDMOS, is proposed and its new current transport mechanism is investigated. It features a trench gate directly extended to the drain, which includes two PN junctions. In on-state, the electron accumulation layers are formed along the sides of the extended gate and introduce two continuous low-resistance current paths from the source to the drain in a cell pitch. This mechanism not only dramatically reduces the R on,sp but also makes the R on,sp almost independent of the n-pillar doping concentration (N n). In off-state, the depletion between the n-pillar and p-pillar within the extended trench gate increases the N n, and further reduces the R on,sp. Especially, the two PN junctions within the trench gate support a high gate-drain voltage in the off-state and on-state, respectively. However, the extended gate increases the gate capacitance and thus weakens the dynamic performance to some extent. Therefore, the CEA-VDMOS is more suitable for low and medium frequencies application. Simulation indicates that the CEA-VDMOS reduces the R on,sp by 80% compared with the conventional super-junction VDMOS (CSJ-VDMOS) at the same high breakdown voltage (BV). Project supported by the National Natural Science Foundation of China (Grant Nos. 61176069 and 61376079) and the Fundamental Research Funds for the Central Universities, China (Grant No. ZYGX2014Z006).

  18. High-Efficiency Solar Thermal Vacuum Demonstration Completed for Refractive Secondary Concentrator

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.

    2001-01-01

    Common to many of the space applications that utilize solar thermal energy--such as electric power conversion, thermal propulsion, and furnaces--is a need for highly efficient, solar concentration systems. An effort is underway at the NASA Glenn Research Center to develop the refractive secondary concentrator, which uses refraction and total internal reflection to efficiently concentrate and direct solar energy. When used in combination with advanced lightweight primary concentrators, the refractive secondary concentrator enables very high system concentration ratios (10,000 to 1) and very high temperatures (>2000 K). The innovative refractive secondary concentrator offers significant advantages over all other types of secondary concentrators. The refractive secondary offers the highest throughput efficiency, provides for flux tailoring, requires no active cooling, relaxes the pointing and tracking requirements of the primary concentrator, and enables very high system concentration ratios. This technology has broad applicability to any system that requires the conversion of solar energy to heat. Glenn initiated the development of the refractive secondary concentrator in support of Shooting Star, a solar thermal propulsion flight experiment, and continued the development in support of Space Solar Power.

  19. High-sensitivity in situ QCLAS-based ammonia concentration sensor for high-temperature applications

    NASA Astrophysics Data System (ADS)

    Peng, W. Y.; Sur, R.; Strand, C. L.; Spearrin, R. M.; Jeffries, J. B.; Hanson, R. K.

    2016-07-01

    A novel quantum cascade laser (QCL) absorption sensor is presented for high-sensitivity in situ measurements of ammonia (hbox {NH}_3) in high-temperature environments, using scanned wavelength modulation spectroscopy (WMS) with first-harmonic-normalized second-harmonic detection (scanned WMS-2 f/1 f) to neutralize the effect of non-absorption losses in the harsh environment. The sensor utilized the sQ(9,9) transition of the fundamental symmetric stretch band of hbox {NH}_3 at 10.39 {\\upmu }hbox {m} and was sinusoidally modulated at 10 kHz and scanned across the peak of the absorption feature at 50 Hz, leading to a detection bandwidth of 100 Hz. A novel technique was used to select an optimal WMS modulation depth parameter that reduced the sensor's sensitivity to spectral interference from hbox {H}_2hbox {O} and hbox {CO}_2 without significantly sacrificing signal-to-noise ratio. The sensor performance was validated by measuring known concentrations of hbox {NH}_3 in a flowing gas cell. The sensor was then demonstrated in a laboratory-scale methane-air burner seeded with hbox {NH}_3, achieving a demonstrated detection limit of 2.8 ± 0.26 ppm hbox {NH}_3 by mole at a path length of 179 cm, equivalence ratio of 0.6, pressure of 1 atm, and temperatures of up to 600 K.

  20. A non-pathogenic and optically high concentrated (R,R)-2,3-butanediol biosynthesizing Klebsiella strain.

    PubMed

    Lee, Soojin; Kim, Borim; Yang, Jeongmo; Jeong, Daun; Park, Soohyun; Lee, Jinwon

    2015-09-10

    The objective of this work was to construct a non-pathogenic Klebsiella pneumonia strain that can produce optically high concentrated (R,R)-2,3-BDO. A K. pneumonia mutant lacking the pathogenic factor was used as the host strain. In order to construct a K. pneumonia strain that would biosynthesize high concentrated (R,R)-2,3-BDO, gene deletion and over-expression methods were combined; firstly, the 2,3-BDO dehydrogenase (budC) gene was deleted to re-direct utilization of the carbon source to (R,R)-2,3-BDO biosynthesis; secondly, the two glycerol dehydrogenase (GDH) enzymes in K. pneumonia (DhaD and GldA) were over-expressed to maximize (R,R)-2,3-BDO biosynthesis; and thirdly, the lactate dehydrogenase (ldhA) gene was deleted to minimize the accumulation of lactate. SGSB112, a non-pathogenic strain of K. pneumonia that can produce optically high concentrated (R,R)-2,3-BDO, was constructed as above. Approximately 36% of the carbon source was converted to (R,R)-2,3-BDO by SGSB112, achieving a production of 61gL(-1) (R,R)-2,3-BDO in a fed-batch fermentation. On the other hand, meso-2,3-BDO was produced 1.4gL(-1) and (S,S)-2,3-BDO was not detected. This study provides an insight into 2,3-BDO biosynthesis in K. pneumonia and demonstrates the achievement of high-yield production of optically high concentrated (R,R)-2,3-BDO through constructing a strain by genetic modification and metabolic engineering.

  1. Zinc Excess Triggered Polyamines Accumulation in Lettuce Root Metabolome, As Compared to Osmotic Stress under High Salinity

    PubMed Central

    Rouphael, Youssef; Colla, Giuseppe; Bernardo, Letizia; Kane, David; Trevisan, Marco; Lucini, Luigi

    2016-01-01

    Abiotic stresses such as salinity and metal contaminations are the major environmental stresses that adversely affect crop productivity worldwide. Crop responses and tolerance to abiotic stress are complex processes for which “-omic” approaches such as metabolomics is giving us a newest view of biological systems. The aim of the current research was to assess metabolic changes in lettuce (Lactuca sativa L.), by specifically probing the root metabolome of plants exposed to elevated isomolar concentrations of NaCl and ZnSO4. Most of the metabolites that were differentially accumulated in roots were identified for stress conditions, however the response was more intense in plants exposed to NaCl. Compounds identified in either NaCl or ZnSO4 conditions were: carbohydrates, phenolics, hormones, glucosinolates, and lipids. Our findings suggest that osmotic stress and the consequent redox imbalance play a major role in determining lettuce root metabolic response. In addition, it was identified that polyamines and polyamine conjugates were triggered as a specific response to ZnSO4. These findings help improve understanding of how plants cope with abiotic stresses. This information can be used to assist decision-making in breeding programs for improving crop tolerance to salinity and heavy metal contaminations. PMID:27375675

  2. Accumulation and conversion of sugars by developing wheat grains. VII. Effect of changes in sieve tube and endosperm cavity sap concentrations on the grain filling rate. [Triticum aestivum

    SciTech Connect

    Fisher, D.B.; Gifford, R.M.

    1987-06-01

    The extent to which wheat grain growth is dependent on transport pool solute concentration was investigated by the use of illumination and partial grain removal to vary solute concentrations in the sieve tube and endosperm cavity saps of the wheat ear (Triticum aestivum L.). Short-term grain growth rates were estimated indirectly from the product of phloem area, sieve tube sap concentration, and /sup 32/P translocation velocity. On a per grain basis, calculated rates of mass transport through the peduncle were fairly constant over a substantial range in other transport parameters (i.e. velocity, concentration, phloem area, and grain number). The rates were about 40% higher than expected; this probably reflects some unavoidable bias on faster-moving tracer in the velocity estimates. Sieve tube sap concentration increased in all experiments (by 20 to 64%), with a concomitant decline in velocity (to as low as 8% of the initial value). Endosperm cavity sucrose concentration also increased in all experiments, but cavity sap osmolality and total amino acid concentration remained nearly constant. No evidence was found for an increase in the rate of mass transport per grain through the peduncle in response to the treatments. This apparent unresponsiveness of grain growth rate to increased cavity sap sucrose concentration conflicts with earlier in vitro endosperm studies showing that sucrose uptake increased with increasing external sucrose concentration up to 150 to 200 millimolar.

  3. Vitamin C at high concentrations induces cytotoxicity in malignant melanoma but promotes tumor growth at low concentrations.

    PubMed

    Yang, Guang; Yan, Yao; Ma, Younan; Yang, Yixin

    2017-03-30

    Vitamin C has been used in complementary and alternative medicine for cancers regardless of its ineffectiveness in clinical trials and the paradoxical effects antioxidants have on cancer. Vitamin C was found to induce cytotoxicity against cancers. However, the mechanisms of action have not been fully elucidated, and the effects of vitamin C on human malignant melanoma have not been examined. This study revealed that vitamin C at millimolar concentrations significantly reduced the cell viability as well as invasiveness, and induced apoptosis in human malignant melanoma cells. Vitamin C displayed stronger cytotoxicity against the Vemurafenib-resistance cell line A2058 compared with SK-MEL-28. In contrast, vitamin C at micromolar concentrations promoted cell growth, migration and cell cycle progression, and protected against mitochondrial stress. Vemurafenib paradoxically activated the RAS-RAF-MEK-ERK signaling pathway in the Vemurafenib-resistant A2058, however, vitamin C abolished the activations. Vitamin C displayed synergistic cytotoxicity with Vemurafenib against the Vemurafenib-resistant A2058. In vivo assay suggested that lower dosage (equivalent to 0.5g/70kg) of vitamin C administered orally increased the melanoma growth. Therefore, vitamin C may exert pro- or anti-melanoma effect depending on concentration. The combination of vitamin C at high dosage and Vemurafenib is promising in overcoming the action of drug resistance. This article is protected by copyright. All rights reserved.

  4. Effect of oxygen concentration in gas phase on sporulation and individual ganoderic acids accumulation in liquid static culture of Ganoderma lucidum.

    PubMed

    Zhang, Wen-Xian; Zhong, Jian-Jiang

    2010-01-01

    Effects of oxygen concentration within 21-100% in gaseous phase on the morphology and ganoderic acids (GAs) production by Ganoderma lucidum in liquid static culture were studied. A higher oxygen concentration increased individual GAs production, and more spores and higher total GA content were obtained at an oxygen level of 80%.

  5. Increased Accumulation of Carbohydrates and Decreased Photosynthetic Gene Transcript Levels in Wheat Grown at an Elevated CO2 Concentration in the Field.

    PubMed Central

    Nie, G.; Hendrix, D. L.; Webber, A. N.; Kimball, B. A.; Long, S. P.

    1995-01-01

    Repression of photosynthetic genes by increased soluble carbohydrate concentrations may explain acclimation of photosynthesis to elevated CO2 concentration. This hypothesis was examined in a field crop of spring wheat (Triticum aestivum L.) grown at both ambient (approximately 360 [mu]mol mol-1) and elevated (550 [mu]mol mol-1) atmospheric CO2 concentrations using free-air CO2 enrichment at Maricopa, Arizona. The correspondence of steady-state levels of mRNA transcripts (coding for the 83-kD photosystem I apoprotein, sedoheptulose-1,7-bisphosphatase, phosphoribulokinase, phosphoglycerokinase, and the large and small subunits of ribulose-1,5-bisphosphate carboxylase/oxygenase) with leaf carbohydrate concentrations (glucose-6-phosphate, glucose, fructose, sucrose, fructans, and starch) was examined at different stages of crop and leaf development and through the diurnal cycle. Overall only a weak correspondence between increased soluble carbohydrate concentrations and decreased levels for nuclear gene transcripts was found. The difference in soluble carbohydrate concentration between leaves grown at elevated and current ambient CO2 concentrations diminished with crop development, whereas the difference in transcript levels increased. In the flag leaf, soluble carbohydrate concentrations declined markedly with the onset of grain filling; yet transcript levels also declined. The results suggest that, whereas the hypothesis may hold well in model laboratory systems, many other factors modified its significance in this field wheat crop. PMID:12228521

  6. TFH cells accumulate in mucosal tissues of humanized-DRAG mice and are highly permissive to HIV-1.

    PubMed

    Allam, Atef; Majji, Sai; Peachman, Kristina; Jagodzinski, Linda; Kim, Jiae; Ratto-Kim, Silvia; Wijayalath, Wathsala; Merbah, Melanie; Kim, Jerome H; Michael, Nelson L; Alving, Carl R; Casares, Sofia; Rao, Mangala

    2015-06-02

    CD4(+) T follicular helper cells (TFH) in germinal centers are required for maturation of B-cells. While the role of TFH-cells has been studied in blood and lymph nodes of HIV-1 infected individuals, its role in the mucosal tissues has not been investigated. We show that the gut and female reproductive tract (FRT) of humanized DRAG mice have a high level of human lymphocytes and a high frequency of TFH (CXCR5(+)PD-1(++)) and precursor-TFH (CXCR5(+)PD-1(+)) cells. The majority of TFH-cells expressed CCR5 and CXCR3 and are the most permissive to HIV-1 infection. A single low-dose intravaginal HIV-1 challenge of humanized DRAG mice results in 100% infectivity with accumulation of TFH-cells mainly in the Peyer's patches and FRT. The novel finding of TFH-cells in the FRT may contribute to the high susceptibility of DRAG mice to HIV-1 infection. This mouse model thus provides new opportunities to study TFH-cells and to evaluate HIV-1 vaccines.

  7. TFH cells accumulate in mucosal tissues of humanized-DRAG mice and are highly permissive to HIV-1

    PubMed Central

    Allam, Atef; Majji, Sai; Peachman, Kristina; Jagodzinski, Linda; Kim, Jiae; Ratto-Kim, Silvia; Wijayalath, Wathsala; Merbah, Melanie; Kim, Jerome H.; Michael, Nelson L.; Alving, Carl R.; Casares, Sofia; Rao, Mangala

    2015-01-01

    CD4+ T follicular helper cells (TFH) in germinal centers are required for maturation of B-cells. While the role of TFH-cells has been studied in blood and lymph nodes of HIV-1 infected individuals, its role in the mucosal tissues has not been investigated. We show that the gut and female reproductive tract (FRT) of humanized DRAG mice have a high level of human lymphocytes and a high frequency of TFH (CXCR5+PD-1++) and precursor-TFH (CXCR5+PD-1+) cells. The majority of TFH-cells expressed CCR5 and CXCR3 and are the most permissive to HIV-1 infection. A single low-dose intravaginal HIV-1 challenge of humanized DRAG mice results in 100% infectivity with accumulation of TFH-cells mainly in the Peyer’s patches and FRT. The novel finding of TFH-cells in the FRT may contribute to the high susceptibility of DRAG mice to HIV-1 infection. This mouse model thus provides new opportunities to study TFH-cells and to evaluate HIV-1 vaccines. PMID:26034905

  8. Determination of water quality variables, endotoxin concentration, and Enterobacteriaceae concentration and identification in southern High Plains dairy lagoons.

    PubMed

    Purdy, C W; Clark, R N; Straus, D C

    2010-04-01

    The objectives of this study were to determine the concentration of endotoxin, determine 20 water quality variables, and identify and enumerate fungal and bacterial pathogens from United States southern High Plains dairy lagoons and control lakes during summer and winter. Water samples were collected in triplicate from the north, south, east, and west quadrants of each body of water. The mean (+/- SEM) winter dairy lagoon endotoxin concentration was significantly higher (9,678+/-1,834 ng/mL) than the summer concentration (3,220+/-810 ng/mL). The mean endotoxin concentration of the 2 control lakes (summer: 58.1+/-8.8 ng/mL; winter: 38.6+/-4.2 ng/mL) was significantly less than that of the dairy lagoons. Two hundred-one Salmonella enterica spp. isolates were identified, 7 serovars were recovered from the dairy lagoons, and 259 Salmonella ssp. were identified from 5 other dairy locations (milk barn, ditch effluent, settling basin, feed alley pad flush, and center pivots). Twenty-eight Salmonella spp. were identified from center pivot water. Escherichia coli O157:H7 pathogens were isolated from other dairy locations but not from lagoons. Neither Salmonella spp. nor E. coli O157:H7 were identified from control lakes. Enterobacteriaceae opportunistic pathogens were isolated from both dairies and control lakes. Important mesophilic and thermophilic catabolic (to manure biosolids) fungal isolates were identified from dairy effluent locations, but no thermophilic fungal isolates were cultured from the control lakes. Adequate curing of green forage following center pivot irrigation is important to kill lagoon water enteric pathogens, even though the lagoon water is mixed with fresh water. Recirculating lagoon water to flush the feed alley pad, where cows stand while eating, to remove manure and using lagoon water to abate dairy dust in loafing pens and unimproved dairy roads is inconsistent with good environmental practice management.

