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Sample records for aerobic conditions results

  1. Aerobic Conditioning Class.

    ERIC Educational Resources Information Center

    Johnson, Neil R.

    1980-01-01

    An aerobic exercise class that focuses on the conditioning of the cardiovascular and muscular systems is presented. Students complete data cards on heart rate, pulse, and exercises to be completed during the forty minute course. (CJ)

  2. Conditioning and Aerobics for Older Americans.

    ERIC Educational Resources Information Center

    Hansen, Joyce

    1980-01-01

    A class designed for the maintenance and gradual improvement of senior citizens' physical fitness includes relaxation training, flexibility and stretching exercises, interval training activities (designed as a link between less strenuous exercise and more strenuous activities), and aerobic exercises. (CJ)

  3. Nitroglycerin degradation mediated by soil organic carbon under aerobic conditions.

    PubMed

    Bordeleau, Geneviève; Martel, Richard; Bamba, Abraham N'Valoua; Blais, Jean-François; Ampleman, Guy; Thiboutot, Sonia

    2014-10-01

    The presence of nitroglycerin (NG) has been reported in shallow soils and pore water of several military training ranges. In this context, NG concentrations can be reduced through various natural attenuation processes, but these have not been thoroughly documented. This study aimed at investigating the role of soil organic matter (SOM) in the natural attenuation of NG, under aerobic conditions typical of shallow soils. The role of SOM in NG degradation has already been documented under anoxic conditions, and was attributed to SOM-mediated electron transfer involving different reducing agents. However, unsaturated soils are usually well-oxygenated, and it was not clear whether SOM could participate in NG degradation under these conditions. Our results from batch- and column-type experiments clearly demonstrate that in presence of dissolved organic matter (DOM) leached from a natural soil, partial NG degradation can be achieved. In presence of particulate organic matter (POM) from the same soil, complete NG degradation was achieved. Furthermore, POM caused rapid sorption of NG, which should result in NG retention in the organic matter-rich shallow horizons of the soil profile, thus promoting degradation. Based on degradation products, the reaction pathway appears to be reductive, in spite of the aerobic conditions. The relatively rapid reaction rates suggest that this process could significantly participate in the natural attenuation of NG, both on military training ranges and in contaminated soil at production facilities.

  4. Aerobic conditions increase isoprenoid biosynthesis pathway gene expression levels for carotenoid production in Enterococcus gilvus.

    PubMed

    Hagi, Tatsuro; Kobayashi, Miho; Nomura, Masaru

    2015-06-01

    Some lactic acid bacteria that harbour carotenoid biosynthesis genes (crtNM) can produce carotenoids. Although aerobic conditions can increase carotenoid production and crtNM expression levels, their effects on the pathways that synthesize carotenoid precursors such as mevalonate and isoprene are not completely understood. In this study, we investigated whether aerobic conditions affected gene expression levels involved in the isoprenoid biosynthesis pathway that includes the mevalonate and isoprene biosynthesis pathways in Enterococcus gilvus using real-time quantitative reverse transcription PCR. NADH oxidase (nox) and superoxide dismutase (sod) gene expression levels were investigated as controls for aerobic conditions. The expression levels of nox and sod under aerobic conditions were 7.2- and 8.0-fold higher, respectively, than those under anaerobic conditions. Aerobic conditions concomitantly increased the expression levels of crtNM carotenoid biosynthesis genes. HMG-CoA synthase gene expression levels in the mevalonate pathway were only slightly increased under aerobic conditions, whereas the expression levels of HMG-CoA reductase and five other genes in the isoprene biosynthesis pathways were 1.2-2.3-fold higher than those under anaerobic conditions. These results demonstrated that aerobic conditions could increase the expression levels of genes involved in the isoprenoid biosynthesis pathway via mevalonate in E. gilvus.

  5. Cyanide toxicity in hepatocytes under aerobic and anaerobic conditions.

    PubMed

    Aw, T Y; Jones, D P

    1989-09-01

    The effect of cyanide on cell viability and mitochondrial function was studied in hepatocytes exposed to air or argon. Cells were more susceptible to cyanide toxicity under air than under argon. Analysis of the disposition of cyanide showed that the difference in susceptibility to KCN was not due to O2-dependent differences in cyanide metabolism or elimination. Studies of mitochondrial function revealed that cyanide under aerobic conditions resulted in substantial swelling of the mitochondria, which corresponded to a matrix loading of phosphate. In addition, cyanide caused a loss of the mitochondrial protonmotive force. This was in contrast to the results for cells exposed to 30 min of anoxia alone in which there was no loss of mitochondrial delta pH, no detectable change in mitochondrial volume, and little matrix loading of phosphate. These results show that at least some of the protective mechanisms elicited by anoxia (B. S. Andersson, T. Y. Aw, and D. P. Jones. Am. J. Physiol. 252 (Cell Physiol. 21): C349-C355, 1987) are not elicited by cyanide alone. Thus cyanide under aerobic conditions does not provide a completely valid model for simple anoxia. Moreover, the results suggest that the molecular sensor necessary to signal suppression of metabolic and transport functions during neahypoxia is dependent on O2 and is neither stimulated nor antagonized by KCN. PMID:2782387

  6. The effects of long-term aerobic conditioning on +Gz tolerance.

    PubMed

    Whinnery, J E; Parnell, M J

    1987-03-01

    Aerobic conditioning programs for aircrews of high performance fighter type aircraft are very important in assuring optimum fitness and health. The aerobic conditioning resulting from running alters the physiologic state of the individual, and whether or not this alteration affects +Gz tolerance is unknown. In this study, 27 long-term (2 years of running) aerobically conditioned subjects were tested for gradual (1 G x 15 s-1) and rapid onset (1 G x s-1) +Gz tolerance. Maximum VO2 and percent body fat measurements were also performed and correlated to the +Gz-tolerance measurements. Although beneficial for optimum health and fitness, increased aerobic condition (VO2max) resulting from long-term running was not found to enhance +Gz-tolerance. No relationship was observed between aerobic condition and +Gz tolerance. An increased susceptibility to motion sickness was found to be associated with long-term aerobic conditioning. Certain individuals were found to be predisposed to cardiac rate and rhythm disturbances (A-V dissociation and transient asystole) which could potentially alter +Gz-tolerance. Optimum physical conditioning programs for aircrew of fighter aircraft have yet to be determined and implemented. Specificity of exercise training and assurance of the absence of exaggerated cardiovascular response to +Gz stress resulting from physiologic alteration of autonomic tone are critical to the design of optimum conditioning programs for fighter aircraft aircrews. PMID:3579801

  7. Parallel pathways of ethoxylated alcohol biodegradation under aerobic conditions.

    PubMed

    Zembrzuska, Joanna; Budnik, Irena; Lukaszewski, Zenon

    2016-07-01

    Non-ionic surfactants (NS) are a major component of the surfactant flux discharged into surface water, and alcohol ethoxylates (AE) are the major component of this flux. Therefore, biodegradation pathways of AE deserve more thorough investigation. The aim of this work was to investigate the stages of biodegradation of homogeneous oxyethylated dodecanol C12E9 having 9 oxyethylene subunits, under aerobic conditions. Enterobacter strain Z3 bacteria were chosen as biodegrading organisms under conditions with C12E9 as the sole source of organic carbon. Bacterial consortia of river water were used in a parallel test as an inoculum for comparison. The LC-MS technique was used to identify the products of biodegradation. Liquid-liquid extraction with ethyl acetate was selected for the isolation of C12E9 and metabolites from the biodegradation broth. The LC-MS/MS technique operating in the multiple reaction monitoring (MRM) mode was used for quantitative determination of C12E9, C12E8, C12E7 and C12E6. Apart from the substrate, the homologues C12E8, C12E7 and C12E6, being metabolites of C12E9 biodegradation by shortening of the oxyethylene chain, as well as intermediate metabolites having a carboxyl end group in the oxyethylene chain (C12E8COOH, C12E7COOH, C12E6COOH and C12E5COOH), were identified. Poly(ethylene glycols) (E) having 9, 8 and 7 oxyethylene subunits were also identified, indicating parallel central fission of C12E9 and its metabolites. Similar results were obtained with river water as inoculum. It is concluded that AE, under aerobic conditions, are biodegraded via two parallel pathways: by central fission with the formation of PEG, and by Ω-oxidation of the oxyethylene chain with the formation of carboxylated AE and subsequent shortening of the oxyethylene chain by a single unit. PMID:27037882

  8. Photoautotrophic hydrogen production by eukaryotic microalgae under aerobic conditions.

    PubMed

    Hwang, Jae-Hoon; Kim, Hyun-Chul; Choi, Jeong-A; Abou-Shanab, R A I; Dempsey, Brian A; Regan, John M; Kim, Jung Rae; Song, Hocheol; Nam, In-Hyun; Kim, Su-Nam; Lee, Woojung; Park, Donghee; Kim, Yongje; Choi, Jaeyoung; Ji, Min-Kyu; Jung, Woosik; Jeon, Byong-Hun

    2014-01-01

    Eukaryotic algae and cyanobacteria produce hydrogen under anaerobic and limited aerobic conditions. Here we show that novel microalgal strains (Chlorella vulgaris YSL01 and YSL16) upregulate the expression of the hydrogenase gene (HYDA) and simultaneously produce hydrogen through photosynthesis, using CO2 as the sole source of carbon under aerobic conditions with continuous illumination. We employ dissolved oxygen regimes that represent natural aquatic conditions for microalgae. The experimental expression of HYDA and the specific activity of hydrogenase demonstrate that C. vulgaris YSL01 and YSL16 enzymatically produce hydrogen, even under atmospheric conditions, which was previously considered infeasible. Photoautotrophic H2 production has important implications for assessing ecological and algae-based photolysis.

  9. Degradation of triclosan under aerobic, anoxic, and anaerobic conditions.

    PubMed

    Gangadharan Puthiya Veetil, Prajeesh; Vijaya Nadaraja, Anupama; Bhasi, Arya; Khan, Sudheer; Bhaskaran, Krishnakumar

    2012-07-01

    Triclosan (2, 4, 4'-trichloro-2'-hydroxyl diphenyl ether) is a broad-spectrum antimicrobial agent present in a number of house hold consumables. Aerobic and anaerobic enrichment cultures tolerating triclosan were developed and 77 bacterial strains tolerating triclosan at different levels were isolated from different inoculum sources. Biodegradation of triclosan under aerobic, anoxic (denitrifying and sulphate reducing conditions), and anaerobic conditions was studied in batch cultures with isolated pure strains and enrichment consortium developed. Under aerobic conditions, the isolated strains tolerated triclosan up to 1 g/L and degraded the compound in inorganic-mineral-broth and agar media. At 10 mg/L level triclosan, 95 ± 1.2% was degraded in 5 days, producing phenol, catechol and 2, 4-dichlorophenol as the degradation products. The strains were able to metabolize triclosan and its degradation products in the presence of monooxygenase inhibitor 1-pentyne. Under anoxic/anaerobic conditions highest degradation (87%) was observed in methanogenic system with acetate as co-substrate and phenol, catechol, and 2, 4-dichlorophenol were among the products. Three of the isolated strains tolerating 1 g/L triclosan were identified as Pseudomonas sp. (BDC 1, 2, and 3).

  10. Soil metabolism of [14C]methiozolin under aerobic and anaerobic flooded conditions.

    PubMed

    Hwang, Ki-Hwan; Lim, Jong-Soo; Kim, Sung-Hun; Chang, Hee-Ra; Kim, Kyun; Koo, Suk-Jin; Kim, Jeong-Han

    2013-07-17

    Methiozolin is a new turf herbicide controlling annual bluegrass in various cool- and warm-season turfgrasses. This study was conducted to investigate the fate of methiozolin in soil under aerobic and anaerobic flooded conditions using two radiolabeled tracers, [benzyl-(14)C]- and [isoxazole-(14)C]methiozolin. The mass balance of applied radioactivity ranged from 91.7 to 104.5% in both soil conditions. In the soil under the aerobic condition, [(14)C]methiozolin degraded with time to remain by 17.9 and 15.9% of the applied in soil at 120 days after treatment (DAT). [(14)C]Carbon dioxide and the nonextractable radioactivity increased as the soil aged to reach up to 41.5 and 35.7% for [benzyl-(14)C]methiozolin at 120 DAT, respectively, but 36.1 and 39.8% for [isoxazole-(14)C]methiozolin, respectively, during the same period. The nonextractable residue was associated more with humin and fulvic acid fractions under the aerobic condition. No significant volatile products or metabolites were detected during this study. The half-life of [(14)C]methiozolin was approximately 49 days in the soil under the aerobic condition; however, it could not be estimated in the soil under the anaerobic flooded condition because [(14)C]methiozolin degradation was limited. On the basis of these results, methiozolin is considered to undergo fast degradation by aerobic microbes, but not by anaerobic microbes in soil. PMID:23772889

  11. Soil metabolism of [14C]methiozolin under aerobic and anaerobic flooded conditions.

    PubMed

    Hwang, Ki-Hwan; Lim, Jong-Soo; Kim, Sung-Hun; Chang, Hee-Ra; Kim, Kyun; Koo, Suk-Jin; Kim, Jeong-Han

    2013-07-17

    Methiozolin is a new turf herbicide controlling annual bluegrass in various cool- and warm-season turfgrasses. This study was conducted to investigate the fate of methiozolin in soil under aerobic and anaerobic flooded conditions using two radiolabeled tracers, [benzyl-(14)C]- and [isoxazole-(14)C]methiozolin. The mass balance of applied radioactivity ranged from 91.7 to 104.5% in both soil conditions. In the soil under the aerobic condition, [(14)C]methiozolin degraded with time to remain by 17.9 and 15.9% of the applied in soil at 120 days after treatment (DAT). [(14)C]Carbon dioxide and the nonextractable radioactivity increased as the soil aged to reach up to 41.5 and 35.7% for [benzyl-(14)C]methiozolin at 120 DAT, respectively, but 36.1 and 39.8% for [isoxazole-(14)C]methiozolin, respectively, during the same period. The nonextractable residue was associated more with humin and fulvic acid fractions under the aerobic condition. No significant volatile products or metabolites were detected during this study. The half-life of [(14)C]methiozolin was approximately 49 days in the soil under the aerobic condition; however, it could not be estimated in the soil under the anaerobic flooded condition because [(14)C]methiozolin degradation was limited. On the basis of these results, methiozolin is considered to undergo fast degradation by aerobic microbes, but not by anaerobic microbes in soil.

  12. Effects of three feedback conditions on aerobic swim speeds

    PubMed Central

    Pérez, Pedro; Llana, Salvador; Brizuela, Gabriel; Encarnación, Alberto

    2009-01-01

    The purpose of this study was twofold: (a) to develop an underwater chronometer capable to provide feedback while the athlete is swimming, as well as being a control tool for the coach, and (b) to analyse its feedback effect on swim pace control compared with feedback provided by the coach and with no feedback, in 25 m and 50 m swimming pools. 30 male swimmers of national level volunteer to participate. Each swimmer swam 3 x 200 m at aerobic speed (AS) and 3 x 200 m just under the anaerobic threshold speed (AnS), each swam repetition with a different feedback condition: chronometer, coach and without feedback. Results (a) validate the chronometer system developed and (b) show that swimmers pace control is affected by the type of feedback provided, the swim speed elected and the size of the swimming pool. Key points Providing concurrent feedback to swimmers improves theis swimming pace control. It is more important to provide feedback to control swim pace when the swimming pool is 50m long. Technological development as this chronometer system, could offload coach work, so coach can focus its time and attention on other performance aspects or other swimmers. Technological developments are more accepted by coaches when they don’t interfere on swimmers execution, that is, whet it is not necessary to implement the swimmer with cables and apparatus. PMID:24150553

  13. Degradation of municipal solid waste in simulated landfill bioreactors under aerobic conditions.

    PubMed

    Slezak, Radoslaw; Krzystek, Liliana; Ledakowicz, Stanislaw

    2015-09-01

    In this study the municipal solid waste degradation processes in simulated landfill bioreactors under aerobic and anaerobic conditions is investigated. The effect of waste aeration on the dynamics of the aerobic degradation processes in lysimeters as well as during anaerobic processes after completion of aeration is presented. The results are compared with the anaerobic degradation process to determine the stabilization stage of waste in both experimental modes. The experiments in aerobic lysimeters were carried out at small aeration rate (4.41⋅10(-3)lmin(-1)kg(-1)) and for two recirculation rates (24.9 and 1.58lm(-3)d(-1)). The change of leachate and formed gases composition showed that the application of even a small aeration rate favored the degradation of organic matter. The amount of CO2 and CH4 released from anaerobic lysimeter was about 5 times lower than that from the aerobic lysimeters. Better stabilization of the waste was obtained in the aerobic lysimeter with small recirculation, from which the amount of CO2 produced was larger by about 19% in comparison with that from the aerobic lysimeter with large leachate recirculation.

  14. Stabilisation of microalgae: Iodine mobilisation under aerobic and anaerobic conditions.

    PubMed

    Han, Wei; Clarke, William; Pratt, Steven

    2015-10-01

    Mobilisation of iodine during microalgae stabilisation was investigated, with the view of assessing the potential of stabilised microalgae as an iodine-rich fertiliser. An iodine-rich waste microalgae (0.35 ± 0.05 mg I g(-1) VS(added)) was stabilised under aerobic and anaerobic conditions. Iodine mobilisation was linearly correlated with carbon emission, indicating iodine was in the form of organoiodine. Comparison between iodine and nitrogen mobilisation relative to carbon emission indicated that these elements were, at least in part, housed separately within the cells. After stabilisation, there were 0.22 ± 0.05 and 0.19 ± 0.01 mg g(-1) VS(added) iodine remaining in the solid in the aerobic and anaerobic processed material respectively, meaning 38 ± 5.0% (aerobic) and 50 ± 8.6% (anaerobic) of the iodine were mobilised, and consequently lost from the material. The iodine content of the stabilised material is comparable to the iodine content of some seaweed fertilisers, and potentially satisfies an efficient I-fertilisation dose.

  15. Degradation of 1-(2-chlorobenzoyl)-3-(4-chlorophenyl) urea by nanoscale zerovalent iron under aerobic and anaerobic conditions.

    PubMed

    Lin, Haiying; Hou, Shaogang; Xie, Guohong; Yao, Ziwei; Zhou, Qingxiang

    2012-01-01

    The goal of present study was to investigate the applicability of nanoscale zerovalent iron (NZVI) on the degradation of 1-(2-chlorobenzoyl)-3-(4-chlorophenyl) urea (CCU) under aerobic and anaerobic conditions, respectively. The experimental results showed that NZVI could effectively degrade CCU, but the removal efficiencies were different under these two different conditions. The best removal efficiencies for CCU were 90.2 and 75.8% under aerobic and anaerobic conditions, respectively. The highly oxidative hydroxyl radicals and reductively hydrogen would account for the rapid degradation of CCU under aerobic and anaerobic conditions, respectively. The experimental results also showed that surfactant Tween 20 significantly inhibited the degradation of CCU under aerobic conditions. However it markedly enhanced the degradation of CCU under anaerobic condition.

  16. Detoxification of furfural in Corynebacterium glutamicum under aerobic and anaerobic conditions.

    PubMed

    Tsuge, Yota; Hori, Yoshimi; Kudou, Motonori; Ishii, Jun; Hasunuma, Tomohisa; Kondo, Akihiko

    2014-10-01

    The toxic fermentation inhibitors in lignocellulosic hydrolysates raise serious problems for the microbial production of fuels and chemicals. Furfural is considered to be one of the most toxic compounds among these inhibitors. Here, we describe the detoxification of furfural in Corynebacterium glutamicum ATCC13032 under both aerobic and anaerobic conditions. Under aerobic culture conditions, furfuryl alcohol and 2-furoic acid were produced as detoxification products of furfural. The ratio of the products varied depending on the initial furfural concentration. Neither furfuryl alcohol nor 2-furoic acid showed any toxic effect on cell growth, and both compounds were determined to be the end products of furfural degradation. Interestingly, unlike under aerobic conditions, most of the furfural was converted to furfuryl alcohol under anaerobic conditions, without affecting the glucose consumption rate. Both the NADH/NAD(+) and NADPH/NADP(+) ratio decreased in the accordance with furfural concentration under both aerobic and anaerobic conditions. These results indicate the presence of a single or multiple endogenous enzymes with broad and high affinity for furfural and co-factors in C. glutamicum ATCC13032.

  17. Nesterenkonia sp. strain F, a halophilic bacterium producing acetone, butanol, and ethanol under aerobic conditions

    PubMed Central

    Amiri, Hamid; Azarbaijani, Reza; Parsa Yeganeh, Laleh; Shahzadeh Fazeli, Abolhassan; Tabatabaei, Meisam; Hosseini Salekdeh, Ghasem; Karimi, Keikhosro

    2016-01-01

    The moderately halophilic bacterium Nesterenkonia sp. strain F, which was isolated from Aran-Bidgol Lake (Iran), has the ability to produce acetone, butanol, and ethanol (ABE) as well as acetic and butyric acids under aerobic and anaerobic conditions. This result is the first report of ABE production with a wild microorganism from a family other than Clostridia and also the first halophilic species shown to produce butanol under aerobic cultivation. The cultivation of Nesterenkonia sp. strain F under anaerobic conditions with 50 g/l of glucose for 72 h resulted in the production of 105 mg/l of butanol, 122 mg/l of acetone, 0.2 g/l of acetic acid, and 2.5 g/l of butyric acid. Furthermore, the strain was cultivated on media with different glucose concentrations (20, 50, and 80 g/l) under aerobic and anaerobic conditions. Through fermentation with a 50 g/l initial glucose concentration under aerobic conditions, 66 mg/l of butanol, 125 mg/l of acetone, 291 mg/l of ethanol, 5.9 g/l of acetic acid, and 1.2 g/l of butyric acid were produced. The enzymes pertaining to the fermentation pathway in the strain were compared with the enzymes of Clostridium spp., and the metabolic pathway of fermentation used by Nesterenkonia sp. strain F was investigated. PMID:26725518

  18. Probing the ArcA regulon under aerobic/ROS conditions in Salmonella enterica serovar Typhimurium

    PubMed Central

    2013-01-01

    Background Hydrogen peroxide (H2O2) is a reactive oxygen species (ROS), which is part of the oxidative burst encountered upon internalization of Salmonella enterica serovar Typhimurium (S. Typhimurium) by phagocytic cells. It has previously been established that, the ArcAB two-component system plays a critical role in ROS resistance, but the genes regulated by the system remained undetermined to date. We therefore investigated the ArcA regulon in aerobically growing S. Typhimurium before and after exposure to H2O2 by querying gene expression and other physiological changes in wild type and ΔarcA strains. Results In the ΔarcA strain, expression of 292 genes showed direct or indirect regulation by ArcA in response to H2O2, of which 141were also regulated in aerobiosis, but in the opposite direction. Gene set enrichment analysis (GSEA) of the expression data from WT and ΔarcA strains, revealed that, in response to H2O2 challenge in aerobically grown cells, ArcA down regulated multiple PEP-PTS and ABC transporters, while up regulating genes involved in glutathione and glycerolipid metabolism and nucleotide transport. Further biochemical analysis guided by GSEA results showed that deletion of arcA during aerobic growth lead to increased reactive oxygen species (ROS) production which was concomitant with an increased NADH/NAD+ ratio. In absence of ArcA under aerobic conditions, H2O2 exposure resulted in lower levels of glutathione reductase activity, leading to a decreased GSH (reduced glutathione)/GSSG (oxidized glutathione) ratio. Conclusion The ArcA regulon was defined in 2 conditions, aerobic growth and the combination of peroxide treatment and aerobic growth in S. Typhimurium. ArcA coordinates a response that involves multiple aspects of the carbon flux through central metabolism, which ultimately modulates the reducing potential of the cell. PMID:24044554

  19. Antibacterial Action of Nitric Oxide-Releasing Chitosan Oligosaccharides against Pseudomonas aeruginosa under Aerobic and Anaerobic Conditions

    PubMed Central

    Reighard, Katelyn P.

    2015-01-01

    Chitosan oligosaccharides were modified with N-diazeniumdiolates to yield biocompatible nitric oxide (NO) donor scaffolds. The minimum bactericidal concentrations and MICs of the NO donors against Pseudomonas aeruginosa were compared under aerobic and anaerobic conditions. Differential antibacterial activities were primarily the result of NO scavenging by oxygen under aerobic environments and not changes in bacterial physiology. Bacterial killing was also tested against nonmucoid and mucoid biofilms and compared to that of tobramycin. Smaller NO payloads were required to eradicate P. aeruginosa biofilms under anaerobic versus aerobic conditions. Under oxygen-free environments, the NO treatment was 10-fold more effective at killing biofilms than tobramycin. These results demonstrate the potential utility of NO-releasing chitosan oligosaccharides under both aerobic and anaerobic environments. PMID:26239983

  20. Nutrient Transformations in Soils Under Aerobic and Anaerobic Conditions

    NASA Astrophysics Data System (ADS)

    Owens, P.; Lee, L.

    2003-12-01

    Poultry litter is most commonly land applied as a fertilizer for pastures. Soils vary according to landscape position and the biogeochemistry changes within the soils depending on the landscape position. This research focuses on nutrient speciation in aerobic and anaerobic environments. A 3.4 kg Ha-1 chicken litter application rate was used to determine the speciation of nutrients in these two environments. A 50 g sample of Ruston soil was placed in 250 mL centrifuge tubes and continuously stirred in anaerobic and aerobic environments. The Eh and pH were measured daily and a sample was collected at 0, 3, 7, 14 and 21 days. The Eh decreased from around 600 mV at day 0 to near 100 at day 2; whereas the aerobic sample had a decrease to around 450 mV. The pH increased from 6.5 to 7.0 in the anaerobic soil and from 6.5 to around 8.0 in the aerobic soil. The anaerobic soils had a rapid decrease in NO3- and a sharp increase in NH4+ to around 100 mg NH4+ kg-1 soil at day 7. The aerobic soil had an increase in NH4+ to 70 mg Nh4+ kg-1 soil at day 7 then decrease in NH4+ with a corresponding increase in NO3-. Both the anaerobic and aerobic soil had a rapid decrease in PO42- concentrations and remained low for 21 d.

  1. The effect of cyclic anaerobic-aerobic conditions on biodegradation of azo dyes.

    PubMed

    Yaşar, Semra; Cirik, Kevser; Cinar, Ozer

    2012-03-01

    The effect of cyclic anaerobic-aerobic conditions on the biodegradative capability of the mixed microbial culture for the azo dye Remazol Brilliant Violet 5R (RBV-5R) was investigated in the sequencing batch reactor (SBR) fed with a synthetic textile wastewater. The SBR had a 12-h cycle time with anaerobic-aerobic periods of 3/9, 6/6 and 9/3 h. General SBR performance was assessed by measurement of catabolic enzymes (catechol 2,3-dioxygenase, azo reductase), chemical oxygen demand (COD), color and amount of aromatic amines. In this study, under steady-state conditions, the anaerobic period of the cyclic SBR was found to allow the reductive decolorization of azo dye. Longer anaerobic periods resulted in higher color removal efficiencies, approximately 71% for the 3-h, 87% for 6-h and 92% for the 9-h duration. Total COD removal efficiencies were over 84% under each of the cyclic conditions and increased as the length of the anaerobic period was increased; however, the highest color removal rate was attained for the cycle with the shortest anaerobic period of 3 h. During the decolorization of RBV-5R, two sulfonated aromatic amines (benzene based and naphthalene based) were formed. Additionally, anaerobic azo reductase enzyme was found to be positively affected with the increasing duration of the anaerobic period; however; it was vice versa for the aerobic catechol 2,3-dioxygenase (C23DO) enzyme.

  2. Antimicrobial Susceptibility of Enteric Gram Negative Facultative Anaerobe Bacilli in Aerobic versus Anaerobic Conditions

    PubMed Central

    Amachawadi, Raghavendra G.; Renter, David G.; Volkova, Victoriya V.

    2016-01-01

    Antimicrobial treatments result in the host’s enteric bacteria being exposed to the antimicrobials. Pharmacodynamic models can describe how this exposure affects the enteric bacteria and their antimicrobial resistance. The models utilize measurements of bacterial antimicrobial susceptibility traditionally obtained in vitro in aerobic conditions. However, in vivo enteric bacteria are exposed to antimicrobials in anaerobic conditions of the lower intestine. Some of enteric bacteria of food animals are potential foodborne pathogens, e.g., Gram-negative bacilli Escherichia coli and Salmonella enterica. These are facultative anaerobes; their physiology and growth rates change in anaerobic conditions. We hypothesized that their antimicrobial susceptibility also changes, and evaluated differences in the susceptibility in aerobic vs. anaerobic conditions of generic E. coli and Salmonella enterica of diverse serovars isolated from cattle feces. Susceptibility of an isolate was evaluated as its minimum inhibitory concentration (MIC) measured by E-Test® following 24 hours of adaptation to the conditions on Mueller-Hinton agar, and on a more complex tryptic soy agar with 5% sheep blood (BAP) media. We considered all major antimicrobial drug classes used in the U.S. to treat cattle: β-lactams (specifically, ampicillin and ceftriaxone E-Test®), aminoglycosides (gentamicin and kanamycin), fluoroquinolones (enrofloxacin), classical macrolides (erythromycin), azalides (azithromycin), sulfanomides (sulfamethoxazole/trimethoprim), and tetracyclines (tetracycline). Statistical analyses were conducted for the isolates (n≥30) interpreted as susceptible to the antimicrobials based on the clinical breakpoint interpretation for human infection. Bacterial susceptibility to every antimicrobial tested was statistically significantly different in anaerobic vs. aerobic conditions on both media, except for no difference in susceptibility to ceftriaxone on BAP agar. A satellite experiment

  3. Antimicrobial Susceptibility of Enteric Gram Negative Facultative Anaerobe Bacilli in Aerobic versus Anaerobic Conditions.

    PubMed

    DeMars, Zachary; Biswas, Silpak; Amachawadi, Raghavendra G; Renter, David G; Volkova, Victoriya V

    2016-01-01

    Antimicrobial treatments result in the host's enteric bacteria being exposed to the antimicrobials. Pharmacodynamic models can describe how this exposure affects the enteric bacteria and their antimicrobial resistance. The models utilize measurements of bacterial antimicrobial susceptibility traditionally obtained in vitro in aerobic conditions. However, in vivo enteric bacteria are exposed to antimicrobials in anaerobic conditions of the lower intestine. Some of enteric bacteria of food animals are potential foodborne pathogens, e.g., Gram-negative bacilli Escherichia coli and Salmonella enterica. These are facultative anaerobes; their physiology and growth rates change in anaerobic conditions. We hypothesized that their antimicrobial susceptibility also changes, and evaluated differences in the susceptibility in aerobic vs. anaerobic conditions of generic E. coli and Salmonella enterica of diverse serovars isolated from cattle feces. Susceptibility of an isolate was evaluated as its minimum inhibitory concentration (MIC) measured by E-Test® following 24 hours of adaptation to the conditions on Mueller-Hinton agar, and on a more complex tryptic soy agar with 5% sheep blood (BAP) media. We considered all major antimicrobial drug classes used in the U.S. to treat cattle: β-lactams (specifically, ampicillin and ceftriaxone E-Test®), aminoglycosides (gentamicin and kanamycin), fluoroquinolones (enrofloxacin), classical macrolides (erythromycin), azalides (azithromycin), sulfanomides (sulfamethoxazole/trimethoprim), and tetracyclines (tetracycline). Statistical analyses were conducted for the isolates (n≥30) interpreted as susceptible to the antimicrobials based on the clinical breakpoint interpretation for human infection. Bacterial susceptibility to every antimicrobial tested was statistically significantly different in anaerobic vs. aerobic conditions on both media, except for no difference in susceptibility to ceftriaxone on BAP agar. A satellite experiment

  4. Aerobic Conditions are Required for Rapid Carbon Losses following Permafrost Thaw

    NASA Astrophysics Data System (ADS)

    Cooper, M. D. A.; Estop-Aragones, C.

    2015-12-01

    Permafrost soils store between 1,330-1,580 billion tonnes of carbon (C), which may start to be released to the atmosphere if warming promotes widespread thaw. Considerable uncertainty remains regarding how rapidly this C may be released and what proportion will be released as the more powerful greenhouse gas, methane (CH4), rather than carbon dioxide (CO2). Central to answering these questions, is quantifying in situ rates of old, previously-frozen C release under aerobic conditions versus anaerobic conditions. To meet this aim, we investigated the amount and form (CH4 versus CO2) of previously-frozen C released in response to 1) forest fire-induced permafrost thaw (aerobic soil conditions) and 2) permafrost plateau collapse in peatlands which results in waterlogging (anaerobic conditions), in the Yukon and Northwest Territories of Canada. We quantified in situ rates of CO2 and CH4 release, using a novel collar design to either include or exclude C released from deep soil layers, and collected samples for 14CO2 and 14CH4 analysis. Our 14CO2 results identified substantial rates of old C release from burnt forests where the organic horizon was thick and deep thaw was observed. In contrast, in the wetlands old C release was barely detectable as CO2 (<1%), and, although high CH4 fluxes were measured, a maximum of 1.5-2g m-2 yr-1 was derived from previously-frozen C. Furthermore, because peat accumulation increased substantially (>4 times), , thaw resulted in net C gain in the wetland. However, the high rate of CH4 release, albeit derived mainly from contemporary sources, means that permafrost plateau collapse can still represent a positive feedback to climate change in terms of global warming potential. Overall, our results indicate a much greater release of permafrost C under aerobic conditions, with little release of previously-frozen C as either CO2 or CH4 under anaerobic conditions.

  5. Biodegradation of three selected benzotriazoles in aquifer materials under aerobic and anaerobic conditions

    NASA Astrophysics Data System (ADS)

    Liu, You-Sheng; Ying, Guang-Guo; Shareef, Ali; Kookana, Rai S.

    2013-08-01

    We investigated the biodegradation of three selected benzotriazoles (BTs), namely benzotriazole (BT), 5-methyl-benzotriazole (5-TTri) and 5-chloro-benzotriazole (CBT), in aquifer materials. Biodegradation experiments were conducted in microcosms with fresh groundwater and aquifer sediment materials under aerobic and anaerobic (nitrate, sulfate, and Fe (III) reducing) conditions. All three BTs were degraded by microorganisms in aquifer materials under aerobic and anaerobic conditions. Under aerobic conditions, BT and 5-TTri were found to be degraded fastest with their half-lives of 43 days and 31 days, respectively, among the redox conditions used. Under anaerobic conditions, CBT was found to be degraded better with its half-life of 21 days under nitrate reducing conditions than under aerobic conditions with its half-life of 47 days. The two BT derivatives 5-TTri and CBT could be biotransformed into BT via demethylation and dechlorination reactions, respectively.

  6. Acetic Acid Increases Stability of Silage under Aerobic Conditions

    PubMed Central

    Danner, H.; Holzer, M.; Mayrhuber, E.; Braun, R.

    2003-01-01

    The effects of various compounds on the aerobic stability of silages were evaluated. It has been observed that inoculation of whole-crop maize with homofermentative lactic acid bacteria leads to silages which have low stability against aerobic deterioration, while inoculation with heterofermentative lactic acid bacteria, such as Lactobacillus brevis or Lactobacillus buchneri, increases stability. Acetic acid has been proven to be the sole substance responsible for the increased aerobic stability, and this acid acts as an inhibitor of spoilage organisms. Therefore, stability increases exponentially with acetic acid concentration. Only butyric acid has a similar effect. Other compounds, like lactic acid, 1,2-propanediol, and 1-propanol, have been shown to have no effect, while fructose and mannitol reduce stability. PMID:12514042

  7. Fate of aerobic bacterial granules with fungal contamination under different organic loading conditions.

    PubMed

    Li, An-jie; Zhang, Tong; Li, Xiao-yan

    2010-01-01

    Aerobic sludge granulation is an attractive new technology for biological wastewater treatment. However, the instability of aerobic granules caused by fungal growth is still one of the main problems encountered in granular bioreactors. In this study, laboratory experiments were conducted to investigate the fate and transformation of aerobic granules under different organic loading conditions. Bacterial granules (2-3mm) in a poor condition with fungi-like black filamentous growth were seeded into two 1L batch reactors. After more than 100d of cultivation, the small seed granules in the two reactors had grown into two different types of large granules (>20mm) with different and unique morphological features. In reactor R1 with a high organic loading rate of 2.0g COD L(-1)d(-1), the black filaments mostly disappeared from the granules, and the dominance of rod-shaped bacteria was recovered. In contrast, at a low loading of 0.5g COD L(-1)d(-1) in reactor R2, the filaments eventually became dominant in the black fungal granules. The bacteria in R1 granules had a unique web-like structure with large pores of a few hundred microm in size, which would allow for effective substrate and oxygen transport into the interior of the granules. DNA-based molecular analysis indicated the evolution of the bacterial population in R1 and that of the eukaryal community in R2. The experimental results suggest that a high loading rate can be an effective means of helping to control fungal bloom, recover bacterial domination and restore the stability of aerobic granules that suffer from fungal contamination.

  8. Microbial bioavailability of pyrene in three laboratory-contaminated soils under aerobic and anaerobic conditions.

    PubMed

    Pravecek, Tasha L; Christman, Russell F; Pfaender, Frederic K

    2006-06-30

    Changes in bioavailability of pyrene in three uncontaminated soils were examined under aerobic and anaerobic conditions. Three soils were aerobically aged with pyrene and [(14)C]pyrene for 63 days, then incubated with water, nitrate, or sulfate under aerobic or anaerobic conditions for one year. Under aerobic conditions, microorganisms in two soils mineralized 58-82% of the added [(14)C]pyrene. The two soils amended with nitrate were seen to have enhanced aerobic mineralization rates. In one of these soils, non-extractable pyrene was seen to decrease over the course of the study due to desorption and mineralization, nitrate amendment enhanced this effect. Under anaerobic conditions, generated with a N(2):CO(2)(g) headspace, two soils with nitrate or sulfate amendment showed an increase in extractable [(14)C]pyrene at 365 days relative to inhibited controls, presumably due to microbially mediated oxidation-reduction potential and pH alteration of the soil environment. These observations in different soils incubated under aerobic and anaerobic conditions have important implications relative to the impact of microbial electron acceptors on bioavailability and transport of non-polar organic compounds in the environment suggesting that, given enough time, under the appropriate environmental conditions, non-extractable material becomes bioavailable. This information should be considered when assessing site specific exposure risks at PAH contaminated locations. PMID:16574273

  9. Silicification-induced cell aggregation for the sustainable production of H2 under aerobic conditions.

    PubMed

    Xiong, Wei; Zhao, Xiaohong; Zhu, Genxing; Shao, Changyu; Li, Yaling; Ma, Weimin; Xu, Xurong; Tang, Ruikang

    2015-10-01

    Photobiological hydrogen production is of great importance because of its promise for generating clean renewable energy. In nature, green algae cannot produce hydrogen as a result of the extreme sensitivity of hydrogenase to oxygen. However, we find that silicification-induced green algae aggregates can achieve sustainable photobiological hydrogen production even under natural aerobic conditions. The core-shell structure of the green algae aggregates creates a balance between photosynthetic electron generation and hydrogenase activity, thus allowing the production of hydrogen. This finding provides a viable pathway for the solar-driven splitting of water into hydrogen and oxygen to develop green energy alternatives by using rationally designed cell-material complexes.

  10. Chemotactic Motility of Pseudomonas fluorescens F113 under Aerobic and Denitrification Conditions

    PubMed Central

    Redondo-Nieto, Miguel; Rivilla, Rafael; Martín, Marta

    2015-01-01

    The sequence of the genome of Pseudomonas fluorescens F113 has shown the presence of multiple traits relevant for rhizosphere colonization and plant growth promotion. Among these traits are denitrification and chemotactic motility. Besides aerobic growth, F113 is able to grow anaerobically using nitrate and nitrite as final electron acceptors. F113 is able to perform swimming motility under aerobic conditions and under anaerobic conditions when nitrate is used as the electron acceptor. However, nitrite can not support swimming motility. Regulation of swimming motility is similar under aerobic and anaerobic conditions, since mutants that are hypermotile under aerobic conditions, such as gacS, sadB, kinB, algU and wspR, are also hypermotile under anaerobic conditions. However, chemotactic behavior is different under aerobic and denitrification conditions. Unlike most pseudomonads, the F113 genome encode three complete chemotaxis systems, Che1, Che2 and Che3. Mutations in each of the cheA genes of the three Che systems has shown that the three systems are functional and independent. Mutation of the cheA1 gene completely abolished swimming motility both under aerobic and denitrification conditions. Mutation of the cheA2 gene, showed only a decrease in swimming motility under both conditions, indicating that this system is not essential for chemotactic motility but is necessary for optimal motility. Mutation of the cheA3 gene abolished motility under denitrification conditions but only produced a decrease in motility under aerobic conditions. The three Che systems proved to be implicated in competitive rhizosphere colonization, being the cheA1 mutant the most affected. PMID:26161531

  11. Aerobic Conditioning Might Protect Against Liver and Muscle Injury Caused by Short-Term Military Training.

    PubMed

    Koury, Josely C; Daleprane, Julio B; Pitaluga-Filho, Mario V; de Oliveira, Cyntia F; Gonçalves, Mariana C; Passos, Magna C F

    2016-02-01

    This study aimed to compare the biochemical markers of muscle and liver injury and total antioxidant capacity in army cadets after a traditional army physical training program and to correlate these effects with aerobic conditioning. Male army cadets (n = 87; age, 20 ± 2 years) were evaluated 12 hours before the start of training (T0), 12 hours after a 30-km march (T1), and 48 hours after military training (T2). Creatine kinase (CK), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) serum levels were measured using an autoanalyzer. Total antioxidant capacity was determined by 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (Sc%). Seventy-four percent of army cadets were classified as having excellent aerobic conditioning (53.9 ± 3.0 ml · kg(-) · min(-1) predicted VO2max from the Cooper test). The median serum concentration of all enzymes increased 12 hours after marching (T1: CK 675%; ALT 59%; AST 336%; AST/ALT ratio 85%; p = 0.001) and 48 hours after the end of training (T2: CK 878%; ALT 256%; AST 418%; AST/ALT ratio 180%; p = 0.001). Sc% was higher in T2 (31.1 ± 9.8%; p = 0.01) than in T0 (3.4% change). Maximal oxygen consumption (ml · kg(-1) · min(-1)) correlated negatively with CK (r = -0.25; p = 0.009) and ALT (r = -0.21; p = 0.03) serum levels, and positively with the change in Sc% (r = 0.22; p = 0.04) at T2. The results indicate that intense military training can cause liver and muscle injury and that aerobic conditioning can be considered as a protective factor for these injuries. PMID:26813633

  12. Biodegradability of biodegradable/degradable plastic materials under aerobic and anaerobic conditions.

    PubMed

    Mohee, R; Unmar, G D; Mudhoo, A; Khadoo, P

    2008-01-01

    A study was conducted on two types of plastic materials, Mater-Bi Novamont (MB) and Environmental Product Inc. (EPI), to assess their biodegradability under aerobic and anaerobic conditions. For aerobic conditions, organic fractions of municipal solid wastes were composted. For the anaerobic process, anaerobic inoculum from a wastewater treatment plant was used. Cellulose filter papers (CFP) were used as a positive control for both mediums. The composting process was monitored in terms of temperature, moisture and volatile solids and the biodegradation of the samples were monitored in terms of mass loss. Monitoring results showed a biodegradation of 27.1% on a dry basis for MB plastic within a period of 72 days of composting. Biodegradability under an anaerobic environment was monitored in terms of biogas production. A cumulative methane gas production of 245 ml was obtained for MB, which showed good degradation as compared to CFP (246.8 ml). However, EPI plastic showed a cumulative methane value of 7.6 ml for a period of 32 days, which was close to the blank (4.0 ml). The EPI plastic did not biodegrade under either condition. The cumulative carbon dioxide evolution after 32 days was as follows: CFP 4.406 cm3, MB 2.198 cm3 and EPI 1.328 cm3. The cumulative level of CO2 varying with time fitted sigmoid type curves with R2 values of 0.996, 0.996 and 0.995 for CFP, MB and EPI, respectively.

  13. Climatic thresholds for pedogenic iron oxides under aerobic conditions: Processes and their significance in paleoclimate reconstruction

    NASA Astrophysics Data System (ADS)

    Long, Xiaoyong; Ji, Junfeng; Barrón, Vidal; Torrent, José

    2016-10-01

    Iron oxides are widely distributed across the surface of the Earth as a result of the aerobic weathering of primary Fe-bearing minerals. Pedogenic iron oxides which consist mainly of hematite (Hm), goethite (Gt), maghemite (Mgh), are often concentrated synchronously in aerobic soils under low to moderate rainfall regimes. Magnetic susceptibility (χ) and redness, which respectively reflect the content of Mgh and Hm in soils, are considered reasonable pedogenic and climatic indicators in soil taxonomy and paleorainfall reconstruction. However, under high rainfall regimes, the grain growth of Mgh and transformation to Hm, combined with the prior formation of Gt under conditions of high relative humidity (RH), can result in magnetic reduction and dramatic yellowing of soils and sediments, which explains the existence of rainfall thresholds for Mgh and Hm at a large scale even before the pedogenic environment turns anaerobic. In order to capture the rainfall thresholds for Mgh and Hm occurring under aerobic conditions, we explored a tropical transect across a granitic region where the soil color turned from red to yellow under a wide rainfall range of 900-2200 mm/yr and a corresponding mean annual RH range of 77%-85%. We observed a lower rainfall threshold of ∼1500 mm/yr and a corresponding RH ∼80% for Mgh and Hm along this transect, as well as a higher rainfall threshold of ∼1700 mm/yr and a corresponding RH of ∼81% for Gt and total pedogenic iron oxides (citrate/bicarbonate/dithionite-extractable Fe, Fed). Cross-referencing with comparable studies in temperate and subtropical regions, we noted that the rainfall or RH thresholds for Fed and Hm or Mgh likewise increase with temperature. Moreover, the different thresholds for total and individual iron oxide phase indicates that a negative correlation between chemical weathering intensity and redness or χ in sediment sequences can occur under the prevalent climate regime just between their thresholds. Finally

  14. Iron plaque formed under aerobic conditions efficiently immobilizes arsenic in Lupinus albus L roots.

    PubMed

    Fresno, Teresa; Peñalosa, Jesús M; Santner, Jakob; Puschenreiter, Markus; Prohaska, Thomas; Moreno-Jiménez, Eduardo

    2016-09-01

    Arsenic is a non-threshold carcinogenic metalloid. Thus, human exposure should be minimised, e.g. by chemically stabilizing As in soil. Since iron is a potential As immobiliser, it was investigated whether root iron plaque, formed under aerobic conditions, affects As uptake, metabolism and distribution in Lupinus albus plants. White lupin plants were cultivated in a continuously aerated hydroponic culture containing Fe/EDDHA or FeSO4 and exposed to arsenate (5 or 20 μM). Only FeSO4 induced surficial iron plaque in roots. LA-ICP-MS analysis accomplished on root sections corroborated the association of As to this surficial Fe. Additionally, As(V) was the predominant species in FeSO4-treated roots, suggesting less efficient As uptake in the presence of iron plaque. Fe/EDDHA-exposed roots neither showed such surficial FeAs co-localisation nor As(V) accumulation; in contrast As(III) was the predominant species in root tissue. Furthermore, FeSO4-treated plants showed reduced shoot-to-root As ratios, which were >10-fold lower compared to Fe/EDDHA treatment. Our results highlight the role of an iron plaque formed in roots of white lupin under aerobic conditions on As immobilisation. These findings, to our knowledge, have not been addressed before for this plant and have potential implications on soil remediation (phytostabilisation) and food security (minimising As in crops). PMID:27263113

  15. Iron plaque formed under aerobic conditions efficiently immobilizes arsenic in Lupinus albus L roots.

    PubMed

    Fresno, Teresa; Peñalosa, Jesús M; Santner, Jakob; Puschenreiter, Markus; Prohaska, Thomas; Moreno-Jiménez, Eduardo

    2016-09-01

    Arsenic is a non-threshold carcinogenic metalloid. Thus, human exposure should be minimised, e.g. by chemically stabilizing As in soil. Since iron is a potential As immobiliser, it was investigated whether root iron plaque, formed under aerobic conditions, affects As uptake, metabolism and distribution in Lupinus albus plants. White lupin plants were cultivated in a continuously aerated hydroponic culture containing Fe/EDDHA or FeSO4 and exposed to arsenate (5 or 20 μM). Only FeSO4 induced surficial iron plaque in roots. LA-ICP-MS analysis accomplished on root sections corroborated the association of As to this surficial Fe. Additionally, As(V) was the predominant species in FeSO4-treated roots, suggesting less efficient As uptake in the presence of iron plaque. Fe/EDDHA-exposed roots neither showed such surficial FeAs co-localisation nor As(V) accumulation; in contrast As(III) was the predominant species in root tissue. Furthermore, FeSO4-treated plants showed reduced shoot-to-root As ratios, which were >10-fold lower compared to Fe/EDDHA treatment. Our results highlight the role of an iron plaque formed in roots of white lupin under aerobic conditions on As immobilisation. These findings, to our knowledge, have not been addressed before for this plant and have potential implications on soil remediation (phytostabilisation) and food security (minimising As in crops).

  16. Field assessment of semi-aerobic condition and the methane correction factor for the semi-aerobic landfills provided by IPCC guidelines

    SciTech Connect

    Jeong, Sangjae; Nam, Anwoo; Yi, Seung-Muk; Kim, Jae Young

    2015-02-15

    Highlights: • CH{sub 4}/CO{sub 2} and CH{sub 4} + CO{sub 2}% are proposed as indices to evaluate semi-aerobic landfills. • A landfill which CH{sub 4}/CO{sub 2} > 1.0 is difficult to be categorized as semi-aerobic landfill. • Field conditions should be carefully investigated to determine landfill types. • The MCF default value for semi-aerobic landfills underestimates the methane emissions. - Abstract: According to IPCC guidelines, a semi-aerobic landfill site produces one-half of the amount of CH{sub 4} produced by an equally-sized anaerobic landfill site. Therefore categorizing the landfill type is important on greenhouse gas inventories. In order to assess semi-aerobic condition in the sites and the MCF value for semi-aerobic landfill, landfill gas has been measured from vent pipes in five semi-aerobically designed landfills in South Korea. All of the five sites satisfied requirements of semi-aerobic landfills in 2006 IPCC guidelines. However, the ends of leachate collection pipes which are main entrance of air in the semi-aerobic landfill were closed in all five sites. The CH{sub 4}/CO{sub 2} ratio in landfill gas, indicator of aerobic and anaerobic decomposition, ranged from 1.08 to 1.46 which is higher than the values (0.3–1.0) reported for semi-aerobic landfill sites and is rather close to those (1.0–2.0) for anaerobic landfill sites. The low CH{sub 4} + CO{sub 2}% in landfill gas implied air intrusion into the landfill. However, there was no evidence that air intrusion has caused by semi-aerobic design and operation. Therefore, the landfills investigated in this study are difficult to be classified as semi-aerobic landfills. Also MCF of 0.5 may significantly underestimate methane emissions compared to other researches. According to the carbon mass balance analyses, the higher MCF needs to be proposed for semi-aerobic landfills. Consequently, methane emission estimate should be based on field evaluation for the semi-aerobically designed landfills.

  17. Impact of ArcA loss in Shewanella oneidensis revealed by comparative proteomics under aerobic and anaerobic conditions

    SciTech Connect

    Yuan, Jie; Wei, Buyun; Lipton, Mary S.; Gao, Haichun

    2012-06-01

    Shewanella inhabit a wide variety of niches in nature and can utilize a broad spectrum of electron acceptors under anaerobic conditions. How they modulate their gene expression to adapt is poorly understood. ArcA, homologue of a global regulator controlling hundreds of genes involved in aerobic and anaerobic respiration in E. coli, was shown to be important in aerobiosis/anaerobiosis of S. oneidensis as well. Loss of ArcA, in addition to altering transcription of many genes, resulted in impaired growth under aerobic condition, which was not observed in E. coli. To further characterize the impact of ArcA loss on gene expression on the level of proteome under aerobic and anaerobic conditions, liquid-chromatography-mass-spectrometry (LC-MS) based proteomic approach was employed. Results show that ArcA loss led to globally altered gene expression, generally consistent with that observed with transcripts. Comparison of transcriptomic and proteomic data permitted identification of 17 high-confidence ArcA targets. Moreover, our data indicate that ArcA is required for regulation of cytochrome c proteins, and the menaquinone level may play a role in regulating ArcA as in E. coli. Proteomic-data-guided growth assay revealed that the aerobic growth defect of ArcA mutant is presumably due to impaired peptide utilization.

  18. Euglena gracilis rhodoquinone:ubiquinone ratio and mitochondrial proteome differ under aerobic and anaerobic conditions.

    PubMed

    Hoffmeister, Meike; van der Klei, Anita; Rotte, Carmen; van Grinsven, Koen W A; van Hellemond, Jaap J; Henze, Katrin; Tielens, Aloysius G M; Martin, William

    2004-05-21

    Euglena gracilis cells grown under aerobic and anaerobic conditions were compared for their whole cell rhodoquinone and ubiquinone content and for major protein spots contained in isolated mitochondria as assayed by two-dimensional gel electrophoresis and mass spectrometry sequencing. Anaerobically grown cells had higher rhodoquinone levels than aerobically grown cells in agreement with earlier findings indicating the need for fumarate reductase activity in anaerobic wax ester fermentation in Euglena. Microsequencing revealed components of complex III and complex IV of the respiratory chain and the E1beta subunit of pyruvate dehydrogenase to be present in mitochondria of aerobically grown cells but lacking in mitochondria from anaerobically grown cells. No proteins were identified as specific to mitochondria from anaerobically grown cells. cDNAs for the E1alpha, E2, and E3 subunits of mitochondrial pyruvate dehydrogenase were cloned and shown to be differentially expressed under aerobic and anaerobic conditions. Their expression patterns differed from that of mitochondrial pyruvate:NADP(+) oxidoreductase, the N-terminal domain of which is pyruvate:ferredoxin oxidoreductase, an enzyme otherwise typical of hydrogenosomes, hydrogen-producing forms of mitochondria found among anaerobic protists. The Euglena mitochondrion is thus a long sought intermediate that unites biochemical properties of aerobic and anaerobic mitochondria and hydrogenosomes because it contains both pyruvate:ferredoxin oxidoreductase and rhodoquinone typical of hydrogenosomes and anaerobic mitochondria as well as pyruvate dehydrogenase and ubiquinone typical of aerobic mitochondria. Our data show that under aerobic conditions Euglena mitochondria are prepared for anaerobic function and furthermore suggest that the ancestor of mitochondria was a facultative anaerobe, segments of whose physiology have been preserved in the Euglena lineage.

  19. Aerobic moving bed biofilm reactor treating thermomechanical pulping whitewater under thermophilic conditions.

    PubMed

    Jahren, Sigrun J; Rintala, Jukka A; Odegaard, Hallvard

    2002-02-01

    The continuously operated laboratory scale Kaldnes moving bed biofilm reactor (MBBR) was used for thermophilic (55 degrees C) aerobic treatment of TMP whitewater. In the MBBR, the biomass is grown on carrier elements that move along with the water in the reactor. Inoculation with mesophilic activated sludge gave 60-65% SCOD removal from the first day onwards. During the 107 days of experiment, the 60-65% SCOD removals were achieved at organic loading rates of 2.5-3.5 kg SCODm(-3) d(-1), the highest loading rates applied during the run and HRT of 13-22h. Carbohydrates, which contributed to 50-60% of the influent SCOD. were removed by 90-95%, while less than 15% of the lignin-like material (30-35% of SCODin) was removed. The sludge yield was 0.23g VSSg SCOD(-1)removed. The results show that the aerobic biofilm process can be successfully operated under thermophilic conditions. PMID:11848344

  20. Effects of environmental conditions on aerobic degradation of a commercial naphthenic acid.

    PubMed

    Kinley, Ciera M; Gaspari, Daniel P; McQueen, Andrew D; Rodgers, John H; Castle, James W; Friesen, Vanessa; Haakensen, Monique

    2016-10-01

    Naphthenic acids (NAs) are problematic constituents in energy-derived waters, and aerobic degradation may provide a strategy for mitigating risks to aquatic organisms. The overall objective of this study was to determine the influence of concentrations of N (as ammonia) and P (as phosphate), and DO, as well as pH and temperatures on degradation of a commercial NA in bench-scale reactors. Commercial NAs provided replicable compounds necessary to compare influences of environmental conditions on degradation. NAs were quantified using high performance liquid chromatography. Microbial diversity and relative abundance were measured in treatments as explanatory parameters for potential effects of environmental conditions on microbial populations to support analytically measured NA degradation. Environmental conditions that positively influenced degradation rates of Fluka NAs included nutrients (C:N 10:1-500:1, C:P 100:1-5000:1), DO (4.76-8.43 mg L(-1)), pH (6-8), and temperature (5-25 °C). Approximately 50% removal of 61 ± 8 mg L(-1) was achieved in less than 2 d after NA introduction, achieving the method detection limit (5 mg L(-1)) by day 6 of the experiment in treatments with a C:N:P ratio of 100:10:1, DO > 8 mg L(-1), pH ∼8-9, and temperatures >23 °C. Microbial diversity was lowest in lower temperature treatments (6-16 °C), which may have resulted in observed slower NA degradation. Based on results from this study, when macro- and micronutrients were available, DO, pH, and temperature (within environmentally relevant ranges) influenced rates of aerobic degradation of Fluka NAs. This study could serve as a model for systematically evaluating environmental factors that influence NA degradation in field scenarios.

  1. Effects of environmental conditions on aerobic degradation of a commercial naphthenic acid.

    PubMed

    Kinley, Ciera M; Gaspari, Daniel P; McQueen, Andrew D; Rodgers, John H; Castle, James W; Friesen, Vanessa; Haakensen, Monique

    2016-10-01

    Naphthenic acids (NAs) are problematic constituents in energy-derived waters, and aerobic degradation may provide a strategy for mitigating risks to aquatic organisms. The overall objective of this study was to determine the influence of concentrations of N (as ammonia) and P (as phosphate), and DO, as well as pH and temperatures on degradation of a commercial NA in bench-scale reactors. Commercial NAs provided replicable compounds necessary to compare influences of environmental conditions on degradation. NAs were quantified using high performance liquid chromatography. Microbial diversity and relative abundance were measured in treatments as explanatory parameters for potential effects of environmental conditions on microbial populations to support analytically measured NA degradation. Environmental conditions that positively influenced degradation rates of Fluka NAs included nutrients (C:N 10:1-500:1, C:P 100:1-5000:1), DO (4.76-8.43 mg L(-1)), pH (6-8), and temperature (5-25 °C). Approximately 50% removal of 61 ± 8 mg L(-1) was achieved in less than 2 d after NA introduction, achieving the method detection limit (5 mg L(-1)) by day 6 of the experiment in treatments with a C:N:P ratio of 100:10:1, DO > 8 mg L(-1), pH ∼8-9, and temperatures >23 °C. Microbial diversity was lowest in lower temperature treatments (6-16 °C), which may have resulted in observed slower NA degradation. Based on results from this study, when macro- and micronutrients were available, DO, pH, and temperature (within environmentally relevant ranges) influenced rates of aerobic degradation of Fluka NAs. This study could serve as a model for systematically evaluating environmental factors that influence NA degradation in field scenarios. PMID:27459161

  2. Differential Isotopic Fractionation during Cr(VI) Reduction by an Aquifer-Derived Bacterium under Aerobic versus Denitrifying Conditions

    SciTech Connect

    Han, R.; Qin, L.; Brown, S. T.; Christensen, J. N.; Beller, H. R.

    2012-01-27

    We studied Cr isotopic fractionation during Cr(VI) reduction by Pseudomonas stutzeri strain RCH2. Finally, despite the fact that strain RCH2 reduces Cr(VI) cometabolically under both aerobic and denitrifying conditions and at similar specific rates, fractionation was markedly different under these two conditions (ε was ~2‰ aerobically and ~0.4‰ under denitrifying conditions).

  3. Decomposition Dynamics and Changes in Chemical Composition of Wheat Straw Residue under Anaerobic and Aerobic Conditions

    PubMed Central

    Gao, Hongjian; Chen, Xi; Wei, Junling; Zhang, Yajie; Zhang, Ligan; Chang, Jiang; Thompson, Michael L.

    2016-01-01

    Soil aeration is a crucial factor that regulates crop residue decomposition, and the chemical composition of decomposing crop residues may change the forms and availability of soil nutrients, such as N and P. However, to date, differences in the chemical composition of crop straw residues after incorporation into soil and during its decomposition under anaerobic vs. aerobic conditions have not been well documented. The objective of the present study was to assess changes in the C-containing functional groups of wheat straw residue during its decomposition in anaerobic and aerobic environments. A 12-month incubation experiment was carried out to investigate the temporal variations of mass, carbon, and nitrogen loss, as well as changes in the chemical composition of wheat (Triticum aestivum L) straw residues under anaerobic and aerobic conditions by measuring C-containing functional groups using solid state nuclear magnetic resonance (NMR) spectroscopy. The residual mass, carbon content, and nitrogen content of the straw residue sharply declined during the initial 3 months, and then slowly decreased during the last incubation period from 3 to 12 months. The decomposition rate constant (k) for mass loss under aerobic conditions (0.022 d-1) was higher than that under anaerobic conditions (0.014 d-1). The residual mass percentage of cellulose and hemicellulose in the wheat straw gradually declined, whereas that of lignin gradually increased during the entire 12-month incubation period. The NMR spectra of C-containing functional groups in the decomposing straw under both aerobic and anaerobic conditions were similar at the beginning of the incubation as well as at 1 month, 6 months, and 12 months. The main alterations in C-containing functional groups during the decomposition of wheat straw were a decrease in the relative abundances of O-alkyl C and an increase in the relative abundances of alkyl C, aromatic C and COO/N-C = O functional groups. The NMR signals of alkyl C

  4. Decomposition Dynamics and Changes in Chemical Composition of Wheat Straw Residue under Anaerobic and Aerobic Conditions.

    PubMed

    Gao, Hongjian; Chen, Xi; Wei, Junling; Zhang, Yajie; Zhang, Ligan; Chang, Jiang; Thompson, Michael L

    2016-01-01

    Soil aeration is a crucial factor that regulates crop residue decomposition, and the chemical composition of decomposing crop residues may change the forms and availability of soil nutrients, such as N and P. However, to date, differences in the chemical composition of crop straw residues after incorporation into soil and during its decomposition under anaerobic vs. aerobic conditions have not been well documented. The objective of the present study was to assess changes in the C-containing functional groups of wheat straw residue during its decomposition in anaerobic and aerobic environments. A 12-month incubation experiment was carried out to investigate the temporal variations of mass, carbon, and nitrogen loss, as well as changes in the chemical composition of wheat (Triticum aestivum L) straw residues under anaerobic and aerobic conditions by measuring C-containing functional groups using solid state nuclear magnetic resonance (NMR) spectroscopy. The residual mass, carbon content, and nitrogen content of the straw residue sharply declined during the initial 3 months, and then slowly decreased during the last incubation period from 3 to 12 months. The decomposition rate constant (k) for mass loss under aerobic conditions (0.022 d-1) was higher than that under anaerobic conditions (0.014 d-1). The residual mass percentage of cellulose and hemicellulose in the wheat straw gradually declined, whereas that of lignin gradually increased during the entire 12-month incubation period. The NMR spectra of C-containing functional groups in the decomposing straw under both aerobic and anaerobic conditions were similar at the beginning of the incubation as well as at 1 month, 6 months, and 12 months. The main alterations in C-containing functional groups during the decomposition of wheat straw were a decrease in the relative abundances of O-alkyl C and an increase in the relative abundances of alkyl C, aromatic C and COO/N-C = O functional groups. The NMR signals of alkyl C

  5. Decomposition Dynamics and Changes in Chemical Composition of Wheat Straw Residue under Anaerobic and Aerobic Conditions.

    PubMed

    Gao, Hongjian; Chen, Xi; Wei, Junling; Zhang, Yajie; Zhang, Ligan; Chang, Jiang; Thompson, Michael L

    2016-01-01

    Soil aeration is a crucial factor that regulates crop residue decomposition, and the chemical composition of decomposing crop residues may change the forms and availability of soil nutrients, such as N and P. However, to date, differences in the chemical composition of crop straw residues after incorporation into soil and during its decomposition under anaerobic vs. aerobic conditions have not been well documented. The objective of the present study was to assess changes in the C-containing functional groups of wheat straw residue during its decomposition in anaerobic and aerobic environments. A 12-month incubation experiment was carried out to investigate the temporal variations of mass, carbon, and nitrogen loss, as well as changes in the chemical composition of wheat (Triticum aestivum L) straw residues under anaerobic and aerobic conditions by measuring C-containing functional groups using solid state nuclear magnetic resonance (NMR) spectroscopy. The residual mass, carbon content, and nitrogen content of the straw residue sharply declined during the initial 3 months, and then slowly decreased during the last incubation period from 3 to 12 months. The decomposition rate constant (k) for mass loss under aerobic conditions (0.022 d-1) was higher than that under anaerobic conditions (0.014 d-1). The residual mass percentage of cellulose and hemicellulose in the wheat straw gradually declined, whereas that of lignin gradually increased during the entire 12-month incubation period. The NMR spectra of C-containing functional groups in the decomposing straw under both aerobic and anaerobic conditions were similar at the beginning of the incubation as well as at 1 month, 6 months, and 12 months. The main alterations in C-containing functional groups during the decomposition of wheat straw were a decrease in the relative abundances of O-alkyl C and an increase in the relative abundances of alkyl C, aromatic C and COO/N-C = O functional groups. The NMR signals of alkyl C

  6. Silicification-induced cell aggregation for the sustainable production of H2 under aerobic conditions.

    PubMed

    Xiong, Wei; Zhao, Xiaohong; Zhu, Genxing; Shao, Changyu; Li, Yaling; Ma, Weimin; Xu, Xurong; Tang, Ruikang

    2015-10-01

    Photobiological hydrogen production is of great importance because of its promise for generating clean renewable energy. In nature, green algae cannot produce hydrogen as a result of the extreme sensitivity of hydrogenase to oxygen. However, we find that silicification-induced green algae aggregates can achieve sustainable photobiological hydrogen production even under natural aerobic conditions. The core-shell structure of the green algae aggregates creates a balance between photosynthetic electron generation and hydrogenase activity, thus allowing the production of hydrogen. This finding provides a viable pathway for the solar-driven splitting of water into hydrogen and oxygen to develop green energy alternatives by using rationally designed cell-material complexes. PMID:26302695

  7. The bifunctional aldehyde-alcohol dehydrogenase controls ethanol and acetate production in Entamoeba histolytica under aerobic conditions.

    PubMed

    Pineda, Erika; Encalada, Rusely; Olivos-García, Alfonso; Néquiz, Mario; Moreno-Sánchez, Rafael; Saavedra, Emma

    2013-01-16

    By applying metabolic control analysis and inhibitor titration we determined the degree of control (flux control coefficient) of pyruvate:ferredoxin oxidoreductase (PFOR) and bifunctional aldehyde-alcohol dehydrogenase (ADHE) over the fluxes of fermentative glycolysis of Entamoeba histolytica subjected to aerobic conditions. The flux-control coefficients towards ethanol and acetate formation determined for PFOR titrated with diphenyleneiodonium were 0.07 and 0.09, whereas for ADHE titrated with disulfiram were 0.33 and -0.19, respectively. ADHE inhibition induced significant accumulation of glycolytic intermediates and lower ATP content. These results indicate that ADHE exerts significant flux-control on the carbon end-product formation of amoebas subjected to aerobic conditions. PMID:23201265

  8. Decolorization of azo dyes under batch anaerobic and sequential anaerobic/aerobic conditions.

    PubMed

    Işik, Mustafa; Sponza, Delia Teresa

    2004-01-01

    Batch anaerobic and sequential anaerobic upflow anaerobic sludge blanket (UASB)/aerobic continuous stirred tank reactor (CSTR) were used to determine the color and COD removals under anaerobic/aerobic conditions. Two azo dyes namely "Reactive Black 5 (RB 5)," "Congo Red (CR)," and glucose as a carbon source were used for synthetic wastewater. The course of the decolorization process approximates to first order and zero order kinetics with respect to dye concentration for RB 5 and Congo Red azo dyes, respectively, in batch conditions. The decolorization kinetic constant (K0) values increased from 3.6 to 11.8 mg(L h)(-1) as increases in dye concentrations from 200 to 3200 mg L(-1) for CR. Increases in dye concentrations from 0 to 3200 mg L(-1) reduce the decolorization rate constant (k1) values from 0.0141 to 0.0019 h(-1) in batch studies performed with RB 5. Decolorization was achieved effectively under test conditions but ultimate decolorization of azo dyes was not observed at all dye concentrations in batch assay conditions. Dye concentrations of 100 mg L(-1) and 3000 mg L(-1) of glucose-COD containing basal medium were used for continuous studies. The effect of organic loadings and HRT, on the color removal efficiencies and methane gas productions were monitored. 94.1-45.4% COD and 79-73% color removal efficiencies were obtained at an organic system during decolorization of Reactive Black 5. 92.3-77.0% COD and 95.3-92.2% decolorization efficiencies were achieved at a organic loading rate of 1.03-6.65 kg (m3 day)(-1) and a HRT of 3.54-0.49 for Congo Red treatment. The results of this study showed that, although decolorization continued, COD removal efficiencies and methane gas production were depressed at high organic loadings under anaerobic conditions. Furthermore, VFA accumulation, alkalinity consumption, and methane gas percentage were monitored at organic loading as high as 2.49-4.74 kg (m3 day)(-1) and 24.60-30.62 kg (m3 day)(-1), respectively, through the

  9. Reductive dechlorination of Tri- and tetrachloroethylenes depends on transition from aerobic to anaerobic conditions.

    PubMed Central

    Kästner, M

    1991-01-01

    Aerobic enrichment cultures from contaminated groundwaters dechlorinated trichloroethylene (TCE) (14.6 mg/liter; 111 mumol/liter) and tetrachloroethylene (PCE) (16.2 mg/liter; 98 mumol/liter) reductively within 4 days after the transition from aerobic to anaerobic conditions. The transformation products were equimolar amounts of cis-1,2-dichloroethylene and traces of 1,1-dichloroethylene. No other chlorinated product and no methane were detected. The change was accompanied by the release of sulfide, which caused a decrease in the redox potential from 0 to -150 mV. In sterile control experiments, sulfide led to the abiotic formation of traces of 1,1-dichloroethylene without cis-1,2-dichloroethylene production. The reductive dechlorination of PCE via TCE depended on these specific transition conditions after consumption of the electron acceptor oxygen or nitrate. Repeated feeding of TCE or PCE to cultures after the change to anaerobic conditions yielded no further dechlorination. Only aerobic subcultures with an air/liquid ratio of 1:4 maintained dechlorination activities; anaerobic subcultures showed no transformation. Bacteria from noncontaminated sites showed no reduction under the same conditions. PMID:1892393

  10. Effect of particulate organic substrate on aerobic granulation and operating conditions of sequencing batch reactors.

    PubMed

    Wagner, Jamile; Weissbrodt, David Gregory; Manguin, Vincent; da Costa, Rejane Helena Ribeiro; Morgenroth, Eberhard; Derlon, Nicolas

    2015-11-15

    The formation and application of aerobic granules for the treatment of real wastewaters still remains challenging. The high fraction of particulate organic matter (XS) present in real wastewaters can affect the granulation process. The present study aims at understanding to what extent the presence of XS affects the granule formation and the quality of the treated effluent. A second objective was to evaluate how the operating conditions of an aerobic granular sludge (AGS) reactor must be adapted to overcome the effects of the presence of XS. Two reactors fed with synthetic wastewaters were operated in absence (R1) or presence (R2) of starch as proxy for XS. Different operating conditions were evaluated. Our results indicated that the presence of XS in the wastewater reduces the kinetic of granule formation. After 52 d of operation, the fraction of granules reached only 21% in R2, while in R1 this fraction was of 54%. The granules grown in presence of XS had irregular and filamentous outgrowths in the surface, which affected the settleability of the biomass and therefore the quality of the effluent. An extension of the anaerobic phase in R2 led to the formation of more compact granules with a better settling ability. A high fraction of granules was obtained in both reactors after an increase of the selection pressure for fast-settling biomass, but the quality of the effluent remained low. Operating the reactors in a simultaneous fill-and-draw mode at a low selection pressure for fast-settling biomass showed to be beneficial for substrate removal efficiency and for suppressing filamentous overgrowth. Average removal efficiencies for total COD, soluble COD, ammonium, and phosphate were 87 ± 4%, 95 ± 1%, 92 ± 10%, and 87 ± 12% for R1, and 72 ± 12%, 86 ± 5%, 71 ± 12%, and 77 ± 11% for R2, respectively. Overall our study demonstrates that the operating conditions of AGS reactors must be adapted according to the wastewater composition. When treating effluents that

  11. P450-catalyzed asymmetric cyclopropanation of electron-deficient olefins under aerobic conditions.

    PubMed

    Renata, Hans; Wang, Z Jane; Kitto, Rebekah Z; Arnold, Frances H

    2014-10-01

    A variant of P450 from Bacillus megaterium five mutations away from wild type is a highly active catalyst for cyclopropanation of a variety of acrylamide and acrylate olefins with ethyl diazoacetate (EDA). The very high rate of reaction enabled by histidine ligation allowed the reaction to be conducted under aerobic conditions. The promiscuity of this catalyst for a variety of substrates containing amides has enabled synthesis of a small library of precursors to levomilnacipran derivatives. PMID:25221671

  12. Plutonium Oxidation State Distribution under Aerobic and Anaerobic Subsurface Conditions for Metal-Reducing Bacteria

    NASA Astrophysics Data System (ADS)

    Reed, D. T.; Swanson, J.; Khaing, H.; Deo, R.; Rittmann, B.

    2009-12-01

    The fate and potential mobility of plutonium in the subsurface is receiving increased attention as the DOE looks to cleanup the many legacy nuclear waste sites and associated subsurface contamination. Plutonium is the near-surface contaminant of concern at several DOE sites and continues to be the contaminant of concern for the permanent disposal of nuclear waste. The mobility of plutonium is highly dependent on its redox distribution at its contamination source and along its potential migration pathways. This redox distribution is often controlled, especially in the near-surface where organic/inorganic contaminants often coexist, by the direct and indirect effects of microbial activity. The redox distribution of plutonium in the presence of facultative metal reducing bacteria (specifically Shewanella and Geobacter species) was established in a concurrent experimental and modeling study under aerobic and anaerobic conditions. Pu(VI), although relatively soluble under oxidizing conditions at near-neutral pH, does not persist under a wide range of the oxic and anoxic conditions investigated in microbiologically active systems. Pu(V) complexes, which exhibit high chemical toxicity towards microorganisms, are relatively stable under oxic conditions but are reduced by metal reducing bacteria under anaerobic conditions. These facultative metal-reducing bacteria led to the rapid reduction of higher valent plutonium to form Pu(III/IV) species depending on nature of the starting plutonium species and chelating agents present in solution. Redox cycling of these lower oxidation states is likely a critical step in the formation of pseudo colloids that may lead to long-range subsurface transport. The CCBATCH biogeochemical model is used to explain the redox mechanisms and final speciation of the plutonium oxidation state distributions observed. These results for microbiologically active systems are interpreted in the context of their importance in defining the overall migration

  13. Aerobic capacity in wild satin bowerbirds: repeatability and effects of age, sex and condition.

    PubMed

    Chappell, Mark A; Savard, Jean-Francois; Siani, Jennifer; Coleman, Seth W; Keagy, Jason; Borgia, Gerald

    2011-10-01

    Individual variation in aerobic capacity has been extensively studied, especially with respect to condition, maturity or pathogen infection, and to gain insights into mechanistic foundations of performance. However, its relationship to mate competition is less well understood, particularly for animals in natural habitats. We examined aerobic capacity [maximum rate of O2 consumption (VO2,max) in forced exercise] in wild satin bowerbirds, an Australian passerine with a non-resource based mating system and strong intermale sexual competition. We tested for repeatability of mass and VO2,max, differences among age and sex classes, and effects of several condition indices. In adult males, we examined interactions between aerobic performance and bower ownership (required for male mating success). There was significant repeatability of mass and VO2,max within and between years, but between-year repeatability was lower than within-year repeatability. VO2,max varied with an overall scaling to mass(0.791), but most variance in VO2,max was not explained by mass. Indicators of condition (tarsus and wing length asymmetry, the ratio of tarsus length to mass) were not correlated to VO2,max. Ectoparasite counts were weakly correlated to VO2,max across all age-sex classes but not within any class. Adult males, the cohort with the most intense levels of mating competition, had higher VO2,max than juvenile birds or adult females. However, there was no difference between the VO2,max of bower-owning males and that of males not known to hold bowers. Thus one major factor determining male reproductive success was not correlated to aerobic performance. PMID:21900466

  14. Binary Interactions of Antagonistic Bacteria with Candida albicans Under Aerobic and Anaerobic Conditions.

    PubMed

    Benadé, Eliska; Stone, Wendy; Mouton, Marnel; Postma, Ferdinand; Wilsenach, Jac; Botha, Alfred

    2016-04-01

    We used both aerobic and anaerobic liquid co-cultures, prepared with Luria Bertani broth, to study the effect of bacteria on the survival of Candida albicans in the external environment, away from an animal host. The bacteria were represented by Aeromonas hydrophila, Bacillus cereus, Bacillus subtilis, Clostridium, Enterobacter, Klebsiella pneumoniae, Kluyvera ascorbata and Serratia marcescens. Under aerobic conditions, the yeast's growth was inhibited in the presence of bacterial growth; however, under anaerobic conditions, yeast and bacterial growth in co-cultures was similar to that observed for pure cultures. Subsequent assays revealed that the majority of bacterial strains aerobically produced extracellular hydrolytic enzymes capable of yeast cell wall hydrolysis, including chitinases and mannan-degrading enzymes. In contrast, except for the A. hydrophila strain, these enzymes were not detected in anaerobic bacterial cultures, nor was the antimicrobial compound prodigiosin found in anaerobic cultures of S. marcescens. When we suspended C. albicans cells in crude extracellular enzyme preparations from K. pneumoniae and S. marcescens, we detected no negative effect on yeast viability. However, we found that these preparations enhance the toxicity of prodigiosin towards the yeast, especially in combination with mannan-degrading enzymes. Analyses of the chitin and mannan content of yeast cell walls revealed that less chitin was produced under anaerobic than aerobic conditions; however, the levels of mannan, known for its low permeability, remained the same. The latter phenomenon, as well as reduced production of the bacterial enzymes and prodigiosin, may contribute to anaerobic growth and survival of C. albicans in the presence of bacteria.

