Carbon dioxide as an under-ice lethal control for invasive fishes

Resource managers need effective tools to control invasive fish populations. In this study, we tested under-ice carbon dioxide (CO₂) injection as a novel piscicide method for non-native Silver Carp (Hypophthalmichthys molitrix), Bighead Carp (Hypophthalmichthys nobilis), Grass Carp (Ctenopharyngodon idella), Common Carp (Cyprinus carpio) and native Bigmouth Buffalo (Ictiobus cyprinellus). Fish were held overwinter in nine outdoor ponds (0.04 ha surface area; 340,000 L volume) treated with no CO₂ (control), 43.5–44.0 kg CO₂ (low treatment), and 87.5–88.5 kg CO₂ (high treatment). Ponds were harvested immediately after ice-out to assess survival and condition. Resulting survival in low (mean = 32%) and high (mean = 5%) CO₂-treated ponds was significantly lower than untreated control ponds (mean = 84%). Lethal efficacy varied across species with no Bighead Carp, Silver Carp, or Bigmouth Buffalo surviving the high CO₂ treatment. External infections were observed more frequently after CO₂ treatments (means = 49–67%) relative to untreated ponds (mean = 2%), suggesting a secondary mechanism for poor survival. This study demonstrates that CO₂ can be used as a lethal control for invasive fishes, but effectiveness may vary by species and CO₂ concentration.     

The role of oxidative stress in rhinovirus induced elaboration of IL-8 by respiratory epithelial cells

A direct correlation has been reported between the severity of symptoms associated with rhinovirus infection and the concentration of interleukin-8 in nasal secretions. The purpose of these studies was to examine the mechanism of rhinovirus-induced IL-8 elaboration. Rhinovirus infection induced oxidative stress in Beas-2b cells and the concentration of H₂O₂ in supernatant media from rhinovirus challenged cells was 12.5 ± 6.1 μM 1 h after challenge compared to 0.7 ± 0.3 μM in supernatant from control cells. N-acetyl cysteine inhibited RV-induced NF-κB activation and IL-8 elaboration. IL-8 concentrations were 36 ± 2 pg/ml and 10 ± 1 pg/ml 6 h after virus challenge in untreated and NAC-treated (30 mM NAC) cells, respectively. Despite the effects of NAC on IL-8 elaboration and NF-κB activation, RV stimulated increases in supernatant H₂O₂ were not altered by NAC. These data suggest that RV stimulation of IL-8 in respiratory epithelium is mediated through production of oxidative species and the subsequent activation of NF-κB.     

Impact of In-Situ CO2 Nano-Bubbles Generation on Freezing Parameters of Selected Liquid Foods

The impact of in-situ CO₂ nano-bubbles generation on the freezing properties of soft serve, milk, and apple juice was investigated. Carbonated (0, 1000, and 2000 ppm) liquid foods contained in a tube were submerged and cooled for 90 min in a pre-set ethylene glycol bath (−15 °C). Before the enclosed liquid reached 0 °C, the vibration was discharged through ultrasound in the bath to create nano-bubbles within the carbonated food samples, and the changes in temperature for 90 min of each food were recorded as a freezing curve. The time for onset of nucleation of control soft serve mix was halved in samples with 2000-ppm CO₂ due to the presence of nano-bubbles. Likewise, the nucleation time for milk with and without nano-bubbles at the same CO₂ concentration of 2000 ppm was 7.9 ± 0.1 and 2.8 ± 0.8 min_, respectively. The generation of CO₂ nano-bubbles from 2000-ppm CO₂ level in 10 ^oBx apple juice displayed −9.3 ± 0.3 °C nucleation temperature while the control one had −11.7 ± 0.9 °C.