  9. X ray attenuation measurements for high-temperature materials characterization and in situ monitoring of damage accumulation

    NASA Astrophysics Data System (ADS)

    Baaklini, George Youssef

    1991-10-01

    The development and application is examined of x ray attenuation measurement systems that are capable of (1) characterizing density variations in high temperature materials, e.g., monolithic ceramics, ceramic and intermetallic matrix composites and (2) noninvasively monitoring damage accumulation and failure sequences in ceramic matrix composites under room temperature tensile testing. Results are presented in the development of (1) a point scan digital radiography system and (2) an in-situ x ray material testing system. The former is used to characterize silicon carbide and silicon nitride specimens and the latter is used to image the failure behavior of silicon carbide fiber reinforced reaction bonded silicon nitride matrix composites. Further, state of the art x ray computed tomography is studied to determine its capabilities and limitations in characterizing density variations of subscale engine components, e.g., a silicon carbide rotor, a silicon nitride blade, and a silicon carbide fiber reinforced beta titanium matrix rod, rotor, and ring. Microfocus radiography, conventional radiography, scanning acoustic microscopy, and metallography are used to substantiate the x ray computed tomography findings. Point scan digital radiography is a viable technique for characterization density variations in monolithic ceramic specimens. But it is very limited and time consuming in characterizing ceramic matrix composities. Precise x ray attenuation measurements, reflecting minute density variations, are achieved by photon counting and by using micro collimators at the source and the detector. X ray computed tomography is found to be a unique x ray attenuation measurement technique capable of providing cross sectional spatial density information in monolithic ceramics and metal matrix composites. X ray computed tomography is proven to accelerate generic composite component development. Radiographic evaluation before, during and after loading show the effect of preexisting

  10. Effect of soil weathering degree on the increase of cotton biomass and silicon mineralomass after amendment with biochar highly concentrated in phytoliths

    NASA Astrophysics Data System (ADS)

    Li, Zimin; Delvaux, Bruno; Yans, Johan; Dufour, Nicolas; Houben, David; Cornelis, Jean-Thomas

    2016-04-01

    Silicon (Si) is beneficial for plants, but not essential. It plays a crucial role in improving the yields of Si-accumulator crops through alleviating various biotic and abiotic stresses. The demand of Si fertilizers will likely increase due to soil desilication and removal of harvested biomass. Since plants accumulate Si in the form of readily soluble phytoliths, plant-derived biochar is considered as a Si source for Si accumulator crops. In addition to its beneficial effects on soil fertility and carbon sequestration, biochar is a promising cost-effective and environmentally friendly alternative to conventional Si amendments. Here, we study the impact of biochar materials with different phytolith concentrations on the bioavailability of Si in soils differing in weathering stage, and its effect on cotton biomass and Si mineralomass. Two biochar materials were used: Miscanthus x giganteus (Si concentration: 34.6 g/kg) and soft woody material (Si concentration: 0.9 g/kg). A conventional wollastonite (CaSiO3) treatment was carried for comparison purpose. The concentration of bioavailable Si was determined through 0.01 M CaCl2 extraction. Biochars were incorporated at the rate of 3% (w/w) in two soils: a slightly weathered Cambisol and a highly weathered Nitisol. The Miscanthus biochar ability to release bioavailable Si in the Cambisol (CaCl2 extractable Si/total Si concentration) is significantly smaller (0.9%) than the one of wollastonite (5.2%). In the highly weathered Nitisol, the Miscanthus biochar ability to release bioavailable Si is much larger (1.4%) than that of wollastonite (0.7%). Miscanthus biochar significantly increases the cotton biomass and Si mineralomass relative to soft wood biochar. The increase is larger in the highly weathered Nitisol than in the slightly weathered Cambisol. Principal component analyses and linear regression show that both the larger release rate of bioavailable Si and CEC are the main factors responsible for the increase of

  11. Quantitation of low concentrations of polysorbates in high protein concentration formulations by solid phase extraction and cobalt-thiocyanate derivatization.

    PubMed

    Kim, Justin; Qiu, Jinshu

    2014-01-02

    A spectrophotometric method was developed to quantify low polysorbate (PS) levels in biopharmaceutical formulations containing high protein concentrations. In the method, Oasis HLB solid phase extraction (SPE) cartridge was used to extract PS from high protein concentration formulations. After loading a sample, the cartridge was washed with 4M guanidine HCl and 10% (v/v) methanol, and the retained PS was eluted by acetonitrile. Following the evaporation of acetonitrile, aqueous cobalt-thiocyanate reagent was added to react with the polyoxyethylene oxide chain of polysorbates to form a blue colored PS-cobaltothiocyante complex. This colored complex was then extracted into methylene chloride and measured spectrophotometrically at 620 nm. The method performance was evaluated on three products containing 30-40 mg L(-1) PS-20 and PS-80 in ≤70 g L(-1) protein formulations. The method was specific (no matrix interference identified in three types of protein formulations), sensitive (quantitation limit of 10 mg L(-1) PS) and robust with good precision (relative standard deviation ≤6.4%) and accuracy (spike recoveries from 95% to 101%). The linear range of the method for both PS-20 and PS-80 was 10 to 80 mg L(-1) PS. By diluting samples with 6M guanidine HCl and/or using different methylene chloride volumes to extract the colored complexes of standards and samples, the method could accurately and precisely quantify 40 mg L(-1) PS in up to 300 g L(-1) protein formulations.

  12. Case study of the 9 April 2009 ‘brown’ cloud: Observations of usually high cloud droplet concentrations in Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Delene, D. J.

    2009-12-01

    Cloud droplets nucleate on aerosol particles termed cloud condensation nuclei (CCN). It is well known that a larger number concentration of CCN results in a larger number concentration of droplets in developing cumulus clouds. However, the conditions where dust particles can serve as cloud condensation nuclei (CCN) and hence change cloud droplet concentration and precipitation formation processes is uncertain. Aircraft measurements of cloud droplet concentration between 13:20 and 13:30 UTC during the 9 April 2009 flight near Riyadh, Saudi Arabia, show total cloud droplet concentration (3-50 µm in diameter) of 800 to 1200 #/cm-3 at a altitude of 18000 ft. Typical cloud droplet concentration for this type of cloud in the Riyadh region is approximately 400 #/cm-3 and is typical of observation made between 13:00 and 13:20 UTC during the 9 April 2009 flight at 18,000 ft. Photographs of ice accumulation on the unprotected leading edge of the aircraft’s wing due to the freezing of super cooled droplets show a color changed from white during the time of low droplet number condensation to brown during the high droplet number concentration. It is hypothesized that high droplet number concentration observations were the result of ingestion of a large about of dust particles by the cloud. : Case Study of the 9 April 2009 ‘Brown’ Cloud: Observations of Usually High Cloud Droplet Concentrations in Saudi Arabia.

  13. Accumulation of 2,3,7,8-tetrachlorodibenzo-p-dioxin by rainbow trout (Onchorhynchus mykiss) at environmentally relevant dietary concentrations

    USGS Publications Warehouse

    Jones, Paul D.; Kannan, Kurunthachalam; Newsted, John L.; Tillitt, Donald E.; Williams, Lisa L.; Giesy, John P.

    2001-01-01

    Rainbow trout were fed a diet containing 1.8, 18, or 90 pg/g 3H-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) for up to 320 d. Concentrations of TCDD were determined in muscle, liver, and ovaries at 100, 150, 200, and 250 d. Concentrations of TCDD reached an apparent steady-state concentration in liver after 100 d of exposure, whereas concentrations in other tissues continued to increase until 150 d of exposure. The greatest portion of the total mass of TCDD was present in the muscle tissue with lesser proportions in other organs. As the ovaries developed before spawning, an increase occurred in the total mass of TCDD present in this tissue. The assimilation rate of TCDD during the initial 100 d of the exposure was determined to be between 10 and 30%. This is somewhat less than estimates derived based on both uptake and elimination constants determined during shorter exposures. Biomagnification factors (BMFs) were estimated for all tissues and exposure concentrations, and at all exposure periods. Lipid-normalized BMFs for muscle ranged from 0.38 to 1.51, which is consistent with the value of 1.0 predicted from fugacity theory. Uptake and depuration rate constants were determined and used to predict individual organ TCDD concentrations. Comparison with observed values indicated that the model could be used to predict tissue concentrations from the known concentrations of TCDD in food. This model will allow more refined risk assessments by predicting TCDD concentrations in sensitive tissues such as developing eggs.

  14. Transient Proliferation of Proanthocyanidin-Accumulating Cells on the Epidermal Apex Contributes to Highly Aluminum-Resistant Root Elongation in Camphor Tree1[W

    PubMed Central

    Osawa, Hiroki; Endo, Izuki; Hara, Yukari; Matsushima, Yuki; Tange, Takeshi

    2011-01-01

    Aluminum (Al) is a harmful element that rapidly inhibits the elongation of plant roots in acidic soils. The release of organic anions explains Al resistance in annual crops, but the mechanisms that are responsible for superior Al resistance in some woody plants remain unclear. We examined cell properties at the surface layer of the root apex in the camphor tree (Cinnamomum camphora) to understand its high Al resistance mechanism. Exposure to 500 μm Al for 8 d, more than 20-fold higher concentration and longer duration than what soybean (Glycine max) can tolerate, only reduced root elongation in the camphor tree to 64% of the control despite the slight induction of citrate release. In addition, Al content in the root apices was maintained at low levels. Histochemical profiling revealed that proanthocyanidin (PA)-accumulating cells were present at the adjacent outer layer of epidermis cells at the root apex, having distinctive zones for cell division and the early phase of cell expansion. Then the PA cells were gradually detached off the root, leaving thin debris behind, and the root surface was replaced with the elongating epidermis cells at the 3- to 4-mm region behind the tip. Al did not affect the proliferation of PA cells or epidermis cells, except for the delay in the start of expansion and the accelerated detachment of the former. In soybean roots, the innermost lateral root cap cells were absent in both PA accumulation and active cell division and failed to protect the epidermal cell expansion at 25 μm Al. These results suggest that transient proliferation and detachment of PA cells may facilitate the expansion of epidermis cells away from Al during root elongation in camphor tree. PMID:21045123

  15. Why are the PCB concentrations of salmonine individuals from the same lake so highly variable?

    USGS Publications Warehouse

    Madenjian, Charles P.; Carpenter, Stephen R.; Rand, Peter S.

    1994-01-01

    An individual-based model (IBM) was applied to the Lake Michigan rainbow trout (Oncorhynchus mykiss) population, with the objectives of explaining the observed variation in growth and in polychlorinated biphenyl (PCB) concentration within the population. When variation in prey PCB concentration was incorporated into the model, variability in PCB concentration among individual rainbow trout was fully explained by the IBM. Although number of spawnings and number of years spent in a stream prior to first entering the lake were factors in determining growth, these life history characteristics appeared to have only a minor impact on PCB accumulation rate in rainbow trout. The IBM application to the rainbow trout population was compared with an application to the Lake Michigan lake trout (Salvelinus namaycush) population. Modeling results indicated that the lower observed PCB concentrations in rainbow trout compared with lake trout were chiefly due to greater longevity in lake trout. The IBM simulations identified gross growth efficiency, assimilation efficiency of PCBs from food, and diet as other important sources of variability in salmonine PCB concentrations.

  16. Design, Fabrication and Test of a High Efficiency Refractive Secondary Concentrator for Solar Applications

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.; Geng, Steven M.; Castle, Charles H.; Macosko, Robert P.

    2000-01-01

    Common to many of the space applications that utilize solar thermal energy such as electric power conversion, thermal propulsion, and furnaces, is a need for highly efficient, solar concentration systems. An effort is underway to develop the refractive secondary concentrator, which uses refraction and total internal reflection to efficiently concentrate and direct solar energy. When used in combination with advanced primary concentrators, the refractive secondary concentrator enables very high system concentration ratios (10,000 to 1) and very high temperatures (greater than 2000 K). Presented is an overview of the effort at the NASA Glenn Research Center to evaluate the performance of a prototype single crystal sapphire refractive secondary concentrator and to compare the performance with analytical models. The effort involves the design and fabrication of a secondary concentrator, design and fabrication of a calorimeter and its support hardware, calibration of the calorimeter, testing of the secondary concentrator in NASA Glenn's Tank 6 solar thermal vacuum facility, and comparing the test results with predictions. Test results indicate an average throughput efficiency of 87%. It is anticipated that reduction of a known reflection loss with an anti-reflective coating would result in a secondary concentrator throughput efficiency of approximately 93%.

  17. Low air exchange rate causes high indoor radon concentration in energy-efficient buildings.

    PubMed

    Vasilyev, A V; Yarmoshenko, I V; Zhukovsky, M V

    2015-06-01

    Since 1995, requirements on energy-efficient building construction were established in Russian Building Codes. In the course of time, utilisation of such technologies became prevailing, especially in multi-storey building construction. According to the results of radon survey in buildings constructed meeting new requirements on energy efficiency, radon concentration exceeds the average level in early-constructed buildings. Preponderance of the diffusion mechanism of radon entry in modern multi-storey buildings has been experimentally established. The experimental technique of the assessment of ventilation rate in dwellings under real conditions was developed. Based on estimates of average ventilation rate, it was approved that measures to increase energy efficiency lead to reduction in ventilation rate and accumulation of higher radon concentrations indoors. Obtained ventilation rate values have to be considered as extremely low.

  18. A high serum iron level causes mouse retinal iron accumulation despite an intact blood-retinal barrier.

    PubMed

    Zhao, Liangliang; Li, Yafeng; Song, Delu; Song, Ying; Theurl, Milan; Wang, Chenguang; Cwanger, Alyssa; Su, Guanfang; Dunaief, Joshua L

    2014-11-01

    The retina can be shielded by the blood-retinal barrier. Because photoreceptors are damaged by excess iron, it is important to understand whether the blood-retinal barrier protects against high serum iron levels. Bone morphogenic protein 6 (Bmp6) knockout mice have serum iron overload. Herein, we tested whether the previously documented retinal iron accumulation in Bmp6 knockout mice might result from the high serum iron levels or, alternatively, low levels of retinal hepcidin, an iron regulatory hormone whose transcription can be up-regulated by Bmp6. Furthermore, to determine whether increases in serum iron can elevate retinal iron levels, we i.v. injected iron into wild-type mice. Retinas were analyzed by real-time quantitative PCR and immunofluorescence to assess the levels of iron-regulated genes/proteins and oxidative stress. Retinal hepcidin mRNA levels in Bmp6 knockout retinas were the same as, or greater than, those in age-matched wild-type retinas, indicating that Bmp6 knockout does not cause retinal hepcidin deficiency. Changes in mRNA levels of L ferritin and transferrin receptor indicated increased retinal iron levels in i.v. iron-injected wild-type mice. Oxidative stress markers were elevated in photoreceptors of mice receiving i.v. iron. These findings suggest that elevated serum iron levels can overwhelm local retinal iron regulatory mechanisms.

  19. High-latitude regions of Siberia and Northeast Russia in the Paleogene: Stratigraphy, flora, climate, coal accumulation

    NASA Astrophysics Data System (ADS)

    Akhmetiev, M. A.

    2015-07-01

    The geological structure and development history of superposed depressions on the Arctic coast of East Siberia and Bering Sea region (Chukotka, Koryakiya, northern Kamchatka) in the Early Paleogene are considered with the analysis of their flora and climatic parameters. The paleofloral analysis revealed thermophilic assemblages that reflect phases of maximum warming at the Paleocene-Eocene transition and in the Early Eocene. The appearance of thermophilic plants (Magnoliaceae, Myrtaceae, Lauraceae, Araliaceae, Loranthaceae, and others) in the Siberian segment of the Arctic region is explained by the stable atmospheric heat transfer from the Tethys to higher latitudes and absence of the latitudinal orographic barrier (Alpine-Himalayan belt). The plants migrated to high latitudes also along the meridional seaway that connected the Tethys with the Arctic Ocean via marine basins of the Eastern Paratethys, Turgai Strait, and West Siberia. The migration from the American continent was realized along the southern coast of Beringia under influence of a warm current flowing from low latitudes along the western coast of North America. The palm genus Sabal migrated to northern Kamchatka and Koryakiya precisely in this way via southern Alaska. In the Oligocene, shallow-water marine sediments in high-latitude regions were replaced by terrestrial facies. The Late Oligocene was marked by maximum cooling. Coal accumulation in Northeast Russia through the Paleogene is reviewed.

  20. Accumulation of High-Value Lipids in Single-Cell Microorganisms: A Mechanistic Approach and Future Perspectives

    PubMed Central

    2015-01-01

    In recent years attention has been focused on the utilization of microorganisms as alternatives for industrial and nutritional applications. Considerable research has been devoted to techniques for growth, extraction, and purification of high-value lipids for their use as biofuels and biosurfactants as well as high-value metabolites for nutrition and health. These successes argue that the elucidation of the mechanisms underlying the microbial biosynthesis of such molecules, which are far from being completely understood, now will yield spectacular opportunities for industrial scale biomolecular production. There are important additional questions to be solved to optimize the processing strategies to take advantage of the assets of microbial lipids. The present review describes the current state of knowledge regarding lipid biosynthesis, accumulation, and transport mechanisms present in single-cell organisms, specifically yeasts, microalgae, bacteria, and archaea. Similarities and differences in biochemical pathways and strategies of different microorganisms provide a diverse toolset to the expansion of biotechnologies for lipid production. This paper is intended to inspire a generation of lipid scientists to insights that will drive the biotechnologies of microbial production as uniquely enabling players of lipid biotherapeutics, biofuels, biomaterials, and other opportunity areas into the 21st century. PMID:24628496

  1. Using variances in hydrocarbon concentration and carbon stable isotope to determine the important influence of irrigated water on petroleum accumulation in surface soil.

