Physical Sciences and Mathematics Commons^™

Changes In Productivity Associated With Replacement Of Heteropogon Cotortus By Aristida Species And Chrysopogon Fallax In The Savannas Of South East Queensland, F P. Wandera, P C. Kerridge, J A. Taylor, H M. Shelton

IGC Proceedings (1977-2023)

Heteropogon contortus-dominated rangelands, which cover 22 million ha, are the most important areas for beef production in northern Australia. Due to overgrazing, this dominant species ,is disappearing and is being replaced by unpalatable species such as Aristida and Chrysopogon in a patchy mosaic pattern. In a large graiing experiment· adjacent to the CSIRO Narayen research station: in south-east Queensland on granite country, patches dominated bf the unpalatable grasses comprised 24-32% of the area. Aristida-dominant and Chrysopogon-dominant patches had lower productivity (1000 and 650 kg/ha, respectively) than areas dominated by Heteropogon contorus (1850 kg/ha). It was estimated that a rangeland …

Dynamics Of Stylosanthes Species In Mixed Pastures In A Marginal Environment, J G. Mcivor, C J. Gardener

IGC Proceedings (1977-2023)

The growth and population dynamics of Stylosanthes hamata cv. Verano and S. scabra cv. Seca were measured in mixed, oversown pastures at Hillgrove (AAR=535 mm) near Charters Towers. Over a 10-year period mean stylo yields ranged from 20 kg/ha to 1800 kg/ha. During the first 3 years Verano outyielded Seca but in the last 7 years Seca had greater yields. Plant density was greater for Verano lhan Seca during the early years but the situation was reversed in later years. The Seca plants lived longer than Verano plants and there was a greater proportion of perennial plants in the Seca …

Distribution And Abundance Of Plant Species In Pastures And Rangelands, John G. Mcivor

IGC Proceedings (1977-2023)

The competition-stress-disturbance (CSD) model of Grime (Plant strategies and vegetation processes, New York, John Wiley 1979) is used as the basis for discussing the forces that influence the distribution and abundan.ce. of plant species. Characteristics of plant strategies (competitive, ruderal and stress-tolerator) in both the established and regenerative phases are summarised. Pasture management can be viewed as the manipulation of competition, stress and disturbance. A number of pasture situations ( disturbance-diversity relationships, pasture degradation, weed invasion, management of abandoned farm land, species conservation) are analysed in ecological terms and the consequences for pasture management are outlined. The CSD model can …

Aspects Of Interference Between Nodding Thistle (Carduus Nutans L.) And Pasture Grasses And Legumes, D A. Wardle, K S. Nicholson, A Rahman

IGC Proceedings (1977-2023)

Nodding thistle (Carduus nutans L.) is an important weed species in New Zealand pastures. The available information on interactions between this species and forage grasses and legumes is summarised and discussed. Nodding thistle inhibits pasture productivity, and allclopathy is probably Important at inhibiting pasture at the later stages of its life cycle. Although, nodding thistle is most susceptible to inhibition by forage species early in its life cycle, a minimum pasture cover may be required for seedlings to establish. Nodding thistle therefore acts as a competitor only at the later stages of its development. Grasses arc both stronger at inhibiting …

Effects Of Herbicides And Fertilizers On Ragwort (Senecio Jacobaea L.) In Hill Country Pastures, A Rahman, K S. Nicholson, D A. Wardle

IGC Proceedings (1977-2023)

A 3-year study was conducted lo determine the influence of 2 herbicides (2,4-D and glyphosate) and 3 fertilisers (containing N, P or K), in conjunctiun with pasture renovation, on ragwort (Senecio jacobaea L.) populations and pasture productivity in a perennial ryegrass-white clover hill country pasture. Glyphosate-treated plots often contained higher ragwort numbers than 2,4-D treated plots, probably because the glyphosate treatment caused greater discontinuity of pasture. Both N and P fertilisers had a consistently strong beneficial effect on pasture, which resulted in substantial inhibition of ragwort populations. During the end of each of the first 2 years of the …

Regeneration Of Themeda Triandra In Humid South African Rangelands, K Adams, J E. Danckwerts

IGC Proceedings (1977-2023)

Themeda triandra seeds were planted into undisturbed, burnt and tilled treatments in degenerate humid grassland. More seedlings emerged and survived on tilled soil than on the other two treatments. The plants on the tilled treatments were also larger (had more tillers with greater mass than the other two). The effect of tillage was attributed to removal of competition from undesirable competitors, which seems essential in the reintroduction of T. triandra into humid grasslands of South Africa.

