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Background: Science poses a unique challenge to the elementary curriculum landscape, because traditionally elementary teachers report low levels of self-efficacy in this subject. Instructional leadership in elementary science therefore, becomes important for a successful integration of a new science education agenda. The Next Generation Science Standards (NGSS) are K-12 science content standards available for adoption by states and school districts in the U.S. Principals are important actors during policy implementation since they are charged with assuming the role of an instructional leader for their teachers in all subject areas. Purpose: This study gathered self-reported survey data from public elementary principals that pertain to their background and experiences in science, and then relate these data to their levels of self-efficacy and instructional leadership capacity for science. The study answers the following three research questions: (1) What type of science backgrounds do elementary principals have? (2) What indicators predict if elementary principals will engage in instructional leadership behaviors in science? (3) Does self-efficacy mediate the relationship between science background and capacity for instructional leadership in science? Data Collection and Analysis: A questionnaire was created by combining two existing subscales to measure instructional leadership practices and self-efficacy in science, and also a series of objective questions to address principals’ background experiences and demographic information. Public school elementary principals serving in 13 states that formally adopted the NGSS through legislative action provided the data analyzed in this study (N = 667). The survey data were analyzed quantitatively for descriptive statistics to answer the first research question, inferential statistics through an Ordinary Least Squares (OLS) hierarchal regression analysis to answer the second, and a mediation analysis to answer the third research question. Findings: The sample data show that 21% of the elementary principals have a formal science degree and 26% have a degree in a STEM field. Most principals have not had recent experience teaching science (75.86%), nor were they every strictly a science teacher (86.66%). The hierarchical regression analysis suggests that there is evidence that both demographic and experiential variables predict instructional leadership practices in science. The analysis also suggests that self-efficacy is a mediating variable for principals’ science teaching experiences related to instructional leadership behaviors. Conclusions: The data from this research reveal potential (a) leadership development opportunities, (b) training and recruitment needs of school districts, (c) areas in need of attention in principal preparation programs, and (d) directions for policy implementation to leverage principal capacity. The findings provide evidence to assist in identifying ways elementary principals could be better prepared to be instructional leaders for their teachers, especially in those settings where the implementation of the NGSS is underway.

In the French Caribbean islands of Guadeloupe and Martinique, the father is stigmatized because he is often absent from the family structure. The possible reasons for his absence can be found in the Code Noir [Black Code] promulgated in 1685 in the French Caribbean colonies and in 1724 in Mauritius and Reunion. The Black Code is intended to regulate the lives of slaves in the colonies by monitoring their lifestyles, their religion (imposed Catholicism) and their status as commodities. More important, the legal document positions women at the head of the household by defining the legal status of children according to that of their mother, and subsequently denying the black man a role in the family except as procreator. Article XII of the Code stipulates that [c]hildren born in marriages between slaves will belong to the masters of the female slaves and not to those of the husband". As for article XIII, it claims that "[i]f the husband married a free woman, their children, boys and girls, will be free like her no matter the status of their father but if the father is free and the mother is a slave, the children will be slaves like their mother". Thus, it is because she is deprived of a spouse who is her equal that the black woman must occupy the two functions of both mother and father in the family. After the abolition of slavery, French colonial authorities called for cheap and abundant labor, coming mainly from India, to replace the former slave population on the plantations. The arrival of Indian indentured servants (called Coolies), initially hired for five years, transformed the existing social, cultural and economic structure of the islands because Indians replaced the former African slaves at the bottom of the social ladder. Consequently, like the former slaves of African descent, Indian laborers experienced a new language, a new land, new standards and more importantly, they were subjected to the laws of the Black Code that were not originally applicable to them, but still prevailed even after the abolition. Therefore, what I call a Black Code mentality, articulated in the passage from African slavery to Indian indentureship, is what determines the relationships between men and women, of both African and Indian origins. The mentality extends to the post-slavery, colonial and postcolonial situations of these societies of the Caribbean and the Indian Ocean, until today. The purpose of my dissertation is to examine the persistence of a widespread monoparental pattern in these regions as a logical consequence of the application of the 1685/1724 Code Noir. My thesis underscores the rearticulation and renegotiation of the role of the father, of African and Indian descent, in both his family structure and his community of origin, as a function that was codified, legitimized and predetermined by the Black Code. Besides, I contend that the ethnic, social and cultural components of these societies are, in many respects, relayed by social laws and decrees that have had a significant impact on family structures in the Caribbean and the Indian Ocean. Through the critical analysis of contemporary literatures and films from Guadeloupe, Martinique, Reunion and Mauritius, my thesis compares two different geographical areas that are legally connected by the Black Code during slavery and evolve, after the abolition, towards a different political status: Guadeloupe, Martinique and Reunion became French Overseas Departments in 1946 whereas Mauritius became independent in 1968. This comparison allows me to question four major critical concepts pertaining to postcolonial theory: Creolization, Creoleness, Indianness and Coolitude, as they relate to the identity politics of two populations present in the Caribbean and the Indian Ocean: the African diaspora and the Indian diaspora.