    PubMed

    Zhang, Juan; Wang, Renqing; Yang, Juncheng; Hou, Hong; Du, Xiaoming; Dai, Jiulan

    2013-05-01

    Hunpu is a wastewater-irrigated area southwest of Shenyang. To evaluate petroleum contamination and identify its sources at the area, the aliphatic hydrocarbons and compound-specific carbon stable isotopes of n-alkanes in the soil, irrigation water, and atmospheric deposition were analyzed. The analyses of hydrocarbon concentrations and geochemical characteristics reveal that the water is moderately contaminated by degraded heavy oil. According to the isotope analysis, inputs of modern C3 plants and degraded petroleum are present in the water, air, and soil. The similarities and dissimilarities among the water, air, and soil samples were determined by concentration, isotope, and multivariate statistical analyses. Hydrocarbons from various sources, as well as the water/atmospheric deposition samples, are more effectively differentiated through principal component analysis of carbon stable isotope ratios (δ(13)C) relative to hydrocarbon concentrations. Redundancy analysis indicates that 57.1 % of the variance in the δ(13)C of the soil can be explained by the δ(13)C of both the water and air, and 35.5 % of the variance in the hydrocarbon concentrations of the soil can be explained by hydrocarbon concentrations of both the water and the air. The δ(13)C in the atmospheric deposition accounts for 28.2 % of the δ(13)C variance in the soil, which is considerably higher than the variance in hydrocarbon concentrations of the soil explained by hydrocarbon concentrations of the atmospheric deposition (7.7 %). In contrast to δ(13)C analysis, the analysis of hydrocarbon concentrations underestimates the effect of petroleum contamination in the irrigated water and air on the surface soil. Overall, the irrigated water exerts a larger effect on the surface soil than does the atmospheric deposition.

  2. High concentration suspended sediment measurments using acontinuous fiber optic in-stream transmissometer

    SciTech Connect

    Campbell, Chris G.; Laycak, Danny T.; Hoppes, William; Tran,Nguyen T.; Shi, Frank G.

    2004-05-26

    Suspended sediment loads mobilized during high flow periods in rivers and streams are largely uncharacterized. In smaller and intermittent streams, a large storm may transport a majority of the annual sediment budget. Therefore monitoring techniques that can measure high suspended sediment concentrations at semi-continuous time intervals are needed. A Fiber optic In-stream Transmissometer (FIT) is presented for continuous measurement of high concentration suspended sediment in storm runoff. FIT performance and precision were demonstrated to be reasonably good for suspended sediment concentrations up to 10g/L. The FIT was compared to two commercially available turbidity devices and provided better precision and accuracy at both high and low concentrations. Both turbidity devices were unable to collect measurements at concentrations greater than 4 g/L. The FIT and turbidity measurements were sensitive to sediment particle size. Particle size dependence of transmittance and turbidity measurement poses the greatest problem for calibration to suspended sediment concentration. While the FIT was demonstrated to provide acceptable measurements of high suspended sediment concentrations, approaches to real-time suspended sediment detection need to address the particle size dependence in concentration measurements.

  3. Novel DDR Processing of Corn Stover Achieves High Monomeric Sugar Concentrations from Enzymatic Hydrolysis (230 g/L) and High Ethanol Concentration (10% v/v) During Fermentation

    SciTech Connect

    Chen, Xiaowen; Jennings, Ed; Shekiro, Joe; Kuhn, Erik M.; O'Brien, Marykate; Wang, Wei; Schell, Daniel J.; Himmel, Mike; Elander, Richard T.; Tucker, Melvin P.

    2015-04-03

    Distilling and purifying ethanol, butanol, and other products from second and later generation lignocellulosic biorefineries adds significant capital and operating cost for biofuels production. The energy costs associated with distillation affects plant gate and life cycle analysis costs. Lower titers in fermentation due to lower sugar concentrations from pretreatment increase both energy and production costs. In addition, higher titers decrease the volumes required for enzymatic hydrolysis and fermentation vessels. Therefore, increasing biofuels titers has been a research focus in renewable biofuels production for several decades. In this work, we achieved over 200 g/L of monomeric sugars after high solids enzymatic hydrolysis using the novel deacetylation and disc refining (DDR) process on corn stover. The high sugar concentrations and low chemical inhibitor concentrations from the DDR process allowed ethanol titers as high as 82 g/L in 22 hours, which translates into approximately 10 vol% ethanol. To our knowledge, this is the first time that 10 vol% ethanol in fermentation derived from corn stover without any sugar concentration or purification steps has been reported. Techno-economic analysis shows the higher titer ethanol achieved from the DDR process could significantly reduce the minimum ethanol selling price from cellulosic biomass.

  4. Quantification of susceptibility change at high-concentrated SPIO-labeled target by characteristic phase gradient recognition.

    PubMed

    Zhu, Haitao; Nie, Binbin; Liu, Hua; Guo, Hua; Demachi, Kazuyuki; Sekino, Masaki; Shan, Baoci

    2016-05-01

    Phase map cross-correlation detection and quantification may produce highlighted signal at superparamagnetic iron oxide nanoparticles, and distinguish them from other hypointensities. The method may quantify susceptibility change by performing least squares analysis between a theoretically generated magnetic field template and an experimentally scanned phase image. Because characteristic phase recognition requires the removal of phase wrap and phase background, additional steps of phase unwrapping and filtering may increase the chance of computing error and enlarge the inconsistence among algorithms. To solve problem, phase gradient cross-correlation and quantification method is developed by recognizing characteristic phase gradient pattern instead of phase image because phase gradient operation inherently includes unwrapping and filtering functions. However, few studies have mentioned the detectable limit of currently used phase gradient calculation algorithms. The limit may lead to an underestimation of large magnetic susceptibility change caused by high-concentrated iron accumulation. In this study, mathematical derivation points out the value of maximum detectable phase gradient calculated by differential chain algorithm in both spatial and Fourier domain. To break through the limit, a modified quantification method is proposed by using unwrapped forward differentiation for phase gradient generation. The method enlarges the detectable range of phase gradient measurement and avoids the underestimation of magnetic susceptibility. Simulation and phantom experiments were used to quantitatively compare different methods. In vivo application performs MRI scanning on nude mice implanted by iron-labeled human cancer cells. Results validate the limit of detectable phase gradient and the consequent susceptibility underestimation. Results also demonstrate the advantage of unwrapped forward differentiation compared with differential chain algorithms for susceptibility

  5. Constitutive high-level SOS1 expression and absence of HKT1;1 expression in the salt-accumulating halophyte Salicornia dolichostachya.

    PubMed

    Katschnig, D; Bliek, T; Rozema, J; Schat, H

    2015-05-01

    We investigated the effects of salinity on ion accumulation and expression of candidate salt tolerance genes in the highly tolerant salt accumulating halophyte Salicornia dolichostachya and the taxonomically related glycophytic Spinacia oleracea. S. dolichostachya, in comparison with S. oleracea, constitutively expressed SOS1 at a high level, but did not detectably express HKT1;1. These findings suggest that the constitutive high level of shoot salt accumulation in S. dolichostachya is accomplished through enhancement of SOS1-mediated Na(+) xylem loading, in combination with complete suppression of HKT1;1-mediated Na(+) retrieval from the xylem. Our findings demonstrate the importance of gene expression comparisons between highly tolerant halophytes and taxonomically related glycophytes to improve the understanding of mechanisms of Na(+) movement and salt tolerance in plants.

  6. Effect of digestion time on anaerobic digestion with high ammonia concentration

    NASA Astrophysics Data System (ADS)

    Oktavitri, Nur Indradewi; Purnobasuki, Hery; Kuncoro, Eko Prasetyo; Purnamasari, Indah; Semma Hadinnata, P.

    2016-03-01

    Anaerobic digestion was developed to treat high concentration organic compound efficiently in certain Digestion Time (DT). High ammonia concentration could influenced removal organic compound in digestion. This bench scale study investigated the effect of digestion time on anaerobic batch reactor with high ammonia concentration. Total Ammonia Nitrogen (TAN) concentration was adjusted 4000 and 5000 mg/1, Digestion time was ranged from 0-26 d, operation temperature was ranged from 28-29°C, inoculum was collected from slaughter house sludge. The degradation of Chemical Oxygen Demand (COD) correlated with digestion time. The concentration of TAN from synthetic wastewater contain 5000 mg/1 of TAN more fluctuated than those use 4000 mg/1 of TAN. However, the biogas production from wastewater contained 4000 mg/1 of TAN gradually increased until 24 d of DT. The reactor contain 5000 mg/1 of TAN only growth until 12 d and steady state at over 12 d of digestion time.

  7. Thiamine status of feedlot cattle fed a high-concentrate diet.

    PubMed

    Karapinar, Tolga; Dabak, Murat; Kizil, Omer

    2010-11-01

    As thiamine status of ruminants is adversely affected by rumen acidity, this study investigated whether or not thiamine deficiency occurs in feedlot cattle fed a high concentrate diet. Fifty 1- to 2-year-old feedlot cattle fed a high concentrate diet (75% barley) for at least 3 mo (high concentrate diet group) and 15 healthy feedlot cattle of similar ages (control group) that were fed a low concentrate diet (30% barley) were used. Rumen fluid samples were obtained by rumenocentesis and their pH was determined with a portable pH meter. Blood samples taken from all animals from a jugular vein were used to determine erythrocyte transketolase enzyme activity, and hence thiamine pyrophosphate (TPP) effect. Odor and mean pH values of ruminal fluid samples from the high concentrate diet and control group were acidic (pH 5.3) and aromatic (pH 6.1), respectively. The mean TPP effect % in the high concentrate diet group (47.2 ± 3.2) was significantly higher than in the control group (19.53 ± 2.5) (P < 0.001). The study provides evidence of a TPP effect in feedlot cattle fed a high concentrate diet.

  8. 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.

  9. Impact of high dietary zinc on zinc accumulation, enzyme activity and proteomic profiles in the pancreas of piglets.

    PubMed

    Pieper, R; Martin, L; Schunter, N; Villodre Tudela, C; Weise, C; Klopfleisch, R; Zentek, J; Einspanier, R; Bondzio, A

    2015-04-01

    The exocrine pancreas plays an important role in zinc homeostasis. Feeding very high (2000-3000mgzinc/kg diet) levels of zinc oxide to piglets for short periods is a common practice in the swine industry to improve performance and prevent diseases. The impact on pancreatic function and possible side effects during long-term feeding of high dietary zinc levels are still poorly understood. A total of 54 weaned piglets were either fed with low (57mg/kg, LZn), normal (164mg/kg, NZn) or high (2425mg/kg, HZn) zinc concentration in the diets. After 4 weeks of feeding, ten piglets per treatment were euthanized and pancreas samples were taken. Tissue zinc concentration and metallothionein abundance was greater with HZn compared with NZn and LZn (P<0.05). Similarly, activity of α-amylase, lipase, trypsin and chymotrypsin was higher with HZn as compared with NZn and LZn diets (P<0.05), whereas elastase activity was unchanged. Total trolox equivalent antioxidative capacity of pancreas tissue was higher with HZn diets compared with the other treatments (P<0.05). Pancreatic protein profiles of NZn and HZn fed piglets were obtained by 2D-DIGE technique and revealed 15 differentially expressed proteins out of 2100 detected spots (P<0.05). The differentially expressed proteins aldose reductase, eukaryotic elongation factor II and peroxiredoxin III were confirmed by immunoblotting. Identified proteins include zinc finger-containing transcription factors and proteins mainly associated with oxidative stress response and signal transduction in HZn compared with NZn pigs. Histologic examination however showed no morphologic changes. The results suggest that long-term supply of very high dietary zinc increases zinc and metallothionein concentration, and digestive enzyme activity, but also triggers oxidative stress reactions in the pancreas of young pigs. The data provide new insights into pancreatic function under outbalanced zinc homeostasis.

  10. Investigating rennet coagulation properties of recombined highly concentrated micellar casein concentrate and cream for use in cheese making.

    PubMed

    Lu, Y; McMahon, D J; Vollmer, A H

    2017-02-01

    Highly concentrated micellar casein concentrate (HC-MCC) contains ∼18% casein with ∼70% of whey proteins removed by microfiltration and diafiltration of skim milk, followed by vacuum evaporation for further concentration. When blended with cream, HC-MCC forms recombined concentrated milk (RCM), which could be used as a starting material in cheese making. Our objective was to investigate the rennet coagulation properties of RCM while varying parameters such as casein level, pH, rennet level, and coagulation temperature. The HC-MCC was mixed with cream using low shear at 50°C for 10 min, followed by cooling to 31, 28, or 25°C and adding rennet, and rheological properties were determined. Rennet coagulation time [RCT, the time at which storage modulus (G') = loss modulus (G″)] decreased from 8.7 to 7.4 min as casein level increased from 3.2 to 5.7%, without a significant additional difference in RCT at casein levels >5.7%. The initial G″ (G″0) increased about 10-fold when casein levels were increased from 3.2 to 10.9%, whereas no change in initial G' (G'0) was observed. When G' was measured relative to RCT (i.e., 1, 1.5, or 2 times RCT after RCT was reached, and expressed as G'1, G'1.5, and G'2), log relationship was found between relative G' and casein level (R(2) > 0.94). Lowering coagulation temperature from 31 to 25°C increased G″0 by 6 fold and extended RCT from 7.4 to 9.5 min. After coagulation, relative G' was initially higher at the lower temperature with G'1 of 3.6 Pa at 25°C and 2.0 Pa at 31°C, but delayed in further development with G'2 of 0.8 kPa at 25°C and 1.1 kPa at 31°C. Lowering pH of RCM from 6.6 to 6.2 resulted in reduced RCT from 11.9 to 6.5 min with increased relative G' after coagulation. When less rennet was used, RCT increased in a linear inverse relationship without changes in relative G' or G″. The microstructure of RCM coagulum (∼11% casein), observed using transmission electron microscopy, confirmed that RCM curd had

  11. 27 CFR 18.52 - Production of high-proof concentrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Production of high-proof concentrate. 18.52 Section 18.52 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS PRODUCTION OF VOLATILE FRUIT-FLAVOR CONCENTRATE...

  12. High accumulation of PCDD, PCDF, and PCB congeners in marine mammals from Brazil: a serious PCB problem.

    PubMed

    Dorneles, Paulo R; Sanz, Paloma; Eppe, Gauthier; Azevedo, Alexandre F; Bertozzi, Carolina P; Martínez, María A; Secchi, Eduardo R; Barbosa, Lupércio A; Cremer, Marta; Alonso, Mariana B; Torres, João P M; Lailson-Brito, José; Malm, Olaf; Eljarrat, Ethel; Barceló, Damià; Das, Krishna

    2013-10-01

    Blubber samples from three delphinid species (false killer whale, Guiana and rough-toothed dolphin), as well as liver samples from franciscana dolphins were analyzed for dioxins and related compounds (DRCs). Samples were collected from 35 cetaceans stranded or incidentally captured in a highly industrialized and urbanized area (Southeast and Southern Brazilian regions). Dioxin-like PCBs accounted for over 83% of the total TEQ for all cetaceans. Non-ortho coplanar PCBs, for franciscanas (82%), and mono-ortho PCBs (up to 80%), for delphinids, constituted the groups of highest contribution to total TEQ. Regarding franciscana dolphins, significant negative correlations were found between total length (TL) and three variables, ΣTEQ-DRCs, ΣTEQ-PCDF and ΣTEQ non-ortho PCB. An increasing efficiency of the detoxifying activity with the growth of the animal may be a plausible explanation for these findings. This hypothesis is reinforced by the significant negative correlation found between TL and PCB126/PCB169 concentration ratio. DRC concentrations (ng/g lipids) varied from 36 to 3006, for franciscana dolphins, as well as from 356 to 30,776, for delphinids. The sum of dioxin-like and indicator PCBs varied from 34,662 to 279,407 ng/g lipids, for Guiana dolphins from Rio de Janeiro state, which are among the highest PCB concentrations ever reported for cetaceans. The high concentrations found in our study raise concern not only on the conservation of Brazilian coastal cetaceans, but also on the possibility of human health problem due to consumption of fish from Brazilian estuaries.

  13. Effect of pH, sulphate concentration and total organic carbon on mercury accumulation in sediments in the Volta Lake at Yeji, Ghana.

