Photograph of a close lightning flash

A lightning flash has been photographed striking a European ash tree at a distance of 60 meters. The tree sustained no external physical damage. The probability of obtaining this photograph is estimated to be 10(-3), or once in 1000 years.     

An unusual phycoerythrin from a marine cyanobacterium

Phycoerythrin conjugates are reagents for cell sorting and analyses in which the argon-ion laser line at 488 nanometers is used for excitation. Many marine Synechococcus strains contain phycoerythrins with absorption maxima at approximately 490 and 550 nanometers; these maxima indicate the presence of phycourobilin and phycoerythrobilin prosthetic groups in the protein. Phycoerythrins of red algae contain both groups, but those of freshwater and soil cyanobacteria contain only phycoerythrobilin. Phycoerythrin purified from Synechococcus WH8103 has molecular properties typical of red algal phycoerythrins, but its phycourobilin content is higher than that of other phycoerythrins. The protein has absorption maxima at 492 and 543 nanometers and corresponding molar extinction coefficients of 2.78 and 1.14 x 10(6); it fluoresces maximally at 565 nanometers with a quantum yield of 0.5. Conjugates of Synechococcus WH8103 phycoerythrin could increase the sensitivity of cell analysis techniques to almost twice that possible with other phycoerythrin conjugates.     

An early center of bovine husbandry in southeast Asia

Non Nok Tha is a prehistoric site in northeast Thailand. The radiocarbon dates suggest that it was first occupied by at least 3500 B.C., and possibly as early as 5000 B.C. The deepest levels contain unexpectedly early evidence for rice cultivation and bronze casting. Multivariate and cultural analyses of the bovine bones suggest that the first inhabitants raised domesticated cattle. This is among the earliest evidence for bovine domestication known.     

Synthesis of carbenes through substitution reactions at a carbene center

An (amino)(phosphino) carbene can be transformed into (amino)(phosphonio) carbenes, which undergo nucleophilic intermolecular as well as intramolecular substitution reactions at the carbene center. A variety of carbenes can be synthesized starting from a single carbene precursor. The resulting gamut of electronic and steric effects possible should open the way not only to a detailed study of the mechanism, but also to the subsequent improvement of catalytic reactions that involve carbene-transition metal complexes.     

An unusual marine crocodyliform from the Jurassic-Cretaceous boundary of Patagonia

Remains of the marine crocodyliform Dakosaurus andiniensis from western South America reveal a lineage that drastically deviated from the skull morphology that characterizes marine crocodyliforms. The snout and lower jaw are extremely robust, short, and high and only bear a few large teeth with serrated edges (resembling those of some terrestrial carnivorous archosaurs). This unusual morphology contrasts with the long and gracile snout and lower jaws bearing numerous teeth, which are present in the closest relatives of D. andiniensis (and interpreted as indicating feeding on small fish or mollusks). Thus, the morphological diversity of pelagic marine crocodyliforms was wider than had been thought.