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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Verification of Post-glacial Speleogenesis and the Origins of Epigene Maze Caves in New York

Cooper, Max P 17 May 2014 (has links)
Dissolutional features called karst exist on the surface, and in the subsurface as caves. In glaciated regions caves were thought to be post-glacial in origin. Work in the 1970s demonstrated that pre-glacial caves existed, but did not answer if a cave could form post-glacially. A model proposed by Mylroie and Carew (1987) states that a post-glacial cave would be controlled entirely by glacial features and the deranged drainage of glaciated terrains. Caves known as maze caves form at maximum rates, and could form to navigable size in the time since deglaciation. Maze caves form in the shallow subsurface, allowing them to be removed in subsequent glaciations. GIS water flow analysis, and calculation of formation times using cross-section data demonstrates that maze caves in the glaciated region of New York are post-glacial in origin fitting in the deranged drainage and forming in the time since deglaciation.
22

Memory modulation produced by post-training exposure to an aversive conditioned stimulus

Holahan, Matthew R. January 1999 (has links)
No description available.
23

The interaction of delay and magnitude of the reward on acquisition and extinction in the straight alley runway

Habley, Peter Charles 01 January 1967 (has links)
The purpose of this study is to clarify and accurately describe the interactive effects of several amounts of reward and delay on acquisition and extinction or rats in a straight runway. A factorial study involving several levels of reward and delay is presented to further describe and possibly predict what effects these independent variables have on learning curves. The major purpose of this paper, then, is to determine the interactive effects of delay and magnitude of reward, and to present the results in a clarifying and informative manner.
24

Behavioural consequences of kindling in the anterior claustrum

Ma, Bonita 30 May 2007
The anterior claustrum (CLA) has been implicated in epileptogenesis and epileptiform activity due to its abundant and widespread bilateral connections to some of the structures believed to play an important role in seizure generalization: the motor cortex, entorhinal cortex, limbic structures, and brainstem sites. Kindling in the CLA has been characterized as comprising two distinct phases: an early phase and a late phase. Early phase seizures progress quickly into generalized seizures, are short in duration, and resemble cortical seizures. Late phase seizures are characterized as being more severe in intensity, having longer durations, and resembling limbic-type seizures.<p>It is unknown whether kindling in the CLA will lead to changes in behaviour as seen after kindling of limbic sites. Thus, I measured the behavioural effects of kindling in the anterior CLA to investigate potential changes in learning, memory, and anxiety-related behaviours. I hypothesized that changes in behaviour would occur after kindling of late phase seizures, because of their close resemblance to limbic-type seizures, but not after kindling of early phase seizures. Anxiety-like behaviour was assessed in the elevated plus maze and open field. Object memory was assessed in an object recognition test, and spatial learning and memory were assessed in the water maze.<p>I found no significant changes in behaviour in the late phase group in comparison to the early phase and control groups. Thus, contrary to my hypothesis, late phase kindling of the CLA does not produce changes in learning and memory or alterations in anxiety-related behaviours.
25

Behavioural consequences of kindling in the anterior claustrum

Ma, Bonita 30 May 2007 (has links)
The anterior claustrum (CLA) has been implicated in epileptogenesis and epileptiform activity due to its abundant and widespread bilateral connections to some of the structures believed to play an important role in seizure generalization: the motor cortex, entorhinal cortex, limbic structures, and brainstem sites. Kindling in the CLA has been characterized as comprising two distinct phases: an early phase and a late phase. Early phase seizures progress quickly into generalized seizures, are short in duration, and resemble cortical seizures. Late phase seizures are characterized as being more severe in intensity, having longer durations, and resembling limbic-type seizures.<p>It is unknown whether kindling in the CLA will lead to changes in behaviour as seen after kindling of limbic sites. Thus, I measured the behavioural effects of kindling in the anterior CLA to investigate potential changes in learning, memory, and anxiety-related behaviours. I hypothesized that changes in behaviour would occur after kindling of late phase seizures, because of their close resemblance to limbic-type seizures, but not after kindling of early phase seizures. Anxiety-like behaviour was assessed in the elevated plus maze and open field. Object memory was assessed in an object recognition test, and spatial learning and memory were assessed in the water maze.<p>I found no significant changes in behaviour in the late phase group in comparison to the early phase and control groups. Thus, contrary to my hypothesis, late phase kindling of the CLA does not produce changes in learning and memory or alterations in anxiety-related behaviours.
26

