Self-regulated learning in virtual worlds – an exploratory study in OpenSim

Computer technologies are increasingly used in education to give the student more autonomy, referred to as student centred learning. One of the assumptions often made in this situation is that students will self-regulate to ensure they achieve the intended learning outcomes. Learning in immersive environments is popular as they are engaging, entertaining and flexible. However, a potential tension exists between configuring a multi-user environment to prohibit actions that can disrupt learning and maintaining the freedom and flexibility that generates learner engagement. This research investigates the importance of student self-regulation for learning in OpenSim. The outcome suggests self-regulation is one of the most important factors needed for successful learning within OpenSim as it preserves engagement while dissuading disruptive behaviour. Moreover, the need for suitable user support is identified as key for promoting student self-regulation within OpenSim

Metals on Titania/HOPG as Models for Heterogeneous Catalysts

The work done in this thesis is mainly focused on understanding the nanoscale morphology and activity of model heterogeneous catalysts. In order to do this we design and prepare model catalytic surfaces in ultrahigh vacuum (UHV) and study these surfaces using electron and ion based microscopies and spectroscopies. The nucleation, growth and chemical activity of mono and bimetallic clusters on TiO2(110) were investigated in order to understand how activity is influenced by cluster sizes, interactions with the oxide support and surface compositions of the bimetallic clusters. For example, Au-based and Pt-based bimetallic clusters such as Co-Au, Co-Pt, and Pt-Re were grown on titania and their activity for CO adsorption as well as methanol reaction were investigated. The nucleation and growth of these metals were found to be dependent upon the mobility of each metal on the titania surface. Furthermore, bimetallic clusters can be grown on the surface by taking advantage of the relative surface mobilities; when clusters of the less mobile metal are deposited first, the subsequent deposition of the second, more mobile metal results in nucleation exclusively at the existing seed clusters. Furthermore, bimetallic Pt-Ru clusters on highly oriented pyrolytic graphite (HOPG) have been studied as model systems for understanding direct methanol fuel cell catalysts. For Pt-Ru clusters deposited on powdered carbon supports, the novel electroless deposition (ED) method produces exclusively bimetallic clusters in contrast to the existing wet impregnation methods. The ED grown clusters were compared with clusters grown via vapor deposition by sequential deposition of Pt on Ru seed clusters. For both ED and vapor deposition, exclusively bimetallic clusters were produced since the deposition of Pt did not result in the formation of new clusters. In addition to bimetallic clusters, we have also successfully synthesized MoS2 clusters on titania to understand the structural changes that occurs in the presence of different reactant molecules since the activity of MoS2 towards hydrodesulphurization type reactions is very sensitive to the structure of the clusters. What we have discovered was that these structures are very stable towards adsorption of MeOH, CO, H2O and H2 in UHV

A case study in user support for managing OpenSim based multi user learning environments

This research was supported by the Commonwealth Scholarship Programme (UK) and the Scottish Informatics and Computer Science Alliance (SICSA).Immersive 3D Multi User Learning Environments (MULE) have shown sufficient success to warrant their consideration as a mainstream educational paradigm. These are based on 3D Multi User Virtual Environment platforms (MUVE), and although they have been used for various innovative educational projects their complex permission systems and large numbers of functions can make their management potentially challenging. It follows that an inadequately managed MULE can be ineffective with respect to intended learning outcomes. The purpose of this research was to determine how management challenges manifest themselves and how to support educators in learning and applying MULE management skills. We utilized the popular OpenSim platform for this study. First, a survey of the need for user support (N=43) is described. Next, the design and evaluation of a guidance tool using graph topologic visualization of OpenSim functions is presented (N=211). The tool is further evaluated in the delivery of a course module. The analysis and user feedback indicated that the tool provides accurate information and helpful support for MULE management. As the final phase of the research, training environments were developed for both basic and advanced OpenSim MULE management. Evaluations of their usability and perceived educational value were carried out with participants (N=68); the outcomes suggest that training for advanced MULE management is more useful for all users, without requiring more time or effort, regardless of the degree of complexity of the MULE being designed.PostprintPeer reviewe

