In biochemical systems, stochastic e↵ects can be caused by the presence of small numbers of certain reactant molecules. In this setting, discrete state-space and stochastic simulation approaches were proved to be more relevant than continuous state-space and deterministic ones. These stochastic models constitute the theory of stochastic reaction networks (SRNs). Furthermore, in some cases, the dynamics of fast and slow time scales can be well separated and this is characterized by what is called sti↵ness. For such problems, the existing discrete space-state stochastic path simulation methods, such as the stochastic simulation algorithm (SSA) and the explicit tau-leap method, can be very slow. Therefore, implicit tau-leap approxima- tions were developed to improve the numerical stability and provide more e cient simulation algorithms for these systems. One of the interesting tasks for SRNs is to approximate the expected values of some observables of the process at a certain fixed time T. This is can be achieved using Monte Carlo (MC) techniques. However, in a recent work, Anderson and Higham in 2013, proposed a more computationally e cient method which combines multi-level Monte Carlo (MLMC) technique with explicit tau-leap schemes. In this MSc thesis, we propose new fast stochastic algorithm, particularly designed 5 to address sti↵ systems, for approximating the expected values of some observables of SRNs. In fact, we take advantage of the idea of MLMC techniques and drift-implicit tau-leap approximation to construct a drift-implicit MLMC tau-leap estimator. In addition to accurately estimating the expected values of a given observable of SRNs at a final time T , our proposed estimator ensures the numerical stability with a lower cost than the MLMC explicit tau-leap algorithm, for systems including simultane- ously fast and slow species. The key contribution of our work is the coupling of two drift-implicit tau-leap paths, which is the basic brick for constructing our proposed drift-implicit MLMC tau-leap estimator. As an example of sti↵ problem, we used the decaying-dimerizing reaction as a test example to show the advantage of our drift-implicit method over the explicit one. Through our numerical experiments, we checked the convergence properties of our coupling algorithm and showed that our proposed estimator is outperforming the explicit MLMC estimator about three times in terms of computational work. We also illustrated in a second example how our drift-implicit MLMC tau-leap estimator can be forty times faster than the explicit MLMC.

This study looked at one classroom's manifestation of inquiry. Looking at tasks as part of the Full Option Science System (FOSS) shed light on the way in which inquiry took shape in the classroom. To do this, detailed descriptions and analysis of the enactment of inquiry-based tasks were conducted in one fifth-grade elementary school classroom during an 8-week period of instruction. A central finding was that the intended tasks differed from the actual tasks. This incongruence occurred primarily due to the actions of individuals in the classroom. These actions shaped tasks and transformed inquiry-based tasks from highly ambiguous, high-risk tasks to a routine set of steps and procedures. Teacher's actions included establishing a classroom culture, creating a flow to classroom events, and making instructional decisions. These actions resulted in implicit structures in the classroom that determined the pace and sequence of events, as well as how the requirements and value of work were understood by students. Implicit structures reflected shared understandings between the teacher and students about work and the overall system of accountability in the classroom.

This experiment was conducted to examine the hypothesis that learning by analogy will invoke characteristics of an implicit mode of learning. On Day 1, dart novices learned to throw darts as close as possible to the centre of a target under one of three scenarios: control (without instruction), implicit (while performing a distracting secondary task), and analogy (while imagining an analogous physical image). Each participant threw 6 blocks of 40 darts, receiving repeated instructions before each block. The next day (Day 2), participants were tested for retention and for transfer by the addition of a secondary distracting task. The results showed that significant learning took place in all groups over a period of six learning blocks on the first day. There was also significant response to retention and transfer testing on Day 2. Learning to throw darts without instruction was shown to be superior to learning under both of the other conditions – analogy and secondary task. The study demonstrated that dart throwing instruction using analogy was insufficient to induce the beneficial features of implicit learning. The chosen elastic analogy, in fact, led to a significant deterioration of performance when compared to controls during transfer on Day 2. Sex and skill differences are unlikely to have played a significant role in the main findings. The findings are discussed within the framework of current literature. / Thesis (Master, Education) -- Queen's University, 2007-11-13 09:40:59.568

