Bacillus solisalsi sp nov., a halotolerant, alkaliphilic bacterium isolated from soil around a salt lake

A novel Gram-positive, motile, rod-shaped bacterium isolated from a saline soil in China was characterized by a polyphasic taxonomic approach. The strain, designated YC1(T), was halotolerant [tolerating up to 15 % (w/v) NaCl] and alkaliphilic (growing at

我国蛇类爬行动物地理分区的聚类分析

本文以属为分类阶元，对我国蛇类爬行动物地理区划的t个区、十八个亚区进行了聚类分析。结果表 明：东洋界和古北界的划分可以明显地从爬行动物的分布中反映出来，但古北界区和亚区的划分则不能反映爬 行动物的地理分布特点。东洋界中，西南区喜马拉雅亚区单独聚为一支，是与其爬行动物主要来自于印度半岛 相～致的；而华南区的台湾亚区则与华中区和西南区的西南山地亚区聚在丁一起，说明将台湾亚区放在华南区 值得商榷。

Know thy neighbour: A normative theory of synaptic depression

Synapses exhibit an extraordinary degree of short-term malleability, with release probabilities and effective synaptic strengths changing markedly over multiple timescales. From the perspective of a fixed computational operation in a network, this seems like a most unacceptable degree of added variability. We suggest an alternative theory according to which short-term synaptic plasticity plays a normatively-justifiable role. This theory starts from the commonplace observation that the spiking of a neuron is an incomplete, digital, report of the analog quantity that contains all the critical information, namely its membrane potential. We suggest that a synapse solves the inverse problem of estimating the pre-synaptic membrane potential from the spikes it receives, acting as a recursive filter. We show that the dynamics of short-term synaptic depression closely resemble those required for optimal filtering, and that they indeed support high quality estimation. Under this account, the local postsynaptic potential and the level of synaptic resources track the (scaled) mean and variance of the estimated presynaptic membrane potential. We make experimentally testable predictions for how the statistics of subthreshold membrane potential fluctuations and the form of spiking non-linearity should be related to the properties of short-term plasticity in any particular cell type.

转反义sGnRH基因败育鲤鱼的性成熟诱导

采用反义转基因技术已成功获得整合CAsGnRHpc-antisense基因的转基因鲤鱼,简称AS-sGnRH F0鲤鱼。通过挤压1年龄AS-sGnRH F0鲤鱼的腹部,发现该群体中有精液/无精液个体比例为33/69,与对照组鲤鱼中有精液/无精液个体比例接近1:1相比存在显著差异。通过注射鲤鱼垂体抽提物诱导无精液AS-sGnRH F0鲤鱼恢复繁殖功能,获得3尾育性被恢复的AS-sGnRH F0鲤鱼。进一步的解剖观察发现,在无精液AS-sGnRH F0鲤鱼群体中,完全无性腺的AS-sGnRH F0鲤鱼比例约3

甲基安非他明及杂质的气相色谱/质谱分析

利用ＤＢ－５弹性石英毛细管柱气相色谱／质谱联用技术分析公安人员缴获非法生产甲基安非他明粗产品，其中含有甲基安非他明８３％，及主要杂质１－苯基丙酮１３．４６％和２－甲亚胺基－１－苯基丙烷１．３３％。此外还检测到了甲基安非他明的分解产物１－丙烯基苯０．１１％。２－丙烯基苯０．０３％和环丙基苯０．０１％等。据此我们可以判断，该甲基安非他明是从１－苯基丙酮和甲胺反应再经催化氢化合成而得。

A 16-term error model based on linear equations of voltage and current variables

Formulation of a 16-term error model, based on the four-port ABCD-matrix and voltage and current variables, is outlined. Matrices A, B, C, and D are each 2 x 2 submatrices of the complete 4 x 4 error matrix. The corresponding equations are linear in terms of the error parameters, which simplifies the calibration process. The parallelism with the network analyzer calibration procedures and the requirement of five two-port calibration measurements are stressed. Principles for robust choice of equations are presented. While the formulation is suitable for any network analyzer measurement, it is expected to be a useful alternative for the nonlinear y-parameter approach used in intrinsic semiconductor electrical and noise parameter measurements and parasitics' deembedding.