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991.
Photoperiodism and rhythmic response to light 总被引:2,自引:1,他引:1
Abstract. Seedlings of Pharhitis nil show a circadian rhythm in the capacity to flower in response to the timing of a second red light pulse given at various times after a first saturating exposure to red when this is given together with a benzyladeninc spray. There are also changes in the photon irradiance required for half maximum response to the second red pulse. The photochemical properties of phytochrome in the photoperiodically sensitive cotyledons were also shown to change rhythmically. Oscillations in both pr→ Pfr and Pfr→ Pr photoconversion characteristics persisted over at least two circadian cycles with a periodicity of about 12 h. There were, however, no significant oscillations in either Pfr peak absorbance or in Δ(ΔA). The changes in sensitivity for the photoconversion of Pr→ Pfr did not parallel the much larger changes in sensitivity of the flowering response to red light. The amplitude of the Pr→ Pfr rhythm was at least as great as that for Pr→ Pfr, but the flowering response to far-red light was not rhythmic, nor was there any large change in sensitivity. The changes in photoconversion properties may reflect a basic biochemical oscillation which affects both photoreceptor properties and sensitivity to photoreceptor input. There was also a marked rhythm in the Pfr/P ratio that would be established by a saturating pulse of red light and this too may have affected the flowering response to such a pulse. Far-red light inhibited flowering when given at any time during the inductive night. After 14 h in darkness, Pfr could still be measured in the cotyledons and it was concluded that far-red light inhibited flowering by removing Pfr As red light also inhibited flowering at this time, there may be two pools of phytochrome with different kinetic properties. 相似文献
992.
DAVID C. HOCKIN 《Biological journal of the Linnean Society. Linnean Society of London》1979,12(3):277-288
The associations of the butterfly fauna of the Japanese islands of Hokkaido, Honshu, Kyushu, Shikoku and Ryukyu Rett are analysed with respect to one another and to the fauna of the far-east U.S.S.R. A faunal discontinuity exists between the fauna of Ryukyu Rett and all other areas. The fauna of Ryukyu Rett can be considered as being of the Oriental region, the faunas of the other Japanese islands as being of the Palaearctic region. This view was reinforced with conclusions drawn from MacArthus&Wilson's theory of island biogeography (1963, 1967). The divergence of die faunas of the Japanese islands is dependent on their isolation - the further the distance between islands, the greater the isolation and the greater the faunal divergence. Thus the fauna of all silands of Japan, except of the Ryukyu Rett, have a close association with the far-east Russian fauna. There is a greater similarity between these faunas than between the fauna of the islands of Hokkaido, Honshu, Kyushu and Shikoku with respect to that of Ryukyu Rett. 相似文献
993.
Growth patterns of Japanese schoolchildren in Hawaii, composed of 2,954 boys and 3,213 girls aged between 11 and 17, were compared with those comparable groups of Japanese schoolchildren in Japan based on the data published by the Japanese Ministry of Education. Growth characteristics studied were height, weight, and relative weight index, weight/(height). The Hawaii-Japanese boys were taller at early ages but the difference disappeared by age 16. Native Japanese girls were shorter than Hawaii-Japanese until age 13, but they overtook the latter by age 14, exceeding them in height after age 15. A similar pattern was found in weights of girls but the Hawaii-Japanese boys remained consistently heavier by 5.0 to 9.0 kg than native Japanese. The relative weight measure indicated that the Hawaii boys were more "obese" than native Japanese boys for the growth period studied; whereas the same tendency was maintained until age 15 in girls. These observations indicate a marked degree of convergence of the patterns of physical growth of the two populations, whose differences were unmistakably in favor of American born children in earlier studies. It is concluded that the convergence is due largely to the improved environmental conditions in Japan in recent years. 相似文献
994.
995.
Effects of habitat differences on feeding behaviors of Japanese monkeys: Comparison between Yakushima and Kinkazan 总被引:5,自引:0,他引:5
Feeding behaviors of Japanese monkeys (Macaca fuscata) were compared between a warm temperate habitat (Yakushima Island: 30°N, 131°E) and a cool temperate habitat (Kinkazan Island:
38°N, 141°E). The composition of diet and the activity budget in the two habitats were very different. Time spent feeding
on Kinkazan Island was 1.7 times that on Yakushima Island. Two factors seem to be responsible for these: (1) the energy required
for thermoregulation of monkeys on Kinkazan Island is greater than that on Yakushima Island; and (2) the food quality, which
affects the intake speed of available energy, is lower on Kinkazan Island. However, monkeys in both habitats increased their
moving time and decreased their feeding time when they fed on foods of relatively high quality. Such foraging strategies are
predicted by optimal foraging models. Time spent social grooming on Yakushima Island was 1.9 times that on Kinkazan Island,
although there were slight seasonal changes in both areas. The difference in time spent social grooming might be explained
by the overall difference in feeding time and day length between the two habitats. 相似文献
996.
