Augmented Reality (AR) has emerged as a rapidly developing technology, capable of a wide scope of applications across a variety of domains. AR technologies allow for a virtual experience to be overlaid on top of a physical environment, creating a hybrid experience in which virtual objects become a part of the user's perceptual and physical environment. Rapid progression of the AR field requires that effective and validated methods of design evaluation be developed. Failure to consider the usability of AR applications during the design process will result in an increase in user errors and accidents, limiting user trust of the technology and undermining user perceptions of the technology, for both AR and Virtual Reality (VR) technologies (Nordrum, 2016). Through a robust and iterative process, a set of Design Heuristics for AR were developed for multidimensional augmented environments with the aim of advancing AR design methods for human factors, ergonomics, and user experience practitioners within the expanding AR community.

Summary1. Herbivores can facilitate macrophyte growth through stimulation of overcompensation pathways, removal of neighbouring or fouling competitors or increasing nutrient availability via nitrogenous waste inputs. 2. We examined the facilitative relationship between the mud snail Ilyanassa obsoleta and two morphologically similar bloom-forming Ulva species, Ulva compressa and Ulva rigida. Through mesocosm experiments, we determined the occurrence and underlying mechanisms responsible for facilitating Ulva growth. In situ snail enclosure experiments determined the occurrence of this facilitative pathway under natural conditions. 3. We found that both U. compressa and U. rigida are facilitated by I. obsoleta, but despite their morphological similarity, the primary facilitative mechanism differed for each species. Ulva compressa experienced increased growth via snail nitrogenous waste inputs, while U. rigida was facilitated by the removal of fouling microalgae. These results suggest that physiological differences exist between these two species, potentially sustaining their coexistence within blooms. 4. Ground tissue assays showed I. obsoleta preference for microalgal foulers in whole-tissue assays was driven by Ulva blade morphology rather than chemical or nutritive properties. This indicates that the underlying mechanism for I. obsoleta's facilitation via grazing is an inability of the snail's radula to effectively puncture Ulva blades, confining their grazing activities to fouling organisms on the blade surface. 5. In contrast to our mesocosm results, in situ experiments failed to find a positive impact of mud snail presence on Ulva blade growth. However, Ulva blades within these experiments were located at a highly eutrophic site and isolated from potential competitors. Consequently, this may have created an environment where I. obsoleta facilitation was not required for maximum Ulva growth. 6. Synthesis. We demonstrated two mechanisms by which top-down forces can facilitate macroalgal growth: herbivore nitrogenous waste inputs and removal of microalgal fouling organisms. This facilitation may occur within the large mats of macroalgae that form during bloom events, exacerbating bloom conditions.

Ancylostoma caninum is a nematode of the canine gastrointestinal tract commonly referred to as hookworm. This study involved eight privately owned adult greyhounds presenting with persistent A. caninum ova shedding despite previous deworming treatments. The dogs received a combination treatment protocol comprising topical moxidectin, followed by pyrantel/febantel/praziquantel within 24 hr. At 7–10 days posttreatment, a fecal examination monitored for parasite ova. Dogs remained on the monthly combination treatment protocol until they ceased shedding detectable ova. The dogs then received only the monthly topical moxidectin maintenance treatment. The dogs remained in the study for 5–14 mo with periodical fecal examinations performed. During the study, three dogs reverted to positive fecal ova status, with two being associated with client noncompliance. Reinstitution of the combination treatment protocol resulted in no detectable ova. Use of monthly doses of combination pyrantel, febantel and moxidectin appears to be an effective treatment for nonresponsive or persistent A. caninum ova shedding. Follow-up fecal examinations were important for verifying the presence or absence of ova shedding despite the use of anthelmintic treatment. Limitations of the current study include small sample size, inclusion of only privately owned greyhounds, and client compliance with fecal collection and animal care.

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