细胞生长自限,节律及宏大运动的研究

采用波动培养及显微培养技术实验研究细菌生长自限、节律及宏大运动的关系。分析了奇异变形杆菌生长节律性及自限产生的环境条件,自限细菌的形态特征及群体细菌宏大运动现象。结果表明细菌生长自限是群本细菌生和节律性及宏大运动的基础。     

细菌潜生体胞内节律振动对温度反应的研究

针对细菌潜生体胞内节律性振动对温度的反应性进行实验,以认识环境因素对波源（ＣｅｌＷａｖｅＯｒｉｇｉｎ）的影响,并进一步分析波源运动的机制。用相差显微镜油镜观察奇异变形杆菌（ＰｒｏｔｅｕｓＭｉｒａｂｉｌｉｓ）潜生体（ＣｒｙｐｔｉｃＧｒｏｗｔｈＣｅｌ,ＣＧＣ）菌落边缘,见到沿多个潜生体细胞长轴方向进行的快速黑白交替流动,温度升高时消失,温度降低时加剧。这种群体细胞在原位的同步节律性振荡是细胞在低温下发生胞内分子节律性凝结－溶解交替过程形成的,为一种胞内前分子马达的运动,我们称之为细胞波源     

低湿度培养诱生变形杆菌复杂群集运动增殖生长模式

探讨低湿度培养环境对奇异变形杆菌集群运动生长模式的影响。用含水量为90％的低湿度平板诱生群集运动增殖能力不同的内环与外环变形杆菌,通过菌落直径比值反映2种菌群集运动增殖能力差异。内环菌菌落直径较小,外环菌菌落直径较大,1、2,3代菌落直径比值分别为（1．83±0．17）、（3．71±0．12）、（4．51±0。12）。外环菌集群运动增殖速率大于内环菌,且有随着培养代数增多差异增大的趋势,直观反映了一种环境变化即可对系统产生巨大的影响。     

桧柏新类型塔柏生长节律的研究

本文应用数学模型及曲线图方法对桧柏新类型塔柏的生长节律进行了对比分析,揭示了塔柏的生长节律     

运动、自噬和瘦素抵抗

瘦素抵抗是人类肥胖症的主要危险因素,高瘦素水平未能抑制摄食和减轻体重,导致机体能量调节失衡。自噬是一种细胞质量控制机制,可对细胞内物质进行周转。许多人类重大疾病的发生与自噬过程有关,如肥胖症、糖尿病和神经退行性疾病等。当细胞自噬出现障碍即自噬缺陷时,会导致机体发生瘦素抵抗。研究发现,运动是维持细胞稳态的自噬有效诱导剂,机体瘦素敏感性的提高可能与运动促进细胞自噬有关,但目前尚缺乏直接证据。     

不同产地苦楝苗期生长节律研究

苦楝在我国分布广泛,具有丰富的遗传变异性。为进一步做好苦楝种源筛选和良种选育工作,该文对不同产地苦楝实生苗生长性状和各阶段的生长特点进行了比较分析,初步揭示了苦楝苗期生长规律。以15个产地的1年生实生苗为试材,对苗高、地径、复叶生长及生物量积累等生长性状进行了观测分析,并用Logistics方程对生长节律进行了拟合。结果表明:(1)不同产地苦楝苗高、地径生长差异均达显著水平,根生物量、茎生物量及复叶相关性状差异均达极显著性水平;(2)苗高和地径生长均呈现慢-快-慢的S型生长规律,且均存在2次生长高峰,与苗高生长高峰出现时间相比,地径生长高峰出现时间较晚;(3)Logistic拟合方程的R²为0.976～0.994,均达到极显著相关水平,说明可用Logistic方程拟合苦楝的生长节律;(4)总体上地径速生期较苗高速生期长20～30 d,北方产地苗高和地径进入速生期和结束速生期的时间均早于南方产地,速生期苗高和地径累积生长量均超过总生长量的60%;(5)各生长指标均与纬度负相关,苗高、生物量及复叶面积与经度正相关,其他指标与经度负相关。综上结果表明,苦楝为全期生长型树种,各生长性状在产地间达显著差异水平,生长受纬度和经度双重控制,以纬度控制为主。     

