Cognitive inflexibility after prefrontal serotonin depletion

Serotonergic dysregulation within the prefrontal cortex (PFC) is implicated in many neuropsychiatric disorders, but the precise role of serotonin within the PFC is poorly understood. Using a serial discrimination reversal paradigm, we showed that upon reversal, selective serotonin depletion of the marmoset PFC produced perseverative responding to the previously rewarded stimulus without any significant effects on either retention of a discrimination learned preoperatively or acquisition of a novel discrimination postoperatively. These results highlight the importance of prefrontal serotonin in behavioral flexibility and are highly relevant to obsessive-compulsive disorder, schizophrenia, and the cognitive sequelae of drug abuse in which perseveration is prominent.     

Cretinism in rats: enduring behavioral deficit induced by tricyanoaminopropene

Rats reared on diets containing tricyanoaminopropene, the antithyroid compound that stimulates RNA synthesis, showed a deficit in performance on automated closed-field maze tests many weeks after discontinuation of the drug. The rats were also tested while still receiving the drug, and performance deficits were indicated in tests of Y-maze reversal and manual closed-field maze performance; rats treated with the drug and with thiouracil behaved in a highly similar fashion on several tasks. No evidence of facilitation by tricyanoaminopropene appeared in any of the eight learning situations used. Exposure to tricyanoaminopropene before and after birth, at doses sufficient to produce anatomical cretinism, apparently induces an enduring behavioral deficit which is similar to that of neonatal thyroidectomy-induced cretinism in rats and which parallels the mental retardation associated with human cretinism.     

Reversal learning and forgetting in bird and fish

Pigeons and goldfish were trained in red-green discrimination in daily sessions, with the rewarded color changed every 2 days. Improvement in the performance of the pigeons could be traced to decrements in retention from each day to the next. The goldfish showed no improvement and no decrements in retention. The results suggest that progressive improvement in habit reversal is a product of proactive interference, and that the absence of improvement in the fish is due, not to the lack of some higher-order process which operates to produce improvement in higher vertebrates, but to a difference in learning-retention mechanisms.     

侧柏等4树种在不同水分亏缺下恢复吸水能力的研究

以生长在呼和浩特地区的侧柏、杜松、沙棘、新疆杨为对象，研究其小枝在不同水分亏缺状态下恢复吸水能力，结果表明：（1）小枝重饱和初始水分亏缺（WSD）程度越大，重饱和相对饱和含水量（RSRWC）越小，失水后水分恢复能力也越低，树木组织受到的伤害越严重。（2）当树木失水达到初始失膨点饱和亏缺（SWDP^π）时，重饱和相对饱和含水量（RSRWC）接近于1，说明树木能恢复其所亏缺的水分，树木未受到脱水的伤害，能保持其原有吸水能力。     

Is face processing species-specific during the first year of life?

Between 6 and 10 months of age, the infant's ability to discriminate among native speech sounds improves, whereas the same ability to discriminate among foreign speech sounds decreases. Our study aimed to determine whether this perceptual narrowing is unique to language or might also apply to face processing. We tested discrimination of human and monkey faces by 6-month-olds, 9-month-olds, and adults, using the visual paired-comparison procedure. Only the youngest group showed discrimination between individuals of both species; older infants and adults only showed evidence of discrimination of their own species. These results suggest that the "perceptual narrowing" phenomenon may represent a more general change in neural networks involved in early cognition.     

Color-discrimination performance of pigeons: effects of reward

Performance of two pigeons given tasks in discriminating colors was examined on trials before and after they had occasionally received rewards for pecking when exposed to light of specific wavelengths. After a reward, the probability that the birds would respond to light svtimuli that were never rewarded was higher than before the reward was given, but paradoxically the birds showed no general decline in their ability to differentiate between stimuli at wavelengths 1 millimicron apart.     

Two magnetoreception pathways in a migratory salamander

Male eastern red-spotted newts (Notophthalmus viridescens) under controlled laboratory conditions exhibit unimodal magnetic compass orientation either in a trained compass direction or in the direction of their home pond. If the vertical component of the magnetic field is inverted, newts exhibiting the simple-compass response undergo a 180 degree reversal in orientation, whereas newts orienting in the home direction are unaffected by this treatment. These results indicate that newts use an axial compass mechanism for simple-compass orientation similar to that found in migrating birds. However, a distinct magnetoreception pathway with polar response properties is involved in homing and is possibly linked in some way to the navigational map.     

