Maternal care, isolation-induced infant ultrasonic calling, and their relations to adult anxiety-related behavior in the rat.

In the rat, variations in maternal care affect the development of stable individual differences in anxiety-related behavior. Here, it was asked whether such experience-dependent differences can be detected already during early life. As a measure for anxiety in pups, isolation-induced ultrasonic vocalizations were used, and their dependency on different maternal behaviors, namely licking, retrieval behavior, and responsiveness to playback of pup calls, was tested. Consistent with reported differences of adult rats with high or low levels of maternal care experienced, the rarely licked offspring appeared to be more anxious, since they emitted more calls when separated from their mother and litter. Based on these findings, it was examined whether infant calling can be used as a predictor of adult anxiety-related behavior. Results show that infant call emission was negatively correlated with immobility and calling during fear conditioning. These relationships seem to be mediated at least partly by maternal care. In total, measuring ultrasonic vocalizations can provide information about an affective trait of infant and adult rats, which gives the opportunity to study the development of emotionality from early life onward. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tolerance to Amphetamine Hypophagia: A Real-Time Depiction of Learning to Suppress Stereotyped Movements in the Rat.

To analyze how tolerance develops to amphetamine-induced hypophagia, the authors recorded real-time licking responses in rats given chronic injections of the drug and access to milk for 30 min. Initially, licking was greatly reduced and occurred only late in the session. The acquisition of tolerance was characterized by a decrease in the latency to initiate licking, a gradual increase in the number of licks, and a reorganization of the temporal licking pattern such that licks were distributed throughout the session, interspersed with pauses. On posttolerance dose-response tests, licking was directly proportional to drug dose in some rats. The results support the view that tolerance to amphetamine hypophagia involves a behavioral adaptation to the motor effects of the drug. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tolerance to amphetamine hypophagia: A miscrostructural analysis of licking behavior in the rat.

The development of tolerance to amphetamine-induced hypophagia was assessed by recording changes in lick parameters in rats given chronic administration of the drug (2 mg/kg) and access to sweetened milk. Although licking and milk intake gradually recovered, the volume of milk ingested per lick remained suppressed. Amphetamine had no effect on the interlick interval or the force per lick. In contrast, the drug caused a sustained increase in the number of lick bursts (defined by pause criteria of 0.5-2.0 s) and a decrease in the number of licks per burst (but only at pause criteria of 0.5 and 1.0 s). These results suggest that tolerant rats frequently interrupt licking, resulting in less efficient capture of milk. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

关于油藏中反常凝析现象解释的质疑

通过对反常凝析现象的研究,认为造成这种现象的原因,并非书本中所认为的那样,而是一种钻入与吞噬造成分子间距离的变化,引起的这种反常凝析现象。     

颗粒级配对矿物饲料舔块压制成形的影响

为提高矿物质饲料舔块的压实密度及抗压强度,对矿物质饲料舔块原料颗粒级配与压制成形的关系进行试验研究,运用MATLAB 6.5软件对试验结果进行分析。结果表明:颗粒级配中粒径为2～4.75、0.5～2、0.5 mm颗粒的质量分数分别为20%～25%、40%～60%、15%～40%时,饲料舔块达到最佳压实密度及抗压强度。合理的颗粒级配可以提高矿物饲料舔块的压实密度和抗压强度。     

Simultaneous contrast: Evidence from licking microstructure and cross-solution comparisons.