自噬介导运动改善心血管疾病的研究进展

心血管疾病是威胁人类健康的重要原因,其死亡率位于所有疾病死亡率的前列.运动作为一种非药物干预手段,可使机体产生代谢适应,保护心血管系统.细胞自噬是存在于真核生物和哺乳动物中的一种重要生物学现象,在维持细胞功能与内环境中发挥关键作用.研究表明,自噬异常与心血管疾病的发生发展密切相关.自噬水平过低或高都可能导致心血管疾病,...     

卡西亚松家系幼林的生长节律

为了解卡西亚松(Pinus kesiya)生长与气象因子间的关系,对17个卡西亚松家系幼林的周年生长性状进行研究。结果表明,17个卡西亚松家系的胸径、树高和抽梢次数存在显著差异(P0.05),可分为速生型(Ⅰ)和慢生型(Ⅱ),其中7、25、61、104、41家系属于速生型,其胸径和树高年均生长量分别为2.03 cm和1.46 m。两类型家系的生长趋势一致,胸径一年内出现2次生长高峰(2和8月),树高出现3次生长高峰(2-3、6和8-10月)。有3次抽梢高峰,分别在5月(春梢)、8-9月(夏梢)和11月(秋梢),一年抽1～4次新梢,以抽2次新梢的植株最多(47%),且在春(71.78%)夏(77.33%)两季抽梢的比例较高。月平均气温对卡西亚松树高的生长影响最大,在1月出现短暂的生长停滞。因此,卡西亚松幼林抚育管理宜在胸径和树高生长高峰之前进行,即5-6和12-翌年1月,1月进行幼林修枝抚育。     

大鵟夏季的活动及取食节律研究

大（Ｂｕｔｅｏｈｅｍｉｌａｓｉｕｓ）于夏季在栖落，梳羽，取食，扑翼飞行，滑翔和捕食上化费的时间分别占整个活动日（１５ｈ）的８１．０１％，８．８６％，４．３９％，３．０９％，２．２４％和０．４１％；从１３０块食物团的分析表明大的食物主要由高原鼢鼠（Ｍｙｏｓｐａｌａｘｂａｉｌｅｙｉ），根田鼠（ＭｉｃｒａｔｕｓＯｅｃｏｎｏｍｕｓ），高原鼠兔（Ｏｃｈｏｔｏｍａｃｕｒｚｏｎｉａ），雀形目小鸟及昆虫组成。一只大平均１ｄ吐１．５±０．６（ｎ＝７），相当于消耗１．６２只鼠。     

蜓日活动节律、食性及繁殖特征的初步研究

蜓白天有两个活动高峰期,第一个出现在８∶００－１２∶００,第二个出现在１６∶００－１８∶００。雨天蜓基本不活动。蜓属肉食性种类,其食谱包括几乎所有在其栖息地分布的陆生无脊椎动物。蜓胃内容物中各类无脊椎动物的数量百分比与栖息地陆生无脊椎动物不同种类数量百分比之间呈显著正相关,表明蜓的食物组成依赖于周围环境中的动物组成。蜓的性比♀／（♀＋♂）＝０７８,雌性个体显著多于雄性个体。雌性个体胎仔数平均６６１±０４３只。蜓捕获前的自然断尾率为２４１４％,表明蜓承受着较大的捕食压力。     

CIRCADIAN RHYTHM IN GROWTH AND DEATH OF ANABAENA FLOS-AQUAE (CYANOBACTERIA)

Circadian periodicity in cell division and death was investigated in the cyanobacterium Anabaena flos-aquae (Lyngb.) Bréb in a phosphorus (P)-limited, N₂-fixing chemostat culture. When entrained under 12:12 h LD cycles, not only cell division but also cell death showed a clear circadian rhythm in this filamentous cyanobacterium. The rhythm persisted under continuous light and was temperature compensated. Circadian rhythm was clearly observed in the steady-state cell number and instantaneous growth rate, μ(t), which reached a maximum at about 2 h before sunset and a minimum at about 2 h before sunrise. The number of dead cells and the instantaneous death rate γ(t) also showed a circadian periodicity; the peak of γ(t) occurred approximately 8 h before that of μ(t). Therefore, cell growth and death in A. flos-aquae appear to be under the control of circadian clocks, and thus it seems that their death is programmed cell death.     

