Effect of phosphogypsum on respiration and methane emissions in sediment.

The impact of adding phosphogypsum (PG) to freshwater wetland areas, and potential effect on methane production and respiration in sediment was studied in the laboratory. Two organic matter levels (native and enriched with 0.5% by weight ground dry plant material) were studied using five sediment treatments each: (1) no PG added, (2) 4% PG by dry weight (homogenized), (3) 20% PG by dry weight (homogenized), (4) 2000 kg ha(-1) (surface applied), and (5) 5000 kg ha (surface applied), and the experiment was run in triplicate. There was a net flux of methane into sediment for all treatments that were maintained at the native organic matter level, indicating net methane oxidation. In the organic-enriched cores, both of the homogenized treatments exhibited no methane emissions, while the surface applied treatments retained the potential for high emissions. Soil respiration was depressed in all treatments when compared to controls, especially in the organic-enriched cores. The results conclude that it may be possible to add PG to non-vegetated areas with few observable effects on sediment respiration, but organic matter content and method of application are critical concerns.

Can vitamin D supplementation prevent winter-time blues? A randomised trial among older women.

BACKGROUND: Seasonal Affective Disorder (SAD) is a sub-type of depression that only occurs during the winter months. A reduction in vitamin D may be linked to SAD. Since vitamin D deficiency has been reported to be common in older people, vitamin D supplementation may be expected to reduce seasonal mood disturbance in this group. OBJECTIVE: To assess the effect of vitamin D supplementation on the mental health of older women. SETTING: Primary care in three areas of the UK (Herts, Newcastle, York). SUBJECTS: Women aged 70 years or more recruited to the trial in the months May-October. INTERVENTION: Eligible women were randomised to receive calcium and vitamin D supplementation or no supplementation. OUTCOME MEASURE: At baseline and the six monthly assessment the mental component score (MCS), calculated from the SF-12 questionnaire was used to assess participants' subjective psychological well-being. RESULTS: A total of 2117 women recruited to the trial had their baseline measures taken between the months of May-October (1205 woman in the control group and 912 women in the intervention group). Of these women, 1621 had a MCS score at baseline and six months. Comparison of the six month mean MCS scores, adjusting for baseline MCS score and age, showed there was no significant difference between the two scores (p = 0.262). CONCLUSIONS: Supplementing elderly women with 800 IU of vitamin D daily did not lead to an improvement in mental health scores.

Risk factors for fracture in a UK population: a prospective cohort study.

BACKGROUND: Common clinical risk factors for fracture in older women have been identified. To date, most of these risk factors have not been confirmed in a UK population. AIM: To confirm the important risk factors for fracture in older women. DESIGN: Comprehensive cohort study (CCS) with a nested randomized controlled trial. METHODS: The CCS included 4292 women aged >70 years. We assessed potential risk factors for fracture, and followed-up participants for 24 months for incidence of non-vertebral fractures. RESULTS: Odds ratios (ORs) for predicting any non-vertebral fracture were: previous fracture, 2.67 (95%CI 2.10-3.40); a fall in the last 12 months, 2.06 (95%CI 1.63-2.59); and age (per year increase), 1.03 (95%CI 1.01-1.05). ORs for predicting hip fracture were: previous fracture, 2.31 (95%CI 1.31-4.08); low body weight (<58 kg), 2.20 (95%CI 1.28-3.77); maternal history of hip fracture, 1.68 (95%CI 0.85-3.31); a fall in the last 12 months, 2.92 (95%CI 1.70-5.01); and age (per year increase), 1.09 (95%CI 1.04-1.13). ORs for predicting wrist fracture were: previous fracture, 2.29 (95%CI 1.56-3.34); and a fall in the last 12 months, 1.60 (95%CI 1.10-2.31). Being a current smoker was not associated with an increase in risk, and was consistent across all fracture types. DISCUSSION: Older women with the clinical risk factors identified in this study should be investigated for osteoporosis or offered preventive treatment.

Impact of redox conditions on metolachlor and metribuzin degradation in Mississippi flood plain soils.

The effect of soil redox conditions on the degradation of metolachlor and metribuzin in two Mississippi soils (Forrestdale silty clay loam and Loring silt loam) were examined in the laboratory. Herbicides were added to soil in microcosms and incubated either under oxidized (aerobic) or reduced (anaerobic) conditions. Metolachlor and metribuzin degradation under aerobic condition in the Forrestdale soil proceeded at rates of 8.83 ngd(-1) and 25 ngd(-1), respectively. Anaerobic degradation rates for the two herbicides in the Forestdale soil were 8.44 ngd(-1) and 32.5 ngd(-1), respectively. Degradation rates for the Loring soil under aerobic condition were 24.8 ngd(-1) and 12.0 ngd(-1) for metolachlor and metribuzin, respectively. Metolachlor and metribuzin degradation rates under anaerobic conditions in the Loring soil were 20.9 ngd(-1) and 5.35 ngd(-1). Metribuzin degraded faster (12.0 ngd(-1)) in the Loring soil under aerobic conditions as compared to anaerobic conditions (5.35 ngd(-1)).