Historical and experimental evidence for enhanced concentration of artemesinin,a global anti-malarial treatment,with recent and projected increases in atmospheric carbon dioxide

Although the role of rising atmospheric carbon dioxide concentration [CO₂] on plant growth and fecundity is widely acknowledged as important within the scientific community; less research is available regarding the impact of [CO₂] on secondary plant compounds, even though such compounds can play a significant role in human health. At present, Artemisia annua, an annual plant species native to China, is widely recognized as the primary source of artemesinin used in artemesinin combination therapies or ACTs. ACTs, in turn, are used globally for the treatment of simple Plasmodium falciparum malaria, the predominant form of malaria in Africa. In this study, artemesinin concentration was quantified for multiple A. annua populations in China using a free-air CO₂ enrichment (FACE) system as a function of [CO₂]-induced changes both in situ and as a function of the foliar ratio of carbon to nitrogen (C:N). The high correlation between artemesinin concentration and C:N allowed an historical examination of A. annua leaves collected at 236 locations throughout China from 1905 through 2009. Both the historical and experimental data indicate that increases in artemesinin foliar concentration are likely to continue in parallel with the ongoing increase in atmospheric [CO₂]. The basis for the [CO₂]-induced increase in artemesinin is unclear, but could be related to the carbon: nutrient hypothesis of Bryant et al. (1983). Overall, these data provide the first evidence that historic and projected increases in atmospheric [CO₂] may be associated with global changes in artemesinin chemistry, potentially allowing a greater quantity of drug available for the same area of cultivation.     

Carbon leakage in aviation policy

ABSTRACT

The inherently global, connected nature of aviation means that carbon leakage from aviation policy does not necessarily behave similarly to leakage from other sectors. We model carbon leakage from a range of aviation policy test cases applied to a specific country (the United Kingdom), motivated by a desire to reduce aviation CO₂ faster than achievable by currently-planned global mitigation efforts in pursuit of a year-2050 net zero CO₂ target. We find that there are two main components to leakage: one related to passenger behaviour, which tends to result in emissions reductions outside the policy area (negative leakage), and one related to airline behaviour, which tends to result in emissions increases outside the policy area (positive leakage). The overall leakage impact of a policy, and whether it is positive or negative, depends on the balance of these two components and the geographic scope used, and varies for different policy types. In our simulations, carbon pricing-type policies were associated with leakage of between +50 and ?150% depending on what is assumed about scope and the values of uncertain parameters. Mandatory biofuel use was associated with positive leakage of around 0–40%, and changes in airport landing costs to promote more fuel-efficient aircraft were associated with positive leakage of 50–150%.

Key policy insights

• Carbon leakage in aviation policy arises from airline responses (typically positive leakage) and passenger responses (typically negative leakage).

• Depending on the geographical scope, policy type and values for uncertain parameters, leakage may be between around ?150 to +150%.

• Of the policies investigated in this study, leakage was typically most negative for carbon pricing and most positive for environmental landing charges.

• Absolute values of leakage are smallest where policies are considered on the basis of all arriving and departing flights.

     

Automated mechanism generation. Part 2: application to atmospheric chemistry of alkanes and oxygenates

In this study, an automated mechanism generation framework was applied to atmospheric chemistry of volatile organic compounds (VOCs) and nitrogen oxides (NO _x ). The framework generates reactions with minimal input based on a small set of reaction operators and includes a hierarchy for specifying rate constants for every reaction created. Mechanisms were generated for formaldehyde-air-NO _x , acetaldehyde-formaldehyde-n-octane-air-NO _x , and acetone-air-NO _x , and the model results were compared to experimental data obtained from smog chambers and to the SAPRC-99 lumped models. The models generated captured the experimental data very well, and their mechanistic formulation provided new insights into the controlling reaction pathways to pollutant formation. The approach applied here is sufficiently general that it can be applied to a wide range of alkane and oxygenate mixtures.     