侧金盏花成株年生长节律生理特性的研究

本文对侧金盏花成株两次生长两次休眠年生长节律的某些生理的月变化进行了研究。发现冬眠期和早春可溶性糖含量、可溶性蛋白质含量、脯氨酸含量、抗氰呼吸明显提高,入冬前淀粉酶活性提高,过氧化氢酶活性在寒冷和高温季节提高。在春天生长旺盛季节,淀粉在根中贮存量高达43%(DW)。     

高寒矮嵩草草甸禾草种群的生长发育节律及环境适应性

本文以矮嵩草(Kobresia humilis)草甸中草质优良,并在畜牧业生产中有重要作用的7种禾草为对象,研究了它们的生长发育节律、干重季节变化以及与环境因子之间的相互关系。其结果表明：7种禾草在矮嵩草草甸中的分布格局属非随机性的集中分布(Aggregated dispersal)。它们的生长发育节律和干重季节变化具明显的差异。单株分蘖数自返青开始随降水量、日照和≥3℃积温的增加而增加,到孕穗初期为最大。禾草种群生长发育的低温临界值为3℃。地上部分干重的积累与生长发育节律、≥5℃、≥10℃的积温,降水量和土壤含水量密切相关,生殖枝株高与≥10℃的积温密切相关。相关分析表明,温度是影响矮嵩草草甸禾草种群生长发育的主导因子(P<0.01),其次是降水量和土壤含水量(P<0.01) 。     

CIRCADIAN GROWTH RHYTHM IN JUVENILE SPOROPHYTES OF LAMINARIALES (PHAEOPHYTA)1

A circadian rhythm in growth was detected by computer-aided image analysis in 3–4-cm-long, juvenile sporophytes of the kelp species Pterygophora California Rupr. and in seven Laminaria spp. In P. californica, the free-running rhythm occurred in continuous white fluorescent light, had a period of 26 h at 10°or 15°C, and persisted for at least 2 weeks in white or blue light. The rhythm became insignificant in continuous green or red light after 3 cycles. Synchronization by white light-dark regimes, e.g. by 16 h light per day, resulted in an entrained period of 24 h and in a shift of the circadian growth minimum into the middle of the light phase. A morning growth peak represented the decreasing portion of the circadian growth curve, and an evening peak the increasing portion. The circadian growth peak was not visible during the dark phase, because growth rate decreased immediately after the onset of darkness. At night, some growth still occurred at 16 or 12 h light per day, whereas growth stopped completely at 8 h light per day, as in continuous darkness. During 11 days of darkness, the thallus area became reduced by 3.5%, but growth rate recovered in subsequent light–dark cycles, and the circadian growth rhythm reappeared in subsequent continuous light.     

香鼬的活动节律和巢区

本文采用无线电遥测技术对栖息在自然环境中香鼬（Ｍｕｓｔｅａｌａｌｔａｉｃａ）的活动节律及其巢区进行了较为系统的研究。结果表明,香鼬多营独居生活．除繁殖期外,无论雌雄个体均无长期稳定的巢穴,经常更换活动的位置。香鼬的每日活动主要为玩耍、自身的修饰、光浴、探视和取食,在繁殖期还有育幼及对幼鼬的保护。在不同时期香鼬日活动高峰和巢区大小均有不同。幼鼬出洞活动前,其亲体雌性成鼬活动呈现两个明显的高峰,１１：００～１３：００和１６：００～１７：００,雄性成鼬则只有一个活动高峰在１１：００左右;在这一时期,成体香鼬的地面活动高峰与其食物──高原鼠兔的地面活动高峰不相吻合,雌性成鼬的巢区面积为７．２１ｈａ,雄性成鼬的巢区面积为１１．７ｈａ。幼鼬出洞活动后,雌性成鼬的活动高峰为８：００～９：００和１７：００～１９：００,巢区面积平均为８２．７２ｈａ。幼鼬扩散期间;雌性成鼬的活动高峰期分别为８：００～９：００和１５：００～２０：００。在这两个时期。成体香鼬的地面活动高峰与高原鼠兔的地面活动高峰趋于一致。影响香鼬活动和巢区大小的主要因素是食物的丰富度、猎物的活动性和繁殖行为,同时种群密度也是主要因素之一。     

