Preventing HIV infection among injecting drug users: Intuitive and counter-intuitive findings

The disease now called AIDS was first reported among injecting drug users in 1981. This article reviews the last 15 years of research on preventing HIV infection and AIDS among injecting drug users. Many of the findings were surprising in the context of previous understandings of the illicit injection of psychoactive drugs—both with respect to the much-larger-than-expected size of the epidemic and the much-greater-than-expected potential for behavior change among drug injectors (IDU). The research is reviewed within a framework of eight issues: the importance of the problem in the United States, the global diffusion of injecting drug use, the global diffusion of HIV among IDUs, potential rapid spread of HIV among IDUs, risk reduction among IDUs, community-level prevention, syringe exchange programs, and developing a public-health perspective on psychoactive drug use.     

Internal and external factors modulate food-calling in domestic hens

Two series of experiments investigated factors affecting utterance of food calls in the domestic hen, Gallus domesticus. The first series of experiments tested the effect of food preference and the hen’s internal state on the utterance of food calls. Different food types were presented first singly and then in a choice test to 20 hens, first when hens were laying, and then when they were maternal. The second series of experiments tested the effect of hunger level on the utterance of food calls in laying hens, and maternal hens with or without chicks. These two series of experiments showed that laying hens and maternal hens showed a similar marked preference for certain types of food, but laying hens very rarely emitted food calls, in contrast to maternal hens. This shows the effect of the bird’s psychophysiological state on her tendency to emit food calls. The more a maternal hen preferred a food type, the more food calls she emitted. This was observed from the beginning of a test in single-food tests as well as in choice tests. Hunger level positively affected food-call production under certain feeding conditions in maternal hens, but not in laying hens. When maternal hens were tested in the absence of their chicks, utterance of food calls was more sustained than in the presence of chicks. Received: 14 May 1998 / Accepted after revision: 11 October 1998     

Preference‐based segmentation: a study of meal preferences among Norwegian teenagers

The primary goal of this study was to examine the applicability of preference‐based segmentation for a broad array of meals in the context of teenagers. A representative sample of 1,168 Norwegian schoolchildren provided an evaluation of 20 common dinner meals in terms of preference (liking). Cluster analysis was used to establish four distinct preference‐based food segments. These four segments were termed Food Lovers, Fish Haters, Fish Lovers and Dislikers. The relationship between these four preference‐based segments and demographic, consumption, attitude and lifestyle variables was finally modelled using a multinomial logit analysis. The results highlight the fact that social and family‐related attitude and lifestyle variables have a greater ability to profile the segments and explain segment membership than demographic variables. The findings indicate that there are distinct and interesting differences between these segments. The findings have some implications for marketers within the industry in terms of effectively targeting the different market segments. Copyright © 2004 Henry Stewart Publications Ltd.     

Sensory modality and stimulus control in the pigeon: Cross-species generality of single-incentive selective-association effects

In earlier studies with rats, the effectiveness of the auditory element of a tone–light discriminative stimulus was enhanced when the conditioned incentive value of the compound was negative rather than positive. The present experiment systematically replicated these results in pigeons trained to press a treadle in the presence of a tone–light compound under food-reinforcement or shock-avoidance schedules. Positive incentive value was conditioned to the compound by associating it with either food or relative safety from shock. The compound was made negative in other groups by associating it with shock or the absence of food. When tone and light were presented separately following this training, control by the auditory element was significantly enhanced in the conditions designed to make the compound negative rather than positive. The similarity of this constraint on learning in rats and pigeons suggests that it involves a fundamental attentional and incentive-motivational process with widespread species generality.     

Development of co-feeding behavior in young wild Japanese macaques (Macaca fuscata)

This study describes the developmental course of the social context of feeding behavior in infants and yearlings of Japanese macaques in a provisioned free-ranging troop. Results of this longitudinal study revealed that infants and yearlings exhibited synchronous feeding behavior in the majority of cases in which they had feeding neighbors within 1 m. They consistently showed feeding behavior more often when their closest neighbor fed than when they did not. In feeding situations, infants tended mainly to be in close proximity with their mothers in the early stages of life and, later, also with peers. The results imply that potential opportunities for the social transmission of food selection habits are available for young Japanese macaques in the wild.     

Reactions to Different Types of Forced Distribution Performance Evaluation Systems

Purpose  We isolate and describe four key elements that distinguish different forms of forced distribution systems (FDS). These key elements are the consequences for low performers, differentiation of rewards for top performers, frequency of feedback, and comparison group size. We examine how these elements influence respondents’ attraction to FDS. Design/methodology/approach  Undergraduate students (n = 163) completed a policy capturing study designed to determine how these four FDS elements influence their attraction to FDS. We examine the relative importance of these elements that most influence attraction to different FDS, as well as individual attributes (i.e., cognitive ability, gender, and major) that may affect those preferences. Findings  Respondents were most attracted to systems with less stringent treatment of low performers, high differentiation of rewards, frequent feedback and large comparison groups. Consequences for low performers were nearly twice as influential as any other element. Respondents with higher cognitive ability favored high reward differentiation and males were less affected by stringent consequences for low performers. Implications  Before practitioners implement FDS, it would be prudent to consider all four elements examined in this study—with the treatment of low performers being the most salient issue. Future accounts of FDS should clarify the nature of these elements when reporting on FDS. Such precision will be useful in generating a knowledge base on FDS. Originality/value   We add precision to the discussion of FDS by identifying four key elements. This is one of the first studies to examine perceptions of FDS from a ratee perspective.

The role of familiarity in dietary development

The rise in inadequate and unhealthily diets in children has led investigations to examine the development of food preferences. This review outlines the ways in which children choose between foods made available to them and the subsequent shaping of their own habitual diet. Children are liable to form preferences to certain hedonic foods, and to exhibit neophobic reactions to the unfamiliar. Unfamiliar foods can elicit anxiety and suspicion. Trust and liking of a once novel food can be gained through exposure, increasing familiarity towards that food. This review examines: visual familiarity (awareness of foods within their environment); taste familiarity (knowledge and experience of the taste of foods); contextual familiarity (knowledge of how foods should be presented); and categorical familiarity (which family foods belong to). The influence of familiarity is also explained with regards to both positive and negative associative learning. These associations are influenced by the specific presentation and the social environment of a novel food. The potential benefits of understanding the nature of children’s learning and preference development for the promotion of healthy nutrition to both parent and child are discussed.     

On Enrolling More Female Students in Science and Engineering

Many people hold this truth to be self-evident that universities should enroll more female students in science and engineering; the main question then being how. Typical arguments include possible benefits to women, possible benefits to the economy, and the unfairness of the current female under-representation. However, when clearly stated and scrutinized these arguments in fact lead to the conclusion that there should be more women in scientific disciplines in higher education in the sense that we should expect more women (which various kinds of discrimination may prevent), not that we should actively enroll more women. Outreach programs towards high school students may therefore be logically incompatible with the arguments supposed to justify them. They should purport to allow women to graduate in a field congruent with her abilities and desires, rather than try to draw as many of them to scientific disciplines as possible: one cannot try to 'recruit' as many female students as possible while claiming to help them choose more freely.