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This study intends to explore the effects of two drying schedules with options of conditioning and post-drying storage on the drying speed and quality of western hemlock timbers. Western hemlock (Tsuga heterophylla), the species of interest in this study, is one of British Columbia's most abundant tree species that accounts for 75 to 80% of British Columbia's exports to Japan. It is usually combined with amabilis fir (Abies amabilis) for processing and economical purposes. Hemlock is difficult to dry due to its compression wood, wetpockets and large spread of initial moisture content and basic density. Consequently, it seems practical to dry hemlock by itself. In this study, hemlock was dried using two different schedules with optional conditioning and optional seven day post-drying storage in a covered and climatized space. These eight experimental runs were compared to a control run, which utilized an established drying schedule. To assess the kiln dried timber quality, twist, diamonding, and checks were evaluated using pre-drying and post-drying and/or post-storage measurements. Drying times and casehardening were also considered. Data analysis and evaluation illustrated that conditioning and the harsher schedule reduced casehardening, while the milder schedule developed less twist and diamonding. Even though it appears that the control run developed less shape distortions than the treatment runs, the control run required longer drying times. When using the harsher schedule the kiln was immediately available for the next run, and the dried timber could be stored in a covered area in order to level out the moisture gradients and alleviate casehardening. As a subsequent step, the timber could be planed to reduce twist, diamonding and superficial checks. / Forestry, Faculty of / Graduate

Percentile reinforcement schedules have been used to systematically alter inter-response times, behavioral variability, breath carbon monoxide levels, duration of social behaviors, and various other properties of behavior. However, none of the previous studies have examined the effectiveness of percentile schedules in relation to the magnitude of muscular contractions. This control over magnitude of muscular responding has important implications relating to the strengthening of muscles and correct movements for patients receiving physical rehabilitation. There would be great utility in percentile schedules that can be implemented in rehabilitation situations by physical therapists and patients themselves to improve treatment outcomes – all of which could be possible without any behavioral training if the procedure is implemented via body sensors and smartphone applications. Using healthy adults and the aforementioned technology, this thesis focused on the design and testing of three percentile reinforcement schedule procedures to increase the strength of the vastus medialis muscle. Results indicate that the magnitude of muscular responses can be shaped using body sensors and contingent feedback, and the percentile schedule procedures have promising applications in the domain of physical therapy.

Metronomic cyclophosphamide (CPA) treatment activates robust anti-tumor immunity and induces regression of implanted tumors in mouse models of brain cancer when administered on an intermittent, every 6-day schedule (CPA/6d), but not on a daily low-dose or a maximum-tolerated dose schedule. Five intermittent metronomic CPA schedules were investigated in GL261 gliomas implanted in scid mice. Metronomic CPA treatments spaced 9 or 12 days apart induced extensive tumor regression, however, tumor-infiltrating natural killer cell responses were not sustained, and tumor growth rapidly resumed after treatment day 24. Increasing the CPA dose prolonged the period of tumor regression on the every 9-day schedule, but natural killer cell activation was markedly decreased. Thus, sustained immune and anti-tumor responses were only achieved on the CPA/6d schedule. Furthermore, CPA/6d treatment eradicated GL261 tumors implanted in immunocompetent C57BL/6 mice by activating anti-tumor CD8-T cell responses and immune memory, which provides proof-of-concept that single agent chemotherapy delivered on an optimized metronomic schedule can cure large established cancers. Transcriptomic profiling, KEGG pathway, and upstream regulator analysis were employed to compare CPA/6d-induced gene expression changes between: immune-responsive GL261 tumors and immune-unresponsive Lewis lung carcinoma (LLC) and B16F10 melanoma tumors; between GL261 tumors implanted in immunocompetent mice versus in scid immunodeficient mice; and between GL261 tumors in scid mice treated with CPA every 6-days or every 9-days. CPA-treated LLC tumors were associated with inhibited VEGFA-targeted genes, down-regulated cell adhesion and transendothelial migration genes, and up-regulated drug metabolism pathways. In B16F10 tumors, CPA activated genes in chemokine signaling and antigen processing and presentation pathways, but no NK cell and T cell effector pathways were activated. GL261 tumors in scid mice were deficient in CPA activation of a subset of cytokine and cytokine receptor genes and T cell receptor signaling genes seen in immunocompetent mice. Cytokine gene expression was lower and drug metabolism gene expression was higher in every 9-day CPA-treated tumors versus CPA/6d-treated tumors. Together, these studies elucidate the dose, schedule, and adaptive immune-dependence of CPA-induced anti-tumor immune responses, giving new insight into the molecular signaling events underlying the deficiencies in immune responses seen in intermittent metronomic CPA-unresponsive tumor models. / 2017-05-31T00:00:00Z

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<p> Software Pipelining is a method of instruction scheduling where loops are scheduled more efficiently by executing operations from more than one iteration of the loop in parallel. Finding an optimal software pipelined schedule is NP-complete, but many heuristic algorithms exist. </p> In iteration i, a software pipelined loop will execute, in parallel, "stage" 1 of iteration i, stage 2 of iteration i- 1 and so on until stage k of iteration i-k+l. </p> <p> We present a new approach to software pipelining based on using a hemistic algorithm to explicitly assign each operation to its stage before the actual scheduling. </p> <p> This explicit assignment allows us to implement control flow mechanisms that are hard to implement with traditional methods of software pipelining, which do not give us direct control over what stages instructions are assigned to. </p> / Thesis / Master of Science (MSc)

