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https://www.readbyqxmd.com/read/28818711/the-influence-of-solid-retention-time-on-ifas-mbr-systems-assessment-of-nitrous-oxide-emission
#1
Giorgio Mannina, Marco Capodici, Alida Cosenza, Vito Armando Laudicina, Daniele Di Trapani
The aim of the present study was to investigate the nitrous oxide (N2O) emissions from a moving bed based Integrated Fixed Film Activated Sludge (IFAS) - membrane bioreactor (MBR) pilot plant, designed according to the University of Cape Town (UCT) layout. The experimental campaign had a duration of 110 days and was characterized by three different sludge retention time (SRT) values (∞, 30 d and 15 d). Results highlighted that N2O concentrations decreased when the biofilm concentrations increased within the aerobic reactor...
August 14, 2017: Journal of Environmental Management
https://www.readbyqxmd.com/read/28817216/functional-neuroimaging-after-severe-anoxic-brain-injury-in-children-may-reveal-preserved-yet-covert-cognitive-function
#2
Adrian M Owen
A growing body of evidence has confirmed that, after severe brain injury in adults, motoric and task-dependent factors that are essential for reliable communication, frequently interfere with an accurate assessment of cognitive status. In the current study, resting state functional magnetic resonance imaging (fMRI) in children who have sustained an anoxic brain injury following a near drowning incident suggests a similar pattern; preserved cognition amidst severe motoric impairment that effectively precludes accurate clinical diagnosis at the bedside...
August 17, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28815366/abiotic-nitrate-loss-and-nitrogenous-trace-gas-emission-from-chinese-acidic-forest-soils
#3
Yajing Wang, Wenchao Cao, Xinmu Zhang, Jingheng Guo
There are an increasing number of studies, which have shown the potential importance of abiotic denitrification in nitrogen biogeochemistry through pure chemical coupling between nitrate/nitrite reduction and Fe(II) oxidation. However, there is little direct evidence showing the environmental significance of abiotic nitrate (NO3(-)) reduction in acidic soils. We assessed the magnitude and gaseous product stoichiometry of abiotic nitrate reduction in acidic forest soils based on sterilized anoxic soil incubations at different soil pHs and nitrate loadings...
August 16, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28808684/constraining-the-rate-of-oceanic-deoxygenation-leading-up-to-a-cretaceous-oceanic-anoxic-event-oae-2-94-ma
#4
Chadlin M Ostrander, Jeremy D Owens, Sune G Nielsen
The rates of marine deoxygenation leading to Cretaceous Oceanic Anoxic Events are poorly recognized and constrained. If increases in primary productivity are the primary driver of these episodes, progressive oxygen loss from global waters should predate enhanced carbon burial in underlying sediments-the diagnostic Oceanic Anoxic Event relic. Thallium isotope analysis of organic-rich black shales from Demerara Rise across Oceanic Anoxic Event 2 reveals evidence of expanded sediment-water interface deoxygenation ~43 ± 11 thousand years before the globally recognized carbon cycle perturbation...
August 2017: Science Advances
https://www.readbyqxmd.com/read/28805078/occurrence-and-predictive-factors-of-heterotopic-ossification-in-severe-acquired-brain-injured-patients-during-rehabilitation-stay-cross-sectional-survey
#5
Stefano Bargellesi, Luisa Cavasin, Federico Scarponi, Antonio De Tanti, Donatella Bonaiuti, Michelangelo Bartolo, Paolo Boldrini, Anna Estraneo
OBJECTIVES: To report occurrence and identify patient's features and risk factors of heterotopic ossifications in patients with severe acquired brain injury in intensive rehabilitation centres. DESIGN: Multicentre cross-sectional survey. SETTING: A total of 48 severe acquired brain injury rehabilitation institutes. PARTICIPANTS: Traumatic and non-traumatic severe brain-injured patients ( N = 689) in rehabilitation centres on 28 May 2016...
August 1, 2017: Clinical Rehabilitation
https://www.readbyqxmd.com/read/28802136/the-role-of-sulfate-in-aerobic-granular-sludge-process-for-emerging-sulfate-laden-wastewater-treatment
#6
Weiqi Xue, Tianwei Hao, Hamish R Mackey, Xiling Li, Richard C Chan, Guanghao Chen
Sulfate-rich wastewaters pose a major threat to mainstream wastewater treatment due to the unpreventable production of sulfide and associated shift in functional bacteria. Aerobic granular sludge could mitigate these challenges in view of its high tolerance and resilience against changes in various environmental conditions. This study aims to confirm the feasibility of aerobic granular sludge in the treatment of sulfate containing wastewater, investigate the impact of sulfate on nutrient removal and granulation, and reveal metabolic relationships in the above processes...
