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Biomedical subjects

J Gunn

Publications and source records attributed to J Gunn.

151 records · Page 9Linked to original sources
PubMedDate not supplied

A study of mastitis bacteria and herd management practices to identify their relationship to high somatic cell counts in bulk tank milk.

Thirty dairy herds, selected to cover a wide range of bulk tank somatic cell count (BTSCC) values, were used to study the relationship between the levels of the principal species of mastitis-causing bacteria, herd management practices and the BTSCC. A good correlation was found between the number of mastitis streptococci (Streptococcus agalactiae, S. dysgalactiae and S. uberis) found in bulk tank milk and the BTSCC. Staphylococcus aureus was less significantly correlated to BTSCC, but was of increasing importance in borderline BTSCC herds, where lower excretion levels into milk were unlikely to trigger hygiene penalties and so alert producers to the presence of a significant mastitis problem. High BTSCC herds had significantly lower yields and were less likely to use a post-milking teat dip or to have a regular programme of milking machine maintenance or automatic cluster removal. These herds also tended to buy in replacements rather than breed their own. Overall the management of high BTSCC herds showed less commitment to implementing mastitis control procedures than herds with a consistently low BTSCC.

Animals↗
PubMedDate not supplied

Effects of regional reductions in sulphur deposition on the chemical and biological recovery of lakes within Killarney Park, Ontario, Canada.

The lakes in Killarney Provincial Park, located 40-60 km southwest of Sudbury, Ontario, were some of the first lakes in North America to be acidified by atmospheric pollutants. Acidification affected thousands of fish and invertebrate populations in dozens of lakes. Since the 1970's, water quality has improved in response to atmospheric pollution reductions and some lakes have already recovered to approximately their pre-industrial pH levels, as inferred from diatom microfossils in lake sediments. Since the 1970's, fish species richness has not changed substantially, but zooplankton species richness has increased in acidified lakes. The critical sulphur load, the amount of SO2-derived acid deposition that can occur while still maintaining suitable water quality, was estimated to be exceeded in 38% of the park area in 1997. Depending on which of four possible North American emission control scenarios (CLR = currently legislated reduction; CLR + 25%; CLR + 50%; CLR + 75%) is achieved by 2010, the projected critical loads will be exceeded in about 0-30% of the park area in the future. There are many factors that can affect biological recovery rates of damaged lakes, but it is expected that biological recovery will lag considerably behind observed chemical recovery rates.

Acid Rain↗
PubMedDate not supplied

Measurement of the symmetry of in vitro stent expansion: a stereo-photogrammetric approach.

Balloon-expandable stents are used routinely in the treatment of coronary artery disease. Their effectiveness is limited by the occurrence of restenosis. Previous studies have suggested that the level of restenosis may be related to the deployed stent geometry, and in particular to the symmetry of the deployment profile. It is suggested that the symmetry of deployment might be influenced by the folding pattern of the balloon on which the stent is delivered. This paper describes a stereo-photogrammetric system for the three-dimensional reconstruction of stent geometry during expansion, including appropriate specification and calibration procedures. Calibration testing of the system indicated an accuracy of +/-0.05 mm in the reconstruction of the position of a point on the stent surface. Methods for processing the 3D data are described, including a technique for quantitatively differentiating between results from two alternative balloon folding patterns. This study may aid future balloon and stent design with respect to the optimization of stent deployment characteristics.

Biomechanical Phenomena↗
PubMedDate not supplied

Biomimicry 1: PC.

The surface properties of stents can be modified by coating them, for example with a polymer. Phosphorylcoline (PC) is the major component of the outer layer of the cell membrane. The haemo- and biocompatibility of a PC-containing polymer is thus based on biomimicry, and has been confirmed by several experiments showing much reduced thrombogenicity of PC-coated surfaces, and porcine coronary artery implants showing no sign of adverse effect. Clinical experience with the PC-coated BiodivYsio appears favourable. The PC coating can be tailored for take up and controlled elution of various drugs for stent-based local delivery, a property which is being actively explored.

Animals↗
PubMedDate not supplied

Effect of a manager training program on sanitary conditions in restaurants.

OBJECTIVE: To evaluate the effectiveness of a food manager training and certification program in increasing compliance with restaurant sanitary codes. METHODS: Using routine sanitary inspection records, the authors compared pre- and post-training inspection scores for 94 restaurants falling into three groups: a "mandatory" group (managers' attendance was mandated for these restaurants); a "voluntary" group (managers attended the training voluntarily); and a control group (no staff attended the training program). RESULTS: Restaurants for which managers were mandated to attend a training and certification program demonstrated a significant improvement in inspection scores, an improvement that was sustained over a two-year follow-up period. The mean inspection scores for a control group did not change significantly over time. However, improvements were not noted in all areas of food safety. CONCLUSIONS: Food manager training and certification programs may be an effective way to improve the sanitary conditions of restaurants and reduce the spread of foodborne illnesses.

Boston↗