  15. Binary Interactions of Antagonistic Bacteria with Candida albicans Under Aerobic and Anaerobic Conditions.

    PubMed

    Benadé, Eliska; Stone, Wendy; Mouton, Marnel; Postma, Ferdinand; Wilsenach, Jac; Botha, Alfred

    2016-04-01

    We used both aerobic and anaerobic liquid co-cultures, prepared with Luria Bertani broth, to study the effect of bacteria on the survival of Candida albicans in the external environment, away from an animal host. The bacteria were represented by Aeromonas hydrophila, Bacillus cereus, Bacillus subtilis, Clostridium, Enterobacter, Klebsiella pneumoniae, Kluyvera ascorbata and Serratia marcescens. Under aerobic conditions, the yeast's growth was inhibited in the presence of bacterial growth; however, under anaerobic conditions, yeast and bacterial growth in co-cultures was similar to that observed for pure cultures. Subsequent assays revealed that the majority of bacterial strains aerobically produced extracellular hydrolytic enzymes capable of yeast cell wall hydrolysis, including chitinases and mannan-degrading enzymes. In contrast, except for the A. hydrophila strain, these enzymes were not detected in anaerobic bacterial cultures, nor was the antimicrobial compound prodigiosin found in anaerobic cultures of S. marcescens. When we suspended C. albicans cells in crude extracellular enzyme preparations from K. pneumoniae and S. marcescens, we detected no negative effect on yeast viability. However, we found that these preparations enhance the toxicity of prodigiosin towards the yeast, especially in combination with mannan-degrading enzymes. Analyses of the chitin and mannan content of yeast cell walls revealed that less chitin was produced under anaerobic than aerobic conditions; however, the levels of mannan, known for its low permeability, remained the same. The latter phenomenon, as well as reduced production of the bacterial enzymes and prodigiosin, may contribute to anaerobic growth and survival of C. albicans in the presence of bacteria. PMID:26566932

  16. Aerobic versus Anaerobic Microbial Degradation of Clothianidin under Simulated California Rice Field Conditions.

    PubMed

    Mulligan, Rebecca A; Tomco, Patrick L; Howard, Megan W; Schempp, Tabitha T; Stewart, Davis J; Stacey, Phillip M; Ball, David B; Tjeerdema, Ronald S

    2016-09-28

    Microbial degradation of clothianidin was characterized under aerobic and anaerobic California rice field conditions. Rate constants (k) and half-lives (DT50) were determined for aerobic and anaerobic microcosms, and an enrichment experiment was performed at various nutrient conditions and pesticide concentrations. Temperature effects on anaerobic degradation rates were determined at 22 ± 2 and 35 ± 2 °C. Microbial growth was assessed in the presence of various pesticide concentrations, and distinct colonies were isolated and identified. Slow aerobic degradation was observed, but anaerobic degradation occurred rapidly at both 25 and 35 °C. Transformation rates and DT50 values in flooded soil at 35 ± 2 °C (k = -7.16 × 10(-2) ± 3.08 × 10(-3) day(-1), DT50 = 9.7 days) were significantly faster than in 25 ± 2 °C microcosms (k= -2.45 × 10(-2) ± 1.59 × 10(-3) day(-1), DT50 = 28.3 days). At the field scale, biodegradation of clothianidin will vary with extent of oxygenation.

  17. Aerobic versus Anaerobic Microbial Degradation of Clothianidin under Simulated California Rice Field Conditions.

    PubMed

    Mulligan, Rebecca A; Tomco, Patrick L; Howard, Megan W; Schempp, Tabitha T; Stewart, Davis J; Stacey, Phillip M; Ball, David B; Tjeerdema, Ronald S

    2016-09-28

    Microbial degradation of clothianidin was characterized under aerobic and anaerobic California rice field conditions. Rate constants (k) and half-lives (DT50) were determined for aerobic and anaerobic microcosms, and an enrichment experiment was performed at various nutrient conditions and pesticide concentrations. Temperature effects on anaerobic degradation rates were determined at 22 ± 2 and 35 ± 2 °C. Microbial growth was assessed in the presence of various pesticide concentrations, and distinct colonies were isolated and identified. Slow aerobic degradation was observed, but anaerobic degradation occurred rapidly at both 25 and 35 °C. Transformation rates and DT50 values in flooded soil at 35 ± 2 °C (k = -7.16 × 10(-2) ± 3.08 × 10(-3) day(-1), DT50 = 9.7 days) were significantly faster than in 25 ± 2 °C microcosms (k= -2.45 × 10(-2) ± 1.59 × 10(-3) day(-1), DT50 = 28.3 days). At the field scale, biodegradation of clothianidin will vary with extent of oxygenation. PMID:27499061

  18. Efficient production and secretion of pyruvate from Halomonas sp. KM-1 under aerobic conditions.

    PubMed

    Kawata, Yoshikazu; Nishimura, Taku; Matsushita, Isao; Tsubota, Jun

    2016-03-01

    The alkaliphilic, halophilic bacterium Halomonas sp. KM-1 can utilize both hexose and pentose sugars for the intracellular storage of bioplastic poly-(R)-3-hydroxybutyric acid (PHB) under aerobic conditions. In this study, we investigated the effects of the sodium nitrate concentration on PHB accumulation in the KM-1 strain. Unexpectedly, we observed the secretion of pyruvate, a central intermediate in carbon- and energy-metabolism processes in all organisms; therefore, pyruvate is widely used as a starting material in the industrial biosynthesis of pharmaceuticals and is employed for the production of crop-protection agents, polymers, cosmetics, and food additives. We then further analyzed pyruvate productivity following changes in culture temperature and the buffer concentration. In 48-h batch-cultivation experiments, we found that wild-type Halomonas sp. KM-1 secreted 63.3 g/L pyruvate at a rate of 1.32 g/(L·h), comparable to the results of former studies using mutant and recombinant microorganisms. Thus, these data provided important insights into the production of pyruvate using this novel strain.

  19. Efficient production and secretion of pyruvate from Halomonas sp. KM-1 under aerobic conditions.

    PubMed

    Kawata, Yoshikazu; Nishimura, Taku; Matsushita, Isao; Tsubota, Jun

    2016-03-01

    The alkaliphilic, halophilic bacterium Halomonas sp. KM-1 can utilize both hexose and pentose sugars for the intracellular storage of bioplastic poly-(R)-3-hydroxybutyric acid (PHB) under aerobic conditions. In this study, we investigated the effects of the sodium nitrate concentration on PHB accumulation in the KM-1 strain. Unexpectedly, we observed the secretion of pyruvate, a central intermediate in carbon- and energy-metabolism processes in all organisms; therefore, pyruvate is widely used as a starting material in the industrial biosynthesis of pharmaceuticals and is employed for the production of crop-protection agents, polymers, cosmetics, and food additives. We then further analyzed pyruvate productivity following changes in culture temperature and the buffer concentration. In 48-h batch-cultivation experiments, we found that wild-type Halomonas sp. KM-1 secreted 63.3 g/L pyruvate at a rate of 1.32 g/(L·h), comparable to the results of former studies using mutant and recombinant microorganisms. Thus, these data provided important insights into the production of pyruvate using this novel strain. PMID:26989057

  20. Modeling of yeast Brettanomyces bruxellensis growth at different acetic acid concentrations under aerobic and anaerobic conditions.

    PubMed

    Yahara, Garcia Alvarado; Javier, Mendez Ancona; Tulio, Mata Jimenez Marco; Javier, Gómez Rodriguez; Guadalupe, Aguilar Uscanga Maria

    2007-11-01

    Glucose utilization by Brettanomyces bruxellensis at different acetic acid concentrations under aerobic and anaerobic conditions was investigated. The presence of the organic acid disturbs the growth and fermentative activity of the yeast when its concentration exceeds 2 g l(-1). A mathematical model is proposed for the kinetic behavior analysis of yeast growing in batch culture. A Matlab algorithm was used for estimation of model parameters, whose confidence intervals were also calculated at a 0.95 probability level using a t-Student distribution for f degrees of freedom. The model successfully simulated the batch kinetics observed at different concentrations of acetic acid under both oxygen conditions.

  1. Molecular characterization of a microbial consortium involved in methane oxidation coupled to denitrification under micro-aerobic conditions

    PubMed Central

    Liu, Jingjing; Sun, Faqian; Wang, Liang; Ju, Xi; Wu, Weixiang; Chen, Yingxu

    2014-01-01

    Methane can be used as an alternative carbon source in biological denitrification because it is nontoxic, widely available and relatively inexpensive. A microbial consortium involved in methane oxidation coupled to denitrification (MOD) was enriched with nitrite and nitrate as electron acceptors under micro-aerobic conditions. The 16S rRNA gene combined with pmoA phylogeny of methanotrophs and nirK phylogeny of denitrifiers were analysed to reveal the dominant microbial populations and functional microorganisms. Real-time quantitative polymerase chain reaction results showed high numbers of methanotrophs and denitrifiers in the enriched consortium. The 16S rRNA gene clone library revealed that Methylococcaceae and Methylophilaceae were the dominant populations in the MOD ecosystem. Phylogenetic analyses of pmoA gene clone libraries indicated that all methanotrophs belonged to Methylococcaceae, a type I methanotroph employing the ribulose monophosphate pathway for methane oxidation. Methylotrophic denitrifiers of the Methylophilaceae that can utilize organic intermediates (i.e. formaldehyde, citrate and acetate) released from the methanotrophs played a vital role in aerobic denitrification. This study is the first report to confirm micro-aerobic denitrification and to make phylogenetic and functional assignments for some members of the microbial assemblages involved in MOD. PMID:24245852

  2. Molecular characterization of a microbial consortium involved in methane oxidation coupled to denitrification under micro-aerobic conditions.

    PubMed

    Liu, Jingjing; Sun, Faqian; Wang, Liang; Ju, Xi; Wu, Weixiang; Chen, Yingxu

    2014-01-01

    Methane can be used as an alternative carbon source in biological denitrification because it is nontoxic, widely available and relatively inexpensive. A microbial consortium involved in methane oxidation coupled to denitrification (MOD) was enriched with nitrite and nitrate as electron acceptors under micro-aerobic conditions. The 16S rRNA gene combined with pmoA phylogeny of methanotrophs and nirK phylogeny of denitrifiers were analysed to reveal the dominant microbial populations and functional microorganisms. Real-time quantitative polymerase chain reaction results showed high numbers of methanotrophs and denitrifiers in the enriched consortium. The 16S rRNA gene clone library revealed that Methylococcaceae and Methylophilaceae were the dominant populations in the MOD ecosystem. Phylogenetic analyses of pmoA gene clone libraries indicated that all methanotrophs belonged to Methylococcaceae, a type I methanotroph employing the ribulose monophosphate pathway for methane oxidation. Methylotrophic denitrifiers of the Methylophilaceae that can utilize organic intermediates (i.e. formaldehyde, citrate and acetate) released from the methanotrophs played a vital role in aerobic denitrification. This study is the first report to confirm micro-aerobic denitrification and to make phylogenetic and functional assignments for some members of the microbial assemblages involved in MOD.

  3. Using a tank flow model with PEARL to measure the variation in pesticide persistence between anaerobic and aerobic soil conditions

    NASA Astrophysics Data System (ADS)

    Real, Joaquin; Seiterle-Winn, Natalie; Frances, Felix

    2013-04-01

    Pesticide leaching is very sensitive to the transformation rate (Boesten and Linden, 1991). The values of the transformation rates of the pesticides differ between aerobic and anaerobic soil conditions. The main objective is to determine if there is a significant variation in pesticide persistence between aerobic and anaerobic soil conditions. An auxiliary hydrological model is used with the PEARL model (Leistra et al, 2001). The auxiliary model determines the degree of saturation of the soil at each time step. The value of the degradation rate for a given pesticide in the PEARL model varies depending on the time periods with saturated or unsaturated soil conditions. The proposed auxiliary model has been conceptualized as a static tank flow model based on the actual evapotranspiration of the crop plants. It is based on the RIBAV model (Garcia-Arias et al. 2012) used for the modeling of riparian vegetation zonation. The tank represents a soil column which also includes the superficial root layer. The lower capacity limit of this tank is the permanent wilting moisture of the soil. The upper capacity limit represents the saturated condition of the soil. The tanks input flows are precipitation and irrigation. In contrast, output flows are the actual evapotranspiration and the discharge of the tank. The most relevant model parameters are the soil retention curves, the crop parameters (specially related to root depths and crop coefficients) and the daily meteorological data (such as precipitation and potential evapotranspiration). The main output of the auxiliary model is the relative soil moisture, which determines if the PEARL model should use the transformation rate value for aerobic or for anaerobic conditions. In order to prove the applicability of the model, it was tested with various pesticides, which cover a wide range of transformation rates. The results show that the auxiliary tank model is able to determine the partition of the pesticides degrading in both

  4. Biodegradation of methyl t-butyl ether by aerobic granules under a cosubstrate condition.

    PubMed

    Zhang, L L; Chen, J M; Fang, F

    2008-03-01

    Aerobic granules efficient at degrading methyl tert-butyl ether (MTBE) with ethanol as a cosubstrate were successfully developed in a well-mixed sequencing batch reactor (SBR). Aerobic granules were first observed about 100 days after reactor startup. Treatment efficiency of MTBE in the reactor during stable operation exceeded 99.9%, and effluent MTBE was in the range of 15-50 microg/L. The specific MTBE degradation rate was observed to increase with increasing MTBE initial concentration from 25 to 500 mg/L, which peaked at 22.7 mg MTBE/g (volatile suspended solids).h and declined with further increases in MTBE concentration as substrate inhibition effects became significant. Microbial-community deoxyribonucleic acid profiling was carried out using denaturing gradient gel electrophoresis of polymerase chain reaction-amplified 16S ribosomal ribonucleic acid. The reactor was found to be inhabited by several diverse bacterial species, most notably microorganisms related to the genera Sphingomonas, Methylobacterium, and Hyphomicrobium vulgare. These organisms were previously reported to be associated with MTBE biodegradation. A majority of the bands in the reactor represented a group of organisms belonging to the Flavobacteria-Proteobacteria-Actinobacteridae class of bacteria. This study demonstrates that MTBE can be effectively degraded by aerobic granules under a cosubstrate condition and gives insight into the microorganisms potentially involved in the process. PMID:18183384

  5. Chromium isotopic fractionation during Cr(VI) reduction by Bacillus sp. under aerobic conditions.

    PubMed

    Xu, Fen; Ma, Teng; Zhou, Lian; Hu, Zhifang; Shi, Liu

    2015-07-01

    This study investigated the fractionation of chromium isotopes during chromium reduction by Bacillus sp. under aerobic condition, variable carbon source (glucose) concentration (0, 0.1, 1, 2.5 and 10mM), and incubation temperatures (4, 15, 25 and 37°C). The results revealed that the δ(53)Cr values in the residual Cr(VI) increased with the degree of Cr reduction, and followed a Rayleigh fractionation model. The addition of glucose only slightly affected cell-specific Cr(VI) reduction rates (cSRR). However, the value of ε (2.00±0.21‰) in the experiments with different concentrations of glucose (0.1, 1, 2.5 and 10mM) was smaller than that from the experiment without glucose (3.74±0.16‰). The results indicated that the cell-specific reduction rate is not the sole control on the degree of isotopic fractionation, and different metabolic pathways would result in differing degrees of Cr isotopic fractionation. The cSRR decreased with decreasing temperature, showing that the values of ε were 7.62±0.36‰, 4.59±0.28‰, 3.09±0.16‰ and 1.99±0.23‰ at temperatures of 4, 15, 25 and 37°C, respectively. It shown that increasing cSRR linked to decreasing fractionations has been associated with increasing temperatures. Overall, our results revealed that temperature is a primary factor affecting Cr isotopic fractionation under microbial actions.

  6. Comparison of Proteomics Profiles of Campylobacter jejuni Strain Bf under Microaerobic and Aerobic Conditions

    PubMed Central

    Rodrigues, Ramila C.; Haddad, Nabila; Chevret, Didier; Cappelier, Jean-Michel; Tresse, Odile

    2016-01-01

    Campylobacter jejuni accounts for one of the leading causes of foodborne bacterial enteritis in humans. Despite being considered an obligate microaerobic microorganism, C. jejuni is regularly exposed to oxidative stress. However, its adaptive strategies to survive the atmospheric oxygen level during transmission to humans remain unclear. Recently, the clinical C. jejuni strain Bf was singled out for its unexpected ability to grow under ambient atmosphere. Here, we aimed to understand better the biological mechanisms underlying its atypical aerotolerance trait using two-dimensional protein electrophoresis, gene expression, and enzymatic activities. Forty-seven proteins were identified with a significantly different abundance between cultivation under microaerobic and aerobic conditions. The over-expressed proteins in aerobiosis belonged mainly to the oxidative stress response, enzymes of the tricarboxylic acid cycle, iron uptake, and regulation, and amino acid uptake when compared to microaerobic conditions. The higher abundance of proteins related to oxidative stress was correlated to dramatically higher transcript levels of the corresponding encoding genes in aerobic conditions compared to microaerobic conditions. In addition, a higher catalase-equivalent activity in strain Bf was observed. Despite the restricted catabolic capacities of C. jejuni, this study reveals that strain Bf is equipped to withstand oxidative stress. This ability could contribute to emergence and persistence of particular strains of C. jejuni throughout food processing or macrophage attack during human infection. PMID:27790195

  7. Impact of oxidative stress defense on bacterial survival and morphological change in Campylobacter jejuni under aerobic conditions.

    PubMed

    Oh, Euna; McMullen, Lynn; Jeon, Byeonghwa

    2015-01-01

    Campylobacter jejuni, a microaerophilic foodborne pathogen, inescapably faces high oxygen tension during its transmission to humans. Thus, the ability of C. jejuni to survive under oxygen-rich conditions may significantly impact C. jejuni viability in food and food safety as well. In this study, we investigated the impact of oxidative stress resistance on the survival of C. jejuni under aerobic conditions by examining three mutants defective in key antioxidant genes, including ahpC, katA, and sodB. All the three mutants exhibited growth reduction under aerobic conditions compared to the wild-type (WT), and the ahpC mutant showed the most significant growth defect. The CFU reduction in the mutants was recovered to the WT level by complementation. Higher levels of reactive oxygen species were accumulated in C. jejuni under aerobic conditions than microaerobic conditions, and supplementation of culture media with an antioxidant recovered the growth of C. jejuni. The levels of lipid peroxidation and protein oxidation were significantly increased in the mutants compared to WT. Additionally, the mutants exhibited different morphological changes under aerobic conditions. The ahpC and katA mutants developed coccoid morphology by aeration, whereas the sodB mutant established elongated cellular morphology. Compared to microaerobic conditions, interestingly, aerobic culture conditions substantially induced the formation of coccoidal cells, and antioxidant treatment reduced the emergence of coccoid forms under aerobic conditions. The ATP concentrations and PMA-qPCR analysis supported that oxidative stress is a factor that induces the development of a viable-but-non-culturable state in C. jejuni. The findings in this study clearly demonstrated that oxidative stress resistance plays an important role in the survival and morphological changes of C. jejuni under aerobic conditions. PMID:25914692

  8. Modeling the influence of varying hydraulic conditions on aerobic respiration and denitrification in the hyporheic zone

    NASA Astrophysics Data System (ADS)

    Trauth, N.; Schmidt, C.; Fleckenstein, J. H.

    2013-12-01

    Exchange of water and solutes across the stream-sediment interface is an important control for biogeochemical transformations in the hyporheic zone (HZ) with measurable impacts on nutrient cycling and solute attenuation in fluvial systems. Here we investigate the interplay between turbulent stream flow and HZ flow under various hydraulic conditions applied to two cases: a) three-dimensional generic pool-riffle sequences with different morphological properties, and b) a real mid-stream gravel-bar. Stream flow is simulated by the open source computational fluid dynamics (CFD) software OpenFOAM which provides the hydraulic head distribution at the streambed. It is sequentially coupled to the top of the groundwater model code MIN3P, simulating flow, solute transport, aerobic respiration (AR) and denitrification (DN) in the HZ. Flow in the HZ is directly influenced by the hydraulic head distribution at the streambed surface and the ambient groundwater flow. Three reactive transport scenarios are considered: 1) stream water as the primary source of dissolved oxygen (DO), nitrate (NO3) and dissolved organic carbon (DOC), 2) upwelling groundwater as an additionally source of NO3, and 3) upwelling groundwater as an additional source of DO in various concentrations. Results show an increase in hyporheic exchange flow for increasing stream discharge with a concurrent decrease in residence time. The fraction of circulating stream water through the HZ is in the range of 1x10-5 to 1x10-6 per unit stream length, decreasing with increasing discharge. Ambient groundwater flow in both the up- and downwelling direction diminishes significantly the hyporheic exchange flow and extent. Biogeochemical processes in the HZ are strongly controlled by ambient groundwater flow, even more so than by changes in stream discharge. AR and DN efficiencies of the HZ are significantly reduced by up- and downwelling groundwater and are positively correlated with median residence times. AR occurs in

  9. The preferential growth of branched GDGT source microorganisms under aerobic conditions in peat revealed by stable isotope probing experiments

    NASA Astrophysics Data System (ADS)

    Huguet, Arnaud; Meador, Travis B.; Laggoun-Défarge, Fatima; Könneke, Martin; Derenne, Sylvie; Hinrichs, Kai-Uwe

    2016-04-01

    , whereas corresponding rates in the anaerobic acrotelm incubations were more than an order of magnitude slower (< 3 ng cm-3 y-1). Production rates of bacterial fatty acids approached or exceeded 1 μg cm-3 y-1 in both aerobic and anaerobic incubations, and were therefore much higher than those of brGDGTs. This suggests that the brGDGT producers are a minor constituent of the microbial community in Sphagnum-dominated peatlands or brGDGTs are a small component of the microbial cell membrane in comparison to fatty acids, despite the typically high brGDGT concentrations observed in peat. In conclusion, our results reveal that brGDGT source microorganisms preferentially grow under oxic to sub-oxic conditions, likely as facultative anaerobes. We show for the first time that these microorganisms are especially active at the peat surface, in contrast to the deeper layers, implying that the high abundance of brGDGTs observed in the catotlem should result from the accumulation of the brGDGTs actively produced in the acrotelm. Reference Weijers, J.W.H., Wiesenberg, G.L.B., Bol, R., Hopmans, E.C., Pancost, R.D., 2010. Biogeosciences 7, 2959-2973.

  10. The preferential growth of branched GDGT source microorganisms under aerobic conditions in peat revealed by stable isotope probing experiments

    NASA Astrophysics Data System (ADS)

    Huguet, Arnaud; Meador, Travis B.; Laggoun-Défarge, Fatima; Könneke, Martin; Derenne, Sylvie; Hinrichs, Kai-Uwe

    2016-04-01

    fen, whereas corresponding rates in the anaerobic acrotelm incubations were more than an order of magnitude slower (< 3 ng cm‑3 y‑1). Production rates of bacterial fatty acids approached or exceeded 1 μg cm‑3 y‑1 in both aerobic and anaerobic incubations, and were therefore much higher than those of brGDGTs. This suggests that the brGDGT producers are a minor constituent of the microbial community in Sphagnum-dominated peatlands or brGDGTs are a small component of the microbial cell membrane in comparison to fatty acids, despite the typically high brGDGT concentrations observed in peat. In conclusion, our results reveal that brGDGT source microorganisms preferentially grow under oxic to sub-oxic conditions, likely as facultative anaerobes. We show for the first time that these microorganisms are especially active at the peat surface, in contrast to the deeper layers, implying that the high abundance of brGDGTs observed in the catotlem should result from the accumulation of the brGDGTs actively produced in the acrotelm. Reference Weijers, J.W.H., Wiesenberg, G.L.B., Bol, R., Hopmans, E.C., Pancost, R.D., 2010. Biogeosciences 7, 2959-2973.

  11. A Model of the Cardiorespiratory Response to Aerobic Exercise in Healthy and Heart Failure Conditions.

    PubMed

    Fresiello, Libera; Meyns, Bart; Di Molfetta, Arianna; Ferrari, Gianfranco

    2016-01-01

    The physiological response to physical exercise is now recognized as an important tool which can aid the diagnosis and treatment of cardiovascular diseases. This is due to the fact that several mechanisms are needed to accommodate a higher cardiac output and a higher oxygen delivery to tissues. The aim of the present work is to provide a fully closed loop cardiorespiratory simulator reproducing the main physiological mechanisms which arise during aerobic exercise. The simulator also provides a representation of the impairments of these mechanisms in heart failure condition and their effect on limiting exercise capacity. The simulator consists of a cardiovascular model including the left and right heart, pulmonary and systemic circulations. This latter is split into exercising and non-exercising regions and is controlled by the baroreflex and metabolic mechanisms. In addition, the simulator includes a respiratory model reproducing the gas exchange in lungs and tissues, the ventilation control and the effects of its mechanics on the cardiovascular system. The simulator was tested and compared to the data in the literature at three different workloads whilst cycling (25, 49 and 73 watts). The results show that the simulator is able to reproduce the response to exercise in terms of: heart rate (from 67 to 134 bpm), cardiac output (from 5.3 to 10.2 l/min), leg blood flow (from 0.7 to 3.0 l/min), peripheral resistance (from 0.9 to 0.5 mmHg/(cm(3)/s)), central arteriovenous oxygen difference (from 4.5 to 10.8 ml/dl) and ventilation (6.1-25.5 l/min). The simulator was further adapted to reproduce the main impairments observed in heart failure condition, such as reduced sensitivity of baroreflex and metabolic controls, lower perfusion to the exercising regions (from 0.6 to 1.4 l/min) and hyperventilation (from 9.2 to 40.2 l/min). The simulator we developed is a useful tool for the description of the basic physiological mechanisms operating during exercise. It can reproduce

  12. A Model of the Cardiorespiratory Response to Aerobic Exercise in Healthy and Heart Failure Conditions

    PubMed Central

    Fresiello, Libera; Meyns, Bart; Di Molfetta, Arianna; Ferrari, Gianfranco

    2016-01-01

    The physiological response to physical exercise is now recognized as an important tool which can aid the diagnosis and treatment of cardiovascular diseases. This is due to the fact that several mechanisms are needed to accommodate a higher cardiac output and a higher oxygen delivery to tissues. The aim of the present work is to provide a fully closed loop cardiorespiratory simulator reproducing the main physiological mechanisms which arise during aerobic exercise. The simulator also provides a representation of the impairments of these mechanisms in heart failure condition and their effect on limiting exercise capacity. The simulator consists of a cardiovascular model including the left and right heart, pulmonary and systemic circulations. This latter is split into exercising and non-exercising regions and is controlled by the baroreflex and metabolic mechanisms. In addition, the simulator includes a respiratory model reproducing the gas exchange in lungs and tissues, the ventilation control and the effects of its mechanics on the cardiovascular system. The simulator was tested and compared to the data in the literature at three different workloads whilst cycling (25, 49 and 73 watts). The results show that the simulator is able to reproduce the response to exercise in terms of: heart rate (from 67 to 134 bpm), cardiac output (from 5.3 to 10.2 l/min), leg blood flow (from 0.7 to 3.0 l/min), peripheral resistance (from 0.9 to 0.5 mmHg/(cm3/s)), central arteriovenous oxygen difference (from 4.5 to 10.8 ml/dl) and ventilation (6.1–25.5 l/min). The simulator was further adapted to reproduce the main impairments observed in heart failure condition, such as reduced sensitivity of baroreflex and metabolic controls, lower perfusion to the exercising regions (from 0.6 to 1.4 l/min) and hyperventilation (from 9.2 to 40.2 l/min). The simulator we developed is a useful tool for the description of the basic physiological mechanisms operating during exercise. It can reproduce

  13. A Model of the Cardiorespiratory Response to Aerobic Exercise in Healthy and Heart Failure Conditions.

    PubMed

    Fresiello, Libera; Meyns, Bart; Di Molfetta, Arianna; Ferrari, Gianfranco

    2016-01-01

    The physiological response to physical exercise is now recognized as an important tool which can aid the diagnosis and treatment of cardiovascular diseases. This is due to the fact that several mechanisms are needed to accommodate a higher cardiac output and a higher oxygen delivery to tissues. The aim of the present work is to provide a fully closed loop cardiorespiratory simulator reproducing the main physiological mechanisms which arise during aerobic exercise. The simulator also provides a representation of the impairments of these mechanisms in heart failure condition and their effect on limiting exercise capacity. The simulator consists of a cardiovascular model including the left and right heart, pulmonary and systemic circulations. This latter is split into exercising and non-exercising regions and is controlled by the baroreflex and metabolic mechanisms. In addition, the simulator includes a respiratory model reproducing the gas exchange in lungs and tissues, the ventilation control and the effects of its mechanics on the cardiovascular system. The simulator was tested and compared to the data in the literature at three different workloads whilst cycling (25, 49 and 73 watts). The results show that the simulator is able to reproduce the response to exercise in terms of: heart rate (from 67 to 134 bpm), cardiac output (from 5.3 to 10.2 l/min), leg blood flow (from 0.7 to 3.0 l/min), peripheral resistance (from 0.9 to 0.5 mmHg/(cm(3)/s)), central arteriovenous oxygen difference (from 4.5 to 10.8 ml/dl) and ventilation (6.1-25.5 l/min). The simulator was further adapted to reproduce the main impairments observed in heart failure condition, such as reduced sensitivity of baroreflex and metabolic controls, lower perfusion to the exercising regions (from 0.6 to 1.4 l/min) and hyperventilation (from 9.2 to 40.2 l/min). The simulator we developed is a useful tool for the description of the basic physiological mechanisms operating during exercise. It can reproduce

  14. Characterization of the Enterobacteriaceae community that developed during storage of minced beef under aerobic or modified atmosphere packaging conditions.

    PubMed

    Doulgeraki, Agapi I; Paramithiotis, Spiros; Nychas, George-John E

    2011-01-31

    The whole cell protein and macrorestriction analysis of DNA of Enterobacteriaceae isolates recovered from minced beef stored at 0, 5, 10 and 15 °C aerobically and under modified atmosphere packaging consisting of 40% CO(2)-30% O(2)-30% N(2) in the presence (MAP+) and absence (MAP-) of oregano essential oil were studied. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) profiles obtained from whole cell protein analysis of the Enterobacteriaceae isolates revealed seven groups. Moreover, application of a modified PFGE protocol with XbaI restriction, resulted into 19 different fingerprints. The Enterobacteriaceae community of fresh meat consisted of Serratia liquefaciens and Serratia proteamaculans. S. liquefaciens strain VK23 was the dominant isolate of Enterobacteriaceae for the most conditions adopted, except 10 °C and 15 °C under MAP + and 10 °C under MAP-. In the latter cases, Hafnia alvei represented the dominant fingerprint. Citrobacter freundii was recovered from minced beef stored aerobically, while H. alvei and Proteus vulgaris were recovered under MAP. Storage conditions affected the Enterobacteriaceae community; modified atmosphere packaging increased both species and strain diversity. PMID:21216482

  15. Adhesion, Biofilm Formation, and Genomic Features of Campylobacter jejuni Bf, an Atypical Strain Able to Grow under Aerobic Conditions.

    PubMed

    Bronnec, Vicky; Turoňová, Hana; Bouju, Agnès; Cruveiller, Stéphane; Rodrigues, Ramila; Demnerova, Katerina; Tresse, Odile; Haddad, Nabila; Zagorec, Monique

    2016-01-01

    Campylobacter jejuni is the leading cause of bacterial enteritis in Europe. Human campylobacteriosis cases are frequently associated to the consumption of contaminated poultry meat. To survive under environmental conditions encountered along the food chain, i.e., from poultry digestive tract its natural reservoir to the consumer's plate, this pathogen has developed adaptation mechanisms. Among those, biofilm lifestyle has been suggested as a strategy to survive in the food environment and under atmospheric conditions. Recently, the clinical isolate C. jejuni Bf has been shown to survive and grow under aerobic conditions, a property that may help this strain to better survive along the food chain. The aim of this study was to evaluate the adhesion capacity of C. jejuni Bf and its ability to develop a biofilm. C. jejuni Bf can adhere to abiotic surfaces and to human epithelial cells, and can develop biofilm under both microaerobiosis and aerobiosis. These two conditions have no influence on this strain, unlike results obtained with the reference strain C. jejuni 81-176, which harbors only planktonic cells under aerobic conditions. Compared to 81-176, the biofilm of C. jejuni Bf is more homogenous and cell motility at the bottom of biofilm was not modified whatever the atmosphere used. C. jejuni Bf whole genome sequence did not reveal any gene unique to this strain, suggesting that its unusual property does not result from acquisition of new genetic material. Nevertheless some genetic particularities seem to be shared only between Bf and few others strains. Among the main features of C. jejuni Bf genome we noticed (i) a complete type VI secretion system important in pathogenicity and environmental adaptation; (ii) a mutation in the oorD gene involved in oxygen metabolism; and (iii) the presence of an uncommon insertion of a 72 amino acid coding sequence upstream from dnaK, which is involved in stress resistance. Therefore, the atypical behavior of this strain under

  16. Adhesion, Biofilm Formation, and Genomic Features of Campylobacter jejuni Bf, an Atypical Strain Able to Grow under Aerobic Conditions

    PubMed Central

    Bronnec, Vicky; Turoňová, Hana; Bouju, Agnès; Cruveiller, Stéphane; Rodrigues, Ramila; Demnerova, Katerina; Tresse, Odile; Haddad, Nabila; Zagorec, Monique

    2016-01-01

    Campylobacter jejuni is the leading cause of bacterial enteritis in Europe. Human campylobacteriosis cases are frequently associated to the consumption of contaminated poultry meat. To survive under environmental conditions encountered along the food chain, i.e., from poultry digestive tract its natural reservoir to the consumer’s plate, this pathogen has developed adaptation mechanisms. Among those, biofilm lifestyle has been suggested as a strategy to survive in the food environment and under atmospheric conditions. Recently, the clinical isolate C. jejuni Bf has been shown to survive and grow under aerobic conditions, a property that may help this strain to better survive along the food chain. The aim of this study was to evaluate the adhesion capacity of C. jejuni Bf and its ability to develop a biofilm. C. jejuni Bf can adhere to abiotic surfaces and to human epithelial cells, and can develop biofilm under both microaerobiosis and aerobiosis. These two conditions have no influence on this strain, unlike results obtained with the reference strain C. jejuni 81-176, which harbors only planktonic cells under aerobic conditions. Compared to 81-176, the biofilm of C. jejuni Bf is more homogenous and cell motility at the bottom of biofilm was not modified whatever the atmosphere used. C. jejuni Bf whole genome sequence did not reveal any gene unique to this strain, suggesting that its unusual property does not result from acquisition of new genetic material. Nevertheless some genetic particularities seem to be shared only between Bf and few others strains. Among the main features of C. jejuni Bf genome we noticed (i) a complete type VI secretion system important in pathogenicity and environmental adaptation; (ii) a mutation in the oorD gene involved in oxygen metabolism; and (iii) the presence of an uncommon insertion of a 72 amino acid coding sequence upstream from dnaK, which is involved in stress resistance. Therefore, the atypical behavior of this strain under

  17. Interaction of Cr(VI) reduction and denitrification by strain Pseudomonas aeruginosa PCN-2 under aerobic conditions.

    PubMed

    He, Da; Zheng, Maosheng; Ma, Tao; Li, Can; Ni, Jinren

    2015-06-01

    Inhibition of efficient denitrification in presence of toxic heavy metals is one of the current problems encountered in municipal wastewater treatment plants. This paper presents how to remove hexavalent chromium (Cr(VI)) and nitrate simultaneously by the novel strain Pseudomonas aeruginosa PCN-2 under aerobic conditions. The capability of strain PCN-2 for Cr(VI) and nitrate reduction was confirmed by PCR analysis of gene ChrR, napA, nirS, cnorB, nosZ, while Cr(VI) reduction was proved via an initial single-electron transfer through Cr(V) detection using electron paramagnetic resonance. Experimental results demonstrated that Cr(VI) and nitrate reduction by strain PCN-2 was much faster at pH 8-9 and higher initial cell concentration. However, increasing Cr(VI) concentration would inhibit aerobic denitrification process and result in an significant delay of nitrate reduction or N2O accumulation, which was attributed to competition between three electron acceptors, i.e., Cr(VI), O2 and nitrate in the electron transport chain.

  18. Bioaugmented composting of Jatropha de-oiled cake and vegetable waste under aerobic and partial anaerobic conditions.

    PubMed

    Chaturvedi, Shivani; Kumar, Ashwani; Singh, Balraj; Nain, Lata; Joshi, Monica; Satya, Santosh

    2013-04-01

    This study was conducted to assess the effect of microbial inoculation in Jatropha cake composting with different vegetable waste. The microbial inoculums composed of fungal strains (Aspergillus awamori, Aspergillus nidulans, Trichoderma viride, Phanerochaete chrysosporium) and bacterial inoculums (Pseudomonas striata as phosphorus solublizer and Azotobacter chroococcum as nitrogen fixer) were added to the compost mixture after the thermophilic phase was over for bioaugmenting of Jatropha cake under aerobic and partial anaerobic conditions. Addition of both fungal and bacterial inoculum with mixed substrate (Jatropha cake + vegetable waste) during composting (aerobic and partial anaerobic) showed, better results as compared to compost with only fungal inoculants. Increased enzymatic activity initially, during composting (like dehydrogenase, alkaline phosphatase activity and FDA) proved role of inoculated microbes in rapid decomposition. Analysis of compost (with both bacterial and fungal inoculum) showed presence of high humus (12.7%), humic acid (0.5%), fulvic acid (5.68%), soluble protein content and low C/N ratio. Decreased in concentration of extractable metals (Cu, Fe and Mn) were recorded at maturity in all the substrate composts. The C/N ratio was significantly correlated to parameters like humic acid, humus, fulvic acid, protein and also microbial activity parameters. We conclude that the composting of de-oiled Jatropha cake with different vegetables waste could be feasible and sustainable approach in recycling of agricultural and industrial residues in huge quantities.

  19. Ovariectomy results in differential shifts in gut microbiota in low versus high aerobic capacity rats.

    PubMed

    Cox-York, Kimberly A; Sheflin, Amy M; Foster, Michelle T; Gentile, Christopher L; Kahl, Amber; Koch, Lauren G; Britton, Steven L; Weir, Tiffany L

    2015-08-01

    The increased risk for cardiometabolic disease with the onset of menopause is widely studied and likely precipitated by the decline in endogenous estradiol (E2), yet the precise mechanisms are unknown. The gut microbiome is involved in estrogen metabolism and has been linked to metabolic disease, suggesting its potential involvement in the postmenopausal phenotype. Furthermore, menopause-associated risk factors, as well as gut ecology, are altered with exercise. Therefore, we studied microbial changes in an ovariectomized (OVX vs. Sham) rat model of high (HCR) and low (LCR) intrinsic aerobic capacity (n = 8-10/group) in relation to changes in body weight/composition, glucose tolerance, and liver triglycerides (TG). Nine weeks after OVX, HCR rats were moderately protected against regional adipose tissue gain and liver TG accumulation (P < 0.05 for both). Microbial diversity and number of the Bacteroidetes phylum were significantly increased in LCR with OVX, but unchanged in HCR OVX relative to Sham. Plasma short-chain fatty acids (SCFA), produced by bacteria in the gut and recognized as metabolic signaling molecules, were significantly greater in HCR Sham relative to LCR Sham rats (P = 0.05) and were decreased with OVX in both groups. These results suggest that increased aerobic capacity may be protective against menopause-associated cardiometabolic risk and that gut ecology, and production of signaling molecules such as SCFA, may contribute to the mediation. PMID:26265751

  20. Ovariectomy results in differential shifts in gut microbiota in low versus high aerobic capacity rats

    PubMed Central

    Cox-York, Kimberly A; Sheflin, Amy M; Foster, Michelle T; Gentile, Christopher L; Kahl, Amber; Koch, Lauren G; Britton, Steven L; Weir, Tiffany L

    2015-01-01

    The increased risk for cardiometabolic disease with the onset of menopause is widely studied and likely precipitated by the decline in endogenous estradiol (E2), yet the precise mechanisms are unknown. The gut microbiome is involved in estrogen metabolism and has been linked to metabolic disease, suggesting its potential involvement in the postmenopausal phenotype. Furthermore, menopause-associated risk factors, as well as gut ecology, are altered with exercise. Therefore, we studied microbial changes in an ovariectomized (OVX vs. Sham) rat model of high (HCR) and low (LCR) intrinsic aerobic capacity (n = 8–10/group) in relation to changes in body weight/composition, glucose tolerance, and liver triglycerides (TG). Nine weeks after OVX, HCR rats were moderately protected against regional adipose tissue gain and liver TG accumulation (P < 0.05 for both). Microbial diversity and number of the Bacteroidetes phylum were significantly increased in LCR with OVX, but unchanged in HCR OVX relative to Sham. Plasma short-chain fatty acids (SCFA), produced by bacteria in the gut and recognized as metabolic signaling molecules, were significantly greater in HCR Sham relative to LCR Sham rats (P = 0.05) and were decreased with OVX in both groups. These results suggest that increased aerobic capacity may be protective against menopause-associated cardiometabolic risk and that gut ecology, and production of signaling molecules such as SCFA, may contribute to the mediation. PMID:26265751

  1. Mood after various brief exercise and sport modes: aerobics, hip-hop dancing, ice skating, and body conditioning.

    PubMed

    Kim, Sungwoon; Kim, Jingu

    2007-06-01

    To investigate the potential psychological benefits of brief exercise and sport activities on positive mood alterations, 45 Korean high school and 232 undergraduate students enrolled in physical education and stress management classes voluntarily participated and were randomly assigned to one of four activities: aerobic exercise, body conditioning, hip-hop dancing, and ice skating. Mood changes from before to after exercise (2 pm to 3 pm) were measured based on a Korean translation of the Subjective Exercise Experiences Scale. The findings suggested that the aerobics and hip-hop dancing groups rated positive well-being higher than the body conditioning and ice skating groups. Immediately after exercise, psychological distress was rated lower in the aerobics and hip-hop dancing groups, as was fatigue.

  2. Biodegradation of three- and four-ring polycyclic aromatic hydrocarbons under aerobic and denitrifying conditions

    SciTech Connect

    McNally, D.L.; Mihelcic, J.R.; Lueking, D.R.

    1998-09-01

    PAHs are thought to be particularly persistent in environments where anaerobic conditions exist. This study presents evidence for the biodegradation of three- and four-ringed PAHs (anthracene, phenanthrene, and pyrene) under strict anaerobic, denitrifying conditions. Three pseudomonad strains, isolated from contrasting environments, were used in this study. All three strains were known PAH degraders and denitrifiers. Degradation proceeded to nondetectable levels in 12--80 h for anthracene, 12--44 h for phenanthrene, and 24--72 h for pyrene. The rates of anaerobic degradation were typically slower than under aerobic conditions in almost all cases, except for strain SAG-R which had similar removal rates for all three and four-ring PAHs. Denitrification activity was verified by monitoring nitrate utilization and nitrous oxide production. Although none of the pseudomonads were adapted to the denitrifying conditions, only the pseudomonad isolated from a noncontaminated site consistently exhibited an adaptation period which approximated 12 h. This study supports growing evidence that the degradation of aromatic hydrocarbons coupled to denitrification may be an important factor affecting the fate of these compounds in natural and engineered systems.

  3. Transcript profiles in cortical cells of maize primary root during ethylene-induced lysigenous aerenchyma formation under aerobic conditions

    PubMed Central

    Takahashi, Hirokazu; Yamauchi, Takaki; Rajhi, Imene; Nishizawa, Naoko K.; Nakazono, Mikio

    2015-01-01

    Background and Aims Internal aeration is important for plants to survive during periods of waterlogging, and the ability to form aerenchyma contributes by creating a continuous gas space between the shoots and the roots. Roots of maize (Zea mays) react to prolonged waterlogging by forming aerenchyma in root cortical cells by programmed cell death (PCD) in response to ethylene. The aim of this study was to understand the molecular mechanisms of ethylene-induced aerenchyma formation by identifying genes that are either up- or downregulated by ethylene treatment in maize root cortical cells. Methods Three-day-old maize seedlings were treated with ethylene for several hours under aerobic conditions. Cortical cells were isolated from the primary roots using laser microdissection (LM), and transcript profiles with and without ethylene treatment were compared by microarray. In addition, the effect on ethylene-induced aerenchyma formation of diphenyleneiodonium (DPI), an inhibitor of NADPH oxidases, was examined in order to assess the involvement of reactive oxygen species (ROS). Key Results A total of 223 genes were identified whose transcript levels were significantly increased or decreased by ethylene treatment in root cortical cells under aerobic conditions. Subsequent tissue-specific quantitative reverse-transcription PCR analyses revealed that ethylene increased the transcript levels of genes related to ethylene signalling in all of the root tissues examined (stelar cells, cortical cells and outer cell layers), whereas it increased the transcript levels of genes related to cell wall modification and proteolysis specifically in the cortical cells. DPI treatment inhibited the ethylene-induced aerenchyma formation and suppressed expression of some cell wall modification-related genes. Conclusions Several genes related to cell wall modification and proteolysis are specifically up- or downregulated in cortical cells during lysigenous aerenchyma formation under aerobic

  4. Laboratory Study of Chemical Speciation of Mercury in Lake Sediment and Water under Aerobic and Anaerobic Conditions

    PubMed Central

    Regnell, Olof; Tunlid, Anders

    1991-01-01

    Chemical speciation and partitioning of radiolabeled HgCl2 were studied in model aquatic systems consisting of undisturbed eutrophic lake sediment and water in plastic cylinders. The cylinders were either gradually made anaerobic by a gentle flow of N2-CO2 or kept aerobic by air flow. The proportion of methylated 203Hg was significantly higher, in both water and sediment, in the anaerobic systems than in the aerobic systems. The composition and total concentration of fatty acids originating from bacterial phospholipids, as well as the concentration of vitamin B12, including related cobalamins, were similar in sediments from the anaerobic and aerobic systems. Bacterial cell numbers were, on average, 3.6 times higher in the anaerobic water columns than in the aerobic ones. Volatilization of 203Hg occurred in all systems except in an autoclaved control and was of similar magnitudes in the anaerobic and aerobic systems. Incorporation of 203Hg into the sediment was significantly faster in the aerobic systems than in the anaerobic systems. These results suggest that episodes of anoxia in bottom waters and sediment cause an increase in net mercury methylation and, hence, an increase in bioavailable mercury. PMID:16348444

  5. Fate of inoculated Escherichia coli O157:H7, cultured under different conditions, on fresh and decontaminated beef transitioned from vacuum to aerobic packaging.

    PubMed

    Ashton, Laura V; Geornaras, Ifigenia; Stopforth, Jarret D; Skandamis, Panagiotis N; Belk, Keith E; Scanga, John A; Smith, Gary C; Sofos, John N

    2006-06-01

    This study evaluated the behavior of Escherichia coli O157:H7 during aerobic storage, after storage in vacuum packages, on beef inoculated with cultures prepared (35 degrees C, 24 h) in tryptic soy broth without dextrose (TSB), nonacid hot water carcass decontamination runoff fluids (washings; pH 6.0; WASH), cells from biofilms formed on stainless steel coupons in WASH (WETB), or WETB dried (25 degrees C, 12 h) before harvesting of cells (DRYB). These inocula were applied to fresh beef pieces (40 cm2), which were then left untreated or treated by immersion in hot water (75 degrees C) followed by 2% lactic acid (55 degrees C; hot water/lactic acid [HW/LA]), for 30 s each. Inoculated samples were vacuum packaged and stored at 0 (30, 60, or 90 days), 4 (7 or 14 days), or 12 degrees C (4 or 8 days) and subsequently transferred to retail packages for aerobic storage at 7 degrees C for 5 days. Populations of E. coli O157:H117, regardless of inoculum type, remained generally unchanged (P > 0.05) after aerobic storage (7 degrees C, 5 days) of untreated or HW/LA-treated beef samples previously stored in vacuum packages at 0 or 4 degrees C. However, reductions in E. coli O157:H7 levels were generally obtained when vacuum packaged, untreated beef samples previously stored at 12 degrees C were transitioned to aerobic conditions. Additionally, despite similar (P > 0.05) levels of E. coli O157:H7 cells of TSB, WASH, WETB, and DRYB origin on vacuum-packaged, untreated samples after 8 days of storage at 12 degrees C, subsequent aerobic storage resulted in larger (P < 0.05) reductions of cells of WETB and DRYB origin than for cells of TSB and WASH origin. For HW/LA-treated beef previously stored at 12 degrees C in vacuum packages, populations of E. coli O157:H7 remained largely unchanged after aerobic storage in retail packages. Results thus indicated that aerobic storage of beef (7 degees C, 5 days) previously stored in vacuum packages at 0 or 4 degrees C did not lead to E. coli O

  6. Cr(VI) reduction under aerobic and denitrifying conditions by an aquifer-derived Pseudomonad

    NASA Astrophysics Data System (ADS)

    Beller, H. R.; Han, R.; Geller, J. T.

    2009-12-01

    Chromium contamination of groundwater is widespread within the Department of Energy (DOE) complex. For example, at DOE’s Hanford 100 Area in Washington state, the volume of Cr-contaminated groundwater is estimated to be 1.5 billion gallons. Bioremediation (in situ reductive immobilization) studies involving injection of a lactate-containing polymer have been conducted in the Hanford 100H area, where we have observed sequential use of the dissolved electron acceptors present in groundwater, namely, oxygen, nitrate, and sulfate. As part of an effort to explore Cr(VI) reduction under relevant electron-accepting conditions and with relevant bacteria, we have conducted studies with strain RCH2, a denitrifying bacterium similar to Pseudomonas stutzeri that was isolated from the Hanford 100H aquifer. Cell suspension studies with lactate demonstrated that Cr(VI) reduction could occur under either denitrifying or aerobic conditions (at comparable rates), and that reduction was much more rapid when the terminal electron acceptor (i.e., nitrate or O2) was present. It appears that, under both aerobic and denitrifying conditions, the chromate reductase gene(s) are not inducible by Cr; this conclusion is based on the fact that these cell suspension studies were conducted with cells grown in the absence of Cr and resuspended in a buffer that included chloramphenicol, which inhibits protein synthesis. As our studies indicate that anaerobic Cr(VI) reduction by strain RCH2 is much more rapid in the presence of nitrate (i.e., during denitrification) than in its absence, we explored molecular methods that could readily assess in situ denitrification. Specifically, we investigated whether the gene and transcript copy number of diagnostic denitrification genes (nirS and narG) in groundwater could be used to estimate in situ denitrification rates. Continuous culture (chemostat) studies showed strong correlations (r2 values > 0.93) between denitrification rate and either nirS or nar

  7. Effects of microbial inoculants on corn silage fermentation, microbial contents, aerobic stability, and milk production under field conditions.

    PubMed

    Kristensen, N B; Sloth, K H; Højberg, O; Spliid, N H; Jensen, C; Thøgersen, R

    2010-08-01

    The present study aimed to investigate the effects of 2 corn silage inoculation strategies (homofermentative vs. heterofermentative inoculation) under field conditions and to monitor responses in silage variables over the feeding season from January to August. Thirty-nine commercial dairy farms participated in the study. Farms were randomly assigned to 1 of 3 treatments: control (nonactive carrier; Chr. Hansen A/S, Hørsholm, Denmark), Lactisil (inoculation with 1 x 10(5)Lactobacillus pentosus and 2.5 x 10(4)Pediococcus pentosaceus per gram of fresh matter; Chr. Hansen A/S), and Lalsil Fresh (inoculation with 3 x 10(5)Lactobacillus buchneri NCIMB 40788 per gram of fresh matter; Lallemand Animal Nutrition, Blagnac, France). Inoculation with Lactisil had no effects on fermentation variables and aerobic stability. On the contrary, inoculation with Lalsil Fresh doubled the aerobic stability: 37, 38, and 80+/-8h for control, Lactisil, and Lalsil Fresh, respectively. The effect of Lalsil Fresh on aerobic stability tended to differ between sampling times, indicating a reduced difference between treatments in samples collected in April. Lalsil Fresh inoculation increased silage pH and contents of acetic acid, propionic acid, propanol, propyl acetate, 2-butanol, propylene glycol, ammonia, and free AA. The contents and ratios of DL-lactic acid, L-lactic acid relative to DL-lactic acid, free glucose, and DL-lactic acid relative to acetic acid decreased with Lalsil Fresh inoculation. Lalsil Fresh inoculation increased the silage counts of total lactic acid bacteria and reduced yeast counts. The Fusarium toxins deoxynivalenol, nivalenol, and zearalenone were detected in all silages at all collections, but the contents were not affected by ensiling time or by inoculation treatment. The effect of inoculation treatments on milk production was assessed by collecting test-day results from the involved farms and comparing the actual milk production with predicted milk production

  8. Bacterially Induced Dolomite Formation in the Presence of Sulfate Ions under Aerobic Conditions

    NASA Astrophysics Data System (ADS)

    Sanchez-Roman, M.; McKenzie, J. A.; Vasconcelos, C.; Rivadeneyra, M.

    2005-12-01

    The origin of dolomite remains a long-standing enigma in sedimentary geology because, although thermodynamically favorable, precipitation of dolomite from modern seawater does not occur. Experiments conducted at elevated temperatures (200 oC) indicated that the presence of small concentrations of sulfate ions inhibits the transformation of calcite to dolomite [1]. Indeed, sulfate ions appeared to inhibit dolomite formation above 2 mM concentration (versus 28 mM in modern seawater). Recently, culture experiments have demonstrated that sulfate-reducing bacteria mediate the precipitation of dolomite at Earth surface conditions in the presence of sustained sulfate ion concentrations [2,3]. Additionally, in a number of modern hypersaline environments, dolomite forms from solutions with high sulfate ion concentrations (2 to 70 times seawater). These observations suggest that the experimentally observed sulfate-ion inhibition [1] may not apply to all ancient dolomite formation. Here, we report aerobic culture experiments conducted at low temperatures (25 and 35 oC) and variable sulfate ion concentrations (0, 0.5, 1 and 2 x seawater values) using moderately halophilic bacteria, Halomonas meridiana. After an incubation period of 15 days, experiments at 35 oC with variable sulfate ion concentrations (0, 0.5 x and seawater values) contained crystals of Ca-dolomite and stochiometric dolomite. The experiment at 35 oC with 2 x seawater sulfate ion concentration produced dolomite crystals after 20 days of incubation. In a parallel set of experiments at 25 oC, precipitation of dolomite was observed after 25 days of incubation in cultures with variable sulfate ion concentrations (0, 0.5 x and seawater values). In the culture with 2 x seawater sulfate ion concentration, dolomite crystals were observed after 30 days. Our study demonstrates that halophilic bacteria (or heterotrophic microorganisms), which do not require sulfate ions for metabolism, can mediate dolomite precipitation

  9. Quantitative proteome and transcriptome analysis of the archaeon Thermoplasma acidophilum cultured under aerobic and anaerobic conditions.

    PubMed

    Sun, Na; Pan, Cuiping; Nickell, Stephan; Mann, Matthias; Baumeister, Wolfgang; Nagy, István

    2010-09-01

    A comparative proteome and transcriptome analysis of Thermoplasma acidophilum cultured under aerobic and anaerobic conditions has been performed. One-thousand twenty-five proteins were identified covering 88% of the cytosolic proteome. Using a label-free quantitation method, we found that approximately one-quarter of the identified proteome (263 proteins) were significantly induced (>2 fold) under anaerobic conditions. Thirty-nine macromolecular complexes were identified, of which 28 were quantified and 15 were regulated under anaerobiosis. In parallel, a whole genome cDNA microarray analysis was performed showing that the expression levels of 445 genes were influenced by the absence of oxygen. Interestingly, more than 40% of the membrane protein-encoding genes (145 out of 335 ORFs) were up- or down-regulated at the mRNA level. Many of these proteins are functionally associated with extracellular protein or peptide degradation or ion and amino acid transport. Comparison of the transcriptome and proteome showed only a weak positive correlation between mRNA and protein expression changes, which is indicative of extensive post-transcriptional regulatory mechanisms in T. acidophilum. Integration of transcriptomics and proteomics data generated hypotheses for physiological adaptations of the cells to anaerobiosis, and the quantitative proteomics data together with quantitative analysis of protein complexes provide a platform for correlation of MS-based proteomics studies with cryo-electron tomography-based visual proteomics approaches.

  10. Monitoring of growth and physiological activities of biofilm during succession on polystyrene from activated sludge under aerobic and anaerobic conditions.

    PubMed

    Naz, Iffat; Batool, Syeda Ain-ul; Ali, Naeem; Khatoon, Nazia; Atiq, Niama; Hameed, Abdul; Ahmed, Safia

    2013-08-01

    The present research work monitored the successive biofilm development and its catabolic role in the degradation of polystyrene (PS). PS material was artificially colonized with biofilm by incubating it with activated sludge under aerobic and anaerobic conditions. Biofilm formation was monitored by gravimetric weight analysis, spectrophotometric absorbance technique, heterotrophic plate count, and scanning electron microscopy under aerobic and anaerobic conditions. The wet weight (1.59 and 1.17 g) and dry weight (0.41 and 0.08 g) of a biofilm showed a significant constant increase under aerobic and anaerobic conditions, respectively, from first till 9 weeks of incubation. Plate count of the selected bacteria (Escherichia coli, Salmonella typhimurium, Shigella dysenteriae, Pseudomonas aeruginosa) considerably declined (90-99 %) in the biofilm after seventh and fifth weeks of incubation under aerobic and anaerobic conditions, respectively, indicating a positive shift from pathogenic to beneficial microbial community. While most probable number index of fecal coliforms and E. coli in the sludge showed more reduction (98 and 99 %) under aerobic as compare to anaerobic conditions (86 and 91 %) after 9 weeks of biofilm formation on PS cubes. Correspondingly, the decreasing levels of chemical oxygen demand and biochemical oxygen demand (up to 73 %) showed signs of sludge digestion. Scanning electron microscope coupled with energy dispersive X-ray spectroscope revealed nature of PS media containing high carbon content. However, biofilm development proved to be involved in the biochemical transformation of the PS medium as indicated by Fourier transform infrared spectroscopy.

  11. Electrolysis of trichloromethylated organic compounds under aerobic conditions catalyzed by the B12 model complex for ester and amide formation.

    PubMed

    Shimakoshi, Hisashi; Luo, Zhongli; Inaba, Takuya; Hisaeda, Yoshio

    2016-06-21

    The electrolysis of benzotrichloride at -0.9 V vs. Ag/AgCl in the presence of the B12 model complex, heptamethyl cobyrinate perchlorate, in ethanol under aerobic conditions using an undivided cell equipped with a platinum mesh cathode and a zinc plate anode produced ethylbenzoate in 56% yield with 92% selectivity. The corresponding esters were obtained when the electrolysis was carried out in various alcohols such as methanol, n-propanol, and i-propanol. Benzoyl chloride was detected by GC-MS during the electrolysis as an intermediate for the ester formation. When the electrolysis was carried out under anaerobic conditions, partially dechlorinated products, 1,1,2,2-tetrachloro-1,2-diphenylethane and 1,2-dichlorostilibenes (E and Z forms), were obtained instead of an ester. ESR spin-trapping experiments using 5,5,-dimethylpyrroline N-oxide (DMPO) revealed that the corresponding oxygen-centered radical and carbon-centered radical were steadily generated during the electrolyses under aerobic and anaerobic conditions, respectively. Applications of the aerobic electrolysis to various organic halides, such as substituted benzotrichlorides, are described. Furthermore, the formation of amides with moderate yields by the aerobic electrolysis of benzotrichloride catalyzed by the B12 model complex in the presence of amines in acetonitrile is reported. PMID:27071703

  12. Summary report on the aerobic degradation of diesel fuel and the degradation of toluene under aerobic, denitrifying and sulfate reducing conditions

    SciTech Connect

    Coyne, P.; Smith, G.

    1995-08-15

    This report contains a number of studies that were performed to better understand the technology of the biodegradation of petroleum hydrocarbons. Topics of investigation include the following: diesel fuel degradation by Rhodococcus erythropolis; BTEX degradation by soil isolates; aerobic degradation of diesel fuel-respirometry; aerobic degradation of diesel fuel-shake culture; aerobic toluene degradation by A3; effect of HEPES, B1, and myo-inositol addition on the growth of A3; aerobic and anaerobic toluene degradation by contaminated soils; denitrifying bacteria MPNs; sulfate-reducing bacteria MPNs; and aerobic, DNB and SRB enrichments.

  13. Investigation of oxidative phosphorylation in continuous cultures. A non-equilibrium thermodynamic approach to energy transduction for Escherichia coli in aerobic condition

    NASA Astrophysics Data System (ADS)

    Ghafuri, Mohazabeh; Nosrati, Mohsen; Hosseinkhani, Saman

    2015-03-01

    Adenosine triphosphate (ATP) production in living cells is very important. Different researches have shown that in terms of mathematical modeling, the domain of these investigations is essentially restricted. Recently the thermodynamic models have been suggested for calculation of the efficiency of oxidative phosphorylation process and rate of energy loss in animal cells using chemiosmotic theory and non-equilibrium thermodynamics equations. In our previous work, we developed a mathematical model for mitochondria of animal cells. In this research, according to similarities between oxidative phosphorylation process in microorganisms and animal cells, Golfar's model was developed to predict the non-equilibrium thermodynamic behavior of the oxidative phosphorylation process for bacteria in aerobic condition. With this model the rate of energy loss, P/O ratio, and efficiency of oxidative phosphorylation were calculated for Escherichia coli in aerobic condition. The results then were compared with experimental data given by other authors. The thermodynamic model had an acceptable agreement with the experimental data.

  14. Optimization of polyhydroxybutyrate production by mixed cultures submitted to aerobic dynamic feeding conditions.

    PubMed

    Serafim, Luísa S; Lemos, Paulo C; Oliveira, Rui; Reis, Maria A M

    2004-07-20

    Activated sludge submitted to aerobic dynamic feeding conditions showed a good and stable capacity to store polyhydroxybutyrate (PHB). The system, working for 2 years, selected a microbial population with a high PHB storage capacity. The influence of carbon and nitrogen concentrations on the PHB accumulation yield was studied in a range of 15-180 Cmmol/l for acetate and 0-2.8 Nmmol/l for ammonia. Low ammonia concentrations favored PHB accumulation. The maximum PHB content, 67.5%, was obtained for 180 Cmmol/l of acetate supplied in one pulse. However, such high substrate concentration proved to be inhibitory for the storage mechanism, causing a slowdown of the specific PHB storage rate. In order to avoid substrate inhibition, 180 Cmmol/l of acetate was supplied in different ways: continuously fed and in three pulses of 60 Cmmol/l each. In both cases the specific PHB storage rate increased and the PHB content obtained were 56.2% and 78.5%, respectively. The latter value of PHB content is similar to that obtained by pure cultures and was never reported for mixed cultures. Addition of acetate by pulses controlled by the oxygen concentration was kept for 16 days, the PHB content being always above 70% of cell dry weight.

  15. Oxidation of aquatic pollutants by ferrous-oxalate complexes under dark aerobic conditions.

    PubMed

    Lee, Jaesang; Kim, Jungwon; Choi, Wonyong

    2014-06-15

    This study evaluates the ability of Fe(II)-oxalate complexes for the generation of OH through oxygen reduction and the oxidative degradation of aquatic pollutants under dark aerobic conditions (i.e., with oxygen but without light). The degradation of 4-chlorophenol (4-CP) was rapid in the mixture of Fe(2+) and oxalate prepared using ultrapure water, but was absent without either Fe(2+) or oxalate. The formation of Fe(II)-oxalate complexes enables two-electron reduction of oxygen to generate H2O2 and subsequent production of OH. The significant inhibition of 4-CP degradation in the presence of H2O2 and OH scavenger confirms such mechanisms. The degradation experiments with varying [Fe(2+)], [oxalate], and initial pH demonstrated that the degradation rate depends on [Fe(II)(Ox)2(2-)], but the degree of degradation is primarily determined by [Fe(II)(Ox)2(2-)]+[Fe(II)(Ox)(0)]. Efficient degradation of diverse aquatic pollutants, especially phenolic pollutants, was observed in the Fe(II)-oxalate complexes system, wherein the oxidation efficacy was primarily correlated with the reaction rate constant between pollutant and OH. The effect of various organic ligands (oxalate, citrate, EDTA, malonate, and acetate) on the degradation kinetics of 4-CP was investigated. The highest efficiency of oxalate for the oxidative degradation is attributed to its high capability to enhance the reducing power and low reactivity with OH.

  16. Understanding the physiological roles of polyhydroxybutyrate (PHB) in Rhodospirillum rubrum S1 under aerobic chemoheterotrophic conditions.

    PubMed

    Narancic, Tanja; Scollica, Elisa; Kenny, Shane T; Gibbons, Helena; Carr, Eibhlin; Brennan, Lorraine; Cagney, Gerard; Wynne, Kieran; Murphy, Cormac; Raberg, Matthias; Heinrich, Daniel; Steinbüchel, Alexander; O'Connor, Kevin E

    2016-10-01

    Polyhydroxybutyrate (PHB) is an important biopolymer accumulated by bacteria and associated with cell survival and stress response. Here, we make two surprising findings in the PHB-accumulating species Rhodospirillum rubrum S1. We first show that the presence of PHB promotes the increased assimilation of acetate preferentially into biomass rather than PHB. When R. rubrum is supplied with (13)C-acetate as a PHB precursor, 83.5 % of the carbon in PHB comes from acetate. However, only 15 % of the acetate ends up in PHB with the remainder assimilated as bacterial biomass. The PHB-negative mutant of R. rubrum assimilates 2-fold less acetate into biomass compared to the wild-type strain. Acetate assimilation proceeds via the ethylmalonyl-CoA pathway with (R)-3-hydroxybutyrate as a common intermediate with the PHB pathway. Secondly, we show that R. rubrum cells accumulating PHB have reduced ribulose 1,5-bisphosphate carboxylase (RuBisCO) activity. RuBisCO activity reduces 5-fold over a 36-h period after the onset of PHB. In contrast, a PHB-negative mutant maintains the same level of RuBisCO activity over the growth period. Since RuBisCO controls the redox potential in R. rubrum, PHB likely replaces RuBisCO in this role. R. rubrum is the first bacterium found to express RuBisCO under aerobic chemoheterotrophic conditions. PMID:27480532

  17. Biodegradation of malachite green by Pseudomonas sp. strain DY1 under aerobic condition: characteristics, degradation products, enzyme analysis and phytotoxicity.

    PubMed

    Du, Lin-Na; Wang, Sheng; Li, Gang; Wang, Bing; Jia, Xiao-Ming; Zhao, Yu-Hua; Chen, Yun-Long

    2011-03-01

    Malachite green (MG), a widely-used and recalcitrant dye, has been confirmed to be carcinogenic and mutagenic against many organisms. The main objective of this study is to investigate the capability of Pseudomonas sp. strain DY1 to decolorize MG, and to explore the possible mechanism. The results showed that this strain demonstrated high decolorizing capability (90.3-97.2%) at high concentrations of MG (100-1,000 mg/l) under shaking condition within 24 h. In static conditions, lower but still effective decolorization (78.9-84.3%) was achieved. The optimal pH and temperature for the decolorization was pH 6.6 and 28-30°C, respectively. Mg(2+) and Mn(2+) (1 mM) were observed to significantly enhance the decolorization. The intermediates of the MG degradation under aerobic condition identified by UV-visible, GC-MS and LC-MS analysis included malachite green carbinol, (dimethyl amino-phenyl)-phenyl-methanone, N,N-dimethylaniline, (methyl amino-phenyl)-phenyl-methanone, (amino phenyl)-phenyl methanone and di-benzyl methane. The enzyme analysis indicated that Mn-peroxidase, NADH-DCIP and MG reductase were involved in the biodegradation of MG. Moreover, phytotoxicity of MG and detoxification for MG by the strain were observed. Therefore, this strain could be potentially used for bioremediation of MG.

  18. Higher Water Temperature and Incubation under Aerobic and Microaerobic Conditions Increase the Recovery and Diversity of Arcobacter spp. from Shellfish

    PubMed Central

    Levican, Arturo; Collado, Luis; Yustes, Clara; Aguilar, Carme

    2014-01-01

    Some Arcobacter species are considered emerging food-borne and waterborne pathogens, and shellfish have been suggested as one of their reservoirs. However, only a few studies have investigated the presence of Arcobacter in this kind of food. This study assesses the prevalence and diversity of Arcobacter spp. in shellfish by multiplex PCR (m-PCR) and culturing methods (under different atmospheric conditions) and evaluates the possible influence of environmental parameters (temperature, salinity, and harvesting bay). Arcobacter was detected by m-PCR and/or culturing in 61 (29.9%) of 204 shellfish samples. Of the positive samples by culturing, 41.1% were obtained under only aerobic incubation conditions, while 23.2% were obtained under only microaerobic conditions. Of 476 investigated isolates, 118 belonged to different enterobacterial repetitive intergenic consensus (ERIC)-PCR genotypes (strains) and to 11 different species. This study shows the highest diversity of Arcobacter species ever observed in samples from any origin. The most prevalent species was Arcobacter butzleri (60.2%), followed by Arcobacter molluscorum (21.2%). The prevalence of Arcobacter was significantly higher during the summer than in other seasons, being associated with an increase in water temperature. Results confirm that shellfish are a reservoir for a remarkable diversity of Arcobacter spp. PMID:24185851

  19. Bacterial survival and association with sludge flocs during aerobic and anaerobic digestion of wastewater sludge under laboratory conditions.

    PubMed Central

    Farrah, S R; Bitton, G

    1983-01-01

    The fate of indicator bacteria, a bacterial pathogen, and total aerobic bacteria during aerobic and anaerobic digestion of wastewater sludge under laboratory conditions was determined. Correlation coefficients were calculated between physical and chemical parameters (temperature, dissolved oxygen, pH, total solids, and volatile solids) and either the daily change in bacterial numbers or the percentage of bacteria in the supernatant. The major factor influencing survival of Salmonella typhimurium and indicator bacteria during aerobic digestion was the temperature of sludge digestion. At 28 degrees C with greater than 4 mg of dissolved oxygen per liter, the daily change in numbers of these bacteria was approximately -1.0 log10/ml. At 6 degrees C, the daily change was less than -0.3 log10/ml. Most of the bacteria were associated with the sludge flocs during aerobic digestion of sludge at 28 degrees C with greater than 2.4 mg of dissolved oxygen per liter. Lowering the temperature or the amount of dissolved oxygen decreased the fraction of bacteria associated with the flocs and increased the fraction found in the supernatant. PMID:6401978

  20. Physiological activities associated with biofilm growth in attached and suspended growth bioreactors under aerobic and anaerobic conditions.

    PubMed

    Naz, Iffat; Seher, Shama; Perveen, Irum; Saroj, Devendra P; Ahmed, Safia

    2015-01-01

    This research work evaluated the biofilm succession on stone media and compared the biochemical changes of sludge in attached and suspended biological reactors operated under aerobic and anaerobic conditions. Stones incubated (30±2°C) with activated sludge showed a constant increase in biofilm weight up to the fifth and seventh week time under anaerobic and aerobic conditions, respectively, where after reduction (>80%) the most probable number index of pathogen indicators on ninth week was recorded. Reduction in parameters such as biological oxygen demand (BOD) (47.7%), chemical oxygen demand (COD, 41%), nitrites (60.2%), nitrates (105.5%) and phosphates (58.9%) and increase in dissolved oxygen (176.5%) of sludge were higher in aerobic attached growth reactors as compared with other settings. While, considerable reductions in these values were also observed (BOD, 53.8%; COD, 2.8%; nitrites, 28.6%; nitrates, 31.7%; phosphates, 41.4%) in the suspended growth system under anaerobic conditions. However, higher sulphate removal was observed in suspended (40.9% and 54.9%) as compared with biofilm reactors (28.2% and 29.3%). Six weeks biofilm on the stone media showed maximum physiological activities; thus, the operational conditions should be controlled to keep the biofilm structure similar to six-week-old biofilm, and can be used in fixed biofilm reactors for wastewater treatment.

  1. Simultaneous phosphorus uptake and denitrification by EBPR-r biofilm under aerobic conditions: effect of dissolved oxygen.

    PubMed

    Wong, Pan Yu; Ginige, Maneesha P; Kaksonen, Anna H; Cord-Ruwisch, Ralf; Sutton, David C; Cheng, Ka Yu

    2015-01-01

    A biofilm process, termed enhanced biological phosphorus removal and recovery (EBPR-r), was recently developed as a post-denitrification approach to facilitate phosphorus (P) recovery from wastewater. Although simultaneous P uptake and denitrification was achieved despite substantial intrusion of dissolved oxygen (DO >6 mg/L), to what extent DO affects the process was unclear. Hence, in this study a series of batch experiments was conducted to assess the activity of the biofilm under various DO concentrations. The biofilm was first allowed to store acetate (as internal storage) under anaerobic conditions, and was then subjected to various conditions for P uptake (DO: 0-8 mg/L; nitrate: 10 mg-N/L; phosphate: 8 mg-P/L). The results suggest that even at a saturating DO concentration (8 mg/L), the biofilm could take up P and denitrify efficiently (0.70 mmol e(-)/g total solids*h). However, such aerobic denitrification activity was reduced when the biofilm structure was physically disturbed, suggesting that this phenomenon was a consequence of the presence of oxygen gradient across the biofilm. We conclude that when a biofilm system is used, EBPR-r can be effectively operated as a post-denitrification process, even when oxygen intrusion occurs. PMID:26398030

  2. A study of the thermal decomposition of adulterated cocaine samples under optimized aerobic pyrolytic conditions.

    PubMed

    Gostic, T; Klemenc, S; Stefane, B

    2009-05-30

    The pyrolysis behaviour of pure cocaine base as well as the influence of various additives was studied using conditions that are relevant to the smoking of illicit cocaine by humans. For this purpose an aerobic pyrolysis device was developed and the experimental conditions were optimized. In the first part of our study the optimization of some basic experimental parameters of the pyrolysis was performed, i.e., the furnace temperature, the sampling start time, the heating period, the sampling time, and the air-flow rate through the system. The second part of the investigation focused on the volatile products formed during the pyrolysis of a pure cocaine free base and mixtures of cocaine base and adulterants. The anaesthetics lidocaine, benzocaine, procaine, the analgesics phenacetine and paracetamol, and the stimulant caffeine were used as the adulterants. Under the applied experimental conditions complete volatilization of the samples was achieved, i.e., the residuals of the studied compounds were not detected in the pyrolysis cell. Volatilization of the pure cocaine base showed that the cocaine recovery available for inhalation (adsorbed on traps) was approximately 76%. GC-MS and NMR analyses of the smoke condensate revealed the presence of some additional cocaine pyrolytic products, such as anhydroecgonine methyl ester (AEME), benzoic acid (BA) and carbomethoxycycloheptatrienes (CMCHTs). Experiments with different cocaine-adulterant mixtures showed that the addition of the adulterants changed the thermal behaviour of the cocaine. The most significant of these was the effect of paracetamol. The total recovery of the cocaine (adsorbed on traps and in a glass tube) from the 1:1 cocaine-paracetamol mixture was found to be only 3.0+/-0.8%, versus 81.4+/-2.9% for the pure cocaine base. The other adulterants showed less-extensive effects on the recovery of cocaine, but the pyrolysis of the cocaine-procaine mixture led to the formation of some unique pyrolytic products

  3. BIODEGRADATION KINETICS AND TOXICITY OF VEGETABLE OIL TRIACYLGLYCEROLS UNDER AEROBIC CONDITIONS

    EPA Science Inventory

    The aerobic biodegradation of five triacylglycerols (TAGs), three liquids [triolein (OOO), trilinolein (LLL), and trilinolenin (LnLnLn)] and two solids [tripalmitin (PPP) and tristearin (SSS)] was studied in water. Respirometry tests were designed and conducted to determine the b...

  4. Degradation of polycyclic aromatic hydrocarbons at low temperature under aerobic and nitrate-reducing conditions in enrichment cultures from northern soils.

    PubMed

    Eriksson, Mikael; Sodersten, Erik; Yu, Zhongtang; Dalhammar, Gunnel; Mohn, William W

    2003-01-01

    The potential for biodegradation of polycyclic aromatic hydrocarbons (PAHs)at low temperature and under anaerobic conditions is not well understood, but such biodegradation would be very useful for remediation of polluted sites. Biodegradation of a mixture of 11 different PAHs with two to five aromatic rings, each at a concentration of 10 micro g/ml, was studied in enrichment cultures inoculated with samples of four northern soils. Under aerobic conditions, low temperature severely limited PAH biodegradation. After 90 days, aerobic cultures at 20 degrees C removed 52 to 88% of the PAHs. The most extensive PAH degradation under aerobic conditions at 7 degrees C,53% removal, occurred in a culture from creosote-contaminated soil. Low temperature did not substantially limit PAH biodegradation under nitrate-reducing conditions. Under nitrate-reducing conditions,naphthalene, 2-methylnaphthalene, fluorene, and phenanthrene were degraded. The most extensive PAH degradation under nitrate-reducing conditions at 7 degrees C, 39% removal, occurred in a culture from fuel-contaminated Arctic soil. In separate transfer cultures from the above Arctic soil, incubated anaerobically at 7 degrees C, removal of 2-methylnaphthalene and fluorene was stoichiometrically coupled to nitrate removal. Ribosomal intergenic spacer analysis suggested that enrichment resulted in a few predominant bacterial populations,including members of the genera Acidovorax,Bordetella, Pseudomonas, Sphingomonas, and Variovorax. Predominant populations from different soils often included phylotypes with nearly identical partial 16S rRNA gene sequences (i.e., same genus) but never included phylotypes with identical ribosomal intergenic spacers (i.e., different species or subspecies). The composition of the enriched communities appeared to be more affected by presence of oxygen, than by temperature or source of the inoculum. PMID:12514005

  5. Degradation of Polycyclic Aromatic Hydrocarbons at Low Temperature under Aerobic and Nitrate-Reducing Conditions in Enrichment Cultures from Northern Soils

    PubMed Central

    Eriksson, Mikael; Sodersten, Erik; Yu, Zhongtang; Dalhammar, Gunnel; Mohn, William W.

    2003-01-01

    The potential for biodegradation of polycyclic aromatic hydrocarbons (PAHs) at low temperature and under anaerobic conditions is not well understood, but such biodegradation would be very useful for remediation of polluted sites. Biodegradation of a mixture of 11 different PAHs with two to five aromatic rings, each at a concentration of 10 μg/ml, was studied in enrichment cultures inoculated with samples of four northern soils. Under aerobic conditions, low temperature severely limited PAH biodegradation. After 90 days, aerobic cultures at 20°C removed 52 to 88% of the PAHs. The most extensive PAH degradation under aerobic conditions at 7°C, 53% removal, occurred in a culture from creosote-contaminated soil. Low temperature did not substantially limit PAH biodegradation under nitrate-reducing conditions. Under nitrate-reducing conditions, naphthalene, 2-methylnaphthalene, fluorene, and phenanthrene were degraded. The most extensive PAH degradation under nitrate-reducing conditions at 7°C, 39% removal, occurred in a culture from fuel-contaminated Arctic soil. In separate transfer cultures from the above Arctic soil, incubated anaerobically at 7°C, removal of 2-methylnaphthalene and fluorene was stoichiometrically coupled to nitrate removal. Ribosomal intergenic spacer analysis suggested that enrichment resulted in a few predominant bacterial populations, including members of the genera Acidovorax, Bordetella, Pseudomonas, Sphingomonas, and Variovorax. Predominant populations from different soils often included phylotypes with nearly identical partial 16S rRNA gene sequences (i.e., same genus) but never included phylotypes with identical ribosomal intergenic spacers (i.e., different species or subspecies). The composition of the enriched communities appeared to be more affected by presence of oxygen, than by temperature or source of the inoculum. PMID:12514005

  6. Fate of nonylphenol ethoxylate (NPEO) and its inhibitory impact on the biodegradation of acetate under aerobic conditions.

