Effects of working-memory training on striatal dopamine release

Updating of working memory has been associated with striato-frontal brain regions and phasic dopaminergic neurotransmission. We assessed raclopride binding to striatal dopamine (DA) D2 receptors during a letter-updating task and a control condition before and after 5 weeks of updating training. Results showed that updating affected DA activity before training and that training further increased striatal DA release during updating. These findings highlight the pivotal role of transient neural processes associated with D2 receptor activity in working memory.     

图书动态馆藏管理新模式——以淮海工学院图书馆新书借阅中心为例

经过实践,动态更新馆藏管理机制,是快速解决新书借阅中心更新馆藏资源,有效预留架位,使新购进图书及时上架,保持"馆藏新、传递快"的特色服务的管理机制,即围绕新书借阅中心的图书利用率为标准,将典藏与流通管理相结合,开展图书下架移库剔出滞书工作,使馆藏资源满足读者层次需求,结构更趋合理.     

The prefrontal cortex: response selection or maintenance within working memory?

It is controversial whether the dorsolateral prefrontal cortex is involved in the maintenance of items in working memory or in the selection of responses. We used event-related functional magnetic resonance imaging to study the performance of a spatial working memory task by humans. We distinguished the maintenance of spatial items from the selection of an item from memory to guide a response. Selection, but not maintenance, was associated with activation of prefrontal area 46 of the dorsal lateral prefrontal cortex. In contrast, maintenance was associated with activation of prefrontal area 8 and the intraparietal cortex. The results support a role for the dorsal prefrontal cortex in the selection of representations. This accounts for the fact that this area is activated both when subjects select between items on working memory tasks and when they freely select between movements on tasks of willed action.     

我国农业发展趋势与对策研究

认为我国农业发展面临的主要矛盾是小农经济与农业现代化的矛盾;从农村人口的思想认识基础的变化得出我国“三农”问题的发展趋势:农民队伍正在萎缩,农业技术难以推广,农村经济发展面临困境,农地荒芜现象日趋严重,粮食安全和农业发展受到威胁。围绕30年后“谁来搞农业”“、怎样搞农业”两个问题展开进一步分析,展望我国未来农业的发展必须依赖于农业企业化、产业化经营;提出了加快农村剩余劳动力转移步伐,放活土地使用权的流转机制,培养新型农业人才,走农业企业化道路等对策建议。     

中华鳑鲏空间认知能力的性别差异

选择16尾中华鳑鲏作为研究对象,对鳑鲏鱼类两性间空间认知能力的差异进行研究。试验使用T型迷宫装置,比较经过训练的雌雄个体进入目标位置所需的消耗时间、方向选择的正确率以及达到学习标准所需的训练次数。数据显示,雌性个体组训练前后的消耗时间变化及方向选择的正确率均大于雄性个体组,而达到学习标准所需的训练次数少于雄性组。试验结果表明处于生殖季节的中华鳑鲏,在经过训练后,都能够完成特定的空间认知任务,但两性间在空间认知能力上存在明显差异,生殖期的雌鱼相对雄鱼具有更好的空间学习能力。     

文理科大学生英语词汇记忆策略培训研究

基于O′Malley＆Chamot的词汇记忆策略分类,以显性和课堂融入相结合的方式对114名福建农林大学2008级文理科大学生进行为期一学年的英语词汇记忆策略培训,旨在研究策略培训效果并对比文理科大学生词汇记忆策略培训效果的差异。研究结果表明：英语词汇记忆策略培训能提高文理科大学生的策略意识,为他们提供更多有效地记忆词汇的方法,扩大他们记忆策略的选择范围,提高他们的词汇水平。策略培训后想象策略和分类策略仍然不常被使用。文理科大学生在反复策略、联想策略、构词策略、分类策略、上下文记忆策略以及词汇水平提高程度上都存在显著差异,其诱因是不同的认知风格和学习动机。     

Small circuits for large tasks: high-speed decision-making in archerfish

The enormous progress made in functional magnetic resonance imaging technology allows us to watch our brains engage in complex cognitive and social tasks. However, our understanding of what actually is computed in the underlying cellular networks is hindered by the vast numbers of neurons involved. Here, we describe a vertebrate system, shaped for top speed, in which a complex and plastic decision is performed by surprisingly small circuitry that can be studied at cellular resolution.     

