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Biomedical subjects

A Galarza

Publications and source records attributed to A Galarza.

11 recordsLinked to original sources
PubMed2003

Evaluation of Bacillus subtilis and coliphage MS2 as indicators of advanced water treatment efficiency.

The assessment of water treatment facilities for their efficiency using alternate indicators is of paramount importance. Current methods for assessing efficiency are limited by the specific characteristics of the microorganisms, such as their different sensitivities to disinfectants. A pilot study was carried out to compare different treatment scenarios for the future upgrade of the Sergio Cuevas Water Treatment plant (the largest in the Caribbean) in San Juan, Puerto Rico. The treatment units under investigation included a coagulation-flocculation-sedimentation unit, dual-media filters, micro-filtration units, intermediate ozone injection and contact columns as well as a biological filtration unit. The plant was challenged at different stages of treatment with Bacillus subtilis spores and MS2 coliphages in an attempt to test them as possible alternate indicators of treatment plant performance. These organisms were chosen because of their resistance to disinfection and desiccation, their low analysis costs and ease of detection. The removal of spores and coliphages by each treatment unit tested was calculated by seeding a known concentration (5-7 log10) of spores and coliphages and following the removal or disinfection rates. The seeded indicators were detected using traditional culture techniques. Ballasted clarification was shown to be highly efficient at removing 99.1% (approximately 3 log10) of the spores and 85.1% (approximately 0.86 log10) of MS2. Ozone treatment inactivated 80.37% (approximately 1.4 log10) spores and 99.95% (approximately 3.07 log10) coliphages. The coliphage inactivation rate obtained confirmed data obtained by previous studies indicating that MS2 was less resistant to ozonation than B subtilis spores. The membrane technology had the best efficiency in terms of physical removal of spores achieving over 99.9% (> 3 log10) removal. Coliphage removal mechanisms remain to be determined and will be a future focus of the study. Preliminary results indicate that aerobic spores and coliphages may be useful as indicators to determine the efficiency of different drinking water treatment technologies.

Bacillus subtilis↗
PubMed2001

Application of mathematical tools to improve the design and operation of activated sludge plants. Case study: the new WWTP of Galindo-Bilbao. Part I: Optimum design.

This paper presents a mathematical formulation for the optimum design of a new activated sludge WWTP. The WWTP optimum design problem has been formulated as a Mathematical Programming problem, which is solved through a nonlinear optimisation method. The plant model has been based on the ASM1. The minimum volume of the biological reactors and the minimum total cost (including construction and exploitation costs) have been considered as optimisation criteria. Some practical results are also included, using as a case study the design of the second stage of the Galindo-Bilbao WWTP.

Algorithms↗
PubMed2001

Application of mathematical tools to improve the design and operation of activated sludge plants. Case study: the new WWTP of Galindo-Bilbao. Part II: Operational strategies and automatic controllers.

This paper presents a new sensitivity analysis methodology for Activated Sludge WWTPs. It is based on both (a) the calculation of the range of "manipulated input variables" that satisfy the restrictions imposed on the "output variables" and (b) on the computation of isolines of the output variables inside the feasible operating space. This analysis allows a more precise description of the operating constraints, facilitates the understanding of the steady-state behaviour of the process and detects possible areas where the process is very sensitive to small disturbances. The feasible operating space for two Activated Sludge WWTP processes for CN removal (RDN, DRDN), using SRT and DO level as "input variables" as well as effluent quality and exploitation costs as the main "output variables" is studied. The proposed methodology facilitates the selection of the appropriate operational strategy and the design of automatic controllers. Some examples of the application of this methodology for the design of automatic controllers in a real WWTP are briefly presented.

Ammonia↗
PubMed1982

[Possible multienzymatic aggregate with glycolytic activity in the digestive gland of the mussel Mytilus galloprovincialis, Lamarck].

The possible presence of a glycolytic multienzyme complex in the digestive gland from the mussel, Mytilus galloprovincialis, Lamarck, has been investigated. The digestive gland homogenate was concentrated an applied to a Sepharose-2B column. The elution profile demonstrates that two species of glycolytic enzymes were eluted from the column. Most of the enzyme activity appeared in the low-molecular-weight region, the enzymes being eluted as individual entities in order of their molecular weights. However, a proportion of each enzyme activity was found in the high-molecular-weight region of eluate, with those activities showing a high degree of co-chromatography. By using a column calibrated with a series of marker proteins of known molecular weight, the activity peak for the high-molecular-weight species corresponded to a molecular weight of 3 X 10(6) +/- 10(5) d. Finally, it has been found that a sample of the high-molecular-weight species was able to catalyse the production of piruvate when it was incubated with different glycolytic substrates and the appropriate cofactors.

Animals↗
PubMed1978

[Studies on the release of dopamine-beta-hydroxylase by nicotine (author's transl)].

Comparative studies were made on the release of DBH by adrenal medullary slices after colinomimetic stimulation with acetylcholine, DMPP or nicotine. The in vivo effects of nicotine on the circulating plasma dopamine-beta-hydroxylase were tested in habitual and non habitual smokers after five cigarettes (12.5 mg of nicotine). The rise of plasma enzyme activity may reflect the increased catecholamine release from adrenal and peripheral adrenergic nerves.

Adrenal Glands↗