August 4, 2017: Water Research
https://www.readbyqxmd.com/read/28800888/clinical-classification-of-post-anoxic-myoclonic-status
#7
Yara Mikhaeil-Demo, Jay R Gavvala, Irena I Bellinski, Micheal P Macken, Aditi Narechania, Jessica W Templer, Stephen VanHaerents, Stephan U Schuele, Elizabeth E Gerard
INTRODUCTION: Despite decades of research into the prognostic significance of post anoxic myoclonic status (MS), no consistent definition has been used to describe its clinical appearance. We set out to characterize the clinical features of MS and hypothesized that there are distinct clinical subtypes that may have prognostic implications. METHODS: Video EEG reports from 2008 to 2016 were searched to identify adult patients with post anoxic MS defined as persistent myoclonus for >30minutes beginning within 3days of cardiac arrest in a comatose patient...
August 8, 2017: Resuscitation
https://www.readbyqxmd.com/read/28798773/planktonic-growth-of-pseudomonas-aeruginosa-around-a-dual-species-biofilm-supports-the-growth-of-fusobacterium-nucleatum-within-that-biofilm
#8
James C Wang, Joehassin Cordero, Yan Sun, Mayank Aranke, Randall Wolcott, Jane A Colmer-Hamood, Abdul N Hamood
PURPOSE: The goal of this study was to understand the potential interaction between Pseudomonas aeruginosa and Fusobacterium nucleatum within the middle ear. METHODS: We examined the microbiota of ear fluid and tympanostomy tubes (TTs) obtained from patients with posttympanostomy tube otorrhea. We also examined biofilms formed by P. aeruginosa and F. nucleatum, singly or together, under aerobic or anaerobic conditions. RESULTS: While the facultative anaerobe P...
2017: International Journal of Otolaryngology
https://www.readbyqxmd.com/read/28798742/preservation-and-significance-of-extracellular-dna-in-ferruginous-sediments-from-lake-towuti-indonesia
#9
Aurèle Vuillemin, Fabian Horn, Mashal Alawi, Cynthia Henny, Dirk Wagner, Sean A Crowe, Jens Kallmeyer
Extracellular DNA is ubiquitous in soil and sediment and constitutes a dominant fraction of environmental DNA in aquatic systems. In theory, extracellular DNA is composed of genomic elements persisting at different degrees of preservation produced by processes occurring on land, in the water column and sediment. Extracellular DNA can be taken up as a nutrient source, excreted or degraded by microorganisms, or adsorbed onto mineral matrices, thus potentially preserving information from past environments. To test whether extracellular DNA records lacustrine conditions, we sequentially extracted extracellular and intracellular DNA from anoxic sediments of ferruginous Lake Towuti, Indonesia...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28797670/the-role-of-alluvial-aquifer-sediments-in-attenuating-a-dissolved-arsenic-plume
#10
Brady A Ziegler, Madeline E Schreiber, Isabelle M Cozzarelli
In a crude-oil-contaminated sandy aquifer at the Bemidji site in northern Minnesota, biodegradation of petroleum hydrocarbons has resulted in release of naturally occurring As to groundwater under Fe-reducing conditions. This study used chemical extractions of aquifer sediments collected in 1993 and 2011-2014 to evaluate the relationship between Fe and As in different redox zones (oxic, methanogenic, Fe-reducing, anoxic-suboxic transition) of the contaminated aquifer over a twenty-year period. Results show that 1) the aquifer has the capacity to naturally attenuate the plume of dissolved As, primarily through sorption; 2) Fe and As are linearly correlated in sediment across all redox zones, and a regression analysis between Fe and As reasonably predicted As concentrations in sediment from 1993 using only Fe concentrations; 3) an As-rich "iron curtain," associated with the anoxic-suboxic transition zone, migrated 30m downgradient between 1993 and 2013 as a result of the hydrocarbon plume evolution; and 4) silt lenses in the aquifer preferentially sequester dissolved As, though As is remobilized into groundwater from sediment after reducing conditions are established...