High Effectiveness of Broad Access Direct-Acting Antiviral Therapy for Hepatitis C in an Australian Real-World Cohort: The REACH-C Study

Australia was one of the first countries with unrestricted access to government subsidized direct-acting antiviral (DAA) therapy for adults with chronic hepatitis C virus. This study assessed real-world DAA treatment outcomes across a diverse range of Australian clinical services and evaluated factors associated with successful treatment and loss to follow-up. Real-world Effectiveness of Antiviral therapy in Chronic Hepatitis C (REACH-C) consisted a national observational cohort of 96 clinical services including specialist clinics and less traditional settings such as general practice. Data were obtained on consecutive individuals who commenced DAAs from March 2016 to June 2019. Effectiveness was assessed by sustained virological response ≥12 weeks following treatment (SVR) using intention-to-treat (ITT) and per-protocol (PP) analyses. Within REACH-C, 10,843 individuals initiated DAAs (male 69%; ≥50 years 52%; cirrhosis 22%). SVR data were available in 85% (9,174 of 10,843). SVR was 81% (8,750 of 10,843) by ITT and 95% (8,750 of 9,174) by PP. High SVR (≥92%) was observed across all service types and participant characteristics. Male gender (adjusted odds ratio [aOR] 0.56, 95% confidence interval [CI] 0.43-0.72), cirrhosis (aOR 0.52, 95% CI 0.41-0.64), recent injecting drug use (IDU; aOR 0.64, 95% CI 0.46-0.91) and previous DAA treatment (aOR 0.50, 95% CI 0.28-0.90) decreased the likelihood of achieving SVR. Multiple factors modified the likelihood of loss to follow-up including IDU ± opioid agonist therapy (OAT; IDU only: aOR 1.75, 95% CI 1.44-2.11; IDU + OAT: aOR 1.39, 95% CI 1.11-1.74; OAT only, aOR 1.36; 95% CI 1.13-1.68) and age (aOR 0.97, 95% CI 0.97-0.98). Conclusion: Treatment response was high in a diverse population and through a broad range of services following universal access to DAA therapy. Loss to follow-up presents a real-world challenge. Younger people who inject drugs were more likely to disengage from care, requiring innovative strategies to retain them in follow-up

Retreatment for hepatitis C virus direct-acting antiviral therapy virological failure in primary and tertiary settings: The REACH-C cohort

Virological failure occurs in a small proportion of people treated for hepatitis C virus (HCV) with direct-acting antiviral (DAA) therapies. This study assessed retreatment for virological failure in a large real-world cohort. REACH-C is an Australian observational study (n = 10,843) evaluating treatment outcomes of sequential DAA initiations across 33 health services between March 2016 to June 2019. Virological failure retreatment data were collected until October 2020. Of 408 people with virological failure (81% male; median age 53; 38% cirrhosis; 56% genotype 3), 213 (54%) were retreated once; 15 were retreated twice. A range of genotype specific and pangenotypic DAAs were used to retreat virological failure in primary (n = 56) and tertiary (n = 157) settings. Following sofosbuvir/velpatasvir/voxilaprevir availability in 2019, the proportion retreated in primary care increased from 21% to 40% and median time to retreatment initiation declined from 294 to 152 days. Per protocol (PP) sustained virological response (SVR12) was similar for people retreated in primary and tertiary settings (80% vs 81%; p = 1.000). In regression analysis, sofosbuvir/velpatasvir/voxilaprevir (vs. other regimens) significantly decreased likelihood of second virological failure (PP SVR12 88% vs. 77%; adjusted odds ratio [AOR] 0.29; 95%CI 0.11–0.81); cirrhosis increased likelihood (PP SVR12 69% vs. 91%; AOR 4.26; 95%CI 1.64–11.09). Indigenous Australians had lower likelihood of retreatment initiation (AOR 0.36; 95%CI 0.15–0.81). Treatment setting and prescriber type were not associated with retreatment initiation or outcome. Virological failure can be effectively retreated in primary care. Expanded access to simplified retreatment regimens through decentralized models may increase retreatment uptake and reduce HCV-related mortality

