Tropical peatlands are hotspots of methane (CH
4
) production but present high variation and emission uncertainties in the Amazon region. This is because the controlling factors of methane production ...in tropical peats are not yet well documented. Although inhibitory effects of nitrogen oxides (NO
x
) on methanogenic activity are known from pure culture studies, the role of NO
x
in the methane cycling of peatlands remains unexplored. Here, we investigated the CH
4
content, soil geochemistry and microbial communities along 1-m-soil profiles and assessed the effects of soil NO
x
and nitrous oxide (N
2
O) on methanogenic abundance and activity in three peatlands of the Pastaza-Marañón foreland basin. The peatlands were distinct in pH, DOC, nitrate pore water concentrations, C/N ratios of shallow soils, redox potential, and
13
C enrichment in dissolved inorganic carbon and CH
4
pools, which are primarily contingent on H
2
-dependent methanogenesis. Molecular 16S rRNA and
mcrA
gene data revealed diverse and novel methanogens varying across sites. Importantly, we also observed a strong stratification in relative abundances of microbial groups involved in NO
x
cycling, along with a concordant stratification of methanogens. The higher relative abundance of ammonia-oxidizing archaea (Thaumarchaeota) in acidic oligotrophic peat than ammonia-oxidizing bacteria (
Nitrospira
) is noteworthy as putative sources of NO
x
. Experiments testing the interaction of NO
x
species and methanogenesis found that the latter showed differential sensitivity to nitrite (up to 85% reduction) and N
2
O (complete inhibition), which would act as an unaccounted CH
4
control in these ecosystems. Overall, we present evidence of diverse peatlands likely differently affected by inhibitory effects of nitrogen species on methanogens as another contributor to variable CH
4
fluxes.
Microbial communities mediate the transformation of organic matter within landfills into methane (CH
). Yet their ecological role in CH
production is rarely evaluated. To characterize the microbiome ...associated with this biotransformation, the overall community and methanogenic
were surveyed in an arid landfill using leachate collected from distinctly aged landfill cells (i.e., younger, intermediate, and older). We hypothesized that distinct methanogenic niches exist within an arid landfill, driven by geochemical gradients that developed under extended and age-dependent waste biodegradation stages. Using 16S rRNA and
gene amplicon sequencing, we identified putative methanogenic niches as follows. The order
was the most abundant order in leachate from younger cells, where leachate temperature and propionate concentrations were measured at 41.8°C ± 1.7°C and 57.1 ± 10.7 mg L
. In intermediate-aged cells, the family
was identified as a putative specialist family under intermediate-temperature and -total dissolved solid (TDS) conditions, wherein samples had a higher alpha diversity index and near CH
concentrations. In older-aged cells, accumulating metals and TDS supported
, "
Bathyarchaeota," and "
Verstraetearchaeota" operational taxonomic units (OTUs). Consistent with the
data, we assayed methanogenic activity across the age gradient through stable isotopic measurements of δ
C of CH
and δ
C of CO
. The majority (80%) of the samples' carbon fractionation was consistent with hydrogenotrophic methanogenesis. Together, we report age-dependent geochemical gradients detected through leachate in an arid landfill seemingly influencing CH
production, niche partitioning, and methanogenic activity.
Microbiome analysis is becoming common in select municipal and service ecosystems, including wastewater treatment and anaerobic digestion, but its potential as a microbial-status-informative tool to promote or mitigate CH
production has not yet been evaluated in landfills. Methanogenesis mediated by
is highly active in solid-waste microbiomes but is commonly neglected in studies employing next-generation sequencing techniques. Identifying methanogenic niches within a landfill offers detail into operations that positively or negatively impact the commercial production of methane known as biomethanation. We provide evidence that the geochemistry of leachate and its microbiome can be a variable accounting for ecosystem-level (coarse) variation of CH
production, where we demonstrate through independent assessments of leachate and gas collection that the functional variability of an arid landfill is linked to the composition of methanogenic
.
Euglycemic diabetic ketoacidosis (EuDKA) is an uncommon diabetic complication. Just like diabetic ketoacidosis (DKA), EuDKA is a medical emergency. EuDKA is primarily related to the imbalance between ...insulin and counter-regulatory hormones, with an elevated insulin/glucagon ratio, and is characterized by blood glucose near normal (blood glucose less than 250 mg/dL) in the background of DKA. There are many factors associated with EuDKA, but the overall mechanism is based on a relative state of carbohydrate deficit, resulting in ketosis while maintaining near-normal glucose levels. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a new oral antidiabetic medication category that can precipitate EuDKA. EuDKA is more common in patients with diabetes mellitus on SGLT2 inhibitors with lower mass index and decreased glycogen store which can be triggered by surgery, infection, trauma, a major illness or reduced food intake and persistent vomiting, gastroparesis, dehydration, and reduced insulin dosages. This is a case of a 34-year-old male, Filipino, diagnosed with type 2 diabetes mellitus, who was maintained on dapagliflozin + metformin 5mg/1000mg taken twice a day with good compliance and was admitted with EuDKA precipitated by decreased food intake and managed with intravenous insulin. Throughout admission, the blood glucose levels did not exceed 250mg/dL. His clinical condition improved through insulin therapy, administration of sodium bicarbonate, and intravenous hydration. EuDKA is an uncommon diabetic complication. High clinical suspicion is required to avoid delay in diagnosis and management since normal blood sugar levels masquerade the underlying DKA. Nevertheless, the cornerstone for the management of DKA and EuDKA remains the same: intravenous hydration and insulin therapy.
