森林草地转换对景观视觉效果的影响

基于景观保护的视点,定量研究了森林草地转换对景观视觉效果的影响．结果表明,中景域的可视区域比近景域和远景域大,草地建设对中景域景观视觉效果的影响也最大,因此,中景域是重要的景观保护对象．对草地内林地的可视量分析可知,各景域的可视林地多分布在400～600m高海拔上。25°以上的坡度范围内分布偏少．并探讨了草地建成后应采取的景观管理和保护对策,以增加草地景观的视觉效果．     

Effect of lidocaine on phospholipid and fatty acid composition of bacterial membranes

The effects of lidocaine on chemical composition of membrane phospholipids and membrane fluidity of Streptococcus mutans have been studied. Increasing concentra-tions of lidocaine induced both an increase in cardiolipin and a decrease in the degree of unsaturation of its fatty acid composition. A lidocaine-dependent decrease of membrane fluidity was observed from an electron spin resonance spectroscopic study. It was considered thal bacteria grown with lidocaine below its minimum inhibitory concentration resisted the effect of the drug by modifying phospholipid and fatty acid composition resulting in a decreased membrane fluidity.     

PHOTOSYNTHETIC NITRITE REDUCTASE II. FURTHER PURIFICATION AND BIOCHEMICAL PROPERTIES OF THE ENZYME

1. Further purification of photosynthetic nitrite reductase (PNiR),which catalyzes the transfer of hydrogen (or electron) fromthe photolytic system to nitrite, is reported in this paper.Chromatography on DEAE- cellulose and Sephadex gel-filtrationwere effective for the purification of PNiR.
2. PNiR could befractionated into two components. It was inferredfrom the dataobtained that one of these components is identicalwith PPNR,and the other one may probably be a hitherto unreportedflavinenzyme containing FMN as prosthetic group.
3. The propertiesof these two components of PNiR were described,and the interrelationshipbetween these catalysts and possibleintermediary carriers ofthis electron transfer system was discussed.

¹Dedicated to Prof. H. TAMIYA on the occasion of his 60th birthday.This investigation was supported by a Grant in Aid for FundamentalScientific Research from the Ministry of Education (No. 407130-1961)and a Grant in Aid for Organized Scientific Research from theMinistry of Education (No. 95037-1960), which are gratefullyacknowledged here. The authors also wish to acknowledge thatthe progress of this study was facilitated by a Grant from theKAISEI-KAI. A preliminary report on this work was read beforethe 25th Annual Meeting of the Botanical Society of Japan (1960,Osaka).     

Diffusion Coefficient of Paramecium as a Function of Temperature1

The motion of Paramecium caudatum has been investigated at various temperatures by measuring the transient behavior of spatial distribution in the diffusion process of organisms that, by electric stimulus, are initially gathered at a single place in the glass culture cell. The spatial distribution through the course of diffusion has a nearly Gaussian profile. Dispersion was obtained at 1 sec intervals and increased linearly with time. The time dependence of the dispersion gave a diffusion coefficient for the random motion of the organisms. The results show that the diffusion coefficient has a maximum at the temperature at which the paramecia were cultivated.     

Localization of Possible Calcium-Binding Sites in the Cilia of Paramecium caudatum

SYNOPSIS. Electron-dense deposits indicating possible Ca-binding sites were found at the ciliary base of Paramecium caudatum fixed in a glutaraldehyde solution containing 5 mM CaCl₂. The deposits appeared mainly at the inner surface of the ciliary membrane above the "ciliary necklace" region, although they could also occur in the space between the outer and the central microtubules. In some cases a ring of exactly 9 deposits was found in a ciliary cross section of a cilium.     

Mechanism of photoinactivation in photosynthetic systems II. The occurrence and properties of two different types of photoinactivation

Photoinactivation of the activity of NADP photoreduction withreduced DPIP or with reduced TMPD as the electron donor wasinhibited by the absence of oxygen in the atmosphere or by thepresence of photosynthetic inhibitors (CMU, DCMU, o-phenanthroline)in the preillumination mixture. Photoinactivation of the photoreductionof NADP or DPIP with water as the electron donor was not affected,or even accelerated, by these conditions of preillumination.The concentrations of inhibitors required for maximum inhibitionin the former case corresponded to those required for inhibitionof photosynthetic electron transport. The results indicatedthe occurrence of 2 different types of photoinactivation, eachspecifically affecting photosystems I and II, and differingin behaviours; including their requirement for oxygen in theatmosphere and their responses toward the presence of photosyntheticinhibitors during the preillumination period. (Received July 30, 1969; )     

Detection of recombinant haplotypes in wild mice (Mus musculus) provides new insights into the origin of Japanese mice

Japanese house mice (Mus musculus molossinus) are thought to be a hybrid lineage derived from two prehistoric immigrants, the subspecies M. m. musculus of northern Eurasia and M. m. castaneus of South Asia. Mice of the western European subspecies M. m. domesticus have been detected in Japanese ports and airports only. We examined haplotype structuring of a 200 kb stretch on chromosome 8 for 59 mice from throughout Eurasia, determining short segments (≈ 370–600 bp) of eight nuclear genes (Fanca, Spire2, Tcf25, Mc1r, Tubb3, Def8, Afg3l1 and Dbndd1) which are intermittently arranged in this order. Where possible we identified the subspecies origin for individual gene alleles and then designated haplotypes for concatenated alleles. We recovered 11 haplotypes among 19 Japanese mice examined, identified either as ‘intact’ haplotypes derived from the subspecies musculus (57.9%), domesticus (7.9%), and castaneus (2.6%), or as ‘recombinant’ haplotypes (31.6%). We also detected recombinant haplotypes unique to Sakhalin. The complex nature of the recombinant haplotypes suggests ancient introduction of all three subspecies components into the peripheral part of Eurasia or complicated genomic admixture before the movement from source areas. ‘Intact’domesticus and castaneus haplotypes in other Japanese wild mice imply ongoing stowaway introductions. The method has general utility for assessing the history of genetic admixture and for disclosing ongoing genetic contamination.