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https://www.readbyqxmd.com/read/28447615/millions-of-boreal-shield-lakes-can-be-used-to-probe-archaean-ocean-biogeochemistry
#1
S L Schiff, J M Tsuji, L Wu, J J Venkiteswaran, L A Molot, R J Elgood, M J Paterson, J D Neufeld
Life originated in Archaean oceans, almost 4 billion years ago, in the absence of oxygen and the presence of high dissolved iron concentrations. Early Earth oxidation is marked globally by extensive banded iron formations but the contributing processes and timing remain controversial. Very few aquatic habitats have been discovered that match key physico-chemical parameters of the early Archaean Ocean. All previous whole ecosystem Archaean analogue studies have been confined to rare, low sulfur, and permanently stratified lakes...
April 27, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28446906/stratified-bacterial-diversity-along-physico-chemical-gradients-in-high-altitude-modern-stromatolites
#2
Diego M Toneatti, Virginia H Albarracín, Maria R Flores, Lubos Polerecky, María E Farías
At an altitude of 3,570 m, the volcanic lake Socompa in the Argentinean Andes is presently the highest site where actively forming stromatolite-like structures have been reported. Interestingly, pigment and microsensor analyses performed through the different layers of the stromatolites (50 mm-deep) showed steep vertical gradients of light and oxygen, hydrogen sulfide and pH in the porewater. Given the relatively good characterization of these physico-chemical gradients, the aim of this follow-up work was to specifically address how the bacterial diversity stratified along the top six layers of the stromatolites which seems the most metabolically important and diversified zone of the whole microbial community...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28446901/anaerobic-methanotrophic-archaea-of-the-anme-2d-cluster-are-active-in-a-low-sulfate-iron-rich-freshwater-sediment
#3
Hannah S Weber, Kirsten S Habicht, Bo Thamdrup
ANaerobic MEthanotrophic (ANME) archaea remove the greenhouse gas methane from anoxic environments and diminish its flux to the atmosphere. High methane removal efficiencies are well documented in marine environments, whereas anaerobic oxidation of methane (AOM) was only recently indicated as an important methane sink in freshwater systems. Freshwater AOM-mediating microorganisms lack taxonomic identification and only little is known about metabolic adaptions to prevailing biogeochemical conditions. One of the first study sites providing information about AOM activity in freshwater sediment is Lake Ørn, a low-sulfate, iron-rich Danish lake...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28442658/predominant-but-previously-overlooked-prokaryotic-drivers-of-reductive-nitrogen-transformation-in-paddy-soils-revealed-by-metatranscriptomics
#4
Yoko Masuda, Hideomi Itoh, Yutaka Shiratori, Kazuo Isobe, Shigeto Otsuka, Keishi Senoo
Waterlogged paddy soils possess anoxic zones in which microbes actively induce reductive nitrogen transformation (RNT). In the present study, a shotgun RNA sequencing analysis (metatranscriptomics) of paddy soil samples revealed that most RNT gene transcripts in paddy soils were derived from Deltaproteobacteria, particularly the genera Anaeromyxobacter and Geobacter. Despite the frequent detection of the rRNA of these microbes in paddy soils, their RNT-associated genes have rarely been identified in previous PCR-based studies...
April 22, 2017: Microbes and Environments
https://www.readbyqxmd.com/read/28442002/n2o-emission-and-hydroxylamine-oxidase-hao-activity-in-a-nitrogen-removal-process-based-on-activated-sludge-with-three-cod-nh4-ratios
#5
Zhi-Xian He, Lin-Jiang Yuan, Yi-Ni Wei, Ya-Ping Nan
  This study dealt with nitrous oxide (N2O) emission and hydroxylamine oxidase (HAO) activity of waste sludge in a nitrification and denitrification process employing three carbon nitrogen (C/N) ratios in a sequencing batch reactor (SBR). The experimental results indicated that N2O emission increased dramatically after the C/N ratio in the sludge increased from 6.5 to 9.3, which was greater than the N2O emission at two other C/N ratios (3.5, 6.5). The HAO activity in the anoxic period was higher with all three C/N ratios than in the aerobic period...
