Physical Sciences and Mathematics Commons^™

Simulation Models As Decision Aids For Management Of Rangeland Ecosystems, J Ross Wight, Clayton L. Hanson

IGC Proceedings (1993-2023)

Rangeland simulation models have been used primarily as research tools to synthesise and organise information and to conceptualise and describe the interacting components of the ecosystem. Their application as decision aids for range management has not been developed. This paper discusses ways simulation models, such as SPUR· (Simulation of Production and Utilisation of Rangelands), can be used to forecast herbage p1oduction and the occurrence of biological windows, enhance monitoring, and predict the impacts of management and climate change on the soil, water, and plant resources including species composition.

Models Of Pasture Production To Aid On-Farm Decision Making In New Zealand, J A. Baars, M D. Rollo

IGC Proceedings (1993-2023)

Two microcomputer-based predictive pasture models, for use in decision making by agricultural consultants and industry, are described. The first model (GRASS) was developed to understand the interactions between environment and management. The second model supplies pasture growth rates for current or predicted weather conditions by adjustment of stored actual average fortnightly pasture growth rates for a wide range of measurement sites. Ways are described in which the models are being used in transfer of technology.

Production Of Dryland Lucerne In The Western And Southern Cape Regions Of South Africa, J M. Van Heerden

IGC Proceedings (1993-2023)

Cutting trials were conducted with lucerne (Medicago sativa) cv. S A Standard under dryland conditions over a period of 8 (1982 to 1989) years at 2 sites, one each in the western (Elsenburg) and southern (Tygerhoek) Cape. The sites differed in soil type and rainfall distribution. Replicated plots were harvested at 3 set frequencies (4·, 6- and 8- weekly). Production was lowest during summer and highest in late spring and increased with decreased harvesting frequency at both sites. These data were used to derive equations for the extrapolation of the seasonal yield. Inputs into the model 11cc average …

Graze Model: Importance Of Simulating Conceptual Grazing Areas Within A Paddock, Otto J. Loewer, L D. Parsch, H D. Scott, C P. West, A L. Goetsch

IGC Proceedings (1993-2023)

The selective grazing logic within the computer simulation model GRAZE was tested to determine if predicted ·results differed appreciably from situations ·where non-selective grazing logic· was used. Results indicated that predictions would_ differ somewhat." The main cause of the differences was determined to be the simulated levels of plant dry matter availability, which were considerably higher when non-selective· grazing was used.

Development Of An Expert System For New Zealand Seasonal-Supply Dairy Farmers, D I. Gray, G A. Lynch, E G. Todd, J C. Lockhart, W J. Parker

IGC Proceedings (1993-2023)

The mechod for developing an expert system for the drying-off decision on seasonal-supply dairy farms is described. The decision-making process ' of 4 expert seasonal-supply dairy farmers and the consultancy process used by 2 New Zealand Dairy Board Consulting Officers were identified in a series e>f interviews. This information ,was used to develop 2 models; one of expertise and the other of user requirements. These models form the basis of an expert system to improve the decision-making ability of. New Zealand seasonal-supply dairy farmers.

Rehabilitation On Public Rangelands In Idaho, Usa: A Change In Emphasis From Grass Monocultures, Mike Pellant, Stephen B. Monsen

IGC Proceedings (1993-2023)

Since the 1940s the Bureau of Land Management has reseeded 485 830 ha of public rangelands in southern Idaho. Introduced wheatgrasses were seeded on most rehabilitation projects, often resulting in monoculture plant communities. Introduced wheatgrasses were relatively inexpensive to seed, established well, excluded weedy annuals and provided additional livestock forage. Concern about extensive shrubland losses after wildfires prompted BLM managers to begin reseeding native shrubs in the early 1980s. Use of different herbaceous plants on rehabilitation projects is increasing. Seed mixtures now include up to 10 species (grass, forb and shrubs) that, when established, meet multiple use resource objectives.