     

Increasing CO2 concentration impact upon nutrient absorption and removal efficiency of supra intensive shrimp pond wastewater by marine microalgae Tetraselmis chui

Abstract

The objective of this study was to investigate the effect of increasing CO₂ concentration on the growth and the capability of Tetraselmis chui. in removal of nitrate, ammonium and phosphate from shrimp pond wastewater (SPWW). The factorial experimental design was used with the treatment of SPWW percentage in culture medium, namely: 100% SPWW, 75% SPWW + 25% Sea Water (SW) and 75% SW + 25% SPWW coupled with three CO₂ concentration treatments: 390?ppm, 550?ppm and 1000?ppm using CO₂ system. Growth of T. chui. for lengh of cultivation period tended to be higher at treatments of 390?ppm CO₂ and 100% SPWW, however there was a declining growth over period of cultivation for both treatments. The growth rate of T. chui was higher for all percentage of SPWW treatments in culture medium at 390?ppm CO₂ concentration compared to other percentage of SPWW treatments and CO₂ concentration treatments. There was a decreasing of growth rate with increasing CO₂ concentration at 100% SPWW and 75% SPWW + 25% SW in culture medium. Nitrogen removal efficiency and removal rate by T. chui. were strongly affected by CO₂ concentration. However, there was no significant effect of increasing CO₂ concentration to removal efficiency and rate of PO₄ by T. chui.     

Burrow depth,carbon dioxide and reproductive success in Sand Martins Riparia riparia

Capsule: Carbon dioxide (CO₂) concentrations in the burrows of Sand Martins Riparia riparia increase with depth but have no detectable impact on fledging success.

Aims: To investigate whether burrow depth and CO₂ concentrations influence reproductive success in Sand Martins.

Methods: We monitored two Sand Martin colonies along the River Lune, Lancashire, UK, to investigate the effect of burrow depth on reproductive success. We also measured CO₂ levels in a sample of burrows to test whether burrow depth predicts CO₂ concentration, and to test for a relationship between CO₂ concentration and breeding success.

Results: Burrow depth was significantly correlated with fledging success, but the correlation was positive in first broods and negative in second broods. The highest CO₂ concentration recorded was 73?650?ppm and the mean concentration across burrows was 31?757?ppm. However, while CO₂ concentrations were positively correlated with burrow depth after controlling for the number and age of nestlings, they were not correlated with reproductive success.

Conclusion: There are reproductive costs associated with deeper burrows in second broods, but these could not be attributed to CO₂ concentrations despite the exceptionally high levels recorded. This study highlights the need for further investigation into gas exchange and the potential impacts of, or adaptations to, CO₂ accumulation in avian burrows.     

Energetic assessment of fixation of CO<Subscript>2</Subscript> and subsequent biofuel production using <Emphasis Type="Italic">B. cereus</Emphasis> SM1 isolated from sewage treatment plant

The ongoing work on global warming resulting from green house gases (GHGs) has led to explore the possibility of bacterial strains which can fix carbon dioxide (CO₂) and can generate value-added products. The present work is an effort in this direction and has carried out an exhaustive batch experiments for the fixation of CO₂ using B. Cereus SM1 isolated from sewage treatment plant (STP). The work has incorporated 5-day batch run for gaseous phase inlet CO₂ concentration of 13 ± 1 % (%v/v). 84.6 (±5.76) % of CO₂ removal was obtained in the gaseous phase at mentioned CO₂ concentration (%v/v). Energetic requirement for CO₂ fixation was assessed by varying Fe[II] ion concentration (0–200 ppm) on the per-day basis. The cell lysate obtained from CO₂ fixation studies (Fe[II] ion = 100 ppm) was analyzed using Fourier transformation infrared spectroscopy (FTIR) and gas chromatography-mass spectroscopy (GC–MS). This analysis confirmed the presence of fatty acids and hydrocarbon as valuable products. The hydrocarbons were found in the range of C₁₁–C₂₂ which is equivalent to light oil. The obtained fatty acids were found in the range of C₁₁–C₁₉. The possibility of fatty acid conversion to biodiesel was explored by carrying out the transesterification reaction. The yield of biodiesel was obtained as 86.5 (±0.048) % under the transesterification reaction conditions. Results of this research work can provide the valuable information in the implementation of biomitigation of CO₂ at real scenario.     

