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1.
本文对观赏植物异色芋(ColocasiaheterochromaH.LietZ.X.Wei)在昆明栽培环境下的生物学特性进行总结,为商品化栽培异色芋提供了理论依据,为其分类也提供了一定的有益补充。结果表明:一年生植株不开花,根茎也不产生分枝;二年生植株开花率为73.6%,根茎平均分枝3.6条。异色芋3月上旬开始萌动,7月中旬抽花梗,8月上旬开花,11月份地上部分枯萎,因此在昆明异色芋生育期约260d。 相似文献
2.
Shibao H Kutsukake M Fukatsu T 《Proceedings. Biological sciences / The Royal Society》2004,271(Z3):S71-S74
For evolution and maintenance of the social system of insect colonies, investment in the sterile caste should be adequately controlled in response to environmental cues. Recent developments using artificial diet rearing techniques have revealed an underlying mechanism of caste control in a gall-forming aphid, Tuberaphis styraci, which has a soldier caste in the second instar. Statistical analyses of field-collected galls detected a significant positive correlation between aphid density and soldier proportion in the natural colonies of T. styraci. Artificial diet experiments showed that soldiers are produced under crowded conditions. Detailed experiments demonstrated that soldiers are produced in a density-dependent manner rather than in a colony size-dependent manner. From these results, it was concluded that aphid density is the crucial cue that triggers soldier production in T. styraci. This study provides, to our knowledge, the first experimental demonstration of an environmental factor involved in aphid soldier differentiation. 相似文献
3.
Nakamura H Kouda K Fan W Takeuchi H 《Journal of PHYSIOLOGICAL ANTHROPOLOGY and Applied Human Science》2002,21(5):223-227
Previous studies have shown that mortality from cardiovascular diseases in fishing villages was lower than that in farming villages. In contrast, few reports on the population living in a tourist village have appeared. Then, we report here the characteristic features of a tourist town, and that in fishing and farming towns. The rural farming town in Gunma prefecture had a population of 15,100. The population working in the primary industry was 17.1%, and the farming population was 17.0%. The fishing town in Shizuoka prefecture had a population of 11,700. The population working in the primary industry was 11.0%, and the fishing population was 10.2%. The rural tourist town in Shizuoka prefecture had a population of 17,800. The population working in the tertiary industry was 60.2%, and the wholesaling or retailing population was 16.6%. Standardized mortality ratios of cardiovascular diseases in the tourist town reported by Shizuoka health officials were higher than the fishing town. The rate of participation at ages of 50-59 years for the basic health examination in the tourist town was lower than the fishing and the farming towns. From the results of the health examination of residents at ages of 50-59 years, the high prevalence of obesity and hypertension in men and high prevalence of hypertension in women were found in the tourist town. In the tourist town, self-employed women at ages of 50-59 years had irregular time of meals and insufficient care of diet in comparison with employed women. Furthermore, the prevalence of hypertension in self-employed women was also higher than that of employed women. We could suggest that health status in communities might be associated with job-related factors. 相似文献
4.
We investigated the mechanism underlying the control of soldier production in colonies of a social aphid, Tuberaphis styraci, which has a sterile soldier caste in the second instar. High aphid density was shown to induce soldier production in T. styraci. Analysis of natural colonies revealed that the soldier proportion tended to increase with aphid density but reached a plateau. Artificial diet experiments identified a similar plateau of soldier proportion under high-density conditions. In order to gain insights into the controlling mechanism of soldier production, the effect of soldiers on reproducing adult aphids was examined using the artificial diet system. It was experimentally demonstrated that soldier production was suppressed by coexisting soldiers, whereas coexisting non-soldiers facilitated soldier production. These results suggested that caste ratio in the colony of T. styraci is controlled by positive and negative feedbacks consisting of density-dependent induction and suppression of soldier differentiation. 相似文献
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6.
Shigeyuki Aoki Utako Kurosu Harunobu Shibao Seiki Yamane Takema Fukatsu 《Journal of Ethology》1998,16(2):91-96
The defensive behavior of the aphidDinipponaphis autumna, which forms small, completely closed galls on leaves ofDistylium racemosum, was observed. In mature galls, in addition to tens of mature or nearly mature aphids of the 3rd generation, there remained
3 – 17 1st-instar nymphs of the same generation, which had well-sclerotized legs and the antennae with developed setae. Despite
their minority, these 1st-instar nymphs clung to experimentally introduced insect larvae and stung them with their stylets.
Fourth-instar wingpadded nymphs, the majority of the 3rd generation at the experiment, also attacked the introduced larvae,
but they were readily spilt from the larvae. Four out of 205 1st-instar nymphs remaining in mature galls had the next instar
cuticle developing inside, indicating that they are not destined to be sterile. 相似文献
7.
