The Use of Green Fluorescent Protein for Transgene Monitoring and Detection of Pollen Distribution and Gene Flow Patterns under Field Conditions.

There have been many recent and new possibilities for crop improvement since the development of techniques, which allow for the transfer of novel genes into host plant genomes. Fitness enhancing genes that confer disease, drought, and herbicide resistance to important food crops such as corn (Zea mays L.), soybean (Glycine max L.), canola (Brassica napus L.), and rice (Oryza sativa L.) will be invaluable tools to feed the exponentially growing human population world wide. This widespread use of transgenic crops has increased the risk of transgene escape into the environment. This risk becomes more significant when engineered crop species have wild relatives growing in close proximity. The potential of transgenes resulting in fitness-enhancement of weedy relatives warrants the need for an in vivo gene monitoring system suitable for use in the field so that the potential risks can be quantified and evaluated. Green fluorescent protein (GFP) has been demonstrated as an effective tool to monitor the expression and possible introgression of transgenes into crop-related wild species (Stewart, 1996; Harper et al., 1999; Halfhill et al., 2001). Therefore, GFP may be an ideal candidate for the detection of gene flow and pollen distribution patterns under field conditions. In this study, the pollen-specific LAT59 promoter was used to express a green fluorescent protein (GFP) gene in tobacco (Nicotiana tabacum L.). The result yielded transgenic tobacco plants, which express GFP protein only within pollen grains. GFP-tagged pollen was developed as a tool for tracking the movement of transgenic tobacco pollen under field conditions. A two-year field study was set up and monitored during the summer f 2001 and 2002. The goal of this research was to characterize spatial distribution patterns of transgenic pollen to gain knowledge about pollination mechanisms under field conditions in tobacco. However, a possible pitfall is that tobacco is normally a self-fertilizing crop so detection of pollen movement in this system may be difficult. Another aspect of this research was to estimate the frequency of out-crossing under field conditions. Transgenic tobacco engineered with the CaMV35s promoter to express GFP throughout the entire plant (WPGFP) was used. Pollen flow from a pollen-donor population of WPGFP tobacco plants to non-transgenic tobacco plants grown at specified distances and directions from the transgenics were assessed. Hybrid frequency was determined by screening the progeny from each wild type recipient plant for the GFP phenotype. Out-crossing in 2001 was 0.009% and 0.07% in 2002. Average out-crossing within the center plot in 2002 was 0.7%. The goal of this research was to determine the dynamics of actual out-crossing events in a field of tobacco. If this system is to be an effective monitoring tool, then GFP transgenic pollen viability and longevity must be tested. Anytime a foreign protein is introduced into a reproductive cell, there is a possibility of adverse effects on cellular regulation or disruption of cell development, which could be detrimental to a tobacco plant’s capacity to reproduce. Expression of GFP has been demonstrated in many different plant parts and species, and toxicity or adverse developmental events have not been observed (Pang et al., 1996; Leffel et al., 1997; Harper et al., 1999; Quaedvlieg et al., 1998; Tian et al., 1999; Molinier et al., 2000). Although GFP expression has not been found previously to have an effect on plant cells, a comparison of pollen tube germination frequencies to those of wild type tobacco pollen were conducted to determine the consequences of GFP expression. Data from these experiments did not suggest that expression of GFP had an effect on pollen fitness. Since GFP can be expressed in tobacco pollen under the control of the LAT59 pollen specific promoter, a system to monitor and detect pollen distribution and gene flow patterns can be developed on a large scale. This could reveal answers to many questions involving ramifications of the introgression of transgenic crop species into the environment

The Art of the Hustle: A Study of the Rap Music Industry in Bogota, Colombia

How do rap artists in Bogota, Colombia come together to make music? What is the process they take to commodify their culture? Why are some rappers able to become socially mobile in this process, while others are less so? What is technology’s role in all of this? This ethnography explores those questions, as it carefully documents the strategies utilized by various rap groups in Bogota, Colombia to create social mobility, commoditize products and to create a different vision of modernity within the hip-hop community, as an alternative to the ideals set forth by mainstream Colombian society. Resistance Art Poetry (RAP), is said to have originated in the United States but has become a form of international music. In conducting ethnographic research from December of 2012 to October 2014, I was able to discover how rappers organize themselves politically, how they commoditize their products and distribute them to create various types of social mobilities. In this dissertation, I constructed models to typologize rap groups in Bogota, Colombia, which I call polities of rappers to discuss how these groups come together, take shape, make plans and execute them to reach their business goals. I was also able to document the inconsistencies, problems and negotiations that the members of these entities encountered as they attempted to become successful musicians in the current global economic environment. This dissertation offers explicit details of how the rap musicians in the polities under study, were able to utilize their social networks in the process of commodifying their products for distribution in the hip-hop market place. I also tackle current academic discussions about how the rappers use digital technologies to assist them with this process. Engaging with concepts from economic anthropology, social mobility literature, political economy and globalization studies, the findings here demonstrate various entrepreneurial strategies utilized by rap musicians in this location

Life History of the River Shiner, Notropis blennius (Cyprinidae), in the Arkansas River of Western Arkansas

The reproductive cycle, food habits, and age and growth of the river shiner, Notropis blennius (Girard), in the Arkansas River of western Arkansas were studied from May 1996 through October 1997. Based on gonadosomatic indices and mean ovumd iameters of females, tubercle development in males, and the first appearance of young-of-year in samples, the breeding season extended from June through August in both 1996 and 1997. The river shiner is a diurnal, generalist feeder that forages on a wide variety of food items. In all four seasons, detritus dominated the diets of adults and juveniles in terms of volume and frequency of occurrence. Aquatic insects and algae were also important food items. It is a short-lived, r-strategist; it has a maximum life expectancy of about two years and has successfully maintained stable populations in the Arkansas River for more than 30 years after the construction of the Arkansas River Navigation System

Parent/child distal relationships: a look at communication used before, during, and after a parental absence

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file viewed on (May 25, 2006)Includes bibliographical references.Vita.Thesis (Ph. D.) University of Missouri-Columbia 2005.Dissertations, Academic -- University of Missouri--Columbia -- Communication.This project examined communication in distal parent-child relationships. Distal relationships are relations in which people are physically separated for a period of time. Little research has focused on distal relationships, but they are a common form of family relationship, and often have considerable impact on all family members. In this study, the focus was families which had a parent leave their partner and child(ren) for 2 months or longer. The study investigated uncertainty reduction and uncertainty management among family members, using systems theory as a general framework for analysis. Participants were 54 parents and children from families who had a parent separated by incarceration or military deployment. Participants were interviewed individually about their experiences within 2 years of the parent's return. Results showed that families who communicated about the absence before departure had less of a negative impact on children's well-being. In addition, this study advances maintenance and uncertainty literature by illustrating that these participants maintained their relationships while the parent was absent by using a set of communication strategies and by managing their emotional climate with three closeness techniques and three distancing techniques. Results illustrated that the return home of the parent was often difficult with issues pertaining to responsibilities, regaining trust, and role changes. The findings in this study have implications for research on communication and meaning, regulating closeness and distance in relationships, and use of relational maintenance behaviors. The findings both support and add to previous research done on personal and family relationships