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Assessing The Relationship Between The Quasi-Biennial Oscillation And D-Region Electron Density, Natalie R. Wirth

Theses and Dissertations

High frequency (HF) communication is a vital aspect of military communication and is highly reliant upon ionospheric conditions. The variation in electron density within the lowest echelon of the ionosphere, the D-region, can significantly impact HF signals, making communication inconsistent and unreliable for these wavelengths. Despite the D-region’s important, research in this area mainly focuses on understanding the impact of space weather anomalies on the upper ionosphere, particularly its higher layers, with relatively little exploration of the D-region. This region, situated closest to the troposphere and stratosphere, has been definitively linked to solar weather events like solar flares and geomagnetic …

Single Particle Analysis Of Operation Roller Coaster Environmental Samples, Caleb J. Sapp

Theses and Dissertations

The release of plutonium and other actinides into the environment following a nuclear detonation or accident, poses a health risk to biological systems. The spread, or transportation of that plutonium and its daughter products through environmental and meteorological means increases the potential affect and inherent danger within the surrounding area. In the 1960’s, a study was conducted in a joint effort by the US and Great Britain to collect information regarding the spread of plutonium released into the environment through a sub-critical detonation. Soil samples from these tests were collected by the USAF in 2015, approximately 50 years after these …

Hardware-In-The-Loop Autonomous Trajectory Generations For On-Orbit Rendezvous And Proximity Operations, Connor Slattery

Theses and Dissertations

Utilizing the C++ version of GPOPS within a robotic operating system to assess efficacy on flight-ready hardware is a vital interest of the space industry today. The findings in this paper show the ability of employing GPOPS in C++ on flight-ready hardware, leveraging optimal control as the main driver to creating a control pipleline to allow a robotic platform to generate and follow an optimized trajectory with minimal user input.

Estimating The Treatment And Prophylactic Economic Value Of New Antimicrobials In Managing Antibiotic Resistance And Serious Infections For Common Pathogens In The Usa: A Population Modelling Study, Jason Gordon, Maria Gheorghe, Cale Harrison, Ryan Miller, James Dennis, Lotte Steuten, Simon Goldenberg, Sumanth Gandra, Amer Al-Taie

2020-Current year OA Pubs

BACKGROUND: Antimicrobial resistance is a growing public health concern. There is a global need to estimate the population-level value of developing new antimicrobials and to ensure the effective use of existing antimicrobials as strategies to counteract antimicrobial resistance. To this aim, population-level value criteria need to be considered alongside conventional value measures.

OBJECTIVE: The objective of this study was to develop a novel modelling approach to estimate the value of new antimicrobials, considering the transmission, diversity and enablement elements of STEDI value.

METHODS: We developed a population-based mathematical model for the assessment of antimicrobial value considering both prophylactic use of …

Antioxidant Properties Of Kombucha Beverage Infused With Ganoderma Lucidum And Green Tea From Camellia Sinensis (L.) Kuntze With Several Fermentation Times, Rizki Rabeca Elfirta, Pamungkas Rizki Ferdian, Iwan Saskiawan, Tri Hadi Handayani, Kayla Faza Gustafri Mandalika, Rini Riffiani, Kasirah Kasirah, Ukhradiya Magharaniq Safira Purwanto

Karbala International Journal of Modern Science

Kombucha is a functional beverage produced through the fermentation of infused tea or Camelia sinensis (L.) Kuntze (CS) by a symbiotic culture of bacteria and yeast. Apparently, the substrate of kombucha can be substituted to enhance its functional properties. Ganoderma lucidum (GL) is a potential substrate reported to have health benefits. This study aims to evaluate antioxidant properties by comparing different formulations and fermentation times. The formulations prepared in the present study varied in the compositions of GL and CS substrates, namely F1 (100% GL), F2 (75% GL: 25% CS), F3 (50% GL: 50% CS), F4 (25% GL: 75% CS), …

Christiaan Huygens' Wave Theory Of Light: A Major Contribution To Seventeenth Century Science, Cari Petersen

