EFFECTS OF ARTIFICIAL DAWN ON SUBJECTIVE RATINGS OF SLEEP INERTIA AND DIM LIGHT MELATONIN ONSET

The timing of work and social requirements has a negative impact on performance and well-being of a significant proportion of the population in our modern society due to a phenomenon known as social jetlag. During workdays, in the early morning, late chronotypes, in particular, suffer from a combination of a nonoptimal circadian phase and sleep deprivation. Sleep inertia, a transient period of lowered arousal after awakening, therefore, becomes more severe. In the present home study, the authors tested whether the use of an alarm clock with artificial dawn could reduce complaints of sleep inertia in people having difficulties in waking up early. The authors also examined whether these improvements were accompanied by a shift in the melatonin rhythm. Two studies were performed: Study 1: three conditions (0, 50, and 250 lux) and Study 2: two conditions (0 lux and self-selected dawn-light intensity). Each condition lasted 2 weeks. In both studies, the use of the artificial dawn resulted in a significant reduction of sleep inertia complaints. However, no significant shift in the onset of melatonin was observed after 2 weeks of using the artificial dawn of 250 lux or 50 lux compared to the control condition. A multilevel analysis revealed that only the presence of the artificial dawn, rather than shift in the dim light melatonin onset or timing of sleep offset, is related to the observed reduction of sleep inertia complaints. Mechanisms other than shift of circadian rhythms are needed to explain the positive results on sleep inertia of waking up with a dawn signal. (Author correspondence: m.c.gimenez@rug.nl)     

硅盐互作下小獐毛植物体内元素分布及生理特性的研究

 以新疆泌盐植物小獐毛(Aeluropus pungens)为材料,研究盐胁迫下小獐毛植物体元素吸收、分泌和过氧化物酶活性的变化以及硅对上述指标的影响。结果表明：在盐分胁迫下,其植物体钠离子浓度升高,钙元素含量降低,其它元素含量变化不明显。叶片硅元素含量随盐胁迫而增加。同时,当盐分浓度由0 mmol·L-1升至120 mmol·L-1浓度时,盐腺对各种离子的分泌作用表现为先加强（60 mmol·L-1）后降低（120 mmol·L-1）的趋势;其叶及根可溶性蛋白变化不明显,但过氧化物酶活性随盐胁迫而升高;可溶性蛋白含量叶片高于根部,而过氧化物酶活性根部高于叶片。同时盐胁迫对小獐毛根部及叶片含水量无明显影响。通过细胞化学定位结果显示, 小獐毛叶表富含硅元素,硅元素在叶表排列沿叶脉方向呈线性分布;在其叶片盐腺上,硅元素分布于帽细胞顶部,在此过氧化物酶（POD）活性也较强。元素分析结果显示,小獐毛体内富积硅元素。在较低的NaCl(60 mmol·L-1)浓度下,施用硅处理可减少叶片钠离子浓度,使地上部对钾、钠元素的相对选择性明显提高。在较高盐浓度（120 mmol·L-1NaCl）下,加硅对叶片钠离子浓度的降低作用效果不明显。在盐胁迫下,加硅未能减少根中钠离子浓度,但可明显增加叶片POD活性。实验结果表明,盐生植物小獐毛可通过维持体内含水量,调节植物体内元素分布以及增加POD活性适应一定程度的盐胁迫。同时低盐条件下施硅处理小獐毛根系培养环境可通过减少盐分向地上部的运输,增加叶片清除自由基的能力从而提高植物抗盐性。     

褪黑素对非生物胁迫下雨生红球藻中虾青素积累的影响

以雨生红球藻Haematococcus pluvialis LUGU株为研究对象, 研究在高光照和缺氮胁迫条件下, 添加不同浓度褪黑素(melatonin, MLT)对雨生红球藻生长、虾青素积累、活性氧(ROS)、信号分子及dxs基因表达量的影响。结果表明, 外源添加10 μmol/L MLT可有效提高藻细胞中虾青素的含量, 最高可达31.32 mg/g, 是对照组(13.27 mg/g)的2.36倍; 抑制了细胞内ROS水平, 上调了信号分子一氧化氮(NO)和水杨酸(SA)的含量; 此外, dxs基因表达水平比对照组明显提高, 最高达11.3倍。研究表明, 在非生物胁迫条件下, 雨生红球藻中虾青素的大量积累可能与外源MLT调控细胞内ROS、信号分子及基因表达有关。     