    PubMed

    Ekdal, Alpaslan

    2014-01-01

    This study evaluated the kinetics of nonylphenol ethoxylate (NPEO) and acetate biodegradation at a moderate sludge age by acclimated culture under aerobic conditions. A laboratory-scale sequencing batch reactor was set and fed only with acetate mixture. The system was operated at steady state with a sludge age of 8 days. Following this stage, a mixture of NPEO and acetate was fed to the mixed culture in order to assess the biodegradation kinetics of NPEO and its impact on acetate utilization. A mechanistic model was developed involving model components and kinetic parameters for both substrates. The model was calibrated with parameters such as oxygen uptake rate and polyhydroxyalkanoates. Biodegradation characteristics and kinetics of acetate and NPEO were estimated by using the model results. Evaluation of calibrated model indicated that exposure of NPEO to non-acclimated sludge caused significant inhibitory impact on the utilization and storage of acetate. However, acclimation ofbiomass greatly suppressed inhibitory effects of NPEO on growth process involved in the degradation of acetate.

  7. Bioconversion of 2,4-diamino-6-nitrotoluene to a novel metabolite under anoxic and aerobic conditions

    SciTech Connect

    Gilcrease, P.C.; Murphy, V.G.

    1995-12-01

    Under nitrate-reducing, nongrowth conditions, a Pseudomonas fluorescens species reduced 2,4,6-trinitrotoluene to aminodinitrotoluenes, which were then further reduced to diaminonitrotoluenes. 2,4-Diamino-6-nitrotoluene (2,4-DANT) was further transformed to a novel metabolite, 4-N-acetylamino-2-amino-6-nitrotoluene (4-N-AcANT), while 2,6-diamino-4-nitrotoluene (2,6-DANT) was persistent. Efforts to further degrade 2,4-DANT and 2,6-DANT under aerobic, nitrogen-limited conditions were unsuccessful; 2,6-DANT remained persistent, and 2,4-DANT was again transformed to the 4-N-AcANT compound.

  8. Bioconversion of 2,4-diamino-6-nitrotoluene to a novel metabolite under anoxic and aerobic conditions.

    PubMed Central

    Gilcrease, P C; Murphy, V G

    1995-01-01

    Under nitrate-reducing, nongrowth conditions, a Pseudomonas fluorescens species reduced 2,4,6-trinitrotoluene to aminodinitrotoluenes, which were then further reduced to diaminonitrotoluenes. 2,4-Diamino-6-nitrotoluene (2,4-DANT) was further transformed to a novel metabolite, 4-N-acetylamino-2-amino-6-nitrotoluene (4-N-AcANT), while 2,6-diamino-4-nitrotoluene (2,6-DANT) was persistent. Efforts to further degrade 2,4-DANT and 2,6-DANT under aerobic, nitrogen-limited conditions were unsuccessful; 2,6-DANT remained persistent, and 2,4-DANT was again transformed to the 4-N-AcANT compound. PMID:8534088

  9. Optimization of operation conditions for preventing sludge bulking and enhancing the stability of aerobic granular sludge in sequencing batch reactors.

    PubMed

    Zhou, Jun; Wang, Hongyu; Yang, Kai; Ma, Fang; Lv, Bin

    2014-01-01

    Sludge bulking caused by loss of stability is a major problem in aerobic granular sludge systems. This study investigated the feasibility of preventing sludge bulking and enhancing the stability of aerobic granular sludge in a sequencing batch reactor by optimizing operation conditions. Five operation parameters have been studied with the aim to understand their impact on sludge bulking. Increasing dissolved oxygen (DO) by raising aeration rates contributed to granule stability due to the competition advantage of non-filamentous bacteria and permeation of oxygen at high DO concentration. The ratio of polysaccharides to proteins was observed to increase as the hydraulic shear force increased. When provided with high/low organic loading rate (OLR) alternately, large and fluffy granules disintegrated, while denser round-shape granules formed. An increase of biomass concentration followed a decrease at the beginning, and stability of granules was improved. This indicated that aerobic granular sludge had the resistance of OLR. Synthetic wastewater combined highly and slowly biodegradable substrates, creating a high gradient, which inhibited the growth of filamentous bacteria and prevented granular sludge bulking. A lower chemical oxygen demand/N favored the hydrophobicity of granular sludge, which promoted with granule stability because of the lower diffusion rate of ammonia. The influence of temperature indicated a relatively low temperature was more suitable.

  10. Diversity of methanotrophs in Zoige wetland soils under both anaerobic and aerobic conditions.

    PubMed

    Yun, Juanli; Ma, Anzhou; Li, Yaoming; Zhuang, Guoqiang; Wang, Yanfen; Zhang, Hongxun

    2010-01-01

    Zoige wetland is one of the most important methane emission centers in China. The oxidation of methane in the wetland affects global warming, soil ecology and atmospheric chemistry. Despite their global significance, microorganisms that consume methane in Zoige wetland remain poorly characterized. In this study, we investigated methanotrophs diversity in soil samples from both anaerobic site and aerobic site in Zoige wetland using pmoA gene as a molecular marker. The cloning library was constructed according to the pmoA sequences detected. Four clusters of methanotrophs were detected. The phylogenetic tree showed that all four clusters detected were affiliated to type I methanotrophs. Two novel clusters (cluster 1, cluster 2) were found to relate to none of the recognized genera of methanotrophs. These clusters have no cultured representatives and reveal an ecological adaptation of particular uncultured methanotrophs in Zoige wetland. Two clusters were belonging to Methylobacter and Methylococcus separately. Denaturing gradient gel electrophoresis gel bands pattern retrieved from these two samples revealed that the community compositions of anaerobic soil and aerobic soil were different from each other while anaerobic soil showed a higher metanotrophs diversity. Real-time PCR assays of the two samples demonstrated that aerobic soil sample in Zoige wetland was 1.5 times as much copy numbers as anaerobic soil. These data illustrated that methanotrophs are a group of microorganisms influence the methane consumption in Zoige wetland.

  11. Aerobic Capacity Following Long Duration International Spaces Station (ISS) Missions: Preliminary Results

    NASA Technical Reports Server (NTRS)

    Moore, Alan D.; Lee, S.M.C.; Everett, M.E.; Guined, J.R.; Knudsen, P.

    2010-01-01

    Maximum oxygen uptake (VO2max) is reduced immediately following space flights lasting <15 d, but has not been measured following long-duration missions. The purpose of this study is to measure VO2max and maximum work rate (WRmax) data from astronauts following ISS flights (91 to 188 d). Methods: Five astronauts [3 M, 2 F: 47+/-6 yr, 174+/-6 cm, 71.9+/-10.9 kg (mean +/- SD)] have participated in the study. Subjects performed upright cycle exercise tests to symptom-limited maximum. An initial test was done approx.270 d before flight to establish work rates for subsequent tests. Subsequent tests, conducted approx.45 d before flight and repeated on the first or second day (R+1/2) and at approx.10 d (R+10) following landing, consisted of 3 5 min stages designed to elicit 25%, 50%, and 75% of preflight VO2max, followed by 25 W(dot)/min increases. VO2, WR, and heart rate (HR) were measured using the ISS Portable Pulmonary Function System [Damec, Odense, DK]. Descriptive statistics are reported. Results: On R+1/2 mean VO2max decreased compared to preflight (Pre: 2.98+/-0.99, R+1/2: 2.63+/-0.56 L(dot)/min); 4 of 5 subjects demonstrated a loss of > 6%. WRmax also decreased on R+1/2 compared to preflight (Pre: 245+/-69, R+1/2: 210+/-45 W). On R+10, VO2max was 2.86+/-0.62 L(dot)/min, with 2 subjects still demonstrating a loss of > 6% from preflight. WRmax on R+10 was 240+/-49 W. HRmax did not change from pre to post-flight. Conclusions: These preliminary results, from the first 5 of 12 planned subjects of an ongoing ISS study, suggest that the majority of astronauts will experience a decrease in VO2max after long-duration space-flight. Interestingly, the two astronauts with the highest preflight VO2max had the greatest loss on R+1/2, and the astronaut with the lowest preflight VO2max increased by 13%. Thus, maintenance of VO2max may be more difficult in astronauts who have a high aerobic capacity, perhaps requiring more intense in-flight exercise countermeasure prescriptions.

  12. Quantification of aerobic biodegradation and volatilization rates of gasoline hydrocarbons near the water table under natural attenuation conditions

    NASA Astrophysics Data System (ADS)

    Lahvis, Matthew A.; Baehr, Arthur L.; Baker, Ronald J.

    1999-03-01

    Aerobic biodegradation and volatilization near the water table constitute a coupled pathway that contributes significantly to the natural attenuation of hydrocarbons at gasoline spill sites. Rates of hydrocarbon biodegradation and volatilization were quantified by analyzing vapor transport in the unsaturated zone at a gasoline spill site in Beaufort, South Carolina. Aerobic biodgradation rates decreased with distance above the water table, ranging from 0.20 to 1.5 g m-3 d-1 for toluene, from 0.24 to 0.38 g m-3 d-1 for xylene, from 0.09 to 0.24 g m-3 d-1 for cyclohexene, from 0.05 to 0.22 g m-3 d-1 for ethylbenzene, and from 0.02 to 0.08 g m-3 d-1 for benzene. Rates were highest in the capillary zone, where 68% of the total hydrocarbon mass that volatilized from the water table was estimated to have been biodegraded. Hydrocarbons were nearly completely degraded within 1m above the water table. This large loss underscores the importance of aerobic biodradation in limiting the transport of hydrocarbon vapors in the unsaturated zone and implies that vapor-plume migration to basements and other points of contact may only be significant if a source of free product is present. Furthermore, because transport of the hydrocarbon in the unsaturated zone can be limited relative to that of oxygen and carbon dioxide, soil-gas surveys conducted at hydrocarbon-spill sites would benefit by the inclusion of oxygen- and carbon-dioxide-gas concentration measurements. Aerobic degradation kinetics in the unsaturated zone were approximately first-order. First-order rate constants near the water table were highest for cyclohexene (0.21-0.65 d-1) and nearly equivalent for ethylbenzene (0.11-0.31 d-1), xylenes (0.10-0.31 d-1), toluene (0.09-0.30 d-1), and benzene (0.07-0.31 d-1). Hydrocarbon mass loss rates at the water table resulting from the coupled aerobic biodgradation and volatilization process were determined by extrapolating gas transport rates through the capillary zone. Mass loss

  13. Construction of CoA-dependent 1-butanol synthetic pathway functions under aerobic conditions in Escherichia coli.

    PubMed

    Kataoka, Naoya; Vangnai, Alisa S; Pongtharangkul, Thunyarat; Tajima, Takahisa; Yakushi, Toshiharu; Matsushita, Kazunobu; Kato, Junichi

    2015-06-20

    1-Butanol is an important industrial platform chemical and an advanced biofuel. While various groups have attempted to construct synthetic pathways for 1-butanol production, efforts to construct a pathway that functions under aerobic conditions have met with limited success. Here, we constructed a CoA-dependent 1-butanol synthetic pathway that functions under aerobic conditions in Escherichia coli, by expanding the previously reported (R)-1,3-butanediol synthetic pathway. The pathway consists of phaA (acetyltransferase) and phaB (NADPH-dependent acetoacetyl-CoA reductase) from Ralstonia eutropha, phaJ ((R)-specific enoyl-CoA hydratase) from Aeromonas caviae, ter (trans-enoyl-CoA reductase) from Treponema denticola, bld (butylraldehyde dehydrogenase) from Clostridium saccharoperbutylacetonicum, and inherent alcohol dehydrogenase(s) from E. coli. To evaluate the potential of this pathway for 1-butanol production, culture conditions, including volumetric oxygen transfer coefficient (kLa) and pH were optimized in a mini-jar fermenter. Under optimal conditions, 1-butanol was produced at a concentration of up to 8.60gL(-1) after 46h of fed-batch cultivation.

  14. Whole-Genome Transcriptional Analysis of Chemolithoautotrophic Thiosulfate Oxidation by Thiobacillus denitrificans Under Aerobic vs. Denitrifying Conditions

    SciTech Connect

    Beller, H R; Letain, T E; Chakicherla, A; Kane, S R; Legler, T C; Coleman, M A

    2006-04-22

    Thiobacillus denitrificans is one of the few known obligate chemolithoautotrophic bacteria capable of energetically coupling thiosulfate oxidation to denitrification as well as aerobic respiration. As very little is known about the differential expression of genes associated with ke chemolithoautotrophic functions (such as sulfur-compound oxidation and CO2 fixation) under aerobic versus denitrifying conditions, we conducted whole-genome, cDNA microarray studies to explore this topic systematically. The microarrays identified 277 genes (approximately ten percent of the genome) as differentially expressed using Robust Multi-array Average statistical analysis and a 2-fold cutoff. Genes upregulated (ca. 6- to 150-fold) under aerobic conditions included a cluster of genes associated with iron acquisition (e.g., siderophore-related genes), a cluster of cytochrome cbb3 oxidase genes, cbbL and cbbS (encoding the large and small subunits of form I ribulose 1,5-bisphosphate carboxylase/oxygenase, or RubisCO), and multiple molecular chaperone genes. Genes upregulated (ca. 4- to 95-fold) under denitrifying conditions included nar, nir, and nor genes (associated respectively with nitrate reductase, nitrite reductase, and nitric oxide reductase, which catalyze successive steps of denitrification), cbbM (encoding form II RubisCO), and genes involved with sulfur-compound oxidation (including two physically separated but highly similar copies of sulfide:quinone oxidoreductase and of dsrC, associated with dissimilatory sulfite reductase). Among genes associated with denitrification, relative expression levels (i.e., degree of upregulation with nitrate) tended to decrease in the order nar > nir > nor > nos. Reverse transcription, quantitative PCR analysis was used to validate these trends.

  15. Quantification of aerobic biodegradation and volatilization rates of gasoline hydrocarbons near the water table under natural attenuation conditions

    USGS Publications Warehouse

    Lahvis, M.A.; Baehr, A.L.; Baker, R.J.

    1999-01-01

    Aerobic biodegradation and volatilization near the water table constitute a coupled pathway that contributes significantly to the natural attenuation of hydrocarbons at gasoline spill sites. Rates of hydrocarbon biodegradation and volatilization were quantified by analyzing vapor transport in the unsaturated zone at a gasoline spill site in Beaufort, South Carolina. Aerobic biodegradation rates decreased with distance above the water table, ranging from 0.20 to 1.5g m-3 d-1 for toluene, from 0.24 to 0.38 g m-3 d-1 for xylene, from 0.09 to 0.24 g m-3 d-1 for cyclohexene, from 0.05 to 0.22 g m-3 d-1 for ethylbenzene, and from 0.02 to 0.08 g m-3 d-1 for benzene. Rates were highest in the capillary zone, where 68% of the total hydrocarbon mass that volatilized from the water table was estimated to have been biodegraded. Hydrocarbons were nearly completely degraded within 1 m above the water table. This large loss underscores the importance of aerobic biodegradation in limiting the transport of hydrocarbon vapors in the unsaturated zone and implies that vapor-plume migration to basements and other points of contact may only be significant if a source of free product is present. Furthermore, because transport of the hydrocarbon in the unsaturated zone can be limited relative to that of oxygen and carbon dioxide, soil, gas surveys conducted at hydrocarbon-spill sites would benefit by the inclusion of oxygen- and carbon-dioxide-gas concentration measurements. Aerobic degradation kinetics in the unsaturated zone were approximately first-order. First-order rate constants near the water table were highest for cyctohexene (0.21-0.65 d-1) and nearly equivalent for ethylbenzene (0.11-20.31 d-1), xylenes (0.10-0.31 d-1), toluene (0.09-0.30 d-1), and benzene (0.07,0.31 d-1). Hydrocarbon mass loss rates at the water table resulting from the coupled aerobic biodegradation and volatilization process were determined by extrapolating gas transport rates through the capillary zone. Mass

  16. New generic mathematical model for WWTP sludge digesters operating under aerobic and anaerobic conditions: Model building and experimental verification.

    PubMed

    de Gracia, M; Grau, P; Huete, E; Gómez, J; García-Heras, J L; Ayesa, E

    2009-10-01

    This paper presents a new mathematical model developed to reproduce the performance of a generic sludge digester working either under aerobic or anaerobic operational conditions. The digester has been modelled as two completely mixed tanks associated with gaseous and liquid volumes. The conversion model has been developed based on a plant wide modelling methodology (PWM) and comprises biochemical transformations, physicochemical reactions and thermodynamic considerations. The model predicts the reactor temperature and the temporary evolution of an extensive vector of model components which are completely defined in terms of elemental mass fractions (C, H, O, N and P) and charge density. Thus, the comprehensive definition of the model components guarantees the continuity of elemental mass and charge in all the model transformations and between any two systems defined by the model. The aim of the generic digester model is to overcome the problems that arise when trying to connect aerobic and anaerobic digestion processes working in series or to connect water and sludge lines in a WWTP. The modelling methodology used has allowed the systematic construction of the biochemical model which acts as an initial illustrative example of an application that has been experimentally verified. The variation of the temperature is also predicted based on a thermal dynamic model. Real data from four different facilities and a straightforward calibration have been used to successfully verify the model predictions in the cases of mesophilic and thermophilic anaerobic digestion as well as autothermal thermophilic aerobic digestion (ATAD). The large amount of data from the full scale ATAD and the anaerobic digestion pilot plants, all of them working under different conditions, has allowed the validation of the model for that case study. PMID:19720390

  17. Interaction between phosphorus removal and hybrid granular sludge formation under low hydraulic selection pressure at alternating anaerobic/aerobic conditions.

    PubMed

    Lang, Longqi; Wan, Junfeng; Zhang, Jing; Wang, Jie; Wang, Yan

    2015-01-01

    The hybrid granular sludge (HGS) formation and its performances on phosphorus removal were investigated in a sequencing batch airlift reactor. Under conditions of low superficial air velocity (SAV = 0.68 cm s(-1)) and relatively long settling time (15-30 min), aerobic granules appeared and coexisted with bio-flocs after 120 days operation. At the stable phase, 54% of total suspended solid (m/m) was granular sludge with the two typical sizes (D(mean) = 1.77 ± 0.33 and 0.89 ± 0.11 mm) in the reactor, where the settling velocity was 98.7 ± 12.4 and 37.8 ± 0.9 m h(-1) for the big and small granules. With progressive extension of anaerobic time from 15 to 60 min before aerobic condition per cycle during the whole experiment, the HGS system can be maintained at a high total phosphorus removal efficiency (ca. 99%) since Day-270. The phosphorus content (wt %) in biomass was respectively 9.54 ± 0.29, 7.60 ± 0.48 and 6.15 ± 0.59 for the big granules, small granules and flocs.

  18. Dietary citrus pulp improves protein stability in lamb meat stored under aerobic conditions.

    PubMed

    Gravador, Rufielyn S; Jongberg, Sisse; Andersen, Mogens L; Luciano, Giuseppe; Priolo, Alessandro; Lund, Marianne N

    2014-06-01

    The antioxidant effects of dried citrus pulp on proteins in lamb meat, when used as a replacement of concentrate in the feed, was studied using meat from 26 male Comisana lambs. The lambs of age 90 days had been grouped randomly to receive one of the three dietary treatments: (1) commercial concentrate with 60% barley (Control, n=8), (2) concentrate with 35% barley and 24% citrus pulp (Cp24, n=9), or (3) concentrate with 23% barley and 35% citrus pulp (Cp35, n=9). Slices from the longissimus thoracis et lomborum muscle were packed aerobically and stored for up to 6days at 4°C in the dark. The citrus pulp groups, Cp24 and Cp35, significantly decreased protein radicals and carbonyls, and preserved more thiols within six days of storage compared to the Control group. The citrus pulp groups significantly slowed down the rate of protein oxidation, indicating that dietary citrus pulp reduced oxidative changes in meat proteins.

  19. Rhythm of carbon and nitrogen fixation in unicellular cyanobacteria under turbulent and highly aerobic conditions.

    PubMed

    Krishnakumar, S; Gaudana, Sandeep B; Viswanathan, Ganesh A; Pakrasi, Himadri B; Wangikar, Pramod P

    2013-09-01

    Nitrogen fixing cyanobacteria are being increasingly explored for nitrogenase-dependent hydrogen production. Commercial success however will depend on the ability to grow these cultures at high cell densities. Photo-limitation at high cell densities leads to hindered photoautotrophic growth while turbulent conditions, which simulate flashing light effect, can lead to oxygen toxicity to the nitrogenase enzyme. Cyanothece sp. strain ATCC 51142, a known hydrogen producer, is reported to grow and fix nitrogen under moderately oxic conditions in shake flasks. In this study, we explore the growth and nitrogen fixing potential of this organism under turbulent conditions with volumetric oxygen mass transfer coefficient (KL a) values that are up to 20-times greater than in shake flasks. In a stirred vessel, the organism grows well in turbulent regime possibly due to a simulated flashing light effect with optimal growth at Reynolds number of approximately 35,000. A respiratory burst lasting for about 4 h creates anoxic conditions intracellularly with near saturating levels of dissolved oxygen in the extracellular medium. This is concomitant with complete exhaustion of intracellular glycogen storage and upregulation of nifH and nifX, the genes encoding proteins of the nitrogenase complex. Further, the rhythmic oscillations in exhaust gas CO2 and O2 profiles synchronize faithfully with those in biochemical parameters and gene expression thereby serving as an effective online monitoring tool. These results will have important implications in potential commercial success of nitrogenase-dependent hydrogen production by cyanobacteria.

  20. Differential sensitivities of the growth of Escherichia coli to acrylate under aerobic and anaerobic conditions and its effect on product formation.

    PubMed

    Arya, Ajay S; Lee, Sarah A; Eiteman, Mark A

    2013-11-01

    The effect of acrylate on the growth of Escherichia coli was determined under aerobic and anaerobic conditions in glucose-defined medium. Growth occurred with up to 35 mM acrylate under aerobic conditions but ceased at 5 mM acrylate under anaerobic conditions. This differential sensitivity can be attributed to inhibition of pyruvate formate lyase and/or pflB gene repression, as this enzyme is necessary for anaerobic growth of E. coli. The effect of acrylate on end-product distribution was also determined by growing E. coli first aerobically, then switching to anaerobic conditions. In the absence of acrylate, E. coli generated the typical distribution of mixed-acid products, with about 12 % of pyruvate being metabolically converted to lactate. In contrast, in the presence of 5 mM acrylate, E. coli converted 83 % of pyruvate to lactate, consistent with a reduction in pyruvate formate lyase activity.

  1. Biological sulfide removal under alkaline and aerobic conditions in a packed recycling reactor.

    PubMed

    González-Sánchez, A; Revah, S

    2009-01-01

    The biological sulfide removal from wastewater caustic streams can be achieved without significant dilution by alkaliphilic microorganisms which usually show lower growth and oxidation rates as compared with acidic and neutral bacteria. To improve volumetric removal rates under alkaline condition (pH 10), an Alkaliphilic Sulfide-oxidizing Bacteria Consortium (ASBC) was studied in a Packed Recycling Reactor (PRR). A commercial Nylon fiber resulted to be a convenient packing support for biofilm development as it has high specific area and similar hydrophobic propertie. The PRR reached a maximum sulfide oxidation rate of 100 mmol L(-1) d(-1) with efficiency close to 100%, representing an enhancement of 56% from the maximum sulfide oxidation rate reached for a free cell continuous culture. Higher sulfide loading rates induced oxygen limiting conditions reducing the biological activity despite the considerable biofilm attached on the nylon fiber.

  2. Biological sulfide removal under alkaline and aerobic conditions in a packed recycling reactor.

    PubMed

    González-Sánchez, A; Revah, S

    2009-01-01

    The biological sulfide removal from wastewater caustic streams can be achieved without significant dilution by alkaliphilic microorganisms which usually show lower growth and oxidation rates as compared with acidic and neutral bacteria. To improve volumetric removal rates under alkaline condition (pH 10), an Alkaliphilic Sulfide-oxidizing Bacteria Consortium (ASBC) was studied in a Packed Recycling Reactor (PRR). A commercial Nylon fiber resulted to be a convenient packing support for biofilm development as it has high specific area and similar hydrophobic propertie. The PRR reached a maximum sulfide oxidation rate of 100 mmol L(-1) d(-1) with efficiency close to 100%, representing an enhancement of 56% from the maximum sulfide oxidation rate reached for a free cell continuous culture. Higher sulfide loading rates induced oxygen limiting conditions reducing the biological activity despite the considerable biofilm attached on the nylon fiber. PMID:19381008

  3. Aerobic granulation utilizing fermented municipal wastewater under low pH and alkalinity conditions in a sequencing batch reactor.

    PubMed

    Leong, Jason; Rezania, Babak; Mavinic, Don S

    2016-01-01

    The aim of this study was to achieve aerobic granulation utilizing fermented municipal wastewater under low pH, and alkalinity conditions. Stable granulation was achieved after a 166-day start-up period. Due to low influent strength, supplemental carbon addition, in the form of sucrose, was added to the feed storage tank on the 82nd day of start-up to facilitate granulation. This increased the system's organic loading rate from 1.43 ± 0.14 to 2.53 ± 0.18 kg COD/m(3)/d, and reduced the influent pH due to fermentation of the added sucrose. Although granulation was successful, the nutrient removal was limited. Removal rates at an influent pH of 6.23 ± 0.06 were 54.4% ± 8.3% for phosphorus, 21.9% ± 4.1% for ammonium, and 84.0% ± 3.0% for total chemical oxygen demand (COD). During the second phase of experimentation, increased amounts of sucrose were added to the feed, which resulted in increased volatile fatty acid concentrations and pH reduction to 5.62 ± 0.12 due to fermentation. Under further reduced pH conditions, phosphorus, ammonium, and total COD removal were found to be 58.9% ± 4.7%, 37.9% ± 4.7%, and 87.1% ± 0.9%, respectively. Settling volume indexes, SVI10 and SVI30, were found to be 148.8 ± 28.9 mL/g, for the influent pH of 6.23 ± 0.06, and 157.5 ± 40.6 mL/g, for the influent pH of 5.62 ± 0.12. This high SVI is indicative of the formation of lower-density granules in comparison to high-ash-content granules. The absence of denitrification-induced chemical phosphorus precipitation within the granule was likely a contributing factor to the low granule density observed in the system.

  4. The determination of the real nano-scale sizes of bacteria in chernozem during microbial succession by means of hatching of a soil in aerobic and anaerobic conditions

    NASA Astrophysics Data System (ADS)

    Gorbacheva, M.

    2012-04-01

    understanding natural mechanisms in soil and will be useful for the development of new soil models in laboratory. Thus, by means of «cascade filtration» method there've been made some results on true size, quantity and biomass of bacteria. Development of a bacteria in various soil horizons and their layers in aerobic and anaerobic conditions and calculations of biomass of bacteria in upper layer horizon A and lower layer horizon B have also become the subjects of the studies. It was identified that the quantity of bacteria in aerobic conditions increase during the microbial succession while bacteria sized 230 and 380 nm were dominating. In anaerobic conditions the process of connecting cells sized 170 nm and bacteria is observed. Biomass of bacteria is higher in anaerobic conditions in upper layer horizon A because of elevated variety of bacteria. In horizon B in anaerobic conditions it is of maximum because of anaerobic situation in situ. Thus, distribution of bacteria's size depends on aeration of soil. That helps to acknowledge the receipt of theory of a great number of researchers about that fact that the size of bacteria in the soil in anaerobic conditions decrease under stress-factors. This work touches upon such a poorly investigated subject as nanobacteria in the soil. But this knowledge plays a significant role in land reclamation oil-cut and prognostication pollution of the soil by pathogenic bacteria.

  5. Light-Driven Hydrogen Production by Hydrogenases and a Ru-Complex inside a Nanoporous Glass Plate under Aerobic External Conditions.

    PubMed

    Noji, Tomoyasu; Kondo, Masaharu; Jin, Tetsuro; Yazawa, Tetsuo; Osuka, Hisao; Higuchi, Yoshiki; Nango, Mamoru; Itoh, Shigeru; Dewa, Takehisa

    2014-07-17

    Hydrogenases are powerful catalysts for light-driven H2 production using a combination of photosensitizers. However, except oxygen-tolerant hydrogenases, they are immediately deactivated under aerobic conditions. We report a light-driven H2 evolution system that works stably even under aerobic conditions. A [NiFe]-hydrogenase from Desulfovibrio vulgaris Miyazaki F was immobilized inside nanoporous glass plates (PGPs) with a pore diameter of 50 nm together with a ruthenium complex and methyl viologen as a photosensitizer and an electron mediator, respectively. After immersion of PGP into the medium containing the catalytic components, an anaerobic environment automatically established inside the nanopores even under aerobic external conditions upon irradiation with solar-simulated light; this system constantly evolved H2 with an efficiency of 3.7 μmol H2 m(-2) s(-1). The PGP system proposed in this work represents a promising first step toward the development of an O2-tolerant solar energy conversion system.

  6. Development of a predictive model for the growth kinetics of aerobic microbial population on pomegranate marinated chicken breast fillets under isothermal and dynamic temperature conditions.

    PubMed

    Lytou, Anastasia; Panagou, Efstathios Z; Nychas, George-John E

    2016-05-01

    The aim of this study was the development of a model to describe the growth kinetics of aerobic microbial population of chicken breast fillets marinated in pomegranate juice under isothermal and dynamic temperature conditions. Moreover, the effect of pomegranate juice on the extension of the shelf life of the product was investigated. Samples (10 g) of chicken breast fillets were immersed in marinades containing pomegranate juice for 3 h at 4 °C following storage under aerobic conditions at 4, 10, and 15 °C for 10 days. Total Viable Counts (TVC), Pseudomonas spp and lactic acid bacteria (LAB) were enumerated, in parallel with sensory assessment (odor and overall appearance) of marinated and non-marinated samples. The Baranyi model was fitted to the growth data of TVC to calculate the maximum specific growth rate (μmax) that was further modeled as a function of temperature using a square root-type model. The validation of the model was conducted under dynamic temperature conditions based on two fluctuating temperature scenarios with periodic changes from 6 to 13 °C. The shelf life was determined both mathematically and with sensory assessment and its temperature dependence was modeled by an Arrhenius type equation. Results showed that the μmax of TVC of marinated samples was significantly lower compared to control samples regardless temperature, while under dynamic temperature conditions the model satisfactorily predicted the growth of TVC in both control and marinated samples. The shelf-life of marinated samples was significantly extended compared to the control (5 days extension at 4 °C). The calculated activation energies (Ea), 82 and 52 kJ/mol for control and marinated samples, respectively, indicated higher temperature dependence of the shelf life of control samples compared to marinated ones. The present results indicated that pomegranate juice could be used as an alternative ingredient in marinades to prolong the shelf life of chicken.

  7. Biodegradation potential of MTBE in a fractured chalk aquifer under aerobic conditions in long-term uncontaminated and contaminated aquifer microcosms.

    PubMed

    Shah, Nadeem W; Thornton, Steven F; Bottrell, Simon H; Spence, Michael J

    2009-01-26

    The potential for aerobic biodegradation of MTBE in a fractured chalk aquifer is assessed in microcosm experiments over 450 days, under in situ conditions for a groundwater temperature of 10 degrees C, MTBE concentration between 0.1 and 1.0 mg/L and dissolved O2 concentration between 2 and 10 mg/L. Following a lag period of up to 120 days, MTBE was biodegraded in uncontaminated aquifer microcosms at concentrations up to 1.2 mg/L, demonstrating that the aquifer has an intrinsic potential to biodegrade MTBE aerobically. The MTBE biodegradation rate increased three-fold from a mean of 6.6+/-1.6 microg/L/day in uncontaminated aquifer microcosms for subsequent additions of MTBE, suggesting an increasing biodegradation capability, due to microbial cell growth and increased biomass after repeated exposure to MTBE. In contaminated aquifer microcosms which also contained TAME, MTBE biodegradation occurred after a shorter lag of 15 or 33 days and MTBE biodegradation rates were higher (max. 27.5 microg/L/day), probably resulting from an acclimated microbial population due to previous exposure to MTBE in situ. The initial MTBE concentration did not affect the lag period but the biodegradation rate increased with the initial MTBE concentration, indicating that there was no inhibition of MTBE biodegradation related to MTBE concentration up to 1.2 mg/L. No minimum substrate concentration for MTBE biodegradation was observed, indicating that in the presence of dissolved O2 (and absence of inhibitory factors) MTBE biodegradation would occur in the aquifer at MTBE concentrations (ca. 0.1 mg/L) found at the front of the ether oxygenate plume. MTBE biodegradation occurred with concomitant O2 consumption but no other electron acceptor utilisation, indicating biodegradation by aerobic processes only. However, O2 consumption was less than the stoichiometric requirement for complete MTBE mineralization, suggesting that only partial biodegradation of MTBE to intermediate organic

  8. Requirement of ArcA for redox regulation in Escherichia coli under microaerobic but not anaerobic or aerobic conditions.

    PubMed

    Alexeeva, Svetlana; Hellingwerf, Klaas J; Teixeira de Mattos, M Joost

    2003-01-01

    In Escherichia coli, the two-component regulatory ArcAB system functions as a major control system for the regulation of expression of genes encoding enzymes involved in both aerobic and anaerobic catabolic pathways. Previously, we have described the physiological response of wild-type E. coli to changes in oxygen availability through the complete range from anaerobiosis to full aerobiosis (S. Alexeeva, B. de Kort, G. Sawers, K. J. Hellingwerf, and M. J. Teixeira de Mattos, J. Bacteriol. 182:4934-4940, 2000, and S. Alexeeva, K. J. Hellingwerf, and M. J. Teixeira de Mattos, J. Bacteriol. 184:1402-1406, 2002). Here, we address the question of the contribution of the ArcAB-dependent transcriptional regulation to this response. Wild-type E. coli and a mutant lacking the ArcA regulator were grown in glucose-limited chemostat cultures at controlled levels of oxygen availability ranging from full aerobiosis to complete anaerobiosis. A flux analysis of the distribution of catabolic fluxes over parallel pathways was carried out, and the intracellular redox state (as reflected by the NADH/NAD ratio) was monitored for all steady states. Deletion of ArcA neither significantly altered the in vivo activity of the pyruvate dehydrogenase complex and pyruvate formate lyase nor significantly affected catabolism under fully aerobic and fully anaerobic conditions. In contrast, profound effects of the absence of ArcA were seen under conditions of oxygen-restricted growth: increased respiration, an altered electron flux distribution over the cytochrome o- and d-terminal oxidases, and a significant change in the intracellular redox state were observed. Thus, the ArcA regulator was found to exert major control on flux distribution, and it is concluded that the ArcAB system should be considered a microaerobic redox regulator.

  9. [Effects of aerobic physical conditioning on the profile of plasma lipoproteins in a group of healthy volunteers].

    PubMed

    Ahumada Ayala, M; Cervera, A; Cardoso, G; Sienra, J C; Fernández de la Vega, P; Marin, J; Posadas, C

    1989-01-01

    To evaluate the effects of aerobic physical conditioning on plasma lipoproteins, we studied 26 previously untrained, apparently healthy, non obese volunteers. All participants underwent a treadmill test performed according to the protocol of Bruce with the direct measurement of maximal oxygen consumption (VO2max). A program of aerobic exercise was prescribed for each volunteer at 70% of their corresponding VO2max. At baseline and at the end of weeks 4, 8 and 12 of the exercise program, cholesterol and triglycerides were measured by enzymatic analysis in total plasma and in the lipoprotein fractions separated by preparative ultracentrifugation and precipitation methods. At the end of week 12, the VO2max measurement was repeated. At the end of the protocol, mean VO2max increased from the value of 39.9 observed at baseline to 94.4 ml/kg/min (p less than 0.01). There were no variations in mean body weight, diet or smoking status of the participants during the exercise program. Cholesterol associated with High-density lipoproteins (C-HDL) increased from 42.5 to 46.1 mg/dl (p less than 0.05). This effect was first noticeable at week 8. We didn't observe significant changes in Total Cholesterol nor the Cholesterol fraction associated with Low-density lipoproteins (C-LDL). Total triglycerides decreased at weeks 4 and 8 but returned to near baseline values at week 12. The C-LDL/C-HDL ratio considered as an index of a high coronary risk decreased from 2.32 at baseline to 2.02 (p less than 0.05) at week 12. Thirteen of the twenty six initial volunteers completed the physical conditioning program as planned, the rest were eliminated at different stages of the protocol due to incomplete adherence to their exercise schedules.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Degradation of 3-chlorobenzoate under low-oxygen conditions in pure and mixed cultures of the anoxygenic photoheterotroph Rhodopseudomonas palustris DCP3 and an aerobic Alcaligenes species.

    PubMed

    Krooneman, J; van den Akker, S; Pedro Gomes, T M; Forney, L J; Gottschal, J C

    1999-01-01

    The presence or absence of molecular oxygen has been shown to play a crucial role in the degradability of haloaromatic compounds. In the present study, it was shown that anaerobic phototrophic 3-chlorobenzoate (3CBA) metabolism by Rhodopseudomonas palustris DCP3 is oxygen tolerant up to a concentration of 3 microM O2. Simultaneous oxidation of an additional carbon source permitted light-dependent anaerobic 3CBA degradation at oxygen input levels which, in the absence of such an additional compound, would result in inhibition of light-dependent dehalogenation. Experiments under the same experimental conditions with strain DCP3 in coculture with an aerobic 3CBA-utilizing heterotroph, Alcaligenes sp. strain L6, revealed that light-dependent dehalogenation of 3CBA did not occur. Under both oxygen limitation (O2 < 0.1 microM) and low oxygen concentrations (3 microM O2), all the 3CBA was metabolized by the aerobic heterotroph. These data suggest that biodegradation of (halo)aromatics by photoheterotrophic bacteria such as R. palustris DCP3 may be restricted to anoxic photic environments. PMID:9872770

  11. TBA biodegradation in surface-water sediments under aerobic and anaerobic conditions

    USGS Publications Warehouse

    Bradley, P.M.; Landmeyer, J.E.; Chapelle, F.H.

    2002-01-01

    The potential for [U-14C] TBA biodegradation was examined in laboratory microcosms under a range of terminal electron accepting conditions. TBA mineralization to CO2 was substantial in surface-water sediments under oxic, denitrifying, or Mn(IV)-reducing conditions and statistically significant but low under SO4-reducing conditions. Thus, anaerobic TBA biodegradation may be a significant natural attenuation mechanism for TBA in the environment, and stimulation of in situ TBA bioremediation by addition of suitable terminal electron acceptors may be feasible. No degradation of [U-14C] TBA was observed under methanogenic or Fe(III)-reducing conditions.

  12. Intracellular Accumulation of Glycine in Polyphosphate-Accumulating Organisms in Activated Sludge, a Novel Storage Mechanism under Dynamic Anaerobic-Aerobic Conditions

    PubMed Central

    Nguyen, Hien Thi Thu; Kristiansen, Rikke; Vestergaard, Mette; Wimmer, Reinhard

    2015-01-01

    Dynamic anaerobic-aerobic feast-famine conditions are applied to wastewater treatment plants to select polyphosphate-accumulating organisms to carry out enhanced biological phosphorus removal. Acetate is a well-known substrate to stimulate this process, and here we show that different amino acids also are suitable substrates, with glycine as the most promising. 13C-labeled glycine and nuclear magnetic resonance (NMR) were applied to investigate uptake and potential storage products when activated sludge was fed with glycine under anaerobic conditions. Glycine was consumed by the biomass, and the majority was stored intracellularly as free glycine and fermentation products. Subsequently, in the aerobic phase without addition of external substrate, the stored glycine was consumed. The uptake of glycine and oxidation of intracellular metabolites took place along with a release and uptake of orthophosphate, respectively. Fluorescence in situ hybridization combined with microautoradiography using 3H-labeled glycine revealed uncultured actinobacterial Tetrasphaera as a dominant glycine consumer. Experiments with Tetrasphaera elongata as representative of uncultured Tetrasphaera showed that under anaerobic conditions it was able to take up labeled glycine and accumulate this and other labeled metabolites to an intracellular concentration of approximately 4 mM. All components were consumed under subsequent aerobic conditions. Intracellular accumulation of amino acids seems to be a novel storage strategy for polyphosphate-accumulating bacteria under dynamic anaerobic-aerobic feast-famine conditions. PMID:25956769

  13. Intracellular Accumulation of Glycine in Polyphosphate-Accumulating Organisms in Activated Sludge, a Novel Storage Mechanism under Dynamic Anaerobic-Aerobic Conditions.

    PubMed

    Nguyen, Hien Thi Thu; Kristiansen, Rikke; Vestergaard, Mette; Wimmer, Reinhard; Nielsen, Per Halkjær

    2015-07-01

    Dynamic anaerobic-aerobic feast-famine conditions are applied to wastewater treatment plants to select polyphosphate-accumulating organisms to carry out enhanced biological phosphorus removal. Acetate is a well-known substrate to stimulate this process, and here we show that different amino acids also are suitable substrates, with glycine as the most promising. (13)C-labeled glycine and nuclear magnetic resonance (NMR) were applied to investigate uptake and potential storage products when activated sludge was fed with glycine under anaerobic conditions. Glycine was consumed by the biomass, and the majority was stored intracellularly as free glycine and fermentation products. Subsequently, in the aerobic phase without addition of external substrate, the stored glycine was consumed. The uptake of glycine and oxidation of intracellular metabolites took place along with a release and uptake of orthophosphate, respectively. Fluorescence in situ hybridization combined with microautoradiography using (3)H-labeled glycine revealed uncultured actinobacterial Tetrasphaera as a dominant glycine consumer. Experiments with Tetrasphaera elongata as representative of uncultured Tetrasphaera showed that under anaerobic conditions it was able to take up labeled glycine and accumulate this and other labeled metabolites to an intracellular concentration of approximately 4 mM. All components were consumed under subsequent aerobic conditions. Intracellular accumulation of amino acids seems to be a novel storage strategy for polyphosphate-accumulating bacteria under dynamic anaerobic-aerobic feast-famine conditions. PMID:25956769

  14. Volatile chemical spoilage indexes of raw Atlantic salmon (salmo salar)stored under aerobic condition in relation to microbiological and sensory shelf lives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of this investigation was to identify and quantify the volatile chemical spoilage indexes (CSIs) for raw Atlantic salmon (Salmo salar) fillets stored under aerobic storage conditions at 4, 10 and 21 degrees C in relation to the determined microbial and sensory shelf lives. The volatile o...

  15. Model based evaluation of a contaminant plume development under aerobic and anaerobic conditions in 2D bench-scale tank experiments.

    PubMed

    Ballarini, E; Beyer, C; Bauer, R D; Griebler, C; Bauer, S

    2014-06-01

    The influence of transverse mixing on competitive aerobic and anaerobic biodegradation of a hydrocarbon plume was investigated using a two-dimensional, bench-scale flow-through laboratory tank experiment. In the first part of the experiment aerobic degradation of increasing toluene concentrations was carried out by the aerobic strain Pseudomonas putida F1. Successively, ethylbenzene (injected as a mixture of unlabeled and fully deuterium-labeled isotopologues) substituted toluene; nitrate was added as additional electron acceptor and the anaerobic denitrifying strain Aromatoleum aromaticum EbN1 was inoculated to study competitive degradation under aerobic /anaerobic conditions. The spatial distribution of anaerobic degradation was resolved by measurements of compound-specific stable isotope fractionation induced by the anaerobic strain as well as compound concentrations. A fully transient numerical reactive transport model was employed and calibrated using measurements of electron donors, acceptors and isotope fractionation. The aerobic phases of the experiment were successfully reproduced using a double Monod kinetic growth model and assuming an initial homogeneous distribution of P. putida F1. Investigation of the competitive degradation phase shows that the observed isotopic pattern cannot be explained by transverse mixing driven biodegradation only, but also depends on the inoculation process of the anaerobic strain. Transient concentrations of electron acceptors and donors are well reproduced by the model, showing its ability to simulate transient competitive biodegradation. PMID:24122285

  16. Conditional independence mapping of DIGE data reveals PDIA3 protein species as key nodes associated with muscle aerobic capacity

    PubMed Central

    Burniston, Jatin G.; Kenyani, Jenna; Gray, Donna; Guadagnin, Eleonora; Jarman, Ian H.; Cobley, James N.; Cuthbertson, Daniel J.; Chen, Yi-Wen; Wastling, Jonathan M.; Lisboa, Paulo J.; Koch, Lauren G.; Britton, Steven L.

    2014-01-01

    Profiling of protein species is important because gene polymorphisms, splice variations and post-translational modifications may combine and give rise to multiple protein species that have different effects on cellular function. Two-dimensional gel electrophoresis is one of the most robust methods for differential analysis of protein species, but bioinformatic interrogation is challenging because the consequences of changes in the abundance of individual protein species on cell function are unknown and cannot be predicted. We conducted DIGE of soleus muscle from male and female rats artificially selected as either high- or low-capacity runners (HCR and LCR, respectively). In total 696 protein species were resolved and LC–MS/MS identified proteins in 337 spots. Forty protein species were differentially (P < 0.05, FDR < 10%) expressed between HCR and LCR and conditional independence mapping found distinct networks within these data, which brought insight beyond that achieved by functional annotation. Protein disulphide isomerase A3 emerged as a key node segregating with differences in aerobic capacity and unsupervised bibliometric analysis highlighted further links to signal transducer and activator of transcription 3, which were confirmed by western blotting. Thus, conditional independence mapping is a useful technique for interrogating DIGE data that is capable of highlighting latent features. PMID:24769234

  17. Metabolite analysis of Mycobacterium species under aerobic and hypoxic conditions reveals common metabolic traits.

    PubMed

    Drapal, Margit; Wheeler, Paul R; Fraser, Paul D

    2016-08-01

    A metabolite profiling approach has been implemented to elucidate metabolic adaptation at set culture conditions in five Mycobacterium species (two fast- and three slow-growing) with the potential to act as model organisms for Mycobacterium tuberculosis (Mtb). Analysis has been performed over designated growth phases and under representative environments (nutrient and oxygen depletion) experienced by Mtb during infection. The procedure was useful in determining a range of metabolites (60-120 compounds) covering nucleotides, amino acids, organic acids, saccharides, fatty acids, glycerols, -esters, -phosphates and isoprenoids. Among these classes of compounds, key biomarker metabolites, which can act as indicators of pathway/process activity, were identified. In numerous cases, common metabolite traits were observed for all five species across the experimental conditions (e.g. uracil indicating DNA repair). Amino acid content, especially glutamic acid, highlighted the different properties between the fast- and slow-growing mycobacteria studied (e.g. nitrogen assimilation). The greatest similarities in metabolite composition between fast- and slow-growing mycobacteria were apparent under hypoxic conditions. A comparison to previously reported transcriptomic data revealed a strong correlation between changes in transcription and metabolite content. Collectively, these data validate the changes in the transcription at the metabolite level, suggesting transcription exists as one of the predominant modes of cellular regulation in Mycobacterium. Sectors with restricted correlation between metabolites and transcription (e.g. hypoxic cultivation) warrant further study to elucidate and exploit post-transcriptional modes of regulation. The strong correlation between the laboratory conditions used and data derived from in vivo conditions, indicate that the approach applied is a valuable addition to our understanding of cell regulation in these Mycobacterium species.

  18. Coenzyme B12 can be produced by engineered Escherichia coli under both anaerobic and aerobic conditions.

    PubMed

    Ko, Yeounjoo; Ashok, Somasundar; Ainala, Satish Kumar; Sankaranarayanan, Mugesh; Chun, Ah Yeong; Jung, Gyoo Yeol; Park, Sunghoon

    2014-12-01

    Coenzyme B12 (Vitamin B12 ) is one of the most complex biomolecules and an essential cofactor required for the catalytic activity of many enzymes. Pseudomonas denitrificans synthesizes coenzyme B12 in an oxygen-dependent manner using a pathway encoded by more than 25 genes that are located in six different operons. Escherichia coli, a robust and suitable host for metabolic engineering was used to produce coenzyme B12 . These genes were cloned into three compatible plasmids and expressed heterologously in E. coli BL21 (DE3). Real-time PCR, SDS-PAGE analysis and bioassay showed that the recombinant E. coli expressed the coenzyme B12 synthetic genes and successfully produced coenzyme B12 . However, according to the quantitative determination by inductively coupled plasma-mass spectrometry, the amount of coenzyme B12 produced by the recombinant E. coli (0.21 ± 0.02 μg/g cdw) was approximately 13-fold lower than that by P. denitrificans (2.75 ± 0.22 μg/g cdw). Optimization of the culture conditions to improve the production of coenzyme B12 by the recombinant E. coli was successful, and the highest titer (0.65 ± 0.03 μg/g cdw) of coenzyme B12 was obtained. Interestingly, although the synthesis of coenzyme B12 in P. denitrificans is strictly oxygen-dependent, the recombinant E. coli could produce coenzyme B12 under anaerobic conditions.

  19. [Population development characteristics of rice crop cultivated on aerobic soil with mulching].

    PubMed

    Sheng, Haijun; Shen, Qirong; Feng, Ke

    2004-01-01

    Field experiments were carried out to study the population development characteristics of rice crop cultivated both on aerobic and waterlogged soil conditions. The results showed that the whole growth duration of rice growing on aerobic soil was one week longer than that on waterlogged soil. Shorter and narrower leaves and smaller LAI of rice population were found on aerobic soil than on waterlogged soil, which resulted in a decreased photosynthesis, smaller amount and lighter weight of rice grains on aerobic soil, compared with those on waterlogged soil. Among the aerobic treatments, more tillers, lower percentage of filled grains and shorter duration of grain forming were found on soils covered with plastic film than on soils covered with semi-decomposed straw or without mulching. The rice grain yield was decreased in the order of waterlogged soil > aerobic soil covered with plastic film > aerobic soil covered with semi-decomposed straw > aerobic soil without mulching.

  20. Fermilab Linac Upgrade: Module conditioning results

    SciTech Connect

    Kroc, T.; Moretti, A.; Popovic, M.

    1992-12-01

    The 805 MHz Side-coupled cavity modules for the Fermilab 400 MeV linac upgrade have been conditioned to accept full power. The sparking rate in the cavities and in the side-cells has been reduced to acceptable levels. It required approximately 40 [times] 10[sup 6] pulses for each module to achieve an adequately low sparking rate. This contribution outlines the commissioning procedure, presents the sparking rate improvements and the radiation level improvements through the commissioning process and disc the near-online commissioning plans for this accelerator.

  1. Fermilab Linac Upgrade: Module conditioning results

    SciTech Connect

    Kroc, T.; Moretti, A.; Popovic, M.

    1992-12-01

    The 805 MHz Side-coupled cavity modules for the Fermilab 400 MeV linac upgrade have been conditioned to accept full power. The sparking rate in the cavities and in the side-cells has been reduced to acceptable levels. It required approximately 40 {times} 10{sup 6} pulses for each module to achieve an adequately low sparking rate. This contribution outlines the commissioning procedure, presents the sparking rate improvements and the radiation level improvements through the commissioning process and disc the near-online commissioning plans for this accelerator.

  2. Molecular analysis of the biomass of a fluidized bed reactor treating synthetic vinasse at anaerobic and micro-aerobic conditions.

    PubMed

    Rodríguez, Elisa; Lopes, Alexandre; Fdz-Polanco, María; Stams, Alfons J M; García-Encina, Pedro A

    2012-03-01

    The microbial communities (Bacteria and Archaea) established in an anaerobic fluidized bed reactor used to treat synthetic vinasse (betaine, glucose, acetate, propionate, and butyrate) were characterized by denaturing gradient gel electrophoresis (DGGE) and phylogenetic analysis. This study was focused on the competitive and syntrophic interactions between the different microbial groups at varying influent substrate to sulfate ratios of 8, 4, and 2 and anaerobic or micro-aerobic conditions. Acetogens detected along the anaerobic phases at substrate to sulfate ratios of 8 and 4 seemed to be mainly involved in the fermentation of glucose and betaine, but they were substituted by other sugar or betaine degraders after oxygen application. Typical fatty acid degraders that grow in syntrophy with methanogens were not detected during the entire reactor run. Likely, sugar and betaine degraders outnumbered them in the DGGE analysis. The detected sulfate-reducing bacteria (SRB) belonged to the hydrogen-utilizing Desulfovibrio. The introduction of oxygen led to the formation of elemental sulfur (S(0)) and probably other sulfur compounds by sulfide-oxidizing bacteria (γ-Proteobacteria). It is likely that the sulfur intermediates produced from sulfide oxidation were used by SRB and other microorganisms as electron acceptors, as was supported by the detection of the sulfur respiring Wolinella succinogenes. Within the Archaea population, members of Methanomethylovorans and Methanosaeta were detected throughout the entire reactor operation. Hydrogenotrophic methanogens mainly belonging to the genus Methanobacterium were detected at the highest substrate to sulfate ratio but rapidly disappeared by increasing the sulfate concentration. PMID:21861082

  3. Isolation of high-salinity-tolerant bacterial strains, Enterobacter sp., Serratia sp., Yersinia sp., for nitrification and aerobic denitrification under cyanogenic conditions.

    PubMed

    Mpongwana, N; Ntwampe, S K O; Mekuto, L; Akinpelu, E A; Dyantyi, S; Mpentshu, Y

    2016-01-01

    Cyanides (CN(-)) and soluble salts could potentially inhibit biological processes in wastewater treatment plants (WWTPs), such as nitrification and denitrification. Cyanide in wastewater can alter metabolic functions of microbial populations in WWTPs, thus significantly inhibiting nitrifier and denitrifier metabolic processes, rendering the water treatment processes ineffective. In this study, bacterial isolates that are tolerant to high salinity conditions, which are capable of nitrification and aerobic denitrification under cyanogenic conditions, were isolated from a poultry slaughterhouse effluent. Three of the bacterial isolates were found to be able to oxidise NH(4)-N in the presence of 65.91 mg/L of free cyanide (CN(-)) under saline conditions, i.e. 4.5% (w/v) NaCl. The isolates I, H and G, were identified as Enterobacter sp., Yersinia sp. and Serratia sp., respectively. Results showed that 81% (I), 71% (G) and 75% (H) of 400 mg/L NH(4)-N was biodegraded (nitrification) within 72 h, with the rates of biodegradation being suitably described by first order reactions, with rate constants being: 4.19 h(-1) (I), 4.21 h(-1) (H) and 3.79 h(-1) (G), respectively, with correlation coefficients ranging between 0.82 and 0.89. Chemical oxygen demand (COD) removal rates were 38% (I), 42% (H) and 48% (G), over a period of 168 h with COD reduction being highest at near neutral pH. PMID:27148718

  4. Optimization of operation conditions for the startup of aerobic granular sludge reactors biologically removing carbon, nitrogen, and phosphorous.

    PubMed

    Lochmatter, Samuel; Holliger, Christof

    2014-08-01

    The transformation of conventional flocculent sludge to aerobic granular sludge (AGS) biologically removing carbon, nitrogen and phosphorus (COD, N, P) is still a main challenge in startup of AGS sequencing batch reactors (AGS-SBRs). On the one hand a rapid granulation is desired, on the other hand good biological nutrient removal capacities have to be maintained. So far, several operation parameters have been studied separately, which makes it difficult to compare their impacts. We investigated seven operation parameters in parallel by applying a Plackett-Burman experimental design approach with the aim to propose an optimized startup strategy. Five out of the seven tested parameters had a significant impact on the startup duration. The conditions identified to allow a rapid startup of AGS-SBRs with good nutrient removal performances were (i) alternation of high and low dissolved oxygen phases during aeration, (ii) a settling strategy avoiding too high biomass washout during the first weeks of reactor operation, (iii) adaptation of the contaminant load in the early stage of the startup in order to ensure that all soluble COD was consumed before the beginning of the aeration phase, (iv) a temperature of 20 °C, and (v) a neutral pH. Under such conditions, it took less than 30 days to produce granular sludge with high removal performances for COD, N, and P. A control run using this optimized startup strategy produced again AGS with good nutrient removal performances within four weeks and the system was stable during the additional operation period of more than 50 days.

  5. Lab scale experiments using a submerged MBR under thermophilic aerobic conditions for the treatment of paper mill deinking wastewater.

    PubMed

    Simstich, Benjamin; Beimfohr, Claudia; Horn, Harald

    2012-10-01

    This paper describes the results of laboratory experiments using a thermophilic aerobic MBR (TMBR) at 50 °C. An innovative use of submerged flat-sheet MBR modules to treat circuit wastewater from the paper industry was studied. Two experiments were conducted with a flux of 8-13 L/m(2)/h without chemical membrane cleaning. COD and BOD(5) elimination rates were 83% and 99%, respectively. Calcium was reduced from 110 to 180 mg/L in the inflow to 35-60 mg/L in the permeate. However, only negligible membrane scaling occurred. The observed sludge yield was very low and amounted to 0.07-0.29 g MLSS/g COD(eliminated). Consequently, the nutrient supply of ammonia and phosphate can be lower compared to a mesophilic process. Molecular-biological FISH analysis revealed a likewise high diversity of microorganisms in the TMBR compared to the mesophilic sludge used for start-up. Furthermore, ammonia-oxidising bacteria were detected at thermophilic operation. PMID:22595101

  6. Microbial aerobic and anaerobic degradation of acrylamide in sludge and water under environmental conditions--case study in a sand and gravel quarry.

    PubMed

    Guezennec, A G; Michel, C; Ozturk, S; Togola, A; Guzzo, J; Desroche, N

    2015-05-01

    Polyacrylamides (PAMs) are used in sand and gravel quarries as water purification flocculants for recycling process water in a recycling loop system where the flocculants remove fine particles in the form of sludge. The PAM-based flocculants, however, contain residual amounts of acrylamide (AMD) that did not react during the polymerization process. This acrylamide is released into the environment when the sludge is discharged into a settling basin. Here, we explore the microbial diversity and the potential for AMD biodegradation in water and sludge samples collected in a quarry site submitted to low AMD concentrations. The microbial diversity, analyzed by culture-dependent methods and the denaturing gradient gel electrophoresis approach, reveals the presence of Proteobacteria, Cyanobacteria, and Actinobacteria, among which some species are known to have an AMD biodegradation activity. Results also show that the two main parts of the water recycling loop-the washing process and the settling basin-display significantly different bacterial profiles. The exposure time with residual AMD could, thus, be one of the parameters that lead to a selection of specific bacterial species. AMD degradation experiments with 0.5 g L(-1) AMD showed a high potential for biodegradation in all parts of the washing process, except the make-up water. The AMD biodegradation potential in samples collected from the washing process and settling basin was also analyzed taking into account on-site conditions: low (12 °C) and high (25 °C) temperatures reflecting the winter and summer seasons, and AMD concentrations of 50 μg L(-1). Batch tests showed rapid (as little as 18 h) AMD biodegradation under aerobic and anaerobic conditions at both the winter and summer temperatures, although there was a greater lag time before activity started with the AMD biodegradation at 12 °C. This study, thus, demonstrates that bacteria present in sludge and water samples exert an in situ and rapid

  7. Influence of aerobic and anaerobic conditions on survival of Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium in Luria-Bertani broth, farm-yard manure and slurry.

    PubMed

    Semenov, Alexander V; van Overbeek, Leo; Termorshuizen, Aad J; van Bruggen, Ariena H C

    2011-03-01

    The influence of aerobic and anaerobic conditions on the survival of the enteropathogens Escherichia coli O157:H7 and Salmonella serovar Typhimurium was investigated in microcosms with broth, cattle manure or slurry. These substrates were inoculated with a green fluorescent protein transformed strain of the enteropathogens at 10(7) cells g(-1) dry weight. Survival data was fitted to the Weibull model. The survival curves in aerobic conditions generally showed a concave curvature, while the curvature was convex in anaerobic conditions. The estimated survival times showed that E. coli O157:H7 survived significantly longer under anaerobic than under aerobic conditions. Survival ranged from approximately. 2 weeks for aerobic manure and slurry to more than six months for anaerobic manure at 16 °C. On average, in 56.3% of the samplings, the number of recovered E. coli O157:H7 cells by anaerobic incubation of Petri plates was significantly (p < 0.05) higher in comparison with aerobic incubation. Survival of Salmonella serovar Typhimurium was not different between aerobic and anaerobic storage of LB broth or manure as well as between aerobic and anaerobic incubation of Petri dishes. The importance of changes in microbial community and chemical composition of manure and slurry was distinguished for the survival of E. coli O157:H7 in different oxygen conditions.

  8. Accelerating aerobic DRO biodegradation in stream bank sediments through oxygen enhancements: Laboratory results and field pilot demonstration

    SciTech Connect

    Sturman, P.J.; Cunningham, A.B.; Wemple, C.

    1997-12-31

    A novel technique has been developed for accomplishing in situ, aerobic bioremediation of low-temperature, low-permeability, high-organic carbon containing stream bank sediments impacted with diesel range petroleum hydrocarbons. Laboratory microcosms tests have demonstrated efficient removal of diesel range organics (DRO) when sediments are amended with oxygen-releasing and solubilizing compounds. This technique was conceived, designed and tested to provide a superior alternative to destructive and costly intrusive remediation for a fragile, pristine, riparian environment. Laboratory microcosm tests using sediments from a DRO impacted mountain stream were amended with surfactant (alcohol ethoxylate 810-4.5), a magnesium peroxide containing mixture (Oxygen Release Compound{reg_sign}, Regenesis, Inc.), hydrogen peroxide, and ethanol to determine the effects of these oxygen-enhancing and solubilizing amendments on biodegradation extent and DRO bioavailability. Laboratory test results and subsequent field toxicity testing using aquatic biota indicated the MgO, mixture to be most suitable for field use at this site. While laboratory microcosm tests showed significant reductions to both DRO and the water surface sheen associated with trapped hydrocarbons, biodegradation endpoints in the range of 500-1000 mg/kg were observed. These non-zero biotreatment endpoints suggest that biodegradation in situ is limited by DRO bioavailability. Because contaminant transport to groundwater and adjacent surface waters is very slow, exposure risk is minimal. Based on successful laboratory testing, a field pilot test was initiated in September 1996 wherein slurried Oxygen Release Compound{reg_sign} (ORC) was pressure-injected into shallow, DRO impacted stream bank sediments.

  9. Recovery of Nickel and Cobalt from Laterite Tailings by Reductive Dissolution under Aerobic Conditions Using Acidithiobacillus Species.

    PubMed

    Marrero, J; Coto, O; Goldmann, S; Graupner, T; Schippers, A

    2015-06-01

    Biomining of sulfidic ores has been applied for almost five decades. However, the bioprocessing of oxide ores such as laterites lags commercially behind. Recently, the Ferredox process was proposed to treat limonitic laterite ores by means of anaerobic reductive dissolution (AnRD), which was found to be more effective than aerobic bioleaching by fungi and other bacteria. We show here that the ferric iron reduction mediated by Acidithiobacillus thiooxidans can be applied to an aerobic reductive dissolution (AeRD) of nickel laterite tailings. AeRD using a consortium of Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans extracted similar amounts of nickel (53-57%) and cobalt (55-60%) in only 7 days as AnRD using Acidithiobacillus ferrooxidans. The economic and environmental advantages of AeRD for processing of laterite tailings comprise no requirement for an anoxic atmosphere, 1.8-fold less acid consumption than for AnRD, as well as nickel and cobalt recovered in a ferrous-based pregnant leach solution (PLS), facilitating the subsequent metal recovery. In addition, an aerobic acid regeneration stage is proposed. Therefore, AeRD process development can be considered as environmentally friendly for treating laterites with low operational costs and as an attractive alternative to AnRD. PMID:25923144

  10. Recovery of Nickel and Cobalt from Laterite Tailings by Reductive Dissolution under Aerobic Conditions Using Acidithiobacillus Species.

    PubMed

    Marrero, J; Coto, O; Goldmann, S; Graupner, T; Schippers, A

    2015-06-01

    Biomining of sulfidic ores has been applied for almost five decades. However, the bioprocessing of oxide ores such as laterites lags commercially behind. Recently, the Ferredox process was proposed to treat limonitic laterite ores by means of anaerobic reductive dissolution (AnRD), which was found to be more effective than aerobic bioleaching by fungi and other bacteria. We show here that the ferric iron reduction mediated by Acidithiobacillus thiooxidans can be applied to an aerobic reductive dissolution (AeRD) of nickel laterite tailings. AeRD using a consortium of Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans extracted similar amounts of nickel (53-57%) and cobalt (55-60%) in only 7 days as AnRD using Acidithiobacillus ferrooxidans. The economic and environmental advantages of AeRD for processing of laterite tailings comprise no requirement for an anoxic atmosphere, 1.8-fold less acid consumption than for AnRD, as well as nickel and cobalt recovered in a ferrous-based pregnant leach solution (PLS), facilitating the subsequent metal recovery. In addition, an aerobic acid regeneration stage is proposed. Therefore, AeRD process development can be considered as environmentally friendly for treating laterites with low operational costs and as an attractive alternative to AnRD.

  11. Controlling the catalytic aerobic oxidation of phenols.

    PubMed

    Esguerra, Kenneth Virgel N; Fall, Yacoub; Petitjean, Laurène; Lumb, Jean-Philip

    2014-05-28

    The oxidation of phenols is the subject of extensive investigation, but there are few catalytic aerobic examples that are chemo- and regioselective. Here we describe conditions for the ortho-oxygenation or oxidative coupling of phenols under copper (Cu)-catalyzed aerobic conditions that give rise to ortho-quinones, biphenols or benzoxepines. We demonstrate that each product class can be accessed selectively by the appropriate choice of Cu(I) salt, amine ligand, desiccant and reaction temperature. In addition, we evaluate the effects of substituents on the phenol and demonstrate their influence on selectivity between ortho-oxygenation and oxidative coupling pathways. These results create an important precedent of catalyst control in the catalytic aerobic oxidation of phenols and set the stage for future development of catalytic systems and mechanistic investigations. PMID:24784319

  12. Bacterial diversity and spoilage-related microbiota associated with freshly prepared chicken products under aerobic conditions at 4°C.

    PubMed

    Liang, Rongrong; Yu, Xiaoqiao; Wang, Renhuan; Luo, Xin; Mao, Yanwei; Zhu, Lixian; Zhang, Yimin

    2012-06-01

    This study analyzed the bacterial diversity and spoilage-related microbiota associated with freshly prepared chicken products stored aerobically at 4°C, using "bone and chicken string," a product popular in the People's Republic of China, as the study subject. Samples collected from three different factories were tray packaged with cling film and stored at 4°C. Bacterial diversity and dominant bacteria were analyzed using PCR amplification and denaturing gradient gel electrophoresis. Combined with selective cultivation of the dominant bacteria and correlation analysis, the dominant spoilage microbiota was determined. The results showed that bacterial diversity varied with different manufacturers. Such bacteria as Acinetobacter sp., Carnobacterium sp., Rahnella sp., Pseudomonas sp., Brochothrix sp., and Weissella sp. were detected in freshly prepared chicken products during storage. And Carnobacterium sp., Pseudomonas sp., and Brochothrix sp. bacteria were the common dominant spoilage bacteria groups in most freshly prepared chicken products from different factories. Carnobacterium was, for the first time, shown to be an important contributor to the spoilage-related microflora of freshly prepared chicken products stored aerobically under refrigeration. Our work shows the bacterial diversity and dominant spoilage microbiota of freshly prepared chicken products stored aerobically under refrigeration.

  13. The effects of aerobic and anaerobic exercise conditioning on resting metabolic rate and the thermic effect of a meal.

    PubMed

    Schmidt, W D; Hyner, G C; Lyle, R M; Corrigan, D; Bottoms, G; Melby, C L

    1994-12-01

    This study examined resting metabolic rate (RMR) and thermic effect of a meal (TEM) among athletes who had participated in long-term anaerobic or aerobic exercise. Nine collegiate wrestlers were matched for age, weight, and fat-free weight with 9 collegiate swimmers. Preliminary testing included maximal oxygen consumption, maximal anaerobic capacity (MAnC) for both the arms and the legs, and percent body fat. On two separate occasions, RMR and TEM were measured using indirect calorimetry. VO2max was significantly higher in the swimmers while MAnC was significantly higher in the wrestlers for both the arms and the legs. RMR adjusted for fat-free weight was not significantly different between groups. The differences in total and percentage of TEM between the groups were not statistically significant, and there were no differences in baseline thyroid hormones. These data suggest that despite significant differences in VO2max and WAnT values following long-term aerobic and anaerobic exercise training, resting energy expenditure does not differ between these college athletes. PMID:7874150

  14. Activated sludge mass reduction and biodegradability of the endogenous residues by digestion under different aerobic to anaerobic conditions: Comparison and modeling.

    PubMed

    Martínez-García, C G; Fall, C; Olguín, M T

    2016-03-01

    This study was performed to identify suitable conditions for the in-situ reduction of excess sludge production by intercalated digesters in recycle-activated sludge (RAS) flow. The objective was to compare and model biological sludge mass reduction and the biodegradation of endogenous residues (XP) by digestion under hypoxic, aerobic, anaerobic, and five intermittent-aeration conditions. A mathematical model based on the heterotrophic endogenous decay constant (bH) and including the biodegradation of XP was used to fit the long-term data from the digesters to identify and estimate the parameters. Both the bH constant (0.02-0.05 d(-1)) and the endogenous residue biodegradation constant (bP, 0.001-0.004 d(-1)) were determined across the different mediums. The digesters with intermittent aeration cycles of 12 h-12 h and 5 min-3 h (ON/OFF) were the fastest, compared to the aerobic reactor. The study provides a basis for rating RAS-digester volumes to avoid the accumulation of XP in aeration tanks.

  15. Activated sludge mass reduction and biodegradability of the endogenous residues by digestion under different aerobic to anaerobic conditions: Comparison and modeling.

    PubMed

    Martínez-García, C G; Fall, C; Olguín, M T

    2016-03-01

    This study was performed to identify suitable conditions for the in-situ reduction of excess sludge production by intercalated digesters in recycle-activated sludge (RAS) flow. The objective was to compare and model biological sludge mass reduction and the biodegradation of endogenous residues (XP) by digestion under hypoxic, aerobic, anaerobic, and five intermittent-aeration conditions. A mathematical model based on the heterotrophic endogenous decay constant (bH) and including the biodegradation of XP was used to fit the long-term data from the digesters to identify and estimate the parameters. Both the bH constant (0.02-0.05 d(-1)) and the endogenous residue biodegradation constant (bP, 0.001-0.004 d(-1)) were determined across the different mediums. The digesters with intermittent aeration cycles of 12 h-12 h and 5 min-3 h (ON/OFF) were the fastest, compared to the aerobic reactor. The study provides a basis for rating RAS-digester volumes to avoid the accumulation of XP in aeration tanks. PMID:26720137

  16. Effective selenium volatilization under aerobic conditions and recovery from the aqueous phase by Pseudomonas stutzeri NT-I.

    PubMed

    Kagami, Tsubasa; Narita, Takanobu; Kuroda, Masashi; Notaguchi, Emi; Yamashita, Mitsuo; Sei, Kazunari; Soda, Satoshi; Ike, Michihiko

    2013-03-01

    Selenium is an important rare metal and its recovery from waste and wastewater is necessary for its sustainable utilization. Microbial selenium volatilization is suitable for selenium recovery from industrial wastewater because volatile selenium can be recovered in recyclable forms free from other chemicals. We found that Pseudomonas stutzeri NT-I can aerobically transform selenate, selenite, and biogenic elemental selenium into dimethyldiselenide as well as dimethylselenide; these were temporarily accumulated in the aqueous phase and then transferred into the gaseous phase. The rate of selenium volatilization using strain NT-I ranged 6.5-7.6 μmol/L/h in flask experiments and was much higher than the rates reported previously for other microbes. The selenium volatilization rate accelerated to 14 μmol/L/h in a jar fermenter. Furthermore, 82% of the selenium volatilized using strain NT-I was recovered with few impurities within 48 h in a simple gas trap with nitric acid, demonstrating that strain NT-I is a promising biocatalyst for selenium recovery through biovolatilization from the aqueous phase.

  17. Delayed formation of zero-valent selenium nanoparticles by Bacillus mycoides SeITE01 as a consequence of selenite reduction under aerobic conditions

    PubMed Central

    2014-01-01

    Background Selenite (SeO32−) oxyanion shows severe toxicity to biota. Different bacterial strains exist that are capable of reducing SeO32− to non-toxic elemental selenium (Se0), with the formation of Se nanoparticles (SeNPs). These SeNPs might be exploited for technological applications due to their physico-chemical and biological characteristics. The present paper discusses the reduction of selenite to SeNPs by a strain of Bacillus sp., SeITE01, isolated from the rhizosphere of the Se-hyperaccumulator legume Astragalus bisulcatus. Results Use of 16S rRNA and GyrB gene sequence analysis positioned SeITE01 phylogenetically close to B. mycoides. On agarized medium, this strain showed rhizoid growth whilst, in liquid cultures, it was capable of reducing 0.5 and 2.0 mM SeO32− within 12 and 24 hours, respectively. The resultant Se0 aggregated to form nanoparticles and the amount of Se0 measured was equivalent to the amount of selenium originally added as selenite to the growth medium. A delay of more than 24 hours was observed between the depletion of SeO32 and the detection of SeNPs. Nearly spherical-shaped SeNPs were mostly found in the extracellular environment whilst rarely in the cytoplasmic compartment. Size of SeNPs ranged from 50 to 400 nm in diameter, with dimensions greatly influenced by the incubation times. Different SeITE01 protein fractions were assayed for SeO32− reductase capability, revealing that enzymatic activity was mainly associated with the membrane fraction. Reduction of SeO32− was also detected in the supernatant of bacterial cultures upon NADH addition. Conclusions The selenite reducing bacterial strain SeITE01 was attributed to the species Bacillus mycoides on the basis of phenotypic and molecular traits. Under aerobic conditions, the formation of SeNPs were observed both extracellularly or intracellullarly. Possible mechanisms of Se0 precipitation and SeNPs assembly are suggested. SeO32− is proposed to be enzimatically reduced to

  18. Selecting Presuppositions in Conditional Clauses. Results from a Psycholinguistic Experiment

    PubMed Central

    Domaneschi, Filippo; Carrea, Elena; Penco, Carlo; Greco, Alberto

    2016-01-01

    In this paper, we propose an experiment concerning presupposition selection in conditional sentences containing a presupposition trigger in the consequent. Many theories claim that sentences like if p, qq'—where q is the presupposition of the assertive component q'—have unconditional presuppositions, namely, they simply project q. Other theories suggest that these kinds of conditional sentences project conditional presuppositions of the form if p, q. Data collected suggest two results: (i) in accordance with other experiments (by Romoli), dependence between the presupposition q and the antecedent p favors the selection of a conditional presupposition if p, q. (ii) presupposition selection in conditional sentences with a trigger in the consequent is affected by speakers' cognitive load: if speakers are highly cognitive loaded, then they are less disposed to select a conditional presupposition. We conclude by arguing that cognitive load represents a key factor for the analysis of linguistic and philosophical theories of context. PMID:26793146

  19. What are the differences between aerobic and anaerobic toxic effects of sulfonamides on Escherichia coli?

    PubMed

    Qin, Mengnan; Lin, Zhifen; Wang, Dali; Long, Xi; Zheng, Min; Qiu, Yanling

    2016-01-01

    Bacteria in the environment face the threat of antibiotics. However, most studies investigating the toxicity and toxicity mechanisms of antibiotics have been conducted on microorganisms in aerobic conditions, while studies examining the anaerobic toxicity and toxicity mechanisms of antibiotics are still limited. In this study, we determined the aerobic and anaerobic toxicities of sulfonamides (SAs) on Escherichia coli. Next, a comparison of the aerobic and anaerobic toxicities indicated that the SAs could be divided into three groups: Group I: log(1/EC50-anaerobic)>log(1/EC50-aerobic) (EC50-anaerobic/EC50-aerobic, the median effective concentration under anaerobic/aerobic conditions), Group II: log(1/EC50-anaerobic)≈log(1/EC50-aerobic), and Group III: log(1/EC50-anaerobic)aerobic). Furthermore, this division was not based on the reactive oxygen species (ROS) level or the interaction energy (Ebinding) value, which represents the affinity between SAs and dihydropteroate synthase (dhps) but rather on the total binding energy. Furthermore, SAs with greatly similar structures were categorized into different groups. This deep insight into the difference between aerobic and anaerobic toxicities will benefit environmental science, and the results of this study will serve as a reference for the risk assessment of chemicals in the environment.

  20. Optimization of operation conditions for the mitigation of nitrous oxide (N2O) emissions from aerobic nitrifying granular sludge system.

    PubMed

    Liu, Rui-Ting; Wang, Xin-Hua; Zhang, Yan; Wang, Ming-Yu; Gao, Ming-Ming; Wang, Shu-Guang

    2016-05-01

    The optimization of operation parameters is a key consideration to minimize nitrous oxide (N2O) emissions in biological nitrogen removal processes. So far, different parameters have only been investigated individually, making it difficult to compare their specific effects and combined influences. In this study, we applied the Plackett-Burman (PB) multifactorial experimental design and response surface methodology (RSM) analysis to find the optimized condition for the mitigation of N2O release in a nitrifying granular sludge system. Seven parameters (temperature, pH, feeding strategy, C/N ratio, aeration rate, Cu(2+) concentration, and aeration mode) were tested in parallel. Five of them (other than chemical oxygen demand/nitrogen (C/N) ratio and Cu(2+) concentration) were selected as influential factors. Since the type of feeding strategies and aeration modes cannot be quantified, continuous feed strategy and anoxic/oxic aeration mode were applied for the following study. Influences of temperature, pH, and aeration rate on N2O emissions were tested with RSM analysis to further investigate the mutual interactions among the parameters and to identify the optimal values that would minimize N2O release. Results showed the minimum emission value could be obtained under the temperature of 22.3 °C, pH of 7.1 and aeration rate of 0.20 m(3)/h. Predicted results were then verified by subsequent validation experiments. The estimated N2O emission value of each design by RSM was also observed in good relationships with experimental result.

  1. Adherence to abiotic surface induces SOS response in Escherichia coli K-12 strains under aerobic and anaerobic conditions.

    PubMed

    Costa, Suelen B; Campos, Ana Carolina C; Pereira, Ana Claudia M; de Mattos-Guaraldi, Ana Luiza; Júnior, Raphael Hirata; Rosa, Ana Cláudia P; Asad, Lídia M B O

    2014-09-01

    During the colonization of surfaces, Escherichia coli bacteria often encounter DNA-damaging agents and these agents can induce several defence mechanisms. Base excision repair (BER) is dedicated to the repair of oxidative DNA damage caused by reactive oxygen species (ROS) generated by chemical and physical agents or by metabolism. In this work, we have evaluated whether the interaction with an abiotic surface by mutants derived from E. coli K-12 deficient in some enzymes that are part of BER causes DNA damage and associated filamentation. Moreover, we studied the role of endonuclease V (nfi gene; 1506 mutant strain) in biofilm formation. Endonuclease V is an enzyme that is involved in DNA repair of nitrosative lesions. We verified that endonuclease V is involved in biofilm formation. Our results showed more filamentation in the xthA mutant (BW9091) and triple xthA nfo nth mutant (BW535) than in the wild-type strain (AB1157). By contrast, the mutant nfi did not present filamentation in biofilm, although its wild-type strain (1466) showed rare filaments in biofilm. The filamentation of bacterial cells attaching to a surface was a consequence of SOS induction measured by the SOS chromotest. However, biofilm formation depended on the ability of the bacteria to induce the SOS response since the mutant lexA Ind(-) did not induce the SOS response and did not form any biofilm. Oxygen tension was an important factor for the interaction of the BER mutants, since these mutants exhibited decreased quantitative adherence under anaerobic conditions. However, our results showed that the presence or absence of oxygen did not affect the viability of BW9091 and BW535 strains. The nfi mutant and its wild-type did not exhibit decreased biofilm formation under anaerobic conditions. Scanning electron microscopy was also performed on the E. coli K-12 strains that had adhered to the glass, and we observed the presence of a structure similar to an extracellular matrix that depended on the

  2. Aerobic microbial mineralization of dichloroethene as sole carbon substrate

    USGS Publications Warehouse

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

    2000-01-01

    Microorganisms indigenous to the bed sediments of a black- water stream utilized 1,2-dichloroethene (1,2-DCE) as a sole carbon substrate for aerobic metabolism. Although no evidence of growth was observed in the minimal salts culture media used in this study, efficient aerobic microbial mineralization of 1,2-DCE as sole carbon substrate was maintained through three sequential transfers (107 final dilution) of the original environmental innoculum. These results indicate that 1,2-DCE can be utilized as a primary substrate to support microbial metabolism under aerobic conditions.Microorganisms indigenous to the bed sediments of a black-water stream utilized 1,2-dichloroethene (1,2-DCE) as a sole carbon substrate for aerobic metabolism. Although no evidence of growth was observed in the minimal salts culture media used in this study, efficient aerobic microbial mineralization of 1,2-DCE as sole carbon substrate was maintained through three sequential transfers (107 final dilution) of the original environmental innoculum. These results indicate that 1,2-DCE can be utilized as a primary substrate to support microbial metabolism under aerobic conditions.

