362 research outputs found

    Methanogens Harboring in Rice Rhizosphere Reduce Labile Organic Carbon Compounds to Produce Methane Gas

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    Submerged rice paddy soils are one of the major anthropogenic sources of methane (CH4) emission to the atmosphere. Methane is the second most important greenhouse gas after carbon dioxide. Methanogens are strictly anaerobic microorganisms and CH4 is the metabolic end product of those methanogens. Methane is produced by methanogens through multi-step enzyme-mediated process. Methanogens convert labile organic carbon compounds in CH4 and application of organic matter in submerged rice field significantly increased CH4 emission from soil to the atmosphere. The rate of methanogenesis may be determined by quantifying biomarkers namely methyl coenzyme M reductase A (mcrA) gene and coenzyme M (2-mercaptoethane sulphonate) in soil. Nickel ions are present as cofactor in enzymes involved in methanogenesis. Methane emission can be mitigated by application of EDTA at suitable rate in the soil of submerged rice field

    Editorial: Role of Microbes in Climate Smart Agriculture

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    Management of Paddy Soil towards Low Greenhouse Gas Emissions and Sustainable Rice Production in the Changing Climatic Conditions

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    Climate change is a vital environmental issue for the twenty-first century, which may significantly affect rice productivity and accelerate greenhouse gas emissions from paddy ecosystem, which is of great environmental concern which is of great environmental concern. Methane (CH4) and nitrous oxide (N2O) are the most important greenhouse gases due to their radiative effects as well as global warming potentials (GWPs). CH4 and N2O gases are simultaneously emitted from rice fields to the atmosphere due to their favorable production, consumption, and transport systems. The intensive rice farming system has been creating excessive pressure on rice fields to produce more rice for the expanding world population, thereby deteriorating soil fertility status and rice paddy ecosystem balance by stimulating more CO2, CH4, and N2O fluxes to the atmosphere. The extreme climatic variables such as high light intensity, high water vapor or relative humidity, high temperature, and drought stress may badly suppress beneficial microbial activity, soil nutrients, and water availability to rice plant; eventually, rice yield may be decreased drastically, and simultaneously, greenhouse gas emissions could be increased significantly. In this situation, conservation tillage, water saving irrigation technique such as alternate wetting and drying, soil amendments with biochar, vermicompost, azolla-cyanobacterial mixture, recommended silicate slag, and phospho-gypsum with minimum NPKSZn fertilizer (IPNS) should be introduced to the field level farmers for sustainable rice production and mitigating greenhouse gas emissions

    Structure-Property Relationship of Fluorinated co-poly(arylene ether sulfide)s and co-poly(arylene ether sulfone)s for Low-loss and Low-birefringence Waveguide Devices

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    Optical properties such as refractive index, birefringence, thermal stability, and optical loss of fluorinated co-poly(arylene ether sulfide)s and co-poly(arylene ether sulfone)s were investigated, and they are related to the molecular structure of the polymers. The refractive index of the optical polymers varies in the range of 1.51∼1.60, and its variation is well described by a Lorentz-Lorenz equation. Their birefringence varies between 0.0027∼0.0039 for the sulfides series and between 0.0009∼0.0025 for the sulfone series at a 1.55-μm wavelength, respectively. The birefringence is analyzed based on the microscopic anisotropic ratio of the polarizability of the molecular repeating unit resulting in good linear relationship between them within the polymer groups. This result implies that the molecular calculation can be utilized to design polymers with low birefringence. The propagation losses of the optical polymers were 0.1∼0.3 and 0.2∼0.5 dB/cm at the wavelength of 1.3 and 1.55 μm, respectively. The optical losses are inversely proportional to fluorine content. The polymers have good thermal stability upon long-term thermal stress at 100°C for 1000 h and short-term thermal stress at 300°C for 1 h

    Diffuse Alveolar Hemorrhage in a 39-year-old Woman: Unusual Initial Presentation of Microscopic Polyangiitis

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    Microscopic polyangiitis (MPA) is a necrotizing vasculitis involving the small vessels without granulomatous inflammation. Most MPA initially presents with renal involvement without pulmonary involvement. Isolated and initially presenting alveolar hemorrhage is very rare. The patient was a 39-year-old female with a progressive cough, dyspnea, and blood-tinged sputum for the previous 5 days. We determined that her condition was MPA though VATS lung biopsy and renal biopsy. After 2 months of steroid therapy, the chest lesions had improved. We report here a rare case of MPA with isolated and initial involvement of the lung with a review of the literature

    Total Gastrectomy in Gastric Conduit Cancer

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    We report a very rare case of surgery on gastric conduit cancer. A 67-year-old male patient underwent esophagectomy and intrathoracic esophagogastrostomy for squamous cell carcinoma of the lower thoracic esophagus 27 months ago. Upon follow-up, a gastric carcinoma at the intra-abdominal part of the gastric conduit was found on an esophagogastroduodenoscopy. We performed total gastrectomy and esophagocolonojejunostomy in the manner of Roux-en-Y anastomosis. The postoperative course was not eventful and an esophagogram on the 10th postoperative day showed no leakage or stenosis of the passage. The patient was discharged on the 17th day with no complications

    Parenchymal Neurocutaneous Melanosis in Association with Intraventricular Dermoid and Dandy-Walker Variant: A Case Report

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    Neurocutaneous melanosis (NCM) is a rare congenital disease that is characterized by the presence of large or multiple congenital melanocytic nevi and melanotic lesions of the central nervous system. We report here on the CT and MR imaging findings of an unusual case of NCM that was associated with intraventricular dermoid and Dandy-Walker malformation

    Aerobic Methanotrophy and Co-occurrence Networks of a Tropical Rainforest and Oil Palm Plantations in Malaysia

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    Oil palm (OP) plantations are gradually replacing tropical rainforest in Malaysia, one of the largest palm oil producers globally. Conversion of lands to OP plantations has been associated with compositional shifts of the microbial community, with consequences on the greenhouse gas (GHG) emissions. While the impact of the change in land use has recently been investigated for microorganisms involved in N2O emission, the response of the aerobic methanotrophs to OP agriculture remains to be determined. Here, we monitored the bacterial community composition, focusing on the aerobic methanotrophs, in OP agricultural soils since 2012, 2006, and 1993, as well as in a tropical rainforest, in 2019 and 2020. High-affinity methane uptake was confirmed, showing significantly lower rates in the OP plantations than in the tropical rainforest, but values increased with continuous OP agriculture. The bacterial, including the methanotrophic community composition, was modified with ongoing OP agriculture. The methanotrophic community composition was predominantly composed of unclassified methanotrophs, with the canonical (Methylocystis) and putative methanotrophs thought to catalyze high-affinity methane oxidation present at higher relative abundance in the oldest OP plantation. Results suggest that the methanotrophic community was relatively more stable within each site, exhibiting less temporal variations than the total bacterial community. Uncharacteristically, a 16S rRNA gene-based co-occurrence network analysis revealed a more complex and connected community in the OP agricultural soil, which may influence the resilience of the bacterial community to disturbances. Overall, we provide a first insight into the ecology and role of the aerobic methanotrophs as a methane sink in OP agricultural soils
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