The Effect of Rho Kinase Inhibitors on Alzheimer's Disease

January 2017 (has links)
abstract: Alzheimer’s disease (AD) is a progressive neurodegenerative disease that affects 5.4 million Americans. AD leads to memory loss, changes in behavior, and death. The key hallmarks of the disease are amyloid plaques and tau tangles, consisting of amyloid-β oligomers and hyperphosphorylated tau, respectively. Rho-associated, coiled-coil-containing protein kinase (ROCK) is an enzyme that plays important roles in neuronal cells including mediating actin organization and dendritic spine morphogenesis. The ROCK inhibitor Fasudil has been shown to increase learning and working memory in aged rats, but another ROCK inhibitor, Y27632, was shown to impair learning and memory. I am interested in exploring how these, and other ROCK inhibitors, may be acting mechanistically to result in very different outcomes in treated animals. Preliminary research on thirteen different ROCK inhibitors provides evidence that while Fasudil and a novel ROCK inhibitor, T343, decrease tau phosphorylation in vitro, Y27632 increases tau phosphorylation at a low dose and decreases at a high dose. Meanwhile, novel ROCK inhibitor T299 increases tau phosphorylation at a high dosage. Further, an in vivo study using triple transgenic AD mice provides evidence that Fasudil improves reference memory and fear memory in both transgenic and wild-type mice, while Y27632 impairs reference memory in transgenic mice. Fasudil also decreases tau phosphorylation and Aβ in vivo, while Y27632 significantly increases the p-tau to total tau ratio. / Dissertation/Thesis / Doctoral Dissertation Neuroscience 2017
27

Age sensitivity of the Barnes Maze and the Morris Water Maze: Associations with cerebellar cortical Purkinje neurons

Kennard, John Andrew January 2012 (has links)
The goal of this study was to examine age-related changes in spatial memory and its neurobiological substrates as assessed by the Morris water maze (MWM) and the Barnes maze. The MWM is one of the most widely used tests of spatial memory and numerous studies suggest that spatial memory abilities decline with age. To contrast, very few studies exist comparing different ages of mice in the less stressful Barnes maze, and no systematic life span analysis of performance has been published. As the cerebellum is one brain structure that undergoes a quantifiable change in anatomy across the life span (loss of Purkinje neurons), this study evaluated these behavioral tests in terms of sensitivity to both age-related changes in learning as well as age-related changes in the cerebellar cortex. A total of 65 CB6F1 mice were tested at one of five ages (4, 8, 12, 18, or 25 months) on the MWM and Barnes maze. Deficits in spatial memory acquisition were most apparent in both tasks when comparing a subset of good learning mice. Impairment began at 25 months in the MWM and 18 months in the Barnes maze. In all mice, retention was impaired at 25 months on the Barnes maze, but no clear retention deficits were found in the MWM. Unbiased stereology revealed an age-related loss in cerebellar cortical Purkinje neurons from 12-25 months, whereas hippocampus volume remained stable across the life span. Purkinje neuron number, but not hippocampus volume, was correlated with spatial learning in the Barnes maze, with impaired learning associated with lower neuron numbers. For the MWM, Purkinje neuron number was associated with performance in a subset of good learning animals. Overall, mice that learned the Barnes maze well had more Purkinje neurons than poor learners. Both tests were sensitive to heterogeneity in aging at each age tested. Comparisons of good and poor learners across the life span, as well as correlations between the two tasks and brain measures, suggested that the MWM and Barnes maze may be sensitive to different spatial learning abilities and mechanisms of aging. / Psychology
28

An Investigation of the Reliability and Validity of Curriculum-based Measurement Maze Probes: A Comparison of 1-minute, 2-minute, and 3-minute Time Frames

Sarasti, Israel A. January 2010 (has links)
Prevention science has suggested that universal screening can enhance educational and mental health outcomes in the schools (Greenberg et al., 2003). A three-tier model of prevention has been proposed by Albers, Glover, and Kratochwill (2007) and Brown-Chidsey and Steege (2005) employing universal screening assessments of basic academic skills at Tier-1. Curriculum-based measurement maze (CBM-maze) probes are universal screeners that were developed as measures of reading comprehension. They are characterized as easy to administer, time-efficient, valid, and reliable (Parker, Hasbrouck, & Tindal, 1992). CBM-maze probes are short stories consisting of 400 words where every seventh word is omitted and replaced with three answer choices. Students are given 3-minutes to read the passage silently and select a word from the answer choices that restores the meaning of the story. Maze probes have been utilized as reading comprehension assessments for universal screening (Tier 1) and progress monitoring (Tier 2 and Tier 3; Espin, Deno, Maruyama, & Cohen, 1989; D. Fuchs & Fuchs, 1992). The current research study was conducted to further extend the research on the reliability and validity of CBM-maze probes. More specifically, it investigated if there were any differences between 1-minute, 2-minute, and 3-minute time frames, alternate form reliability, concurrent validity, and social validity of the maze probes. Results indicated differences in correct word selections (CWS) between 1-minute, 2-minute, and 3-minute time frames with significant interaction effects noted for the 2-minute maze probe. Alternate form reliability correlation were statistically significant and moderately strong (r = .47 to .71). Concurrent validity correlations between the STAR Reading norm referenced test (computer adaptive reading comprehension test) and CBM-maze probes yielded statistically significant and moderate correlations (r = .30 to .50). Tabulations of the assessment rating scale indicated that students perceived maze probes as acceptable measures for reading comprehension. Implications for practice, cautions in interpreting the results, and future directions are discussed. / School Psychology
29