  3. Enhanced selection of micro-aerobic pentachlorophenol degrading granular sludge.

    PubMed

    Lv, Yuancai; Chen, Yuancai; Song, Wenzhe; Hu, Yongyou

    2014-09-15

    Column-type combined reactors were designed to cultivate micro-aerobic pentachlorophenol (PCP) degrading granular sludge under oxygen-limited conditions (0.1-0.2 mgL(-1)) over 39-day experimental period. Micro-aerobic granular had both anaerobic activity (SMA: 2.34 mMCH4/hg VSS) and aerobic activity (SOUR: 2.21 mMO2/hg VSS). Metabolite analysis results revealed that PCP was sequentially dechlorinated to TCP, DCP, and eventually to MCP. Methanogens were not directly involved in the dechlorination of PCP, but might played a vital role in stabilizing the overall structure of the granule sludge. For Eubacteria, the Shannon Index (2.09 in inoculated granular sludge) increased both in micro-aerobic granular sludge (2.61) and PCP-degradation granular sludge (2.55). However, for Archaea, it decreased from 2.53 to 1.85 and 1.84, respectively. Although the Shannon Index demonstrated slight difference between micro-aerobic granular sludge and PCP-degradation granular sludge, the Principal Component Analysis (PCA) indicated obvious variance of the microbial composition, revealing significant effect of micro-aerobic condition and PCP on microbial community. Furthermore, nucleotide sequencing indicated that the main microorganisms for PCP degradation might be related to Actinobacterium and Sphingomonas. These results provided insights into situ bioremediation of environments contaminated by PCP and had practical implications for the strategies of PCP degradation.

  4. Hydrogen photoproduction by nutrient-deprived Chlamydomonas reinhardtii cells immobilized within thin alginate films under aerobic and anaerobic conditions.

    PubMed

    Kosourov, Sergey N; Seibert, Michael

    2009-01-01

    A new technique for immobilizing H2-photoproducing green algae within a thin (<400 microm) alginate film has been developed. Alginate films with entrapped sulfur/phosphorus-deprived Chlamydomonas reinhardtii, strain cc124, cells demonstrate (a) higher cell density (up to 2,000 microg Chl mL(-1) of matrix), (b) kinetics of H2 photoproduction similar to sulfur-deprived suspension cultures, (c) higher specific rates (up to 12.5 micromol mg(-1) Chl h(-1)) of H2 evolution, (d) light conversion efficiencies to H2 of over 1% and (e) unexpectedly high resistance of the H2-photoproducing system to inactivation by atmospheric O2. The algal cells, entrapped in alginate and then placed in vials containing 21% O2 in the headspace, evolved up to 67% of the H2 gas produced under anaerobic conditions. The results indicate that the lower susceptibility of the immobilized algal H2-producing system to inactivation by O2 depends on two factors: (a) the presence of acetate in the medium, which supports higher rates of respiration and (b) the capability of the alginate polymer itself to effectively separate the entrapped cells from O2 in the liquid and headspace and restrict O2 diffusion into the matrix. The strategy presented for immobilizing algal cells within thin polymeric matrices shows the potential for scale-up and possible future applications. PMID:18823051

  5. Constitutive expression of Campylobacter jejuni truncated hemoglobin CtrHb improves the growth of Escherichia coli cell under aerobic and anaerobic conditions.

    PubMed

    Yang, Jiang-Ke; Xiong, Wei; Xu, Li; Li, Jia; Zhao, Xiu-Ju

    2015-01-01

    Bacteria hemoglobin could bind to the oxygen, transfer it from the intracellular microenvironment to the respiration process and sustain the energy for the metabolism and reproduction of cells. Heterologous expression of bacteria hemoglobin gene could improve the capacity of the host on oxygen-capturing and allow it to grow even under microaerophilic condition. To develop a system based on hemoglobin to help bacteria cells overcome the oxygen shortage in fermentation, in this study, Campylobacter jejuni truncated hemoglobin (CtrHb) gene was synthesized and expressed under the control of constitutive expression promoters P2 and P(SPO1-II) in Escherichia coli. As showed by the growth curves of the two recombinants P2-CtrHb and P(SPO1-II)-CtrHb, constitutive expression of CtrHb improved cell growth under aerobic shaking-flasks, anaerobic capped-bottles and bioreactor conditions. According to the NMR analysis, this improvement might come from the expression of hemoglobin which could boost the metabolism of cells by supplying more oxygen to the respiratory chain processes. Through semi-quantitative RT-PCR and CO differential spectrum assays, we further discussed the connection between the growth patterns of the recombinants, the expression level of CtrHb and oxygen binding capacity of CtrHb in cells. Based on the growth patterns of these recombinants in bioreactor, a possible choice on different type of recombinants under specific fermentation conditions was also suggested in this study.

  6. The effect of salinization and freshening events in coastal aquifers on nutrient characteristics as deduced from column experiments under aerobic and anaerobic conditions

    NASA Astrophysics Data System (ADS)

    Russak, A.; Sivan, O.; Herut, B.; Lazar, B.; Yechieli, Y.

    2015-10-01

    This study experimentally quantified the effect of seawater intrusion (salinization) and freshening events in coastal aquifers on nutrient (N, P and DSi) dynamics across the fresh-saline groundwater interface. Laboratory column experiments were conducted under aerobic and anaerobic conditions in order to simulate the processes occurring in the fresh-saline interface. They were performed with aquifer sediments, simulating the natural conditions during alterations of natural fresh groundwater to seawater and vice versa. The salinization and freshening experiments showed that NH4+ and PO43- and DSi were affected mainly by ion exchange processes while microbial activity controlled the nitrogen species NO3- and NO2-. Due to the cation exchange, salinization generated enrichment (above the expected conservative behavior) of NH4+, up to 80 μmol L-1 (an order of magnitude higher than in seawater or fresh groundwater). Under anaerobic conditions NO3- was removed by denitrification, as demonstrated by the decrease in NO3- concentrations, the increase in NO2- concentrations, and the increase in δ15N by 15-25‰. Clear evidence was shown for anion exchange of PO43-, which competes with HCO3- and boron on adsorption sites. DSi seems to take part in the exchange process, similar to PO43-.

  7. Constitutive expression of Campylobacter jejuni truncated hemoglobin CtrHb improves the growth of Escherichia coli cell under aerobic and anaerobic conditions.

    PubMed

    Yang, Jiang-Ke; Xiong, Wei; Xu, Li; Li, Jia; Zhao, Xiu-Ju

    2015-01-01

    Bacteria hemoglobin could bind to the oxygen, transfer it from the intracellular microenvironment to the respiration process and sustain the energy for the metabolism and reproduction of cells. Heterologous expression of bacteria hemoglobin gene could improve the capacity of the host on oxygen-capturing and allow it to grow even under microaerophilic condition. To develop a system based on hemoglobin to help bacteria cells overcome the oxygen shortage in fermentation, in this study, Campylobacter jejuni truncated hemoglobin (CtrHb) gene was synthesized and expressed under the control of constitutive expression promoters P2 and P(SPO1-II) in Escherichia coli. As showed by the growth curves of the two recombinants P2-CtrHb and P(SPO1-II)-CtrHb, constitutive expression of CtrHb improved cell growth under aerobic shaking-flasks, anaerobic capped-bottles and bioreactor conditions. According to the NMR analysis, this improvement might come from the expression of hemoglobin which could boost the metabolism of cells by supplying more oxygen to the respiratory chain processes. Through semi-quantitative RT-PCR and CO differential spectrum assays, we further discussed the connection between the growth patterns of the recombinants, the expression level of CtrHb and oxygen binding capacity of CtrHb in cells. Based on the growth patterns of these recombinants in bioreactor, a possible choice on different type of recombinants under specific fermentation conditions was also suggested in this study. PMID:26047918

  8. Hydrogen Photoproduction by Nutrient-Deprived Chalamydomonas reinhardtii Cells Immobilized Within Thin Alginate Films Under Aerobic and Anaerobic Conditions

    SciTech Connect

    Kosourov, S. N.; Seibert, M.

    2009-01-01

    A new technique for immobilizing H{sub 2}-photoproducing green algae within a thin (<400 {micro}m) alginate film has been developed. Alginate films with entrapped sulfur/phosphorus-deprived Chlamydomonas reinhardtii, strain cc124, cells demonstrate (a) higher cell density (up to 2,000 {micro}g Chl mL{sup -1} of matrix), (b) kinetics of H{sub 2} photoproduction similar to sulfur-deprived suspension cultures, (c) higher specific rates (up to 12.5 {micro}mol mg{sup -1} Chl h{sup -1}) of H{sub 2} evolution, (d) light conversion efficiencies to H{sub 2} of over 1% and (e) unexpectedly high resistance of the H{sub 2}-photoproducing system to inactivation by atmospheric O{sub 2}. The algal cells, entrapped in alginate and then placed in vials containing 21% O{sub 2} in the headspace, evolved up to 67% of the H{sub 2} gas produced under anaerobic conditions. The results indicate that the lower susceptibility of the immobilized algal H{sub 2}-producing system to inactivation by O{sub 2} depends on two factors: (a) the presence of acetate in the medium, which supports higher rates of respiration and (b) the capability of the alginate polymer itself to effectively separate the entrapped cells from O{sub 2} in the liquid and headspace and restrict O{sub 2} diffusion into the matrix. The strategy presented for immobilizing algal cells within thin polymeric matrices shows the potential for scale-up and possible future applications.

  9. Experimental results from containment piping bellows subjected to severe accident conditions: Results from bellows tested in corroded conditions. Volume 2

    SciTech Connect

    Lambert, L.D.; Parks, M.B.

    1995-10-01

    Bellows are an integral part of the containment pressure boundary in nuclear power plants. They are used at piping penetrations to allow relative movement between piping and the containment wall, while minimizing the load imposed on the piping and wall. Piping bellows are primarily used in steel containments; however, they have received limited use in some concrete (reinforced and prestressed) containments. In a severe accident they may be subjected to pressure and temperature conditions that exceed the design values, along with a combination of axial and lateral deflections. A test program to determine the leak-tight capacity of containment penetration bellows is being conducted at Sandia National Laboratories under the sponsorship of the US Nuclear Regulatory Commission. Several different bellows geometries, representative of actual containment bellows, have been subjected to extreme deflections along with pressure and temperature loads. The bellows geometries and loading conditions are described along with the testing apparatus and procedures. A total of nineteen bellows have been tested. Thirteen bellows were tested in ``like-new`` condition (results reported in Volume 1), and six were tested in a corroded condition. The tests showed that bellows in ``like-new`` condition are capable of withstanding relatively large deformations, up to, or near, the point of full compression or elongation, before developing leakage, while those in a corroded condition did not perform as well, depending on the amount of corrosion. The corroded bellows test program and results are presented in this report.

  10. Additional Results of Ice-Accretion Scaling at SLD Conditions

    NASA Technical Reports Server (NTRS)

    Bond, Thomas H. (Technical Monitor); Anderson, David N.; Tsao, Jen-Ching

    2005-01-01

    To determine scale velocity an additional similarity parameter is needed to supplement the Ruff scaling method. A Weber number based on water droplet MVD has been included in several studies because the effect of droplet splashing on ice accretion was believed to be important, particularly for SLD conditions. In the present study, ice shapes recorded at Appendix-C conditions and recent results at SLD conditions are reviewed to show that droplet diameter cannot be important to main ice shape, and for low airspeeds splashing does not appear to affect SLD ice shapes. Evidence is presented to show that while a supplementary similarity parameter probably has the form of a Weber number, it must be based on a length proportional to model size rather than MVD. Scaling comparisons were made between SLD reference conditions and Appendix-C scale conditions using this Weber number. Scale-to-reference model size ratios were 1:1.7 and 1:3.4. The reference tests used a 91-cm-chord NACA 0012 model with a velocity of approximately 50 m/s and an MVD of 160 m. Freezing fractions of 0.3, 0.4, and 0.5 were included in the study.

  11. Additional Results of Glaze Icing Scaling in SLD Conditions

    NASA Technical Reports Server (NTRS)

    Tsao, Jen-Ching

    2016-01-01

    New guidance of acceptable means of compliance with the super-cooled large drops (SLD) conditions has been issued by the U.S. Department of Transportation's Federal Aviation Administration (FAA) in its Advisory Circular AC 25-28 in November 2014. The Part 25, Appendix O is developed to define a representative icing environment for super-cooled large drops. Super-cooled large drops, which include freezing drizzle and freezing rain conditions, are not included in Appendix C. This paper reports results from recent glaze icing scaling tests conducted in NASA Glenn Icing Research Tunnel (IRT) to evaluate how well the scaling methods recommended for Appendix C conditions might apply to SLD conditions. The models were straight NACA 0012 wing sections. The reference model had a chord of 72 in. and the scale model had a chord of 21 in. Reference tests were run with airspeeds of 100 and 130.3 kn and with MVD's of 85 and 170 micron. Two scaling methods were considered. One was based on the modified Ruff method with scale velocity found by matching the Weber number WeL. The other was proposed and developed by Feo specifically for strong glaze icing conditions, in which the scale liquid water content and velocity were found by matching reference and scale values of the nondimensional water-film thickness expression and the film Weber number Wef. All tests were conducted at 0 deg AOA. Results will be presented for stagnation freezing fractions of 0.2 and 0.3. For nondimensional reference and scale ice shape comparison, a new post-scanning ice shape digitization procedure was developed for extracting 2-D ice shape profiles at any selected span-wise location from the high fidelity 3-D scanned ice shapes obtained in the IRT.

  12. [Experimental Conditions and Reliability Analysis of Results of COD components].

    PubMed

    Li, Zhi-hua; Zhang, Yin; Han, Xing; Yu, Ke; Li, Ru-jia

    2015-10-01

    The present study attempts to use SF( OUR(max)/OUR(en)) instead of S(0)/X(0) as an index of optimal initial conditions for determination of COD components by means of respirometry, thereby simplifying the measuring process and the operation can be automated. Further, the ratio of COD consumed by the growth of biomass can be used for the reliability assessment of results. Experimental results show that, experimental conditions for obtaining good results as follows: (1) for samples that composed of a large amount of easily biodegradable components (e. g., synthetic wastewater made by sodium acetate), SF should be in the range of 2.8 to 5.3, and the ratio of COD consumed by growth of biomass should be less than 30%; (2) for samples that composed of both readily biodegradable and slowly biodegradable components (i. e., typical domestic wastewater), SF should be in the range of 5.8 to 6.4, and the ratio of COD consumed by growth of biomass should be less than 30%; (3) and for samples that composed of a large amount of slowly biodegradable industrial wastewater (i. e., landfill leachate), SF should be 15 or less, and the ratio of COD consumed by growth of biomass should be approximately 40%. Therefore, when respirometry is used for the determination of COD components, the optimal conditions in terms of SF increase with the complexity of carbon source.

  13. Comparison of Aerobic and Anaerobic Biodegradation of Sugarcane Vinasse.

    PubMed

    Mota, V T; Araújo, T A; Amaral, M C S

    2015-07-01

    Vinasse is the main liquid waste from ethanol production, and it has a considerable pollution potential. Biological treatment is a promising alternative to reduce its organic load. The aim of this study was to analyze the biodegradation of sugarcane juice vinasse in aerobic and anaerobic conditions. The content of carbohydrates, proteins and volatile fatty acids was evaluated. Vinasse samples showed a high biodegradability (>96.5 %) and low percentage of inert chemical oxygen demand (COD) (<3.2 %) in both aerobic and anaerobic conditions. The rates of substrate utilization were slightly higher in aerobic reactors, but COD stabilization occurred simultaneously in the anaerobic reactors, confirming its suitability for anaerobic digestion. Inert COD in anaerobic conditions was lower than in aerobic conditions. On the other hand, COD from metabolic products in the anaerobic reactors was higher than in the aerobic ones, indicating an increased release of soluble microbial products (SMPs) by anaerobic microorganisms. The results indicated that carbohydrates were satisfactorily degraded and protein-like substances were the major components remaining after biological degradation of vinasse. PMID:25957273

  14. Quantifying factors limiting aerobic degradation during aerobic bioreactor landfilling.

    PubMed

    Yazdani, Ramin; Mostafid, M Erfan; Han, Byunghyun; Imhoff, Paul T; Chiu, Pei; Augenstein, Don; Kayhanian, Masoud; Tchobanoglous, George

    2010-08-15

    A bioreactor landfill cell at Yolo County, California was operated aerobically for six months to quantify the extent of aerobic degradation and mechanisms limiting aerobic activity during air injection and liquid addition. The portion of the solid waste degraded anaerobically was estimated and tracked through time. From an analysis of in situ aerobic respiration and gas tracer data, it was found that a large fraction of the gas-filled pore space was in immobile zones where it was difficult to maintain aerobic conditions, even at relatively moderate landfill cell-average moisture contents of 33-36%. Even with the intentional injection of air, anaerobic activity was never less than 13%, and sometimes exceeded 65%. Analyses of gas tracer and respiration data were used to quantify rates of respiration and rates of mass transfer to immobile gas zones. The similarity of these rates indicated that waste degradation was influenced significantly by rates of oxygen transfer to immobile gas zones, which comprised 32-92% of the gas-filled pore space. Gas tracer tests might be useful for estimating the size of the mobile/immobile gas zones, rates of mass transfer between these regions, and the difficulty of degrading waste aerobically in particular waste bodies. PMID:20704218

  15. Biodegradability of Poly-3-hydroxybutyrate/Bacterial Cellulose Composites under Aerobic Conditions, Measured via Evolution of Carbon Dioxide and Spectroscopic and Diffraction Methods.

    PubMed

    Ruka, Dianne R; Sangwan, Parveen; Garvey, Christopher J; Simon, George P; Dean, Katherine M

    2015-08-18

    Poly-3-hydroxybutyrate (PHB) and bacterial cellulose (BC) are both natural polymeric materials that have the potential to replace traditional, nonrenewable polymers. In particular, the nanofibrillar form of bacterial cellulose makes it an effective reinforcement for PHB. Neat PHB, bacterial cellulose, and a composite of PHB/BC produced with 10 wt % cellulose were composted under accelerated aerobic test conditions, with biodegradability measured by the carbon dioxide evolution method, in conjunction with spectroscopic and diffraction methods to assess crystallinity changes during the biodegradation process. The PHB/BC composite biodegraded at a greater rate and extent than that of PHB alone, reaching 80% degradation after 30 days, whereas PHB did not reach this level of degradation until close to 50 days of composting. The relative crystallinity of PHB and PHB in the PHB/BC composite was found to increase in the initial weeks of degradation, with degradation occurring primarily in the amorphous region of the material and some recrystallization of the amorphous PHB. Small angle X-ray scattering indicates that the change in PHB crystallinity is accompanied by a change in morphology of semicrystalline lamellae. The increased rate of biodegradability suggests that these materials could be applicable to single-use applications and could rapidly biodegrade in compost on disposal.

  16. Tellurite-mediated damage to the Escherichia coli NDH-dehydrogenases and terminal oxidases in aerobic conditions.

    PubMed

    Díaz-Vásquez, Waldo A; Abarca-Lagunas, María J; Cornejo, Fabián A; Pinto, Camilo A; Arenas, Felipe A; Vásquez, Claudio C

    2015-01-15

    Escherichia coli exposed to tellurite shows augmented membrane lipid peroxidation and ROS content. Also, reduced thiols, protein carbonylation, [Fe-S] center dismantling, and accumulation of key metabolites occur in these bacteria. In spite of this, not much is known about tellurite effects on the E. coli electron transport chain (ETC). In this work, tellurite-mediated damage to the E. coli ETC's NADH dehydrogenases and terminal oxidases was assessed. Mutant lacking ETC components showed delayed growth, decreased oxygen consumption and increased ROS in the presence of the toxicant. Membranes from tellurite-exposed E. coli exhibited decreased oxygen consumption and dNADH/NADH dehydrogenase activity, showing an impairment of NDH-I but not of NDH-II activity. Regarding terminal oxidases, only the bo oxidase complex was affected by tellurite. When assaying NDH-I and NDH-II activity in the presence of superoxide, the NDH-I complex was preferentially damaged. The activity was partly restored in the presence of reducing agents, sulfide and Fe(2+) under anaerobic conditions, suggesting that damage affects NDH-I [4Fe-4S] centers. Finally, augmented membrane protein oxidation along with reduced oxidase activity was observed in the presence of the toxicant. Also, the increased expression of genes encoding alternative terminal oxidases probably reflects a cell's change towards anaerobic respiration when facing tellurite. PMID:25447814

  17. Assessment of Aerobic and Respiratory Growth in the Lactobacillus casei Group

    PubMed Central

    Zotta, Teresa; Ricciardi, Annamaria; Ianniello, Rocco G.; Parente, Eugenio; Reale, Anna; Rossi, Franca; Iacumin, Lucilla; Comi, Giuseppe; Coppola, Raffaele

    2014-01-01

    One hundred eighty four strains belonging to the species Lactobacillus casei, L. paracasei and L. rhamnosus were screened for their ability to grow under aerobic conditions, in media containing heme and menaquinone and/or compounds generating reactive oxygen species (ROS), in order to identify respiratory and oxygen-tolerant phenotypes. Most strains were able to cope with aerobic conditions and for many strains aerobic growth and heme or heme/menaquinone supplementation increased biomass production compared to anaerobic cultivation. Only four L. casei strains showed a catalase-like activity under anaerobic, aerobic and respiratory conditions and were able to survive in presence of H2O2 (1 mM). Almost all L. casei and L. paracasei strains tolerated menadione (0.2 mM) and most tolerated pyrogallol (50 mM), while L. rhamnosus was usually resistant only to the latter compound. This is the first study in which an extensive screening of oxygen and oxidative stress tolerance of members of the L. casei group has been carried out. Results allowed the selection of strains showing the typical traits of aerobic and respiratory metabolism (increased pH and biomass under aerobic or respiratory conditions) and unique oxidative stress response properties. Aerobic growth and respiration may confer technological and physiological advantages in the L. casei group and oxygen-tolerant phenotypes could be exploited in several food industry applications. PMID:24918811

  18. Can arbuscular mycorrhizal fungi improve grain yield, As uptake and tolerance of rice grown under aerobic conditions?

    PubMed

    Li, H; Ye, Z H; Chan, W F; Chen, X W; Wu, F Y; Wu, S C; Wong, M H

    2011-10-01

    The effects of arbuscular mycorrhizal fungi (AMF) -Glomus intraradices and G. geosporum on arsenic (As) and phosphorus (P) uptake by lowland (Guangyinzhan) and upland rice (Handao 502) were investigated in soil, spiked with and without 60 mg As kg(-1). In As-contaminated soil, Guangyinzhan inoculated with G. intraradices or Handao 502 inoculated with G. geosporum enhanced As tolerance, grain P content, grain yield. However, Guangyinzhan inoculated with G. geosporum or Handao 502 inoculated with G. intraradices decreased grain P content, grain yield and the molar ratio of grain P/As content, and increased the As concentration and the ratio of grain/straw As concentration. These results show that rice/AMF combinations had significant (p < 0.05) effects on grain As concentration, grain yield and grain P uptake. The variation in the transfer and uptake of As and P reflected strong functional diversity in AM (arbuscular mycorrhizal) symbioses. PMID:21737190

  19. Grey water treatment in a series anaerobic--aerobic system for irrigation.

    PubMed

    Abu Ghunmi, Lina; Zeeman, Grietje; Fayyad, Manar; van Lier, Jules B

    2010-01-01

    This study aims at treatment of grey water for irrigation, focusing on a treatment technology that is robust, simple to operate and with minimum energy consumption. The result is an optimized system consisting of an anaerobic unit operated in upflow mode, with a 1 day operational cycle, a constant effluent flow rate and varying liquid volume. Subsequent aerobic step is equipped with mechanical aeration and the system is insulated for sustaining winter conditions. The COD removal achieved by the anaerobic and aerobic units in summer and winter are 45%, 39% and 53%, 64%, respectively. Sludge in the anaerobic and aerobic reactor has a concentration of 168 and 8 mg VSL(-1), respectively. Stability of sludge in the anaerobic and aerobic reactors is 80% and 93%, respectively, based on COD. Aerobic effluent quality, except for pathogens, agrees with the proposed irrigation water quality guidelines for reclaimed water in Jordan.

  20. Using deuterium as an isotopic tracer to study the energy metabolism of infective juveniles of Steinernema carpocapsae under aerobic conditions.

    PubMed

    Qiu, L; Lacey, M J; Bedding, R A

    2000-11-01

    Changes in survival, mean dry weight, levels of key energy reserve compounds and respiration of non-feeding infective juveniles (IJs) of Steinernema carpocapsae incubated in various ratios of D2O/H2O on a shaker at 28 degrees C were determined. Patterns of deuterium distribution in trehalose, glycogen and key fatty acids of the IJs incubated in 50% (v/v) D2O/H2O were also examined. The rates of decline in mean dry weight and lipid levels of IJs incubated in D2O/H2O were proportional, while the survival times of IJs were inversely proportional, to the ratio of D2O/H2O. Deuterium was randomly and extensively incorporated into the C-H bonds of trehalose and glycogen but was barely incorporated in fatty acid moieties of the IJs. The changes in the patterns and the extents of deuterium incorporation, as well as the levels of trehalose, glycogens and fatty acids during the experimental period indicate that: (1) The lipogenesis pathway is not functioning in the Ijs. (2) Trehalose and glycogen are constantly consumed and replenished and they are mainly derived from lipids. (3) Futile cycles involving trehalose and glycogen, which enable IJs to regulate the levels of these two compounds more effectively, may exist. The results support the view that lipids are the primary energy reserve of the IJs while trehalose, glycogen and proteins can be used for energy generation, even though this is not their primary role.

  1. Self-determination and exercise stages of change: results from the Diabetes Aerobic and Resistance Exercise trial.

    PubMed

    Fortier, Michelle S; Sweet, Shane N; Tulloch, Heather; Blanchard, Chris M; Sigal, Ronald J; Kenny, Glen P; Reid, Robert D

    2012-01-01

    Little longitudinal research exists on the relationship between exercise self-determination and stage of change. This study investigated how self-determined motivation changes in patients with type 2 diabetes (N = 175) as they moved through the stages of change over a six-month exercise trial. Hierarchical linear modelling revealed that patients who progressed through the stages of exercise change had an overall increase in self-determined motivation, while non-progressors experienced a reduction in self-determined motivation from three to six months. These results indicate that individuals engaging in regular exercise at six months maintain initial increases in self-determined motivation. Findings are discussed in light of self-determination theory.

  2. Aerobic Dancing--A Rhythmic Sport.

    ERIC Educational Resources Information Center

    Sorensen, Jacki

    Fitness programs now and in the future must offer built-in cardiovascular conditioning, variety, novelty, and change to meet the physical, mental, and emotional needs of our society. Aerobic dancing (dancing designed to train and strengthen the heart, lungs, and vascular system) is one of the first indoor group Aerobic exercise programs designed…

  3. Volatile chemical spoilage indexes of raw Atlantic salmon (Salmo salar) stored under aerobic condition in relation to microbiological and sensory shelf lives.

    PubMed

    Mikš-Krajnik, Marta; Yoon, Yong-Jin; Ukuku, Dike O; Yuk, Hyun-Gyun

    2016-02-01

    The purpose of this investigation was to identify and quantify the volatile chemical spoilage indexes (CSIs) for raw Atlantic salmon (Salmo salar) fillets stored under aerobic storage conditions at 4, 10 and 21 °C in relation to microbial and sensory shelf lives. The volatile organic compounds (VOCs) were analyzed with SPME-GC-MS technique. Through multivariate chemometric method, hierarchical cluster analysis (HCA) and Pearson's correlations, the CSIs: trimethylamine (TMA), ethanol (EtOH), 3-methyl-1-butanol (3Met-1But), acetoin and acetic acid (C2) were selected from the group of 28 detected VOCs. At the moment of microbiological shelf life established at total viable count (TVC) of 7.0 log CFU/g, the CSIs achieved levels of 11.5, 38.3, 0.3, 24.0 and 90.7 μg/g of salmon for TMA, EtOH, 3M-1But, acetoin and C2, respectively. Pseudomonas spp. was found as major specific spoilage organism (SSOs), suitable for shelf life prediction using modified Gompertz model at the cut-off level of 6.5 log CFU/g. H2S producing bacteria and Brochothrix thermosphacta were considered as important spoilage microorganisms; however, they were not suitable for shelf life estimation. Partial least square (PLS) regression revealed possible associations between microorganisms and synthetized VOCs, showing correlations between Pseudomonas spp. and 3Met-1But and aldehydes synthesis, lactic acid bacteria were linked with EtOH, C2 and esters, and B. thermosphacta with acetoin formation. PMID:26678146

  4. Volatile chemical spoilage indexes of raw Atlantic salmon (Salmo salar) stored under aerobic condition in relation to microbiological and sensory shelf lives.

    PubMed

    Mikš-Krajnik, Marta; Yoon, Yong-Jin; Ukuku, Dike O; Yuk, Hyun-Gyun

    2016-02-01

    The purpose of this investigation was to identify and quantify the volatile chemical spoilage indexes (CSIs) for raw Atlantic salmon (Salmo salar) fillets stored under aerobic storage conditions at 4, 10 and 21 °C in relation to microbial and sensory shelf lives. The volatile organic compounds (VOCs) were analyzed with SPME-GC-MS technique. Through multivariate chemometric method, hierarchical cluster analysis (HCA) and Pearson's correlations, the CSIs: trimethylamine (TMA), ethanol (EtOH), 3-methyl-1-butanol (3Met-1But), acetoin and acetic acid (C2) were selected from the group of 28 detected VOCs. At the moment of microbiological shelf life established at total viable count (TVC) of 7.0 log CFU/g, the CSIs achieved levels of 11.5, 38.3, 0.3, 24.0 and 90.7 μg/g of salmon for TMA, EtOH, 3M-1But, acetoin and C2, respectively. Pseudomonas spp. was found as major specific spoilage organism (SSOs), suitable for shelf life prediction using modified Gompertz model at the cut-off level of 6.5 log CFU/g. H2S producing bacteria and Brochothrix thermosphacta were considered as important spoilage microorganisms; however, they were not suitable for shelf life estimation. Partial least square (PLS) regression revealed possible associations between microorganisms and synthetized VOCs, showing correlations between Pseudomonas spp. and 3Met-1But and aldehydes synthesis, lactic acid bacteria were linked with EtOH, C2 and esters, and B. thermosphacta with acetoin formation.

  5. Sweat Rates During Continuous and Interval Aerobic Exercise: Implications for NASA Multipurpose Crew Vehicle (MPCV) Missions

    NASA Technical Reports Server (NTRS)

    Ryder, Jeffrey W.; Scott, Jessica; Ploutz-Snyder, Lori L.

    2016-01-01

    Aerobic deconditioning is one of the effects spaceflight. Impaired crewmember performance due to loss of aerobic conditioning is one of the risks identified for mitigation by the NASA Human Research Program. Missions longer than 8 days will involve exercise countermeasures including those aimed at preventing the loss of aerobic capacity. The NASA Multipurpose Crew Vehicle (MPCV) will be NASA's centerpiece architecture for human space exploration beyond low Earth orbit. Aerobic exercise within the small habitable volume of the MPCV is expected to challenge the ability of the Air Revitalization System, especially in terms of moisture and temperature control. Exercising humans contribute moisture to the environment by increased respiratory rate (exhaling air saturated with moisture) and sweat. Current acceptable values are based on theoretical models that rely on an "average" crew member working continuously at 75% of their aerobic capacity (Human Systems Integration Requirements Document). Evidence suggests that high intensity interval exercise for much shorter durations are equally effective or better in building and maintaining aerobic capacity. This investigation will examine metabolic moisture and heat production for operationally relevant continuous and interval aerobic exercise protocols. The results will directly inform what types of aerobic exercise countermeasures will be feasible to prescribe for crewmembers aboard the MPCV.

  6. Sweat Rates During Continuous and Interval Aerobic Exercise: Implications for NASA Multipurpose Crew Vehicle (MPCV) Missions

    NASA Technical Reports Server (NTRS)

    Ryder, Jeffrey W.; Scott, Jessica; Ploutz-Snyder, Robert; Ploutz-Snyder, Lori L.

    2016-01-01

    Aerobic deconditioning is one of the effects spaceflight. Impaired crewmember performance due to loss of aerobic conditioning is one of the risks identified for mitigation by the NASA Human Research Program. Missions longer than 8 days will involve exercise countermeasures including those aimed at preventing the loss of aerobic capacity. The NASA Multipurpose Crew Vehicle (MPCV) will be NASA's centerpiece architecture for human space exploration beyond low Earth orbit. Aerobic exercise within the small habitable volume of the MPCV is expected to challenge the ability of the environmental control systems, especially in terms of moisture control. Exercising humans contribute moisture to the environment by increased respiratory rate (exhaling air at 100% humidity) and sweat. Current acceptable values are based on theoretical models that rely on an "average" crew member working continuously at 75% of their aerobic capacity (Human Systems Integration Requirements Document). Evidence suggests that high intensity interval exercise for much shorter durations are equally effective or better in building and maintaining aerobic capacity. This investigation will examine sweat and respiratory rates for operationally relevant continuous and interval aerobic exercise protocols using a variety of different individuals. The results will directly inform what types of aerobic exercise countermeasures will be feasible to prescribe for crewmembers aboard the MPCV.

  7. Aerobic Denitrifying Bacteria That Produce Low Levels of Nitrous Oxide

    PubMed Central

    Takaya, Naoki; Catalan-Sakairi, Maria Antonina B.; Sakaguchi, Yasushi; Kato, Isao; Zhou, Zhemin; Shoun, Hirofumi

    2003-01-01

    Most denitrifiers produce nitrous oxide (N2O) instead of dinitrogen (N2) under aerobic conditions. We isolated and characterized novel aerobic denitrifiers that produce low levels of N2O under aerobic conditions. We monitored the denitrification activities of two of the isolates, strains TR2 and K50, in batch and continuous cultures. Both strains reduced nitrate (NO3−) to N2 at rates of 0.9 and 0.03 μmol min−1 unit of optical density at 540 nm−1 at dissolved oxygen (O2) (DO) concentrations of 39 and 38 μmol liter−1, respectively. At the same DO level, the typical denitrifier Pseudomonas stutzeri and the previously described aerobic denitrifier Paracoccus denitrificans did not produce N2 but evolved more than 10-fold more N2O than strains TR2 and K50 evolved. The isolates denitrified NO3− with concomitant consumption of O2. These results indicated that strains TR2 and K50 are aerobic denitrifiers. These two isolates were taxonomically placed in the β subclass of the class Proteobacteria and were identified as P. stutzeri TR2 and Pseudomonas sp. strain K50. These strains should be useful for future investigations of the mechanisms of denitrifying bacteria that regulate N2O emission, the single-stage process for nitrogen removal, and microbial N2O emission into the ecosystem. PMID:12788710

  8. [Heterotrophic Nitrification and Aerobic Denitrification of the Hypothermia Aerobic Denitrification Bacterium: Arthrobacter arilaitensis].

    PubMed

    He, Teng-xia; Ni, Jiu-pai; Li, Zhen-lun; Sun, Quan; Ye Qing; Xu, Yi

    2016-03-15

    High concentrations of ammonium, nitrate and nitrite nitrogen were employed to clarify the abilities of heterotrophic nitrification and aerobic denitrification of Arthrobacter arilaitensis strain Y-10. Meanwhile, by means of inoculating the strain suspension into the mixed ammonium and nitrate, ammonium and nitrite nitrogen simulated wastewater, we studied the simultaneous nitrification and denitrification ability of Arthrobacter arilaitensis strain Y-10. In addition, cell optical density was assayed in each nitrogen removal process to analyze the relationship of cell growth and nitrogen removal efficiency. The results showed that the hypothermia denitrification strain Arthrobacter arilaitensis Y-10 exhibited high nitrogen removal efficiency during heterotrophic nitrification and aerobic denitrification. The ammonium, nitrate and nitrite removal rates were 65.0%, 100% and 61.2% respectively when strain Y-10 was cultivated for 4 d at 15°C with initial ammonium, nitrate and nitrite nitrogen concentrations of 208.43 mg · L⁻¹, 201.16 mg · L⁻¹ and 194.33 mg · L⁻¹ and initial pH of 7.2. Nitrite nitrogen could only be accumulated in the medium containing nitrate nitrogen during heterotrophic nitrification and aerobic denitrification process. Additionally, the ammonium nitrogen was mainly removed in the inorganic nitrogen mixed synthetic wastewater. In short, Arthrobacter arilaitensis Y-10 could conduct nitrification and denitrification effectively under aerobic condition and the ammonium nitrogen removal rate was more than 80.0% in the inorganic nitrogen mixed synthetic wastewater. PMID:27337904

  9. The degradability of biodegradable plastics in aerobic and anaerobic waste landfill model reactors.

    PubMed

    Ishigaki, Tomonori; Sugano, Wataru; Nakanishi, Akane; Tateda, Masafumi; Ike, Michihiko; Fujita, Masanori

    2004-01-01

    Degradabilities of four kinds of commercial biodegradable plastics (BPs), polyhydroxybutyrate and hydroxyvalerate (PHBV) plastic, polycaprolactone plastic (PCL), blend of starch and polyvinyl alcohol (SPVA) plastic and cellulose acetate (CA) plastic were investigated in waste landfill model reactors that were operated as anaerobically and aerobically. The application of forced aeration to the landfill reactor for supplying aerobic condition could potentially stimulate polymer-degrading microorganisms. However, the individual degradation behavior of BPs under the aerobic condition was completely different. PCL, a chemically synthesized BP, showed film breakage under the both conditions, which may have contributed to a reduction in the waste volume regardless of aerobic or anaerobic conditions. Effective degradation of PHBV plastic was observed in the aerobic condition, though insufficient degradation was observed in the anaerobic condition. But the aeration did not contribute much to accelerate the volume reduction of SPVA plastic and CA plastic. It could be said that the recalcitrant portions of the plastics such as polyvinyl alcohol in SPVA plastic and the highly substituted CA in CA plastic prevented the BP from degradation. These results indicated existence of the great variations in the degradability of BPs in aerobic and anaerobic waste landfills, and suggest that suitable technologies for managing the waste landfill must be combined with utilization of BPs in order to enhance the reduction of waste volume in landfill sites.

  10. The aerobic activity of metronidazole against anaerobic bacteria.

    PubMed

    Dione, Niokhor; Khelaifia, Saber; Lagier, Jean-Christophe; Raoult, Didier

    2015-05-01

    Recently, the aerobic growth of strictly anaerobic bacteria was demonstrated using antioxidants. Metronidazole is frequently used to treat infections caused by anaerobic bacteria; however, to date its antibacterial activity was only tested in anaerobic conditions. Here we aerobically tested using antioxidants the in vitro activities of metronidazole, gentamicin, doxycycline and imipenem against 10 common anaerobic and aerobic bacteria. In vitro susceptibility testing was performed by the disk diffusion method, and minimum inhibitory concentrations (MICs) were determined by Etest. Aerobic culture of the bacteria was performed at 37°C using Schaedler agar medium supplemented with 1mg/mL ascorbic acid and 0.1mg/mL glutathione; the pH was adjusted to 7.2 by 10M KOH. Growth of anaerobic bacteria cultured aerobically using antioxidants was inhibited by metronidazole after 72h of incubation at 37°C, with a mean inhibition diameter of 37.76mm and an MIC of 1μg/mL; however, strains remained non-sensitive to gentamicin. No growth inhibition of aerobic bacteria was observed after 24h of incubation at 37°C with metronidazole; however, inhibition was observed with doxycycline and imipenem used as controls. These results indicate that bacterial sensitivity to metronidazole is not related to the oxygen tension but is a result of the sensitivity of the micro-organism. In future, both culture and antibiotic susceptibility testing of strictly anaerobic bacteria will be performed in an aerobic atmosphere using antioxidants in clinical microbiology laboratories.

  11. Teaching Aerobic Fitness Concepts.

    ERIC Educational Resources Information Center

    Sander, Allan N.; Ratliffe, Tom

    2002-01-01

    Discusses how to teach aerobic fitness concepts to elementary students. Some of the K-2 activities include location, size, and purpose of the heart and lungs; the exercise pulse; respiration rate; and activities to measure aerobic endurance. Some of the 3-6 activities include: definition of aerobic endurance; heart disease risk factors;…

  12. Acclimation of aerobic-activated sludge degrading benzene derivatives and co-metabolic degradation activities of trichloroethylene by benzene derivative-grown aerobic sludge.

    PubMed

    Wang, Shizong; Yang, Qi; Bai, Zhiyong; Wang, Shidong; Wang, Yeyao; Nowak, Karolina M

    2015-01-01

    The acclimation of aerobic-activated sludge for degradation of benzene derivatives was investigated in batch experiments. Phenol, benzoic acid, toluene, aniline and chlorobenzene were concurrently added to five different bioreactors which contained the aerobic-activated sludge. After the acclimation process ended, the acclimated phenol-, benzoic acid-, toluene-, aniline- and chlorobenzene-grown aerobic-activated sludge were used to explore the co-metabolic degradation activities of trichloroethylene (TCE). Monod equation was employed to simulate the kinetics of co-metabolic degradation of TCE by benzene derivative-grown sludge. At the end of experiments, the mixed microbial communities grown under different conditions were identified. The results showed that the acclimation periods of microorganisms for different benzene derivatives varied. The maximum degradation rates of TCE for phenol-, benzoic acid-, toluene-, aniline- and chlorobenzene-grown aerobic sludge were 0.020, 0.017, 0.016, 0.0089 and 0.0047 mg g SS(-1) h(-1), respectively. The kinetic of TCE degradation in the absence of benzene derivative followed Monod equation well. Also, eight phyla were observed in the acclimated benzene derivative-grown aerobic sludge. Each of benzene derivative-grown aerobic sludge had different microbial community composition. This study can hopefully add new knowledge to the area of TCE co-metabolic by mixed microbial communities, and further the understanding on the function and applicability of aerobic-activated sludge.

  13. [Formation Mechanism of Aerobic Granular Sludge and Removal Efficiencies in Integrated ABR-CSTR Reactor].

    PubMed

    Wu, Kai-cheng; Wu, Peng; Xu, Yue-zhong; Li, Yue-han; Shen, Yao-liang

    2015-08-01

    Anaerobic Baffled Reactor (ABR) was altered to make an integrated anaerobic-aerobic reactor. The research investigated the mechanism of aerobic sludge granulation, under the condition of continuous-flow. The last two compartments of the ABR were altered into aeration tank and sedimentation tank respectively with seeded sludge of anaerobic granular sludge in anaerobic zone and conventional activated sludge in aerobic zone. The HRT was gradually decreased in sedimentation tank from 2.0 h to 0.75 h and organic loading rate was increased from 1.5 kg x (M3 x d)(-1) to 2.0 kg x (M3 x d)(-1) while the C/N of 2 was controlled in aerobic zone. When the system operated for 110 days, the mature granular sludge in aerobic zone were characterized by compact structure, excellent sedimentation performance (average sedimentation rate was 20.8 m x h(-1)) and slight yellow color. The system performed well in nitrogen and phosphorus removal under the conditions of setting time of 0.75 h and organic loading rate of 2.0 kg (m3 x d)(-1) in aerobic zone, the removal efficiencies of COD, NH4+ -N, TP and TN were 90%, 80%, 65% and 45%, respectively. The results showed that the increasing selection pressure and the high organic loading rate were the main propulsions of the aerobic sludge granulation.

  14. Aerobic biological activated carbon (BAC) treatment of a phenolic wastewater

    SciTech Connect

    Wei Lin; Weber, A.S. )

    1992-05-01

    Organic removal rates achieved in the aerobic BAC process were comparable to rates typically reported for traditional aerobic fixed-film systems. When operated at organic loading rates lower than 0.03 g COD/g GAC-d and air as the oxygen source, greater than 90% COD removal and 99% phenol removal was achieved. At higher organic loading rates, oxygen limitations resulted in less than optimal performance. Observed oxygen limitations were mitigated by the use of pure oxygen. Long-term stability of operation of the BAC process was excellent with one aerobic BAC column operated under the same conditions in excess of 260 days. During that time, consistent column performance was achieved without the need to provide supplemental carbon or carbon regeneration. System biomass yields ranged from 0.05 to 0.30 g VSS/g COD removed and increased with effluent COD concentration.

  15. Some results for the primitive equations with physical boundary conditions

    NASA Astrophysics Data System (ADS)

    Evans, Lawrence Christopher; Gastler, Robert

    2013-12-01

    In this paper, we consider the (simplified) 3-dimensional primitive equations with physical boundary conditions. We show that the equations with constant forcing have a bounded absorbing ball in the H 1-norm and that a solution to the unforced equations has its H 1-norm decay to 0. From this, we argue that there exists an invariant measure (on H 1) for the equations under random kick-forcing.

  16. Guidelines for interpretation of 16S rRNA gene sequence-based results for identification of medically important aerobic Gram-positive bacteria.

    PubMed

    Woo, Patrick C Y; Teng, Jade L L; Wu, Jeff K L; Leung, Fion P S; Tse, Herman; Fung, Ami M Y; Lau, Susanna K P; Yuen, Kwok-Yung

    2009-08-01

    This study is believed to be the first to provide guidelines for facilitating interpretation of results based on full and 527 bp 16S rRNA gene sequencing and MicroSeq databases used for identifying medically important aerobic Gram-positive bacteria. Overall, full and 527 bp 16S rRNA gene sequencing can identify 24 and 40 % of medically important Gram-positive cocci (GPC), and 21 and 34 % of medically important Gram-positive rods (GPR) confidently to the species level, whereas the full-MicroSeq and 500-MicroSeq databases can identify 15 and 34 % of medically important GPC and 14 and 25 % of medically important GPR confidently to the species level. Among staphylococci, streptococci, enterococci, mycobacteria, corynebacteria, nocardia and members of Bacillus and related taxa (Paenibacillus, Brevibacillus, Geobacillus and Virgibacillus), the methods and databases are least useful for identification of staphylococci and nocardia. Only 0-2 and 2-13 % of staphylococci, and 0 and 0-10 % of nocardia, can be confidently and doubtfully identified, respectively. However, these methods and databases are most useful for identification of Bacillus and related taxa, with 36-56 and 11-14 % of Bacillus and related taxa confidently and doubtfully identified, respectively. A total of 15 medically important GPC and 18 medically important GPR that should be confidently identified by full 16S rRNA gene sequencing are not included in the full-MicroSeq database. A total of 9 medically important GPC and 21 medically important GPR that should be confidently identified by 527 bp 16S rRNA gene sequencing are not included in the 500-MicroSeq database. 16S rRNA gene sequence results of Gram-positive bacteria should be interpreted with basic phenotypic tests results. Additional biochemical tests or sequencing of additional gene loci are often required for definitive identification. To improve the usefulness of the MicroSeq databases, bacterial species that can be confidently identified by 16S r

  17. Aerobic rice mechanization: techniques for crop establishment

    NASA Astrophysics Data System (ADS)

    Khusairy, K. M.; Ayob, H.; Chan, C. S.; Fauzi, M. I. Mohamed; Mohamad Fakhrul, Z. O.; Shahril Shah, G. S. M.; Azlan, O.; Rasad, M. A.; Hashim, A. M.; Arshad, Z.; E, E. Ibrahim; Saifulizan, M. N.

    2015-12-01

    Rice being the staple food crops, hundreds of land races in it makes the diversity of rice crops. Aerobic rice production was introduced which requires much less water input to safeguard and sustain the rice production and conserve water due to decreasing water resources, climatic changes and competition from urban and industrial users. Mechanization system plays an important role for the success of aerobic rice cultivation. All farming activities for aerobic rice production are run on aerobic soil conditions. Row seeder mechanization system is developed to replace conventional seeding technique on the aerobic rice field. It is targeted for small and the large scale aerobic rice farmers. The aero - seeder machine is used for the small scale aerobic rice field, while the accord - seeder is used for the large scale aerobic rice field. The use of this mechanization machine can eliminate the tedious and inaccurate seeding operations reduce labour costs and increases work rate. The machine is easy to operate and it can increase crop establishment rate. It reduce missing hill, increasing planting and crop with high yield can be produce. This machine is designed for low costs maintenance and it is easy to dismantle and assemble during maintenance and it is safe to be used.

  18. Quantitative assessment of the toxic effects of heavy metals on 1,2-dichloroethane biodegradation in co-contaminated soil under aerobic condition.

    PubMed

    Olaniran, Ademola Olufolahan; Balgobind, Adhika; Pillay, Balakrishna

    2011-10-01

    1,2-Dichloroethane (1,2-DCA) is one of the most hazardous pollutant of soil and groundwater, and is produced in excess of 5.44×10⁹ kg annually. Owing to their toxicity, persistence and potential for bioaccumulation, there is a growing interest in technologies for their removal. Heavy metals are known to be toxic to soil microorganisms at high concentrations and can hinder the biodegradation of organic contaminants. In this study, the inhibitory effect of heavy metals, namely; arsenic, cadmium, mercury and lead, on the aerobic biodegradation of 1,2-DCA by autochthonous microorganisms was evaluated in soil microcosm setting. The presence of heavy metals was observed to have a negative impact on the biodegradation of 1,2-DCA in both soil samples tested, with the toxic effect being more pronounced in loam soil, than in clay soil. Generally, 75 ppm As³⁺, 840 ppm Hg²⁺, and 420 ppm Pb²⁺ resulted in 34.24%, 40.64%, and 45.94% increase in the half live (t½) of 1,2-DCA, respectively, in loam soil, while concentrations above 127.5 ppm Cd²⁺, 840 ppm Hg²⁺ and 420 ppm of Pb²⁺ and less than 75 ppm As³⁺ was required to cause a >10% increase in the t½ of 1,2-DCA in clay soil. A dose-dependent relationship between degradation rate constant (k₁) of 1,2-DCA and metal ion concentrations was observed for all the heavy metals tested, except for Hg²⁺. This study demonstrated that different heavy metals have different impacts on the degree of 1,2-DCA degradation. Results also suggest that the degree of inhibition is metal specific and is also dependent on several factors including; soil type, pH, moisture content and available nutrients.

  19. Fit women are not able to use the whole aerobic capacity during aerobic dance.

    PubMed

    Edvardsen, Elisabeth; Ingjer, Frank; Bø, Kari

    2011-12-01

    Edvardsen, E, Ingjer, F, and Bø, K. Fit women are not able to use the whole aerobic capacity during aerobic dance. J Strength Cond Res 25(12): 3479-3485, 2011-This study compared the aerobic capacity during maximal aerobic dance and treadmill running in fit women. Thirteen well-trained female aerobic dance instructors aged 30 ± 8.17 years (mean ± SD) exercised to exhaustion by running on a treadmill for measurement of maximal oxygen uptake (VO(2)max) and peak heart rate (HRpeak). Additionally, all subjects performed aerobic dancing until exhaustion after a choreographed videotaped routine trying to reach the same HRpeak as during maximal running. The p value for statistical significance between running and aerobic dance was set to ≤0.05. The results (mean ± SD) showed a lower VO(2)max in aerobic dance (52.2 ± 4.02 ml·kg·min) compared with treadmill running (55.9 ± 5.03 ml·kg·min) (p = 0.0003). Further, the mean ± SD HRpeak was 182 ± 9.15 b·min in aerobic dance and 192 ± 9.62 b·min in treadmill running, giving no difference in oxygen pulse between the 2 exercise forms (p = 0.32). There was no difference in peak ventilation (aerobic dance: 108 ± 10.81 L·min vs. running: 113 ± 11.49 L·min). In conclusion, aerobic dance does not seem to be able to use the whole aerobic capacity as in running. For well endurance-trained women, this may result in a lower total workload at maximal intensities. Aerobic dance may therefore not be as suitable as running during maximal intensities in well-trained females.

  20. When Worlds Collide: Microbial Ecophysiology at the Aerobic/Anaerobic Interface

    NASA Astrophysics Data System (ADS)

    Girguis, P. R.

    2015-12-01

    The aerobic/anaerobic interface is a transition zone, where conditions, from chemical concentrations to pH, vary along the oxycline. It has long been known that microbes flourish at such interfaces, presumably due to the potential energy available from catalyzing reduction-oxidation reactions using chemicals derived from the anaerobic and aerobic milieus. Indeed, some studies suggest that both microbial diversity and activity is greatest in such settings, and evidenced by the 2-10 fold greater cell abundances associated with such transition zones. That said, the nature of microbial activity found in such transition zones, and the precise extent of their activity, is usually poorly constrained. At hydrothermal vents, for example, scientists have found that distinct communities are associated with each microhabitat, yet our recent studies have shown that canonical anaerobic microbes are found to be active in fully aerobic waters, seemingly well beyond the aerobic/anaerobic interface. Moreover, our research has also shown that the activity of microbes at the aerobic/anaerobic interface can -through extracellular electron transfer- directly influence the activity of microbes in canonically reduced or oxidized habitats. Here we will present these results and discuss the implications for our understanding of how aerobic and anaerobic microbial communities are physiologically coupled across the aerobic/anaerobic interface.

  1. Technical note: enumeration of mesophilic aerobes in milk: evaluation of standard official protocols and Petrifilm aerobic count plates.

    PubMed

    Freitas, R; Nero, L A; Carvalho, A F

    2009-07-01

    Enumeration of mesophilic aerobes (MA) is the main quality and hygiene parameter for raw and pasteurized milk. High levels of these microorganisms indicate poor conditions in production, storage, and processing of milk, and also the presence of pathogens. Fifteen raw and 15 pasteurized milk samples were submitted for MA enumeration by a conventional plating method (using plate count agar) and Petrifilm Aerobic Count plates (3M, St. Paul, MN), followed by incubation according to 3 official protocols: IDF/ISO (incubation at 30 degrees C for 72 h), American Public Health Association (32 degrees C for 48 h), and Brazilian Ministry of Agriculture (36 degrees C for 48 h). The results were compared by linear regression and ANOVA. Considering the results from conventional methodology, good correlation indices and absence of significant differences between mean counts were observed, independent of type of milk sample (raw or pasteurized) and incubation conditions (IDF/ISO, American Public Health Association, or Ministry of Agriculture). Considering the results from Petrifilm Aerobic Count plates, good correlation indices and absence of significant differences were only observed for raw milk samples. The microbiota of pasteurized milk interfered negatively with the performance of Petrifilm Aerobic Count plates, probably because of the presence of microorganisms that poorly reduce the dye indicator of this system.

  2. Effects of Testing Conditions on Conceptual Survey Results

    ERIC Educational Resources Information Center

    Ding, Lin; Reay, Neville W.; Lee, Albert; Bao, Lei

    2008-01-01

    Pre-testing and post-testing is a commonly used method in Physics Education Research to assess student learning gains. It is well recognized in the community that timings and incentives in delivering conceptual tests can impact test results. However, it is difficult to control these variables across different studies. As a common practice, a…

  3. Green synthesis of Pd/CuO nanoparticles by Theobroma cacao L. seeds extract and their catalytic performance for the reduction of 4-nitrophenol and phosphine-free Heck coupling reaction under aerobic conditions.

    PubMed

    Nasrollahzadeh, Mahmoud; Sajadi, S Mohammad; Rostami-Vartooni, Akbar; Bagherzadeh, Mojtaba

    2015-06-15

    We report the green synthesis of palladium/CuO nanoparticles (Pd/CuO NPs) using Theobroma cacao L. seeds extract and their catalytic activity for the reduction of 4-nitrophenol and Heck coupling reaction under aerobic conditions. The catalyst was characterized using the powder XRD, TEM, EDS, UV-vis and FT-IR. This method has the advantages of high yields, elimination of surfactant, ligand and homogeneous catalysts, simple methodology and easy work up. The catalyst can be recovered from the reaction mixture and reused several times without any significant loss of catalytic activity.

  4. One-pot approach to 1,2-disubstituted indoles via Cu(II)-catalyzed coupling/cyclization under aerobic conditions and its application for the synthesis of polycyclic indoles.

    PubMed

    Gao, Jilong; Shao, Yingying; Zhu, Jiaoyan; Zhu, Jiaqi; Mao, Hui; Wang, Xiaoxia; Lv, Xin

    2014-10-01

    A straightforward assembly of 1,2-disubstituted indoles has been developed through a Cu(II)-catalyzed domino coupling/cyclization process. Under aerobic conditions, a wide range of 1,2-disubstituted indole derivatives were efficiently and facilely synthesized from 2-alkynylanilines and boronic acids. 2-(2-Bromoaryl)-1-aryl-1H-indoles, which were selectively generated in one pot under the Cu catalysis, afforded the indolo[1,2-f]phenanthridines via Pd-catalyzed intramolecular direct C(sp(2))-H arylation. The one-pot tandem approaches to the polycyclic indole derivatives were also successfully achieved. PMID:25211172

  5. Characteristics of a Novel Aerobic Denitrifying Bacterium, Enterobacter cloacae Strain HNR.

    PubMed

    Guo, Long-Jie; Zhao, Bin; An, Qiang; Tian, Meng

    2016-03-01

    A novel aerobic denitrifier strain HNR, isolated from activated sludge, was identified as Enterobacter cloacae by16S rRNA sequencing analysis. Glucose was considered as the most favorable C-source for strain HNR. The logistic equation well described the bacterial growth, yielding a maximum growth rate (μmax) of 0.283 h(-1) with an initial NO3 (-)-N concentration of 110 mg/L. Almost all NO3 (-)-N was removed aerobically within 30 h with an average removal rate of 4.58 mg N L(-1) h(-1). Nitrogen balance analysis revealed that proximately 70.8 % of NO3 (-)-N was removed as gas products and only 20.7 % was transformed into biomass. GC-MS result indicates that N2 was the end product of aerobic denitrification. The enzyme activities of nitrate reductase and nitrite reductase, which are related to the process of aerobic denitrification, were 0.0688 and 0.0054 U/mg protein, respectively. Thus, the aerobic denitrification of reducing NO3 (-) to N2 by strain HNR was demonstrated. The optimal conditions for nitrate removal were C/N ratio 13, pH value 8, shaking speed 127 rpm and temperature 30 °C. These findings show that E. cloacae strain HNR has a potential application on wastewater treatment to achieve nitrate removal under aerobic conditions.

  6. Aerobic fitness ecological validity in elite soccer players: a metabolic power approach.

    PubMed

    Manzi, Vincenzo; Impellizzeri, Franco; Castagna, Carlo

    2014-04-01

    The aim of this study was to examine the association between match metabolic power (MP) categories and aerobic fitness in elite-level male soccer players. Seventeen male professional soccer players were tested for VO2max, maximal aerobic speed (MAS), VO2 at ventilatory threshold (VO2VT and %VO2VT), and speed at a selected blood lactate concentration (4 mmol·L(-1), V(L4)). Aerobic fitness tests were performed at the end of preseason and after 12 and 24 weeks during the championship. Aerobic fitness and MP variables were considered as mean of all seasonal testing and of 16 Championship home matches for all the calculations, respectively. Results showed that VO2max (from 0.55 to 0.68), MAS (from 0.52 to 0.72), VO2VT (from 0.72 to 0.83), %VO2maxVT (from 0.62 to 0.65), and V(L4) (from 0.56 to 0.73) were significantly (p < 0.05 to 0.001) large to very large associated with MP variables. These results provide evidence to the ecological validity of aerobic fitness in male professional soccer. Strength and conditioning professionals should consider aerobic fitness in their training program when dealing with professional male soccer players. The MP method resulted an interesting approach for tracking external load in male professional soccer players.

  7. The Energetics of Aerobic versus Anaerobic Respiration.

    ERIC Educational Resources Information Center

    Champion, Timothy D.; Schwenz, Richard W.

    1990-01-01

    Background information, laboratory procedures, and a discussion of the results of an experiment designed to investigate the difference in energy gained from the aerobic and anaerobic oxidation of glucose are presented. Sample experimental and calculated data are included. (CW)

  8. Aerobic methane emissions from stinkweed (Thlaspi arvense) capsules

    PubMed Central

    Qaderi, Mirwais M; Reid, David M

    2014-01-01

    Aerobic methane (CH4) emission from plant vegetative parts has been confirmed by many studies. However, the origin of aerobic CH4 from plants and its emission from reproductive parts have not been well documented. We determined the effects of developmental stages (early, mid, late) and incubation conditions (darkness, dim light, bright light) on CH4 emissions from stinkweed (Thlaspi arvense) capsules. We found that CH4 emissions from capsules varied with developmental stage and incubation light. Methane emission was highest for the late harvested capsules and for those incubated under lower (dim) light condition. Our results also showed a significant negative correlation between CH4 emission and capsule moisture content. We conclude that CH4 emissions vary with capsule age and diurnal light environment. PMID:25482797

  9. Influence of aeration intensity on mature aerobic granules in sequencing batch reactor.

    PubMed

    Gao, Da-Wen; Liu, Lin; Liang, Hong

    2013-05-01

    Aeration intensity is well known as an important factor in the formation of aerobic granules. In this research, two identical lab-scale sequencing batch reactors with aeration intensity of 0.8 (R1) and 0.2 m(3)/h (R2) were operated to investigate the characteristics and kinetics of matured aerobic granules. Results showed that both aeration intensity conditions induced granulation, but they showed different effects on the characteristics of aerobic granules. Compared with the low aeration intensity (R2), the aerobic granules under the higher aeration intensity (R1) had better physical characteristics and settling ability. However, the observed biomass yield (Y obs) in R1 [0.673 kg mixed liquor volatile suspended solids (MLVSS)/kg chemical oxygen demand (COD)] was lower than R2 (0.749 kg MLVSS/kg COD). In addition, the maximum specific COD removal rates (q max) and apparent half rate constant (K) of mature aerobic granular sludge under the two aeration intensities were at a similar level. Therefore, the matured aerobic granule system does not require to be operated in a higher aeration intensity, which will reduce the energy consumption.

  10. [Study on technological characters of anaerobic-aerobic bioreactor landfill].

    PubMed

    Chen, Zhu-Lei; Zhou, Chuan-Bin; Liu, Ting; Jiang, Juan; Cao, Li; Lü, Zhi-Zhong; Li, Xi-Kun; Li, Xiao-Bao

    2007-04-01

    A technology of anaerobic-aerobic landfill bioreactor aimed at reusing landfill site is studied, and it's based on landfill bioreactor technology. A set of stimulating equipment is designed, and the technology characters are studied. In the anaerobic period, technological conditions are controlled by the means of leachate recirculation. The main experimental results are: pH, R1 rises to 6.7 - 7.8 in 6 weeks, and R2 is under 6.8 in 17 weeks; COD concentration of leachate, R1 declines to 10 617 mg/L in 13 weeks, while R2 rises to 60 000 mg/L in 5 weeks, and keeps stabilization in long time; the cumulating methane production, R1 reaches 44% in 8 weeks, while R2 almost cannot produce methane. The stabilization can be evaluated by pH of leachate, COD and BOD5/COD decreasing ratio, and cumulating methane production. They are main evidences to transform anaerobic period to aerobic period. In the aerobic period, odor and moisture are reduced by the means of aeration. The main experimental results are: ammonia concentration reduces to 1.16 mg/m3 in 19 days, and the odor concentration reduces to 19 in 23 days; the moisture of the wastes reduces to 26% in 14 days. The technological indexes to evaluate finishing of this period can be determined by the ultimately purpose of exploited wastes. Numerical modeling has been researched with the use of experimental data. The succession of microbes in the anaerobic-aerobic course is studied by RISA (ribosomal intergenic spacer analysis) analysis. There are 4 preponderant groups in this course, and some facultative anaerobes play important roles in the transition of anaerobic period to aerobic period.

  11. Engineering of a modular and synthetic phosphoketolase pathway for photosynthetic production of acetone from CO2 in Synechococcus elongatus PCC 7942 under light and aerobic condition.

    PubMed

    Chwa, Jun-Won; Kim, Wook Jin; Sim, Sang Jun; Um, Youngsoon; Woo, Han Min

    2016-08-01

    Capture and conversion of CO2 to valuable chemicals is intended to answer global challenges on environmental issues, climate change and energy security. Engineered cyanobacteria have been enabled to produce industry-relevant chemicals from CO2 . However, the final products from cyanobacteria have often been mixed with fermented metabolites during dark fermentation. In this study, our engineering of Synechococcus elongatus PCC 7942 enabled continuous conversion of CO2 to volatile acetone as sole product. This process occurred during lighted, aerobic culture via both ATP-driven malonyl-CoA synthesis pathway and heterologous phosphoketolase (PHK)-phosphotransacetylase (Pta) pathway. Because of strong correlations between the metabolic pathways of acetate and acetone, supplying the acetyl-CoA directly from CO2 in the engineered strain, led to sole production of acetone (22.48 mg/L ± 1.00) without changing nutritional constraints, and without an anaerobic shift. Our engineered S. elongatus strains, designed for acetone production, could be modified to create biosolar cell factories for sustainable photosynthetic production of acetyl-CoA-derived biochemicals. PMID:26879003

  12. A proposed aerobic granules size development scheme for aerobic granulation process.

    PubMed

    Dahalan, Farrah Aini; Abdullah, Norhayati; Yuzir, Ali; Olsson, Gustaf; Salmiati; Hamdzah, Myzairah; Din, Mohd Fadhil Mohd; Ahmad, Siti Aqlima; Khalil, Khalilah Abdul; Anuar, Aznah Nor; Noor, Zainura Zainon; Ujang, Zaini

    2015-04-01

    Aerobic granulation is increasingly used in wastewater treatment due to its unique physical properties and microbial functionalities. Granule size defines the physical properties of granules based on biomass accumulation. This study aims to determine the profile of size development under two physicochemical conditions. Two identical bioreactors namely Rnp and Rp were operated under non-phototrophic and phototrophic conditions, respectively. An illustrative scheme was developed to comprehend the mechanism of size development that delineates the granular size throughout the granulation. Observations on granules' size variation have shown that activated sludge revolutionised into the form of aerobic granules through the increase of biomass concentration in bioreactors which also determined the changes of granule size. Both reactors demonstrated that size transformed in a similar trend when tested with and without illumination. Thus, different types of aerobic granules may increase in size in the same way as recommended in the aerobic granule size development scheme.

  13. A Putative ABC Transporter Permease Is Necessary for Resistance to Acidified Nitrite and EDTA in Pseudomonas aeruginosa under Aerobic and Anaerobic Planktonic and Biofilm Conditions

    PubMed Central

    McDaniel, Cameron; Su, Shengchang; Panmanee, Warunya; Lau, Gee W.; Browne, Tristan; Cox, Kevin; Paul, Andrew T.; Ko, Seung-Hyun B.; Mortensen, Joel E.; Lam, Joseph S.; Muruve, Daniel A.; Hassett, Daniel J.

    2016-01-01

    Pseudomonas aeruginosa (PA) is an important airway pathogen of cystic fibrosis and chronic obstructive disease patients. Multiply drug resistant PA is becoming increasing prevalent and new strategies are needed to combat such insidious organisms. We have previously shown that a mucoid, mucA22 mutant PA is exquisitely sensitive to acidified nitrite (A-NO2−, pH 6.5) at concentrations that are well tolerated in humans. Here, we used a transposon mutagenesis approach to identify PA mutants that are hypersensitive to A-NO2−. Among greater than 10,000 mutants screened, we focused on PA4455, in which the transposon was found to disrupt the production of a putative cytoplasmic membrane-spanning ABC transporter permease. The PA4455 mutant was not only highly sensitive to A-NO2−, but also the membrane perturbing agent, EDTA and the antibiotics doxycycline, tigecycline, colistin, and chloramphenicol, respectively. Treatment of bacteria with A-NO2− plus EDTA, however, had the most dramatic and synergistic effect, with virtually all bacteria killed by 10 mM A-NO2−, and EDTA (1 mM, aerobic, anaerobic). Most importantly, the PA4455 mutant was also sensitive to A-NO2− in biofilms. A-NO2− sensitivity and an anaerobic growth defect was also noted in two mutants (rmlC and wbpM) that are defective in B-band LPS synthesis, potentially indicating a membrane defect in the PA4455 mutant. Finally, this study describes a gene, PA4455, that when mutated, allows for dramatic sensitivity to the potential therapeutic agent, A-NO2− as well as EDTA. Furthermore, the synergy between the two compounds could offer future benefits against antibiotic resistant PA strains. PMID:27064218

  14. Aerobic mineralization of MTBE and tert-butyl alcohol by stream-bed sediment microorganisms

    USGS Publications Warehouse

    Bradley, P.M.; Landmeyer, J.E.; Chapelle, F.H.

    1999-01-01

    Microorganisms indigenous to the stream-bed sediments at two gasoline- contaminated groundwater sites demonstrated significant mineralization of the fuel oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Up to 73% of [U-14C]-MTBE and 84% of [U-14C]-TBA were degraded to 14CO2 under mixed aerobic/anaerobic conditions. No significant mineralization was observed under strictly anaerobic conditions. The results indicate that, under the mixed aerobic/anaerobic conditions characteristic of stream-bed sediments, microbial processes may provide a significant environmental sink for MTBE and TBA delivered to surface water bodies by contaminated groundwater or by other sources.Microorganisms indigenous to the stream-bed sediments at two gasoline-contaminated groundwater sites demonstrated significant mineralization of the fuel oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Up to 73% of [U-14C]-MTBE and 84% of [U-14C]-TBA were degraded to 14CO2 under mixed aerobic/anaerobic conditions. No significant mineralization was observed under strictly anaerobic conditions. The results indicate that, under the mixed aerobic/anaerobic conditions characteristic of stream-bed sediments, microbial processes may provide a significant environmental sink for MTBE and TBA delivered to surface water bodies by contaminated groundwater or by other sources.

  15. Aerobic and anaerobic growth of Paracoccus denitrificans on methanol.

    PubMed

    Bamforth, C W; Quayle, J R

    1978-10-01

    1. The dye-linked methanol dehydrogenase from Paracoccus denitrificans grown aerobically on methanol has been purified and its properties compared with similar enzymes from other bacteria. It was shown to be specific and to have high affinity for primary alcohols and formaldehyde as substrate, ammonia was the best activator and the enzyme could be linked to reduction of phenazine methosulphate. 2. Paracoccus denitrificans could be grown anaerobically on methanol, using nitrate or nitrite as electron acceptor. The methanol dehydrogenase synthesized under these conditions could not be differentiated from the aerobically-synthesized enzyme. 3. Activities of methanol dehydrogenase, formaldehyde dehydrogenase, formate dehydrogenase, nitrate reductase and nitrite reductase were measured under aerobic and anaerobic growth conditions. 4. Difference spectra of reduced and oxidized cytochromes in membrane and supernatant fractions of methanol-grown P. denitrificans were measured. 5. From the results of the spectral and enzymatic analyses it has been suggested that anaerobic growth on methanol/nitrate is made possible by reduction of nitrate to nitrite using electrons derived from the pyridine nucleotide-linked dehydrogenations of formaldehyde and formate, the nitrite so produced then functioning as electron acceptor for methanol dehydrogenase via cytochrome c and nitrite reductase. PMID:718372

  16. Treatment of packaging board whitewater in anaerobic/aerobic biokidney.

    PubMed

    Alexandersson, T; Malmqvist, A

    2005-01-01

    Whitewater from production of packaging board was treated in a combined anaerobic/aerobic biokidney, both in laboratory scale and pilot plant experiments. Both the laboratory experiments and the pilot plant trial demonstrate that a combined anaerobic/aerobic process is suitable for treating whitewater from a packaging mill. It is also possible to operate the process at the prevailing whitewater temperature. In the laboratory under mesophilic conditions the maximal organic load was 12 kg COD/m3*d on the anaerobic reactor and 6.7 kg COD/m3*d on the aerobic reactor. This gave a hydraulic retention time, HRT, in the anaerobic reactor of 10 hours and 2 hours in the aerobic reactor. The reduction of COD was between 85 and 90% after the first stage and the total reduction was between 88 to 93%. Under thermophilic conditions in the laboratory the organic load was slightly lower than 9.6 COD/m3*d and between 10 and 16 COD/m3*d, respectively. The HRT was 16.5 and 3.4 hours and the removal was around 75% after the anaerobic reactor and 87% after the total process. For the pilot plant experiment at a mill the HRT in the anaerobic step varied between 3 and 17 hours and the corresponding organic load between 4 and 44 kg COD/m3*d. The HRT in the aerobic step varied between 1 and 6 hours and the organic load between 1.5 and 26 kg COD/m3*d. The removal of soluble organic matter was 78% in the anaerobic step and 86% after the combined treatment at the lowest loading level. The removal efficiency at the highest loading level was about 65% in the anaerobic step and 77% after the aerobic step. In the pilot plant trial the removal efficiency was not markedly affected by the variations in whitewater composition that were caused by change of production. The variations, however, made the manual control of the nutrient dosage inadequate and resulted in large variations in effluent nutrient concentration. This demonstrates the need for an automatic nutrient dosage system. The first step

  17. Comparison of Leachate Quality from Aerobic and Anaerobic Municipal Solid Waste Bioreactors

    NASA Astrophysics Data System (ADS)

    Borglin, S. E.; Hazen, T. C.; Oldenburg, C. M.

    2002-12-01

    Municipal solid waste landfills are becoming a drain on the resources of local municipalities as the requirements for stabilization and containment become increasingly stringent. Current regulations limit the moisture in the landfill to minimize leachate production and lower the potential for release of leachate to the environment. Recent research has shown that addition and recycling of moisture in the waste optimizes the biodegradation of stabilization and also provides a means for leachate treatment. This study compares the characteristics of leachate produced from aerobic and anaerobic laboratory bioreactors, and leachate collected from a full-scale anaerobic bioreactor. The laboratory reactors consisted of 200-liter tanks filled with fresh waste materials with the following conditions: (a) aerobic (air injection with leachate recirculation), (b) anaerobic (leachate recirculation). The leachate from the reactors was monitored for metals, nutrients, organic carbon, and microbiological activity for up to 500 days. Leachate from the aerobic tank had significantly lower concentrations of all potential contaminants, both organic and metal, after only a few weeks of operation. Metals leaching was low throughout the test period for the aerobic tanks, and decreased over time for the anaerobic tanks. Organic carbon as measured by BOD, COD, TOC, and COD were an order of magnitude higher in the leachate from the anaerobic system. Microbiological assessment by lipid analysis, enzyme activity assays, and cell counts showed high biomass and diversity in both the aerobic and anaerobic bioreactors, with higher activity in the anaerobic leachate. Results from the full-scale anaerobic bioreactor were not significantly different from those of the laboratory anaerobic bioreactor. The reduction in noxious odors was a significant advantage of the aerobic system. These results suggest that aerobic management of landfills could reduce or eliminate the need for leachate treatment

  18. [Application of Micro-aerobic Hydrolysis Acidification in the Pretreatment of Petrochemical Wastewater].

    PubMed

    Zhu, Chen; Wu, Chang-yong; Zhou, Yue-xi; Fu, Xiao-yong; Chen, Xue-min; Qiu, Yan-bo; Wu, Xiao-feng

    2015-10-01

    Micro-aerobic hydrolysis acidification technology was applied in the reconstruction of ananaerobic hydrolysis acidification tank in a north petrochemical wastewater treatment plant. After put into operation, the monitoring results showed that the average removal rate of COD was 11.7% when influent COD was 490.3-673.2 mg x L(-1), hydraulic retention time (HRT) was 24 and the dissolved oxygen (DO) was 0.2-0.35 mg x L(-1). In addition, the BOD5/COD value was increased by 12.4%, the UV254 removal rate reached 11.2%, and the VFA concentration was increased by 23.0%. The relative molecular weight distribution (MWD) results showed that the small molecule organic matter (< 1 x 10(3)) percentage was increased from 59.5% to 82.1% and the high molecular organic matter ( > 100 x 10(3)) percentage was decreased from 31.8% to 14.0% after micro-aerobic hydrolysis acidification. The aerobic biodegradation batch test showed that the degradation of petrochemical wastewater was significantly improved by the pretreatment of micro-aerobic hydrolysis acidification. The COD of influent can be degraded to 102.2 mg x L(-1) by 48h aerobic treatment while the micro-aerobic hydrolysis acidification effluent COD can be degraded to 71.5 mg x L(-1) on the same condition. The effluent sulfate concentration of micro-aerobic hydrolysis acidification tank [(930.7 ± 60.1) mg x L(-1)] was higher than that of the influent [(854.3 ± 41.5) mg x L(-1)], indicating that sulfate reducing bacteria (SRB) was inhibited. The toxic and malodorous gases generation was reduced with the improvement of environment.

  19. Dance--Aerobic and Anaerobic.

    ERIC Educational Resources Information Center

    Cohen, Arlette

    1984-01-01

    This article defines and explains aerobic exercise and its effects on the cardiovascular system. Various studies on dancers are cited indicating that dance is an anaerobic activity with some small degree of aerobic benefit. (DF)

  20. Methods to determine aerobic endurance.

    PubMed

    Bosquet, Laurent; Léger, Luc; Legros, Patrick

    2002-01-01

    Physiological testing of elite athletes requires the correct identification and assessment of sports-specific underlying factors. It is now recognised that performance in long-distance events is determined by maximal oxygen uptake (V(2 max)), energy cost of exercise and the maximal fractional utilisation of V(2 max) in any realised performance or as a corollary a set percentage of V(2 max) that could be endured as long as possible. This later ability is defined as endurance, and more precisely aerobic endurance, since V(2 max) sets the upper limit of aerobic pathway. It should be distinguished from endurance ability or endurance performance, which are synonymous with performance in long-distance events. The present review examines methods available in the literature to assess aerobic endurance. They are numerous and can be classified into two categories, namely direct and indirect methods. Direct methods bring together all indices that allow either a complete or a partial representation of the power-duration relationship, while indirect methods revolve around the determination of the so-called anaerobic threshold (AT). With regard to direct methods, performance in a series of tests provides a more complete and presumably more valid description of the power-duration relationship than performance in a single test, even if both approaches are well correlated with each other. However, the question remains open to determine which systems model should be employed among the several available in the literature, and how to use them in the prescription of training intensities. As for indirect methods, there is quantitative accumulation of data supporting the utilisation of the AT to assess aerobic endurance and to prescribe training intensities. However, it appears that: there is no unique intensity corresponding to the AT, since criteria available in the literature provide inconsistent results; and the non-invasive determination of the AT using ventilatory and heart rate

  1. HANDBOOK: GUIDANCE ON SETTING PERMIT CONDITIONS AND REPORTING TRIAL BURN RESULTS

    EPA Science Inventory

    This Handbook provides guidance for establishing operational conditions for incinerators. he document provides a means for state and local agencies to achieve a level of consistency in setting permit conditions that will result in establishment of more uniform permit conditions n...

