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Las leguminosas son el segundo grupo de plantas en importancia agronómica. Sin embargo, se conoce poco sobre sus procesos de floración, a pesar de la importancia que tienen en los sistemas de producción de las mismas. En el presente trabajo, se utilizó como sistema modelo la leguminosa Medicago truncatula para estudiar la floración en este grupo de plantas. Se pretendía aislar y caracterizar genes de la familia MADS-box en esta especie, los cuales están involucrados en el desarrollo floral y la transducción de señales. Se estudiaron 11 genes MADS-box: dos genes de clase B (MtTM6 y MtNMH7), tres genes de clase C (MtSHP, MtAGa y MtAGb), un gen de clase E (MtSEP) y cinco genes que no forman parte del modelo ABC(DE) (MtAGL6, MtAGL6-like, MtSOC1a, MtSOC1b y MtSOC1-like). Los patrones de expresión de estos genes se analizaron mediante Northern blot e hibridación in situ, observando que todos se expresan en diferentes tejidos florales y/o diferentes estadios de desarrollo floral. Se prestó especial atención a la caracterización funcional de los genes de clase C, debido a su importancia en los procesos reproductivos de las plantas, por lo que se estudiaron los genes MtAGa y MtAGb, homólogos al gen de clase C AGAMOUS. Se analizaron plantas transgénicas con construcciones de RNA interferente y un mutante de pérdida de función C etiquetado por el retrotransposón Tnt1. Además, utilizando la tecnología VIGS se obtuvieron plantas de M. truncatula y de Pisum sativum (leguminosa filogenéticamente cercana) con pérdida de función de los genes MtAGa/MtAGb y PsAGa/PsAGb, respectivamente. También se realizaron experimentos de ganancia de función mediante la expresión constitutiva en el sistema heterólogo Arabidopsis thaliana. Los resultados obtenidos indican que MtAGa y MtAGb son genes de clase C que además de ser funcionalmente redundantes, se han subfuncionalizado, distribuyendo la función C ancestral entre ambos parálogos, de tal manera que MtAGa tiene un papel prioritario en la determinación del meristemo floral, mientras que MtAGb juega un papel clave en la especificación de la identidad de los órganos reproductores florales. / Serwatowska, J. (2012). Aislamiento y caracterización de genes MADS-box en Medicago truncatula: duplicaciones génicas y subfuncionalización en el linaje euAGAMOUS [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/15077

Adjacent box beam bridges are economical bridge systems for accelerated bridge construction. The box beams are constructed at precast plants and are traditionally connected by a shear key filled with grout. This system is ideal for short spans with low clearance restrictions. However, due to the grout deteriorating and debonding from the precast concrete in the shear key, reflective cracking propogates through the deck allowing water and chemicals to leak down into the joints. This can lead to the prestressing steel inside the precast member and the transverse tie steel corroding. This necessitates the bridge being rehabilitated or replaced which shortens the life-span of the bridge system and negates the economical value it had to begin with. This research project aimed to design a rehabilitation plan for an adjacent box beam bridge with deteriorated joints using Very High Performance Concrete (VHPC). VHPC was chosen as an economical alternative to the proprietary Ultra High Performance Concrete (UHPC) and extensive material tests were performed. The results of the material testing of VHPC and grout revealed that VHPC had higher compressive and tensile strengths, a higher modulus of elasticity, gained strength faster, bonded better to precast concrete, was more durable over time, and shrank less than conventional grout. The results of this research project were applied to rehabilitate the Buffalo Branch Bridge and further testing will be completed to determine the effectiveness of the rehabilitation. / Master of Science

