一个包含Euler函数的方程

目的研究方程φ(φ(n))=2ω(n)的可解性。方法利用初等方法以及Euler函数的性质。结果给出了方程φ(φ(n))=2ω(n)的所有正整数解。结论确定该方程共有20个正整数解。     

一个包含Smarandache函数的方程

目的应罗马尼亚数论专家F.Smarandache教授的要求,求证一个包含Smarandache函数的方程的性质。方法利用初等方法和解析方法。结果解得这个方程的性质。获得了这个方程解的个数的渐近公式。结论发展了F.Smarandache教授在Only Problems,Not Solution一书(XiquanPublishing House,1993)中涉及的相关研究工作。     

Hardy不等式的凸函数推广

将Hardy不等式推广到凸函数上，获得了一些有趣的结果.     

一个包含Smarandache函数的同余方程

目的 研究一个包含Smarandache函数S(n)同余方程的可解性.方法 利用初等方法及原根的性质.结果 证明了该同余方程有无穷多个正整数解.结论 给出了正整数n是该同余方程解的充分条件.     

一类包含Smarandache和Euler函数的方程

对于任意正整数 ,设 和 分别是关于 的Euler函数和Smarandache函数. 利用初等的方法,得到了方程 当 时的所有正整数解.     

一个包含Smarandache LCM对偶函数的方程

在初等数论和分类讨论方法的基础上使用java程序研究函数方程∑d|n1SL*(d)=3Ω(n)的可解性,并给出这个方程的所有正整数解的具体形式.     

Retinotopic order appears before ocular separation in developing visual pathways

In mammals, the major subcortical visual structures receive projections from both eyes, with the uncrossed projection being smaller than the crossed. Each projection is arranged as a separate orderly map of one hemiretina. Although these hemiretinal maps are separate in the nuclei, they are aligned so that the representations of points in the visual field are in register, thus there is a continuity of visual field representation between them. During the early development of the binocular pathways, terminals from the two eyes overlap almost entirely. As development proceeds, terminals arising from each eye segregate to form the adult pattern. In the present study, local retinal lesions were made in ferrets at various stages in development before the separation of the projections from the two eyes. A neuronal tracer was then injected into the damaged eye, defining the pattern of projection from that eye. As reported here, the lesion resulted in a limited interruption in the pattern of terminal label on both sides of the brain, demonstrating that terminals from each eye are arranged in an orderly retinotopic manner at this stage. hence, during later development, as one projection is reduced relative to the other, the two maps must slide in relation to each other.     

一个包含F．Smarandache对偶函数的方程

目的 研究一类包含F.Smarandache对偶函数方程的可解性.方法 初等方法.结果 获得了给定方程的所有正整数解.结论 证明方程∑S*(d)=w(n)Ω(n)有且仅有3种形式的解.     

Invariant visual representation by single neurons in the human brain

It takes a fraction of a second to recognize a person or an object even when seen under strikingly different conditions. How such a robust, high-level representation is achieved by neurons in the human brain is still unclear. In monkeys, neurons in the upper stages of the ventral visual pathway respond to complex images such as faces and objects and show some degree of invariance to metric properties such as the stimulus size, position and viewing angle. We have previously shown that neurons in the human medial temporal lobe (MTL) fire selectively to images of faces, animals, objects or scenes. Here we report on a remarkable subset of MTL neurons that are selectively activated by strikingly different pictures of given individuals, landmarks or objects and in some cases even by letter strings with their names. These results suggest an invariant, sparse and explicit code, which might be important in the transformation of complex visual percepts into long-term and more abstract memories.     

Inhibin beta in central neural pathways involved in the control of oxytocin secretion

Inhibin (I) a gonadal hormone glycoprotein which suppresses follicle-stimulating hormone (FSH) secretion from the anterior pituitary, is a heterodimer consisting of an alpha subunit and one of two distinct beta subunits. S1 nuclease analysis has revealed that RNAs encoding all three subunits (alpha, beta A and beta B) are expressed in rat brain. We report here on the localization, and a potential function, of inhibin beta in the rat brain. A cell group centred in the nucleus of the solitary tract (NTS), a major recipient of visceral sensory information, was stained immunohistochemically with antisera against synthetic fragments of I beta, but not I alpha. The distribution of I beta-stained fibres is consistent with known NTS projections, and includes a prominent projection to oxytocinergic aspects of the magnocellular neurosecretory system.     

Sensory neurones recognise defined pathways in Drosophila central nervous system

An analysis of the central projection of various sensory neurones in the homoeotic mutant bithorax postbithorax, and in flies where an adult nerve had been experimentally misrouted, reveals that neurones are able to develop a normal projection even if they enter the central nervous system at an unusual place.     

一个算术函数与最大素因子函数的混合均值

在Smarandache函数S(n)及因子积数列{Pd(n)}的基础上,构造并研究了∑n≤x(S(Pd(n))-21d(n)P(n))2的一种均值分布性质,利用初等方法和素数定理研究了混合均值问题,给出了它的一个较强的渐进公式.     

Distinct memory traces for two visual features in the Drosophila brain

The fly Drosophila melanogaster can discriminate and remember visual landmarks. It analyses selected parts of its visual environment according to a small number of pattern parameters such as size, colour or contour orientation, and stores particular parameter values. Like humans, flies recognize patterns independently of the retinal position during acquisition of the pattern (translation invariance). Here we show that the central-most part of the fly brain, the fan-shaped body, contains parts of a network mediating visual pattern recognition. We have identified short-term memory traces of two pattern parameters--elevation in the panorama and contour orientation. These can be localized to two groups of neurons extending branches as parallel, horizontal strata in the fan-shaped body. The central location of this memory store is well suited to mediate translational invariance.     

Latent synaptic pathways revealed after tetanic stimulation in the hippocampus

Synaptic plasticity may result from changes at existing synapses or from alterations in the number of functional synaptic connections. In the hippocampus excitatory synaptic strength is persistently enhanced after tetanic stimulation. Here we report that latent synaptic pathways may also become functional. Simultaneous intracellular recordings were made from pairs of CA3 pyramidal cells in slices from guinea pig hippocampus. After stimulating afferent fibres repetitively, polysynaptic excitatory pathways between previously unconnected cells became apparent. The efficacy of recurrent inhibitory circuits was also reduced. The loss of inhibitory control is of interest because latent excitatory pathways are revealed after pharmacological suppression of inhibition. This plasticity in local synaptic circuits leads to the emergence of synchronous firing in groups of CA3 cells. The formation of groups of associated cells and the ability of some cells to initiate synchronous firing in a larger cell group through recurrent pathways is reminiscent of several models of information storage and recall in the cortex.     

一个包含Smarandache函数的方程及其正整数解

研究数论函数的各种性质是初等数论的一个重要内容,而著名的Smarandache函数S(n)是重要的数论函数之一,它是由美籍罗马尼亚著名数论专家Florentin Smarandache教授首先提出的.许多学者对Smarandache函数的性质及含有Smarandache函数的方程的可解性做了深入的研究,并取得了丰硕的成果.文章正明了包含Smarandache函数的方程φ(n)=S(n10)的可解性,并给出了该方程的全部正整数解.