The development of multiplicative thinking and proportional reasoning: Models of conceptual learning and transfer

This thesis considers the development of multiplicative thinking and proportional reasoning from two perspectives. Firstly, it examines the research literature on progressions in conceptual understanding to create a Hypothetical Learning Trajectory (HLT). Secondly, it surveys modern views of how transfer by learners occurs in and between situations, contrasting object views of abstraction with knowledge in pieces views. Case studies of six students aged 11-13 years illustrate conceptual changes that occur during the course of a school year. The students are involved in a design experiment in which I (the researcher) co-teach with the classroom teacher. The students represent a mix of gender, ethnicity and level of achievement. Comparison of the HLT with the actual learning trajectory for each student establishes its validity as a generic growth path. Examination of the data suggests that two models of learning and by inference, transfer, describe the conceptual development of the students. There is consideration of students’ use of anticipated actions on physical and imaged embodiments as objects of thought with a focus on the significance of object creation for conceptual growth, and the encapsulation, completeness and contextual detachment of objects. There is broad consistency in students’ progress through the phases of the HTL within each sub-construct though the developmental patterns of individual are variable and temporal alignment across the sub-constructs does not uniformly hold. Some consistency of order effect in concept development is noted. Discussion on the limitations of the HTL includes the difference between knowledge types from a pedagogical perspective, absence of significant model-representation-situation transfer, and order relations in conceptual development. Considerable situational variation occurs as students solve problems that involve applications of the same concepts. Partial construction of concepts is common. This was true of all learners, irrespective of level of achievement. High-achieving students more readily anticipate actions and trust these anticipations as objects of thought than middle and low achievers. The data supports knowledge in pieces views of conceptual development. Complexity for learners in observing affordances in situations, and in co-ordinating the fine-grained knowledge required, explains the difficulty of transfer. While supporting the anticipation of action as significant from a learning perspective the research suggests that expertise in applying concepts involves a process of noticing similarity across contextually bound situations and cueing appropriate knowledge resources

Tapered, tubular polyester fabric

A tapered tubular polyester sleeve is described to serve as the flexible foundation for a spacesuit limb covering. The tube has a large end and a small end with a length to be determined. The ratio of taper is also determined by scale factors. All the warp yarns extend to the large end. A requisite number of warp yarns extend the full length of the sleeve. Other warp yarns extend from the large end but are terminated along the length of the sleeve. It is then woven with a filling yarn which extends in a full circle along the full length of the sleeve to thereby define the tapered sleeve. The sleeve after fabrication is then placed on a mandrel, heated in an oven, and then attached to the arm or other limb of the spacesuit

Exploiting Action Impact Regularity and Exogenous State Variables for Offline Reinforcement Learning

Offline reinforcement learning -- learning a policy from a batch of data -- is known to be hard for general MDPs. These results motivate the need to look at specific classes of MDPs where offline reinforcement learning might be feasible. In this work, we explore a restricted class of MDPs to obtain guarantees for offline reinforcement learning. The key property, which we call Action Impact Regularity (AIR), is that actions primarily impact a part of the state (an endogenous component) with limited impact on the remaining part of the state (an exogenous component). AIR is a strong assumption, but it nonetheless holds in a number of real-world domains including financial markets. We discuss algorithms that exploits the AIR property, and provide a theoretical analysis for an algorithm based on Fitted-Q Iteration. Finally, we demonstrate that the algorithm outperforms existing offline reinforcement learning algorithms across different data collection policies in simulated and real world environments where the regularity holds

Comparison of Photosynthetic Ability In Single and Double Palisade Parenchyma Leaves in Southern California

