Asynchronous Assistance: a Social Network Analysis of Influencing Peer Interactions in PeerWise

This mixed methods, investigative case study explored student patterns of use within the online PeerWise platform to identify the most influencing activities and to build a model capable of predicting performance based on these influencing activities. Peerwise is designed to facilitate student peer-to-peer engagement through creating, answering and ranking multiple choice questions; this study sought to understand the relationship between student engagement in Peerwise and learning performance. To address the research question, various usage metrics were explored, visualized and modelled, using social network analysis with Gephi, Tableau and Python. These findings were subsequently analyzed in light of the qualitative survey data gathered. The most significant activity metrics were evaluated leading to rich data visualisations and identified the activities that influenced academic performance in this study. The alignment of the key qualitative and quantitative findings converged on answering questions as having the greatest positive impact on learner performance. Furthermore, from a quantitative perspective the Average Comment Length and Average Explanation Length correlated positively with superior academic performance. Qualitatively, the motivating nature of PeerWise community also engaged learners. The key limitation of the size of the data set within the investigative case study suggests further research, with additional student cohorts as part of an action research paradigm, to broaden these findings

Surface Autonomous Vehicle for Emergency Rescue

The goal of this document is to clearly define the problem parameters and project objectives and to clearly describe the design process, planned final design, and manufacturing and testing procedures for the senior design project of Team 26: SAVER -- the Surface Autonomous Vehicle for Emergency Rescue. This is both for the purpose of project planning and for clear communication between all parties involved in the project. The objective of the SAVER project is to develop a proof of concept for an autonomous maritime search and rescue vehicle for aiding in man-overboard missions. To accomplish this goal, a list of specifications was developed based on background research and interviews with potential customers. These specifications, discussed later in this document, guided the design process, analysis, and testing plans, which are also covered. Based on this research and analysis, the SAVER team developed a final design consisting of a structural hull and frame made from fiberglass and MDF, respectively, which was to be waterproofed and filled with foam. An electronics system would monitor the relative positions of the vehicle and victim via GPS and actuate a thruster and rudder. This prototype was designed to be safe, reliable, and effective, and was expected to meet all specifications. By April 2020, due to the COVID-19 pandemic, the Cal Poly campus was shut down and all work was being carried out remotely. Without access to campus labs or shops, the team’s ability to complete work on this project was seriously limited. Through meetings with their sponsor and advisor, the project’s scope underwent major changes, and a new plan was established. The team was to focus on completing the mechatronics portion of the build and fully documenting all current and future design plans so that a future senior project team could complete the work at a later time. These scope changes as well as all manufacturing and testing work completed both before and after the scope change are discussed in this document as well. In order to make it possible for a future senior project team to complete work on this project, detailed plans for manufacturing, assembly, and testing of the device, as well as thorough documentation of the completed electronics build and device firmware are also included. Additionally, a “Guide for Future Team” is included as Appendix Q, which discusses a few of the biggest concerns and issues that the team has faced as well as some advice and references to assist future engineers with the continuation of this project

Genetic Ablation of Kir2.1 Channels and its Effects on Micturition in Conscious Mice

Detrusor muscle overactivity in the bladder wall is the hallmark symptom of overactive bladder syndrome and the principal target of therapy that seeks to reduce incontinence and urinary urgency. However, these interventions typically fail to alleviate long-term detrusor overactivity and simply mask the underlying pathology while also potentially introducing undesirable side effects that disrupt quality of life. One alternative mechanism driving of overactive bladder is attributed to ischemia within the bladder, which is subject to enormous swings in pressure and tension on its vasculature restricting blood flow. This observation, coupled with the fact that healthy vascular tissue within the bladder lacks a myogenic response to increasing intraluminal pressures, provides a potential pathological explanation and new therapeutic targets for managing overactive bladder. We evaluated whether conscious voiding behavior in mice is impacted with the introduction of myogenic tone into the bladder vasculature via knock out of the inward-rectifier potassium channel, KIR2.1. The voiding activity of 10 smooth muscle-specific tamoxifen-inducible KIR2.1 knockout mice were observed pre- and post-tamoxifen treatment using the UroVoid System: a novel apparatus for measuring micturition events in real time. A consistent difference of voiding behavior between knockout and control treatment groups could not be demonstrated. However, voiding frequency of all mice within the trials are elevated above established literature values as well as prior trials of different mice within the UroVoid. Absent controls and potential confounding factors from the environment in which the trials take place obscured a definitive conclusion from the data while emphasizing the importance of comprehensive environmental vetting and strict protocol adherence prior to conducting UroVoid experiments. Thus, future experiments can still effectively test the role of KIR2.1 channels in bladder health as long as the confounding factors are accounted for

Varying potential silicon carbide gas sensor

A hydrocarbon gas detection device operates by dissociating or electro-chemically oxidizing hydrocarbons adsorbed to a silicon carbide detection layer. Dissociation or oxidation are driven by a varying potential applied to the detection layer. Different hydrocarbon species undergo reaction at different applied potentials so that the device is able to discriminate among various hydrocarbon species. The device can operate at temperatures between 100.degree. C. and at least 650.degree. C., allowing hydrocarbon detection in hot exhaust gases. The dissociation reaction is detected either as a change in a capacitor or, preferably, as a change of current flow through an FET which incorporates the silicon carbide detection layers. The silicon carbide detection layer can be augmented with a pad of catalytic material which provides a signal without an applied potential. Comparisons between the catalytically produced signal and the varying potential produced signal may further help identify the hydrocarbon present