May 1, 2017: Water Environment Research: a Research Publication of the Water Environment Federation
https://www.readbyqxmd.com/read/28437728/is-a-a-o-process-effective-in-toxicity-removal-case-study-with-coking-wastewater
#6
Liu Shi, Dong Wang, Di Cao, Chunhong Na, Xie Quan, Ying Zhang
The anaerobic-anoxic-oxic (A/A/O) process is the commonly used biological wastewater treatment process, especially for the coking wastewater. However, limit is known about its ability in bio-toxicity removal from wastewater. In this study, we evaluated the performance of A/A/O process in bio-toxicity removal from the coking wastewater, using two test species (i.e. crustacean (Daphnia magna) and zebra fish (Danio rerio)) in respect of acute toxicity, oxidative damage and genotoxicity. Our results showed that the acute toxicity of raw influent was reduced gradually along with A/A/O process and the effluent presented no acute toxicity to Daphnia magna (D...
April 21, 2017: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/28424678/microbial-and-isotopic-evidence-for-methane-cycling-in-hydrocarbon-containing-groundwater-from-the-pennsylvania-region
#7
Adrien Vigneron, Andrew Bishop, Eric B Alsop, Kellie Hull, Ileana Rhodes, Robert Hendricks, Ian M Head, Nicolas Tsesmetzis
The Pennsylvania region hosts numerous oil and gas reservoirs and the presence of hydrocarbons in groundwater has been locally observed. However, these methane-containing freshwater ecosystems remain poorly explored despite their potential importance in the carbon cycle. Methane isotope analysis and analysis of low molecular weight hydrocarbon gases from 18 water wells indicated that active methane cycling may be occurring in methane-containing groundwater from the Pennsylvania region. Consistent with this observation, multigenic qPCR and gene sequencing (16S rRNA genes, mcrA, and pmoA genes) indicated abundant populations of methanogens, ANME-2d (average of 1...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28419952/antimony-and-arsenic-exhibit-contrasting-spatial-distributions-in-the-sediment-and-vegetation-of-a-contaminated-wetland
#8
Jan Warnken, Rohana Ohlsson, David T Welsh, Peter R Teasdale, Ariella Chelsky, William W Bennett
Antimony is a priority environmental contaminant that is relatively poorly studied compared to other trace metal(loid)s. In particular, the behaviour of antimony in wetland sediments, where anaerobic conditions often dominate, has received considerably less attention compared to well-drained terrestrial soil environments. Here we report the results of a spatial assessment of antimony in the sediments and vegetation of a freshwater wetland exposed to stibnite tailings for the past forty years. The concentration of antimony in the sediment decreased rapidly with distance from the tailings deposit, from a maximum of ∼22,000 mg kg(-1) to ∼1000 mg kg(-1) at a distance of ∼150 m...
April 12, 2017: Chemosphere
https://www.readbyqxmd.com/read/28419718/shifting-microbial-communities-sustain-multiyear-iron-reduction-and-methanogenesis-in-ferruginous-sediment-incubations
#9
M S Bray, J Wu, B C Reed, C B Kretz, K M Belli, R L Simister, C Henny, F J Stewart, T J DiChristina, J A Brandes, D A Fowle, S A Crowe, J B Glass
Reactive Fe(III) minerals can influence methane (CH4 ) emissions by inhibiting microbial methanogenesis or by stimulating anaerobic CH4 oxidation. The balance between Fe(III) reduction, methanogenesis, and CH4 oxidation in ferruginous Archean and Paleoproterozoic oceans would have controlled CH4 fluxes to the atmosphere, thereby regulating the capacity for CH4 to warm the early Earth under the Faint Young Sun. We studied CH4 and Fe cycling in anoxic incubations of ferruginous sediment from the ancient ocean analogue Lake Matano, Indonesia, over three successive transfers (500 days in total)...
April 17, 2017: Geobiology
https://www.readbyqxmd.com/read/28419573/impella-2-5-initiated-prior-to-unprotected-left-main-pci-in-acute-myocardial-infarction-complicated-by-cardiogenic-shock-improves-early-survival
#10
Perwaiz M Meraj, Rajkumar Doshi, Theodore Schreiber, Brijeshwar Maini, William W O'Neill
OBJECTIVES: To assess post-procedural outcomes when Impella 2.5 percutaneous left ventricular assist device (pLVAD) support is initiated either prior to or after percutaneous coronary intervention (PCI) on unprotected left main coronary artery (ULMCA) culprit lesion in the context of acute myocardial infarction cardiogenic shock (AMICS). BACKGROUND: Initiation of Impella 2.5 pLVAD prior to PCI is associated with significant survival benefit in the setting of AMICS...
