Application of an entropy-based Bayesian optimization technique to the redesign of an existing monitoring network for single air pollutants.

We apply the entropy-based Bayesian optimizing approach of Le and Zidek to the spatial redesign of the extensive air pollution monitoring network operated by Metro Vancouver, in the Lower Fraser Valley, British Columbia. This method is chosen because of its statistical sophistication, relative to other possible approaches, and because of the very rich, two-decade long data record available from this network. The redesign analysis is applied to ozone, carbon monoxide and PM(2.5) pollutants. The analysis provides guidance with regard to stations monitoring the three pollutants. For both ozone and PM(2.5), the analysis indicates a need for more stations in the eastern part of the monitoring domain. A parallel analysis indicates that stations may be removed from the more central parts of the domain. An analysis of the carbon monoxide network produces results that are not nearly as clearly defined as those for the other two pollutants, presumably because carbon monoxide is a primary pollutant with many locally important sources. The work demonstrates the great utility of the analysis technique, and also provides statistically defensible guidance on the spatial redesign of this important monitoring network.

Effect of synchronization of energy and nitrogen supply on ruminal characteristics and microbial growth.

The effect of energy and N synchronization in the rumen on microbial growth was investigated. The same daily amount of readily available energy and N sources (19 g of ruminally degradable N/kg of fermentable OM) was supplied intraruminally to sheep, according to different patterns, namely both energy and N as 12-hourly pulse-doses (fast synchronized supply), energy as 12-hourly pulse-doses and N as a continuous infusion (unsynchronized supply), energy as a continuous infusion and N as 12-hourly pulse doses (unsynchronized supply), and both energy and N as continuous infusions (slow synchronized supply). The study was done near maintenance (Exp. 1) and at a higher level of nutrition (Exp. 2). The degree of energy and N synchronization affected neither microbial flow nor efficiency of growth (P > .2 for energy x N interaction). Continuous infusion of energy resulted in a 17% (P < .05) and 14% (P = .18) higher efficiency of microbial growth than did pulse dosing in Exp. 1 and 2, respectively. This coincided with lower (P < .01) ruminal pH and higher (P < .05) ruminal lactic acid concentration for energy pulse-dose treatments. The results suggest that merely improving the degree of synchronization between energy and N release rates in the rumen does not increase microbial yield. Dietary manipulation, rather, should be aimed at first obtaining the most even ruminal energy supply pattern, and then at providing the appropriate amount of ruminally available N. Thereafter some further advantage may be gained in also ensuring a more even N supply pattern, particularly avoiding too rapid a ruminal N release.

The use of methyl methacrylate bone cement as an internal splint in the treatment of fractures of the canine axis.

Three dogs with fractures of the body of the axis showing moderate to severe displacement were presented for treatment. The fractures were exposed, screws were fixed into each fragment and the heads of the screws were embedded in bone cement to serve as an internal splint. The surgical approach and technique are described.

An experimental study on the use of a carbon fibre prosthesis for the repair of the cranial cruciate ligament in the dog.

The severed cranial cruciate ligament of Beagles was replaced with a carbon fibre tow. Post-operatively the animals were evaluated clinically and radiographically. The animals were sacrificed and specimens collected for histology. There was marked infiltration of the implant by granulation tissue which matured into longitudinally orientated collagen fibres to form a new ligament. A foreign body reaction which occurred at about 12 weeks subsided after a few more weeks. Fracture of the implant was present in a high percentage of knees. The advantages and disadvantages are discussed and technical errors identified.

The use of carbon fibre to replace the torn cranial cruciate ligament in the dog--a clinical procedure.

Carbon fibre implants were used on 52 knees to repair the torn cranial cruciate ligament. A surgical technique similar to the "over-the-top" method utilizing carbon fibre instead of fascia lata was used. The advantages and disadvantages of this technique are discussed. It is, however, necessary to do long term assessment of the results.

Blood chemical and haematological changes in diarrhoeic baboons (Papio ursinus).

Blood was collected for blood chemical and haematological determinations from untreated surviving and non-surviving diarrhoeic baboons. The significance of changes in blood chemical and haematological values is discussed and the importance of supportive treatment is emphasized.

A congenital oesophagotracheal fistula in a two-year-old dog.

A congenital oesophagotracheal fistula in a two-year-old dog is reported. An account is given of the clinical symptoms, radiographic appearance, the supportive therapy, surgical correction and the post mortem findings.

The Enterobacteriaceae of South African baboons.

The results of routine rectal swab examinations, carried out on 776 baboons on the day of arrival at the colony and also on 394 animals which subsequently developed diarrhoea, are described. A dramatic increase was observed in the incidence of both pathogenic and non-pathogenic organisms during the diarrhoeic phase. The significance of bacterial species which are not pathogenic under normal circumstances as the possible cause of disease in animals subjected to stress is discussed.

Standard serum chemical and haematological values in the chacma baboon (Papio ursinus).

Blood chemical and haematological determinations were carried out on 64 baboons. The blood chemical and haematological values determined were found to be in general agreement with the values for man and other primate species. Some blood constituents however, did show noteworthy differences. Marked sex differences were demonstrated in some blood chemical and haematological parameters.

The effects of captivity stress on the blood chemical values of the chacma baboon (Papio ursinus).

Baboons were trapped and transported to the colony within 3 days of being captured. Blood was collected on Tuesdays and Fridays for blood chemical determinations. The changes in albumin and globulin resulted in marked changes in the albumin: globulin ratio. Cholesterol values showed a sudden and marked drop and the values were still below normal at the end of 9 weeks. Blood sugar values increased to significantly elevated levels and marked changes occurred in the enzyme activity and plasma corticosteroid activity. Male and female animals differed in their response with regard to the values found in some parameters. A period of adaptation or conditioning of 8 weeks was found to be required for an animal to reach stability in its blood chemical values.