Wireless microphone for studies of animal vocalizations.

A microphone collar for obtaining good quality recordings of animal vocalizations is described. An inexpensive, commercially available wireless microphone was modified and mounted on a collar with a hearing-aidbattery pack. The complete assembly weighs 25 g, and is readily accepted by domestic cats.     

Simple chromosome banding technique for farm animal investigations]

For routine cytogenetic investigations, a simple banding technique on chromosomes is described. Used on different cell material, a visible banding appearance is produced which makes the typing of chromosomes precise and fast. On 2 examples of cattle and rabbit chromosomes, the identification of a centric fusion and a trisomic is shown.     

New method for determination of radioactivity in vegetal and animal tissues

Riassunto L'autore descrive un nuovo metodo per l'osservazione di substrati biologici radioattivati, basato sull'impiego della camera a diffusione.Questo strumento presenta notevoli vantaggi su quelli sinora impiegati in radiobiologia, perchè permette di osservare ad occhio nudo, fotografare ed identificare le caratteristiche di qualsiasi tipo di particelle ionizzanti, indipendentemente dalla loro energia.La camera a diffusione è particolarmente indicata per lo studio delle radiazioni ionizzanti di bassa energia.I risultati ottenuti dall'autore durante le osservazioni su organi animali e vegetali, su liquidi e minerali, sono stati assai soddisfacenti.     

Functional aspects of animal microRNAs

MicroRNAs (miRNAs) are a recently discovered family of small regulatory molecules that function by modulating protein production. There are approximately 500 known mammalian miRNA genes, and each miRNA may regulate hundreds of different protein-coding genes. Mature miRNAs bind to target mRNAs in a protein complex known as the miRNA-induced silencing complex (miRISC), sometimes referred to as the miRNP (miRNA-containing ribonucleoprotein particles), where mRNA translation is inhibited or mRNA is degraded. These actions of miRNAs have been shown to regulate several developmental and physiological processes including stem cell differentiation, haematopoiesis, cardiac and skeletal muscle development, neurogenesis, insulin secretion, cholesterol metabolism and the immune response. Furthermore, aberrant expression has been implicated in a number of diseases including cancer and heart disease. The role of miRNAs in these developmental, physiological and pathological processes will be reviewed. Received 3 August 2007; received after revision 3 October 2007; accepted 5 October 2007     

基于加权最小二乘的无线传感器网络Euclidean定位算法

针对Euclidean定位算法中定位精度及覆盖率受锚节点密度影响较大的问题,提出一种改进的节点定位算法。根据节点初始定位精度及测距精度提出一种新的加权方法。定位后的节点升级为辅助信标点。未知节点根据更新的锚节点位置信息循环求精。仿真表明该定位系统既能提高定位覆盖率又能减少定位累积误差,从而提高整个网络的定位精度。     

Implications of ancient DNA for phylogenetic studies

The utility of DNA sequence characters from fossil specimens is examined from a phylogenetic perspective. Four ways that fossil characters can alter phylogenetic hypotheses are discussed. Two empirical examples and a third hypothetical example concerning amber-preserved insects are presented to illustrate these phenomena. Fossil DNA sequences as characters will be affected by the problem of missing data and missing taxa. In general, cladogram accuracy will be more greatly affected by missing taxa and cladogram resolution will be affected more acutely by missing data. Due to these points, an examination of the importance of the phylogenetic question being addressed, the utility of the fossil DNA sequences and the rarity of the fossil should be considered before damage of a fossil is undertaken.     

