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Biomedical subjects

T D Wilson

Publications and source records attributed to T D Wilson.

At least 37 records · Page 2Linked to original sources
PubMed1994

Mental contamination and mental correction: unwanted influences on judgments and evaluations.

We define mental contamination as the process whereby a person has an unwanted response because of mental processing that is unconscious or uncontrollable. This type of bias is distinguishable from the failure to know or apply normative rules of inference and can be further divided into the unwanted consequences of automatic processing and source confusion, which is the confusion of 2 or more causes of a response. Mental contamination is difficult to avoid because it results from both fundamental properties of human cognition (e.g., a lack of awareness of mental processes) and faulty lay beliefs about the mind (e.g., incorrect theories about mental biases). People's lay beliefs determine the steps they take (or fail to take) to correct their judgments and thus are an important but neglected source of biased responses. Strategies for avoiding contamination, such as controlling one's exposure to biasing information, are discussed.

Cognition↗
PubMed1994

Reproductive performance in South Australian dairy herds.

Herd breeding records (161) were examined from a random 10% sample of dairy farms (96) in South Australia with more than 40 cows and suitable breeding records for 1988 and/or 1989. Of these farms, 53 (55.2%) had a year-round calving pattern, 42 (43.8%) claimed to be seasonal and one was changing from a year-round to a seasonal pattern. Only 14.6% of farmers observed oestrous behaviour outside milking times and 18.8% used tailpaint. Overall, the average proportion of unobserved heats was estimated to be 32%. Artificial insemination (AI) was carried out on 85.4% of farms (16.7% used AI alone and 68.7% also used bulls) of which 32.9% used commercial technicians and 67.1% were do-it-yourself operators. Overall, the average 30-day submission rate was 59.9% and the average 49-day non-return to service rate was 58.9%. Investigation into the probable causes of suboptimal reproductive performance gave a tentative diagnosis of inefficient oestrous detection, deferral of service, inadequate nutrition, poor AI technique, insufficient bulls, and venereal/other diseases in 69.1, 32.1, 27.2, 28.4, 13.6 and 7.4% of records, respectively.

Animal Nutritional Physiological Phenomena↗
PubMed1993

Calorimetric studies of dissolution of hydroxypropyl methylcellulose E5 (HPMC E5) in water.

The interaction of water with polymers is important because it directly or indirectly affects various properties such as rheological and transport properties. In this study, the hydration/dissolution of a hydrophilic polymer was investigated by calorimetric techniques. Hydroxypropyl methylcellulose E5 (Methocel, HPMC E5) was used as the model polymer. A water-insoluble, hydrophobic polymer, ethyl cellulose E4 (Ethocel, EC E4), was selected for comparison. The number of moles of non-freezing and freezing water were determined by differential scanning calorimetry. Moles of non-freezing water per polymer repeat unit were 6.2 +/- 1.3 and 1.6 +/- 0.3 for HPMC E5 and EC E4, respectively. The hydration/dissolution of HPMC E5 was exothermic, with a total heat of dissolution of -24.1 +/- 1.1 cal/g (n = 4). The heat of hydration of water-insoluble EC E4 was -2.6 cal/g (n = 2). The specific heat capacity value of HPMC E5 increased due to the addition of water. The heat of solution and an increase in specific heat capacity values were associated mainly with the addition of tightly bound water to the polymer. The dissolution of HPMC E5 in water is believed to have endothermic and exothermic components. In summary, the study provided insight into the dissolution of a representative hydrophilic polymer in water. The heat of solution and the specific heat capacity values were mainly dependent on the addition of tightly bound water.

Calorimetry↗
PubMed1992

Self-emulsifying drug delivery systems: formulation and biopharmaceutic evaluation of an investigational lipophilic compound.

