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Eco-geographic patterns of genetic diversity of African rice, Oryza glaberrima, in Benin (West Africa)
No full textGenetic erosion is a phenomenon that is currently of concern because of the loss of biodiversity, especially from crop populations in centers of origin and diversity due to a narrowing of the genetic base caused by various factors. The rate of erosion depends on the crop, the region, and the specific environment and cropping conditions. There is now a need for new gene sources and reinstatement of genetic diversity. Studies on the genetic diversity available, especially in traditional agricultural ecosystems are therefore needed. The genus Oryza contains 22 species: two are cultivated, Asian rice (Oryza sativa) and African rice (Oryza glaberrima) and 20 are wild. In West Africa, which is considered the center of origin of Oryza glaberrima, the two cultivated species are often grown alongside one another on farmers' fields. Yet, few investigations have been undertaken to study African rice landraces (traditional varieties) in West Africa, and the impact of the introduction of new varieties on their diversity. The main goal of this dissertation is to explore the spatial distribution of Oryza glaberrima and its landraces managed at the farmer's level in different geographical regions and help supply a basis for further investigations for the management of Oryza glaberrima landraces in Benin, West Africa. Various methodologies were utilized and focused on three modes of inquiry: the collection of socio-economic data using 150 ethnographic surveys; molecular analysis of 253 rice accessions collected in the field from farmers using 12 fluorescent labeled microsatellites organized in 3 panels; and the utilization of Geographic Information Systems to integrate physical and socio-economic conditions to identify the areas of unique and high diversity. The results show that 1) landraces and modern cultivars are grown in conjunction on farmers' fields, 2) peak genetic diversity occurs in areas with intermediate environmental variables, and 3) a systematic rather than opportunistic targeting of populations and areas for both ex situ and in situ conservation can be elaborated. These results can be used as part of a national program to complement the rice germplasm collection and the genetic analysis ongoing in Benin, to effectively target the area of greatest diversity, and to identify the most effective strategy for the conservation of this diversity. Keywords: Agrobiodiversity, Ethnographic surveys, ex situ and in situ conservation, Genetic diversity, Landraces, Geographic Information Systems, Oryza glaberrima, Oryza sativa
Ergodic Ontogeny: Influences of Interactive Media on Identity
No full textVideo games represent the future of storytelling, changing the impact of cultural narratives in important ways through a process of learning and internalization of game content that alters players’ perceptions of self and reality. Continued rigorous research of interactive media is necessary because of the speed at which technology changes its capabilities and the dominant nature of its format – it is how many people will tell, hear, and experience stories, culture, and values in the coming years. This dissertation argues that a deeper understanding of how people play video games and what these play experiences mean must rely on interdisciplinary lenses of analysis that value player reports, programming choices, and cultural narratives equally. I establish a theoretical and methodological approach that defines elements of what it means to play video games, and study the qualitative influence of game–play on thought and behavior through pragmatic analysis of interview data. Samples of masculine discourses of game play in the United States provide a starting point for this exploration of video game impact through discussions of play theory, narratology, game programming and interaction with interactive media hardware. Common social concerns regarding increased violence, aggression, or de–socialization as a result of this medium were not represented in the population presented in this dissertation. Players recognized the allure of the so–called negative aspects of video games, but ultimately expressed a decided disconnect between the real world and virtual experiences of play, describing cathartic and therapeutic reasons for their enjoyment of those elements. An interdisciplinary approach to video game research must be embraced, despite a constant call for quick, universal answers to their most common critiques. Foundational themes for understanding the influence of interactive digital play experiences on personal identity and ideology construction are demonstrated through thematic and sociolinguistic analyses of in–depth interview data. These include play theory, narratology, human–computer interaction theory, and player report data. I draw on the established theoretical backgrounds of these disciplines to suggest a new term, ergodic ontogeny, to describe this complex process of personal development resulting from influences of interactive digital media gaming that reach beyond play experiences
Randomized Trial of Common Elements Training in School Mental Health Care: Clinician Knowledge, Attitudes, and Practice
