Analysis of mammalian brain architecture.

The mammalian brain is composed of several distinct parts which show different growth in evolution. Clark, Mitra and Wang found that the two main cortices of the brain - the cerebral (neo-) cortex and the cerebellum - show very different growth, and that whereas the ratio of neocortex volume to total brain volume increases with evolution, the cerebellum occupies a constant proportion in different species. Here I compare the surface areas of the two cortices in different species and find that these show a simple proportionality. Contrary to the conclusion drawn by Clark et al., this linear dependence of size implies that the two major cortices increase their computational capacity in parallel, suggesting a functional dependence of the one upon the other.     

Resting state brain activity and functional brain mapping

Functional brain imaging studies commonly use either resting or passive task states as their control conditions, and typically identify the activation brain region associated with a specific task by subtracting the resting from the active task conditions. Numerous studies now suggest, however, that the resting state may not reflect true mental "rest" conditions. The mental activity that occurs during "rest" might therefore greatly influence the functional neuroimaging observations that are collected through the usual subtracting analysis strategies. Exploring the ongoing mental processes that occur during resting conditions is thus of particular importance for deciphering functional brain mapping results and obtaining a more comprehensive understanding of human brain functions. In this review article, we will mainly focus on the discussion of the current research background of functional brain mapping at resting state and the physiological significance of the available neuroimaging data.     

Design and implementation of a cognitive engine functional architecture

Intelligence is the most important characteristic for cognitive wireless networks. A cognitive engine built on reconfigurable wireless networks is the key to implementing this characteristic. The design and implementation of a cognitive engine is important in research on the theory of initiative cognition for cognitive wireless networks. This paper first discusses research on cognitive loops, then investigates cognitive functions in the loop through the design of a universal cognitive engine functional architecture, and finally verifies the architecture on the platform of a cognitive engine prototype system.     

论"固有色"及"固有色彩观念"

进行色彩写生必须具有科学的光色变化观念,从客观物象当时当地的具体色彩实际出发,排除“固有色彩观念”的干扰,抛弃对“固有色”的盲目追求,以自然为师,努力表现一切被画物象极为丰富的色彩变化。     

A functional correlate for the dihydropyridine binding site in rat brain

Calcium channels, controlling the influx of extracellular Ca2+ and hence neurotransmitter release, exist in the brain. However, drugs classed as calcium antagonists and which inhibit Ca2+ entry through voltage-activated Ca2+ channels in heart and smooth muscle, seem not to affect any aspect of neuronal function in the brain at pharmacologically relevant concentrations. Yet the dihydropyridine calcium antagonists (for example, nitrendipine) bind stereospecifically with high affinity to a recognition site on brain-cell membranes thought to represent the Ca2+ channel and consequently, the physiological relevance of these sites has been questioned. However, activation of voltage-dependent Ca2+ channels can increase cytoplasmic Ca2+ and neurotransmitter release in neuronal tissue. We show here that Bay K8644, a dihydropyridine Ca2+-channel activator, can augment K+-stimulated release of serotonin from rat frontal cortex slices and that these effects can be antagonized by low concentrations of calcium antagonists. As 3H-dihydropyridine binding to cortical membrane preparations resembles the binding in heart and smooth muscle where there are good functional correlates we conclude that the dihydropyridine binding sites in the brain represent functional Ca2+ channels that can be unmasked under certain circumstances.     

建筑中的动

文章以建筑中的"动"为切人点,从建筑形态、空间、环境、文脉、真正的动的建筑等方面,探析建筑中的动态元素.从人的需求和外部环境的角度,结合相应的实际案例对这一新型建筑设计方向进行研究和思考.解析了动态建筑的基本精神一动态与自然;动态建筑的基本特征--多文化、多维度、复杂动态的功能空间、回归自然的梦想;剖析了动态建筑思想的...     

A functional circuit underlying male sexual behaviour in the female mouse brain

In mice, pheromone detection is mediated by the vomeronasal organ and the main olfactory epithelium. Male mice that are deficient for Trpc2, an ion channel specifically expressed in VNO neurons and essential for VNO sensory transduction, are impaired in sex discrimination and male-male aggression. We report here that Trpc2-/- female mice show a reduction in female-specific behaviour, including maternal aggression and lactating behaviour. Strikingly, mutant females display unique characteristics of male sexual and courtship behaviours such as mounting, pelvic thrust, solicitation, anogenital olfactory investigation, and emission of complex ultrasonic vocalizations towards male and female conspecific mice. The same behavioural phenotype is observed after VNO surgical removal in adult animals, and is not accompanied by disruption of the oestrous cycle and sex hormone levels. These findings suggest that VNO-mediated pheromone inputs act in wild-type females to repress male behaviour and activate female behaviours. Moreover, they imply that functional neuronal circuits underlying male-specific behaviours exist in the normal female mouse brain.     

The temporal response of the brain after eating revealed by functional MRI

After eating, the human brain senses a biochemical change and then signals satiation, but precisely when this occurs is unknown. Even for well-established physiological systems like glucose-insulin regulation, the timing of interaction between hormonal processes and neural events is inferred mostly from blood sampling. Recently, neuroimaging studies have provided in vivo information about the neuroanatomical correlates of the regulation of energy intake. Temporal orchestration of such systems, however, is crucial to the integration of neuronal and hormonal signals that control eating behaviour. The challenge of this functional magnetic resonance imaging study is to map not only where but also when the brain will respond after food ingestion. Here we use a temporal clustering analysis technique to demonstrate that eating-related neural activity peaks at two different times with distinct localization. Importantly, the differentiated responses are interacting with an internal signal, the plasma insulin. These results support the concept of temporal parcellation of brain activity, which reflects the different natures of stimuli and responses. Moreover, this study provides a neuroimaging basis for detecting dynamic processes without prior knowledge of their timing, such as the acute effects of medication and nutrition in the brain.     

