Determining optimal primary sawing and ripping machine settings in the wood manufacturing chain

for wood manufacturers around the world, the single biggest cost factor is known to be its raw material. Maximum volume recovery of this raw material is, therefore, of key importance for the industry. The wood products industry consists of several interrelated manufacturing steps for converting trees into logs and logs into finished lumber. Each operation usually optimises its functionality in isolation from the preceding and following operations. It is a well documented fact that the optimisation of decisions through the whole chain of operations is considerably more profitable than the optimisation of individual operations. The objective of this study was to determine the optimal machine settings for two interrelated operations, namely the sawing and ripping operations which have tradition? ally been optimised individually. A model, having two decision variables, was developed which aims to satisfy market demand at a minimal cost. The first decision was how to saw the log supply into different thicknesses by choosing specific sawing patterns. The second was to decide on a rip saw's priority value settings, which determines how the products from the primary sawing operation are ripped into products of a certain thickness and width. The techniques used to determine the machine settings included static simulation with the SIMSAW software to represent the sawing operation and mixed integer programming to model the ripping operation. A metaheuristic, namely the Population Based Incremental Learning algorithm, was used to link the simulation and mixed integer models and to determine the optimal settings for the combined process. The model's objective function was to minimise the cost of production. This cost included the raw material waste cost and the over or under production cost. The over production cost included the stock keeping costs and the under production cost was estimated as the buy?in cost of under supplied products from another wood supplier. The model performed well against current decision software available, namely the Sawmill Production Planning System package, which combines simulation and mixed integer programming techniques to maximise profit. The model added further value by modelling and determining the ripping priority settings in addition to the primary sawing patterns.     

Efficacy against Fasciola hepatica and the pharmacokinetics of triclabendazole administered by oral and topical routes

Objective   To determine the efficacy of triclabendazole (TCBZ) against 28-day-old, early immature liver fluke in cattle and its pharmacokinetics following administration by the oral or topical (pour-on) route.
Procedures   Cattle (n = 18) were infected with 500 TCBZ-susceptible liver fluke metacercariae and randomly allocated to three groups. At 28 days after infection, the groups were: (1) untreated controls; (2) treated with oral TCBZ at 12 mg/kg in combination with oxfendazole and selenium (TOS); (3) treated with pour-on TCBZ at 30 mg/kg in combination with abamectin (TA). Blood samples were taken immediately prior to treatment and serially after treatment to assess the plasma profile of TCBZ metabolites. Ten weeks after treatment all animals were slaughtered and total liver fluke counts, fluke egg counts and liver pathology were assessed.
Results   Both the TOS and TA treatments resulted in significant reductions of 28-day-old liver fluke, as assessed by fluke counts and fluke egg counts at slaughter, and the reductions following TOS treatment were significantly greater than those following TA treatment. The blood profile of TCBZ metabolites in TOS-treated animals showed a significantly greater area under the plasma concentration time curve and a higher maximum observed concentration than those treated with TA. There was significantly less liver pathology in TOS-treated animals than in the TA-treated animals.
Conclusion   TCBZ administered orally at 12 mg/kg resulted in greater efficacy against 28-day-old, early immature liver fluke than was achieved by topical administration at 30 mg/kg. Plasma metabolites of TCBZ were higher and liver pathology was less in TOS-treated animals than in TA-treated animals.     