    PubMed

    Kwaansa-Ansah, E E; Voegborlo, R B; Adimado, A A; Ephraim, J H; Nriagu, J O

    2012-03-01

    In this study, pH, total organic carbon, sulphate concentration and mercury concentrations of sediment samples from the Volta Lake at Yeji in the northern part of Ghana were determined. The results indicate that pH ranged from 6.32 to 8.21, total organic carbon ranged from 0.17 to 3.02 g/kg and sulphate concentration from 10.00 to 57.51 mg/kg. Total mercury concentrations ranged from 32.61 to 700 ng/g which is below the International Atomic Energy Agency recommended value of 810 ng/g. Humic substance-bound mercury ranged from 81.15 to 481.31 mg/kg in sediments and its two fractions existed as humic acid-bound mercury > fulvic acid-bound mercury with the ratio of humic substance-bound mercury to fulvic acid-bound mercury as 1.62 on the average. Humic substance-bound mercury and the two fractions fulvic acid-bound mercury and humic substance-bound mercury in sediments were favorably determined and found to correlate significantly positive with total organic carbon (r = 0.538) and total mercury (r = 0.574). However, there were poor correlations between SO(4) (2-) concentrations and humic substance-bound mercury (r = -0.391) as well as the two fractions; fulvic acid (r = -0.406) and humic acid (r = -0.381). By assuming that methyl mercury is mostly formed in sediments, these significant relations suggest that the efficiency of mercury being methylated from a given inorganic form depends on the amount, and most likely biochemical composition of total organic carbon in the lake sediment but not the SO(4) (2-) concentration.

  14. High Concentrations of Ozone Air Pollution on Mount Everest: Health Implications for Sherpa Communities and Mountaineers.

    PubMed

    Semple, John L; Moore, G W Kent; Koutrakis, Petros; Wolfson, Jack M; Cristofanelli, Paolo; Bonasoni, Paolo

    2016-12-01

    Semple, John L., G.W. Kent Moore, Petros Koutrakis, Jack M. Wolfson, Paolo Cristofanelli, and Paolo Bonasoni. High concentrations of ozone air pollution on Mount Everest: health implications for Sherpa communities and mountaineers. High Alt Med Biol. 17:365-369, 2016.-Introduction: Populations in remote mountain regions are increasingly vulnerable to multiple climate mechanisms that influence levels of air pollution. Few studies have reported on climate-sensitive health outcomes unique to high altitude ecosystems. In this study, we report on the discovery of high-surface ozone concentrations and the potential impact on health outcomes on Mount Everest and the high Himalaya.

  15. Investigating cold gelation properties of recombined highly concentrated micellar casein concentrate and cream for use in cheese making.

    PubMed

    Lu, Y; McMahon, D J; Vollmer, A H

    2016-07-01

    Highly concentrated micellar casein concentrate (HC-MCC), a potential ingredient for cheese making, contains ~20% casein with ~70% of serum proteins removed by microfiltration and diafiltration of skim milk, followed by vacuum evaporation. Our objective was to investigate cold gelation properties of recombined concentrated milk (RCM) by mixing thawed frozen HC-MCC and cream under different casein levels, pH, and protein-to-fat ratios, and with addition of sodium citrate or calcium. The HC-MCC was recombined with cream using low shear at 50°C for 30 min, and rheological measurements were conducted. Cold-gelling temperature [the temperature at which storage modulus (G')=loss modulus (G″)] was linearly correlated with casein levels from 8.6 to 11.5% (R(2)=0.71), pH from 6.6 to 7.0 (R(2)=0.96), and addition of sodium citrate from 0 to 0.36mmol/g of casein (R(2)=0.80). At pH 7.0, gelation occurred at 12, 26, and 38°C with 9, 10, and 11% casein, respectively. At pH 6.6, 6.8, and 7.0, RCM with 12% casein gelled at a mean temperature of 12, 26, and 37°C, respectively. Adding calcium chloride at 0.17mmol/g of casein significantly increased cold-gelling temperature from 18 to ≥50°C, whereas no significant change was observed at levels up to 0.12mmol/g of casein. Different protein to fat ratios ranging from 0.8 to 1.2 did not significantly influence gelling temperature. In transmission electron micrographs of RCM with 12% casein, casein micelles were nonspherical and partially dissociated into small protein strands. Upon addition of calcium chloride at 0.21mmol/g of casein, casein micelles were more spherical and retained colloidal structure with the presence of aggregated casein micelles. These gelation processes of RCM with or without addition of trisodium citrate were both reversible. We propose that cold gelation of RCM occurs when protein strands that have been partially released from the casein micelles entangle, restrict their mobility, and form a fine

  16. A High-Efficiency Refractive Secondary Solar Concentrator for High Temperature Solar Thermal Applications

    NASA Technical Reports Server (NTRS)

    Piszczor, Michael F., Jr.; Macosko, Robert P.

    2000-01-01

    A refractive secondary solar concentrator is a non-imaging optical device that accepts focused solar energy from a primary concentrator and redirects that light, by means of refraction and total internal reflection (TIR) into a cavity where the solar energy is used for power and/or propulsion applications. This concept offers a variety of advantages compared to typical reflective secondary concentrators (or the use of no secondary at all): higher optical efficiency, minimal secondary cooling requirements, a smaller cavity aperture, a reduction of outgassing from the cavity and flux tailoring of the solar energy within the heat receiver. During the past 2 years, NASA Lewis has been aggressively developing this concept in support of the NASA Marshall Shooting Star Flight Experiment. This paper provides a brief overview of the advantages and technical challenges associated with the development of a refractive secondary concentrator and the fabrication of a working unit in support of the flight demonstration program.

  17. Paternal High Fat Diet in Rats Leads to Renal Accumulation of Lipid and Tubular Changes in Adult Offspring

    PubMed Central

    Chowdhury, Sabiha S.; Lecomte, Virginie; Erlich, Jonathan H.; Maloney, Christopher A.; Morris, Margaret J.

    2016-01-01

    Along with diabetes and obesity, chronic kidney disease (CKD) is increasing across the globe. Although some data support an effect of maternal obesity on offspring kidney, the impact of paternal obesity is unknown; thus, we have studied the effect of paternal obesity prior to conception. Male Sprague Dawley rats were fed chow diet or high fat diet (HFD) for 13–14 weeks before mating with chow-fed females. Male offspring were weaned onto chow and killed at 27 weeks for renal gene expression and histology. Fathers on HFD were 30% heavier than Controls at mating. At 27 weeks of age offspring of obese fathers weighed 10% less; kidney triglyceride content was significantly increased (5.35 ± 0.84 vs. 2.99 ± 0.47 μg/mg, p < 0.05, n = 8 litters per group. Histological analysis of the kidney demonstrated signs of tubule damage, with significantly greater loss of brush border, and increased cell sloughing in offspring of obese compared to Control fathers. Acat1, involved in entry of fatty acid for beta-oxidation, was significantly upregulated, possibly to counteract increased triglyceride storage. However other genes involved in lipid metabolism, inflammation and kidney injury showed no changes. Paternal obesity was associated with renal triglyceride accumulation and histological changes in tubules, suggesting a mild renal insult in offspring, who may be at risk of developing CKD. PMID:27563922

  18. Accumulated metabolites of hydroxybutyric acid serve as diagnostic and prognostic biomarkers of ovarian high-grade serous carcinomas

    PubMed Central

    Hilvo, Mika; de Santiago, Ines; Gopalacharyulu, Peddinti; Schmitt, Wolfgang D.; Budczies, Jan; Kuhberg, Marc; Dietel, Manfred; Aittokallio, Tero; Markowetz, Florian; Denkert, Carsten; Sehouli, Jalid; Frezza, Christian

    2016-01-01

    Ovarian cancer is a heterogeneous disease of low prevalence, but poor survival. Early diagnosis is critical for survival, but is often challenging because the symptoms of ovarian cancer are subtle and become apparent only during advanced stages of the disease. Therefore, the identification of robust biomarkers of early disease is a clinical priority. Metabolomic profiling is an emerging diagnostic tool enabling the detection of biomarkers reflecting alterations in tumor metabolism, a hallmark of cancer. In this study, we performed metabolomic profiling of serum and tumor tissue from 158 patients with high-grade serous ovarian cancer (HGSOC) and 100 control patients with benign or non-neoplastic lesions. We report metabolites of hydroxybutyric acid (HBA) as novel diagnostic and prognostic biomarkers associated with tumor burden and patient survival. The accumulation of HBA metabolites caused by HGSOC was also associated with reduced expression of succinic semialdehyde dehydrogenase (encoded by ALDH5A1), and with the presence of an epithelial-to-mesenchymal transition (EMT) gene signature, implying a role for these metabolic alterations in cancer cell migration and invasion. In conclusion, our findings represent the first comprehensive metabolomics analysis in HGSOC and propose a new set of metabolites as biomarkers of disease with diagnostic and prognostic capabilities. PMID:26685161

  19. Cinnamaldehyde supplementation prevents fasting-induced hyperphagia, lipid accumulation, and inflammation in high-fat diet-fed mice.

    PubMed

    Khare, Pragyanshu; Jagtap, Sneha; Jain, Yachna; Baboota, Ritesh K; Mangal, Priyanka; Boparai, Ravneet K; Bhutani, Kamlesh K; Sharma, Shyam S; Premkumar, Louis S; Kondepudi, Kanthi K; Chopra, Kanwaljit; Bishnoi, Mahendra

    2016-01-01

    Cinnamaldehyde, a bioactive component of cinnamon, is increasingly gaining interest for its preventive and therapeutic effects against metabolic complications like type-2 diabetes. This study is an attempt to understand the effect of cinnamaldehyde in high-fat diet (HFD)-associated increase in fasting-induced hyperphagia and related hormone levels, adipose tissue lipolysis and inflammation, and selected cecal microbial count in mice. Cinnamaldehyde, at 40 µM dose, prevented lipid accumulation and altered gene expression toward lipolytic phenotype in 3T3-L1 preadipocyte cell lines. In vivo, cinnamaldehyde coadministration prevented HFD-induced body weight gain, decreased fasting-induced hyperphagia, as well as circulating leptin and leptin/ghrelin ratio. In addition to that, cinnamaldehyde altered serum biochemical parameters related to lipolysis, that is, glycerol and free fatty acid levels. At transcriptional level, cinnamaldehyde increased anorectic gene expression in hypothalamus and lipolytic gene expression in visceral white adipose tissue. Furthermore, cinnamaldehyde also decreased serum IL-1β and inflammatory gene expression in visceral white adipose tissue. However, cinnamaldehyde did not modulate the population of selected gut microbial (Lactobacillus, Bifidibaceria, and Roseburia) count in cecal content. In conclusion, cinnamaldehyde increased adipose tissue lipolysis, decreased fasting-induced hyperphagia, normalized circulating levels of leptin/ghrelin ratio, and reduced inflammation in HFD-fed mice, which augurs well for its antiobesity role.

  20. D-psicose increases energy expenditure and decreases body fat accumulation in rats fed a high-sucrose diet.

    PubMed

    Ochiai, Masaru; Onishi, Kana; Yamada, Takako; Iida, Tetsuo; Matsuo, Tatsuhiro

    2014-03-01

    We investigated the anti-obesity effects of D-psicose by increasing energy expenditure in rats pair-fed the high-sucrose diet (HSD). Wistar rats were divided into two dietary groups: HSD containing 5% cellulose (C) and 5% d-psicose (P). The C dietary group was further subdivided into two groups: rats fed the C diet ad libitum (C-AD) and pair-fed the C diet along with those in the P group (C-PF). Resting energy expenditure during darkness and lipoprotein lipase activity in the soleus muscle were significantly higher in the P group than in the C-PF group. Serum levels of glucose, leptin and adiponectin; glucose-6-phosphate dehydrogenase activities in the liver and perirenal adipose tissue; and body fat accumulation were all significantly lower in the P group than in the C-PF group. The anti-obesity effects of D-psicose could be induced not only by suppressing lipogenic enzyme activity but also by increasing EE in rats.

  1. Korean Pine Nut Oil Attenuated Hepatic Triacylglycerol Accumulation in High-Fat Diet-Induced Obese Mice.

    PubMed

    Park, Soyoung; Shin, Sunhye; Lim, Yeseo; Shin, Jae Hoon; Seong, Je Kyung; Han, Sung Nim

    2016-01-21

    Korean pine nut oil (PNO) has been reported to influence weight gain and lipid metabolism. We examined whether PNO replacement in a high-fat diet (HFD) can ameliorate HFD-induced hepatic steatosis. Five-week-old male C57BL mice were fed control diets containing 10% of the energy from fat from PNO or soybean oil (SBO) (PC, SC) or HFDs with 45% of the energy from fat, with 10% from PNO or SBO and 35% from lard (PHFD, SHFD), for 12 weeks. Body weight gain and amount of white adipose tissue were lower in PHFD (10% and 18% lower, respectively) compared with SHFD. Hepatic triacylglycerol (TG) level was significantly lower in PHFD than the SHFD (26% lower). PNO consumption upregulated hepatic ACADL mRNA levels. The hepatic PPARG mRNA level was lower in the PC than in the SC. Expression of the sirtuin (SIRT) 3 protein in white adipose tissue was down-regulated in the SHFD and restored in the PHFD to the level in the lean control mice. SIRT 3 was reported to be upregulated under conditions of caloric restriction (CR) and plays a role in regulating mitochondrial function. PNO consumption resulted in lower body fat and hepatic TG accumulation in HFD-induced obesity, which seemed to be associated with the CR-mimetic response.

  2. Korean Pine Nut Oil Attenuated Hepatic Triacylglycerol Accumulation in High-Fat Diet-Induced Obese Mice

    PubMed Central

    Park, Soyoung; Shin, Sunhye; Lim, Yeseo; Shin, Jae Hoon; Seong, Je Kyung; Han, Sung Nim

    2016-01-01

    Korean pine nut oil (PNO) has been reported to influence weight gain and lipid metabolism. We examined whether PNO replacement in a high-fat diet (HFD) can ameliorate HFD-induced hepatic steatosis. Five-week-old male C57BL mice were fed control diets containing 10% of the energy from fat from PNO or soybean oil (SBO) (PC, SC) or HFDs with 45% of the energy from fat, with 10% from PNO or SBO and 35% from lard (PHFD, SHFD), for 12 weeks. Body weight gain and amount of white adipose tissue were lower in PHFD (10% and 18% lower, respectively) compared with SHFD. Hepatic triacylglycerol (TG) level was significantly lower in PHFD than the SHFD (26% lower). PNO consumption upregulated hepatic ACADL mRNA levels. The hepatic PPARG mRNA level was lower in the PC than in the SC. Expression of the sirtuin (SIRT) 3 protein in white adipose tissue was down-regulated in the SHFD and restored in the PHFD to the level in the lean control mice. SIRT 3 was reported to be upregulated under conditions of caloric restriction (CR) and plays a role in regulating mitochondrial function. PNO consumption resulted in lower body fat and hepatic TG accumulation in HFD-induced obesity, which seemed to be associated with the CR-mimetic response. PMID:26805879

  3. Subcellular targeting is a key condition for high-level accumulation of cellulase protein in transgenic maize seed.

    PubMed

    Hood, Elizabeth E; Love, Robert; Lane, Jeff; Bray, Jeff; Clough, Richard; Pappu, Kamesh; Drees, Carol; Hood, Kendall R; Yoon, Sangwoong; Ahmad, Atta; Howard, John A

    2007-11-01

    Ethanol from lignocellulosic biomass is being pursued as an alternative to petroleum-based transportation fuels. To succeed in this endeavour, efficient digestion of cellulose into monomeric sugar streams is a key step. Current production systems for cellulase enzymes, i.e. fungi and bacteria, cannot meet the cost and huge volume requirements of this commodity-based industry. Transgenic maize (Zea mays L.) seed containing cellulase protein in embryo tissue, with protein localized to the endoplasmic reticulum, cell wall or vacuole, allows the recovery of commercial amounts of enzyme. E1 cellulase, an endo-beta-1,4-glucanase from Acidothermus cellulolyticus, was recovered at levels greater than 16% total soluble protein (TSP) in single seed. More significantly, cellobiohydrolase I (CBH I), an exocellulase from Trichoderma reesei, also accumulated to levels greater than 16% TSP in single seed, nearly 1000-fold higher than the expression in any other plant reported in the literature. The catalytic domain was the dominant form of E1 that was detected in the endoplasmic reticulum and vacuole, whereas CBH I holoenzyme was present in the cell wall. With one exception, individual transgenic events contained single inserts. Recovery of high levels of enzyme in T2 ears demonstrated that expression is likely to be stable over multiple generations. The enzymes were active in cleaving soluble substrate.

