Egg rejection behaviour in the great reed warbler (<Emphasis Type="Italic">Acrocephalus arundinaceus</Emphasis>): the effect of egg type

Egg discrimination in hosts of the common cuckoo Cuculus canorus is frequently studied by experimental parasitism, using model cuckoo eggs. We compared egg rejection behaviour of the great reed warbler Acrocephalus arundinaceus to either model cuckoo eggs made of plastic or painted real host eggs. We simultaneously parasitised host nests by two different egg types to simulate cuckoo parasitism. A previous study revealed very similar, ca. 70%, rejection rates against both of these egg types (beige or bluish background colour maculated with dark brown) when they were used for single parasitism. In the present study we showed 96% average rejection rates against these egg types when they were applied in multiple experimental parasitism, causing a more predictable output for rejection behaviour. Hard plastic eggs and painted real eggs were rejected at similar frequencies, and videotaping revealed that model egg rejection caused extra work for great reed warblers. We revealed a new type of rejection behaviour, when hosts tried to eject hard-shelled model cuckoo eggs: Hosts made little holes in the middle part of these plastic eggs by pecking them several times before ejection, as if seeking the possibility to pierce and hold these eggs in their bills. Painted real eggs were rejected by actually puncturing the eggshell and holding them in the bill during ejection. No instances of grasp ejection were recorded during filming. Most experimental eggs of either type were ejected within 1 day after the introduction of the eggs, indicating that hosts made their rejection decisions quickly. Our observations suggest the lack of plasticity in the mode and timing of ejection behaviour towards experimental cuckoo eggs of different types in great reed warblers.     

系统理论指导下辩证思维模式与抗休克决策

休克是由于有效循环血量不足引发的微循环障碍而表现一系列症候群,作为一种系统性疾病,病因十分复杂多样,诊疗过程中的临床决策应全面而富有针对性,并充分考虑到救治措施的协调一致和互相配合。系统论主张整体大于部分之和强调的就是措施之间的整体化效果,充分考虑到患者个体间差异,辩证分析不同类型休克、不同个体间不同表现,在系统理论指导下的富有针对性措施间协调一致的决策模式才是较为完整的休克救治临床决策模式。     

A fruit in the hand or two in the bush? Divergent risk preferences in chimpanzees and bonobos

Human and non-human animals tend to avoid risky prospects. If such patterns of economic choice are adaptive, risk preferences should reflect the typical decision-making environments faced by organisms. However, this approach has not been widely used to examine the risk sensitivity in closely related species with different ecologies. Here, we experimentally examined risk-sensitive behaviour in chimpanzees (Pan troglodytes) and bonobos (Pan paniscus), closely related species whose distinct ecologies are thought to be the major selective force shaping their unique behavioural repertoires. Because chimpanzees exploit riskier food sources in the wild, we predicted that they would exhibit greater tolerance for risk in choices about food. Results confirmed this prediction: chimpanzees significantly preferred the risky option, whereas bonobos preferred the fixed option. These results provide a relatively rare example of risk-prone behaviour in the context of gains and show how ecological pressures can sculpt economic decision making.     

General practitioner attitudes towards referral of eating-disordered patients: a vignette study based on the theory of planned behaviour

Objective The study examined individual differences between general practitioners (GPs) to determine their impact on variations in intention to refer a hypothetical patient with disordered eating to specialist eating disorder services. The study also examined the impact of patient weight on intention to refer.Method GPs within three primary care trusts (PCTs) were posted a vignette depicting a patient with disordered eating, described as either normal weight or underweight. A questionnaire was developed from the theory of planned behaviour to assess the GPs' attitudes, perception of subjective norms, perceived behavioural control, and intention to refer the patient. Demographic details were also collected.Results Responses were received from 88 GPs (33%). Intention to refer the patient was significantly related to subjective norms and cognitive attitudes. Together these predictors explained 86% of the variance in the intention to refer. GP or practice characteristics did not have a significant effect on the GPs' intention to refer, and nor did the patient's weight.Conclusion Despite National Institute for Health and Clinical Excellence current guidance, patient weight did not influence GPs' decisions to refer. Much of the variance in actual referral behaviour may be explained by cognitive attitudes and subjective norms. Interventions to reduce this variation should be focused on informing GPs about actual norms, and best practice guidelines.     