Impact of elevated CO<Subscript>2</Subscript> in <Emphasis Type="Italic">Casuarina equisetifolia</Emphasis> rooted stem cuttings inoculated with <Emphasis Type="Italic">Frankia</Emphasis>

Impact of different levels of elevated CO ₂ on the activity of Frankia (Nitrogen-fixing actinomycete) in Casuarina equisetifolia rooted stem cuttings has been studied to understand the relationship between C. equisetifolia, Frankia and CO₂. The stem cuttings of C. equietifolia were collected and treated with 2000 ppm of Indole Butyric Acid (IBA) for rooting. Thus vegetative propagated rooted stem cuttings of C. equisetifolia were inoculated with Frankia and placed in the Open top chambers (OTC) with elevated CO₂ facilities. These planting stocks were maintained in the OTC for 12 months under different levels of elevated CO₂ (ambient control, 600 ppm, 900 ppm). After 12 months, the nodule numbers, bio mass, growth, and photosynthesis of C. equisetifolia rooted stem cuttings inoculated with Frankia were improved under 600 ppm of CO₂. The rooted stem cuttings of C. equisetifolia inoculated with Frankia showed a higher number of nodules under 900 ppm of CO₂ and cuttings without Frankia inoculation exhibited poor growth. Tissue Nitrogen (N) content was also higher under 900 ppm of CO₂ than ambient control and 600 ppm levels. The photosynthetic rate was higher (17.8 μ mol CO₂ m^?2 s^?1) in 900 ppm of CO₂ than in 600 ppm (13.2 μ mol CO₂ m^?2 s^?1) and ambient control (8.3 μ mol CO₂ m^?2 s^?1). This study showed that Frankia can improve growth, N fixation and photosynthesis of C. equietifolia rooted stem cuttings under extreme elevated CO₂ level conditions (900 ppm).     

Impact of modified atmospheres on respiration of last instar larvae of the rice moth,Corcyra cephalonica (Lepidoptera: Pyralidae)

Abstract

Effect of modified atmospheres (MAs) containing CO₂ at 20, 40, 60 and 80% or containing N₂ at 97 and 98% on the mortality of Corcyra cephalonica Stainton (Lepidoptera: Pyralidae) sixth instar larvae was studied to determine the LT values at 30?°C. The respiration rates of untreated and treated larvae with 60% CO₂ and/or 98% N₂ at LT₅₀ were measured using Q-Box RP1LP low range respirometry package. Total protein and triglycerides of treated and untreated larvae were assayed. Complete larval mortality was recorded after 72 and 144?h of treatment with 60% CO₂ and 98% N₂, respectively. Calculated LT₅₀ values were 39.3 at 60% CO₂ and 87.5?h at 98% N₂ MAs. Respiration quotient (RQ) in the light of consumed O₂ and produced CO₂ of untreated larvae was 1.0 while it was 0.85 at 60% CO₂ and 0.72 at 98% N₂. Duration time necessary for produced CO₂ curve to reach the maximum point (2000?ppm) was significantly shorter at untreated larvae (27.64?min) in comparison with that recorded at CO₂ (35.48?min) which also significantly less than that obtained at N₂ (98.54?min). At all treatments, total protein was decreased while triglycerides were increased in comparison with control.     