Waveshapes of continuing currents and properties of M-components in natural negative cloud-to-ground lightning from high-speed video observations

Continuing current is a continuous mode of charge transfer to ground in a lightning flash. The extent to which the continuing current contributes to the total negative charge lowered to earth is large. In order to study the waveshape of the continuing currents of natural flashes, we developed a computational algorithm that analyzes the pixels of the images obtained by a high-speed camera and plots luminosity-versus-time. Tower measurements have shown that during the continuing current phase of the flash the luminosity of the channel is directly proportional to the current that flows through it. Using this information it was possible to infer the continuing current waveshape for 63 natural discharges and classify them into six different types. Statistics on some characteristics of 345 M-components (that occurred during the same 63 events) are also presented. As far as we know, this is the first study on waveshapes of continuing currents for natural lightning.     

Tectonics and sedimentation of SW Sarawak basin,Malaysia, NW Borneo

Structurally SW Sarawak basin is a southward sloping basement characterized by passive margin tectonic that has undergone through varioius tectonic phases viz., Triassic extension, Cretaceous transpression and Oligo-Miocene compression. Rock types and sedimentation of deeper basin zone situated between Schwaner mountains block to the south and SW Sarawak basin to the north suggest progressive marine sedimentation. E-W trending Cretaceous carbonate platform (CCP) occurs in the SW Sarawak basin signify a shelf zone where shallow marine sedimentation progressed during Cretaceous transpression. Oligo-Miocene volcanics from subduction melts intercepted basin profusely forming northwest-southeast trending continental arc zone derived from partial melting of subducting slab underneath SW Sarawak basin. Back-arc extension prevailed during Oligo-Miocene and formed several extensional features. Oligo-Miocene subduction also resulted in closure and exhumation of Sri Aman marginal sea-basin to the east. SW Sarawak basin is further divided in two sub-basins viz., Senibong to the west and Kuching to the east separated by a northeast trending morphotectonic ridge that signify structural element formed due to shearing. Marine sedimentation progressed in these sub-basins mainly during Triassic–Jurassic while tidal and fluviatile sedimentation progressed during early to mid-Tertiary having total thickness of sediments about 9 km. Basin closure and exhumation is marked mainly by the formation of Cretaceous carbonate build-up that has been intruded and dissected by the Oligo-Miocene volcanics. Senibong and Kuching sub-basins are characterized by wide range of transpressive features, while, Sri Aman marginal sea-basin is characterized by oceanic assemblages, ophiolite, serpentinite and pillow basalt.     

Interspecific association of heavy minerals in late Paleozoic Gondwana sandstones of Singrauli sub-basin,central India: Implications for provenance

Heavy mineral analysis of the late Paleozoic Barakar and Raniganj sandstones from the Singrauli Gondwana sub-basin shows relative abundance of garnet, epidote, zircon, tourmaline and muscovite in the Raniganj Sandstone and epidote, garnet, rutile and tourmaline in the Barakar sandstones. Stratigraphically, the heavy mineral crops donot exhibit marked variation in their relative abundance, though garnet, epidote and muscovite form the bulk of the heavy minerals. Significant interspecific association among heavy minerals and provenance of the Barakar and Raniganj sandstones are evaluated by using σ-M multivariate model. Quantitative result suggests that the Barakar Sandstone are characterized by the basic pair match significantly more than expected due to chance alone (p value <<0.05) are garnet-tourmaline and epidote-rutile, whereas, the succeeding Raniganj sandstone are characterized by zircon-rutile and epidote-garnet. These basic pairs may be regarded as interspecific association among the heavy minerals. The basic pairs deduced from heavy mineral suites suggest that the source rocks of late Paleozoic Barakar and Raniganj sandstones have been principally derived from the acid plutonic rocks and low to high grade metasediments lying to the south and southeast of the Singrauli Gondwana sub-basin.     