GSM无线网络性能测试及优化

GSM网络日渐成熟,规模日趋完善,而移动通信业务却在迅猛发展,无线网络的具体情况也在随着环境改变,如何利用现有的网络资源最大限度的提高网络质量,使得网络性能测试和优化成为一项长期而艰巨的任务。本文首先对网络性能测试方法进行阐述,然后针对可能出现的问题进行网络优化。     

Chemistry of some potent animal toxins

Conclusion I have discussed in this article only the most active toxins, with the result that many interesting substances have been omitted, e.g. the toxins from bee and wasp venoms (apamin, melittin, etc.), of many amphibians (bufotoxins, etc.), ciguatoxins, and many more. Poisons are found in every phylum except birds. Shrews exemplify venomous mammals. One gets a good illustration of the number of poisonous animals by studying the monumental and impressive work byHalstead ¹⁰⁶ which consequently excludes terrestrial animals. An interesting fact in this connection is that there are about 20,000 species of spiders, most of which are poisonous.A toxin ranking list has to be included in an article of this kind. The list is, of course, far from complete. Data on molecular weights, mouse lethal doses, etc. are lacking for many potent toxins, such as the dysentery toxin, a neurotoxin with a toxicity comparable to that of the botulinus toxins¹⁰⁷, the toxins from the jelly fishChironex fleckeri ¹⁰⁶.A comparison on molar basis gives a better notion of the toxicities. Curare has about 1/30 of the toxicity of the curarimimetic snake venom neurotoxins, clearly indicating that curare has a much lower affinity for the acetylcholine receptor.Toxic organisms have developed during millions of years more and more refined toxins, and this evolution has probably brought into existence toxins against every physiological function. Neurochemistry is to a great extent unexplored. Progress in this field will in the nearest future depend on specific toxins from various natural sources. Toxins from spiders, scorpions, snakes, frogs, and fishes are therefore not mere curiosities but valuable tools for research on the molecular mechanisms of neural function and synaptic transmission.     

Lymphatic metastasis of transplantable animal neoplasms

Résumé L'injection de 5 millions de cellules tumorales RD3 dans la patte du rat, fait apparaître des dépôts métastasique sous forme de ganglions lymphatiques poplitétaux. L'examen histologique détaillé montre qu'ils sont vraies métastases. Des résultats pareils sont apparus dans 2 autres tumeurs qui étaient histologiquement malignes, mais non dans celles qui étaient bénignes. Cette technique semble convenir à étude de la métastase lymphatique.     

Re-examination of Rattus norvegicus as an animal model for Aeromonas-associated enteritis in man

We have developed an oral feeding model for Aeromonas hydrophila enteritis using Rattus norvegicus with clindamycin pretreatment. All animals in the clindamycin group developed a self-limited, loose stool by day four of feeding. Intestinal examination revealed evidence of enteritis. Moreover, antibiotic usage may be a predisposing risk factor to infection.     

A simple apparatus for the rapid extraction and weighing of small animal brains

Summary The construction and use of an inexpensive apparatus for the rapid extraction and weighing of small animal brains is described.     

Porcine skeletal muscle for physiological studies

Summary The common digital extensor (lateral head) is one of the few porcine muscles of convenient dimensions for in vitro studies of intact cells. Its removal and use in physiological studies are described.Acknowledgments. The pigs used in this investigation were provided by Drs D. G. Topel, L. L. Christian and G. A. Gronert whose cooperation is appreciated. Gratitude is also expressed to Dr N. G. Ghoshal for assistance with anatomical identifications.     

基于节点状态的多接口多信道WMN信道分配算法

多接口多信道无线Mesh两络信道分配的目的在于提升网络容量以及保持网络连通的同时,降低干扰,增强信道负载平衡.由此,提出一种基于节点状态的信道分配方案.该方案是一种基于优先级的多项式时间贪婪混合式算法.NS2仿真结果表明,该算法不仅可以较好地解决信道负载平衡,提升网络容量,而且即使在节点接口的数量少于有效信道数量时,也能使信道得到有效的分配,保证网络的连接通畅.     

一种基于软件再生的无线传感器网络簇头节点管理策略

本文构建了一种软件再生模型,采用主动再生与自我修复方法,研究WSN中簇头的有用性与生存性。实验表明：该方法能有效提高簇头的有用性和生存性。