May 2, 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28793929/shifts-in-coastal-sediment-oxygenation-cause-pronounced-changes-in-microbial-community-composition-and-associated-metabolism
#11
Elias Broman, Johanna Sjöstedt, Jarone Pinhassi, Mark Dopson
BACKGROUND: A key characteristic of eutrophication in coastal seas is the expansion of hypoxic bottom waters, often referred to as 'dead zones'. One proposed remediation strategy for coastal dead zones in the Baltic Sea is to mix the water column using pump stations, circulating oxygenated water to the sea bottom. Although microbial metabolism in the sediment surface is recognized as key in regulating bulk chemical fluxes, it remains unknown how the microbial community and its metabolic processes are influenced by shifts in oxygen availability...
August 9, 2017: Microbiome
https://www.readbyqxmd.com/read/28792534/primary-bovine-skeletal-muscle-cells-enters-apoptosis-rapidly-via-the-intrinsic-pathway-when-available-oxygen-is-removed
#12
Sissel Beate Rønning, Petter Vejle Andersen, Mona Elisabeth Pedersen, Kristin Hollung
Muscle cells undergo changes post-mortem during the process of converting muscle into meat, and this complex process is far from revealed. Recent reports have suggested programmed cell death (apoptosis) to be important in the very early period of converting muscle into meat. The dynamic balance that occurs between anti-apoptotic members, such as Bcl-2, and pro-apoptotic members (Bid, Bim) helps determine whether the cell initiates apoptosis. In this study, we used primary bovine skeletal muscle cells, cultured in monolayers in vitro, to investigate if apoptosis is induced when oxygen is removed from the growth medium...
2017: PloS One
https://www.readbyqxmd.com/read/28782075/extracellular-enzymatic-activity-of-two-hydrolases-in-wastewater-treatment-for-biological-nutrient-removal
#13
Jorge Mario Berrio-Restrepo, Julio César Saldarriaga, Mauricio Andrés Correa, Néstor Jaime Aguirre
Due to the complex nature of the wastewater (both domestic and non-domestic) composition, biological processes are widely used to remove nutrients, such as carbon (C), nitrogen (N), and phosphorous (P), which cause instability and hence contribute to the damage of water bodies. Systems with different configurations have been developed (including anaerobic, anoxic, and aerobic conditions) for the joint removal of carbon, nitrogen, and phosphorus. The goal of this research is to evaluate the extracellular activity of β-glucosidase and phosphatase enzymes in a University of Cape Town (UCT) system fed with two synthetic wastewaters of different molecular complexity...
August 7, 2017: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/28777994/nitrogen-removal-and-n2o-emission-in-subsurface-wastewater-infiltration-systems-with-without-intermittent-aeration-under-different-organic-loading-rates
#14
Yingying Jiang, Yafei Sun, Jing Pan, Shiyue Qi, Qiuying Chen, Deli Tong
Nitrogen removal, N2O emission and nitrogen removal functional gene abundances in intermittent aerated (IA) and non-aerated (NA) subsurface wastewater infiltration systems (SWISs) under different organic loading rates (OLRs) were investigated. Aeration successfully created aerobic condition at 50cm depth and did not change anoxic or anaerobic condition at 80 and 110cm depths under OLR of 5.3, 10.9 and 16.5g BOD/(m(2)d). Meanwhile, aeration enhanced COD, NH4(+)-N, TN removal and the enrichment of nitrogen removal functional genes (amoA, nxrA, napA, narG, nirS, nirK, qnorB and nosZ) compared to NA SWIS...
July 26, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28772023/evidence-for-h2-consumption-by-uncultured-desulfobacterales-in-coastal-sediments
#15
Stefan Dyksma, Petra Pjevac, Kin Ovanesov, Marc Mussmann
Molecular hydrogen (H2 ) is the key intermediate in the anaerobic degradation of organic matter. Its removal by H2 -oxidizing microorganisms is essential to keep anaerobic degradation energetically favorable. Sulfate-reducing microorganisms (SRM) are known as the main H2 scavengers in anoxic marine sediments. Although the community of marine SRM has been extensively studied, those consuming H2 in situ are completely unknown. We combined metagenomics, PCR-based clone libraries, single-amplified genomes (SAGs) and metatranscriptomics to identify potentially H2 -consuming SRM in anoxic coastal sediments...