DIEL RHYTHM OF ALGAL PHOSPHATE UPTAKE RATES IN P‐LIMITED CYCLOSTATS AND SIMULATION OF ITS EFFECT ON GROWTH AND COMPETITION1

Oscillations in the phosphate (P_i) uptake rates for three species of green algae were examined in a P‐limited cyclostat. For Ankistrodesmus convolutus Corda and Chlorella vulgaris Beyerinck, the P_i uptake rates increased during the daytime and decreased at night. In contrast, Chlamydomonas sp. exhibited the opposite uptake pattern. Cell densities also oscillated under a light:dark cycle, dividing at a species‐specific timing rather than continuously. In general, the cell densities exhibited an inverse relationship with the P_i uptake rates. A competition experiment between A. convolutus and C. vulgaris in a P‐limited cyclostat resulted in the dominance of C. vulgaris, regardless of the relative initial cell concentrations. Chlorella vulgaris also dominated in a mixed culture with Chlamydomonas sp., irrespective of the initial seeding ratio and dilution rate. However, Chlamydomonas sp. and A. convolutus coexisted in the competition experiment with gradual decrease of Chlamydomonas sp. when equally inoculated. Mathematical expressions of the oscillations in the P_i uptake rate and species‐specific cell division gate were used to develop a simulation model based on the Droop equation. The simulation results for each of the species conformed reasonably well to the experimental data. The results of the competition experiments also matched the competition simulation predictions quite well, although the experimental competition was generally more delayed than the simulations. In conclusion, the model simulation that incorporated the effect of diel rhythms in nutrient uptake clearly demonstrated that species diversity could be enhanced by different oscillation patterns in resource uptake, even under the condition of limitation by the same resource.     

大熊猫的昼夜活动节律

本文采用无线电遥测、跟踪和直接观察等方法,研究了四川卧龙自然保护区野外5只大熊猫1981-1982年的昼夜活动。大熊猫昼夜有两个活动高峰,最高是18:00时,次高是04:00时;有两个低谷,最低是09:00时,次低是24:00时;年平均昼夜活动率为57-66%。     