Self-emulsifying drug delivery systems (SEDDSs) represent a possible alternative to traditional oral formulations of lipophilic compounds. In the present study, a lipophilic compound, WIN 54954, was formulated in a medium chain triglyceride oil/nonionic surfactant mixture which exhibited self-emulsification under conditions of gentle agitation in an aqueous medium. The efficiency of emulsification was studied using a laser diffraction sizer to determine particle size distributions of the resultant emulsions. An optimized formulation which consisted of 25% (w/w) surfactant, 40% (w/w) oil, and 35% (w/w) WIN 54954 emulsified rapidly with gentle agitation in 0.1 N HCl (37 degrees C), producing dispersions with mean droplet diameters of less than 3 microns. The self-emulsifying preparation was compared to a polyethylene glycol 600 (PEG 600) solution formulation by administering each as prefilled soft gelatin capsules to fasted beagle dogs in a parallel crossover study. Pharmacokinetic parameters were determined and the absolute bioavailability of the drug was calculated by comparison to an i.v. injection. The SEDDS improved the reproducibility of the plasma profile in terms of the maximum plasma concentration (Cmax) and the time to reach the maximum concentration (tmax). There was no significant difference in the absolute bioavailability of WIN 54954 from either the SEDDS or the PEG formulations.

Administration, Oral↗
PubMed1991

Costs of primary health care at the Alexandra Health Centre.

This study provides a detailed analysis of costs and expenditure patterns at a primary health care centre serving an impoverished community of about 200,000 people. Data were collected on costs and utilisation of services at the Alexandra Health Centre and University Clinic (AHC) for the financial year ending March 1990. Capital and running costs were kept separate. The sources of data collection were statistics routinely collected in the different sections of the clinic, the accounting records, staff duty rosters and a prospective study done to collect information to apportion drug costs and to calculate the cost of a prescription. The audited operating expenditure at AHC for the 1990 financial year was R3.9 million, or R4,45 million with donations (mainly drugs and staff). Sixty-three per cent of total costs went on staff, 16% on drugs and supplies, 9% on buildings, furniture and transport, 3% on laboratory services, 2% on security and 8% on other items. The outpatients department accounted for 57% of expenditure, the 24-hour unit 37% and the outreach section 6%. Looked at another way, 66% went on curative services, 32% on preventive and promotive (including 13% on maternity costs) services, and 2% on rehabilitation services. The average cost per visit to each of 14 services is presented. The cost of a visit to casualty is R38.85, to the antenatal clinic R18.65 and to the child health outreach programme for immunisation R6.67. The component costs of each visit are analysed. The major cost component of a consultation is usually clinical staff, and detailed staff allocations for each section are given.(ABSTRACT TRUNCATED AT 250 WORDS)

Budgets↗
PubMed1991

Monosomy and trisomy in bovine embryos sired by bulls heterozygous for the 1 29 Robertsonian translocation chromosome.

Mature cows (n = 37) were superovulated and inseminated with semen from either bulls heterozygous for the 1 29 Robertsonian translocation or bulls with a normal karyotype. A total of 163 embryos was recovered, and preparations suitable for cytogenetic analysis were obtained from 67 (41.1%) of these. The karyotype was unbalanced in three (4.5%) of the embryos sired by semen from a bull carrying the translocation, whereas no karyotypic imbalance was recognized in the control group of embryos. Two of the unbalanced embryos were monosomic, while the third embryo was trisomic.

Journal Article↗
PubMed1991

Thinking too much: introspection can reduce the quality of preferences and decisions.

In Study 1, college students' preferences for different brands of strawberry jams were compared with experts' ratings of the jams. Students who analyzed why they felt the way they did agreed less with the experts than students who did not. In Study 2, college students' preferences for college courses were compared with expert opinion. Some students were asked to analyze reasons; others were asked to evaluate all attributes of all courses. Both kinds of introspection caused people to make choices that, compared with control subjects', corresponded less with expert opinion. Analyzing reasons can focus people's attention on nonoptimal criteria, causing them to base their subsequent choices on these criteria. Evaluating multiple attributes can moderate people's judgments, causing them to discriminate less between the different alternatives.

Adult↗
PubMed1990

Identification of the 1/29 Robertsonian translocation chromosome in British Friesian cattle.

