Physical Sciences and Mathematics Commons^™

Rangeland Rehydration: Collaboration Between Land Managers, Government And Private Experts, P. Theakston, H. J. R. Pringle, L. Mashford

IGC Proceedings (1993-2023)

In the rangelands of New South Wales, Australia, many successful soil erosion control techniques have been developed. These techniques have been implemented by the Western Local Land Services (WLLS), rehabilitating 23,000 ha since 2004. However the focus was on degraded land with little regard to catchment dynamics and the threatening processes that were causing the degradation.

With the introduction of Ecosystem Management Understanding (EMU)™ in 2016, the focus was broadened to address grazing properties in a drainage ecosystem context. There is a focus on understanding landscape function and designing projects that address threatening processes.

With the integration of the WLLS …

Plant Root Mass Fraction Response To Soil Resource Limitation In The Context Of Dry Mediterranean Rangeland, Guy Dovrat

IGC Proceedings (1993-2023)

Root mass fraction (RMF) was proposed as a stable measurement of plant resource partitioning that can represent plant acquisition–conservation trade‐offs. We examined the effects of soil resources availability on RMF of abundant annual plant species of water-limited rangeland. We used data from controlled experiments in which nine species were grown under variable water and nitrogen availabilities and their root and shoot biomass were examined at flowering time. In legumes we examined also presence of N₂-fixation. In all of the species, reduced water and/or nitrogen availability was associated with increased RMF. However, the magnitude of variation in RMF found …

Climate Variability In The Woodbush Granite Grasslands Of South Africa: Effects On Grassland Diversity, M. Muller, F. Siebert, A. Linstädter, D. I. Thompson, S. J. Siebert

IGC Proceedings (1993-2023)

South African old-growth grasslands are hyper-diverse ecosystems which evolved under naturally occurring rainfall variability. It is predicted that future precipitation patterns will become more variable, which could lead to increased frequencies of extreme and prolonged drought events. This study aimed to investigate the effects of climate variability on plant diversity of the fragmented pristine, mistbelt grasslands of the Woodbush Granite Grasslands (WGG) at Haenertsburg, South Africa. It has been reported that species composition has changed substantially in this area, as disturbance-tolerant species enter these systems or existing competitor species become more dominant. A Temporal Beta-diversity Index (TBI) was used to …

Recursive And Viterbi Estimation For Semi-Markov Chains, Robert J. Elliott, W. P. Malcolm

Journal of Stochastic Analysis

No abstract provided.

Physics Inventory Of Quantitative Literacy: A Tool For Assessing Mathematical Reasoning In Introductory Physics, Suzanne W. Brahmia, Alexis Olsho, Trevor I. Smith, Andrew Boudreaux, Philip Eaton, Charlotte Zimmerman

Physics & Astronomy

One desired outcome of introductory physics instruction is that students will develop facility with reasoning quantitatively about physical phenomena. Little research has been done regarding how students develop the algebraic concepts and skills involved in reasoning productively about physics quantities, which is different from either understanding of physics concepts or problem-solving abilities. We introduce the Physics Inventory of Quantitative Literacy (PIQL) as a tool for measuring Quantitative Literacy, a foundation of mathematical reasoning, in the context of introductory physics. We present the development of the PIQL and evidence of its validity for use in calculus-based introductory physics courses. Unlike …

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Legacy Scout Tickets from Pure Oil Company

No abstract provided.

Swift Trust And Sensemaking In Fast Response Virtual Teams, Xiaodan Yu, Yuanyanhang Shen, Deepak Khazanchi

Information Systems and Quantitative Analysis Faculty Publications

Fast-response virtual teams (FRVTs) have been developed as a response to emergent challenges faced by organizations that need to be addressed urgently. Even though FRVTs offer enormous potential in terms of their benefits, their success is not guaranteed. When used, the need for high performing FRVTs has become critical for organizational success. However, there is a lack of detailed understanding of how sensemaking can potentially influence FRVT performance. Drawing on social exchange theory, we identify swift trust as a potential antecedent of sensemaking. In this paper, we report the results of a study that examined the effects of swift trust …

Tectonic And Geotechnical Review Of Bengal Basin For Seismic Risk Assessment In Bangladesh, Mir Fazlul Karim, Jnana Ranjan Kayal, Daya Shanker, Nazrul I. Khandaker, Arif M. Sikder, M Zillur Rahman, Muhammad Qumrul Hassan

Publications and Research

Four major geotectonic provinces of the basin are recognized: 1) the continental slope to the west of the Hinge Zone, 2) the stable shelf, 3) the deep central trough (Sylhet-Hatiya) and 4) the Chittagong-Tripura fold belt to the east. The ~300 km long Dauki Fault demarcates the elevated Shillong Plateau, part of the Indian Shield to the north and the deep basin to the south. The basin experienced three strong to major intraplate earthquakes: a) 1885 Bengal earthquake (rev. Mw 6.8) close to the Hinge Zone, b) 1918 Srimangal earthquake (rev. Mw 7.1) on the Sylhet (trough) fault and c) …

Improved Neutron Lifetime Measurement With Ucn Τ, Alexander Komives, Et Al.