Effects Of The Fire Regime On Grassland And Savanna Rangelands In Southern Africa, Winston S.W Trollope

IGC Proceedings (1977-2023)

Fire is regarded as a natural factor of the environment in southern Africa and the effect of fire on rangeland depends upon the fire regime, i.e., type and intensity of fire and season and frequency of burning, The most common types of fire in grassland and savanna areas are surface fires burning either as head or back fires. Head fires have the least depressive effect on the recovery of the grass sward and cause high« topkill of stems and branches of trees and shrubs than back r1res, Fire intensity has no significant effect on the recovery of the grass sward …

Sward Characteristics Of A Diploid And Tetraploid Cultivar Of Perennial Ryegrass As Measured By Different Sampling Techniques, J H. Neuteboom, E A. Lantinga, H Schlepers, L 'T Mannetje

IGC Proceedings (1977-2023)

In a grazing experiment with monocultures of 2 perennial ryegrass (Lolium perenne L.) cultivars it was found that over a 6-year period the tiller density of the tetraploid Condesa was on average 27% lower than that of the diploid Wendy. The lower tiller density of Condesa went along with a more open sward structure and higher weed proportions after 6 years, Sward structure was suitably characterised by means of absence frequency estimations of rooted perennial ryegrass tillers from concentric sampling quadrats.

Effect Of Localized And Epsidodic Nutrient Supplies And Salinity On Growth Of Selected Grass Species, M M. Wolfson, J Caetano

IGC Proceedings (1977-2023)

The efficient use of non•uniform nutrient supplies may be an important component of plant nutrient relationships in soils, especially where inputs of available nutrients by mineralisation may be slow and unpredictable. The experiments reported here examined the effects of periodic supplies of nutrients as well as localised nutrient supplies on the growth of grass species which are common in cultivated soils and pastures. Most plants cannot produce significant yields when grown under saline conditions owing to the difficulty the plant has adjusting to the osmotic potential of the growth medium and its limited capacity to cope with accumulated c1· and …

Analysis Of A Natural Pasture Of The Karst Region (North-East Italy) Under Chemical Fertilization, G Parente, R Ardiani, F Bozzo, M Onofrii, M Scimone, S Venerus

IGC Proceedings (1977-2023)

To characterise the vegetation changes in a natural pasture, a mineral fertilisation and a 4-year grazing test (1987-1990) were carried out on a typical karstic natural grassland, at that time not grazed by livestock and frequently devastated by fire. Mineral fertiliser and year-long animal grazing have modified the vegetation and seem not to have damaged the agro-ecosystem. An increase of the Arrhenatheretum species and, consequently, higher dry matter production, have been recorded, as well as an extension of the growth period and a greater quantity of grass during the summer. Animal performance has been quite satisfactory as the milk production …

Effect Of Elevation On Vegetation In The Southern Alburz Chain, Iran, Masoud Mohammad-Aliha

IGC Proceedings (1977-2023)

The effects of elevation on the vegetation composition of the southern rangelands (about 20 000 ha) of the Alburz Chain was studied. The attitudinal zones of the study area were located between 1200 and 3600 m asl. Twenty-three sites were selected alongside the attitudinal gradients (every 200 m change in height was allocated a substation). Twenty-one vegetation types were distinguished and 3 ecological sites (stations) selected. Also some grasses alongside the study area have been considered.

Assessing The Productivity Of Pastures In The Central Highlands Region Of Queensland, Australia, J Willcocks, P Filet

IGC Proceedings (1977-2023)

A sustainable grazing industry requires careful management of pastures. This study measured the growth potential and productivity of different pasture types in the Central Highlands region of Queensland to develop recommendations on stocking rates which are sustainable in the long term. The most productive pasture measured, buffet grass (Cenchrus clliaris) is generally used for fattening prior to sale to the meatworks. The least productive, a mixed native pasture under a eucalypt forest, is generally used for maintaining breeding stock. Forest Mitchell grass (Bothrioclrloa ewartiana) has intermediate levels of productivity and is used for both breeding and …

Seedling Emergence From Buried Seed In Unsown And Oversown Hill Pasture, M E. Wedderburn, W J. Pengelly, L A. Greaves

IGC Proceedings (1977-2023)

Seedling recruitment from buried seed was measured in hill country after the resident vegetation was suppressed or killed using herbicide, and either Yatsyn ryegrass, hill ryegrass or a low fertility grass mix was oversown. Unsown plots serves as a control. The total number of seedlings emerging per m2 was similar for all treatments but differences between treatments occurred in the species composition of seedling populations. Ryegrass seedling density in sown plots was 3 times that in unsown plots and white clover seedling numbers were 6 times greater. Other grasses were present in numbers equivalent to sown ryegrass. Subterranean clover and …

