Schedule-induced behavior in rats: Pellets versus powder

Food-deprived rats develop polydipsia on an intermittent schedule (fixed time 60 sec) of food pellet delivery, but not on an identical schedule of food powder delivery. This result was demonstrated with separate groups receiving each type of food and was replicated using rats as their own controls. Powdered food not only prevented the development of polydipsia, but it abruptly terminated ongoing polydipsia in rats that were switched from the scheduled delivery of pellets to powder. Ethological analysis of the behavior showed that the rats receiving powder were not engaging excessively in some behavior other than drinking. After discounting several factors, we concluded that the amount of oral activity associated with feeding, which occurred immediately after food delivery, was reciprocally related to the level of drinking.     

Factors affecting schedule-induced wood-chewing in rats: Percentage and rate of reinforcement,and operant requirement

In Experiment 1, rats were allowed to acquire either schedule-induced drinking or schedule-induced wood-chewing behavior under a fixed-interval (FI) 60-sec schedule of food reinforcement, following which food was omitted from 20% and then 50% of interreinforcement intervals. Omission of food severely disrupted induced drinking but had relatively little effect on induced wood-chewing. Experiment 2 investigated wood-chewing as a function of reinforcement rate, using a range of FI schedules from 5 to 180 sec in duration. Both the amount of chewing per session and the relative time spent chewing were bitonically related to reinforcement rate. In Experiment 3, schedule-induced chewing that had been acquired under a response-dependent schedule was found to persist under a response-independent schedule. Induced wood-chewing resembles other induced behaviors in important respects, but quantitative differences are also apparent.     

Schedule-induced polydipsia contrast in the rat

Schedule-induced polydipsia was studied using a behavioral contrast paradigm. Food pellets were delivered to food-deprived rats on a response-independent FT 1-min schedule. Licking on a tube produced water on a MULT FR 10 FR 10, MULT FR 10 EXT, or MIXED FR 10 EXT for three rats (Experiment 1) and on a MULT VI VI, MULT VI EXT, or MIXED VI EXT schedule for three other rats (Experiment 2). On the FR schedules, rats could drink more water by increasing lick rates, but on the VI schedules the amount of drinking was fixed by the schedule parameters and was relatively unaffected by lick rates. Relative to MULT FR FR, positive polydipsia contrast was clearly demonstrated on MULT and MIXED FR EXT; but relative to MULT VI VI, contrast was not demonstrated on MULT and MIXED VI EXT. These data suggest that polydipsia contrast occurs only if increased licking permits increased drinking.     

Effects of pre-pregnancy body mass index and gestational weight gain on neonatal birth weight

To evaluate the effects of maternal pre-pregnancy body mass index (pre-BMI) and gestational weight gain (GWG) on neonatal birth weight (NBW) in the population of Chinese healthy pregnant women, attempting to guide weight control in pregnancy. A retrospective cohort study of 3772 Chinese women was conducted. The population was stratified by maternal pre-BMI categories as underweight (<18.5 kg/m²), normal weight (18.5–23.9 kg/m²), overweight (24.0–27.9 kg/m²), and obesity (≥28.0 kg/m²). The NBW differences were tested among the four groups, and then deeper associations among maternal pre-BMI, GWG, and NBW were investigated by multivariate analysis. NBW increased significantly with the increase of maternal pre-BMI level (P<0.05), except overweight to obesity (P>0.05). The multivariate analysis showed that both pre-BMI and GWG were positively correlated with NBW (P<0.05). Compared with normal pre-BMI, underweight predicted an increased odds ratio of small-for-gestational-age (SGA) and decreased odds ratio for macrosomia and large-for-gestational-age (LGA), and the results were opposite for overweight. With the increase of GWG, the risk of SGA decreased and the risks of macrosomia and LGA increased. In addition, in different pre-BMI categories, the effects of weight gain in the first trimester on NBW were different (P<0.05). NBW is positively affected by both maternal pre-BMI and GWG, extreme pre-BMI and GWG are both associated with increased risks of abnormal birth weight, and maternal pre-BMI may modify the effect of weight gain in each trimester on NBW. A valid GWG guideline for Chinese women is an urgent requirement, whereas existing recommendations seem to be not very suitable for the Chinese.     

建鲤苗种体长与体重关系数学模型的构建

利用建鲤实测体长和体重数据,应用统计分析方法进行体长一体重线性回归分析.结果表明:建鲤体长和体重之间呈曲线相关关系,其相关公式为:W=0.011L3.077(相关系数R=0.992 1),其中W为体重,L为体长.     

Effects of acute shock on body weight are mediated by changes in food intake

We examined the causal role of decreased food intake in the body weight pattern observed after exposure to intermittent footshock. In Experiment 1, relative to controls, shocked animals decreased food intake and lost weight in the 24-h test. An unshocked group whose food intake was yoked to the shocked group (food-yoked group) for the poststress period revealed that food intake was a sufficient cause of the body weight loss. In Experiment 2, after the first 24 h, the shock group recovered food intake and body weight gain but did not compensate for the initial losses. Body weights of food-yoked animals again indicated that food intake was a sufficient cause of these effects. The lowered body weight of shocked animals at the end of testing was due to a transient hypoingestion and a failure to subsequently show a compensatory hyperingestion. Dess’s (1991) regulatory shift hypothesis is refined in the light of these findings.     