Physics & Astronomy Faculty publications

We report an improved measurement of the free neutron lifetime τn using the UCNτ apparatus at the Los Alamos Neutron Science Center. We count a total of approximately 38×106 surviving ultracold neutrons (UCNs) after storing in UCNτ’s magnetogravitational trap over two data acquisition campaigns in 2017 and 2018. We extract τn from three blinded, independent analyses by both pairing long and short storage time runs to find a set of replicate τn measurements and by performing a global likelihood fit to all data while self-consistently incorporating the β-decay lifetime. Both techniques achieve consistent results and find a value τn=877.75±0.28stat+0.22/−0.16syst  s. …

Measuring Cosmic Density Of Neutral Hydrogen Via Stacking The Dingo-Vla Data, Qingxiang Chen, Martin Meyer, Attila Popping, Lister Staveley-Smith, Julia Bryant, Jacinta Delhaize, Benne Holwerda, M E. Cluver, J Loveday, Angel R. Lopez-Sanchez, Martin Zwaan, E N. Taylor, A M. Hopkins, Angus Wright, Simon Driver, S Brough

Faculty and Staff Scholarship

We use the 21-cm emission-line data from the Deep Investigation of Neutral Gas Origin-Very Large Array (DINGO-VLA) project to study the atomic hydrogen gas H I of the Universe at redshifts z < 0.1. Results are obtained using a stacking analysis, combining the H I signals from 3622 galaxies extracted from 267 VLA pointings in the G09 field of the Galaxy and Mass Assembly Survey (GAMA). Rather than using a traditional one-dimensional spectral stacking method, a three-dimensional cubelet stacking method is used to enable deconvolution and the accurate recovery of average galaxy fluxes from this high-resolution interferometric data set. By probing down to galactic scales, this experiment also overcomes confusion corrections that have been necessary to include in previous single-dish studies. After stacking and deconvolution, we obtain a 30σ H I mass measurement from the stacked spectrum, indicating an average H I mass of MHI=(1.67±0.18)×109 M⊙" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; font-variant: inherit; font-stretch: inherit; line-height: normal; font-family: inherit; vertical-align: baseline; display: inline; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; position: relative;">MHI=(1.67±0.18)×109 M⊙MHI=(1.67±0.18)×109 M⊙⁠. The corresponding cosmic density of neutral atomic hydrogen is ΩHI=(0.38±0.04)×10−3" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; font-variant: inherit; font-stretch: inherit; line-height: normal; font-family: inherit; vertical-align: baseline; display: inline; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; position: relative;">ΩHI=(0.38±0.04)×10−3ΩHI=(0.38±0.04)×10−3 at redshift of z = 0.051. These values are in good agreement with …

Mitigating The Externality Of Diseases Of Poverty Through Health Aid, Kamal Jnawali, Michael G. Tyshenko, Tamer Oraby

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Externality exists in healthcare when an individual benefits from others being healthy as it reduces the probability of getting sick from illness. Healthy workers are considered to be the more productive labourers leading to a country’s positive economic growth over time. Several research studies have modelled disease transmission and its economic impact on a single country in isolation. We developed a two-country diseaseeconomy model that explores disease transmission and crossborder infection of disease for its impacts. The model includes aspects of a worsening and rapid transmission of disease juxtaposed by positive impacts to the economy from tourism. We found that …

Effects Of Thinning Density On Soil Water Content Of Alfalfa And David Peach Intercropping In The Hilly Loess Plateau, China, Z. X. Chen, X. L. Yang, G. H. Wang, Yuying Shen

IGC Proceedings (1993-2023)

Intercropping alfalfa (Medicago sativa) between the four meters inter-row spacing of David peach (Amygdalus davidiana) is one of replantation practices at the Longtan catchment in Gansu province of the western Loess Plateau in the early 1980’s. However, both alfalfa and David peach are deep-rooted species and their intercropping results in excessive consumption of soil water in the hilly Loess Plateau. To alleviate this, we set up four density/intercrop treatments, which includes: David peach+alfalfa (PA), David peach (P), 60% David peach+alfalfa (60% P+A) and 60% David peach (60% P). TRIME was used to quantify the soil water …