Atmospheric nitrous oxide (N
O) is a potent greenhouse gas thought to be mainly derived from microbial metabolism as part of the denitrification pathway. Here we report that in unexplored peat soils ...of Central and South America, N
O production can be driven by abiotic reactions (≤98%) highly competitive to their enzymatic counterparts. Extracted soil iron positively correlated with in situ abiotic N
O production determined by isotopic tracers. Moreover, we found that microbial N
O reduction accompanied abiotic production, essentially closing a coupled abiotic-biotic N
O cycle. Anaerobic N
O consumption occurred ubiquitously (pH 6.4-3.7), with proportions of diverse clade II N
O reducers increasing with consumption rates. Our findings show that denitrification in tropical peat soils is not a purely biological process but rather a 'mosaic' of abiotic and biotic reduction reactions. We predict that hydrological and temperature fluctuations differentially affect abiotic and biotic drivers and further contribute to the high N
O flux variation in the region.
Despite impressive efforts invested in epigenetic research in the last 50 years, clinical applications are still lacking. Only a few university hospital centers currently use epigenetic biomarkers at ...the bedside. Moreover, the overall concept of precision medicine is not widely recognized in routine medical practice and the reductionist approach remains predominant in treating patients affected by major diseases such as cancer and cardiovascular diseases. By its' very nature, epigenetics is integrative of genetic networks. The study of epigenetic biomarkers has led to the identification of numerous drugs with an increasingly significant role in clinical therapy especially of cancer patients. Here, we provide an overview of clinical epigenetics within the context of network analysis. We illustrate achievements to date and discuss how we can move from traditional medicine into the era of network medicine (NM), where pathway-informed molecular diagnostics will allow treatment selection following the paradigm of precision medicine.
Interpreting volcanic unrest is a highly challenging and non-unique problem at calderas, since large hydrothermal systems may either hide or amplify the dynamics of buried magma(s). Here we use the ...exceptional ground displacement and geochemical datasets from the actively degassing Campi Flegrei caldera (Southern Italy) to show that ambiguities disappear when the thermal evolution of the deep hydrothermal system is accurately tracked. By using temperatures from the CO
-CH
exchange of
C and thermodynamic analysis of gas ascending in the crust, we demonstrate that after the last 1982-84 crisis the deep hydrothermal system evolved through supercritical conditions under the continuous isenthalpic inflow of hot CO
-rich gases released from the deep (~8 km) magma reservoir of regional size. This resulted in the drying of the base of the hot hydrothermal system, no more buffered along the liquid-vapour equilibrium, and excludes any shallow arrival of new magma, whose abundant steam degassing due to decompression would have restored liquid-vapour equilibrium. The consequent CO
-infiltration and progressive heating of the surrounding deforming rock volume cause the build-up of pore pressure in aquifers, and generate the striking temporal symmetry that characterizes the ongoing uplift and the post-1984 subsidence, both originated by the same but reversed deformation mechanism.
Coccolithophores have influenced the global climate for over 200 million years. These marine phytoplankton can account for 20 per cent of total carbon fixation in some systems. They form blooms that ...can occupy hundreds of thousands of square kilometres and are distinguished by their elegantly sculpted calcium carbonate exoskeletons (coccoliths), rendering them visible from space. Although coccolithophores export carbon in the form of organic matter and calcite to the sea floor, they also release CO2 in the calcification process. Hence, they have a complex influence on the carbon cycle, driving either CO2 production or uptake, sequestration and export to the deep ocean. Here we report the first haptophyte reference genome, from the coccolithophore Emiliania huxleyi strain CCMP1516, and sequences from 13 additional isolates. Our analyses reveal a pan genome (core genes plus genes distributed variably between strains) probably supported by an atypical complement of repetitive sequence in the genome. Comparisons across strains demonstrate that E. huxleyi, which has long been considered a single species, harbours extensive genome variability reflected in different metabolic repertoires. Genome variability within this species complex seems to underpin its capacity both to thrive in habitats ranging from the equator to the subarctic and to form large-scale episodic blooms under a wide variety of environmental conditions.
The transformer-2 gene is involved in sex determination in tephritid flies (Tephritidae). It is required for the auto-regulation of the transformer gene (the memory device for sex determination in ...these insects) and for the female-specific splicing of doublesex pre-mRNA, the last gene in the sex determination gene cascade. The present manuscript addressed the question of the functional conservation of the tephritid Anastrepha Tra2 protein to direct sexual development in Drosophila (Drosophilidae). To express this protein in Drosophila, the GAL4-UAS system was used. The Anastrepha Tra2 protein supplies tra-2 function in Drosophila: this protein would form a complex with the endogenous Drosophila Tra protein to promote the female-specific splicing of the Drosophila doublesex pre-mRNA. The feminisation produced by the Anastrepha Tra2 protein was, however, partial.
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