筋骨草素C在碱性条件下的脱水反应

具有较为特殊化学结构的蜕皮甾酮筋骨草素C,在碱性条件下发生脱水反应,这是一个较为少见的脱水反应。我们对此反应提出了一个可能的机制;并从热力学及分子轨道理论基础上作了一些定性解释。     

不同酸性条件对双歧杆菌存活的影响

以胡萝卜复合汁为保存基质,试验了不同的基质起始PH值、常用的酸味剂和盐酸、不同比例的乳酸乙酸混合酸对两歧双歧杆菌（Bb）和长双歧杆菌（Bl）存活的影响。结果表明,适于菌体存活的pH值,Bb为6．2,Bl为4．5～5．0;常用的酸味剂和盐酸对Bb存活的影响次序为柠檬酸＞盐酸＞乳酸＞乙酸,对Bl则为乳酸＞盐酸＞柠檬酸＞乙酸;对Bb和Bl存活最为不利的乳酸：乙酸（摩尔）比例分别为肝1:1和1:1．5.总体上,Bl的保存性优于Bb.     

红景天中药复方对低氧劳动能力的影响

我们研制了以藏产大花红景天为主要成分的中药复方用以提高机体的低氧劳动能力。在模拟海拔１００００ｍ的小鼠游泳实验中,药物组和对照组动物的存活时间分别为７３．２±３．８和６０．５±４．０ｍｍ（Ｐ＜０．０５）;游泳６０ｍｉｎ（相当于对照组的平均存活时间）以后死亡的百分数分别为５３．０％和３５．８％（Ｐ＜０．０５）。大鼠在模拟海拔５０００ｍ游泳１ｈ,药物组和对照组动物的血乳酸含量分别为１４．６±１．８和２１．１±１．９ｍｍｏｌ／Ｌ（Ｐ＜０．０５）。在模拟海拔４３００ｍ低压舱内人体运动负荷试验中,药物组和对照组受试者的ＰＷＣ１７０分别为９８０．４±５２．８和８６６．４±３０．０（Ｐ＜０．０１）。提示,红景天中药复方能明显提高低氧劳动能力。     

DIFFERENT RECOVERY METHODS AND MUSCLE PERFORMANCE AFTER EXHAUSTING EXERCISE: COMPARISON OF THE EFFECTS OF ELECTRICAL MUSCLE STIMULATION AND MASSAGE

In this study we assessed the influence of the three different recovery interventions massage (MSG), electrical muscle stimulation (EMS), and passive rest (PR) on lactate disappearance and muscle recovery after exhausting exercise bouts. Twelve healthy male sport students participated in the study. They attended the laboratory on five test days. After measurement of V.O₂max and a baseline Wingate test (WG_b), the three recovery interventions were tested in random counterbalanced order. High intensity exercise, which consisted of six exhausting exercise bouts (interspersed with active recovery), was followed by MSG, EMS or PR application (24 minutes); then the final Wingate test (WG_f) was performed. Lactate, heart rate, peak and mean power, rating of perceived exertion (RPE), and total quality of recovery (TQR) were recorded. In WG_f mean power was significantly higher than in WG_b for all three recovery modalities (MSG 6.29%, EMS 5.33%, PR 4.84% increase, p < 0.05), but no significant differences in mean and peak power were observed between the three recovery modes (p > 0.05). The heart rate response and the changes in blood lactate concentration were identical in all three interventions during the entire protocol (p = 0.817, p = 0.493, respectively). RPE and TQR scores were also not different among the three interventions (p > 0.05). These results provide further evidence that MSG and EMS are not more effective than PR in the process of recovery from high intensity exercise.     