Extreme reversed sexual dichromatism in a bird without sex role reversal

Brilliant plumage is typical of male birds, reflecting differential enhancement of male traits when females are the limiting sex. Brighter females are thought to evolve exclusively in response to sex role reversal. The striking reversed plumage dichromatism of Eclectus roratus parrots does not fit this pattern. We quantify plumage color in this species and show that very different selection pressures are acting on males and females. Male plumage reflects a compromise between the conflicting requirements for camouflage from predators while foraging and conspicuousness during display. Females are liberated from the need for camouflage but compete for rare nest hollows.     

Trigeminal deafferentation and feeding in the pigeon: sensorimotor and motivational effects

The role of oral sensations in the control of hunger and thirst in the pigeon was studied in birds in which the trigeminal sensory nerves had been sectioned bilaterally. Trigeminal deafferentation, although it does not impair drinking, disrupts both the neurosensory and the motivational control of feeding behavior. These two types of deficit may be experimentally dissociated.     

调亏灌溉对蚕豆产量和水分利用效率的影响

通过大田试验,在甘肃秦王川灌区研究了调亏灌溉下蚕豆的产量、水分利用效率和经济效益,发现在苗期或拔节期轻度缺水条件下(土壤含水率为田间持水量的60%～65%),比充分灌溉条件下(土壤含水率为田间持水量的70%～75%)蚕豆增产14.05%和9.09%,节水10.92%和4.14%,经济效益提高16.16%和21.94%.因此认为,苗期或拔节期轻度水分亏缺是蚕豆调亏灌溉的适宜调亏时期和适宜调亏程度.     

不同水分亏缺对向日葵产量、水分利用效率及经济效益的影响

通过盆栽试验对向日葵进行不同水分亏缺处理,研究其产量、水分效应及经济效益的变化。结果表明,向日葵高水分处理的产量高于低水分处理,切不可在作物临界期进行水分亏缺,不可对作物3个生育期连续亏缺;适宜调亏灌溉可以提高向日葵水分利用效率;耗水量和产量有极大的相关性,随着耗水量的增多产量增大;在水资源充足的情况下,充分灌溉经济效益固然高,但在不能满足充分灌溉时,适宜水分亏缺可提高作物经济效益。     

Effect of Different Oligosaccharides on Immunity, and Cecal Microflora in Broilers

One hundred and forty-four Avin broilers (1 d old) were randomly divided into six treatments, with three replicates of eight birds each to investigate the effect of different oligosaccharides on index of immune organ, cecal weight and microflora in broilers. The control group (Group Ⅰ) was fed with corn-soybean meal as basal diet, and the trial groups (group Ⅱ, Ⅲ, Ⅳ, Ⅴ and Ⅵ ) were fed with basal diet plus 0.1% manoligosaccharides (MOS), 0.3% soybean-oligosaccharides (SBOS), 0.3% fructooligosaccharides (FOS), 0.3% α -glucooligosaccharides(α -GOS) and 0.03% chlortetracycline (CTC), respectively. The results showed that oligosaccharides supplementation significantly (P＜0.05) increased bifidobacteria concentration ofyoung broilers and did not affect on bifidobacteria or escherichia coli concentration of the birds ( P ＞0.05). Cecal weights of 21 d old broilers fed with FOS and α -GOS were significantly (P ＜0.05) increased, higher than those with MOS and SBOS, but addition of oligosaccharides had no effect on the birds. The effect of oligosaccharides on the cecal length was the same as on the cecal weights. Oligosaccharides supplement did not affect on indexes of immune organs.     

