Covid Journey

Classes have become all digital and it’s crazy to think that the next time I will be on Longwood’s campus, which my hopeful plan is in August, I will be a senior on his way to graduating from college!https://digitalcommons.longwood.edu/covid19/1007/thumbnail.jp

Real Time and High Fidelity Quadcopter Tracking System

This project was conceived as a desired to have an affordable, flexible and physically compact tracking system for high accuracy spatial and orientation tracking. Specifically, this implementation is focused on providing a low cost motion capture system for future research. It is a tool to enable the further creation of systems that would require the use of accurate placement of landing pads, payload acquires and delivery. This system will provide the quadcopter platform a coordinate system that can be used in addition to GPS. Field research with quadcopter manufacturers, photographers, agriculture and research organizations were contact and interviewed for information on what components of a quadcopter system were lacking and what barriers currently limited desired drone operation. Distilling this information and after exploring various projects in the field of quadcopter and autonomous control, the idea was found to develop a system that could track the motion of quadcopters to jump start other projects. Specifically, live feedback was explored to be used as hardware in the loop testing systems where commands are relayed to the quadcopter and its response can be accurately measured. This can be extremely beneficial in new equipment testing such as new propeller design, motor design, and frame response. A further stretch objective for this project is to unify input commands to the quadcopter with its physical position in order to train control systems to fly new platforms running “piloted” platforms such as BetaFlight, RaceFlight and KISS platforms typically associated with drone racing as well as hobby grade semi-autonomous flight controller such as ArduPilot Mega (APM) & PixHawk

The Interconnectivity of Trust and Appreciative Advising

Academic advisors can harness the interconnectivity of trust-building frameworks and Appreciative Advising to build relationships with students. This article proposes the integration of two trust-building frameworks within the Appreciative Advising Theory-to-Practice Framework (Bloom et al., 2008). Utilizing findings and insights from Frei and Morriss’ (2020) research on trust, the authors discuss ways that authenticity, logic, and empathy support the practice of Appreciative Advising. Exploring research from Brown (2019), the article reviews the roles of boundaries, reliability, accountability, the vault, integrity, non-judgment, and generosity in each of the six phases of Appreciative Advising. A matrix displays the intersections of trust-building actions and the Appreciative Advising phases, and the article presents examples of the impact of trust in an advising context

Riots in London

The chaos all started from a police shooting which occurred in Tottenham on Thursday, August 4, 2011. Twenty-nine-year-old Mark Duggan was part of a pre-planned police operation under Trident, a unit which investigates gun crime in the African and Caribbean communities of England. The police were trying to stop Duggan’s car to arrest him when gun-fire began. Duggan was shot and killed by the police

Ungulate Herbivores as Drivers of Aspen Recruitment and Understory Composition Throughout Arid Montane Landscapes

Herbivory by wild and domestic ungulates can influence tree recruitment and understory forest communities throughout the world. Herbivore-driven declines in tree recruitment have been observed for quaking aspen (Populus tremuloides), a foundation species whose health and management is recognized as a critical priority throughout much of its range. Livestock fencing is commonly used to promote aspen regeneration, but its effectiveness is rarely assessed, especially across large spatial scales. Using a livestock-reduction experiment, we evaluated the effects of ungulate herbivory on aspen in the Great Basin and southern Cascades, an expansive and environmentally heterogeneous region where aspen faces the interacting threats of climate change, conifer encroachment, and herbivory. We found that livestock fencing only reduced the intensity of herbivore browsing on aspen when wild ungulate abundance was low and did not increase stem densities of aspen recruits. Contrary to expectations, wild ungulate abundance was a strong driver of browsing intensity on juvenile aspen within fenced, but not unfenced, aspen stands, and when the abundance of these herbivores was high, browsing intensity in fenced stands exceeded that in unfenced stands. The density of aspen recruits decreased with browsing intensity on juvenile aspen and with the density of both adult aspen and conifers, suggesting that both herbivory and intra- and interspecific competition are important drivers of recruitment. Fire history was also an important driver of recruitment, with stands that burned 10–20 years ago having the greatest density of aspen recruits. Finally, in the stand understory, we found that livestock fencing decreased forb cover, increased shrub species richness, and increased the cover of exotic annual grasses, a group dominated by Bromus tectorum. This latter finding suggests that livestock fencing may not be appropriate in areas where controlling the spread of this invader is a priority. In sum, our findings indicate that aspen recruitment is limited by browsing by both wild and domestic ungulates, is mediated by competition with neighboring trees and fire history, and will require management actions beyond livestock fencing, as this approach does not control browsing by wild ungulates

