Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

University of Kentucky

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 3661 - 3690 of 18111

Full-Text Articles in Entire DC Network

Effect Of Plant Density On Yield And Yield Components And Seed Chemical Composition Of Some Sunflower Varieties, N A. Noueldin, M E. El-Bially, B A. El-Ahmer, M G. El-Baz Jul 2024

Effect Of Plant Density On Yield And Yield Components And Seed Chemical Composition Of Some Sunflower Varieties, N A. Noueldin, M E. El-Bially, B A. El-Ahmer, M G. El-Baz

IGC Proceedings (1977-2023)

The objective of this research is to study the effect of varieties (Mayak, Elorida 2000 and sigce 475), hill distance (20, 30 and 40 cm) and ridge width (50, 60 and 70 cm) on productivity of sunflower (Helianthus annus L.). The highest oil % was obtained by sowing sigco 475 at a 40 cm hills distince under 60 cm. ridge width and the highest oil yield feddan-1* as well as seed yield feddan-1 was obtained by sowing Mayak on 20cm hills under a 50cm ridge width.


Seed Banks In A Natural Pasture In Tasmania, Australia: Implications For Species Composition Change, D A. Friend, A S. Cameron, A J. Povey, P L. Dolan Jul 2024

Seed Banks In A Natural Pasture In Tasmania, Australia: Implications For Species Composition Change, D A. Friend, A S. Cameron, A J. Povey, P L. Dolan

IGC Proceedings (1977-2023)

Seed banks in a natural pasture in Tasmania were examined as part of a study of the effects of grazing on changes in species composition. The dominant native perennial grasses had relatively low seed banks, whereas annual grasses, sedges, rushes and a number of forbs had relatively high seed banks. The results confirm the vulnerability of the native grasses to local extinction in the event of loss of the established plants, e.g. through overgrazing.


Tropical Forage Seed Production In Southeast Asia: Current Status And Prospects, C Phaikaew, L Guodao, A Abdullah, M Tuhulele, E Magboo, B Bouahom, W Stur Jul 2024

Tropical Forage Seed Production In Southeast Asia: Current Status And Prospects, C Phaikaew, L Guodao, A Abdullah, M Tuhulele, E Magboo, B Bouahom, W Stur

IGC Proceedings (1977-2023)

The demand for forage seed in southeast Asia has increased in recent years. More than 1,200 tons of seed were produced in Thailand in 1995 with smaller quantities of seed having been produced in China, Lao PDR, Malaysia, Philippines and Indonesia. Large quantities have been produced of Brachiaria ruziziensis, Stylosanthes hamata, Stylosanthes guianensis and Panicum maximum. There are good prospects to increase forage seed production and to develop trade between countries in the southeast Asian region. There is a need to increase seed production of widely adapted species, and expand production of forages for other purposes such as turf …


Traditional Grassland And Fodder Management Systems In Tanzania And Potential For Improvement, R M. Otsyina, I Essai, D Asenga Jul 2024

Traditional Grassland And Fodder Management Systems In Tanzania And Potential For Improvement, R M. Otsyina, I Essai, D Asenga

IGC Proceedings (1977-2023)

The “Ngitiri” fodder conservation system was developed by the Sukuma agro-pastoralists as a strategy to alleviate acute dry season fodder constraints. This traditional agroforestry system provides the basis and opportunities for development of improved silvipastoral systems. Ngitiri is a major source of dry season fodder supply for livestock and thatch for roofing. The system is widespread in the Sukuma landuse system in central Tanzania. This paper presents the scope and importance of the Ngitiri system, management aspects, constraints, and farmers’ perceptions on improvement. Implications for agroforestry technology development in the Sukuma agropastoral system are also discussed.