半干旱生态条件下植物个体的综合生态效应的空间距离分布规律

通过对有关生态因子的空间距离变化规律的测定和引入相应的生态效应系数综合分析,得到在半干旱生态条件下植物个体的综合生态效应的空间距离分布规律为: E=α_1E_(1o)[1 (x/hc)~2]-3/2 (α_NE_(NO) α_WE_(WO))[1 (x/hr)~2]-3/2 (α_cE_(co) α_hE_(ho))[1 (x/hc)~2]-1/2由于具抑制效应的因子的生态效应随相对空间距离增加而减弱的速度大于其互惠效应的因子,在一定相对空间距离处(w/h=6.8)综合生态效应由干扰转变为互惠。定义了生态场的概念。     

饲料中添加壳聚糖季铵盐对凡纳滨对虾生长及非特异免疫的影响

实验研究壳聚糖季铵盐对凡纳滨对虾生长性能及非特异性免疫能力的影响。在饲料中分别添加0、0.05%、0.10%、0.15%和0.20%的壳聚糖季铵盐, 制成5组等氮等能饲料。将900尾[初体质量(3.820.34) g]健康的凡纳滨对虾随机分成5组(45尾4平行), 养殖时间56d。结果表明:饲料中添加壳聚糖季铵盐显著影响凡纳滨对虾的生长, 0.15%实验组凡纳滨对虾的增重率和特定生长率最佳(P0.05)。饲料中添加壳聚糖季铵盐0.1%、0.15%和0.20%能显著提高凡纳滨对虾血清溶菌酶和碱性磷酸酶及酚氧化酶的活性(P0.05)。饲料中添加壳聚糖季铵盐可显著提高凡纳滨对虾抗副溶血弧菌感染的能力(P0.05), 0.15%组的保护效果最好, 其相对免疫保护率为33.24%。壳聚糖季铵盐能显著提高凡纳滨对虾的生长性能和抗病能力, 本实验条件下适宜的添加量为0.15%。     

培养条件对养殖真鲷弧菌病病原菌毒素产生的影响

研究了温度、酸碱度、气体环境、营养成分及培养时间等培养条件对真鲷病原菌最小弧菌Vm-Pm毒素产生的影响。结果表明,温度对Vm-Pm毒素的产生有显著影响,在30℃培养时产生最高;当pH在弱碱性环境（7.2左右）时,Vm-Pm毒素产量最高;振荡通气能极大地促进Vm-Pm毒素的产生,显著提高其产量;Vm-Pm毒素的产量随着培养时间的延长而逐步增加,到36h即可达到最高水平,并维持至72h;改良海水营养培养基与普通海水营养培养基相比,更有利于毒素的产生,毒素产量可提高1倍。     

自然状况下头状沙拐枣对水分条件变化的响应

 对塔克拉玛干沙漠南缘沙漠-绿洲过渡带前沿人工植被头状沙拐枣(Calligonum caput-medusae)水分关系的研究表明：头状沙拐枣在生长季节中一直保持着正的膨压,水分亏缺的发展并不严重,植被所受水分胁迫在正常范围内,因而在现存条件下干旱引起的水分胁迫不足以威胁植被的存在。在生长进程中,随着环境胁迫的加剧,头状沙拐枣依然维持了比较高的水势和渗透势,实验结果也显示植株体内可溶性物质(NsDM)的累积程度并没有升高,因而其生理过程仍然在比较宽松的环境中进行。相对含水量（RWCp）在生长季节一直保持很高的水平,这对植株保持体内水分防止水分过度损失有利。头状沙拐枣在干旱胁迫下表现出的这些生理特点说明,植物对干旱环境的生理适应类型属于抵抗型。在叶水平上植株对干旱胁迫的水分生理适应主要表现为质外体水比例的增高,细胞壁弹性的增加,持续较高的相对含水量（RWCp）以及灌水后RWCp和枝条水分比值（WCsat）的增加上。夏季的引洪灌溉有助于头状沙拐枣水分状况的恢复,并很可能是植被免于严重水分胁迫的原因之一。     