Exploring Drivers Of Invasiveness Of The Plant Species Senna Obtusifolia In Rangelands To Secure Forage Production In West Africa, O. Ouédraogo, A. Zaré, C. Bougma, S. Kambou, A. Linstädter

IGC Proceedings (1993-2023)

Rangelands in Sahelian countries are continuously over-grazed decreasing forage resources and causing rapid environmental changes. Senna obtusifolia is a less palatable plant species that becomes increasingly invasive. This research explored drivers of its invasiveness in the perspective to propose solutions to secure forage production in the pastoral reserves. Species composition and herbaceous aboveground biomass were assessed in rangelands with different levels of invasion of Senna obtusifolia along a climatic and land-use pressure gradient. A greenhouse experiment was conducted to test the competitiveness of this species. The development of Senna obtusifolia in rangelands affected significantly forage quantity. Indeed the biomass of …

Enhanced Grazing Management Assessment Using Drone-Based Lidar Measurements, V. W. Temu, W. C. Hession, P. Sforza, H. Wang

IGC Proceedings (1993-2023)

Globally, there is an urgent need of research-based technologies for small ruminant producers to benefit from rapidly growing market demands for ruminant meat and related food products from forage-based operations. However, effective forage-based animal production requires a rapid assessment, and monitoring of grazing management needs to adjust stocking rates and/or spatial animal distribution in a timely manner. Applicability of unmanned aerial vehicles (drones) for grazing management offers opportunities to rapidly estimate biomass build-ups, ground coverage, and monitor animal behaviour. The reliability of drone-based laser scanning (DLS) for monitoring warm-season grass responses to simulated grazing intensities was assessed at Virginia State …

Effects Of Parthenium Hysterophorus On Grassland Community In Nyando Sub-County, Kisumu County, Kenya, B. M. Mutua, W. Chiuri

IGC Proceedings (1993-2023)

Parthenium hysterophorus is an invasive alien species native to South and Central America. The plant is ranked as one of the most dreaded weeds of the world. Parthenium hysterophorus affects grassland community through the release of allelochemicals that inhibit the germination and growth of grass species. However, little is known about its effects on native grassland community in Nyando sub-county of Kenya. Therefore, this study sought to investigate the effects of P. hysterophorus on grass species, livestock production and its control. A total of 121 farm household heads were interviewed using semi-structured interview schedules. Descriptive analysis and the T-test at …

Ecorestore: Decision Support System To Restore The Productivity Of Degraded Rangelands In Southern Africa, Klaus Kellner, Dirk Pretorius, C. Marais

IGC Proceedings (1993-2023)

Land degradation is a multifaceted problem that affects the agricultural productivity of land due to a loss of vegetation cover and can often be ascribed to bush encroachment in savanna and grassland rangelands. Bush encroachment entails the increase in abundance and density of indigenous and alien woody vegetation (i.e. shrub thickening), which has a negative impact on the tree-grass ratio, biodiversity, as well as on a range of ecosystem services that affect the well-being of land users, often causing an increase in poverty and the introduction of non-sustainable land management practices, especially in arid- and semi-arid regions mostly affected by …

Rangeland Management In A Changing World – Active And Passive Restoration Case Studies From Ethiopia, Tanzania, And South Africa, A. C. Treydte, S. A. Baumgartner, S. K. Tuffa, A. A. Abdeta

IGC Proceedings (1993-2023)

Rangelands cover almost 50% of the earth’s land surface and are often found in marginal areas that often face climate extremes. The production of herbaceous biomass has strongly declined over the last decades due to overgrazing and adverse climatic conditions such as frequent droughts and flooding. While different rangeland restoration methods are being used, their effect on vegetation quality and quantity over time has rarely been experimentally tested and monitored. Our research comprises experiments of various rangeland restoration tools we have used across eastern and southern Africa. We conducted passive restoration through exclosure experiments and compared vegetation in and outside …

Counteracting Green Alder Shrub Expansion By Low-Input Grazing, M. K. Schneider, T. Zehnder, J. Berard, C. Pauler, M. Staudinger, Michael Kreuzer, A. Lüscher

IGC Proceedings (1993-2023)

In the past decades, the decline of traditional agriculture has caused an abandonment of marginal pastures in many mountain areas of Europe. In the Swiss Alps, green alder (Alnus viridis) is the most abundant successional shrub. A survey of 24 pasture-shrub gradients showed that the encroachment by green alder, in contrast to other shrubs, is associated with a substantial decline in plant species richness. The understorey of alder is primarily populated by very few, broad-leaved herbaceous species benefitting from the atmospheric nitrogen fixed by actinomycetes in symbiosis with green alder. However, the understory vegetation also provides an underestimated …