ON THE GROWTH AND RESPIRATION OF SULFUR-OXIDIZING BACTERIA

1. It is shown that Sulfomonas thiooxidans oxidizes elementary sulfur completely to sulfuric acid. Sodium thiosulfate is oxidized by this organism completely to sulfate. Sulfomonas thiooxidans differs, in this respect, from various other sulfur-oxidizing bacilli which either produce elementary sulfur, from the thiosulfate, or convert it into sulfates and persulfates. 2. The organism derives its carbon from the CO₂ of the atmosphere, but is incapable of deriving the carbon from carbonates or organic matter. 3. The S:C, or ratio between the amount of sulfur oxidized to sulfate and amount of carbon assimilated chemosynthetically from the CO₂ of the atmosphere, is, with elementary sulfur as a source of energy, 31.8, and with thiosulfate 64.2. The higher ratio in the case of the thiosulfate is due to the smaller amount of energy liberated in the oxidation of sulfur compound than in the elementary form. 4. Of the total energy made available in the oxidation of the sulfur to sulfuric acid, only 6.65 per cent is used by the organism for the reduction of atmospheric CO₂ and assimilation of carbon. 5. Sulfates do not exert any injurious effect upon sulfur oxidation by Sulfomonas thiooxidans. Any effect obtained is due to the cation rather than the sulfate radical. Nitrates exert a distinctly injurious action both on the growth and respiration of the organism. 6. There is a definite correlation between the amount of sulfur present and velocity of oxidation, very similar to that found in the growth of yeasts and nitrifying bacteria. Oxidation reaches a maximum with about 25 gm. of sulfur added to 100 cc. of medium. However, larger amounts of sulfur have no injurious effect. 7. Dextrose does not exert any appreciable injurious effect in concentrations less than 5 per cent. The injurious effect of peptone sets in at 0.1 per cent concentration and brings sulfur oxidation almost to a standstill in 1 per cent concentration. Dextrose does not exert any appreciable influence upon sulfur oxidation and carbon assimilation from the carbon dioxide of the atmosphere. 8. Sulfomonas thiooxidans can withstand large concentrations of sulfuric acid. The oxidation of sulfur is affected only to a small extent even by 0.25 molar initial concentration of the acid. In 0.5 molar solutions, the injurious effect becomes marked. The organism may produce as much as 1.5 molar acid, without being destroyed. 9. Growth is at an optimum at a hydrogen ion concentration equivalent to pH 2.0 to 5.5, dropping down rapidly on the alkaline side, but not to such an extent on the acid, particularly when a pure culture is employed. 10. Respiration of the sulfur-oxidizing bacteria can be studied by using the filtrate of a vigorously growing culture, to which a definite amount of sulfur is added, and incubating for 12 to 24 hours.     

INFLUENCE OF DIETARY INTAKE AND PHYSICAL ACTIVITY ON ANNUAL RHYTHM OF HUMAN BLOOD CHOLESTEROL CONCENTRATIONS

Seasonal variation in the plasma total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) have been repeatedly reported, with contradictory results regarding the pattern of seasonal variation of these parameters. Furthermore, it is still not well established whether the variation is due to changes in the nutrition or changes in physical activity depending on the season. The aim of this study was therefore to determine plasma TC and HDL-C in different groups of healthy participants: 19 vegetarians with a constant diet independent of the season, 14 athletes with almost constant physical activity over the year, and 114 controls in the age groups 20–26 years (mean age 24+1.5 years) and 40–48 years (mean age 44.3+2.1 years). Over 2 years, blood samples were collected every 2–3 months and were analyzed for plasma TC and HDL-C. At all visits, body mass index (BMI) and waist-to-hip ratio (WHR) were calculated, and nutrition and physical activity profiles were obtained. The seasonal model was calculated using object-oriented software for the analysis of longitudinal data in S (OSWALD); multiple regression analysis was used to determine the influence of age, gender, diet, and physical activity on seasonal changes of the lipid parameters. In all groups, we found an annual rhythm of the plasma TC and HDL-C concentrations, which can be mathematically described by a sine curve with a maximum in winter and a minimum in summer. This rhythm was independent of the age, gender, BMI, diet, or physical activity. The observed seasonal differences between the maximum and the minimum were about 5%–10% for TC and about 5%–8% for HDL-C concentration. These differences were greater than the determined circadian (TC 3.5%, HDL-C 4%) and day-to-day changes for TC and HDL-C (coefficient of variation <5% for both). In conclusion, annual rhythm of TC and HDL-C is not primarily induced by seasonal differences in dietary intake or physical activity. Therefore, the annual rhythm in cholesterol levels is most likely determined by endogenous factors or factors directly related to seasonal changes in the environment. (Chronobiology International, 18(3), 541–557, 2001)     

产胞外黑色素菌株的筛选*

对不同来源获得的47株菌株在酪素培养基上生长、产色素情况进行了对比研究。从中选取了T4和Neurospora crassa AS3．1602,比较了二利用5种不同培养基产黑色素的能力。对T4菌株产生的黑色素做了初步研究,并初步鉴定T4菌株为奇异变形杆菌(Proteus mirabilis）。