Effects of Preillumination on Dark Nitrogen Fixation and Respiration by Anabaena Cylindrica

In whole filaments of Anabaena cylindrica dark nitrogen-fixingactivity (measured as acetylene reduction) and respiration increasedwith the light intensity of a fixed period of preillumination,saturating at ca. 10,000 lux. With saturating light during preillumination,the amount and duration of dark nitrogen-fixing activity increasedwith length of preillumination, but respiration declined rapidlyin the dark. At dark respiration rates below 250 nmol O₂ uptake mg protein^–1?h^–1(State 1) no significant nitrogen-fixing activity is observed.From 250 to 550 nmol O₂ uptake?mg protein^–1?h^–1(State 2), nitrogen-fixing activity depends on O₂ uptake whileabove 550 nmol O₂ uptake?mg protein^–1?h^–1 (State3), nitrogen-fixing activity no longer increases with furtherincrease in O₂ uptake rate. (Received June 18, 1983; Accepted November 10, 1983)     

Effect of High-intensity Light Given Prior to Low-temperature Treatment on the Long-day Flowering of Pharbitis nil

Pharbitis nil, strain Violet which had been exposed to high-intensitylight (18,000 lux at 23?C) for 7 days followed by a low-temperaturetreatment (13–14?C) for 7 days initiated flower buds evenunder continuous light, but plants given these treatments inreverse order failed to bud. Three days of high-intensity lightat 23?C was most effective in promoting the flower-inducingeffect of the subsequent low-temperature period. Six days oflow temperature following the 3-day high-intensity light periodinduced near-maximum flowering response. DCMU (5?10^–6M) given during the high-intensity light period inhibited flowering,but when given during or after the low-temperature period itwas ineffective. DCMU at the same concentration given before,during or after an inductive 16-hr dark period at 26?C did notinhibit flowering. Sucrose, ATP, NADPH and some other reducingagents tested did not nullify the DCMU effect nor substitutefor the effect of high-intensity light. But, the high-intensitylight effect could be substituted, at least partly, by 5-chlorosalicylicacid, 3,4-dichlorobenzoic acid and some other benzoic acid derivatives,which are highly effective in inducing long-day flowering inthe short-day plant, Lemna paucicostata. (Received October 20, 1981; Accepted February 3, 1982)     

Differential effects of oxygen on N2 fixation and C2H2 reduction by Anabaena cylindrica

Both nitrogen fixation and acetylene reduction by intact cellsof Anabaena cylindrica were inhibited by oxygen, but nitrogenfixation was invariably less sensitive than acetylene reduction.The C₂H₂/N₂ ratio ranged from 6 to 8 in the absence of oxygen,and it decreased with increase in partial pressure of oxygento 2 at a pO₂ of 0.3 atm. (Received June 5, 1979; )     

Roles of Inorganic Nitrogen in Gametophytic Growth and in Initiation and Development of Sporophytic Shoots of Equisetum arvense

The formation of sporophytic shoots, which is induced by treatmentwith benzylaminopurine of gametophyte tissue of Equisetum arvense,can be divided into initiation and developmental phases. Thenitrogen in MS medium was suitable for two phases as well as gametophytic growth, buta reduction in the concentration of available nitrogen was neededfor the development of shoots. ions alone were effective for gametophytic growth and the initiationof sporophytic shoots, but both and ions was required for the developmental phase. (Received February 18, 1992; Accepted April 14, 1992)     

Parturition in a free-ranging Japanese monkey (Macaca fuscata)

Parturition behavior of a multiparous female and her interactions with group members throughout the birth process were recorded for a free-ranging Japanese monkey (Macaca fuscata). The female showed evidence of 18 contractions during the 35 min prior to delivery, with a mean duration and a mean intercontraction interval of 30 sec and 96 sec, respectively. These values were similar to those in individually caged Japanese monkeys. Some adult females remained in proximity to the female who was giving birth during the prepartum phase, and her 2-year-old daughter watched the delivery of the infant. Even during the prepartum phase the female moved in order to keep up with the group which traveled from the feeding site to a sleeping site in the forest.     

Evaluation of chemical pretreatment for enzymatic solubilization of rice straw

Summary Rice straw was treated with NaOH, peracetic acid (PA), and sodium chlorite (NaClO₂). Quantitative changes in the composition of the treated straw, crystallinity of the treated straw and extracted cellulose, and susceptibility of the treated straw to Trichoderma reesei cellulase were studied. The alkali treatment resulted in a remarkable decrease in hemicellulose as well as lignin. Consequently, the recovery of residual straw after NaOH treatment was lowest among the three chemical reagents evaluated. The treatment with PA or NaCIO₂ resulted in a slight loss in hemicellulose and cellulose in the straw. The three chemical treatments caused little or no breakdown of the crystalline structure of cellulose in the straw. The treated straw was solubilized with the culture filtrate of T. reesei. The degree of enzymatic solubilization relative to the amount of residual straw was 69% after treatment with 0.25 N NaOH, 42% after treatment with 20% PA, and 50% after treatments with NaClO₂ (twice). The degree of enzymatic solubilization relative to the amount of the untreated straw, however, was 30% after treatment with 0.25 N NaOH, 32% after treatment with 20% PA, and 37% after treatments with NaClO₂ (twice).     

Polyploid cytotypes and their habitat preferences inLycopodium clavatum

Morphological, cytological and ecological observations were made onLycopodium clavatum. Among 121 individuals from 26 populations studied 31 were of the diploid cytotype with 2n=68, 45 were of the triploid cytotype with 2n=102 and 45 were of the tetraploid cytotype with 2n=136. The populations were divided into three types: (1) the sole type—characterized by a single cytotype occupying an entire population, (2) the mixed type A—characterized by two or three cytotypes occupying together the same population, but each cytotype choosing different habitats, (3) the mixed type B—characterized by two or three cytotypes occupying together the same population and sharing the same habitat with each other. The mixed type B populations were found in the places of the early phase of secondary succession in a plant community. In the sole type and the mixed type A, the habitat preference for each cytotype was described as follows: the habitat for the diploid was in humid and shady places, that for the tetraploid was in open and sunny, unstable places, and that for the triploid was intermediate between the other two. Each cytotype can progress towards occupying their optimum habitat successively from the mixed type B population to the mixed type A population and finally reaching the sole type population.