The microstructure of rats' licking responses was analyzed to investigate both “classic” simultaneous contrast (e.g., Flaherty & Largen, 1975) and a novel discrete-trial contrast procedure where access to an 8% test solution of sucrose was preceded by a sample of either 2%, 8%, or 32% sucrose (Experiments 1 and 2, respectively). Consumption of a given concentration of sucrose was higher when consumed alongside a low rather than high concentration comparison solution (positive contrast) and consumption of a given concentration of sucrose was lower when consumed alongside a high rather than a low concentration comparison solution (negative contrast). Furthermore, positive contrast increased the size of lick clusters while negative contrast decreased the size of lick clusters. Lick cluster size has a positive monotonic relationship with the concentration of palatable solutions and so positive and negative contrasts produced changes in lick cluster size that were analogous to raising or lowering the concentration of the test solution respectively. Experiment 3 utilized the discrete-trial procedure and compared contrast between two solutions of the same type (sucrose-sucrose or maltodextrin-maltodextrin) or contrast across solutions (sucrose-maltodextrin or maltodextrin-sucrose). Contrast effects on consumption were present, but reduced in size, in the cross-solution conditions. Moreover, lick cluster sizes were not affected at all by cross-solution contrasts as they were by same-solution contrasts. These results are consistent with the idea that simultaneous contrast effects depend, at least partially, on sensory mechanisms. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Effects of neuropeptide Y on feeding microstructure: Dissociation of appetitive and consummatory actions.

The effects of intracerebroventricular application of Neuropeptide Y (NPY) on licking microstructure for sucrose, saccharin, and water solutions were evaluated. In Experiment 1, NPY increased meal size for three sucrose concentrations (0.03 M, 0.3 M, and 1.0 M) by increasing licking burst number but not size and by extending meals more than four-fold in duration with a slow, sustained rate of ingestion in late phases of the meal. Results are consistent with the interpretation that NPY suppressed inhibitory postingestive feedback. Experiment 2 supported this conclusion. NPY significantly increased the number of meals initiated for water, 0.1% saccharin, and 1.0 M sucrose solutions, but meal size was only increased for 1.0 M sucrose. Therefore, NPY also increased appetitive feeding behaviors, but its consummatory effects were limited to caloric solutions. The results are discussed with regard to their potential to explain current discrepancies in the literature. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

PX2精梳系统粘卷现象探讨

从原棉的含糖、准备工序的工艺和车间温湿度三方面分析了精梳小卷粘卷的原因，并提出了解决问题的措施，指出目前存在的不足。     

Reduced palatability in lithium- and activity-based, but not in amphetamine-based, taste aversion learning.

Conditioned taste aversions (CTA) based on lithium chloride (Experiment 1), amphetamine (Experiment 2), and wheel running (Experiment 3) were examined using the analysis of the microstructure of licking to measure the palatability of the taste serving as the conditioned stimulus (CS). Pairing saccharin with amphetamine reduced saccharin intake without reducing the size of licking clusters, initial lick rate, or the distribution of inter-lick intervals (ILIs) within a cluster. By contrast, pairing saccharin with lithium or wheel-running reduced saccharin intake as well as lick cluster size, initial lick rate, and the distribution of ILIs within a cluster. As lick cluster size, initial lick rate, and ILI distribution can be used as indices of stimulus palatability, the current results indicate that taste aversions based on either lithium or activity reduced the palatability of the CS. This suggests that aversions based on both lithium and wheel running involve conditioned nausea to the CS taste. The absence of similar changes in licking microstructure with amphetamine-based CTA is consistent with other evidence indicating this does not involve nausea. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mother-Infant Interactions in Rats Lacking CCKA Receptors.

Mediation of mother-infant interactions by the brain-gut peptide cholecystokinin (CCK) was examined by observing behavior of Otsuka Long-Evans Tokushima Fatty (OLETF) rats, which lack functional CCKA receptors because of a genetic abnormality. OLETF (n = 10) and control (Long-Evans Tokushima Otsuka [LETO] n = 10) dams interacted with 1 pup of each line on Postpartum Days 6-9. OLETF pups received more body and anogenital licking and emitted substantially more ultrasonic vocalizations than LETO pups. OLETF dams carried pups less frequently and showed a nursing position more frequently than LETO dams. No significant Pup X Dam Line interactions or line differences in dams' activity were detected. The results provide convergent validity to previous pharmacological studies implicating CCK mediation of both infant and maternal behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)