scholarly journals Correction: Long-term in situ permafrost thaw effects on bacterial communities and potential aerobic respiration

2019 ◽  
Vol 13 (8) ◽  
pp. 2140-2142
Author(s):  
Sylvain Monteux ◽  
James T. Weedon ◽  
Gesche Blume-Werry ◽  
Konstantin Gavazov ◽  
Vincent E. J. Jassey ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Aerobic Respiration ◽  
Permafrost Thaw

scholarly journals Long-term in situ permafrost thaw effects on bacterial communities and potential aerobic respiration

2018 ◽  
Vol 12 (9) ◽  
pp. 2129-2141 ◽  
Author(s):  
Sylvain Monteux ◽  
James T. Weedon ◽  
Gesche Blume-Werry ◽  
Konstantin Gavazov ◽  
Vincent E. J. Jassey ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Aerobic Respiration ◽  
Permafrost Thaw

Decade of permafrost thaw in a subarctic palsa mire alters carbon fluxes without affecting net carbon balance

2020 ◽  
Author(s):  
Carolina Olid ◽  
Jonatan Klaminder ◽  
Sylvain Monteux ◽  
Margareta Johansson ◽  
Ellen Dorrepaal
Keyword(s):  
Global Climate ◽  
Net Ecosystem Production ◽  
Climate System ◽  
Winter Warming ◽  
Permafrost Thaw ◽  
C Storage ◽  
C Balance ◽  
Ecosystem Production

<p>Snow depth increases observed in some artic regions and its insulations effects have led to a winter-warming of permafrost-containing peatlands. Permafrost thaw and the temperature-dependent decomposition of previously frozen carbon (C) is currently considered as one of the most important feedbacks between the artic and the global climate system. However, the magnitude of this feedback remains uncertain because winter effects are rarely integrated and predicted from mechanisms active in both surface (young) and thawing deep (old) peat layers.</p><p>Laboratory incubation studies of permafrost soils, in situ carbon flux measurements in ecosystem-scale permafrost thaw experiments, or measurements made across naturally degrading permafrost gradients have been used to improve our knowledge about the net effects of winter-warming in permafrost C storage. The results from these studies, however, are biased by imprecision in long-term (decadal to millennial) effects due to the short time scale of the experiments. Gradient studies may show longer-term responses but suffer from uncertainties because measurements are usually taken during the summer, thus ignoring the long cold season. The need for robust estimates of the long-term effect of permafrost thaw on the net C balance, which integrates year-round C fluxes sets the basis of this study.</p><p>Here, we quantified the effects of long-term in situ permafrost thaw in the net C balance of a permafrost-containing peatland subjected to a 10-years snow manipulation experiment. In short, we used a peat age modelling approach to quantify the effect of winter-warming on net ecosystem production as well as on the underlying changes in surface C inputs and losses along the whole peat continuum. Contrary to our hypothesis, winter-warming did not affect the net ecosystem production regardless of the increased old C losses. This minimum overall effect is due to the strong reduction on the young C losses from the upper active layer associated to the new water saturated conditions and the decline in bryophytes. Our findings highlight the need to incorporate long-term year-round responses in C fluxes when estimating the net effect of winter-warming on permafrost C storage. We also demonstrate that thaw-induced changes in moisture conditions and plant communities are key factors to predicting future climate change feedbacks between the artic soil C pool and the global climate system.</p>

scholarly journals Corncob structures in dental plaque reveal microhabitat taxon specificity

2021 ◽  
Author(s):  
Viviana Morillo-Lopez ◽  
Alexandra Sjaarda ◽  
Imon Islam ◽  
Gary G. Borisy ◽  
Jessica Mark Welch
Keyword(s):  
Bacterial Communities ◽  
Dental Plaque ◽  
Spatial Organization ◽  
Physical Distance ◽  
Small Subset ◽  
Long Term Stability ◽  
Natural Laboratory ◽  
Microhabitat Specialization