  4. High concentrations of glucose reduce the oxidative metabolism of dog neutrophils in vitro

    PubMed Central

    2013-01-01

    Background Dogs are commonly affected by hyperglycemic conditions. Hyperglycemia compromises the immune response and favors bacterial infections; however, reports on the effects of glucose on neutrophil oxidative metabolism and apoptosis are conflicting in humans and rare in dogs. Considering the many complex factors that affect neutrophil oxidative metabolism in vivo, we investigated in vitro the specific effect of high concentrations of glucose on superoxide production and apoptosis rate in neutrophils from healthy dogs. Results The capacity of the neutrophils to reduce tetrazolium nitroblue decreased significantly in the higher concentration of glucose (15.13 ± 9.73% (8 mmol/L) versus 8.93 ± 5.71% (16 mmol/L)). However, there were no changes in tetrazolium nitroblue reduction at different glucose concentrations when the neutrophils were first activated with phorbol myristate acetate. High concentrations of glucose did not affect the viability and apoptosis rate of canine neutrophils either with or without prior camptothecin stimulation. This study provides the first evidence that high concentrations of glucose inhibit the oxidative metabolism of canine neutrophils in vitro in a manner similar to that which occurs in humans, and that the decrease in superoxide production did not increase the apoptosis rate. Conclusions A high concentration of glucose reduces the oxidative metabolism of canine neutrophils in vitro. It is likely that glucose at high concentrations rapidly affects membrane receptors responsible for the activation of NADPH oxidase in neutrophils; therefore, the nonspecific immune response can be compromised in dogs with acute and chronic hyperglycemic conditions. PMID:23388121

  5. Effect of TiO2 nanoparticle-accumulated bilayer photoelectrode and condenser lens-assisted solar concentrator on light harvesting in dye-sensitized solar cells

    PubMed Central

    2013-01-01

    TiO2 nanoparticles (NPs) with a size of 240 nm (T240), used as a light-scattering layer, were applied on 25-nm-sized TiO2 NPs (T25) that were used as a dye-absorbing layer in the photoelectrodes of dye-sensitized solar cells (DSSCs). In addition, the incident light was concentrated via a condenser lens, and the effect of light concentration on the capacity of the light-scattering layer was systematically investigated. At the optimized focal length of the condenser lens, T25/T240 double layer (DL)-based DSSCs with the photoactive area of 0.36 cm2 were found to have the short circuit current (Isc) of 11.92 mA, the open circuit voltage (Voc) of 0.74 V, and power conversion efficiency (PCE) of approximately 4.11%, which is significantly improved when they were compared to the T25 single layer (SL)-based DSSCs without using a solar concentrator (the corresponding values were the Isc of 2.53 mA, the Voc of 0.69, and the PCE of 3.57%). Thus, the use of the optimized light harvesting structure in the photoelectrodes of DSSCs in conjunction with light concentration was found to significantly enhance the power output of DSSCs. PMID:23758633

  6. Consumption of low doses of fat prevents the postprandial rise in chylomicron particle concentration and remnant accumulation in healthy normolipidaemic males

    PubMed Central

    James, Anthony P.; Mamo, John C.

    2012-01-01

    Chylomicron particles are continually synthesised and secreted from the intestine even in the absence of ingested fat. It is possible that following consumption of low doses of fat the basal level of chylomicron secretion and subsequent metabolism are sufficient to metabolise this fat without an increase in postprandial chylomicron concentrations. To test this hypothesis, healthy male subjects were randomised to receive, on three separate occasions, meals containing a range of doses of fat (average 8·1–19 g) and effects on postprandial lipaemia and chylomicron concentration were determined. Furthermore, to delineate the effect on lipid-rich v. lipid-poor (remnant) forms lipid levels were also determined in a density <1·006 g/ml fraction. Following consumption of the very low dose of fat the postprandial concentration of chylomicrons was unaltered, whereas following the medium dose postprandial chylomicron concentrations were significantly increased. Interestingly, this increase was only detected in the lipid-rich chylomicron fraction, with postprandial levels of chylomicron remnants remaining unchanged. In conclusion, it appears that consumption of what would be considered low to medium doses of fat are not associated with transient postprandial increases in chylomicron remnants in healthy male subjects. PMID:25191552

  7. Ecotoxicological investigation of the effect of accumulation of PAH and possible impact of dispersant in resting high arctic copepod Calanus hyperboreus.

    PubMed

    Nørregaard, Rasmus Dyrmose; Gustavson, Kim; Møller, Eva Friis; Strand, Jakob; Tairova, Zhanna; Mosbech, Anders

    2015-10-01

    Due to high lipid content and a slow metabolism, there is a higher risk of bioaccumulation of oil compounds in Arctic than in temperate copepods. There is also a concern that the bioavailability of oil compounds is higher when oil is dispersed with dispersants. The purpose of this project was to increase the knowledge on how the use of dispersants on an oil spill may affect the passive uptake of PAHs in resting high arctic copepods using Calanus hyperboreus as a model organism. To evaluate this, resting high arctic C. hyperboreus were caught in Disko Bay at>250 meters depth, November 2013, and subsequent experimental work was initiated immediately after, at nearby Arctic Station at Disko Island Western Greenland. C. hyperboreus females were incubated in phenanthrene (111, 50 and 10 nM), pyrene (57, 28 and 6 nM) and benzo(a) pyrene (10, 5 and 1 nM) for three days in treatments with and without oil (corn oil) and dispersant (AGMA DR372). After exposure, the highest measured concentrations of respectively phenanthrene, pyrene and benzo(a) pyrene in the copepods were 129, 30 and 6 nmol PAH g female(-1). Results showed that with addition of oil and dispersant to the water, the accumulation of PAH was significantly reduced, due to the deposition of the PAHs in the oil phase, decreasing the available PAHs for copepod uptake. While PAH metabolites and a depuration of the PAHs were observed, the copepods still contained PAHs after 77 days of incubation in clean seawater. Differences of treatments with and without oil and dispersant on the egg production were not statistically conclusive, although it is the most likely an effect of the highly variable day-to-day egg production between individual copepods. Equally, although there was an indication that the addition of dispersant and oil increased the mortality rate, there was no statistical difference.

  8. Concentration influences on recovery in a high gradient magnetic separation axial filter

    SciTech Connect

    Murariu, V.; Rezlescu, N.; Rotariu, O.; Badescu, V.

    1998-05-01

    The buildup differential equations for the case of a single wire in high gradient magnetic filtration (HGMF)-axial configuration taking into account the suspension concentration are solved. A new equation for the deposit contour surface at different moments and for different suspension concentrations are obtained. The existence of a particulate suspension concentration, for which the radial extension velocity of deposit is maximum, is evidenced. The recovery for an ordered ferromagnetic matrix is calculated. The influence of the solid particle concentration from suspension on the filtration efficiency is presented.

  9. Differences in nitrite-oxidizing communities and kinetics in a brackish environment after enrichment at low and high nitrite concentrations.

    PubMed

    Tangkitjawisut, Wipasanee; Limpiyakorn, Tawan; Powtongsook, Sorawit; Pornkulwat, Preeyaporn; Suwannasilp, Benjaporn Boonchayaanant

    2016-04-01

    Nitrite accumulation in shrimp ponds can pose serious adverse effects to shrimp production and the environment. This study aims to develop an effective process for the enrichment of ready-to-use nitrite-oxidizing bacteria (NOB) inocula that would be appropriate for nitrite removal in brackish shrimp ponds. To achieve this objective, the effects of nitrite concentrations on NOB communities and nitrite oxidation kinetics in a brackish environment were investigated. Moving-bed biofilm sequencing batch reactors and continuous moving-bed biofilm reactors were used for the enrichment of NOB at various nitrite concentrations, using sediment from brackish shrimp ponds as seed inoculum. The results from NOB population analysis with quantitative polymerase chain reaction (qPCR) show that only Nitrospira were detected in the sediment from the shrimp ponds. After the enrichment, both Nitrospira and Nitrobacter coexisted in the reactors controlling effluent nitrite at 0.1 and 0.5 mg-NO2(-)-N/L. On the other hand, in the reactors controlling effluent nitrite at 3, 20, and 100 mg-NO2(-)-N/L, Nitrobacter outcompeted Nitrospira in many orders of magnitude. The half saturation coefficients (Ks) for nitrite oxidation of the enrichments at low nitrite concentrations (0.1 and 0.5 mg-NO2(-)-N/L) were in the range of 0.71-0.98 mg-NO2(-)-N/L. In contrast, the K(s) values of NOB enriched at high nitrite concentrations (3, 20, and 100 mg-NO2(-)-N/L) were much higher (8.36-12.20 mg-NO2(-)-N/L). The results suggest that the selection of nitrite concentrations for the enrichment of NOB inocula can significantly influence NOB populations and kinetics, which could affect the effectiveness of their applications in brackish shrimp ponds.

  10. Triglyceride accumulation and fatty acid profile changes in Chlorella (Chlorophyta) during high pH-induced cell cycle inhibition

    SciTech Connect

    Guckert, J.B.; Cooksey, K.E. )

    1990-03-01

    Alkaline pH stress resulted in triglyceride (TG) accumulation in Chlorella CHLOR1 and was independent of medium nitrogen or carbon levels. Based on morphological observations, alkaline pH inhibited autospore release, thus increasing the time for cell cycle completion. Autospore release has been postulated to coincide with TG utilization within the microalgal cell division cycle. The alkaline pH stress affected lipid accumulation by inhibiting the cell division cycle prior to autospore release and, therefore, prior to TG utilization. Cells inhibited in this manner showed an increase in TG accumulation but a decrease in both membrane lipid classes (glycolipid and polar lipid). Unlike TG fatty acid profiles, membrane lipid fatty acid profiles were not stable during TG accumulation. The membrane profiles became similar to the TG, i.e. less unsaturated than in the membrane lipids of unstressed control cells.

  11. [Evaluation of penicillin expandase mutants and complex substrate inhibition characteristics at high concentrations of penicillin G].

    PubMed

    Wu, Linjun; Fan, Keqiang; Ji, Junjie; Yang, Keqian

    2015-12-01

    Penicillin expandase, also known as deacetoxycephalosporin C synthase (DAOCS), is an essential enzyme involved in cephalosporin C biosynthesis. To evaluate the catalytic behaviors of penicillin expandase under high penicillin G concentration and to identify mutants suitable for industrial applications, the specific activities of wild-type DAOCS and several mutants with increased activities toward penicillin G were determined by HPLC under high penicillin G concentrations. Their specific activity profiles were compared with theoretical predictions by different catalytic dynamics models. We evaluated the specific activities of wild-type DAOCS and previous reported high-activity mutants H4, H5, H6 and H7 at concentrations ranging from 5.6 to 500 mmol/L penicillin G. The specific activities of wild-type DAOCS and mutant H4 increased as penicillin G concentration increased, but decreased when concentrations of substrate go above 200 mmol/L. Other mutants H5, H6 and H7 showed more complex behaviors under high concentration of penicillin G. Among all tested enzymes, mutant H6 showed the highest activity when concentration of penicillin G is above 100 mmol/L. Our results revealed that the substrate inhibition to wild-type DAOCS' by penicillin G is noncompetitive. Other DAOCS mutants showed more complex trends in their specific activities at high concentration of penicillin G (>100 mmol/L), indicating more complex substrate inhibition mechanism might exist. The substrate inhibition and activity of DAOCS mutants at high penicillin G concentration provide important insight to help select proper mutants for industrial application.

  12. Two-phase partitioning bioreactor for the biodegradation of high concentrations of pentachlorophenol using Sphingobium chlorophenolicum DSM 8671.

    PubMed

    Zilouei, Hamid; Guieysse, Benoit; Mattiasson, Bo

    2008-08-01

    An organic-aqueous two-liquid-phase partitioning system was developed to degrade high concentrations of pentachlorophenol (PCP). Dioctyl sebacate was selected among 12 non-aqueous phases as the most suitable solvent to control the delivery of PCP to the aqueous phase for being non-biodegradable and biocompatible. In shake-flask experiments, the two-phase system was able to support the removal of 1g PCP l(-1) of total liquid phase. The performance of the two-liquid phase partitioning system (TLPPS) in shake-flask was evaluated under different conditions. At the initial biomass concentrations of 7, 25, and 58 mg dry weight l(-1), the volumetric removal rates of PCP obtained were 25.7+/-0.5, 32.1+/-0.1, and 39.3+/-2.9 mg PCP l(-1)h(-1), respectively. Higher performance was observed at lower organic-aqueous phase ratios (16% and 28%) than higher ones (37% and 44%). In a 2-l TLPPS, the degradation of 10 g PCP was completed in less than 100 h at a total volumetric rate of 142 mg l(-1) h(-1). Kinetics study using Monod model showed that compared to monophasic systems, the biphasic system significantly enhanced the maximum specific growth rate and PCP removal rate. Results of this biphasic system showed no accumulation of unknown by-product(s) which has been reported for physical-pretreatment or high-performance biphasic systems of PCP degradation.

  13. Nanoscale Analyses of High-Nickel Concentration Martensitic High-Strength Steels

    NASA Astrophysics Data System (ADS)

    Isheim, Dieter; Hunter, Allen H.; Zhang, Xian J.; Seidman, David N.

    2013-07-01

    Austenite reversion in martensitic steels is known to improve fracture toughness. This research focuses on characterizing mechanical properties and the microstructure of low-carbon, high-nickel steels containing 4.5 and 10 wt pct Ni after a QLT-type austenite reversion heat treatment: first, martensite is formed by quenching ( Q) from a temperature in the single-phase austenite field, then austenite is precipitated by annealing in the upper part of the intercritical region in a lamellarization step ( L), followed by a tempering ( T) step at lower temperatures. For the 10 wt pct Ni steel, the tensile strength after the QLT heat treatment is 910 MPa (132 ksi) at 293 K (20 °C), and the Charpy V-notch impact toughness is 144 J (106 ft-lb) at 188.8 K (-84.4 °C, -120 °F). For the 4.5 wt pct Ni steel, the tensile strength is 731 MPa (106 ksi) at 293 K (20 °C) and the impact toughness is 209 J (154 ft-lb) at 188.8 K (-84.4 °C, -120 °F). Light optical microscopy, scanning electron and transmission electron microscopies, synchrotron X-ray diffraction, and local-electrode atom-probe tomography (APT) are utilized to determine the morphologies, volume fractions, and local chemical compositions of the precipitated phases with sub-nanometer spatial resolution. The austenite lamellae are up to 200 nm in thickness, and up to several micrometers in length. In addition to the expected partitioning of Ni to austenite, APT reveals a substantial segregation of Ni at the austenite/martensite interface with concentration maxima of 10 and 23 wt pct Ni for the austenite lamellae in the 4.5 and 10 wt pct Ni steels, respectively. Copper-rich and M2C-type metal carbide precipitates were detected both at the austenite/martensite interface and within the bulk of the austenite lamellae. Thermodynamic phase stability, equilibrium compositions, and volume fractions are discussed in the context of Thermo-Calc calculations.

  14. High-accuracy measurements of N2O concentration and isotopic composition of low and high concentration samples with small volume injections using Cavity Ring-Down Spectroscopy

    NASA Astrophysics Data System (ADS)

    Saad, Nabil; Palmer, Melissa; Huang, Kuan

    2015-04-01

    Nitrous oxide (N2O) gas is among the major contributors to global warming and ozone depletion in stratosphere. Quantitative estimate of N2O production in various pathways and N2O fluxes across different reservoirs is the key to understanding the role of N2O in the global change. To achieve this goal, accurate and concurrent measurement of both N2O concentration ([N2O]) and its associated isotopic ratios (δ 15Nα , δ 15{N}β & δ 18O) is desired. Recent developments in Cavity Ring-Down Spectroscopy (CRDS) have enabled high-precision measurements of [N2O] and Site-Preference-δ 15N (SP-δ 15N) and δ 18O of a continuous gas flow. However, many N2O samples are discrete with limited volume ( 2 ppm), and are not suitable for direct continuous measurements by CRDS. Here we present results of a small sample introduction and handling device, labelled as Small Sample Isotope Module (SSIM), coupled to and automatically coordinated with a Picarro isotopic N2O CRDS analyzer to handle and measure high concentration and/or small volume samples. The SSIM requires 20 ml of sample volume per analysis at STP, and transfers the sample to the CRDS for high-precision concentration and isotope ratio measurements. When the injected sample is

  15. Impaired clearance of accumulated lysosomal glycogen in advanced Pompe disease despite high-level vector-mediated transgene expression

    PubMed Central

    Sun, Baodong; Zhang, Haoyue; Bird, Andrew; Li, Songtao; Young, Sarah P.; Koeberl, Dwight D.

    2013-01-01

    Background Infantile-onset glycogen storage disease type II (GSD-II; Pompe disease; MIM 232300) causes death early in childhood from cardiorespiratory failure in absence of effective treatment, whereas late-onset Pompe disease causes a progressive skeletal myopathy. The limitations of enzyme replacement therapy could potentially be addressed with adeno-associated virus (AAV) vector-mediated gene therapy. Methods AAV vectors containing tissue-specific regulatory cassettes, either liver-specific or muscle-specific, were administered to 12 and 17 month old Pompe disease mice to evaluate the efficacy of gene therapy in advanced Pompe disease. Biochemical correction was evaluated through GAA activity and glycogen content analyses of the heart and skeletal muscle. Western blotting, urinary biomarker, and Rotarod performance were evaluated following vector administration. Results The AAV vector containing the liver-specific regulatory cassette secreted high-level hGAA into the blood and corrected glycogen storage in the heart and diaphragm. The biochemical correction of the heart and diaphragm was associated with efficacy, as reflected by increased Rotarod performance; however, the clearance of glycogen from skeletal muscles was relatively impaired, in comparison with younger Pompe disease mice. An alternative vector containing a muscle-specific regulatory cassette transduced skeletal muscle with high efficiency, but also failed to achieve complete clearance of accumulated glycogen. Decreased transduction of the heart and liver in older mice, especially in females, was implicated as a cause for reduced efficacy in advanced Pompe disease. Conclusion The impaired efficacy of AAV vector-mediated gene therapy in old Pompe disease mice emphasized the need for early treatment to achieve full efficacy. PMID:19621331

  16. High Silicon Accumulation in the Shoot is Required for Down-Regulating the Expression of Si Transporter Genes in Rice.

