A critical evaluation of combined engineered and aquifer treatment systems in water recycling.

Australian experience at five research sites where stormwater and reclaimed water have been stored in aquifers prior to reuse, have yielded valuable information about water treatment processes in anaerobic and aerobic aquifers. One of these sites is the stormwater to potable water ASTR project at the City of Salisbury, a demonstration project within the broader EC project 'RECLAIM WATER'. A framework for characterising the effectiveness of such treatment for selected organic chemicals, natural organic matter, and pathogens is being developed for inclusion in new Australian Guidelines for Management of Aquifer Recharge. The combination of pre-treatments (including passive systems such as reed beds) and aquifer treatment effectiveness in relation to source waters and intended uses of recovered water will be described. Advantages and disadvantages of various types of pre-treatments in relation to effectiveness and sustainability of managed aquifer recharge will be discussed taking account of aquifer characteristics. These observations will be consolidated into a draft set of principles to assist in selection of engineered treatments compatible with passive treatment in aquifers.

Effects of selective inactivation of individual genes for low-molecular-mass subunits on the assembly of photosystem II, as revealed by chloroplast transformation: the psbEFLJoperon in Nicotiana tabacum.

Photosystem (PSII) is a supramolecular polypeptide complex found in oxygenic photosynthetic membranes, which is capable of extracting electrons from water for the reduction of plastoquinone. An intriguing feature of this assembly is the fact that it includes more than a dozen low-mass polypeptides of generally unknown function. Using a transplastomic approach, we have individually disrupted the genes of the psbEFLJoperon in Nicotiana tabacum, which encode four such polypeptides, without impairing expression of downstream loci of the operon. All four mutants exhibited distinct phenotypes; none of them was capable of photoautotrophic growth. All mutants bleached rapidly in the light. Disruption of psbEand psbF, which code for the alpha and beta apoproteins of cytochrome b(559), abolished PSII activity, as expected; Delta psbL and Delta psbJ plants displayed residual PSII activity in young leaves. Controlled partial solubilisation of thylakoid membranes uncovered surprisingly severe impairment of PSII structure, with subunit and assembly patterns varying depending on the mutant considered. In the Delta psbL mutant PSII was assembled primarily in a monomeric form, the homodimeric form was preponderant in Delta psbJ, and, unlike the case in Delta psbZ, the thylakoids of both mutants released some PSII supercomplexes. On the other hand, Photosystem I (PSI), the cytochrome b(6)f complex, ATP synthase, LHCII, and CP24/CP26/CP29 antennae were present in near wild-type levels. The data are discussed in terms of their implications for structural, biogenetic and functional aspects of PSII.

Deregulation of electron flow within photosystem II in the absence of the PsbJ protein.

The photosystem II (PSII) complex of photosynthetic oxygen evolving membranes comprises a number of small proteins whose functions remain unknown. Here we report that the low molecular weight protein encoded by the psbJ gene is an intrinsic component of the PSII complex. Fluorescence kinetics, oxygen flash yield, and thermoluminescence measurements indicate that inactivation of the psbJ gene in Synechocystis 6803 cells and tobacco chloroplasts lowers PSII-mediated oxygen evolution activity and increases the lifetime of the reduced primary acceptor Q(A)(-) (more than a 100-fold in the tobacco DeltapsbJ mutant). The decay of the oxidized S(2,3) states of the oxygen-evolving complex is considerably accelerated, and the oscillations of the Q(B)(-)/S(2,3) recombination with the number of exciting flashes are damped. Thus, PSII can be assembled in the absence of PsbJ. However, the forward electron flow from Q(A)(-) to plastoquinone and back electron flow to the oxidized Mn cluster of the donor side are deregulated in the absence of PsbJ, thereby affecting the efficiency of PSII electron flow following the charge separation process.

Molecular adaptation of Drosophila melanogaster lysozymes to a digestive function.

A lysozyme (pI 5.5) was purified to homogeneity from heated acid extracts of Drosophila melanogaster larvae, using gel filtration in a Superose column and ion-exchange chromatography in a Mono Q column. The final yield was 67%. The purified lysozyme with Mr 13,700 (determined by SDS-polyacrylamide gel electrophoresis) decreases in activity and has its pH optimum displaced towards acidic values and Km increases as the ionic strength of the medium becomes higher. The lysozyme is resistant to a cathepsin D-like proteinase present in cyclorrhaphous Diptera and displays a chitinase activity which is 11-fold higher than that of chicken lysozyme. Microsequencing of an internal peptide of the purified lysozyme showed that this enzyme is the product of the previously sequenced Lys D gene. The results suggest that the product of the Lys P gene has pI 7.2, a pH optimum around 5 and is not a true digestive enzyme. The most remarkable sequence convergence of D. melanogaster lysozyme D and lysozymes from vertebrate foregut fermenters are serine 104 and a decrease in the number of basic amino acids, suggesting that these features are necessary for digestive function in an acid environment. Adaptive residues putatively conferring stability in an acid proteolytic environment differ between insects and vertebrates, probably because they depend on the overall three-dimensional structure of the lysozymes. A maximum likelihood phylogeny and inferences from insect lysozyme sequences showed that the recruitment of lysozymes as digestive enzymes is an ancestral condition of the flies (Diptera: Cyclorrhapha).

[Comparison of the values of automatic ECG analysis according to the Smith and the Pipberger diagnostic programs by means of a serial study in a large industry]. / Vergleich der Aussagefähigkeit der automatischen Ekg-Analyse nach den Diagnoseprogrammen von Smith und Pipberger anhand einer Reihenuntersuchung in einem Grossbetrieb.

It could be shown that an ECG-screening could be integrated into the routine work of a factory outpatient department. As a result of the automatical analysis of the ECG we got an exact knowledge of the efficiency of Smith's and Pipberger's diagnostic programmes. The suitability of the two programmes for screening examinations resulted from the 91% and 97% certain separation of normal and pathological findings and the small proportion of falsely negative results (Smith, Pipberger). Concerning the exact differentiation of pathological ECG the frequency of recognition of Pipberger's programme still surpassed that one of Smith's programme. However, the two programmes show a diagnostic security which lies above the visual diagnosing. The establishment of findings performed off line per week ascertained a rapid disposal of results. In comparison to former examinations newly detected cases could be established only in a small percentage. The importance for health polities of such examinations results from the necessity of the prophylaxis of cardio-vascular diseases, the numbers of morbidity and mortality of which are permanently increasing.