Filtration of Green Algae and Cyanobacteria by Freshwater Mussels in the Partitioned Aquaculture System

Abstract.— The freshwater mussel Elliptio complanata was provided water containing green algae and cyanobacteria delivered from the Partitioned Aquaculture System (PAS) at eight flow rates to determine algal filtration rates as mg of particulate organic carbon (POC)/kg wet tissue weight per h. The dominant taxon in cyanobacterial waters was Microcystis while the dominant taxa in green algal waters were Scenedesmus and Ankistrodesmus . The cell counts of Scenedesmus and Ankistrodesmus were the only algal taxa that were significantly different between the incoming water and water filtered by mussels. Filtration rates of POC obtained from green algal water were significantly greater than from cyanobacteria-dominated waters at all flow rates. A significant increase in mean filtration rate was observed as flow rates increased. The filtration rate of green algae increased as POC concentration increased, peaking at 28 mg C/L. A maximum filtration rate was not observed with cyanobacterial waters.     

Anesthesia for patients with severe systemic debilitation.

Any patient presenting for anesthesia and surgery who has a severe debilitating problem is at great risk for a prolonged recovery, renal failure, or hypotension. A stable hemodynamic state should be maintained. Fluid homeostasis should be ensured. Anesthetic induction techniques using narcotics and benzodiazepines are my preferred approach, with maintenance of anesthesia incorporating isoflurane, narcotics, or both or the use of regional anesthesia.     

Leeching as initial treatment in a cat with polycythaemia vera.

Polycythaemia vera was diagnosed in a three-year-old domestic shorthaired cat referred because of seizures and a high packed cell volume (PCV). Laboratory examination revealed severe erythrocytosis (PCV 79 per cent). Diagnosis was reached by excluding causes for relative and secondary absolute polycythaemia. As phlebotomy proved impossible for initial treatment due to hyperviscosity, four leeches were used to suck blood and the PCV was consequently reduced to 64 per cent. A further 24 hours later, when bleeding at the sites of sucking had stopped, the PCV was 56 per cent. Long-term management of the condition was achieved with hydroxyurea (100 mg/cat once daily) and intermittent phlebotomy. Initial treatment using leeches in cases of polycythaemia vera is a simple, non-invasive, well tolerated and effective method where phlebotomy is not possible.     

The effect of exploratory laparotomy on the serum and peritoneal haptoglobin concentrations of the pony.

Serum haptoglobin concentration was used as an indicator of the acute phase response in ponies undergoing exploratory laparotomy. Preoperative, 1 h intraoperative, 3 h, 6 h, 12 h and 24 h postoperative blood samples and 48 h postoperative peritoneal fluid samples were obtained for haptoglobin analysis. A spectrophotometric assay based on cyanmethemoglobin binding capacity (CyanBC) was used to determine haptoglobin concentrations. The preoperative reference range for serum haptoglobin concentrations in these ponies was 25-60 mg CyanBC/dL. Intraoperative and 3 h postoperative blood samples had decreased haptoglobin concentrations when compared to preoperative values. Serum haptoglobin concentrations began to rise by the 6 h postoperative sample and were generally elevated above preoperative values by the 24 h postoperative sample. Two of the ten ponies had mild signs of postoperative colic which were associated with twofold elevations in serum haptoglobin concentrations and fivefold elevations in peritoneal fluid haptoglobin concentrations.     

Effect of age on absorption and immune responses to weaning or introduction of novel dietary antigens in pigs

Pigs weaned at three weeks old absorb food protein antigens from the intestine. The amount of antigen absorbed declines over the next three weeks, and this decline is associated with an increasing level of serum antibody to the fed proteins. There was no difference in the rate of immune elimination of intravenously injected antigen in fed and unfed controls. The reduction of serum antigen is thus likely to reflect reduced absorption, possibly mediated by locally produced antibody. Pigs weaned at 10 weeks old also absorbed antigens and produced an antibody response when introduced to soya; and after three weeks of feeding soya the absorption of antigen was substantially reduced. This latter exclusion was specific for soya as a second novel protein (ovalbumin) was absorbed when introduced to the diet at this time. At six months, pigs no longer absorbed soya proteins when they were introduced to the diet. Furthermore, pigs of this age had serum 'antibody' to soya and other proteins such as keyhole limpet haemocyanin to which they had never been exposed.     

Multiresidue assay for benzimidazole anthelmintics by liquid chromatography and confirmation by gas chromatography/selected-ion monitoring electron impact mass spectrometry

A multiresidue method utilizing all-disposable labware has been developed for 8 benzimidazole anthelmintics from ovine, bovine, and swine muscle and liver tissues. After an initial extraction with ethyl acetate and subsequent evaporation, a 3-component extraction using hexane, ethanol, and 0.2N HCl was used for final cleanup. Clean extracts were produced for separation and determination by reverse-phase liquid chromatography at 298 nm, using methanol and aqueous buffer as mobile phase. A synthesized internal standard, 2-(n-butylmercapto)benzimidazole, was used for quantitation of all drugs. Results are included along with statistical information verifying the performance of the method. Spiked control tissues and incurred drug tissues were used for an intralaboratory study with a concentration range of 50-1470 ppb. A series of standard curves at 0, 50, 100, and 200 ppb were analyzed. Overall recovery at the 100 ppb level averaged 92% (CV 8%) in liver tissues, across all 3 species and 88% (CV 5%) in muscle tissues across all 3 species. Results were confirmed by gas chromatography/mass spectrometry with acid hydrolysis of the remaining extract in 2N HCl followed by re-extraction of the amine and derivatization to the tert-butyldimethylsilyl derivative. The anthelmintics were identified by gas chromatography/selected ion monitoring electron-impact mass spectrometry. Ion ratio measurements were taken and compared to standard material. CVs averaged 10% or less for all drugs tested.