Giant cannibals drive selection for inducible defence in heterospecific prey

Author(s):  
Kunio Takatsu ◽  
Volker H. W. Rudolf ◽  
Osamu Kishida

Parasitology ◽  
1990 ◽  
Vol 100 (S1) ◽  
pp. S53-S61 ◽  
Author(s):  
C. D. Harvell

SummaryDefences against parasites are characterized by inducible, amplifiable responses, often with a memory component. Inducible defences with similar properties are common in a variety of other types of interactions, for example many aquatic invertebrates produce inducible structural defences against their predators and competitors. Most inducible defences have the following properties: (1) a threshold of activation; (2) an amplification of response with increasing stimulus; (3) a memory component. Specificity, amplification and memory are the basis for defining a defence as ‘immune’ (Klein, 1982), and these properties are present in both the vertebrate and invertebrate internal defence responses to pathogens. Invertebrates differ in the absence of immunoglobulins and therefore in reduced specificity. Although the reduced specificity of invertebrate internal defence systems is often viewed as proof of their ‘primitiveness’, the differences in defence systems of vertebrates and invertebrates may be more related to their respective selection regimes than to phylogeny. The syngeneic recognition system of vertebrates functions to recognize small departures from self, such as would arise from neoplasia. Are vertebrates under more intense selection from neoplasia, perhaps due to a greater incidence of hormonal imbalance or hypersensitivity reactions? The invertebrate internal defence systems are all less discriminating than the vertebrate, but there are marked differences in degree of discrimination depending on whether the group is colonial or not. Even the phyla of colonial animals with quite simple body plans, the sponges and cnidarians, have a more discriminating recognition system than the phyla of solitary animals with more complex body plans, such as the molluscs and arthropods. The primary effectors of all invertebrate responses to parasites are encapsulation and phagocytosis, although in some phyla there are specific antibacterial proteins that can also be induced. A primary effector of the vertebrate immune system is also based on phagocytosis, but is mediated largely by immunoglobulins. Although memory is a widespread property of inducible defence systems, the mechanisms, underlying memory components are unknown except in the vertebrate immune response. The function and adaptiveness of many of these accelerated or amplified second-set responses remain unclear, although it is tempting to conclude that a memory component is a beneficial adaptation to multiple, intermittent stimuli. From this review I conclude that the conditions that favour the evolution of inducible defences include: (1) an intermittent, unpredictable selective regime; (2) selection for a ‘camouflaged’ defence, to slow parasite counter-adaptation; (3) reliable cues and (4) high costs of defence.



2019 ◽  
Vol 28 (3) ◽  
pp. 1000-1009
Author(s):  
Allison Bean ◽  
Lindsey Paden Cargill ◽  
Samantha Lyle

Purpose Nearly 50% of school-based speech-language pathologists (SLPs) provide services to school-age children who use augmentative and alternative communication (AAC). However, many SLPs report having insufficient knowledge in the area of AAC implementation. The objective of this tutorial is to provide clinicians with a framework for supporting 1 area of AAC implementation: vocabulary selection for preliterate children who use AAC. Method This tutorial focuses on 4 variables that clinicians should consider when selecting vocabulary: (a) contexts/environments where the vocabulary can be used, (b) time span during which the vocabulary will be relevant, (c) whether the vocabulary can elicit and maintain interactions with other people, and (d) whether the vocabulary will facilitate developmentally appropriate grammatical structures. This tutorial focuses on the role that these variables play in language development in verbal children with typical development, verbal children with language impairment, and nonverbal children who use AAC. Results Use of the 4 variables highlighted above may help practicing SLPs select vocabulary that will best facilitate language acquisition in preliterate children who use AAC.



2013 ◽  
Vol 22 (1) ◽  
pp. 4-15 ◽  
Author(s):  
Laura J. Ball ◽  
Joanne Lasker

Abstract For adults with acquired communication impairment, particularly those who have communication disorders associated with stroke or neurodegenerative disease, communication partners play an important role in establishing and maintaining communicative competence. In this paper, we assemble some evidence on this topic and integrate it with current preferred practice patterns (American Speech-Language-Hearing Association, 2004). Our goals are to help speech-language pathologists (SLPs) identify and describe partner-based communication strategies for adults with acquired impairment, implement evidence-based approaches for teaching strategies to communication partners, and employ a Personnel Framework (Binger et al., 2012) to clarify partners? roles in acquiring and supporting communication tools for individuals with acquired impairments. We offer specific guidance about AAC techniques and message selection for communication partners involved with chronic, degenerative, and end of life communication. We discuss research and provide examples of communication partner supports for person(s) with aphasia and person(s) with amyotrophic lateral sclerosis who have complex communication needs.





Methodology ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 177-188 ◽  
Author(s):  
Martin Schultze ◽  
Michael Eid

Abstract. In the construction of scales intended for the use in cross-cultural studies, the selection of items needs to be guided not only by traditional criteria of item quality, but has to take information about the measurement invariance of the scale into account. We present an approach to automated item selection which depicts the process as a combinatorial optimization problem and aims at finding a scale which fulfils predefined target criteria – such as measurement invariance across cultures. The search for an optimal solution is performed using an adaptation of the [Formula: see text] Ant System algorithm. The approach is illustrated using an application to item selection for a personality scale assuming measurement invariance across multiple countries.



2019 ◽  
Vol 19 (3) ◽  
pp. 261-272 ◽  
Author(s):  
Jonathan W. Ivy ◽  
Julie Payne ◽  
Nancy A. Neef


2008 ◽  
Author(s):  
Lycia A. Carter ◽  
Dwayne G. Norris ◽  
Mark A. Wilson ◽  
Lee Ann D. Wadsworth ◽  
Kelley J. Krokos


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