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Three Essays on Climate Change Impacts on the U.S. Livestock Sector
No full textThis dissertation contains three essays and their contents are summarized as follows. The first essay contains a literature review regarding climate and climate change related decision possibilities as they impact livestock productivity and decisions. We covered impacts, emissions, adaptation possibilities and mitigation alternatives. We pointed out research gaps on non-ruminant animals and on settings involving developing countries.
The second essay reports on an application of econometric models to explore how climate affects livestock performance. We investigated climate impacts on the productive and reproductive performance for US cattle, hogs and chickens, using temperature humidity index (THI) as a proxy of heat stress. Our results show that climate factors play an important role in livestock productivity. Future climate projections reveal a decrease in all major livestock yield metrics, with the projected changes in yield showing geographical variations across the country.
The third essay reports on an analysis of implications of omitting or including livestock impacts within an agricultural-sector-based climate change impact appraisal. Previous agricultural sector studies have largely ignored impacts on livestock just concentrating on crops. By integrating the livestock impact projections from the second essay, we find introducing livestock impacts causes a 2.5B (22.1%) decline under RCP 4.5
From Remote Work to Virtual Collaboration: Toward the Design of Collaborative Virtual Reality Environments
No full textRecently the world was hit by the COVID-19 pandemic, during this time mandatory social distancing went into effect to stop the spread of the virus. Due to the social distancing mandates many schools and businesses were forced to close their doors for an undisclosed amount of time, opening the door for online and remote work. Individuals who worked on collaborative teams during this time were forced to adopt new methods of collaboration. Although teleconferencing applications such as Zoom, Google Hangouts and Microsoft Teams provided online support for collaboration the human-human social interaction was lacking. Like these teleconferencing applications Virtual Reality (VR) has taken off during these unprecedented times. Recent developments into VR have created immersive applications that allow users to meet socially and professionally in virtual environments, bringing back the human-human social interaction. This research seeks to understand how and to what extent collaborative VR environments can support interdisciplinary team collaboration. A series of five studies was conducted to first explore how collaborative teams work with each other in different environments (face-to-face vs virtual). The following studies will investigate user preferences of Virtual Characters (VCs) in immersive VR environments. A final study will observe an interdisciplinary team to compare team collaboration face-to-face, virtually and in a commercially available collaborative VR application. From these five studies this body of work will contribute a set of design guidelines to be used in the development of collaborative VR environments
An Innovative Algorithm for Assessing Instance Segmentation in Autofluorescence Microscopy Images
No full textNumerous methods have been created to segment individual cells in microscopy images, highlighting the need for an effective way to evaluate segmented results. Traditionally, the comparison of segmented images with their corresponding ground-truth images is conducted on a pixel-by-pixel basis. However, this approach often overlooks the misallocation of pixels between adjacent objects. In response, we introduce a per-object segmentation evaluation algorithm (POSEA), which assesses the accuracy of segmentation for each object in comparison to a ground truth image. The efficacy of POSEA is validated through the analysis of precision, recall, and f-measure scores, contrasting these with those derived from traditional pixel-based assessments across simulated and segmented fluorescence microscopy images of three distinct cell types. Notably, POSEA identifies a higher rate of segmentation errors due to its accurate recognition of pixels misattributed to adjacent objects. As a result, POSEA offers precise metrics for evaluating the segmentation of adjacent objects, proving its effectiveness for evaluating segmentation algorithms for autofluorescence microscopy images
A Multiphysics Model for Predicting Spatiotemporal Temperature Profiles in Microwave-Heated CO2 Direct Air Capture Processes