Forage Seed Production In Egypt For Domestic Marker And For Export, M A. El-Nahrawy, A Rammah, O Niemelainen Jul 2024

Forage Seed Production In Egypt For Domestic Marker And For Export, M A. El-Nahrawy, A Rammah, O Niemelainen

IGC Proceedings (1977-2023)

In Egypt, no major effort is made to provide local and export markets with seeds of correctly identified and pure cultivars of forage crops in spite of the existence of all the essential factors for a successful seed industry. A wide genetic base of indigenous forage crops such as berseem clover and alfalfa, proper irrigation, a harvest and seed maturation period free from rain, sunshine and clear sky all year and highly fertile soils in isolated areas are available. Moreover, uncertified, uncontrolled and unidentified local seeds of berseem clover and alfalfa are highly demanded by foreign markets due to their …


Protease Expression In The Human And Rat Cumulus–Oocyte Complex During The Periovulatory Period: A Role In Cumulus–Oocyte Complex Migration, Ketan Shrestha, Muraly Puttabyatappa, Michelle Arelia Ann Wynn, Patrick R. Hannon, Linah Al-Alem, Katherine L. Rosewell, James Akin, Thomas E. Curry Jul 2024

Protease Expression In The Human And Rat Cumulus–Oocyte Complex During The Periovulatory Period: A Role In Cumulus–Oocyte Complex Migration, Ketan Shrestha, Muraly Puttabyatappa, Michelle Arelia Ann Wynn, Patrick R. Hannon, Linah Al-Alem, Katherine L. Rosewell, James Akin, Thomas E. Curry

UK CARES Faculty Publications

The migratory and matrix-invading capacities of the cumulus–oocyte complex have been shown to be important for the ovulatory process. In metastatic cancers, these capacities are due to increased expression of proteases, however, there is limited information on protease expression in the cumulus–oocyte complexes. The present study examined cumulus–oocyte complex expression of plasmins, matrix metalloproteases, and A Disintegrin and Metalloproteinase with Thrombospondin Motifs family members in the rat and human. In the rat, human chorionic gonadotropin (hCG) administration increased cumulus–oocyte complex expression of Mmp2, Mmp9, Mmp13, Mmp14, Mmp16, Adamts1, and the protease inhibitors Timp1, Timp3, and Serpine1 by 8–12 h. This …


Mapping Recent Timber Harvest Activity In A Temperate Forest Using Single Date Airborne Lidar Surveys And Machine Learning: Lessons For Conservation Planning, G. Bursh Fisher, Andrew J. Elmore, Matthew C. Fitzpatrick, Darin J. Mcneil, Jeff W. Atkins, Jeffery L. Larkin Jul 2024

Mapping Recent Timber Harvest Activity In A Temperate Forest Using Single Date Airborne Lidar Surveys And Machine Learning: Lessons For Conservation Planning, G. Bursh Fisher, Andrew J. Elmore, Matthew C. Fitzpatrick, Darin J. Mcneil, Jeff W. Atkins, Jeffery L. Larkin

Earth and Environmental Sciences Faculty Publications

Effective planning for natural resource management and wildlife conservation requires detailed information on vegetation structure at landscape scales and how structure is influenced by land- use practices. In many forested landscapes, the largest impacts of land use on forest structure are driven by forest management activities, which can include invasive species control, prescribed fire, partial harvests (e.g. shelterwood harvests) or overstory removals and clearcuts. Active timber management is often used to achieve forest conservation objectives, but to be used effectively, managers require knowledge of harvest frequency and extent in adjacent forests and at landscape scales. In this paper, we develop …


Decentralized Clinical Trials For Medications To Reduce The Risk Of Dementia: Consensus Report And Guidance, Leanne Howard, Carla Abdelnour, Erin Abner, Ricardo F. Allegri, Hiroko H. Dodge, Serge Gauthier, Camilla M. Hoyos, Gregory Jicha, Patrick G. Kehoe, Catherine J. Mummery, Adesola Ogunniyi, Nikolaos Scarmeas, Xiaoying Chen, Jodie R. Titiner, Christopher R. Weber, Ruth Peters Jul 2024