Characterization Of Degree Of Eco-Restoration By Tree-Grass Interaction In Degraded Lands Of Semi-Arid Tropics, R. V. Kumar, A. Ghosh, A. K. Singh, Sunil Kumar, A. K. Roy, Kamini Gautam

IGC Proceedings (1993-2023)

Land degradation majorly declines soil health. Eco-restoration through tree-grass interaction provides a perfect solution to restore degraded lands. The study was carried out at Jhansi district of India during 2010 to 2019 with three fodder trees viz namely, Ficus infectoria, Morus alba, and Acacia nilotica and a shrub Leucaena leucocephala (along with three grasses (Cenchrus ciliaris, Chrysopogon fulvus and Panicum maximum). The main objectives of these study were to a) assess the changes in soil organic carbon pools and responses of soil enzymes as impacted by different eco-restoration strategies involving trees and grasses; and b) …

Bee-Friendly Beef: Developing Biodiverse Pastures To Increase Ecosystem Services, J. Wagner, S. Ghajar, M. O’Rourke, B. Tracy

IGC Proceedings (1993-2023)

The capacity of grasslands to provide ecosystem services, such as pollinator resources, is often limited by lack of plant biodiversity. This is true of grasslands in the eastern US that are dominated by tall fescue (Festuca arundinacea) a non-native, cool-season grass that is typically toxic to cattle. This paper summarizes a research project in Virginia, USA exploring the idea that ecosystem services provided by tall fescue-dominated grasslands can be improved by increasing the plant biodiversity available to beef cattle and bees. Within three 6.5 ha tall fescue grasslands, we established 0.8 ha plots with a 17 species mix …

Effects Of Herding On Rangeland Use Efficiency In Kenya, A. Seidel, F. Asch, B. Warth

IGC Proceedings (1993-2023)

Within each foraging itinerary, herders can intervene in the forage selection process, encouraging herds to use highly palatable and less palatable rangeland resources. Such a herding strategy could prevent rangeland degradation and increase livestock productivity. The objectives of this study were to examine forage availability and identify factors influencing stocking rates around night resting places on a ranch in Laikipia County, Kenya.

Forage availability was measured along six regularly spaced transects around night resting places corralling one herd of camels, one mixed herd of goats and sheep, and two herds of cattle, with biomass sampling points at 50-, 150-, 250-, …

Rangeland In Marajó Island, Brazilian Amazon, A Long History Of Commons For Small-Breeders, T. Barbosa, M. Opplert, R. Folhes, S. Carvalho, Jean François Tourrand

IGC Proceedings (1993-2023)

Rangelands cover almost one third of the earth's surface and are characterized by a low productivity and high sociocultural value. But the lack of recognition of the environmental, social and economic values of rangelands, along with the expansion of agribusiness, tourism and urban sprawl give rise to a rangeland dilemma. This dilemma is found in various regions of the world, where this set of factors leads to the generally irreversible destruction of the rangeland. The process is recent in the Amazon rangeland, such as the eastern part of Marajó Island and the Low Amazon wetlands. A survey conducted on 90 …

Identifying Land Use Options For Networked Māori Owned Land Blocks To Deliver On Collective Aspirations In New Zealand, N. Mccrossin, F. A. Walker, M. E. Wedderburn, R. Mato, W. Mcmillan

IGC Proceedings (1993-2023)

Māori (the indigenous people of New Zealand) have many opportunities and challenges to realise the potential provided by their whenua (land), wai (water) and tangata (people) to deliver to their goals and aspirations. The challenges are old and new, including environmental constraints, governance, geographic isolation, fragmented land ownership, access to finance, and lack of appropriate skills, knowledge, and networks. Extension programmes aimed at the general primary production sector have failed to attract or retain any or many Māori participants. Landowner to landowner learning built around landowner aspirations along with collective action has the potential to inform an extension approach of …

Livestock Policy In Special Areas, Alberta, Canada, P. L. Strankman

IGC Proceedings (1993-2023)

Special Areas, Alberta, Canada, is a rural municipality of 2.1 million hectares (about 5 million acres) in south-eastern Alberta. It is home to almost 5000 residents, with a unique governance arrangement in Alberta. Most of the farms and ranches utilize a mix of crop and livestock primarily annual cereal and oil seed cultivation and beef cattle. These production units are usually a mosaic of privately-owned land and Crown land leased from the government.