  2. Copper-catalyzed aerobic radical C–C bond cleavage of N–H ketimines

    PubMed Central

    Tnay, Ya Lin; Ang, Gim Yean

    2015-01-01

    Summary We report herein studies on copper-catalyzed aerobic radical C–C bond cleavage of N–H ketimines. Treatment of N–H ketimines having an α-sp3 hybridized carbon under Cu-catalyzed aerobic reaction conditions resulted in a radical fragmentation with C–C bond cleavage to give the corresponding carbonitrile and carbon radical intermediate. This radical process has been applied for the construction of oxaspirocyclohexadienones as well as in the electrophilic cyanation of Grignard reagents with pivalonitrile as a CN source. PMID:26664613

  3. Micropollutants removal in an anaerobic membrane bioreactor and in an aerobic conventional treatment plant.

    PubMed

    Abargues, M R; Robles, A; Bouzas, A; Seco, A

    2012-01-01

    The paper expresses an attempt to tackle the problem due to the presence of micropollutants in wastewater which may be able to disrupt the endocrine system of some organisms. These kinds of compounds are ubiquitously present in municipal wastewater treatment plant (WWTP) effluents. The aim of this paper is to compare the fate of the alkylphenols-APs (4-(tert-octyl)) phenol, t-nonylphenol and 4-p-nonylphenol and the hormones (estrone, 17β-estradiol and 17α-ethinylestradiol) in a submerged anaerobic membrane bioreactor (SAMBR) pilot plant and in a conventional activated sludge wastewater treatment plant (CTP). The obtained results are also compared with the results obtained in a previous study carried out in an aerobic MBR pilot plant. The results showed that the APs soluble concentrations in the SAMBR effluent were always significantly higher than the CTP ones. Moreover, the analyses of the suspended fraction revealed that the AP concentrations in the SAMBR reactor were usually higher than in the CTP reactor, indicating that under anaerobic conditions the APs were accumulated in the digested sludge. The aerobic conditions maintained both in the CTP system and in the aerobic MBR favoured the APs and hormones degradation, and gave rise to lower concentrations in the effluent and in the reactor of these systems. Furthermore, the results also indicated that the degradation of APs under aerobic conditions was enhanced working at high solid retention time (SRT) and hydraulic retention time (HRT) values. PMID:22643422

  4. Effects of permafrost thaw on carbon emissions under aerobic and anaerobic environments in the Great Hing'an Mountains, China.

    PubMed

    Song, Changchun; Wang, Xianwei; Miao, Yuqing; Wang, Jiaoyue; Mao, Rong; Song, Yanyu

    2014-07-15

    The carbon (C) pool of permafrost peatland is very important for the global C cycle. Little is known about how permafrost thaw could influence C emissions in the Great Hing'an Mountains of China. Through aerobic and anaerobic incubation experiments, we studied the effects of permafrost thaw on CH4 and CO2 emissions. The rates of CH4 and CO2 emissions were measured at -10, 0 and 10°C. Although there were still C emissions below 0°C, rates of CH4 and CO2 emissions significantly increased with permafrost thaw under aerobic and anaerobic conditions. The C release under aerobic conditions was greater than under anaerobic conditions, suggesting that permafrost thaw and resulting soil environment change should be important influences on C emissions. However, CH4 stored in permafrost soils could affect accurate estimation of CH4 emissions from microbial degradation. Calculated Q10 values in the permafrost soils were significantly higher than values in active-layer soils under aerobic conditions. Our results highlight that permafrost soils have greater potential decomposability than soils of the active layer, and such carbon decomposition would be more responsive to the aerobic environment.

  5. Mutagenicity of anaerobic fenitrothion metabolites after aerobic biodegradation.

    PubMed

    Matsushita, Taku; Matsui, Yoshihiko; Saeki, Ryo; Inoue, Takanobu

    2005-12-01

    Previous studies have revealed that the mutagenicity of fenitrothion increases during anaerobic biodegradation, suggesting that this insecticide's mutagenicity could effectively increase after it pollutes anaerobic environments such as lake sediments. To investigate possible changes to the mutagenicity of fenitrothion under aerobic conditions after it had already been increased by anaerobic biodegradation, batch incubation cultures were maintained under aerobic conditions. The mutagenicity, which had increased during anaerobic biodegradation, decreased under aerobic conditions with aerobic or facultative bacteria, but did not disappear completely in 22 days. In contrast, it did not change under aerobic conditions without bacteria or under continued anaerobic conditions. These observations suggest that the mutagenicity of anaerobically metabolized fenitrothion would not necessarily decrease after it arrives in an aerobic environment: this would depend on the presence of suitable bacteria. Therefore, fenitrothion-derived mutagenic compounds may pollute the water environment, including our drinking water sources, after accidental pollution of aerobic waters. Although amino-fenitrothion generated during anaerobic biodegradation of fenitrothion was the principal mutagen, non-trivial contributions of other, unidentified metabolites to the mutagenicity were also observed. PMID:16263383

  6. Preliminary Results: Release Of Metals From Acid-Mine Drainage Contaminated Streambed Sediments Under Anaerobic Conditions

    EPA Science Inventory

    Many miles of streams in the western U.S. are contaminated with acid-mine drainage (AMD) from abandoned metal mines. Treatment of these streams may include removal of the existing sediments, with subsequent burial (e.g., in a repository). Burial of previously aerobic sediments ma...

  7. 5-Carboxamido-5-formamido-2-iminohydantoin, in Addition to 8-oxo-7,8-Dihydroguanine, Is the Major Product of the Iron-Fenton or X-ray Radiation-Induced Oxidation of Guanine under Aerobic Reducing Conditions in Nucleoside and DNA Contexts

    PubMed Central

    2016-01-01

    Exogenously and endogenously produced reactive oxygen species attack the base and sugar moieties of DNA showing a preference for reaction at 2′-deoxyguanosine (dG) sites. In the present work, dG was oxidized by HO• via the Fe(II)-Fenton reaction or by X-ray radiolysis of water. The oxidized lesions observed include the 2′-deoxynucleosides of 8-oxo-7,8-dihydroguanine (dOG), spiroiminodihydantoin (dSp), 5-guanidinohydantoin (dGh), oxazolone (dZ), 5-carboxamido-5-formamido-2-iminohydantoin (d2Ih), 5′,8-cyclo-2′-deoxyguanosine (cyclo-dG), and the free base guanine (Gua). Reactions conducted with ascorbate or N-acetylcysteine as a reductant under aerobic conditions identified d2Ih as the major lesion formed. Studies were conducted to identify the role of O2 and the reductant in product formation. From these studies, mechanisms are proposed to support d2Ih as a major oxidation product detected under aerobic conditions in the presence of the reductant. These nucleoside observations were then validated in oxidations of oligodeoxynucleotide and λ-DNA contexts that demonstrated high yields of d2Ih in tandem with dOG, dSp, and dGh. These results identify dG oxidation to d2Ih to occur in high yields leading to a hypothesis that d2Ih could be found from in cells stressed with HO•. Further, the distorted ring structure of d2Ih likely causes this lesion to be highly mutagenic. PMID:26092110

  8. Communal microaerophilic-aerobic biodegradation of Amaranth by novel NAR-2 bacterial consortium.

    PubMed

    Chan, Giek Far; Rashid, Noor Aini Abdul; Chua, Lee Suan; Ab llah, Norzarini; Nasiri, Rozita; Ikubar, Mohamed Roslan Mohamad

    2012-02-01

    A novel bacterial consortium, NAR-2 which consists of Citrobacter freundii A1, Enterococcus casseliflavus C1 and Enterobacter cloacae L17 was investigated for biodegradation of Amaranth azo dye under sequential microaerophilic-aerobic condition. The NAR-2 bacterial consortium with E. casseliflavus C1 as the dominant strain enhanced the decolorization process resulting in reduction of Amaranth in 30 min. Further aerobic biodegradation, which was dominated by C. freundii A1 and E. cloacae L17, allowed biotransformation of azo reduction intermediates and mineralization via metabolic pathways including benzoyl-CoA, protocatechuate, salicylate, gentisate, catechol and cinnamic acid. The presence of autoxidation products which could be metabolized to 2-oxopentenoate was elucidated. The biodegradation mechanism of Amaranth by NAR-2 bacterial consortium was predicted to follow the steps of azo reduction, deamination, desulfonation and aromatic ring cleavage. This is for the first time the comprehensive microaerophilic-aerobic biotransformation pathways of Amaranth dye intermediates by bacterial consortium are being proposed.

  9. Combined thermophilic aerobic process and conventional anaerobic digestion: effect on sludge biodegradation and methane production.

    PubMed

    Dumas, C; Perez, S; Paul, E; Lefebvre, X

    2010-04-01

    The efficiency of hyper-thermophilic (65 degrees Celsius) aerobic process coupled with a mesophilic (35 degrees Celsius) digester was evaluated for the activated sludge degradation and was compared to a conventional mesophilic digester. For two Sludge Retention Time (SRT), 21 and 42 days, the Chemical Oxygen Demand (COD) solubilisation and biodegradation processes, the methanisation yield and the aerobic oxidation were investigated during 180 days. The best results were obtained at SRT of 44 days; the COD removal yield was 30% higher with the Mesophilic Anaerobic Digestion/Thermophilic Aerobic Reactor (MAD-TAR) co-treatment. An increase of the sludge intrinsic biodegradability is also observed (20-40%), showing that the unbiodegradable COD in mesophilic conditions becomes bioavailable. However, the methanisation yield was quite similar for both processes at a same SRT. Finally, such a process enables to divide by two the volume of digester with an equivalent efficiency.

  10. 49 CFR 236.528 - Restrictive condition resulting from open hand-operated switch; requirement.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Restrictive condition resulting from open hand... Instructions; Roadway § 236.528 Restrictive condition resulting from open hand-operated switch; requirement. When a facing point hand-operated switch is open one-fourth inch or more, a trailing point...

  11. 49 CFR 236.528 - Restrictive condition resulting from open hand-operated switch; requirement.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Restrictive condition resulting from open hand... Instructions; Roadway § 236.528 Restrictive condition resulting from open hand-operated switch; requirement. When a facing point hand-operated switch is open one-fourth inch or more, a trailing point...

  12. 49 CFR 236.528 - Restrictive condition resulting from open hand-operated switch; requirement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Restrictive condition resulting from open hand... Instructions; Roadway § 236.528 Restrictive condition resulting from open hand-operated switch; requirement. When a facing point hand-operated switch is open one-fourth inch or more, a trailing point...

  13. 49 CFR 236.528 - Restrictive condition resulting from open hand-operated switch; requirement.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Restrictive condition resulting from open hand... Instructions; Roadway § 236.528 Restrictive condition resulting from open hand-operated switch; requirement. When a facing point hand-operated switch is open one-fourth inch or more, a trailing point...

  14. The relationship between childhood aerobic fitness and brain functional connectivity.

    PubMed

    Kamijo, Keita; Takeda, Yuji; Takai, Yohei; Haramura, Miki

    2016-10-01

    Several studies have indicated that higher levels of childhood aerobic fitness is associated with superior cognitive function, and this association is disproportionately observed in tasks requiring greater top-down control. We designed the current study to clarify the relationship between childhood fitness and top-down control in terms of functional connectivity among brain regions, by evaluating phase-locking values (PLVs), which is a measure of frequency-specific phase synchrony between electroencephalographic signals during a visual search task. Lower-fit and higher-fit children performed a visual search task that included feature search and conjunction search conditions. The conjunction search condition required greater top-down control to reduce interference from task-irrelevant distractors that shared a basic feature with the target. Results indicated that higher-fit children exhibited higher response accuracy relative to lower-fit children across search conditions. The results of PLVs showed that higher-fit children had greater functional connectivity for the conjunction relative to the feature search condition, whereas lower-fit children showed no difference in functional connectivity between search conditions. Furthermore, PLVs showed different time courses between groups; that is, higher-fit children sustained upregulation of top-down control throughout the task period, whereas lower-fit children transiently upregulated top-down control after stimulus onset and could not sustain the upregulation. These findings suggest that higher levels of childhood aerobic fitness is related to brain functional connectivity involved in the sustained upregulation of top-down control.

  15. The Twin Arginine Translocation System Is Essential for Aerobic Growth and Full Virulence of Burkholderia thailandensis

    PubMed Central

    Wagley, Sariqa; Hemsley, Claudia; Thomas, Rachael; Moule, Madeleine G.; Vanaporn, Muthita; Andreae, Clio; Robinson, Matthew; Goldman, Stan; Wren, Brendan W.; Butler, Clive S.

    2014-01-01

    The twin arginine translocation (Tat) system in bacteria is responsible for transporting folded proteins across the cytoplasmic membrane, and in some bacteria, Tat-exported substrates have been linked to virulence. We report here that the Tat machinery is present in Burkholderia pseudomallei, B. mallei, and B. thailandensis, and we show that the system is essential for aerobic but not anaerobic growth. Switching off of the Tat system in B. thailandensis grown anaerobically resulted in filamentous bacteria, and bacteria showed increased sensitivity to some β-lactam antibiotics. In Galleria mellonella and zebrafish infection models, the Tat conditional mutant was attenuated. The aerobic growth-restricted phenotype indicates that Tat substrates may play a functional role in oxygen-dependent energy conservation. In other bacteria, aerobic growth restriction in Tat mutants has been attributed to the inability to translocate PetA, the Rieske iron-sulfur protein which forms part of the quinol-cytochrome c oxidoreductase complex. Here, we show that PetA is not responsible for aerobic growth restriction in B. thailandensis. However, we have identified an operon encoding 2 proteins of unknown function (BTH_I2176 and BTH_I2175) that play a role in aerobic growth restriction, and we present evidence that BTH_I2176 is Tat translocated. PMID:24214943

  16. Aerobic Oxidation of an Osmium(III) N-Hydroxyguanidine Complex To Give Nitric Oxide.

    PubMed

    Xiang, Jing; Wang, Qian; Yiu, Shek-Man; Man, Wai-Lun; Kwong, Hoi-Ki; Lau, Tai-Chu

    2016-05-16

    The aerobic oxidation of the N-hydroxyguanidinum moiety of N-hydroxyarginine to NO is a key step in the biosynthesis of NO by the enzyme nitric oxide synthase (NOS). So far, there is no chemical system that can efficiently carry out similar aerobic oxidation to give NO. We report here the synthesis and X-ray crystal structure of an osmium(III) N-hydroxyguanidine complex, mer-[Os(III){NH═C(NH2)(NHOH)}(L)(CN)3](-) (OsGOH, HL = 2-(2-hydroxyphenyl)benzoxazole), which to the best of our knowledge is the first example of a transition metal N-hydroxyguanidine complex. More significantly, this complex readily undergoes aerobic oxidation at ambient conditions to generate NO. The oxidation is pH-dependent; at pH 6.8, fac-[Os(NO)(L)(CN)3](-) is formed in which the NO produced is bound to the osmium center. On the other hand, at pH 12, aerobic oxidation of OsGOH results in the formation of the ureato complex [Os(III)(NHCONH2)(L)(CN)3](2-) and free NO. Mechanisms for this aerobic oxidation at different pH values are proposed. PMID:27135258

  17. Aerobic and Anaerobic Bacteriology of Hidradenitis Suppurativa: A Study of 22 Cases

    PubMed Central

    Katoulis, Alexandros C.; Koumaki, Dimitra; Liakou, Aikaterini I.; Vrioni, Georgia; Koumaki, Vasiliki; Kontogiorgi, Dimitra; Tzima, Korina; Tsakris, Athanasios; Rigopoulos, Dimitris

    2015-01-01

    Introduction Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease of unclear etiology. The role of bacteria in the pathogenesis of disease remains controversial. Materials and Methods Specimens were obtained from 22 HS patients by direct percutaneous needle aspiration. The collected material was cultured in aerobic and anaerobic conditions, and sensitivity tests were performed. Results Of the 22 patients, 32% were culture negative and 68% were culture positive. A total of 16 isolates was obtained, 14 aerobic and 2 anaerobic. Aerobic bacteria were present in 86% of the specimens, whereas only anaerobic bacteria were isolated in 7%. The predominant aerobic species were Proteus mirabilis, Staphylococcus haemolyticus and Staphylococcus lugdunensis. The isolated anaerobic bacteria were Dermacoccus nishinomiyaensis and Propionibacterium granulosum. Conclusion A variety of aerobic and anaerobic bacteria was isolated from the HS lesions of our patients. In contrast to previous studies, fewer patients were found to be culture positive, and Staphylococcus aureus was isolated in only 1 of them. More studies are necessary to elucidate the controversial role of bacteria in the pathogenesis of HS. PMID:27170935

  18. Degradation of acid orange 7 in an aerobic biofilm.

    PubMed

    Coughlin, Michael F; Kinkle, Brian K; Bishop, Paul L

    2002-01-01

    A stable microbial biofilm community capable of completely mineralizing the azo dye acid orange 7 (AO7) was established in a laboratory scale rotating drum bioreactor (RDBR) using waste liquor from a sewage treatment plant. A broad range of environmental conditions including pH (5.8-8.2), nitrification (0.0-4.0 mM nitrite), and aeration (0.2-6.2 mg O2 l(-1)) were evaluated for their effects on the biodegradation of AO7. Furthermore the biofilm maintained its biodegradative ability for over a year while the effects of these environmental conditions were evaluated. Reduction of the azo bond followed by degradation of the resulting aromatic amine appears to be the mechanism by which this dye is biodegraded. Complete loss of color, sulfanilic acid, and chemical oxygen demand (COD) indicate that AO7 is mineralized. To our knowledge this is the first reported occurrence of a sulfonated phenylazonaphthol dye being completely mineralized under aerobic conditions. Two bacterial strains (ICX and SAD4i) originally isolated from the RDBR were able to mineralize, in co-culture, up to 90% of added AO7. During mineralization of AO7, strain ICX reduces the azo bond under aerobic conditions and consumes the resulting cleavage product 1-amino-2-naphthol. Strain SAD4i consumes the other cleavage product, sulfanilic acid. The ability of the RDBR biofilm to aerobically mineralize an azo dye without exogenous carbon and nitrogen sources suggests that this approach could be used to remediate industrial wastewater contaminated with spent dye.

  19. Complete nitrogen removal from municipal wastewater via partial nitrification by appropriately alternating anoxic/aerobic conditions in a continuous plug-flow step feed process.

    PubMed

    Ge, Shijian; Peng, Yongzhen; Qiu, Shuang; Zhu, Ao; Ren, Nanqi

    2014-05-15

    This study assessed the technical feasibility of removing nitrogen from municipal wastewater by partial nitrification (nitritation) in a continuous plug-flow step feed process. Nitrite in the effluent accumulated to over 81.5  ± 9.2% but disappeared with the transition of process operation from anoxic/oxic mode to the anaerobic/anoxic/oxic mode. Batch tests showed obvious ammonia oxidizing bacteria (AOB) stimulation (advanced ammonia oxidation rate) and nitrite (NOB) oxidizing bacteria inhibition (reduced nitrite oxidation rate) under transient anoxic conditions. Two main factors contributed to nitritation in this continuous plug-flow process: One was the alternating anoxic and oxic operational condition; the step feed strategy guaranteed timely denitrification in anoxic zones, allowing a reduction in energy supply (nitrite) to NOB. Fluorescence in Situ Hybridization and quantitative real-time polymerase chain reaction analysis indicated that NOB population gradually decreased to 1.0  ± 0.1% of the total bacterial population (dominant Nitrospira spp., 1.55 × 10(9) copies/L) while AOB increased approximately two-fold (7.4  ± 0.9%, 1.25 × 10(10) copies/L) during the above anoxic to anaerobic transition. Most importantly, without addition of external carbon sources, the above wastewater treatment process reached 86.0  ± 4.2% of total nitrogen (TN) removal with only 7.23 ± 2.31 mg/L of TN in the effluent, which met the discharge requirements. PMID:24602864

  20. Response of aerobic rice to Piriformospora indica.

    PubMed

    Das, Joy; Ramesh, K V; Maithri, U; Mutangana, D; Suresh, C K

    2014-03-01

    Rice cultivation under aerobic condition not only saves water but also opens up a splendid scope for effective application of beneficial root symbionts in rice crop unlike conventional puddled rice cultivation where water logged condition acts as constraint for easy proliferation of various beneficial soil microorganisms like arbuscular mycorrhizal (AM) fungi. Keeping these in view, an in silico investigation were carried out to explore the interaction of hydrogen phosphate with phosphate transporter protein (PTP) from P. indica. This was followed by greenhouse investigation to study the response of aerobic rice to Glomusfasciculatum, a conventional P biofertilizer and P. indica, an alternative to AM fungi. Computational studies using ClustalW tool revealed several conserved motifs between the phosphate transporters from Piriformospora indica and 8 other Glomus species. The 3D model of PTP from P. indica resembling "Mayan temple" was successfully docked onto hydrogen phosphate, indicating the affinity of this protein for inorganic phosphorus. Greenhouse studies revealed inoculation of aerobic rice either with P. indica, G. fasciculatum or both significantly enhanced the plant growth, biomass and yield with higher NPK, chlorophyll and sugar compared to uninoculated ones, P. indica inoculated plants being superior. A significantly enhanced activity of acid phosphatase and alkaline phosphatase were noticed in the rhizosphere soil of rice plants inoculated either with P. indica, G. fasciculatum or both, contributing to higher P uptake. Further, inoculation of aerobic rice plants with P. indica proved to be a better choice as a potential biofertilizer over mycorrhiza. PMID:24669667

  1. Experimental results for improving the matrix condition using a hybrid optical system.

    PubMed

    Klapp, Iftach; Mendlovic, David

    2012-03-01

    We present preliminary experimental results for implementing the "blurred trajectories" method on three parallel optics (PO) systems. The "main" system and "auxiliary" optics were simple laboratory graded lenses attached to an iris diaphragm. When applying the blurred trajectories method we first show an improvement in the matrix condition, as the matrix condition number decreased in a range of factors of 3 to 418 relative to the main system. Following that, image restoration by weak regularization was performed so that the system matrix condition dominated the restoration process. It was shown that the restoration results of the PO are better than those of the main system and the auxiliary optics separately. In addition, the quality of the restoration follows the system's matrix condition. The improvement in the matrix condition achieved by the PO system improved the immunity to detection noise. Finally, a comparison to Wiener filtering restoration shows that it is also generally inferior to the proposed method.

  2. The Effect of Aerobic Exercise on Neuroplasticity within the Motor Cortex following Stroke

    PubMed Central

    Murdoch, Kate; Buckley, Jonathan D.; McDonnell, Michelle N.

    2016-01-01

    Background Aerobic exercise is associated with enhanced plasticity in the motor cortex of healthy individuals, but the effect of aerobic exercise on neuroplasticity following a stroke is unknown. Objective The aim of this study was to compare corticomotoneuronal excitability and neuroplasticity in the upper limb cortical representation following a single session of low intensity lower limb cycling, or a rest control condition. Methods We recruited chronic stroke survivors to take part in three experimental conditions in a randomised, cross-over design. Corticomotoneuronal excitability was examined using transcranial magnetic stimulation to elicit motor evoked potentials in the affected first dorsal interosseus muscle. Following baseline measures, participants either cycled on a stationary bike at a low exercise intensity for 30 minutes, or remained resting in a seated position for 30 minutes. Neuroplasticity within the motor cortex was then examined using an intermittent theta burst stimulation (iTBS) paradigm. During the third experimental condition, participants cycled for the 30 minutes but did not receive any iTBS. Results Twelve participants completed the study. We found no significant effect of aerobic exercise on corticomotoneuronal excitability when compared to the no exercise condition (P > 0.05 for all group and time comparisons). The use of iTBS did not induce a neuroplastic-like response in the motor cortex with or without the addition of aerobic exercise. Conclusions Our results suggest that following a stroke, the brain may be less responsive to non-invasive brain stimulation paradigms that aim to induce short-term reorganisation, and aerobic exercise was unable to induce or improve this response. PMID:27018862

  3. Fatiguing upper body aerobic exercise impairs balance.

    PubMed

    Douris, Peter C; Handrakis, John P; Gendy, Joseph; Salama, Mina; Kwon, Dae; Brooks, Richard; Salama, Nardine; Southard, Veronica

    2011-12-01

    Douris, PC, Handrakis, JP, Gendy, J, Salama, M, Kwon, D, Brooks, R, Salama, N, and Southard, V. Fatiguing upper body aerobic exercise impairs balance. J Strength Cond Res 25(12): 3299-3305, 2011-There are many studies that have examined the effects of selectively fatiguing lower extremity muscle groups with various protocols, and they have all shown to impair balance. There is limited research regarding the effect of fatiguing upper extremity exercise on balance. Muscle fiber-type recruitment patterns may be responsible for the difference between balance impairments because of fatiguing aerobic and anaerobic exercise. The purpose of our study was to investigate the effect that aerobic vs. anaerobic fatigue, upper vs. lower body fatigue will have on balance, and if so, which combination will affect balance to a greater degree. Fourteen healthy subjects, 7 men and 7 women (mean age 23.5 ± 1.7 years) took part in this study. Their mean body mass index was 23.6 ± 3.2. The study used a repeated-measures design. The effect on balance was documented after the 4 fatiguing conditions: aerobic lower body (ALB), aerobic upper body (AUB), anaerobic lower body, anaerobic upper body (WUB). The aerobic conditions used an incremental protocol performed to fatigue, and the anaerobic used the Wingate protocol. Balance was measured as a single-leg stance stability score using the Biodex Balance System. A stability score for each subject was recorded immediately after each of the 4 conditions. A repeated-measures analysis of variance with the pretest score as a covariate was used to analyze the effects of the 4 fatiguing conditions on balance. There were significant differences between the 4 conditions (p = 0.001). Post hoc analysis revealed that there were significant differences between the AUB, mean score 4.98 ± 1.83, and the WUB, mean score 4.09 ± 1.42 (p = 0.014) and between AUB and ALB mean scores 4.33 ± 1.40 (p = 0.029). Normative data for single-leg stability testing for

  4. Comparative study of emerging micropollutants removal by aerobic activated sludge of large laboratory-scale membrane bioreactors and sequencing batch reactors under low-temperature conditions.

    PubMed

    Kruglova, Antonina; Kråkström, Matilda; Riska, Mats; Mikola, Anna; Rantanen, Pirjo; Vahala, Riku; Kronberg, Leif

    2016-08-01

    Four emerging micropollutants ibuprofen, diclofenac, estrone (E1) and 17α-ethinylestradiol (EE2) were studied in large laboratory-scale wastewater treatment plants (WWTPs) with high nitrifying activity. Activated sludge (AS) with sludge retention times (SRTs) of 12days and 14days in sequencing batch reactors (SBRs) and 30days, 60days and 90days in membrane bioreactors (MBRs) were examined at 8°C and 12°C. Concentrations of pharmaceuticals and their main metabolites were analysed in liquid phase and solid phase of AS by liquid chromatography-tandem mass spectrometry (LC-MS/MS). A remarkable amount of contaminants were detected in solids of AS, meaning the accumulation of micropollutants in bacterial cells. The biodegradation rate constants (Kbiol) were affected by SRT and temperature. MBR with a 90-day SRT showed the best results of removal. Conventional SBR process was inefficient at 8°C showing Kbiol values lower than 0.5lgSS(-1)d(-1) for studied micropollutants. PMID:27128192

  5. Comparative study of emerging micropollutants removal by aerobic activated sludge of large laboratory-scale membrane bioreactors and sequencing batch reactors under low-temperature conditions.

    PubMed

    Kruglova, Antonina; Kråkström, Matilda; Riska, Mats; Mikola, Anna; Rantanen, Pirjo; Vahala, Riku; Kronberg, Leif

    2016-08-01

    Four emerging micropollutants ibuprofen, diclofenac, estrone (E1) and 17α-ethinylestradiol (EE2) were studied in large laboratory-scale wastewater treatment plants (WWTPs) with high nitrifying activity. Activated sludge (AS) with sludge retention times (SRTs) of 12days and 14days in sequencing batch reactors (SBRs) and 30days, 60days and 90days in membrane bioreactors (MBRs) were examined at 8°C and 12°C. Concentrations of pharmaceuticals and their main metabolites were analysed in liquid phase and solid phase of AS by liquid chromatography-tandem mass spectrometry (LC-MS/MS). A remarkable amount of contaminants were detected in solids of AS, meaning the accumulation of micropollutants in bacterial cells. The biodegradation rate constants (Kbiol) were affected by SRT and temperature. MBR with a 90-day SRT showed the best results of removal. Conventional SBR process was inefficient at 8°C showing Kbiol values lower than 0.5lgSS(-1)d(-1) for studied micropollutants.

  6. Unraveling characteristics of simultaneous nitrification, denitrification and phosphorus removal (SNDPR) in an aerobic granular sequencing batch reactor.

    PubMed

    He, Qiulai; Zhang, Shilu; Zou, Zhuocheng; Zheng, Li-An; Wang, Hongyu

    2016-11-01

    An aerobic granular sequencing batch reactor (SBR) on an aerobic/oxic/anoxic (AOA) mode was operated for 50days with acetate sodium as the sole carbon source for simultaneous carbon, nitrogen and phosphorus removal. Excellent removal efficiencies for chemical oxygen demand (COD) (94.46±3.59%), nitrogen (96.56±3.44% for ammonia nitrogen (NH4(+)-N) and 93.88±6.78% for total inorganic nitrogen (TIN)) and phosphorus (97.71±3.63%) were obtained over operation. Mechanisms for simultaneous nutrients removal were explored and the results indicated that simultaneous nitrification, denitrification and phosphorus removal (SNDPR) under aerobic conditions was mainly responsible for most of nitrogen and phosphorus removal. Identification and quantification of the granular AOA SBR revealed that higher rates of nutrients removal and more potentials were to be exploited by optimizing the operating conditions including time durations for AOA mode and the feeding compositions. PMID:27599624

  7. Differential sensitivity of aerobic gram-positive and gram-negative microorganisms to 2,4,6-trinitrotoluene (TNT) leads to dissimilar growth and TNT transformation: Results of soil and pure culture studies

    SciTech Connect

    Fuller, M.E.; Manning, J.F. Jr.

    1996-07-30

    The effects of 2,4,6-trinitrotoluene (TNT) on indigenous soil populations and pure bacterial cultures were examined. The number of colony-forming units (CFU) appearing when TNT-contaminated soil was spread on 0.3% molasses plates decreased by 50% when the agar was amended with 67 {mu}g TNT mL{sup -1}, whereas a 99% reduction was observed when uncontaminated soil was plated. Furthermore, TNT-contaminated soil harbored a greater number of organisms able to grow on plates amended with greater than 10 {mu}g TNT mL{sup -1}. The percentage of gram-positive isolates was markedly less in TNT-contaminated soil (7%; 2 of 30) than in uncontaminated soil (61%; 20 of 33). Pseudomonas aeruginosa, Pseudomonas corrugate, Pseudomonasfluorescens and Alcaligenes xylosoxidans made up the majority of the gram-negative isolates from TNT-contaminated soil. Gram-positive isolates from both soils demonstrated marked growth inhibition when greater than 8-16 {mu}g TNT mL{sup -1} was present in the culture media. Most pure cultures of known aerobic gram-negative organisms readily degraded TNT and evidenced net consumption of reduced metabolites. However, pure cultures of aerobic gram-positive bacteria were sensitive to relatively low concentrations of TNT as indicated by the 50% reduction in growth and TNT transformation which was observed at approximately 10 {mu}g TNT mL{sup -1}. Most non-sporeforming gram-positive organisms incubated in molasses media amended with 80 {mu}g TNT mL{sup -1} or greater became unculturable, whereas all strains tested remained culturable when incubated in mineral media amended with 98 {mu}g TNT mL{sup -1}, indicating that TNT sensitivity is likely linked to cell growth. These results indicate that gram-negative organisms are most likely responsible for any TNT transformation in contaminated soil, due to their relative insensitivity to high TNT concentrations and their ability to transform TNT.

  8. Aerobic landfill bioreactor

    DOEpatents

    Hudgins, Mark P; Bessette, Bernard J; March, John C; McComb, Scott T.

    2002-01-01

    The present invention includes a system of decomposing municipal solid waste (MSW) within a landfill by converting the landfill to aerobic degradation in the following manner: (1) injecting air via the landfill leachate collection system (2) injecting air via vertical air injection wells installed within the waste mass; (3) applying leachate to the waste mass using a pressurized drip irrigation system; (4) allowing landfill gases to vent; and (5) adjusting air injection and recirculated leachate to achieve a 40% to 60% moisture level and a temperature between 120.degree. F. and 140.degree. F. in steady state.

  9. Aerobic landfill bioreactor

    DOEpatents

    Hudgins, Mark P; Bessette, Bernard J; March, John; McComb, Scott T.

    2000-01-01

    The present invention includes a method of decomposing municipal solid waste (MSW) within a landfill by converting the landfill to aerobic degradation in the following manner: (1) injecting air via the landfill leachate collection system (2) injecting air via vertical air injection wells installed within the waste mass; (3) applying leachate to the waste mass using a pressurized drip irrigation system; (4) allowing landfill gases to vent; and (5) adjusting air injection and recirculated leachate to achieve a 40% to 60% moisture level and a temperature between 120.degree. F. and 140.degree. F. in steady state.

  10. Aerobic landfill bioreactor

    SciTech Connect

    Hudgins, M.P.; Bessette, B.J.; March, J.; McComb, S.T.

    2000-02-15

    The present invention includes a method of decomposing municipal solid waste (MSW) within a landfill by converting the landfill to aerobic degradation in the following manner: (1) injecting air via the landfill leachate collection system (2) injecting air via vertical air injection wells installed within the waste mass; (3) applying leachate to the waste mass using a pressurized drip irrigation system; (4) allowing landfill gases to vent; and (5) adjusting air injection and recirculated leachate to achieve a 40% to 60% moisture level and a temperature between 120 F and 140 F in steady state.

  11. Biodegradation of ethylene dibromide (1,2-dibromoethane [EDB]) in microcosms simulating in situ and biostimulated conditions.

    PubMed

    McKeever, Robert; Sheppard, Diane; Nüsslein, Klaus; Baek, Kyung-Hwa; Rieber, Khalil; Ergas, Sarina J; Forbes, Rose; Hilyard, Mark; Park, Chul

    2012-03-30

    Although 1,2-dibromoethane (EDB) is a common groundwater contaminant, there is the lack of knowledge surrounding EDB biodegradation, especially under aerobic conditions. We have performed an extensive microcosm study to investigate the biodegradation of EDB under simulated in situ and biostimulated conditions. The materials for soil microcosms were collected from an EDB-contaminated aquifer at the Massachusetts Military Reservation in Cape Cod, MA. This EDB plume has persisted for nearly 40 years in both aerobic and anaerobic EDB zones of the aquifer. Microcosms were constructed under environmentally relevant conditions (field EDB and DO concentrations; incubated at 12°C). The results showed that natural attenuation occurred under anaerobic conditions but not under aerobic conditions, explaining why aerobic EDB contamination is so persistent. EDB degradation rates were greater under biostimulated conditions for both the aerobic and anaerobic microcosms. Particularly for aerobic biostimulation, methane-amended microcosms degraded EDB, on average, at a first order rate eight times faster than unamended microcosms. The best performing replicate achieved an EDB degradation rate of 7.0 yr(-1) (half-life (t(1/2))=0.10 yr). Residual methane concentrations and the emergence of methanotrophic bacteria, measured by culture independent bacterial analysis, provided strong indications that EDB degradation in aerobic methane-amended microcosms occurred via cometabolic degradation. These results indicate the potential for enhanced natural attenuation of EDB and that methane could be considered co-substrate for EDB bioremediation for the EDB-contaminated groundwater in aerobic zone.

  12. Aerobic and anaerobic in vitro testing of feed additives claiming to detoxify deoxynivalenol and zearalenone.

    PubMed

    Hahn, Irene; Kunz-Vekiru, Elisavet; Twarużek, Magdalena; Grajewski, Jan; Krska, Rudolf; Berthiller, Franz

    2015-01-01

    Deoxynivalenol (DON) and zearalenone (ZEN) are mycotoxins produced by fungi of the genus Fusarium which frequently contaminate maize and grain cereals. Mycotoxin-contaminated feed endangers animal health and leads to economic losses in animal production. Several mycotoxin elimination strategies, including the use of commercially available DON and ZEN detoxifying agents, have been developed. However, frequently there is no scientific proof of the efficacy of such adsorbents and degrading products. We therefore tested 20 commercially available products claiming to detoxify DON and/or ZEN either by biodegradation (4 products) or a combination of degradation and adsorption (16 products) under aerobic and anaerobic conditions at approx. pH 7. Under the applied conditions, a complete reduction of DON and consequent formation of the known non-toxic metabolite DOM-1 was exclusively observed in samples taken from the anaerobic degradation experiment of one product. For all other products, incubated under aerobic and anaerobic conditions, a maximum DON reduction of 17% after 72 h of incubation was detected. Aerobic and anaerobic incubation of only one tested product resulted in complete ZEN reduction as well as in the formation of the less-toxic metabolites DHZEN and HZEN. With this product, 68-97% of the toxin was metabolised within 3 h. After 24 h, a ZEN reduction ≥ 60% was obtained with four additional products during aerobic incubation only. Six of the 20 investigated products produced α- and/or β-ZEL, which are metabolites showing similar oestrogenic activity compared to ZEN. Aerobic and anaerobic degradation to unknown metabolites with unidentified toxicity was obtained with 10 and 3 products, respectively. The results of our study demonstrate the importance of in vitro experiments to critically screen agents claiming mycotoxin detoxification.

  13. Fungal degradation of nitrocellulose under aerobic conditions

    SciTech Connect

    Sharma, A.; Sundaram, S.T.; Zhang, Y.Z.; Brodman, B.W.

    1995-12-31

    Mycelial fungi were screened alone or in combinations for their ability to degrade nitrocellulose (3 g/L) in liquid medium. All of the fungi tested used nitrocellulose to a varying extent, but a combination of Sclerotium rolfsii ATCC 24459 and Fusarium solani IFO 31093 was found to be the best because it significantly degraded nitrocellulose. About 38% of the nitrocellulose was degraded by these fungi in a 7-day period when the culture medium was buffered at pH 6.0 with morphilino ethane sulfonic acid.

  14. Low-Impact Aerobics: Better than Traditional Aerobic Dance?

    ERIC Educational Resources Information Center

    Koszuta, Laurie Einstein

    1986-01-01

    A form of dance exercise called low-impact aerobics is being touted as a misery-free form of aerobic dance. Because this activity is relatively new, the exact kinds and frequencies of injuries are not known and the fitness benefits have not been examined. (MT)

  15. Factors associated with low levels of aerobic fitness among adolescents

    PubMed Central

    Gonçalves, Eliane Cristina de Andrade; Silva, Diego Augusto Santos

    2016-01-01

    Abstract Objective: To evaluate the prevalence of low aerobic fitness levels and to analyze the association with sociodemographic factors, lifestyle and excess body fatness among adolescents of southern Brazil. Methods: The study included 879 adolescents aged 14-19 years the city of São José/SC, Brazil. The aerobic fitness was assessed by Canadian modified test of aerobic fitness. Sociodemographic variables (skin color, age, sex, study turn, economic level), sexual maturation and lifestyle (eating habits, screen time, physical activity, consumption of alcohol and tobacco) were assessed by a self-administered questionnaire. Excess body fatness was evaluated by sum of skinfolds triceps and subscapular. We used logistic regression to estimate odds ratios and 95% confidence intervals. Results: Prevalence of low aerobic fitness level was 87.5%. The girls who spent two hours or more in front screen, consumed less than one glass of milk by day, did not smoke and had an excess of body fatness had a higher chance of having lower levels of aerobic fitness. White boys with low physical activity had had a higher chance of having lower levels of aerobic fitness. Conclusions: Eight out of ten adolescents were with low fitness levels aerobic. Modifiable lifestyle factors were associated with low levels of aerobic fitness. Interventions that emphasize behavior change are needed. PMID:26743851

  16. Synthesis, in vitro aerobic and hypoxic cytotoxicity and radiosensitizing activity of novel metronidazole tethered 5-fluorouracil

    PubMed Central

    2013-01-01

    Background and the purpose of the study Several 2, 4-dinitrophenyl and 2,4-dinitrophenylamine tethered 5-FU (5-fluorouracil) compared to their components have shown minimal or no cytotoxicity to HT-29 cell line under aerobic conditions but high cytotoxicity and radiosensitizing effects under hypoxic conditions. In the present study the cytotoxicity and radiation potentiation of three novel analogues of these compounds by replacing 2,4-dinitrophenyl moiety with 2-methyl-5-nitroimidazole, a known radiosensitizer and cytotoxic agent was investigated. Methods Tethered compounds 7–9 were prepared by the reaction of 1-(t-butoxycarbonyl)-5-fluorouracil 6 with metronidazole esters 2–4 followed by removal of the t-butoxycarbonyl protecting group. Cytotoxicity of compounds in HT-29 cells with or without radiation were determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), propidium iodide (PI)-digitonin and clonogenic assays. Results Tethered compounds 7–9 induced time-and concentration–dependent cytotoxicity under hypoxia but had no significant effect under aerobic conditions. These compounds also showed selective and concentration- dependent radiosensitization effects under hypoxic conditions. Conclusion Tethered compounds 7–9 compared to 5-FU 5 showed minimal cytotoxicities under aerobic and selective radiosensitizing activities under hypoxic conditions. Also effects of these compounds were higher than those of metronidazole 1 which is a known cytotoxin and radiosensitizer under hypoxic conditions. PMID:24359860

  17. Transcriptomic and metabolomic profiling of Zymomonas mobilis during aerobic and anaerobic fermentations

    SciTech Connect

    Yang, Shihui; Tschaplinski, Timothy J; Engle, Nancy L; Carroll, Sue L; Martin, S L.; Davison, Brian H; Palumbo, Anthony Vito; Brown, Steven D

    2009-01-01

    abundant under anaerobic conditions in the stationary phase based on quantitative-PCR results. We also identified differentially expressed ZM4 genes predicted by The Institute for Genomic Research (TIGR) that were not predicted in the primary annotation. High oxygen concentrations present during Z. mobilis fermentations negatively influence fermentation performance. The maximum specific growth rates were not dramatically different between aerobic and anaerobic conditions, yet oxygen did affect the physiology of the cells leading to the buildup of metabolic byproducts that ultimately led to greater differences in transcriptomic profiles in stationary phase.

  18. Assessing aerobic natural attenuation of trichloroethene at four DOE sites

    SciTech Connect

    Koelsch, Michael C.; Starr, Robert C.; Sorenson, Jr., Kent S.

    2005-03-01

    A 3-year Department of Energy Environmental Science Management Program (EMSP) project is currently investigating natural attenuation of trichloroethane (TCE) in aerobic groundwater. This presentation summarizes the results of a screening process to identify TCE plumes at DOE facilities that are suitable for assessing the rate of TCE cometabolism under aerobic conditions. In order to estimate aerobic degradation rates, plumes had to meet the following criteria: TCE must be present in aerobic groundwater, a conservative co-contaminant must be present and have approximately the same source as TCE, and the groundwater velocity must be known. A total of 127 TCE plumes were considered across 24 DOE sites. The four sites retained for the assessment were: (1) Brookhaven National Laboratory, OU III; (2) Paducah Gaseous Diffusion Plant, Northwest Plume; (3) Rocky Flats Environmental Technology Site, Industrialized Area--Southwest Plume and 903 Pad South Plume; and (4) Savannah River Site, A/M Area Plume. For each of these sites, a co-contaminant derived from the same source area as TCE was used as a nonbiodegrading tracer. The tracer determined the extent to which concentration decreases in the plume can be accounted for solely by abiotic processes such as dispersion and dilution. Any concentration decreases not accounted for by these processes must be explained by some other natural attenuation mechanism. Thus, ''half-lives'' presented herein are in addition to attenuation that occurs due to hydrologic mechanisms. This ''tracer-corrected method'' has previously been used at the DOE's Idaho National Engineering and Environmental Laboratory in conjunction with other techniques to document the occurrence of intrinsic aerobic cometabolism. Application of this method to other DOE sites is the first step to determining whether this might be a significant natural attenuation mechanism on a broader scale. Application of the tracer-corrected method to data from the Brookhaven

  19. Comparison of aerobic and anaerobic biotreatment of municipal solid waste.

    PubMed

    Borglin, Sharon E; Hazen, Terry C; Oldenburg, Curtis M; Zawislanski, Peter T

    2004-07-01

    To increase the operating lifetime of landfills and to lower leachate treatment costs, an increasing number of municipal solid waste (MSW) landfills are being managed as either aerobic or anaerobic bioreactors. Landfill gas composition, respiration rates, and subsidence were measured for 400 days in 200-L tanks filled with fresh waste materials to compare the relative effectiveness of the two treatments. Tanks were prepared to provide the following conditions: (1) air injection and leachate recirculation (aerobic), (2) leachate recirculation (anaerobic), and (3) no treatment (anaerobic). Respiration tests on the aerobic wet tank showed a steady decrease in oxygen consumption rates from 1.3 mol/day at 20 days to 0.1 mol/day at 400 days. Aerobic wet tanks produced, on average, 6 mol of carbon dioxide (CO2)/kg of MSW as compared with anaerobic wet tanks, which produced 2.2 mol methane/kg of MSW and 2.0 mol CO2/kg methane. Over the test period, the aerobic tanks settled on average 35%, anaerobic tanks settled 21.7%, and the no-treatment tank settled 7.5%, equivalent to overall mass loss in the corresponding reactors. Aerobic tanks reduced stabilization time and produced negligible odor compared with anaerobic tanks, possibly because of the 2 orders of magnitude lower leachate ammonia levels in the aerobic tank. Both treatment regimes provide the opportunity for disposal and remediation of liquid waste.

  20. Further results on iterative learning control with convergence conditions for linear time-variant discrete systems

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Dong; Ho, John K. L.

    2011-06-01

    This article is concerned with some further results on iterative learning control (ILC) algorithms with convergence conditions for linear time-variant discrete systems. By converting two-Dimensional (2-D) ILC process of the linear time-variant discrete systems into 1-D linear time-invariant discrete systems, this article presents convergent ILC algorithms with necessary and sufficient conditions for two classes of linear time-variant discrete systems. Main results in (Li, X.-D., Ho, J.K.L., and Chow, T.W.S. (2005), 'Iterative Learning Control for Linear Time-variant Discrete Systems Based on 2-D System Theory', IEE Proceedings, Control Theory and Applications, 152, 13-18 and Huang, S.N., Tan, K.K., and Lee, T.H. (2002), 'Necessary and Sufficient Condition for Convergence of Iterative Learning Algorithm', Automatica 38, 1257-1260) are extended and generalised.

  1. An assessment of consistence of exhaust gas emission test results obtained under controlled NEDC conditions

    NASA Astrophysics Data System (ADS)

    Balawender, K.; Jaworski, A.; Kuszewski, H.; Lejda, K.; Ustrzycki, A.

    2016-09-01

    Measurements concerning emissions of pollutants contained in automobile combustion engine exhaust gases is of primary importance in view of their harmful impact on the natural environment. This paper presents results of tests aimed at determining exhaust gas pollutant emissions from a passenger car engine obtained under repeatable conditions on a chassis dynamometer. The test set-up was installed in a controlled climate chamber allowing to maintain the temperature conditions within the range from -20°C to +30°C. The analysis covered emissions of such components as CO, CO2, NOx, CH4, THC, and NMHC. The purpose of the study was to assess repeatability of results obtained in a number of tests performed as per NEDC test plan. The study is an introductory stage of a wider research project concerning the effect of climate conditions and fuel type on emission of pollutants contained in exhaust gases generated by automotive vehicles.

  2. Aerobic Fitness and School Children.

    ERIC Educational Resources Information Center

    Hinkle, J. Scott

    1997-01-01

    Provides school counselors with information on aerobic exercise (specifically running) and the psychological, behavioral, and physical benefits children obtained by participating in fitness programs. Recommends collaboration between school counselors and physical education teachers and gives a preliminary discussion of aerobic running and its…

  3. Aerobic Fitness and School Children.

    ERIC Educational Resources Information Center

    Hinkle, J. Scott

    1992-01-01

    Provides school counselors with information regarding aerobic exercise (specifically running), and the psychological, behavioral, and physical benefits children obtain by participating in fitness programs. Presents methods of collaboration between school counselors and physical education teachers. Offers preliminary discussion of aerobic running…

  4. Exercise, Animal Aerobics, and Interpretation?

    ERIC Educational Resources Information Center

    Oliver, Valerie

    1996-01-01

    Describes an aerobic activity set to music for children that mimics animal movements. Example exercises include walking like a penguin or jumping like a cricket. Stresses basic aerobic principles and designing the program at the level of children's motor skills. Benefits include reaching people who normally don't visit nature centers, and bridging…

  5. Inactivation of Mg chelatase during transition from anaerobic to aerobic growth in Rhodobacter capsulatus.

    PubMed

    Willows, Robert D; Lake, Vanessa; Roberts, Thomas Hugh; Beale, Samuel I

    2003-06-01

    The facultative photosynthetic bacterium Rhodobacter capsulatus can adapt from an anaerobic photosynthetic mode of growth to aerobic heterotrophic metabolism. As this adaptation occurs, the cells must rapidly halt bacteriochlorophyll synthesis to prevent phototoxic tetrapyrroles from accumulating, while still allowing heme synthesis to continue. A likely control point is Mg chelatase, the enzyme that diverts protoporphyrin IX from heme biosynthesis toward the bacteriochlorophyll biosynthetic pathway by inserting Mg(2+) to form Mg-protoporphyrin IX. Mg chelatase is composed of three subunits that are encoded by the bchI, bchD, and bchH genes in R. capsulatus. We report that BchH is the rate-limiting component of Mg chelatase activity in cell extracts. BchH binds protoporphyrin IX, and BchH that has been expressed and purified from Escherichia coli is red in color due to the bound protoporphyrin IX. Recombinant BchH is rapidly inactivated by light in the presence of O(2), and the inactivation results in the formation of a covalent adduct between the protein and the bound protoporphyrin IX. When photosynthetically growing R. capsulatus cells are transferred to aerobic conditions, Mg chelatase is rapidly inactivated, and BchH is the component that is most rapidly inactivated in vivo when cells are exposed to aerobic conditions. The light- and O(2)-stimulated inactivation of BchH could account for the rapid inactivation of Mg chelatase in vivo and provide a mechanism for inhibiting the synthesis of bacteriochlorophyll during adaptation of photosynthetically grown cells to aerobic conditions while still allowing heme synthesis to occur for aerobic respiration.

  6. Results of the Housing Building Condition Evaluation Survey at the University of Georgia.

    ERIC Educational Resources Information Center

    Casey, John M.

    A complete campus building condition evaluation survey was conducted at the University of Georgia in 1989 and results for the housing department were analyzed. The survey design was based on a model developed by Harlan Bareither at the University of Illinois that separates building deficiencies into seven general headings. Data were collected at…

  7. 38 CFR 21.9675 - Conditions that result in reduced rates or no payment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2012-07-01 2012-07-01 false Conditions that result in reduced rates or no payment. 21.9675 Section 21.9675 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill...

  8. 38 CFR 21.9675 - Conditions that result in reduced rates or no payment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2014-07-01 2014-07-01 false Conditions that result in reduced rates or no payment. 21.9675 Section 21.9675 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill...

  9. 38 CFR 21.9675 - Conditions that result in reduced rates or no payment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Conditions that result in reduced rates or no payment. 21.9675 Section 21.9675 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill...

  10. 38 CFR 21.9675 - Conditions that result in reduced rates or no payment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2013-07-01 2013-07-01 false Conditions that result in reduced rates or no payment. 21.9675 Section 21.9675 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill...

  11. INVITED SESSION: THE 2011 NATIONAL WETLAND CONDITION ASSESSMENT: TECHNICAL UNDERPINNINGS AND RESULTS

    EPA Science Inventory

    The first-ever National Wetland Condition Assessment (NWCA) was conducted in 2011 by the US Environmental Protection Agency (USEPA) and its federal and state partners, using a survey design allowing extrapolation of results to national and regional scales. At each of 1138 locatio...

  12. Hippocampal Structural Plasticity Accompanies the Resulting Contextual Fear Memory Following Stress and Fear Conditioning

    ERIC Educational Resources Information Center

    Giachero, Marcelo; Calfa, Gaston D.; Molina, Victor A.

    2013-01-01

    The present research investigated the resulting contextual fear memory and structural plasticity changes in the dorsal hippocampus (DH) following stress and fear conditioning. This combination enhanced fear retention and increased the number of total and mature dendritic spines in DH. Intra-basolateral amygdala (BLA) infusion of midazolam prior to…

  13. Acute exercise and aerobic fitness influence selective attention during visual search.

    PubMed

    Bullock, Tom; Giesbrecht, Barry

    2014-01-01

    Successful goal directed behavior relies on a human attention system that is flexible and able to adapt to different conditions of physiological stress. However, the effects of physical activity on multiple aspects of selective attention and whether these effects are mediated by aerobic capacity, remains unclear. The aim of the present study was to investigate the effects of a prolonged bout of physical activity on visual search performance and perceptual distraction. Two groups of participants completed a hybrid visual search flanker/response competition task in an initial baseline session and then at 17-min intervals over a 2 h 16 min test period. Participants assigned to the exercise group engaged in steady-state aerobic exercise between completing blocks of the visual task, whereas participants assigned to the control group rested in between blocks. The key result was a correlation between individual differences in aerobic capacity and visual search performance, such that those individuals that were more fit performed the search task more quickly. Critically, this relationship only emerged in the exercise group after the physical activity had begun. The relationship was not present in either group at baseline and never emerged in the control group during the test period, suggesting that under these task demands, aerobic capacity may be an important determinant of visual search performance under physical stress. The results enhance current understanding about the relationship between exercise and cognition, and also inform current models of selective attention.

  14. Biodegradation and detoxification of textile azo dyes by bacterial consortium under sequential microaerophilic/aerobic processes

    PubMed Central

    Lade, Harshad; Kadam, Avinash; Paul, Diby; Govindwar, Sanjay

    2015-01-01

    Release of textile azo dyes to the environment is an issue of health concern while the use of microorganisms has proved to be the best option for remediation. Thus, in the present study, a bacterial consortium consisting of Providencia rettgeri strain HSL1 and Pseudomonas sp. SUK1 has been investigated for degradation and detoxification of structurally different azo dyes. The consortium showed 98-99 % decolorization of all the selected azo dyes viz. Reactive Black 5 (RB 5), Reactive Orange 16 (RO 16), Disperse Red 78 (DR 78) and Direct Red 81 (DR 81) within 12 to 30 h at 100 mg L-1 concentration at 30 ± 0.2 °C under microaerophilic, sequential aerobic/microaerophilic and microaerophilic/aerobic processes. However, decolorization under microaerophilic conditions viz. RB 5 (0.26 mM), RO 16 (0.18 mM), DR 78 (0.20 mM) and DR 81 (0.23 mM) and sequential aerobic/microaerophilic processes viz. RB 5 (0.08 mM), RO 16 (0.06 mM), DR 78 (0.07 mM) and DR 81 (0.09 mM) resulted into the formation of aromatic amines. In distinction, sequential microaerophilic/ aerobic process doesn’t show the formation of amines. Additionally, 62-72 % reduction in total organic carbon content was observed in all the dyes decolorized broths under sequential microaerophilic/aerobic processes suggesting the efficacy of method in mineralization of dyes. Notable induction within the levels of azoreductase and NADH-DCIP reductase (97 and 229 % for RB 5, 55 and 160 % for RO 16, 63 and 196 % for DR 78, 108 and 258 % for DR 81) observed under sequential microaerophilic/aerobic processes suggested their critical involvements in the initial breakdown of azo bonds, whereas, a slight increase in the levels of laccase and veratryl alcohol oxidase confirmed subsequent oxidation of formed amines. Also, the acute toxicity assay with Daphnia magna revealed the nontoxic nature of the dye-degraded metabolites under sequential microaerophilic/aerobic processes. As biodegradation under sequential microaerophilic/aerobic

  15. Biodegradation and detoxification of textile azo dyes by bacterial consortium under sequential microaerophilic/aerobic processes.

    PubMed

    Lade, Harshad; Kadam, Avinash; Paul, Diby; Govindwar, Sanjay

    2015-01-01

    Release of textile azo dyes to the environment is an issue of health concern while the use of microorganisms has proved to be the best option for remediation. Thus, in the present study, a bacterial consortium consisting of Providencia rettgeri strain HSL1 and Pseudomonas sp. SUK1 has been investigated for degradation and detoxification of structurally different azo dyes. The consortium showed 98-99 % decolorization of all the selected azo dyes viz. Reactive Black 5 (RB 5), Reactive Orange 16 (RO 16), Disperse Red 78 (DR 78) and Direct Red 81 (DR 81) within 12 to 30 h at 100 mg L(-1) concentration at 30 ± 0.2 °C under microaerophilic, sequential aerobic/microaerophilic and microaerophilic/aerobic processes. However, decolorization under microaerophilic conditions viz. RB 5 (0.26 mM), RO 16 (0.18 mM), DR 78 (0.20 mM) and DR 81 (0.23 mM) and sequential aerobic/microaerophilic processes viz. RB 5 (0.08 mM), RO 16 (0.06 mM), DR 78 (0.07 mM) and DR 81 (0.09 mM) resulted into the formation of aromatic amines. In distinction, sequential microaerophilic/ aerobic process doesn't show the formation of amines. Additionally, 62-72 % reduction in total organic carbon content was observed in all the dyes decolorized broths under sequential microaerophilic/aerobic processes suggesting the efficacy of method in mineralization of dyes. Notable induction within the levels of azoreductase and NADH-DCIP reductase (97 and 229 % for RB 5, 55 and 160 % for RO 16, 63 and 196 % for DR 78, 108 and 258 % for DR 81) observed under sequential microaerophilic/aerobic processes suggested their critical involvements in the initial breakdown of azo bonds, whereas, a slight increase in the levels of laccase and veratryl alcohol oxidase confirmed subsequent oxidation of formed amines. Also, the acute toxicity assay with Daphnia magna revealed the nontoxic nature of the dye-degraded metabolites under sequential microaerophilic/aerobic processes. As biodegradation under sequential microaerophilic/aerobic

  16. Preliminary mixed-layer model results for FIRE marine stratocumulus IFO conditions

    NASA Technical Reports Server (NTRS)

    Barlow, R.; Nicholls, S.

    1990-01-01

    Some preliminary results from the Turton and Nicholls mixed layer model using typical FIRE boundary conditions are presented. The model includes entrainment and drizzle parametrizations as well as interactive long and shortwave radiation schemes. A constraint on the integrated turbulent kinetic energy balance ensures that the model remains energetically consistent at all times. The preliminary runs were used to identify the potentially important terms in the heat and moisture budgets of the cloud layer, and to assess the anticipated diurnal variability. These are compared with typical observations from the C130. Sensitivity studies also revealed the remarkable stability of these cloud sheets: a number of negative feedback mechanisms appear to operate to maintain the cloud over an extended time period. These are also discussed. The degree to which such a modelling approach can be used to explain observed features, the specification of boundary conditions and problems of interpretation in non-horizontally uniform conditions is also raised.

  17. Results on the survival of cryptobiotic cyanobacteria samples after exposure to Mars-like environmental conditions

    NASA Astrophysics Data System (ADS)

    de Vera, J.-P.; Dulai, S.; Kereszturi, A.; Koncz, L.; Lorek, A.; Mohlmann, D.; Marschall, M.; Pocs, T.

    2014-01-01

    Tests on cyanobacteria communities embedded in cryptobiotic crusts collected in hot and cold deserts on Earth were performed under Mars-like conditions. The simulations were realized as a survey, to find the best samples for future research. During the tests organisms have to resist Mars-like conditions such as atmospheric composition, pressure, variable humidity (saturated and dry conditions) and partly strong UV irradiation. Organisms were tested within their original habitat inside the crust. Nearly half of the cryptobiotic samples from various sites showed survival of a substantial part of their coexisting organisms. The survival in general depended more on the nature of the original habitat and type of the sample than on the different conditions they were exposed to. The best survival was observed in samples from United Arab Emirates (Jebel Ali, 25 km SW of Dubai town) and from Western Australia (near the South edge of Lake Barley), by taxa: Tolypothrix byssoidea, Gloeocapsopsis pleurocapsoides, Nostoc microscopicum, Leptolyngbya or Symploca sp. At both places in salty desert areas members of the Chenopodiaceae family dominated among the higher plants and in the cryptobiotic crust cyanobacterial taxa Tolypothrix was dominant. These organisms were all living in salty locations with dry conditions most of the year. Among them Tolypothrix, Gloeocapsopsis and Symploca sp. were tested in Mars simulation chambers for the first time. The results suggest that extremophiles should be tested with taken into account the context of their original microenvironment, and also the importance to analyse communities of microbes beside single organisms.

  18. [Aerobic microbial degradation of polybrominated diphenyl ethers].

    PubMed

    Ding, Juan; Zhou, Juan; Jiang, Wei-Ying; Gao, Shi-Xiang

    2008-11-01

    The biodegradation of 4, 4'-dibromodipheny ether (BDE15) and decabromodiphenyl ether (BDE209) by white rot fungi under aerobic conditions was studied. Effects of non-ionic surfactant Tween 80 and beta-cyclodextrin as solubilizers on the apparent solubilities and biodegradation rates of BDE15 and BDE209 were also evaluated. The results showed that both BDE15 and BDE209 were efficiently degraded by white rot fungi. The degradation rates were 43.0% and 62.5% for BDE209 and BDE15, respectively, after 10 d incubation. The degradation of BDE209 was greatly enhanced by addition of Tween 80 (< or = 700 mg/L) and beta-cyclodextrin, which may own to their solubilization effects on BDE209. However, Tween 80 at a high concentration (900 mg/L) would restrain the fungal growth, thereby decrease the degradation of BDE209. Addition of Tween 80 and beta-cyclodextrin exhibited some negative effects on the degradation of BDE15, which may due to decreased concentration of free BDE15 in water solution resulted from inclusion function of Tween 80 micelles and beta-cyclodextrin cavity, although the apparent solubility of BDE15 was drastically increased by both of them. PMID:19186824

  19. Growth and energy metabolism in aerobic fed-batch cultures of Saccharomyces cerevisiae: Simulation and model verification

    SciTech Connect

    Pham, H.T.B.; Larsson, G.; Enfors, S.O.

    1998-11-20

    Some yeast species are classified as being glucose sensitive, which means that they may produce ethanol also under aerobic conditions when the sugar concentration is high. A kinetic model of overflow metabolism in Saccharomyces cerevisiae was used for simulation of aerobic fed-batch cultivations. An inhibitory effect of ethanol on the maximum respiration of the yeast was observed in the experiments and included in the model. The model predicts respiration, biomass, and ethanol formation and the subsequent ethanol consumption, and was experimentally validated in fed-batch cultivations. Oscillating sugar feed with resulting oscillating carbon dioxide production did not influence the maximum respiration rate, which indicates that the pyruvate dehydrogenase complex is not involved as a bottleneck causing aerobic ethanol formation.

  20. Progressive hypoxia decouples activity and aerobic performance of skate embryos

    PubMed Central

    Di Santo, Valentina; Tran, Anna H.; Svendsen, Jon C.

    2016-01-01

    Although fish population size is strongly affected by survival during embryonic stages, our understanding of physiological responses to environmental stressors is based primarily on studies of post-hatch fishes. Embryonic responses to acute exposure to changes in abiotic conditions, including increase in hypoxia, could be particularly important in species exhibiting long developmental time, as embryos are unable to select a different environment behaviourally. Given that oxygen is key to metabolic processes in fishes and aquatic hypoxia is becoming more severe and frequent worldwide, organisms are expected to reduce their aerobic performance. Here, we examined the metabolic and behavioural responses of embryos of a benthic elasmobranch fish, the little skate (Leucoraja erinacea), to acute progressive hypoxia, by measuring oxygen consumption and movement (tail-beat) rates inside the egg case. Oxygen consumption rates were not significantly affected by ambient oxygen levels until reaching 45% air saturation (critical oxygen saturation, Scrit). Below Scrit, oxygen consumption rates declined rapidly, revealing an oxygen conformity response. Surprisingly, we observed a decoupling of aerobic performance and activity, as tail-beat rates increased, rather than matching the declining metabolic rates, at air saturation levels of 55% and below. These results suggest a significantly divergent response at the physiological and behavioural levels. While skate embryos depressed their metabolic rates in response to progressive hypoxia, they increased water circulation inside the egg case, presumably to restore normoxic conditions, until activity ceased abruptly around 9.8% air saturation. PMID:27293746

  1. Evolution of Molybdenum Nitrogenase during the Transition from Anaerobic to Aerobic Metabolism

    PubMed Central

    Boyd, Eric S.; Costas, Amaya M. Garcia; Hamilton, Trinity L.; Mus, Florence

    2015-01-01

    ABSTRACT Molybdenum nitrogenase (Nif), which catalyzes the reduction of dinitrogen to ammonium, has modulated the availability of fixed nitrogen in the biosphere since early in Earth's history. Phylogenetic evidence indicates that oxygen (O2)-sensitive Nif emerged in an anaerobic archaeon and later diversified into an aerobic bacterium. Aerobic bacteria that fix N2 have adapted a number of strategies to protect Nif from inactivation by O2, including spatial and temporal segregation of Nif from O2 and respiratory consumption of O2. Here we report the complement of Nif-encoding genes in 189 diazotrophic genomes. We show that the evolution of Nif during the transition from anaerobic to aerobic metabolism was accompanied by both gene recruitment and loss, resulting in a substantial increase in the number of nif genes. While the observed increase in the number of nif genes and their phylogenetic distribution are strongly correlated with adaptation to utilize O2 in metabolism, the increase is not correlated with any of the known O2 protection mechanisms. Rather, gene recruitment appears to have been in response to selective pressure to optimize Nif synthesis to meet fixed N demands associated with aerobic productivity and to more efficiently regulate Nif under oxic conditions that favor protein turnover. Consistent with this hypothesis, the transition of Nif from anoxic to oxic environments is associated with a shift from posttranslational regulation in anaerobes to transcriptional regulation in obligate aerobes and facultative anaerobes. Given that fixed nitrogen typically limits ecosystem productivity, our observations further underscore the dynamic interplay between the evolution of Earth's oxygen, nitrogen, and carbon biogeochemical cycles. IMPORTANCE Molybdenum nitrogenase (Nif), which catalyzes the reduction of dinitrogen to ammonium, has modulated the availability of fixed nitrogen in the biosphere since early in Earth's history. Nif emerged in an anaerobe and

  2. Effect of applying lactic acid bacteria and propionic acid on fermentation quality and aerobic stability of oats-common vetch mixed silage on the Tibetan plateau.

    PubMed

    Zhang, Jie; Guo, Gang; Chen, Lei; Li, Junfeng; Yuan, Xianjun; Yu, Chengqun; Shimojo, Masataka; Shao, Tao

    2015-06-01

    The objective of this study was to evaluate effects of lactic acid bacteria and propionic acid on the fermentation quality and aerobic stability of oats-common vetch mixed silage by using a small-scale fermentation system on the Tibetan plateau. (i) An inoculant (Lactobacillus plantarum) (L) or (ii) propionic acid (P) or (iii) inoculant + propionic acid (PL) were used as additives. After fermenting for 60 days, silos were opened and the aerobic stability was tested for the following 15 days. The results showed that all silages were well preserved with low pH and NH3 -N, and high lactic acid content and V-scores. L and PL silages showed higher (P < 0.05) lactic acid and crude protein content than the control silage. P silage inhibited lactic acid production. Under aerobic conditions, L silage had similar yeast counts as the control silage (> 10(5) cfu/g fresh matter (FM)); however, it numerically reduced aerobic stability for 6 h. P and PL silages showed fewer yeasts (< 10(5) cfu/g FM) (P < 0.05) and markedly improved the aerobic stability (> 360 h). The result suggested that PL is the best additive as it could not only improved fermentation quality, but also aerobic stability of oats-common vetch mixed silage on the Tibetan plateau.

  3. Effects of Solar Wind Conditions on the Plasma Wake Within a Polar Crater: Preliminary Results

    NASA Technical Reports Server (NTRS)

    Zimmerman, M. I.; Farrell, W. M.; Stubbs, T. J.

    2011-01-01

    As the solar wind sweeps horizontally past a shadowed lunar crater it simultaneously diffuses toward the surface through an ambipolar process, forming a plasma wake (e.g., Figure 1). Importantly, the resulting electric field structure diverts solar wind protons toward the cold crater floor where they may represent a source of surficial hydrogen. We present a handful of two-dimensional kinetic simulations exploring the range of wake structures and surface particle fluxes possible under various background plasma conditions.

  4. Reduced swim performance and aerobic capacity in adult zebrafish exposed to waterborne selenite.

    PubMed

    Massé, Anita J; Thomas, Jith K; Janz, David M

    2013-04-01

    Although dietary exposure of adult fish to organoselenium in contaminated aquatic ecosystems has been reported to bioaccumulate and cause larval deformities in offspring, subtle physiological effects produced through low level waterborne selenium exposure in fish such as swim performance and aerobic capacity have not been investigated. To evaluate potential effects of selenite on these responses, adult zebrafish (Danio rerio) were exposed to nominal aqueous concentrations of 0, 10 or 100 μg/L sodium selenite for 14 days. Upon completion of the exposure period, fish underwent two successive swim trials in a swim tunnel respirometer to determine critical swim speed (Ucrit), oxygen consumption (MO2), standard and active metabolic rates, aerobic scope (AS) and cost of transport (COT) followed by analysis of whole body triglyceride and glycogen concentrations. Selenite exposure had a significant negative effect on Ucrit and aerobic capacity. Active metabolic rates and AS significantly decreased in both selenite exposure groups after the second swim trial. No significant effect was observed in MO2, standard metabolic rate, COT, triglyceride and glycogen levels, or condition factor between groups. These results suggest that aqueous selenite exposure at environmentally relevant concentrations produces adverse effects on aerobic capacity that can diminish endurance and maximum swim speeds, which may lower fish survivability.

  5. Positional Role Differences in the Aerobic and Anaerobic Power of Elite Basketball Players.

    PubMed

    Pojskić, Haris; Šeparović, Vlatko; Užičanin, Edin; Muratović, Melika; Mačković, Samir

    2015-12-22

    The aim of the present study was to compare the aerobic and anaerobic power and capacity of elite male basketball players who played multiple positions. Fifty-five healthy players were divided into the following three different subsamples according to their positional role: guards (n = 22), forwards (n = 19) and centers (n = 14). The following three tests were applied to estimate their aerobic and anaerobic power and capacities: the countermovement jump (CMJ), a multistage shuttle run test and the Running-based Anaerobic Sprint Test (RAST). The obtained data were used to calculate the players' aerobic and anaerobic power and capacities. To determine the possible differences between the subjects considering their different positions on the court, one-way analysis of variance (ANOVA) with the Bonferroni post-hoc test for multiple comparisons was used. The results showed that there was a significant difference between the different groups of players in eleven out of sixteen measured variables. Guards and forwards exhibited greater aerobic and relative values of anaerobic power, allowing shorter recovery times and the ability to repeat high intensity, basketball-specific activities. Centers presented greater values of absolute anaerobic power and capacities, permitting greater force production during discrete tasks. Coaches can use these data to create more individualized strength and conditioning programs for different positional roles. PMID:26839622

  6. Elevated CO2 enhances aerobic scope of a coral reef fish.

    PubMed

    Rummer, Jodie L; Stecyk, Jonathan A W; Couturier, Christine S; Watson, Sue-Ann; Nilsson, Göran E; Munday, Philip L

    2013-01-01

    The uptake of anthropogenic CO2 by the ocean has been suggested to impact marine ecosystems by decreasing the respiratory capacity of fish and other water breathers. We investigated the aerobic metabolic scope of the spiny damselfish, Acanthochromis polyacanthus, from the Great Barrier Reef, Australia when exposed for 17 days to CO2 conditions predicted for the end of the century (946 μatm CO2). Surprisingly, resting O2 consumption rates were significantly lower and maximal O2 consumption rates significantly higher in high-CO2-exposed fish compared with control fish (451 μatm CO2). Consequently, high-CO2-exposed fish exhibited an unexpected increase in absolute (38%) and factorial aerobic scopes (47%). Haematological and muscle water changes associated with exercise were not affected by CO2 treatment. Thus, contrary to predictions, our results suggest that elevated CO2 may enhance aerobic scope of some fish species. Long-term experiments are now required to assess the response to elevated CO2 further, because developmental and transgenerational effects can be dramatic in fish. Ultimately, understanding the variability among species regarding the effects of CO2 on aerobic scope will be critical in predicting the impacts of ocean acidification on marine communities and ecosystems.

  7. Positional Role Differences in the Aerobic and Anaerobic Power of Elite Basketball Players

    PubMed Central

    Pojskić, Haris; Šeparović, Vlatko; Užičanin, Edin; Muratović, Melika; Mačković, Samir

    2015-01-01

    The aim of the present study was to compare the aerobic and anaerobic power and capacity of elite male basketball players who played multiple positions. Fifty-five healthy players were divided into the following three different subsamples according to their positional role: guards (n = 22), forwards (n = 19) and centers (n = 14). The following three tests were applied to estimate their aerobic and anaerobic power and capacities: the countermovement jump (CMJ), a multistage shuttle run test and the Running-based Anaerobic Sprint Test (RAST). The obtained data were used to calculate the players’ aerobic and anaerobic power and capacities. To determine the possible differences between the subjects considering their different positions on the court, one-way analysis of variance (ANOVA) with the Bonferroni post-hoc test for multiple comparisons was used. The results showed that there was a significant difference between the different groups of players in eleven out of sixteen measured variables. Guards and forwards exhibited greater aerobic and relative values of anaerobic power, allowing shorter recovery times and the ability to repeat high intensity, basketball-specific activities. Centers presented greater values of absolute anaerobic power and capacities, permitting greater force production during discrete tasks. Coaches can use these data to create more individualized strength and conditioning programs for different positional roles. PMID:26839622

  8. Positional Role Differences in the Aerobic and Anaerobic Power of Elite Basketball Players.

    PubMed

    Pojskić, Haris; Šeparović, Vlatko; Užičanin, Edin; Muratović, Melika; Mačković, Samir

    2015-12-22

    The aim of the present study was to compare the aerobic and anaerobic power and capacity of elite male basketball players who played multiple positions. Fifty-five healthy players were divided into the following three different subsamples according to their positional role: guards (n = 22), forwards (n = 19) and centers (n = 14). The following three tests were applied to estimate their aerobic and anaerobic power and capacities: the countermovement jump (CMJ), a multistage shuttle run test and the Running-based Anaerobic Sprint Test (RAST). The obtained data were used to calculate the players' aerobic and anaerobic power and capacities. To determine the possible differences between the subjects considering their different positions on the court, one-way analysis of variance (ANOVA) with the Bonferroni post-hoc test for multiple comparisons was used. The results showed that there was a significant difference between the different groups of players in eleven out of sixteen measured variables. Guards and forwards exhibited greater aerobic and relative values of anaerobic power, allowing shorter recovery times and the ability to repeat high intensity, basketball-specific activities. Centers presented greater values of absolute anaerobic power and capacities, permitting greater force production during discrete tasks. Coaches can use these data to create more individualized strength and conditioning programs for different positional roles.

  9. The ontogeny of aerobic and diving capacity in the skeletal muscles of Weddell seals.

    PubMed

    Kanatous, S B; Hawke, T J; Trumble, S J; Pearson, L E; Watson, R R; Garry, D J; Williams, T M; Davis, R W

    2008-08-01

    Our objective was to determine the ontogenetic changes in the skeletal muscles of Weddell seals that transform a non-diving pup into an elite diving adult. Muscle biopsies were collected from pups, juveniles and adults and analyzed for changes in fiber type, mitochondrial density, myoglobin concentrations and aerobic, lipolytic and anaerobic enzyme activities. The fiber type results demonstrated a decrease in slow-twitch oxidative (Type I) fibers and a significant increase in fast-twitch oxidative (Type IIA) fibers as the animals mature. In addition, the volume density of mitochondria and the activity of lipolytic enzymes significantly decreased as the seals matured. To our knowledge, this is the first quantitative account describing a decrease in aerobic fibers shifting towards an increase in fast-twitch oxidative fibers with a significant decrease in mitochondrial density as animals mature. These differences in the muscle physiology of Weddell seals are potentially due to their three very distinct stages of life history: non-diving pup, novice diving juvenile, and elite deep diving adult. During the first few weeks of life, pups are a non-diving terrestrial mammal that must rely on lanugo (natal fur) for thermoregulation in the harsh conditions of Antarctica. The increased aerobic capacity of pups, associated with increased mitochondrial volumes, acts to provide additional thermogenesis. As these future elite divers mature, their skeletal muscles transform to a more sedentary state in order to maintain the low levels of aerobic metabolism associated with long-duration diving.

  10. Aerobic and anaerobic cellulase production by Cellulomonas uda.

    PubMed

    Poulsen, Henrik Vestergaard; Willink, Fillip Wolfgang; Ingvorsen, Kjeld

    2016-10-01

    Cellulomonas uda (DSM 20108/ATCC 21399) is one of the few described cellulolytic facultative anaerobes. Based on these characteristics, we initiated a physiological study of C. uda with the aim to exploit it for cellulase production in simple bioreactors with no or sporadic aeration. Growth, cellulase activity and fermentation product formation were evaluated in different media under both aerobic and anaerobic conditions and in experiments where C. uda was exposed to alternating aerobic/anaerobic growth conditions. Here we show that C. uda behaves as a true facultative anaerobe when cultivated on soluble substrates such as glucose and cellobiose, but for reasons unknown cellulase activity is only induced under aerobic conditions on insoluble cellulosic substrates and not under anaerobic conditions. These findings enhance knowledge on the limited number of described facultative cellulolytic anaerobes, and in addition it greatly limits the utility of C. uda as an 'easy to handle' cellulase producer with low aeration demands.

  11. Aerobic and anaerobic cellulase production by Cellulomonas uda.

    PubMed

    Poulsen, Henrik Vestergaard; Willink, Fillip Wolfgang; Ingvorsen, Kjeld

    2016-10-01

    Cellulomonas uda (DSM 20108/ATCC 21399) is one of the few described cellulolytic facultative anaerobes. Based on these characteristics, we initiated a physiological study of C. uda with the aim to exploit it for cellulase production in simple bioreactors with no or sporadic aeration. Growth, cellulase activity and fermentation product formation were evaluated in different media under both aerobic and anaerobic conditions and in experiments where C. uda was exposed to alternating aerobic/anaerobic growth conditions. Here we show that C. uda behaves as a true facultative anaerobe when cultivated on soluble substrates such as glucose and cellobiose, but for reasons unknown cellulase activity is only induced under aerobic conditions on insoluble cellulosic substrates and not under anaerobic conditions. These findings enhance knowledge on the limited number of described facultative cellulolytic anaerobes, and in addition it greatly limits the utility of C. uda as an 'easy to handle' cellulase producer with low aeration demands. PMID:27154570

  12. Theoretical results on fractionally integrated exponential generalized autoregressive conditional heteroskedastic processes

    NASA Astrophysics Data System (ADS)

    Lopes, Sílvia R. C.; Prass, Taiane S.