Melaleuca quinquenervia is a myrtle (family Myrtaceae) with a propensity for invasiveness. The leaves feature an isobilateral orientation: vertically aligned with a layer of palisade parenchyma on both the adaxial and abaxial sides. Quercus agrifolia (Fagaceae) is a native evergreen with one layer of palisade parenchyma. Due to this structural difference, it was hypothesized that Melaleuca would have a higher rate of photosynthesis (Pn) and less reflectance (NDVI) of green light than Quercus. These two variables were compared using an unpaired t-test, yielding p-values of 0.1366 for NDVI and 0.04428 for photosynthetic rate. No significant difference was found between the NDVI of the two species, but a significant difference was observed in photosynthetic rate (with Melaleuca having the greater Pn). Thus we found evidence that appears to support our hypothesis in part, though the results concerning NDVI were inconclusive

In vivo Mechanisms of Antibody-Mediated Neurological Disorders:Animal Models and Potential Implications

Over the last two decades, the discovery of antibodies directed against neuronal surface antigens (NSA-Abs) in patients with different forms of encephalitis has provided a basis for immunotherapies in previously undefined disorders. Nevertheless, despite the circumstantial clinical evidence of the pathogenic role of these antibodies in classical autoimmune encephalitis, specific criteria need to be applied in order to establish the autoimmune nature of a disease. A growing number of studies have begun to provide proof of the pathogenicity of NSA-Abs and insights into their pathogenic mechanisms through passive transfer or, more rarely, through active immunization animal models. Moreover, the increasing evidence that NSA-Abs in the maternal circulation can reach the fetal brain parenchyma during gestation, causing long-term effects, has led to models of antibody-induced neurodevelopmental disorders. This review summarizes different methodological approaches and the results of the animal models of N-methyl-d-aspartate receptor (NMDAR), leucine-rich glioma-inactivated 1 (LGI1), contactin-associated protein 2 (CASPR2), and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) antibody-mediated disorders and discuss the results and the limitations. We also summarize recent experiments that demonstrate that maternal antibodies to NMDAR and CASPR2 can alter development in the offspring with potential lifelong susceptibility to neurological or psychiatric disorders

In vivo Mechanisms of Antibody-Mediated Neurological Disorders: Animal Models and Potential Implications

Over the last two decades, the discovery of antibodies directed against neuronal surface antigens (NSA-Abs) in patients with different forms of encephalitis has provided a basis for immunotherapies in previously undefined disorders. Nevertheless, despite the circumstantial clinical evidence of the pathogenic role of these antibodies in classical autoimmune encephalitis, specific criteria need to be applied in order to establish the autoimmune nature of a disease. A growing number of studies have begun to provide proof of the pathogenicity of NSA-Abs and insights into their pathogenic mechanisms through passive transfer or, more rarely, through active immunization animal models. Moreover, the increasing evidence that NSA-Abs in the maternal circulation can reach the fetal brain parenchyma during gestation, causing long-term effects, has led to models of antibody-induced neurodevelopmental disorders. This review summarizes different methodological approaches and the results of the animal models of N-methyl-d-aspartate receptor (NMDAR), leucine-rich glioma-inactivated 1 (LGI1), contactin-associated protein 2 (CASPR2), and a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) antibody-mediated disorders and discuss the results and the limitations. We also summarize recent experiments that demonstrate that maternal antibodies to NMDAR and CASPR2 can alter development in the offspring with potential lifelong susceptibility to neurological or psychiatric disorders

Resurgent Insurgents:Quantitative Research Into Jihadists Who Get Suspended but Return on Twitter

Jihadists are very active on Twitter but their accounts frequently get suspended. A substantial debate over the effectiveness of suspension has arisen; an important factor is that Jihadists quickly create new accounts, resurging back like a game of whack-a-mole. This causes biases for terrorism and intelligence analysts. Whilst widely acknowledged, little research addresses the problem. In this study we identify resurging Jihadist accounts with novel methods, and provide detailed analysis going beyond previous case-studies. We show that suspension is less disruptive to terrorists than previously thought, whilst the bias and disruption caused to terrorism research has been underestimated

An accurate spline polynomial cubature formula for double integration with logarithmic singularity