The accuracy of modern digital human models has led to the development of human simulation engines capable of performing a complex analysis of the biometrics and kinematics / dynamics of a digital model. While the capabilities of these simulations have seen much progress in recent years, they are hindered by a fundamental limitation regarding the diversity of the models compatible with the simulation engine, which in turn results in a reduction in the scope of the applications available to the simulation. This is typically due to the necessary implementation of a musculoskeletal structure within the model, as well as the inherent mass and inertial data that accompany it. As a result a significant amount of time and expertise is required to make a digital human model compatible with the simulation. In this research I present a solution to this limitation by outlining a process to develop a set of mutually compatible human models that spans the range of feasible body shapes and allows for a “free” exploration of body shape within the shape manifold. Additionally, a method is presented to represent the human body shapes with a reduction of dimensionality, via a spectral shape descriptor, that enables a statistical analysis that is both more computationally efficient and anthropometrically accurate than traditional methods. This statistical analysis is then used to develop a set of representative models that succinctly represent the full scope of human body shapes across the population, with applications reaching beyond the research-oriented simulations into commercial human-centered product design and digital modeling.

Previous natural observations have found a robust correlation between infants’ spontaneous gesture production and vocabulary development: the onset and frequency of infants’ pointing gestures are significantly correlated to their subsequent vocabulary size (Colonnesi, Stams, Koster, & Noom, 2010). The present study first examined the correlations between pointing and vocabulary size in an experimental setting, and then experimentally manipulated responses to pointing, to investigate the role of pointing in infants’ forming word-object associations. In the first experiment, we elicited 12- to 24-month old infants’ pointing gestures to 8 familiar and 8 novel objects. Their vocabulary was assessed by the MacArthur Communicative Development Inventory (MCDI): Words and Gestures. Results showed that 12-16 month old infants’ receptive vocabulary was positively correlated to infants’ spontaneous pointing. This correlation, however, was not significant in 19-24 month old infants. This experiment thus generalizes the previous naturalistic observation findings to an experimental setting, and shows a developmental change in the relation between pointing and receptive vocabulary. Together with prior studies, it suggests a possible positive social feedback loop of pointing and language skills in infants younger than 18 months old: the bigger vocabulary size infants have, the more likely they point, the more words they hear, and then the faster they develop their vocabulary. In the second experiment, we tested whether 16-month-old infants’ pointing gestures facilitate infants’ word learning in the moment. Infants were randomly assigned to one of three conditions: the experimenter labeled an unfamiliar object with a novel name 1) immediately after the infant pointed to it (the point contingent condition); 2) when the infant looked at it; or 3) at a schedule predetermined by a vocabulary-matched infant in the point contingent condition. After hearing the objects’ names, infants were presented with a word learning test. Results showed that infants successfully selected the correct referent above chance level only in the point contingent condition, and their performance was significantly better in the point contingent condition than the other two conditions. Therefore, only words that were provided contingently after pointing were learned. Taken together, these two studies further our understanding of the correlation between early gesture and vocabulary development and suggest that pointing plays a role in early word learning.