Adaptation Of Grassland For Recreational And Amenity Use, R J. Gibbs, K W. Mcauliffe, R W. Brougham

IGC Proceedings (1977-2023)

Adaptation of grassland for intensive sport and recreational use introduces constraints not normally experienced under agricultural pasture production. For example, turfgrass is expected to grow in deliberately compacted soils and structureless, inert sands. It is also expected to provide a surface for sports as diverse as golf and horse racing. This paper examines aspects of turfgrass management that differ from agricultural pasture production. These aspects include the ability of turf grass to withstand intensive wear, its ability to produce a dense, low growing and even sward and the specific drainage and playing quality demands of different sports. The key role …

Hypogene Speleogenesis In Carbonates By Cooling Hydrothermal Flow: The Case Of Mt. Berenike Caves, Israel, Roi Roded, Boaz Langford, Einat Aharonov, Piotr Szymczak, Micka Ullman, Shemesh Yaaran, Boaz Lazar, Amos Frumkin

International Journal of Speleology

The Berenike hypogenic cave system near Lake Kinneret, Israel, provides a valuable case study for investigating the recently proposed Confined-Cooling-Flow (CCF) speleogenesis model. Field and speleological surveys, along with existing research, are used to provide a thorough analysis. The CCF model relies on a simple thermo-hydro-chemical scenario, involving the rise of CO2-rich hydrothermal fluids discharging into a confined layer. The cooling of these CO2-rich fluids turns them into aggressive solutions due to the inverse relation between temperature and solubility of carbonates (retrograde solubility). Previous geochemical and numerical analyses of the CCF model predict localized and persistent dissolution and speleogenesis on …

Spatio-Temporal Changes In The Gravity And Post-Mining Seismic Activity In Abandoned Deep Coal Mine Kazimierz-Juliusz During Flooding, Andrzej Kotyrba, Łukasz Kortas, Sławomir Siwek

Journal of Sustainable Mining

The flooding of an underground hard coal mine, resulting in the filling of post-mining voids (workings and goafs) and the repeated saturation of pore and interstitial spaces of the adjacent rock with water, change the mass and its distribution in the near-surface part of the earth’s crust. This process is slow and lasts many years. As a result, the local gravity field undergoes dynamic changes. It depends on the surface morphology and the density of geological strata, which is related to their water content. Changes in the local gravity field can be monitored by periodic gravity surveys performed in the …

Mapping Urban Tree Canopy Using Publicly Available Satellite Data, Rosemary Mcguinness

Theses and Dissertations

This project addresses the need for accessible, cost-effective tools for quantifying spatial and temporal changes in tree canopy cover in urban areas. Urban tree canopy provides a wide range of ecosystem services, including lowering air temperatures, reducing pollution, and mitigating stormwater runoff. Cities around the world have placed the expansion of their urban forests at the center of their sustainability goals. Consistent and timely data on urban tree canopy is essential for urban greening initiatives to succeed. Existing methods of accessing information about urban tree canopy are highly technical, costly, and labor-intensive, while the freely available source of tree canopy …

Optimizing The Protein Yield Of The Collagen Mimetic Peptide: Col108, Fahmida Akter

Theses and Dissertations

Abstract

The fibril-forming collagen mimetic peptide Col108, produced in E. Coli, has shown potential for innovative biomaterial applications. However, further research is constrained by its limited yield. My study aims to enhance the experimental parameters and has successfully pinpointed rifampicin as an efficient method to boost the production of Col108.

Development And Optimization Of A 1-Dimensional Convolutional Neural Network-Based Keyword Spotting Model For Fpga Acceleration, Trysten E. Dembeck

Masters Theses

Spoken Keyword Spotting (KWS) has steadily remained one of the most studied and implemented technologies in human-facing artificially intelligent systems and has enabled them to detect specific keywords in utterances. Modern machine learning models, such as the variants of deep neural networks, have significantly improved the performance and accuracy of these systems over other rudimentary techniques. However, they often demand substantial computational resources, use large parameter spaces, and introduce latencies that limit their real-time applicability and offline use. These speed and memory requirements have become a tremendous problem where faster and more efficient KWS methods dominate and better meet industry …

Impact Of Climate Change And Restoration On Phosphorus Loading In An Impaired Wetland, Katherine M. Lucas

