Departments View all
Recent Publications View all
- SourceAvailable from: Lars Chittka[Show abstract] [Hide abstract]
ABSTRACT: The learning capacities of males and females may differ with sex-specific behavioural requirements. Bumblebees provide a useful model system to explore how different lifestyles are reflected in learning abilities, because their (female but sterile) workers and males engage in fundamentally different behaviour routines. Bumblebee males, like workers, embark on active flower foraging but in contrast to workers they have to trade off their feeding with mate search, potentially affecting their abilities to learn and utilize floral cues efficiently during foraging. We used a serial colour-learning task with freely flying males and workers to compare their ability to flexibly learn visual floral cues with reward in a foraging scenario that changed over time. Male bumblebees did not differ from workers in both their learning speed and their ability to overcome previously acquired associations, when these ceased to predict reward. In all foraging tasks we found a significant improvement in choice accuracy in both sexes over the course of the training. In both sexes, the characteristics of the foraging performance depended largely on the colour difference of the two presented feeder types. Large colour distances entailed fast and reliable learning of the rewarding feeders whereas choice accuracy on highly similar colours improved significantly more slowly. Conversely, switching from a learned feeder type to a novel one was fastest for similar feeder colours and slow for highly different ones. Overall, we show that behavioural sex dimorphism in bumblebees did not affect their learning abilities beyond the mating context. We discuss the possible drivers and limitations shaping the foraging abilities of males and workers and implications for pollination ecology. We also suggest stingless male bumblebees as an advantageous alternative model system for the study of pollinator cognition.
- [Show abstract] [Hide abstract]
ABSTRACT: Background: Studies suggest that cervical cancer screening practice in the United States is inefficient. The cost and health implications of nonadherence in the screening process compared with recommended guidelines are uncertain. Objective: To estimate the benefits, costs, and cost-effectiveness of current cervical cancer screening practice and assess the value of screening improvements. Design: Model-based cost-effectiveness analysis. Data sources: New Mexico HPV Pap Registry; medical literature. Target population: Cohort of women eligible for routine screening. Time horizon: Lifetime. Perspective: Societal. Intervention: Current cervical cancer screening practice; improved adherence to guidelines-based screening interval, triage testing, diagnostic referrals, and precancer treatment referrals. Outcome measures: Reductions in lifetime cervical cancer risk, quality-adjusted life-years (QALYs), lifetime costs, incremental cost-effectiveness ratios, and incremental net monetary benefits (INMBs). Results of base-case analysis: Current screening practice was associated with lower health benefit and was not cost-effective relative to guidelines-based strategies. Improvements in the screening process were associated with higher QALYs and small changes in costs. Perfect adherence to screening every 3 years with cytologic testing and adherence to colposcopy/biopsy referrals were associated with the highest INMBs ($759 and $741, respectively, at a willingness-to-pay threshold of $100 000 per QALY gained); together, the INMB increased to $1645. Results of sensitivity analysis: Current screening practice was inefficient in 100% of simulations. The rank ordering of screening improvements according to INMBs was stable over a range of screening inputs and willingness-to-pay thresholds. Limitation: The effect of human papillomavirus vaccination was not considered. Conclusions: The added health benefit of improving adherence to guidelines, especially the 3-year interval for cytologic screening and diagnostic follow-up, may justify additional investments in interventions to improve U.S. cervical cancer screening practice. Primary funding source: U.S. National Cancer Institute.
- [Show abstract] [Hide abstract]
ABSTRACT: Following from previous research on intensity bias and the accessibility model of emotional self-report, the present study examined the role of emotional exhaustion in explaining the discrepancy in teachers' reports of their trait (habitual) versus state (momentary, "real") emotions. Trait reports (habitual emotions, exhaustion) were assessed via trait questionnaires, and state reports (momentary emotions) were assessed in real time via the experience sampling method by using personal digital assistants (N = 69 high school teachers; 1,089 measures within teachers). In line with our assumptions, multi-level analyses showed that, as compared to the state assessment, teachers reported higher levels of habitual teaching-related emotions of anger, anxiety, shame, boredom, enjoyment, and pride. Additionally, the state-trait discrepancy in self-reports of negative emotions was accounted for by teachers' emotional exhaustion, with high exhaustion levels corresponding with a greater state-trait discrepancy. Exhaustion levels did not moderate the state-trait discrepancy in positive emotions indicating that perceived emotional exhaustion may reflect identity-related cognitions specific to the negative belief system. Implications for research and educational practice are discussed.
Information provided on this web page is aggregated encyclopedic and bibliographical information relating to the named institution. Information provided is not approved by the institution itself. The institution’s logo (and/or other graphical identification, such as a coat of arms) is used only to identify the institution in a nominal way. Under certain jurisdictions it may be property of the institution.
Rg score distribution
No data available.