Until recently, Tetrahymena thermophila has rarely been isolated from nature. With improved sampling procedures, T. thermophila has been found in ponds in many northeastern states. The availability of resident populations makes possible both population and ecological genetic studies. All seven known mating types have been recovered; no eighth mating type has been found. Crosses among whole‐genome homozygotes derived from Pennsylvania isolates reveal a spectrum genotypes with mating type alleles resembling traditional A (IV‐ and VII‐) and B(I‐) categories. The genotypes differ significantly with respect to mating type frequency, both among themselves and from previously described genotypes. One A‐category genotype appears to lack mating type II, while one A‐category and all B‐category genotypes have low frequencies of mating type III, thus accounting for the low frequency of III in the pond. The low frequency of III in all five B‐category genotypes examined suggests that the founding allele in this region was low for III. These and other differences are discussed both in terms of mating type frequencies in the pond and in terms of the possible molecular structure of mat alleles. By contrast, numerous variants of the cell surface immobilization antigen are found in addition to the previously described i‐antigens. Variants of the known SerH alleles include those with restriction fragment length polymorphisms and temperature sensitivity as well as alleles with new antigenic specificity. Multiple alleles are present in single ponds. Genes exhibiting serially dominant epistasis over SerH genes also are found. In two instances (K and C), families of antigenically similar polypeptides are expressed in place of H i‐antigen. Molecular weight differences suggest that these paralogous i‐antigen genes evolve by gene duplication and unequal crossing over within central repeats. The existence of complex patterns of epistasis together with seasonal changes in i‐ag frequencies suggest that i‐ag play an important, but as yet unknown, ecological role related to the occurrence of frequent conjugation.
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Language presents an insightful lens through which to consider issues of identity and interdisciplinarity within the field of information science. Through a multiphase research project, we seek to facilitate discussion among practitioners, graduate students and faculty about the way words shape our conceptualizations of information research. This work reports on the theoretical underpinnings of our inquiry and provides preliminary results from the first phase of our project, which included a workshop with 22 members of the iSchool community. During this arts‐based workshop, participants created keyword cards and word dice to generate dialogues about the role of language in the field of information research. Moving forward, we will adopt a Social Interactional Approach (De Fina & Georgakopoulou, 2008) to the narrative analysis of these artefacts, exploring the ways scholars used them to frame their research and construct their professional identities.
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Designers' considerations of whom to include as a participant in design research continue to broaden, listening to individuals and communities previously unheard. Some even argue that other-thanhuman entities should be recognized as a type of participant, advocating for non-humans to have a voice in the design process. Through this paper we contribute to this conversation, arguing for a remembering of how to attend to our interactions with diverse forms of life. We refer to these entities as 'pervasive peripheral participants', drawing on early scholarship of Jean Lave and Etienne Wenger. We use this provocative phrase deliberately, to prompt us to consider how we learn with and through these relationships. Non-human, peripheral participants are ubiquitous in all aspects of life, and may inspire designers throughout their project's lifetime, from the environments in which they work, to the resources they use. These participants implicate and are implicated through design. While we recognize that the inclusion of pervasive peripheral participants in design processes is a challenging step to take, this paper holds up scholarly contributions which offer insights to those willing to join this work. We look to projects that do not limit participation in design to human-centred perspectives. These projects offer examples of how to engage with other-than-human ways of being, responding to Daniel Heath Justice's call to "imagine otherwise" (danielheathjustice.com). Learning from these approaches, we imagine how we might attend to relations with otherthan-humans through relinquishing control, fostering collaboration and relationality, practicing reciprocal acts of care, and valuing other temporalities. In doing so, we envision a future when interaction design practice welcomes a broader array of participation, creating space for more ethical and diverse worlds.
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