Effects of elevated CO2 on chloroplast pigments of spruce (Picea abies) and beech (Fagus sylvatica) in model ecosystems as modified by provenance, soil type, and nitrogen supply

Young beech (Fagus sylvatica L.) and spruce (Picea abies [L,] Karst.) trees, each from two different provenances, were grown in competition in model ecosystems in open-top chambers for four years. The treatments consisted of elevated concentrations of CO, (370 μL L-1 versus 590 μL L-1), increased wet deposition of nitrogen (7 versus 70 kg N ha-1 y-1) and two different forest soils (acidic versus calcareous). Chloroplast pigments in dark- and light-adapted leaf material sampled in the last year of the experiment were analysed. Differences in pigment composition between provenances were observed only in beech trees. Soil type significantly affected the pigment composition in both species. Trees grown under calcareous conditions had higher contents of chlorophylls, whereas acidic soil conditions caused significantly enhanced levels of ß-carotene and xanthophylls as well as increased values of the xanthophyll de-epoxidation status. For both tree species light-adapted samples had higher carotenoid concentrations and de-epoxidation state values than dark-adapted foliage, whereas neither C02 nor N-treatment affected these parameters. Elevated CO, application induced decreased concentrations of total chlorophyll contents in both species. Nitrogen deposition had no effects on pigment composition neither for spruce nor for beech trees. Interactions between CO, and nitrogen application were not observed for both tree species

Effects of elevated CO2 on chloroplast pigments of spruce (Picea abies) and beech (Fagus sylvatica) in model ecosystems as modified by provenance, soil type, and nitrogen supply

Young beech (Fagus sylvatica L.) and spruce (Picea abies [L,] Karst.) trees, each from two different provenances, were grown in competition in model ecosystems in open-top chambers for four years. The treatments consisted of elevated concentrations of CO, (370 μL L-1 versus 590 μL L-1), increased wet deposition of nitrogen (7 versus 70 kg N ha-1 y-1) and two different forest soils (acidic versus calcareous). Chloroplast pigments in dark- and light-adapted leaf material sampled in the last year of the experiment were analysed. Differences in pigment composition between provenances were observed only in beech trees. Soil type significantly affected the pigment composition in both species. Trees grown under calcareous conditions had higher contents of chlorophylls, whereas acidic soil conditions caused significantly enhanced levels of ß-carotene and xanthophylls as well as increased values of the xanthophyll de-epoxidation status. For both tree species light-adapted samples had higher carotenoid concentrations and de-epoxidation state values than dark-adapted foliage, whereas neither C02 nor N-treatment affected these parameters. Elevated CO, application induced decreased concentrations of total chlorophyll contents in both species. Nitrogen deposition had no effects on pigment composition neither for spruce nor for beech trees. Interactions between CO, and nitrogen application were not observed for both tree species

The effect of exercise on the absorption of inhaled human insulin via the AERx insulin diabetes management system in people with type 1 diabetes

OBJECTIVE - This study investigated the effect of moderate exercise on the absorption of inhaled insulin via the AERx insulin diabetes management system (iDMS). RESEARCH DESIGN AND METHODS - in this randomized, open-label, four-period crossover, glucose clamp study 23 nonsmoking subjects with type I diabetes received a dose of 0.19 units/kg inhaled human insulin followed in random order by either 1) no exercise (NOEX group) or 30 min exercise starting, 2) 30 min after dosing (EX30), 3) 120 min after dosing (EX120), or 4) 240 min after dosing (EX240). RESULTS - Exercise changed the shape of the free plasma insulin curves, but compared with the NOEX group the area under the curve for free plasma insulin (AUC(ins)) for the first 2 h after the start of exercise was unchanged for EX30 and EX240, while it was 15% decreased for EX120 (P < 0.01). The overall insulin absorption during 6 and 10 h after dosing was 13% decreased for EX30 (P < 0.005), 11% decreased for EX120 (P < 0.01), and unchanged for EX240. Exercise.), while the time to C-max was 22 min did not influence the maximum insulin concentration (C-max) earlier for EX30 (P = 0.04). The AUC for the glucose infusion rate (AUC(GIR)) for 2 h after the start of exercise increased by 58% for EX30, 45% for EX120, and 71% for EX240 (all P < 0.02) compared with the NOEX group. CONCLUSIONS - Thirty minutes of moderate exercise led to unchanged or decreased absorption of inhaled insulin via AERx iDMS and faster C-max for early exercise. Thus, patients using AERx iDMS can adjust insulin dose as usual independent of time of exercise, but they should be aware of the faster effect if exercising early after dosing