No full textDue to alarming rise in atmospheric CO2 ppm levels, the direct air capture process has been engineered to capture low concentrations of CO2 directly from the atmosphere using chemisorbents. However, the regeneration of chemisorbents is highly energy-intensive and inefficient. To enhance this, microwave is employed for selective and targeted heating of the chemisorbent. Existing measurement techniques struggle to accurately capture the spatiotemporal temperature profile of solvent impregnated polymer (SIP) under microwave heating. Therefore, it becomes crucial to determine the spatiotemporal temperature distribution inside the polymer phase to expedite CO2 desorption, improve energy efficiency, and prevent material degradation. Motivated by these considerations, we propose a 3D-multiphysics model to study the spatiotemporal distribution of temperature inside a hybrid nanoscale multi-functional material. We focus on the microwave heating of a novel heterogeneous system comprising a SIP with a ferromagnetic additive, further solving the heat diffusion and Maxwell���s electromagnetic equations to analyze the temperature variation inside the SIP system. By coupling the physics of electromagnetism and heat transfer, our model allows for a comprehensive analysis of the temperature distribution and heating effects inside the chemisorbent. The proposed model is validated experimentally by the surface temperature findings of the SIP from IR-sensor. Additionally, we conduct sensitivity analysis of spatiotemporal temperature profile on various thermal and dielectric parameters, as well as the size and location of the Fe3O4 layer, to optimize desorption rates and make the regeneration process more energy-efficient
Duane Schilitter field not book: SP4068-SP7676_assorted_Schlitter.pdf
No full textEach page/AP number corresponds to a karyotype slide data and/or unique specimen.Data pages for SP4068-SP7676_assorted_Schlitter corresponding to unique identifiers of specimens/samples examined for biological research. Specimens are primarily housed at Texas A&M University; Biodiverstiy Research and Teaching Collections; Carnegi
When Modes of Learning Shift Unexpectedly: How Instructors Choose Online Teaching Strategies
No full textThis study examined how in-person instructors selected online teaching and learning strategies when shifting to a different mode of learning during the COVID-19 pandemic. As many in-person instructors have little to no experience with online learning or instructional design, examining how strategies were selected during this time provides an understanding of what strategies worked, the challenges in shifting to a different mode of learning, and practices that were retained moving back to in-person instruction. The findings revealed that instructors selected strategies during these shifts through adapting existing in-person instructional strategies to address the changing circumstance
Art (Spaces) Imitates Life? An Exploration of Arts-Centered Spaces and Their Degree of Accessibility to Immigrant Communities
No full textThis literature review is designed to answer two questions. First, whether art spaces are welcoming spaces for immigrants? Second, what conditions may prompt immigrants to interact or disengage with art spaces? Literature from cultural geography, sociology of culture, urban studies, race, ethnicity, and migration have demonstrated that institutions such as the art museum have historically been sites of domination (Anderson 2006; Cooks 2011; Lonetree 2012). Despite this, museums have displayed an effort to change, while marginalized communities embody the capacity to partake in placemaking endeavors regardless of these constraints (Hooper-Greenhill 2000; Roberts 2018, 2020; Lipsitz 2011; Cook 2011; Lonetree 2012; Jenkins 2010; Jamal 2010, Espiritu 2010, Maira 2010, Stern et. al. 2010). Moreover, art-spaces have been shown to benefit people in both an individual and communal sense (Grodach 2010, 2011; Eaves 2014; Eisner 2012). At the same time, the literature shows that immigrants tend to prefer more informal or private venues to partake in the consumption or creation of art. Although this is the case, we cannot discern exactly why this dynamic is occurring (Stern et. al 2010). Literature regarding cultural capital and strategic assimilation point to possible theoretical explanations of this dynamic, but further research must be conducted to fully address this discrepancy (Bourdieu 1977; Lamont and Lareau 1988; Lacy 2007). In the completion of this literature review, I also offer suggestions to improve existing art spaces based upon the concepts of the Black Spatial Imaginary and Community Asset Mapping (Lipsitz 2011; Villanueva 2020, 2021)
ScrollStats: An Automated Tool for Deciphering Meander Scrolls and Uncovering the Hidden Paths of Meander Migration
No full textScroll bars are arcuate, elongated landforms deposited along the inner banks of meandering rivers. This deposition occurs within zones of flow separation typically during discrete high-flow events. As the channel meanders, scroll bars are deposited successively in its wake and are preserved by stabilizing vegetation, leaving behind a well-preserved, visually intuitive migration history in the resulting ridge and swale topography (RST). Because of this episodic deposition, bar location and orientation can serve as a record for migration history while specific bar morphology can contain information about the hydrologic conditions under which the bar was deposited. ScrollStats is an open-source GIS tool developed to digitize and extract this morphological information from DEMs of the RST of meandering bends. ScrollStats produces two primary data products 1) migration pathways derived from preserved scroll bar location and orientation and 2) a ridge area raster delineating the ridge areas within the DEM. From these data products, ScrollStats calculates a suite of ridge morphometrics (ridge width, amplitude, and spacing) for every intersection of an identified ridge and migration pathway, covering the entirety of the bend's interior. In this paper, we showcase the capabilities of ScrollStats on a compound bend of the Lower Brazos River, Texas, USA. We also demonstrate how ScrollStats compares to other methods previously used to extract morphometrics from RST and how it can be used to expand upon previous findings in the literature. ScrollStats allows researchers to extract floodplain morphometrics previously unavailable, enabling new research into bend-scale migration dynamics and linkages between hydrologic process and the resulting landforms