No full textEmpirically-supported treatments (ESTs) consistently outperform usual care in efficacy trials, but transportability to real world settings has been historically poor. The current study examined the impact of different training methods for the Common Elements approach to ESTs on school mental health (SMH) clinicians' knowledge, attitudes and use of empirically supported techniques. Random assignment of 45 SMH clinicians to one of two conditions for training in the Common Elements approach to ESTs as compared to 36 clinicians trained in a prevention program revealed within-group improvements in knowledge and familiarity with empirically supported techniques. Neither clinician attitudes toward nor self-reported use of ESTs changed over time; mean attitude scores were very positive at baseline. Between-group differences were not detected, perhaps as a function of group contamination. Qualitative interview data suggest that adoption and implementation of ESTs are more complex than existing literature indicates. The resulting grounded theory includes contextual factors of the clinicians' experience and SMH care setting which influence adoption and implementation among all training groups
Kid Simple (2013)
No full textPromotional materials produced for Kid Simple, perfomed by the UMBC Theatre Department in November 2013. Includes playbill, program, and ten publicity photographs.November 21-November 24, 201
IMMIGRANT IDENTITIES IN THE DIGITAL AGE: PORTRAITS OF SPANISH-SPEAKING YOUNG MEN LEARNING IN A COMMUNITY-BASED SETTING
No full textCurrently the United States is home to a large and increasing immigrant population. Many of these immigrant students use community-based programs for their educational needs. Despite the large number of immigrant students who currently use alternate resources, such as churches and community centers, for education, adult language learners in nonacademic settings remain understudied. Today's students need language and literacy skills along with specialized skills required by the current globalizations of marketplaces. Community organizations providing language and literacy services to immigrants need a better understanding of clients and how to provide the experiences that will allow their students to participate in the modern workforce and society. This is a qualitative ethnographic study that follows nine Spanish-speaking adult males through one portion of their lives as recent immigrants. Using a sociocultural definition of literacy and portraiture as a method of analysis, this study looks at data obtained from classroom assignments, digital stories created by the subjects, and online social media to investigate the performance of identity across literacy events. Analysis supported the existence of complex, hybrid, and situated identities for students. Identity performance differed across literacy events and the inclusion of digital stories and online social media provided evidence of identities not present in traditional classroom activities
Development of Chromatofocusing Techniques Employing Mixed-Mode Column Packings for Biomolecule Separations
No full textIn this thesis, a novel category of mixed-mode separation methods was developed which combines the technique of chromatofocusing with complementary chromatographic methods that utilize nonelectrostatic interaction, such as hydrophobic interactions or size exclusion effects. In the study of the hydrophobic interaction chromatofocusing method, two commercial mixed-mode column packings, one based on mercapto-ethyl-pyridine and the other based on hexylamine were investigated with regard to their ability to separate proteins when using internally generated, retained pH gradients. The effects of added salt and urea on the behavior of the retained pH gradient and the protein separation achieved were also investigated for this case. Numerical simulations were shown to be a useful method to select the compositions of the starting and elution buffers in order to achieve desired shapes for the pH and ionic strength gradients. The use of the method to fractionate blood plasma was explored as a prototype example application. The size-exclusion chromatography combined with chromatofocusing was investigated using a bonded silica column packing where the underivatized silanol groups provided the electrostatic functionality. A multiple-charge state model was developed to describe the adsorption process in these cases which is asymptotically exact in the limit of a low ionic strength mobile phase and weak adsorption affinity. This model accounts for the salt effect on the hydrophobic interaction, the effect of charge regulation where adsorption changes the protein charge, the size-exclusion effect, and the effect of changing pH. Calculations using both the Donnan potential and the surface potential to fit adsorption data for lysozyme suggested that the electrostatic repulsive component of the overall adsorption affinity in the mixed mode chromatography systems considered likely results from both localized charged regions on the protein adjacent to the column packing surface and the net overall charge on the protein. In addition, a family of tetrazole-functionalized mixed-mode column packings based on both polystyrene-divinylbenzene (PS-DVB) and agarose was synthesized which incorporates both hydrophobic and weak-acid cation exchange functionalities. This material was studied with regard to its usefulness in mixed-mode chromatofocusing
Dynamic Stability of a Class of Second-Order Distributed Structural Systems With Sinusoidally Varying Velocities
