195 research outputs found

    The Progressive Increase of Food Waste in America and Its Environmental Impact

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    Food waste contributes to excess consumption of freshwater and fossil fuels which, along with methane and CO2 emissions from decomposing food, impacts global climate change. Here, we calculate the energy content of nationwide food waste from the difference between the US food supply and the food consumed by the population. The latter was estimated using a validated mathematical model of metabolism relating body weight to the amount of food eaten. We found that US per capita food waste has progressively increased by ∼50% since 1974 reaching more than 1400 kcal per person per day or 150 trillion kcal per year. Food waste now accounts for more than one quarter of the total freshwater consumption and ∼300 million barrels of oil per year

    Editorial

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    This issue of the Bulletin of Entomological Research is a little different, in that it includes eight papers from a conference held last year at the University of Innsbruck, Austria, entitled ‘Molecular approaches to study trophic interactions: current progress and future directions’. Details of the meeting can still be found at www.mti-symposium.at. The meeting was organised to bring together researchers in the growing fields of molecular analysis of predation and parasitism. The aim was to discuss and synthesize the latest progress in these fields, to discuss techniques, to identify promising avenues for future research and to stimulate cooperation and collaboration. A major objective was also to attract those new to, or interested in, using these approaches and to provide a workshop that would help them get started and to understand the advantages and limitations of molecular approaches. The meeting was deliberately cross-discipline, bringing together people working on vertebrates and invertebrates, terrestrial and aquatic systems, but all with a common interest in trophic relationships and their study using molecular approaches. There were over 70 researchers and students from 15 countries at this highly diverse, three-day conference. Four sessions were held and introduced by keynote speakers, each an international leader in his field: Simon Jarman (Australian Antarctic Division, Australia) introduced the session on predation in aquatic systems, and Andrew King (Cardiff University, UK) provided us with an overview on predation in terrestrial systems. The session on the analysis of blood meals was opened by Steven Torr (University of Greenwich, UK), while Matt Greenstone (USDA, USA) provided (remotely) a keynote address on molecular approaches to study endoparasitism. The keynote presentations were followed by an array of highly interesting talks, complemented by posters. This special issue of Bulletin of Entomological Research, therefore, includes papers form this techniques-based meeting that are by no means all entomological. Our justification for this diversion from our usual editorial policies is that the molecular approaches used are widely applicable across taxonomic divisions. Thus, a technique developed to detect dietary components in the guts of krill might be equally useful to someone working on predation by carabid beetles or ladybirds. We make no apologies, therefore, for including papers on the gut microflora of lumbricid earthworms and the diets of rock lobsters alongside more familiar entomological studies on predation and parasitism. These papers clearly demonstrate that molecular analyses are providing us with exciting new ways to study trophic relationships within food webs in a range of aquatic and terrestrial ecosystems. We would like to thank all participants at the Symposium who made this conference such a rewarding and productive meeting, but especially those who have contributed to this special edition. We look forward to regular future symposia in this fast-moving field

    A Homogeneous Actor-Based Monitor Language for Adaptive Behaviour

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    This paper describes a structured approach to encoding monitors in an actor language. Within a configuration of actors, each of which publishes a history, a monitor is an independent actor that triggers an action based on patterns occurring in the histories. We define a monitor language based on linear temporal logic and show how it can be homogeneously embedded within an actor language. The approach is demonstrated through a number of examples and evaluated in terms of a real-world actor-based simulation

    Prey availability and temporal partitioning modulate felid coexistence in Neotropical forests

