Simultaneous measurements of clear air turbulence at the tropopause by high-power radar and instrumented aircraft

Large amplitude Kelvin-Helmholtz billows observed by radar at a height of almost 11 km are shown to have been associated with clear air turbulence which produced a vertical aircraft acceleration of 0.65g.     

Geomagnetic polarity change, volcanic maxima and faunal extinction in the South Pacific

Studies of deep-sea sedimentary cores from Antarctic Pacific waters show that some volcanic maxima occurred when the geomagnetic polarity was changing. Upper mantle activity and geomagnetic polarity change may therefore be related. Coincidences of faunal extinction and geomagnetic polarity change may be explained by corresponding volcanically induced climatic changes.     

Antisense oligodeoxynucleotides to GS protein alpha-subunit sequence accelerate differentiation of fibroblasts to adipocytes.

Fully-differentiated mouse 3T3-L1 fibroblasts accumulate large amounts of lipid at 7-10 days after induction by insulin or by dexamethasone and a methyl xanthine. G proteins mediate transmembrane signalling from a diverse group of cell-surface receptors to effector units that include phospholipase C, adenylyl cyclase and ion channels. They are also targets of regulation themselves. 3T3-L1 fibroblasts display marked changes in levels of G protein when induced to differentiate to adipocytes. Here we show that cholera toxin, which ADP-ribosylates and activates the G protein subunit Gs alpha, blocks the induction of differentiation, whereas increasing intracellular cyclic AMP directly with the dibutyryl analogue or indirectly with pertussis toxin or forskolin does not affect differentiation. Oligodeoxynucleotides antisense to the sequence encoding Gs alpha accelerate differentiation markedly. The time course of adipogenesis declined from 7-10 days in controls to roughly 3 days in cultures treated with antisense-Gs alpha oligodeoxynucleotides, whereas oligodeoxynucleotides, antisense to Gi alpha 1, Gi alpha 3, and sense and missense to Gs alpha, had no such effect. Antisense-Gs alpha alone induced differentiation by day 7, indicating that Gs alpha activity modulates differentiation in 3T3-L1 cells, acting in a new role which is independent of increased intracellular cAMP.     

The early Kant’s (anti-) Newtonianism

It is well known that during his pre-Critical period, Kant was a major proponent of Newtonian physics, for the project of the Universal Natural History explicitly uses “Newtonian principles” to explain the formation of the various bodies that constitute our solar system as well as those that lie beyond. What has not been widely noted, however, is that the early Kant also developed a major criticism of Newton, one that is based on subtle metaphysical issues pertaining to God, which are most at home in philosophical theology. Interestingly, this criticism is neither an inchoate precursor of his later criticisms of Newton’s account of absolute space, nor isolated to the abstract realm of metaphysics, but has a wide range of implications for the way in which a scientific account of the formation and constitution of the heavenly bodies ought to be developed, that is, for the kind of argument Newton offered in the Principia. That Kant remained interested in this set of issues later in his Critical period suggests that, alongside the revolutionary changes that comprise transcendental idealism, there are deep continuities not only in his Newtonian commitments, but in his anti-Newtonian tendencies as well.     

Effects of monovalent cations on the responses of motoneurones to different groups of amino acid excitants in frog and rat spinal cord

Summary Classification of excitatory amino acids into different groups, of possible value for transmitter identification, can be made on the basis of the differential effects of altered external [Na⁺] and [K⁺] on motoneurone depolarization in frog and immature rat spinal cord.Acknowledgments. We thank Mr D. J. Oakes for skilled technical assistance. This work was supported from the Medical Research Council.     

Value of curiosity-oriented research

Is the most profit to be had from research inspired by curiosity or by foresight of practical applications? A recent suggestion that the answer could be found by evaluating curiosity-oriented projects has proved hard to follow up.     

Observations of clear air turbulence by high power radar

Clear air turbulence is a hazard to aviation and is thought to have important effects on atmospheric dynamics. This article describes the structure and evolution of clear air turbulence at high altitudes as revealed by a high power radar and vertical soundings of wind and temperature.