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131.
In all social species, information relevant to survival and reproduction can be obtained in two main ways: through personal interaction with the environment (i.e. ‘personal’ information) and from the performance of others (i.e. ‘public’ information). While public information is less costly to obtain than personal information, it may be inappropriate or inaccurate. When deciding how much to rely on public information, individuals should therefore assess its potential quality, but this possibility requires empirical testing in animals. Here, we use the sentinel system of cooperatively breeding pied babblers (Turdoides bicolor) to investigate how behavioural decisions of foragers are influenced by potential variation in the quality of anti-predator information from a vigilant groupmate. When sentinels moved to a higher position, from where their probability of detecting predators is likely to be greater, foragers reduced their vigilance, spread out more widely and were more likely to venture into the open. Consequently, they spent more time foraging and increased their foraging efficiency, resulting in a profound increase in biomass intake rate. The opposite behavioural changes, and consequent foraging outcomes, were found when sentinels moved lower. A playback experiment demonstrated that foragers can use vocal cues alone to assess sentinel height. This is the first study to link explicitly a measure of the potential quality of public information with a fitness measure from those relying on the information, and our results emphasize that a full understanding of the evolution of communication in complex societies requires consideration of the reliability of information.  相似文献   
132.
ABSTRACT This report contains the newest directions for preparation of the synthetic nutrient medium for some Tetrahymena species that do not require lipids. In the standard medium T. thermophila. strains SB 210 and 281, multiply at 37°C with doubling times of around 2 h and at 26°C around 5 h. We have established multiplication rates as functions of variations in the composition of the medium. In media in which all components are present at one-third of the normal concentrations and only the essential amino acids are included, growth and multiplication become sharply dependent on glucose in strain SB 281. Such media may be used for selection and enrichment of certain specified cell lines.  相似文献   
133.
Seed dispersal is an ecological process crucial for forest regeneration and recruitment. To date, most studies on frugivore seed dispersal have used the seed dispersal effectiveness framework and have documented seed-handling mechanisms, dispersal distances and the effect of seed handling on germination. In contrast, there has been no exploration of “disperser reliability” which is essential to determine if a frugivore is an effective disperser only in particular regions/years/seasons or across a range of spatio-temporal scales. In this paper, we propose a practical framework to assess the spatial reliability of frugivores as seed dispersers. We suggest that a frugivore genus would be a reliable disperser of certain plant families/genera if: (a) fruits of these plant families/genera are represented in the diets of most of the species of that frugivore, (b) these are consumed by the frugivore genus across different kinds of habitats, and (c) these fruits feature among the yearly staples and preferred fruits in the diets of the frugivore genus. Using this framework, we reviewed frugivory by the genus Macaca across Asia to assess its spatial reliability as seed dispersers. We found that the macaques dispersed the seeds of 11 plant families and five plant genera including at least 82 species across habitats. Differences in fruit consumption/preference between different groups of macaques were driven by variation in plant community composition across habitats. We posit that it is essential to maintain viable populations of macaques across their range and keep human interventions at a minimum to ensure that they continue to reliably disperse the seeds of a broad range of plant species in the Anthropocene. We further suggest that this framework be used for assessing the spatial reliability of other taxonomic groups as seed dispersers.  相似文献   
134.
Photo analysis offers a simple, noninvasive approach to characterizing and quantifying skin lesions in cetaceans; however, this process involves methodological considerations that have often gone unaddressed or have varied in approach among investigators. Subjectivity associated with classifying skin lesion types of unknown etiology and quantifying measures of skin lesion prevalence and extent from photo data raises questions about observer bias and agreement (i.e., interrater reliability), which are often ignored. The purpose of the present study was to improve upon data quality control and assessment practices when studying skin lesions using only photo data. Specifically, we tested interrater reliability of a skin lesion classification system, compared methods of quantifying skin lesion extent, and determined the validity of the dorsal fin as a proxy for skin lesions on the entire body. Acceptable levels of interrater reliability were achieved for only 7 of 17 defined lesion types, but reliability was high for the two tested measures of lesion extent. Skin lesion extent measured from the dorsal fin alone was not a decent proxy for the whole visible surface; disparities between measures were as high as 43%. We discuss the potential pitfalls discovered and provide recommendations for others attempting similar approaches.  相似文献   
135.
