Trapped radiation belts of saturn: first look

Pioneer 11 has made the first exploration of the magnetosphere and trapped radiation belts of Saturn. Saturn's magnetosphere is intermediate in size between Earth's and Jupiter's, with trapped particle intensities comparable to Earth's. The outer region of Saturn's magnetosphere contains lower energy radiation and is variable with time; the inner region contains higher energy particles. The pitch angle distributions show a remarkable variety of field-aligned and locally mirroring configurations. The moons and especially the rings of Saturn are effective absorbers of trapped particles; underneath the rings, the trapped radiation is completely absorbed. We confirm the discovery of a new ring, called the F ring, a new division, the Pioneer division, and a moon, called 1979 S 2. The latter has probably been seen from Earth. There may be evidence for more bodies like 1979 S 2, but at this stage the interpretation of the data is ambiguous. Using particle diffusion rates, we estimate that the cross-sectional area of the F ring is > 7 x 10(13) square centimeters and that the opacity is > 10(-5). Cosmic-ray albedo neutron decay should be looked into as a source of energetic particles in the inner magnetosphere of Saturn.     

Sulfide Deposits from the East Pacific Rise Near 21{degrees}N

Massive sulfide deposits were discovered from the diving saucer Cyana on the accreting plate boundary region of the East Pacific Rise near 21 degrees N. The deposits form conical and tubular structures lying on a basaltic basement. Mineralogical and geochemical analyses showed two main types of intimately associated products: a polymetallic sulfide-rich material composed of pyrite and marcasite in association, zinc-rich phases, and copper-rich compounds, and an iron-rich oxide and hydroxide material (also called gossan) composed largely of goethite and limonite. Silicate phases such as opaline, silica, iron-silicon clay, and trace amounts of mica and zeolite are encountered in both types of material. Possible mechanisms for the formation of the sulfide deposits on the East Pacific Rise are discussed.     

Nitric oxide air pollution: detection by optoacoustic spectroscopy

Nitric oxide is detected by a new technique in which tunable infrared radiation from a spin-flip Raman laser is used to measure the absorption spectrumn of a gas sample by optoacoustic spectroscopy. This technique is sensitive enough to detect a concentration of 0.01 part per million of nitric oxide pollution in air samples.     

Glazed lunar rocks: origin by impact

The glassy coating of lunar rock 12017 is enriched in 15 trace elements relative to the crystalline interior. It apparently consists chiefly of shock-melted rock, somewhat richer in rare earth elements and alkali metals than rock 12017 itself. The glass has been contaminated by about 0.5 percent carbonaceous-chondrite-like material or, alternatively, by a mixture of 0.06 to 0.3 percent fractionated meteoritic material and approximately 10 to 15 percent local soil. The glazing seems to represent molten material splashed from a nearby meteorite impact and not in situ melting by a sudden increase in solar luminosity.     

Human C'3: evidence for the liver as the primary site of synthesis

The liver is the primary, if not sole, site of synthesis of the third component of human complement, as shown by a change in the recipient from C'3 FS(0.6) to C'3 SS, the donor type, following homotransplantation of the liver.     

棉花品種抗黄萎病的初步研究:

一、緒言棉花黄萎病是危害我國棉花生產的重要病害之一,分佈範圍很廣。幾年來在老棉區如:關中、晉南、冀東、遼陽等地黄萎病還在繼續擴展。據1956年關中棉區估計陝西經惠渠灌溉區,棉田發病率一般在30%左右,嚴重地區發病逹90%,估計平均減產20%,同時黄萎病也已在新疆新棉區發生,因此為着保證棉花生產,必須積極防治黄萎病。1955年植物保護會議决定棉花黄萎病的研究課题是鑑定病原,明確傅染途徑及寄主範圍,找出防治方法和抗病品種。我們感到棉花抗黄萎病品種的鑑定是尋找和培育抗病品種的基礎。必須組織各地試驗場所的力量,在統一計劃下,進行鑑定才能事半功倍。這個意見得到農業部棉產處,中央農業科學院等備處和各合作單位的支持,使棉花抗黄萎病品種的鑑定試驗得在遼陽、唐山、臨汾、涇陽等四個試驗站、華北科學研究所和北京農業大學(與中國科學院應用真菌學研究所合作)等六個地點同時進行,以期通過田間之試驗,比較各品種在不同地區抗病性的强弱,以了解各地黄萎病菌的差異,為選育抗病豈產品種而打下基礎。     

Ras p21 as a potential mediator of insulin action in Xenopus oocytes

The oncogene protein product (p21) of the ras gene has been implicated in mediating the effects of a variety of growth factors and hormones. Microinjection of monoclonal antibody 6B7, which is directed against a synthetic peptide corresponding to a highly conserved region of p21 (amino acids 29 to 44) required for p21 function, specifically inhibited Xenopus oocyte maturation induced by incubation with insulin. The inhibition was dose-dependent and specific since (i) the same antibody had no effect on progesterone-induced maturation, (ii) immunoprecipitation and Western blotting indicated that the antibody recognized a single protein of molecular weight 21,000 in oocyte extracts, and (iii) inhibition was not observed with identical concentrations of normal immunoglobulin. Thus, p21 appears to be involved in mediating insulin-induced maturation of Xenopus oocytes. Furthermore, the mechanism may involve phosphorylation of p21, as p21 was found to be a substrate of the insulin receptor kinase.     

The molecular basis of the sparse fur mouse mutation

The ornithine transcarbamylase-deficient sparse fur mouse is an excellent model to study the most common human urea cycle disorder. The mutation has been well characterized by both biochemical and enzymological methods, but its exact nature has not been revealed. A single base substitution in the complementary DNA for ornithine transcarbamylase from the sparse fur mouse has been identified by means of a combination of two recently described techniques for rapid mutational analysis. This strategy is simpler than conventional complementary DNA library construction, screening, and sequencing, which has often been used to find a new mutation. The ornithine transcarbamylase gene in the sparse fur mouse contains a C to A transversion that alters a histidine residue to an asparagine residue at amino acid 117.