Genetically defined syngeneic mouse models of ovarian cancer as tools for the discovery of combination immunotherapy

Despite advances in immuno-oncology, the relationship between tumor genotypes and response to immunotherapy remains poorly understood, particularly in high-grade serous tubo-ovarian carcinomas (HGSC). We developed a series of mouse models that carry genotypes of human HGSCs and grow in syngeneic immunocompetent hosts to address this gap. We transformed murine-fallopian tube epithelial cells to phenocopy homologous recombination-deficient tumors through a combined loss of p53, Brca1, Pten, Nf1, and overexpression of Myc and p53R172H, which was contrasted to an identical model carrying wild-type Brca1. For homologous recombination-proficient tumors, we constructed genotypes combining loss of p53, and overexpression of Ccne1, Akt2, p53R172H, and driven by KRASG12V or Brd4 or Smarca4 overexpression. These lines form tumors recapitulating human disease, including genotype-driven responses to treatment, and enabled us to identify follistatin as a driver of resistance to checkpoint inhibitors. These data provide proof of concept that our models can identify new immunotherapy targets in HGSC

Surface Optimization of Siloxane-Polyurethane Marine Coatings for Improved Fouling-Release Properties

Biofouling has been an economically and environmentally costly problem to mankind ever since they set sail. Biofouling causes frictional drag leading to slow vessel speeds, and increased fuel costs. Antifouling (AF) coatings containing biocides have been used for decades, however, since some biocides have shown undesired effects towards the environment, a non-toxic solution to combat fouling is desired. Subsequently, fouling release (FR) coatings quickly gained acceptance as a non-toxic approach to contend with biofouling. Unlike AF coatings, FR coatings not necessarily prevent settlement of organisms, they permit weak adhesion which is easily released by water shear or light grooming. The siloxane-polyurethane (SiPU) coatings based on the concept of self-stratification is a non-toxic and durable approach to prepare FR coatings. In this work, several approaches were considered to optimize surface properties of SiPU coatings. Incorporation of phenyl-methyl silicone oils led to improved FR properties towards several marine organisms in laboratory assays and in ocean field immersion. Enhancement in FR properties may be attributed to slowly exuding silicone oil providing surface lubricity, weakening the adhesion of marine organisms. Addition of diphenyldimethyl siloxane in to SiPU coatings at different ratios resulted in micro-scale surface topographical features which negatively affected microfouling-release while several coatings displayed good FR performance towards macrofouling organisms. In another study, decreasing the acid group content helped to improve FR performance towards barnacles, but FR performance towards diatoms were compromised. Novel amphiphilic siloxane-polyurethane (AmSiPU) coatings from polyisocyanate pre-polymers modified with polydimethyl siloxane and polyethylene glycol displayed excellent FR properties towards several marine organisms during laboratory assays. These AmSiPU coatings show promise as contenders to commercial FR standards. Initial development of SiPU coatings with hydrophilic surfaces showed promise, as the coatings showed rapidly rearranging surfaces with comparable FR performance to commercial standards which claim hydrophilic surface properties. During freshwater field immersion trials, SiPU coatings displayed excellent mussel FR performance up to 3 years. Surface analysis suggested that solvent content affected self-stratification and morphology of SiPU coatings. The SiPU coating system is a highly tunable, tough, environmentally friendly, and practical FR solution which can evolve along with non-toxic commercial marine coatings.Office of Naval Research (Grant number N00014-12-1-0482)SSPCValparAmerican Coatings AssociationNorth Dakota State University. College of Science and Mathematic

An evaluation of user support strategies for managed learning in a multi user virtual environment