Models for forest ecosystem management: a European perspective

BACKGROUND: Forest management in Europe is committed to sustainability. In the face of climate change and accompanying risks, however, planning in order to achieve this aim becomes increasingly challenging, underlining the need for new and innovative methods. Models potentially integrate a wide range of system knowledge and present scenarios of variables important for any management decision. In the past, however, model development has mainly focused on specific purposes whereas today we are increasingly aware of the need for the whole range of information that can be provided by models. It is therefore assumed helpful to review the various approaches that are available for specific tasks and to discuss how they can be used for future management strategies. SCOPE: Here we develop a concept for the role of models in forest ecosystem management based on historical analyses. Five paradigms of forest management are identified: (1) multiple uses, (2) dominant use, (3) environmentally sensitive multiple uses, (4) full ecosystem approach and (5) eco-regional perspective. An overview of model approaches is given that is dedicated to this purpose and to developments of different kinds of approaches. It is discussed how these models can contribute to goal setting, decision support and development of guidelines for forestry operations. Furthermore, it is shown how scenario analysis, including stand and landscape visualization, can be used to depict alternatives, make long-term consequences of different options transparent, and ease participation of different stakeholder groups and education. CONCLUSIONS: In our opinion, the current challenge of forest ecosystem management in Europe is to integrate system knowledge from different temporal and spatial scales and from various disciplines. For this purpose, using a set of models with different focus that can be selected from a kind of toolbox according to particular needs is more promising than developing one overarching model, covering ecological, production and landscape issues equally well.     

Spatial Uncertainty and Ecological Models

Applied ecological models that are used to understand and manage natural systems often rely on spatial data as input. Spatial uncertainty in these data can propagate into model predictions. Uncertainty analysis, sensitivity analysis, error analysis, error budget analysis, spatial decision analysis, and hypothesis testing using neutral models are all techniques designed to explore the relationship between variation in model inputs and variation in model predictions. Although similar methods can be used to answer them, these approaches address different questions. These approaches differ in (a) whether the focus is forward or backward (forward to evaluate the magnitude of variation in model predictions propagated or backward to rank input parameters by their influence); (b) whether the question involves model robustness to large variations in spatial pattern or to small deviations from a reference map; and (c) whether processes that generate input uncertainty (for example, cartographic error) are of interest. In this commentary, we propose a taxonomy of approaches, all of which clarify the relationship between spatial uncertainty and the predictions of ecological models. We describe existing techniques and indicate a few areas where research is needed.     

Bayesian Statistics-Based Procedure for Sampling of Contaminated Sites

A variable density sampling pattern based on Bayesian statistics is presented and compared to a uniform density statistical pattern and a judgmental approach in a real case study. The Bayesian statistics, supported by a software tool, supplied a soil sampling plan similar to the judgmental one, especially for the number of sampling points and their location. It allowed statistical goals to be set and expert judgment to be included in the sampling strategy in a transparent and systematic procedure. For these reasons, it appears quite suitable for inclusion into Quality Assurance Quality Control plans.     

Decision‐Making Deficits and Overeating: A Risk Model for Obesity

Objective: To demonstrate that human overeating is not just a passive response to salient environmental triggers and powerful physiological drives; it is also about making choices. The ventromedial prefrontal cortex has been strongly implicated in the neural circuitry necessary for making advantageous decisions when various options for action are available. Decision‐making deficits have been found in patients with ventromedial prefrontal cortex lesions and in those with substance dependence—impairments that reflect an inability to advantageously assess future consequences. That is, they choose immediate rewards in the face of future long‐term negative consequences. Research Methods and Procedures: We extended this research to the study of overeating and overweight, testing a regression model that predicted that poor decision making (as assessed by a validated computerized gambling task) and a tendency to overeat under stress would correlate with higher BMI in a group of healthy adult women (N = 41) representing a broad range of body weights. Results: We found statistically significant main effects for both independent variables in the predicted direction (p < 0.05; R² = 0.35). Indeed, the decision‐making impairments across the 100 trials of the computer task were greater in those with high BMI than in previous studies with drug addicts. Discussion: Findings suggested that cortical and subcortical processes, which regulate one's ability to inhibit short‐term rewards when the long‐term consequences are deleterious, may also influence eating behaviors in a culture dominated by so many, and such varied, sources of palatable and calorically dense sources of energy.     

Decision analysis approach to risk/benefit evaluation in the ethical review of controlled human infection studies

Risks and benefit evaluation for controlled human infection studies, where healthy volunteers are deliberately exposed to infectious agents to evaluate vaccine efficacy, should be explicit, systematic, thorough, and non-arbitrary. Decision analysis promotes these qualities using four steps: (1) determining explicit criteria and measures for evaluation, (2) identifying alternatives to the study, (3) defining the models used to estimate the measures for each alternative, and (4) running the models to produce the estimates and compare the alternatives. In this paper, we describe how decision analysis might be applied by funders and regulators, as well as by others contemplating the use of novel controlled human infection studies for vaccine development and evaluation.