Release of CO2 and CH4 from lakes and drainage ditches in temperate wetlands

Shallow fresh water bodies in peat areas are important contributors to greenhouse gas fluxes to the atmosphere. In this study we determined the magnitude of CH₄ and CO₂ fluxes from 12 water bodies in Dutch wetlands during the summer season and studied the factors that might regulate emissions of CH₄ and CO₂ from these lakes and ditches. The lakes and ditches acted as CO₂ and CH₄ sources of emissions to the atmosphere; the fluxes from the ditches were significantly larger than the fluxes from the lakes. The mean greenhouse gas flux from ditches and lakes amounted to 129.1 ± 8.2 (mean ± SE) and 61.5 ± 7.1 mg m^?2 h^?1 for CO₂ and 33.7 ± 9.3 and 3.9 ± 1.6 mg m^?2 h^?1 for CH₄, respectively. In most water bodies CH₄ was the dominant greenhouse gas in terms of warming potential. Trophic status of the water and the sediment was an important factor regulating emissions. By using multiple linear regression 87% of the variation in CH₄ could be explained by PO₄ ^3? concentration in the sediment and Fe²⁺ concentration in the water, and 89% of the CO₂ flux could be explained by depth, EC and pH of the water. Decreasing the nutrient loads and input of organic substrates to ditches and lakes by for example reducing application of fertilizers and manure within the catchments and decreasing upward seepage of nutrient rich water from the surrounding area will likely reduce summer emissions of CO₂ and CH₄ from these water bodies.     

Effects of elevated CO2 and temperature on the growth,elemental composition,and cell size of two marine diatoms: potential implications of global climate change

Two pennate diatoms, Amphora coffeaeformis and Nitzschia ovalis, were used to evaluate potential responses to the future CO₂ and temperature increases with respect to cell-specific growth rate, elemental composition, size, population growth rate, and carrying capacity. Diatoms were subjected to four different treatments over a 2 week period (approximately 4 generations): a control (28°C and present-day CO₂, ~400 ppm), high CO₂ (28°C with high CO₂, ~750 ppm), high temperature (31°C and present-day CO₂, ~400 ppm), and greenhouse-effect treatment (31°C with high CO₂, ~750 ppm). The results indicated that both the cell-specific growth rates and the carrying capacity of A. coffeaeformis decreased at the higher temperature treatment, whereas N. ovalis did not differ among all treatments. No significant difference was found in either species’ elemental cell composition, but higher C:N and C:P ratios were observed for A. coffeaeformis and N. ovalis, respectively, in high CO₂ and greenhouse-effect treatments. Smaller cell sizes were observed for both species under the greenhouse-effect treatment, a phenomenon that could alter benthic food webs in the future.     

Reduction of Insulin Resistance and Plasma Glucose Level by Salsalate Treatment in Persons With Prediabetes

ObjectiveTo evaluate the effect of salsalate as an antiinflammatory agent on insulin resistance and glycemic control in persons with prediabetes.MethodsIn this double-blind, placebo-controlled clinical trial, 66 persons who had prediabetes on the basis of the American Diabetes Association criteria were enrolled. They were randomly assigned to receive salsalate (3 g daily) or placebo for 12 weeks. Fasting plasma glucose (FPG) and insulin, glucose 2 hours after oral administration of 75 g of glucose, hemoglobin A_1c, lipid profile, homeo stasis model assessment of insulin resistance (HOMA-IR), and homeostasis model assessment of beta-cell function were determined before and after treatment.ResultsSalsalate treatment reduced the FPG level from 5.86 ± 0.07 mmol/L to 5.20 ± 0.11 mmol/L and HOMA-IR from 4.2 ± 0.9 to 3.8 ± 0.3 (P = .01 for both changes). Homeostasis model assessment of beta-cell func tion increased in the salsalate-treatment group from 139.8 ± 11.0 to 189.4 ± 24.6 (P = .01). At the end of the study, FPG, HOMA-IR, and insulin levels were significantly different between salsalate and placebo groups (5.20 ± 0.11 mmol/L versus 5.53 ± 0.10 mmol/L, 3.8 ± 0.3 versus 4.4 ± 0.9, and 16.1 ± 1.9 μIU/mL versus 18.2 ± 2 μIU/mL, respectively; P < .05 for all). There were no persistent complications after salsalate therapy.ConclusionTreatment with salsalate can reduce insu lin resistance and the FPG level in subjects with predia betes. Determination of the long-term safety and efficacy of the use of salsalate necessitates further investigation. (Endocr Pract. 2012;18:826-833)     