高信息化下高校图书馆藏书的剔旧

高信息时代,高校图书馆文献数字化、信息更新频率飞速,图书馆的馆藏建设是每个高校图书馆开展服务的物质基础,加快新书采访,优化藏书结构,加强藏书建设是就成了当务之急。藏书剔旧是藏书建设的根本之一,本文提出了图书剔旧的概念、迫切性,确定藏书剔旧的对象、范围,以及藏书剔旧遵循的原则和意义。     

Intracerebral saline: effect on memory of trained mice treated with puromycin

It was shown that puromycin administered to mice 1 or more days after maze-learning blocks expression of memory; the blockage can be removed by intracerebral injections of saline. We present evidence that intracerebral injections of saline are relatively ineffective in restoring memory when puromycin is administered either before or immediately after training; in these two situations puromycin appears to interfere with consolidation of memory.     

基于卷积神经网络的番茄目标检测

番茄目标检测有利于提升番茄采摘的智能化程度。本文针对番茄目标检测问题,提出了一种基于Yolo3的目标检测方法。通过对数据集手工标注,并利用kmeans聚类算法更新先验框参数,实现了数据模型的训练测试与模型评估。实验结果表明,所采用方法的目标检测mAP为96.34%,能够有效地实现番茄目标检测。     

Selective D2 receptor actions on the functional circuitry of working memory

Prefrontal neurons engaged by working memory tasks express a sequence of phasic and tonic activations linked to a train of sensory, mnemonic, and response-related events. Here, we report that the dopamine D2 receptor selectively modulates the neural activities associated with memory-guided saccades in oculomotor delayed-response tasks yet has little or no effect on the persistent mnemonic-related activity, which is instead modulated by D1 receptors. This associates the D2 receptor with a specific component of working memory circuitry and fractionates the modulatory effects of D1 and D2 receptors on the neural machinery of a cognitive process.     

高职园林规划设计课程实践教学方法研究

园林规划设计是高职园林类专业的核心课程,是一门课程基础知识宽广、实践操作能力要求很高的课程,能反映专业人才培养目标的达成情况。本文分析了园林规划设计课程的培养目标,并将实践教学作为实现课程培养目标的载体进行了实践教学设计,总结了实践教学方法,以期为高职园林规划设计课程实践教学提供参考。     

Auditory association cortex lesions impair auditory short-term memory in monkeys

Monkeys that were trained to perform auditory and visual short-term memory tasks (delayed matching-to-sample) received lesions of the auditory association cortex in the superior temporal gyrus. Although visual memory was completely unaffected by the lesions, auditory memory was severely impaired. Despite this impairment, all monkeys could discriminate sounds closer in frequency than those used in the auditory memory task. This result suggests that the superior temporal cortex plays a role in auditory processing and retention similar to the role the inferior temporal cortex plays in visual processing and retention.     

Electroconvulsive shock effects on a reactivated memory trace: further examination

Rats showed amnesia for conditioned fear training if given an electroconvulsive shock immediately after training. Retention was unimpaired, however, when the electroconvulsive shock treatment was given 1 day after training immediately after the presentation of the stimulus used in the fear conditioning training. These results support the view that electroconvulsive shock disrupts memory trace consolidation but does not disrupt a recently reactivated memory trace.     

How Big Is a Chunk?: By combining data from several experiments, a basic human memory unit can be identified and measured

I have explored some of the interactions between research on higher mental processes over the past decade or two and laboratory experiments on simpler cognitive processes. I have shown that, by viewing experimentation in a parameter-estimating paradigm instead of a hypothesis-testing paradigm, one can obtain much more information from experiments-information that, combined with contemporary theoretical models of the cognitive processes, has implications for human performance on tasks quite different from those of the original experiments. The work of identifying and measuring the basic parameters of the human information processing system has just begun, but already important information has been gained. The psychological reality of the chunk has been fairly well demonstrated, and the chunk capacity of short-term memory has been shown to be in the range of five to seven. Fixation of information in longterm memory has been shown to take about 5 or 10 seconds per chunk. Some other "magical numbers" have been estimated-for example, visual scanning speeds and times required for simple grammatical transformations-and no doubt others remain to be discovered. But even the two basic constants discussed in this article-short-term memory capacity and rate of fixation in long-term memory-organize, systematize, and explain a wide range of findings, about both simple tasks and more complex cognitive performances that have been reported in the psychological literature over the past 50 years or more.     