August 3, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28771968/metabolic-potential-and-in-situ-activity-of-marine-marinimicrobia-bacteria-in-an-anoxic-water-column
#16
Anthony D Bertagnolli, Cory C Padilla, Jennifer B Glass, Bo Thamdrup, Frank J Stewart
Marinimicrobia bacteria are widespread in sub-euphotic areas of the oceans and particularly abundant in oxygen minimum zones (OMZs). Information on Marinimicrobia metabolism is sparse, making the biogeochemical influence of this group challenging to predict. Here, metagenome-assembled genomes representing Marinimicrobia subgroups PN262000N21 and ARCTIC96B-7 were retrieved to near completion (97% and 94%) from OMZ metagenomes, with contamination (14.1%) observed only in ARCTIC96B-7. Genes for aerobic carbon monoxide (CO) oxidation, polysulfide metabolism, and hydrogen utilization were identified only in PN262000N21, while genes for partial denitrification occurred in both genomes...
August 3, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28771908/bacteriohopanepolyols-along-redox-gradients-in-the-humboldt-current-system-off-northern-chile
#17
E D Matys, J Sepúlveda, S Pantoja, C B Lange, M Caniupán, F Lamy, R E Summons
Marine oxygen minimum zones (OMZs) are characterized by the presence of subsurface suboxic or anoxic waters where diverse microbial processes are responsible for the removal of fixed nitrogen. OMZs have expanded over past decades and are expected to continue expanding in response to the changing climate. The implications for marine biogeochemistry, particularly nitrogen cycling, are uncertain. Cell membrane lipids (biomarkers), such as bacterial bacteriohopanepolyols (BHPs) and their degradation products (hopanoids), have distinctive structural attributes that convey information about their biological sources...
August 3, 2017: Geobiology
https://www.readbyqxmd.com/read/28769904/global-biogeographic-analysis-of-methanogenic-archaea-identifies-community-shaping-environmental-factors-of-natural-environments
#18
Xi Wen, Sizhong Yang, Fabian Horn, Matthias Winkel, Dirk Wagner, Susanne Liebner
Methanogenic archaea are important for the global greenhouse gas budget since they produce methane under anoxic conditions in numerous natural environments such as oceans, estuaries, soils, and lakes. Whether and how environmental change will propagate into methanogenic assemblages of natural environments remains largely unknown owing to a poor understanding of global distribution patterns and environmental drivers of this specific group of microorganisms. In this study, we performed a meta-analysis targeting the biogeographic patterns and environmental controls of methanogenic communities using 94 public mcrA gene datasets...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28769885/novel-pelagic-iron-oxidizing-zetaproteobacteria-from-the-chesapeake-bay-oxic-anoxic-transition-zone
#19
Beverly K Chiu, Shingo Kato, Sean M McAllister, Erin K Field, Clara S Chan
Chemolithotrophic iron-oxidizing bacteria (FeOB) could theoretically inhabit any environment where Fe(II) and O2 (or nitrate) coexist. Until recently, marine Fe-oxidizing Zetaproteobacteria had primarily been observed in benthic and subsurface settings, but not redox-stratified water columns. This may be due to the challenges that a pelagic lifestyle would pose for Zetaproteobacteria, given low Fe(II) concentrations in modern marine waters and the possibility that Fe oxyhydroxide biominerals could cause cells to sink...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28767128/inter-and-intra-specific-variability-in-physiological-traits-and-post-anoxia-recovery-of-photosynthetic-efficiency-in-grasses-under-oxygen-deprivation
#20
A Pompeiano, T Huarancca Reyes, T M Moles, M Villani, M Volterrani, L Guglielminetti, A Scartazza
Low oxygen conditions occur in grass sites due to high and frequent precipitation, poor soil quality, and over-irrigation followed by slow drainage. Three warm-season and one cool-season grasses were analyzed at metabolic level during a time-course experiment performed in a controlled anoxic environment. Prolonged oxygen depletion proved detrimental by leading to premature death to all the species, with the exception of seashore paspalum. Moreover, the anoxia tolerance observed in these grasses has been associated with slow use of carbohydrates, rather than with their relative abundance, which was more important than their antioxidant capacity...
August 2, 2017: Physiologia Plantarum
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