Micro-Computer Version Of The Database On Feed Commodities Derived From Pastures And Green Crops, H T. Ostrowski-Meissner

IGC Proceedings (1993-2023)

The subunit of the national feed database devoted specifically to feeds derived from grasslands and green crops is presented. This collection of chemical and nutritional data is the result of 20 years of data collection from analyses conducted from 62 laboratories Australia-wide, The data entries are classified according to each Australian state and laboratory which provided the analytical and nutritional characteristics of fodder. Each entry is classified according to the International Feed Numbering (IFN) system as maintained by the International Network of Feed Information Centres (INFIC), The data in the collection as presented in the paper are an integral part …

A Computer Model For Determining When To Start Spring Grazing, Dennis R. Buckmaster, Warren J. Parker

IGC Proceedings (1993-2023)

A simple computer model is presented for determining the earliest grazing date after winter freezing. The model also illustrates principles of rotational grazing management and projects when forage should be conserved during the spring. Inputs to the model include initial herbage cover, herbage growth rate, herbage quality, a post•grazing residual dry matter target, a harvest set•aside threshold, and a description of the grazing animals.

Comparison Of Methods For Assessing Productivity Of Native Pastures In Queensland, K A. Day, G M. Mckeon, D M. Orr

IGC Proceedings (1993-2023)

The relationship between seasonal climatic conditions and observed seasonal pasture growth was examined for 3 native pasture sites in south-east Queensland for periods of up to 5 years. Nine indices of seasonal climatic conditions were considered. Across sites, between year differences in observed growth were best accounted for by the average daily ratio of calculated transpiration and vapour pressure deficit, This index accounted for 83% of the between year variation in observed growl h.

Application Of Neural Networks To The Extraction Of Various Types Of Grasslands In Japan Using Landsat Thematic Mapper Data, Mikinori Tsuiki, Shigeo Takahashi, Toshiki Oku

IGC Proceedings (1993-2023)

A neural network was applied to the extraction of various types of grasslands using Landsat Thematic Mapper (TM) data. Training fields contained 12 classes (water, paddy field, farmland, sands and rocks, urban area, coniferous forest, deciduous forest, golf course, Sasa­type grassland, Miscanthus type grassland, meadow before culling and meadow after cutting). Classification performance using the neural network was 99.4%, which was 2.4% higher than that obtained using the maximum likelihood method. For all types of grasslands, classification performance was 99.8%. The results of the classification area obtained using the neural network and the maximum likelihood method resembled each other. …

Use Of A Simple Model Of Continuous And Rotational Grazing To Compare Herbage Consumption, Simon J.R Woodward, G `C Wake, D G. Mccall, A B. Pleasants

IGC Proceedings (1993-2023)

A simple mathematical model (a linear dynamical system) was constructed to predict herbage consumption by grazing animals. This model was used to compare 3 grazing methods over a range of stocking rates at low pasture mass. The grazing methods compared were: continuous grazing (CTS), rotational grazing with equal time intervals (BQ), and rotational grazing where the time of shift was optimal for maximising intake (OPT). The rotational methods were the simplest possible, the land being subdivided into 2 fields, each of which was grazed once. The order of grazing the fields was also considered. The model predicts (I) that at …

Pasture Plant Identification In The Western Queensland Arid Zone, J A. Milson, I F. Beale, J A. Reynolds, J J. Bushwell, D Phelps

IGC Proceedings (1993-2023)

Since plant species composition is an important indicator of the health or condition of pastures and therefore the land, a first step for graziers interested in conserving the total range resource is to understand vegetation species and thus be able to identify them and to recognise species changes. This project is aimed at producing and distributing colour leaflets of the major native and problem plant species (including woody weeds) in the four major community types in western Queensland. The number of colour leaflels for the series totals 60. The number of species represented is about 230. These leaflets are dislributed …

Farm Monitoring, A Way To Improve Performance On Sheep And Beef Farms, R W. Webby, G W. Sheath

IGC Proceedings (1993-2023)

A programme that centres on monitoring the performance of sheep and beef farms is being used to encourage farmers to make decisions based on objective measurements, Monitor farmers are supported by their farming peers in groups that include extension and science personnel. Key biological performance indicators such as animal numbers, weights; weight gains, pasture production; and financial returns from meat and wool are monitored. Farmers are encouraged to be in a position to use this information and identify opportunities. Processors of sheep and beef products are demanding the production of livestock to tighter specifications. Close monitoring by farmers will be …

Use Of A Model To Investigate The Profitability Of Fertilizer Application, T.J M. Johnston, D G. Mccall, P R. Marshall

IGC Proceedings (1993-2023)

Use of a model to investigate the payback to alternative phosphate (P) fertiliser programmes is described. Input for the model is fertiliser history (kg P/ho/year) over 5-15 years. A site fertility index is established by summing discounted P applications. The index is related to relative pasture yield (annual yield/non P limited yield) for a soil type. The economics of P use are evaluated by scaling current gross margin/ha for changes in relative pasture yield and subtracting fertiliser costs. The model provides the decision maker with yearly cashflow information and a I 0-year net present value (NPV) analysis of the relative …