Wireless mesh networks have received increasing interest in recent years due to the fast expanding Wi-Fi market. More and more, individual communities and companies are beginning to set up intranets with multiple Wi-Fi access points, so that clients can communicate using wireless connections. Because the traditional IEEE 802.11 standard cannot provide efficient performance for mesh networks, the IEEE set up a task group in 2001 to establish a wireless mesh network standard, IEEE 802.11s. For compatibility, IEEE 802.11s will be an extension of the IEEE 802.11 MAC/PHY, and as a result, the new standard has inherited both the pros and cons of IEEE 802.11. Co-channel and inner-channel interference are the dominant factors affecting the system performance of wireless networks. Since there are a number of available non-overlapping channels one can always use these in order to eliminate inner-channel interference. However, the number of channels is not sufficient for an ESS Mesh if channel reuse is not considered, not only because of the network size, but also because of the non-licensed nature of the IEEE 802.11 PHY ISM band, where the network will suffer interference from other co-located networks. For this reason, channel reuse in an ESS Mesh is essential and reducing co-channel interference is a key issue in channel assignment. In this thesis, we investigate the performance of deterministic traffic scheduling with channel assignment in an ESS Mesh based on a TDMA MAC framework while still using the IEEE 802.11 PHY. We first analyze an upper bound on channel assignment performance, considering both binary interference models and cumulative interference models. Then, a scheduling solution for deterministic traffic is proposed, based on heuristic channel assignment and path selection algorithms. Our simulation results show that the scheduling solution is feasible and the performance is close to the theoretical value. / Thesis / Master of Applied Science (MASc)

Previous research suggests that employees can experience different types of demands at work. Challenge demands are motivating and goal oriented, whereas hindrance demands are excessively difficult and / or goal irrelevant. Similarly, previous research indicates that employees may think about work in different ways. Affective rumination involves unproductive, emotionally negative work-related thoughts, whereas problem-solving pondering involves productive, unemotional work-related thoughts. I assess challenge and hindrance demands as potential antecedents to the facets of work-related rumination and indicators of employee recovery and well-being (exhaustion and vigor) in both within- and between-person analyses. I additionally consider the role of work schedule and assess my hypothesized model on a sample including both traditionally scheduled and shift workers. My final sample consisted of 92 full-time (80 traditionally scheduled, 12 shift) employees who were sent three surveys per day over a 28-day survey period. Using multilevel structural equation modeling, I found evidence that work-related rumination may operate as a mechanistic pathway linking work demands to recovery indicators. Additionally, evidence from this dissertation suggests that problem-solving pondering may be detrimental to employee recovery at the daily level, but that it may be beneficial to employee recovery at the between-person level. This dissertation contributes to scientific understanding of potential antecedents of the different types of rumination and suggests that hindrance demands, which are almost universally treated as detrimental to employee recovery, may have competing positive and negative relationships with employee recovery. / Doctor of Philosophy / Research suggests that the demands of a job can be thought of as motivating, attainable challenges or as useless or impassible hindrances. Research additionally suggests that when we think about work during non-work time, those thoughts can be problem focused and productive or emotionally driven and unproductive. This dissertation explores the relationships between these two types of work demands, these two types of work-related rumination, and indicators of employee recovery from work (exhaustion and vigor). Additionally, I consider whether work schedule (traditional 9:00-5:00 vs. shift work) changes the ways these variables relate to each other. In a sample of 92 full-time workers (80 traditional, 12 shift), I find evidence to suggest that these types of work demands do relate to work-related rumination. Additionally, these types of work demands have different patterns of relationships with exhaustion and vigor. By assessing this model both in terms of changes in relationships for a person day to day (within-person) and in terms of changes in relationships between different people on average (between-person), I find evidence for potentially competing beneficial and harmful consequences of hindrance demands on employee recovery.

Autism spectrum disorder is a developmental disorder characterized by social, behavioral, and communicative deficits. Although there is no known cure for autism, there are many research-based interventions that aid in strengthening such deficits, especially those associated with failures of stimulus control One way to address such failures is to provide additional stimuli that enhance or override information provided by naturally occurring stimuli. Contingency maps are one such example. This study uses an observing response (i.e., hand-raising) to allow the subjects to request contingency maps. The purpose of this study is to identify if contingency maps function as reinforcers and if requests for information can be acquired using an observing-response paradigm. Major findings of the present study indicate that requests for information can be acquired and maintained by access to CMs.

Rationale: Amphetamine abuse by adolescents predicts long-term drug dependence. Heightened vulnerability to drug abuse could be due to higher sensitivity to drug’s reinforcing effects. Rodents are used to study age-related sensitivities to drugs. Objective: We compared intravenous amphetamine self-administration between adolescent and adult male rats on an operant schedule of reinforcement measuring the reinforcing efficacy of a drug. Methods: After surgery, adolescent and adult rats acquired lever-pressing behavior reinforced by amphetamine infusions. Results: Both age groups exhibited more infusions per session as dose increased. However, neither the number of infusions per session nor total amphetamine intake differed across age groups. Conclusion: Although rapid transition is reliable to test reinforcing properties of stimulants, results suggest that amphetamine is an equally efficacious reinforcer among both age groups. In regards to humans, these results suggest that other factors, like social influences, explain higher rates of drug intake by adolescent compared with adult humans.