Developing a Gene Editing System to Study Haplodiploidy in the Jewel Wasp, Nasonia Vitripennis

Hymenopteran insects, which include all ants, bees and wasps, reproduce through a poorly understood form of reproduction known as haplodiploidy. A promising experimental system for understanding this developmental process is the jewel wasp, Nasonia vitripennis. A critical aspect of using Nasonia as a model is establishing an effective means for editing specific genes of interest so that their functions can be studied through genetic means. For my thesis research, I performed a pilot study of the gene editing method known as CRISPR in Nasonia. I targeted the single heterochromatin protein 1 (HP1) gene present in the Nasonia genome in order to assess the feasibility of this gene editing approach. Targeting HP1 would provide a clear phenotype when this gene is mutated due to its essential functions in early development known from studies in other eukaryotes. Additionally, creating a mutant of this gene will provide a means for studying the role of HP1 in wasp spermatogenesis, an aim that interlinks with the broader chromatin-based goals of our laboratory. Through this study I worked out a streamlined procedure for injecting CRISPR molecules into young wasp embryos, conducting genetic crosses with injected wasps, and screening through their progeny for potential mutants. I observed no mutant phenotypes in injected wasps, but instead, I isolated four potential mutants in F1 progeny. My work has helped to create a solid framework for improving this procedure in Nasonia, and they allow for a better overall understanding of the limitations of producing mutants through CRISPR gene editing in non-model organisms such as Nasonia

City-Wide Perceptions of Neighbourhood Quality using Street View Images

The interactions of individuals with city neighbourhoods is determined, in part, by the perceived quality of urban environments. Perceived neighbourhood quality is a core component of urban vitality, influencing social cohesion, sense of community, safety, activity and mental health of residents. Large-scale assessment of perceptions of neighbourhood quality was pioneered by the Place Pulse projects. Researchers demonstrated the efficacy of crowd-sourcing perception ratings of image pairs across 56 cities and training a model to predict perceptions from street-view images. Variation across cities may limit Place Pulse's usefulness for assessing within-city perceptions. In this paper, we set forth a protocol for city-specific dataset collection for the perception: 'On which street would you prefer to walk?'. This paper describes our methodology, based in London, including collection of images and ratings, web development, model training and mapping. Assessment of within-city perceptions of neighbourhoods can identify inequities, inform planning priorities, and identify temporal dynamics. Code available: https://emilymuller1991.github.io/urban-perceptions/

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Examining Predictors of First Year College Student Retention

The researchers developed a mixed-methods study to determine what characteristics of the student experience are associated with college student retention. The study used the College Persistence Questionnaire (CPQ) as the primary tool to evaluate students’ likeliness to persist at their university and then conducted individual interviews with students to gain a greater understanding of their academic and social habits. The findings suggest that efforts to improve student retention must impact student experiences both in and out of the classroom

Examining Predictors of First Year College Student Retention

The researchers developed a mixed-methods study to determine what characteristics of the student experience are associated with college student retention. The study used the College Persistence Questionnaire (CPQ) as the primary tool to evaluate students’ likeliness to persist at their university and then conducted individual interviews with students to gain a greater understanding of their academic and social habits. The findings suggest that efforts to improve student retention must impact student experiences both in and out of the classroom.

Exact distributions of intraclass correlation and Cronbach's alpha with Gaussian data and general covariance

Intraclass correlation and Cronbach’s alpha are widely used to describe reliability of tests and measurements. Even with Gaussian data, exact distributions are known only for compound symmetric covariance (equal variances and equal correlations). Recently, large sample Gaussian approximations were derived for the distribution functions

Chemical patterns of colony membership and mother- offspring similarity in Antarctic fur seals are reproducible

Tebbe J, Humble E, Stoffel MA, et al. Chemical patterns of colony membership and mother-offspring similarity in Antarctic fur seals are reproducible. PeerJ. 2020;8: e10131.Replication studies are essential for evaluating the validity of previous research findings. However, it has proven challenging to reproduce the results of ecological and evolutionary studies, partly because of the complexity and lability of many of the phenomena being investigated, but also due to small sample sizes, low statistical power and publication bias. Additionally, replication is often considered too difficult in field settings where many factors are beyond the investigator’s control and where spatial and temporal dependencies may be strong. We investigated the feasibility of reproducing original research findings in the field of chemical ecology by performing an exact replication of a previous study of Antarctic fur seals (Arctocephalus gazella). In the original study, skin swabs from 41 mother-offspring pairs from two adjacent breeding colonies on Bird Island, South Georgia, were analyzed using gas chromatography-mass spectrometry. Seals from the two colonies differed significantly in their chemical fingerprints, suggesting that colony membership may be chemically encoded, and mothers were also chemically similar to their pups, hinting at the possible involvement of phenotype matching in mother-offspring recognition. In the current study, we generated and analyzed chemical data from a non-overlapping sample of 50 mother-offspring pairs from the same two colonies 5 years later. The original results were corroborated in both hypothesis testing and estimation contexts, with p-values remaining highly significant and effect sizes, standardized between studies by bootstrapping the chemical data over individuals, being of comparable magnitude. However, exact replication studies are only capable of showing whether a given effect can be replicated in a specific setting. We therefore investigated whether chemical signatures are colony-specific in general by expanding the geographic coverage of our study to include pups from a total of six colonies around Bird Island. We detected significant chemical differences in all but a handful of pairwise comparisons between colonies. This finding adds weight to our original conclusion that colony membership is chemically encoded, and suggests that chemical patterns of colony membership not only persist over time but can also be generalized over space. Our study systematically confirms and extends our previous findings, while also implying more broadly that spatial and temporal heterogeneity need not necessarily negate the reproduction and generalization of ecological research findings

Helping Their Child, Helping Each Other: Parents’ Mediated Social Support in the Children's Hospital

During a health crisis, such as the hospitalization of a child with a serious illness, families must adjust and support each other in coordinating care. CSCW researchers have shown the potential for collaborative technologies to enhance social support in different settings. However, less is known about the potential for CSCW technologies to augment social support practices within family caregiving circles. In this poster, we describe findings from 14 interviews with parents of children hospitalized for cancer treatment. We categorized the support practices between parents and found that they rely heavily on technology to support each other from a distance. We identified opportunities for designing future collaborative technology to augment social support in caregiving teams