Memory impairment after subcutaneous injection of acetoxycycloheximide

Subcutaneous injection of 240 micrograms of acetoxycycloheximide in mice rapidly produces marked inhibition of cerebral protein synthesis. Treated mice were trained to escape shock by choosing the lighted limb of a T-maze. When trained five or more minutes after injection, they had a normal capacity to learn. They remembered normally 3 hours after training, but 6 hours after training they had markedly impaired retention. Amnesia persisted thereafter. Injections immediately after training had a less marked but significant amnesic effect. These studies suggest that protein synthesis is not necessary for learning or for memory for 3 hours after training but that it is required for long-term memory. The protein synthesis which appears to be necessary for long-term e3memory occurs during training, or within minutes after training, or both.     

Calcium-permeable AMPA receptor dynamics mediate fear memory erasure

Traumatic fear memories can be inhibited by behavioral therapy for humans, or by extinction training in rodent models, but are prone to recur. Under some conditions, however, these treatments generate a permanent effect on behavior, which suggests that emotional memory erasure has occurred. The neural basis for such disparate outcomes is unknown. We found that a central component of extinction-induced erasure is the synaptic removal of calcium-permeable α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptors (AMPARs) in the lateral amygdala. A transient up-regulation of this form of plasticity, which involves phosphorylation of the glutamate receptor 1 subunit of the AMPA receptor, defines a temporal window in which fear memory can be degraded by behavioral experience. These results reveal a molecular mechanism for fear erasure and the relative instability of recent memory.     

基于迁移学习和卷积神经网络的生菜鲜重估测

为提高设施生产中对各生长阶段生菜鲜重的无损估测精度进而更好地指导生产，提出一种利用生菜冠层图像为输入，基于迁移学习技术和卷积神经网络估测鲜重的方法，对比分析AlexNet、VGG-16、GoogLeNet和ResNet-18模型迁移学习后在生菜鲜重估测任务上的效果；同时，对比不同迁移学习方法对模型性能的影响，通过冻结卷积层和减少全连接层改善模型的参数量和训练速度。结果表明:1)AlexNet和VGG-16两种模型能较好的实现生菜鲜重的估测，AlexNet模型的决定系数R²为0.928 0，标准均方根误差NRMSE为19.08%，VGG-16模型的R²为0.938 0，NRMSE为17.71%，但VGG-16模型存在参数量大训练慢的问题，综合考虑选取AlexNet模型迁移学习后作为生菜鲜重估测模型；2)与全新学习方法相比，在预训练模型基础上对生菜鲜重数据集进行迁移学习，可以明显提升生菜鲜重估测模型的训练速度和准确度；3)冻结卷积层能显著加快模型的训练速度，训练时间可减少18%，减少全连接层在保持精度的前提下能大幅度减少模型的参数量。基于迁移学习的卷积神经网络模型可用于生菜鲜重的快速估测，该方法也可以拓展应用到其他叶类蔬菜的鲜重估测中。     

浅谈《生物化学》的教学

《生物化学》教学受传统教育观念的影响,教学效果难以达到人才培养的要求。本文从更新教育思想观念、优化教学方法入手,在改进《生物化学》的教学方面进行了一些有益的探索,并取得较好的效果。     

基于CDIO的食品加工与安全专业硕士培养模式构建

基于食品加工与安全专业硕士的国内高校培养情况,借鉴CDIO国内外培养模式的发展情况,从明确教学培养目标、更新教学模式、提升实践能力和提高学位论文质量等方面来构建食品加工与安全专业硕士的培养模式,从而提高研究生的实践和创新能力,改善了专业人才技能培养效果。