    PubMed

    Mitani-Ueno, Namiki; Yamaji, Naoki; Ma, Jian Feng

    2016-12-01

    Rice requires high silicon (Si) for its high and sustainable yield. The efficient uptake of Si in rice is mediated by two transporters OsLsi1 and OsLsi2, which function as influx and efflux transporters, respectively. Our previous studies showed that the mRNA expression levels of these transporter genes were down-regulated by Si. Herein we investigated the mechanism underlying regulation of OsLsi1 and OsLsi2 expression. There was a negative correlation between the expression level of OsLsi1 and OsLsi2 and shoot Si accumulation when the rice seedlings were exposed to different Si supply conditions. A split root experiment showed that the expression of both OsLsi1 and OsLsi2 was also down-regulated in half the roots without direct Si exposure when the other half of the roots were exposed to Si. Analysis with transgenic rice carrying different lengths of OsLsi1 promoter regions fused with green fluorescent protein (GFP) as a reporter gene revealed that the region responsible for the Si response of OsLsi1 expression is present between -327 to -292 in the promoter. However, this region was not associated with the tissue and cellular localization of OsLsi1. In conclusion, the Si-induced down-regulation of Si transporter genes is controlled by shoot Si, not root Si, and the region between -327 and -292 in the OsLsi1 promoter is involved in this regulation of OsLsi1 expression in rice.

  17. Mature-stem expression of a silencing-resistant sucrose isomerase gene drives isomaltulose accumulation to high levels in sugarcane.

    PubMed

    Mudge, Stephen R; Basnayake, Shiromi W V; Moyle, Richard L; Osabe, Kenji; Graham, Michael W; Morgan, Terence E; Birch, Robert G

    2013-05-01

    Isomaltulose (IM) is a natural isomer of sucrose. It is widely approved as a food with properties including slower digestion, lower glycaemic index and low cariogenicity, which can benefit consumers. Availability is currently limited by the cost of fermentative conversion from sucrose. Transgenic sugarcane plants with developmentally-controlled expression of a silencing-resistant gene encoding a vacuole-targeted IM synthase were tested under field conditions typical of commercial sugarcane cultivation. High yields of IM were obtained, up to 483 mm or 81% of total sugars in whole-cane juice from plants aged 13 months. Using promoters from sugarcane to drive expression preferentially in the sugarcane stem, IM levels were consistent between stalks and stools within a transgenic line and across consecutive vegetative field generations of tested high-isomer lines. Germination and early growth of plants from setts were unaffected by IM accumulation, up to the tested level around 500 mm in flanking stem internodes. These are the highest yields ever achieved of value-added materials through plant metabolic engineering. The sugarcane stem promoters are promising for strategies to achieve even higher IM levels and for other applications in sugarcane molecular improvement. Silencing-resistant transgenes are critical to deliver the potential of these promoters in practical sugarcane improvement. At the IM levels now achieved in field-grown sugarcane, direct production of IM in plants is feasible at a cost approaching that of sucrose, which should make the benefits of IM affordable on a much wider scale.

  18. Physical strength in boys with different levels of fat accumulation and BMI: report on South Korean junior high school boys.

    PubMed

    Tanakal, Nozomi; Fujii, Katsunori

    2012-12-01

    The figpurpose of this study was to investigate the evaluation of differences in morphological qualities in physical strength of South Korean junior high school boys. The subjects were 201 first-year junior high school boys (13.6 +/- 0.3 years, 59.0 +/- 12.8 kg, 163.1 +/- 7.4 cm, in whom height, weight, BMI, fat mass, body fat percentage and soft lean mass were measured. Items of physical strength measured were the sit and reach, 20-m shuttle run, push-ups, and sit-ups. Morphological quality was judged from two aspects, a BMI evaluation of obesity or leanness and an evaluation of the level of fat accumulation derived from regression polynomials of body fat percentage against BMI. The subjects were classified into 9 groups according to differences in morphological quality. Of the physical measurement items, boys with underdevelopment of fat in the BMI slim and normal groups showed superior results in the 20-m shuttle run, push-ups and sit-ups. In contrast, boys with overdevelopment of fat in the BMI fatty group showed significantly poorer results in these items. Meanwhile, boys with underdevelopment of fat in the BMI fatty group showed a level comparable to boys in the BMI normal and excessive fat groups in the 20-m shuttle run; boys with normal and excessive fat in the BMI normal group and boys with excessive fat in the BMI slim group in push-ups; and boys with underdevelopment of fat in the BMI slim group in sit-ups. Performance in these measurements was evaluated in detail for boys with different morphological qualities, and multiple considerations from the two aspects of physique and physical composition may be necessary to evaluate the physical strength of students in each grade.

  19. Inhibitory effect of high concentrations of ferric ions on the activity of Acidithiobacillus ferrooxidans.

    PubMed

    Kawabe, Yoshishige; Inoue, Chihiro; Suto, Koichi; Chida, Tadashi

    2003-01-01

    The influence of high concentrations of ferric ions on the biochemical activity of Acidithiobacillus ferrooxidans was studied using intact cells. The specific oxidation rate of ferrous ions decreased with increasing ferric ion concentration. Lineweaver-Burk plots revealed typical competitive inhibition kinetics, because the slopes varied with the ferric ion concentration. A linear relationship between the slope and the square of the ferric ion concentration revealed that the iron-oxidizing enzyme system of A. ferrooxidans was competitively inhibited by about two molecules of ferric ion. The kinetic equation based on this inhibition model agreed with the experimental observation at a high ferric ion concentration where the bacterium is usually exposed in bioleaching and biooxidation plants.

  20. Incomplete ion dissociation underlies the weakened attraction between DNA helices at high spermidine concentrations.

    PubMed

    Yang, Jie; Rau, Donald C

    2005-09-01

    We have investigated the salt sensitivity of the hexagonal-to-cholesteric phase transition of spermidine-condensed DNA. This transition precedes the resolubilization of precipitated DNA that occurs at high spermidine concentration. The sensitivity of the critical spermidine concentration at the transition point to the anion species and the NaCl concentration indicates that ion pairing of this trivalent ion underlies this unusual transition. Osmotic pressure measurements of spermidine salt solutions are consistent with this interpretation. Spermidine salts are not fully dissociated at higher concentrations. The competition for DNA binding among the fully charged trivalent ion and the lesser charged complex species at higher concentrations significantly weakens attraction between DNA helices in the condensed state. This is contrary to the suggestion that the binding of spermidine at higher concentrations causes DNA overcharging and consequent electrostatic repulsion.

  1. 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

  2. Stable, concentrated solutions of high molecular weight polyaniline and articles therefrom

    DOEpatents

    Mattes, Benjamin R.; Wang, Hsing-Lin

    2000-01-01

    Stable, concentrated solutions of high molecular weight polyaniline. In order to process high quality fibers and other articles possessing good mechanical properties, it is known that solution concentrations of the chosen polymer should be in the range from 15-30% (w/w). Moreover, it is desirable to use the highest molecular weight consistent with the solubility properties of the polymer. However, such solutions are inherently unstable, forming gels before processing can be achieved. The present invention describes the addition gel inhibitors (GIs) to the polymer solution, thereby permitting high concentrations (>15% (w/w)) of high molecular weight ((M.sub.w)>120,000, and (M.sub.n)>30,000) emeraldine base (EB) polyaniline to be dissolved. Secondary amines have been used for this purpose in concentrations which are small compared to those which might otherwise be used in a cosolvent role therefor. The resulting solutions are useful for generating excellent fibers, films, coatings and other objects, since the solutions are stable for significant time periods, and the GIs are present in too small concentrations to cause polymer deterioration. It is demonstrated that the GIs found to be useful do not act as cosolvents, and that gelation times of the solutions are directly proportional to the concentration of GI. In particular, there is a preferred concentration of GI, which if exceeded causes structural and electrical conductivity degradation of resulting articles. Heating of the solutions significantly improves solubility.

  3. Stable, concentrated solutions of high molecular weight polyaniline and articles therefrom

    DOEpatents

    Mattes, Benjamin R.; Wang, Hsing-Lin

    1999-11-09

    Stable, concentrated solutions of high molecular weight polyaniline. In order to process high quality fibers and other articles possessing good mechanical properties, it is known that solution concentrations of the chosen polymer should be in the range from 15-30% (w/w). Moreover, it is desirable to use the highest molecular weight consistent with the solubility properties of the polymer. However, such solutions are inherently unstable, forming gels before processing can be achieved. The present invention describes the addition gel inhibitors (GIs) to the polymer solution, thereby permitting high concentrations (between 15% and 30% (w/w)) of high molecular weight ((M.sub.w)>120,000, and (M.sub.n)>30,000) emeraldine base (EB) polyaniline to be dissolved. Secondary amines have been used for this purpose in concentrations which are small compared to those which might otherwise be used in a cosolvent role therefor. The resulting solutions are useful for generating excellent fibers, films, coatings and other objects, since the solutions are stable for significant time periods, and the GIs are present in too small concentrations to cause polymer deterioration. It is demonstrated that the GIs found to be useful do not act as cosolvents, and that gelation times of the solutions are directly proportional to the concentration of GI. In particular, there is a preferred concentration of GI, which if exceeded causes structural and electrical conductivity degradation of resulting articles. Heating of the solutions significantly improves solubility.

  4. Metals and metalloids in fruits of tomatoes (Solanum lycopersicum) and their cultivation soils in the Basque Country: concentrations and accumulation trends.

    PubMed

    Rodriguez-Iruretagoiena, Azibar; Trebolazabala, Josu; Martinez-Arkarazo, Irantzu; de Diego, Alberto; Madariaga, Juan Manuel

    2015-04-15

    The concentrations of several elements (Al, Fe, As, Cu, Cd, Co, Cr, Mn, Ni, Pb, Sn, V, and Zn) were measured in soils and the edible part of different vegetables (tomatoes (Solanum lycopersicum "Raf") peppers (Capsicum annuum), chards (Betavulgaris var. cicla), artichokes (Cynarascholymus)) and fruits (Raspberries (Rubusidaeus)) from 13 orchards in the Basque Country affected by different pollution sources. Multivariate analysis of data was used to look for possible correlations between metals in soil and metals in the edible part of the plant. Only manganese showed a correlation significantly different from zero. The metal concentrations found in the edible part were always below the upper limits recommended by the European legislation in force. The Bioaccumulation Index was used to investigate how efficient the plant is to uptake an element from the cultivation soil and to preserve its edible part from the element.

  5. Argon, oxygen, and boron isotopic evidence documenting 40ArE accumulation in phengite during water-rich high-pressure subduction metasomatism of continental crust

    NASA Astrophysics Data System (ADS)

    Menold, Carrie A.; Grove, Marty; Sievers, Natalie E.; Manning, Craig E.; Yin, An; Young, Edward D.; Ziegler, Karen

    2016-07-01

    were even older, exceeding the time of eclogite formation by a factor of 1.7. In contrast, lower pressure retrograde muscovite present within the host gneiss and in discrete shear zones cutting the selvage yield 40Ar/39Ar ages that were younger than the time of HP metamorphism and consistent with regional cooling age patterns. Our observation of high 40ArE concentrations in phengite from schistose rocks infiltrated by regionally extensive fluids at HP conditions runs contrary to widely held expectations. Conventional wisdom dictates that low phengite/fluid partition coefficients for argon (Dphg/fluid Ar =10-3to 10-5) coupled with the dry, closed systems conditions that are widely reported to characterize HP metamorphism of continental crust explains why high concentrations of 40ArE partitions are able to accumulate within phengite. We alternatively propose that phengite/fluid partition coefficients for argon increase linearly with pressure to values as high as 10-2 to allow phengites to accumulate large amounts of 40ArE from aqueous fluids under HP to UHP conditions.

  6. Improvement in high-fat diet-induced obesity and body fat accumulation by a Nelumbo nucifera leaf flavonoid-rich extract in mice.

    PubMed

    Wu, Cheng-Hsun; Yang, Mon-Yuan; Chan, Kuei-Chuan; Chung, Pei-Jun; Ou, Ting-Tsz; Wang, Chau-Jong

    2010-06-09

    Diets high in fat lead to excessive lipid accumulation in adipose tissue, which is a crucial factor in the development of obesity, hepatitis, and hyperlipidemia. In this study, we investigated the antiobesity effect of a flavonoid-enriched extract from Nelumbo nucifera leaf (NLFE) in vivo. C57BL/6 mice were fed with a high-fat diet (HFD) to induce obesity. NLFE reduced the body weight, body lipid accumulation, and activities of fatty acid synthase (FAS), glutamic oxaloacetic transaminase, and glutamic pyruvic transaminase. NLFE also suppressed the expression of FAS, acetyl-CoA carboxylase, and HMGCoA reductase and increased the phosphorylation of AMP-activated protein kinase in the liver. Taken together, we demonstrated that NLFE targets lipid-regulated enzymes and may be effective in attenuating body lipid accumulation and preventing obesity.

  7. Trace element concentrations and gastrointestinal parasites of Arctic terns breeding in the Canadian High Arctic.

    PubMed

    Provencher, J F; Braune, B M; Gilchrist, H G; Forbes, M R; Mallory, M L

    2014-04-01

    Baseline data on trace element concentrations are lacking for many species of Arctic marine birds. We measured essential and non-essential element concentrations in Arctic tern (Sterna paradisaea) liver tissue and brain tissue (mercury only) from Canada's High Arctic, and recorded the presence/absence of gastrointestinal parasites during four different phases of the breeding season. Arctic terns from northern Canada had similar trace element concentrations to other seabird species feeding at the same trophic level in the same region. Concentrations of bismuth, selenium, lead and mercury in Arctic terns were high compared to published threshold values for birds. Selenium and mercury concentrations were also higher in Arctic terns from northern Canada than bird species sampled in other Arctic areas. Selenium, mercury and arsenic concentrations varied across the time periods examined, suggesting potential regional differences in the exposure of biota to these elements. For unknown reasons, selenium concentrations were significantly higher in birds with gastrointestinal parasites as compared to those without parasites, while bismuth concentrations were higher in Arctic terns not infected with gastrointestinal parasites.

  8. Exercise duration and blood lactate concentrations following high intensity cycle ergometry.

    PubMed

    Baker, Julien S; Thomas, Non; Cooper, Steve M; Davies, Bruce; Robergs, Robert A

    2012-04-01

    The aim of this study was to investigate differences in blood lactate accumulation following 10 and 20 sec of maximal cycle ergometer exercise. Body mass, stature, and age of the group was determined prior to testing (82.57 ± 5.94 kg 177 ± 5.94 cm and 21.42 ± 1.61 yrs, respectively). Eight male rugby union players performed two maximal sprints in a random fashion of 10 and 20 sec duration on a cycle ergometer. During the 10 and 20 sec trial, blood lactate levels measured were as follows 1.58 ± 0.78, 4.43 ± 1.4, and 3.5 ± 1.2 mmol.l⁻¹ vs. 1.72 ± 0.65, 6.14 ± 2, and 5.68 ± 2.22 mmol.l⁻¹, respectively. Differences were found (P < 0.01) from rest to 5 and 10 min postexercise in both groups. Differences in concentration also were found between groups at both postexercise stages (P < 0.01). The reduction in blood lactate concentrations observed between the 5 to 10 min recovery stages were 0.91 ± 0.58 mmol.l⁻¹ vs. 0.46 ± 0.48 mmol.l⁻¹ following 10 and 20 sec of maximal exercise, respectively (P > 0.05). The concentrations observed are interesting and may influence recovery time and subsequent exercise performance.

  9. Ferric citrate decreases ruminal hydrogen sulphide concentrations in feedlot cattle fed diets high in sulphate.

    PubMed

    Drewnoski, Mary E; Doane, Perry; Hansen, Stephanie L

    2014-01-28

    Dissimilatory reduction of sulphate by sulphate-reducing bacteria in the rumen produces sulphide, which can lead to a build-up of the toxic gas hydrogen sulphide (H2S) in the rumen when increased concentrations of sulphate are consumed by ruminants. We hypothesised that adding ferric Fe would competitively inhibit ruminal sulphate reduction. The effects of five concentrations and two sources (ferric citrate or ferric ammonium citrate) of ferric Fe were examined in vitro (n 6 per treatment). Rumen fluid was collected from a steer that was adapted to a high-concentrate, high-sulphate diet (0·51 % S). The addition of either source of ferric Fe decreased (P< 0·01) H2S concentrations without affecting gas production (P= 0·38), fluid pH (P= 0·80) or in vitro DM digestibility (P= 0·38) after a 24 h incubation. An in vivo experiment was conducted using eight ruminally fistulated steers (543 (sem 12) kg) in a replicated Latin square with four periods and four treatments. The treatments included a high-concentrate, high-sulphate control diet (0·46 % S) or the control diet plus ferric ammonium citrate at concentrations of 200, 300 or 400 mg Fe/kg diet DM. The inclusion of ferric Fe did not affect DM intake (P= 0·21). There was a linear (P< 0·01) decrease in the concentration of ruminal H2S as the addition of ferric Fe concentrations increased. Ferric citrate appears to be an effective way to decrease ruminal H2S concentrations, which could allow producers to safely increase the inclusion of ethanol co-products.

  10. Ginger Essential Oil Ameliorates Hepatic Injury and Lipid Accumulation in High Fat Diet-Induced Nonalcoholic Fatty Liver Disease.

