218 research outputs found

    The Potential for ‘Next-Generation’, Microalgae-Based Feed Ingredients for Salmonid Aquaculture in Context of the Blue Revolution

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    Microalgae-based ingredients have potential to ensure continued growth of salmonid aquaculture for global sustainable food security in the blue economy. Algal biorefineries must valorize the entire crop to grow profitable microalgae-based economies. With massive growth and demand for novel sustainable ingredients, farmed salmonid feed sectors are highly promising areas to focus on. Microalgae-based ingredients for salmonid feeds may have market advantages in terms of lower input costs, aerial foot-print, wastewater remediation benefits and carbon credits for industrial CO2 conversion. A handful of microalgae-based ingredients have been proposed as candidates to supply well-balanced nutrients and immunostimulatory compounds. However, technical gaps exist and need addressing before the industry could economically incorporate microalgae-based ingredients into commercial feeds. Current knowledge on comprehensive biochemical composition is incomplete, highly heterogeneous, and information on their nutritional value is scattered and/or inconsistent. The aim of this chapter is to consolidate relatively fragmented data on biochemical composition and nutritional value of microalgae-based ingredients focusing on farmed salmonid feeds. Presented are discussions on the potential for such ‘next-generation’ ingredients, opportunities/challenges for their use and a compendium of studies evaluating their performance in feeds for economically relevant farmed salmonids, including rainbow trout (Oncorhynchus mykiss), Arctic charr (Salvelinus alpinus) and Atlantic salmon (Salmo salar)

    Facial Patterns are a Conventional Signal of Agonistic Ability in Polistes exclamans Paper Wasps

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    Some animals minimize the high costs of aggressive conflict by using conventional signals of agonistic ability to assess rivals prior to interacting. Conventional signals are more controversial than other signals of agonistic ability because they lack an inherent physical or physiological link with their bearer’s agonistic ability. Here, we test whether the variable brown facial stripes in Polistes exclamans paper wasps function as a conventional signal. Polistes exclamans were given the option of challenging or avoiding a rival with an experimentally altered facial pattern. Our results show that rival assessment is based on the facial patterns of rivals, as well as an individual’s own size, facial patterns, and nesting strategy. Individuals with larger body size and larger brown facial stripes were more likely to challenge rivals than individuals with smaller body size and smaller brown facial stripes. In addition, large individuals were more likely to challenge rivals with large brown facial stripes than small individuals, while an individual’s own body size did not influence whether or not they challenged rivals with small brown stripes. Individuals who previously nested in multiple queen groups approached rivals more rapidly than individuals who previously nested alone, suggesting that social experience also plays a role in rival assessment. Finally, rivals with small facial stripes were challenged more rapidly than those with large facial stripes. These results demonstrate that P. exclamans facial patterns function as a signal used to minimize the cost of conflict. However, individuals do not make simple decisions based on their rival’s signal alone, as an individual’s own social experience and agonistic abilities also influence rival assessment decisions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87088/1/j.1439-0310.2011.01967.x.pd

    EVOLUTION OF IDENTITY SIGNALS: FREQUENCY-DEPENDENT BENEFITS OF DISTINCTIVE PHENOTYPES USED FOR INDIVIDUAL RECOGNITION

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74986/1/j.1558-5646.2009.00833.x.pd

    How Does Individual Recognition Evolve? Comparing Responses to Identity Information in P olistes Species with and Without Individual Recognition

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    A wide range of complex social behaviors are facilitated by the recognition of individual conspecifics. Individual recognition requires sufficient phenotypic variation to provide identity information as well as receivers that process and respond to identity information. Understanding how a complex trait such as individual recognition evolves requires that we consider how each component has evolved. Previous comparative studies have examined phenotypic variability in senders and receiver learning abilities, although little work has compared receiver responses to identity information among related species with and without individual recognition. Here, we compare responses to identity information in two Polistes paper wasps: P. fuscatus, which visually recognizes individuals, and P. metricus , which does not normally show evidence of individual recognition. Although the species differ in individual recognition, the results of this study show that receiver responses to experimentally manipulated identity information are surprisingly similar in both species. Receivers direct less aggression toward identifiable individuals than unidentifiable individuals. Therefore, the responses necessary for individual recognition may pre‐date its evolution in the P. fuscatus lineage. Additionally, our data demonstrate the apparent binary differences in a complex behavior between the two species, such as individual recognition, likely involve incremental differences along a number of axes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102093/1/eth12191.pd

    Specialized visual learning of facial signals of quality in the paper wasp, P olistes dominula

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109618/1/bij12394.pd

    Respiratory culture nudge improves antibiotic prescribing for Moraxella catarrhalis and Haemophilus influenzae lower respiratory tract infections

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    We compared optimal antibiotic prescribing before and after implementing an interpretive ÎČ-lactamase microbiology comment for Haemophilus influenzae and Moraxella catarrhalis in lower respiratory-tract infections. The postintervention group was associated with 5-fold increased odds of optimal de-escalation (adjusted odds ratio, 5.03; 95% confidence interval, 2.57-9.87)

    Heritable variation in colour patterns mediating individual recognition

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    Understanding the developmental and evolutionary processes that generate and maintain variation in natural populations remains a major challenge for modern biology. Populations of Polistes fuscatus paper wasps have highly variable colour patterns that mediate individual recognition. Previous experimental and comparative studies have provided evidence that colour pattern diversity is the result of selection for individuals to advertise their identity. Distinctive identity-signalling phenotypes facilitate recognition, which reduces aggression between familiar individuals in P. fuscatus wasps. Selection for identity signals may increase phenotypic diversity via two distinct modes of selection that have different effects on genetic diversity. Directional selection for increased plasticity would greatly increase phenotypic diversity but decrease genetic diversity at associated loci. Alternatively, heritable identity signals under balancing selection would maintain genetic diversity at associated loci. Here, we assess whether there is heritable variation underlying colour pattern diversity used for facial recognition in a wild population of P. fuscatus wasps. We find that colour patterns are heritable and not Mendelian, suggesting that multiple loci are involved. Additionally, patterns of genetic correlations among traits indicated that many of the loci underlying colour pattern variation are unlinked and independently segregating. Our results support a model where the benefits of being recognizable maintain genetic variation at multiple unlinked loci that code for phenotypic diversity used for recognition

    Heritable variation in colour patterns mediating individual recognition

    Get PDF
    Understanding the developmental and evolutionary processes that generate and maintain variation in natural populations remains a major challenge for modern biology. Populations of Polistes fuscatus paper wasps have highly variable colour patterns that mediate individual recognition. Previous experimental and comparative studies have provided evidence that colour pattern diversity is the result of selection for individuals to advertise their identity. Distinctive identity-signalling phenotypes facilitate recognition, which reduces aggression between familiar individuals in P. fuscatus wasps. Selection for identity signals may increase phenotypic diversity via two distinct modes of selection that have different effects on genetic diversity. Directional selection for increased plasticity would greatly increase phenotypic diversity but decrease genetic diversity at associated loci. Alternatively, heritable identity signals under balancing selection would maintain genetic diversity at associated loci. Here, we assess whether there is heritable variation underlying colour pattern diversity used for facial recognition in a wild population of P. fuscatus wasps. We find that colour patterns are heritable and not Mendelian, suggesting that multiple loci are involved. Additionally, patterns of genetic correlations among traits indicated that many of the loci underlying colour pattern variation are unlinked and independently segregating. Our results support a model where the benefits of being recognizable maintain genetic variation at multiple unlinked loci that code for phenotypic diversity used for recognition.journal articl
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