Conditioned "anxiety" and punishment effects on operant behavior of goldfish (carassius auratus)

Hungry goldfish learned to press a lever for worms on a 2-minute variable-interval schedule of reinforcement. Lever pressing was suppressed in the presence of a flashing light by (i) pairing the light with a brief electric shock ("anxiety") and (ii) punishing the lever-pressing behavior with electric shocks.     

Puromycin and retention in the goldfish

A first experiment compared the behavior of goldfish injected with puromycin immediately after each of a weekly series of brief discriminative training sessions in the shuttlebox to that of appropriate controls. Discrimination was not prevented, nor was escape from shock impaired, but probability of response to the conditioned stimuli, both positive and negative, was reduced substantially. These results suggest that puromycin interferes with the consolidation of conditioned fear. The null outcome of a second experiment, in which all training was given in a single long session instead of a series of short sessions, suggests (contrary to recent indications) that consolidation begins in the training session. The conditioned-fear hypothesis is supported by the results of a third experiment in which the animals were shocked upon entering a goalbox to which they had previously learned to swim for food; animals injected with puromycin, immediately after the shock, entered the goalbox more readily 1 week later than did appropriate controls.     

Olfactory plasticity is regulated by pheromonal signaling in Caenorhabditis elegans

Population density-dependent dispersal is a well-characterized strategy of animal behavior in which dispersal rate increases when population density is higher. Caenorhabditis elegans shows positive chemotaxis to a set of odorants, but the chemotaxis switches from attraction to dispersal after prolonged exposure to the odorants. We show here that this plasticity of olfactory behavior is dependent on population density and that this regulation is mediated by pheromonal signaling. We show that a peptide, suppressor of NEP-2 (SNET-1), negatively regulates olfactory plasticity and that its expression is down-regulated by the pheromone. NEP-2, a homolog of the extracellular peptidase neprilysin, antagonizes SNET-1, and this function is essential for olfactory plasticity. These results suggest that population density information is transmitted through the external pheromone and endogenous peptide signaling to modulate chemotactic behavior.     

Magnesium pemoline: effect on avoidance conditioning in rats

Rats administered 20 milligrams of magnesium pemoline per kilo gram of body weight learned to avoid shock in a jump-out apparatus in fewer trials than did controls. However, the results suggested that the principal effect of the drug was to facilitate the avoidance behavior of those animals that tended to "freeze" in response to electric grid shock. No differences in retention were observed between experimental and control animals that had achieved equal levels of learnine.     

灰潮土 Cd Pb复合污染对萝卜产量品质和矿质元素吸收的影响

以C d、Pb为胁迫因子,以白萝卜为对象,采用盆栽试验方法,研究了武汉市灰潮土受重金属污染后对萝卜产量、品质和矿质元素吸收的影响。结果表明,C d处理降低萝卜的生物产量,Pb处理增加其产量;C d和Pb能显著降低萝卜体内维生素C的含量,且C d对维生素C含量的影响比Pb大;C d、Pb单独作用对萝卜含糖量有显著增加作用,但C d、Pb复合在一定程度抑制萝卜体内糖分的形成和积累;萝卜根和叶中C d、Pb含量均与污染土壤中C d、Pb含量成正相关。Pb的存在能促进萝卜对C d的吸收,而C d的存在抑制萝卜对Pb的吸收。C d、Pb对其他矿质元素吸收存在不同程度的影响,且在作物不同部位影响的主要元素也不尽相同。     

芜菁营养生长期叶片光谱特性及对氮的敏感性

【目的】分析芜菁营养生长期叶片光谱反射率对N的响应,研究采用叶片光谱指数诊断N敏感时期,为新疆芜菁简便快捷的非破坏性N营养诊断提供最佳时间窗。【方法】利用Unispec-SC光谱仪测定不同芜菁幼苗期、叶片生长旺盛期、肉质根生长盛期、成熟期叶片的光谱反射率。【结果】芜菁营养生长期叶片光谱反射率波动取决于波长,在可见光波段的变异最小。芜菁营养生长期不同发育阶段光谱指数(ND₇₀₅)之间均存在显著差异(P＜0.05)或者极显著差异(P＜0.01)。【结论】叶片生长旺盛期为长黄蔓菁、新星圆蔓菁、美国小芜菁、天地禾芜菁氮素光谱营养诊断的敏感时期,叶片生长旺盛期与肉质根生长盛期为新星圆蔓菁(二代)氮素光谱营养诊断的敏感时期。幼苗期和成熟期可以作为区分几个品种芜菁氮素光谱营养诊断的敏感生育期。     

