[Localization of E(wa) in Drosophila melanogaster using rearrangement]

The white-apricot (wa) allele differs from the wild type white gene by the presence of the retrovirus-like transposable element copia within the transcription unit. The activity of wa is reduced in trans by a semidominant mutation in the gene Enhancer-of white-apricot (E(wa)). The map position of E(wa) is refined by analyzing recombination among three genes: px, E(wa) and sp. The recombinational distance between E(wa) and sp is 0.2 cM, which places E(wa) at 2-106.8. To localize E(wa) cytologically, four Y; 2 translocations, one 1;2 translocation and three 2R deficiency stocks were crossed to the suitable E(wa) stocks and the wa sons were scored for intensity of pigment and the speck at the axis of wings. The E(wa) was placed in the distal portion of 60B. The one E(wa) mutation and two sp mutations derived from our gamma-ray mutagenesis were used for examination of polytene chromosome. The former was a revertant which has a cytologically visible insertion of material from an unknown source at 60B5-13, most likely in the 60B8-9. It is likely that this insertion is within the E(wa) gene. The latter shows breakpoint at 60C1-2, where is likely the location of the sp gene. Combining the data of both cytological localization and recombinational mapping, the E(wa) was localized at 60B5-13, most likely in the 60B8-9, the left of sp but very close to it.

Life security of the elderly: rural population control

"This article will examine the life security among the elderly in rural China and its impact on the population control in those areas." Data are from a fertility survey conducted in five rural villages in 1990.

Geometry for contouring by electronic speckle pattern interferometry based on shifting illumination beams

When the method of contouring an object surface by electronic speckle pattern interferometry is based on shifting the illumination beams, the shifted phase of the interference speckle pattern has a new relationship with the depth of the test surface. Therefore the contour interval as well as the fringe sensitivity of this method has new forms. The geometry of such a situation, which differs from that of either the method of two-wavelength contouring or the method of contouring by tilting the test object is presented. The requirements on the experimental conditions for this method are also presented. Experimental results are in agreement with these analyses.

Contouring by electronic speckle pattern interferometry with quadruple-beam illumination

We present a new arrangement for contouring by electronic speckle pattern interferometry with four illumination beams, thereby making it unnecessary to move anything during the.

High-pressure 31P NMR study of dipalmitoylphosphatidylcholine bilayers

High-pressure 31P NMR was used for the first time to investigate the effects of pressure on the structure and dynamics of the phosphocholine headgroup in pure 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) multilamellar aqueous dispersions and in DPPC bilayers containing the positively charged form of the local anesthetic tetracaine (TTC). The 31P chemical shift anisotropies, delta sigma, and the 31P spin-lattice relaxation times, T1, were measured as a function of pressure from 1 bar to 5 kbar at 50 degrees C for both pure DPPC and DPPC/TTC bilayers. This pressure range permitted us to explore the rich phase behavior of DPPC from the liquid-crystalline (LC) phase through various gel phases such as gel I (P beta'), gel II (L beta'), gel III, gel IV, gel X, and the interdigitated, Gi, gel phase. For pure DPPC bilayers, pressure had an ordering effect on the phospholipid headgroup within the same phase and induced an interdigitated Gi gel phase which was formed between the gel I (P beta') and gel II (L beta') phases. The 31P spin-lattice relaxation time measurements showed that the main phase transition (LC to gel I) was accompanied by the transition between the fast and slow correlation time regimes. Axially symmetric 31P NMR lineshapes were observed at pressures up to approximately 3 kbar but changed to characteristic axially asymmetric rigid lattice lineshapes at higher pressures (3.1-5.1 kbar).(ABSTRACT TRUNCATED AT 250 WORDS)

Cystitis, urolithiasis and cystic calculi in ageing guineapigs

Nineteen cases of cystitis were diagnosed at necropsy and/or by histology in a group of 170 (96 females, 74 males) guineapigs (11.2%). Seventeen of the 19 cases (89.4%) were females. The mean age of guineapigs with cystitis was 34.7 months, which was higher than the mean age of 24 months of the 170 members of the study group. In addition, 6 cases of urolithiasis and cystic calculi in 5 females and one male were also found in the 170 guineapigs (3.5%). The mean age of the 6 cases was 30 months, which was also higher than the mean age of the 170 animals. The study suggests that aged female guineapigs were much more predisposed to cystitis and urolithiasis or cystic calculi than male and young guineapigs. The cause may be related to infection with Escherichia coli and Staphylococcus sp, cystic calculi, diabetes mellitus and female guineapig urogenital anatomy and function.

Effect of cage population density on plasma corticosterone and peripheral lymphocyte populations of laboratory mice

The effect of different population densities of mice per cage on plasma corticosterone, peripheral lymphocytes and specific lymphocyte subpopulations was investigated. The animals were housed in groups of 2, 4 or 8 mice per cage and the blood samples were taken from each animal of these groups on days one, 7 and 14. A significant elevation (P less than 0.05) in plasma corticosterone concentration was observed in the group of 8 mice per cage on days one and 7 as compared with those of 2 or 4 mice per cage. The number of peripheral lymphocytes was significantly decreased in the groups of 2 (P less than 0.01) and 8 (P less than 0.05) mice per cage as compared with the group of 4 mice per cage on day one. A significantly decreased number of lymphocytes (P less than 0.01) in the group of 8 mice per cage continued to day 7. There were no significant differences in specific lymphocyte subpopulations observed among these groups. The results of this study suggest that a population density of 4 mice per cage induced minimal stress compared to that induced by the population densities of 2 or 8 mice per cage. Since stress is known to induce alteration in a variety of biological functions, the population density of mice per cage should be considered in the interpretation of research data.