This is a sampling of costume and lighting design work for theatre as presented at the University of Iowa.

The vibraphone has been associated with improvisation since the beginning of the twentieth century. There have been many documents designed to guide students in both technical studies on the vibraphone and improvisational skills. This document includes three instructional courses dedicated to the teaching of those skills. It uses only materials found on the website vibesworkshop.com, which is curated by Philadelphia-based vibist Tony Miceli. These courses are designed for undergraduate college students through advanced amateurs or professionals. Many college curricula include insufficient vibraphone studies or do not include them at all. Currently, most college percussion studio professors specialize in areas other than vibraphone. Because of their lack of experience, professors supplement their teaching methods with materials that approach vibraphone in a subpar manner. Such materials instruct students to internalize and regurgitate bland materials instead of creating and developing their own ideas. The vibesworkshop.com courses aim to assist those professors and students by replacing older instructional materials with a system that cultivates students' affinity with the vibraphone, allowing them to continue contributing to the online vibes community after participation in these courses.

Infection with Plasmodium species leads to nearly 400,000 deaths a year despite widespread use of mosquito bed nets, insecticides, and anti-malarial drugs. To date, there is not a licensed vaccine capable of providing complete protection from Plasmodium infection to vaccinees. Whole parasite vaccination of humans and rodents can achieve complete protection in vaccines, but the dose of sporozoites, number of administrations, and production concerns in generating these types of vaccines will likely prevent these approaches from achieving worldwide use. However, the protective immunological responses against Plasmodium parasites engendered by these vaccination approaches can be studied and aid in the development of advanced subunit vaccines against Plasmodium. Using rodent models of malaria to elucidate the features of protective immunity engendered by whole parasite vaccination, it has been repeatedly shown that CD8 T cell responses directed against liver-stage parasite antigens can provide complete protection with some contribution by CD4 T cells and antibody responses depending on the model system studied. However, the quantatitive and qualitative requirements for CD8 T cell immunity against Plasmodium remains largely undefined. To enhance our understanding of how to generate protective immunity against Plasmodium, I have utilized rodent models of malaria to study the superior protection afforded from single-dose vaccination with virulent sporozoites administered under prophylatic chloroquine-cover, referred to as chemoprophylaxis sporozoites (CPS) vaccination, compared to the well-studied approach of administering radiation-attenuated Plasmodium sporozoites (RAS). RAS vaccination has long been considered the “gold standard” in vaccination due the ability of RAS vaccination to engender complete protection following sporozoite challenge of vaccinated humans and rodents. However, CPS vaccination is arguably a superior vaccination approach since it can achieve protection through less vaccine administrations relative to RAS vaccination, but the immunological basis of this enhanced CPS vaccine-induced immune response was unclear. In my study, I utilized a stringent host/parasite model to find that C57Bl/6 mice administered CPS vaccination with P. yoelii sporozoites elicit substantially higher parasite-specific CD8 T cell responses than RAS vaccination, but CPS-induced CD8 T cells were not necessary for protection following liver-stage sporozoite or blood-stage parasite challenge. CPS vaccination resulted in a low grade, transient parasitemia shortly following cessation of chloroquine treatment, which lead to the generation of potent antibody responses to blood-stage parasites; this blood-stage parasite-specific antibody response correlated with sterilizing protection in sporozoite challenged CPS-vaccinated mice. Therefore, my data provide a mechanistic basis for enhanced protective immunity elicited by single-dose CPS vaccination in a rodent model that is independent of CD8 T cells. The other portion of my work examines how CD8 T cell specificity impacts protective capacity against Plasmodium. I show that robust CD8 T cell responses of similar phenotype are mounted following prime-boost immunization against three novel Plasmodium berghei protein-derived epitopes in addition to a previously described protective, immunodominant epitope. I show that only CD8 T cells specific to sporozoite surface-expressed protein-derived epitopes, but not the intracellular protein-derived epitopes, are efficiently recognized by sporozoite-infected hepatocytes in vitro. These results suggest that antigenic targets must be efficiently presented by infected hepatocytes for CD8 T cells to eliminate liver-stage Plasmodium infection and proteins expressed on the surface of sporozoites may be good target antigens for protective CD8 T cells. Collectively, my work highlights the ability to generate protective CD8 T cell independent and dependent immunity against Plasmodium infections, whether achieved through potent blood-stage-specific antibody responses, or via numerically large monospecific CD8 T cell responses that target parasite antigens that are efficiently presented during liver-stage infection. These studies are relevant in understanding how to efficiency engender protective immunity against Plasmodium, and could aid in the advancement of subunit vaccination approaches that generate immunity through the priming of responses from multiple arms of the immune response, targeting both the liver- and blood-stages of Plasmodium.