The growth of <Emphasis Type="Italic">Chlorella sorokiniana</Emphasis> as influenced by CO<Subscript>2</Subscript>, light,and flue gases

In order to achieve recognition as environmentally friendly production, flue gases should be used as a CO₂ source for growing the microalgae Chlorella sorokiniana when used for hydrogen production. Flue gases from a waste incinerator and from a silicomanganese smelter were used. Before testing the flue gases, the algae were grown in a laboratory at 0.04, 1.3, 5.9, and 11.0 % (v/v) pure CO₂ gas mixed with fresh air. After 5 days of growth, the dry biomass per liter algal culture reached its maximum at 6.1 % CO₂. A second experiment was conducted in the laboratory at 6.2 % CO₂ at photon flux densities (PFD) of 100, 230, and 320 μmol photons m^?2 s^?1. After 4 days of growth, increasing the PFD increased the biomass production by 67 and 108 % at the two highest PFD levels, as compared with the lowest PFD. A bioreactor system containing nine daylight-exposed tubes and nine artificial light-exposed tubes was installed on the roof of the waste incinerator. The effect of undiluted flue gas (10.7 % CO₂, 35.8 ppm NO _x , and 38.6 ppm SO₂), flue gas diluted with fresh air to give 4.2 % CO₂ concentration, and 5.0 % pure CO₂ gas was studied in daylight (21.4?±?9.6 mol photons m^?2 day^?1 PAR, day length 12.0 h) and at 135 μmol photons m^?2 s^?1 artificial light given 24 h day^?1 (11.7?±?0.0 mol photons m^?2 day^?1 PAR). After 4 days’ growth, the biomass production was the same in the two flue gas concentrations and the 5 % pure CO₂ gas control. The biomass production was also the same in daylight and artificial light, which meant that, in artificial light, the light use efficiency was about twice that of daylight. The starch concentration of the algae was unaffected by the light level and CO₂ concentration in the laboratory experiments (2.5–4.0 % of the dry weight). The flue gas concentration had no effect on starch concentration, while the starch concentration increased from about 1.5 % to about 6.0 % when the light source changed from artificial light to daylight. The flue gas from the silicomanganese smelter was characterized by a high CO₂ concentration (about 17 % v/v), low oxygen concentration (about 4 %), about 100 ppm NO _x , and 1 ppm SO₂. The biomass production using flue gas significantly increased as compared with about 5 % pure CO₂ gas, which was similar to the biomass produced at a CO₂ concentration of 10–20 % mixed with N₂. Thus, the enhanced biomass production seemed to be related to the low oxygen concentration rather than to the very high CO₂ concentration.     

When Water Vanishes: Magnitude and Regulation of Carbon Dioxide Emissions from Dry Temporary Streams

Most fluvial networks worldwide include watercourses that recurrently cease to flow and run dry. The spatial and temporal extent of the dry phase of these temporary watercourses is increasing as a result of global change. Yet, current estimates of carbon emissions from fluvial networks do not consider temporary watercourses when they are dry. We characterized the magnitude and variability of carbon emissions from dry watercourses by measuring the carbon dioxide (CO₂) flux from 10 dry streambeds of a fluvial network during the dry period and comparing it to the CO₂ flux from the same streambeds during the flowing period and to the CO₂ flux from their adjacent upland soils. We also looked for potential drivers regulating the CO₂ emissions by examining the main physical and chemical properties of dry streambed sediments and adjacent upland soils. The CO₂ efflux from dry streambeds (mean ± SD = 781.4 ± 390.2 mmol m^?2 day^?1) doubled the CO₂ efflux from flowing streambeds (305.6 ± 206.1 mmol m^?2 day^?1) and was comparable to the CO₂ efflux from upland soils (896.1 ± 263.2 mmol m^?2 day^?1). However, dry streambed sediments and upland soils were physicochemically distinct and differed in the variables regulating their CO₂ efflux. Overall, our results indicate that dry streambeds constitute a unique and biogeochemically active habitat that can emit significant amounts of CO₂ to the atmosphere. Thus, omitting CO₂ emissions from temporary streams when they are dry may overlook the role of a key component of the carbon balance of fluvial networks.     

