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Control of fed-batch bioreactors. Part II

This chapter addresses the control of glucose feeding in fed-batchreactors. The feeding strategy is based on a pulse technique, whichdoes not require a priori knowledge of the process. A feedbackalgorithm optimizes the feed rate with respect to the constraints ofaerobic conditions and overfeeding. Stability and performance analysisare performed on a simplified model of the reactor, using standard

Telomeric DNA in Chironomus, a naturally telomerase-free system

Popular Abstract in Swedish Kromosomer, långa linjära DNA molekyler som finns i eukaryota organismers cellkärna i komplex med proteiner, är bärare av genetisk information. Kromosomer är samlingar av gener men de innehåller också regioner utan gener som är oumbärliga för kromosomstabiliteten och för att gener ska fördelas jämt vid varje celldelning. De strukturer som finns i slutet av linjära kromoTelomeres are specialized complexes of DNA and associated proteins that protect the ends of eukaryotic chromosomes. Although most organisms have short repeated DNA sequences at their telomeres, which are specified and maintained by the enzyme telomerase, there are a few exceptions. Dipteran insects, including the genus Chironomus (non-biting midges), lack telomerase and have atypical terminal sequ

A Quantum Chemical Study of Hydrogen Abstraction from Manganese-Coordinated Water by a Tyrosyl Radical: A Model for Water Oxidation in Photosystem II

Recently, water oxidation in photosystem II was proposed to involve direct abstraction of hydrogen atoms from water molecules terminally ligated to manganese ions in the oxygen-evolving complex by the oxidized tyrosine radical, TyrZ. This model is tested here by performing quantum chemical calculations. An empirically parametrized hybrid density functional method is used, and both monomeric and di

Effects of ultraviolet radiation on marine phytoplankton

This thesis examines the effects of artificial and solar ultraviolet radiation on photosynthesis, growth rate, phototactic orientation and motility of marine phytoplankton. The effects of UV-B (280-320 nm) radiation in combination with humic substances, as well as the ability of the organisms to adapt and/or recover from exposure to UV-B radiation, were also investigated. Phototactic orientation a