EFFECTS OF NONRANDOM SEED ABORTION ON PROGENY PERFORMANCE IN PHASEOLUS COCCINEUS L

In this study, we sought to determine if Phaseolus coccineus normally aborts potentially viable seeds, and whether seed abortion is nonrandom with respect to progeny vigor. The ovaries of Phaseolus coccineus typically have six linearly arranged ovules. The three ovule positions at the stylar end are more likely to mature seeds than the three ovules at the basal end of the ovary. When we destroyed the developing ovules at the stylar end of the fruit after fertilization but before seed abortion, there was a significant increase in the probability that the ovules in the three basal positions would produce a mature seed. The probability of seed maturation in control fruits (no ovules destroyed) ranged from 38.3 to 42.7% over the three field seasons, whereas in the experimental fruits it ranged from 64.3 to 79.7% (similar to that of ovules at the stylar end in control fruits). We did not find any significant change in the probability of seed production in the three ovule positions in the stylar end of the ovary (the positions with high probability of seed maturation) when the basal ovules were experimentally destroyed. These results indicate that potentially viable seeds are regularly aborted in P. coccineus, with seed abortion more frequent in the basal ovule positions than at the stylar positions. In two greenhouse studies and one field study, we compared the vigor of progeny produced in the control fruits with the vigor of progeny produced in fruits where three ovules (either stylar or basal end) were destroyed. We found that the performance of the progeny from the three positions at the stylar end of the control fruits did not differ from the performance of the progeny from experimental fruits in which the three basal ovule positions were destroyed. In contrast, the progeny from the basal positions of the control fruits outperformed the progeny from the experimental fruits when the seeds were produced in the three basal ovules (stylar ovules destroyed). Our findings indicate that when the experimental treatment increased the probability of seed maturation, there was a significant decrease in the average vigor of the progeny in the remaining (basal) ovule positions.     

相同条件下的5种甘草中甘草酸含量的比较研究

通过双波长薄层扫描对同一生长环境下生长时间相同的5种甘草进行了甘草酸含量的分析、比较,并首次分析了采收时间对甘草中甘草酸含量的影响。同时通过HPLC法对刺果甘草进行了甘草酸的定性分析。为甘草的质量评价、采收时间及种间鉴别提供了依据。     

幼虫期食物量对致倦库蚊实验种群动态的影响

在室温26±1℃和相对湿度80%的条件下,以食物充足和食物缺少两种处理饲养致倦库蚊Culex quinquefasciatus Say幼虫.实验表明,幼虫期食物量不仅对幼虫有影响,而且对成蚊期一系列种群参数均有明显影响.净增殖率R₀、内禀增长能力r_m和有限速率γ降低,种群增长受抑制不仅是由于幼虫期食物量减少使幼虫发育速率减慢、存活率下降所致,且与成蚊的年龄特征存活率及年龄特征产雌率有关.各年龄组雌蚊所产的卵的孵出率随年龄的增长而下降,故以卵孵出数计算产雌率m_x所得的种群参数值较为客观,而以卵孵出率与年龄关系的回归方程校正以卵数计算的m.,同样达到上述目的.本文还提供广州致倦库蚊实验种群生命表特征的资料.     

溶氧水平对瓦氏黄颡鱼幼鱼静止耗氧率和临界游泳运动能力的影响

为了研究瓦氏黄颡鱼(Peltebagrus vachelli)在不同溶氧水平(DO)下的游泳运动能力、限制性机制及能量适应对策, 在25℃分别对不同溶氧水平(125%、100%、75%、50%和25% 空气饱和度)条件下瓦氏黄颡鱼幼鱼静止耗氧率、临界游泳速度(Ucrit)、活跃耗氧率进行了测定。研究发现瓦氏黄颡鱼的静止耗氧率随溶氧水平下降而显著下降(P2crit)为14.52%空气饱和度(1.16 mg/L)。当溶氧水平从100%下降到25%空气饱和度时, 其活跃耗氧率随溶氧的下降而显著下降(PPP<0.05)。研究结果提示: 在低氧条件下, 瓦氏黄颡鱼的临界游泳速度受中心的心鳃系统的限制, 而在常氧条件下,受外周的运动系统(肌肉组织)的限制。       