Decentralized Clinical Trials For Medications To Reduce The Risk Of Dementia: Consensus Report And Guidance, Leanne Howard, Carla Abdelnour, Erin Abner, Ricardo F. Allegri, Hiroko H. Dodge, Serge Gauthier, Camilla M. Hoyos, Gregory Jicha, Patrick G. Kehoe, Catherine J. Mummery, Adesola Ogunniyi, Nikolaos Scarmeas, Xiaoying Chen, Jodie R. Titiner, Christopher R. Weber, Ruth Peters

Neurology Faculty Publications

INTRODUCTION: Recent growth in the functionality and use of technology has prompted an increased interest in the potential for remote or decentralized clinical trials in dementia. There are many potential benefits associated with decentralized medication trials, but we currently lack specific recommendations for their delivery in the dementia field.

METHODS: A modified Delphi method engaged an expert panel to develop recommendations for the conduct of decentralized medication trials in dementia prevention. A working group of researchers and clinicians with expertise in dementia trials further refined the recommendations.

RESULTS: Overall, the recommendations support the delivery of decentralized trials in dementia prevention …


Type-2 Diabetes, Pancreatic Amylin, And Neuronal Metabolic Remodeling In Alzheimer's Disease, Noah Leibold, James R. Bain, Florin Despa Jul 2024

Type-2 Diabetes, Pancreatic Amylin, And Neuronal Metabolic Remodeling In Alzheimer's Disease, Noah Leibold, James R. Bain, Florin Despa

Neurology Faculty Publications

Type-2 diabetes raises the risk for Alzheimer’s disease (AD)-type dementia and the conversion from mild cognitive impairment to dementia, yet mechanisms connecting type-2 diabetes to AD remain largely unknown. Amylin, a pancreatic 𝜷-cell hormone co-secreted with insulin, participates in the central regulation of satiation, but also forms pancreatic amyloid in persons with type-2 diabetes and synergistically interacts with brain amyloid 𝜷 (A𝜷) pathology, in both sporadic and familial Alzheimer’s disease (AD). Growing evidence from studies of tumor growth, together with early observations in skeletal muscle, indicates amylin as a potential trigger of cellular metabolic reprogramming. Because the blood, cerebrospinal fluid, …


A Mini-Review Of Strategies For Recruiting Older African Americans To Alzheimer's Disease Research., Darlingtina Esiaka, Christina C Yarborough, Bernadette A Fausto, Mark A Gluck Jul 2024

A Mini-Review Of Strategies For Recruiting Older African Americans To Alzheimer's Disease Research., Darlingtina Esiaka, Christina C Yarborough, Bernadette A Fausto, Mark A Gluck

Behavioral Science Faculty Publications

African Americans experience higher incidence and prevalence of Alzheimer's disease (AD). Yet, they continue to be underrepresented in AD research, limiting the ability to generalize findings to the increasingly diverse US population. To reduce AD disparities, targeted efforts are needed to increase the representation of African Americans in AD research. This mini review identified evidence-based strategies that increased research participation among older African Americans. Four recruitment strategies emerged from eight published peer-reviewed studies that directly evaluated the effectiveness of strategies aimed at increasing the number of African American participants in Alzheimer's research. The strategies include community outreach and education, face-to-face …


Applying Machine Learning Models Derived From Administrative Claims Data To Predict Medication Nonadherence In Patients Self-Administering Biologic Medications For Inflammatory Bowel Disease, Christian Rhudy, Courtney Perry, Michael Wesley, David Fardo, Cody Bumgardner, Syed Hassan, Terrence Barrett, Jeffery Talbert Jul 2024

Applying Machine Learning Models Derived From Administrative Claims Data To Predict Medication Nonadherence In Patients Self-Administering Biologic Medications For Inflammatory Bowel Disease, Christian Rhudy, Courtney Perry, Michael Wesley, David Fardo, Cody Bumgardner, Syed Hassan, Terrence Barrett, Jeffery Talbert

Biostatistics Faculty Publications

BACKGROUND: Adherence to self-administered biologic therapies is important to induce remission and prevent adverse clinical outcomes in Inflammatory bowel disease (IBD). This study aimed to use administrative claims data and machine learning methods to predict nonadherence in an academic medical center test population.