上海市奉贤区黄浦江水源涵养林鸟类调查

对上海市奉贤区黄浦江水源涵养林的4次野生鸟类调查结果表明:调查地区共有鸟类44种,分属7目17科;其中留鸟14种(31.8%),冬候鸟16种(36.4%),旅鸟7种(15.9%),夏候鸟7种(15.9%)。共记录到鸟类707只,其中留鸟308只(43.6%),冬候鸟344只(48.7%),旅鸟25只(3.5%),夏候鸟30只(4.2%)。迁徙鸟类的种类占68.2%,数量占56.4%。以迁徙鸟类为主的调查结果与上海市鸟类记录情况一致。调查期间还记录到上海市重点保护鸟类4种88只。     

亚麻油对中后期蛋用种公鸡抗氧化性能的影响

【目的】本试验旨在探讨日粮添加不同水平亚麻油对中后期蛋用种公鸡抗氧化性能的影响。【方法】选取96只399日龄蛋用种公鸡,随机分为4个处理,每处理6个重复,每个重复4只鸡,分别饲喂含不同水平亚麻油(0%、1%、2%和4%)日粮。预饲期7d,正式期28d。于试验期末,取血液、肝脏和睾丸,测定抗氧化指标。【结果】2%亚麻油组血浆、肝脏和睾丸中抗氧化酶活性显著高于对照组(P0.05),丙二醛(MDA)含量显著低于对照组(P0.05),4%亚麻油组抗氧化酶活性降低,MDA含量升高,但与对照组比差异不显著(P0.05)。【结论】日粮添加2%亚麻油可显著增强种公鸡机体抗氧化防御能力。     

甘蔗近缘种蔗茅(Erianthus fulvus)光合气体交换特性的差异分析

【目的】研究蔗茅无性系气体交换特性,筛选高光效种质资源,为开展高光效品种培育等相关研究奠定基础。【方法】在自然条件下,利用Li-6400便携式光合仪测定36份蔗茅种质资源的光合气体交换参数,如叶片净光合速率、气孔导度、胞间CO_2浓度、蒸腾速率、叶片饱和水汽压亏缺、蒸腾效率、叶片瞬时水分利用效率。【结果】36份蔗茅种质资源平均净光合速率为17.61μmol·m~(-2)·s~(-1),倍数变化为2.28;平均气孔导度为0.15 mol·m~(-2)·s~(-1),倍数变化为2.88;平均胞间CO_2浓度为163.49μmol·mol~(-1),倍数变化为2.29;平均蒸腾速率为2.17 mmol·m~(-2)·s~(-1),倍数变化为1.96;平均叶片饱和水汽压亏缺为1.38 MPa,倍数变化为1.60;平均蒸腾效率为124.43μmol CO_2·mol~(-1)H_2O,倍数变化为1.93;平均叶片瞬时水分利用效率为8.12μmol CO_2·mmol~(-1)H_2O,倍数变化为1.75。36份蔗茅无性系光合气体交换参数变异系数范围为11.79%—26.79%,其中,气孔导度变异系数最高(26.79%),净光合速率次之(21.48%),叶片瞬时利用效率最低(11.79%),36份蔗茅无性系光合气体交换参数间存在较大差异。净光合速率与蒸腾速率、气孔导度、叶片瞬时水分利用效率呈显著正相关,与叶片饱和水汽压亏缺呈显著负相关;气孔导度与胞间CO_2浓度、蒸腾速率呈显著正相关,与叶片饱和水汽压亏缺、蒸腾效率呈显著负相关。环境因子相关分析表明,叶片饱和水汽压亏缺与经度呈正相关,与海拔、纬度呈负相关,依据海拔划分为高海拔和低海拔,高海拔拥有相对较高的光合速率。进一步利用主成分分析选出2个主成分,方差累计贡献率达到89.79%,净光合速率、气孔导度、蒸腾速率即光合效率作为第一主成分的主导因子;胞间CO_2浓度、叶片瞬时水分利用效率、蒸腾效率即水分利用效率因子作为第二主成分的主要因子。36份蔗茅无性系材料可划分为五类,分别划分为光合效率高、较高、中、低、较低和水分利用效率高、较高、中、低、较低类5个类群。在聚类基础上进行逐步判别分析,7个光合气体交换参数有5个进入判别函数,建立了5个判别能力较高的判别模型,回判的准确率达97.22%。【结论】第Ⅳ大类群具有较高光合效率和较高水分利用效率,材料丰富,拥有较好的育种应用前景。     