Microeukaryote Metabolism Across The Western North Atlantic Ocean Revealed Through Autonomous Underwater Profiling, Natalie R. Cohen, Arianna I. Krinos, Riss M. Kell, Rebecca J. Chmiel, Dawn M. Moran, Matthew R. Mcilvin, Paloma Z. Lopez, Brianna A. Alanis, Eric W. Chan, John A. Breier

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Microeukaryotes are key contributors to marine carbon cycling. Their physiology, ecology, and interactions with the chemical environment are poorly understood in offshore ecosystems, and especially in the deep ocean. Using the Autonomous Underwater Vehicle Clio, microbial communities along a 1050 km transect in the western North Atlantic Ocean were surveyed at 10–200 m vertical depth increments to capture metabolic signatures spanning oligotrophic, continental margin, and productive coastal ecosystems. Microeukaryotes were examined using a paired metatranscriptomic and metaproteomic approach. Here we show a diverse surface assemblage consisting of stramenopiles, dinoflagellates and ciliates represented in both the transcript and protein fractions, …

Exploration Of Positive Deviance In Prevention Of Underweight In The Under-Five: A Qualitative Study On Low-Income Urban Families, Irwan Budiono, Lukman Fauzi, Dewi Sari Rochmayani

Kesmas

Children under the age of five (the under-five) from low-income families are more vulnerable to experience underweight. This nutritional vulnerability is evident in the preliminary study, where 35.1% of the under-five experience underweight, and 28.48% are low-income families. This study aimed to explore Positive Deviance (PD) behaviors in preventing underweight among the under-five. The study applied a qualitative approach with a case study design. Data collection took place in July-August 2022, focusing on low-income families in the Gunung Brintik area. Data were collected through two focus group discussions, seven in-depth interviews, and five key informant interviews. Coding, subtheme, and theme …

Risk Factors For Cognitive Impairment In Adult Population Of Coastal Area: A Cross-Sectional Study In Maringkik Island, Indonesia, Herpan Syafii Harahap, Arina Windri Rivarti, Nurhidayati Nurhidayati, Fitriannisa Faradina Zubaidi, Dini Suryani, Legis Ocktaviana Saputri, Yanna Indrayana, Athalita Andhera, Muhammad Hilam, Abiyyu Didar Haq

Kesmas

Cognitive impairment is a medical condition commonly found in elderly populations, which can be due to vascular risk factors in patients. There remains limited data on risk factors for cognitive impairment among coastal region populations. This study aimed to investigate risk factors for cognitive impairment in the adult population of Maringkik Island, West Nusa Tenggara Province, Indonesia. Data collected were age, sex, education level, hypertension, antihypertensive treatment, diabetes mellitus, cigarette smoking, and body mass index status. A total of 114 participants were recruited using a consecutive sampling method. The participants’ cognitive function assessment used the Mini-Cog instrument. The cognitive impairment …

An Online Nanoinformatics Platform Empowering Computational Modeling Of Nanomaterials By Nanostructure Annotations And Machine Learning Toolkits., Tong Wang, Daniel P Russo, Philip Demokritou, Xuelian Jia, Heng Huang, Xinyu Yang, Hao Zhu

College of Science & Mathematics Departmental Research

Modern nanotechnology has generated numerous datasets from in vitro and in vivo studies on nanomaterials, with some available on nanoinformatics portals. However, these existing databases lack the digital data and tools suitable for machine learning studies. Here, we report a nanoinformatics platform that accurately annotates nanostructures into machine-readable data files and provides modeling toolkits. This platform, accessible to the public at https://vinas-toolbox.com/, has annotated nanostructures of 14 material types. The associated nanodescriptor data and assay test results are appropriate for modeling purposes. The modeling toolkits enable data standardization, data visualization, and machine learning model development to predict properties and bioactivities …

Molecular Docking, Pharmacological Profiling, And Molecular Dynamics Simulation Of Potential Antihyperuricemic Agent From Secondary Metabolites Of Dillenia Philippinensis Rolfe (Dilleniaceae), Louie Rince C. Suyo, John P. Paulin, Nicole Clarence Louise L. Gapaz, Markus Brent S. Arevalo, Vince Tyrell P. Yongco, Librado A. Santiago