芫根粗总皂苷对糖尿病小鼠的降血糖作用

【目的】研究芫根粗总皂苷（ST）对四氧嘧啶所致糖尿病小鼠血糖的影响。【方法】以体积分数 70%乙醇加热提取芫根,并分别以石油醚和正丁醇萃取,得到芫根ST,测定正丁醇萃取相中总皂苷的含量;给昆明小鼠尾静脉注射 85 mg/kg 四氧嘧啶,建立糖尿病小鼠模型;用剂量为 500和1 000 mg/kg的ST对糖尿病小鼠灌胃7 d后,测定初始空腹血糖和最终空腹血糖,并在试验结束时处死小鼠,取胸腺、肝脏、脾脏和肾脏组织称质量计算脏器指数,分析ST对糖尿病小鼠口服耐糖量（OGTT）的改善情况。【结果】正丁醇萃取物中总皂苷的质量分数为（31.5±1.7）%（以薯蓣皂苷元计）;ST 500和 1 000 mg/kg灌胃组糖尿病模型小鼠在连续给药7 d后,小鼠血糖显著降低（P＜0.05）,并且其脏器指数得到了明显改善;500 mg/kg剂量的ST可以显著提高糖尿病模型小鼠的耐糖量。【结论】芫根粗总皂苷可显著降低四氧嘧啶致糖尿病小鼠的血糖。     

白菜型冬油菜铁超氧化物歧化酶（Fe-SOD） 基因的克隆及表达分析

【目的】了解SOD酶蛋白家族Fe-SOD在超强抗寒冬油菜中的表达情况及其在低温胁迫下的作用。【方法】采用RT-PCR技术克隆超强抗寒白菜型冬油菜陇油7号Fe-SOD的cDNA序列。对该序列进行生物信息学分析,采用半定量以及相对定量RT-PCR研究Fe-SOD在低温胁迫下的表达模式,采用氮蓝四唑（NBT）光还原法测定冬油菜叶片和根中的总SOD酶活性。【结果】获得Fe-SOD,GenBank登录号为KF178713,该基因cDNA片段全长645 bp,包含一个639 bp完整的开放阅读框,编码212个氨基酸的蛋白质,与白菜(Chiifu)的蛋白质氨基酸序列同源性高达99%。该基因编码的酶蛋白是1个主要由α-螺旋组成的亲水性稳定蛋白,无信号肽,无跨膜结构域。Fe-SOD表达模式分析显示初期低温胁迫下（4℃）,该基因上调表达,继续低温胁迫处理（-4℃和-8℃）,Fe-SOD表达量受到抑制。总SOD酶活性测定显示冬油菜根中酶活性高于叶片,以利于冬油菜安全越冬。【结论】从白菜型冬油菜克隆的Fe-SOD具有已知物种Fe-SOD的特征。Fe-SOD在冬油菜品种陇油7号抗寒过程中起作用。     

盐胁迫对芜菁种子萌发的影响

[目的]盐胁迫对芜菁种子萌发的影响,为芜菁栽培土壤选择及抗盐品种的选育提供理论依据.[方法]实验设置5个NaCl浓度梯度20、50、100、150和200 mmol/L和5个Na<,2>SO<,4>浓度梯度10、50、100、150和200mmol/L,对芜菁种子进行盐胁迫处理,测定其种子发芽率、发芽势、发芽指数和活力指数等.[结果]在NaCl浓度低于150 mmoL/L时,芜菁种子的发芽率、发芽势、相对盐害率与对照差异不大,在浓度为200 mmol/L时受抑制较大,150 mmol/L NaCl溶液适合于芜菁种子耐盐性的选择;在Na<,2>SO<,4>浓度低于100 mmol/L时对芜菁种子萌发的抑制作用相对较小,当超过150 mmol/L时出现明显的抑制作用,种子的萌发、相对活力指数等指标均呈明显下降的趋势.[结论]盐胁迫对芜菁种子萌发有明显抑制效应,而且随着盐浓度的增加,发芽率、发芽势、相对活力指数逐渐降低、相对盐害率升高,芜菁种子在萌发期间具有一定的耐盐性.     

