Intense equatorial flux spots on the surface of the Earth's core

A large number of high-accuracy vector measurements of the Earth's magnetic field have recently become available from the satellite Oersted, complementing previous vector data from the satellite Magsat, which operated in 1979/80. These data can be used to infer the morphology of the magnetic field at the surface of the fluid core, approximately 2,900 km below the Earth's surface. Here I apply a new methodology to these data to calculate maps of the magnetic field at the core surface which show intense flux spots in equatorial regions. The intensity of these features is unusually large--some have intensities comparable to high-latitude flux patches near the poles, previously identified as the major component of the dynamo field. The tendency for pairing of some of these spots to the north and south of the geographical equator suggests they might be associated with the tops of equatorially symmetric columnar structures in the fluid, or their antisymmetric equivalents. The drift of the equatorial features may represent material flow or could represent wave motion; discrimination of these two effects based on future data could provide new information on the strength of the hidden toroidal magnetic field of the Earth.     

有机硫对维多利亚褐煤液化的催化作用之穆斯堡尔研究

我们以Morwell和Coolungoolun两种维多利亚褐煤进行实验,对铁和锡在煤的液化中的催化作用进行了比较,发现锡对低硫的Morwell煤较为有效,而铁则更适合于高硫的Coolungoolun煤。对液化余渣的穆斯堡尔分析的结果,使我们可以用低硫煤中元素态锡的形成以及在高硫煤中磁黄铁矿（Fe_(0.92)S）的形成来对观察到的现象作出解释。硫的损耗数据表明,磁黄铁矿的存在使得煤中的硫转化为气相的量增加了。     

Russell Ackoff's Jerusalem

This brief article looks at the influence of russ Ackoff's work, using as a focus of attention a maxim of the poet and philosopher William Blake. In particular, it considers Ackoff s contribution to the development of community operational research.     

Wound-induced alterations in survival of 60Co irradiated mice: importance of wound timing

Wounding mice shortly before or shortly after lethal 60Co irradiation enhances survival. Survival of wounded-irradiated mice may be due to enhanced hematopoietic recovery as measured by endogenous spleen colony (E-CFU-s) formation.     

Human CtIP promotes DNA end resection

In the S and G2 phases of the cell cycle, DNA double-strand breaks (DSBs) are processed into single-stranded DNA, triggering ATR-dependent checkpoint signalling and DSB repair by homologous recombination. Previous work has implicated the MRE11 complex in such DSB-processing events. Here, we show that the human CtIP (RBBP8) protein confers resistance to DSB-inducing agents and is recruited to DSBs exclusively in the S and G2 cell-cycle phases. Moreover, we reveal that CtIP is required for DSB resection, and thereby for recruitment of replication protein A (RPA) and the protein kinase ATR to DSBs, and for the ensuing ATR activation. Furthermore, we establish that CtIP physically and functionally interacts with the MRE11 complex, and that both CtIP and MRE11 are required for efficient homologous recombination. Finally, we reveal that CtIP has sequence homology with Sae2, which is involved in MRE11-dependent DSB processing in yeast. These findings establish evolutionarily conserved roles for CtIP-like proteins in controlling DSB resection, checkpoint signalling and homologous recombination.