Effects of combined exenatide and pioglitazone therapy on hepatic fat content in type 2 diabetes

We examined the effects of combined pioglitazone (peroxisome proliferator‐activated receptor‐γ (PPAR‐γ) agonist) and exenatide (GLP‐1 receptor agonist) therapy on hepatic fat content and plasma adiponectin levels in patients with type 2 diabetes (T2DM). Twenty‐one T2DM patients (age = 52 ± 3 years, BMI = 32.0 ± 1.5, hemoglobin A_1c (HbA_1c) = 8.2 ± 0.4%) on diet and/or metformin received additional treatment with either pioglitazone 45 mg/day for 12 months (n = 10) or combined therapy with pioglitazone (45 mg/day) and exenatide (10 µg subcutaneously twice daily) for 12 months (n = 11). At baseline, hepatic fat content and plasma adiponectin levels were similar between the two treatment groups. Pioglitazone reduced fasting plasma glucose (FPG) (P < 0.05), fasting free fatty acid (FFA) (P < 0.05), and HbA_1c (Δ = 1.0%, P < 0.01), while increasing plasma adiponectin concentration by 86% (P < 0.05). Hepatic fat (magnetic resonance spectroscopy (MRS)) was significantly reduced following pioglitazone treatment (11.0 ± 3.1 to 6.5 ± 1.9%, P < 0.05). Plasma triglyceride concentration decreased by 14% (P < 0.05) and body weight increased significantly (Δ = 3.7 kg). Combined pioglitazone and exenatide therapy was associated with a significantly greater increase in plasma adiponectin (Δ = 193%) and a significantly greater decrease in hepatic fat (12.1 ± 1.7 to 4.7 ± 1.3%) and plasma triglyceride (38%) vs. pioglitazone therapy despite the lack of a significant change in body weight (Δ = 0.2 kg). Hepatic injury biomarkers aspartate aminotransferase and alanine aminotransferase (ALT) were significantly decreased by both treatments; however, the reduction in ALT was significantly greater following combined pioglitazone and exenatide therapy. We conclude that combined in patients with T2DM, pioglitazone and exenatide therapy is associated with a greater reduction in hepatic fat content as compared to the addition of pioglitazone therapy (Δ = 61% vs. 41%, P < 0.05).     

Impact of Different Carbon Dioxide Concentrations in the Olfactory Response of Sipha flava (Hemiptera: Aphididae) and its Predators

The increasing level CO₂ may altered host plant physiology and hence affect the foraging behavior of herbivore insects and predator. Hence, the aim of this study was provides evidence that host plants grown at different levels of CO₂ can alter the choice behavior of aphid, Sipha flava and their natural enemies, Cycloneda sanguinea and Diomus seminulus. The plant used was Pennisetum purpureum, cultivar Cameron Piracicaba growing in greenhouse (mean value of CO₂?=?440 ppm), climatic chamber with constant value of CO₂?=?500 ppm and climatic chamber with fluctuating CO₂ (mean value?=?368 ppm). A glass Y-shape olfactometer was used to verify the insects responses towards elephant grass plants cultivated under different conditions. The aphids were statistically more attracted by plants grown with constant CO₂ level (500 ppm) than by plants grown with fluctuating CO₂ level or plants grown in greenhouse. There was no difference in S. flava preference to non-infested versus infested plants by conspecifics. The predator C. sanguinea did not show difference between plants grown with constant CO₂ level and infested or not with S. flava. However, the predator D. seminulus showed higher preference to plants grown with constant CO₂ level and infested with S. flava. This study showed that the response of S. flava and its predators were affected by plants grown under different levels of CO₂.     