It provides an interesting case study for the local, and national challenges facing western Canadian agriculture. It also provides an opportunity to contrast with different bioclimatic and …

Collaborative Construction Of A Method That Contributes To Improve The Decision Making In Associative Ranches By Controlling The Grass Allowance In A Context Of Climate Variability, Emilio Duarte Esteves, Rómulo Cesar, Javier Fernández, Marcelo Ghelfi, Valentina Herrera, Virginia Caravia, Rodrigo Iribarne, Federico De Brum, Héctor Rodríguez, Marcelo Pereira Machín

IGC Proceedings (1993-2023)

Pasture management and the particular conditions of each year are responsible for productive results, farm income, and condition of the pasture. A simple and robust method that relates the available grass and the required grass was built in a participatory manner, and contributes to a critical reflection process among the group of decision-making, adapting to their context. In 17 farms from the Basalt region in Uruguay, grass and animals were monitored seasonally. A simple method was developed with farmers, and from de offer needed to meet production targets (KgMS/KgPV) the amount of grass requires was calculated. The grass height was …

C3 Perennial Grass Dominates Mixed C3/C4 Grasslands After Invasion By A C3 Woody Sprouter, C. E. Cooper, R. J. Ansley, T. J. Steffens, D. B. Murray, T. Zhang

IGC Proceedings (1993-2023)

Honey mesquite (Prosopis glandulosa) encroachment has resulted in decreased C₄ mid-grass production and increased C₃ mid-grass in the Southern Great Plains of the US. Woody legumes have had similar effects in Africa, Australia, and South America. Prosopis initially facilitates Texas wintergrass (Nassella leucotricha) growth under canopies, in part because N-fixation by this woody legume enriches subcanopy soils, favoring C₃ species. As stand density increases, Nassella extends into interspaces between trees as well. Here we report Nassella responses in several studies that either reduced Prosopis to indirectly impact Nassella or treated Nassella directly. In …

Metamorphism Of The Sierra De Maz And Implications For The Tectonic Evolution Of The Mara Terrane, Andrew Tholt, Sean R. Mulcahy, William C. Mcclelland, Sarah M. Roeske, Vinícius T. Meira, Patricia Webber, Emily Houlihan, Matthew A. Coble, Jeffrey D. Vervoort

Geology Faculty Publications

The Mesoproterozoic MARA terrane of western South America is a composite igneous-metamorphic complex that is important for Paleozoic paleogeographic reconstructions and the relative positions of Laurentia and Gondwana. The magmatic and detrital records of the MARA terrane are consistent with a Laurentian origin; however, the metamorphic and deformation records lack sufficient detail to constrain the correlation of units within the MARA terrane and the timing and mechanisms of accretion to the Gondwana margin.

Combined regional mapping, metamorphic petrology, and garnet and monazite geochronology from the Sierra de Maz of northwest Argentina suggest that the region preserves four distinct litho-tectonic units …

Mgrre_Pureoilscouttickets_Spitler Et Al_1_21127017990000, Mgrre

Legacy Scout Tickets from Pure Oil Company

No abstract provided.

Mosaic: A Satellite Constellation To Enable Groundbreaking Mars Climate System Science And Prepare For Human Exploration, Robert J. Lillis, David Mitchell, Luca Montabone, Nicholas Heavens, Tanya Harrison, Cassie Stuurman, Et. Al.

Publications

The Martian climate system has been revealed to rival the complexity of Earth's. Over the last 20 yr, a fragmented and incomplete picture has emerged of its structure and variability; we remain largely ignorant of many of the physical processes driving matter and energy flow between and within Mars' diverse climate domains. Mars Orbiters for Surface, Atmosphere, and Ionosphere Connections (MOSAIC) is a constellation of ten platforms focused on understanding these climate connections, with orbits and instruments tailored to observe the Martian climate system from three complementary perspectives. First, low-circular near-polar Sun-synchronous orbits (a large mothership and three smallsats spaced …

Using Lie Sphere Geometry To Study Dupin Hypersurfaces In R^N, Thomas E. Cecil

Mathematics and Computer Science Department Faculty Scholarship

A hypersurface M in Rⁿ or Sⁿ is said to be Dupin if along each curvature surface, the corresponding principal curvature is constant. A Dupin hypersurface is said to be proper Dupin if each principal curvature has constant multiplicity on M, i.e., the number of distinct principal curvatures is constant on M. The notions of Dupin and proper Dupin hypersurfaces in Rⁿ or Sⁿ can be generalized to the setting of Lie sphere geometry, and these properties are easily seen to be invariant under Lie sphere transformations. This makes Lie sphere geometry an effective …