Visual-cliff preference by infant rats: effects of rearing and test conditions

In monocular tests, normally reared infant rats, aged 21 to 22 days, fail to show a side preference on the visual-cliff apparatus. Rats of the same age, but reared in an "enriched" environment, prefer the shallow side of the apparatus. In binocular tests, even normally reared animals prefer the shallow side, although experimentally reared animals show a stronger preference. The results appear to reopen the question of what cues are employed on the visual cliff.     

种内密度效应对豌豆蚜种群增长的影响

[目的]明确红色型和绿色型豌豆蚜(Acyrthosiphon pisum)的种群数量变化机制,探索2种色型豌豆蚜的种内密度效应对其种群增长的影响。[方法]在温室内设置不同的密度梯度,单种色型豌豆蚜密度设置为8、16、24、32头/株,2种色型共存时红色型和绿色型密度分别设置为4∶4、8∶8、16∶16头/株。[结果]单种色型豌豆蚜从密度8头/株增至32头/株时,随着密度的升高,2种色型豌豆蚜的产蚜期和寿命显著缩短,产蚜量显著降低,说明2种色型豌豆蚜种群密度效应均存在一定的负效应。在总密度为8和16头/株时,2种色型豌豆蚜混合饲养的产蚜期、寿命与单种色型饲养相比无显著差异;在单种色型饲养的密度与混合饲养的同一色型密度相同时,由于混合饲养的总密度高于单种色型饲养,混合饲养的产蚜期、寿命显著短于单种色型饲养,产蚜量显著低于单种色型饲养;在密度为32头/株时,单种群饲养的产蚜期、寿命、单头产蚜量与混合饲养时无显著差异。在单种色型饲养条件下,同一密度下(16头/株除外)红色型豌豆蚜的发育历期显著长于绿色型豌豆蚜,在相同密度条件下,红色型豌豆蚜的产蚜期、寿命、产蚜量与绿色型豌豆蚜相比无显著差异;混合饲养中,在同一密度条件下,红色型豌豆蚜的产蚜期、寿命、产蚜量与绿色型豌豆蚜相比无显著差异。[结论]红色型豌豆蚜在该环境条件下的竞争力与绿色型豌豆蚜相当,红色型豌豆蚜与绿色型豌豆蚜共存对环境表现了一定的适生性。     

Steady potential correlates of positive reinforcement: reward contingent positive variation

A positive reinforcement with food produced high-voltage bursts of alpha activity over the posterior marginal gyrus in a cat deprived of food and water. This synchronization was always associated with a large (180 to 300 microvolt), positive steady potential shift comparable to that occurring during the onset of sleep. Since this shift was contingent upon the relative appropriateness and desirability of food reward, it was termed reward contingent positive variation.     

Association of illness with prior ingestion of novel foods

Rats were permitted to ingest a novel food and a familiar food. One hour later they were x-irradiated. When they were subsequently allowed to choose between these foods, their preference for the novel food was less than that exhibited by appropriate controls.     

瓯江彩鲤体色与生长的遗传-环境互作分析

对五种体色的瓯江彩鲤进行稻田、网箱和水泥池生长对比试验,探讨体色与生长的遗传-环境互作。结果表明:瓯江彩鲤的体色与生长率存在一定程度的互作效应,在稻田中,“全红”和“麻花”彩鲤的生长率显著地高于其它三种体色(P<0.05);在网箱中,“大花”、“粉玉”和“粉花”彩鲤的生长率显著地高于“全红”和“麻花”彩鲤(P<0.05);在池塘中,“大花”彩鲤的生长率极显著高于其它四种体色彩鲤(P<0.01),而其它四种体色彩鲤的生长性能不存在显著差异(P>0.05)。由此认为,“全红”和“麻花”彩鲤比较适合稻田饲养,“大花”、“粉玉”和“粉花”彩鲤比较适合网箱或池塘饲养。“粉花”彩鲤与环境的互作效应最大。     

瓯江彩鲤体色与生长的遗传-环境互作分析

对五种体色的瓯江彩鲤进行稻田、网箱和水泥池生长对比试验,探讨体色与生长的遗传-环境互作。结果表明:瓯江彩鲤的体色与生长率存在一定程度的互作效应,在稻田中,“全红”和“麻花”彩鲤的生长率显著地高于其它三种体色(P<0.05);在网箱中,“大花”、“粉玉”和“粉花”彩鲤的生长率显著地高于“全红”和“麻花”彩鲤(P<0.05);在池塘中,“大花”彩鲤的生长率极显著高于其它四种体色彩鲤(P<0.01),而其它四种体色彩鲤的生长性能不存在显著差异(P>0.05)。由此认为,“全红”和“麻花”彩鲤比较适合稻田饲养,“大花”、“粉玉”和“粉花”彩鲤比较适合网箱或池塘饲养。“粉花”彩鲤与环境的互作效应最大。     

Early experiences accelerate maturation of the 24-hour adrenocortical rhythm

Rats reared under 12-hour alternating periods of light and dark were killed at times corresponding to the times at which the maximum or minimum plasma corticosterone concentrations occur in mature animals. The characteristic 24-hour adrenocortical rhythm was first observed in rats 21 to 25 days old. In rats handled or stimulated with electric shock, the rhythm developed as early as 16 days.     

