Matching Items (70)

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Elucidating the Effects of PRAS40 on Learning and Memory

Description

The mammalian target of rapamycin (mTOR) is integral in regulating cell growth as it maintains a homeostatic balance of proteins by modulating their synthesis and degradation. In the brain, mTOR

The mammalian target of rapamycin (mTOR) is integral in regulating cell growth as it maintains a homeostatic balance of proteins by modulating their synthesis and degradation. In the brain, mTOR regulates protein-driven neuroplastic changes that modulate learning and memory. Nevertheless, upregulation of mTOR can cause detrimental effect in spatial memory and synaptic plasticity. The proline-rich Akt-substrate 40 kDa (PRAS40) is a key negative regulator of mTOR, as it binds mTOR and directly reduces its activity. To investigate the role of PRAS40 on learning and memory, we generated a transgenic mouse model in which we used the tetracycline-off system to regulate the expression of PRAS40 specifically in neurons of the hippocampus. After induction, we found that mice overexpressing PRAS40 performed better than control mice in the Morris Water Maze behavioral test. We further show that the improvement in memory was associated with a decrease in mTOR signaling, an increase in dendritic spines in hippocampal pyramidal neurons, and an increase in the levels of brain-derived neurotrophic factor (BDNF), a neurotrophin necessary for learning and memory. This is the first evidence that shows that increasing PRAS40 in the mouse brain enhances learning and memory deficits.

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Date Created
  • 2018-05

Memory Wipe

Description

Memory Wipe is a 22 minute, video art piece that utilizes home movie footage filmed on VHS and 8mm, as well as television and cartoon ephemera, to explore the way

Memory Wipe is a 22 minute, video art piece that utilizes home movie footage filmed on VHS and 8mm, as well as television and cartoon ephemera, to explore the way in which personal memory is constructed and altered through the process of recording and viewing. Three recent events in my life inspired work: the discovery of a box containing my favorite childhood media, the revelation that I am the last male of my family, and the impending sale of my family's farmland. My mother never used a video camera, insisting that her childhood was lost in footage filmed but never watched. It should also be noted that not once do I appear in this piece; therefore, I decided to extract myself from the narrative. Rather than simply guide the audience along with anecdotes from my life, I instead invite viewers to draw their own meanings and create their own nostalgias from the piece. Originally, Memory Wipe was to be accompanied by live narration, but all things considered, I thought I would let it speak for itself. Video link: https://www.youtube.com/watch?v=-E42a6Koma4

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Created

Date Created
  • 2015-05

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Current Sensing Amplifier Design for RRAM Crossbar Arrays

Description

Resistive Random Access Memory (RRAM) is an emerging type of non-volatile memory technology that seeks to replace FLASH memory. The RRAM crossbar array is advantageous in its relatively small cell

Resistive Random Access Memory (RRAM) is an emerging type of non-volatile memory technology that seeks to replace FLASH memory. The RRAM crossbar array is advantageous in its relatively small cell area and faster read latency in comparison to NAND and NOR FLASH memory; however, the crossbar array faces design challenges of its own in sneak-path currents that prevent proper reading of memory stored in the RRAM cell. The Current Sensing Amplifier is one method of reading RRAM crossbar arrays. HSpice simulations are used to find the associated reading delays of the Current Sensing Amplifier with respect to various sizes of RRAM crossbar arrays, as well as the largest array size compatible for accurate reading. It is found that up to 1024x1024 arrays are achievable with a worst-case read delay of 815ps, and it is further likely 2048x2048 arrays are able to be read using the Current Sensing Amplifier. In comparing the Current Sensing Amplifier latency results with previously obtained latency results from the Voltage Sensing Amplifier, it is shown that the Voltage Sensing Amplifier reads arrays in sizes up to 256x256 faster while the Current Sensing Amplifier reads larger arrays faster.

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Date Created
  • 2016-12

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The first in its class? The cognitive effects of the contraceptive hormone drospirenone when given with and without an estrogen

Description

Drospirenone (DRSP) is a novel, pharmacologically unique synthetic progestin with properties more similar to the endogenous progestogen, progesterone, than any other progestin currently on the market. While a significant amount

