Molecular dissolved organic matter composition and environmental parameters from a laboratory incubation study

Dissolved organic matter (DOM) in the oceans constitutes a major carbon pool involved in global biogeochemical cycles. More than 96% of the marine DOM resists microbial degradation for thousands of years. The composition of this refractory DOM (RDOM) exhibits a molecular signature which is ubiquitously detected in the deep oceans. Surprisingly efficient microbial transformation of labile into RDOM was shown experimentally, implying that microorganisms produce far more RDOM than needed to sustain the global pool. By assessing the microbial formation and transformation of DOM in unprecedented molecular detail for 3 years, we show that most of the newly formed RDOM is molecularly different from deep sea RDOM. Only <0.4% of the net community production was channeled into RDOM molecularly undistinguishable from deep sea DOM. Our study provides novel experimentally derived molecular evidence and data for global models on the production, turnover and accumulation of marine DOM.

Effect of compost and slow-release fertilizers addition on soil biochemistry and yield of maize (Zea mays L.) in Oaxaca, Mexico

The effect of Bokashi (B, a fermented compost), slow-release fertilizers (SRFs) and their combined application on mycorrhizal colonization (MC), soil invertase, cellulase, acid (AcP) and alkaline (AlP) phosphatases activities and maize (Zea mays L.) yield was investigated in terrace (TS) and valley (VS) soils in Oaxaca, Mexico. A complete randomized design, seven fertilizer treatments and four replications were used: unamended control (C); conventional fertilization (90-46-00 NPK) (CF); B; SRF1 (Multigro 6®, 21-14-10 NPK); SRF2 (Multigro 3®, 24-05-14 NPK); B+SRF1; B+SRF2. Highest root colonization percentage: CF in VS, and SRF2 in TS. Highest extraradical mycelium length: B, B+SRF1, CF in VS, and B+SRF1 in TS. In both soils, B increased the spore number. Highest AcP activity: B, SRF2 in VS, and B+SRF1, B+SRF2 in TS. Highest AlP activity: B+SRF1, CF in VS, and C in TS. Highest invertase activity: B+SRF1, SRF2, CF in VS, and B in TS. Grain yield only increased with B in VS. The significant interaction soil type × fertilizer treatment for the majority of the biological soil properties analyzed suggests that MC and soil enzyme activity response to fertilization was influenced by soil type. Bokashi, alone or combined with SRFs improves biological soil fertility in maize fields.

Misoprostol in addition to routine treatment of postpartum hemorrhage: A hospital-based randomized-controlled trial in Karachi, Pakistan

Background: Postpartum hemorrhage (PPH) remains a major killer of women worldwide. Standard uterotonic treatments used to control postpartum bleeding do not always work and are not always available. Misoprostol's potential as a treatment option for PPH is increasingly known, but its use remains ad hoc and available evidence does not support the safety or efficacy of one particular regimen. This study aimed to determine the adjunct benefit of misoprostol when combined with standard oxytocics for PPH treatment. Methods: A randomized controlled trial was conducted in four Karachi hospitals from December 2005 – April 2007 to assess the benefit of a 600 mcg dose of misoprostol given sublingually in addition to standard oxytocics for postpartum hemorrhage treatment. Consenting women had their blood loss measured after normal vaginal delivery and were enrolled in the study after losing more than 500 ml of blood. Women were randomly assigned to receive either 600 mcg sublingual misoprostol or matching placebo in addition to standard PPH treatment with injectable oxytocics. Both women and providers were blinded to the treatment assignment. Blood loss was collected until active bleeding stopped and for a minimum of one hour after PPH diagnosis. Total blood loss, hemoglobin measures, and treatment outcomes were recorded for all participants. Results: Due to a much lower rate of PPH than expected (1.2%), only sixty-one patients were diagnosed and treated for their PPH in this study, and we were therefore unable to measure statistical significance in any of the primary endpoints. The addition of 600 mcg sublingual misoprostol to standard PPH treatments does, however, suggest a trend in reduced postpartum blood loss, a smaller drop in postpartum hemoglobin, and need for fewer additional interventions. Women who bled less overall had a significantly smaller drop in hemoglobin and received fewer additional interventions. There were no hysterectomies or maternal deaths among study participants. The rate of transient shivering and fever was significantly higher among women receiving misoprostol Conclusion: A 600 mcg dose of misoprostol given sublingually shows promise as an adjunct treatment for PPH and its use should continue to be explored for its life-saving potential in the care of women experiencing PPH. Trial Registration: Clinical trials.gov, Registry No. NCT00116480