Large quantities of mineral dust particles are frequently ejected into the atmosphere through the action of wind. The surface of dust particles acts as a sink for many gases, such as sulfur dioxide. It is well known that under most conditions, sulfur dioxide reacts on dust particle surfaces, leading to the production of sulfate ions. In this report, for specific atmospheric conditions, we provide evidence for an alternate pathway in which a series of reactions under solar UV light produces first gaseous sulfuric acid as an intermediate product before surface-bound sulfate. Metal oxides present in mineral dust act as atmospheric photocatalysts promoting the formation of gaseous OH radicals, which initiate the conversion of SO 2 to H 2 SO 4 in the vicinity of dust particles. Under low dust conditions, this process may lead to nucleation events in the atmosphere. The laboratory findings are supported by recent field observations near Beijing, China, and Lyon, France.

Wetland forests, known as coal forests, extended over large areas of the palaeotropics during the Late Carboniferous and the Permian Periods. They were initiated during the Serpukhovian Age as a response to lowering sea levels having exposed large areas of continental shelf. They expanded dramatically during the late Bashkirian Age, but then contracted by over one‐half during the Kasimovian Age. The estimated loss of carbon sink probably resulted in an annual increase in atmospheric CO2 of about 2–5 ppm, and coincided with clear evidence of global warming in both the northern and southern high latitudes. A return to cooler conditions in very Early Permian times coincided with an expansion of the palaeotropical coal forests in the Far East, but this was short‐lived and most of the rest of the Permian was a time of global warming. The Palaeozoic evidence clearly confirms that there is a correlation between levels of atmospheric CO2 and global climates. However, care must be taken in extrapolating this evidence to the present‐day tropical forests, which do not act as a comparable unsaturated carbon sink.

IMPF: 00.66A synthesis of the upper Moscovian sedimentotogical and palaeontological record of terrestrial habitats across the Variscan foreland and adjacent intramontane basins (an area which is referred to here as Variscan Euramerica) suggests a contraction and progressive westward shift of the coal swamps. These changes can be correlated with pulses of tectonic activity (tectonic phases) resulting from the northwards migration of the Variscan Front. This tectonic activity caused disruption to the landscapes and drainage patterns where the coat swamps were growing, which became less suitable to growth of the dominant plants of the swamps, the arborescent lycopsids. They were progressively replaced by vegetation dominated by marattialean ferns, which through a combination of slower growth and larger canopies resulted in less evapo-transpiration. This in turn caused localised reductions in rainfall, which further affected the ability of the lycopsids to dominate the swamp vegetation. These changes were initially localised and where the coat swamps were able to survive the lycopsids and pteridosperms show little change in either species diversity or biogeography, indicating that at this time there was minimal regional-scale climate change taking place. By Asturian times, however, the process had accelerated and the swamps in Variscan Euramerica became progressively replaced by predominantly conifer and cordaite vegetation that favoured much drier substrates. Except in localised pockets in intramontane basins of the Variscan Mountains, the last development of coat swamps in Variscan Euramerica was of early Cantabrian age. Further west, lycopsid-dominated coal swamps persisted for a little longer. The last remnants of the lycopsid-dominated coal swamps in the Illinois Basin disappeared probably by middle-late Cantabrian times, as the cycle of contracting wetlands and regional reductions in rainfall generated its own momentum, and no longer needed the impetus of tectonic instability. This tectonically-driven decline in the Euramerican coal swamps was probably responsible for an annual increase in atmospheric CO2 of c. 0.37 ppm, and may have been implicated in the marked increase in global temperatures near the Moscovian - Kasimovian boundary, and the onset of the Late Pennsylvanian interglacial.Peer reviewe

Mosquito-borne diseases are a major challenge for Human health as they affect nearly 700 million people every year and result in over 1 million deaths. Reliable information on the evolution of population and spatial distribution of key insects species is of major importance in the development of eco-epidemiologic models. This paper reports on the remote characterization of flying mosquitoes using a continuous-wave infrared optical remote sensing system. The system is setup in a controlled environment to mimic long-range lidars, mosquitoes are free flying at a distance of ~ 4 m from the collecting optics. The wing beat frequency is retrieved from the backscattered light from mosquitoes transiting through the laser beam. A total of 427 transit signals have been recorded from three mosquito species, males and females. Since the mosquito species and gender are known a priori, we investigate the use of wing beat frequency as the sole predictor variable for two Bayesian classifications: gender alone (two classes) and species/gender (six classes). The gender of each mosquito is retrieved with a 96.5% accuracy while the species/gender of mosquitoes is retrieved with a 62.3% accuracy. Known to be an efficient mean to identify insect family, we discuss the limitations of using wing beat frequency alone to identify insect species.

Lepidostrobus is a genus that was established by Brongniart for Palaeozoic lycopod cones. Since then the genus has been used for a variety of cones that have similar characters. There is now compelling evidence that the genus represents a heterogeneous group of monosporangiate and bisporangiate cone species and that it should be divided. Lepidostrobus is rediagnosed as a genus of microsporangiate cones. Ftemingites Carruthers is rediagnosed as a genus of those bisporangiate cones formerly included in Lepidostrobus.

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20An UV-VIS polarization Lidar has been designed and specified for aerosols monitoring in the 21 troposphere, showing the ability to precisely address low particle depolarization ratios, in the range

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