METHODS: A model-training dataset of beneficiaries with IBD and the first unique dispense of a self-administered biologic between June 30, 2016 and June 30, 2019 was extracted from the Commercial Claims and Encounters and Medicare Supplemental Administrative Claims Database. Known correlates of medication nonadherence were identified in the dataset. Nonadherence to biologic therapies was defined as a …


Β-Aminopropionitrile Induces Distinct Pathologies In The Ascending And Descending Thoracic Aortic Regions Of Mice, Michael K. Franklin, Hisashi Sawada, Sohei Ito, Deborah A. Howatt, Naofumi Amioka, Ching Ling Liang, Nancy Zhang, David B. Graf, Jessica J. Moorleghen, Yuriko Katsumata, Hong S. Lu, Alan Daugherty Jul 2024

Β-Aminopropionitrile Induces Distinct Pathologies In The Ascending And Descending Thoracic Aortic Regions Of Mice, Michael K. Franklin, Hisashi Sawada, Sohei Ito, Deborah A. Howatt, Naofumi Amioka, Ching Ling Liang, Nancy Zhang, David B. Graf, Jessica J. Moorleghen, Yuriko Katsumata, Hong S. Lu, Alan Daugherty

Biostatistics Faculty Publications

BACKGROUND: β-aminopropionitrile (BAPN) is a pharmacological inhibitor of LOX (lysyl oxidase) and LOXLs (LOX-like proteins). Administration of BAPN promotes aortopathies, although there is a paucity of data on experimental conditions to generate pathology. The objective of this study was to define experimental parameters and determine whether equivalent or variable aortopathies were generated throughout the aortic tree during BAPN administration in mice. METHODS: BAPN was administered in drinking water for a period ranging from 1 to 12 weeks. The impacts of BAPN were first assessed with regard to BAPN dose, and mouse strain, age, and sex. BAPN-induced aortic pathological characterization was …


Ceramide-Mediated Orchestration Of Oxidative Stress Response Through Filopodia-Derived Small Extracellular Vesicles, Zainuddin Quadri, Ahmed Elsherbini, Simone M. Crivelli, Salim S. El-Amouri, Priyanka Tripathi, Zhihui Zhu, Xiaojia Ren, Liping Zhang, Stefka D. Spassieva, Mariana N. Nikolova‑Karakashian, Erhard Bieberich Jul 2024

Ceramide-Mediated Orchestration Of Oxidative Stress Response Through Filopodia-Derived Small Extracellular Vesicles, Zainuddin Quadri, Ahmed Elsherbini, Simone M. Crivelli, Salim S. El-Amouri, Priyanka Tripathi, Zhihui Zhu, Xiaojia Ren, Liping Zhang, Stefka D. Spassieva, Mariana N. Nikolova‑Karakashian, Erhard Bieberich

Markey Cancer Center Faculty Publications

Extracellular vesicles (EVs) are shed from the plasma membrane, but the regulation and function of these EVs remain unclear. We found that oxidative stress induced by H 2 O 2 in Hela cells stimulated filopodia formation and the secretion of EVs. EVs were small (150 nm) and labeled for CD44, indicating that they were derived from filopodia. Filopodia-derived small EVs (sEVs) were enriched with the sphingolipid ceramide, consistent with increased ceramide in the plasma membrane of filopo- dia. Ceramide was colocalized with neutral sphingomyelinase 2 (nSMase2) and acid sphingomyelinase (ASM), two sphingomyelinases generating ceramide at the plasma membrane. Inhibition of …


Soxb1 Transcription Factors Are Essential For Initiating And Maintaining Neural Plate Border Gene Expression, Elizabeth Schock, Joshua R. York, Austin P. Li, Ashlyn Y. Tu, Carole Labonne Jul 2024

Soxb1 Transcription Factors Are Essential For Initiating And Maintaining Neural Plate Border Gene Expression, Elizabeth Schock, Joshua R. York, Austin P. Li, Ashlyn Y. Tu, Carole Labonne