Water velocity dependence of phosphate uptake on a coral-dominated fringing reef flat,La Réunion Island,Indian Ocean

Phosphate uptake (P-uptake) into coral reef communities has been hypothesized to be mass-transfer limited. One method of demonstrating mass-transfer limitation of P-uptake is to show dependence of P-uptake on water velocity. Water velocity across reef flats varies with tides and swell; thus, we measured P-uptake over the entire reef flat on eight different days, representing a range in water velocities. P-uptake was calculated from changes in P concentration of the water column. Changes in P concentration were measured by water sampling at six sites along a 300-m cross-reef transect while simultaneously measuring water velocity. To smooth the variability in phosphate concentrations, peristaltic pumps were used to get time-integrated water samples for 4–6 h at each site. Water velocities were measured in the middle of the transect using an acoustic Doppler current profiler and were averaged to match the time-integrated water sampling. Depth-averaged cross-reef water velocities were 0.031 ± 0.013 m s⁻¹ (mean ± SD), while the root-mean-square water velocities, accounting for oscillatory flow, averaged 3.3 times higher, 0.101 ± 0.021 m s⁻¹ (mean ± SD). Phosphate decreased along all transects. The first-order rate constant for P-uptake (S) was 8.5 ± 2.4 m d⁻¹ (mean ± SD) and increased linearly with root-mean-square water velocity. The Stanton number derived from oscillatory flow, the ratio of the first-order rate constant for P-uptake to the root-mean-square water velocity (S/U _rms), was (9.4 ± 1.2) × 10⁻⁴ (mean ± SD). P-uptake ranged from 0.2 to 1.1 mmol P m⁻² d⁻¹, demonstrating that P-uptake is variable on short time scales and is directly related to P concentration and water velocity.

     

An estimate of greenhouse gas (N2O and CO2) mitigation potential under various scenarios of nitrogen use efficiency in Chinese croplands

It is well recognized that improving nitrogen use efficiency (NUE) can directly reduce nitrous oxide (N₂O) emission in cropland and indirectly reduce carbon dioxide (CO₂) release from nitrogen (N) production, while such a reduction has not been well quantified in China. We estimated the greenhouse gas (GHG; N₂O and CO₂) mitigation potential (MP) from Chinese cropland and its regional distribution by quantifying NUE and determining the amount of over‐applied synthetic N under various scenarios of NUE. We estimated that synthetic NUE in the late 1990s was 31±11% (mean±SD) for rice, 33±13% for wheat, and 31±11% for maize cultivation. Improving NUE to 50% could cut 6.6 Tg of synthetic N use per year, accounting for 41% of the total used. As a result of this reduction, the direct N₂O emission from croplands together with CO₂ emission from the industrial production and transport of synthetic N could be reduced by 39%, equivalent to 60 Tg CO₂ yr^?1. The MP was probably underestimated because organic N supply was not taken into account when estimating NUE. It was concluded that improving N management can greatly reduce GHG (N₂O and CO₂) emissions in Chinese croplands, and mitigation in the Jiangsu, Henan, Shandong, Sichuan, Hubei, Anhui, and Hebei provinces should be given priority.     