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Funktionella brister i ett abstract kan leda till att den vetenskapliga rapporten riskerar att inte bli läst medan ett välskrivet abstract kan fungera som en inträdesbiljett till den vetenskapliga arenan. Vetenskaplig sakprosa ska enligt genrens krav vara opersonlig och transparent, vilket oftast betyder ett restriktivt uttryck av författarröst. Syftet med den här studien är att undersöka hur lärarstudenter använder författarröst i abstract. Studiens material består av 60 abstract från tre lärarinriktningar, indelade efter utbildningslängd. Abstracten analyserades genom närläsning med hjälp av en analysmodell avsedd att fånga de olika uttryck av författaröst som ryms i abstracten. Analysmodellen är inspirerad av Tang & Johns studie från 1999, där sex olika identitetsroller identifieras i studenternas bruk av författarröst. Dessutom analyserades bruket av explicit och implicit författarröst kvantitativt för att kartlägga skillnader mellan de tre studentgrupperna. Resultaten visar att studenterna inom lärarprogrammet för grundskolans senare år och gymnasiet uttrycker författarröst mer restriktivt än studenterna inom lärarprogrammet för förskola och förskoleklass. Vid genomläsning av abstract riskerar därför de blivande förskollärarnas undersökningar att gallras bort på grund av ett icke genreanpassat bruk av författarröst. Detta väcker frågor om undervisning, dels i hur abstract bör skrivas, dels om hur författarröst bör och kan uttryckas i vetenskaplig sakprosa.

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In the wake of the death of a prominent atheist figure in 2011, an especially unsavory side of anti-atheist prejudice became evident as many celebrated the death of a prominent atheist, rejoicing that he would be in hell. The current study explores how these attitudes reveal a sense of schadenfreude in anti-atheist prejudice previously unexplored in the literature. Potential origins of this schadenfreude are discussed, and a study to experimentally explore this phenomenon was carried out. Using the repeated taste-test paradigm, this study gave participants atheist primes and hell primes between identical drinks and measure perceived taste after these manipulations, intending for the hell primes to induce schadenfreude after atheist primes as a result from participants thinking about the atheists going to hell for their lack of faith. All predicted main effects and interactions were non-significant. Exploratory analyses were carried out to explain these null results. Implications and future directions are discussed.

The purpose of this study was to examine possible links between relationship beliefs (Implicit Theories of Relationships and Importance of intimacy and passion), love experiences (experience of Intimacy and Passion) and attachment styles (the dimensions of Avoidance and Anxiety), in order to predict what kind of experiences and attachment patterns, would lead to which belief. A survey consisting of four different measures was filled out by 165 participants. The results showed Destiny and Growth beliefs were both predicted by Attachment avoidance. Destiny belief was also predicted by Experience of passion. Importance of passion and Importance of intimacy were both predicted by Attachment anxiety, Importance of passion by Experience of passion and Importance of intimacy by Experience of intimacy. People with different levels of Implicit Theories of Relationships showed a significant difference in Importance of passion.

Fluid flow network simulation codes are commonly used as a design and analysis tool for many engineering problems such as gas distribution networks, power plants and heat pumps. Two formulations of conservation of momentum have been widely applied in fluid flow network simulation models namely those based on static pressure and those based on total pressure. The total pressure formulations are convenient in that they eliminate the difficulties associated with the calculation of the convective terms and components such as pipe junctions are treated in a straightforward manner based on total pressure losses. However, the different formulations of total pressure for compressible and incompressible flow require different formulations of the momentum conservation equation, which is inconvenient for implementation in a generic network simulation code. In this thesis a united total pressure formulation is first derived which is valid for all fluids and therefore eliminates the inconvenience of switching between the compressible and incompressible formulations. A non-iterative method for the solution of the non-isothermal discretised equations based on the total pressure formulation is then introduced and consistency is illustrated. The method appears to be very stable for subsonic flows, while rapid steady state convergence is observed. A systematic comparison is also done with traditional static pressure based methods and the similarities and differences between the two formulations are illuminated. The different time scales involved in the simulation of transient flow in fluid networks are problematic when conventional fixed time step methods are used for time-wise integration. The time scales associated with acoustic and kinematic wave phenomena as well as storage effects can differ by orders in magnitude. This thesis also presents a simple adaptive time step algorithm which can be readily used in conjunction with all the commonly used first order methods for fluid flow networks. Two test problems are selected to demonstrate the efficiency and savings obtained with this procedure. The adaptive time step algorithm correctly selects appropriate time steps for all phenomena and significant computational savings are observed for accurate integration. In addition, a procedure is implemented which automatically selects the appropriate integration method. The resulting algorithm is a fully adaptive algorithm which switches between a fully implicit method and a semi-implicit method. Two test problems are once again used to demonstrate the efficiency and savings. The fully adaptive algorithm correctly selects appropriate methods for all phenomena and significant additional computational savings are observed. / Thesis (PhD (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2013