建筑学专业“建筑材料”课程教学改革研究

城市建设的高速发展需要高素质的建筑设计人员,但传统建筑学专业的教学模式无法满足新世纪人才培养的要求。针对建筑学专业的特点和原有建筑材料课程教学模式存在的主要问题,讨论了课程的重新定位及在教学目标、内容、方法等方面的改革尝试,最后评析了改革后该课程教学的应用实效。     

解构主义建筑浅谈

自二十世纪九十年代以来,世界各地出现了一些引人注目的解构主义建筑作品。它们的数量不多,影响力却不小,直接原因就是这些作品以完全违反常规的方式和手段来处理建筑形式问题,人们的传统价值观和审美标准等产生了一定冲击。从解构主义建筑产生的思想来源来阐述解构主义建筑的建筑意象和审美价值,为大家理解解构主义建筑提供一点参考。     

静息状态下脑网络建模及功能连接特性

实验采集静息状态下功能磁共振成像数据,经预处理后结合种子相关分析方法、t-检验法以及复杂网络理论和方法构建正常人脑功能网络.针对脑网络构建中种子相关分析法存在阈值设定随意性大的问题,引入两个原则,即设定的阈值需保证网络的整体性和小世界特性,使建立的脑网络模型充分具有实际系统的特征.在建模基础上进一步研究脑网络功能连接特性,发现网络具有明显的小世界特性;并通过计算网络中心化指标推测出后扣带回、楔前叶、楔叶以及顶上小叶等是静息状态下脑功能网络的关键脑区.     

近代中国西方古典建筑的细部分析

近代中国西方古典形式的建筑异常丰富，多变的细部表现是一个重要因素。这些形式中包含了它特有的细部特征，它既有自己一定的细部法则，也反映了中西融合与变异的历史背景，同时还带有装饰与象征的效果，在细部做法中，折中形式较之正统古典手法有着更多的应用，其中，巴洛克和洛可可成为中国工匠折中处理的主要素材。这应归因于这两种形式与中国传统文化的相通以及当时的社会风尚，折中建筑出现的意义还在于它取代了传统官式建筑而成为新兴官僚身份的象征，同时也反映出民众从伊洋到崇洋的社会心理变化过程。     

建筑流线研究

建筑流线是指人在建筑中的活动路线,它受到建筑使用者的行为和建筑功能的影响,它和建筑空间是相辅相成的关系,由于建筑的多样性和复杂性,建筑流线的组织形式也分为好几种.文章对不同建筑中的流线进行分析和归纳,以期对今后的建筑设计有一定的指导作用.     

Cloning and expression of a functional serotonin transporter from rat brain

Selective antagonism of serotonin (5-hydroxytryptamine, 5HT) and noradrenaline transport by antidepressants is a key element in the 'amine' hypothesis of affective disorders. Uptake and/or transport sites of 5HT have been reported to be reduced in platelets of patients suffering from depression and in post-mortem brain samples of depressed patients and suicide victims. To date there has been little molecular information available on the structure and regulation of 5HT transporters. Using the polymerase chain reaction with degenerate oligonucleotides derived from two highly conserved regions of the transporters for noradrenaline and gamma-aminobutyric acid (GABA), we have identified a large family of related gene products expressed in rodent brain. One of these products hybridizes to a single 3.7-kilobase RNA restricted to rat midbrain and brainstem, where it is highly enriched within the serotonergic raphe complex. Transfection with a single 2.3-kilobase brainstem complementary DNA clone is sufficient to confer expression of a Na(+)-dependent 5HT transporter upon nonneural cells, with transport selectively and potently antagonized by 5HT uptake-specific antidepressants, including paroxetine, citalopram and fluoxetine.     

异丁烯在强酸性阳离子交换树脂上的齐聚动力学

以强酸性阳离子交换树脂为催化剂,对异丁烯齐聚反应动力学进行了研究。首先通过机理分析建立了齐聚反应动力学模型。用高斯-牛顿法,根据实验数据进行参数估算,得到了相应的动力学模型参数,经统计检验表明,动力学模型是适当的,而齐聚反应液中各组分浓度与时间的关系曲线则显示异丁烯的齐聚具有一级串联不可逆反应的特征。异丁烯二聚和三聚的速率方程分别为-dcIB/dt=2kIBcIB,dcDIB/dt=kIBcDIB-kDIBcDIB,反应速率常数kIB=3.08×106exp(-54 520/RT),kDIB=3.10×103exp(-36 670/RT)。     

赖氨酸本质荧光现象初探

通过与精氨酸和甘氨酸的对比实验,赖氨酸在可见光区有较强的荧光,且其吸收也相对较强。赖氨酸在不同溶剂中荧光强度发生变化。同时对赖氨酸的荧光寿命进行了分析测定。实验结果表明,赖氨酸的荧光性质明显区别于其它氨基酸,这与其特殊6-氨基官能团密切相关,且可归属于氮原子的本质荧光。     

浅谈徽州古建筑中的三雕艺术

文章意在阐明徽州古建筑中的砖、木、石三雕在建筑中的作用和意义,建筑三雕体现了徽州匠师的艺术创造和审美观,通过建筑形式的塑造,成就了明清时期皖南民居建筑风格.徽州三雕题材生动、寓意吉祥、经久耐用、装饰效果好,充分体现了地方特色,是不可多得的艺术奇葩,应该加大力度保护、整理和利用.