Reliability of Hallux Rigidus Radiographic Grading System

Introduction. The purpose of this study was to determine the inter- and intra-observer reliability of a clinical radiographic scale for hallux rigidus. Methods. A total of 80 patients were retrospectively selected from the patient population of two foot and ankle orthopaedic surgeons. Each corresponding series of radiographic images (weight-bearing anteroposterior, weight-bearing lateral, and oblique of the foot) was randomized and evaluated. Re-randomization was performed and the corresponding radiograph images re-numbered. Four orthopaedic foot and ankle surgeons graded each patient, and each rater reclassified the re-randomized radiographic images three weeks later. Results. Sixty-one out of 80 patients (76%) were included in this study. For intra-observer reliability, most of the raters showed “excellent” agreement except one rater had a “substantial” agreement. For inter-observer reliability, only 14 out of 61 cases (23%) showed total agreement between the eight readings from the four surgeons, and 11 out of the 14 cases (79%) were grade 3 hallux rigidus. One of the raters had a tendency to grade at a higher grade resulting in poorer agreement. If this rater was excluded, the results demonstrated a “substantial” agreement by using this classification. Conclusion. The hallux rigidus radiographic grading system should be used with caution. Although there is an “excellent” level of intra-observer agreement, there is only “moderate” to “substantial” level of inter-observer reliability

Invasive Candidiasis in Various Patient Populations: Incorporating Non-Culture Diagnostic Tests into Rational Management Strategies

Mortality rates due to invasive candidiasis remain unacceptably high, in part because the poor sensitivity and slow turn-around time of cultures delay the initiation of antifungal treatment. β-d-glucan (Fungitell) and polymerase chain reaction (PCR)-based (T2Candida) assays are FDA-approved adjuncts to cultures for diagnosing invasive candidiasis, but their clinical roles are unclear. We propose a Bayesian framework for interpreting non-culture test results and developing rational patient management strategies, which considers test performance and types of invasive candidiasis that are most common in various patient populations. β-d-glucan sensitivity/specificity for candidemia and intra-abdominal candidiasis is ~80%/80% and ~60%/75%, respectively. In settings with 1%–10% likelihood of candidemia, anticipated β-d-glucan positive and negative predictive values are ~4%–31% and ≥97%, respectively. Corresponding values in settings with 3%–30% likelihood of intra-abdominal candidiasis are ~7%–51% and ~78%–98%. β-d-glucan is predicted to be useful in guiding antifungal treatment for wide ranges of populations at-risk for candidemia (incidence ~5%–40%) or intra-abdominal candidiasis (~7%–20%). Validated PCR-based assays should broaden windows to include populations at lower-risk for candidemia (incidence ≥~2%) and higher-risk for intra-abdominal candidiasis (up to ~40%). In the management of individual patients, non-culture tests may also have value outside of these windows. The proposals we put forth are not definitive treatment guidelines, but rather represent starting points for clinical trial design and debate by the infectious diseases community. The principles presented here will be applicable to other assays as they enter the clinic, and to existing assays as more data become available from different populations

Annealing Would Improve beta" - Alumina Solid Electrolyte

A pre-operational annealing process is under investigation as a potential means of preventing a sudden reduction of ionic conductivity in a Beta"-alumina solid electrolyte (BASE) during use. On the basis of tests, the sudden reduction of ionic conductivity, followed by a slow recovery, has been found to occur during testing of the solid electrolyte and electrode components of an alkali metal thermal-to-electric converter (AMTEC) cell. At this time, high-temperature tests of limited duration have indicated the superiority of the treated BASE, but reproducible tests over thousands of hours are necessary to confirm that microcracking has been eliminated. The ionic conductivity of the treated BASE is also measured to be higher than untreated BASE at 1,073 K in low-pressure sodium vapor. Microcracking resulting in loss of conductivity was not observed with treated BASE in one high-temperature experiment, but this result must be duplicated over very long testing times to be sure of the effect. Shorter annealing times (10 to 20 hours) were found to result in significantly less loss of mass; it may be necessary for the packed powder mixture to evolve some Na2O before the Na2O can leave the ceramic

Evaluating the Likelihood of Tree Failure in Naples, Florida (United States) Following Hurricane Irma

Trees in residential landscapes provide many benefits, but can injure persons and damage property when they fail. In hurricane-prone regions like Florida, USA, the regular occurrence of hurricanes has provided an opportunity to assess factors that influence the likelihood of wind-induced tree failure and develop species failure profiles. We assessed open-grown trees in Naples, Florida, following the passage of Hurricane Irma in September 2017 to determine the effect of relevant factors on the degree of damage sustained by individual trees. Of 4034 assessed individuals (n = 15 species), 74% sustained no damage, 4% sustained only minor damage (i.e., minimal corrective pruning needed), 6% sustained significant damage (i.e., major corrective pruning needed), and 15% were whole-tree failures (i.e., overturned trees or trees requiring removal). The proportion of individuals in each damage category varied among species, stem diameter at 1.4 m above ground, and the presence of utility lines, which was a proxy for maintenance. We compared our results with the findings of seven previous hurricanes in the region to explore species’ resilience in hurricanes