Rates and pathways of CH4 oxidation in ferruginous Lake Matano,Indonesia

This study evaluates rates and pathways of methane (CH₄) oxidation and uptake using ¹⁴C‐based tracer experiments throughout the oxic and anoxic waters of ferruginous Lake Matano. Methane oxidation rates in Lake Matano are moderate (0.36 nmol L^?1 day^?1 to 117 μmol L^?1 day^?1) compared to other lakes, but are sufficiently high to preclude strong CH₄ fluxes to the atmosphere. In addition to aerobic CH₄ oxidation, which takes place in Lake Matano's oxic mixolimnion, we also detected CH₄ oxidation in Lake Matano's anoxic ferruginous waters. Here, CH₄ oxidation proceeds in the apparent absence of oxygen (O₂) and instead appears to be coupled to some as yet uncertain combination of nitrate (), nitrite (), iron (Fe) or manganese (Mn), or sulfate () reduction. Throughout the lake, the fraction of CH₄ carbon that is assimilated vs. oxidized to carbon dioxide (CO₂) is high (up to 93%), indicating extensive CH₄ conversion to biomass and underscoring the importance of CH₄ as a carbon and energy source in Lake Matano and potentially other ferruginous or low productivity environments.     

Impact of clinical pathway on clinical outcomes in the management of COPD exacerbation

ABSTRACT: BACKGROUND: Exacerbations, a leading cause of hospitalization in patients with chronic obstructive pulmonary disease (COPD), affect the quality of life and prognosis. Treatment recommendations as provided in the evidence-based guidelines are not consistently followed, partly due to absence of simplified task-oriented approach to care. In this study, we describe the development and implementation of a clinical pathway (CP) and evaluate its effectiveness in the management of COPD exacerbation. METHODS: We developed a CP and evaluated its effectiveness in a non-randomized prospective study with historical controls on patients admitted for exacerbation of COPD to UniversitiKebangsaan Malaysia Medical Centre (UKMMC). Consecutive patients who were admitted between June 2009 and December 2010 were prospectively recruited into the CP group. Non-CP historical controls were obtained from case records of patients admitted between January 2008 and January 2009. Clinical outcomes were evaluated by comparing the length of stay (LOS), complication rates, readmissions, and mortality rates. RESULTS: Ninety-five patients were recruited in the CP group and 98 patients were included in the non-CP historical group. Both groups were comparable with no significant differences in age, sex and severity of COPD (p = 0.641). For clinical outcome measures, patients in the CP group had shorter length of stay than the non-CP group (median (IQR): 5 (4-7) days versus 7 (7-9) days, p < 0.001) and 24.1% less complications (14.7% versus 38.8%, p < 0.001). We did not find any significant differences in readmission and mortality rates. CONCLUSION: The implementation of CP -reduced the length of stay and complication rates of patients hospitalized for acute exacerbation of COPD.