Karbala International Journal of Modern Science

Crystal accumulation in the joints due to increased serum uric acid (sUA) may lead to an inflammatory condition called gout. Increased sUA is caused by the excessive reabsorption of the urate anion transporter-1 (URAT-1). Therefore, URAT-1 inhibition will promote uric acid excretion and reduce the risk of having gout. Dillenia philippinensis Rolfe, often known as katmon, is an endemic plant in the Philippines with bioactive compounds associated with several therapeutic benefits. The present study represents the first scientific inquiry into the antihyperuricemic potential of compounds isolated from D. philippinensis. This study aimed to assess the interaction of URAT-1 with …

Impact Of Energy Allocation On Fish's Age And Weight At Maturation By Mathematical Models, Siyi Zhang

Electronic Thesis and Dissertation Repository

The age and weight at maturation are crucial traits in an organism’s life cycle, influencing its growth, survival, and reproduction. We propose a biphasic energy allocation model, distinguishing pre-maturity and post-maturity, to study the mechanisms of maturation and estimate the age and weight at maturation. This model is parameterized for female lake whitefish (Coregonus clupeaformis). We compare different functions involved in the model, estimate parameters, and do sensitivity analysis. Our results indicate that (i) weight at maturation is positively related to the fraction of energy allocated to growth which, by data fitting, is almost a constant; (ii) age …

Wildcat Hills Rare Plant Survey Final Report, Steven B. Rolfsmeier

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

This survey report summarizes fifteen days of field work in eleven sites scattered across the Wildcat Ridge that were completed between May and August of 1996. Forty-five occurrences of 15 plant species on the Nebraska Natural Heritage element list were found. Ten tracts of high quality (or otherwise noteworthy) native communities were identified. Included in the report are site descriptions and element occurrences.

Northern Fur Ssal Vibrissae Organochlorine Contaminant Concentrations, Dimitri Giarikos, Amy Hirons, Courtney White

SECLER Data

The eastern Pacific stock of northern fur seals (Callorhinus ursinus) on the Pribilof Islands has experienced population declines since 1980. The decline may be due to anthropogenic persistent organic pollutants (POPs) which bioaccumulate, are toxic, and persistent. This study conducted a comparison of 21 organochlorine (OC) and 39 polybrominated diphenyl ether (PBDE) analyte concentrations utilizing archived vibrissae (whiskers) from individual fur seals sampled in 1993 (n=30) and 2013 (n=41). The PBDEs had values five times greater than the legacy status OCs. There were no significant mean concentration differences between 1993 and 2013 for total organochlorines (ΣOCs), or total …

Northern Fur Seal Vibrissae Polybrominateddiphenylether Concentrations, Dimitri Giarikos, Amy Hirons, Courtney White

SECLER Data

The eastern Pacific stock of northern fur seals (Callorhinus ursinus) on the Pribilof Islands has experienced population declines since 1980. The decline may be due to anthropogenic persistent organic pollutants (POPs) which bioaccumulate, are toxic, and persistent. This study conducted a comparison of 21 organochlorine (OC) and 39 polybrominated diphenyl ether (PBDE) analyte concentrations utilizing archived vibrissae (whiskers) from individual fur seals sampled in 1993 (n=30) and 2013 (n=41). The PBDEs had values five times greater than the legacy status OCs. There were no significant mean concentration differences between 1993 and 2013 for total organochlorines (ΣOCs), or total …

Chinese Tallow Long-Term Impact On Stand Dynamics In A Bottomland Hardwood Forest Following Vegetation Management, Nicklaus R. Langlois

Electronic Theses and Dissertations

Chinese tallow (Triadica sebifera (L.) Small) is an invasive tree known to have negative impacts on bottomland hardwood forests. Chinese tallow is proficient in reproducing and surviving in bottomland hardwood forests because it is more flood and shade tolerant than most native trees. The long-term effectiveness of Chinese tallow control is an important topic to research as only a few long-term studies of Chinese tallow control have been conducted. A 10-year re-measurement of 22 paired plots installed in 2012 on the Pineywoods Mitigation Bank near Diboll, Texas following herbicide treatments examined Chinese tallow and native tree stand structure. Each …

Assimilating Satellite-Derived Snow Cover And Albedo Data To Improve 3-D Weather And Photochemical Models, Colleen Jones, Huy Tran, Trang Tran, Seth Lyman

