The Multimedia Internet Terminal (MInT)

The Multimedia Internet Terminal (MInT)\protect\footnotemark[1] is a flexible multimedia tool set that allows the establishment and control of multimedia sessions across the Internet. The system architecture is fully distributed, with no central components. For each participant, a coordinating application manages a set of loosely coupled media and control agents. Using the coordinating application, session members can control the sending and receiving of several audio and video streams, invite other users to the session and negotiate the order in which members are allowed to speak. The different components of MInT are separate processes that are independent from one another, yet can easily communicate with each other using a simple interprocess communication protocol based on local multicast. Individual components can be replaced without affecting the operation of other components. The same media agents can be used in applications ranging from mediaondemand retrieval to Internet telephony and distance learning, simply by using different control tools. To improve the quality of service of the multimedia sessions MInT is enhanced with a suite of QoS control mechanisms including resource reservation based on RSVP, adaptive media control and the ability to send video data in hierarchically layered streams. Thus, the tool set can accommodate a range of capabilities and available network bandwidths in heterogeneous environments.     

A simple method for the preparation of furosine and pyridosine reference material

After heatingN -acetyllysine and glucose for 4 h at 90 °C in the dry state and subsequent acid hydrolysis with 7.8 N HCl, preparative fractionation of the dihydrochlorides of furosine and pyridosine was achieved by cation-exchange chromatography. The lysine derivatives could be prepared with high yield and sufficient purity for the use as reference material.

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Ein einfaches Verfahren zur Darstellung von Furosin- und Pyridosin-Standards

Zusammenfassung Nach dem Erhitzen vonN -Acetyllysin und Glucose für 4 h bei 90 °C in trockenem Zustand und nachfolgender Hydrolyse mit 7.8 N HCl erfolgte eine präparative Fraktionierung der Dihydrochloride von Furosin und Pyridosin durch Kationenaustauschchromatographie. Die Lysinderivate wurden in guter Ausbeute und in für Referenzmaterial ausreichender Reinheit erhalten.

     

Comparing trees via crossing minimization

We consider the following problem (and variants thereof) that has important applications in the construction and evaluation of phylogenetic trees: Two rooted unordered binary trees with the same number of leaves have to be embedded in two layers in the plane such that the leaves are aligned in two adjacent layers. Additional matching edges between the leaves give a one-to-one correspondence between pairs of leaves of the different trees. Our goal is to find two planar embeddings of the two trees (drawn without crossings) that minimize the number of crossings of the matching edges. We derive both (classical) complexity results and (parameterized) algorithms for this problem (and some variants thereof).¹     

The Structures of Three [2.2]Paracyclophane Derivatives with Anellated Four-Membered Rings

The structures of the three benzocyclobutenophanes 1 a , 1 b (2 stereoisomers), and 11 have been determined by NMR spectroscopy and X-ray structural analysis. The preparation of 11 from 4,5-diethynyl[2.2]paracyclophane ( 9 ) is described.     

Coupling of Phosphates on Alumina Surfaces for Bioactivation

This paper reports on a new surface treatment, coupling phosphates on alumina surfaces for bioactivation. Alumina samples were treated in monoaluminumphosphate solution at 1400°C. Strongly coupled aluminum phosphates due to the treatment were proved by X-ray diffraction and infrared spectroscopy. Contact angle measurements proved the hydrophilic nature of the treated surface. In vitro tests in simulated body fluid indicated a bioactive behavior by means of apatite-forming ability. Such functionalized alumina ceramics imply the potential for a new class of bioactive high-strength ceramic implant materials, due to a pronounced affinity of bioactive phosphate groups to particular amino acid sequences of proteins.     

将危险降到最低——新电容器能满足无功功率补偿的新需求

没有电容器，要进行无功功率补偿和滤波几乎是不可能的。常规的高压交流（HVAC）电容器都需要用油，因，此会造成漏油并存在发生火灾的危险，以及造成环境污染。ABB着手研制的新一代电容器可解决上述问题，是一种不用油的电容器。     

Role of microcystins in poisoning and food ingestion inhibition of Daphnia galeata caused by the cyanobacterium Microcystis aeruginosa

The effects of microcystins on Daphnia galeata, a typical filter-feeding grazer in eutrophic lakes, were investigated. To do this, the microcystin-producing wild-type strain Microcystis aeruginosa PCC7806 was compared with a mcy- PCC7806 mutant, which could not synthesize any variant of microcystin due to mutation of a microcystin synthetase gene. The wild-type strain was found to be poisonous to D. galeata, whereas the mcy- mutant did not have any lethal effect on the animals. Both variants of PCC7806 were able to reduce the Daphnia ingestion rate. Our results suggest that microcystins are the most likely cause of the daphnid poisoning observed when wild-type strain PCC7806 is fed to the animals, but these toxins are not responsible for inhibition of the ingestion process.