Masters Theses

Restoring wetlands can increase biodiversity and water quality in both the wetland and connecting ecosystems; however, failing to consider past land uses can result in negative water quality effects. Prior agricultural practices at a coastal wetland restoration site in West Michigan have caused high legacy phosphorus (P) concentrations in sediments, as well as high P levels in the water column. Sediment dredging is being considered as a restoration tool to control internal phosphorus loading (IPL). In addition, climate warming is resulting in increases in both mean temperature and temperature extremes, which may affect IPL. I examined the effects of both …

Non-Receptor Tyrosine Kinases: Their Structure And Mechanistic Role In Tumor Progression And Resistance, Abdulaziz M. Eshaq, Thomas W. Flanagan, Sofie Yasmin Hassan, Sara A. Al Asheikh, Waleed A. Al-Amoudi, Simeon Santourlidis, Sarah Lilly Hassan, Maryam O. Alamodi, Marcelo L. Bendhack, Mohammed O. Alamodi, Youssef Haikel, Mossad Megahed, Mohamed Hassan

School of Graduate Studies Faculty Publications

Protein tyrosine kinases (PTKs) function as key molecules in the signaling pathways in addition to their impact as a therapeutic target for the treatment of many human diseases, including cancer. PTKs are characterized by their ability to phosphorylate serine, threonine, or tyrosine residues and can thereby rapidly and reversibly alter the function of their protein substrates in the form of significant changes in protein confirmation and affinity for their interaction with protein partners to drive cellular functions under normal and pathological conditions. PTKs are classified into two groups: one of which represents tyrosine kinases, while the other one includes the …

A Measurement Of The Differential Drell-Yan Cross Section As A Function Of Invariant Mass In Proton–Proton Collisions At √ S = 13 Tev, William Robert Tabb

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The Drell-Yan process, a crucial mechanism for producing lepton pairs in highenergy hadron collisions, serves as an essential probe for testing the Standard Model of particle physics. This dissertation presents a comprehensive measurement of the differential cross section with respect to the invariant mass of the lepton pairs, utilizing data collected by the CMS experiment at CERN from 2016 to 2018. Cross sections are essential for refining our understanding of parton distribution functions and the underlying quantum chromodynamics processes, thereby providing constraints on theoretical predictions. In this analysis, the cross sections are compared to theoretical models and simulations, offering new …

Radiation-Tolerant Thin-Film Reference Electrodes And Potentiometric Sensors, Bingyuan Zhao, Alexander Wei

Department of Chemistry Faculty Publications

The integration of electronic sensors into single-use systems for bioprocessing is challenged by their sensitivity to sterilizing γ-irradiation. This challenge also applies to reference electrodes (REs), whose potentials may be destabilized upon ionization and drift over time. Here we evaluate the performance of thin-film Ag/AgCl REs over a two-month window following γ-ray sterilization using a 60Co source. γ-REs display a characteristic voltage decay function ascribed to the dissipation of radiation-induced charge defects, and exhibit long-term potentiometric stability when stored in phosphate-buffered saline (PBS) with a 95% confidence interval of 4 mV over 60 days. γ-REs have a mean insensitivity (inertness) …

Peri-Gondwanan Sediment In The Arkoma Basin Derived From The North: The Detrital Zircon Record Of A Uniquely Concentrated Non-Laurentian Source Signal In The Late Paleozoic, Tyson M. Smith, Marieke Deshesne, Jaime A.M. Hirtz, Glenn R. Sharman, Mark R. Hudson, Brandon M. Lutz, Neil Griffis

Geosciences Faculty Publications and Presentations

During the assembly of Pangea, peri-Gondwanan terranes collided with the eastern and southern margins of Laurentia and brought with them unique detrital zircon U-Pb signatures. Discriminating between individual peri-Gondwanan terranes in the detrital record is difficult due to their similar geologic histories. However, characterization of this provenance is critical for understanding late Paleozoic sediment routing during development of Pangea. Along southeastern Laurentia, in the Arkoma Basin (present-day Arkansas and eastern Oklahoma, southeastern United States), we identified Middle Pennsylvanian (Desmoinesian) strata that exhibit a concentrated peri-Gondwanan detrital zircon signature (e.g., ca. 800–550 Ma). Although several southern peri-Gondwanan terranes (e.g., Maya, Suwannee) …