    2014-05-01

    Here we present a theoretical study on the main properties of Fractionally Integrated Exponential Generalized Autoregressive Conditional Heteroskedastic (FIEGARCH) processes. We analyze the conditions for the existence, the invertibility, the stationarity and the ergodicity of these processes. We prove that, if { is a FIEGARCH(p,d,q) process then, under mild conditions, { is an ARFIMA(q,d,0) with correlated innovations, that is, an autoregressive fractionally integrated moving average process. The convergence order for the polynomial coefficients that describes the volatility is presented and results related to the spectral representation and to the covariance structure of both processes { and { are discussed. Expressions for the kurtosis and the asymmetry measures for any stationary FIEGARCH(p,d,q) process are also derived. The h-step ahead forecast for the processes {, { and { are given with their respective mean square error of forecast. The work also presents a Monte Carlo simulation study showing how to generate, estimate and forecast based on six different FIEGARCH models. The forecasting performance of six models belonging to the class of autoregressive conditional heteroskedastic models (namely, ARCH-type models) and radial basis models is compared through an empirical application to Brazilian stock market exchange index.

  13. IMAGE Project: Results of Laboratory Tests on Tracers for Supercritical Conditions.

    NASA Astrophysics Data System (ADS)

    Brandvoll, Øyvind; Opsahl Viig, Sissel; Nardini, Isabella; Muller, Jiri

    2016-04-01

    The use of tracers is a well-established technique for monitoring dynamic behaviour of water and gas through a reservoir. In geothermal reservoirs special challenges are encountered due to high temperatures and pressures. In this work, tracer candidates for monitoring water at supercritical conditions (temperature > 374°C, pressure ca 218 bar), are tested in laboratory experiments. Testing of tracers at supercritical water conditions requires experimental set-ups which tolerate harsh conditions with respect to high temperature and pressure. In addition stringent HES (health, environment and safety) factors have to be taken into consideration when designing and performing the experiments. The setup constructed in this project consists of a pressure vessel, high pressure pump, instrumentation for pressure and temperature control and instrumentation required for accurate sampling of tracers. In order to achieve accurate results, a special focus has been paid to the development of the tracer sampling technique. Perfluorinated cyclic hydrocarbons (PFCs) have been selected as tracer candidates. This group of compounds is today commonly used as gas tracers in oil reservoirs. According to the literature they are stable at temperatures up to 400°C. To start with, five PFCs have been tested for thermal stability in static experiments at 375°C and 108 bar in the experimental setup described above. The tracer candidates will be further tested for several months at the relevant conditions. Preliminary results indicate that some of the PFC compounds show stability after three months. However, in order to arrive at conclusive results, the experiments have to be repeated over a longer period and paying special attention to more accurate sampling procedures.

  14. Heritability of aerobic power of individuals in northeast Brazil.

    PubMed

    Alonso, L; Souza, Ec; Oliveira, Mv; do Nascimento, Lfe; Dantas, Pms

    2014-12-01

    The objective of this study was to evaluate the genetic and environmental contribution to variation in aerobic power in monozygotic (MZ) and dizygotic (DZ) twins. The sample consisted of 20 MZ individuals (12 females and 8 males) and 16 DZ individuals (12 females and 4 males), aged from 8 to 26 years, residents in Natal, Rio Grande do Norte. The twins were assessed by a multistage fitness test. The rate of heritability found for aerobic power was 77%. Based on the results, the estimated heritability was largely responsible for the differences in aerobic power. This implies that such measures are under strong genetic influence.

  15. Effect of Aerobic Priming on the Response of Echinochloa crus-pavonis to Anaerobic Stress (Protein Synthesis and Phosphorylation).

    PubMed Central

    Zhang, F.; Lin, J. J.; Fox, T. C.; Mujer, C. V.; Rumpho, M. E.; Kennedy, R. A.

    1994-01-01

    Echinochloa species differ in their ability to germinate and grow in the absence of oxygen. Seeds of Echinochloa crus-pavonis (H.B.K.) Schult do not germinate under anoxia but remain viable for extended periods (at least 30 d) when incubated in an anaerobic environment. E. crus-pavonis can be induced to germinate and grow in an anaerobic environment if the seeds are first subjected to a short (1-18 h) exposure to aerobic conditions (aerobic priming). Changes in polypeptide patterns (constitutive and de novo synthesized) and protein phosphorylation induced by aerobic priming were investigated. In the absence of aerobic priming protein degradation was not evident under anaerobic conditions, although synthesis of a 20-kD polypeptide was induced. During aerobic priming, however, synthesis of 37- and 55-kD polypeptides was induced and persisted upon return of the seeds to anoxia. Furthermore, phosphorylation of two 18-kD polypeptides was observed only in those seeds that were labeled with 32PO4 during the aerobic priming period. Subsequent chasing in an anaerobic environment resulted in a decrease in phosphorylation of these polypeptides. Likewise, phosphorylation of the 18-kD polypeptides was not observed if the seeds were labeled in an anaerobic atmosphere. These results suggest that the regulated induction of the 20-, 37-, and 55- kD polypeptides may be important for anaerobic germination and growth of E. crus-pavonis and that the specific phosphorylation of the 18-kD polypeptides may be a factor in regulating this induction. PMID:12232272

  16. Effect of Aerobic Priming on the Response of Echinochloa crus-pavonis to Anaerobic Stress (Protein Synthesis and Phosphorylation).

    PubMed

    Zhang, F.; Lin, J. J.; Fox, T. C.; Mujer, C. V.; Rumpho, M. E.; Kennedy, R. A.

    1994-08-01

    Echinochloa species differ in their ability to germinate and grow in the absence of oxygen. Seeds of Echinochloa crus-pavonis (H.B.K.) Schult do not germinate under anoxia but remain viable for extended periods (at least 30 d) when incubated in an anaerobic environment. E. crus-pavonis can be induced to germinate and grow in an anaerobic environment if the seeds are first subjected to a short (1-18 h) exposure to aerobic conditions (aerobic priming). Changes in polypeptide patterns (constitutive and de novo synthesized) and protein phosphorylation induced by aerobic priming were investigated. In the absence of aerobic priming protein degradation was not evident under anaerobic conditions, although synthesis of a 20-kD polypeptide was induced. During aerobic priming, however, synthesis of 37- and 55-kD polypeptides was induced and persisted upon return of the seeds to anoxia. Furthermore, phosphorylation of two 18-kD polypeptides was observed only in those seeds that were labeled with 32PO4 during the aerobic priming period. Subsequent chasing in an anaerobic environment resulted in a decrease in phosphorylation of these polypeptides. Likewise, phosphorylation of the 18-kD polypeptides was not observed if the seeds were labeled in an anaerobic atmosphere. These results suggest that the regulated induction of the 20-, 37-, and 55- kD polypeptides may be important for anaerobic germination and growth of E. crus-pavonis and that the specific phosphorylation of the 18-kD polypeptides may be a factor in regulating this induction.

  17. Internal recycle to improve denitrification in a step feed anoxic/aerobic activated sludge system.

    PubMed

    Boyle, C A; McKenzie, C J; Morgan, S

    2009-01-01

    During periods of low load (weekends and holidays) the Mangere wastewater treatment plant effluent has breached the summer consent conditions for total nitrogen. The purpose of this research was to determine if an internal recycle would improve nitrogen removal in the anoxic/aerobic activated sludge reactors sufficient to meet the summer resource consent standard. The recycle returned nitrate rich mixed liquor from the downstream aerobic zone back to the initial anoxic zone, thus potentially improving denitrification. A full scale trial showed that installation of the internal recycle on each RC would have satisfied the resource consent for total nitrogen in most cases over the three summer resource consent periods since the upgrade. However, further modifications of the internal recycle would be required to ensure that consent conditions were satisfied at all times and to improve the consistency of the results.

  18. Cardioprotective Properties of Aerobic and Resistance Training Against Myocardial Infarction.

    PubMed

    Barboza, C A; Souza, G I H; Oliveira, J C M F; Silva, L M; Mostarda, C T; Dourado, P M M; Oyama, L M; Lira, F S; Irigoyen, M C; Rodrigues, B

    2016-06-01

    We evaluated the effects of aerobic and resistance exercise training on ventricular morphometry and function, physical capacity, autonomic function, as well as on ventricular inflammatory status in trained rats prior to myocardial infarction. Male Wistar rats were divided into the following groups: sedentary+Sham, sedentary+myocardial infarction, aerobic trained+myocardial infarction, and resistance trained+myocardial infarction. Sham and myocardial infarction were performed after training periods. In the days following the surgeries, evaluations were performed. Aerobic training prevents aerobic (to a greater extent) and resistance capacity impairments, ventricular dysfunction, baroreflex sensitivity and autonomic disorders (vagal tonus decrease and sympathetic tonus increase) triggered by myocardial infarction. Resistance training was able to prevent negative changes to aerobic and resistance capacity (to a greater extent) but not to ventricular dysfunction, and it prevented cardiovascular sympathetic increments. Additionally, both types of training reduced left ventricle inflammatory cytokine concentration. Our results suggest that aerobic and, for the first time, dynamic resistance training were able to reduce sympathetic tonus to the heart and vessels, as well as preventing the increase in pro-inflammatory cytokine concentrations in the left ventricle of trained groups. These data emphasizes the positive effects of aerobic and dynamic resistance training on the prevention of the negative changes triggered by myocardial infarction.

  19. Results and lessons learned from conditioning 1 MW CW 350 MHz coaxial vacuum windows

    SciTech Connect

    Cummings, K.; Cordova, R.; Rees, D.; Roybal, W.; Risbud, S.; Wilcox, D.

    1998-12-31

    The reliability of the radio frequency (RF) windows on the Low Energy Demonstration Accelerator (LEDA) is critical to the success of the Accelerator Production of Tritium Program (APT). On the APT accelerator there will be over 1,000 windows, each passing on the order of 250 kW of CW RF power. This power level is well above power levels historically used in RF windows. Based on the high-power RF test results of the RF window prototypes from vendors, the coaxial windows made by EEV Ltd. of Chelmsford, England, were selected for LEDA. This paper describes the high-power RF testing of the 16 EEV coaxial windows. The RF window diagnostic equipment, data acquisition system and test stand are described. The results of the high power RF testing of the windows are presented. The successes and failures in the conditioning, manufacturing and testing techniques of the windows are presented. The conditioning timeline, power profile and the conditioning waveform are also discussed.

  20. Experimental results from containment piping bellows subjected to severe accident conditions. Volume 1, Results from bellows tested in `like-new` conditions

    SciTech Connect

    Lambert, L.D.; Parks, M.B.

    1994-09-01

    Bellows are an integral part of the containment pressure boundary in nuclear power plants. They are used at piping penetrations to allow relative movement between piping and the containment wall, while minimizing the load imposed on the piping and wall. Piping bellows are primarily used in steel containments; however, they have received limited use in some concrete (reinforced and prestressed) containments. In a severe accident they may be subjected to pressure and temperature conditions that exceed the design values, along with a combination of axial and lateral deflections. A test program to determine the leak-tight capacity of containment penetration bellows is being conducted under the sponsorship of the US Nuclear Regulatory Commission at Sandia National Laboratories. Several different bellows geometries, representative of actual containment bellows, have been subjected to extreme deflections along with pressure and temperature loads. The bellows geometries and loading conditions are described along with the testing apparatus and procedures. A total of thirteen bellows have been tested, all in the `like-new` condition. (Additional tests are planned of bellows that have been subjected to corrosion.) The tests showed that bellows are capable of withstanding relatively large deformations, up to, or near, the point of full compression or elongation, before developing leakage. The test data is presented and discussed.

  1. Exome sequencing results in successful riboflavin treatment of a rapidly progressive neurological condition

    PubMed Central

    Petrovski, Slavé; Shashi, Vandana; Petrou, Steven; Schoch, Kelly; McSweeney, Keisha Melodi; Dhindsa, Ryan S.; Krueger, Brian; Crimian, Rebecca; Case, Laura E.; Khalid, Roha; El-Dairi, Maysantoine A.; Jiang, Yong-Hui; Mikati, Mohamad A.; Goldstein, David B.

    2015-01-01

    Genetically targeted therapies for rare Mendelian conditions are improving patient outcomes. Here, we present the case of a 20-mo-old female suffering from a rapidly progressing neurological disorder. Although diagnosed initially with a possible autoimmune condition, analysis of the child's exome resulted in a diagnosis of Brown–Vialetto–Van Laere syndrome 2 (BVVLS2). This new diagnosis led to a change in the therapy plan from steroids and precautionary chemotherapy to high-dose riboflavin. Improvements were reported quickly, including in motor strength after 1 mo. In this case, the correct diagnosis and appropriate treatment would have been unlikely in the absence of exome sequencing and careful interpretation. This experience adds to a growing list of examples that emphasize the importance of early genome-wide diagnostics. PMID:27148561

  2. Whole lichen thalli survive exposure to space conditions: results of Lithopanspermia experiment with Aspicilia fruticulosa.

    PubMed

    Raggio, J; Pintado, A; Ascaso, C; De La Torre, R; De Los Ríos, A; Wierzchos, J; Horneck, G; Sancho, L G

    2011-05-01

    The Lithopanspermia space experiment was launched in 2007 with the European Biopan facility for a 10-day spaceflight on board a Russian Foton retrievable satellite. Lithopanspermia included for the first time the vagrant lichen species Aspicilia fruticulosa from Guadalajara steppic highlands (Central Spain), as well as other lichen species. During spaceflight, the samples were exposed to selected space conditions, that is, the space vacuum, cosmic radiation, and different spectral ranges of solar radiation (λ ≥ 110, ≥200, ≥290, or ≥400 nm, respectively). After retrieval, the algal and fungal metabolic integrity of the samples were evaluated in terms of chlorophyll a fluorescence, ultrastructure, and CO(2) exchange rates. Whereas the space vacuum and cosmic radiation did not impair the metabolic activity of the lichens, solar electromagnetic radiation, especially in the wavelength range between 100 and 200 nm, caused reduced chlorophyll a yield fluorescence; however, there was a complete recovery after 72 h of reactivation. All samples showed positive rates of net photosynthesis and dark respiration in the gas exchange experiment. Although the ultrastructure of all flight samples showed some probable stress-induced changes (such as the presence of electron-dense bodies in cytoplasmic vacuoles and between the chloroplast thylakoids in photobiont cells as well as in cytoplasmic vacuoles of the mycobiont cells), we concluded that A. fruticulosa was capable of repairing all space-induced damage. Due to size limitations within the Lithopanspermia hardware, the possibility for replication on the sun-exposed samples was limited, and these first results on the resistance of the lichen symbiosis A. fruticulosa to space conditions and, in particular, on the spectral effectiveness of solar extraterrestrial radiation must be considered preliminary. Further testing in space and under space-simulated conditions will be required. Results of this study indicate

  3. Whole Lichen Thalli Survive Exposure to Space Conditions: Results of Lithopanspermia Experiment with Aspicilia fruticulosa

    NASA Astrophysics Data System (ADS)

    Raggio, J.; Pintado, A.; Ascaso, C.; De La Torre, R.; De Los Ríos, A.; Wierzchos, J.; Horneck, G.; Sancho, L. G.

    2011-05-01

    The Lithopanspermia space experiment was launched in 2007 with the European Biopan facility for a 10-day spaceflight on board a Russian Foton retrievable satellite. Lithopanspermia included for the first time the vagrant lichen species Aspicilia fruticulosa from Guadalajara steppic highlands (Central Spain), as well as other lichen species. During spaceflight, the samples were exposed to selected space conditions, that is, the space vacuum, cosmic radiation, and different spectral ranges of solar radiation (λ ≥ 110, ≥ 200, ≥ 290, or ≥ 400 nm, respectively). After retrieval, the algal and fungal metabolic integrity of the samples were evaluated in terms of chlorophyll a fluorescence, ultrastructure, and CO2 exchange rates. Whereas the space vacuum and cosmic radiation did not impair the metabolic activity of the lichens, solar electromagnetic radiation, especially in the wavelength range between 100 and 200 nm, caused reduced chlorophyll a yield fluorescence; however, there was a complete recovery after 72 h of reactivation. All samples showed positive rates of net photosynthesis and dark respiration in the gas exchange experiment. Although the ultrastructure of all flight samples showed some probable stress-induced changes (such as the presence of electron-dense bodies in cytoplasmic vacuoles and between the chloroplast thylakoids in photobiont cells as well as in cytoplasmic vacuoles of the mycobiont cells), we concluded that A. fruticulosa was capable of repairing all space-induced damage. Due to size limitations within the Lithopanspermia hardware, the possibility for replication on the sun-exposed samples was limited, and these first results on the resistance of the lichen symbiosis A. fruticulosa to space conditions and, in particular, on the spectral effectiveness of solar extraterrestrial radiation must be considered preliminary. Further testing in space and under space-simulated conditions will be required. Results of this study indicate that the

  4. Adaptive learning can result in a failure to profit from good conditions: implications for understanding depression

    PubMed Central

    Trimmer, Pete C.; Higginson, Andrew D.; Fawcett, Tim W.; McNamara, John M.; Houston, Alasdair I.

    2015-01-01

    Background and objectives: Depression is a major medical problem diagnosed in an increasing proportion of people and for which commonly prescribed psychoactive drugs are frequently ineffective. Development of treatment options may be facilitated by an evolutionary perspective; several adaptive reasons for proneness to depression have been proposed. A common feature of many explanations is that depressive behaviour is a way to avoid costly effort where benefits are small and/or unlikely. However, this viewpoint fails to explain why low mood persists when the situation improves. We investigate whether a behavioural rule that is adapted to a stochastically changing world can cause inactivity which appears similar to the effect of depression, in that it persists after the situation has improved. Methodology: We develop an adaptive learning model in which an individual has repeated choices of whether to invest costly effort that may result in a net benefit. Investing effort also provides information about the current conditions and rates of change of the conditions. Results: An individual following the optimal behavioural strategy may sometimes remain inactive when conditions are favourable (i.e. when it would be better to invest effort) when it is poorly informed about the current environmental state. Initially benign conditions can predispose an individual to inactivity after a relatively brief period of negative experiences. Conclusions and implications: Our approach suggests that the antecedent factors causing depressed behaviour could go much further back in an individual s history than is currently appreciated. The insights from our approach have implications for the ongoing debate about best treatment options for patients with depressive symptoms. PMID:25916884

  5. Skill-based conditioning games as an alternative to traditional conditioning for rugby league players.

    PubMed

    Gabbett, Tim J

    2006-05-01

    This study investigated the effects of skill-based conditioning games and traditional conditioning for improving speed, agility, muscular power, and maximal aerobic power in rugby league players. Sixty-nine subelite rugby league players performed either a skill-based conditioning games program (N = 32) or a traditional conditioning (i.e., running activities with no skill component) program (N = 37). Each player participated in a 9-week in-season training program, performed over 2 competitive seasons. Players performed 2 organized field-training sessions each week. Players underwent measurements of speed (10-m, 20-m, and 40-m sprint), muscular power (vertical jump), agility (L run), and maximal aerobic power (multi-stage fitness test) before and after the training period. Skill-based conditioning games induced a significant improvement (p < 0.05) in 10-m, 20-m, and 40-m speed, muscular power, and maximal aerobic power, whereas traditional conditioning activities improved 10-m speed and maximal aerobic power only. No significant differences (p > 0.05) were detected between the traditional conditioning and skill-based conditioning games groups for changes in 10-m speed, agility, and maximal aerobic power. Both groups won 6 of 8 matches played within the training period, resulting in a win-loss ratio of 75%. However, on average, the skill-based conditioning games group scored more points in attack (p < 0.05) and had a greater (p < 0.05) points differential than the traditional conditioning group. The results of this study demonstrate that skill-based conditioning games offer an effective method of in-season conditioning for rugby league players. In addition, given that skills learned from skill-based conditioning games are more likely to be applied in the competitive environment, their use may provide a practical alternative to traditional conditioning for improving the physiological capacities and playing performance of rugby league players. PMID:16686558

  6. Anaerobic versus aerobic degradation of dimethyl sulfide and methanethiol in anoxic freshwater sediments

    SciTech Connect

    Lomans, B.P.; Op den Camp, H.J.M.; Pol, A.; Vogels, G.D.

    1999-02-01

    Degradation of dimethyl sulfide and methanethiol in slurries prepared from sediments of minerotrophic peatland ditches were studied under various conditions. Maximal aerobic dimethyl sulfide-degrading capacities, measured in bottles shaken under an air atmosphere, were 10-fold higher than the maximal anaerobic degrading capacities determined from bottles shaken under N{sub 2} or H{sub 2} atmosphere. Incubations under experimental conditions which mimic the in situ conditions, however, revealed that aerobic degradation of dimethyl sulfide and methanethiol in freshwater sediments is low due to oxygen limitation. Inhibition studies with bromoethanesulfonic acid and sodium tungstate demonstrated that the degradation of dimethyl sulfide and methanethiol in these incubations originated mainly from methanogenic activity. Prolonged incubation under a H{sub 2} atmosphere resulted in lower dimethyl sulfide degradation rates. Kinetic analysis of the data resulted in apparent K{sub m} values (6 to 8 {micro}M) for aerobic dimethyl sulfide degradation which are comparable to those reported for Thiobacillus spp., Hyphomicrobium spp., and other methylotrophs. Apparent K{sub m} values determined for anaerobic degradation of dimethyl sulfide were of the same order of magnitude. The low apparent K{sub m} values obtained explain the low dimethyl sulfide and methanethiol concentrations in freshwater sediments that they reported previously. The observations point to methanogenesis as the major mechanism of dimethyl sulfide and methanethiol consumption in freshwater sediments.

  7. Results of attenuation measurements for optical wireless channels under dense fog conditions regarding different wavelengths

    NASA Astrophysics Data System (ADS)

    Flecker, B.; Gebhart, M.; Leitgeb, E.; Sheikh Muhammad, S.; Chlestil, C.

    2006-08-01

    Free Space Optics (FSO) has gained considerable importance in this decade of demand for high bandwidth transmission capabilities. FSO can provide the last mile solution, but the availability and reliability issues concerned with it can not be ignored, and requires thorough investigations. In this work, we present our results about light attenuation at 950 and 850 nm wavelengths in continental city fog conditions with peak values up to 130 dB/km and compare them with attenuation under dense maritime conditions with peak values up to 480 dB/km. Dense fog is the most severe limiting factor in terrestrial optical wireless applications and light propagation in fog has properties in the spatial, spectral and the time domain, which are of importance to free-space optic data communication. In 2004 (within a short term scientific mission of COST 270) measurements of very dense maritime fog and low clouds were made in the mountains of La Turbie, close to the coast of southern France. Using the same equipment, the measurements were continued for the conditions of the continental city of Graz, Austria. This campaign was done in the winter months from 2004 to 2005 and 2005 to 2006 and allows us to compare fog properties for different environments, and the impact of snow fall. We provide detail analysis of a fog and a snow event for better understanding of their attenuation behavior.

  8. Mineral-catalyzed dehydrogenation of C6 cyclic hydrocarbons: results from experimental studies under hydrothermal conditions

    NASA Astrophysics Data System (ADS)

    Venturi, S.; Tassi, F.; Gould, I.; Shock, E.; Lorance, E. D.; Bockisch, C.; Fecteau, K.

    2015-12-01

    Volatile organic compounds (VOCs) are ubiquitously present in volcanic and hydrothermal gases. Their relative abundances have been demonstrated to be sensitive to physical and chemical parameters, suggesting VOCs as potential tools for evaluating deep reservoir conditions. Nevertheless, reaction pathways for VOC production at hydrothermal conditions are still poorly understood. Reversible catalytic reforming may be responsible for the high abundance of benzene observed in hydrothermal gases relative to saturated hydrocarbons. The dehydrogenation of n-hexane to benzene could proceed with C6 cyclic hydrocarbons as intermediates, as suggested by the relative enrichment in cyclic hydrocarbons observed in gases originating at T <150 °C. In this study, laboratory experiments were carried out to investigate the production of benzene from cyclic hydrocarbons at 300°C and 85 bar. At these conditions in pure water, negligible benzene is produced from cyclohexane after 10 days. The presence of a mineral phase, especially sphalerite, favored the formation of both benzene and cyclohexene. The efficiency of dehydroaromatization reaction increased at increasing mineral/cyclohexane ratio, pointing to a surface catalyzed reaction. The catalytic action of sphalerite on the C-H bonds was confirmed by the large abundance of deuterated cyclohexane resulted in D2O experiments. The same experiment carried out using cyclohexene in pure water mainly produced methyl-cyclopentenes (via isomerization) and cyclohexanol (via oxygenation). In presence of sphalerite, the production of significant amounts of benzene confirmed the critical role of this mineral for the aromatization of cyclic compounds under hydrothermal conditions. Contrarily, products from cyclohexene solution phase oxidation using Cu(II) mainly consisted of oxygenated VOCs.

  9. Burnout, working conditions and gender - results from the northern Sweden MONICA Study

    PubMed Central

    2010-01-01

    Background Sick-leave because of mental and behavioural disorders has increased considerably in Sweden since the late nineties, and especially in women. The aim of this study was to assess the level of burnout in the general working population in northern Sweden and analyse it's relation to working conditions and gender. Methods In this cross-sectional study the survey from the MONICA-study (Monitoring of Trends and Determinants in Cardiovascular Disease) in northern Sweden 2004 was used. A burnout instrument, the Shirom Melamed Burnout Questionnaire (SMBQ), was incorporated in the original survey which was sent to a random sample of 2500 individuals with a response rate of 76%. After including only actively working people, aged 25-64 years, our study population consisted of 1000 participants (497 women and 503 men). ANOVA and multiple linear regression models were used. Results The prevalence of a high level of burnout (SMBQ >4.0) was 13%. Women had a higher level of burnout than men with the most pronounced difference in the age group 35-44 years. In both sexes the level of burnout decreased with age. Demand and control at work, and job insecurity were related to burnout. In women the level of education, socioeconomic position, work object, and working varying hours were of importance. Interaction effects were found between sex and work object, and sex and working hours. In a multiple regression analysis almost half of the gender difference could be explained by work related and life situational factors. Conclusions Working life conditions contributed to the level of burnout in this actively working sample from the general population in northern Sweden. Especially in women, socioeconomic position was associated with burnout. The high level of burnout in women compared to men was partly explained by more unfavourable working conditions and life situational factors. Efforts to level out gender differences in burnout should probably focus on improving both working

  10. Aerobic Microbial Respiration in Oceanic Oxygen Minimum Zones

    NASA Astrophysics Data System (ADS)

    Kalvelage, Tim; Lavik, Gaute; Jensen, Marlene M.; Revsbech, Niels Peter; Schunck, Harald; Loescher, Carolin; Desai, Dhwani K.; LaRoche, Julie; Schmitz-Streit, Ruth; Kuypers, Marcel M. M.

    2014-05-01

    In the oxygen minimum zones (OMZs) of the tropical oceans, sluggish ventilation combined with strong microbial respiration of sinking organic matter results in the depletion of oxygen (O2). When O2 concentrations drop below ~5 µmol/L, organic matter is generally assumed to be respired with nitrate, ultimately leading to the loss of fixed inorganic nitrogen via anammox and denitrification. However, direct measurements of microbial O2 consumption at low O2 levels are - apart from a single experiment conducted in the OMZ off Peru - so far lacking. At the same time, consistently observed active aerobic ammonium and nitrite oxidation at non-detectable O2 concentrations (<1 µmol/L) in all major OMZs, suggests aerobic microorganisms, likely including heterotrophs, to be well adapted to near-anoxic conditions. Consequently, microaerobic (≤5 µmol/L) remineralization of organic matter, and thus release of ammonium, in low- O2 environments might be significantly underestimated at present. Here we present extensive measurements of microbial O2 consumption in OMZ waters, combined with highly sensitive O2 (STOX) measurements and meta-omic functional gene analyses. Short-term incubation experiments with labelled O2 (18-18O2) carried out in the Namibian and Peruvian OMZ, revealed persistent aerobic microbial activity at depths with non-detectable concentrations of O2 (≤50 nmol/L). In accordance, examination of metagenomes and metatranscriptomes from Chilean and Peruvian OMZ waters identified genes encoding for terminal respiratory oxidases with high O2 affinities as well as their expression by diverse microbial communities. Oxygen consumption was particularly enhanced near the upper OMZ boundaries and could mostly (~80%) be assigned to heterotrophic microbial activity. Compared to previously identified anaerobic microbial processes, microaerobic organic matter respiration was the dominant remineralization pathway and source of ammonium (~90%) in the upper Namibian and

  11. Influence of Initial Geometry and Boundary Conditions on Flat Subduction Models and Resulting Topography

    NASA Astrophysics Data System (ADS)

    Nelson, P.; Moucha, R.

    2014-12-01

    Numerical investigations of surface deformation in response to flat slab subduction began with seminal papers by Bird (1988) and Mitrovica et al. (1989). Recently, a number of numerical studies have begun to explore the complexity in the dynamics of flat-slab subduction initiation and continuation, but did not address the corresponding surface deformation (English et al., 2003; Pérez-Campos et al., 2008; Liu et al., 2010; Jones et al., 2011; Arrial and Billen, 2013; Vogt and Gerya, 2014). Herein, we explore the conditions that lead to flat-slab subduction and characterize the resulting surface deformation using a 2D finite-difference marker-in-cell method. We specifically explore how initial model geometry and boundary conditions affect the evolution of the angle at which a slab subducts in the presence/absence of a buoyant oceanic plateau and the resulting surface topography. In our simulations, the surface is tracked through time as an internal erosion/sedimentation surface. The top boundary of the crust is overlaid by a "sticky" (viscous 10^17 Pa.s) water/air layer with correspondingly stratified densities. We apply a coupled surface processes model that solves the sediment transport/diffusion erosion equation at each time step to account for the corresponding crustal mass flux and its effect on crustal deformation. Model results show the initial angle of subduction has a substantial impact on the subduction angle of the slab and hence the evolution of topography. The results also indicate plate velocity and the presence of an oceanic plateau in a forced subduction only have a moderate effect on the angle of subduction.

  12. Aerobic and anaerobic metabolism of bovine ciliary process: effects of metabolic and transport inhibitors.

    PubMed

    Braunagel, S C; Yorio, T

    1987-01-01

    In the present study we have measured the oxygen consumption and lactic acid production, under aerobic and anaerobic conditions, in the bovine ciliary process epithelium (CPE) in the presence and absence of transport modifiers. Basal oxygen consumption was 8-15 microliters O2 consumed/mg protein/hr and decreased by 35% when sodium was removed or ouabain was added to the media. Anaerobic metabolism as measured by lactate production was also attenuated by sodium-free or ouabain treatment. When O2 consumption was severely limited by cyanide, lactic acid production increased significantly ("Pasteur effect"), whereas 2-deoxyglucose reduced lactate formation. Both chloride-free and acetazolamide treated CPE increased their dependency on aerobic glycolysis, and this response was also observed under anaerobic conditions, suggesting the presence of an anion transport mechanism. A net lactate production was also found to occur across the aqueous epithelium under aerobic and anaerobic conditions. These results are consistent with the presence of a bicarbonate-sensitive anion transport system located in the ciliary process epithelium.

  13. Influence of Earth crust composition on continental collision style in Precambrian conditions: Results of supercomputer modelling

    NASA Astrophysics Data System (ADS)

    Zavyalov, Sergey; Zakharov, Vladimir

    2016-04-01

    A number of issues concerning Precambrian geodynamics still remain unsolved because of uncertainity of many physical (thermal regime, lithosphere thickness, crust thickness, etc.) and chemical (mantle composition, crust composition) parameters, which differed considerably comparing to the present day values. In this work, we show results of numerical supercomputations based on petrological and thermomechanical 2D model, which simulates the process of collision between two continental plates, each 80-160 km thick, with various convergence rates ranging from 5 to 15 cm/year. In the model, the upper mantle temperature is 150-200 ⁰C higher than the modern value, while the continental crust radiogenic heat production is higher than the present value by the factor of 1.5. These settings correspond to Archean conditions. The present study investigates the dependence of collision style on various continental crust parameters, especially on crust composition. The 3 following archetypal settings of continental crust composition are examined: 1) completely felsic continental crust; 2) basic lower crust and felsic upper crust; 3) basic upper crust and felsic lower crust (hereinafter referred to as inverted crust). Modeling results show that collision with completely felsic crust is unlikely. In the case of basic lower crust, a continental subduction and subsequent continental rocks exhumation can take place. Therefore, formation of ultra-high pressure metamorphic rocks is possible. Continental subduction also occurs in the case of inverted continental crust. However, in the latter case, the exhumation of felsic rocks is blocked by upper basic layer and their subsequent interaction depends on their volume ratio. Thus, if the total inverted crust thickness is about 15 km and the thicknesses of the two layers are equal, felsic rocks cannot be exhumed. If the total thickness is 30 to 40 km and that of the felsic layer is 20 to 25 km, it breaks through the basic layer leading to

  14. Characteristics of aerobic granulation at mesophilic temperatures in wastewater treatment.

    PubMed

    Cui, Fenghao; Park, Seyong; Kim, Moonil

    2014-01-01

    Compact and structurally stable aerobic granules were developed in a sequencing batch reactor (SBR) at mesophilic temperatures (35°C). The morphological, biological and chemical characteristics of the aerobic granulation were investigated and a theoretical granulation mechanism was proposed according to the results of the investigation. The mature aerobic granules had compact structure, small size (mean diameter of 0.24 mm), excellent settleability and diverse microbial structures, and were effective for the removal of organics and nitrification. The growth kinetics demonstrated that the biomass growth depended on coexistence and interactions between heterotrophs and autotrophs in the granules. The functions of heterotrophs and autotrophs created a compact and secure layer on the outside of the granules, protecting the inside sludge containing environmentally sensitive and slow growing microorganisms. The mechanism and the reactor performance may promise feasibility and efficiency for treating industry effluents at mesophilic temperatures using aerobic granulation. PMID:24211486

  15. Saline storage of aerobic granules and subsequent reactivation.

    PubMed

    Wan, Chunli; Lee, Duu-Jong; Yang, Xue; Wang, Yayi; Lin, Lin

    2014-11-01

    Loss of structural stability and bioactivity during long-term storage and operation is primary challenge to field applications of aerobic granular processes. This study for the first time stored aerobic granules in 5%w/w NaCl solution at 4°C for 187d. The stored granules were then successfully reactivated and used for 85d in sequencing batch reactors (SBR) and continuous-flow reactors (CFR) at varying levels of chemical oxygen demand (COD). High-throughput sequencing results reveal that Thauera sp., Paracoccus sp., and Nitrosomonas sp. were the predominant in the stored aerobic granules, and Pseudoxanthomonas sp. accumulated during the reactivation process. Saline storage, in which cells are in an unculturable state by saline stress, is a promising storage process for aerobic granules. PMID:25270079

  16. Preliminary results on the ability of pentatomidae to transfer fire blight Erwinia amylovora under controlled conditions.

    PubMed

    Peusens, G; Schoofs, H; Deckers, T; Belien, T

    2013-01-01

    With their piercing-sucking mouthparts stink bugs (Heteroptera: Pentatomidae), a major pest in especially organic orchards, create wounds in fruit of pear trees. As Erwinia amylovora (Burrill, Winslow et al.), a wide spread bacterial disease affecting many rosaceous plants including pome fruit trees and hawthorn, enters through openings in flowers, leaves, shoots and fruit, feeding punctures caused by these bugs might be inoculated with Erwinia bacteria. In order to investigate the ability of the bugs Pentotoma rufipes L. and Polomena prasina L. to transmit fire blight, insects were caught in an organically managed orchard without fire blight, brought into contact with artificially inoculated immature pear fruit/slices and transferred to healthy, mechanically wounded pear fruit/slices. After an incubation period potential transmission of bacteria was examined by evaluation of symptom expression (necrosis, ooze production). To assess the presence of bacteria on the exoskeleton of the tested bugs, all bugs were forced to walk on a semiselective nutrient agar medium. In another experiment the viability of Ea on the exoskeleton was tested -after previous contact with ooze- through washing and plating of the wash water. All experiments were conducted under optimal climatological conditions and according to quarantine standards. Results demonstrated the ability of stink bugs to transfer E. amylovora to fruit and the viability of bacteria on stink bugs externally - both under lab conditions.

  17. Accumulation of pharmaceuticals in groundwater under arid climate conditions - Results from unsaturated column experiments.

    PubMed

    Zemann, M; Majewsky, M; Wolf, L

    2016-07-01

    Intense reuse of treated wastewater in agriculture is practiced all over the world, especially in arid and water-scarce regions. In doing so, pharmaceutical residues in the water are irrigated to the soil and subsequently can percolate into the local aquifers. Since evaporation rates in these areas are typically high, persistent substances might enrich in the groundwater recharge of closed catchments like the Jordan Valley. Against this background, unsaturated column tests were conducted to investigate the potential for evaporative accumulation of the two pharmaceuticals bezafibrate and carbamazepine under simulated arid climate conditions. Parallel tests were conducted with inhibited microbiological activity where both substances showed an increase in the effluent concentrations proportional to the evaporation loss of the inflow solution. The mean accumulation factors of the pharmaceuticals correspond to the evaporated water loss. The experiments indicate the accumulation potential for pharmaceuticals with high persistence against biodegradation. For the first time, the overall potential for evaporative enrichment could be demonstrated for pharmaceuticals. Under the given experimental conditions, the two investigated pharmaceuticals did not enrich faster than chloride, which might result in soil salting prior to reaching harmful pharmaceutical concentrations in soil water. The findings are relevant to future assessments of environmental impacts of persistent trace substances, which need to take into account that concentrations in the aquatic cycle might increase further due to evaporative enrichment. PMID:27085060

  18. Preliminary results on the ability of pentatomidae to transfer fire blight Erwinia amylovora under controlled conditions.

    PubMed

    Peusens, G; Schoofs, H; Deckers, T; Belien, T

    2013-01-01

    With their piercing-sucking mouthparts stink bugs (Heteroptera: Pentatomidae), a major pest in especially organic orchards, create wounds in fruit of pear trees. As Erwinia amylovora (Burrill, Winslow et al.), a wide spread bacterial disease affecting many rosaceous plants including pome fruit trees and hawthorn, enters through openings in flowers, leaves, shoots and fruit, feeding punctures caused by these bugs might be inoculated with Erwinia bacteria. In order to investigate the ability of the bugs Pentotoma rufipes L. and Polomena prasina L. to transmit fire blight, insects were caught in an organically managed orchard without fire blight, brought into contact with artificially inoculated immature pear fruit/slices and transferred to healthy, mechanically wounded pear fruit/slices. After an incubation period potential transmission of bacteria was examined by evaluation of symptom expression (necrosis, ooze production). To assess the presence of bacteria on the exoskeleton of the tested bugs, all bugs were forced to walk on a semiselective nutrient agar medium. In another experiment the viability of Ea on the exoskeleton was tested -after previous contact with ooze- through washing and plating of the wash water. All experiments were conducted under optimal climatological conditions and according to quarantine standards. Results demonstrated the ability of stink bugs to transfer E. amylovora to fruit and the viability of bacteria on stink bugs externally - both under lab conditions. PMID:25145257

  19. Conditional pair distributions in many-body systems: exact results for Poisson ensembles.

    PubMed

    Rohrmann, René D; Zurbriggen, Ernesto

    2012-05-01

    We introduce a conditional pair distribution function (CPDF) which characterizes the probability density of finding an object (e.g., a particle in a fluid) to within a certain distance of each other, with each of these two having a nearest neighbor to a fixed but otherwise arbitrary distance. This function describes special four-body configurations, but also contains contributions due to the so-called mutual nearest neighbor (two-body) and shared neighbor (three-body) configurations. The CPDF is introduced to improve a Helmholtz free energy method based on space partitions. We derive exact expressions of the CPDF and various associated quantities for randomly distributed, noninteracting points at Euclidean spaces of one, two, and three dimensions. Results may be of interest in many diverse scientific fields, from fluid physics to social and biological sciences.

  20. Results comparison and model validation for flood loss functions in Australian geographical conditions

    NASA Astrophysics Data System (ADS)

    Hasanzadeh Nafari, R.; Ngo, T.; Lehman, W.

    2015-06-01

    Rapid urbanisation, climate change and unsustainable developments are increasing the risk of floods, namely flood frequency and intensity. Flood is a frequent natural hazard that has significant financial consequences for Australia. The emergency response system in Australia is very successful and has saved many lives over the years. However, the preparedness for natural disaster impacts in terms of loss reduction and damage mitigation has been less successful. This study aims to quantify the direct physical damage to residential structures that are prone to flood phenomena in Australia. In this paper, the physical consequences of two floods from Queensland have been simulated, and the results have been compared with the performance of two selected methodologies and one newly derived model. Based on this analysis, the adaptability and applicability of the selected methodologies will be assessed in terms of Australian geographical conditions. Results obtained from the new empirically-based function and non-adapted methodologies indicate that it is apparent that the precision of flood damage models are strongly dependent on selected stage damage curves, and flood damage estimation without model validation results in inaccurate prediction of losses. Therefore, it is very important to be aware of the associated uncertainties in flood risk assessment, especially if models have not been adapted with real damage data.

  1. The characteristics of a novel heterotrophic nitrification-aerobic denitrification bacterium, Bacillus methylotrophicus strain L7.

    PubMed

    Zhang, Qing-Ling; Liu, Ying; Ai, Guo-Min; Miao, Li-Li; Zheng, Hai-Yan; Liu, Zhi-Pei

    2012-03-01

    Bacillus methylotrophicus strain L7, exhibited efficient heterotrophic nitrification-aerobic denitrification ability, with maximum NH(4)(+)-N and NO(2)(-)-N removal rate of 51.58 mg/L/d and 5.81 mg/L/d, respectively. Strain L7 showed different gaseous emitting patterns from those strains ever described. When (15)NH(4)Cl, or Na(15)NO(2), or K(15)NO(3) was used, results of GC-MS indicated that N(2)O was emitted as the intermediate of heterotrophic nitrification or aerobic denitrification, while GC-IRMS results showed that N(2) was produced as end product when nitrite was used. Single factor experiments suggested that the optimal conditions for heterotrophic nitrification were sodium succinate as carbon source, C/N 6, pH 7-8, 0 g/L NaCl, 37 °C and a wide range of NH(4)(+)-N from 80 to 1000 mg/L. Orthogonal tests showed that the optimal conditions for aerobic denitrification were C/N 20, pH 7-8, 10 g/L NaCl and DO 4.82 mg/L (shaking speed 50 r/min) when nitrite was served as substrate.

  2. A single bout of high-intensity aerobic exercise facilitates response to paired associative stimulation and promotes sequence-specific implicit motor learning.

    PubMed

    Mang, Cameron S; Snow, Nicholas J; Campbell, Kristin L; Ross, Colin J D; Boyd, Lara A

    2014-12-01

    The objectives of the present study were to evaluate the impact of a single bout of high-intensity aerobic exercise on 1) long-term potentiation (LTP)-like neuroplasticity via response to paired associative stimulation (PAS) and 2) the temporal and spatial components of sequence-specific implicit motor learning. Additionally, relationships between exercise-induced increases in systemic brain-derived neurotrophic factor (BDNF) and response to PAS and motor learning were evaluated. Sixteen young healthy participants completed six experimental sessions, including the following: 1) rest followed by PAS; 2) aerobic exercise followed by PAS; 3) rest followed by practice of a continuous tracking (CT) task and 4) a no-exercise 24-h retention test; and 5) aerobic exercise followed by CT task practice and 6) a no-exercise 24-h retention test. The CT task included an embedded repeated sequence allowing for evaluation of sequence-specific implicit learning. Slope of motor-evoked potential recruitment curves generated with transcranial magnetic stimulation showed larger increases when PAS was preceded by aerobic exercise (59.8% increase) compared with rest (14.2% increase, P = 0.02). Time lag of CT task performance on the repeated sequence improved under the aerobic exercise condition from early (-100.8 ms) to late practice (-75.2 ms, P < 0.001) and was maintained at retention (-79.2 ms, P = 0.004) but did not change under the rest condition (P > 0.16). Systemic BDNF increased on average by 3.4-fold following aerobic exercise (P = 0.003), but the changes did not relate to neurophysiological or behavioral measures (P > 0.42). These results indicate that a single bout of high-intensity aerobic exercise can prime LTP-like neuroplasticity and promote sequence-specific implicit motor learning.

  3. A single bout of high-intensity aerobic exercise facilitates response to paired associative stimulation and promotes sequence-specific implicit motor learning

    PubMed Central

    Mang, Cameron S.; Snow, Nicholas J.; Campbell, Kristin L.; Ross, Colin J. D.

    2014-01-01

    The objectives of the present study were to evaluate the impact of a single bout of high-intensity aerobic exercise on 1) long-term potentiation (LTP)-like neuroplasticity via response to paired associative stimulation (PAS) and 2) the temporal and spatial components of sequence-specific implicit motor learning. Additionally, relationships between exercise-induced increases in systemic brain-derived neurotrophic factor (BDNF) and response to PAS and motor learning were evaluated. Sixteen young healthy participants completed six experimental sessions, including the following: 1) rest followed by PAS; 2) aerobic exercise followed by PAS; 3) rest followed by practice of a continuous tracking (CT) task and 4) a no-exercise 24-h retention test; and 5) aerobic exercise followed by CT task practice and 6) a no-exercise 24-h retention test. The CT task included an embedded repeated sequence allowing for evaluation of sequence-specific implicit learning. Slope of motor-evoked potential recruitment curves generated with transcranial magnetic stimulation showed larger increases when PAS was preceded by aerobic exercise (59.8% increase) compared with rest (14.2% increase, P = 0.02). Time lag of CT task performance on the repeated sequence improved under the aerobic exercise condition from early (−100.8 ms) to late practice (−75.2 ms, P < 0.001) and was maintained at retention (−79.2 ms, P = 0.004) but did not change under the rest condition (P > 0.16). Systemic BDNF increased on average by 3.4-fold following aerobic exercise (P = 0.003), but the changes did not relate to neurophysiological or behavioral measures (P > 0.42). These results indicate that a single bout of high-intensity aerobic exercise can prime LTP-like neuroplasticity and promote sequence-specific implicit motor learning. PMID:25257866

  4. Sport Engagement by Accelerometry under Field Conditions in German Adolescents: Results from GINIPlus

    PubMed Central

    Smith, Maia; Berdel, Dietrich; Nowak, Dennis; Heinrich, Joachim; Schulz, Holger

    2015-01-01

    Introduction Sporting activities differ in their ability to promote moderate-to-vigorous physical activity (MVPA). To assess adolescents’ engagement in sport under field conditions we used accelerometers to measure their MVPA levels during sport. We pay special attention to differences between team and individual sport and between common sports. Methods Diary data and 7-day accelerometry from 1054 Germans ages 15–17 were combined to measure physical activity. 1373 diaried episodes of more than 40 common sports were identified from 626 participants and grouped into team and individual sport. We modeled the effect of team and individual sport, and described levels of MVPA and episodes of no MVPA for all recorded sports. Results German boys and girls averaged 43 (SD 21) and 37 (SD 24) minutes MVPA per day. Boys got 2.2 times as much MVPA per minute during team compared to individual sport (p<0.0001) but there was no significant difference for girls. Percent of time spent in MVPA during sport ranged from 6% for weight training to 74% for jogging, with individual sports averaging 10–30% and team sports 30–50%. 11% of sport episodes had no MVPA: half of episodes of cycling, 5% of jogging, and none for tennis or badminton. An episode of individual sport was 17 times more likely to have no MVPA than an episode of team sport (p<0.0001). Conclusion Under field condition, adolescents were active for only a fraction of diaried sporting time. As measured by accelerometry, individual sport often produced no MVPA. Characteristics of the sport, such as team vs. individual, were more predictive of MVPA than were characteristics of the participant, such as background activity levels. PMID:26291984

  5. Experimental demonstration of quantitation errors in MR spectroscopy resulting from saturation corrections under changing conditions

    NASA Astrophysics Data System (ADS)

    Galbán, Craig J.; Ellis, Scott J.; Spencer, Richard G. S.

    2003-04-01

    Metabolite concentration measurements in in vivo NMR are generally performed under partially saturated conditions, with correction for partial saturation performed after data collection using a measured saturation factor. Here, we present an experimental test of the hypothesis that quantitation errors can occur due to application of such saturation factor corrections in changing systems. Thus, this extends our previous theoretical work on quantitation errors due to varying saturation factors. We obtained results for two systems frequently studied by 31P NMR, the ischemic rat heart and the electrically stimulated rat gastrocnemius muscle. The results are interpreted in light of previous theoretical work which defined the degree of saturation occurring in a one-pulse experiment for a system with given spin-lattice relaxation times, T1s, equilibrium magnetizations, M0s, and reaction rates. We found that (i) the assumption of constancy of saturation factors leads to quantitation errors on the order of 40% in inorganic phosphate; (ii) the dominant contributor to the quantitation errors in inorganic phosphate is most likely changes in T1; (iii) T1 and M0 changes between control and intervention periods, and chemical exchange contribute to different extents to quantitation errors in phosphocreatine and γ-ATP; (iv) relatively small increases in interpulse delay substantially decreased quantitation errors for metabolites in ischemic rat hearts; (v) random error due to finite SNR led to approximately 4% error in quantitation, and hence was a substantially smaller contributor than were changes in saturation factors.

  6. Hybridization within Saccharomyces Genus Results in Homoeostasis and Phenotypic Novelty in Winemaking Conditions.

    PubMed

    da Silva, Telma; Albertin, Warren; Dillmann, Christine; Bely, Marina; la Guerche, Stéphane; Giraud, Christophe; Huet, Sylvie; Sicard, Delphine; Masneuf-Pomarede, Isabelle; de Vienne, Dominique; Marullo, Philippe

    2015-01-01

    Despite its biotechnological interest, hybridization, which can result in hybrid vigor, has not commonly been studied or exploited in the yeast genus. From a diallel design including 55 intra- and interspecific hybrids between Saccharomyces cerevisiae and S. uvarum grown at two temperatures in enological conditions, we analyzed as many as 35 fermentation traits with original statistical and modeling tools. We first showed that, depending on the types of trait--kinetics parameters, life-history traits, enological parameters and aromas -, the sources of variation (strain, temperature and strain * temperature effects) differed in a large extent. Then we compared globally three groups of hybrids and their parents at two growth temperatures: intraspecific hybrids S. cerevisiae * S. cerevisiae, intraspecific hybrids S. uvarum * S. uvarum and interspecific hybrids S. cerevisiae * S. uvarum. We found that hybridization could generate multi-trait phenotypes with improved oenological performances and better homeostasis with respect to temperature. These results could explain why interspecific hybridization is so common in natural and domesticated yeast, and open the way to applications for wine-making.

  7. Hybridization within Saccharomyces Genus Results in Homoeostasis and Phenotypic Novelty in Winemaking Conditions.

    PubMed

    da Silva, Telma; Albertin, Warren; Dillmann, Christine; Bely, Marina; la Guerche, Stéphane; Giraud, Christophe; Huet, Sylvie; Sicard, Delphine; Masneuf-Pomarede, Isabelle; de Vienne, Dominique; Marullo, Philippe

    2015-01-01

    Despite its biotechnological interest, hybridization, which can result in hybrid vigor, has not commonly been studied or exploited in the yeast genus. From a diallel design including 55 intra- and interspecific hybrids between Saccharomyces cerevisiae and S. uvarum grown at two temperatures in enological conditions, we analyzed as many as 35 fermentation traits with original statistical and modeling tools. We first showed that, depending on the types of trait--kinetics parameters, life-history traits, enological parameters and aromas -, the sources of variation (strain, temperature and strain * temperature effects) differed in a large extent. Then we compared globally three groups of hybrids and their parents at two growth temperatures: intraspecific hybrids S. cerevisiae * S. cerevisiae, intraspecific hybrids S. uvarum * S. uvarum and interspecific hybrids S. cerevisiae * S. uvarum. We found that hybridization could generate multi-trait phenotypes with improved oenological performances and better homeostasis with respect to temperature. These results could explain why interspecific hybridization is so common in natural and domesticated yeast, and open the way to applications for wine-making. PMID:25946464

  8. Hybridization within Saccharomyces Genus Results in Homoeostasis and Phenotypic Novelty in Winemaking Conditions

    PubMed Central

    Dillmann, Christine; Bely, Marina; la Guerche, Stéphane; Giraud, Christophe; Huet, Sylvie; Sicard, Delphine; Masneuf-Pomarede, Isabelle; de Vienne, Dominique; Marullo, Philippe

    2015-01-01

    Despite its biotechnological interest, hybridization, which can result in hybrid vigor, has not commonly been studied or exploited in the yeast genus. From a diallel design including 55 intra- and interspecific hybrids between Saccharomyces cerevisiae and S. uvarum grown at two temperatures in enological conditions, we analyzed as many as 35 fermentation traits with original statistical and modeling tools. We first showed that, depending on the types of trait – kinetics parameters, life-history traits, enological parameters and aromas –, the sources of variation (strain, temperature and strain * temperature effects) differed in a large extent. Then we compared globally three groups of hybrids and their parents at two growth temperatures: intraspecific hybrids S. cerevisiae * S. cerevisiae, intraspecific hybrids S. uvarum * S. uvarum and interspecific hybrids S. cerevisiae * S. uvarum. We found that hybridization could generate multi-trait phenotypes with improved oenological performances and better homeostasis with respect to temperature. These results could explain why interspecific hybridization is so common in natural and domesticated yeast, and open the way to applications for wine-making. PMID:25946464

  9. Organic micropollutants in aerobic and anaerobic membrane bioreactors: Changes in microbial communities and gene expression.

    PubMed

    Harb, Moustapha; Wei, Chun-Hai; Wang, Nan; Amy, Gary; Hong, Pei-Ying

    2016-10-01

    Organic micro-pollutants (OMPs) are contaminants of emerging concern in wastewater treatment due to the risk of their proliferation into the environment, but their impact on the biological treatment process is not well understood. The purpose of this study is to examine the effects of the presence of OMPs on the core microbial populations of wastewater treatment. Two nanofiltration-coupled membrane bioreactors (aerobic and anaerobic) were subjected to the same operating conditions while treating synthetic municipal wastewater spiked with OMPs. Microbial community dynamics, gene expression levels, and antibiotic resistance genes were analyzed using molecular-based approaches. Results showed that presence of OMPs in the wastewater feed had a clear effect on keystone bacterial populations in both the aerobic and anaerobic sludge while also significantly impacting biodegradation-associated gene expression levels. Finally, multiple antibiotic-type OMPs were found to have higher removal rates in the anaerobic MBR, while associated antibiotic resistance genes were lower.

  10. Organic micropollutants in aerobic and anaerobic membrane bioreactors: Changes in microbial communities and gene expression.

    PubMed

    Harb, Moustapha; Wei, Chun-Hai; Wang, Nan; Amy, Gary; Hong, Pei-Ying

    2016-10-01

    Organic micro-pollutants (OMPs) are contaminants of emerging concern in wastewater treatment due to the risk of their proliferation into the environment, but their impact on the biological treatment process is not well understood. The purpose of this study is to examine the effects of the presence of OMPs on the core microbial populations of wastewater treatment. Two nanofiltration-coupled membrane bioreactors (aerobic and anaerobic) were subjected to the same operating conditions while treating synthetic municipal wastewater spiked with OMPs. Microbial community dynamics, gene expression levels, and antibiotic resistance genes were analyzed using molecular-based approaches. Results showed that presence of OMPs in the wastewater feed had a clear effect on keystone bacterial populations in both the aerobic and anaerobic sludge while also significantly impacting biodegradation-associated gene expression levels. Finally, multiple antibiotic-type OMPs were found to have higher removal rates in the anaerobic MBR, while associated antibiotic resistance genes were lower. PMID:27441825

  11. Enhancing the Efficacy of Behavior Therapy for Obesity: Effects of Aerobic Exercise and a Multicomponent Maintenance Program.

    ERIC Educational Resources Information Center

    Perri, Michael G.; And Others

    1986-01-01

    Moderately obese volunteers were randomly assigned to two treatment conditions (behavior therapy or behavior therapy plus aerobic exercise) and two posttreatment conditions (no further contact or a multicomponent maintenance program). Clients in the aerobic exercise condition lost significantly more weight than those who received behavior therapy…

  12. Die aerobe Glykolyse der Tumorzelle

    NASA Astrophysics Data System (ADS)

    Schneider, Friedhelm

    1981-01-01

    A high aerobic glycolysis (aerobic lactate production) is the most significant feature of the energy metabolism of rapidly growing tumor cells. Several mechanisms, which may be different in different cell lines, seem to be involved in this characteristic of energy metabolism of the tumor cell. Changes in the cell membrane leading to increased uptake and utilization of glucose, a high level of fetal types of isoenzymes, a decreased number of mitochondria and a reduced capacity to metabolize pyruvate are some factors which must be taken into consideration. It is not possible to favour one of them at the present time.

  13. The effect of three months of aerobic training on stroop performance in older adults.

    PubMed

    Predovan, David; Fraser, Sarah A; Renaud, Mélanie; Bherer, Louis

    2012-01-01

    Growing evidence supports the use of physical training interventions to improve both physical and cognitive performances in healthy older adults. Few studies have examined the impact of aerobic exercise on Stroop task performance, a measure of executive functions. In the current 3-month aerobic training study, 50 older adults (mean age = 67.96 ± 6.25 years) were randomly assigned to either a three-month physical training group or to a control group (waiting list). Training sessions were 3 times per week for 60 minutes. All participants completed pre- and post-test measures of cognitive performance using the modified Stroop task and physical performance (Rockport one-mile test). Compared to controls, the training group showed significant improvements in physical capacity (P < 0.001) and enhanced Stroop performance, but only in the inhibition/switching condition (P < 0.03). Furthermore, the increase in aerobic capacity induced by the training regimen correlated negatively with reaction time in the inhibition/switching condition of the Stroop task at posttest (r = -0.538; P = 0.007). Importantly, the reported gains in cognitive performance were observed after only three months of physical training. Taken together, the results suggest that even short-term physical interventions can enhance older adults' executive functions. PMID:23304504

  14. The effect of three months of aerobic training on stroop performance in older adults.

    PubMed

    Predovan, David; Fraser, Sarah A; Renaud, Mélanie; Bherer, Louis

    2012-01-01

    Growing evidence supports the use of physical training interventions to improve both physical and cognitive performances in healthy older adults. Few studies have examined the impact of aerobic exercise on Stroop task performance, a measure of executive functions. In the current 3-month aerobic training study, 50 older adults (mean age = 67.96 ± 6.25 years) were randomly assigned to either a three-month physical training group or to a control group (waiting list). Training sessions were 3 times per week for 60 minutes. All participants completed pre- and post-test measures of cognitive performance using the modified Stroop task and physical performance (Rockport one-mile test). Compared to controls, the training group showed significant improvements in physical capacity (P < 0.001) and enhanced Stroop performance, but only in the inhibition/switching condition (P < 0.03). Furthermore, the increase in aerobic capacity induced by the training regimen correlated negatively with reaction time in the inhibition/switching condition of the Stroop task at posttest (r = -0.538; P = 0.007). Importantly, the reported gains in cognitive performance were observed after only three months of physical training. Taken together, the results suggest that even short-term physical interventions can enhance older adults' executive functions.

  15. Experimental results and modeling tests of an adsorptive air-conditioning unit

    SciTech Connect

    Guilleminot, J.J.; Poyelle, F.; Meunier, F.

    1998-10-01

    Experimental tests have been performed on a zeolite-water adsorptive system suitable for air conditioning and consisting of two adsorbers filled with a consolidated composite made of zeolite mixed with a highly conductive matrix. This paper describes the experimental results of such a heat pump unit operating with a heat and mass recovery cycle. An important enhancement of the specific cooling power (SCP) has been achieved. At evaporating temperature T = 4 C, mass transfer resistance controls the process and limits the expected COP. Tests carried out at higher evaporating pressure make it possible to achieve the predicted COP and SCP. A predictive model developed and validated elsewhere in order to describe the temperature evolution of components and the heat and mass transfer in the adsorbers explains the mass transfer resistance in the adsorbent. Last, a new highly conductive adsorbent composite with good mass transfer properties is developed. The model is used to predict the performances of this new material. Very good SCP and COP can be achieved.

  16. Post-impact climate conditions on early Mars: preliminary results from GCM simulations

    NASA Astrophysics Data System (ADS)

    Steakley, Kathryn; Murphy, Jim; Kahre, Melinda A.; Haberle, Robert

    2016-10-01

    Observations imply that liquid water was stable on Mars' surface during the late Noachian/early Hesperian era, with valley networks forming roughly 3.5-3.75 billion years ago, possibly from precipitation and runoff (Fassett & Head 2008, Icarus 195, 61; Hynek et al., 2010, JGR Planets, 115, E09008). Climate models, however, struggle to reproduce such warm conditions (Forget et al., 2013, Icarus 21, 81). Volcanism and impacts have been suggested as mechanisms of either inducing a warm and wet environment or causing local melting in a cold and wet environment. Comets and asteroids are capable of injecting into the atmosphere both kinetic energy from the impact and water from the object itself and from vaporized surface and subsurface ice. Segura et al. (2008, JGR Planets 113, E11007) find using a 1-D atmospheric model that significant rainfall and periods of above-freezing temperatures lasting months to years can follow impacts of objects between 30 and 100 km in diameter. We revisit this work utilizing a 3-D global climate model (GCM) to consider the effects of dynamics, topography, global surface ice variations, etc. We present preliminary results from the NASA ARC Mars GCM investigating global temperature and precipitation behavior in a post-impact, early Mars environment.

  17. Aerobic sludge granulation at high temperatures for domestic wastewater treatment.

    PubMed

    Ab Halim, Mohd Hakim; Nor Anuar, Aznah; Azmi, Siti Izaidah; Jamal, Nur Syahida Abdul; Wahab, Norhaliza Abdul; Ujang, Zaini; Shraim, Amjad; Bob, Mustafa M

    2015-06-01

    With inoculum sludge from a conventional activated sludge wastewater treatment plant, three sequencing batch reactors (SBRs) fed with synthetic wastewater were operated at different high temperatures (30, 40 and 50±1°C) to study the formation of aerobic granular sludge (AGS) for simultaneous organics and nutrients removal with a complete cycle time of 3h. The AGS were successfully cultivated with influent loading rate of 1.6CODg(Ld)(-1). The COD/N ratio of the influent wastewater was 8. The results revealed that granules developed at 50°C have the highest average diameter, (3.36mm) with 98.17%, 94.45% and 72.46% removal efficiency observed in the system for COD, ammonia and phosphate, respectively. This study also demonstrated the capabilities of AGS formation at high temperatures which is suitable to be applied for hot climate conditions. PMID:25851807

  18. Aerobic sludge granulation at high temperatures for domestic wastewater treatment.

    PubMed

    Ab Halim, Mohd Hakim; Nor Anuar, Aznah; Azmi, Siti Izaidah; Jamal, Nur Syahida Abdul; Wahab, Norhaliza Abdul; Ujang, Zaini; Shraim, Amjad; Bob, Mustafa M

    2015-06-01

    With inoculum sludge from a conventional activated sludge wastewater treatment plant, three sequencing batch reactors (SBRs) fed with synthetic wastewater were operated at different high temperatures (30, 40 and 50±1°C) to study the formation of aerobic granular sludge (AGS) for simultaneous organics and nutrients removal with a complete cycle time of 3h. The AGS were successfully cultivated with influent loading rate of 1.6CODg(Ld)(-1). The COD/N ratio of the influent wastewater was 8. The results revealed that granules developed at 50°C have the highest average diameter, (3.36mm) with 98.17%, 94.45% and 72.46% removal efficiency observed in the system for COD, ammonia and phosphate, respectively. This study also demonstrated the capabilities of AGS formation at high temperatures which is suitable to be applied for hot climate conditions.

  19. Arizona Teacher Working Conditions: Designing Schools for Educator and Student Success. Results of the 2006 Phase-In Teacher Working Conditions Survey

    ERIC Educational Resources Information Center

    Hirsch, Eric; Emerick, Scott

    2006-01-01

    Many schools across the country face persistent teacher working condition challenges that are closely related to high teacher turnover rates and chronic difficulties in recruiting and retaining teachers. Center for Teaching Quality (CTQ) research examining working conditions survey results in both North Carolina and South Carolina demonstrates…

  20. Aerobic fitness is associated with greater hippocampal cerebral blood flow in children.

    PubMed

    Chaddock-Heyman, Laura; Erickson, Kirk I; Chappell, Michael A; Johnson, Curtis L; Kienzler, Caitlin; Knecht, Anya; Drollette, Eric S; Raine, Lauren B; Scudder, Mark R; Kao, Shih-Chun; Hillman, Charles H; Kramer, Arthur F

    2016-08-01

    The present study is the first to investigate whether cerebral blood flow in the hippocampus relates to aerobic fitness in children. In particular, we used arterial spin labeling (ASL) perfusion MRI to provide a quantitative measure of blood flow in the hippocampus in 73 7- to 9-year-old preadolescent children. Indeed, aerobic fitness was found to relate to greater perfusion in the hippocampus, independent of age, sex, and hippocampal volume. Such results suggest improved microcirculation and cerebral vasculature in preadolescent children with higher levels of aerobic fitness. Further, aerobic fitness may influence how the brain regulates its metabolic demands via blood flow in a region of the brain important for learning and memory. To add specificity to the relationship of fitness to the hippocampus, we demonstrate no significant association between aerobic fitness and cerebral blood flow in the brainstem. Our results reinforce the importance of aerobic fitness during a critical period of child development. PMID:27419884

  1. The Transition from Aerobic to Anaerobic Metabolism.

    ERIC Educational Resources Information Center

    Skinner, James S.; McLellan, Thomas H.

    1980-01-01

    The transition from aerobic to anaerobic metabolism is discussed. More research is needed on different kinds of athletes and athletic activities and how they may affect aerobic and anaerobic metabolisms. (CJ)

  2. Anaerobic/aerobic treatment of selected azo dyes in wastewater

    SciTech Connect

    Seshadri, S.; Bishop, P.L. . Dept. of Civil and Environmental Engineering); Agha, A.M. . Faculty of Civil Engineering)

    1994-01-01

    Azo dyes represent the largest class of dyes in use today. Current environmental concern with these dyes revolves around the potential carcinogenic health risk presented by these dyes or their intermediate biodegradation products when exposed to microflora in the human digestive tract. These dyes may build up in the environment, since many wastewater treatment plants allow these dyes to pass through the system virtually untreated. The initial step in the degradation of these dyes is the cleavage of the Azo bond. This cleavage is often impossible under aerobic conditions, but has been readily demonstrated under anaerobic conditions. The focus of the study was to determine the feasibility of using an anaerobic fluidized-bed reactor to accomplish this cleavage. The effects of typical process variables such as hydraulic retention time (HRT), influent dye concentration levels, and degree of bed fluidization on removal efficiencies were also studied. The four dyes selected for this study were Acid-Orange 7, Acid-Orange 8, Acid-Orange 10, and Acid-Red 14. The effectiveness of using a bench-scale-activated sludge reactor as a sequenced second stage was also examined. Results indicate that nearly complete cleavage of the Azo bond is easily accomplished for each of the four dyes under hydraulic retention times of either 12 or 24 h. Initial results indicate, though, that aromatic amine by-products remain. The sequenced second stage was able to remove the remaining Chemical Oxygen Demand (COD) load to acceptable levels. Work is presently underway to determine the face of the anaerobic by-products in the aerobic second stage.

  3. Modification of Pulsed Electric Field Conditions Results in Distinct Activation Profiles of Platelet-Rich Plasma

    PubMed Central

    Frelinger, Andrew L.; Gerrits, Anja J.; Garner, Allen L.; Torres, Andrew S.; Caiafa, Antonio; Morton, Christine A.; Berny-Lang, Michelle A.; Carmichael, Sabrina L.; Neculaes, V. Bogdan; Michelson, Alan D.

    2016-01-01

    presence of platelet-derived microparticles, platelets, and platelet aggregates whereas SMHEF pulses primarily resulted in platelet-derived microparticles. Microparticles and platelets in PRP activated with SMLEF bipolar pulses had significantly lower annexin V-positivity than those following SMHEF activation. In contrast, the % P-selectin positivity and surface P-selectin expression (MFI) for platelets and microparticles in SMLEF bipolar pulse activated PRP was significantly higher than that in SMHEF-activated PRP, but not significantly different from that produced by thrombin activation. Higher levels of EGF were observed following either SMLEF bipolar pulses or SMHEF pulses of PRP than after bovine thrombin activation while VEGF, PDGF, and PF4 levels were similar with all three activating conditions. Cell proliferation was significantly increased by releasates of both SMLEF bipolar pulse and SMHEF pulse activated PRP compared to plasma alone. Conclusions PEF activation of PRP at bipolar low vs. monopolar high field strength results in differential platelet-derived microparticle production and activation of platelet surface procoagulant markers while inducing similar release of growth factors and similar capacity to induce cell proliferation. Stimulation of PRP with SMLEF bipolar pulses is gentler than SMHEF pulses, resulting in less platelet microparticle generation but with overall activation levels similar to that obtained with thrombin. These results suggest that PEF provides the means to alter, in a controlled fashion, PRP properties thereby enabling evaluation of their effects on wound healing and clinical outcomes. PMID:27556645

  4. Waiting to inhale: HIF-1 modulates aerobic respiration.

    PubMed

    Boutin, Adam T; Johnson, Randall S

    2007-04-01

    The hypoxia-inducible factor HIF-1 is known to promote anaerobic respiration during low oxygen conditions (hypoxia). In this issue, Fukuda et al. (2007) expand the range of HIF-1's functions by showing that it modulates aerobic respiration as well.

  5. AEROBIC BIODEGRADATION OF GASOLINE OXYGENATES MTBE AND TBA

    EPA Science Inventory

    MTBE degradation was investigated using a continuously stirred tank reactor (CSTR) with biomass retention (porous pot reactor) operated under aerobic conditions. MTBE was fed to the reactor at an influent concentration of 150 mg/l (1.70 mmol/l). A second identifical rector was op...

  6. Cocaine Use in the Infertile Male Population: A Marker for Conditions Resulting in Subfertility

    PubMed Central

    Samplaski, Mary K.; Bachir, Bassel G.; Lo, Kirk C.; Grober, Ethan D.; Lau, Susan; Jarvi, Keith A.

    2015-01-01

    Introduction We sought to evaluate the incidence and effect of cocaine use in the infertile male population. Materials and Methods Men presenting for fertility evaluation reporting cocaine usage were identified via prospectively collected database. Data were analyzed for usage patterns, reproductive history, associated drug use and medical conditions, hormonal and semen parameters. Results Thirty-eight out of 4,400 (0.9%) men reported cocaine use. Most used cocaine every 3 months or less. Compared with non-cocaine using men, cocaine users reported more recreational drug use (89 vs. 9.2%), marijuana use (78.9 vs. 11.4%), chlamydia (10.5 vs. 3%), herpes (7.9 vs. 2.5%), and tobacco use (55.3 vs. 19.5%). After excluding men with causes for azoospermia, the mean semen parameters for cocaine users were: volume 2.47 ± 1.02 ml; concentration 53.55 ± 84.04 × 106/ml; motility 15.72 ± 12.26%; total motile sperm count 76.67 ± 180.30 × 106. Conclusions Few (< 1%) men in our infertile population reported the use of cocaine, and the frequency of use was low. Given the low use rates and limitations of reporting bias, it is difficult to determine the direct effect of cocaine use on male fertility. However, while infrequent cocaine use seems to have limited impact on semen parameters, men reporting cocaine use represent a different cohort of men than the overall infertile population, with higher rates of concurrent substance abuse, tobacco use and infections, all of which may negatively impact their fertility. Reported cocaine users should be screened for concurrent drug use and infections. PMID:26195962

  7. Aerobic Activity in Prevention & Symptom Control of Osteoarthritis

    PubMed Central

    Semanik, Pamela; Chang, Rowland W.; Dunlop, Dorothy D.

    2014-01-01

    Almost 27 million US adults suffer from some form of osteoarthritis (OA). An epidemic of arthritis-associated disability is expected in the US over the next 2 decades, largely fueled by the aging population and the tremendous growth in the prevalence of knee osteoarthritis (OA). Regular physical activity (PA), particularly strengthening and aerobic activity, can reduce pain and improve function and health status among patients with knee and hip osteoarthritis. The focus of this review is to examine the impact of aerobic activity on OA progression and symptom control. In general, both strengthening and aerobic exercise are associated with improvements in pain, perceived physical function, and performance measures for those with lower limb OA; although comparisons of strengthening versus aerobic exercise on these outcomes is unusual. Structural disease progression in persons with established OA has been directly evaluated by a limited number of PA clinical trials in knee OA, but these protocols focused on strength training exclusively. In healthy subjects, it appears that overall PA is beneficial, rather than detrimental, to knee joint health. Possibly the most important reason for engaging in PA is to prevent obesity, which has independently been associated with many serious chronic diseases, including OA incidence and progression. More research is needed to determine the optimal types and dosing of aerobic conditioning. PMID:22632701

  8. Aerobic activity in prevention and symptom control of osteoarthritis.

    PubMed

    Semanik, Pamela A; Chang, Rowland W; Dunlop, Dorothy D

    2012-05-01

    Almost 27 million adults in the United States experience some form of osteoarthritis (OA). An epidemic of arthritis-associated disability is expected in the United States during the next 2 decades, largely fueled by the aging population and the tremendous growth in the prevalence of knee OA. Regular physical activity (PA), particularly strengthening and aerobic activity, can reduce pain and improve function and health status among patients with knee and hip OA. The focus of this review is on the impact of aerobic activity on the progression and symptom control of OA. In general, both strengthening and aerobic exercise are associated with improvements in pain, perceived physical function, and performance measures for persons with lower limb OA, although comparisons of strengthening versus aerobic exercise on these outcomes are unusual. Structural disease progression in persons with established OA has been directly evaluated by a limited number of PA clinical trials for persons with knee OA, but these protocols focused on strength training exclusively. In healthy subjects, it appears that overall PA is beneficial, rather than detrimental, to knee joint health. Possibly the most important reason for engaging in PA is to prevent obesity, which independently has been associated with many serious chronic diseases, including the incidence and progression of OA. More research is needed to determine the optimal types and dosing of aerobic conditioning.

  9. [Identification and denitrification characteristics of a psychrotolerant facultative basophilic aerobic denitrifier].

    PubMed

    Wang, Zhao-Yang; Chen, Guo-Yao; Jiang, Ke; Xu, Pei-Ya

    2014-06-01

    An aerobic denitrifier was isolated from the activated sludge of landfill leachate through traditional microbiological methods. Based on its morphological feature, physiological and biochemical properties, and 16S rDNA sequence analysis, this strain was identified as Pseudomonas sp., named as GL19 with an accession number of KC710974 in GenBank. Its aerobic denitrification characteristics and nitrification function were studied to show that the factors including carbon source, C/N, pH and cultivation temperature were important for denitrification. The optimized condition for aerobic denitrification was as follows: sodium citrate as the carbon resource, C/N no less than 15, pH of 6-10, DO of 4.8-7.7 mg x L(-1), culture temperature of 15-34 degrees C and the initial nitrate nitrogen of 140 mg x L(-1). Combining these conditions, the removal rate of nitrate nitrogen and average removal rate of TN reached 100% and 96.5%, respectively, without the accumulation of nitrite nitrogen. The strain had the capability to utilize nitrite nitrogen or ammonia nitrogen to achieve high nitrogen removal efficiency: the nitrite nitrogen removal rate reached 100% in 20 hours with an initial nitrite nitrogen of 140 mg x L(-1); the ammonia nitrogen was efficiently removed from 280 mg x L(-1) to 3.11 mg x L(-1) in 28 hours with the removal rate of up to 98.9%. These results suggested that strain GL19 with the function of cold resistance and highly effective aerobic denitrification could achieve simultaneous nitrification and denitrification. Hence, GL19 could have high potential in practical wastewater treatment in winter of south area. PMID:25158516

  10. Membrane thickening aerobic digestion processes.

    PubMed

    Woo, Bryen

    2014-01-01

    Sludge management accounts for approximately 60% of the total wastewater treatment plant expenditure and laws for sludge disposal are becoming increasingly stringent, therefore much consideration is required when designing a solids handling process. A membrane thickening aerobic digestion process integrates a controlled aerobic digestion process with pre-thickening waste activated sludge using membrane technology. This process typically features an anoxic tank, an aerated membrane thickener operating in loop with a first-stage digester followed by second-stage digestion. Membrane thickening aerobic digestion processes can handle sludge from any liquid treatment process and is best for facilities obligated to meet low total phosphorus and nitrogen discharge limits. Membrane thickening aerobic digestion processes offer many advantages including: producing a reusable quality permeate with minimal levels of total phosphorus and nitrogen that can be recycled to the head works of a plant, protecting the performance of a biological nutrient removal liquid treatment process without requiring chemical addition, providing reliable thickening up to 4% solids concentration without the use of polymers or attention to decanting, increasing sludge storage capacities in existing tanks, minimizing the footprint of new tanks, reducing disposal costs, and providing Class B stabilization.

  11. Arthritis and Aerobic Exercise: A Review.

    ERIC Educational Resources Information Center

    Ike, Robert W.; And Others

    1989-01-01

    Arthritic patients who regularly do aerobic exercise make significant gains in aerobic and functional status, and in subjective areas like pain tolerance and mood. Still, they are often advised to curtail physical activity. Guidelines are presented for physicians prescribing aerobic exercise. An exercise tolerance test is recommended. (SM)

  12. Distinct stress conditions result in aggregation of proteins with similar properties

    PubMed Central

    Weids, Alan J.; Ibstedt, Sebastian; Tamás, Markus J.; Grant, Chris M.

    2016-01-01

    Protein aggregation is the abnormal association of proteins into larger aggregate structures which tend to be insoluble. This occurs during normal physiological conditions and in response to age or stress-induced protein misfolding and denaturation. In this present study we have defined the range of proteins that aggregate in yeast cells during normal growth and after exposure to stress conditions including an oxidative stress (hydrogen peroxide), a heavy metal stress (arsenite) and an amino acid analogue (azetidine-2-carboxylic acid). Our data indicate that these three stress conditions, which work by distinct mechanisms, promote the aggregation of similar types of proteins probably by lowering the threshold of protein aggregation. The proteins that aggregate during physiological conditions and stress share several features; however, stress conditions shift the criteria for protein aggregation propensity. This suggests that the proteins in aggregates are intrinsically aggregation-prone, rather than being proteins which are affected in a stress-specific manner. We additionally identified significant overlaps between stress aggregating yeast proteins and proteins that aggregate during ageing in yeast and C. elegans. We suggest that similar mechanisms may apply in disease- and non-disease settings and that the factors and components that control protein aggregation may be evolutionary conserved. PMID:27086931

  13. Correlation between Aerobic Fitness and Body Composition in Middle School Students

    PubMed Central

    Minasian, Vazgen; Marandi, Sayed Mohammad; Kelishadi, Roya; Abolhassani, Hossein

    2014-01-01

    Background: Since correlations have been found between body composition and physical activity in different parts of the world, inactivity and poor physical condition likely contributes main factors in childhood obesity. This study was implemented to determine the relationship between cardiovascular fitness and body-composition in a group of Iranian middle school students. Methods: In this descriptive study, subjects comprised of 12,946 students (10,531 girls and 2,415 boys aged 11–13 years) in the city of Isfahan. Height, weight, body-fat percent, body mass index, and cardiovascular fitness of the aforesaid students were measured by valid tests. Results: This study showed that fat percentage and aerobic fitness (VO2 max) of girls were 24.73%, and 29.5 (ml/kg/min) and boys19.32% and 36.4 (ml/kg/min) respectively. Results also revealed that there was a negative significant correlation between fat percent and aerobic fitness of boys (r = −0.81), and girls (r = −0.77) respectively. Conclusions: To conclude, this study signifies that fat percentage augmentation leads to a decrease in aerobic fitness of children. Thus, fat percentage can be associated with different chronic diseases such as cardiovascular ones. PMID:26157558

  14. Preliminary Results: Release Of Metals From Acid-Mine Drainage Contaminated Streambed Sediments Under Anaerobic Conditions (Presentation)

    EPA Science Inventory

    Many miles of streams in the western U.S. are contaminated with acid-mine drainage (AMD) from abandoned metal mines. Treatment of these streams may include removal of the existing sediments, with subsequent burial (e.g., in a repository). Burial of previously aerobic sediments ma...