Blood samples for cytogenetic analysis were obtained from 23 animals closely related to a pedigree British Friesian bull which was heterozygous for a Robertsonian translocation, and from 35 of its daughters. The aberration was found in one of its relatives and in 19 (54.3 per cent) of its progeny and was identified as the 1/29 Robertsonian translocation by G- and C-banding techniques. It is considered likely that the translocation formed de novo recently.

Animals↗
PubMed1990

Liquid chromatographic methods validation for pharmaceutical products.

The current status of validation in LC methods for the analysis of pharmaceuticals has been reviewed with special reference to compatibility testing methods. Validation data were provided in terms of method linearity, accuracy, precision, system suitability, specificity, use of alternate methods, injection order, application of peak height or area measurements and of internal or external standards.

Chromatography, High Pressure Liquid↗
PubMed1990

Stability of milrinone and epinephrine, atropine sulfate, lidocaine hydrochloride, or morphine sulfate injection.

The stability of both drug components of admixtures of milrinone and epinephrine, atropine sulfate, lidocaine hydrochloride, morphine sulfate, calcium chloride, or sodium bicarbonate injections was studied. Duplicate solutions of admixtures of milrinone injection 1 mg/mL and epinephrine injection 1:10,000, atropine sulfate injection 1 mg/mL, lidocaine hydrochloride injection 1%, morphine sulfate injection 8 mg/mL, calcium chloride injection 10%, or sodium bicarbonate injection 7.5% were prepared and stored in glass containers at 22-23 degrees C under fluorescent light. Samples were taken immediately and after 20 minutes for assay by high-performance liquid chromatography (HPLC). Milrinone at initial concentrations of 0.10-0.73 mg/mL showed no degradation in any of the solutions during the study period, nor was any degradation observed for lidocaine, morphine, atropine, or epinephrine. Milrinone 0.10-0.73 mg/mL is compatible with atropine sulfate, lidocaine hydrochloride, epinephrine, calcium chloride, or sodium bicarbonate in glass containers stored for 20 minutes at room temperature. These results support the use of milrinone in combination with these agents immediately after the preparation of admixtures.

Atropine↗
PubMed1989

Compliance with chemotherapy in childhood leukaemia in Africa.

Compliance with chemotherapy in childhood leukaemia is usually good because of parental fear of the disease. However, poor compliance and refusal of treatment have been reported from both the USA and the UK. Little is known about African concepts of leukaemia, attitudes to treatment or compliance. A study was undertaken to investigate factors which might affect compliance in 15 black and 30 white families of leukaemic children in Johannesburg. The socio-economic and educational status of the black families was lower than that of the white. Only 53% of black children attended hospital on the appointed day compared with 90% of white children. Less than 50% of black parents understood the nature of their child's illness. Both black and white families had unused medication at home. White parents more frequently reported toxic effects related to chemotherapy and more white children than black children exhibited lymphopenia during maintenance therapy. Assessment of drug compliance should be included as an independent variable when evaluating factors affecting response to chemotherapy in communities of diverse ethnic, socio-economic and cultural backgrounds.

Black or African American↗
PubMed1989

Preferences as expectation-driven inferences: effects of affective expectations on affective experience.

Presents a model arguing that affect and emotion are often formed in an expectation-driven fashion. A pilot study and 2 experiments manipulated undergraduate Ss' affective expectations (e.g., how funny they expected a set of cartoons to be) and whether Ss' expectations were confirmed (e.g., whether the cartoons really were funny). When the value of a stimulus was consistent with an affective expectation, people formed evaluations relatively quickly. Even when the value of a stimulus was discrepant from an affective expectation, people sometimes assimilated the value of the stimulus to their expectations. Other times, such as when making a more fine-grained evaluation of the cartoons, people noticed that they were discrepant from their affective expectations. Under these conditions, people appeared to have more difficulty forming preferences. They took longer to evaluate and spent more time thinking about the cartoons.

Adult↗