    PubMed

    Lai, Yi-Syuan; Lee, Wan-Ching; Lin, Yu-En; Ho, Chi-Tang; Lu, Kuan-Hung; Lin, Shih-Hang; Panyod, Suraphan; Chu, Yung-Lin; Sheen, Lee-Yan

    2016-03-16

    The objective of this study was to investigate the hepatoprotective efficacy and mechanism of action of ginger essential oil (GEO) against the development of nonalcoholic fatty liver disease (NAFLD). Mice were maintained on either a control diet or high-fat diet (HFD) supplemented with GEO (12.5, 62.5, and 125 mg/kg) or citral (2.5 and 25 mg/kg) for 12 weeks. We demonstrated that GEO and its major component (citral) lowered HFD-induced obesity in a dose-dependent manner, accompanied by anti-hyperlipidemic effects by reducing serum free fatty acid, triglyceride, and total cholesterol levels. Moreover, liver histological results showed that administration of 62.5 and 125 mg/kg GEO and 25 mg/kg citral significantly reduced hepatic lipid accumulation. Further assessment by Western blotting and investigation of the lipid metabolism revealed that hepatic protein expression of sterol regulatory element-binding protein-1c (SREBP-1c), acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), and cytochrome P450 2E1 (CYP2E1) were down-regulated by GEO and citral, indicating that GEO and citral suppressed HFD-stimulated lipid biosynthesis and oxidative stress. Furthermore, GEO and citral effectively enhanced the antioxidant capacities and reduced inflammatory response in mouse liver, which exerted protective effects against steatohepatitis. Collectively, GEO and citral exhibited potent hepatoprotective effects against NAFLD induced by HFD in obese mice. Thus, GEO might be an effective dietary supplement to ameliorate NAFLD-related metabolic diseases, and citral could play a vital role in its management.

  11. Physiological differences in response to di-n-butyl phthalate (DBP) exposure between low- and high-DBP accumulating cultivars of Chinese flowering cabbage (Brassica parachinensis L.).

    PubMed

    Zhao, Hai-Ming; Du, Huan; Xiang, Lei; Li, Yan-Wen; Li, Hui; Cai, Quan-Ying; Mo, Ce-Hui; Cao, Gang; Wong, Ming-Hung

    2016-01-01

    To increase understanding on the mechanisms of cultivar difference in contaminant accumulation in crops, this study was designed to compare the physiological responses to di-n-butyl phthalate (DBP) exposure between low (Lvbao70) and high (Huaguan) DBP cultivars of Chinese flowering cabbage (Brassica parachinensis L.). Under high DBP exposure, significant differences in various physiological responses were observed between the two cultivars, which might account for the variation in DBP accumulation. Ultrastructure observation also showed different alterations or damages in the mesophyll cell structures between both cultivars, especially for the chloroplast disintegration, starch grain quantity, and plastoglobuli accumulation. Compared with Huaguan, Lvbao70 suffered greater decreases in biomass, chlorophyll content, carbon assimilation, gas exchange parameters, photosynthetic electron transport capacity, and antioxidase activities, which would have resulted in a great reduction of photosynthetic capacity. Although Lvbao70 enhanced energy dissipation and activities of some antioxidant enzymes, they did not provide sufficient protection against oxidative damage caused by DBP. The result suggested that the lower DBP tolerance of Lvbao70 might be associated with its poor physiological performances, which was responsible for its lower DBP accumulation to protect itself from toxicity. Additionally, Lvbao70 had a significantly lower transpiration rate and stomatal conductance than Huaguan, which might be the factors regulating DBP-accumulation variation.

  12. Spatiotemporal models for predicting high pollen concentration level of Corylus, Alnus, and Betula

    NASA Astrophysics Data System (ADS)

    Nowosad, Jakub

    2016-06-01

    Corylus, Alnus, and Betula trees are among the most important sources of allergic pollen in the temperate zone of the Northern Hemisphere and have a large impact on the quality of life and productivity of allergy sufferers. Therefore, it is important to predict high pollen concentrations, both in time and space. The aim of this study was to create and evaluate spatiotemporal models for predicting high Corylus, Alnus, and Betula pollen concentration levels, based on gridded meteorological data. Aerobiological monitoring was carried out in 11 cities in Poland and gathered, depending on the site, between 2 and 16 years of measurements. According to the first allergy symptoms during exposure, a high pollen count level was established for each taxon. An optimizing probability threshold technique was used for mitigation of the problem of imbalance in the pollen concentration levels. For each taxon, the model was built using a random forest method. The study revealed the possibility of moderately reliable prediction of Corylus and highly reliable prediction of Alnus and Betula high pollen concentration levels, using preprocessed gridded meteorological data. Cumulative growing degree days and potential evaporation proved to be two of the most important predictor variables in the models. The final models predicted not only for single locations but also for continuous areas. Furthermore, the proposed modeling framework could be used to predict high pollen concentrations of Corylus, Alnus, Betula, and other taxa, and in other countries.

  13. Spatiotemporal models for predicting high pollen concentration level of Corylus, Alnus, and Betula.

    PubMed

    Nowosad, Jakub

    2016-06-01

    Corylus, Alnus, and Betula trees are among the most important sources of allergic pollen in the temperate zone of the Northern Hemisphere and have a large impact on the quality of life and productivity of allergy sufferers. Therefore, it is important to predict high pollen concentrations, both in time and space. The aim of this study was to create and evaluate spatiotemporal models for predicting high Corylus, Alnus, and Betula pollen concentration levels, based on gridded meteorological data. Aerobiological monitoring was carried out in 11 cities in Poland and gathered, depending on the site, between 2 and 16 years of measurements. According to the first allergy symptoms during exposure, a high pollen count level was established for each taxon. An optimizing probability threshold technique was used for mitigation of the problem of imbalance in the pollen concentration levels. For each taxon, the model was built using a random forest method. The study revealed the possibility of moderately reliable prediction of Corylus and highly reliable prediction of Alnus and Betula high pollen concentration levels, using preprocessed gridded meteorological data. Cumulative growing degree days and potential evaporation proved to be two of the most important predictor variables in the models. The final models predicted not only for single locations but also for continuous areas. Furthermore, the proposed modeling framework could be used to predict high pollen concentrations of Corylus, Alnus, Betula, and other taxa, and in other countries.

  14. Relationship between valve activity, microalgae concentration in the water and toxin accumulation in the digestive gland of the Pacific oyster Crassostrea gigas exposed to Alexandrium minutum.

    PubMed

    Haberkorn, Hansy; Tran, Damien; Massabuau, Jean-Charles; Ciret, Pierre; Savar, Véronique; Soudant, Philippe

    2011-06-01

    The complexity of the relationships between Alexandrium minutum (A.m.) concentration in the water ([A.m.](w)), Paralytic Shellfish Poisoning contamination in the digestive gland ([PSP](dg)) and valve behavior was explored in oysters Crassostrea gigas. Two experiments were conducted, during which oysters' valve behaviour were analyzed. Oysters, first acclimated for 10-days with the non harmful microalgae Heterocapsa triquetra (H.t.), were exposed to four microalgae mixtures at constant total concentrations of 10×10(3)cells ml(-1) (experiment-1) and 5×10(3)cells ml(-1) (experiment-2): 100% A.m.; 50% A.m.-50% H.t.; 25% A.m.-75% H.t.; 100% H.t. At the end of experiment-2, [PSP](dg) were measured. At 10×10(3)cells ml(-1), the microalgal ingestion decreased (p<0.05) with increasing [A.m.](w) but not at 5×10(3)cells ml(-1) (p>0.05). The frequency of microclosures specifically increased with [A.m.](w) (p<0.05) and the opening duration with [PSP](dg) (p<0.0001). Oysters exhibiting the maximum increase in opening duration also exhibited the highest [PSP](dg). The results are discussed in terms of oyster physiology and origin of the behavioral response.

  15. Concentrating and spectrum splitting optical device in high efficiency CPV module with five bandgaps

    NASA Astrophysics Data System (ADS)

    Taudien, Jerker Y.; Kern, Ludwig A.

    2013-09-01

    There is a need for a high efficiency low cost solar energy conversion system. Currently, most concentrating photovoltaic (CPV) systems concentrate the solar spectrum onto triple junction cells to strive for high conversion efficiencies and low cost. Other approaches to high efficiency use spectrum splitting. Triple junction systems are limited in efficiency and spectrum splitting systems are usually too costly for mass production. The objective is to design a spectrum splitting solar concentrator, using reverse ray tracing methods, to overcome the efficiency and cost limitations of current systems by using a single low cost optical device to concentrate and split the solar spectrum onto a large number of target photovoltaic (PV) cells. Dispersive properties of standard optical materials, such as glass or plastic, are utilized to achieve the desired spectral separation. Reverse ray tracing is used to simultaneously optimize the shape of the top and bottom interfaces of the solar concentrator to achieve the desired split spectrum at the target PV cells. Additional strategies to increase system efficiency and minimize optical losses, including draft surface shading and corner rounding losses, are explored. A CPV module, including the spectrum splitting solar concentrator and five PV cells of different bandgaps, is proposed. This spectrum splitting CPV system has a calculated aggregate cell conversion efficiency that exceeds 45%, has the potential to be mass produced, and meets the need for a high efficiency low cost solar energy conversion system.

  16. 40 CFR 52.1164 - Localized high concentrations-carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Localized high concentrations-carbon... Localized high concentrations—carbon monoxide. (a) Not later than October 1, 1975, the Commonwealth shall... quality standards for carbon monoxide. Once such localized areas have been identified, the...

  17. 40 CFR 52.1164 - Localized high concentrations-carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Localized high concentrations-carbon... Localized high concentrations—carbon monoxide. (a) Not later than October 1, 1975, the Commonwealth shall... quality standards for carbon monoxide. Once such localized areas have been identified, the...

  18. 40 CFR 52.1164 - Localized high concentrations-carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Localized high concentrations-carbon... Localized high concentrations—carbon monoxide. (a) Not later than October 1, 1975, the Commonwealth shall... quality standards for carbon monoxide. Once such localized areas have been identified, the...

  19. 40 CFR 52.1164 - Localized high concentrations-carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Localized high concentrations-carbon... Localized high concentrations—carbon monoxide. (a) Not later than October 1, 1975, the Commonwealth shall... quality standards for carbon monoxide. Once such localized areas have been identified, the...

  20. 40 CFR 52.1164 - Localized high concentrations-carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Localized high concentrations-carbon... Localized high concentrations—carbon monoxide. (a) Not later than October 1, 1975, the Commonwealth shall... quality standards for carbon monoxide. Once such localized areas have been identified, the...

  1. Highly Efficient Cpf1-Mediated Gene Targeting in Mice Following High Concentration Pronuclear Injection

    PubMed Central

    Watkins-Chow, Dawn E.; Varshney, Gaurav K.; Garrett, Lisa J.; Chen, Zelin; Jimenez, Erin A.; Rivas, Cecilia; Bishop, Kevin S.; Sood, Raman; Harper, Ursula L.; Pavan, William J.; Burgess, Shawn M.

    2016-01-01

    Cpf1 has emerged as an alternative to the Cas9 RNA-guided nuclease. Here we show that gene targeting rates in mice using Cpf1 can meet, or even surpass, Cas9 targeting rates (approaching 100% targeting), but require higher concentrations of mRNA and guide. We also demonstrate that coinjecting two guides with close targeting sites can result in synergistic genomic cutting, even if one of the guides has minimal cutting activity. PMID:28040780

  2. Highly Efficient Cpf1-Mediated Gene Targeting in Mice Following High Concentration Pronuclear Injection.

    PubMed

    Watkins-Chow, Dawn E; Varshney, Gaurav K; Garrett, Lisa J; Chen, Zelin; Jimenez, Erin A; Rivas, Cecilia; Bishop, Kevin S; Sood, Raman; Harper, Ursula L; Pavan, William J; Burgess, Shawn M

    2017-02-09

    Cpf1 has emerged as an alternative to the Cas9 RNA-guided nuclease. Here we show that gene targeting rates in mice using Cpf1 can meet, or even surpass, Cas9 targeting rates (approaching 100% targeting), but require higher concentrations of mRNA and guide. We also demonstrate that coinjecting two guides with close targeting sites can result in synergistic genomic cutting, even if one of the guides has minimal cutting activity.

  3. Carbon accumulation rates recorded in the last 150years in tropical high mountain peatlands of the Atlantic Rainforest, SE - Brazil.

    PubMed

    Lourençato, Lúcio F; Caldeira, Pedro P; Bernardes, Marcelo C; Buch, Andressa C; Teixeira, Daniel C; Silva-Filho, Emmanoel V

    2017-02-01

    Peatlands are environmental matrices that store large amounts of organic carbon (TOC) and work as records of environmental changes. Recent record of organic carbon accumulated were assessed in two Forest National Parks, Itatiaia and Serra dos Órgãos in the Southeastern of Brazil. Based on organic and inorganic characterization, the cores from peatlands presented a predominance of organic material in an advanced stage of decomposition and those soils were classified as typical Haplosaprists Histosols. The combination of favorable topographic and climatic conditions led to rapid C accumulation across coastal mountain in the tropical peatlands studied, presenting an average accumulation rate of C, in the last century, of 194gCm(-2)yr(-1) about 7 higher times than the rate found in boreal and subarctic peatlands, those higher values may be related to changes in the hydrological cycle occurred since 1950s.

  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. Influence of Southeast Asian Haze episodes on high PM10 concentrations across Brunei Darussalam.

    PubMed

    Dotse, Sam-Quarcoo; Dagar, Lalit; Petra, Mohammad Iskandar; De Silva, Liyanage C

    2016-12-01

    Particulate matter (PM10) is the key indicator of air quality index in Brunei Darussalam and the principal pollutant for haze related episodes in Southeast Asia. This study examined the temporal and spatial distribution of PM10 base on a long-term monitoring data (2009-2014) in order to identify the emission sources and favorable meteorological conditions for high PM10 concentrations across the country. PM10 concentrations measured at the various locations differ significantly but the general temporal characteristics show clear patterns of seasonal variations across the country with the highest concentrations recorded during the southwest monsoon. The high PM10 values defined in the study were not evenly distributed over the years but occurred mostly within the southwest monsoon months of June to September. Further investigations with bivariate polar concentrations plots and k-means clustering demonstrated the significant influence of Southeast Asian regional biomass fires on the high PM10 concentrations recorded across the country. The results of the polar plots and cluster analyses were further confirmed by the evaluations with Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) backward air masses trajectories analysis and the Moderate Resolution Imaging Spectroradiometer (MODIS) fire records. Among the meteorological variables considered, temperature, rainfall and relative humidity were the most important meteorological variables that influence the concentration throughout the year. High PM10 values are associated with high temperatures and low amounts of rainfall and relative humidity. In addition, wind speed and direction also play significant role in the recorded high PM10 concentrations and were mainly responsible for its seasonality during the study period.

  6. Novel bioevaporation process for the zero-discharge treatment of highly concentrated organic wastewater.

    PubMed

    Yang, Benqin; Zhang, Lei; Lee, Yongwoo; Jahng, Deokjin

    2013-10-01

    A novel process termed as bioevaporation was established to completely evaporate wastewater by metabolic heat released from the aerobic microbial degradation of the organic matters contained in the highly concentrated organic wastewater itself. By adding the glucose solution and ground food waste (FW) into the biodried sludge bed, the activity of the microorganisms in the biodried sludge was stimulated and the water in the glucose solution and FW was evaporated. As the biodegradable volatile solids (BVS) concentration in wastewater increased, more heat was produced and the water removal ratio increased. When the volatile solids (VS) concentrations of both glucose and ground FW were 120 g L(-1), 101.7% and 104.3% of the added water was removed, respectively, by completely consuming the glucose and FW BVS. Therefore, the complete removal of water and biodegradable organic contents was achieved simultaneously in the bioevaporation process, which accomplished zero-discharge treatment of highly concentrated organic wastewater.

  7. [Synthesis of high-concentration polyaluminum chloride and its aluminium species distribution and transformation].

    PubMed

    Zhao, Hua-zhang; Cai, Gu-ping; Luan, Zhao-kun

    2004-09-01

    Using solid CaO as basification agent, the high-concentration polyaluminum chloride (PAC) was prepared by feeding total alkali at a time. The characteristics of the reaction and the distribution and transformation of the aluminium species were also studied. The experimental results show that the distinctive hydration of CaO can contribute to the high-concentration PAC whose Al concentration (Al(T)) and basicity (B) can reach 2.1 mol/L and 2.1 respectively. There is an optimal B value in any concentration of PAC, at which the Al(b) content is the highest. The optimal B value and the highest Al(b) content drops with the increasing of Al(T). The predominant reaction is the formation of Al(b) if B is less than the optimal B value, and the formation of Al(c) if B is more than the optimal B value.