哈尔滨道路绿地亮化光源对红皮云杉的影响

选择道路绿化生境相同、植株长势一致的红皮云杉作为样地供试材料,分别于不同颜色光源环境下,研究其净光合速率、蒸腾速率、叶绿素含量、干物重及叶色的变化,设其中无光环境为对照。结果表明,不同颜色光源以及光源距植物距离的不同对红皮云杉的光合生理影响不同,其中绿光对植株的影响最小,黄光和紫光对其影响较大。城市道路光源是影响红皮云杉生长的重要因素之一。     

Sex pheromone of the queen butterfly: biology

Males of the queen butterfly Danaus gilippus berenice, deprived of the two extrusible brushlike "hairpencils" at the rear of their abdomen, are capable of courting females but incapable of seducing them. In normal courtship, an aphrodisiac secretion associated with the hairpencils is transferred by way of tiny cuticular "dust" particles to the antennae of the females. Of the two substances identified from the secretion, one (the ketone) acts as the chemical messenger that induces the females to mate. The only known function of the other compound (the diol) is to serve as a glue that sticks the dust to the female. Males were reared under conditions in which they produced subnormal amounts of ketone and showed reduced seductive capacity. Under certain experimental circumstances, the competence of these males was restored by addition of synthetic ketone.     

Tracing food webs with stable hydrogen isotopes

The hydrogen isotopic content of an animal's food, not water, determines that animal's hydrogen isotopic content. Liver and muscle tissue from mice reared on a diet such that the ratio of deuterium to hydrogen (DIH) of their food and water was kept constant, have the same average D/H ratio as the food source. In a simple, natural population of snails and their possible algal diets, Littorina obtusata (northern Atlantic intertidal snails that feed almost exclusively on the brown alga Fucus vesiculosus) has the same D/H ratio as Fucus vesiculosis and not that of the other algae available to the snails.     

居住区楼间绿化对建筑采光条件影响的数字模拟研究

  目的  良好的建筑采光条件是保证居室卫生、改善小气候、提高居住环境舒适度的重要因素。研究楼间绿化对建筑采光条件的影响,分析其影响程度和具体影响因素,可以为北京市居住小区楼间绿地植物群落的优化构建、绿地环境与景观的改善提供科学依据。  方法  以北京地区居住小区多层住宅楼间绿地为对象,运用Photoshop、Image-Pro Plus及Rhino软件计算植物树冠疏透度并建立植物及建筑模型;使用Ecotect Analysis软件模拟北京市光照情况,通过分析样本大寒日楼间绿地北侧建筑受光面的日照情况,探究影响建筑采光的多种因素。  结果  （1）研究样本居住区绿化常用木本植物50种,植物组成结构中乔木比例高且生长量均处于较高水平。（2）建筑朝向对采光条件的影响表现为:正南正北朝向的建筑采光条件最佳;当建筑偏斜角度相同时,受北京地区经纬度影响,朝向偏东的建筑采光条件优于偏西的建筑。建筑受光面日照时数随建筑间距的减小、建筑长度的增加而降低。（3）调研样本普遍表现（85%）为绿化严重影响建筑采光,样本建筑受光面普遍受到较大面积的影响,日照时数显著减少,影响范围主要集中在1 ~ 4层;对建筑采光影响明显的楼间绿化,其主要特征表现为常绿树过多、植物体量过大、植物与建筑距离过近等;乔木与建筑的距离小于5 m时对建筑采光有较大影响,大于5 m时依然对建筑低层采光产生影响。  结论  （1）楼间绿化的基本特征表现为乔木种类较多,常绿树较少,而少量常绿树种的高频度应用是造成建筑采光条件受到不良影响的主要原因。（2）建筑布局本身存在影响建筑低层采光的情况。（3）楼间绿化显著影响建筑采光,主要影响因素为植物体量,其次是植物与建筑的距离以及植物树冠疏透度。      

粉垄活化资源构建绿色农业“3+1”产业体系的探讨

发明的农耕新方法——粉垄技术,利用自走式粉垄机械螺旋型钻头深垦深松土壤,它可比传统耕作加深1倍,且全耕层土壤均匀细碎疏松,扩建新的土壤“四库”(养分库、水库、氧气库和微生物库),在化肥农药、灌溉用水、人工投入等“三不增投”情况下,各种作物增产10％～30％(多个省水稻玉米小麦等粮食作物23个点专家测产平均增幅25.48％),提质5％,保水1倍,粉垄耕作一次之后2～3年可持续增产;比较效益可达20％左右.探讨提出粉垄活化耕地、盐碱地、草原和江河等资源,驱动构建绿色农业“3+1”产业体系,在中国甚至全球将可促进实现可利用农业资源总量、优质食物来源总量、可利用水资源总量“三个增加”,实现对生态环境恶化、气候变暖等“两个应对”,实现人类与自然更加和谐共生.     

