Public health priority setting on a national scale: The Scottish experience.

Objectives: Scotland has the lowest life expectancy in Western Europe and significant health inequalities. A national review of public health in 2015 found that there was a lack of coherent action across organisational boundaries, inhibiting progress. This paper describes a rapid (four-month) systematic approach to prioritisation of Scotland's public health challenges, which was evidence-based, transparent and made use of significant stakeholder engagement. Study design: Cross-sectional survey of stakeholders in deliberative meetings. Methods: An independent Expert Advisory Group (EAG) was formed to develop a typology of public health priorities, a long-list of potential priorities and ranking criteria. Deliberative stakeholder events were held at which the criteria were refined and priorities scored by participants from a wide range of stakeholder organisations. Results: The proposed typology identified three types of public health priorities: risk factors, social factors and system factors; medically defined disease entities were not used deliberately, to facilitate broad stakeholder participation. Fifteen criteria were identified to help identify priority issues, based on the scope of their burden, amenability to change, and multi-stakeholder preferences. Six public health priorities were selected by the EAG based on stakeholder scoring of a long-list against these criteria. Conclusion: Prioritisation is important in modern public health but it is challenging due to limited data availability, lack of agreed evidence on effectiveness and efficiency of interventions, and divergent stakeholder views. The Scottish experience nevertheless shows that useful public health priorities can be agreed upon by a wide range of stakeholders through a transparent, participatory and logical process.

An investigation of colour discrimination with horses (Equus caballus).

The ability of four horses (Equus caballus) to discriminate coloured (three shades of blue, green, red, and yellow) from grey (neutral density) stimuli, produced by back projected lighting filters, was investigated in a two response forced-choice procedure. Pushes of the lever in front of a coloured screen were occasionally reinforced, pushes of the lever in front of a grey screen were never reinforced. Each colour shade was randomly paired with a grey that was brighter, one that was dimmer, and one that approximately matched the colour in terms of brightness. Each horse experienced the colours in a different order, a new colour was started after 85% correct responses over five consecutive sessions or if accuracy showed no trend over sessions. All horses reached the 85% correct with blue versus grey, three horses did so with both yellow and green versus grey. All were above chance with red versus grey but none reached criterion. Further analysis showed the wavelengths of the green stimuli used overlapped with the yellow. The results are consistent with histological and behavioural studies that suggest that horses are dichromatic. They differ from some earlier data in that they indicate horses can discriminate yellow and blue, but that they may have deficiencies in discriminating red and green.

The fate of environmental coliforms in a model water distribution system.

A series of experiments to determine the survival characteristics of environmental and faecal coliforms in a 1.3 km long experimental pipe distribution system is described. In the first experiments, tertiary treated effluent (10(3)-10(4) coliforms ml-1) was inoculated directly into the distribution system. Coliform organisms were not detected in any samples taken downstream of the inoculation point. By comparison, laboratory jar tests showed low level survival for coliforms at the same chloramine residuals (0.3 mg l-1) for up to 48 h. In the second series of experiments, a by-pass pipe in the experimental distribution system was isolated, drained, and filled with tertiary treated effluent (10(3)-10(4) coliforms ml-1) to simulate the conditions in a dead-end. Coliform numbers were monitored and found to decrease rapidly, but they were still detectable at low levels after 7 weeks. The water in the by-pass section was then released into the main pipe-rig and sampled downstream. No coliforms were detected in water samples or in samples swabbed from the pipe walls. Finally, the flow in the main pipe-rig and in the by-pass was increased to dislodge any deposits and biofilm into the water. The absence of coliforms in any water samples taken during or after the flow increases is contrary to the widely accepted understanding that coliforms survive and grow in biofilms on pipe walls.

Predicting and scaling hens' preferences for topographically different responses.

Six hens were exposed to several concurrent (second-order) variable-interval schedules in which the response requirements on the alternatives were varied. The response requirements were one key peck versus five key pecks, one key peck versus one door push, and five key pecks versus one door push. Response- and time-allocation ratios undermatched the obtained reinforcement ratios but were well described by the generalized matching law. Time and response bias estimates from two pairs of response requirements were used to predict bias in the third pairing. The predicted values were close to those obtained; this result supports the notion that both numerically and topographically different responses act as constant sources of bias within the generalized matching law. The differences between the response and time biases could be accounted for by the different times needed to complete each response requirement. The results also suggest that the door push is a useful operant for research with domestic hens.

A unique selenoprotein isolated from yellowfin tuna (Thunnus albacares) liver.

A selenoprotein, with an approximate molecular weight of 2000, was isolated from yellowfin tuna (Thunnus albacares) liver. The selenium (Se) content of this selenoprotein fraction represented greater than 50% of the Se in the original liver extract. Most of the unrecovered Se was left in the pellet following homogenization. Although the protein was very sensitive to oxidizing conditions, it remained stable in the presence of reducing agents such as glutathione and dithiothreitol under a nitrogen atmosphere. After preparative isoelectric focusing of the purified selenoprotein, selenium was detected in three distinct bands, with the predominant band occurring at pH 6.2.