Guidelines For Pursuing and Revealing Data Abstractions

Many data abstraction types, such as networks or set relationships, remain unfamiliar to data workers beyond the visualization research community. We conduct a survey and series of interviews about how people describe their data, either directly or indirectly. We refer to the latter as latent data abstractions. We conduct a Grounded Theory analysis that (1) interprets the extent to which latent data abstractions exist, (2) reveals the far-reaching effects that the interventionist pursuit of such abstractions can have on data workers, (3) describes why and when data workers may resist such explorations, and (4) suggests how to take advantage of opportunities and mitigate risks through transparency about visualization research perspectives and agendas. We then use the themes and codes discovered in the Grounded Theory analysis to develop guidelines for data abstraction in visualization projects. To continue the discussion, we make our dataset open along with a visual interface for further exploration

Dependence of ablative ability of high-intensity focused ultrasound cavitation-based histotripsy on mechanical properties of agar

Cavitation-based histotripsy uses high-intensity focused ultrasound at low duty factor to create bubble clouds inside tissue to liquefy a region, and provides better fidelity to planned lesion coordinates and the ability to perform real-time monitoring. The goal of this study was to identify the most important mechanical properties for predicting lesion dimensions, among these three: Young\u27s modulus, bending strength, and fracture toughness. Lesions were generated inside tissue-mimicking agar, and correlations were examined between the mechanical properties and the lesion dimensions, quantified by lesion volume and by the width and length of the equivalent bubble cluster. Histotripsy was applied to agar samples with varied properties. A cuboid of 4.5mm width (lateral to focal plane) and 6mm depth (along beam axis) was scanned in a raster pattern with respective step sizes of 0.75 and 3mm. The exposure at each treatment location was either 15, 30, or 60s. Results showed that only Young\u27s modulus influenced histotripsy\u27s ablative ability and was significantly correlated with lesion volume and bubble cluster dimensions. The other two properties had negligible effects on lesion formation. Also, exposure time differentially affected the width and depth of the bubble cluster volume

A Comprehensive GC–MS Sub-Microscale Assay for Fatty Acids and its Applications

Fatty acid analysis is essential to a broad range of applications including those associated with the nascent algal biofuel and algal bioproduct industries. Current fatty acid profiling methods require lengthy, sequential extraction and transesterification steps necessitating significant quantities of analyte. We report the development of a rapid, microscale, single-step, in situ protocol for GC–MS lipid analysis that requires only 250 μg dry mass per sample. We furthermore demonstrate the broad applications of this technique by profiling the fatty acids of several algal species, small aquatic organisms, insects and terrestrial plant material. When combined with fluorescent techniques utilizing the BODIPY dye family and flow cytometry, this micro-assay serves as a powerful tool for analyzing fatty acids in laboratory and field collected samples, for high-throughput screening, and for crop assessment. Additionally, the high sensitivity of the technique allows for population analyses across a wide variety of taxa