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    Carnivores have long been used as model organisms to examine mechanisms that allow coexistence among ecologically similar species. Interactions between carnivores, including competition and predation, comprise important processes regulating local community structure and diversity. We use data from an intensive camera-trapping monitoring program across eight Neotropical forest sites to describe the patterns of spatiotemporal organization of a guild of five sympatric cat species: jaguar (Panthera onca), puma (Puma concolor), ocelot (Leopardus pardalis), jaguarundi (Herpailurus yagouaroundi) and margay (Leopardus wiedii). For the three largest cat species, we developed multi-stage occupancy models accounting for habitat characteristics (landscape complexity and prey availability) and models accounting for species interactions (occupancy estimates of potential competitor cat species). Patterns of habitat-use were best explained by prey availability, rather than habitat structure or species interactions, with no evidence of negative associations of jaguar on puma and ocelot occupancy or puma on ocelot occupancy. We further explore temporal activity patterns and overlap of all five felid species. We observed a moderate temporal overlap between jaguar, puma and ocelot, with differences in their activity peaks, whereas higher temporal partitioning was observed between jaguarundi and both ocelot and margay. Lastly, we conducted temporal overlap analysis and calculated species activity levels across study sites to explore if shifts in daily activity within species can be explained by varying levels of local competition pressure. Activity patterns of ocelots, jaguarundis and margays were similarly bimodal across sites, but pumas exhibited irregular activity patterns, most likely as a response to jaguar activity. Activity levels were similar among sites and observed differences were unrelated to competition or intraguild killing risk. Our study reveals apparent spatial and temporal partitioning for most of the species pairs analyzed, with prey abundance being more important than species interactions in governing the local occurrence and spatial distribution of Neotropical forest felids

    Intraguild Predation and Native Lady Beetle Decline

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    Coccinellid communities across North America have experienced significant changes in recent decades, with declines in several native species reported. One potential mechanism for these declines is interference competition via intraguild predation; specifically, increased predation of native coccinellid eggs and larvae following the introduction of exotic coccinellids. Our previous studies have shown that agricultural fields in Michigan support a higher diversity and abundance of exotic coccinellids than similar fields in Iowa, and that the landscape surrounding agricultural fields across the north central U.S. influences the abundance and activity of coccinellid species. The goal of this study was to quantify the amount of egg predation experienced by a native coccinellid within Michigan and Iowa soybean fields and explore the influence of local and large-scale landscape structure. Using the native lady beetle Coleomegilla maculata as a model, we found that sentinel egg masses were subject to intense predation within both Michigan and Iowa soybean fields, with 60.7% of egg masses attacked and 43.0% of available eggs consumed within 48 h. In Michigan, the exotic coccinellids Coccinella septempunctata and Harmonia axyridis were the most abundant predators found in soybean fields whereas in Iowa, native species including C. maculata, Hippodamia parenthesis and the soft-winged flower beetle Collops nigriceps dominated the predator community. Predator abundance was greater in soybean fields within diverse landscapes, yet variation in predator numbers did not influence the intensity of egg predation observed. In contrast, the strongest predictor of native coccinellid egg predation was the composition of edge habitats bordering specific fields. Field sites surrounded by semi-natural habitats including forests, restored prairies, old fields, and pasturelands experienced greater egg predation than fields surrounded by other croplands. This study shows that intraguild predation by both native and exotic predators may contribute to native coccinellid decline, and that landscape structure interacts with local predator communities to shape the specific outcomes of predator-predator interactions

    The effects of multiple features of alternatively spliced exons on the K(A)/K(S )ratio test

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    BACKGROUND: The evolution of alternatively spliced exons (ASEs) is of primary interest because these exons are suggested to be a major source of functional diversity of proteins. Many exon features have been suggested to affect the evolution of ASEs. However, previous studies have relied on the K(A)/K(S )ratio test without taking into consideration information sufficiency (i.e., exon length > 75 bp, cross-species divergence > 5%) of the studied exons, leading to potentially biased interpretations. Furthermore, which exon feature dominates the results of the K(A)/K(S )ratio test and whether multiple exon features have additive effects have remained unexplored. RESULTS: In this study, we collect two different datasets for analysis – the ASE dataset (which includes lineage-specific ASEs and conserved ASEs) and the ACE dataset (which includes only conserved ASEs). We first show that information sufficiency can significantly affect the interpretation of relationship between exons features and the K(A)/K(S )ratio test results. After discarding exons with insufficient information, we use a Boolean method to analyze the relationship between test results and four exon features (namely length, protein domain overlapping, inclusion level, and exonic splicing enhancer (ESE) frequency) for the ASE dataset. We demonstrate that length and protein domain overlapping are dominant factors, and they have similar impacts on test results of ASEs. In addition, despite the weak impacts of inclusion level and ESE motif frequency when considered individually, combination of these two factors still have minor additive effects on test results. However, the ACE dataset shows a slightly different result in that inclusion level has a marginally significant effect on test results. Lineage-specific ASEs may have contributed to the difference. Overall, in both ASEs and ACEs, protein domain overlapping is the most dominant exon feature while ESE frequency is the weakest one in affecting test results. CONCLUSION: The proposed method can easily find additive effects of individual or multiple factors on the K(A)/K(S )ratio test results of exons. Therefore, the system can analyze complex conditions in evolution where multiple features are involved. More factors can also be added into the system to extend the scope of evolutionary analysis of exons. In addition, our method may be useful when orthologous exons can not be found for the K(A)/K(S )ratio test