The role of procaine in adverse reactions to procaine penicillin in horses

Procaine penicillin is a commonly used antibiotic in equine medicine but its use is associated with a substantial incidence of adverse reactions. Soluble procaine concentrations were determined by HPLC in several commercially available procaine penicillin preparations, including some that were involved in adverse reactions. The mean (+/- SEM) soluble procaine concentrations in the veterinary preparations was 20.18 +/- 5.07 mg/ml, which was higher than the concentration in the only procaine penicillin preparation for use in humans in Australia of 7.3 mg/ml. Heating the veterinary procaine penicillin preparations to 50 degrees C for 1 day led to a significant (P less than 0.01) increase in the amount of soluble procaine. Heating to 50 degrees C for 7 days also produced a significant (P less than 0.02) increase. Soluble procaine tended to return to baseline concentrations when veterinary procaine penicillin preparations were heated to 50 degrees C for 2 days then stored for 7 days at room temperature. Administration of procaine HCl intravenously (IV) at 2, 5, and 10 mg/kg produced behavioural, locomotor and vascular reactions, which were clinically similar to those reported in adverse reactions to procaine penicillin. The more severe reactions occurred at higher doses, although different horses responded variably at the same dose. Some adverse reactions lead to recumbency but none were fatal. The blood procaine concentrations 1 min after IV administration averaged 19.0 +/- 12.6 and 25.3 +/- 16 micrograms/ml at 2.5 mg/kg and 5 mg/kg, respectively. Ten min after administration, blood procaine concentrations were significantly higher (P less than 0.001) in the 5 mg/kg group than in the 2.5 mg/kg group. Intramuscular (IM) procaine HCl at 5 mg/kg produced significantly lower (P less than 0.001) blood concentrations than similar IV doses, and, in contrast to the IV doses, the amount of procaine in the blood was significantly higher 5 and 10 min after administration than it was after 1 min. Mild excitatory reactions in 4/5 horses were noted 5 to 10 min after IM administration. Administration of diazepam 20 s before procaine HCl prevented the excitatory adverse reaction in 2/2 horses, but administration after the procaine did not influence the outcome.     

Field evaluation of a mixture of albendazole sulphoxide and levamisole against Ostertagia and Trichostrongylus spp in sheep

The efficacy of a mixture of albendazole sulphoxide and levamisole, 3.6 and 8.25 mg/kg respectively, at single and double dose rates, was compared with the recommended dose rate of each anthelmintic alone. The comparison was conducted on groups of 6 to 14-week-old lambs on 22 farms, 16 of which had evidence of multiple resistance to benzimidazole and levamisole. A single dose of the mixture reduced mean egg counts by 95% on half the farms with multiple resistance and on all the remaining farms. Consequently, the mixture should be included in an assessment of effective anthelmintics on farms to determine its value for nematode control. A double dose rate of mixture was effective on all but 4 farms. Reductions caused by the mixture were due to the additive actions of the drugs on 18 of 22 farms; synergistic action was noted on only 3 farms. It was concluded that the mixture of albendazole sulphoxide and levamisole offered many farmers an effective anthelmintic for use in preventive control programs. Recommendations for such programs include annual rotation of effective anthelmintics as a means of delaying selection for drug resistance.     

Concurrent gastro-oesophageal intussusception,trichobezoar and hiatal hernia in a cat

CASE HISTORY: An adult male Birman cat was evaluated for recurrent, intermittent vomiting or regurgitation, occasionally associated with abdominal discomfort.

CLINICAL FINDINGS AND DIAGNOSIS: Radiographs, including an oesophogram, indicated an oesophageal obstruction. Prior to treatment, the cat's condition deteriorated and it was euthanised at the owner's request. Post-mortem examination revealed a gastro-oesophageal intussusception, a trichobezoar impacted into the intussusceptum, and a dilated oesophageal hiatus consistent with a chronic hiatal hernia.

CLINICAL RELEVANCE: Gastro-oesophageal intussusception is a rare condition in cats. Its aetiology in relation to a pre-existing hiatal hernia and a trichobezoar is discussed.     

Adverse reaction to procaine penicillin G in horses

Adverse reactions to intramuscular injections of procaine penicillin G are reported in 11 horses, five of which died. The clinical findings are presented and suggest central nervous involvement in most cases. Post mortem findings in one horse were consistent with anaphylaxis whereas in other cases the clinical findings, duration of treatment, speed of onset and subsequent completion of treatment supports diagnosis of an acute procaine toxicity syndrome.