<Superscript>1</Superscript>H NMR-based serum metabolic profiling of <Emphasis Type="Italic">Carassius auratus gibelio</Emphasis> under the toxicity of Pb<Superscript>2+</Superscript> and Cd<Superscript>2+</Superscript>

Lead and cadmium are the two widely recognized toxic metals, with known ecological risk to freshwater fish in contaminated ecosystems. However, their effect at environmentally realistic level in a mixture has been rarely investigated. In the present study, serum metabolic responses of Crucian carp exposed to Pb (30 µgL^?1), Cd (100 µgL^?1) and Pb+Cd (30 + 100 µgL^?1) for 21 days were investigated by ¹H NMR-based metabolomics. The metabolic responses were compared to control by multivariate techniques (PCA, PLS-DA and OPLS-DA), and metabolites that significantly contributed to the variation were identified. Metal dependent metabolic responses revealed a decline of alanine, lysine and tyrosine in Pb exposed fish, indicating changes in neurotransmitters, and amino acid metabolism, while fish exposed to Cd showed significant decrease in lysine, isoleucine, leucine, alanine and increase in 3-hydroxybutyrate, acetone, lactate, choline, inosine, guanosine and threonine. The coexposure of Pb and Cd had additive effect on metabolic profile with increase in pyruvate, guanosine and inosine. The overall metabolic changes due to Pb and Cd were characterized by disturbed energy metabolism, impaired osmotic regulation and a shift from aerobic to anaerobic respiration. Moreover, ¹H NMR-based metabolomics was proved to be a powerful tool in elucidating the toxic effects of environmental pollutants and underlying mechanism.     

Pedo and biogeochemical studies of mafic and ultramfic rocks in the Mingora and Kabal areas,Swat, Pakistan

This study highlights the heavy metals (HMs) distribution in soils and their uptake by wild plants grown in the soils derived from the mafic and ultramafic terrains. Plant and soil samples were analyzed for Cu, Pb, Zn, Cr, Ni and Cd using atomic absorption spectrophotometer. The data indicate that almost all the HMs in the soil samples collected from the study area exceeded the reference and normal agricultural soils. Greater variability was noticed in the uptake of HMs by various plants grown on the studied soils. High concentrations of Cu and Zn in Cannabis sativa L. (seft hemp), Pb in Ailanthus altissima (Mill.) (Ailanto), Ni and Cr in Indigofrra gerardiana Wall. ex Baker (sage), and Saccharum griffihii Munro ex Boiss. (plume grass) were noticed among the studied plants. The multifold enrichments of Cr and Ni in the Indigofrra gerardiana and Saccharum griffihii as compared to the other plants of the study area suggested that these plants have the ability to uptake and translocate high concentrations of Cr and Ni. The excessive concentrations of Cr and Ni in these plants can be used for mineral prospecting but their main concern could be of serious environmental problems and health risks in the inhabitants of the study areas.     

Biodegradation of Cypermethrin by Pseudomonas in a batch activated sludge process

The biodegradation of Cypermethrin (20 to 125 mg/L) in an effluent using batch activated sludge was studied. Degradation was found to occur to a great extent only in the presence of Pseudomonas (IES-Ps-1) culture. Under aerobic conditions using mechanical aerators, Cypermethrin (20 mg/L) was almost completely degraded in just over 48 h at ambient temperature. Further loading of organic compound in subsequent experiments demonstrated that IES-PS-1was capable to degrade 82 % Cypermethrin at 40 mg/L dose in approximately 48 h. When the concentration was increased to 80 mg/L, 50% degradation of this compound was observed. Over this time period the cells could utilize only 17 % of Cypermethrin when it was given 125 mg/L, respectively. These findings indicate that increased concentration of Cypermethrin has a marked effect on biodegradation performance of IES-Ps-1 with a modest increased in the duration of lag phase, but did not lead to complete inhibition or cell death. These results proved that IES-Ps-1 is responsible for Cypermethrin degradation. Such finding may be useful in designing a scale-up in situ or on-site hazardous waste bioremediation process for field application.