水流速度对黑鲷和美国红鱼续航游泳能力及生理代谢的影响

为了确保黑鲷(Acanthopagrus schlegeli)和美国红鱼(Sciaenops ocellatus)在开放海域的养殖产量和鱼类养殖福利,在20℃下,对体长差异性不显著(P>0.05)的两种鱼进行续航游泳能力测试。首先,确定不同流速下的耐力游泳时间,然后选择耐力游泳时间为150min时的速度进行续航游泳实验。其中黑鲷和美国红鱼分别被迫以3.15和4.32 BL/s的恒定游泳速度,进行0、30min、60min、90min、120min和150min的测试,解剖鱼获得肌肉、血液和肝脏,测定样品在6个时间点的代谢物浓度,每个时间点保证3组有效数据。对0和150min的实验组对比,结果显示,两种鱼肝糖原、背肌乳酸和血糖浓度差异显著(P<0.05),肌肉糖原浓度差异不显著(P>0.05)。双变量相关分析显示,随着疲劳程度增加,肝糖原浓度下降,背肌乳酸和血糖上升。灰度关联分析和主成分分析显示,血糖和肝糖原浓度是影响疲劳的主要因素,但黑鲷相比美国红鱼,其浓度变化范围更大。综上:(1)美国红鱼比黑鲷拥有更强的游泳能力,而且黑鲷和美国红鱼不适合养殖在流速超过3.15和4....     

半干旱生态条件下春小麦群体生态场的空间分布

在冠幅半径只有株距一半的三叶期,群体重庆场呈以每株立地点为峰顶的相对独立的小凸起,随着个体生长,拔节期群体的生态场成为一个稍见起伏的大凸峰,将行距加倍后,场强在行间出现明显的低谷;株距也加们后,在株间出现同样的低谷。群体的相对密度对其场强分布趋势起重要作用。由于边行效应使群体在发育后期边行的场强增高从而使群体强分布呈近似平顶凸起状。     

重力钝感的水稻突变体在重力和微重力条件下淀粉体的观察分析

植物向重性的研究一直受到关注,主要的研究集中在双子叶模式生物拟南芥中,而对单子叶植物的研究却很少。植物对重力感受的方式存在多种解释,但目前大量证据表明淀粉体—平衡石理论较为合理,它认为淀粉体作为平衡石在植物向重性反应中发挥了重要的作用。经过100多年的研究,现已从生理学与遗传学的角度证实了含有淀粉体的根冠中柱细胞和茎的内皮层细胞是植物重力感受的部位,淀粉体作为重力感受器被越来越多的实验证据证明。地球上重力无处不在,要研究微重力对植物体极性生长的影响只能借助于能模拟失重环境的回转器。近年来,人们对植物向重性机制的了解主要来自缺失或缺少     

EXPRESSION OF GENETIC VARIATION IN BODY SIZE OF THE COLLARED FLYCATCHER UNDER DIFFERENT ENVIRONMENTAL CONDITIONS

Heritability of body size in two experimentally created environments, representing good and poor feeding conditions, respectively, was estimated using cross-fostered collared flycatcher Ficedula albicollis nestlings. Young raised under poor feeding conditions attained smaller body size (tarsus length) than their full-sibs raised under good feeding conditions. Parent-offspring regressions revealed lower heritability (h²) of body size under poor than under good feeding conditions. Hence, as the same set of parents were used in the estimation of h² in both environments, this suggests environment-dependent change in additive genetic component of variance (V_A), or that the genetic correlation between parental and poor offspring environment was less than that between parental and good offspring environment. However, full-sib analyses failed to find evidence for genotype-environment interactions, although the power of these tests might have been low. Full-sib heritabilities in both environments tended to be higher than estimates from parent-offspring regressions, indicating that prehatching or early posthatching common environment/maternal effects might have inflated full-sib estimates of V_A. The effect of sibling competition on estimates of V_A was probably small as the nestling size-hierarchy at day 2 posthatch was not generally correlated with size-hierarchy at fledging. Furthermore, there was no correlation between maternal body condition during the incubation and final size of offspring, indicating that direct maternal effects related to nutritional status were small. A review of earlier quantitative genetic studies of body size variation in birds revealed that in eight of nine cases, heritability of body size was lower in poor than in good environmental conditions. The main implication of this relationship will be a decreased evolutionary response to selection under poor environmental conditions. On the other hand, this will retard the loss of genetic variation by reducing the accuracy of selection and might help explain the moderate to high heritabilities of body-size traits under good environmental conditions.