Markey Cancer Center Faculty Publications

SoxB1 transcription factors (Sox2/3) are well known for their role in early neural fate specification in the embryo, but little is known about functional roles for SoxB1 factors in non-neural ectodermal cell types, such as the neural plate border (NPB). Using Xenopus laevis, we set out to determine whether SoxB1 transcription factors have a regulatory function in NPB formation. Here, we show that SoxB1 factors are necessary for NPB formation, and that prolonged SoxB1 factor activity blocks the transition from a NPB to a neural crest state. Using ChIP-seq, we demonstrate that Sox3 is enriched upstream of NPB genes in …


14-3-3Ζ Suppresses Rankl Signaling By Destabilizing Traf6, R. Ayyasamy, S. Fan, P. Czernik, B. Lecka-Czernik, Somsubhra Chattopadhyay, R. Chakravarti Jul 2024

14-3-3Ζ Suppresses Rankl Signaling By Destabilizing Traf6, R. Ayyasamy, S. Fan, P. Czernik, B. Lecka-Czernik, Somsubhra Chattopadhyay, R. Chakravarti

Markey Cancer Center Faculty Publications

Macrophages are essential regulators of inflammation and bone loss. Receptor activator of nuclear factor-κβ ligand (RANKL), a pro-inflammatory cytokine, is responsible for macrophage differentiation to osteoclasts and bone loss. We recently showed that 14-3-3ζ-knockout (YwhazKO) rats exhibit increased bone loss in the inflammatory arthritis model. 14-3-3ζ is a cytosolic adaptor protein that actively participates in many signaling transductions. However, the role of 14-3-3ζ in RANKL signaling or bone remodeling is unknown. We investigated how 14-3-3ζ affects osteoclast activity by evaluating its role in RANKL signaling. We utilized 14-3-3ζ-deficient primary bone marrow–derived macrophages obtained from wildtype and YwhazKO …


Diffuse Reflectance Spectroscopy For Optical Characterizations Of Orthotopic Head And Neck Cancer Models In Vivo, Pranto Soumik Saha, Jing Yan, Caigang Zhu Jul 2024

Diffuse Reflectance Spectroscopy For Optical Characterizations Of Orthotopic Head And Neck Cancer Models In Vivo, Pranto Soumik Saha, Jing Yan, Caigang Zhu

Markey Cancer Center Faculty Publications

We demonstrated an easy-to-build, portable diffuse reflectance spectroscopy device along with a Monte Carlo inverse model to quantify tissue absorption and scattering-based parameters of orthotopic head and neck cancer models in vivo. Both tissue-mimicking phantom studies and animal studies were conducted to verify the optical spectroscopy system and Monte Carlo inverse model for the accurate extraction of tissue optical properties. For the first time, we reported the tissue absorption and scattering coefficients of mouse normal tongue tissues and tongue tumor tissues. Our in vivo animal studies showed reduced total hemoglobin concentration, lower tissue vascular oxygen saturation, and increased tissue scattering …


A Probabilistic Approach To Estimate The Temporal Order Of Pathway Mutations Accounting For Intra-Tumor Heterogeneity, Menghan Wang, Yanqi Xie, Jinpeng Liu, Austin Li, Li Chen, Arnold Stromberg, Susanne Arnold, Chunming Liu, Chi Wang Jul 2024

A Probabilistic Approach To Estimate The Temporal Order Of Pathway Mutations Accounting For Intra-Tumor Heterogeneity, Menghan Wang, Yanqi Xie, Jinpeng Liu, Austin Li, Li Chen, Arnold Stromberg, Susanne Arnold, Chunming Liu, Chi Wang

Markey Cancer Center Faculty Publications

The development of cancer involves the accumulation of somatic mutations in several essential biological pathways. Delineating the temporal order of pathway mutations during tumori- genesis is crucial for comprehending the biological mechanisms underlying cancer development and identifying potential targets for therapeutic intervention. Several computational and statistical methods have been introduced for estimating the order of somatic mutations based on mutation profile data from a cohort of patients. However, one major issue of current methods is that they do not take into account intra-tumor heterogeneity (ITH), which limits their ability to accurately discern the order of pathway mutations. To address this …


