Karyotype in two himalayan species of polygonatum

Zusammenfassung Die Chromosomenzahl und der Karyotypus vonPolygonatum verticillatum Allioni (2n = 30, 64) undP. cirrifolium Royle (2n = 38), die im Himalaya vorkommen, wurden mit früher untersuchten europäischen Formen verglichen. Die beobachteten Unterschiede lassen sich durch die Annahme erklären, dass die europäischen Formen aus den Himalaya-Formen durch den Vorgang der Chromosomenverminderung und Veränderungen des Karyotypus hervorgingen.     

On the contribution of haemolymph to the salivary proteins of the red cotton bug,Dysdercus koenigii F. (Heteroptera,Pyrrhocoridae)

Summary Polyacrylamide gel electrophoresis of haemolymph and the salivary gland of adult maleDysdercus koenigii has been carried out. The presence of common bands in the electropherograms of the salivary gland and haemolymph shows the possible elaboration of haemolymph protein into the salivary glands as also evidenced by leucomethylene blue incorporation into the salivary gland lobules. The results are discussed in the light of our present state of knowledge.I wish to acknowledge the financial support from the C.S.I.R., New Delhi, India. Grateful acknowledgements are made to Prof. P.S. Ramamurty for encouragements, and to Zoology Department, Banaras Hindu University for the working facilities.     

Effect ofβ-Aminoethylisothiuronium-bromide-hydrobromide on the acetate-1-14C incorporation into tissue lipids of irradiated rats

Zusammenfassung Einfluss von Bestrahlung auf die Lipidsynthese, wobei festgestellt wird, dass der Strahlungsschutzstoff AET die Lipidsynthese hemmt.     

Plasma devices to guide and collimate a high density of MeV electrons

The development of ultra-intense lasers has facilitated new studies in laboratory astrophysics and high-density nuclear science, including laser fusion. Such research relies on the efficient generation of enormous numbers of high-energy charged particles. For example, laser-matter interactions at petawatt (10(15) W) power levels can create pulses of MeV electrons with current densities as large as 10(12) A cm(-2). However, the divergence of these particle beams usually reduces the current density to a few times 10(6) A cm(-2) at distances of the order of centimetres from the source. The invention of devices that can direct such intense, pulsed energetic beams will revolutionize their applications. Here we report high-conductivity devices consisting of transient plasmas that increase the energy density of MeV electrons generated in laser-matter interactions by more than one order of magnitude. A plasma fibre created on a hollow-cone target guides and collimates electrons in a manner akin to the control of light by an optical fibre and collimator. Such plasma devices hold promise for applications using high energy-density particles and should trigger growth in charged particle optics.     

Modelling disease outbreaks in realistic urban social networks

Most mathematical models for the spread of disease use differential equations based on uniform mixing assumptions or ad hoc models for the contact process. Here we explore the use of dynamic bipartite graphs to model the physical contact patterns that result from movements of individuals between specific locations. The graphs are generated by large-scale individual-based urban traffic simulations built on actual census, land-use and population-mobility data. We find that the contact network among people is a strongly connected small-world-like graph with a well-defined scale for the degree distribution. However, the locations graph is scale-free, which allows highly efficient outbreak detection by placing sensors in the hubs of the locations network. Within this large-scale simulation framework, we then analyse the relative merits of several proposed mitigation strategies for smallpox spread. Our results suggest that outbreaks can be contained by a strategy of targeted vaccination combined with early detection without resorting to mass vaccination of a population.     

Impedance and ferroelectric properties of Sr2+ modified PZT-PMN ceramics

Sr^2＋ modified polycrystalline PZT-PMN ceramics were synthesized by a semi-wet route. Impedance spectroscopy studies indicate the bulk and grain boundary effects of PZT-PMN material along with the negative temperature coefficient of resistance. The bulk conductiv-ity exhibits an Arrhenius-type thermally activated hopping process which is supported by the AC conductivity behavior as a function of fre-quency and temperature. It is observed that the remnant polarization increases with an increase in the Sr2＋content in PZT-PMN.     

中国公路沥青路面水损害气候影响分区方案

为了了解中国气候条件对沥青路面水损害的影响情况,对沥青路面水损害研究成果进行了回顾与分析,认为影响沥青路面水损害的主要气候因素为:降水、高温以及冻融循环过程.降水与高温过程组合以及降水与冻融循环过程组合是影响沥青路面水损害的两个主要气候过程.针对这两个主要气候过程,构建了降水气温指数和降水冰冻指数,用于评价上述气候过程对沥青路面水损害的影响.分析结果表明:利用降水气温指数和降水冰冻指数划分中国公路沥青路面水损害气候影响分区是合理可行的;根据各个气候指数的工程意义和等概率原则,确定了分区界限,拟定了包含14个区的分区方案.     

Human oestrogen receptor cDNA: sequence, expression and homology to v-erb-A

We have cloned and sequenced the complete complementary DNA of the oestrogen receptor (ER) present in the breast cancer cell line MCF-7. The expression of the ER cDNA in HeLa cells produces a protein that has the same relative molecular mass and binds oestradiol with the same affinity as the MCF-7 ER. There is extensive homology between the ER and the erb-A protein of the oncogenic avian erythroblastosis virus.     

Interruption of acoustic communication and mating in a leafhopper and a planthopper by aerial sound vibrations picked up by plants

Summary Each sex of the cotton leafhopper and the rice brown planthopper communicates with the opposite sex by certain specific sound vibrations which travel through the plant surface and lead to mating. External sounds of certain frequencies, viz., 200 c/sec, generated by a harmonium or an audio-oscillator are picked up from the air by the plants and interrupt the acoustic communication as well as mating of the insects. Notes with harmonics are effective whereas pure notes are ineffective.The authors gratefully acknowledge P.L. 480 grant No. FG-IN-551 from the US Department of Agriculture for project No. IN-ARS-90, under which this work was carried out.