No full textParametric instability in a system is caused by periodically varying coefficients in its governing differential equations. In this work, parametric instability regions of a second-order non-dispersive distributed structural system, which consists of a translating string with a constant tension and a sinusoidally varying velocity, and two boundaries that axially move with a sinusoidal velocity relative to the string, are obtained using the wave solution and the fixed point theory. Unlike parametric instability regions of lumped-parameter systems that are classified as principal, secondary, and combination instability regions, the parametric instability regions considered here are classified as period-1 and period-i (i>1) instability regions, where period-1 parametric instability regions are analytically obtained and period-i (i>1) parametric instability regions can be numerically calculated using bifurcation diagrams. The parametric instability phenomenon discovered here is characterized by a bounded displacement and an unbounded vibratory energy, due to formation of infinitely compressed shock-like waves. Five non-trivial cases that involve different combinations of string and boundary motions are investigated for their instability regions, wave patterns, and vibratory energy growth. The stable and unstable responses of the linear model in the first case are compared with those of a corresponding nonlinear model that considers the coupled transverse and longitudinal vibrations of the translating string and an intermediate linear model that includes the effect of the tension change due to axial acceleration of the string on its transverse vibration. The parametric instability in the original linear model can exist in the nonlinear and intermediate linear models with a slower energy growth rate
Operational Modal Analysis of a Rectangular Plate Using Non-contact Excitation and Measurement
No full textThis work presents a non-contact experimental technique for measuring modal parameters of a rectangular aluminum plate using only the output data. Operational modal analysis (OMA), or output-only modal analysis, has been widely used especially when the input is unknown and difficult to measure. OMA is used to analyze both the out-of-plane and in-plane vibrations of the plate in the frequency range of up to 15000 Hz under white noise acoustic excitation in a direction of interest. It is shown that OMA can be performed when the types of measurement at the measurement and reference points are different. A single-point laser vibrometer and a free-field microphone are used to simultaneously measure the responses of the plate in a non-contact manner, with the microphone measurement serving as the reference. The pressure measured by the microphone near the reference point is shown to be proportional to the normal surface acceleration at the reference point, and the cross power spectral densities obtained by the current test method can be used for modal parameter estimation. A method for measuring the in-plane modes of the plate by shining the laser beam on the plate surface with an incident angle is developed. Experimental modal analysis (EMA) is also performed on the plate using an impact hammer and the laser vibrometer. The measured natural frequencies and mode shapes of the out-of-plane and in-plane modes of the plate using OMA and EMA are compared well with those calculated using commercial finite element software
urCF: An Approach to Integrating User Reviews into Memory-based Collaborative Filtering
No full textBlessed by the Internet age, many online retailers (e.g., Amazon.com) have deployed recommender systems to help their customers identify products that may be of their interest in order to improve cross-selling and enhance customer loyalty. Collaborative Filtering (CF) is the most successful technique among different approaches to generating recommendations. Collaborative filtering automates the word-of-mouth process of recommendations by aggregating item ratings of other like-minded users. Although it has achieved huge success in both research and industry, traditional CF suffers a fundamental problem because of its dependence on users' numeric ratings as its sole source of user preference information. However, user ratings are often unable to fully represent user preferences. As a result, it is difficult to identify the true similarity among users based on ratings only. On the other hand, people are more and more comfortable with expressing themselves online using free-form text (e.g., blogs). As a result, user text reviews on different products have become a common source for consumers to share and receive information about products. Recent studies have also found that user reviews have significant impact on online businesses' sales. Inspired by the results of these studies, I propose an integrated approach to collaborative filtering called urCF (User Review enhanced Collaborative Filtering) that integrates user text reviews into memory-based collaborative filtering in order to better model users' preferences and in turn enhance the performance of CF-based recommender systems. This research uses existing text mining techniques to extract user opinions on item features. It proposes a new weighting scheme based on TF-IDF to measure the priority of item features in influencing users' overall opinions of different items. This study also explores and compares several different approaches to integrating user opinion information extracted from user text reviews into the user similarity measurement of traditional CF-based recommender systems. The proposed urCF system is evaluated against existing approaches using a dataset collected from Yahoo! Movies. The results show that the proposed urCF system significantly improved the performance of memory-based recommender systems