The Influence of Charge Transport Layer Interfaces on the Performance of Electroluminescent Colloidal Quantum Dot Light-Emitting Devices

Electroluminescent quantum dot light-emitting devices (QDLEDs) are a relatively new technology for displays that have all of the benefits of emissive displays commonly associated with organic light-emitting devices (OLEDs) such as low power draw, deeper black levels, and fast refresh rates. However, QD emitters confer additional valuable characteristics for displays due to their high photoluminescence quantum yield (PLQY) approaching 100%, narrow emission full-width at half maximum (FWHM < 20 nm), the tunability of their peak luminescence wavelengths across the entire visible spectrum, and their solution-processability which makes them compatible to low-cost and flexible fabrication techniques. Unfortunately, like their organic counterpart, the long-term stability of QDLEDs has been limited for many years. While high-efficiency red and green QDLEDs have recently been demonstrated with electroluminescence lifetimes of over 1,000,000 hours, this may not be suitable for some applications given the luminance of the devices for which these lifetimes are rated. Furthermore, like OLEDs, blue QDLEDs are far less stable than red and green with the record lifetime being orders of magnitude less. Therefore, it is important to understand the mechanisms governing QDLED stability in order to improve device lifetimes. In general, the main degradation mechanism affecting QDLEDs has been attributed to multi-charge carrier interactions referred to as Auger recombination which uniquely affects QDs to a greater degree due to their nanoscale structure but also the inherent charge imbalance within QDLEDs. However, there is little focus on the degradation of devices outside of this process. Given the similarity in structure between QDLEDs and OLEDs, this work aims to elucidate upon additional degradation mechanisms that may influence the long-term stability of these devices by considering the degradation mechanisms that affect organic semiconductors. This thesis investigates each interface present within the QDLED structure to identify its influence on QDLED performance, with strategies to improve efficiency in addition to the main focus of device stability. The primary interfaces of interest occur between the electron transport layer (ETL) and the QD emission layer (EML) as well as between the QD EML and the hole transport layer (HTL). However, the interface between the HTL and the hole injection layer (HIL) will also be shown to influence the electroluminscence stability of QDLEDs despite not interacting with the QD layer directly. This work utilizes the hybrid inverted QDLED structure which consists of an inorganic ETL and an organic HTL as this structure has proven to be far superior to devices with all-organic or all-inorganic transport layers. Therefore, it is the HTL that will be of particular interest in this thesis. Red and green QDs were utilized as the EML over the course of this work, but the primary focus will be on the red QDLEDs as they resulted in the most efficient and long-lives devices allowing for a better environment in which the influence of the interfaces on QDLED performance could be evaluated. However, the results should be applicable to a wide range of QD EMLs of different colours and compositions. The role of the ETL / EML interface in QDLED performance was investigated by introducing the wide band gap work function modification layer between the two layers. While a 1.6× improvement in maximum EQE was observed, this coincided with a worsening of the charge imbalance. Rather than a result of improved charge balance, this efficiency enhancement was attributed to a reduction in QD exciton quenching by the ZnO due to the passivation of surface states at this interface. While this resulted in a negligible effect on the EL stability of these QDLEDs at the time, further experiments investigating the effect of excitons at the EML / HTL interface would identify these excitons as an issue for long-term QDLED stability. Ultimately, the main influence of the ETL / EML interface on QDLED performance lies in the exciton quenching effect of ZnO surface states which limits the QD film PLQY. The influence of the ETL and EML layers on morphological stability was investigated by a systematic study on the processing parameters of ZnO and the QDs for spherical and rod-shape QDs. The main factor determining the degree of morphological degradation in the emissive area homogeneity was the roughness of each layer. This is also a limitation in OLED morphological stability, as the organic semiconductors are prone to crystallization when deposited on rough surfaces. Therefore, although rough layers are the catalyst of this morphological instability, it is the organic HTL that is the limiting factor in long-term morphological stability. The role of degradation of the HTL on overall QDLED stability was further investigated through PL measurements from QDLEDs over time while irradiated with UV light. By measuring changes in the QD PL over time under constant UV illumination in devices with a variety of organic semiconductors, it became clear that the HTL has a significant influence over the loss in QD PLQY during aging. While the QDs individually are relatively stable during the measurement period, the PLQY loss in the QDLEDs correlated to the individual PLQY loss of the organic layers. It was therefore found that the exciton-induced degradation of the organic molecules at the QD / HTL interface that is particularly deleterious to QDLED stability. A multi-layer HTL structure was investigated in order to improve charge balance and reduce hole accumulation at the QD / HTL interface. With the optimized structure, a 25× enhancement in QDLED lifetime was observed. This HTL structure allows for the use of alternate HILs which do not damage the underlying organic layers during device fabrication, restricts the accumulation of holes at the QD / HTL interface and reduces charging of the QD layer, and limits degradation of the HTL at the QD / HTL interface. Ultimately, this work has identified and characterized a degradation mechanism affecting long-term EL stability of QDLEDs and presents a device structure which utilizes a cascading HTL with small gaps between each component’s HOMO energy level with an organic HIL minimizing the effects of this mechanism on QDLED EL stability

