136879 research outputs found
Sort by
Enacting Distant and Digital Citizenship: The Ethiopian Diaspora Online and the Grand Ethiopian Renaissance Dam
No full textConventionally, water security concerns of the Nile Basin waters focuses on local mobilization. The presented research explores water security concerns by focusing on the role diasporic communities play in water politics while subverting national borders. In this project, I interrogated how social media facilitates citizenship participation by the Ethiopian diaspora and its effect on the transboundary water management of the Grand Ethiopian Renaissance Dam (GERD). Three research questions were asked: (1) how has the Ethiopian diaspora reacted to the construction of GERD? (2) Is #Adwa and its historical and symbolic potency compounded to #GERD to inspire support? (3) are online sentiments regarding GERD the same as offline sentiments? Data sets were extracted from Twitter between 2018 and 2022 and analyzed via three methodologies: a Social Network Analysis (SNA), a Thematic analysis of Twitter content, and offline interviews with 9 Ethiopians in the diaspora. Through the SNA, the findings revealed a dense overlap between diasporic nodes and homeland nodes which suggests diasporic communities engaged with GERD contents in similar patterns as local communities. It further revealed four distinct communities. Inductive coding of the specific tweets in each of the four groups revealed clusters separated not by their location but by the content of their tweets. The four communities emphatically showed their support for GERD and the restructuring of access to the Nile River. However, the narrative of why GERD is central to Ethiopia and what to do about it changes slightly across the four communities. Through a thematic analysis of #Adwa and #GERD, symbols used in the mobilization of GERD, the findings show that compounding symbols that have historical potency plays a central role in the mobilization of an intra-varied group. Finally, through interviews, the findings reveal that online mobilization fairly captures what happens offline but with much lesser complexity and nuance. It further revealed a less emphatic support for GERD due to current political tensions and conflicts. The results of this study contribute to the understanding of how transnational practices related to long-distance nationalism are transformed by the proliferation of social media
Status, Distribution, and Population Modeling of Red-Crowned Parrots and Conservation Opportunities of Naturalized Parrots
No full textUrbanization and the global transport of animals are interconnected aspects of ecology that play significant roles in the conservation of species. Both scenarios are viewed in a mostly negative light ��� in part, urbanization can destroy habitat while the establishment of animals outside their native range can wreak havoc on ecosystems. In contrast, these urban landscapes may provide unique opportunities for some species which can take advantage of highly modified environments. Red-crowned Parrots are an Endangered species of Amazona parrot which are native to northeastern Mexico and the lower Rio Grande Valley of Texas, but also have naturalized populations in urban regions of southern California and Florida. My research sought to discover a timeline of the bird���s arrival in south Texas, determine current population size and productivity, as well as determine habitat use and threats. Species distribution modeling was also utilized to determine Red-crowned Parrot���s levels of dependency on urban areas throughout the United States. Besides Red-crowned Parrots, upwards of 59 parrot species have established naturalized populations outside their normal ranges, and while much has been written about the real and potential negative aspects of these populations, little effort has been made to describe the real or potential positives. In that essence, I set to review the benefits of naturalized parrot populations with a focus on conservation, research, and societal impacts. My work found a healthy and growing population of Red-crowned Parrots in south Texas which is heavily reliant on urban and suburban areas. In addition, populations found in southern California and Florida showed similar urban dependencies. Threats to these populations include poaching and hybridization with other naturalized and closely related Amazona parrots; after quantifying levels of hybridization and modeling the future of the south Texas population relative to this threat, I found that management actions may be needed to ensure the genetic integrity of this threatened population. Naturalized populations of threatened and endangered parrots hold potential to help mitigate population declines elsewhere and could represent valuable genetic reservoirs. When these populations are located within highly modified habitats, they may also help mitigate the potential biodiversity loss created by urbanization. Whether the birds were purposefully introduced or accidentally released or escaped captivity, those that do become naturalized may provide unique opportunities for researchers and conservation
Selection History and the Strategic Control of Attention
No full textAttention influences how we process perceptual information by prioritizing one or some stimuli over others. Prior studies have shown that learned associations between a particular stimulus and reward, as well as a history of a particular stimulus serving as a searched-for target, can result in a persistent attentional bias for the stimulus, reflecting an influence of what has been termed selection history on the control of attention. While these studies investigated the influence of selection history on stimulus-driven attention, or the involuntary allocation of attention on the basis of particular stimulus features, people can also voluntarily direct their attention to particular stimuli on the basis of task goals, reflecting the strategic control of attention. Whether selection history can also modulate the strategic control of attention remains unknown. In this thesis, I utilized the Adaptive Choice Visual Search (ACVS) Task to examine the influence of reward history (Chapter 2) and search history (Chapter 3) on how participants strategically chose to search through a display in an effort to find one of two possible targets. The results show a bias to adopt search strategies that participants have been rewarded for using in the past, even when it is suboptimal to search in this way, and that prior experience with task displays in which a particular search strategy is highly optimal creates a strong bias to persist in using this strategy even when it is otherwise not favored by participants without such prior experience. Overall, we see converging evidence that selection history not only biases attention to specific stimuli via stimulus-driven mechanisms, but also exerts an influence on how people choose to conduct a visual search
Influence of Irrigation Water Quality and Quantity on Peanut Production in the Texas High Plains
No full text
Using Comparative Genomics to Explore Serpentine Tolerance in the Santa Barbara Jewelflower, Caulanthus amplexicaulis var. barbarae (Brassicaceae)
No full textPlants living in harsh soils have been of special interest in understanding the adaptive mechanisms needed to tolerate selective edaphic pressures. Specifically, plants endemic to serpentine soils are exposed to a suite of stresses such as low essential nutrients, low calcium-to-magnesium ratios, low water retention, and elevated levels of toxic heavy metals. To understand what genetic changes must occur to enable serpentine tolerance, the serpentine endemic Caulanthus amplexicaulis var. barbarae (CAB) and its granite-living sister taxa Caulanthus amplexicaulis var. amplexicaulis (CAA) were compared.
High quality chromosomal reference genomes of CAB and CAA were assembled and annotated. Comparative mapping and analysis between the genomes and other common ancestors revealed a recent whole genome duplication event and the transition from a common ancestor with the haploid state of n=7 to the C. amplexicaulis n=14. Paralogs in both taxa show periods of polyploidization. CAB to CAA synonymous mutation rate (Ks) ortholog distributions suggested a period of divergence and then recent introgression. Furthermore, a collection of candidate genes under positive selection has been proposed for confirmation of their roles in serpentine tolerance.
To understand the genetic basis of serpentine tolerance, recombinant inbred lines and parental dried biomass data were collected from plants grown in low calcium media, nickel media, or serpentine soils. Quantitative trait locus analysis of each nutrient or soil showed independent loci on six chromosomes. An integrative data approach was used to identify candidate genes with roles associated with living on serpentine soils such as heavy metal chaperones, WRKY DNA-binding proteins, potassium channels, and MYB genes. These genes will be used in functional validation studies to explore their respective roles in serpentine tolerance