La Imagen del Recuerdo: Sagrada Memoria y Always from Somewhere Else de Marjorie Agos��n
No full textEl presente trabajo propone un an��lisis comparativo de Sagrada memoria (1994) y Always from somewhere else (1998) de la escritora chilena Marjorie Agos��n. Estas obras presentan los recuerdos de Frida y Mois��s Agos��n, los padres de la autora, pero constituyen un testimonio que va m��s all�� de sus vivencias personales. Estos testimonios trascienden el ��mbito familiar conformando memorias colectivas, siendo el retrato de la realidad heredada por los supervivientes del Holocausto que emigraron a Latinoam��rica. Los recuerdos, marcados por la imaginaci��n y subjetividad, son reflejo de experiencias discriminatorias antisemitas, pero tambi��n raciales y de g��nero. El presente estudio tiene como principal objetivo el an��lisis comparativo de dichas memorias en cuanto a conceptos como testimonio, memoria, postmemoria e imaginaci��n ic��nica, entre otros. Dicho an��lisis nos lleva a encontrar las siguientes tem��ticas comunes: el mandato jud��o de recordar, el trauma heredado, la imposibilidad de narrar el recuerdo, el antisemitismo, el exilio, la identidad del sujeto diasp��rico, la subjetividad, el imaginario o memoria social o colectiva y el reconocimiento. Estas tem��ticas permiten establecer nexos entre estas memorias y la concepci��n art��stica de la artista judeo-chilena Patricia Israel, cuya obra tambi��n conjuga la imagen y la palabra con el fin de abordar la memoria tanto privada como colectiva. La imaginaci��n ic��nica juega un papel importante en la elaboraci��n de im��genes verbales, lo que permite establecer relaciones entre la narraci��n y algunas de las obras del pintor jud��o Marc Chagall que propongo como un intertexto visual, as�� como entender el significado simb��lico que los tatuajes y los trenes adquirieron a partir del Holocausto. Adem��s, el contraste entre las memorias permite realizar una lectura de g��nero que manifiesta los estereotipos codificados en cuanto a la vida y funciones de la madre y del padre
Improving the In Vitro-to-In Vivo Extrapolation to Predict Environmental Chemicals Toxicokinetics and Hazard by Construction of New In Silico Models with In Vitro Testing Data
No full textIn light of the vast number of chemicals present in diverse environmental media, necessitating exposure assessments to protect human health, in vivo studies have traditionally been considered gold standards for providing hazard and kinetic data for risk assessments. However, their limited throughput and higher costs mean only a fraction of chemicals possess sufficient toxicity data for assessing health risks. To address this crucial data gap, New Approach Methodologies (NAM), particularly the application of in vitro-to-in vivo extrapolation (IVIVE) with in vitro studies and in silico computational models, have been developed. The demand for assessing risks for numerous chemicals necessitates effective and high-throughput methodologies. Nonetheless, IVIVE faces challenges, including the accuracy of in silico predictions on toxicokinetic (TK) properties based on in vitro datasets and linking in vitro adverse outcomes to whole-organ level phenotypes.
We here hypothesized that that innovative computational approaches integrated with in vitro studies will enhance TK predictions and hazard identification for environmental chemicals while advancing high-throughput screening methodologies. To test this hypothesis, three specific aims were proposed: (1) developing a physiologically-based gut absorption model for probabilistic prediction of environmental chemical bioavailability based on in vitro permeability measurements, (2) improving the prediction of renal clearance for per- and polyfluoroalkyl substances by integrating in vitro toxicokinetic datasets from different assays with physiologically-based kidney model to implement IVIVE, and (3) identifying the proarrhythmic potential of environmental chemicals by integrating an in vitro human model with Bayesian population modeling.
The achievement of these aims will demonstrate how novel in silico models and in vitro datasets can enhance the prediction of hazards and toxicokinetics for environmental chemicals. Additionally, these studies will facilitate the application of in vitro datasets in high-throughput screening of chemicals for risk assessment. Ultimately, we anticipate that these endeavors will contribute to filling critical data gaps related to TK properties and hazards for environmental chemicals, aligning with the long-term goal of protecting human health from exposures to hazardous environmental chemicals