Objective: To determine whether home‐based and clinic‐based dental examinations of older people are comparable. Background: Despite a number of studies which have examined the concordance between different examiners or examination circumstances, none has directly compared an oral examination conducted at home with one conducted in an appropriate clinical setting. Materials and methods: Dentate participants (n = 61) aged between 65 and 74 years underwent two clinical examinations, one in a conventional dental clinic and the other in the person’s home. Kappa statistics, intra‐class correlation coefficients and ‘Difference against mean’ plots were used to determine the nature and extent of any bias. Results: The summary estimates for missing teeth and dental caries were close, although the home‐based examinations resulted in a lower estimate of the mean number of decayed teeth and of untreated coronal decay. The lowest reliability statistics were observed with respect to the prevalence of untreated coronal caries, filled root surfaces and root surface (Decayed or Filled Surfaces) DFS. The periodontitis prevalence estimates were closer, but the reliability statistics were relatively low. The extent of bleeding on probing was relatively under‐estimated in the home‐based examinations. ‘Difference against mean’ plots indicated that, overall, the clinic‐based examinations detected more disease (although this was not observed for all clinical parameters which were measured). Conclusion: While clinic‐based examinations will remain the preferred option, the potential loss of information associated with home‐based examinations is unlikely to be great enough to preclude using them where required, although surveys with larger samples (and therefore more accurate estimates) should restrict their proportion of home‐based examinations to no more than 10%. As they are less precise, surveys with samples of 300 or fewer can safely accommodate up to about one‐third of their examinations being conducted in participants’ homes.  相似文献   
136.
How can decision makers reconcile the demand for increasingly reliable services drawn from the environment (including water and power) with the desire for both a better environment and more environmental amenities? In this paper, which is based on US case studies of ecosystem rehabilitation initiatives in the San Francisco Bay-Delta, the Columbia River Basin in the Pacific Northwest, and the Florida Everglades, we focus on several notable problems in current management practice. We assess the role of adaptive management and identify five areas of major innovation by which ecologists and the authorities that operate large water and hydropower systems attempt to reconcile the tension between maintaining service reliability and promoting ecological rehabilitation. The implications of the findings for a wider framework within which ecosystems can be matched to the most appropriate management regime are related specifically to aquatic-terrestrial ecosystems. Finally, we emphasize the importance of redefining ecosystem functions and services so that the inherent conflict between high-reliability services and ecosystem rehabilitation can be reconciled.  相似文献   
137.
Objective: To validate a culturally relevant body image instrument among urban African Americans through three distinct studies. Research Methods and Procedures: In Study 1, 38 medical practitioners performed content validity tests on the instrument. In Study 2, three research staff rated the body image of 283 African‐American public housing residents (75% women, mean age = 44 years), with the residents completing body image, BMI, and percentage body fat measures. In Study 3, 35 African Americans (57% men, mean age = 42) completed body image measures and evaluated their cultural relevance. Results: In Study 1, 97% to 100% of practitioners sorted the jumbled figures into the correct ascending order. The correlation between the body image figures and the practitioners’ weight classifications of the figures was high (r = 0.91). In Study 2, observers arrived at similar ratings of body size with excellent consistency (α = 0.95). Ratings of body image were strongly correlated with participant BMI (r = 0.89 to 0.93 across observers and 0.81 for all participants) and percentage of body fat (r = 0.77 to 0.89 across observers and 0.76 for all participants). In Study 3, body image ratings with the new scale were positively correlated with other validated figural scales. The majority of participants reported that figures in the new body image scale looked most like themselves and other African Americans and were easiest to identify themselves with. Discussion: The instrument displayed strong psychometric performance and cultural relevance, suggesting that the scale is a promising tool for examining body image and obesity among African Americans.  相似文献   
138.
