Mandatory fortification with folic acid: what would hippocrates say?

In October 2006, the Australian and New Zealand Food Regulation Ministerial Council asked for a review of the proposed food standard permitting mandatory fortification of bread with folic acid. This article contributes to the policy debate associated with the standard’s review by discussing the potential benefits and risks to the target population and the wider Australian population with emphasis on recent (2006) literature.

Knowledge, risk perceptions and condom usage in male sex workers from three Australian cities

The study identifies factors associated with knowledge and perception of risk of HIV/AIDS, as well as attitudes to and usage of condoms by a sample of male sex workers (MSW). One hundred and eighty-five male sex workers completed a self-reported questionnaire, including knowledge about HIV transmission, attitudes to condom use and perceptions and personal susceptibility to HIV and sexually transmitted infection (STI) risk, and a two-week diary recording use of condom during commercial sex encounters. The findings reveal that condom use was found in 77.7% of the encounters with clients and the majority of the respondents perceived themselves to be at no risk for HIV because of sex work. Independent sex workers from Melbourne and workers who owned their place of residence used condoms in a significant lower proportion. Generally speaking, knowledge about the risks associated with AIDS was high, with respondents showing lower knowledge about the risks associated with unprotected receptive or active oral sex. Participants held a positive attitude to condom use; most considered the provisions of condoms to be their responsibility rather than clients; and they were more worried about contracting an STI than HIV. Those who scored higher on the knowledge scale had more positive attitudes to condom use and those who had a more positive attitude to condom use recorded a perceived lower risk of contracting STI but not HIV. The study discusses the relevance of these findings for public health risk reduction and sexual health education campaigns.

Demographic differences in usage and attitudes to milk

Declining milk consumption is a potential public health problem because milk provides nutrients that are not abundant in other foods. Identification of the factors that may influence milk consumption may lead to development of interventions to promote more healthful behaviours.

Attitudes and beliefs about food appear to be strong predictors of dietary behaviour. The objective of this study was to survey a random sample of consumers in regard to their milk consumption and attitudes and beliefs about milk. Two telephone surveys were conducted one year apart. The questionnaire included attitude items that reflected the main themes of consumers' interest in milk.

The respondents' attitudes were complex and were related to demographics and milk consumption. In general, people's concerns about milk related to what was important in their lives; what threatened them physically and emotionally. Women held more positive attitudes, but they were concerned about the fat content of milk. Men were less aware of milk's nutritional benefits and, as a result, were less appreciative of its value.

The findings from this investigation provide an opportunity to develop appropriate public health initiatives to promote the consumption of high calcium foods and to address the barriers to drinking milk. Nutrition communications in collaboration with other health agencies and the milk industry could support these initiatives.

Mandatory folate fortification - will benefits outweigh risks?

The article considers the concerns raised about the implementation of mandatory food fortification in Australia. Mandatory food fortification, the compulsory addition of nutrients to food products, is a powerful policy approach for public health nutrition. The danger in exposing every Australians to increased amounts of nutrients is discussed. Mandate folate fortification is being assessed by Food Standards Australia New Zealand due to the increased cases of neural tube defects in Australia.

Hyperstereopsis in helmet-mounted NVDs : absolute distance perception

Modern helmet-mounted night vision devices, such as the Thales TopOwl helmet, project imagery from intensifiers mounted on the side of the helmet onto the helmet faceplate. The increased separation of the cameras induces hyperstereopsis - the exaggeration of the stereoscopic disparities that support the perception of relative depth around the point of fixation. Increased camera separation may also affect absolute depth perception, because it increases the amount of vergence (crossing) of the eyes required for binocular fusion, and because the differential perspective from the viewpoints of the two eyes is increased. The effect of hyperstereopsis on the perception of absolute distance was investigated using a large-scale stereoscopic display system. A fronto-parallel textured surface was projected at a distance of 6 metres. Three stereoscopic viewing conditions were simulated - hyperstereopsis (four times magnification), normal stereopsis, and hypostereopsis (one quarter magnification). The apparent distance of the surface was measured relative to a grid placed in a virtual "leaf room" that provided rich monocular cues, such as texture gradients and linear perspective, to absolute distance as well as veridical sterescopic disparity cues. The different stereoscopic viewing conditions had no differential effect on the apparent distance of the textured surface at this viewing distance

