Colonization and survival of Phoma macrostoma, a weed biocontrol fungus

Non-Peer ReviewedCanada thistle, dandelion, chickweed, and scentless chamomile are common broadleaf weed pests of economic importance in western Canada. The fungus Phoma macrostoma demonstrates bioherbicidal activity and is being developed for control of these weed pests. However, little is known about the fate of the fungus in soil and plants. The aim of this research was to monitor the colonization of plant tissues by the fungus, and its movement and persistence in soil environments using a molecular detection method

The Challenges of Evaluating the Usability of Augmented Reality (AR)

Augmented reality (AR) is a new and emerging technology that could benefit from evaluating its usability to better the user’s experience with the device or application. This is often done through usability testing and heuristic evaluations. However, AR technology presents some challenges when completing these usability evaluations. Practitioners need to keep in mind the hardware limitations of AR devices that may not be present with other computerized technology, consistency of the users’ environment plays a larger role in the AR experience, recognize that a novelty effect may occur and affect subjective scores, and choose heuristic sets that will best evaluate AR applications. Practitioners need to be aware of these challenges and overcome them to accurately assess the usability of these products to gain insights about what should be changed to make the overall experience with the product better

Gameplay in Mixed Reality: How It Differs from Mobile Gameplay

With the growing demand for the use and applications of modern extended reality (XR) technology, recent studies have investigated the user experience of augmented reality (AR) and virtual reality (VR) for gaming purposes. Despite AR’s and VR’s pervasiveness in the video game industry, research studies into the effects of mixed reality (MR) on video game experience are scarce. Consequently, this study examines the impact of MR on video game satisfaction. Participants will play the same strategy video game across two gaming platforms, including an MR head-mounted display, the Magic Leap 1, and a mobile device. A short version of the psychometrically validated Game User Experience Satisfaction Scale (GUESS-18), which consists of nine constructs, and the Enjoyment Scale (ENJOY) will be used to measure video game satisfaction and enjoyment, respectively. Furthermore, we will then analyze the correlation between satisfaction, enjoyment, and performance in each platform. Results will demonstrate the impact of MR for gameplay on user satisfaction and performance when compared to mobile gameplay. Additionally, the potential of future video games in mixed reality environments will be discussed

Extended Reality (XR) Hardware: One Size Doesn’t Fit All, Yet.

Extended Reality (XR) encompasses virtual reality (VR), augmented reality (AR), and mixed reality (MR). Virtual content continues to be incorporated into our real world as more devices become available to support it. It has been accepted into the entertainment space (games like Beat Saber and Pokémon GO), social media apps (SnapChat and TikTok filters), training, and education. Soon everyone will be able to put on a headset or pick up a phone and see virtual holograms in action. But, is XR built inclusively, for everyone? Inclusive design has been defined as, designing a diversity of ways for users to participate so that everyone has a sense of belonging” (Holmes, 2018). We evaluated the inclusivity of popular XR devices: head-mounted displays, smart glasses, and mobile devices – both the physical design and user interaction methods. Results demonstrate that the devices have room for improvement to be fully inclusive

Microfabricated pinholes for high contrast imaging testbeds

In order to reach contrast ratios of $10^{-8}$ and beyond, coronagraph testbeds need source optics that reliably emulate nearly-point-like starlight, with microfabricated pinholes being a compelling solution. To verify, a physical optics model of the Space Coronagraph Optical Bench (SCoOB) source optics, including a finite-difference time-domain (FDTD) pinhole simulation, was created. The results of the FDTD simulation show waveguide-like behavior of pinholes. We designed and fabricated microfabricated pinholes for SCoOB made from an aluminum overcoated silicon nitride film overhanging a silicon wafer substrate, and report characterization of the completed pinholes.Comment: Submitted to SPIE Optical Engineering + Applications (OP23O

The speaking vocabulary of grade two

Thesis (M.A.)--Boston Universit

Evaluation of land preparation methods for soil stabilization, revegetation, and renewed productivity in semi-arid climates

In the Williston Basin, land-preparation treatments have not been compared in side-by-side trials to evaluate performance for parameters such as runoff, erosion, and vegetation establishment. Thus, four treatments of wheat-straw crimping, land imprinting, wood-fiber hydromulch, and the combination of land imprinting and hydromulch were evaluated against a bare soil control in a replicated and randomized completed block field experiment near Williston, ND. Rainfall simulations were performed in September 2020 and June 2021 to examine the effectiveness of the treatments to reduce runoff and sediment losses. Vegetation establishment was also evaluated in August 2021. The wheat straw treatment reduced the equivalent depth of runoff by 60% as compared to the bare soil control in 2021. By 2021, the imprinted area had largely become similar in roughness as the control plots and thus sediment losses were not different between these treatments. However, relic effects of the straw and hydromulch treatments reduced sediment loss by 50% or more. Vegetation establishment was not significantly different among treatments and the bare soil control using broadcast seeding, which may have been due to drought conditions causing low establishment in all plots. All the land-preparation practices evaluated in this study may have limitations in assisting plant establishment during severe or persistent droughts

The incidence of breast cancer in the General Practice Research Database compared with national cancer registration data

Breast cancer incidence rates in the UK from 1990 to 1996 among women aged 35–69 estimated from the General Practice Research Database (GPRD) were closely similar to those reported by the Office for National Statistics from cancer registration data (ONS). The GPRD is a valuable and up-to-date resource for further study of the incidence of breast cancer in the UK as well as changes in cancer treatment and their relation to survival trends. © 2000 Cancer Research Campaign http://www.bjcancer.co

Enhanced real-time pose estimation for closed-loop robotic manipulation of magnetically actuated capsule endoscopes

Pose estimation methods for robotically guided magnetic actuation of capsule endoscopes have recently enabled trajectory following and automation of repetitive endoscopic maneuvers. However, these methods face significant challenges in their path to clinical adoption including the presence of regions of magnetic field singularity, where the accuracy of the system degrades, and the need for accurate initialization of the capsule's pose. In particular, the singularity problem exists for any pose estimation method that utilizes a single source of magnetic field if the method does not rely on the motion of the magnet to obtain multiple measurements from different vantage points. We analyze the workspace of such pose estimation methods with the use of the point-dipole magnetic field model and show that singular regions exist in areas where the capsule is nominally located during magnetic actuation. Since the dipole model can approximate most magnetic field sources, the problem discussed herein pertains to a wider set of pose estimation techniques. We then propose a novel hybrid approach employing static and time-varying magnetic field sources and show that this system has no regions of singularity. The proposed system was experimentally validated for accuracy, workspace size, update rate and performance in regions of magnetic singularity. The system performed as well or better than prior pose estimation methods without requiring accurate initialization and was robust to magnetic singularity. Experimental demonstration of closed-loop control of a tethered magnetic device utilizing the developed pose estimation technique is provided to ascertain its suitability for robotically guided capsule endoscopy. Hence, advances in closed-loop control and intelligent automation of magnetically actuated capsule endoscopes can be further pursued toward clinical realization by employing this pose estimation system