草药牛蒡子对运动大鼠体重及力竭时间的影响

牛蒡子为常用中药在医药,食品业中的应用十分广泛.目前国内外对牛蒡子与运动关系的研究少见报道,所以我们建立运动动物模型,研究目的在于探计补充牛蒡子对运动大鼠运动能力和防御体系的影响,为将其用于运动员的食品中提供参考.     

Concurrent schedule responding as a function of body weight

Five pigeons pecked for food reinforcement on several concurrent schedules. Their body weights were varied from 80% to 110% of their free-feeding weights. A number of predictions of the equations proposed by Herrnstein (1970) were tested. As predicted, the relative rate of responding equalled the relative rate of reinforcement for all subjects, on all schedules, at all body weights. And, as predicted, the overall rates of responding on the components of a concurrent schedule were slower than the local rates of responding on the components of an identical multiple schedule. Contrary to prediction, the total rate of responding generated by the concurrent schedules did not increase with increases in the total rate of reinforcement they provided. And, contrary to prediction, the k parameter did not remain constant, and the R₀ parameter did not increase with increases in body weight. It was concluded that Herrnstein’s matching law and his interpretation of the m parameter are correct but that the interpretations of k and R₀ require further investigation.     

儿童人体数字化建模及其在校车座椅设计中的应用

为构建我国儿童人体数字化模型以促进儿童类产品的开发,提出了采用AIP软件平台创建儿童人体模型的思路及方法。该方法首先基于我国未成年人人体尺寸基础数据,构建了儿童人体iPart肢体参数化模型,进而通过iAssembly装配机制产生可实现参数驱动变换的不同年龄段所有标准百分位的儿童人体数字化模型。通过校车学生座椅系统人机工程设计应用,确定了校车座椅关键结构参数选择范围,完成了某校车小学生和幼儿学生座椅系统结构设计。座椅生产后依据校车座椅安全法规进行碰撞试验,试验结果达到法规要求,验证了基于该儿童人体数字化模型进行校车座椅设计的正确性和实用性,该模型及设计方法可为儿童安全座椅等其他儿童产品的人机工程设计提供一定参考。     

K+ +Al(Au)反应的B-E关联及其方向性

研究了250 GeV/c下K＋＋Al（Au）和K＋＋Au反应的B—E关联,用Q-νKν（Q）分布拟合实验数据得出r0=3.5fm（K＋＋Al）,4.1fm（K＋＋Au）.对同一实验,进一步分析B—E关联的角关系,得出a=0.53&#177;0.13fm（K＋＋Al）,0.33&#177;0.21fm（K＋＋Au）.在c,m,s系中,π介子发射源在碰撞轴方向被拉长.     

比体和赋体：象征性诗歌意象研究

象征性诗歌是以意象暗示、呈现象征意义的。其意象的构成方式主要有两种：一种是以意象与意象间具有的比喻关系构成的,即比体象征;一种是以意象的连续的铺展、延伸构成的,即赋体象征。这两种象征意象在诸多方面都存在着不同,弄清它们的构成方式及其特点,将有助于我们的诗歌创作和诗歌鉴赏。     

Effects of chromium nanoparticle dosage on growth,body composition,serum hormones and tissue chromium in Sprague-Dawley rats

This 6-week study was conducted to evaluate the effects of seven different levels of dietary chromium (Cr) (0, 75, 150,300, 450, 600, and 1200 ppb Cr) in the form of Cr nanoparticle (CrNano) on growth, body composition, serum hormones and tissue Cr in Sprague-Dawley (SD) rats. Seventy male SD rats (average initial body weight of (83.2±4.4) g) were randomly assigned to seven dietary treatments (n=10). At the end of the trial, body composition was assessed via dual energy X-ray absorptiometry (DEXA). All rats were then sacrificed to collect samples of blood, organs and tissues for determination of serum hormones and tissue Cr contents. The results indicated that lean body mass was significantly increased (P＜0.05) due to the addition of 300 and 450 ppb Cr from CrNano. Supplementation of 150, 300, 450, and 600 ppb Cr decreased (P＜0.05) percent body fat significantly. Average daily gain was increased (P＜0.05) by addition of 75, 150, and 300 ppb Cr and feed efficiency was increased (P＜0.05) by supplementation of 75, 300, and 450 ppb Cr. Addition of 300 and 450 ppb Cr decreased (P＜0.05) the insulin level in serum greatly. Cr contents in liver and kidney were greatly increased (P＜0.05) by the addition of Cr as CrNano in the dosage of from 150 ppb to 1200 ppb. In addition, Supplementation of 300, 450, and 600 ppb Cr significantly increased (P＜0.05) Cr content in the hind leg muscle. These results suggest that supplemental CrNano has beneficial effects on growth performance and body composition, and increases tissue Cr concentration in selected muscles.     

