Based on these findings, we recommend that studies of functional divergence in systems where recombination is plausible can, and should, include a pre-test for recombination. Application of all methods to the core genome of Prochlorococcus reveals a substantial lack of concordance among results. Based on analysis of both real and simulated datasets we present some guidelines for the investigation of recombination in genes that may have experienced functional divergence.”
“Reactivity of polycyclic aromatic compounds (PACs) adsorbed on natural aerosol particles exposed to different atmospheric oxidants (O-3, OH and NO2/O-3 mixture)

was studied. Decay of polycyclic aromatic hydrocarbons (PAHs) and formation/decay of oxygenated PAHs (OPAHs) and nitrated PAHs (NPAHs) were monitored. Overall, benzo[a]pyrene appeared GF120918 cell line selleck chemical to be the most reactive PAH (degradation of 50%). Only its nitrated derivative, 6-nitrobenzo[a]pyrene, was significantly formed explaining just 0.4% of reacted benzo [a]pyrene. No other

nitrated or oxygenated benzo[a]pyrene derivatives were detected. Interestingly, B[e]P and In[1,2,3,c,d]P, which are usually considered as quite stable PAHs, also underwent decay in all experiments. In presence of O-3, ketones were significantly formed but their amount was not totally explained by decay of parent PAH. These results suggest that PAH derivatives could be formed from the reaction of other compounds than their direct parent PAHs and raise the question to know if the oxidation of methyl-PAHs, identified in vehicle-exhausts, could constitute this missing source of OPAHs. NPAHs were significantly formed in presence of O-3/NO2 and OH. Surprisingly, NPAH formation was clearly observed during O-3 experiments. Nitrated species, already associated with aerosol particles (NO3-, NO2-) or formed by zonation

of particulate nitrogen organic matter, could react with PAHs to form NPAHs. Heterogeneous formation of 2-nitropyrene from pyrene oxidation was for the first time observed, questioning its use as an indicator of NPAH formation in gaseous phase. Equally, formation of 2-nitrofluoranthene by heterogeneous selleck chemicals llc reaction of fluoranthene with O-3/NO2 was clearly shown, while only its formation by homogeneous processes (gaseous phase) is reported in the literature. Finally, results obtained highlighted the dependence of heterogeneous PAH reactivity with the substrate nature and the importance to focus reactivity studies on natural particles, whatever the quality of the models previously studied. (C) 2012 Elsevier Ltd. All rights reserved.”
“A new endemic deltocephaline leafhopper, Tetramelasma gen. n. is described from the Grassland Biome of South Africa, comprising four new species: T. litopyx sp. n., T. nodosatha sp. n., T. scolosatha sp. n. and T. tanyphysis sp. n.