The Thetean: A Student Journal for Scholarly Historical Writing

The phenomena of light have been subject to much speculation and controversy throughout history. The ancient Hebrews believed that light was formed by God's command on the first day of creation. The ancient Egyptians worshipped the sun, the source of light, and called it Ra; the Persians worshipped the sun as Mithras. By the fifth century B.C. the Greek's quest to comprehend light came under natural investigation instead of a supernatural mysticism. Through logic, the ancient Greek philosopher, Empedocles, reasoned that light must have a measurable speed since it takes time for light to get from one place to another. …

Relocating Lubra Village And Visualizing Himalayan Flood Damages With Remote Sensing, Ronan Wallace, Yungdrung Tsewang Gurung, Ryan Kastner

Journal of Critical Global Issues

As weather patterns change worldwide, isolated communities impacted by climate change go unnoticed and we need community-driven solutions. In Himalayan Mustang, Nepal, indigenous Lubra Village faces threats of increasing flash flooding. After every flood, residual muddy sediment hardens across the riverbed like concrete, causing the riverbed elevation to rise. As elevation increases, sediment encroaches on Lubra’s agricultural fields and homes, magnifying flood vulnerability. In the last monsoon season alone, the Lubra community witnessed floods swallowing several agricultural fields and damaging two homes. One solution considers relocating the village to a new location entirely. However, relocation poses a challenging task, as …

Environmental Analysis Of Codfish Production And Consumption In Portugal, Ayla Frost, Joana Almeida, Joana Dionisio, Radu Godina, Cátia Magro

Journal of Critical Global Issues

Codfish, a typical dish consumed frequently in Portugal, is fished in the cold Northern Atlantic waters far from the Portuguese coast. Thus, regional tensions and the environmental impacts of Portuguese codfish importation and production are significant current issues. The present study uses a life cycle assessment methodology to evaluate the array of environmental impacts of the production of 1 kg of codfish, following a cradle to gate approach. The life cycle inventory was grouped into catch and preprocessing, transit, and curing stages. The data collection of products and processes in each stage was based on scientific peer reviewed documents, technical …

One-Pot Synthesis Of Dextran-Based Silver Nanocomposite Hydrogel As A Vehicle For Sustained Co-Delivery Of 5-Fluorouracil And Cisplatin, Amos Luanda, Manohar Mahadev, Rompicherla Narayana Charyulu, Vishalakshi Badalamoole

International Conference on ‘NANOSCIENCE AND NANOTECHNOLOGY'

No abstract provided.

Examination Of The Delphi Method For Establishing A Quantitative Literacy Framework In Undergraduate Mathematics Course, Emily Elrod, Joo Young Park

Numeracy

The increased relevancy and importance of quantitative literacy (QL) have called for educational reform in undergraduate mathematics course offerings. However, lack of clear guidelines has led to wide variability in the content and outcomes of math courses meant to address QL. Therefore, having an expert consensus regarding content and outcomes for an undergraduate mathematics course focusing on QL would advance the quantitative literacy initiative in higher education. The authors propose the Delphi Method to aid in developing a framework based on expert opinions. The authors explain the Method and suggest the result of this process should yield a research-based framework …

Germplasm Enhancement Of Annual Forage Legumes Suitable For Use In Cold Highland Environments, H K. Firincioglu, N Karagullu, S Unal, A M. Abd-El Moneim

IGC Proceedings (1977-2023)

The Central Highlands (CH) of Turkey are characterized by cold winters and dry summers. Under these extreme air temperatures, forage crops are still underexploited as a part of crop rotations. Half of the total vetch hectarage in Turkey is in the CH, and farmers still use the local cultivars that have good adaptability but low yield potential. Therefore, with the aim of identifying and improving the annual forage legume species for the cold and dry environment of the CH, research work was carried out during the 1993/94 and 1994/ 95 crop seasons. Initial results showed that Hungarian vetch (Vicia …

Use Of The Grazing Animal In Forage Breeding, J H. Bouton, C S. Hoveland, R N. Gates

IGC Proceedings (1977-2023)

The objective of these studies was to determine, in the context of a forage breeding program, the effect of cattle grazing on survival of alfalfa (Medicago sativa L.), red clover (Trifolium pratense L.), and tall fescue (Festuca arundinacea Schreb.). Different cultivars of each species were compared in grazed and ungrazed areas. Results consistently demonstrated that grazing reduced plant stands when compared to ungrazed conditions for each species tested. In alfalfa, however, cultivars developed for grazing tolerance showed much better grazing survival. Infection with the fungal endophyte, Acremonium coenophialum Morgan-Jones & Gams, likewise substantially increased grazing survival in …