This dissertation examines the “buffer effect,” an important but understudied feature of computer-mediated communication (CMC). Research on the buffer effect posits that CMC venues provide a buffering “screen” that users can literally and figuratively hide behind. The buffer can make people feel more comfortable during interactions, and is theorized to be especially relevant in contexts where self-presentation is threatened. This study employs transgressions as ideal sites for examining the buffer effect because of the high level of threatened self-presentation involved therein. The current project tests whether people perceive different levels of a buffer in different channels of communication, and how the buffer effect is related to other widely studied features of CMC, such as interactivity, synchronicity, and social presence. It also tests outcomes of the buffer effect for both senders and receivers of transgressive messages. Specifically, it posits that the buffer effect is beneficial to senders of transgressive messages, and is detrimental to receivers of those messages. Furthermore, in the context of transgressions, the amount of responsibility that a person takes for the transgression is a factor that influences how others perceive the situation. Therefore, the current study also considers receivers' perceptions of the level of responsibility the sender accepts, and specifically posits that senders' higher levels of responsibility are associated with positive outcomes for receivers. The dissertation is comprised of two studies. In Study One, participants responded to a survey to test their perceptions of the buffer effect and of other features of CMC in various channels. Participants also responded to a hypothetical situation to indicate how the buffer effect influences outcomes when sending a transgressive message. Study Two employed an experimental procedure to test how senders and receivers perceive the buffer effect in actual interactions, as well as how senders' acceptance of responsibility affects outcomes for receivers. Half of the participants were assigned the role of sender and were trained to provide a transgressive message to the receiver. Specifically, senders were trained to say that they had to leave the experiment early without completing the study, rendering the receiver ineligible for course credit. Both the channel (i.e., face-to-face, instant messaging, text messaging) and the senders' level of responsibility (i.e., low/high) were manipulated. Results suggested that the buffer effect manifests in different levels for various channels of communication, such that face-to-face environments provide the lowest buffer, followed by video chat, social networking sites, instant messaging, and email. Text messaging provides the highest buffer. The buffer effect is negatively related to other features of CMC (i.e., synchronicity, interactivity, and social presence) for low-buffer channels, and is either positively or not significantly related to these features in high-buffer channels. Results also suggest that the buffer effect is associated with benefits for senders in both hypothetical and actual interactions, but does not affect receivers' outcomes. Receivers' perceptions of the level of responsibility that senders accept affects receivers' outcomes, but only within environments with a low and moderate buffer. These results extend research on CMC and on transgressive communication. Results also offer practical implications for how people might elect to use channels and modify the content of their message when communicating a transgression to a friend.