The management of online learning environments so that they are effective and efficient presents a significant challenge for institutions and lecturers due to the complexity of requirements in the learning and teaching domain. The use of 3D Multi User Virtual Environments (MUVEs) for education introduces a novel set of management challenges. MUVEs were designed to cater for entertainment and commercial needs and as such do not intrinsically support managed learning. When MUVEs are used for educational purposes, forming 3D Multi User Learning Environments (MULEs), user support for learning management becomes an important factor. This thesis highlights the importance of managed learning in MULEs. It proposes a coordinated approach which accommodates the existing education institutional infrastructure. The research has focused on two very widely used and closely compatible MUVEs, Second Life (SL) and OpenSim. The thesis presents system and user studies that have been carried out on these selected MUVEs. The findings reveal the challenges that academics and students can experience if they do not have sufficient knowhow to manage learning activities in SL/OpenSim. User guidance and training tools were then developed for supporting learning management strategies in the context of SL/OpenSim and demonstrated in exemplar use-case scenarios. The user support models and tools which were developed have been extensively evaluated for their usability and educational value using diverse participant groups. The results validate the efficacy of these contributions, defending the research thesis. These contributions can be used in future research on managing MUVE supported education

User support for managed immersive education : an evaluation of in-world training for OpenSim

Part of this research was support by the Commonwealth Scholarship (UK) and SICSA Prize studentship.Supporting users for a competent interaction with 3 dimensional virtual worlds can increase their user experience within the immersive education environment. User manuals and other guide documents are popular supporting instruments for training new users of a software system. Quite often these documents have many screenshots of the application user interface which are used to steer a new user through sequential orders of actions. However, for complex scenarios of user interactions, such as those found in virtual worlds, these types of documents can become unhelpfully lengthy and unintuitive. The first part of this research was a comparative analysis of traditional document-based user support with an in-world approach; a prototype training island was developed in OpenSim and evaluated for its training support against the OpenSim user guide documents. The results suggested in-world training can be a better option of training for OpenSim than training documents. Second part of this research was to evaluate a completed training environment, which consist of two OpenSim islands, one for basic user training and one for training advanced OpenSim management. The results suggested that training for advanced OpenSim management, which is not covered in user guide documents, make users competent for managing their immersive environment. The final part of the research, a case study, examined the effective use of this complete training environment for module teaching and learner support. The results suggest that for learning the skills essential for productive use of OpenSim-based educational environments, an in-world approach covering advanced management functions of OpenSim is likely to be a better option than traditional user manuals for the future needs for immersive education as a mainstream practice.Publisher PDFPeer reviewe

Readiness of Sri Lankan medium and large scale IT organizations to manage IT professionals to enhance their productivity

Previous research has shown that, there is a direct relationship between retention of IT professionals and organization's HR practices[l], [2], [3], [4], [5]. This research aims to find the readiness of Sri Lankan software companies to incorporate best suite of HR practices for IT professionals to retain them. Research was carried out in three phases; Literature Review, a series of interviews with HR managers and an employee survey. This research reveals that, Sri Lankan IT industry is in the process of unveiling the strategic importance of incorporating HR practices to manage and retain IT professionals. HR professionals have identified that IT professionals have different set of needs compared to other professionals. As a result many IT companies today have taken steps to establish HR as a separate role. HR practices used in Sri Lankan IT organizations found to be compatible with the world best HR practices. According to HR managers they have given high importance to practice them within the organizations. On the other hand research revealed that IT professionals' career expectations were not fully met by the organizations' HR practices. These contradicting responses showed that there is a gap between how HR professionals and IT professionals perceive HR practices of an organization. It is interesting to note that, as a percentage, HR professionals who are qualified in the HR stream and up to date with world's 'latest trends are considerably low in Sri Lankan IT sector. Line managers' taking over HR functionality is fast becoming a world trend in the IT industry where as local. line managers still have not undertaken the HR functionality. This is due to lack of knowledge and emphasis in people management in training them before and after recruitment. Based on these research findings it can be concluded that the readiness of Sri Lankan. I'T organizations to incorporate best HR suite for fulfilling the IT professionals' career expectations are yet to be evolved even though the HR managers are well aware of the importance and need for a different way of managing the IT professionals