Study Of Genotype X Environment Interaction In Alfalfa Forage Yield, S N. Acharya, G C. Kozub, H Najda, A Aasen

IGC Proceedings (1977-2023)

The response of alfalfa (Medicago sativa L.) forage yield to eight Alberta test sites was studied for the 1990 and 1991 production years. Cluster analysis was used to group locations and cultivars. Analyses of variances indicated genotype x environment (location) interaction for the first cut yield, the total yield and the difference between first and second cut yields. The Brooks, Bow Island (irrigation), Bow Island (dryland) and Provost locations always clustered together indicating that three of these four test sites may be eliminated without sacrificing reliability.

Selection For Self-Fertility And Self-Fertility In Alfalfa As A Tool For Breeding Strategy Assessment, D Rosellini, F Veronesi, F Lorenzetti

IGC Proceedings (1977-2023)

Cultivar development in alfalfa relies on heterosis, that has been mainly exploited by intercrossing selected clones from diverse gemplasm sources; an alternative way was proposed, based on developing double cross cultivars obtained by crossing clones selected for self-sterility, propagated by somatic seed. A different breeding strategy was recently emphasized based on population improvement through inbreeding and recurrent selection; in this case, self-sterility would be selected against. If self-sterility is determined by genetic load, the second strategy should be preferred, and selecting for self-fertility may bring about positive correlated responses for forage yield. Divergent selection for self-fertility was applied in a …

Morphological And Rapd Variations And Regenerants Derived From Cell Suspension Culture Of Pangolagrass, C S. Chen, S M. Wang, Y K. Cheng

IGC Proceedings (1977-2023)

Pangolagrass cv. A254, a sterile strain, is one of Taiwan's major forage sources but recently has faced serious disease problems. Tissue culture was expected to generate variations in the breeding program of pangolagrass. The purpose of this study is to examine the somaclonal variation of regenerated plants by means of phenotypic characters survey and RAPD analysis. After long-term suspension culture and EMS mutagenesis, many regenerated plants with morphological variations have been found. Among the regenerants, 10 clones with obviously different characteristics were selected for further studies. Nine of them showed significant differences in morphological trains as compared to A254. By …

Phylogenetics Of Apomictic Common Dallisgrass (Paspalum Dilatatum), B L. Burson, M A. Hussey

IGC Proceedings (1977-2023)

Common dallisgrass, Paspalum dilatatum Poir., an important warm season forage grass, is an obligate apomict with 50 chromosomes which associate as 20 bivalents and 10 univalents during meiosis. Because efforts to improve the grass have not been successful, a phylogenetic investigation was initiated to identify the progenitors of common dallisgrass in an effort to circumvent the apomictic barrier to improvement. The genomic composition has been determined for four dallisgrass biotypes: yellow-anthered (2n=4x=40) IIJJ; common (2n=5x=50) IIJJX; Uruguayan (2n=6x=60) IIJJXX; and Uruguaiana (2n=6x=60) IIJJXX. While the source of the X genome is unknown, the genes controlling apomixis are on at least …

Increased Longevity Of Red Clover Through Selection For Persistence And Disease Resistance, R R. Smith

IGC Proceedings (1977-2023)

Red clover (Trifolium pratense L.), an excellent perennial forage legume, has been considered for many years to be a short-lived, two to three years, forage. Selection for resistance to foliar and root rot diseases and for longevity of stand over the past four decades has improved the persistence of the currently available cultivars. The present studies were conducted to evaluate the progress from selection for longevity and disease resistance. Selection for stand longevity and improved disease resistance has reliably extended the production of red clover into the third and fourth year. Selection for healthy plants in 3- or …

Backcrosses Of Diploid Lolium-Festuca Hybrids To Festuca, W Nitzche

IGC Proceedings (1977-2023)

Fertile diploid hybrids of Lolium x Festuca -backcrosses were produced by colchicine-treatment without chromosome doubling. The hybrids have new combinations of their characters, not known in the natural species.