April 17, 2017: Journal of Interventional Cardiology
https://www.readbyqxmd.com/read/28417168/rdx-degradation-in-bioaugmented-model-aquifer-columns-under-aerobic-and-low-oxygen-conditions
#11
Mark E Fuller, Paul B Hatzinger, Charles W Condee, Christina Andaya, Rachel Rezes, Mandy M Michalsen, Fiona H Crocker, Karl J Indest, Carina M Jung, G Alon Blakeney, Jonathan D Istok, Steven A Hammett
Degradation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in laboratory columns following biostimulation and bioaugmentation was investigated using sediment and groundwater from a contaminated aquifer at a US Navy facility. No RDX degradation was observed following aerobic biostimulation with either fructose or lactate (both 0.1 mM) prior to bioaugmentation. Replicate columns were then bioaugmented with either Gordonia sp. KTR9, Pseudomonas fluorescens I-C (Ps I-C), or both strains. Under aerobic conditions (influent dissolved oxygen (DO) >6 mg/L), RDX was degraded following the addition of fructose, and to a lesser extent with lactate, in columns bioaugmented with KTR9...
April 17, 2017: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/28412628/4-nitroso-sulfamethoxazole-generation-in-soil-under-denitrifying-conditions-field-observations-versus-laboratory-results
#12
Monica Brienza, Céline Duwig, Sandra Pérez, Serge Chiron
The formation of 4-nitroso-sulfamethoxazole and 4-nitro-SMX, two transformation products (TPs) of sulfamethoxazole (SMX) was investigated under batch soil slurry experiments and in a field study. Due to their low occurrence levels (ng/L) in environmental waters, a suitable analytical method based on liquid chromatography - high resolution - mass spectrometry was developed. Consequently, field observations revealed, for the first time, the occurrence of 4-nitroso-SMX in groundwater at concentrations as high as 18ng/L...
April 7, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28411224/concurrent-haloalkanoate-degradation-and-chlorate-reduction-by-pseudomonas-chloritidismutans-aw-1-t
#13
Peng Peng, Ying Zheng, Jasper J Koehorst, Peter J Schaap, Alfons J M Stams, Hauke Smidt, Siavash Atashgahi
Haloalkanoates are environmental pollutants that can be degraded aerobically by microorganisms producing hydrolytic dehalogenases. However, there is lack of information about anaerobic degradation of haloalkanoates. Genome analysis of Pseudomonas chloritidismutans AW-1(T), a facultative anaerobic chlorate-reducing bacterium, showed presence of two putative haloacid dehalogenase genes, l-dex and dehI, encoding an L-2-haloacid dehalogenase (L-DEX) and a halocarboxylic acid dehydrogenase (DehI). Hence, we studied concurrent degradation of haloalkanoates and chlorate as a yet unexplored trait of strain AW-1(T) The deduced amino acid sequences of L-DEX and DehI revealed 33-37% and 26-86% identities with biochemically/structurally characterized L-DEX and D-, DL-2-haloacid dehalogenase enzymes, respectively...
April 14, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28411061/a-nuanced-view-of-post-anoxic-myoclonus
#14
EDITORIAL
Jonathan Elmer, Claudio Sandroni
No abstract text is available yet for this article.
April 11, 2017: Resuscitation
https://www.readbyqxmd.com/read/28409034/increased-intracranial-pressure-during-hemodialysis-in-a-patient-with-anoxic-brain-injury
#15
Anton Lund, Mette B Damholt, Ditte G Strange, Jesper Kelsen, Hasse Møller-Sørensen, Kirsten Møller
Dialysis disequilibrium syndrome (DDS) is a serious neurological complication of hemodialysis, and patients with acute brain injury are at increased risk. We report a case of DDS leading to intracranial hypertension in a patient with anoxic brain injury and discuss the subsequent dialysis strategy. A 13-year-old girl was admitted after prolonged resuscitation from cardiac arrest. Computed tomography (CT) revealed an inferior vena cava aneurysm and multiple pulmonary emboli as the likely cause. An intracranial pressure (ICP) monitor was inserted, and, on day 3, continuous renal replacement therapy (CRRT) was initiated due to acute kidney injury, during which the patient developed severe intracranial hypertension...
