1,720,959 research outputs found
En route to resources: Foraging strategies of plant‐associated insects to identify resources in complex dynamic environments
No full textAbstract In plant‐associated communities, foraging insects aim to find different resources of interest. Herbivores look for the most nutritious plant tissues, pollinators for sweet nectar and protein‐rich pollen, and carnivores for their preferred prey. Although these foragers look for different resources, they face similar problems: resource cues are often highly variable and need to be detected in complex environments among non‐resources. Search templates—a subset of stimuli that is likely correlated with the occurrence of a particular resource—help foragers across trophic levels to find their resources. However, search‐template‐based foraging can also cause perception errors. Here, we synthesize knowledge on foraging by insects from functional groups belonging to different trophic levels to reveal common problems experienced by foragers and strategies to solve such problems. We focus mostly on volatile‐based foraging because this searching strategy is best studied across functional groups. We argue that search templates are both multimodal (including multiple trait types, e.g. odour and visual) and hierarchical (including multiple foraging steps). Search templates are plastic and updated by experience to match the dynamic foraging environment over time. By comparing insects from different functional groups spanning multiple trophic levels, we have identified important missing gaps on cue use and foraging strategies which should be addressed in the future in order to reduce knowledge asymmetries among functional groups about search‐template‐based foraging. We propose a way to achieve this goal arguing that studies on less well investigated functional groups can advance rapidly by borrowing, testing and adjusting already available hypotheses and theories formulated for other insect groups. Knowledge of search‐template‐based foraging across functional groups will give new insights into the evolution of foraging behaviour in complex ecological communities, help predict ecological consequences of large‐scale human‐made disturbances and help optimize insect‐delivered ecosystem services (pollination and biological control) in cropping systems. Read the free Plain Language Summary for this article on the Journal blog
En route to resources: Foraging strategies of plant-associated insects to identify resources in complex dynamic environments
Full text linkIn plant-associated communities, foraging insects aim to find different resources of interest. Herbivores look for the most nutritious plant tissues, pollinators for sweet nectar and protein-rich pollen, and carnivores for their preferred prey. Although these foragers look for different resources, they face similar problems: resource cues are often highly variable and need to be detected in complex environments among non-resources. Search templates—a subset of stimuli that is likely correlated with the occurrence of a particular resource—help foragers across trophic levels to find their resources. However, search-template-based foraging can also cause perception errors. Here, we synthesize knowledge on foraging by insects from functional groups belonging to different trophic levels to reveal common problems experienced by foragers and strategies to solve such problems. We focus mostly on volatile-based foraging because this searching strategy is best studied across functional groups. We argue that search templates are both multimodal (including multiple trait types, e.g. odour and visual) and hierarchical (including multiple foraging steps). Search templates are plastic and updated by experience to match the dynamic foraging environment over time. By comparing insects from different functional groups spanning multiple trophic levels, we have identified important missing gaps on cue use and foraging strategies which should be addressed in the future in order to reduce knowledge asymmetries among functional groups about search-template-based foraging. We propose a way to achieve this goal arguing that studies on less well investigated functional groups can advance rapidly by borrowing, testing and adjusting already available hypotheses and theories formulated for other insect groups. Knowledge of search-template-based foraging across functional groups will give new insights into the evolution of foraging behaviour in complex ecological communities, help predict ecological consequences of large-scale human-made disturbances and help optimize insect-delivered ecosystem services (pollination and biological control) in cropping systems. Read the free Plain Language Summary for this article on the Journal blog
Putative Signals of Generalist Plant Species Adaptation to Local Pollinator Communities and Abiotic Factors
No full textThe reproductive success of flowering plants with generalized pollination systems is influenced by interactions with a diverse pollinator community and abiotic factors. However, knowledge about the adaptative potential of plants to complex ecological networks and the underlying genetic mechanisms is still limited. Based on a pool-sequencing approach of 21 natural populations of Brassica incana in Southern Italy, we combined a genome-environmental association analysis with a genome scan for signals of population genomic differentiation to discover genetic variants associated with the ecological variation. We identified genomic regions putatively involved in the adaptation of B. incana to the identity of local pollinator functional categories and pollinator community composition. Interestingly, we observed several shared candidate genes associated with long-tongue bees, soil texture, and temperature variation. We established a genomic map of potential generalist flowering plant local adaptation to complex biotic interactions, and the importance of considering multiple environmental factors to describe the adaptive landscape of plant populations
Understanding insect foraging in complex habitats by comparing trophic levels: insights from specialist host-parasitoid-hyperparasitoid systems
Full text linkInsects typically forage in complex habitats in which their resources are surrounded by non-resources. For herbivores, pollinators, parasitoids, and higher level predators research has focused on how specific trophic levels filter and integrate information from cues in their habitat to locate resources. However, these insights frequently build specific theory per trophic level and seldom across trophic levels. Here, we synthesize advances in understanding of insect foraging behavior in complex habitats by comparing trophic levels in specialist host-parasitoid-hyperparasitoid systems. We argue that resources may become less apparent to foraging insects when they are member of higher trophic levels and hypothesize that higher trophic level organisms require a larger number of steps in their foraging decisions. We identify important knowledge gaps of information integration strategies by insects that belong to higher trophic levels
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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