Genes, microbes and man

Inaugural lecture delivered at Rhodes UniversityRhodes University Libraries (Digitisation

Abnormal Perceptual Sensitivity in Body-Focused Repetitive Behaviors

Objective Several compulsive grooming habits such as hair pulling, skin picking, and nail biting are collectively known as body-focused repetitive behaviors (BFRBs). Although subclinical BFRBs are common and benign, more severe and damaging manifestations exist that are difficult to manage. Researchers have suggested that BFRBs are maintained by various cognitive, affective, and sensory contingencies. Although the involvement of cognitive and affective processes in BFRBs has been studied, there is a paucity of research on sensory processes. Methods The current study tested whether adults with subclinical or clinical BFRBs would report abnormal patterns of sensory processing as compared to a healthy control sample. Results Adults with clinical BFRBs (n = 26) reported increased sensory sensitivity as compared to persons with subclinical BFRBs (n = 48) and healthy individuals (n = 33). Elevations in sensation avoidance differentiated persons with clinical versus subclinical BFRBs. Sensation seeking patterns were not different between groups. Unexpectedly, BFRB severity was associated with lower registration of sensory stimuli, but this finding may be due to high psychiatric comorbidity rates in the BFRB groups. Conclusions These findings suggest that several sensory abnormalities may underlie BFRBs. Implications for the etiology and treatment of BFRBs are discussed

Finding qualitative research: an evaluation of search strategies

BACKGROUND: Qualitative research makes an important contribution to our understanding of health and healthcare. However, qualitative evidence can be difficult to search for and identify, and the effectiveness of different types of search strategies is unknown. METHODS: Three search strategies for qualitative research in the example area of support for breast-feeding were evaluated using six electronic bibliographic databases. The strategies were based on using thesaurus terms, free-text terms and broad-based terms. These strategies were combined with recognised search terms for support for breast-feeding previously used in a Cochrane review. For each strategy, we evaluated the recall (potentially relevant records found) and precision (actually relevant records found). RESULTS: A total yield of 7420 potentially relevant records was retrieved by the three strategies combined. Of these, 262 were judged relevant. Using one strategy alone would miss relevant records. The broad-based strategy had the highest recall and the thesaurus strategy the highest precision. Precision was generally poor: 96% of records initially identified as potentially relevant were deemed irrelevant. Searching for qualitative research involves trade-offs between recall and precision. CONCLUSIONS: These findings confirm that strategies that attempt to maximise the number of potentially relevant records found are likely to result in a large number of false positives. The findings also suggest that a range of search terms is required to optimise searching for qualitative evidence. This underlines the problems of current methods for indexing qualitative research in bibliographic databases and indicates where improvements need to be made

Emotion Regulation Deficits in Persons with Body-Focused Repetitive Behavior Disorders

Background Conceptualizations of emotion dysregulation (ED) and body-focused repetitive behavior disorders (BFRBDs) imply that ED may be a central component of BFRBDs as well as a factor that distinguishes BFRBDs from non-impairing, subclinical body-focused repetitive behaviors (BFRBs). The current study empirically tested these observations. Methods One hundred thirty-eight undergraduates (of 1900 who completed a screening survey) completed self-report measures assessing four emotion regulation (ER) deficits hypothesized to underlie ED (alexithymia, maladaptive emotional reactivity, experiential avoidance, and response inhibition when distressed); 34 of these participants had BFRBDs, 64 had subclinical BFRBs, and 42 were unaffected by BFRBs. Results Results indicated that participants with BFRBDs reported higher levels of maladaptive emotional reactivity, experiential avoidance, and response inhibition when distressed than participants with subclinical BFRBs and participants unaffected by BFRBs. These results held even when controlling for comorbidity and total number of reported BFRBs. Participants did not differ on alexithymia. Limitations Limitations of the current study include the BFRB groups’ different distributions of BFRB types (e.g., hair pulling versus skin picking), the sample\u27s demographic uniformity, and the fact that negative affectivity was not controlled when exploring BFRB group differences on ER deficits. Future research should improve on these limitations. Conclusions The current results suggest that ED is a factor that differentiates BFRBDs from subclinical BFRBs. Such results may be useful for generating hypotheses regarding mechanisms responsible for BFRBs’ development into BFRBDs. Furthermore, these results may provide insight into factors that explain the efficacy of more contemporary behavioral treatments for BFRBDs

Cognitive engineering in aerospace application: Pilot interaction with cockpit automation

Because of recent incidents involving glass-cockpit aircraft, there is growing concern with cockpit automation and its potential effects on pilot performance. However, little is known about the nature and causes of problems that arise in pilot-automation interaction. The results of two studies that provide converging, complementary data on pilots' difficulties with understanding and operating one of the core systems of cockpit automation, the Flight Management System (FMS) is reported. A survey asking pilots to describe specific incidents with the FMS and observations of pilots undergoing transition training to a glass cockpit aircraft served as vehicles to gather a corpus on the nature and variety of FMS-related problems. The results of both studies indicate that pilots become proficient in standard FMS operations through ground training and subsequent line experience. But even with considerable line experience, they still have difficulties tracking FMS status and behavior in certain flight contexts, and they show gaps in their understanding of the functional structure of the system. The results suggest that design-related factors such as opaque interfaces contribute to these difficulties which can affect pilots' situation awareness. The results of this research are relevant for both the design of cockpit automation and the development of training curricula specifically tailored to the needs of glass cockpits

A MARKETING-SYSTEM APPROACH TO REMOVING DISTRIBUTION BARRIERS CONFRONTING SMALL-VOLUME FRUIT AND VEGETABLE GROWERS

Marketing,

PUBLIC MARKETS AND THE DEVELOPMENT OF THE FRESH-PRODUCE INDUSTRY

Agribusiness,

State Department of Agriculture Participation in Fresh Produce Marketing in Georgia, Kentucky, North Carolina, and Tennessee

Agricultural and Food Policy,

Investigating Habituation to Premonitory Urges in Behavior Therapy for Tic Disorders

Behavior therapy is effective for Persistent Tic Disorders (PTDs), but behavioral processes facilitating tic reduction are not well understood. One process, habituation, is thought to create tic reduction through decreases in premonitory urge severity. The current study tested whether premonitory urges decreased in youth with PTDs (N = 126) and adults with PTDs (N = 122) who participated in parallel randomized clinical trials comparing behavior therapy to psychoeducation and supportive therapy (PST). Trends in premonitory urges, tic severity, and treatment outcome were analyzed according to the predictions of a habituation model, whereby urge severity would be expected to decrease in those who responded to behavior therapy. Although adults who responded to behavior therapy showed a significant trend of declining premonitory urge severity across treatment, results failed to demonstrate that behavior therapy specifically caused changes in premonitory urge severity. In addition, reductions in premonitory urge severity in those who responded to behavior therapy were significant greater than those who did not respond to behavior therapy but no different than those who responded or did not respond to PST. Children with PTDs failed to show any significant changes in premonitory urges. Reductions in premonitory urge severity did not mediate the relationship between treatment and outcome in either adults or children. These results cast doubt on the notion that habituation is the therapeutic process underlying the effectiveness of behavior therapy, which has immediate implications for the psychoeducation and therapeutic rationale presented in clinical practice. Moreover, there may be important developmental changes in premonitory urges in PTDs, and alternative models of therapeutic change warrant investigation