Minoru Yoshida Hisayoshi Ohta Youji Yamaguchi Yukio Seki Morihisa Sagi Kentarou Yamazaki Yawara Sumi 《Biological trace element research》1998,63(2):167-175
Samples of liver, renal cortex, and medulla were obtained from 55 forensic autopsies (0- to 95-yr-old Japanese). Metallothionein
(MT) was determined by the Ag-hem or Cd-hem method. Zinc (Zn), copper (Cu), and cadmium (Cd) were determined by atomic absorption
spectrophotometry. The mean levels of MT were 250 μg/g in the liver, and 394 μg/g (cortex) and 191 μg/g (medulla) in the kidney.
Age-dependent changes were observed in both the liver and kidney. In the liver, MT level decreased during infancy and increased
thereafter with age. Similar age-dependent changes in the levels of Zn and Cu were observed. In the kidney cortex, MT level
increased with age, although no correlation was found after middle age. The levels of Cd and Zn also increased with age until
middle age; however, they decreased thereafter. These results suggest that age-dependent changes in renal MT levels are associated
with accumulation of Cd. 相似文献
997.
998.
Identification of the gene variations in human CD22 总被引:4,自引:0,他引:4
CD22, a member of the immunoglobulin superfamily, is a B-cell transmembrane glycoprotein that acts as an accessory-signaling
component of the B-cell antigen receptor (BCR). Recent evidence indicating the role of CD22 as a negative regulator of BCR
signal transduction prompted us to test the possibility that genetic variations of human CD22 may be associated with autoimmune diseases. In this study, variation screening of the entire CD22 coding region was performed,
and possible association with rheumatic diseases was tested, using the genomic DNA from 207 healthy Japanese individuals,
68 patients with systemic lupus erythematosus (SLE), and 119 patients with rheumatoid arthritis (RA). Through the variation
screening, seven non-synonymous and four synonymous substitutions were identified. In addition, single base substitutions
were found in two introns flanking exon-intron junctions. Among these variations, Q152E substitution within the second extracellular
domain was observed with a marginally higher frequency in the patients with SLE (3/68, 4.4%) than that in healthy individuals
(1/207, 0.5%) (P=0.048. SLE vs healthy individuals), although this difference was no longer significant after correction for the number of
comparisons (Pc=0.62). No significant association was observed between any of the variations and RA. These findings indicate that a number
of genetic variants are present in CD22, and suggest that CD22 could be considered a candidate for the susceptibility genes to autoimmune diseases.
Received: 14 July 1998 / Revised: 7 September 1998 相似文献
999.
1000.
Male dominance rank and reproductive success in an enclosed group of Japanese macaques: with special reference to post-conception mating 总被引:2,自引:0,他引:2
Miho Inoue Fusako Mitsunaga Masumi Nozaki Hideyuki Ohsawa Akiko Takenaka Yukimaru Sugiyama Keiko Shimizu Osamu Takenaka 《Primates; journal of primatology》1993,34(4):503-511
The mating behaviour and reproductive success of male Japanese macaques (Macaca fuscata) were studied in relation to the female sexual cycles, which were monitored from the plasma profiles of gonadotropins and
ovarian hormones. Based on observations of the mating behaviour during four successive mating seasons and paternity identification
by DNA fingerprinting in 35 out of 37 offspring born in the subsequent birth seasons, the correlations between (1) male dominance
rank and timing of mating, and (2) male dominance rank and reproductive success were examined. The results may be summarized
as follows. (1) The number of copulations with ejaculation by any male was positively correlated with the male dominance rank,
but not with the identified numbers of offspring fathered by each male. (2) Males could not choose ovulatory females as mating
partners: the number of copulations with ejaculation with females during ovulatory weeks was not related to the male's rank.
Monopolized copulations in consortship were mostly observed between high-ranking males and non-lactating parous females after
conception. (3) Paternity testing showed that the male copulating most frequently with a female was not the identified father
in 11 out of 15 cases. Prediction of the fathers of offspring was difficult even from the number of copulations occurring
at around the estimated time of ovulation. An adaptive explanation of these correlations is discussed. 相似文献