几种杀菌剂对葡萄园典型陆生生物的初级风险评估

葡萄在种植过程中,易感染真菌性病害。即使有大量已登记的杀菌剂产品,仍有未登记的杀菌剂被用于防治或被推荐用于防治葡萄真菌性病害。未登记杀菌剂的施用是否会对葡萄园环境生物造成危害,需引起足够的关注。本研究选取葡萄上未登记但有残留检出或被推荐使用的杀菌剂三唑酮、乙霉威、四氟醚唑、吡唑萘菌胺、乙烯菌核利,对葡萄园环境生物鸟类、蜜蜂、非靶标节肢动物及土壤生物进行了初级风险评估。结果显示,三唑酮及四氟醚唑对鸟类的长期暴露风险商值大于1,风险不可接受;乙霉威对捕食性非靶标节肢动物的危害商值大于5,初级风险不可接受。吡唑萘菌胺及乙烯菌核利对所评估的陆生生物风险均可接受。本研究为所选杀菌剂在葡萄上的科学施用及后续的农药登记提供参考。     

Memory in the Japanese quail: effects of puromycin and acetoxycycloheximide

Intracerebral injections of puromycin produced memory deficits in naive quail trained to discriminate between red and green stimuli. Puromycin aminonucleoside, acetoxycycloheximide, and saline had no such effect. After a single reversal of the visual cues, naive quail treated with puromycin performed better than control birds. Also, puromycin had no effect on performance when injected into previously trained animals. High doses both of puromycin and acetoxycycloheximide inhibited ribonucleic acid and protein synthesis to a similar extent, while low doses of puromycin inhibited only protein synthesis. Since only puromycin inhibited memory, the basis for its effect appears more likely to be mediated by the action of peptidyl-puromycin rather than by the quantitative inhibition of macromolecular synthesis or by some nonspecific toxic action.     

河套灌区调亏畦灌对加工番茄生长发育、产量和果实品质的影响

采用大田畦灌试验,研究花期和坐果期分别实施67%和33%的灌水量对河套地区加工番茄生长发育、产量和果实品质的影响。结果表明:花期水分亏缺会使土壤电导率显著增大,而坐果期不明显。各调亏处理的硬度均显著增大,储藏性能得到了提高。调亏处理后口感品质指标(可溶性固形物、有机酸与糖酸比)和营养品质指标(维生素C、可溶性糖与番茄红素)平均值均高于充分灌溉处理,且随亏缺度加深而不同幅度增加,但只有可溶性固形物TSS和维生素C含量在重度亏缺时达到显著差异;在轻度亏缺下,坐果期处理优于花期,有效产量和水分生产率相对对照分别提高了10.25%和7.28%。在加工番茄果期实施67%灌水量的轻度亏缺,可以得到最高有效产量和水分生产率,且各外观品质、储藏品质、口感品质和营养品质均有所提高。     

不同水分处理对膜下滴灌棉花生理指标及产量的影响

20 0 0年 5～ 8月在新疆石河子炮台土壤改良试验站 ,进行了不同水分处理对膜下滴灌棉花生长和产量影响的研究。结果表明 ,为了获得较高的皮棉产量和水分利用率 ,膜下滴灌棉花全生育期的耗水量应在 345～380 m m;特定阶段和程度的水分亏缺虽然降低了总生物量 ,但提高了生殖器官在总生物量中的分配比例 ;与对照相比 ,苗期每次灌水推迟 2 d,蕾期恢复正常供水 ,花铃后期每次灌水推迟 2 d,是适合于当地膜下滴灌棉花需水规律的灌水模式     

冬小麦不同调亏量灌溉试验研究

用轻度、中度、重度三种不同调亏灌溉量,在冬小麦浇灌冻水和拔节水时进行调亏处理,结果显示,重度调亏处理在比正常灌水量减少40%的情况下,产量、千粒质量和穗粒数均低于对照,分别比对照减少56.25 kg、6.2 g和5.7粒;中度调亏处理在比正常灌水量减少25%情况下,产量、穗粒数也呈下降趋势,但差异不明显;轻度调亏处理在比正常灌水量减少15%情况下,产量、千粒质量、穗粒数等项指标或高于对照或等同于对照。