Abstract Background The human mouth is a natural laboratory for studying how bacterial communities differ across habitats. Different bacteria colonize different surfaces in the mouth – teeth, tongue dorsum, and keratinized and non-keratinized epithelia – despite the short physical distance between these habitats and their connection through saliva. We sought to determine whether more tightly defined microhabitats might have more tightly defined sets of resident bacteria. A microhabitat may be characterized, for example, as the space adjacent to a particular species of bacterium. Corncob structures of dental plaque, consisting of coccoid bacteria bound to filaments of Corynebacterium cells, present an opportunity to analyze the community structure of one such well-defined microhabitat within a complex natural biofilm. Here we investigate by fluorescence in situ hybridization and spectral imaging the composition of the cocci decorating the filaments. Results The range of taxa observed in corncobs was limited to a small subset of the taxa present in dental plaque. Among four major groups of dental plaque streptococci, two were the major constituents of corncobs, including one that was the most abundant Streptococcus species in corncobs despite being relatively rare in dental plaque overall. Images showed both Streptococcus types in corncobs in all individual donors, suggesting that the taxa possess different ecological roles or that mechanisms exist for stabilizing the persistence of functionally redundant taxa in the population. Direct taxon-taxon interactions were observed not only between the Streptococcus cells and the central corncob filament but also between Streptococcus cells and the limited subset of other plaque bacteria detected in the corncobs, indicating microhabitat specialization involving these taxa as well. Conclusions The spatial organization we observed in corncobs suggests that each of the microbial participants is capable of interacting with multiple, albeit limited, potential partners, a feature that may encourage the long-term stability of the community. Additionally, our results suggest the general principle that a precisely defined microhabitat will be inhabited by a small and well-defined set of microbial taxa.

scholarly journals Experimental Evidence for Manure-Borne Bacteria Invasion in Soil During a Coalescent Event: Influence of the Antibiotic Sulfamethazine

2022 ◽  
Author(s):  
Loren Billet ◽  
Stéphane Pesce ◽  
Fabrice Martin-Laurent ◽  
Marion Devers-Lamrani
Keyword(s):  
Bacterial Communities ◽  
Soil Microorganisms ◽  
Organic Amendment ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Abundant Otus ◽  
Rdna Sequencing ◽  
Different Soils

Abstract The fertilization of agricultural soil by organic amendment that may contain antibiotics, like manure, can transfer bacterial pathogens and antibiotic-resistant bacteria to soil communities. However, the invasion by manure-borne bacteria in amended soil remains poorly understood, being hardly observed. Here, we assessed the invasions of manure-borne bacteria during a coalescence event between manure and soil, in different soils and in the presence or absence of antibiotics. To this end, microcosms of four different soils were amended or not with manure at an agronomical dose and/or exposed or not to the antibiotic sulfamethazine (SMZ). After one month of incubation, the diversity, structure and composition of bacterial communities of the soils were assessed by 16S rDNA sequencing. The invasion of manure-borne bacteria was still perceptible one month after the soil amendment. The results obtained with the soil already amended in situ with manure six months prior to the experiment suggest that some of the bacterial invaders were established in the community over the long term. Even if differences were observed between soils, the invasion was mainly attributable to some of the most abundant OTUs of manure (mainly Firmicutes). SMZ exposure had a limited influence on soil microorganisms. It was significant in only one soil, where it enhanced the invasion potential of some manure-borne invaders.

THE ROLE OF BACTERIAL COMMUNITIES ON IN-SITU ARSENIC AND IRON CYCLING IN RIVERBANKS ALONG THE MEGHNA RIVER, BANGLADESH

2020 ◽  
Author(s):  
Kimberly D. Myers ◽  
◽  
Katrina Lee Jewell ◽  
P.S.K. Knappett ◽  
Mehtaz M. Lipsi ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Iron Cycling

Effects of long-term biochar and biochar-based fertilizer application on brown earth soil bacterial communities

2021 ◽  
Vol 309 ◽  
pp. 107285
Author(s):  
Mengyu Gao ◽  
Jinfeng Yang ◽  
Chunmei Liu ◽  
Bowen Gu ◽  
Meng Han ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Fertilizer Application ◽  
Soil Bacterial Communities ◽  
Soil Bacterial

scholarly journals Global soil moisture data derived through machine learning trained with in-situ measurements

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Sungmin O. ◽  
Rene Orth
Keyword(s):  
Machine Learning ◽  
Soil Moisture ◽  
Large Scale ◽  
Short Term Memory ◽  
Temporal Dynamics ◽  
Soil Moisture Data ◽  
Wide Range ◽  
Global Soil