Drospirenone (DRSP) is a novel, pharmacologically unique synthetic progestin with properties more similar to the endogenous progestogen, progesterone, than any other progestin currently on the market. While a significant amount of research has been conducted on the risks associated with DRSP, the impact of DRSP on cognition, especially in reference to learning and memory, is not well understood. However, it is imperative to fully understand the cognitive effects of DRSP, both alone and in combination with EE (as taken in a combined oral contraceptive [COC]), so that women and their physicians can make a fully-informed decision when deciding to take a DRSP-containing COC. Study 1 examined the effects of three doses of DRSP in order to determine the optimal dose for combining with EE, and found that the medium dose of DRSP (30 µg/day) enhanced spatial working memory performance. In Study 2, the medium dose of DRSP from Study 1 was combined with low (0.125 µg/day) and high (0.3 µg/day) doses of EE to examine the effects of DRSP as taken with EE in a COC. The results from Study 2 indicated that when DRSP was combined with a low, but not high, dose of EE, spatial working memory impairments were seen at the highest working memory load. Anxiety-like behavior was evaluated using the OFT, and DRSP was shown to decrease measures of anxiety-like behavior. Additionally, while treatment with a high dose of EE decreased several measures of anxiety-like behavior, a low dose of EE did not, suggestive of a dose response. Taken together, the findings presented from both studies suggest that some of the cognitive effects of the combination of DRSP with EE are different than those of either hormone administered on its own. Further exploration in a preclinical, ovary-intact animal model is a next step to fully understand these effects in the translational context of a contraceptive, given that women taking an EE-DRSP combination are typically ovary-intact.

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Created

Date Created
  • 2017-05

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Mood Influences Working Memory Capacity

Description

Working memory is the cognitive system responsible for storing and maintaining information in short-term memory and retrieving cues from long-term memory. Working memory capacity (WMC) is needed for goal maintenance

Working memory is the cognitive system responsible for storing and maintaining information in short-term memory and retrieving cues from long-term memory. Working memory capacity (WMC) is needed for goal maintenance and to ignore task-irrelevant stimuli (Engle & Kane, 2003). Emotions are one type of task-irrelevant stimuli that could distract an individual from a task (Smallwood, Fitzgerald, Miles, & Phillips, 2009). There are studies that show there is a relation between emotions and working memory capacity. The direction of this relationship, though, is unclear (Kensinger, 2009). In this study, emotions served as a distractor and task performance was examined for differences in the effect of emotion depending on participants' working memory capacity. The participants watched a mood induction video, then were told to complete a complex-span working memory task. The mood induction was successful- participants watching the negative emotional video were in a less positive mood after watching the video than the participants that watched a neutral video. However, the results of the complex-span working memory task showed no significant difference in the results between participants in the negative versus neutral mood. These results may provide support to an alternative hypothesis: cognitive tasks can diminish the effects of emotions (Dillen, Heslenfeld, & Koole, 2009).

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Created

Date Created
  • 2017-05

Attention and Memory Problems in Everyday Life Among Young Adult Cannabis Users

Description

The need to fully understand the possible consequences of young-adult cannabis use has become increasingly critical as a result of major cannabis policy changes. The purpose of this study was

The need to fully understand the possible consequences of young-adult cannabis use has become increasingly critical as a result of major cannabis policy changes. The purpose of this study was to determine if young-adult users exhibit cognitive deficits on laboratory-based tests and memory and attention deficits in everyday life. Participants were 152 students from a large U.S. university enrolled in introductory psychology courses and the top and bottom 10% of the 12-item Yale University PRIME Screening Test for psychotic-like experiences. Participants were asked about their cannabis use and were given six cognitive tests spanning executive function and memory. To test functional impairment in memory and attention, participants were asked to nominate informants (people who knew them well) and these rated the participants on an attention problems scale of four items and a memory problems scale of three items. Results showed that individuals who used cannabis more frequently were rated as having more attention and memory problems and that, consistent with prior research, more frequent cannabis use was associated with worse memory test performance, though the association was not present between frequency of use and executive function test performance. Additionally, it was found that informant-reported attention problems were associated with poorer performance on two of the executive function cognitive tests. The present findings suggest that individuals who use cannabis more frequently experience noticeable memory and attention problems in everyday life, despite the lack of significant correlation between this functional impairment and cognitive test performance. Informant reports, therefore, may be useful in future research for understanding or predicting cognitive impairment in young adults.

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  • 2016-12

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An Evaluation of the Cognitive Effects of Clinically Used Combination Hormone Therapy

Description

Estradiol (E2) and Levonorgestrel (Levo) are two hormones commonly used in hormone therapy (HT) to decrease symptoms associated with menopause. Both of these hormones have been shown to have beneficial

