LaPSvS1, a (1→3)-β-galactan sulfate and its effect on angiogenesis in vivo and in vitro

LaPSvS1, a highly sulfated branched (1→3)-β-galactan was prepared from the arabino-galactan from Larix decidua Miller by partial hydrolysis and subsequent sulfation with SO3-pyridine in DMF. The molecular weight was analyzed by GPC and the sulfate content was determined by ion chromatography. LaPSvS1 exhibited good antiangiogenic and antiinflammatory effects in two different modifications of the known CAM-assay. In vitro results obtained in the FGF-2-trypsin-assay and in fluorospectrometric experiments revealed that LaPSvS1 interacts with the fibroblast growth factor 2 system. This interaction is correlated with the in vivo effect of LaPSvS1 on FGF-2 induced angiogenesis. A highly sulfated branched (1→3)-β-galactan (LaPSvS1) exhibits good antiangiogenic and antiinflammatory effects in CAM-assays. In vitro results reveal that LaPSvS1 interacts with the FGF-2 system correlating with the in vivo effect of LaPSvS1 on FGF-2 induced angiogenesis

An argumentative knowledge-based model construction approach for Bayesian networks

In this paper, an argumentative knowledge-based model construction (KBMC) technique for Bayesian networks is presented. This approach allows an agent to collect and instantiate the most accepted subset of an imperfect knowledge base to dynamically construct a Bayesian network. Arguments are constructed to represent active paths through an agent's knowledge base - paths consisting of information that is computationally relevant in the evaluation of a query Pr(Q|E). Argumentation over paths is used to select the valid or most accepted information according to the preferences of the agent. This information is consequently formed into candidate network structures by accrual. This work is presented as an extension of the KBMC approach of Haddawy [5]. The potential of the approach to be used in multi-agent network construction is discussed.2008Sixth European Workshop on Multi-Agent Systems: EUMAS 200

Measurements of light atmospheric hydrocarbons over the Atlantic in regions of low biological activity

More than 200 in situ measurements of several selected nonmethane hydrocarbons (NMHCs) were made in the remote marine atmosphere over the Atlantic between 40°S and 50°N. Ethane, the by far longest lived of the NMHCs, showed southern hemispheric mixing ratios around 280 ppt, comparable in magnitude to most other previous measurements. The mixing ratios of ethene, propene, propane, and i‐ and n‐butane in the southern hemisphere were in the range of 10–30 ppt. For i‐pentane and n‐pentane the atmospheric mixing ratios in the southern hemisphere were below the detection limit of 15–20 ppt. These values are rather low compared to other published measurements in the marine atmosphere. This is due to the remoteness of the measuring locations and the very low biological activity in the surrounding ocean areas. For all alkanes the latitudinal profiles exhibit a considerable decrease from north to south. The relative hydrocarbon patterns show that the alkanes in the northern hemisphere are primarily due to long‐range transport from continental or coastal areas. In general the transport times exceed several days. Consequently, the observed northern hemispheric ethene and propene mixing ratios must be, with few exceptions, primarily the result of oceanic emissions. The average difference of these compounds by a factor of 2 between the southern and the northern hemisphere can be explained by change of the phytoplankton concentration in ocean water. There is little or no indication for the existence of significant diurnal cycles for these two alkenes

Modelling pH-optimized degradation of microgel-functionalized polyesters

We establish a novel mathematical model to describe and analyze pH levels in the vicinity of poly(N-vinylcaprolactam-co-acetoacetoxyethyl methacrylate-co-N-vinylimidazole) (VCL/AAEM/VIm) microgel-functionalized polymers during biodegradation. Biodegradable polymers, especially aliphatic polyesters (polylactide/polyglycolide/polycaprolactone homo- and copolymers), have a large range of medical applications including delivery systems, scaffolds, or stents for the treatment of cardiovascular diseases. Most of those applications are limited by the inherent drop of pH level during the degradation process. The combination of polymers with VCL/AAEM/VIm-microgels, which aims at stabilizing pH levels, is innovative and requires new mathematical models for the prediction of pH level evaluation. The mathematical model consists of a diffusion-reaction PDE system for the degradation including reaction rate equations and diffusion of acidic degradation products into the vicinity. A system of algebraic equations is coupled to the degradation model in order to describe the buffering action of the microgel. The model is validated against the experimental pH-monitored biodegradation of microgel-functionalized polymer foils and is available for the design of microgel-functionalized polymer components