Prediction of Athletic Injury with a Functional Movement Screen

The Functional Movement Screen[superscript]TM (FMS) is a screening tool designed to quantify movement quality. The ability of the FMS to identify individuals likely to be injured has been examined in athletic and military settings. However, the predictive ability of the FMS has not been examined in a cohort of intercollegiate football players. PURPOSE: The purpose of this study was to determine if the FMS, body mass index (BMI), or two bilateral body mass asymmetry measures accurately predict injury in intercollegiate football players over the course of one season. METHODS: Participants (N = 81) were tested using the FMS protocol. Seven tests were scored on a 0 to 3 scale resulting in a possible composite score of 21. Participants were categorized as having positive or negative tests based on 14-point and 15-point cutoff scores. BMI was calculated from measured height and weight. Participants were categorized as having positive or negative tests based on a BMI [greater than or equal to] 30 kg·m�². Bilateral body mass asymmetry was assessed twice by weighing participants on two identical scales with one foot on each scale. Feet were placed a standardized distance (one-third of height) apart for one measure and shoulder width apart for the second measure. Participants were categorized as having positive or negative tests based on a difference between the two scales of [greater than or equal to] 5% of body mass. Injury reports were obtained from the athletic training staff. Musculoskeletal injuries were classified via NCAA Injury Surveillance System criteria. Participants were categorized as injured or not injured based on injury reports. Intrarater reliability was estimated for the FMS on all participants by viewing videotaped procedures. Interrater reliability was estimated on 18 participants viewed in real time by two raters. Sensitivity and specificity were calculated to examine the accuracy of the different screening measures to identify participants who were injured or not injured. RESULTS: Participants had a mean composite FMS score of 15.4 ± 1.7) and a mean BMI of 30.1 (± 5.3) kg·m�². Bilateral body mass asymmetry measures averaged 4 (± 3) percent of body mass for the standardized difference and 5 (± 5) percent of body mass for the shoulder width difference. Intraclass correlation coefficients for intrarater reliability (.94) and interrater reliability (.92) for the composite FMS score were high. Forty-three injuries (17 direct contact, 12 indirect contact, 11 non-contact, 2 overuse, and 1 unknown mechanism) to 31 players were reported. No significant relationship was found between the FMS, BMI, or the bilateral body mass asymmetry measures and injury (p > .05). Sensitivity values were: FMS 14-point cutoff = .26, FMS 15-point cutoff = .42, BMI cutoff = .42, bilateral body mass asymmetry standardized difference cutoff = .31, bilateral body mass asymmetry shoulder width difference cutoff = .52. Specificity values were: FMS 14-point cutoff = .70, FMS 15-point cutoff = .51, BMI cutoff = .64, bilateral body mass asymmetry standardized difference cutoff = .74, bilateral body mass asymmetry shoulder width difference cutoff = .68. CONCLUSIONS: The FMS can be used reliably with intercollegiate football players, but the validity of the FMS to predict athletic injury is questionable. The FMS did not predict injury more accurately than anthropometrically derived measurements. Although as accurate as the FMS, BMI and the two bilateral body mass asymmetry measures did not accurately predict injury.M.S

Molecular characterization of Trichomonas gallinae isolates recovered from the Canadian Maritime provinces’ wild avifauna reveals the presence of the genotype responsible for the European finch trichomonosis epidemic and additional strains