Hirabayashi A Mukaiyama H Kobayashi H Shiohara H Nakayama S Ozawa M Tsuji E Miyazawa K Misawa K Ohnota H Isaji M 《Bioorganic & medicinal chemistry》2008,16(20):9247-9260
Spleen tyrosine kinase (Syk) and zeta-associated protein kinase of 70k Da (ZAP-70) are members of the Syk family and non-receptor-type protein tyrosine kinases, which play crucial roles in B- and T-cell activation. Therefore, a Syk family tyrosine kinases inhibitor would be a useful therapeutic agent for the treatment of various allergic disorders and autoimmune diseases. Previously, we reported that 1,2,4-triazolo[4,3-c]pyrimidine derivative 1 and 1,2,4-triazolo[1,5-c]pyrimidine derivative 2 showed strong inhibitory activities against Syk family kinases. These compounds also exhibited high-level suppression of IL-2 in cellular assays. However, their oral efficacies were poor in a mouse model of IL-2 production. To improve oral effectiveness, we investigated a new series of Syk family kinases inhibitors. We found that imidazo[1,2-c]pyrimidine derivatives potently inhibited the Syk family kinases. Among these agents, compound 9f not only showed strong inhibitory activities against Syk and ZAP-70 kinases in vitro, but its oral administration resulted in the in vivo suppression of both the passive cutaneous anaphylaxis reaction and Concanavalin A-induced IL-2 production in a mouse model. 相似文献
8.
Although the study of adaptation is central to biology, two types of adaptation are recognized in the biological field: physiological
adaptation (accommodation or acclimation; an individual organism’s phenotype is adjusted to its environment) and evolutionary–biological
adaptation (adaptation is shaped by natural selection acting on genetic variation). The history of the former concept dates
to the late nineteenth and early twentieth centuries, and has more recently been systemized in the twenty-first century. Approaches
to the understanding of phenotypic plasticity and learning behavior have only recently been developed, based on cellular–histological
and behavioral–neurobiological techniques as well as traditional molecular biology. New developments of the former concepts
in phenotypic plasticity are discussed in bacterial persistence, wing di-/polymorphism with transgenerational effects, polyphenism
in social insects, and defense traits for predator avoidance, including molecular biology analyses. We also discuss new studies
on the concept of genetic accommodation resulting in evolution of phenotypic plasticity through a transgenerational change
in the reaction norm based on a threshold model. Learning behavior can also be understood as physiological phenotypic plasticity,
associating with the brain–nervous system, and it drives the accelerated evolutionary change in behavioral response (the Baldwin
effect) with memory stock. Furthermore, choice behaviors are widely seen in decision-making of animal foragers. Incorporating
flexible phenotypic plasticity and learning behavior into modeling can drastically change dynamical behavior of the system.
Unification of biological sciences will be facilitated and integrated, such as behavioral ecology and behavioral neurobiology
in the area of learning, and evolutionary ecology and molecular developmental biology in the theme of phenotypic plasticity. 相似文献
9.
Itani H Ito H Sakata Y Hatakeyama Y Oohashi H Satoh Y 《Bioorganic & medicinal chemistry letters》2002,12(5):757-761
Novel benzo[a]cycloheptene derivatives were prepared for the purpose of searching new neuropeptide Y-Y5 (NPY-Y5) receptor antagonists. The structure-activity relationships are described and compound 2o (FR226928) showed the most potent affinity for Y5 receptor of all we prepared and was found to have higher potency and better selectivity for Y5 over Y1 receptor affinities when compared with the known lead compound 1. 相似文献
10.
广东省穿山甲种群数量调查与资源蕴藏量 总被引:4,自引:0,他引:4
20 0 0年 1 2月至 2 0 0 1年 3月 ,利用“洞口记数法”对大雾岭自然保护区穿山甲华南亚种的种群密度与种群数量进行了调查 ,结果表明 :保护区内穿山甲的种群数量为 65 2 7~1 5 6 5 9头 ,平均密度为 1 85~ 4 43ind /km2 ;不同栖息生境穿山甲的种群平均密度为 2 46~ 5 90ind /km2 ,密度大小依次为针阔混交林 >阔叶林 >灌木林 >针叶林。各栖息生境的洞口密度平均为 5 1 39± 1 8 31个 /km2 ,以针阔混交林的洞口密度最大 ,其次是阔叶林和灌木林 ,最小的是针叶林 ,且洞口密度大小存在极显著差异 (F =1 6 96>F0 0 1 ,3/30 =4 5 1>F0 0 1 ,3/36)。根据保护区内穿山甲的密度值 ,估计广东全省穿山甲的资源量为 1 42 73 0 9± 5 863 79头。 相似文献