The role of GA3 in the germination process of high-mountain endemic and threatened species: Leontopodium nivalePinguicula fiorii and Soldanella minima subsp. samnitica (central Apennines,Italy)

The ex situ conservation of biodiversity is an essential tool for environmental protection interventions. Germination studies of seeds that belong to endangered species are essential for ex situ conservation strategies. In this study, we investigate the germination responses of three high-altitude endemic and vulnerable species (Leontopodium nivale, Pinguicula fiorii and Soldanella minima subsp. samnitica). Specifically we identified potential dormancy mechanisms by investigating the responses of germination percentage and rate to different concentrations of gibberellic acid (GA₃), by performing a general linear model. L. nivale reached a germination percentage of 98.0 ± 2.0% (mean ± SE) under control conditions (20°C; 12/12 photoperiod; no GA₃ addition). P. fiorii showed the highest germination percentage (78.0 ± 2.0%) in the treatment with GA₃ 500 ppm. S. minima subsp. samnitica did not show sensitivity to GA₃ but responded positively to cold stratification (6 month at 5°C) with a germination percentage of 90 ± 6%. This study made it possible to acquire important information on the germination process of threatened and rare endemic taxa.     

A chemical modification of myeloperoxidase and lactoperoxidase with 2-(O-methoxypolyethylene glycol)-4,6-dichloro-s-triazine (activated PEG1)

The modification of myeloperoxidase and lactoperoxidase with 2-(O-methoxypolethylene glycol)-4, 6-dichloro-s-triazine, an activated polyethylene glycol (PEG₁), was investigated. The modification caused a shift of the Soret band in the light absorption spectrum, from 430 nm to 418 nm in the case of myeloperoxidase (native ferric form), and from 412 nm to 406 nm in the case of lactoperoxidase (native ferric form). PEG₁-modified myeloperoxidase and PEG₁-modified lactoperoxidase both failed to bind with antiserum to the respective native enzyme, but both retained respectively 4·5±0·3 per cent (mean±SE, n=5) and 0·6±0·2 per cent (mean±SE, n=5) of the activities of peroxidation of the hydrogen donor o-methoxyphenol in comparison with the native enzyme, and 1·5±0·2 per cent (mean±SE, n=5) and 1·2±0·2 per cent (mean±SE, n=5) of the activities of destruction of fuchsin basic in the presence of hydrogen peroxide and a halide, bromide. The pH dependencies of the peroxidating activities were almost the same as those of the corresponding native enzymes, but both the optimal pHs of the reactions involving the destruction of fuchsin basic were shifted by approximately 1·0 pH unit toward neutral pH compared with the respective native enzymes. © 1998 John Wiley & Sons, Ltd.     

Tritrophic Interactions of Cowpea [Vigna unguiculata subsp unguiculata(L.)], Aphids [Aphis craccivora (Koch)] and Coccinellids [Menochilus sexmaculatus (Fab.)] under eCO2 and eTemp

Experiments were conducted to understand the direct and indirect effects of temperature and elevated CO₂ (eCO₂), on tritrophic interactions of cowpea (Vigna unguiculata subsp. unguiculata L.), legume aphid Aphis craccivora Koch and coccinellid predator Menochilus sexmaculatus Fab. Reduction of the leaf nitrogen (6%), amino acid (6%) and protein (7%) of cowpea foliage with increased carbon (13%) and C:N ratio (21%) at eCO₂ over aCO₂ indicated the dilution of biochemical constituents at first trophic level. Shortened development time, DT and increment of reproductive rate, RR at eCO₂ over ambient CO₂(aCO₂)was significant with increase in temperature from 20 to 35?°C. Reduction of the mean degree day, DD requirement of both nymphal (75.79?±?15.163) and adult stages (157.15?±?67.04) at eCO₂ over aCO₂ and same was reflected in the summation DD for both the stages at eCO₂ (232.96?±?80.32)and aCO₂ (247.07?±?64.77) across six temperatures. The ‘r_m’ and ‘R_o’ increased gradually with increase in temperature followed the non-linear trend and reached maximum values at 27?°C with shortened ‘T’ across 20 to 35?°C temperatures at eCO₂ indicating the significant variation of growth and development at the second trophic level. Decreased grub duration (23%) with increased predation capacity (19%) of M. sexmaculatus on A. craccivora at eCO₂ over ambient was noted, indicating the incidence of A. craccivora is likely to be higher with increased predation in the future climate change scenario.