2017: Case Reports in Critical Care
https://www.readbyqxmd.com/read/28408694/determinants-of-hypoxia-inducible-factor-hif-activity-in-the-intestinal-mucosa
#16
Raphael R Fagundes, Cormac T Taylor
The intestinal mucosa is exposed to fluctuations in oxygen levels due to constantly changing rates of oxygen demand and supply and its juxtaposition with the anoxic environment of the intestinal lumen. This frequently results in a state of hypoxia in the healthy mucosa even in the physiologic state. Furthermore, pathophysiologic hypoxia (which is more severe and extensive) is associated with chronic inflammatory diseases including inflammatory bowel disease (IBD). The hypoxia-inducible factor (HIF), a ubiquitously expressed regulator of cellular adaptation to hypoxia, is central to both the adaptive and the inflammatory responses of cells of the intestinal mucosa in IBD patients...
April 13, 2017: Journal of Applied Physiology
https://www.readbyqxmd.com/read/28407427/microenvironmental-characteristics-and-physiology-of-biofilms-in-chronic-infections-of-cf-patients-are-strongly-affected-by-the-host-immune-response
#17
REVIEW
Peter Ø Jensen, Mette Kolpen, Kasper N Kragh, Michael Kühl
In vitro studies of Pseudomonas aeruginosa and other pathogenic bacteria in biofilm aggregates have yielded detailed insight into their potential growth modes and metabolic flexibility under exposure to gradients of substrate and electron acceptor. However, the growth pattern of P. aeruginosa in chronic lung infections of cystic fibrosis (CF) patients is very different from what is observed in vitro, for example, in biofilms grown in flow chambers. Dense in vitro biofilms of P. aeruginosa exhibit rapid O2 depletion within <50-100 μm due to their own aerobic metabolism...
April 2017: APMIS: Acta Pathologica, Microbiologica, et Immunologica Scandinavica
https://www.readbyqxmd.com/read/28407285/spatial-variation-in-bacterial-community-in-natural-wetland-river-sea-ecosystems
#18
Hongxia Zhang, Shiling Zheng, Jiawang Ding, Oumei Wang, Fanghua Liu
Wetland-estuarine-marine environments are typical oxic/anoxic transition zones and have complex water flow-paths within the zone of mixing where freshwater interacts with ocean water. Little is known about the impact of this interaction on bacterial community structures or the relationship between bacterial community and geochemical factors in such transitional mixing environments. Hence, we investigated the distribution patterns and diversity in bacterial communities in the Yellow River estuary-coastal wetland-Bohai Sea transition zone by analyzing 39 samples from 13 ordered sites...
April 13, 2017: Journal of Basic Microbiology
https://www.readbyqxmd.com/read/28403704/nursing-management-of-reflex-anoxic-seizures-in-children
#19
Neal Patel, Rowan Kerr-Liddell, Louise Challis, Siba Prosad Paul
Children who present with transient loss of consciousness (T-LOC) are often first seen in emergency departments (EDs). Reflex anoxic seizure (RAS), vasovagal syncope and prolonged respiratory apnoea are benign, syncopal events that can be generally managed by explanation and reassurance. RAS is a short, paroxysmal, self-reverting episode of asystole that is triggered by pain, fear or anxiety and is caused by increased vagal response. It is an important differential diagnosis in pre-school age children who present with T-LOC, but is often underdiagnosed and can sometimes be misdiagnosed as epilepsy...
April 13, 2017: Emergency Nurse: the Journal of the RCN Accident and Emergency Nursing Association
https://www.readbyqxmd.com/read/28402906/applying-fermentation-liquid-of-food-waste-as-carbon-source-to-a-pilot-scale-anoxic-oxic-membrane-bioreactor-for-enhancing-nitrogen-removal-microbial-communities-and-membrane-fouling-behaviour
#20
Jialing Tang, Xiaochang C Wang, Yisong Hu, Huu Hao Ngo, Yuyou Li, Yongmei Zhang
Fermentation liquid of food waste (FLFW) was applied as an external carbon source in a pilot-scale anoxic/oxic-membrane bioreactor (A/O-MBR) system to enhance nitrogen removal for treating low COD/TN ratio domestic wastewater. Results showed that, with the FLFW addition, total nitrogen removal increased from lower than 20% to 44-67% during the 150days of operation. The bacterial metabolic activities were obviously enhanced, and the significant change in microbial community structure promoted pollutants removal and favored membrane fouling mitigation...
April 2, 2017: Bioresource Technology
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