Independence of short- and long-term memory: a neural system analysis

Rats were given electrical stimulation to the midbrain reticular formation or to the hippocampus 4 seconds after they received shocks contingent on the animals' bar-press responses. They were retested for memory of the shocks 64 seconds or 24 hours after the shocks. The animals that received stimulation to the midbrain reticular formation showed amnesia at the 64-second retest and memory at the 24-hour retest. In contrast, animals that received stimulation to the hippocampus showed memory at the 64-second retest and amnesia at the 24-hour retest. The data support a dual, parallel-processing model of memory.     

Ecological chemistry and the palatability spectrum

A new bioassay for comparing the palatability to avian predators of monarch butterflies reared on various asclepiadaceous food plants containing cardiac glycosides indicates a palatability spectrum. The monarchs reared on one plant species are six times as emetic as those fed another, while those raised on an asclepiad which lacks cardiac glycosides are not emetic at all.     

烟青虫幼虫味觉可塑性行为研究

[目的]研究烟青虫幼虫的可塑性行为,为害虫防治提供参考。[方法]采用行为试验双选法和切除味觉感受器研究了不同取食经历烟青虫5龄幼虫对取食抑制素的味觉可塑性行为。[结果]正常人工饲料饲养幼虫对取食抑制素十分敏感,切除了侧栓锥感受器的幼虫对取食抑制素的反应与正常幼虫相似,切除了中栓锥感受器的幼虫对取食抑制素不敏感。而用含有低浓度取食抑制素的人工饲料饲养的幼虫对取食抑制素不敏感。[结论]中栓锥感受器中含有对取食抑制素敏感的味觉神经元,不同取食经历的烟青虫幼虫对取食抑制素具有行为可塑性。     

在循环养殖系统中不同溶氧量对虹鳟幼鱼代谢水平的影响

在循环养殖系统中设置四种溶氧水平,分别为7.05、8.82、11.84和15.80 mg/L,其中8.82 mg/L为对照组,对虹鳟幼鱼（体长13.0-18.5 cm）的代谢水平及生长率进行了研究。结果表明,饲养30 d后7.05mg/L的低溶氧使虹鳟幼鱼耗氧率和排氨率下降,11.84和15.80 mg/L溶氧下饲养的鱼耗氧率明显增加,15.80 mg/L使鱼的排氨率显著高于对照组。并且11.84和15.80 mg/L组虹鳟幼鱼在24 h内都具有高的代谢水平。随着溶氧量提高,虹鳟幼鱼的增重率、特定生长率和饲料转化率均随之升高,表现出生长指标的明显变化。     

在循环养殖系统中不同溶氧量对虹鳟幼鱼代谢水平的影响

在循环养殖系统中设置四种溶氧水平,分别为7.05、8.82、11.84和15.80 mg/L,其中8.82 mg/L为对照组,对虹鳟幼鱼（体长13.0-18.5 cm）的代谢水平及生长率进行了研究。结果表明,饲养30 d后7.05mg/L的低溶氧使虹鳟幼鱼耗氧率和排氨率下降,11.84和15.80 mg/L溶氧下饲养的鱼耗氧率明显增加,15.80 mg/L使鱼的排氨率显著高于对照组。并且11.84和15.80 mg/L组虹鳟幼鱼在24 h内都具有高的代谢水平。随着溶氧量提高,虹鳟幼鱼的增重率、特定生长率和饲料转化率均随之升高,表现出生长指标的明显变化。     

Escape from self-produced rates of brain stimulation

Rats were allowed to self-stimulate while their responses were being recorded on tape. Subsequently, prerecorded patterns of their brain stimulation were "played back" to them. All subjects learned to escape brain stimulation delivered in exactly the same manner as they had previously elected to receive it.     

Selection of social partners as a function of peer contact during rearing

In the report "Selection of social partners as a function of peer contact during rearing" by C. L. Pratt and G. P. Sackett (3 Mar., p. 1133), the third sentence of the first paragraph should read as follows: "Monkeys reared in isolation tend to withdraw from other animals and huddle by themselves in social situations. If such animals prefer each other over more normal monkeys, they may not be effectively exposed to the stimuli which lead to some degree of social adjustment."     

Microwaves: effect on thermoregulatory behavior in rats

Rats, with their fur clipped, pressed a lever to turn on an infrared lamp while in a cold chamber. When they were exposed to continuous-wave microwaves at 2450 megahertz for 15-minute periods, the rate at which they turned on the infrared lamp decreased as a function of the microwave power density, which ranged between 5 and 20 milliwatts per square centimeter. This result indicates that behaviorally significant levels of heating may occur at an exposure duration and intensities that do not produce measurable changes in many other behavioral measures or in colonic temperature. Further study of how microwaves affect thermoregulatory behavior may help us understand such phenomena as the reported "nonthermal" behavioral effects of microwaves.