外源MeJA对芜菁幼苗生长及抗氧化酶活性的影响

【目的】研究外源茉莉酸甲酯(MeJA)对芜菁幼苗形态指标及抗氧化酶活性的影响,为茉莉酸参与芜菁抗逆机理提供理论参考。【方法】以温州盘菜和卡玛古两个商业品种的芜菁作为材料,将萌发的芜菁种子培养于添加不同浓度MeJA的1/2MS培养基中,7 d后测定芜菁幼苗的生长指标、渗透调节物质含量、抗氧化酶活性等生理指标。【结果】随着MeJA浓度增加,芜菁幼苗长度及干、鲜重呈降低趋势,叶片中SOD活性先升高后降低,POD、CAT、APX活性逐渐增高,渗透调节物质可溶性糖、可溶性蛋白、脯氨酸含量逐渐增高,MDA、H₂O₂和O₂·^-含量逐渐增高,叶绿素含量逐渐降低。【结论】施加外源MeJA增加了芜菁幼苗的抗氧化酶活性,降低了芜菁幼苗的生长指标,抑制了幼苗的生长。     

七种常用杀虫剂对菜缢管蚜毒力测定

本试验用乐果、辛硫磷、杀灭菊酯、氯氰菊酯、好年冬、辟蚜雾和鱼藤精等7种常用杀虫剂对广东5个市县的菜缢管蚜进行毒力测定。试验结果说明不同用药水平地区的蚜虫种群抗药性有差异。并筛选出3种较高效杀虫剂。     

降温处理对白菜型油菜品种抗寒生理指标的影响

研究了零上低温处理对白菜型油菜品种抗寒生理指标的影响。结果表明,在10℃以下,各品种伴随着叶片含水量的下降,丙二醛(MDA)含量和膜透性显著增加,可溶性糖和游离脯氨酸含量急剧上升,其中876、天油2号、渭原冬油菜和陈家咀品种(系)表现出较强的抗寒性。相关分析结果表明,总含水量和可溶性糖含量与越冬存活率关系密切。     

Comparison Between a Tetraploid Turnip and Its Diploid Progenitor（Brassica rapa L.）：The Adaptation to Salinity Stress

Polyploidy is pursued in plant breeding programs due mainly to its ability to yield larger vegetative or reproductive organs. In controlled growth chamber experiments, a tetraploid turnip (cv. Aijiaohuang, 4n) and its diploid progenitor (cv.Aijiaohuang, 2n) were evaluated for their tolerance to salinity stress via investigations on a group of physiological parameters. The results indicate that the tetraploid turnip exhibit better adaptation to a high concentration salt medium(200 mmol L-1), as evidenced by a less-affected germination rate and a healthier morphological appearance at the seedling stage. Furthermore, an extension of salinity stress up to a certain period of time at the 5-7-leaf stage shows differences between the tetraploid turnip and its diploid progenitor. The former had a higher K+/Na+ ratio in the roots, higher glutathione concentration and antioxidant activities in the leaves, and smaller reductions in photosynthetic capacity in terms of leaf chlorophyll content. Studies on the differences between an autopolyploid and its respective relative, from which the autopolyploid originated, in terms of their tolerance to salinity and/or other abiotic stresses, have remained rather limited. The comparison is interesting due to a homogenous genetic background.     