Estradiol (E2) and Levonorgestrel (Levo) are two hormones commonly used in hormone therapy (HT) to decrease symptoms associated with menopause. Both of these hormones have been shown to have beneficial effects on cognition when given alone in a rodent model of menopause. However, it is unknown whether these hormones, when taken in combination, are beneficial or harmful to cognition. This is a critically important question given that these hormones are most often given in combination versus separately. This thesis is composed of two studies examining the cognitive effects of E2 and Levo using a rat model of surgical menopause. Study 1 assessed how the dose of E2 treatment in rats impacted cognitive performance, and found that low dose E2 enhanced working memory performance. Next, based on the results from Study 1, Study 2 used low dose E2 in combination with different doses of Levo to examine the cognitive effects of several E2 to Levo ratio combinations. The results from Study 2 demonstrated that the combination of low dose E2 with a high dose of Levo at a 1:2 ratio impaired cognition, and that the ratio currently used in HT, 3:1, may also negatively impact cognition. Indeed, there was a dose response effect indicating that working and reference memory performance was incrementally impaired as Levo dose increased. The findings in this thesis suggest that the E2 plus Levo combination is likely not neutral for cognitive function, and prompts further evaluation in menopausal women, as well as drug discovery research to optimize HT using highly controlled preclinical models.

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Date Created
  • 2016-12

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Sculpture of Resistance: Symbolic Reparations in Post-Apartheid Art in District Six, Cape Town

Description

This essay outlines public art in District Six, Cape Town, South Africa and how public art can manifest itself to reconstruct cultural memory, provide a space for healing and processing

This essay outlines public art in District Six, Cape Town, South Africa and how public art can manifest itself to reconstruct cultural memory, provide a space for healing and processing collective trauma, and produce critical public pedagogy. Public art also has the power to provide symbolic reparations, an approach proposed by the Truth and Reconciliation Committee but one that I believe was not properly or effectively handled by the South African government. In this paper I will cover two specific public art projects and one established museum, all three framed within the context of both institutionalized and individual approaches to public art. Such projects extend to the District Six Museum, the Public Arts Festival of 1997, and the Black Arts Collective visual-media project, ‘Returning the Gaze.’ This paper proposes that the concept of public art should be reconsidered; I argue that its purpose is not to solely beautify urban landscapes, but rather to provide platforms for survivors of abuse to relay their experiences, influence popular discourse, and challenge hegemonic notions of race, identity, and culture.

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Date Created
  • 2020-05

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The Perils of Periodization: Memory and Intertextuality between the Achaemenid and Hasmonean Dynasties

Description

Historians periodize the ancient past in order to better facilitate its study. From period to period, the ideas, figures and discussions that define as distinct become trapped within the walls

Historians periodize the ancient past in order to better facilitate its study. From period to period, the ideas, figures and discussions that define as distinct become trapped within the walls that historians have artificially imposed. However, history is not nearly so clean, and that which we have selected to define each period may be carried forward beyond their period or retrojected into a past period. This thesis will explore how ideas and concepts travel backward and forward in time, through construction of memory and through cultural hybridity and intertextuality, by casting the royal ideology of the Hasmoneans as seen in I and II Maccabees in light of the legacy and memory of the Achaemenid Persian Dynasty. The first two chapters discuss the development of Achaemenid Royal Ideology, beginning with the conquest of Babylon by Cyrus II and his adoption of the ancient Near Eastern “Restorer of Order” literary paradigm to restructure the past for political legitimacy, and continues to the rise to power of Darius I, who in many ways built off of the Restorer of Order paradigm but innovated in establishing a new, more equal relationship between the divine and the royal receiver of the divine mandate to rule. The second two chapters begin with a discussion of II Maccabees and its use of the Restorer of Order paradigm, but goes more into detail on how it constructs an “idyllic past” that not only connects the Maccabees to mythic biblical figures but also reconstructs the Persian past of the Jewish people that mirrors and legitimizes Hasmonean royal ideology in sacred time, and ends with a discussion of how the innovations of Darius might have shaped the eventual conflict between the Hasmonean dynasty and their opponents over the correct responsibilities of the High Priest in Jerusalem.

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Date Created
  • 2020-05

Reevaluating the Relationship between Contingency and Congruency via the Flanker Task

Description

The purpose of this project was to extend Whitehead 2016 to determine what neural substrates supported conflict-mediated learning. Unfortunately, as a result of the COVID-19 pandemic we were unable

The purpose of this project was to extend Whitehead 2016 to determine what neural substrates supported conflict-mediated learning. Unfortunately, as a result of the COVID-19 pandemic we were unable to address this. To repurpose the collected data, an analysis of which features of the Flanker task subjects were learning was conducted. Specifically, we wanted to know if subjects were learning by using the flanking stimuli to predict the central target or vice versa. Over 14 blocks comprised of 120 trials, we found that subjects made more stroop errors than flanker and target errors, indicating subjects were responding to stimuli in context of the flanker rather than the stroop effect.

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Date Created
  • 2020-12