Artificial shelters show great promise as novel, non-invasive tools for studying hellbenders, but their use thus far has faced several challenges. During initial trials in multiple river networks, artificial shelters routinely became blocked by sediment and dislodged during high stream discharge events, and were rarely used by hellbenders. We sought to determine whether these complications could be overcome via alternative shelter design, placement, and maintenance. Between 2013 and 2018, we deployed 438 artificial shelters of two different designs across ten stream reaches and three rivers in the upper Tennessee River Basin. We assessed evidence for several hypotheses, postulating broadly that the availability, stability, and use of artificial shelters by hellbenders would depend on how shelters were constructed, deployed, and/or maintained. We found that maintaining shelters at least once every 40 days limited sediment blockage, and building ~ 40 kg shelters with 3-4 cm thick walls and recessed lids improved their stability during high discharge events. Additionally, we found that hellbenders most frequently occupied and nested in artificial shelters when they were deployed in deeper (~50+ cm) portions of reaches with high adult hellbender densities. Our results suggest that artificial shelters can serve as effective tools for studying hellbenders when designed, deployed, and maintained with these advancements, but also highlight some limitations of their use. / Master of Science / Hellbenders are large, fully-aquatic salamanders that live primarily in cool, rocky, swift-flowing streams in portions of Appalachia and the lower Midwest. They are imperiled across most of their native range due to human-caused habitat degradation, but their declines, conservation needs, and population status have historically been difficult to study due to the fact that they spend the majority of their lives beneath large, often inaccessible boulders. While these boulders are sometimes possible to lift, doing so can disturb critical hellbender habitat. Therefore, alternate, less invasive hellbender sampling methods are necessary in order to improve knowledge about their conservation status and needs. Artificial shelters, which are large, hollow, concrete structures that mimic natural boulder crevices and feature removable lids, show promise as a novel, innovative tool for non-invasively studying hellbenders. However, initial trials of these shelters have yielded mixed results, with shelters often becoming swept away and destroyed during floods, becoming blocked by sand and sediment and thus inaccessible to hellbenders, or simply not being used by hellbenders when accessible. We sought to determine whether these complications could be overcome by optimizing the way that shelters were constructed, deployed, and maintained in streams inhabited by hellbenders. Between 2013 and 2018, we deployed 438 artificial shelters of two different designs across ten stream reaches and three rivers in the upper Tennessee River Basin. Using multiple analyses, we tested one broad overall hypothesis: that the efficacy of using artificial shelters to study hellbenders would depend on how they were constructed, how frequently they were maintained, and where they were placed in the stream. We found that maintaining shelters at least once every 40 days limited sediment blockage, and building ~ 40 kg shelters with 3-4 cm thick walls and recessed lids improved their stability during flood events. Additionally, we found that hellbenders most frequently occupied and nested in artificial shelters when they were deployed in deeper (~50+ cm) portions of reaches with high adult hellbender densities. Our results suggest that artificial shelters are effective tools for studying hellbenders when designed optimally, maintained frequently enough, and placed in appropriate locations. However, exceptions to these findings may exist in certain heavily degraded stream reaches.

A key cryptographic research interest is developing an automatic, black-box method to provide a relative security strength measure for symmetric ciphers, particularly for proprietary cyber-physical systems (CPS) and lightweight block ciphers. This thesis work extends the work of the recently-developed neural cryptanalysis method, which trains neural networks on a set of plaintext/ciphertext pairs to extract meaningful bitwise relationships and predict corresponding ciphertexts given a set of plaintexts. As opposed to traditional cryptanalysis, the goal is not key recovery but achieving a mimic accuracy greater than a defined base match rate. In addition to reproducing tests run with the Data Encryption Standard, this work applies neural cryptanalysis to round-reduced versions and components of the SIMON/SPECK family of block ciphers and the Advanced Encryption Standard. This methodology generated a metric able to rank the relative strengths of rounds for each cipher as well as algorithmic components within these ciphers. Given the current neural network suite tested, neural cryptanalysis is best-suited for analyzing components of ciphers rather than full encryption models. If these models are improved, this method presents a promising future in measuring the strength of lightweight symmetric ciphers, particularly for CPS. / Master of Science / Cryptanalysis is the process of systematically measuring the strength of ciphers, algorithms used to secure data and information. Through encryption, a cipher is applied to an original message or plaintext to generate muddled message or ciphertext. The inverse of this operation, translating ciphertext back into plaintext, is decryption. Symmetric ciphers only require one shared secret key that is used during for both encryption and decryption. Machine learning is a data analysis method that automates computers to learn certain data properties, which can be used to predict outputs given a set of inputs. Neural networks are one type of machine learning used to uncover relationships, chaining a series of nodes together that individually perform some operations to determine correlations. The topic of this work is neural cryptanalysis, a new approach to evaluate cipher strength relying on machine learning. In this method, the goal is to "learn" the ciphers, using machine learning to predict what the ciphertext will be for an inputted plaintext. This is done by training the networks on plaintext/ciphertext pairs to extract meaningful relationships. If a cipher is easier to predict, it is easier to crack and thus less secure. In this work, neural cryptanalysis was applied to different real-world symmetric ciphers to rank their relatively security. This technique worked best on analyzing smaller components of the cipher algorithms rather than the entire cipher, as the ciphers were complex and the neural networks were simpler.