Massive Consumption of Gelatinous Plankton by Mediterranean Apex Predators

Stable isotopes of carbon and nitrogen were used to test the hypothesis that stomach content analysis has systematically overlooked the consumption of gelatinous zooplankton by pelagic mesopredators and apex predators. The results strongly supported a major role of gelatinous plankton in the diet of bluefin tuna (Thunnus thynnus), little tunny (Euthynnus alletteratus), spearfish (Tetrapturus belone) and swordfish (Xiphias gladius). Loggerhead sea turtles (Caretta caretta) in the oceanic stage and ocean sunfish (Mola mola) also primarily relied on gelatinous zooplankton. In contrast, stable isotope ratios ruled out any relevant consumption of gelatinous plankton by bluefish (Pomatomus saltatrix), blue shark (Prionace glauca), leerfish (Lichia amia), bonito (Sarda sarda), striped dolphin (Stenella caerueloalba) and loggerhead sea turtles (Caretta caretta) in the neritic stage, all of which primarily relied on fish and squid. Fin whales (Balaenoptera physalus) were confirmed as crustacean consumers. The ratios of stable isotopes in albacore (Thunnus alalunga), amberjack (Seriola dumerili), blue butterfish (Stromaeus fiatola), bullet tuna (Auxis rochei), dolphinfish (Coryphaena hyppurus), horse mackerel (Trachurus trachurus), mackerel (Scomber scombrus) and pompano (Trachinotus ovatus) were consistent with mixed diets revealed by stomach content analysis, including nekton and crustaceans, but the consumption of gelatinous plankton could not be ruled out completely. In conclusion, the jellyvorous guild in the Mediterranean integrates two specialists (ocean sunfish and loggerhead sea turtles in the oceanic stage) and several opportunists (bluefin tuna, little tunny, spearfish, swordfish and, perhaps, blue butterfish), most of them with shrinking populations due to overfishing

Doctor of Philosophy

dissertationIteration is a ubiquitous need across many different visualization design workflows. For visual design, practitioners often need to transition between the automated generation of visuals and manual drawing; however, existing software makes free-form iteration between these modalities difficult or impossible. A similar challenge exists for data as well: data abstractions often need to be adjusted; however, many data reshaping operations- particularly graph wrangling operations-have support only in programming environ- ments that may not be accessible to many visualization designers. This dissertation begins with an effort to better understand how graphic designers, a specific subset of the broader visualization community, work with data. The lessons from that effort inspire our remaining contributions, which are directed toward the broader community of visualization practitioners: first, we present a software model and a system that make it possible to iterate between drawing and generative visualization. Second, we present a visual technique that enables inquiry into the relationship between two specific graph data wrangling operations: pivoting and filtering. Finally, we present an interface that supports a broader range of graph data wrangling operations that enable iteration between many different graph data abstractions

Visualizing a Moving Target: A Design Study on Task Parallel Programs in the Presence of Evolving Data and Concerns

Common pitfalls in visualization projects include lack of data availability and the domain users' needs and focus changing too rapidly for the design process to complete. While it is often prudent to avoid such projects, we argue it can be beneficial to engage them in some cases as the visualization process can help refine data collection, solving a "chicken and egg" problem of having the data and tools to analyze it. We found this to be the case in the domain of task parallel computing where such data and tooling is an open area of research. Despite these hurdles, we conducted a design study. Through a tightly-coupled iterative design process, we built Atria, a multi-view execution graph visualization to support performance analysis. Atria simplifies the initial representation of the execution graph by aggregating nodes as related to their line of code. We deployed Atria on multiple platforms, some requiring design alteration. We describe how we adapted the design study methodology to the "moving target" of both the data and the domain experts' concerns and how this movement kept both the visualization and programming project healthy. We reflect on our process and discuss what factors allow the project to be successful in the presence of changing data and user needs.United States Department of Defense through DTICUnited States Department of Defense [FA8075-14-D-0002-0007]; National Science FoundationNational Science Foundation (NSF) [NSF III-1656958]This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Bringing Climate Into the Classroom: Inside a Teaching Retreat Around Naomi Klein’s This Changes Everything

Jill Howdyshell lives and teaches 5th grade in Togiak, a small Yu’pik fishing village in southwestern Alaska. In Togiak, harvesting berries is a practice that goes back countless generations. The berries are the key ingredient in akutaq, called eskimo ice cream. In her classes, Howdyshell’s students write identity poems with lines proclaiming “I am from akutaq,” and describing cherished excursions with parents and grandparents. In 2014, residents discovered that there would be no berries that year: the tundra had not frozen for a sufficient length of time for the berries to regenerate. With a dramatic rise in temperatures, Yu’pik people can no longer rely on digging deep into the permafrost to store food in makeshift freezers. And most distressing: as a result of rising seas, during the next few years, Yu’pik people will be forced to relocate large parts of their community