依托与依赖:独立学院与母体高校关系思辨

依托母体高校对于办好独立学院,对于推进我国高等教育大众化进程具有十分重要的意义,但一味依赖母体高校将给独立学院和母体高校的发展带来严重危害。对独立学院与母体高校二者的关系进行了剖析,并提出了正确处理依托关系的思路。     

低分子质量聚醋酸乙烯酯的合成与亲二氧化碳性能研究

为了提高碳氢类聚合物在二氧化碳中的溶解性能,通过合成2-丙酸甲酯基乙基黄原酸酯作为链转移剂,采用可逆加成断裂链转移(RAFT)聚合制备了低分子质量(Mn<8 000g/mol)、窄分子质量分布(Mw/Mn<1.6)的聚醋酸乙烯酯(PVAc)。该聚合过程具有明显的可控/活性特征,并以异丙醇作为氢原子供体有效去除PVAc末端的双硫酯基团。采用核磁共振(1 HNMR)、凝胶渗透色谱(GPC)表征PVAc的结构与分子质量,得到的结果与理论计算的目标分子质量一致。浊点测试结果表明:PVAc在二氧化碳中的溶解度随着分子质量的增大和溶解温度的升高而降低;PVAc分子链末端的双硫酯基团不利于聚合物溶解在二氧化碳中,且分子质量越低,影响越显著。     

Genetic analysis for brix weight per stool and its component traits in sugarcane (Saccharum officinarum)

Brix weight per stool (BW) of sugarcane is a complex trait, which is the final product of a combination of many components. Diallel cross experiments were conducted during a period of two years for BW and its five component traits, in- cluding stalk diameter (SD), stalk length (SL), stalk number (SN), stalk weight (SW), and brix scale (BS) of sugarcane. Phenotypic data of all the six traits were analyzed by mixed linear model and their phenotype variances were portioned into additive (A), dominance (D), additive×environment interaction (AE) and dominance×environment interaction (DE) effects, and the correlations of A, D, AE and DE effects between BW and its components were estimated. Conditional analysis was employed to investigate the contribution of the components traits to the variances of A, D, AE and DE effects of BW. It was observed that the heritabilities of BW were significantly attributed to A, D and DE by 23.9%, 30.9% and 28.5%, respectively. The variance of A effect for BW was significantly affected by SL, SN and BS by 25.3%, 93.7% and 17.4%, respectively. The variances of D and DE effects for BW were also significantly influenced by all the five components by 5.1%～85.5%. These determinants might be helpful in sugarcane breeding and provide valuable information for multiple-trait improvement of BW.     

基于熵权G1法的水匮乏指数计算新方法及应用研究

水匮乏指数较客观地反映了水的紧缺程度与社会经济发展之间的密切关系。以往在计算水匮乏指数过程中确定权重时,常采用的是等权法。而实际情况是各指标的权重应该根据其重要程度不同而有所差别。针对这一问题,提出基于熵权G1法的水匮乏指数计算新方法,并对该方法进行了实证研究。新方法考虑了各个分指标重要性程度的区别,弥补了等权法的缺点和不足,使计算结果更加客观合理。最后,以黑龙江省2009~2011年的水匮乏指数为研究对象对该模型进行了应用研究。     

穴位埋线对运动性疲劳大鼠耐力改善的影响及其机制

为穴位埋线改善耐力的临床应用提供理论依据,本文采用递增跑台训练的方法构建运动性疲劳大鼠模型,考察穴位埋线对疲劳训练大鼠运动能力的影响,将大鼠随机分为空白组、跑台组、埋线跑台组Ⅰ、埋线跑台组Ⅱ,记录各组大鼠力竭运动时间并对各组大鼠相关脏器进行采集及生化指标的测定。实验结果表明:对于运动性疲劳大鼠,穴位埋线可减控体质量,并能降低CORT水平、增加肌糖原浓度、降低血清游离Ca2+浓度及提高LDH活性(P<0.05)。     

关于司法独立的几个问题

在理论上 ,由于与法官承担的功能与角色差异很大 ,检察官不宜独立 ,故我国司法独立主体应仅限于法院及法官。同时 ,为尊重司法的科学特性 ,法官依法裁判仅服从宪法及法律 ,不受政党、国家机关及个人 (包括法官自己 )干涉。不过由于历史及现实的种种原因 ,我国目前司法中充满了政治及行政化色彩 ,司法的科学性未得到有效发扬     

当代科学对技术的依赖性

由于当代科学技术的一体化和当代科学的功用性和实践性特征的发展，技术的介入既是科学研究的需要，也成为当代科学活动的主要目的。在此背景下，通过对技术在当代科学活动中的决定性作用的分析，文章认为当代科学是依赖技术的科学；并指出，引进和发展先进技术是不发达国家推进科学事业的必由之路。