Selection For Herbage Yield And Flowering In Ladino White Clover, J A. Garcia

IGC Proceedings (1977-2023)

A geno-phenotypic recurrent selection program is being carried out on ladino white clover (Trifolium repens L.) aiming to combine good DM and seed yields. Selection criteria includes plant density, vigor, winter growth, flowering and diseases resistance. The performance of selections in terms of DM yields and seed production was evaluated in separate trials. Two cycles of selection increased flowering by 36% and seed yield by 59%. Preliminary data on herbage yields shows a very good performance of the selected material and suggests the feasibility of combining high DM and seed yields.

Selection For Field Survival Increases Freezing Tolerance In Festulolium, M D. Casler, P G. Pitts, P C. Bilkey, C A. Rose-Fricker

IGC Proceedings (1977-2023)

Festulolium (Festulolium braunii K.A.) is marginally adapted to the north central and northeastern USA and southern Canada. The purpose of this study was to evaluate four festulolium populations selected for field survival under harsh winter conditions for their freezing tolerance in controlled environments. Progenies of all four populations showed some improvement in freezing tolerance compared to their parents. Improvements were dependent on the temperature at which measurements were made and varied among germplasms. Improvements were manifested in both decreased plant mortality and decreased injury to surviving plants. Genetic variation for freezing tolerance appears to be a viable mechanism …

Fitness Of Apomictic And Sexual Buffelgrass Germplasm, M A. Hussey, Yue-Wen Wang, B L. Burson

IGC Proceedings (1977-2023)

Breeding apomictic grasses is based on either the direct selection of apomictic landraces or the hybridization of sexual and apomictic types and selection of apomictic F1 hybrids. Little is known about the potential of sexual hybrids as cultivars in apomictic species. To determine if method of reproduction (MOR) was related to plant vigor, parental, S1, and F1 hybrids of buffelgrass differing in method of reproduction (apomictic or sexual) were established in a common garden in 1994 and 1995. In both years severe inbreeding depression was observed in the S1 progeny as they were shorter, produced less biomass, and had low …

Selection For Nitrogen Use Efficiency In Perennial Ryegrass Using Hydroponics, E N. Van Loo, A.J. P. Van Wijk, O Dolstra, H.J. P. Marvin, C.H. A. Snijders

IGC Proceedings (1977-2023)

A selection method was tested for improving nitrogen use efficiency of perennial ryegrass (Lolium perenne L.) using a hydroponics system that controls the plant nitrogen concentration. Divergent selection for plant production, leaf area increase and dry matter distribution in six segregating populations under limiting nitrogen supply resulted in differences between offspring of upward and downward selections larger than 20 % in most characteristics. Moderately high realized heritabilities were found for some characteristics (up to 0.88). It is concluded that early selection for nitrogen use efficiency is feasible using this hydroponics system.

Development Of A Multicross Cultivars Of Stylosanthes Spp., B Grof, C D. Fernandes, C B. Almeida, A V. Dos Santos

IGC Proceedings (1977-2023)

A synthetic population, referred to as multicross, has been developed from an interspecific mixture of Stylosanthes capitata and S.macrocephala germplasm. This basic population evolved in a farming situation subject to uncontrolled, continuous, heavy grazing. Natural selection and systematically programmed intercrossing among anthracnose-resistant Venezuelan and Brazilian genotypes of S.capitata have played major roles in the subsequent development of this heterogeneous population. Eight anthracnose-resistant Venezuelan and two Brazilian accessions of S.capitata were introgressed into the basic population. Genetic diversity was further increased by adding seed of four selected accessions of S. macrocephala to the synthetic which had already included …

Selection Of Stylosanthes Guianensis For The Cerrados Of Brazil, B Grof, C D. Fernandes, A V. Dos Santos, C B. Almeida

IGC Proceedings (1977-2023)

Progenies of intervarietal hybrid stylos (Stylosanthes guianensis var.vulgaris x S.guianensis var.pauciflora) with mid-season maturity date (early-and mid-June), high dry matter and seed yields have been identified at the National Beef Cattle Research Center (CNPGC), Campo Grande, MS, Brazil. Dry matter yields of the best selections were comparable to those of the late-flowering control, cv. Mineirão. Several mid-season hybrids produced 150 to 200 kg/ha of seed-inpod and a single plant selection yielded in excess of 300 kg/ha. The high degree of resistance to anthracnose observed in the advanced generations is attributed to the immense genetic diversity of these …