  15. Breakage and growth towards a stable aerobic granule size during the treatment of wastewater.

    PubMed

    Verawaty, Marieska; Tait, Stephan; Pijuan, Maite; Yuan, Zhiguo; Bond, Philip L

    2013-09-15

    To better understand granule growth and breakage processes in aerobic granular sludge systems, the particle size of aerobic granules was tracked over 50 days of wastewater treatment within four sequencing batch reactors fed with abattoir wastewater. These experiments tested a novel hypothesis stating that granules equilibrate to a certain stable granule size (the critical size) which is determined by the influence of process conditions on the relative rates of granule growth and granule breakage or attrition. For granules that are larger than the critical size, granule breakage and attrition outweighs granule growth, and causes an overall reduction in granule size. For granules at the critical size, the overall growth and size reduction processes are balanced, and granule size is stable. For granules that are smaller than the critical size, granule growth outweighs granule breakage and attrition, and causes an overall increase in granule size. The experimental reactors were seeded with mature granules that were either small, medium, or large sized, these having respective median granule sizes of 425 μm, 900 μm and 1125 μm. An additional reactor was seeded with a mixture of the sized granules to represent the original source of the granular sludge. The experimental results were analysed together with results of a previous granule formation study that used mixed seeding of granules and floccular sludge. The analysis supported the critical size hypothesis and showed that granules in the reactors did equilibrate towards a common critical size of around 600-800 μm. Accordingly, it is expected that aerobic granular reactors at steady-state operation are likely to have granule size distributions around a characteristic critical size. Additionally, the results support that maintaining a quantity of granules above a particular size is important for granule formation during start-up and for process stability of aerobic granule systems. Hence, biomass washout needs to be

  16. A Catalyst-Controlled Aerobic Coupling of ortho-Quinones and Phenols Applied to the Synthesis of Aryl Ethers.

    PubMed

    Huang, Zheng; Lumb, Jean-Philip

    2016-09-12

    ortho-Quinones are underutilized six-carbon-atom building blocks. We herein describe an approach for controlling their reactivity with copper that gives rise to a catalytic aerobic cross-coupling with phenols. The resulting aryl ethers are generated in high yield across a broad substrate scope under mild conditions. This method represents a unique example where the covalent modification of an ortho-quinone is catalyzed by a transition metal, creating new opportunities for their utilization in synthesis. PMID:27513295

  17. Behaviour and fate of nine recycled water trace organics during managed aquifer recharge in an aerobic aquifer

    NASA Astrophysics Data System (ADS)

    Patterson, B. M.; Shackleton, M.; Furness, A. J.; Bekele, E.; Pearce, J.; Linge, K. L.; Busetti, F.; Spadek, T.; Toze, S.

    2011-03-01

    The fate of nine trace organic compounds was evaluated during a 12 month large-scale laboratory column experiment. The columns were packed with aquifer sediment and evaluated under natural aerobic and artificial anaerobic geochemical conditions, to assess the potential for natural attenuation of these compounds during aquifer passage associated with managed aquifer recharge (MAR). The nine trace organic compounds were bisphenol A (BPA), 17β-estradiol (E2), 17α-ethynylestradiol (EE2), N-nitrosodimethylamine (NDMA), N-nitrosomorpholine (NMOR), carbamazepine, oxazepam, iohexol and iodipamide. In the low organic carbon content Spearwood sediment, all trace organics were non-retarded with retardation coefficients between 1.0 and 1.2, indicating that these compounds would travel at near groundwater velocities within the aquifer. The natural aerobic geochemical conditions provided a suitable environment for the rapid degradation for BPA, E2, iohexol (half life < 1 day). Lag-times for the start of degradation of these compounds ranged from < 15 to 30 days. While iodipamide was persistent under aerobic conditions, artificial reductive geochemical conditions promoted via the addition of ethanol, resulted in rapid degradation (half life < 1 days). Pharmaceuticals (carbamazepine and oxazepam) and disinfection by-products (NDMA and NMOR) did not degrade under either aerobic or anaerobic aquifer geochemical conditions (half life > 50 days). Field-based validation experiments with carbamazepine and oxazepam also showed no degradation. If persistent trace organics are present in recycled waters at concentrations in excess of their intended use, natural attenuation during aquifer passage alone may not result in extracted water meeting regulatory requirements. Additional pre treatment of the recycled water would therefore be required.

  18. NALC/MEXICO LAND-COVER MAPPING RESULTS: IMPLICATIONS FOR ASSESSING LANDSCAPE CONDITION

    EPA Science Inventory

    An inventory of land-cover conditions throughout Mexico was performed using North American Landscape Characterization (NLAC) Landsat Mult-Spectral Scann (MSS) 'triplicate' images, corresponding to the 1970s, 1980s and 1990s epoch periods. The equivalents of 300 image scenes were...

  19. NATIONAL RESULTS FROM THE 2011 NATIONAL WETLAND CONDITION ASSESSMENT (NWCA) SOILS ANALYSIS

    EPA Science Inventory

    In 2011, US Environmental Protection Agency conducted the first National Wetland Condition Assessment (NWCA). Field crews conducted one-day surveys of over 1000 wetlands across the contiguous United States. For every wetland sampled, soils were collected by layer (i.e., horizon)...

  20. Wooden breast condition results in reduced thaw loss in frozen-thawed broiler breast fillets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wooden breast condition (WBC) is an emerging quality issue with broiler breast meat that significantly affects both raw and cooked meat properties. The objective of this study was to investigate the effects of WBC on meat water-holding capacity (WHC) estimated with different methods. Broiler breast ...

  1. NALC/MEXICO LAND-COVER MAPPING RESULTS: IMPLICATIONS FOR ASSESSING LANDSCAPE CONDITION

    EPA Science Inventory

    An inventory of land-cover conditions throughout Mexico was performed using North American Landscap Characterization ( NALC) Landsat Multi-Spectral Scanner (MSS) 'triplicate' images, corresponding to the 1970s, 1980s and1990s epoch periods. The equivalent of 300 image scenes were...

  2. Preliminary Results from a Mesocosm Marsh Experiment with Treatments Simulating Three Tidal Flooding and Precipitation Conditions

    EPA Science Inventory

    Our goal was to observe and quantify the effects of low, medium and high tidal flooding regimes and various precipitation conditions on both Spartina alterniflora and Typha angustifolia in greenhouse mesocosms. The experiment was maintained for 4 months. Each of 3 tanks (600L) ha...

  3. Anaerobes unleashed: Aerobic fuel cells of Geobacter sulfurreducens

    NASA Astrophysics Data System (ADS)

    Nevin, Kelly P.; Zhang, Pei; Franks, Ashley E.; Woodard, Trevor L.; Lovley, Derek R.

    One of the limitations of power generation with microbial fuel cells is that the anode must typically be maintained under anaerobic conditions. When oxygen is present in the anode chamber microorganisms oxidize the fuel with the reduction of oxygen rather than electron transfer to the anode. A system in which fuel is provided from within a graphite anode and diffuses out to the outer surface of the anode was designed to overcome these limitations. A biofilm of Geobacter sulfurreducens strain KN400, pregrown on the surface of a graphite electrode in a traditional two-chambered system with an anaerobic anode chamber and acetate as an external fuel source, produced current just as well under aerobic conditions when acetate was provided via diffusion from an internal concentrated acetate solution. No acetate was detectable in the external medium. In contrast, aerobic systems in which acetate was provided in the external medium completely failed within 48 h. Internally fed anodes colonized by a strain of KN400 adapted to grow at marine salinities produced current in aerobic seawater as well as an anaerobic anode system. The ability to generate current with an anode under aerobic conditions increases the potential applications and design options for microbial fuel cells.

  4. Stability of β-Lapachone upon Exposure to Various Stress Conditions: Resultant Efficacy and Cytotoxicity.

    PubMed

    Kim, Ki Hyun; Park, So-Hyun; Adhikary, Pratik; Cho, Jin Hun; Kang, Nae-Gyu; Jeong, Seong Hoon

    2016-01-01

    Even though β-lapachone is a promising compound with antitumor, antiinflammatory, antineoplastic, and wound-healing effects, there are still issues concerning its chemical stability and degradation mechanisms. The objective of this study was to obtain degradation profiles of β-lapachone and evaluate its chemical stability under various stress conditions. Moreover, the correlation between stability and efficacy was evaluated. The degradation study of β-lapachone was performed using heat, acid, base, oxidation, and light conditions. Kinetics and degradation profiles were investigated with HPLC and LC-MS. The stability indicated in the LC method was validated according to the International Conference on Harmonization guidelines. Human dermal fibroblast (HDF) cells were cultured with the standard and its degraded samples in the cellular activity and cytotoxicity test. β-Lapachone was relatively unstable upon exposure to light, and its photodegradation was accelerated with high relative humidity. Three degradants were identified, and their degradation followed zero-order kinetics. It was shown to degrade to phthalic acid under oxidative conditions, and the degradation kinetics were dependent on the concentration of hydrogen peroxide. Two degradation products were identified upon exposure to basic conditions, which followed first-order kinetics. β-Lapachone was relatively stable under acidic and thermal conditions. It increased the synthesis of collagen compared with the control. However, as the contents decreased, the synthesis of collagen also decreased in the photodegraded samples. β-Lapachone did not exert cytotoxic effects at the effective concentration in the cytotoxicity test. Therefore, in order to ensure efficacy and safety, the chemical stability of β-lapachone needs to be controlled carefully while considering instability mechanisms. PMID:27150470

  5. Impact of nitrite on aerobic phosphorus uptake by poly-phosphate accumulating organisms in enhanced biological phosphorus removal sludges.

    PubMed

    Zeng, Wei; Li, Boxiao; Yang, Yingying; Wang, Xiangdong; Li, Lei; Peng, Yongzhen

    2014-02-01

    Impact of nitrite on aerobic phosphorus (P) uptake of poly-phosphate accumulating organisms (PAOs) in three different enhanced biological phosphorus removal (EBPR) systems was investigated, i.e., the enriched PAOs culture fed with synthetic wastewater, the two lab-scale sequencing batch reactors (SBRs) treating domestic wastewater for nutrient removal through nitrite-pathway nitritation and nitrate-pathway nitrification, respectively. Fluorescence in situ hybridization results showed that PAOs in the three sludges accounted for 72, 7.6 and 6.5% of bacteria, respectively. In the enriched PAOs culture, at free nitrous acid (FNA) concentration of 0.47 × 10(-3) mg HNO₂-N/L, aerobic P-uptake and oxidation of intercellular poly-β-hydroxyalkanoates were both inhibited. Denitrifying phosphorus removal under the aerobic conditions was observed, indicating the existence of PAOs using nitrite as electron acceptor in this culture. When the FNA concentration reached 2.25 × 10(-3) mg HNO2-N/L, denitrifying phosphorus removal was also inhibited. And the inhibition ceased once nitrite was exhausted. Corresponding to both SBRs treating domestic wastewater with nitritation and nitrification pathway, nitrite inhibition on aerobic P-uptake by PAOs did not occur even though FNA concentration reached 3 × 10(-3) and 2.13 × 10(-3) mg HNO₂-N/L, respectively. Therefore, PAOs taken from different EBPR activated sludges had different tolerance to nitrite.

  6. A heme oxygenase isoform is essential for aerobic growth in the cyanobacterium Synechocystis sp. PCC 6803: modes of differential operation of two isoforms/enzymes to adapt to low oxygen environments in cyanobacteria.

    PubMed

    Aoki, Rina; Goto, Takeaki; Fujita, Yuichi

    2011-10-01

    Heme oxygenase (HO) catalyzes the oxygen-dependent cleavage of heme to produce biliverdin IXα in phycobilin biosynthesis. In the genome of the cyanobacterium Synechocystis sp. PCC 6803 there are two genes, ho1 (sll1184) and ho2 (sll1875), encoding HO isoforms. Reverse transcription-PCR indicated that ho1 is constitutively expressed, and ho2 is induced under micro-oxic conditions. A mutant lacking ho1 (Δho1) failed to grow under aerobic conditions while it did grow at a significantly slower rate than the wild type under anaerobic (micro-oxic) conditions. When micro-oxically grown Δho1 was incubated under aerobic conditions, the cells underwent chlorosis with a significant decrease in phycocyanin accompanied by anomalous accumulation of protoporphyrin IX. These results suggested that HO1 is essential for aerobic growth as the sole HO and is dispensable under micro-oxic conditions. A mutant lacking ho2 (Δho2) grew under both aerobic and micro-oxic conditions like the wild type at low light intensity (50 μmol(photon) m⁻² s⁻¹). At higher light intensity (120 μmol(photon) m⁻² s⁻¹) the Δho2 mutant showed significant growth retardation under micro-oxic conditions. It is suggested that HO2 operates as a dominant HO under high light and micro-oxic environments and acts as an accessory HO at low light intensity. Constitutive expression of HO2 in a neutral site of the chromosome restored aerobic growth of Δho1, suggesting that HO2 has an activity high enough to substitute for HO1 under aerobic conditions. The differential operation of two isoforms/enzymes in cyanobacterial tetrapyrrole biosynthesis to adapt to low oxygen environments is discussed, including three other reactions.

  7. Effect of aerobic exercises on stuttering

    PubMed Central

    Khan, Illays; Nawaz, Irum; Amjad, Imran

    2016-01-01

    Background and Objective: Stuttering is one of the most common speech disorders in adolescents than adults. Stuttering results in depression, anxiety, behavioral problem, social isolation and communication problems in daily life. Our objective was to determine the effect of Aerobic Exercises (AE) on stuttering. Methods: A quasi trail was conducted at National Institute of Rehabilitation Medicine (NIRM) from January to June 2015. Thirty patients were selected and placed in three different groups Experimental Group A, (EG = 10 patients, age between 7-14 years), Experimental Group B (EG =10 patients age between 15-28 years) and control group –group C, (CG = 10 patients, age between 7-28 years). Patient who stutter were included in this study and those with any other pathology or comorbidity of speech disorders were excluded. The assessment tool used was Real-Time analysis of speech fluency scale. Participants in all the groups received speech therapy while only the EG – A and B received aerobic exercises (AE) using treadmill and stationary bicycle along with the speech therapy. Pre-interventional and post interventional assessments were analyzed using the SPSS 21 in order to determine the significance of new treatment approach and the effectiveness of physical therapy on speech disorders. Results: All the groups showed significant treatment effects but both the EG groups (Group A, Group B) showed high improvement in the severity level of stuttering as compared to control group C. The results also showed that AE treated group B had significant difference in p-value (p=0.027) as compared to control group (p<0.05) while experimental group A had no significant difference (p > 0.05) between these groups. Conclusion: The eclectic approach of aerobic exercises with the traditional speech therapy provides proximal rehabilitation of stuttering. PMID:27648057

  8. Effect of aerobic exercises on stuttering

    PubMed Central

    Khan, Illays; Nawaz, Irum; Amjad, Imran

    2016-01-01

    Background and Objective: Stuttering is one of the most common speech disorders in adolescents than adults. Stuttering results in depression, anxiety, behavioral problem, social isolation and communication problems in daily life. Our objective was to determine the effect of Aerobic Exercises (AE) on stuttering. Methods: A quasi trail was conducted at National Institute of Rehabilitation Medicine (NIRM) from January to June 2015. Thirty patients were selected and placed in three different groups Experimental Group A, (EG = 10 patients, age between 7-14 years), Experimental Group B (EG =10 patients age between 15-28 years) and control group –group C, (CG = 10 patients, age between 7-28 years). Patient who stutter were included in this study and those with any other pathology or comorbidity of speech disorders were excluded. The assessment tool used was Real-Time analysis of speech fluency scale. Participants in all the groups received speech therapy while only the EG – A and B received aerobic exercises (AE) using treadmill and stationary bicycle along with the speech therapy. Pre-interventional and post interventional assessments were analyzed using the SPSS 21 in order to determine the significance of new treatment approach and the effectiveness of physical therapy on speech disorders. Results: All the groups showed significant treatment effects but both the EG groups (Group A, Group B) showed high improvement in the severity level of stuttering as compared to control group C. The results also showed that AE treated group B had significant difference in p-value (p=0.027) as compared to control group (p<0.05) while experimental group A had no significant difference (p > 0.05) between these groups. Conclusion: The eclectic approach of aerobic exercises with the traditional speech therapy provides proximal rehabilitation of stuttering.

  9. Effect of temperature on oxygen stores during aerobic diving in the freshwater turtle Mauremys caspica leprosa.

    PubMed

    Fuster, J F; Pagés, T; Palacios, L

    1997-01-01

    Oxygen stores available for aerobic diving were studied in the freshwater turtle (Mauremys caspica leprosa) at three constant body temperatures (15 degrees, 25 degrees, and 35 degrees C) and during the thermal transient (30 degrees-15 degrees C) induced by immersion in cold water. The term "aerobic dive limit" has been defined as the maximal duration of the dive before lactate increases. This increase occurs when a critical PO2 value is reached, and it is well characterized at lung level by a sharp increase in the lung apnoeic respiratory quotient. Kinetic analysis of lung gas composition during forced dives at fixed body temperature shows that critical PO2 values rise with temperature and that the postventilatory PO2 at the beginning of a dive decreases, so that the two temperature-dependent factors lead to a significant decrease with temperature in the lung O2 stores available for aerobic diving. During dives with transient body cooling, a natural condition in M. caspica leprosa, temperature equilibration occurs fast enough to expand aerobic scope by bearing the critical PO2 to the same value obtained at a fixed temperature of 15 degrees C. These dives are characterized by reversed CO2 transport (from lung to tissues) and therefore by negative values of the lung respiratory quotient; a decrease in temperature increases CO2 capacitance of tissues, resulting in a fall in PCO2 at constant CO2 content. Because this does not occur in the gas phase, PCO2 difference can lead to diffusion in the direction opposite from normal. This pattern may favour lung-to-tissue O2 transfer, through the Bohr effect. Therefore, the aerobic dive limit is reduced at high temperature not only through a metabolic rate effect but also through a marked decrease in the available O2 stores; fast body cooling (30 degrees-15 degrees C) associated with immersion in cold water extends the O2 stores available for aerobic diving to a level similar to that of immersions at constant body temperatures

  10. [Effect of different volume loading of aerobic/anaerobic zone on nitrogen and phosphorus removal by biofilm and granular sludge coupling process].

    PubMed

    Yin, Hang; Liu, Chang; Gao, Hui; Gao, Da-Wen

    2014-05-01

    The effect of different aerobic/anaerobic zone volume loading on nitrogen and phosphorus removal by biological film and granular coupling process was investigated using a self-designed Biofilm/Granular sludge coupling reactor. Three operating modes were conducted in the experiment. In operating mode I ,the volume of aerobic zone was 9. 66 L, and the volume of anaerobic zone was 15. 34 L. In operating mode II , the volume of aerobic zone was 12. 56 L, and the volume of anaerobic zone was 12. 44 L. In operating mode III , the volume of aerobic zone was 15.42 L, and the volume of anaerobic zone was 9.58 L. Three operating modes expressed different volume loading of the reactor because of different aerobic/anaerobic zone. The results showed that the performance of ammonia nitrogen and phosphorus removal was a bit poor in operating mode I , the effluent nitrate nitrogen was higher in operating mode III compared with other modes, which brought the total nitrogen removal efficiency lower. The operating mode II was optimal for nitrogen and phosphorus removal. In operating mode II , the ammonia nitrogen removal efficiency was about 80. 63% , the volume loading rate of nitrogen removal was about 150. 27 g(m3 d)-1, and the COD removal efficiency was higher than 83.24%; the amounts of phosphorus release and uptake under anaerobic conditions were 7. 23 mg L-1 and 11. 93 mg L-1.

  11. Heart rate during aerobics classes in women with different previous experience of aerobics.

    PubMed

    Laukkanen, R M; Kalaja, M K; Kalaja, S P; Holmala, E B; Paavolainen, L M; Tummavuori, M; Virtanen, P; Rusko, H K

    2001-01-01

    This study measured heart rate during floor and step aerobic classes at three intensity levels. A group of 20 female occasional exercisers [mean age 33 (SD 8) years, mean body mass index 21 (SD 2) kg.m-2 volunteered to participate in six aerobic classes (three floor classes, three step classes) and in a laboratory test as members of one of two groups according to their prestudy regular participation in aerobics classes. Subjects in group A had participated four or more times a week and those of group B less than twice a week. The characteristics of the groups were as follows: group A, n = 10, mean maximal oxygen uptake (VO2max) 38.7 (SD 3.6) ml.kg-1.min-1, mean maximal heart rate (HRmax) 183 (SD 8) beats.min-1; group B, n = 10, VO2max 36.1 (SD 3.6) ml.kg-1.min-1, HRmax 178 (SD 7) beats.min-1. Each class consisted of a warm-up, a 20 min period of structured aerobic exercise (cardiophase) and a cool-down. The cardiophase was planned and guided as light, (rate of perceived exertion, RPE 11-12), moderate (RPE 13-14) or heavy (RPE 15-17) by an experienced instructor. The mean heart rates during the light classes were 72 (step) and 74 (floor) %HRmax in group A and 75 (step) and 79 (floor) %HRmax in group B; during the moderate classes, 84 (step) and 80 (floor) %HRmax in group A and 82 (step) and 83 (floor) %HRmax in group B, and during the heavy classes 89 (step and floor) %HRmax in group A and 88 (step) and 92 (floor) %HRmax in group B. Differences in heart rate and %HRmax were not statistically significant between the groups. However, differences in heart rate and %HRmax between the intensities (light vs moderate, moderate vs heavy and light vs heavy) were significant within both groups (all, P < 0.01). Based on the results, we conclude that intensity management during the aerobics classes was generally successful regardless of the participants' prior participation in aerobics. However, some individuals who were older and/or had less prior participation tended to

  12. Boundary conditions for creeping flow along periodic or random rough surfaces : experimental and theoretical results

    NASA Astrophysics Data System (ADS)

    Lecoq, Nicolas

    2012-12-01

    Hydrodynamic interactions between particles and walls are relevant for the open problem of specifying boundary conditions for suspension flows. The Reynolds number around a small particle close to a wall is usually low and creeping flow equations apply. From the solution of these equations, the drag coefficient on a sphere becomes infinite when the gap between the sphere and a smooth wall vanishes, so that contact may not occur. Physically, the drag is finite because of various reasons, one of them being the particle and wall roughness. Then, for vanishing gap, even though some layers of fluid molecules may be left between the particle and wall roughness peaks, it may conventionally be said that contact occurs. In this paper, we are considering the example of a smooth sphere moving towards a rough wall. The roughness considered here consist of random rough planes or parallel periodic wedges, the characteristic length of which is small compared with the sphere radius. This problem is considered both experimentally and theoretically. The motion of a millimetre size bead settling towards a corrugated horizontal wall in a viscous oil is measured with laser interferometry giving an accuracy on the displacement of 0.2μm. Several random rough planes and wedge shaped walls were used, with various wavelengths and wedge angles. From the results, it is observed that the velocity of the sphere is, except for small gaps, similar to that towards a smooth plane that is shifted down from the top of corrugations. For the periodic wedges, the creeping flow is calculated as a series in the slope of the roughness grooves. The convergence of the series for the shift distance in term of the slope is accelerated by use of Euler transformation and of the existence of a limit for large slope. The cases of a flow along and across the grooves are considered separately. The shift is larger in the former case. Slightly flattened tops of the wedges used in experiments are also considered in

  13. Characterization and aerobic biodegradation of selected monoterpenes

    SciTech Connect

    Misra, G.; Pavlostathis, S.G.; Li, J.; Purdue, E.M.

    1996-12-31

    Monoterpenes are biogenic chemicals and occur in abundance in nature. Large-scale industrial use of these chemicals has recently been initiated in an attempt to replace halogenated solvents and chlorofluorocarbons which have been implicated in the stratospheric depletion of ozone. This study examined four hydrocarbon monoterpenes (d-limonene, {alpha}-pinene, {gamma}-terpinene, and terpinolene) and four alcohols (arbanol, linalool, plinol, and {alpha}-terpineol). Water solubility, vapor pressure, and octanol/water partition coefficients were estimated. Aerobic biodegradability tests were conducted in batch reactors by utilizing forest soil extract and enriched cultures as inoculum. The hydrophobic nature and high volatility of the hydrocarbons restricted the investigation to relatively low aqueous concentrations. Each monoterpene was analyzed with a gas chromatograph equipped with a flame ionization detector after extraction from the aqueous phase with isooctane. Terpene mineralization was tested by monitoring liquid-phase carbon, CO{sub 2} production and biomass growth. All four hydrocarbons and two alcohols readily degraded under aerobic conditions. Plinol resisted degradation in assays using inocula from diverse sources, while arbanol degraded very slowly. The intrinsic biokinetics coefficients for the degradation of d-limonene and {alpha}-terpineol were estimated by using cultures enriched with the respective monoterpenes. Monoterpene biodegradation followed Monod kinetics.

  14. Results of an outpatient-based stem cell allotransplant program using nonmyeloablative conditioning regimens.

    PubMed

    Ruiz-Argüelles, G J; Gómez-Almaguer, D; Ruiz-Argüelles, A; González-Llano, O; Cantú, O G; Jaime-Pérez, J C

    2001-04-01

    Using nonmyeloablative, immunosuppressive, fludarabine (FLU)-based conditioning regimens, we have performed allogeneic peripheral blood stem cell transplants in 26 patients (8 with chronic myelogenous leukemia, 6 with acute myelogenous leukemia, 10 with acute lymphoblastic leukemia, 1 with myelodysplasia, and 1 with thalassemia major). Conditioning consisted of FLU/busulphan/cyclophosphamide/cyclosporin-A (CyA)/methotrexate, or FLU/melphalan/CyA/methotrexate. The median granulocyte recovery time to 0.5 x 10(9)/l was 11 days, whereas the median platelet recovery time to 20 x 10(9)/l was 12 days. Twelve patients did not need red blood cell transfusions, and 8 did not need platelet transfusions. In 21 individuals (81%), the procedure could be completed fully on an outpatient basis. Follow-up times range between 30 and 600 days: one patient failed to engraft and recovered endogenous hemopoiesis; six out of 26 patients developed acute graft-versus-host disease (GVHD) whereas 7/22 developed chronic GVHD. Twelve patients (46%) have died, nine of them with a relapsing disease and three with GVHD; median post-transplant survival (SV) was 300 days, whereas the 12-month SV was 42%. The 100-day mortality was 3.8% and the transplant-related mortality was 11.5%. This procedure is substantially less costly than its counterpart, using in-hospital myeloablative conditioning regimens, and it may represent another approach in the management of patients requiring an allogeneic stem cell transplant.

  15. Fuel performance under normal PWR conditions: A review of relevant experimental results and models

    NASA Astrophysics Data System (ADS)

    Charles, M.; Lemaignan, C.

    1992-06-01

    Experiments conducted at Grenoble (CEA/DRN) over the past 20 years in the field of nuclear fuel behaviour are reviewed. Of particular concern is the need to achieve a comprehensive understanding of and subsequently overcome the limitations associated with high burnup and load-following conditions (pellet-cladding interaction (PCI), fission gas release (FGR), water-side corrosion). A general view is given of the organization of research work as well as some experimental details (irradiation, postirradiation examination — PIE). Based on various experimental programmes (Cyrano, Medicis, Anemone, Furet, Tango, Contact, Cansar, Hatac, Flog, Decor), the main contributions of the thermomechanical behaviour of a PWR fuel rod are described: thermal conductivity, in-pile densification, swelling, fission gas release in steady state and moderate transient conditions, gap thermal conductance, formation of primary and secondary ridges under PCI conditions. Specific programmes (Gdgrif, Thermox, Grimox) are devoted to the behaviour of particular fuels (gadolinia-bearing fuel, MOX fuel). Moreover, microstructure-based studies have been undertaken on fission gas release (fine analysis of the bubble population inside irradiated fuel samples), and on cladding behaviour (PCI related studies on stress-corrosion cracking (SCO, irradiation effects on zircaloy microstructure).

  16. Anaerobic and aerobic transformations affecting stability of dewatered sludge during long-term storage in a lagoon.

    PubMed

    Lukicheva, Irina; Tian, Guanglong; Cox, Albert; Granato, Thomas; Pagilla, Krishna

    2012-01-01

    The goal of this work was to study long-term behavior of anaerobically digested and dewatered sludge (biosolids) in a lagoon under anaerobic and aerobic conditions to determine the stability of the final product as an indicator of its odor potential. Field lagoons were sampled to estimate spatial and temporal variations in the physical-chemical properties and biological stability characteristics such as volatile solids content, accumulated oxygen uptake, and soluble protein content and odorous compound assessment. The analyses of collected data suggest that the surface layer of the lagoon (depth of above 0.15 m) undergoes long-term aerobic oxidation resulting in a higher degree of stabilization in the final product. The subsurface layers (depth 0.15 m below the surface and deeper) are subjected to an anaerobic environment where the conditions favor the initial rapid organic matter degradation within approximately the first year, followed by slow degradation. PMID:22368823

  17. Comparison of aerobic denitrifying activity among three cultural species with various carbon sources.

    PubMed

    Otani, Y; Hasegawa, K; Hanaki, K

    2004-01-01

    Abilities of three aerobic denitrifiers such as Alcaligenes faecalis, Microvirgula aerodenitrificans and Paracoccus pantotrophus were compared from the viewpoints of nitrate removal efficiency and organic matter utilization. First, the effect of carbon source was investigated. Although nitrate reduction was observed in all strains under aerobic conditions, a change of carbon source considerably affected the denitrification ability. In the case of P. pantotrophus, nitrate and nitrite were completely removed in three days under sodium acetate or leucine as a carbon source. In the case of A. faecalis, sufficient nitrate removal was observed only when sodium acetate or ethanol was added. P. pantotrophus and A. faecalis showed a higher ability of nitrate removal than that of M. aerodenitrificans. Therefore, P. pantotrophus was selected in order to investigate the effects of concentration and repetitive addition of carbon. Sodium acetate was used as a sole carbon source. Nitrate was not reduced when the carbon concentration was below 500 mgC/L. However, when carbon source was added repeatedly, nitrate was reduced under 100 mgC/L after the optical density of the bacterium reached above 1.0. This result indicated that a high enough level of bacterial density was necessary to express aerobic denitrification activity. PMID:15566182

  18. Measuring aerobic respiration in stream ecosystems using the resazurin-resorufin system

    NASA Astrophysics Data System (ADS)

    GonzáLez-Pinzón, Ricardo; Haggerty, Roy; Myrold, David D.

    2012-09-01

    The use of smart tracers to study hydrologic systems is becoming more widespread. Smart tracers are compounds that irreversibly react in the presence of a process or condition under investigation. Resazurin (Raz) is a smart tracer that undergoes an irreversible reduction to resorufin (Rru) in the presence of cellular metabolic activity. We quantified the relationship between the transformation of Raz and aerobic bacterial respiration in pure culture experiments using two obligate aerobes and two facultative anaerobes, and in colonized surface and shallow (<10 cm) hyporheic sediments using reach-scale experiments. We found that the transformation of Raz to Rru was nearly perfectly (minr2 = 0.986), positively correlated with aerobic microbial respiration in all experiments. These results suggest that Raz can be used as a surrogate to measure respiration in situ and in vivoat different spatial scales, thus providing an alternative to investigate mechanistic controls of solute transport and stream metabolism on nutrient processing. Lastly, a comparison of respiration and mass-transfer rates in streams suggests that field-scale respiration is controlled by the slower of respiration and mass transfer, highlighting the need to understand both biogeochemistry and physics in stream ecosystems.

  19. Nonlinear Dielectric Properties of Yeast Cells Cultured in Different Environmental Conditions

    NASA Astrophysics Data System (ADS)

    Kawanishi, Gomon; Fukuda, Naoki; Muraji, Masafumi

    The harmonics of the electric current through yeast suspensions, the nonlinear dielectric properties of yeast cells, have particular patterns according to the biological activity of the cells and the measurement of these patterns is a technique for determining the activity of living cells. The concentration of glucose and oxygen in yeast culture medium influences the manifestation of fermentation or respiration of yeast cells. Measurements were made with yeast cells (Saccharomyces cerevisiae) cultured aerobically and anaerobically in sufficient glucose concentration, aerobic fermentation and anaerobic fermentation, and aerobically in limited glucose concentration, respiration. The results showed that the harmonics were barely apparent for yeast cells in aerobic fermentation and respiratory; however, cells in the anaerobic fermentation displayed substantial third and fifth harmonics. We can say that environmental condition affects the yeast cells' nonlinear properties, from another viewpoint, the measurements of the nonlinear properties are available to determine the activity of yeast cells adjusted to the conditions of their cultivation.

  20. Effects of acute physical exercise on executive functions: a comparison between aerobic and strength exercise.

    PubMed

    Alves, Christiano Rodrigues; Gualano, Bruno; Takao, Pollyana Pereira; Avakian, Paula; Fernandes, Rafael Mistura; Morine, Diego; Takito, Monica Yuri

    2012-08-01

    The aim of this study was to compare the effects of acute aerobic and strength exercises on selected executive functions. A counterbalanced, crossover, randomized trial was performed. Forty-two healthy women were randomly submitted to three different conditions: (1) aerobic exercise, (2) strength exercise, and (3) control condition. Before and after each condition, executive functions were measured by the Stroop Test and the Trail Making Test. Following the aerobic and strength sessions, the time to complete the Stroop "non-color word" and "color word" condition was lower when compared with that of the control session. The performance in the Trail Making Test was unchanged. In conclusion, both acute aerobic and strength exercises improve the executive functions. Nevertheless, this positive effect seems to be task and executive function dependent. PMID:22889693

  1. Beyond vascularization: aerobic fitness is associated with N-acetylaspartate and working memory.

    PubMed

    Erickson, Kirk I; Weinstein, Andrea M; Sutton, Bradley P; Prakash, Ruchika Shaurya; Voss, Michelle W; Chaddock, Laura; Szabo, Amanda N; Mailey, Emily L; White, Siobhan M; Wojcicki, Thomas R; McAuley, Edward; Kramer, Arthur F

    2012-01-01

    Aerobic exercise is a promising form of prevention for cognitive decline; however, little is known about the molecular mechanisms by which exercise and fitness impacts the human brain. Several studies have postulated that increased regional brain volume and function are associated with aerobic fitness because of increased vascularization rather than increased neural tissue per se. We tested this position by examining the relationship between cardiorespiratory fitness and N-acetylaspartate (NAA) levels in the right frontal cortex using magnetic resonance spectroscopy. NAA is a nervous system specific metabolite found predominantly in cell bodies of neurons. We reasoned that if aerobic fitness was predominantly influencing the vasculature of the brain, then NAA levels should not vary as a function of aerobic fitness. However, if aerobic fitness influences the number or viability of neurons, then higher aerobic fitness levels might be associated with greater concentrations of NAA. We examined NAA levels, aerobic fitness, and cognitive performance in 137 older adults without cognitive impairment. Consistent with the latter hypothesis, we found that higher aerobic fitness levels offset an age-related decline in NAA. Furthermore, NAA mediated an association between fitness and backward digit span performance, suggesting that neuronal viability as measured by NAA is important in understanding fitness-related cognitive enhancement. Since NAA is found exclusively in neural tissue, our results indicate that the effect of fitness on the human brain extends beyond vascularization; aerobic fitness is associated with neuronal viability in the frontal cortex of older adults.

  2. Constraining flooding conditions for early historic and prehistoric hurricanes from resultant deposits preserved in Florida sinkholes

    NASA Astrophysics Data System (ADS)

    Brandon, C. M.; Woodruff, J. D.; Lane, P.; Donnelly, J. P.

    2011-12-01

    Instrumental records of hurricane strikes in the United States are relatively short, extending back only ~160 years. Sediment deposits created by hurricane-induced coastal inundation serve as valuable proxies of storm activity and can extend these records back several millennia. Here we provide a record of hurricane inundation preserved within the sediments of Callahan Pond, a small coastal sinkhole located within the Florida Panhandle. This 15 m deep pond has remained relatively undisturbed over the last 2000 years allowing it to accumulate fine grained organic-rich sediments punctuated by well-preserved quartz sand layers likely associated with hurricane surges. An event deposit located within surface sediments from the pond likely corresponds to a hurricane that struck the area in 1941, and is used as a modern analogue to help evaluate flooding conditions for older event layers preserved within the depositional record. Grain size analyses are performed on each event-deposit to help constrain flow conditions required for erosion and transport. The Regional Ocean Modeling System (ROMS) is then employed to perform a series of 2-D coastal inundation simulations at the site to assess the near-shore flooding conditions required to produce each of the observed event-deposits. Probability distribution functions are generated to assess the Saffir-Simpson storm category for each event-deposit. Age constraints on the deposits are developed by using carbon-14 and cesium-137 radiometric dating techniques. A period of increased storm activity is observed from ~500 to ~1200 AD, encompassing the Medieval Warm Period and a period of decreased storm activity is observed from ~1450 AD to the present, encompassing the Little Ice Age.

  3. Aerobic microbial enhanced oil recovery

    SciTech Connect

    Torsvik, T.; Gilje, E.; Sunde, E.

    1995-12-31

    In aerobic MEOR, the ability of oil-degrading bacteria to mobilize oil is used to increase oil recovery. In this process, oxygen and mineral nutrients are injected into the oil reservoir in order to stimulate growth of aerobic oil-degrading bacteria in the reservoir. Experiments carried out in a model sandstone with stock tank oil and bacteria isolated from offshore wells showed that residual oil saturation was lowered from 27% to 3%. The process was time dependent, not pore volume dependent. During MEOR flooding, the relative permeability of water was lowered. Oxygen and active bacteria were needed for the process to take place. Maximum efficiency was reached at low oxygen concentrations, approximately 1 mg O{sub 2}/liter.

  4. Precarious employment conditions affect work content in education and social work: results of work analyses.

    PubMed

    Seifert, Ana Maria; Messing, Karen; Riel, Jessica; Chatigny, Céline

    2007-01-01

    Work content is adversely affected by precarious employment conditions, with consequences for workers and clients/customers. Three examples are taken from professions involving long-term relations between workers and clients. Adult education teachers hired on short-term contracts to teach primarily immigrant populations prepare their courses under less favorable conditions than regular teachers and their employment context foments hostility among teachers. Special education technicians are hired on a seasonal basis which interferes with their ability to coordinate and plan their efforts in collaboration with teachers. Workers in shelters for women suffering conjugal violence who were hired on a casual or on-call basis were unable to follow up with women they helped during their shifts and more rarely engaged in one-on-one counseling. Precarious work contracts can affect mental health not only through employment insecurity but also through negative effects on the ability to do one's job and take pride in one's work, as well as weakening the interpersonal relationships on which successful, productive work depends. PMID:17631963

  5. [EPIDEMIOLOGICAL, CLINICAL AND MICROBIOLOGICAL FINDINGS IN WOMEN WITH AEROBIC VAGINITIS].

    PubMed

    Dermendjiev, T; Pehlivanov, B; Hadjieva, K; Stanev, S

    2015-01-01

    Aerobic vaginitis (AV) is an alterarion of the normal lactobacillic flora accompanied by signs of inflammation, presence of mainly aerobic microorganisms from intestinal commensals or other aerobic pathogens. Clinical symptoms may vary by type and intensity and are marked by a high tendency for recurrence and chronification. Inflammation and ulcerations in AV could increase the risk of contracting HIV or other sexually transmitted infections. The aim is to study some epidemiological, clinical and microbiological features of the aerobic vaginitis in patients of the specialized Obstetric and Gynecological Clinic in Plovdiv, Bulgaria. In a retrospective research 4687 vaginal smears have been gathered in Microbiological laboratory at "St. George" Hospital - Plovdiv. We used clinical, microbiological and statistical methods. Information processing is performed by variation, alternative, correlation and graphical analysis using specialized package SPSS v13.0. The overall prevalence rate of AV in the studied population is 11.77%. The levels of prevalence of AV in pregnant and non-pregnant women are respectively 13.08% and 4.34%. The highest frequency of AV is in the age group 21-30 years (32.3%). The results show a marked association between Escherichia coli and the cases of AV (p < 0.001). AV is a common cause of vaginal symptoms in patients of specialized ambulatory outpatient. One in ten women with vaginal complaints suffers from AV Streptococcus agalactiae and Escherichia coli are most often isolated aerobic microorganisms. PMID:26863788

  6. Degradation of TCE using sequential anaerobic biofilm and aerobic immobilized bed reactor

    NASA Technical Reports Server (NTRS)

    Chapatwala, Kirit D.; Babu, G. R. V.; Baresi, Larry; Trunzo, Richard M.

    1995-01-01

    Bacteria capable of degrading trichloroethylene (TCE) were isolated from contaminated wastewaters and soil sites. The aerobic cultures were identified as Pseudomonas aeruginosa (four species) and Pseudomonas fluorescens. The optimal conditions for the growth of aerobic cultures were determined. The minimal inhibitory concentration values of TCE for Pseudomonas sps. were also determined. The aerobic cells were immobilized in calcium alginate in the form of beads. Degradation of TCE by the anaerobic and dichloroethylene (DCE) by aerobic cultures was studied using dual reactors - anaerobic biofilm and aerobic immobilized bed reactor. The minimal mineral salt (MMS) medium saturated with TCE was pumped at the rate of 1 ml per hour into the anaerobic reactor. The MMS medium saturated with DCE and supplemented with xylenes and toluene (3 ppm each) was pumped at the rate of 1 ml per hour into the fluidized air-uplift-type reactor containing the immobilized aerobic cells. The concentrations of TCE and DCE and the metabolites formed during their degradation by the anaerobic and aerobic cultures were monitored by GC. The preliminary study suggests that the anaerobic and aerobic cultures of our isolates can degrade TCE and DCE.

  7. Degradation of TCE using sequential anaerobic biofilm and aerobic immobilized bed reactor

    NASA Astrophysics Data System (ADS)

    Chapatwala, Kirit D.; Babu, G. R. V.; Baresi, Larry; Trunzo, Richard M.

    1995-03-01

    Bacteria capable of degrading trichloroethylene (TCE) were isolated from contaminated wastewaters and soil sites. The aerobic cultures were identified as Pseudomonas aeruginosa (four species) and Pseudomonas fluorescens. The optimal conditions for the growth of aerobic cultures were determined. The minimal inhibitory concentration values of TCE for Pseudomonas sps. were also determined. The aerobic cells were immobilized in calcium alginate in the form of beads. Degradation of TCE by the anaerobic and dichloroethylene (DCE) by aerobic cultures was studied using dual reactors - anaerobic biofilm and aerobic immobilized bed reactor. The minimal mineral salt (MMS) medium saturated with TCE was pumped at the rate of 1 ml per hour into the anaerobic reactor. The MMS medium saturated with DCE and supplemented with xylenes and toluene (3 ppm each) was pumped at the rate of 1 ml per hour into the fluidized air-uplift-type reactor containing the immobilized aerobic cells. The concentrations of TCE and DCE and the metabolites formed during their degradation by the anaerobic and aerobic cultures were monitored by GC. The preliminary study suggests that the anaerobic and aerobic cultures of our isolates can degrade TCE and DCE.

  8. [Evaluating dependency of medical rehabilitation results in occupational polyneuropathy patiens on treatment strategy and work conditions].

    PubMed

    Boiko, I V; Loginova, N N; Klitsenko, O A

    2015-01-01

    The authors evaluated efficiency of rehabilitation in patients with upper limbs occupational polyneuropathy, in accordance with length of service under physical overstrain. The study was based on follow-up of 268 patients. Treatment was initiated after the patients discontinued work hazardous for health. Drug and sanatorium treatment was effective in 67-86% of patients (with differences in occupational groups). The effect was only transitory (for 15-60 days) decrease of the disease clinical manifestations. Rehabilitation prognosis was reliably better in patients who worked during the disease development in conditions with number of stereotypic working movements of hands within hygienic norms. The treatment efficiency is reliably higher when started at younger age, regular drug and sanatorium treatment for many years. Placement of the patients on jobs avoiding physical overstrain enabled nowadays to prevent progression of occupational polyneuropathy.

  9. Can psychosocial work conditions protect against age-related cognitive decline? Results from a systematic review.

    PubMed

    Nexø, Mette Andersen; Meng, Annette; Borg, Vilhelm

    2016-07-01

    According to the use it or lose it hypothesis, intellectually stimulating activities postpone age-related cognitive decline. A previous systematic review concluded that a high level of mental work demands and job control protected against cognitive decline. However, it did not distinguish between outcomes that were measured as cognitive function at one point in time or as cognitive decline. Our study aimed to systematically review which psychosocial working conditions were prospectively associated with high levels of cognitive function and/or changes in cognitive function over time. Articles were identified by a systematic literature search (MEDLINE, Web of Science (WOS), PsycNET, Occupational Safety and Health (OSH)). We included only studies with longitudinal designs examining the impact of psychosocial work conditions on outcomes defined as cognitive function or changes in cognitive function. Two independent reviewers compared title-abstract screenings, full-text screenings and quality assessment ratings. Eleven studies were included in the final synthesis and showed that high levels of mental work demands, occupational complexity or job control at one point in time were prospectively associated with higher levels of cognitive function in midlife or late life. However, the evidence to clarify whether these psychosocial factors also affected cognitive decline was insufficient, conflicting or weak. It remains speculative whether job control, job demands or occupational complexity can protect against cognitive decline. Future studies using methodological advancements can reveal whether workers gain more cognitive reserve in midlife and late life than the available evidence currently suggests. The public health implications of a previous review should thereby be redefined accordingly. PMID:27178844

  10. Can psychosocial work conditions protect against age-related cognitive decline? Results from a systematic review

    PubMed Central

    Nexø, Mette Andersen; Meng, Annette; Borg, Vilhelm

    2016-01-01

    According to the use it or lose it hypothesis, intellectually stimulating activities postpone age-related cognitive decline. A previous systematic review concluded that a high level of mental work demands and job control protected against cognitive decline. However, it did not distinguish between outcomes that were measured as cognitive function at one point in time or as cognitive decline. Our study aimed to systematically review which psychosocial working conditions were prospectively associated with high levels of cognitive function and/or changes in cognitive function over time. Articles were identified by a systematic literature search (MEDLINE, Web of Science (WOS), PsycNET, Occupational Safety and Health (OSH)). We included only studies with longitudinal designs examining the impact of psychosocial work conditions on outcomes defined as cognitive function or changes in cognitive function. Two independent reviewers compared title-abstract screenings, full-text screenings and quality assessment ratings. Eleven studies were included in the final synthesis and showed that high levels of mental work demands, occupational complexity or job control at one point in time were prospectively associated with higher levels of cognitive function in midlife or late life. However, the evidence to clarify whether these psychosocial factors also affected cognitive decline was insufficient, conflicting or weak. It remains speculative whether job control, job demands or occupational complexity can protect against cognitive decline. Future studies using methodological advancements can reveal whether workers gain more cognitive reserve in midlife and late life than the available evidence currently suggests. The public health implications of a previous review should thereby be redefined accordingly. PMID:27178844

  11. Results of thermal performance evaluation of the Owens-Illinois sunpack liquid solar collector at indoor conditions

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Test procedures and results of the thermal performance of a liquid, evacuated tube, solar collector under simulated conditions are presented. The collector tested was a module used on the early demonstration projects.

  12. Assessment of bacterial and structural dynamics in aerobic granular biofilms

    PubMed Central

    Weissbrodt, David G.; Neu, Thomas R.; Kuhlicke, Ute; Rappaz, Yoan; Holliger, Christof

    2013-01-01

    Aerobic granular sludge (AGS) is based on self-granulated flocs forming mobile biofilms with a gel-like consistence. Bacterial and structural dynamics from flocs to granules were followed in anaerobic-aerobic sequencing batch reactors (SBR) fed with synthetic wastewater, namely a bubble column (BC-SBR) operated under wash-out conditions for fast granulation, and two stirred-tank enrichments of Accumulibacter (PAO-SBR) and Competibacter (GAO-SBR) operated at steady-state. In the BC-SBR, granules formed within 2 weeks by swelling of Zoogloea colonies around flocs, developing subsequently smooth zoogloeal biofilms. However, Zoogloea predominance (37–79%) led to deteriorated nutrient removal during the first months of reactor operation. Upon maturation, improved nitrification (80–100%), nitrogen removal (43–83%), and high but unstable dephosphatation (75–100%) were obtained. Proliferation of dense clusters of nitrifiers, Accumulibacter, and Competibacter from granule cores outwards resulted in heterogeneous bioaggregates, inside which only low abundance Zoogloea (<5%) were detected in biofilm interstices. The presence of different extracellular glycoconjugates detected by fluorescence lectin-binding analysis showed the complex nature of the intracellular matrix of these granules. In the PAO-SBR, granulation occurred within two months with abundant and active Accumulibacter populations (56 ± 10%) that were selected under full anaerobic uptake of volatile fatty acids and that aggregated as dense clusters within heterogeneous granules. Flocs self-granulated in the GAO-SBR after 480 days during a period of over-aeration caused by biofilm growth on the oxygen sensor. Granules were dominated by heterogeneous clusters of Competibacter (37 ± 11%). Zoogloea were never abundant in biomass of both PAO- and GAO-SBRs. This study showed that Zoogloea, Accumulibacter, and Competibacter affiliates can form granules, and that the granulation mechanisms rely on the dominant

  13. Supplementary Low-Intensity Aerobic Training Improves Aerobic Capacity and Does Not Affect Psychomotor Performance in Professional Female Ballet Dancers

    PubMed Central

    Smol, Ewelina; Fredyk, Artur

    2012-01-01

    We investigated whether 6-week low-intensity aerobic training program used as a supplement to regular dance practice might improve both the aerobic capacity and psychomotor performance in female ballet dancers. To assess their maximal oxygen uptake (VO2max) and anaerobic threshold (AT), the dancers performed a standard graded bicycle ergometer exercise test until volitional exhaustion prior to and after the supplementary training. At both these occasions, the psychomotor performance (assessed as multiple choice reaction time) and number of correct responses to audio-visual stimuli was assessed at rest and immediately after cessation of maximal intensity exercise. The supplementary low-intensity exercise training increased VO2max and markedly shifted AT toward higher absolute workload. Immediately after completion of the graded exercise to volitional exhaustion, the ballerinas’ psychomotor performance remained at the pre-exercise (resting) level. Neither the resting nor the maximal multiple choice reaction time and accuracy of responses were affected by the supplementary aerobic training. The results of this study indicate that addition of low-intensity aerobic training to regular dance practice increases aerobic capacity of ballerinas with no loss of speed and accuracy of their psychomotor reaction. PMID:23485962

  14. Selecting anti-microbial treatment of aerobic vaginitis.

    PubMed

    Donders, Gilbert G G; Ruban, Katerina; Bellen, Gert

    2015-05-01

    Aerobic vaginitis (AV) is a vaginal infectious condition which is often confused with bacterial vaginosis (BV) or with the intermediate microflora as diagnosed by Nugent's method to detect BV on Gram-stained specimens. However, although both conditions reflect a state of lactobacillary disruption in the vagina, leading to an increase in pH, BV and AV differ profoundly. While BV is a noninflammatory condition composed of a multiplex array of different anaerobic bacteria in high quantities, AV is rather sparely populated by one or two enteric commensal flora bacteria, like Streptococcus agalactiae, Staphylocuccus aureus, or Escherichia coli. AV is typically marked by either an increased inflammatory response or by prominent signs of epithelial atrophy or both. The latter condition, if severe, is also called desquamative inflammatory vaginitis. As AV is per exclusionem diagnosed by wet mount microscopy, it is a mistake to treat just vaginal culture results. Vaginal cultures only serve as follow-up data in clinical research projects and are at most used in clinical practice to confirm the diagnosis or exclude Candida infection. AV requires treatment based on microscopy findings and a combined local treatment with any of the following which may yield the best results: antibiotic (infectious component), steroids (inflammatory component), and/or estrogen (atrophy component). In cases with Candida present on microscopy or culture, antifungals must be tried first in order to see if other treatment is still needed. Vaginal rinsing with povidone iodine can provide rapid relief of symptoms but does not provide long-term reduction of bacterial loads. Local antibiotics most suitable are preferably non-absorbed and broad spectrum, especially those covering enteric gram-positive and gram-negative aerobes, like kanamycin. To achieve rapid and short-term improvement of severe symptoms, oral therapy with amoxyclav or moxifloxacin can be used, especially in deep dermal vulvitis and

  15. Steps Counts among Middle School Students Vary with Aerobic Fitness Level

    ERIC Educational Resources Information Center

    Le Masurier, Guy C.; Corbin, Charles B.

    2006-01-01

    The purpose of this study was to examine if steps/day taken by middle school students varied based on aerobic fitness classification. Middle school students (N = 223; 112 girls, 111 boys) were assigned to three aerobic fitness categories (HIGH, MOD, LOW) based on results of the FITNESSGRAM PACER test. Four weekdays of pedometer monitoring…

  16. Conditioning matrices from high level waste resulting from pyrochemical processing in fluorine salt

    SciTech Connect

    Grandjean, Agnes; Advocat, Thierry; Bousquet, Nicolas; Jegou, Christophe

    2007-07-01

    Separating the actinides from the fission products through reductive extraction by aluminium in a LiF/AlF{sub 3} medium is a process investigated for pyrometallurgical reprocessing of spent fuel. The process involves separation by reductive salt-metal extraction. After dissolving the fuel or the transmutation target in a salt bath, the noble metal fission products are first extracted by contacting them with a slightly reducing metal. After extracting the metal fission products, then the actinides are selectively separated from the remaining fission products. In this hypothesis, all the unrecoverable fission products would be conditioned as fluorides. Therefore, this process will generate first a metallic waste containing the 'reducible' fission products (Pd, Mo, Ru, Rh, Tc, etc.) and a fluorine waste containing alkali-metal, alkaline-earth and rare earth fission products. Immobilization of these wastes in classical borosilicate glasses is not feasible due to the very low solubility of noble metals, and of fluoride in these hosts. Alternative candidates have therefore been developed including silicate glass/ceramic system for fluoride fission products and metallic ones for noble metal fission products. These waste-forms were evaluated for their confinement properties like homogeneity, waste loading, volatility during the elaboration process, chemical durability, etc. using appropriate techniques. (authors)

  17. Long working hours in Korea: results of the 2010 Working Conditions Survey.

    PubMed

    Park, Jungsun; Kwon, Oh Jun; Kim, Yangho

    2012-01-01

    Long working hours adversely affect workers' safety and health. In 2004, Korea passed legislation limiting the working week to 40 h, to improve quality-of-life and to increase business competitiveness. In the present study, we explored the characteristics of work in Korea and compared our data of the second Korean Working Conditions Survey (KWCS) with those of the first KWCS. We found that the average number of hours worked weekly has been reduced but the proportions of workers who work for more than 48 h per week has increased over the 4 yr between the two Korean surveys in all categories studied (male, female, employee, self-employed, and employer). We also found that self-employed and employers work much longer hours than do employees, who are protected by the Labor Standards Act. This was particularly true in the accommodation and food service sectors. In conclusion, Korean workers work longer than do workers of EU countries. The use of average figures masks differences in the numbers of working hours among those engaged in various types of employment, or in certain work sectors. Therefore, the Korean government should not simply monitor reductions in average weekly working hours, but should identify employees working for over 60 h weekly, and reduce their working time. PMID:22878357

  18. Estimating surface water risk at Oak Ridge National Laboratory: Effects of site conditions on modeling results

    SciTech Connect

    Curtis, A.H. III

    1996-08-01

    Multiple source term and groundwater modeling runs were executed to estimate surface water {sup 90}Sr concentrations resulting from leaching of sludges in five 180,000 gallon Gunite{trademark} tanks at Oak Ridge National Laboratory. Four release scenarios were analyzed: (1) leaching of unstabilized sludge with immediate tank failure; (2) leaching of unstabilized sludge with delayed tank failure due to chemical degradation; (3) leaching of stabilized sludge with immediate tank failure; and (4) leaching of residual contamination out of the shells of empty tanks. Source terms and concentrations of {sup 90}Sr in the stream directly downgradient of the tanks were calculated under these release scenarios. The following conclusions were drawn from the results of the modeling: (1) small changes in soil path length resulted in relatively large changes in the modeled {sup 90}Sr concentrations in the stream; (2) there was a linear relationship between the amount of sludge remaining in a tank and the peak concentration of {sup 90}Sr in the stream; (3) there was a linear relationship between the cumulative {sup 90}Sr release from a tank and the peak concentration of {sup 90}Sr in the stream; (4) sludge stabilization resulted in significantly reduced peak concentrations of {sup 90}Sr in the stream; and (5) although radioactive decay of {sup 90}Sr during the period of tank degradation resulted in incrementally lower peak {sup 90}Sr concentrations in surface water than under the immediate tank failure scenarios these concentrations were equivalent under the two scenarios after about 90 years.

  19. Effects of 12 weeks of aerobic training on autonomic modulation, mucociliary clearance, and aerobic parameters in patients with COPD

    PubMed Central

    Leite, Marceli Rocha; Ramos, Ercy Mara Cipulo; Kalva-Filho, Carlos Augusto; Freire, Ana Paula Coelho Figueira; de Alencar Silva, Bruna Spolador; Nicolino, Juliana; de Toledo-Arruda, Alessandra Choqueta; Papoti, Marcelo; Vanderlei, Luiz Carlos Marques; Ramos, Dionei

    2015-01-01

    Introduction Patients with chronic obstructive pulmonary disease (COPD) exhibit aerobic function, autonomic nervous system, and mucociliary clearance alterations. These parameters can be attenuated by aerobic training, which can be applied with continuous or interval efforts. However, the possible effects of aerobic training, using progressively both continuous and interval sessions (ie, linear periodization), require further investigation. Aim To analyze the effects of 12-week aerobic training using continuous and interval sessions on autonomic modulation, mucociliary clearance, and aerobic function in patients with COPD. Methods Sixteen patients with COPD were divided into an aerobic (continuous and interval) training group (AT) (n=10) and a control group (CG) (n=6). An incremental test (initial speed of 2.0 km·h−1, constant slope of 3%, and increments of 0.5 km·h−1 every 2 minutes) was performed. The training group underwent training for 4 weeks at 60% of the peak velocity reached in the incremental test (vVO2peak) (50 minutes of continuous effort), followed by 4 weeks of sessions at 75% of vVO2peak (30 minutes of continuous effort), and 4 weeks of interval training (5×3-minute effort at vVO2peak, separated by 1 minute of passive recovery). Intensities were adjusted through an incremental test performed at the end of each period. Results The AT presented an increase in the high frequency index (ms2) (P=0.04), peak oxygen uptake (VO2peak) (P=0.01), vVO2peak (P=0.04), and anaerobic threshold (P=0.02). No significant changes were observed in the CG (P>0.21) group. Neither of the groups presented changes in mucociliary clearance after 12 weeks (AT: P=0.94 and CG: P=0.69). Conclusion Twelve weeks of aerobic training (continuous and interval sessions) positively influenced the autonomic modulation and aerobic parameters in patients with COPD. However, mucociliary clearance was not affected by aerobic training. PMID:26648712

  20. Aerobic deterioration stimulates outgrowth of spore-forming Paenibacillus in corn silage stored under oxygen-barrier or polyethylene films.

    PubMed

    Borreani, Giorgio; Dolci, Paola; Tabacco, Ernesto; Cocolin, Luca

    2013-08-01

    The occurrence of Bacillus and Paenibacillus spores in silage is of great concern to dairy producers because their spores can survive pasteurization and some strains are capable of subsequently germinating and growing under refrigerated conditions in pasteurized milk. The objectives of this study were to verify the role of aerobic deterioration of corn silage on the proliferation of Paenibacillus spores and to evaluate the efficacy of oxygen-barrier films used to cover silage during fermentation and storage to mitigate these undesirable bacterial outbreaks. The trial was carried out on whole-crop maize (Zea mays L.) inoculated with a mixture of Lactobacillus buchneri, Lactobacillus plantarum, and Enterococcus faecium. A standard polyethylene film and a polyethylene-polyamide film with an enhanced oxygen barrier were used to produce the silage bags for this experiment. The silos were stored indoors at ambient temperature (18 to 22°C) and opened after 110 d. The silage was sampled after 0, 2, 5, 7, 9, and 14 d of aerobic exposure to quantify the growth of endospore-forming bacteria during the exposure of silages to air. Paenibacillus macerans (gram-positive, facultatively anaerobic bacteria) was able to develop during the aerobic exposure of corn silage. This species was present in the herbage at harvesting, together with clostridial spores, and survived ensiling fermentation; it constituted more than 60% of the anaerobic spore formers at silage opening. During silage spoilage, the spore concentration of P. macerans increased to values greater than 7.0 log10 cfu/g of silage. The use of different plastic films to seal silages affected the growth of P. macerans and the number of spores during aerobic exposure of silages. These results indicate that the number of Paenibacillus spores could greatly increase in silage after exposure to air, and that oxygen-barrier films could help to reduce the potential for silage contamination of this important group of milk spoilage

  1. The influence of an acute bout of aerobic exercise on cortical contributions to motor preparation and execution

    PubMed Central

    Thacker, Jonathan S.; Middleton, Laura E.; McIlroy, William E.; Staines, W. Richard

    2014-01-01

    Abstract Increasing evidence supports the use of physical activity for modifying brain activity and overall neurological health. Specifically, aerobic exercise appears to have a positive effect on cognitive function, which some have suggested to be a result of increasing levels of arousal. However, the role of aerobic exercise on movement‐related cortical activity is less clear. We tested the hypothesis that (1) an acute bout of exercise modulates excitability within motor areas and (2) transient effects would be sustained as long as sympathetic drive remained elevated (indicated by heart rate). In experiment 1, participants performed unimanual self‐paced wrist extension movements before and after a 20‐min, moderate intensity aerobic exercise intervention on a recumbent cycle ergometer. After the cessation of exercise, Bereitschaftspotentials (BP), representative cortical markers for motor preparation, were recorded immediately postexercise (Post) and following a return to baseline heart rate (Post[Rest]). Electroencephalography (EEG) was used to measure the BP time‐locked to onset of muscle activity and separated into three main components: early, late and reafferent potentials. In experiment 2, two additional time points postexercise were added to the original protocol following the Post[Rest] condition. Early BP but not late BP was influenced by aerobic exercise, evidenced by an earlier onset, indicative of a regionally selective effect across BP generators. Moreover, this effect was sustained for up to an hour following exercise cessation and this effect was following a return to baseline heart rate. These data demonstrate that acute aerobic exercise may alter and possibly enhance the cortical substrates required for the preparation of movement. PMID:25355852

  2. Survival of lichens and bacteria exposed to outer space conditions - Results of the Lithopanspermia experiments

    NASA Astrophysics Data System (ADS)

    de la Torre, Rosa; Sancho, Leopoldo G.; Horneck, Gerda; Ríos, Asunción de los; Wierzchos, Jacek; Olsson-Francis, Karen; Cockell, Charles S.; Rettberg, Petra; Berger, Thomas; de Vera, Jean-Pierre P.; Ott, Sieglinde; Frías, Jesus Martinez; Melendi, Pablo Gonzalez; Lucas, Maria Mercedes; Reina, Manuel; Pintado, Ana; Demets, René

    2010-08-01

    In the space experiments Lithopanspermia, experimental support was provided to the likelihood of the lithopanspermia concept that considers a viable transport of microorganisms between the terrestrial planets by means of meteorites. The rock colonising lichens Rhizocarpon geographicum and Xanthoria elegans, the vagrant lichen Aspicilia fruticulosa, and endolithic and endoevaporitic communities of cyanobacteria and bacteria with their natural rock substrate were exposed to space for 10 days onboard the Biopan facility of the European Space Agency (ESA). Biopan was closed during launch and re-entry. In addition, in the Stone facility, one sample of R. geographicum on its natural granitic substrate was attached at the outer surface of the re-entry capsule close to the stagnation point, only protected by a thin cover of glass textolite. Post-flight analysis, which included determination of the photosynthetic activity, LIVE/DEAD staining, and germination capacity of the ascospores, demonstrated that all three lichen were quite resistant to outer space conditions, which include the full spectrum of solar extraterrestrial electromagnetic radiation or selected wavelength ranges. This high resistance of the lichens to space appears to be due to their symbiotic nature and protection by their upper pigmented layer, the cortex. In contrast, the rock- or halite-inhabiting bacteria were severely damaged by the same exposure. After atmospheric re-entry, the granite of the Stone sample was transformed into a glassy, nearly homogenous material, with several friction striae. None of the lichen cells survived this re-entry process. The data suggest that lichens are suitable candidates for testing the concept of lithopanspermia, because they are extremely resistant to the harsh environment of outer space. The more critical event is the atmospheric re-entry after being captured by a planet. Experiments simulating the re-entry process of a microbe-carrying meteoroid did not show any

  3. PRELIMINARY RESULTS: RELEASE OF METALS FROM ACID-MINE DRAINAGE CONTAMINATED STREAMBED SEDIMENTS UNDER ANOXIC CONDITIONS

    EPA Science Inventory

    Many miles of streams are contaminated with acid-mine drainage (AMD) from abandoned metal mines in the western U.S. Treatment of these streams may include dredging of the existing sediments, with subsequent burial. Burial of previously toxic sediments may result in release of met...

  4. Copper intoxication inhibits aerobic nucleotide synthesis in Streptococcus pneumoniae

    PubMed Central

    Johnson, Michael D. L.; Kehl-Fie, Thomas E.; Rosch, Jason W.

    2015-01-01

    Copper is universally toxic in excess, a feature exploited by the human immune system to facilitate bacterial clearance. The mechanism of copper intoxication remains unknown for many bacterial species. Here, we demonstrate that copper toxicity in Streptococcus pneumoniae is independent from oxidative stress but, rather, is the result of copper inhibiting the aerobic dNTP biosynthetic pathway. Furthermore, we show that copper-intoxicated S. pneumoniae is rescued by manganese, which is an essential metal in the aerobic nucleotide synthesis pathway. These data provide insight into new targets to enhance copper-mediated toxicity during bacterial clearance. PMID:25730343

  5. Forecast of long term coal supply and mining conditions: Model documentation and results

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A coal industry model was developed to support the Jet Propulsion Laboratory in its investigation of advanced underground coal extraction systems. The model documentation includes the programming for the coal mining cost models and an accompanying users' manual, and a guide to reading model output. The methodology used in assembling the transportation, demand, and coal reserve components of the model are also described. Results presented for 1986 and 2000, include projections of coal production patterns and marginal prices, differentiated by coal sulfur content.

  6. AG Channel Measurement and Modeling Results for Over-Sea Conditions

    NASA Technical Reports Server (NTRS)

    Matolak, David; Sun, Rouyu

    2014-01-01

    This report describes results from flight tests conducted in an over-sea environment, for the purpose of characterizing the air-to-ground (AG) channel, for future unmanned aircraft system (UAS) communication system analysis and design. These results are for the first of a set of several flight tests conducted in different ground site (GS) environments. An ultimate aim of all these tests is the development of models for the AG channel that can be used in communication system evaluation. In this report we provide measured results for propagation path loss, root-mean square delay spread (RMS-DS), and the correlation coefficient of the primary received signal components on the four antennas (two antennas for C-band, two for L-band). For path loss, the curved-earth two-ray model provides a reasonable fit to the measured data, altered by several dB at the shortest link distances by aircraft antenna pattern effects. This two-ray model also accounts for the majority of measured RMS-DS results of a few tens of nanoseconds, except for the occasional intermittent reflections from surface objects. These intermittent reflections yield RMS-DS values up to several hundred nanoseconds. For portions of the flight path that were over a harbor area highly populated with boats, the channel was found to be more "continuously dispersive," with RMS-DS reaching approximately 250 ns. A separate model will be developed for this over-harbor setting. The correlation coefficient results are still undergoing analysis; preliminary observations are that correlation between signals on the same-band antennas is generally large (>0.6) for the C-band straight flight paths, whereas for the L-band signals and for the oval-shaped flight paths the correlation is generally small (below 0.4). Inter-band correlations are typically very small, and are well modeled as zero-mean Gaussian in distribution, with a standard deviation less than 0.2. Hence the over-sea channel effects in the two bands can be

  7. Results.

    ERIC Educational Resources Information Center

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

    2001-01-01

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

  8. LLNL heart valve condition classification project anechoic testing results at the TRANSDEC evaluation facility

    SciTech Connect

    Candy, J V

    1999-10-31

    This report first briefly outlines the procedures and support/activation fixture developed at LLNL to perform the heart valve tests in an anechoic-like tank at the US Navy Transducer Evaluation Facility (TransDec) located in San Diego, CA. Next they discuss the basic experiments performed and the corresponding experimental plan employed to gather meaningful data systematically. The signal processing required to extract the desired information is briefly developed along with some of the data. Finally, they show the results of the individual runs for each valve, point out any of the meaningful features and summaries.

  9. Acute effects of aerobic exercise promote learning

    PubMed Central

    Perini, Renza; Bortoletto, Marta; Capogrosso, Michela; Fertonani, Anna; Miniussi, Carlo

    2016-01-01

    The benefits that physical exercise confers on cardiovascular health are well known, whereas the notion that physical exercise can also improve cognitive performance has only recently begun to be explored and has thus far yielded only controversial results. In the present study, we used a sample of young male subjects to test the effects that a single bout of aerobic exercise has on learning. Two tasks were run: the first was an orientation discrimination task involving the primary visual cortex, and the second was a simple thumb abduction motor task that relies on the primary motor cortex. Forty-four and forty volunteers participated in the first and second experiments, respectively. We found that a single bout of aerobic exercise can significantly facilitate learning mechanisms within visual and motor domains and that these positive effects can persist for at least 30 minutes following exercise. This finding suggests that physical activity, at least of moderate intensity, might promote brain plasticity. By combining physical activity–induced plasticity with specific cognitive training–induced plasticity, we favour a gradual up-regulation of a functional network due to a steady increase in synaptic strength, promoting associative Hebbian-like plasticity. PMID:27146330

  10. Fatal autoimmunity results from the conditional deletion of Snai2 and Snai3

    PubMed Central

    Pioli, Peter D.; Chen, Xinjian; Weis, Janis J.; Weis, John H.

    2015-01-01

    Transcriptional regulation of gene expression is a key component of orchestrating proper immune cell development and function. One strategy for maintaining these transcriptional programs has been the evolution of transcription factor families with members possessing overlapping functions. Using the germ line deletion of Snai2 combined with the hematopoietic specific deletion of Snai3, we report that these factors function redundantly to preserve the development of B and T cells. Such animals display severe lymphopenia, alopecia and dermatitis as well as profound autoimmunity manifested by the production of high levels of autoantibodies as early as 3 weeks of age and die by 30 days after birth. Autoantibodies included both IgM and IgG isotypes and were reactive against cytoplasmic and membranous components. A regulatory T cell defect contributed to the autoimmune response in that adoptive transfer of wild type regulatory T cells alleviated symptoms of autoimmunity. Additionally, transplantation of Snai2/Snai3 double deficient bone marrow into Snai2 sufficient Rag2−/− recipients resulted in autoantibody generation. The results demonstrated that appropriate expression of Snai2 and Snai3 in cells of hematopoietic derivation plays an important role in development and maintenance of immune tolerance. PMID:25732600

  11. AG Channel Measurement and Modeling Results for Over-Water and Hilly Terrain Conditions

    NASA Technical Reports Server (NTRS)

    Matolak, David W.; Sun, Ruoyu

    2015-01-01

    This report describes work completed over the past year on our project, entitled "Unmanned Aircraft Systems (UAS) Research: The AG Channel, Robust Waveforms, and Aeronautical Network Simulations." This project is funded under the NASA project "Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS)." In this report we provide the following: an update on project progress; a description of the over-freshwater and hilly terrain initial results on path loss, delay spread, small-scale fading, and correlations; complete path loss models for the over-water AG channels; analysis for obtaining parameter statistics required for development of accurate wideband AG channel models; and analysis of an atypical AG channel in which the aircraft flies out of the ground site antenna main beam. We have modeled the small-scale fading of these channels with Ricean statistics, and have quantified the behavior of the Ricean K-factor. We also provide some results for correlations of signal components, both intra-band and inter-band. An updated literature review, and a summary that also describes future work, are also included.

  12. Aerobic granular processes: Current research trends.

    PubMed

    Zhang, Quanguo; Hu, Jianjun; Lee, Duu-Jong

    2016-06-01

    Aerobic granules are large biological aggregates with compact interiors that can be used in efficient wastewater treatment. This mini-review presents new researches on the development of aerobic granular processes, extended treatments for complicated pollutants, granulation mechanisms and enhancements of granule stability in long-term operation or storage, and the reuse of waste biomass as renewable resources. A discussion on the challenges of, and prospects for, the commercialization of aerobic granular process is provided. PMID:26873285

  13. Electrical resistivity measurements of brine saturated porous media near reservoir conditions: Awibengkok preliminary results

    SciTech Connect

    Bonner, B; Duba, A; Roberts, J

    1999-06-28

    Laboratory measurements of the electrical resistivity of rocks and synthetic rocks with confining pressures up to 100 bars and temperatures between 20 and 211 C were performed to further investigate how the pore-size distribution and capillarity affects boiling in porous media. Similar to previous measurements on samples from The Geysers, CA, we observed a gradual increase in resistivity when pore pressure was decreased below the phase-boundary pressure of free water, an indication that boiling is controlled not only by temperature and pressure, but also by pore size distribution. Other important phenomena observed were strong resistance fluctuations during boiling that may be chaotic, and salt deposition that caused sample cracking. If confirmed in further experiments, these results may lead to a new geophysical diagnostic for locating boiling in high permeability areas of geothermal reservoirs and for methods of permeability alteration.

  14. Characterization of aerobically fit individuals with cardiovascular disease.

    PubMed

    Lesser, Iris A; Farias-Godoy, Alejandra; Isserow, Saul; Myers, Jonathan; Lear, Scott A

    2014-01-01

    With an ageing population there is an increased prevalence of individuals living with cardiovascular disease (CVD). Characteristics of older aerobically fit individuals with previously diagnosed CVD have not been studied. Therefore, our knowledge is limited as to how, or if, aerobically fit individuals with CVD attempt to adapt their physical activity and the intensity of their training programmes. The objective of this paper is to characterise the physical activity habits and behaviours of older aerobically fit individuals with CVD. We identified 28 aerobically fit patients with CVD from those who completed a minimum of 15 and 12 min of the Bruce treadmill protocol for men and women, respectively. Consenting participants responded to questionnaires regarding physical activity levels, competitive event participation and self-monitoring since diagnosis of heart disease. Average age and treadmill time of participants were 56 and 49 years and 15.6 and 13.0 min for males and females, respectively. Data were obtained regarding recent medical history (medical diagnoses, surgeries/procedures). Despite the majority of individuals participating in the same or more activity since their diagnosis, 25% indicated that their condition limited their activity and 39% reported having symptoms during activity. Nearly all participants (93%) indicated that they monitored their heart rate during exercise. However, only 14% of participants stated that their physician advised them on how to exercise safely. It is necessary for physicians and cardiac rehabilitation programmes to be involved in safe and effective exercise programming to allow individuals to return to sport after CVD. PMID:24433153

  15. Characterization of aerobic ethanol productions in a computerized auxostat

    SciTech Connect

    Fraleigh, S.P.

    1989-01-01

    For many valuable bioproducts high productivity is associated with rapid growth. However, most continuous microbial cultures become unstable when the dilution rate is fixed near the value for maximum growth rate. The auxostat culture technique employs feedback control of a nutrient or metabolite to stabilize the biomass at its maximum potential growth rate. An auxostat device is therefore ideal for study of bioprocesses involving the overproduction of primary metabolites such as ethanol. Oxidoreductive transformations involving ethanol are utilized by Saccharomyces yeasts when normal respiration cannot satisfy energy needs. When rapid growth or other stress creates oxidoreductive conditions in aerobic Saccharomyces cultures, very high specific ethanol formation rates are established and biomass yield drops to levels more typical of anaerobic fermentation. Although the physiology is favorable, the potential for large-scale aerobic ethanol processes to compete with traditional anaerobic fermentations has not previously been assessed. In this study, a fully computerized auxostat device was constructed and used to characterize the specific and volumetric aerobic ethanol productivity of the yeast Saccharomyces cerevisiae. To divert substrate away from biomass and into product formation, aerobic cultures were stressed with variations of ionic balance (via extreme K{sup +} and H{sup +} setpoints) in the auxostat device. During growth with limiting K{sup +} concentrations, the goal of very low biomass yield was attained but the rate of ethanol production was poor. However, with excess K{sup +} the volumetric productivity reached 6.1 g/I,-h, a value that is comparable to optimized, continuous anaerobic cultures.

  16. Disturbance of aerobic metabolism accompanies neurobehavioral changes induced by nickel in mice.

    PubMed

    He, Min-Di; Xu, Shang-Cheng; Zhang, Xin; Wang, Yan; Xiong, Jia-Chuan; Zhang, Xiao; Lu, Yong-Hui; Zhang, Lei; Yu, Zheng-Ping; Zhou, Zhou

    2013-09-01

    The oral ingestion of soluble nickel compounds leads to neurological symptoms in humans. Deficiencies in aerobic metabolism induced by neurotoxic stimulus can cause an energy crisis in the brain that results in a variety of neurotoxic effects. In the present study, we focused on the aerobic metabolic states to investigate whether disturbance of aerobic metabolism was involved in nickel-induced neurological effects in mice. Mice were orally administered nickel chloride, and neurobehavioral performance was evaluated using the Morris water maze and open field tests at different time points. Aerobic metabolic states in the cerebral cortex were analyzed at the same time points at which neurobehavioral changes were evident. We found that nickel exposure caused deficits in both spatial memory and exploring activity in mice and that nickel was deposited in their cerebral cortex. Deficient aerobic metabolism manifested as decreased O2 consumption and ATP concentrations, lactate and NADH accumulation, and oxidative stress. Meanwhile, the activity of prototypical iron-sulfur clusters (ISCs) containing enzymes that are known to control aerobic metabolism, including complex I and aconitase, and the expression of ISC assembly scaffold protein (ISCU) were inhibited following nickel deposition. Overall, these data suggest that aerobic metabolic disturbances, which accompanied the neurobehavioral changes, may participate in nickel-induced neurologic effects. The inactivation of ISC containing metabolic enzymes may result in the disturbance of aerobic metabolism. A better understanding of how nickel impacts the energy metabolic processes may provide insight into the prevention of nickel neurotoxicity.

  17. Is the effect of aerobic exercise on cognition a placebo effect?

    PubMed

    Stothart, Cary R; Simons, Daniel J; Boot, Walter R; Kramer, Arthur F

    2014-01-01

    A number of studies and meta-analyses conclude that aerobic fitness (walking) interventions improve cognition. Such interventions typically compare improvements from these interventions to an active control group in which participants engage in non-aerobic activities (typically stretching and toning) for an equivalent amount of time. However, in the absence of a double-blind design, the presence of an active control group does not necessarily control for placebo effects; participants might expect different amounts of improvement for the treatment and control interventions. We conducted a large survey to explore whether people expect greater cognitive benefits from an aerobic exercise intervention compared to a control intervention. If participants expect greater improvement following aerobic exercise, then the benefits of such interventions might be due in part to a placebo effect. In general, expectations did not differ between aerobic and non-aerobic interventions. If anything, some of the results suggest the opposite (e.g., respondents expected the control, non-aerobic intervention to yield bigger memory gains). These results provide the first evidence that cognitive improvements following aerobic fitness training are not due to differential expectations.

