Long-term stability of the hippocampal neural code as a substrate for episodic memory

The hippocampus supports the initial formation and recall of episodic memories, as well as the consolidation of short-term into long-term memories. The ability of hippocampal neurons to rapidly change their connection strengths during learning and maintain these changes over long time-scales may provide a mechanism supporting memory. However, little evidence currently exists concerning the long-term stability of information contained in hippocampal neuronal activity, likely due to limitations in recording extracellular activity in vivo from the same neurons across days. In this thesis I employ calcium imaging in freely moving mice to longitudinally track the activity of large ensembles of hippocampal neurons. Using this technology, I explore the proposal that long-term stability of hippocampal information provides a substrate for episodic memory in three different ways. First, I tested the hypothesis that hippocampal activity should remain stable across days in the absence of learning. I found that place cells – hippocampal neurons containing information about a mouse’s position – maintain a coherent map relative to each other across long time-scales but exhibit instability in how they anchor to the external world. Furthermore, I found that coherent maps were frequently used to represent a different environment and incorporated learning via changes in a subset of neurons. Next, I examined how learning a spatial alternation task impacts neuron stability. I found that splitter neurons whose activity patterns reflected an animal’s future or past trajectory emerged relatively slowly when compared to place cells. However, splitter neurons remained more consistently active and relayed more consistent spatial information across days than did place cells, suggesting that the utility of information provided by a neuron influences its long term stability. Last, I investigated how protein synthesis, known to be necessary for long-term maintenance of changes in hippocampal neuron connection strengths and for proper memory consolidation, influences their activity patterns across days. I found that along with blocking memory consolidation, inhibiting protein synthesis induced a profound, long-lasting decrease in neuronal activity up to two days later. These results combined demonstrate the importance of rapid, lasting changes in the hippocampal neuronal code to supporting long-term memory

Delivering a MOOC using a social networking site: The SMOOC design model

This paper articulates a design model for a SMOOC or Social networking site situated MOOC. A noncredit open online course entitled Social Media Tools and Supporting Your Professional Learning (AUSMT) is one example of a SMOOC that the researchers have designed and delivered. The course was delivered within a social networking site (SNS) group and the learning activities utilized social media tools for content delivery and student engagement. A secondary outcome of the course is a persistent “group” repository of resources and activities for students who have access to the specific SNS. The AUSMT course can be characterized as a type of Massive Open Online Courses (MOOC) as it has similar organization and delivery of learner activities/engagement. Developed using the Networked Learning Framework (NLF), this course is an example of an implementation that makes use of a SNS “group” as an organizational structure and virtual meeting place for learners. One challenge identified in the literature with respect to MOOCs is the lack of control that may be needed for pedagogical or organizational reasons. The SMOOC model addresses this challenge and provides other benefits which make the concept useable in more formalized learning. Additional research detailing the specific student activities and resources resulting in student learning in a SMOOC, as well as how these can be assessed for more formalized learning are topics identified for future research

Applying Constructionist Principles to Online Teacher Professional Development

This report explores the first iteration of a teacher professional development courseletgrounded in constructionist theory and activities. This online teacher professional development(oTPD) courselet provided opportunities for teachers to engage in just-in-time, ongoingTPD within a social networking site for educators. The topic of the oTPD was Roboticsand Hands-on Activities in the Classroom. The courselet was designed for teachers who areinterested in integrating constructionist pedagogies into their practice. Key findings of thefirst delivery of the oTPD courselet point to a need for flexible access, sharing of resources,and support for constructionist pedagogical activities as a PD value for participants. Findingsfurther support the potential for an ongoing online community of practice around roboticsin the classroom. The approach taken in this oTPD courselet of study continues toinform a model of oTPD delivery within a social-networking-enabled environment

Phase Angle Adaptation to Exercise Training in Cancer Patients Undergoing Treatment

Phase angle is a measure of cellular resistance and reactance to bioelectrical impedance analysis. This measurement is useful as a marker of cell membrane integrity and is used as a prognostic marker in several clinical populations. Cancer and its related treatments impact cell membrane integrity, leading to poor cell function. Exercise is shown to increase phase angle, resulting in lowered risk of hospitalization and cardiovascular events. However, the effect of chronic exercise training on phase angle in the cancer population is unclear. Purpose: To assess the effect of chronic exercise on phase angle in cancer patients who are actively undergoing chemotherapy and/or radiation. Methods: A total of 56 cancer patients who were actively undergoing chemotherapy and/or radiotherapy were recruited to participate in a 12 week exercise-based rehabilitation program at the University of Northern Colorado Cancer Rehabilitation Institute. Each participant underwent an initial assessment of physiological parameters, including body composition and phase angle analysis. Results of this assessment were used to develop an individualized exercise prescription. Each participant received prescribed, supervised, one-on-one training from a Clinical Cancer Exercise Specialist, three times per week for one hour each session. After 12 weeks, each participant underwent a follow-up assessment of physiological parameters. Results: After 12 weeks of exercise training, significant increases in whole body (Initial: 4.55 ± 0.72, Follow-up: 4.68 ± 0.68; p = 0.02), right arm (Initial: 4.45 ± 0.76, Follow-up: 4.57 ± 0.72; p = 0.03), and left arm (Initial: 4.28 ± 0.79, Follow-up: 4.39 ± 0.75; p = 0.03) phase angle was observed. Conclusion: This study demonstrates that prescribed exercise training can increase phase angle in cancer survivors even while undergoing chemotherapy and/or radiation treatments. These changes may provide insight into the protective and rehabilitative benefits (e.g., cellular health, membrane integrity, disease risk) that exercise may have in this population