Development Of Red Clover With High Levels Of Resistance To Root-Knot Nematodes, K H. Quesenberry, R A. Dunn, D E. Moon

IGC Proceedings (1977-2023)

Red clover (Trifolium pratense L.), is grown in many areas of the world, but production in subtropical regions may be limited by susceptibility to root-knot nematodes (Meloidogyne spp.) (RKN). Selection for early vigor in RKN infested soils resulted in moderate RKN tolerance in ‘Cherokee’. However, improved RKN resistance in red clover was needed. Seven additional cycles of greenhouse selection using Cherokee as a base population developed a population (FLMR7) with high RKN resistance. When FLMR7 was infested with M. arenaria, M. hapla, M. incognita, or M. javanica, numbers of galls and egg masses …

Evaluating White Clover For Resistance To Cylindrocladium Root Rot, D S. Wofford, A Amaya

IGC Proceedings (1977-2023)

A rapid screening technique was developed for use in evaluating white clover (Trifolium repens L.) for resistance to Cylindrocladium root rot incited by Cylindrocladium crotalariae. Culture plates of the fungus were evaluated for number of infective propagules after four weeks of growth on potato dextrose agar, and no differences were detected among plates. Seedlings of ‘Osceola’ white clover were exposed in the greenhouse to four levels of inoculum over a six-week period, with resistance based on percent survival of uninoculated controls. It was shown that suspending 1 culture plate in 100ml of water and rating plants four weeks …

Characterization Of Chilling Sensitivity Of Tropical And Temperate Grasses, M Ebina, K Okumura, H Matsu-Ura, Y Tsurumi

IGC Proceedings (1977-2023)

C16-C18 fatty acid composition of some lipids in several species of temperate and tropical grasses were measured. The fatty acid composition of phosphatidylglycerol (PG) and sulfoquinovosyl diglyceride (SQDG) indicated significant differences between temperate and tropical grasses. Especially the differences of the fatty acid composition of PG were remarkable. The unsaturated fatty acid content of PG in tropical grasses was lower than the contents in temperate grasses. These differences constantly appeared through the year. These differences were caused by the low content of polyunsaturated fatty acids, or the low contents of C18 fatty acids.

Characterization Of Somatic Hybrids Between Festuca Arundinacea And Lolium Multiflorum, M Fujimori, T Takamizo, K Suginobu

IGC Proceedings (1977-2023)

Metabolically inactivated tall fescue (Festuca arundinacea Schreb.) protoplasts and X-ray irradiated Italian ryegrass (Lolium multiflorum Lam.) protoplasts were electrofused resulting in the regeneration of twenty-six plantlets. Southern blot analysis using three mitochondrial probes and random amplified polymorphic DNA (RAPD) analysis revealed that the regenerants were intergeneric somatic hybrids. All regenerated plants were male sterile and some of them had stamens that exhibited the pistillode appearance.

Selecting Lucerne (Medicago Sativa Complex) For Traits Conferring Adaptation To Grazing, E Piano, L Pecetti, M Romani

IGC Proceedings (1977-2023)

A germplasm collection of the Medicago sativa complex was evaluated to select genotypes possessing traits possibly conferring adaptation to grazing. Deep-crowned plants, either creeping-rooted or rhizomatous, were found with different frequencies, in all “taxonomic” groups examined. Although belonging to subsp. sativa, “mielga” wild populations from Spain were closer to subsp. falcata for morpho-physiological traits. Deep-crowned plants could be categorised into four top-growth models, to which corresponded a fairly distinct underground morphology: three were rhizomatous and one creeping-rooted. Cultivars selected for creeping-rootedness did not outyield rhizomatous populations of subsp. x varia which, in turn, had better spreading ability. In a …

Selection For Seed Size And Coleoptile Length In Timothy (Phleum Pratense L.), Hans Arne Jonsson

IGC Proceedings (1977-2023)

The intention of this study was to show the effect of selection for seed weight and coleoptile length on morphology and agronomically important characters in timothy (Phleum pratense L.). Two cycles of selection increased the seed weight as well as the length of coleoptile and root. The emergence from deep sowing in sand and in the field were insignificantly increased, whereas the percentage stand and the dry matter yield were decreased, albeit insignificantly. Inbreeding and linkage effects were considered possible causes for this.