Prospects For Time-Domain And Multi-Messenger Science With Axis, Riccardo Arcodia, Franz E. Bauer, S. Bradley Cenko, Kristen C. Dage, Daryl Haggard, Wynn C.G. Ho, Erin Kara, Michael Koss, Tingting Liu, Labani Mallick, Michela Negro, Pragati Pradhan, J. Quirola-Vásquez, Mark T. Reynolds, Claudio Ricci, Richard E. Rothschild, Navin Sridhar, Eleonora Troja, Yuhan Yao

Publications

The Advanced X-ray Imaging Satellite (AXIS) promises revolutionary science in the X-ray and multi-messenger time domain. AXIS will leverage excellent spatial resolution (< 1.5 arcsec), sensitivity (80× that of Swift), and a large collecting area (5–10× that of Chandra) across a 24-arcmin diameter field of view at soft X-ray energies (0.3–10.0 keV) to discover and characterize a wide range of X-ray transients from supernova-shock breakouts to tidal disruption events to highly variable supermassive black holes. The observatory’s ability to localize and monitor faint X-ray sources opens up new opportunities to hunt for counterparts to distant binary neutron star mergers, fast radio bursts, and exotic phenomena like fast X-ray transients. AXIS will offer a response time of < 2 h to community alerts, enabling studies of gravitational wave sources, high-energy neutrino emitters, X-ray binaries, magnetars, and other targets of opportunity. This white paper highlights some of the discovery science that will be driven by AXIS in this burgeoning field of time domain and multi-messenger astrophysics. This White Paper is part of a series commissioned for the AXIS Probe Concept Mission; additional AXIS White Papers can be found at the AXIS website.

The Product Of Science, Rolf A.E Mueller

IGC Proceedings (1977-2023)

The relationships between agricultural science, invention, production and consumption are conventionally considered in a hierarchical model with consumption at the basis and science at the pinnacle of the hierarchy. -Two important shortcomings of that model as a basis for organising and manag\ng agricultural research are identified. First, the model does not specify how the direction and intensity of research Is guided in the absence of markets for the outputs from research. Second, the model does not identify the flows of specific information from the consumption and agricultural production sphere to the research sphere where such information is crucial for the …

From Technology Transfer To Resource Management, Janice Jiggins

IGC Proceedings (1977-2023)

Six models of technological innovation are examined. The implications for the roles and functions of research and extension, and of agricultural education systems, are analysed. The models are assessed against issues of gender, natural resource management and poverty, with consideration of who pays, and who benefits. The conclusion is drawn that the Transfer of Technology model is not a generalisable model to all circumstances, clients and policy goals. Client-driven systems and participatory approaches which build partnerships among researchers, extensionists, producers and other users of grassland landscapes, can be more effective and efficient.

Combining Agricultural Agent Training In Forages With Graduate Credit, Garry Lacefield, Jimmy Henning, M Rasnake, C Forsythe, L Davis

IGC Proceedings (1977-2023)

An intensive agent training programme in alfalfa (Medicago sativa L.) production nnd utilisation was initialed in 1990. The training was organised by slate extension forage specialists to meet the needs of agricultural agents. Previous programmes have offered similar training but did nol resull in graduate credit. This unique approach offered intensive training to agents presented by a multidisciplinary learn of scientists. All requirements for graduate credit were met and the course completion resulted in 3 hours of graduate credit. The course has been rated "superior" by students. When properly organised and implemented, intensive agent training can be offered that …

A Grazing Land Conservation Plan, R G. Hendricks

IGC Proceedings (1977-2023)

In a sample planning scenario, a ranching operation in the USA demonstrates a typical conservation problem on grazing lands. Using SCS conservation planning techniques, problems and objectives are identified, resources are inventoried, data are analysed, solutions formulated and conservation practices implemented to solve the resource problem. With use of the economic analysis routine in Grazing Land Applications (OLA) version 1.1 decision suppott software, return on investment was largest when the client installed a combination of rest-rotation grazing, prescribed burning, and initiated a hunting lease programme.

Range Conservation Planning: The Usda- Soil Conservation Service Method, Rhett H. Johnson

IGC Proceedings (1977-2023)

The USDA-Soil Conservation Service has responsibility for providing one-on-one conservation planning assistance with the private rangeland managers of over 160 million ha in the USA. This assistance is provided on voluntary basis at the request of the private land user through a local conservation district. Through SO years of experience, a successful planning process has evolved, known as the Ten Elements Of Conservation Planning. These elements are: (1) provide information, (2) request assistance, (3) develop resource inventories, (4) recognise problems and opportunities, (5) determine objectives, (6) develop and evaluate alternatives, (7) make decisions, (8) document decisions, (9) implement decisions, and …