  8. The influence of climate change on recent peat accumulation patterns of Distichia muscoides cushion bogs in the high-elevation tropical Andes of Colombia

    NASA Astrophysics Data System (ADS)

    Benavides, Juan C.; Vitt, Dale H.; Wieder, R. Kelman

    2013-12-01

    Extensive cushions of Distichia muscoides found at high elevations in the Andes form deep deposits of peat and function as peatland. The location of Distichia peatlands at the highest elevations makes them susceptible to the effects of global change including global warming. Accumulation rates of organic matter are the key function of peatland ecosystems and are highly susceptible to changes in climate. This study used 210Pb chronologies to infer the recent dynamics of three Distichia muscoides peatlands located above 4000 m in elevation. Chronological markers from dated volcanic eruptions were correlated to the 210Pb chronologies of Distichia peat and validated the 210Pb chronologies. Changes in 210Pb activity with depth indicated rapid accumulation in recent times. Organic matter had a mean accumulation rate of 1400 g m-2 yr-1 during the past 10 years, with values well above the observed regional accumulation rate of 300-400 g m-2 yr-1. The same pattern was observed in peat accretion rates, with growth rates of 1-2 cm per year during the last 10 years. Cushion plants engineer their own environment, allowing the system to be less susceptible to direct changes in climate. However, the high rates of peat accretion in recent times may be originated from increasing temperatures and excess water from nearby glacier melt. However, glaciers are predicted to disappear during the next 20 years in the northern Andes, reducing water inputs in tropical high-elevation ecosystems.

  9. Design and Evaluation of the Highly Concentrated Human IgG Formulation Using Cyclodextrin Polypseudorotaxane Hydrogels.

    PubMed

    Higashi, Taishi; Tajima, Anna; Ohshita, Naoko; Hirotsu, Tatsunori; Abu Hashim, Irhan Ibrahim; Motoyama, Keiichi; Koyama, Sawako; Iibuchi, Ruriko; Mieda, Shiuhei; Handa, Kenji; Kimoto, Tomoaki; Arima, Hidetoshi

    2015-12-01

    To achieve the potent therapeutic effects of human immunoglobulin G (IgG), highly concentrated formulations are required. However, the stabilization for highly concentrated human IgG is laborious work. In the present study, to investigate the potentials of polypseudorotaxane (PPRX) hydrogels consisting of polyethylene glycol (PEG) and α- or γ-cyclodextrin (α- or γ-CyD) as pharmaceutical materials for highly concentrated human IgG, we designed the PPRX hydrogels including human IgG and evaluated their pharmaceutical properties. The α- and γ-CyDs formed PPRX hydrogels with PEG (M.W. 20,000) even in the presence of highly concentrated human IgG (>100 mg/mL). According to the results of (1)H-NMR, powder X-ray diffraction, and Raman microscopy, the formation of human IgG/CyD PPRX hydrogels was based on physical cross-linking arising from their columnar structures. The release profiles of human IgG from the hydrogels were in accordance with the non-Fickian diffusion model. Importantly, the stabilities of human IgG included into the hydrogels against thermal and shaking stresses were markedly improved. These findings suggest that PEG/CyD PPRX hydrogels are useful to prepare the formulation for highly concentrated human IgG.

  10. NMR high-resolution magic angle spinning rotor design for quantification of metabolic concentrations

    NASA Astrophysics Data System (ADS)

    Holly, R.; Damyanovich, A.; Peemoeller, H.

    2006-05-01

    A new high-resolution magic angle spinning nuclear magnetic resonance technique is presented to obtain absolute metabolite concentrations of solutions. The magnetic resonance spectrum of the sample under investigation and an internal reference are acquired simultaneously, ensuring both spectra are obtained under the same experimental conditions. The robustness of the technique is demonstrated using a solution of creatine, and it is shown that the technique can obtain solution concentrations to within 7% or better.

  11. High Concentrating GaAs Cell Operation Using Optical Waveguide Solar Energy System

    NASA Technical Reports Server (NTRS)

    Nakamura, T.; Case, J. A.; Timmons, M. L.

    2004-01-01

    This paper discusses the result of the concentrating photovoltaic (CPV) cell experiments conducted with the Optical Waveguide (OW) Solar Energy System. The high concentration GaAs cells developed by Research Triangle Institute (RTI) were combined with the OW system in a "fiber-on-cell" configuration. The sell performance was tested up to the solar concentration of 327. Detailed V-I characteristics, power density and efficiency data were collected. It was shown that the CPV cells combined with the OW solar energy system will be an effective electric power generation device.

  12. Photorespiration and carbon concentrating mechanisms: two adaptations to high O2, low CO2 conditions.

    PubMed

    Moroney, James V; Jungnick, Nadine; Dimario, Robert J; Longstreth, David J

    2013-11-01

    This review presents an overview of the two ways that cyanobacteria, algae, and plants have adapted to high O2 and low CO2 concentrations in the environment. First, the process of photorespiration enables photosynthetic organisms to recycle phosphoglycolate formed by the oxygenase reaction catalyzed by ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). Second, there are a number of carbon concentrating mechanisms that increase the CO2 concentration around Rubisco which increases the carboxylase reaction enhancing CO2 fixation. This review also presents possibilities for the beneficial modification of these processes with the goal of improving future crop yields.

  13. High temperature stimulates acetic acid accumulation and enhances the growth inhibition and ethanol production by Saccharomyces cerevisiae under fermenting conditions.

    PubMed

    Woo, Ji-Min; Yang, Kyung-Mi; Kim, Sae-Um; Blank, Lars M; Park, Jin-Byung

    2014-07-01

    Cellular responses of Saccharomyces cerevisiae to high temperatures of up to 42 °C during ethanol fermentation at a high glucose concentration (i.e., 100 g/L) were investigated. Increased temperature correlated with stimulated glucose uptake to produce not only the thermal protectant glycerol but also ethanol and acetic acid. Carbon flux into the tricarboxylic acid (TCA) cycle correlated positively with cultivation temperature. These results indicate that the increased demand for energy (in the form of ATP), most likely caused by multiple stressors, including heat, acetic acid, and ethanol, was matched by both the fermentation and respiration pathways. Notably, acetic acid production was substantially stimulated compared to that of other metabolites during growth at increased temperature. The acetic acid produced in addition to ethanol seemed to subsequently result in adverse effects, leading to increased production of reactive oxygen species. This, in turn, appeared to cause the specific growth rate, and glucose uptake rate reduced leading to a decrease of the specific ethanol production rate far before glucose depletion. These results suggest that adverse effects from heat, acetic acid, ethanol, and oxidative stressors are synergistic, resulting in a decrease of the specific growth rate and ethanol production rate and, hence, are major determinants of cell stability and ethanol fermentation performance of S. cerevisiae at high temperatures. The results are discussed in the context of possible applications.

  14. Evidence of Cholesterol Accumulated in High Curvature Regions: Implication ot the Curvature Elastic Energy for Lipid Mixtures

    SciTech Connect

    Wang,W.; Yang, L.; Huang, H.

    2007-01-01

    Recent experiments suggested that cholesterol and other lipid components of high negative spontaneous curvature facilitate membrane fusion. This is taken as evidence supporting the stalk-pore model of membrane fusion in which the lipid bilayers go through intermediate structures of high curvature. How do the high-curvature lipid components lower the free energy of the curved structure? Do the high-curvature lipid components modify the average spontaneous curvature of the relevant monolayer, thereby facilitate its bending, or do the lipid components redistribute in the curved structure so as to lower the free energy? This question is fundamental to the curvature elastic energy for lipid mixtures. Here we investigate the lipid distribution in a monolayer of a binary lipid mixture before and after bending, or more precisely in the lamellar, hexagonal, and distorted hexagonal phases. The lipid mixture is composed of 2:1 ratio of brominated di18:0PC and cholesterol. Using a newly developed procedure for the multiwavelength anomalous diffraction method, we are able to isolate the bromine distribution and reconstruct the electron density distribution of the lipid mixture in the three phases. We found that the lipid distribution is homogenous and uniform in the lamellar and hexagonal phases. But in the distorted hexagonal phase, the lipid monolayer has nonuniform curvature, and cholesterol almost entirely concentrates in the high curvature region. This finding demonstrates that the association energies between lipid molecules vary with the curvature of membrane. Thus, lipid components in a mixture may redistribute under conditions of nonuniform curvature, such as in the stalk structure. In such cases, the spontaneous curvature depends on the local lipid composition and the free energy minimum is determined by lipid distribution as well as curvature.

  15. Heavy metal accumulation in some aquatic insects (Coleoptera: Hydrophilidae) and tissues of Chondrostoma regium (Heckel, 1843) relevant to their concentration in water and sediments from Karasu River, Erzurum, Turkey.

    PubMed

    Aydoğan, Zeynep; Şişman, Turgay; İncekara, Ümit; Gürol, Ali

    2017-02-28

    The objectives of this research were to determine and compare the heavy element concentrations in two study areas in Erzurum, Turkey (Aşkale and Dumlu sites). Assessment of some heavy elements in sediment, water, fish (Chondrostoma regium) tissues, and some aquatic insects (Coleoptera: Hydrophilidae) were carried out in June to August 2014. Heavy element levels in aquatic insect samples and their associated water and sediment were analyzed by energy dispersive X-ray fluorescence (EDXRF) spectrometer. Fish tissues, from the same habitat, were measured by inductively coupled plasma mass spectrometry (ICP-MS). Eleven elements (Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, Hg, Pb) were measured in fish tissues, and 14 elements (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Br, Pb) were measured in insects. According to the results, it can be said that insects were contaminated by water and sediment, thus accumulated higher concentration of some elements than their environment. The fish, which was caught from Aşkale station, accumulates significantly higher level of heavy metals than Dumlu station's fish. The results were compared with national and international standards. The values of some heavy elements were found at higher concentration than the acceptable limits. The possible consequences of these results are briefly discussed from the point of potential hazards to ecology and human health. Element concentrations in fish tissue are below the limits, which are proposed by Turkish Food Codex, FAO/WHO, and EC, and safe for human consumption in the edible parts of fish species in the regions.

  16. Three-phase metal kinetics in terrestrial invertebrates exposed to high metal concentrations.

    PubMed

    Laskowski, Ryszard; Bednarska, Agnieszka J; Spurgeon, David; Svendsen, Claus; van Gestel, Cornelis A M

    2010-08-15

    Models of metal toxicokinetics are critically evaluated using both newly generated data in the NoMiracle project as well as those originating from older studies. The analysis showed that the most frequently used one-compartment two-phase toxicokinetic model, with one assimilation and one elimination rate constant, does not describe correctly certain data sets pertaining particularly to the pattern of assimilation of trace elements. Using nickel toxicokinetics in carabid beetles and earthworms as examples, we showed that Ni in fact exhibits a three-phase kinetics with a short phase of fast metal accumulation immediately after exposure, followed by partial elimination to an equilibrium concentration at a later stage of a metal exposure phase, and by final elimination upon transfer to an uncontaminated food/soil. A similar phenomenon was also found for data on cadmium kinetics in ground beetles and copper kinetics in earthworms in data already published in the literature that was not accounted for in the earlier analysis of the data. The three-phase model suggests that the physiology of controlling body metal concentrations can change shortly after exposure, at least in some cases, by increasing the elimination rate and/or decreasing metal assimilation. Hence, the three-phase model, that allows for different assimilation and/or elimination rates in different phases of exposure to a toxicant, may provide insight into temporal changes in the physiology of metal handling. Consequently, this alternative model should always be tested when describing metal toxicokinetics when temporal patterns of internal metal concentration exhibit an initial "overshoot" in body metal concentrations.

  17. High Voltage Solar Concentrator Experiment with Implications for Future Space Missions

    NASA Technical Reports Server (NTRS)

    Mehdi, Ishaque S.; George, Patrick J.; O'Neill, Mark; Matson, Robert; Brockschmidt, Arthur

    2004-01-01

    This paper describes the design, development, fabrication, and test of a high performance, high voltage solar concentrator array. This assembly is believed to be the first ever terrestrial triple-junction-cell solar array rated at over 1 kW. The concentrator provides over 200 W/square meter power output at a nominal 600 Vdc while operating under terrestrial sunlight. Space-quality materials and fabrication techniques were used for the array, and the 3005 meter elevation installation below the Tropic of Cancer allowed testing as close as possible to space deployment without an actual launch. The array includes two concentrator modules, each with a 3 square meter aperture area. Each concentrator module uses a linear Fresnel lens to focus sunlight onto a photovoltaic receiver that uses 240 series-connected triple-junction solar cells. Operation of the two receivers in series can provide 1200 Vdc which would be adequate for the 'direct drive' of some ion engines or microwave transmitters in space. Lens aperture width is 84 cm and the cell active width is 3.2 cm, corresponding to a geometric concentration ratio of 26X. The evaluation includes the concentrator modules, the solar cells, and the materials and techniques used to attach the solar cells to the receiver heat sink. For terrestrial applications, a finned aluminum extrusion was used for the heat sink for the solar cells, maintaining a low cell temperature so that solar cell efficiency remains high.

  18. High concentrations of myeloperoxidase in the equine uterus as an indicator of endometritis.

    PubMed

    Parrilla-Hernandez, Sonia; Ponthier, Jérôme; Franck, Thierry Y; Serteyn, Didier D; Deleuze, Stéfan C

    2014-04-15

    Intraluminal fluid and excessive abnormal hyperedema are regularly used for the diagnosis of endometritis in the mare, which is routinely confirmed by the presence of neutrophils on endometrial smears. Studies show a relation between neutrophils and myeloperoxidase (MPO), an enzyme contained in and released by neutrophils during degranulation or after cell lysis. This enzyme has been found in many fluids and tissues, and associated with different inflammatory pathologies in the horse. The aims of this study were to assess the presence and concentration of MPO in the equine uterus, and to investigate its relation with neutrophils, and other clinical signs of endometritis. Mares (n = 51) were evaluated for the presence of intraluminal fluid and excessive endometrial edema before breeding, and a small volume lavage and cytology samples were obtained. From 69 cycles, supernatant of the uterine flushes was analyzed with a specific equine MPO ELISA assay to measure MPO concentration. Cytology samples were used for the diagnosis of endometritis. Myeloperoxidase was present in the uterus of all estrus mares in highly variable concentrations. Myeloperoxidase concentrations were significantly (P < 0.05) higher in samples with positive cytologies and in the presence of intraluminal fluid. Occasionally, some samples with negative cytologies showed high MPO concentration, but the opposite was never observed. Cycles presenting hyperedema weren't associated with high concentration of MPO, intraluminal fluid, or positive cytology, making it a poor diagnostic tool of endometritis.

  19. Understanding sugar yield loss and enzyme inhibition due to oligosaccharides accumulation during high solids-loading enzymatic hydrolisis.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During enzymatic hydrolysis of biomass, polysaccharides are cleaved by glycosyl hydrolases to soluble oligosaccharides and further hydrolyzed by ß-glucosidase, ß-xylosidase and other enzymes to monomeric sugars. However, not all oligosaccharides can be fully hydrolyzed and they may accumulate to 18-...

  20. A High Frequency Response Relaxed Eddy Accumulation Flux Measurement System for Sampling Short-Lived Biogenic Volatile Organic Compounds

    EPA Science Inventory

    A second-generation relaxed eddy accumulation system was built and tested with the capability to measure vertical biogenic volatile organic compound (VOC) fluxes at levels as low as 10 µg C m−2 hr−1. The system features a continuous, integrated gas-phase ozo...

  1. Deriving in vivo biotransformation rate constants and metabolite parent concentration factor/stable metabolite factor from bioaccumulation and bioconcentration experiments: An illustration with worm accumulation data.

    PubMed

    Kuo, Dave Ta Fu; Chen, Ciara Chun

    2016-12-01

    Growing concern for the biological fate of organic contaminants and their metabolites and the urge to connect in vitro and in vivo toxicokinetics have prompted researchers to characterize the biotransformation behavior of organic contaminants in biota. The whole body biotransformation rate constant (kM ) is currently determined by the difference approach, which has significant methodological limitations. A new approach for determining kM from the kinetic observations of the parent contaminant and its intermediate metabolites is proposed. In this method, kM can be determined by fitting kinetic data of the parent contaminant and the metabolites to analytical equations that depict the bioaccumulation kinetics. The application of the proposed method is illustrated using worm bioaccumulation-biotransformation data collected from the literature. Furthermore, a metabolite parent concentration factor (MPCF) is also proposed to characterize the persistence of the metabolite in biota. Because both the proposed kM method and MPCF build on the existing theoretical framework for bioaccumulation, they can be readily incorporated into standard experimental bioaccumulation protocols or risk assessment procedures or frameworks. Possible limitations, implications, and future directions are elaborated. Environ Toxicol Chem 2016;35:2903-2909. © 2016 SETAC.

  2. Genetic manipulation of proline accumulation influences the concentrations of other amino acids in soybean subjected to simultaneous drought and heat stress.

    PubMed

    Simon-Sarkadi, Livia; Kocsy, Gábor; Várhegyi, Agnes; Galiba, Gábor; de Ronde, Jacoba A

    2005-09-21

    The effect of simultaneous drought and heat stress on free amino acid levels was compared in wild type and transgenic soybean (Glycine max (L.) Merr cv Ibis) plants transformed with the cDNA coding for the last enzyme of Pro biosynthesis, l-Delta(1)-pyrroline-5-carboxylate reductase (EC 1.5.1.2), in sense and antisense directions. The most rapid increase in Pro content was found in the sense transformants that exhibited the least water loss, while the slowest elevation of Pro levels was detected in the antisense transformants that exhibited the greatest water loss during stress. Correspondingly, the level of the Pro precursors Glu and Arg was higher in sense transformants and lower in antisense ones compared to the wild type plants during the initial part of the stress. Interestingly, genetic manipulation of Pro levels also affected the stress-induced changes in the concentration of several other amino acids, which indicates the coordinated regulation of their metabolic pathways.