  18. [Aerobic capacity and quality of life in school children from 8 to 12].

    PubMed

    Gálvez Casas, Arancha; Rodríguez García, Pedro L; García-Cantó, Eliseo; Rosa Guillamón, Andrés; Pérez-Soto, Juan J; Tarraga Marcos, Loreto; Tarraga Lopez, Pedro

    2015-01-01

    Aerobic capacity is a powerful physiological indicator of the overall health status. The objective of this study was to analyse the relationship between aerobic capacity and quality of life in a sample of 298 (159 girls) school children aged 8-12 years. Aerobic capacity was tested using the Course-Navette test. Quality of life was assessed using the KIDSCREEN-10 Index scale. Males showed higher performance in the Course-Navette test and highest values of VO2max (P<.001 for both). ANOVA statistical analysis showed that the quality of life was significantly higher in school children with increased level of aerobic capacity compared to those with a low level (P=.001). Children with high aerobic capacity showed higher quality of life scores in relation to their peers with low scores (P<.001). As for the females, significant differences were found among those with high aerobic capacity level and their peers low levels (P<.031). The results of this study suggest that school children with higher level of aerobic capacity show better results in the quality of life index. Long-term intervention studies are needed to verify if an aerobic capacity development programme may upgrade the quality of life of children and adolescents.

  19. Lower limb loading in step aerobic dance.

    PubMed

    Wu, H-W; Hsieh, H-M; Chang, Y-W; Wang, L-H

    2012-11-01

    Participation in aerobic dance is associated with a number of lower extremity injuries, and abnormal joint loading seems to be a factor in these. However, information on joint loading is limited. The purpose of this study was to investigate the kinetics of the lower extremity in step aerobic dance and to compare the differences of high-impact and low-impact step aerobic dance in 4 aerobic movements (mambo, kick, L step and leg curl). 18 subjects were recruited for this study. High-impact aerobic dance requires a significantly greater range of motion, joint force and joint moment than low-impact step aerobic dance. The peak joint forces and moments in high-impact step aerobic dance were found to be 1.4 times higher than in low-impact step aerobic dance. Understanding the nature of joint loading may help choreographers develop dance combinations that are less injury-prone. Furthermore, increased knowledge about joint loading may be helpful in lowering the risk of injuries in aerobic dance instructors and students.

  20. Gait characteristics of individuals with multiple sclerosis before and after a 6-month aerobic training program.

    PubMed

    Rodgers, M M; Mulcare, J A; King, D L; Mathews, T; Gupta, S C; Glaser, R M

    1999-07-01

    Individuals who have multiple sclerosis (MS) typically experience problems with physical activities such as walking, resulting from the combined effects of skeletal muscle weakness, sensory disturbances, spasticity, gait ataxia, and reduction in aerobic capacity. The aim of this study was to determine whether a 6-mo exercise program designed for aerobic conditioning might also affect gait abnormalities in individuals with MS. Subjects included 18 individuals with MS who presented a range of disability. Passive range of motion (PROM) in the lower limbs was measured and gait analyzed before and after exercise conditioning. Three-dimensional kinematics, ground reaction forces (GRF), and electromyographic information were acquired as subjects walked at self-selected velocities. Hip PROM increased following conditioning. Mean walking velocity, cadence, and posterior shear GRF (push-off force) decreased. During walking, maximum ankle dorsiflexion decreased and ankle plantarflexion increased. Total knee flexion/extension range during the walking cycle decreased slightly as did maximum hip extension. Results suggest this 6-mo training program had minimal effect on gait abnormalities. PMID:10659801

  1. Condition Assessment of PCI Bridge Girder a Result of The Reduction Prestressing Force

    NASA Astrophysics Data System (ADS)

    Suangga, Made; Hidayat, Irpan; Lutter, Bobby

    2014-03-01

    PCI bridge girders is known and widely used for many construction e.g.: bridge, wharf, flyover, and other application. PC Bridge girders have two types: Pre - tensioned girders and post - tensioned girders. In pre tensioned girders, prestressing in carried out first then after that the fresh concrete poured. The prestressing process in only carried off after the concrete has sufficient strength. In this study, analysis was conducted for PCI bridge girder with span is 40 meters. Based on the data geometry bridge dimension girder, material girder, and material strands cable, it will be analyzed to calculate the natural frequencies and moment capacity using finite element program (Midas/Civil program). So it can be estimated how much the percentage reduction prestress force on the bridge until PCI bridge structure collapses. From the calculation, it found that the pattern comparison between reduction prestressing force and natural frequency are linear. These results are also similar for natural frequency versus moment capacity.PCI bridge will collapse when the reduction prestreesing force of 45 % to 50 % from the total loss of prestressing.

  2. Conditional abrogation of Atm in osteoclasts extends osteoclast lifespan and results in reduced bone mass

    PubMed Central

    Hirozane, Toru; Tohmonda, Takahide; Yoda, Masaki; Shimoda, Masayuki; Kanai, Yae; Matsumoto, Morio; Morioka, Hideo; Nakamura, Masaya; Horiuchi, Keisuke

    2016-01-01

    Ataxia-telangiectasia mutated (ATM) kinase is a central component involved in the signal transduction of the DNA damage response (DDR) and thus plays a critical role in the maintenance of genomic integrity. Although the primary functions of ATM are associated with the DDR, emerging data suggest that ATM has many additional roles that are not directly related to the DDR, including the regulation of oxidative stress signaling, insulin sensitivity, mitochondrial homeostasis, and lymphocyte development. Patients and mice lacking ATM exhibit growth retardation and lower bone mass; however, the mechanisms underlying the skeletal defects are not fully understood. In the present study, we generated mutant mice in which ATM is specifically inactivated in osteoclasts. The mutant mice did not exhibit apparent developmental defects but showed reduced bone mass due to increased osteoclastic bone resorption. Osteoclasts lacking ATM were more resistant to apoptosis and showed a prolonged lifespan compared to the controls. Notably, the inactivation of ATM in osteoclasts resulted in enhanced NF-κB signaling and an increase in the expression of NF-κB-targeted genes. The present study reveals a novel function for ATM in regulating bone metabolism by suppressing the lifespan of osteoclasts and osteoclast-mediated bone resorption. PMID:27677594

  3. Radiometric calibration of SUMER: refinement of the laboratory results under operational conditions on SOHO.

    PubMed

    Wilhelm, K; Lemaire, P; Feldman, U; Hollandt, J; Schühle, U; Curdt, W

    1997-09-01

    The radiometric calibration of the solar telescope and spectrometer SUMER was carried out in the laboratory before delivery of the instrument for integration into the SOHO (Solar and Heliospheric Observatory) spacecraft. Although this effort led to a reasonable coverage of the wavelength range from 53.70 to 146.96 nm, uncalibrated portions of the sensitivity curves remained before SUMER became operational in early 1996. Thereafter it was possible to perform extrapolations and interpolations of the calibration curves of detector A to shorter, longer, and intermediate wavelengths by using emission line pairs with known intensity ratios. The spectra of the stars alpha and rho Leonis were also observed on the KBr (potassium bromide) photocathode and the bare microchannel plate (MCP) in the range from 120 to 158 nm. In addition, the sensitivity ratios of the KBr photocathode to the bare MCP were determined for many solar lines as well as the H i Lyman and the thermal continua. The results have been found to be consistent with published laboratory data. The uncertainty is +/-15% (1 varsigma) in the wavelength range from 54 to 125 nm.

  4. The effects of acute aerobic activity on cognition and cross-domain transfer to eating behavior.

    PubMed

    Lowe, Cassandra J; Hall, Peter A; Vincent, Corita M; Luu, Kimberley

    2014-01-01

    Prior studies have demonstrated that a single session of aerobic exercise can enhance cognitive functioning; specifically, the inhibition facet of executive function (EF). Additionally, previous research has demonstrated that inhibitory abilities are essential for effective dietary self-control. However, it is currently unknown whether exercise induced enhancements in EF also facilitate self-control in the dietary domain. The present study sought to determine whether a single session of aerobic exercise enhances EF, and whether there is a transfer effect to dietary self-control. Thirty four undergraduate students were randomly assigned to one of three exercise conditions: (1) minimal exercise; (2) moderate intensity exercise (30% heart rate reserve); (3) vigorous intensity exercise (50% heart rate reserve). After the exercise bout, participants completed three standardized EF tasks followed by a bogus taste test for three appetitive snack foods (milk chocolate and potato chips) and two control foods (dark chocolate and crackers). The amount of food consumed during the taste test was covertly measured. The results revealed a significant main effect of treatment condition on the Stroop task performance, but not Go-NoGo (GNG) and Stop Signal task performance. Findings with respect to food consumption revealed that EF moderated the treatment effect, such that those with larger exercise effects on Stroop performance in the moderate intensity exercise condition consumed more control foods (but not less appetitive foods). These findings support the contention that a single bout of aerobic exercise enhances EF, and may have transfer effects to the dietary domain, but that such effects may be indirect in nature. PMID:24808850

  5. Peak Aerobic Fitness of Visually Impaired and Sighted Adolescent Girls.

    ERIC Educational Resources Information Center

    Williams, C. A.; And Others

    1996-01-01

    A study compared 10 visually impaired and 10 sighted girls on a discontinuous incremental treadmill test and found no significant difference between the peak oxygen intake of the 2 groups. The results indicate that visually impaired children can attain aerobic fitness levels similar to those of sighted children. (Author/CR)

  6. Aerobic Exercise Equipment Preferences among Older Adults: A Preliminary Investigation.

    ERIC Educational Resources Information Center

    Looney, Marilyn A.; Rimmer, James H.

    2003-01-01

    Developed an instrument to measure the aerobic exercise equipment preference of a frail older population and applied many-facet Rasch analysis to study construct validity and equipment preferences. Results for 16 participants show the usefulness of many-facet Rasch analysis in guiding instrument revision. (SLD)

  7. Is Low-Impact Aerobic Dance an Effective Cardiovascular Workout?

    ERIC Educational Resources Information Center

    Williford, Henry N.; And Others

    1989-01-01

    Presents results of an investigation comparing energy cost and cardiovascular responses of aerobic dance routines performed at different intensity levels in varying amounts of energy expenditure. For low-impact dance to meet minimum guidelines suggested by the American College of Sports Medicine, it should be performed at high intensity. (SM)

  8. Metabolic Engineering of an Aerobic Sulfate Reduction Pathway and Its Application to Precipitation of Cadmium on the Cell Surface

    PubMed Central

    Wang, Clifford L.; Maratukulam, Priya D.; Lum, Amy M.; Clark, Douglas S.; Keasling, J. D.

    2000-01-01

    The conversion of sulfate to an excess of free sulfide requires stringent reductive conditions. Dissimilatory sulfate reduction is used in nature by sulfate-reducing bacteria for respiration and results in the conversion of sulfate to sulfide. However, this dissimilatory sulfate reduction pathway is inhibited by oxygen and is thus limited to anaerobic environments. As an alternative, we have metabolically engineered a novel aerobic sulfate reduction pathway for the secretion of sulfides. The assimilatory sulfate reduction pathway was redirected to overproduce cysteine, and excess cysteine was converted to sulfide by cysteine desulfhydrase. As a potential application for this pathway, a bacterium was engineered with this pathway and was used to aerobically precipitate cadmium as cadmium sulfide, which was deposited on the cell surface. To maximize sulfide production and cadmium precipitation, the production of cysteine desulfhydrase was modulated to achieve an optimal balance between the production and degradation of cysteine. PMID:11010904

  9. Waste degradation and gas production with enzymatic enhancement in anaerobic and aerobic landfill bioreactors.

    PubMed

    Hettiaratchi, J P A; Jayasinghe, P A; Bartholameuz, E M; Kumar, S

    2014-05-01

    The presence of lignin is the limiting factor at later stages of biodegradation of municipal solid waste under aerobic or anaerobic conditions. Supplying enzymes into the system could facilitate lignin degradation, thereby aiding anaerobic and aerobic waste degradation processes. A comprehensive set of laboratory experiments were conducted under both anaerobic and aerobic conditions to evaluate the feasibility of using enzymes in accelerating lignin-rich waste degradation. After 30 days of anaerobic operation, MnP and LiP enzyme treated reactors produced 36 and 23 times higher cumulative methane (CH4), respectively, compared to that of the control reactor devoid of enzyme treatments. The carbon dioxide (CO2) yield of MnP enhanced aerobic reactor showed more than two-fold increase.

  10. Waste degradation and gas production with enzymatic enhancement in anaerobic and aerobic landfill bioreactors.

    PubMed

    Hettiaratchi, J P A; Jayasinghe, P A; Bartholameuz, E M; Kumar, S

    2014-05-01

    The presence of lignin is the limiting factor at later stages of biodegradation of municipal solid waste under aerobic or anaerobic conditions. Supplying enzymes into the system could facilitate lignin degradation, thereby aiding anaerobic and aerobic waste degradation processes. A comprehensive set of laboratory experiments were conducted under both anaerobic and aerobic conditions to evaluate the feasibility of using enzymes in accelerating lignin-rich waste degradation. After 30 days of anaerobic operation, MnP and LiP enzyme treated reactors produced 36 and 23 times higher cumulative methane (CH4), respectively, compared to that of the control reactor devoid of enzyme treatments. The carbon dioxide (CO2) yield of MnP enhanced aerobic reactor showed more than two-fold increase. PMID:24684817

  11. Complete remediation of PCE contaminated unsaturated soils by sequential anaerobic-aerobic bioventing.

    PubMed

    Mihopoulos, P G; Suidan, M T; Sayles, G D

    2001-01-01

    Bioventing principles have been applied to completely dechlorinate tetrachloroethylene vapors in the unsaturated zone in a sequential anaerobic-aerobic pattern. The aerobic step yields trans-DCE and VC as PCE reductive dechlorination byproducts, while TCE and cis-DCE are observed as intermediates. The aerobic step results in rapid oxidation of the VC and trans-DCE to carbon dioxide. Hydrogen was delivered in the gas phase as a reducing agent for the anaerobic step at levels of 1%, and oxygen at 4.2% was used as an electron acceptor in the aerobic step. PCE and VC half lives in the anaerobic and aerobic steps respectively, where less than 10 min.

  12. Performance of Healthy Braced Participants During Aerobic and Anaerobic Capacity Tasks

    PubMed Central

    Rishiraj, Neetu; Taunton, Jack E.; Niven, Brian; Lloyd-Smith, Robert; Regan, William; Woollard, Robert

    2011-01-01

    Context: Knee braces were introduced in sports approximately 30 years ago. However, the effects of a functional knee brace (FKB) on aerobic and anaerobic performance after fatigue are unknown. Objective: To investigate whether FKB use in noninjured participants hindered performance during aerobic (Léger beep test) and anaerobic (repeated high-intensity shuttle test [RHIST]) tasks. Design: Crossover study. Setting: Laboratory. Patients or Other Participants: Twenty-seven healthy male provincial and national basketball and field hockey athletes (age = 19.4 ± 3.0 years, range, 17–26 years; height = 182.6 ± 6.8 cm, range, 168–196 cm; mass = 80.0 ± 9.1 kg, range, 66–108 kg). Interventions : Each participant was provided a custom-fitted FKB and performed 5 nonbraced (NBR) testing sessions over 3 days, followed by 5 braced (BR) testing sessions over 3 days, for a total of 17.5 hours of testing per condition. During each testing session, participants performed 1 trial of the Léger beep test and 1 trial of the RHIST in each condition. Main Outcome Measure(s): Predicted maximal oxygen consumption (V˙o2max) and time performance measures were recorded for each NBR and BR trial. Results: Initial performance levels were lower for BR than NBR for both the Léger beep test (BR = 44.3 mL/kg/min, NBR = 47.3 mL/kg/min; F1,26 = 8.726; P = .007) and the RHIST (BR = 16.5 seconds, NBR = 16.2 seconds; F1,26 = 13.98, P = .001). However, with continued FKB use, the aerobic performance measure remained higher for only the first 2 BR testing sessions (NBR = 46.9 mL/kg/min, BR = 42.4 mL/kg/min; F3.0,79.8 = 4.95, P = .003). For the anaerobic test, no performance difference was noted between the testing conditions (NBR = 16.2 seconds, BR = 16.4 seconds; P = .7), whereas fatigue levels were lower during BR testing sessions (NBR = 33%, BR = 31%). After 14.0 hours of FKB use, performance levels were almost equal between the testing conditions (NBR = 47.6 mL/kg/min, BR = 46.1 m

  13. Aerobic microorganism for the degradation of chlorinated aliphatic hydrocarbons

    DOEpatents

    Fliermans, Carl B.

    1989-01-01

    A chlorinated aliphatic hydrocarbon-degrading microorganism, having American Type Culture Collection accession numbers ATCC 53570 and 53571, in a biologically pure culture aseptically collected from a deep subsurface habitat and enhanced, mineralizes trichloroethylene and tetrachloroethylene to HCl, H.sub.2 O and Co.sub.2 under aerobic conditions stimulated by methane, acetate, methanol, tryptone-yeast extract, propane and propane-methane.

  14. Aerobic biodegradation of iso-butanol and ethanol and their relative effects on BTEX biodegradation in aquifer materials.

    PubMed

    Schaefer, Charles E; Yang, Xiaomin; Pelz, Oliver; Tsao, David T; Streger, Sheryl H; Steffan, Robert J

    2010-11-01

    The aerobic biodegradability of iso-butanol, a new biofuel, and its impact on benzene, toluene, ethylbenzene and xylenes (BTEX) degradation was investigated in aerobic microcosms consisting of groundwater and sediment from a California site with a history of gasoline contamination. To the best of our knowledge this is the first study directly examining the effects of iso-butanol on BTEX degradation. Microcosms that received either low (68 μM) or high (3400 μM) concentrations of iso-butanol showed complete biodegradation of iso-butanol within 7 and 23 d, respectively, of incubation at 15°C under aerobic conditions. A maximum utilization rate coefficient of 2.3±0.1×10⁻⁷ μmol cell⁻¹ h⁻¹ and a half saturation constant of 610±54 μM were regressed from the iso-butanol data. Iso-butanol biodegradation resulted in transient formation of the degradation intermediate products iso-butylaldehyde and iso-butyric acid, and both compounds were subsequently degraded within the timeframe of the experiments. Ethanol was biodegraded more slowly than iso-butanol. Ethanol also exhibited greater adverse impacts on BTEX biodegradation than iso-butanol. Results of the study suggest that iso-butanol added to fuels will be readily biodegraded in the environment under aerobic conditions without the accumulation of major intermediate products (iso-butylaldehyde and iso-butyric acid), and that it will pose less impacts on BTEX biodegradation than ethanol.

  15. Catalytic Aerobic Dehydrogenation of Nitrogen Heterocycles Using Heterogeneous Cobalt Oxide Supported on Nitrogen-Doped Carbon.

    PubMed

    Iosub, Andrei V; Stahl, Shannon S

    2015-09-18

    Dehydrogenation of (partially) saturated heterocycles provides an important route to heteroaromatic compounds. A heterogeneous cobalt oxide catalyst, previously employed for aerobic oxidation of alcohols and amines, is shown to be effective for aerobic dehydrogenation of various 1,2,3,4-tetrahydroquinolines to the corresponding quinolines. The reactions proceed in good yields under mild conditions. Other N-heterocycles are also successfully oxidized to their aromatic counterparts.

  16. Skeletal Muscle Hypertrophy after Aerobic Exercise Training

    PubMed Central

    Konopka, Adam R.; Harber, Matthew P.

    2014-01-01

    Current dogma suggests aerobic exercise training has minimal effect on skeletal muscle size. We and others have demonstrated that aerobic exercise acutely and chronically alters protein metabolism and induces skeletal muscle hypertrophy. These findings promote an antithesis to the status quo by providing novel perspective on skeletal muscle mass regulation and insight into exercise-countermeasures for populations prone to muscle loss. PMID:24508740

  17. Filamentous bacteria existence in aerobic granular reactors.

    PubMed

    Figueroa, M; Val del Río, A; Campos, J L; Méndez, R; Mosquera-Corral, A

    2015-05-01

    Filamentous bacteria are associated to biomass settling problems in wastewater treatment plants. In systems based on aerobic granular biomass they have been proposed to contribute to the initial biomass aggregation process. However, their development on mature aerobic granular systems has not been sufficiently studied. In the present research work, filamentous bacteria were studied for the first time after long-term operation (up to 300 days) of aerobic granular systems. Chloroflexi and Sphaerotilus natans have been observed in a reactor fed with synthetic wastewater. These filamentous bacteria could only come from the inoculated sludge. Thiothrix and Chloroflexi bacteria were observed in aerobic granular biomass treating wastewater from a fish canning industry. Meganema perideroedes was detected in a reactor treating wastewater from a plant processing marine products. As a conclusion, the source of filamentous bacteria in these mature aerobic granular systems fed with industrial effluents was the incoming wastewater.

  18. Supplementation with vitamin A enhances oxidative stress in the lungs of rats submitted to aerobic exercise.

    PubMed

    Gasparotto, Juciano; Petiz, Lyvia Lintzmaier; Girardi, Carolina Saibro; Bortolin, Rafael Calixto; de Vargas, Amanda Rodrigues; Henkin, Bernardo Saldanha; Chaves, Paloma Rodrigues; Roncato, Sabrina; Matté, Cristiane; Zanotto-Filho, Alfeu; Moreira, José Cláudio Fonseca; Gelain, Daniel Pens

    2015-12-01

    Exercise training induces reactive oxygen species production and low levels of oxidative damage, which are required for induction of antioxidant defenses and tissue adaptation. This process is physiological and essential to improve physical conditioning and performance. During exercise, endogenous antioxidants are recruited to prevent excessive oxidative stress, demanding appropriate intake of antioxidants from diet or supplements; in this context, the search for vitamin supplements that enhance the antioxidant defenses and improve exercise performance has been continuously increasing. On the other hand, excess of antioxidants may hinder the pro-oxidant signals necessary for this process of adaptation. The aim of this study was to investigate the effects of vitamin A supplementation (2000 IU/kg, oral) upon oxidative stress and parameters of pro-inflammatory signaling in lungs of rats submitted to aerobic exercise (swimming protocol). When combined with exercise, vitamin A inhibited biochemical parameters of adaptation/conditioning by attenuating exercise-induced antioxidant enzymes (superoxide dismutase and glutathione peroxidase) and decreasing the content of the receptor for advanced glycation end-products. Increased oxidative damage to proteins (carbonylation) and lipids (lipoperoxidation) was also observed in these animals. In sedentary animals, vitamin A decreased superoxide dismutase and increased lipoperoxidation. Vitamin A also enhanced the levels of tumor necrosis factor alpha and decreased interleukin-10, effects partially reversed by aerobic training. Taken together, the results presented herein point to negative effects associated with vitamin A supplementation at the specific dose here used upon oxidative stress and pro-inflammatory cytokines in lung tissues of rats submitted to aerobic exercise.

  19. [Characteristics of Nitrogen Removal by a Heterotrophic Nitrification-Aerobic Denitrification Bacterium YL].

    PubMed

    Liang, Xian; Ren, Yong-xiang; Yang, Lei; Zhao, Si-qi; Xia, Zhi-hong

    2015-05-01

    Traditional process of autotrophic nitrification-anaerobic denitrification usually has problems of long procedure and low efficiency. To overcome these problems, a heterotrophic nitrification-aerobic denitrification bacterium YL was isolated from a domesticated mature SBR reactor with efficient simultaneous nitrification and denitrification ability, and was identified as Pseudomonas aeruginosa YL. Meanwhile, the characteristics of the nitrogen removal of strain YL was investigated through single-factor experiments and an orthogonal experiment. The results showed that the preferred conditions were: succinate as the carbon source, C/N ratio of 10, pH of 7.0, temperature of 30°C, and the shaking speed of 160-200 r · min(-1), while the removal rate of ammonia oxidation was 5. 05 mg · (g · h)(-1), the transformation rate of TOC was 45.95 mg · (g · h)(-1), and the removal rates of nitrogen and TOC were 100% and 90.8%, respectively. Nitrite, nitrate and hydroxylamine could also be metabolized by strain YL, and the removal rates were 92.7%, 93.6% and 94.8%, respectively. The most important influencing factor on aerobic denitrification of strain YL was C/N ratio. Under the optimal conditions (C/N = 10, T = 30°C , r = 200 r · min(-1), pH = 7), the removal rates of nitrate and total nitrogen were 94.6% and 76.3%, respectively. Hence, strain YL could remove nitrogen by heterotrophic nitrification-aerobic denitrification independently, quickly, and effectively.

  20. Physiology of Resistant Deinococcus geothermalis Bacterium Aerobically Cultivated in Low-Manganese Medium

    PubMed Central

    Peltola, Minna; Bernhardt, Jörg; Neubauer, Peter

    2012-01-01

    This dynamic proteome study describes the physiology of growth and survival of Deinococcus geothermalis, in conditions simulating paper machine waters being aerobic, warm, and low in carbon and manganese. The industrial environment of this species differs from its natural habitats, geothermal springs and deep ocean subsurfaces, by being highly exposed to oxygen. Quantitative proteome analysis using two-dimensional gel electrophoresis and bioinformatic tools showed expression change for 165 proteins, from which 47 were assigned to a function. We propose that D. geothermalis grew and survived in aerobic conditions by channeling central carbon metabolism to pathways where mainly NADPH rather than NADH was retrieved from the carbon source. A major part of the carbon substrate was converted into succinate, which was not a fermentation product but likely served combating reactive oxygen species (ROS). Transition from growth to nongrowth resulted in downregulation of the oxidative phosphorylation observed as reduced expression of V-type ATPase responsible for ATP synthesis in D. geothermalis. The battle against oxidative stress was seen as upregulation of superoxide dismutase (Mn dependent) and catalase, as well as several protein repair enzymes, including FeS cluster assembly proteins of the iron-sulfur cluster assembly protein system, peptidylprolyl isomerase, and chaperones. Addition of soluble Mn reinitiated respiration and proliferation with concomitant acidification, indicating that aerobic metabolism was restricted by access to manganese. We conclude that D. geothermalis prefers to combat ROS using manganese-dependent enzymes, but when manganese is not available central carbon metabolism is used to produce ROS neutralizing metabolites at the expense of high utilization of carbon substrate. PMID:22228732

  1. Prevention of the incubation of cocaine seeking by aerobic exercise in female rats

    PubMed Central

    Zlebnik, Natalie E.; Carroll, Marilyn E.

    2015-01-01

    BACKGROUND Recent research has demonstrated that aerobic exercise can attenuate craving for drugs of abuse and reduce escalation and reinstatement of drug-seeking behavior in animal models. The present study examined the effects of aerobic exercise on the development of the incubation of cocaine-seeking behavior or the progressive increase in cocaine seeking over a protracted withdrawal period from cocaine self-administration. METHODS Female rats were trained to self-administer cocaine (0.4 mg/kg/inf) during daily 6-h sessions for 10 days. Subsequently, access to cocaine and cocaine-paired cues was discontinued during a 3- or 30-day withdrawal period when rats had access to either a locked or unlocked running wheel. At the end of the withdrawal period, rats were reintroduced to the operant conditioning chamber and reexposed to cocaine-paired cues to examine cocaine-seeking behavior under extinction conditions. RESULTS Rats with access to a locked running wheel during 30 days of withdrawal had significantly greater cue-induced cocaine-seeking behavior than rats that had access to an unlocked running wheel for 30 days. Further, there was robust incubation of cocaine seeking in rats with access to a locked running wheel as cocaine seeking was notably elevated at 30 vs. 3 days of withdrawal. However, cocaine-seeking behavior did not differ between rats with access to an unlocked running wheel for 30 vs. 3 days, indicating that incubation of cocaine seeking was suppressed following access to exercise for 30 days. CONCLUSION Aerobic exercise during extended withdrawal from cocaine self-administration decreased incubation of cue-induced cocaine-seeking behavior and may reduce vulnerability to relapse. PMID:26159456

  2. Characterization of Two Efficient Aerobic Denitrifying Strains Isolated from Shallow Aquifers in Suzhou City, China

    NASA Astrophysics Data System (ADS)

    Ruan, X.; Zhu, X.; Sun, H.; Li, M.

    2010-12-01

    Sixty two stains that can utilize nitrate as source of nitrogen under aerobic conditions were isolated from shallow aquifer samples in Suzhou city, China. Two of the strains, XK42 and PJ21, can convert nitrate into nitrogen gas efficiently without obvious accumulation of nitite. According to morphological, biochemical/biophysical and 16S rDNA gene sequence analysis, XK42 and PJ21 were identified as Pseudomonas Stutzeri and Pseudomonas Mendocica, respectively. The generation time, optimum pH value range and optimum growth temperature range were 4.64h, 6.5˜8.0, 25˜35°C for XK42 and 8.39h, 6.5˜8.5, 25˜35°C for PJ21. Under aerobic conditions (DO=6.9˜7.8 mg/L), the nitrate concentrations in the medium inoculated with XK42 and PJ21 decreased to 42.35 mg/L and 35.69 mg/L with initial nitrate concentration of 276.25 mg/L within 12 hours, respectively. The nitrite concentrations reached to 3.06 mg/L and 3.70 mg/L, and their nitrate removal rates reached 18.24 mg/L●h and 17.51 mg/L●h. The total nitrogen loss through denitrification of XK42 and PJ21 were 70.9% and 66.3%, respectively. The nitrate reduction efficiencies within 60 hours was up to 95.13% (strain XK42) and 95.55% (strain PJ21). The results indicate that the isolated strians XK42 and PJ21 are aerobic denitrifiers with high nitrogen removal efficiency, and can be used for in-situ bioremediation of nitrogen-contaminated shallow groundwater and biotreatment of wasterwater.

  3. Assessment of Environmental Qualification Practices and Condition Monitoring Techniques for Low-Voltage Electric Cables: LOCA Test Results

    SciTech Connect

    Lofaro, R.; Grove, E.; Villaran, M.; Soo, P.; Hsu, F.

    2001-02-01

    This report documents the results of a research program addressing issues related to the qualification process for low-voltage instrumentation and control (I&C) electric cables used in commercial nuclear power plants. Three commonly used types of I&C cable were tested: Cross-Linked Polyethylene (XLPE) insulation with a Neoprene® jacket, Ethylene Propylene Rubber (EPR) insulation with an unbonded Hypalon® jacket, and EPR with a bonded Hypalon® jacket. Each cable type received accelerated aging to simulate 20, 40, and 60 years of qualified life. In addition, naturally aged cables of the same types were obtained from decommissioned nuclear power plants and tested. The cables were subjected to simulated loss-of-coolant-accident (LOCA) conditions, which included the sequential application of LOCA radiation followed by exposure to steam at high temperature and pressure, as well as to chemical spray. Periodic condition monitoring (CM) was performed using nine different techniques to obtain data on the condition of the cable, as well as to evaluate the effectiveness of those CM techniques for in situ monitoring of cables. Volume 1 of this report presents the results of the LOCA tests, and Volume 2 discusses the results of the condition monitoring tests.

  4. Effects of acrosomal conditions of frozen-thawed spermatozoa on the results of artificial insemination in Japanese Black cattle

    PubMed Central

    KISHIDA, Kazumi; SAKASE, Mitsuhiro; MINAMI, Kenta; ARAI, Miyuki M.; SYOJI, Reiko; KOHAMA, Namiko; AKIYAMA, Takayuki; OKA, Akio; HARAYAMA, Hiroshi; FUKUSHIMA, Moriyuki

    2015-01-01

    The purposes of this study were to examine the relationship between male artificial insemination (AI) fertility and sperm acrosomal conditions assessed by new and conventional staining techniques and to identify possible reproductive dysfunctions causing low conception rates in AI using frozen-thawed spermatozoa with poor acrosomal conditions in Japanese Black bulls. We investigated individual differences among bulls in the results concerning (1) acrosomal conditions of frozen-thawed spermatozoa as assessed by not merely peanut agglutinin-lectin staining (a conventional staining technique) but also immunostaining of acrosomal tyrosine-phosphorylated proteins (a new staining technique), (2) routine AI using frozen-thawed spermatozoa as assessed by pregnancy diagnosis, (3) in vivo fertilization of frozen-thawed spermatozoa and early development of fertilized eggs as assessed by superovulation/AI-embryo collection tests and (4) in vitro fertilization of frozen-thawed spermatozoa with oocytes. The percentages of frozen-thawed spermatozoa with normal acrosomal conditions assessed by the abovementioned staining techniques were significantly correlated with the conception rates of routine AI, rates of transferable embryos in superovulation/AI-embryo collection tests and in vitro fertilization rates. These results are consistent with new suggestions that the distribution of acrosomal tyrosine-phosphorylated proteins as well as the acrosomal morphology of frozen-thawed spermatozoa are AI fertility-associated markers that are valid for the prediction of AI results and that low conception rates in AI using frozen-thawed spermatozoa with poor acrosomal conditions result from reproductive dysfunctions in the processes between sperm insemination into females and early embryo development, probably failed fertilization of frozen-thawed spermatozoa with oocytes. PMID:26300347

  5. Simplified Space Conditioning in Low-Load Homes: Results from the Fresno, California, Retrofit Unoccupied Test House

    SciTech Connect

    Stecher, Dave; Poerschke, Andrew

    2014-02-01

    In this study, the Building America team, IBACOS, sought to determine cost-effective, energy-efficient solutions for heating and cooling houses. To this end, the team performed field testing in a retrofit unoccupied test house in Fresno, California, to evaluate three air-based heating, ventilation, and air conditioning (HVAC) distribution systems during heating, cooling, and midseason conditions. These included a typical airflow ducted system to the bedrooms, a low airflow ducted system to the bedrooms, and a system with no ductwork to the bedrooms. The relative ability of each of the three systems was assessed with respect to relevant Air Conditioning Contractors of America (ACCA) and ASHRAE standards for house temperature uniformity and stability, respectively. Computational fluid dynamics modeling also was performed and refined based on comparison to field test results to determine the air flow rate into the bedrooms of over-door and bottom-of-door air transfer grilles.

  6. Simplified Space Conditioning in Low-Load Homes: Results from the Fresno, California, Retrofit Unoccupied Test House

    SciTech Connect

    Stecher, D.; Poerschke, A.

    2014-02-01

    Field testing was performed in a retrofit unoccupied test house in Fresno, California. Three air-based heating, ventilation, and air conditioning (HVAC) distribution systems -- a typical airflow ducted system to the bedrooms, a low airflow ducted system to the bedrooms, and a system with no ductwork to the bedrooms -- were evaluated during heating, cooling, and midseason conditions. The relative ability of each of the three systems was assessed with respect to relevant Air Conditioning Contractors of America (ACCA) and ASHRAE standards for house temperature uniformity and stability, respectively. Computational fluid dynamics (CFD) modeling also was performed and refined based on comparison to field test results to determine the air flow rate into the bedrooms of over-door and bottom-of-door air transfer grilles.

  7. Effects of acute aerobic exercise on a task-switching protocol and brain-derived neurotrophic factor concentrations in young adults with different levels of cardiorespiratory fitness.

    PubMed

    Tsai, Chia-Liang; Pan, Chien-Yu; Chen, Fu-Chen; Wang, Chun-Hao; Chou, Feng-Ying

    2016-07-01

    What is the central question of this study? Neurocognitive functions can be enhanced by acute aerobic exercise, which could be associated with changes in serum brain-derived neurotrophic factor (BDNF) concentrations. We aimed to explore acute exercise-induced changes in BDNF concentrations, neuropsychological and neurophysiological performances when individuals with different levels of cardiorespiratory fitness performed a cognitive task. What is the main finding and its importance? Only young adults with higher cardiorespiratory fitness could attain switching cost and neurophysiological benefits via acute aerobic exercise. The mechanisms might be fitness dependent. Although acute aerobic exercise could enhance serum BDNF concentrations, changes in peripheral BDNF concentrations could not be the potential factor involved in the beneficial effects on neurocognitive performance. This study investigated the effects of acute aerobic exercise on neuropsychological and neurophysiological performances in young adults with different cardiorespiratory fitness levels when performing a task-switching protocol and explored the potential associations between acute aerobic exercise-induced changes in serum brain-derived neurotrophic factor (BDNF) concentrations and various neurocognitive outcomes. Sixty young adults were categorized into one control group (i.e. non-exercise-intervention; n = 20) and two exercise-intervention (EI) groups [i.e. higher (EIH , n = 20) and lower (EIL , n = 20) cardiorespiratory fitness] according to their maximal oxygen consumption. At baseline and after either an acute bout of 30 min of moderate-intensity aerobic exercise or a control period, the neuropsychological and neurophysiological performances and serum BDNF concentrations were measured when the participants performed a task-switching protocol involving executive control and greater demands on working memory. The results revealed that although acute aerobic exercise decreased reaction

  8. Effects of acute aerobic exercise on a task-switching protocol and brain-derived neurotrophic factor concentrations in young adults with different levels of cardiorespiratory fitness.

    PubMed

    Tsai, Chia-Liang; Pan, Chien-Yu; Chen, Fu-Chen; Wang, Chun-Hao; Chou, Feng-Ying

    2016-07-01

    What is the central question of this study? Neurocognitive functions can be enhanced by acute aerobic exercise, which could be associated with changes in serum brain-derived neurotrophic factor (BDNF) concentrations. We aimed to explore acute exercise-induced changes in BDNF concentrations, neuropsychological and neurophysiological performances when individuals with different levels of cardiorespiratory fitness performed a cognitive task. What is the main finding and its importance? Only young adults with higher cardiorespiratory fitness could attain switching cost and neurophysiological benefits via acute aerobic exercise. The mechanisms might be fitness dependent. Although acute aerobic exercise could enhance serum BDNF concentrations, changes in peripheral BDNF concentrations could not be the potential factor involved in the beneficial effects on neurocognitive performance. This study investigated the effects of acute aerobic exercise on neuropsychological and neurophysiological performances in young adults with different cardiorespiratory fitness levels when performing a task-switching protocol and explored the potential associations between acute aerobic exercise-induced changes in serum brain-derived neurotrophic factor (BDNF) concentrations and various neurocognitive outcomes. Sixty young adults were categorized into one control group (i.e. non-exercise-intervention; n = 20) and two exercise-intervention (EI) groups [i.e. higher (EIH , n = 20) and lower (EIL , n = 20) cardiorespiratory fitness] according to their maximal oxygen consumption. At baseline and after either an acute bout of 30 min of moderate-intensity aerobic exercise or a control period, the neuropsychological and neurophysiological performances and serum BDNF concentrations were measured when the participants performed a task-switching protocol involving executive control and greater demands on working memory. The results revealed that although acute aerobic exercise decreased reaction

  9. Effects of Aerobic Exercise on Mild Cognitive Impairment

    PubMed Central

    Baker, Laura D.; Frank, Laura L.; Foster-Schubert, Karen; Green, Pattie S.; Wilkinson, Charles W.; McTiernan, Anne; Plymate, Stephen R.; Fishel, Mark A.; Stennis Watson, G.; Cholerton, Brenna A.; Duncan, Glen E.; Mehta, Pankaj D.; Craft, Suzanne

    2011-01-01

    Objectives To examine the effects of aerobic exercise on cognition and other biomarkers associated with Alzheimer disease pathology for older adults with mild cognitive impairment, and assess the role of sex as a predictor of response. Design Six-month, randomized, controlled, clinical trial. Setting Veterans Affairs Puget Sound Health Care System clinical research unit. Participants Thirty-three adults (17 women) with amnestic mild cognitive impairment ranging in age from 55 to 85 years (mean age,70 years). Intervention Participants were randomized either to a high-intensity aerobic exercise or stretching control group. The aerobic group exercised under the supervision of a fitness trainer at 75% to 85% of heart rate reserve for 45 to 60 min/d, 4 d/wk for 6 months. The control group carried out supervised stretching activities according to the same schedule but maintained their heart rate at or below 50% of their heart rate reserve. Before and after the study, glucometabolic and treadmill tests were performed and fat distribution was assessed using dual-energy x-ray absorptiometry. At baseline, month 3, and month 6, blood was collected for assay and cognitive tests were administered. Main Outcome Measures Performance measures on Symbol-Digit Modalities, Verbal Fluency, Stroop, Trails B, Task Switching, Story Recall, and List Learning. Fasting plasma levels of insulin, cortisol, brain-derived neurotrophic factor, insulinlike growth factor-I, and β-amyloids 40 and 42. Results Six months of high-intensity aerobic exercise had sex-specific effects on cognition, glucose metabolism, and hypothalamic-pituitary-adrenal axis and trophic activity despite comparable gains in cardiorespiratory fitness and body fat reduction. For women, aerobic exercise improved performance on multiple tests of executive function, increased glucose disposal during the metabolic clamp, and reduced fasting plasma levels of insulin, cortisol, and brain-derived neurotrophic factor. For men

  10. Spectroscopic characterization of organic matter of a soil and vinasse mixture during aerobic or anaerobic incubation

    SciTech Connect

    Doelsch, Emmanuel Masion, Armand; Cazevieille, Patrick

    2009-06-15

    Mineralization potentials are often used to classify organic wastes. These methods involve measuring CO{sub 2} production during batch experiments, so variations in chemical compounds are not addressed. Moreover, the physicochemical conditions are not monitored during the reactions. The present study was designed to address these deficiencies. Incubations of a mixture of soil and waste (vinasse at 20% dry matter from a fermentation industry) were conducted in aerobic and anaerobic conditions, and liquid samples obtained by centrifugation were collected at 2 h, 1 d and 28 d. Dissolved organic carbon (DOC) patterns highlighted that: there was a 'soil effect' which increased organic matter (OM) degradation in all conditions compared to vinasse incubated alone; and OM degradation was faster under aerobic conditions since 500 mg kg{sup -1} of C remained after aerobic incubation, as compared to 4000 mg kg{sup -1} at the end of the anaerobic incubation period. No changes were detected by Fourier transform infrared spectroscopy (FTIR) between 2 h and 1 d incubation. At 28 days incubation, the FTIR signal of the aerobic samples was deeply modified, thus confirming the high OM degradation. Under anaerobic conditions, the main polysaccharide contributions ({nu}(C-O)) disappeared at 1000 and 1200 cm{sup -1}, as also confirmed by the {sup 13}C NMR findings. Under aerobic incubation, a 50% decrease in the polysaccharide proportion was observed. Under anaerobic conditions, significant chemical modifications of the organic fraction were detected, namely formation of low molecular weight organic acids.

  11. Adolescent traumatic stress experience results in less robust conditioned fear and post-extinction fear cue responses in adult rats.

    PubMed

    Moore, Nicole L T; Gauchan, Sangeeta; Genovese, Raymond F

    2014-05-01

    Early exposure to a traumatic event may produce lasting effects throughout the lifespan. Traumatic stress during adolescence may deliver a distinct developmental insult compared with more-often studied neonatal or juvenile traumatic stress paradigms. The present study describes the lasting effects of adolescent traumatic stress upon adulthood fear conditioning. Adolescent rats were exposed to a traumatic stressor (underwater trauma, UWT), then underwent fear conditioning during adulthood. Fear extinction was tested over five conditioned suppression extinction sessions three weeks later. The efficacies of two potential extinction-enhancing compounds, endocannabinoid reuptake inhibitor AM404 (10mg/kg) and M1 muscarinic positive allosteric modulator BQCA (10mg/kg), were also assessed. Finally, post-extinction fear responses were examined using a fear cue (light) as a prepulse stimulus. Rats traumatically stressed during adolescence showed blunted conditioned suppression on day 1 of extinction training, and AM404 reversed this effect. Post-extinction startle testing showed that fear conditioning eliminates prepulse inhibition to the light cue. Startle potentiation was observed only in rats without adolescent UWT exposure. AM404 and BQCA both ameliorated this startle potentiation, while BQCA increased startle in the UWT group. These results suggest that exposure to a traumatic stressor during adolescence alters developmental outcomes related to stress response and fear extinction compared to rats without adolescent traumatic stress exposure, blunting the adulthood fear response and reducing residual post-extinction fear expression. Efficacy of pharmacological interventions may also vary as a factor of developmental traumatic stress exposure.

  12. Aerobic fitness predicts relational memory but not item memory performance in healthy young adults.

    PubMed

    Baym, Carol L; Khan, Naiman A; Pence, Ari; Raine, Lauren B; Hillman, Charles H; Cohen, Neal J

    2014-11-01

    Health factors such as an active lifestyle and aerobic fitness have long been linked to decreased risk of cardiovascular disease, stroke, and other adverse health outcomes. Only more recently have researchers begun to investigate the relationship between aerobic fitness and memory function. Based on recent findings in behavioral and cognitive neuroscience showing that the hippocampus might be especially sensitive to the effects of exercise and fitness, the current study assessed hippocampal-dependent relational memory and non-hippocampal-dependent item memory in young adults across a range of aerobic fitness levels. Aerobic fitness was assessed using a graded exercise test to measure oxygen consumption during maximal exercise (VO2max), and relational and item memory were assessed using behavioral and eye movement measures. Behavioral results indicated that aerobic fitness was positively correlated with relational memory performance but not item memory performance, suggesting that the beneficial effects of aerobic fitness selectively affect hippocampal function and not that of the surrounding medial temporal lobe cortex. Eye movement results further supported the specificity of this fitness effect to hippocampal function, in that aerobic fitness predicted disproportionate preferential viewing of previously studied relational associations but not of previously viewed items. Potential mechanisms underlying this pattern of results, including neurogenesis, are discussed.

  13. Comparison of dry medium culture plates for mesophilic aerobic bacteria in milk, ice cream, ham, and codfish fillet products.

    PubMed

    Park, Junghyun; Kim, Myunghee

    2013-12-01

    This study was performed to compare the performance of Sanita-Kun dry medium culture plate with those of traditional culture medium and Petrifilm dry medium culture plate for the enumeration of the mesophilic aerobic bacteria in milk, ice cream, ham, and codfish fillet. Mesophilic aerobic bacteria were comparatively evaluated in milk, ice cream, ham, and codfish fillet using Sanita-Kun aerobic count (SAC), Petrifilm aerobic count (PAC), and traditional plate count agar (PCA) media. According to the results, all methods showed high correlations of 0.989~1.000 and no significant differences were observed for enumerating the mesophilic aerobic bacteria in the tested food products. SAC method was easier to perform and count colonies efficiently as compared to the PCA and PAC methods. Therefore, we concluded that the SAC method offers an acceptable alternative to the PCA and PAC methods for counting the mesophilic aerobic bacteria in milk, ice cream, ham, and codfish fillet products. PMID:24551829

  14. Comparison of dry medium culture plates for mesophilic aerobic bacteria in milk, ice cream, ham, and codfish fillet products.

    PubMed

    Park, Junghyun; Kim, Myunghee

    2013-12-01

    This study was performed to compare the performance of Sanita-Kun dry medium culture plate with those of traditional culture medium and Petrifilm dry medium culture plate for the enumeration of the mesophilic aerobic bacteria in milk, ice cream, ham, and codfish fillet. Mesophilic aerobic bacteria were comparatively evaluated in milk, ice cream, ham, and codfish fillet using Sanita-Kun aerobic count (SAC), Petrifilm aerobic count (PAC), and traditional plate count agar (PCA) media. According to the results, all methods showed high correlations of 0.989~1.000 and no significant differences were observed for enumerating the mesophilic aerobic bacteria in the tested food products. SAC method was easier to perform and count colonies efficiently as compared to the PCA and PAC methods. Therefore, we concluded that the SAC method offers an acceptable alternative to the PCA and PAC methods for counting the mesophilic aerobic bacteria in milk, ice cream, ham, and codfish fillet products.

  15. Microbial decolorization of reactive black-5 in a two-stage anaerobic-aerobic reactor using acclimatized activated textile sludge.

    PubMed

    Mohanty, Sagarika; Dafale, Nishant; Rao, Nageswara Neti

    2006-10-01

    A two-stage anaerobic-aerobic treatment process based on mixed culture of bacteria isolated from textile dye effluent was used to degrade reactive black 5 dye (RB-5). The anaerobic step was studied in more detail by varying the dye concentration from 100 to 3000 mg l(-1). The results showed that major decolorization was achieved during the anaerobic process. The time required for decolorization by > 90% increased as the concentration of the dye increased. It was also found that maintaining dissolved oxygen (DO) concentration below 0.5 mg l(-1 )and addition of a co-substrate viz., glucose, facilitates anaerobic decolorization reaction remarkably. An attempt was made to identify the metabolites formed in anaerobic process by using high performance liquid chromatography (HPLC) and UV-VIS spectrophotometry. A plate assay was performed for the detection of dominant decolorizing bacteria. Only a few bacterial colonies with high clearing zones (decolorization zones) were found. The results showed that under anaerobic condition RB-5 molecules were reduced and aromatic amines were generated. The aromatic amine metabolite was partly removed in subsequent aerobic bio-treatment. It was possible to achieve more than 90% decolorization and approximately 46% reduction in amine metabolite concentration through two-stage anaerobic-aerobic treatment after a reaction period of 2 days.

  16. A Pilot Study of Women’s Affective Responses to Common and Uncommon Forms of Aerobic Exercise

    PubMed Central

    Stevens, Courtney J.; Smith, Jane Ellen; Bryan, Angela D.

    2015-01-01

    Objective To test the extent to which participants exposed to an uncommon versus common exercise stimulus would result in more favourable affect at post task. Design Experimental design. Participants, (N = 120) American women aged 18–45 years, were randomly assigned to complete 30-minutes of either the uncommon (HOOP; n = 58) or common (WALK; n = 62) exercise stimulus. Main Outcome Measures Self-reported affect and intentions for future exercise were measured before and after the 30-minute exercise bout. Results Analyses of covariance (ANCOVA) were run to compare post-task affect across the HOOP and WALK conditions. At post-task, participants assigned to HOOP reported more positively valenced affect, higher ratings of positive activated affect, lower ratings of negative deactivated affect, and stronger intentions for future aerobic exercise compared to participants assigned to WALK. Conclusions Participants who completed an uncommon bout of aerobic exercise (HOOP) reported more favourable affect post-exercise, as well as stronger intentions for future exercise, compared to participants who completed a common bout of aerobic exercise (WALK). Future work using a longitudinal design is needed to understand the relationships between familiarity with an exercise stimulus, affective responses to exercise, motivation for future exercise behaviour, and exercise maintenance over time. PMID:26394246

  17. Aerobic biotransformation and mineralization of 2,4,6-trinitrotoluene

    SciTech Connect

    Bae, B.H.; Autenrieth, R.L.; Bonner, J.S.

    1995-12-31

    Respirometric mineralization studies of 2,4,6-trinitrotoluene (TNT) were conducted with microorganisms isolated from a site contaminated with munitions waste in Illinois. Nine aerobic bacterial species were isolated under a carbon- and nitrogen-limited condition and tentatively identified as: one Pseudomonas species; one Enterobacter species; and seven Alcaligenes species. Experiments were performed using each of the nine organisms individually and with a consortium of all nine bacterial species. The aerobic microorganisms were cultured in a sterile nutrient solution with glucose and 20 mg/L TNT. Mineralization was determined using uniformly ring-labeled {sup 14}C-TNT in a respirometer that trapped the evolved CO{sub 2}. Biodegradation behavior was characterized based on oxygen consumption, distribution of {sup 14}C activity, and high-performance liquid chromatography (HPLC) analysis of TNT and its transformation products.

  18. Small-sided game training improves aerobic capacity and technical skills in basketball players.

    PubMed

    Delextrat, A; Martinez, A

    2014-05-01

    The aim of this study was to compare the effects of 2 training interventions based on small-sided games (SGG) and high-intensity interval training (HIT) on physical and technical performance of male junior basketball players. A secondary objective was to investigate if these effects were similar in starting and bench players. 18 players participated in a pre-testing session, 6-weeks intervention period and a post-testing session. Pre- and post-sessions involved assessments of aerobic fitness, repeated sprint ability (RSA), defensive and offensive agility, upper and lower body power, shooting and passing skills. Mixed-design analysis of variance (ANOVA) with Bonferroni corrected pairwise comparisons examined the effects of time and type of intervention on physical and technical performances. The main results showed that both interventions resulted in similar improvements in aerobic capacity (+3.4% vs. +4.1%), with greater improvements in bench players compared to starting players (+7.1% vs. +1.1%, P<0.05). However, RSA was unchanged after both interventions. In addition, compared to HIT, SSG resulted in greater improvements in defensive agility (+4.5% vs. -2.7%, P<0.05), shooting skills (+7.4% vs. -2.4%, P<0.05) and upper body power (+7.9% vs. -2.0%, P<0.05). These results suggest that SSG should be prioritized in physical conditioning of junior basketball players during the season. However, when RSA is targeted, more specific training seems necessary.

  19. Simultaneous heterotrophic nitrification and aerobic denitrification by the marine origin bacterium Pseudomonas sp. ADN-42.

    PubMed

    Jin, Ruofei; Liu, Tianqi; Liu, Guangfei; Zhou, Jiti; Huang, Jianyu; Wang, Aijie

    2015-02-01

    Recent research has highlighted the existence of some bacteria that are capable of performing heterotrophic nitrification and have a phenomenal ability to denitrify their nitrification products under aerobic conditions. A high-salinity-tolerant strain ADN-42 was isolated from Hymeniacidon perleve and found to display high heterotrophic ammonium removal capability. This strain was identified as Pseudomonas sp. via 16S rRNA gene sequence analysis. Gene cloning and sequencing analysis indicated that the bacterial genome contains N2O reductase function (nosZ) gene. NH3-N removal rate of ADN-42 was very high. And the highest removal rate was 6.52 mg/L · h in the presence of 40 g/L NaCl. Under the condition of pure oxygen (DO >8 mg/L), NH3-N removal efficiency was 56.9 %. Moreover, 38.4 % of oxygen remained in the upper gas space during 72 h without greenhouse gas N2O production. Keeping continuous and low level of dissolved oxygen (DO <3 mg/L) was helpful for better denitrification performance. All these results indicated that the strain has heterotrophic nitrification and aerobic denitrification abilities, which guarantee future application in wastewater treatment.

  20. Simultaneous heterotrophic nitrification and aerobic denitrification by the marine origin bacterium Pseudomonas sp. ADN-42.

    PubMed

    Jin, Ruofei; Liu, Tianqi; Liu, Guangfei; Zhou, Jiti; Huang, Jianyu; Wang, Aijie

    2015-02-01

    Recent research has highlighted the existence of some bacteria that are capable of performing heterotrophic nitrification and have a phenomenal ability to denitrify their nitrification products under aerobic conditions. A high-salinity-tolerant strain ADN-42 was isolated from Hymeniacidon perleve and found to display high heterotrophic ammonium removal capability. This strain was identified as Pseudomonas sp. via 16S rRNA gene sequence analysis. Gene cloning and sequencing analysis indicated that the bacterial genome contains N2O reductase function (nosZ) gene. NH3-N removal rate of ADN-42 was very high. And the highest removal rate was 6.52 mg/L · h in the presence of 40 g/L NaCl. Under the condition of pure oxygen (DO >8 mg/L), NH3-N removal efficiency was 56.9 %. Moreover, 38.4 % of oxygen remained in the upper gas space during 72 h without greenhouse gas N2O production. Keeping continuous and low level of dissolved oxygen (DO <3 mg/L) was helpful for better denitrification performance. All these results indicated that the strain has heterotrophic nitrification and aerobic denitrification abilities, which guarantee future application in wastewater treatment. PMID:25432342

  1. C4-Dicarboxylate Utilization in Aerobic and Anaerobic Growth.

    PubMed

    Unden, Gottfried; Strecker, Alexander; Kleefeld, Alexandra; Kim, Ok Bin

    2016-06-01

    C4-dicarboxylates and the C4-dicarboxylic amino acid l-aspartate support aerobic and anaerobic growth of Escherichia coli and related bacteria. In aerobic growth, succinate, fumarate, D- and L-malate, L-aspartate, and L-tartrate are metabolized by the citric acid cycle and associated reactions. Because of the interruption of the citric acid cycle under anaerobic conditions, anaerobic metabolism of C4-dicarboxylates depends on fumarate reduction to succinate (fumarate respiration). In some related bacteria (e.g., Klebsiella), utilization of C4-dicarboxylates, such as tartrate, is independent of fumarate respiration and uses a Na+-dependent membrane-bound oxaloacetate decarboxylase. Uptake of the C4-dicarboxylates into the bacteria (and anaerobic export of succinate) is achieved under aerobic and anaerobic conditions by different sets of secondary transporters. Expression of the genes for C4-dicarboxylate metabolism is induced in the presence of external C4-dicarboxylates by the membrane-bound DcuS-DcuR two-component system. Noncommon C4-dicarboxylates like l-tartrate or D-malate are perceived by cytoplasmic one-component sensors/transcriptional regulators. This article describes the pathways of aerobic and anaerobic C4-dicarboxylate metabolism and their regulation. The citric acid cycle, fumarate respiration, and fumarate reductase are covered in other articles and discussed here only in the context of C4-dicarboxylate metabolism. Recent aspects of C4-dicarboxylate metabolism like transport, sensing, and regulation will be treated in more detail. This article is an updated version of an article published in 2004 in EcoSal Plus. The update includes new literature, but, in particular, the sections on the metabolism of noncommon C4-dicarboxylates and their regulation, on the DcuS-DcuR regulatory system, and on succinate production by engineered E. coli are largely revised or new.

  2. C4-Dicarboxylate Utilization in Aerobic and Anaerobic Growth.

    PubMed

    Unden, Gottfried; Strecker, Alexander; Kleefeld, Alexandra; Kim, Ok Bin

    2016-06-01

    C4-dicarboxylates and the C4-dicarboxylic amino acid l-aspartate support aerobic and anaerobic growth of Escherichia coli and related bacteria. In aerobic growth, succinate, fumarate, D- and L-malate, L-aspartate, and L-tartrate are metabolized by the citric acid cycle and associated reactions. Because of the interruption of the citric acid cycle under anaerobic conditions, anaerobic metabolism of C4-dicarboxylates depends on fumarate reduction to succinate (fumarate respiration). In some related bacteria (e.g., Klebsiella), utilization of C4-dicarboxylates, such as tartrate, is independent of fumarate respiration and uses a Na+-dependent membrane-bound oxaloacetate decarboxylase. Uptake of the C4-dicarboxylates into the bacteria (and anaerobic export of succinate) is achieved under aerobic and anaerobic conditions by different sets of secondary transporters. Expression of the genes for C4-dicarboxylate metabolism is induced in the presence of external C4-dicarboxylates by the membrane-bound DcuS-DcuR two-component system. Noncommon C4-dicarboxylates like l-tartrate or D-malate are perceived by cytoplasmic one-component sensors/transcriptional regulators. This article describes the pathways of aerobic and anaerobic C4-dicarboxylate metabolism and their regulation. The citric acid cycle, fumarate respiration, and fumarate reductase are covered in other articles and discussed here only in the context of C4-dicarboxylate metabolism. Recent aspects of C4-dicarboxylate metabolism like transport, sensing, and regulation will be treated in more detail. This article is an updated version of an article published in 2004 in EcoSal Plus. The update includes new literature, but, in particular, the sections on the metabolism of noncommon C4-dicarboxylates and their regulation, on the DcuS-DcuR regulatory system, and on succinate production by engineered E. coli are largely revised or new. PMID:27415771

  3. Effects of a single bout of lower-body aerobic exercise on muscle activation and performance during subsequent lower- and upper-body resistance exercise workouts.

    PubMed

    Tan, Jeremy G; Coburn, Jared W; Brown, Lee E; Judelson, Daniel A

    2014-05-01

    A single bout of lower-body aerobic exercise may negatively affect a subsequent lower-body resistance exercise workout. However, less is known regarding the effects of a lower-body aerobic workout on muscle activation and performance during a subsequent upper-body resistance exercise workout. Therefore, the purpose of this study was to compare muscle activation and performance during lower- and upper-body resistance exercise workouts after a single bout of lower-body aerobic exercise on an elliptical machine. Fourteen men (mean age = 24.1 ± 2.3 years, height = 180.8 ± 6.9 cm, body mass = 91.9 ± 16.4 kg) completed 4 trials in random order. Two trials consisted of 30 minutes on the elliptical machine, using the lower body only, at 70% of age-predicted maximum heart rate before either a back squat or bench press workout, consisting of 3 sets to failure performed at 75% 1 repetition maximum. The other 2 trials consisted of only the back squat or bench press resistance workouts. To quantify muscle activation, bipolar surface electromyography electrodes were placed on the rectus femoris and vastus lateralis or pectoralis major. Acute lower-body aerobic exercise on an elliptical machine significantly reduced the number of repetitions completed for the back squat but not the bench press exercise. There was no significant difference in muscle activation between the elliptical and no elliptical conditions. However, for both exercises and conditions, muscle activation increased significantly between the first and final repetitions for the first 2 sets but not for the third set. These results suggest that to optimize the quality of a lower-body resistance-training workout, the workout should not be preceded by lower-body aerobic exercise.

  4. Aerobic exercise modulates intracortical inhibition and facilitation in a nonexercised upper limb muscle

    PubMed Central

    2014-01-01

    Background Despite growing interest in the relationship between exercise and short-term neural plasticity, the effects of exercise on motor cortical (M1) excitability are not well studied. Acute, lower-limb aerobic exercise may potentially modulate M1 excitability in working muscles, but the effects on muscles not involved in the exercise are unknown. Here we examined the excitability changes in an upper limb muscle representation following a single session of lower body aerobic exercise. Investigating the response to exercise in a non-exercised muscle may help to determine the clinical usefulness of lower-body exercise interventions for upper limb neurorehabilitation. Methods In this study, transcranial magnetic stimulation was used to assess input–output curves, short-interval intracortical inhibition (SICI), long-interval intracortical inhibition (LICI) and intracortical facilitation (ICF) in the extensor carpi radialis muscle in twelve healthy individuals following a single session of moderate stationary biking. Additionally, we examined whether the presence of a common polymorphism of the brain-derived neurotrophic factor (BDNF) gene would affect the response of these measures to exercise. Results We observed significant increases in ICF and decreases in SICI following exercise. No changes in LICI were detected, and no differences were observed in input–output curves following exercise, or between BDNF groups. Conclusions The current results demonstrate that the modulation of intracortical excitability following aerobic exercise is not limited to those muscles involved in the exercise, and that while exercise does not directly modulate the excitability of motor neurons, it may facilitate the induction of experience-dependent plasticity via a decrease in intracortical inhibition and increase in intracortical facilitation. These findings indicate that exercise may create favourable conditions for adaptive plasticity in M1 and may be an effective adjunct to

  5. The reverse Warburg effect: aerobic glycolysis in cancer associated fibroblasts and the tumor stroma.

    PubMed

    Pavlides, Stephanos; Whitaker-Menezes, Diana; Castello-Cros, Remedios; Flomenberg, Neal; Witkiewicz, Agnieszka K; Frank, Philippe G; Casimiro, Mathew C; Wang, Chenguang; Fortina, Paolo; Addya, Sankar; Pestell, Richard G; Martinez-Outschoorn, Ubaldo E; Sotgia, Federica; Lisanti, Michael P

    2009-12-01

    Here, we propose a new model for understanding the Warburg effect in tumor metabolism. Our hypothesis is that epithelial cancer cells induce the Warburg effect (aerobic glycolysis) in neighboring stromal fibroblasts. These cancer-associated fibroblasts, then undergo myo-fibroblastic differentiation, and secrete lactate and pyruvate (energy metabolites resulting from aerobic glycolysis). Epithelial cancer cells could then take up these energy-rich metabolites and use them in the mitochondrial TCA cycle, thereby promoting efficient energy production (ATP generation via oxidative phosphorylation), resulting in a higher proliferative capacity. In this alternative model of tumorigenesis, the epithelial cancer cells instruct the normal stroma to transform into a wound-healing stroma, providing the necessary energy-rich micro-environment for facilitating tumor growth and angiogenesis. In essence, the fibroblastic tumor stroma would directly feed the epithelial cancer cells, in a type of host-parasite relationship. We have termed this new idea the "Reverse Warburg Effect." In this scenario, the epithelial tumor cells "corrupt" the normal stroma, turning it into a factory for the production of energy-rich metabolites. This alternative model is still consistent with Warburg's original observation that tumors show a metabolic shift towards aerobic glycolysis. In support of this idea, unbiased proteomic analysis and transcriptional profiling of a new model of cancer-associated fibroblasts (caveolin-1 (Cav-1) deficient stromal cells), shows the upregulation of both (1) myo-fibroblast markers and (2) glycolytic enzymes, under normoxic conditions. We validated the expression of these proteins in the fibroblastic stroma of human breast cancer tissues that lack stromal Cav-1. Importantly, a loss of stromal Cav-1 in human breast cancers is associated with tumor recurrence, metastasis, and poor clinical outcome. Thus, an absence of stromal Cav-1 may be a biomarker for the "Reverse

  6. Aerobic exercise attenuates pulmonary inflammation induced by Streptococcus pneumoniae.

    PubMed

    Olivo, Clarice R; Miyaji, Eliane N; Oliveira, Maria Leonor S; Almeida, Francine M; Lourenço, Juliana D; Abreu, Rodrigo M; Arantes, Petra M M; Lopes, Fernanda Dtqs; Martins, Milton A

    2014-11-01

    Aerobic exercise has been recognized as a stimulator of the immune system, but its effect on bacterial infection has not been extensively evaluated. We studied whether moderate aerobic exercise training prior to Streptococcus pneumoniae infection influences pulmonary inflammatory responses. BALB/c mice were divided into four groups: Sedentary Untreated (sedentary without infection); Sedentary Infected (sedentary with infection); Trained Untreated (aerobic training without infection); and Trained Infected (aerobic training with infection). Animals underwent aerobic training for 4 wk, and 72 h after last exercise training, animals received a challenge with S. pneumoniae and were evaluated either 12 h or 10 days after instillation. In acute phase, Sedentary Infected group had an increase in respiratory system resistance and elastance; number of neutrophils, lymphocytes, and macrophages in bronchoalveolar lavage fluid (BAL); polymorphonuclear cells in lung parenchyma; and levels of keratinocyte-derived chemokine (KC), tumor necrosis factor-α (TNF-α), and interleukin (IL)-1β (IL-1β) in lung homogenates. Exercise training significantly attenuated the increase in all of these parameters and induced an increase in expression of antioxidant enzymes (CuZnSOD and MnSOD) in lungs. Trained Infected mice had a significant decrease in the number of colony-forming units of pneumococci in the lungs compared with Sedentary Infected animals. Ten days after infection, Trained Infected group exhibited lower numbers of macrophages in BAL, polymorphonuclear cells in lung parenchyma and IL-6 in lung homogenates compared with Sedentary Infected group. Our results suggest a protective effect of moderate exercise training against respiratory infection with S. pneumoniae. This effect is most likely secondary to an effect of exercise on oxidant-antioxidant balance.

  7. Aerobic exercise augments muscle transcriptome profile of resistance exercise.

    PubMed

    Lundberg, Tommy R; Fernandez-Gonzalo, Rodrigo; Tesch, Per A; Rullman, Eric; Gustafsson, Thomas

    2016-06-01

    Recent reports suggest that aerobic exercise may boost the hypertrophic response to short-term resistance training. This study explored the effects of an acute aerobic exercise bout on the transcriptional response to subsequent resistance exercise. Ten moderately trained men performed ∼45 min cycling on one leg followed by 4 × 7 maximal knee extensions for each leg, 15 min later. Thus, one limb performed aerobic and resistance exercise (AE + RE) while the opposing leg did resistance exercise only (RE). Biopsies were obtained from the vastus lateralis muscle of each leg 3 h after the resistance exercise bout. Using DNA microarray, we analyzed differences [≥1.5-fold, false discovery rate (FDR) ≤10%] in gene expression profiles for the two modes of exercise. There were 176 genes up (127)- or downregulated (49) by AE + RE compared with RE. Among the most significant differentially expressed genes were established markers for muscle growth and oxidative capacity, novel cytokines, transcription factors, and micro-RNAs (miRNAs). The most enriched functional categories were those linked to carbohydrate metabolism and transcriptional regulation. Upstream analysis revealed that vascular endothelial growth factor, cAMP-response element-binding protein, Tet methylcytosine dioxygenase, and mammalian target of rapamycin were regulators highly activated by AE + RE, whereas JnK, NF-κβ, MAPK, and several miRNAs were inhibited. Thus, aerobic exercise alters the skeletal muscle transcriptional signature of resistance exercise to initiate important gene programs promoting both myofiber growth and improved oxidative capacity. These results provide novel insight into human muscle adaptations to diverse exercise modes and offer the very first genomic basis explaining how aerobic exercise may augment, rather than compromise, muscle growth induced by resistance exercise. PMID:27101291

  8. Aerobic exercise augments muscle transcriptome profile of resistance exercise.

    PubMed

    Lundberg, Tommy R; Fernandez-Gonzalo, Rodrigo; Tesch, Per A; Rullman, Eric; Gustafsson, Thomas

    2016-06-01

    Recent reports suggest that aerobic exercise may boost the hypertrophic response to short-term resistance training. This study explored the effects of an acute aerobic exercise bout on the transcriptional response to subsequent resistance exercise. Ten moderately trained men performed ∼45 min cycling on one leg followed by 4 × 7 maximal knee extensions for each leg, 15 min later. Thus, one limb performed aerobic and resistance exercise (AE + RE) while the opposing leg did resistance exercise only (RE). Biopsies were obtained from the vastus lateralis muscle of each leg 3 h after the resistance exercise bout. Using DNA microarray, we analyzed differences [≥1.5-fold, false discovery rate (FDR) ≤10%] in gene expression profiles for the two modes of exercise. There were 176 genes up (127)- or downregulated (49) by AE + RE compared with RE. Among the most significant differentially expressed genes were established markers for muscle growth and oxidative capacity, novel cytokines, transcription factors, and micro-RNAs (miRNAs). The most enriched functional categories were those linked to carbohydrate metabolism and transcriptional regulation. Upstream analysis revealed that vascular endothelial growth factor, cAMP-response element-binding protein, Tet methylcytosine dioxygenase, and mammalian target of rapamycin were regulators highly activated by AE + RE, whereas JnK, NF-κβ, MAPK, and several miRNAs were inhibited. Thus, aerobic exercise alters the skeletal muscle transcriptional signature of resistance exercise to initiate important gene programs promoting both myofiber growth and improved oxidative capacity. These results provide novel insight into human muscle adaptations to diverse exercise modes and offer the very first genomic basis explaining how aerobic exercise may augment, rather than compromise, muscle growth induced by resistance exercise.

  9. Biodegradation of industrial-strength 2,4-dichlorophenoxyacetic acid wastewaters in the presence of glucose in aerobic and anaerobic sequencing batch reactors.

    PubMed

    Elefsiniotis, Panagiotis; Wareham, David G

    2013-01-01

    This research explored the biodegradability of 2,4-dichlorophenoxyacetic acid (2,4-D) in two laboratory-scale sequencing batch reactors (SBRs) that operated under aerobic and anaerobic conditions. The potential limit of 2,4-D degradation was investigated at a hydraulic retention time of 48 h, using glucose as a supplemental substrate and increasing feed concentrations of 2,4-D; namely 100 to 700 mg/L (i.e. industrial strength) for the aerobic system and 100 to 300 mg/L for the anaerobic SBR. The results revealed that 100 mg/L of 2,4-D was completely degraded following an acclimation period of 29 d (aerobic SBR) and 70 d (anaerobic SBR). The aerobic system achieved total 2,4-D removal at feed concentrations up to 600 mg/L which appeared to be a practical limit, since a further increase to 700 mg/L impaired glucose degradation while 2,4-D biodegradation was non-existent. In all cases, glucose was consumed before the onset of 2,4-D degradation. In the anaerobic SBR, 2,4-D degradation was limited to 120 mg/L.

  10. [Reactive changes in psychological condition and behaviour in children of parents with cancer--results of an epidemiological survey].

    PubMed

    Bergelt, Corinna; Ernst, Johanna Christine; Beierlein, Volker; Inhestern, Laura; Holes, Sarah; Möller, Birgit; Romer, Georg; Koch, Uwe

    2012-01-01

    Children of cancer patients are at risk for developing psychological symptoms. The parental appraisal of the child's psychological condition is a key variable for the utilization of child-centred psychosocial services. This study aimed at the systematic analysis of parental appraisals of changes in the emotional condition or behaviour of their children. We conducted an epidemiologic survey with a sample size of 1,809 patients with different cancer diagnoses, giving information about 2,581 children aged 21 years or younger at time of diagnosis. Quantitative information on children's distress during the disease and on changes in psychological condition or behaviour and qualitative information on the kind of changes were analysed. About half of the children were considered to be psychologically strongly affected during the disease. For about 25 % negative changes in psychological condition or behaviour are reported, positive changes are reported for 20 % of the children. Negative changes are most frequently described in young children (up to five years), positive changes are most frequently described in young adults (18 to 21 years). The results indicate that from the cancer parent's view many children are substantially distressed. Thus, the implementation of additional preventive psychosocial services seems reasonable and necessary. PMID:22950334

  11. Days Out of Role Due to Mental and Physical Conditions: Results from the Singapore Mental Health Study

    PubMed Central

    Abdin, Edimansyah; Ong, Clarissa; Chong, Siow Ann; Vaingankar, Janhavi Ajit; Subramaniam, Mythily

    2016-01-01

    Objective The aim of the current study was to evaluate the relative contributions of mental and physical conditions to days out of role among adults aged 18 years and above in Singapore. Methods The Singapore Mental Health Study was a cross-sectional epidemiological survey of a nationally representative sample of residents aged 18 years or older. Diagnosis of mental disorders was established using the Composite International Diagnostic Interview; while chronic physical conditions were established using a checklist. Days out of role were assessed using a WHO Disability Assessment Schedule item. Multivariate regression analyses were used to estimate individual-level and societal-level effects of disorders. Results Overall, 8.7% of respondents reported at least one day out of role, with a mean of 5.8 days. The most disabling conditions at the individual level were cancer (118.9 additional days), cardiovascular diseases (93.5), and bipolar disorder (71.0). At the societal level, cardiovascular diseases contributed the highest population attributable risk proportion (45%), followed by cancer (39.3%), and hypertension (13.5%). Conclusions Mental and physical conditions are linked to significant losses in productivity for society as well as role disability for individuals, underscoring the need to enhance prevention and intervention efforts to increase overall productivity and improve individual functioning. PMID:26840741

  12. Stress, temperature, heart rate, and hibernating factors in hamsters. [pathophysiological conditions resulting from exposure to zero gravity

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.

    1974-01-01

    Pathophysiological conditions resulting from prolonged exposure to zero gravity, cabin constraint, altered ambient environment, whether it be noise, vibrations, high temperatures, or combinations of such factors, are studied in laboratory animals and applied to manned space flight. Results and plans for further study are presented. Specific topics covered include: thermoregulation and its role in reflecting stress and adaptation to the gravity free environment and cabin confinement with its altered circadian forcings; renal function and its measurement in electrolyte distribution and blood flow dynamics; gastronintestinal function and an assessment of altered absorptive capacity in the intestinal mucosa; and catecholamine metabolism in terms of distribution and turnover rates in specific tissues.

  13. Quantitative analysis of microbial biomass yield in aerobic bioreactor.

    PubMed

    Watanabe, Osamu; Isoda, Satoru

    2013-12-01

    We have studied the integrated model of reaction rate equations with thermal energy balance in aerobic bioreactor for food waste decomposition and showed that the integrated model has the capability both of monitoring microbial activity in real time and of analyzing biodegradation kinetics and thermal-hydrodynamic properties. On the other hand, concerning microbial metabolism, it was known that balancing catabolic reactions with anabolic reactions in terms of energy and electron flow provides stoichiometric metabolic reactions and enables the estimation of microbial biomass yield (stoichiometric reaction model). We have studied a method for estimating real-time microbial biomass yield in the bioreactor during food waste decomposition by combining the integrated model with the stoichiometric reaction model. As a result, it was found that the time course of microbial biomass yield in the bioreactor during decomposition can be evaluated using the operational data of the bioreactor (weight of input food waste and bed temperature) by the combined model. The combined model can be applied to manage a food waste decomposition not only for controlling system operation to keep microbial activity stable, but also for producing value-added products such as compost on optimum condition. PMID:25078821

  14. Isolation of an aerobic vinyl chloride oxidizer from anaerobic groundwater.

    PubMed

    Fullerton, Heather; Rogers, Rebecca; Freedman, David L; Zinder, Stephen H

    2014-11-01

    Vinyl chloride (VC) is a known human carcinogen and common groundwater contaminant. Reductive dechlorination of VC to non-toxic ethene under anaerobic conditions has been demonstrated at numerous hazardous waste sites. However, VC disappearance without stoichiometric production of ethene has also been observed at some sites and in microcosms. In this study we identify an organism responsible for this observation in presumably anaerobic microcosms and conclude that oxygen was not detectable based on a lack of color change from added resazurin. This organism, a Mycobacterium sp. closely related to known VC oxidizing strains, was present in high numbers in 16S rRNA gene clone libraries from a groundwater microcosm. Although the oxidation/reduction indicator resazurin remained in the clear reduced state in these studies, these results suggest inadvertent oxygen contamination occurred. This study helps to elucidate the dynamic behavior of chlorinated ethenes in contaminated groundwater, through the isolation of a strictly aerobic organism that may be responsible for at least some disappearance of VC without the concomitant production of ethene in groundwater considered anaerobic.

  15. Aerobic Mercury-resistant bacteria alter Mercury speciation and retention in the Tagus Estuary (Portugal).

    PubMed

    Figueiredo, Neusa L; Canário, João; O'Driscoll, Nelson J; Duarte, Aida; Carvalho, Cristina

    2016-02-01

    Aerobic mercury-resistant bacteria were isolated from the sediments of two highly mercury-polluted areas of the Tagus Estuary (Barreiro and Cala do Norte) and one natural reserve area (Alcochete) in order to test their capacity to transform mercury. Bacterial species were identified using 16S rRNA amplification and sequencing techniques and the results indicate the prevalence of Bacillus sp. Resistance patterns to mercurial compounds were established by the determination of minimal inhibitory concentrations. Representative Hg-resistant bacteria were further tested for transformation pathways (reduction, volatilization and methylation) in cultures containing mercury chloride. Bacterial Hg-methylation was carried out by Vibrio fluvialis, Bacillus megaterium and Serratia marcescens that transformed 2-8% of total mercury into methylmercury in 48h. In addition, most of the HgR bacterial isolates showed Hg(2+)-reduction andHg(0)-volatilization resulting 6-50% mercury loss from the culture media. In summary, the results obtained under controlled laboratory conditions indicate that aerobic Hg-resistant bacteria from the Tagus Estuary significantly affect both the methylation and reduction of mercury and may have a dual face by providing a pathway for pollution dispersion while forming methylmercury, which is highly toxic for living organisms.

  16. Vertebrate blood cell volume increases with temperature: implications for aerobic activity.

    PubMed

    Gillooly, James F; Zenil-Ferguson, Rosana

    2014-01-01

    Aerobic activity levels increase with body temperature across vertebrates. Differences in these levels, from highly active to sedentary, are reflected in their ecology and behavior. Yet, the changes in the cardiovascular system that allow for greater oxygen supply at higher temperatures, and thus greater aerobic activity, remain unclear. Here we show that the total volume of red blood cells in the body increases exponentially with temperature across vertebrates, after controlling for effects of body size and taxonomy. These changes are accompanied by increases in relative heart mass, an indicator of aerobic activity. The results point to one way vertebrates may increase oxygen supply to meet the demands of greater activity at higher temperatures.

  17. Conditions that may result in (de-)phosphorylation of hepatic acyl-CoA:cholesterol acyltransferase result also in modulation of substrate s