Chemistry and Biochemistry Faculty Publications

During wintertime temperature inversion episodes, ozone in the Uinta Basin sometimes exceeds the standard of 70 ppb set by the US Environmental Protection Agency. Since ozone formation depends on sunlight, and less sunlight is available during winter, wintertime ozone can only form if snow cover and albedo are high. Researchers have encountered difficulties replicating high albedo values in 3-D weather and photochemical transport model simulations for winter episodes. In this study, a process to assimilate MODIS satellite data into WRF and CAMx models was developed, streamlined, and tested to demonstrate the impacts of data assimilation on the models’ performance. Improvements …

Coffee In Brasil: Sustainability And The Role Of Intermediaries, Livia Petzinger

Capstone Collection

ABSTRACT

Coffee is traded in a highly complex global value chain where countless sustainability initiatives have emerged to address social, economic, and environmental issues, challenges which persist due to dominance of the market structure by largescale traders and roasters. Specialty coffee and direct trade have emerged as alternative trade arrangements that promote high-quality coffee through the use of sustainable practices, transparency, and a shortened supply chain. This research analyzes the role that intermediaries in the Brazilian specialty coffee supply chain play in the implementation of sustainability initiatives asking what kinds of sustainability practices they implement and why, and how this …

Impact Of Land Use Dynamics On The Water Yields In The Gorgan River Basin, Masoomeh Yaghoobi, Aram Fathi, Shahryar Fazli, Wenzhao Li, Elham Haghshenas, Vahid Shokri Kuchak, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

This research investigates the future dynamics of water yield services in the Gorgan River Basin in the North of Iran by analyzing land cover changes from 1990 to 2020, using Landsat images and predicting up to 2040 with the Land Change Modeler and InVEST model under three scenarios: continuation, conservation, and mitigation. The results indicate significant shifts in agricultural land impacted water yields, which fluctuated from 324.7 million cubic meters (MCM) in 1990 to 279.7 MCM in 2010, before rising to 320.1 MCM by 2020. The study uniquely assesses the effects of land use changes on water yields, projecting a …

Multi-Species Toxicity Testing Of Iprnhc: A Candidate For Organic Coating Enhancements, Maryam Khalilvand Nahid

Electronic Thesis and Dissertation Repository

Corrosion is a natural process affecting the longevity and integrity of metals. N-Heterocyclic carbenes (NHCs) are robust organic compounds that can form strong σ-bonds with metal atoms, allowing for the formation of monolayers on the metal surface. This property makes NHCs promising for coating metals. However, their long-term effects on the aquatic environment are not well understood. The present study investigated the ecotoxicity of 1,3-diisopropyl-1H-benzoimidazolium bicarbonate (iPrNHC NCO₃^-), a candidate for organic coating enhancements, on various species of aquatic organisms. The results showed that high concentrations of iPrNHC significantly increased mortality rates in zebrafish embryos, planarians, Daphnia, …

Effects Of Cutting Management On Herbage Production And Tiller Population In Smooth Bromegrass (Bromus Inermis Leyss), J X. Xia, J Hodgson, A.C P. Chu, P Wang, F Y. Liu

IGC Proceedings (1993-2023)

This paper reports the results of an experiment with smooth bromegrass (Bromus inermis Leyss) under cutting management at Beijing Agricultural University, China from June-October 1989. The main treatments were cutting intervals (l month v. 2 months) and cutting height (10 cm v. 30 cm) with 2 additional treatments (uncut control, and delayed first cut) and 4 replications. Frequent cutting decreased tiller population density, herbage accumulation and underground biomass. Tiller populations were greater under lax than hard cutting, though closer cutting resulted in greater green herbage accumulation. Delaying cutting until flowering was completed resulted in a subsequent depression in herbage …

Relative Productivity And Persistense Of White Clover Cultivars Under Cutting Or Continuous Stocking By Sheep, D A. Davies, M Fothergill

IGC Proceedings (1993-2023)

Perennial ryegrass-white clover (Lolium perenne-Trlfollium repens) swards of 3 clover cultivars were studied at a lowland (30 m) and upland (340 m) site in mid Wales over 3 years (1989-91). Lamb production from small-leaved Aberystwyth S 184 at 1021 kg/ha was 25% and 1191, more than from small-leaved Ac3351 and medium-leaved Grasslands Huia respectively. The relative lamb output from Huia was poorer at the upland location. Clover production, survival and morphology under a number of cutting heights and frequencies were different from those in the continuously stocked pastures. Cutting every 10 days at 2-3 cm resulted in poor clover and …