    The specificity and the development of social-emotional competence in a multi-ethnic-classroom

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    <p>Abstract</p> <p>Background</p> <p>Ethnic diversity in schools increases due to globalization. Thus, the children's social-emotional competence development must be considered in the context of a multi-ethnic classroom.</p> <p>Methods</p> <p>In this study, the social-emotional competence of 65 Asian-American and Latin-American children was observed at the beginning and the end of their kindergarten year.</p> <p>Results</p> <p>Initially, significant differences existed among these ethnic groups in respect to moral reasoning. Furthermore, the male children showed more dysregulated aggression but the female children implemented more moral reasoning than their male counterparts. These ethnic specificities did not disappear over the course of the year. In addition, a significant change in avoidance strategies as well as expressed emotions in the narrative took place over the course of one year.</p> <p>Conclusion</p> <p>Ethnic specificity in social-emotional competence does exist independent of gender at the beginning as well as at the end of the kindergarten year in a multi-ethnic kindergarten classroom.</p

    Rapid Plant Identification Using Species- and Group-Specific Primers Targeting Chloroplast DNA

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    Plant identification is challenging when no morphologically assignable parts are available. There is a lack of broadly applicable methods for identifying plants in this situation, for example when roots grow in mixture and for decayed or semi-digested plant material. These difficulties have also impeded the progress made in ecological disciplines such as soil- and trophic ecology. Here, a PCR-based approach is presented which allows identifying a variety of plant taxa commonly occurring in Central European agricultural land. Based on the trnT-F cpDNA region, PCR assays were developed to identify two plant families (Poaceae and Apiaceae), the genera Trifolium and Plantago, and nine plant species: Achillea millefolium, Fagopyrum esculentum, Lolium perenne, Lupinus angustifolius, Phaseolus coccineus, Sinapis alba, Taraxacum officinale, Triticum aestivum, and Zea mays. These assays allowed identification of plants based on size-specific amplicons ranging from 116 bp to 381 bp. Their specificity and sensitivity was consistently high, enabling the detection of small amounts of plant DNA, for example, in decaying plant material and in the intestine or faeces of herbivores. To increase the efficacy of identifying plant species from large number of samples, specific primers were combined in multiplex PCRs, allowing screening for multiple species within a single reaction. The molecular assays outlined here will be applicable manifold, such as for root- and leaf litter identification, botanical trace evidence, and the analysis of herbivory

    DNA-Based Diet Analysis for Any Predator

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    Background: Prey DNA from diet samples can be used as a dietary marker; yet current methods for prey detection require a priori diet knowledge and/or are designed ad hoc, limiting their scope. I present a general approach to detect diverse prey in the feces or gut contents of predators. Methodology/Principal Findings: In the example outlined, I take advantage of the restriction site for the endonuclease Pac I which is present in 16S mtDNA of most Odontoceti mammals, but absent from most other relevant non-mammalian chordates and invertebrates. Thus in DNA extracted from feces of these mammalian predators Pac I will cleave and exclude predator DNA from a small region targeted by novel universal primers, while most prey DNA remain intact allowing prey selective PCR. The method was optimized using scat samples from captive bottlenose dolphins (Tursiops truncatus) fed a diet of 6–10 prey species from three phlya. Up to five prey from two phyla were detected in a single scat and all but one minor prey item (2% of the overall diet) were detected across all samples. The same method was applied to scat samples from free-ranging bottlenose dolphins; up to seven prey taxa were detected in a single scat and 13 prey taxa from eight teleost families were identified in total. Conclusions/Significance: Data and further examples are provided to facilitate rapid transfer of this approach to any predator. This methodology should prove useful to zoologists using DNA-based diet techniques in a wide variety of study systems
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