Yes / This paper proposes a new design concept for a steel truss-reinforced concrete box girder which incorporates a steel truss instead of longitudinal bars and stirrups. A comprehensive assessment of the flexural and shear behavior of the proposed steel truss-reinforced concrete box girders was conducted through the testing of twelve girders until failure. All test specimens had the same concrete depth and width of 400 mm and 300 mm, but the length of concrete in the shear and flexural specimens were 3300 mm and 3100 mm, respectively. Moreover, the reinforcing steel truss configuration and member sizes were different. The effects of the angle steel size of the lower chord, vertical webs spacing, shear span ratio and presence of diagonal webs on the cracking, yield and ultimate loads, crack patterns, failure modes, vertical load-deflection curves and strain distribution of these steel truss-reinforced concrete box girders were studied. The test results showed that the flexural capacity of the steel truss-reinforced concrete box girder increases with the increase of angle steel size of the lower chord. Moreover, the spacing of vertical webs and presence of diagonal webs have little effect on the flexural capacity of steel truss-reinforced concrete box girders tested. With the decrease of the shear span ratio and vertical webs spacing, the shear capacity of the steel truss-reinforced concrete box girder increases. Finally, simplified formulae for calculating the flexural and shear capacities of steel truss-reinforced concrete box girders were proposed, showing good agreement with the experimental results.

“Big-Box Nation: Target, Retail, and Creating the American Landscape” focuses on Minneapolis-based retailer Target Corporation to examine how big-box stores became a common feature of the American landscape, whether in rural Iowa or urban Boston. Retail emerged as one of the most powerful industries in the United States during the twentieth century by mastering the mass distribution counterpart to mass production. As retail’s influence grew, so too did its impact on American life and government. Such influence made retail an important part of twentieth-century urban planning, from downtown consumer palaces to postwar suburban shopping centers, and from urban revitalization projects to brownfield redevelopments. The rise of modern environmental legislation during the 1970s, however, posed an unprecedented threat to retailers. While other industries faced the full brunt of environmental regulation, retail—despite its large environmental impact from its promotion of auto-dependency and its connection of consumers with ecologically damaging global supply chains—largely escaped the state’s regulatory reach. Target promoted consumer choice as an American value, lobbied at Congressional hearings to avoid penalties under the Clean Air Act and other environmental legislation, partnered with the federal government to build favorable relations, and launched corporate public relations campaigns to promote itself as a public citizen and retail as an environmentally responsible industry. The dissertation is the first to examine the political and environmental history of retail. Historical studies on big-box stores have overwhelmingly focused on Walmart and its connection to the rise of the service economy, modern conservatism and rural, blue-collar neopopulism. Target’s midwestern origin in urban, liberal Minneapolis complicates previous narratives of big-box retail and reveals the ways in which business looked to the state as an ally in their rise. Environmental historians, on the other hand, have detailed many ways in which twentieth-century mass consumption affected landscapes in the United States and across the world, yet the material and domestic sites where Americans purchased the products made from the labor, energy, and resources of these distant places has not yet been examined as a window onto a unique form of environmental negotiation and corporate power. / 2026-09-18T00:00:00Z