Hyperstereopsis in helmet-mounted NVDs : time to contact estimation

The side mounting of the night-vision sensors on some helmet-mounted systems creates a situation of hyperstereopsis in which the binocular cues available to the operator are exaggerated such that distances around the point of fixation are increased. For a moving surface approaching the observer, the increased apparent distance created by hyperstereopsis should result in greater apparent speed of approach towards the surface and so an operator will have the impression they have reached the surface before contact actually occurs. We simulated motion towards a surface with hyperstereopsis and compared judgements of time to contact with that under normal stereopsis as well as under binocular viewing without stereopsis. We simulated approach of a large, random-field textured and found that time to contact estimates were shorter under the hyperstereoscopic condition than those under normal stereo and no stereo, indicating that hyperstereopsis may cause observers to underestimate time to contact leading operators to undershoot the ground plane when landing.

Hyperstereopsis in helmet-mounted NVDs : slope perception

Modern helmet-mounted night vision devices, such as the Thales TopOwl helmet, project imagery from intensifiers mounted on the sides of the helmet onto the helmet faceplate. This produces a situation of hyperstereopsis in which binocular disparities are magnified. This has the potential to distort the perception of slope in depth (an important cue to landing), because the slope cue provided by binocular disparity conflicts with veridical cues to slope, such as texture gradients and motion parallax. In the experiments, eight observers viewed sparse and dense textured surfaces tilted in depth under three viewing conditions: normal stereo hyper-stereo (4 times magnification), and hypostereo (1 / 4 magnification). The surfaces were either stationary, or rotated slowly around a central vertical axis. Stimuli were projected at 6 metres to minimise conflict between accommodation and convergence, and stereo viewing was provided by a Z-screen and passive polarised glasses. Observers matched perceived visual slope using a small tilt table set by hand. We found that slope estimates were distorted by hyperstereopsis, but to a much lesser degree than predicted by disparity magnification. The distortion was almost completely eliminated when motion parallax was present.

The web in marketing : information cue usage in two commercial domains

The study reported in this paper involves a comparison of Resnik & Stern’s (e.g., 1977) information cue usage in websites registered in two commercial domains of the World Wide Web (Web)—.com (global domain managed by VeriSign) and .com.au (a country domain, auDomain, managed by the Australian Domain Name Administrator—AUDA). The hypothesised higher use of information cues by digital marketers with .com registered domain names relative to .com.au registered domain names is not supported. Examination of the audited websites in the two-domain comparison confirms that the Web provides a richer marketing communication medium than other media analysed in a meta-analysis of 117 datasets by Abernethy & Franke (1996). The study is important given the acknowledged influence of advertising information on consumer responses to ads and the brands they relate, to both in traditional and new media (Aaker & Stayman, 1990; Brown & Stayman, 1992; Bruner & Kumar, 2000).

Power demand and energy usage of container crane - comparison between AC and DC drives

The electrical data of two quay cranes, one has a DC drive system and the other has an AC drive system, in actual working conditions at a container terminal are measured and presented in this paper. Peak demand, energy usage, power factor and power quality are examined and compared.

Information source usage and enthusiasm in opera : a comparative study

The research reported in this paper investigated the relationship between information usage and individual ticket-purchasing activity of Opera Australia customers in relation to specific Opera Australia products, namely, operetta and opera. The results provide some support for the notion that consumers of operetta and opera can be distinguished on the basis of their different behaviour in some areas. However, there is substantial “crossing-over” or inconsistency in the data. Longevity of association with the art-form, and purchasing tickets to both types of productions, tended to be related to increased reliance on information sources closer to Opera Australia.