The paper studied the integration of logarithmic singularity problem J(ӯ) = ∫∫Δζ(ӯ)log|ӯ - ӯ 0∗|dA, where ӯ=(α,β), y0=(α0,β0) the domain Δ is rectangle Δ = [r1, r2] × [r3, r4], the arbitrary point ӯ ϵ Δ and the fixed point ӯ0 ϵ Δ. The given density function ζ(ӯ), is smooth on the rectangular domain Δ and is in the functions class C2,τ (Δ). Cubature formula (CF) for double integration with logarithmic singularities (LS) on a rectangle Δ is constructed by applying type (0, 2) modified spline function DΓ(P). The results obtained by testing the density functions ζ(ӯ) as linear and absolute value functions shows that the constructed CF is highly accurate

Le jeu des stéréotypes féminins et masculins en droit international : influences et conséquences pour les victimes de viol en période de conflits armés

Le présent mémoire traite du jeu des stéréotypes féminins et masculins dans la création des normes internationales à l’encontre du viol militaire. Il questionne les influences et les conséquences des stéréotypes de sexe faible et de victimes passives attribués aux femmes et ceux de sexe fort et de combattants actifs assignés aux hommes en période de conflits armés. Plus précisément, les généralisations excessives qui découlent des stéréotypes de genre et qui encouragent le paradigme femmes-victimes et hommes-auteurs de viols sont remises en question. Afin de comprendre le sens d’un tel jeu, une analyse critique de l’évolution normative du droit international est proposée en deux temps. La première partie aborde les influences du jeu des stéréotypes dans la création des normes de protection et des normes pénales à l’encontre du viol. L’étude de ces normes internationales expose que, malgré les progrès dus aux efforts des féministes, ce jeu des stéréotypes de genre se maintient encore en droit international et que des conséquences en découlent autant pour les femmes que pour les hommes en période de conflits armés. La deuxième partie porte sur l’analyse de telles conséquences normatives qui confinent les femmes dans un rôle de victimes passives, sans capacité d’action positive ou négative lors des conflits armés, et négligent de considérer la situation des hommes qui ne sont pas tous des combattants actifs et qui peuvent donc aussi requérir des protections contre les viols militaires. Ce mémoire conclut que les dichotomies de la binarité du genre présentes dans les normes internationales contre le viol devraient être appelées à disparaître, sans quoi le jeu des stéréotypes risque d’être perpétué. Ces normes, influencées par la catégorisation des genres féminin et masculin, pourraient plutôt laisser place à la protection du genre humain, exempt de distinction essentialiste basée sur le sexe, et donc exempt de discrimination basée sur les stéréotypes de genre.This thesis looks at the interplay between female and male stereotypes in the creation of international norms against military rape. The influences and consequences of female stereotypes, such as the weak sex or the passive victims, as well as male stereotypes, such as the strong sex or the active fighters, in armed conflict settings are questioned. Specifically, the excessive generalizations derived from gender-based stereotypes, which encourage the paradigm of women-victims and men-perpetrators of rape are questioned. In order to understand the interplay between gender-based stereotypes, a two-pronged approach is used to conduct an in-depth analysis of the normative evolution of international law. First, the influences of gender-based stereotypes in the creation of protection norms and penal norms against rape are studied. The review of these international norms shows that, despite the progress attributed to feminists’ efforts, the interplay of gender-based stereotypes is perpetuated in international law. Further, both women and men suffer the consequences in times of armed conflicts. Second, it reviews the impact of such normative consequences, which confine women to the role of passive victims, without the capacity of positive or negative actions during armed conflicts, while neglecting to consider the situation of men, who are not necessarily active fighters, and who may therefore require protection against military rape. This thesis concludes that the gender binarity dichotomy present in international norms against rape should disappear. Otherwise, the interplay of gender-based stereotypes may be perpetuated. Instead of those norms being influenced by a gender-based categorization, they could be replaced by norms that protect the human race; free of essentialist distinctions based on sex, thus free from stereotypical gender-based discrimination