Finch trichomonosis, caused by Trichomonas gallinae, emerged in the Canadian Maritime provinces in 2007 and has since caused ongoing mortality in regional purple finch (Carpodacus purpureus) and American goldfinch (Carduelis tristis) populations. Trichomonas gallinae was isolated from (1) finches and rock pigeons (Columbia livia) submitted for post-mortem or live-captured at bird feeding sites experiencing trichomonosis mortality; (2) bird seed at these same sites; and (3) rock pigeons live-captured at known roosts or humanely killed. Isolates were characterized using internal transcribed spacer (ITS) region and iron hydrogenase (Fe-hyd) gene sequences. Two distinct ITS types were found. Type A was identical to the UK finch epidemic strain and was isolated from finches and a rock pigeon with trichomonosis; apparently healthy rock pigeons and finches; and bird seed at an outbreak site. Type B was obtained from apparently healthy rock pigeons. Fe-hyd sequencing revealed six distinct subtypes. The predominant subtype in both finches and the rock pigeon with trichomonosis was identical to the UK finch epidemic strain A1. Single nucleotide polymorphisms in Fe-hyd sequences suggest there is fine-scale variation amongst isolates and that finch trichomonosis emergence in this region may not have been caused by a single spill-over event

Eco-System Services and the Circular Economy for Textiles

The concept of industrial ecology has made important contributions to sustainable manufacturing. The discipline majored on applications of systems theory and modelling flows of materials energy and information. However, recognition of the importance of management and policy issues has moved thinking towards industrial ecosystems. This provides the context for interest in the circular economy (CE). The aim of this research, which emerges from the EU-funded Resyntex project, is to appraise the potential for CE in textiles to supplant the present linear supply chains where discarded materials end up in landfill or incinerated. There are major challenges adding value to textile wastes, especially as the materials are mostly from commodity products where price competition is intense. Preliminary work suggests that the business case for CE technologies and processes is not strong enough to attract potential investors. The research reported here draws on the concept of industrial ecosystem services to identify benefits not normally costed when making a financial appraisal. Some of these services can be measured financially, whereas others are indirect and can only be quantified by incorporating policy-related assumptions. However, when textile ecosystem services are quantified and incorporated into the business model, the outcome for CE is considerably more healthy

Tinnitus and sleep difficulties after cochlear implantation

OBJECTIVES: To estimate and compare the prevalence of and associations between tinnitus and sleep difficulties in a sample of UK adult cochlear implant users and those identified as potential candidates for cochlear implantation. DESIGN: The study was conducted using the UK Biobank resource, a population-based cohort of 40- to 69-year olds. Self-report data on hearing, tinnitus, sleep difficulties, and demographic variables were collected from cochlear implant users (n = 194) and individuals identified as potential candidates for cochlear implantation (n = 211). These "candidates" were selected based on (i) impaired hearing sensitivity, inferred from self-reported hearing aid use and (ii) impaired hearing function, inferred from an inability to report words accurately at negative signal to noise ratios on an unaided closed-set test of speech perception. Data on tinnitus (presence, persistence, and related distress) and on sleep difficulties were analyzed using logistic regression models controlling for gender, age, deprivation, and neuroticism. RESULTS: The prevalence of tinnitus was similar among implant users (50%) and candidates (52%; p = 0.39). However, implant users were less likely to report that their tinnitus was distressing at its worst (41%) compared with candidates (63%; p = 0.02). The logistic regression model suggested that this difference between the two groups could be explained by the fact that tinnitus was less persistent in implant users (46%) compared with candidates (72%; p < 0.001). Self-reported difficulties with sleep were similar among implant users (75%) and candidates (82%; p = 0.28), but participants with tinnitus were more likely to report sleep difficulties than those without (p < 0.001). The prevalence of sleep difficulties was not related to tinnitus persistence (p = 0.28) or the extent to which tinnitus was distressing (p = 0.55). CONCLUSIONS: The lack of association between tinnitus persistence and sleep difficulties is compatible with the notion that tinnitus is suppressed in implant users primarily during active electrical stimulation and may return when the implant is switched off at night time. This explanation is supported by the similar prevalence of sleep problems among implant users and potential candidates for cochlear implantation, despite differences between the groups in tinnitus persistence and related emotional distress. Cochlear implantation may therefore not be an appropriate intervention where the primary aim is to alleviate sleep difficulties