Labirintų generavimo programa / Labyrinth’s Generation Program

Steišiūnas, Aivaras 03 September 2010 (has links)
Tikslas: Sukurti labirintų generavimo programą. Analitinėje dalyje nagrinėjami aspektai: labirintų klasifikacija ir labirintų generavimo algoritmai. Kuriamo produkto prototipai: deadalus 2.2, mazemaker 1.0, mazeworks. Technologinis sprendimas: HTML, Java, XML, PNG. Panaudota programinė įranga: NetBeans, Paint, Microsoft Word, Internet Explorer, Altova Umodel, Natepad++. Naudotos UML diagramos: panaudos atvejų diagrama iliustruoja, kokius veiksmus su programine įranga gali atlikti vartotojas; Veiklos konteksto diagrama – vaizduoja materialiuosius srautus tarp vartotojo ir programinės įrangos; Būsenų diagrama – labirinto būsenos programos veikimo metu; Dvi sekų diagramos – parodo, kokia eilės tvarka atliekami veiksmai labirinto generavimo metu; Dvi veiklos diagramos - detalus algoritmo realizavimas; Klasių diagrama – parodo, kiek yra klasių ir kaip jos siejasi tarpusavyje; Komponentų diagrama – programinės įrangos posistemės. Testavimo apimtis: testuotas generavimas, atvaizdavimas, sprendimas, redagavimas, saugojimas ir įkėlimas. Vartotojo dokumentacijos sudedamosios dalys: apie programą, nustatymai, labirinto generavimas, labirinto įkėlimas iš failo, labirinto išsaugojimas, labirinto vaizdo išsaugojimas, failo struktūra, labirinto sprendimas, labirinto kūrimas, labirinto generavimas. / This is a documentation of maze creation and generation. First of all you will find some history about labyrinths. After is described a maze classification and types of mazes. Also there are five maze generation algorithms. In next chapter are established the requirements for software development. Some information about existing solutions. In third chapter is graphically described code which implements the algorithms. You can find out how algorithms works. How many classes are used in the project and how it's related. Also you can find software test results and user guide.
30

Paths, players, places : towards an understanding of mazes and spaces in videogames

Gazzard, A. January 2010 (has links)
This thesis contributes to the field of academic game studies by reworking and updating the established theories of Espen Aarseth, Janet Murray and Marie-Laure Ryan in understanding the path in videogames. It also draws upon the more recent theoretical discussions of figures such as Jesper Juul, Lev Manovich, Frans Mäyrä and James Newman in order to explore the player’s experience along these paths in the gameworld. By defining a vocabulary of routes through space, the thesis uses the maze in particular as a way of understanding the paths of videogames. The research starts by examining our cultural understanding of the maze within videogames. Various mazes around the UK were walked in order to understand their design and how this may translate into the virtual world of the videogame. The thesis examines the uses of real world mazes through the work of Penelope Doob, and Herman Kern to discuss how the videogame may rework our cultural understanding of the maze due to its increasingly ubiquitous nature. This enables a discussion of maze-paths found within many videogames that are not necessarily categorised by what is often discussed as the maze genre of games. A morphology of maze-paths is devised through comparing the mazes of the real world and the virtual mazes of the videogame. This is achieved by breaking down the maze into separate path types and shows how these paths may link to one another. The thesis argues that the paths of the videogame are generated by the player’s actions. Therefore the focus of this thesis is on the player’s experience along these paths and the objects found at points on them. In acknowledging how to overcome obstacles along the path it is also possible to understand the role of the path in the player’s learning and mastery of the gameworld. This leads to discussions of different types of play experienced by the player in the videogame. Play is separated into what I term purposeful play, being the activities intended by the designer, and appropriated play which is the play formed out of the player’s exploration of the game system. These two terms help to understand player’s incentives for playing along the ruled paths of the gameworld as well as exploring the game’s system further to find new types of play outside of the pre-determined rules. As this thesis is concerned with videogames involving the player’s avatar having a direct relationship with the path, the research also investigates what happens when certain devices break these paths. It was discovered that warp devices reconstruct both temporal and narrative elements within the gamespace, and cause the player’s avatar to temporarily move on tracks through the gameworld. In defining a vocabulary of movement through space on a fixed track, as opposed to a player-determined path, there is a further understanding of the player experience related to each type of route taken in the game. Through an understanding of the maze and defining a vocabulary of maze-paths, tracks and objects found along them, this thesis adds a new contribution to knowledge. It also acknowledges the importance of different types of play within videogames and how these can shape the player experience along the paths of the game.

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