不同来源地芜菁农艺性状分析

【目的】研究芜菁种质资源农艺性状分析为芜菁新品种选育,提高芜菁种质资源研究和利用率提供科学依据。【方法】收集30份芜菁种质资源为材料,对其35个农艺性状进行了调查,并进行Q型聚类分析和相关性分析。【结果】不同种源地的芜菁农艺性状差异较大、类型丰富,其中株高极差为44.48 cm,变异系数达到24.91%,单株重极差为410.00 g,变异系数达37.55%;Q型聚类分析表明:30份材料可分为典型的三大类,6亚类,第Ⅰ类分为2个亚类,共计6个品种;第Ⅱ类分为2个亚类,共计15个品种;第Ⅲ类分为2个亚种,共计9品种;相关性分析结果表明,单株重与株高、叶长、叶宽、根长、根宽、根皮厚呈极显著正相关,大多数的农艺性状之间都是呈相关性的,并且正相关和负相关都有。【结论】不同来源地的芜菁农艺性状差异较大,不同种源地的芜菁株高、单株重、叶形、根形等35个农艺性状指标进行Q型聚类分析,可分为三类,芜菁主要是绿皮白肉型品种,大多数的农艺性状之间都是呈现相关性的。     

Memory and hibernation in Citellus lateralis

Squirrels learned to escape from a water bath by making a visual discrimination. Twenty-four hours after reaching criterion for learned behavior, the animals were exposed to the first of two 11-day cold exposures. The animals that hibernated had better retention of the learned behavior.     

白菜型冬油菜品种的抗寒性及其生理生化特性

研究了8个白菜型冬油菜品种在越冬过程中叶片的超氧化物歧化酶（SOD）活性、过氧化物酶（POD）活性、游离脯氨酸含量、可溶性蛋白含量、可溶性糖含量变化及其与品种抗寒性的关系。结果表明：整个越冬期间，各品种的酶活性、可溶性物质含量的变化趋势基本一致，但变化幅度各品种之间有差异，表现为越冬率高的品种酶活性较高、可溶性物质含量较高。其中POD活性、可溶性蛋白含量、可溶性糖含量与品种抗寒性关系密切，在不同低温条件下可以作为选择抗寒性品种的指标。     

Phenocopies of pigmentary and behavioral effects of the yellow mutant in Drosophila induced by alpha-dimethyltyrosine

alpha-Dimethyltyrosine induces a phenocopy of the body color mutant yellow when fed to larvae of Drosophila melanogaster. The compound also induces changes in male courtship behavior which are similar to the effects of the mutant gene.     

Distribution of phytophagous insects on oilseed crucifers under conditions of a dry vegetation period

The species composition and distribution of the main pests on rapeseed with three planting dates, Indian mustard, and spring turnip rape are studied under conditions of a dry and hot vegetation period. It is suggested to use leaf turnip for turnip flea beetles and early-planted rapeseed for pollen beetle as trap crops.     

牛双芽巴贝斯虫热休克蛋白基因外显子的克隆与原核表达

从患牛焦虫病的牛全血样品中抽提总RNA,通过设计特异性引物,经RT-PCR扩增牛双芽巴贝斯虫热休克蛋白20（HSP20）基因的外显子,将其插入pMD18-T载体进行测序、鉴定,构建原核表达质粒载体PGEX-4T-2-HSP20（exon）。试验结果显示牛双芽巴贝斯虫HSP20基因外显子已被成功克隆。该基因的外显子序列与国际标准株HSP20外显子的序列存在两个碱基的突变,导致其编码的蛋白质出现了一个氨基酸的变异。测序结果还表明,克隆出的牛双芽巴贝斯虫HSP20基因外显子已正向插入原核质粒表达载体PGEX-4T-2,成功构建了PGEX-4T-2-HSP20（exon）表达载体,并在大肠杆菌BL21（DE3）中的得到表达。     

Puromycin effect on successive phases of memory storage

Mice injected bitemporally with puromycin 5 hours before training learned to escape or to avoid shock by choosing the correct limb of a Y-maze. When retested 15 minutes after training they had normal retention. In the ensuing 2(3/4) hours the animals injected with puromycin, unlike the controls, showed a progressive decrease of savings to less than 7 percent.