萤火虫的发光行为及其功能起源

下载PDF阅读器发光生物因其活体能自发荧光而倍受关注,萤火虫(鞘翅目:萤科)是被研究最多的发光生物,因为成虫发光在其性选择以及求偶交配中起着重要作用.由于萤火虫的发光是一个消耗能量(ATP),的化学反应过程,因而其发光在成虫之外的虫态也具有重要意义.本文就萤火虫成虫和幼虫的发光行为、功能意义进行了综述,并结合萤火虫的饲养观察对其卵和蛹的发光行为进行了描述,探讨了卵和蛹的形态阶段发光的生物学功能以及生物荧光的起源进化.这将有助于理解萤火虫及其它生物自发荧光的本质和起源进化过程.

Final report of the baseline data reconstruction for the Quality Assurance for Fish Marketing Project

A baseline survey for the project which had been conducted in 2009 had gaps that could not allow assessment of project performance in the outcome and impact indicators to be made. This study was, therefore, commissioned to reconstruct the baseline data, aligned to the impact and outcome indicators on the project logframe and results framework, against which project achievements could be assessed. The purpose and scope of the study was to reconstruct the baseline data and analysis describing the situation prior to QAFM Project inception, taking 2008 as the baseline year, which was aligned to the project logframe outcome and impact indicators; to collect data on current status to compare project outcome (and where possible impact) in improved fish handling sites in comparison with the baseline as well as with comparable non-improved fish landing sites as control group. The study was conducted through secondary data search from sources at NaFIRRI, DFR and ICEIDA. Field data collection was carried out using a sample survey covering 312 respondents including boat and gear owners, crew members, processors and traders at eight project and two control landing sites. Key Informant Interviews were conducted with DFOs and BMU leaders in the study districts and landing sites respectively.

慢性应激对大鼠空间学习记忆及海马和前脑皮层突触体膜流动性的影响

慢性应激对学习记忆功能的影响是神经科学的热点问题,在脑内,海马和前额叶是与学习记忆功能密切相关的重要脑区,也是应激易累及损伤的主要靶区。膜流动性的改变在神经细胞功能活动中起重要作用。为探讨慢性应激对大鼠空间学习记忆功能的影响及前脑皮层和海马突触体膜流动性的作用。采用多因素慢性应激动物模型,通过开场试验和Morris水迷宫测试大鼠行为及空间学习记忆能力;并且测定大鼠前脑皮层和海马突触体膜流动性和突触体内游离Ca2+浓度的变化。研究结果显示,与对照组相比,应激组大鼠在应激后即刻,在新异环境中的自发活动和探究行为显著降低(p<0.05,p<0.01),空间学习记忆能力明显下降(p<0.05,p<0.01);并且应激组大鼠前脑皮层和海马突触体膜流动性显著降低(p<0.05,p<0.01);而突触体内游离Ca2+浓度的显著增加(p<0.05,p<0.01)。停止应激后一周,应激大鼠的各项指标有所恢复,但仍未达到正常水平。研究结果提示,慢性应激引起大鼠明显的开场行为改变和空间学习记忆功能障碍,这些变化可能与突触体膜流动性和突触体内游离Ca2+浓度的变化密切相关。

Integrated avalanche diode for 600 v Trench IGBT over-voltage protection

Avalanche multiplication has been one of the major destructive failure mechanisms in IGBTs; in order to avoid operating an IGBT under abnormal conditions, it is desirable to develop peripheral protecting circuits monolithically integrated without compromising the operation and performance of the IGBT. In this paper, a monolithically integrated avalanche diode (D av) for 600V Trench IGBT over-voltage protection is proposed. The mix-mode transient simulation proves the clamping capability of the D av when the IGBT is experiencing over-voltage stress in unclamped inductive switching (UIS) test. The spread of avalanche energy, which prevents hot-spot formation, through the help of the avalanche diode feeding back a large fraction of the avalanche current to a gate resistance (R G) is also explained. © 2011 IEEE.

中国橙腹长吻松鼠种下分类的探讨

中国西南部的橙腹长吻松鼠应分为四个亚种。西藏东南部米什米山区、察隅和云南西北部高黎贡山一带的D.l.Subflavientris应为一有效亚种; 西藏南部聂拉木等地的橙腹长吻松鼠D.l. nielamuensis为新亚种, 它们有头骨小、体色浅等特点; 西藏南部雅鲁藏布江大拐弯以西的墨脱亚种D.l. motuoensis也为有效亚种; 南亚亚种D.l. garonum亦应有效。图1表5参9

盘qu属鱼类口吸盘的形态分化及其意义

具大、小吸盘的两个类群是盘qu鱼类在演化进程中分化成的两个自然类群, 它们为适应不同的栖息环境, 吸盘的微观结构和须的长短等进一步分化, 分化途径在两个类群各不相同。图版2参9

Separation and purification of ovulation-inducing factors in the seminal plasma of the Bactrian camel (Camelus bactrianus)

Ovulation in the Bactrian camel depends upon ovulation-inducing factors in the seminal plasma. The present study was conducted to isolate and purify the bioactive fractions from the seminal plasma of these camels. The seminal plasma was fractionated by anion-exchange chromatography, and six fractions were obtained. The bioactive potential of each fraction was estimated from its effect on rat pituitary tissue cultured in vitro and by the effect of an intramuscular injection of the fraction into female camels in vivo. Both the third fraction (F3) and the fifth fraction (F5) stimulated the release of LH in vitro and in vivo. In addition, female camels ovulated within 48 h after intramuscular injection of F3. However, neither F3 nor F5 had any significant effect on the secretion of FSH, either in vitro or in vivo. When F3 was further fractionated into four subfractions, the third subfraction (F3-3) still stimulated the in vitro release of LH, but not of FSH. An attempt to further purify the ovulation-inducing factors in F3-3 failed owing to the similarity of the molecular characters.

On-line policy optimisation of spoken dialogue systems via live interaction with human subjects

Statistical dialogue models have required a large number of dialogues to optimise the dialogue policy, relying on the use of a simulated user. This results in a mismatch between training and live conditions, and significant development costs for the simulator thereby mitigating many of the claimed benefits of such models. Recent work on Gaussian process reinforcement learning, has shown that learning can be substantially accelerated. This paper reports on an experiment to learn a policy for a real-world task directly from human interaction using rewards provided by users. It shows that a usable policy can be learnt in just a few hundred dialogues without needing a user simulator and, using a learning strategy that reduces the risk of taking bad actions. The paper also investigates adaptation behaviour when the system continues learning for several thousand dialogues and highlights the need for robustness to noisy rewards. © 2011 IEEE.