Prostate cancer presents a significant paradox: it is very common, yet rarely fatal. To wit, the prostate is the most common non-skin tissue for cancer diagnosis in men in the United States. Despite its high incidence, fatal malignancy occurs in only a small fraction of diagnosed men. The fatal cases are characteristically defined by distant spread in the body, also known as metastasis. In order to metastasize a cancer cell must complete several sequential steps. These include degradation of and invasion through the epithelial basement membrane, typically through the loss of static intracellular adhesions with fellow epithelial cells; entrance into the blood stream (intravasation); survival within circulation; exit from the blood stream upon arrival at a new tissue (extravasation); and survival and colonization at the secondary site. At the time of diagnosis, it is not currently possible to accurately predict future metastasis and thereby clinicians cannot delineate those men at high risk for fatal disease from the vast majority of men who are likely to experience an indolent disease course. Consequently, we examined the behavior of cancer cells in several steps of the metastatic cascade. In doing so, we uncovered both molecular and biophysical characteristics of cancer cells that may facilitate successful metastatic dissemination and tumor outgrowth. Epithelial-to-mesenchymal transition (EMT) is physiological process of transdifferentiation that is normally initiated during vertebrate development, but has recently been implicated in tumor development, progression, and metastases. The EMT program results in dramatic changes, including the exchange of epithelial for mesenchymal markers, altered cellular morphology, and gain of motility. EMT-like cellular alterations have been implicated most strongly in the metastasis steps of invasion and survival of cells at primary tumors sites. How EMT-like changes may facilitate survival and growth in the microenvironment of a micrometastatic niche has been less clearly elucidated. Consequently, we evaluated how EMT-like changes may affect the survival and subsequent outgrowth of prostate cancer cell lines following restrictive growth conditions. We observed that EMT-like cells as compared to their more epithelial counterparts displayed enhanced maintenance of their proliferative potential following extended culture in nutrient restriction. This phenotype depended on an EMT-associated increase in autophagy. Notably, the post-stress outgrowth phenotype could be conferred through a paracrine signaling mechanism that may involve autophagy-derived exosome-like extracellular vesicles. These studies demonstrated that EMT-like cells have a resistance to nutrient restriction through enhanced autophagy and may have uncovered a novel autophagy-dependent exosomal secretion pathway. Metastatic efficiency is thought to be strongly limited by the destruction of circulating tumor cells by the hemodynamic shear forces within the vasculature. However, such a persistent belief has little appropriate published experimental evidence. We developed an in vitro assay to expose cells to fluid shear stress (FSS). By monitoring the viability of the cells, we determined that transformed cells had a highly conserved ability to resist even very high FSS. The mechanism depended on the capacity to patch membrane defects, extracellular calcium, and a dynamic cytoskeleton. We also observed a stiffening of cancer cell membranes after exposure to FSS. Taken together, these studies expand the understanding of how cancer cells survive in circulation and indicate that metastatic efficiency is less limited by hemodynamic forces than previously thought. The steps of hematogenous metastasis between intravasation and extravasation necessitate the existence of circulating tumor cells (CTCs). Collection, enumeration, and study of CTCs have the potential to serve as a "liquid biopsy" of the metastatic cascade. In prostate cancer, the enumeration of CTCs by detection of the expression of epithelial markers has displayed limited clinical utility. We hypothesized that the prognostic value of CTC number may be enhanced by detection of cells which have undergone the pro-metastatic EMT-like program. We developed a flow cytometry-based experimental assay for enumeration of CTCs using epithelial (EpCAM) and mesenchymal-like (N-cadherin) surface proteins. We detected from prostatectomy patients before and after surgery events expressing EpCAM, N-cadherin, and both. However, the detection of background events from healthy control subjects was unacceptably high. These studies support the idea of mesenchymal-like tumor cells in circulation, but will require further assay development for reliable conclusions to be drawn. In sum, the work described above has provided descriptive and mechanistic insight to molecular and biophysical properties that may facilitate prostate cancer metastasis. It is our hope that these data will result in the development of relevant preventative, diagnostic, and therapeutic clinical strategies for prostate cancer.