AbstractWhile soil moisture information is essential for a wide range of hydrologic and climate applications, spatially-continuous soil moisture data is only available from satellite observations or model simulations. Here we present a global, long-term dataset of soil moisture derived through machine learning trained with in-situ measurements, SoMo.ml. We train a Long Short-Term Memory (LSTM) model to extrapolate daily soil moisture dynamics in space and in time, based on in-situ data collected from more than 1,000 stations across the globe. SoMo.ml provides multi-layer soil moisture data (0–10 cm, 10–30 cm, and 30–50 cm) at 0.25° spatial and daily temporal resolution over the period 2000–2019. The performance of the resulting dataset is evaluated through cross validation and inter-comparison with existing soil moisture datasets. SoMo.ml performs especially well in terms of temporal dynamics, making it particularly useful for applications requiring time-varying soil moisture, such as anomaly detection and memory analyses. SoMo.ml complements the existing suite of modelled and satellite-based datasets given its distinct derivation, to support large-scale hydrological, meteorological, and ecological analyses.

scholarly journals A Study of UVER in Santiago, Chile Based on Long-Term In Situ Measurements (Five Years) and Empirical Modelling

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 368
Author(s):  
Lisdelys González-Rodríguez ◽  
Amauri Pereira de Oliveira ◽  
Lien Rodríguez-López ◽  
Jorge Rosas ◽  
David Contreras ◽  
...  
Keyword(s):  
Urban Areas ◽  
Solar Spectrum ◽  
Sun Exposure ◽  
Great Accuracy ◽  
In Situ Measurements ◽  
Uv Index ◽  
Empirical Modelling ◽  
The People

Ultraviolet radiation is a highly energetic component of the solar spectrum that needs to be monitored because is harmful to life on Earth, especially in areas where the ozone layer has been depleted, like Chile. This work is the first to address the long-term (five-year) behaviour of ultraviolet erythemal radiation (UVER) in Santiago, Chile (33.5° S, 70.7° W, 500 m) using in situ measurements and empirical modelling. Observations indicate that to alert the people on the risks of UVER overexposure, it is necessary to use, in addition to the currently available UV index (UVI), three more erythema indices: standard erythemal doses (SEDs), minimum erythemal doses (MEDs), and sun exposure time (tery). The combination of UVI, SEDs, MEDs, and tery shows that in Santiago, individuals with skin types III and IV are exposed to harmfully high UVER doses for 46% of the time that UVI indicates is safe. Empirical models predicted hourly and daily values UVER in Santiago with great accuracy and can be applied to other Chilean urban areas with similar climate. This research inspires future advances in reconstructing large datasets to analyse the UVER in Central Chile, its trends, and its changes.

scholarly journals In-Situ Annealed Ti3C2Tx MXene Based All-Solid-State Flexible Zn-Ion Hybrid Micro Supercapacitor Array with Enhanced Stability

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
La Li ◽  
Weijia Liu ◽  
Kai Jiang ◽  
Di Chen ◽  
Fengyu Qu ◽  
...  
Keyword(s):  
High Energy ◽  
High Rate ◽  
High Energy Density ◽  
Electrochemical Performances ◽  
Integrated Electronics ◽  
Long Term Stability ◽  
Hybrid Supercapacitors ◽  
Portable Electronics

AbstractZn-ion hybrid supercapacitors (SCs) are considered as promising energy storage owing to their high energy density compared to traditional SCs. How to realize the miniaturization, patterning, and flexibility of the Zn-ion SCs without affecting the electrochemical performances has special meanings for expanding their applications in wearable integrated electronics. Ti3C2Tx cathode with outstanding conductivity, unique lamellar structure and good mechanical flexibility has been demonstrated tremendous potential in the design of Zn-ion SCs, but achieving long cycling stability and high rate stability is still big challenges. Here, we proposed a facile laser writing approach to fabricate patterned Ti3C2Tx-based Zn-ion micro-supercapacitors (MSCs), followed by the in-situ anneal treatment of the assembled MSCs to improve the long-term stability, which exhibits 80% of the capacitance retention even after 50,000 charge/discharge cycles and superior rate stability. The influence of the cathode thickness on the electrochemical performance of the MSCs is also studied. When the thickness reaches 0.851 µm the maximum areal capacitance of 72.02 mF cm−2 at scan rate of 10 mV s−1, which is 1.77 times higher than that with a thickness of 0.329 µm (35.6 mF cm−2). Moreover, the fabricated Ti3C2Tx based Zn-ion MSCs have excellent flexibility, a digital timer can be driven by the single device even under bending state, a flexible LED displayer of “TiC” logo also can be easily lighted by the MSC arrays under twisting, crimping, and winding conditions, demonstrating the scalable fabrication and application of the fabricated MSCs in portable electronics.

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