One hectare of primary forest in Central Kalimantan was enumerated and all trees 10 cm dbh tagged and identified to species as far as possible. Two informants, regarded as the most knowledgeable on forest trees by the local community, supplied the vernacular names for the trees. The study found that only 12% of vernacular names given by one informant and 22% by the second could be equated consistently to taxa. Of these taxa 77% were given the same vernacular name by both informants and the remaining 23% had an obvious common origin (cognate). Many of these taxa were distinctive or had a use to the informants. The results have important implications for the conversion of vernacular names to scientific names by anyone carrying out inventory work in Kalimantan.  相似文献   
139.
In Germany all keepers of livestock are legally required to record animal welfare indicators as part of their on-farm self-assessment. The Association for Technology and Structures in Agriculture (Kuratorium für Technik und Bauwesen in der Landwirtschaft e.V. (KTBL)) has suggested the use of a particular set of animal welfare indicators in their publication Animal welfare indicators: Practical guide – Pigs. The aim of the present study was to evaluate the inter-observer reliability (Inter-OR) and intra-observer reliability (Intra-OR) of these indicators with respect to the welfare of fattening pigs. For the assessment of Inter-OR, three observers evaluated six KTBL animal welfare indicators. The Inter-OR of the indicators was calculated from the results using intra-class correlation coefficients (ICC). ‘Excellent’ Inter-OR results were found for the indicators tail length (ICC 0.89), skin lesions (ICC 0.77) and ear lesions (ICC 0.80). In contrast, the Inter-OR of the indicators tail lesions (ICC 0.46) and faecal soiling (ICC 0.47) were considered to be only ‘fair’ and that of the indicator lameness (ICC 0.36) as ‘poor’. For the evaluation of the Intra-OR, the same three observers assessed the welfare of 162 to 200 fattening pigs using the same welfare indicators in total eight times. Again ICCs, here per indicator and observer, were used to calculate the Intra-OR. The Intra-OR of the indicators faecal soiling (ICC 0.81) and ear lesions (ICC 0.97) lay in the ‘excellent’ range on average. While the Intra-OR of the indicators skin lesions (ICC 0.67), tail length (ICC 0.74) and lameness (ICC 0.60) could still be considered as being ‘good’, the Intra-OR of the indicator tail lesions (ICC 0.52) could only be assessed as being ‘fair’. From these results the significance of the KTBL indicators could be judged as follows: it is possible to use all the chosen indicators apart from the indicator tail lesions as an internal controlling instrument or as part of an internal weak-point analysis as long as the indicators are evaluated by the same person. A comparison of the indicators tail lesions, lameness and faecal soiling when assessed by different observers should be considered critically because the Inter-OR of these three indicators could only be considered as being ‘poor’ to ‘fair’.  相似文献   
140.
In 2008, Zwart and colleagues observed that the fraction of the structures deposited in the PDB alleged to have “pseudosymmetry” or “special noncrystallographic symmetry” (NCS) was about 6%, and that this percentage was rising annually. A few years later, Poon and colleagues found that 2% of all the crystal structures in the PDB belonged to higher symmetry space groups than those assigned to them. Here, I report an analysis of the X-ray diffraction data deposited for this class of structures, which shows that most of the “pseudosymmetry” and “special NCS” that has been reported is in fact true crystallographic symmetry (CS). This distinction is important because the credibility of crystal structures depends heavily on quality control statistics such as Rfree that are unreliable when they are computed incorrectly, which they often are when CS is misidentified as “special NCS” or “pseudosymmetry”. When mistakes of this kind are made, artificially low values of Rfree can give unjustified confidence in the accuracy of the reported structures.  相似文献   
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