School of Music Holiday Concert

The Kennesaw State University School of Music presents its 2019 Holiday Concert.https://digitalcommons.kennesaw.edu/musicprograms/2277/thumbnail.jp

Kennesaw State University Holiday Concert

Many ensembles from KSU\u27s School of Music come together in the dynamic 2020 Holiday Concert. Selected works include Christmas Classics, traditional works, and contemporary pieces. Presented virtually from Morgan Concert Hall of the Bailey Performance Center.https://digitalcommons.kennesaw.edu/musicprograms/2350/thumbnail.jp

The ACS Survey Of Globular Clusters. V. Generating A Comprehensive Star Catalog For Each Cluster

The ACS Survey of Globular Clusters has used Hubble Space Telescope's Wide-Field Channel to obtain uniform imaging of 65 of the nearest globular clusters to provide an extensive homogeneous data set for a broad range of scientific investigations. The survey goals required not only a uniform observing strategy, but also a uniform reduction strategy. To this end, we designed a sophisticated software program to process the cluster data in an automated way. The program identifies stars simultaneously in the multiple dithered exposures for each cluster and measures them using the best available point-spread function models. We describe here in detail the program's rationale, algorithms, and output. The routine was also designed to perform artificial-star tests, and we ran a standard set of similar to 10(5) tests for each cluster in the survey. The catalog described here will be exploited in a number of upcoming papers and will eventually be made available to the public via the World Wide Web.Astronom

The ACS survey of globular clusters. XIII. Photometric calibration in comparison with Stetson standards

In this study we compare the photometric data of 34 Milky Way globular clusters, observed within the ACS Treasury Program (PI: Ata Sarajedini) with the corresponding ground-based data, provided by the Photometric Standard Field Catalogs of Stetson (2000, 2005). We focus on the transformation between the HST/ACS F606W to V-band and F814W to I-band only. The goal is to assess the validity of the filter transformation equations by Sirianni et al.(2005) with respect to their dependence on metallicity, Horizontal Branch morphology, mass and integrated (V-I) colour of the various globular clusters. Such a dependence is expected due to the fact that the transformation equations are based on the observations of only one globular cluster, i.e., NGC 2419. Surprisingly, the correlation between offset and metallicity is found to be weak, with a low level significance. The correlation between offset and Horizontal Branch structure, as well as total cluster mass is still weaker. Based on the available data we do not find the photometric offset to be linked to multiple stellar populations, e.g., as found in NGC 0288, NGC 1851, and NGC 5139. The results of this study show that there are small systematic offsets between the transformed ACS- and observed ground based photometry, and that these are only weakly correlated, if at all, with various cluster parameters and their underlying stellar populations. As a result, investigators wishing to transform globular cluster photometry from the Sirianni et al.(2005) ground-based V, I system onto the Stetson (2000) system simply need to add 0.040 (+/-0.012) to the V-band magnitudes and 0.047 (+/-0.011) to the I-band magnitudes. This in turn means that the transformed ACS (V-I) colours match the ground-based values from Stetson (2000) to within ~0.01 mag.Comment: 28 pages, 14 figures, accepted for publication in ApJ

The ACS Survey Of Galactic Globular Clusters. VI. NGC 6366: A Heavily Stripped Galactic Globular Cluster

We have used observations obtained as part of the Hubble Space Telescope/ACS Survey of Galactic globular clusters (GCs) to construct a color-magnitude diagram for the bulge cluster, NGC 6366. The luminosity function derived from those data extends to M(F606W) similar to 9, or masses of similar to 0.3 M(circle dot). Unlike most GCs, the mass function peaks near the main-sequence turnoff with significantly fewer low-mass stars even after correction for completeness and mass segregation. Using a multimass King model, we extrapolate the global cluster behavior and find the global mass function to be poorly matched by a power law, with a particular deficit of stars with masses between 0.5 and 0.7 M(circle dot). We briefly discuss this interesting anomaly within the context of tidal stripping.NASA GO-10775, 5-26555Space Telescope Science InstituteInstituto de Astrofisica de Canarias P3-94Ministry of Education and Science of the Kingdom of Spain AYA-2008-67913Astronom

The ACS Survey of Galactic Globular Clusters. viii. Effects of Environment on Globular Cluster Global Mass Functions

We have used observations obtained as part of the Hubble Space Telescope/ACS Survey of Galactic Globular Clusters to construct global present-day mass functions for 17 globular clusters utilizing multi-mass King models to extrapolate from our observations to the global cluster behavior. The global present-day mass functions for these clusters are well matched by power laws from the turnoff, ≈0.8 M ☉, to 0.2-0.3 M ☉ on the lower main sequence. The slopes of those power-law fits, α, have been correlated with an extensive set of intrinsic and extrinsic cluster properties to investigate which parameters may influence the form of the present-day mass function. We do not confirm previous suggestions of correlations between α and either metallicity or Galactic location. However, we do find a strong statistical correlation with the related parameters central surface brightness, μ V , and inferred central density, ρ0. The correlation is such that clusters with denser cores (stronger binding energy) tend to have steeper mass functions (a higher proportion of low-mass stars), suggesting that dynamical evolution due to external interactions may have played a key role in determining α. Thus, the present-day mass function may owe more to nurture than to nature. Detailed modeling of external dynamical effects is therefore a requisite for determining the initial mass function for Galactic globular clusters