Response To Replication Stress And Maintenance Of Genome Stability By Wrn, The Werner Syndrome Protein, David K. Orren, Amrita Machwe Jul 2024

Response To Replication Stress And Maintenance Of Genome Stability By Wrn, The Werner Syndrome Protein, David K. Orren, Amrita Machwe

Markey Cancer Center Faculty Publications

Werner syndrome (WS) is an autosomal recessive disease caused by loss of function of WRN. WS is a segmental progeroid disease and shows early onset or increased frequency of many characteristics of normal aging. WRN possesses helicase, annealing, strand exchange, and exonuclease activities and acts on a variety of DNA substrates, even complex replication and re- combination intermediates. Here, we review the genetics, biochemistry, and probably physiological functions of the WRN protein. Although its precise role is unclear, evidence suggests WRN plays a role in pathways that respond to replication stress and maintain genome stability particularly in telomeric regions.


Serotonin Receptor-Mediated Vasorelaxation Occurs Primarily Through 5-Ht4 Activation In Bovine Lateral Saphenous Vein, Ronald J. Trotta, David L. Harmon, James L. Klotz Jul 2024

Serotonin Receptor-Mediated Vasorelaxation Occurs Primarily Through 5-Ht4 Activation In Bovine Lateral Saphenous Vein, Ronald J. Trotta, David L. Harmon, James L. Klotz

Animal and Food Sciences Faculty Publications

To better understand mechanisms of serotonin- (5-HT) mediated vasorelaxation, isolated lateral saphenous veins from cattle were assessed for vasoactivity using myography in response to increasing concentrations of 5-HT or selective 5-HT receptor agonists. Vessels were pre-contracted with 1 × 10−4 M phenylephrine and exposed to increasing concentrations of 5-HT or 5-HT receptor agonists that were selective for 5-HT1B, 5-HT2B, 5-HT4, and 5-HT7. Vasoactive response data were normalized as a percentage of the maximum contractile response induced by the phenylephrine pre-contraction. At 1 × 10−7 M 5-HT, a relaxation was observed …


The Potential Impact Of Endangered Species Legislation On Federal Grazing Lands And The Livestock Industry, G M. Luciuk, B Bristol, T W. Weins, D M. Boyle Jun 2024

The Potential Impact Of Endangered Species Legislation On Federal Grazing Lands And The Livestock Industry, G M. Luciuk, B Bristol, T W. Weins, D M. Boyle

IGC Proceedings (1977-2023)

Crown based grazing is an integral part of the management structure of cattle operations, and is very important to the economic fabric of rural communities. Federal crown lands, such as the PFRA operated community pastures are an integral part of the resource conservation efforts in western Canada. These lands represent a significant reservoir of the remaining natural lands which are important for wildlife habitat. Sustainable management of such contiguous blocks of land is essential for the maintenance of biodiversity. Proposed endangered species legislation would require the development of recovery plans on federal lands for endangered, threatened and extirpated species. Rural …


Concepts For Mining Landscape Development In Eastern Germany With Grazing Animals And Agroforestry, S Eichler, F Herzog Jun 2024

Concepts For Mining Landscape Development In Eastern Germany With Grazing Animals And Agroforestry, S Eichler, F Herzog

IGC Proceedings (1977-2023)

Leipzig South (Saxony) has been heavily transformed by open cast lignite mining. Alternative forms of land use are sought which contribute to an increase of biodiversity and an improvement of soil quality. This could be achieved by the selective introduction of grazing animals and perennials. Specific scenarios for open pits, dumping areas, open pits’ slopes and land reclaimed for agriculture are proposed. Socio-economic drawbacks are outlined.


The Use Of Grasslands To Improve Water Quality In The New York City Watershed, D J. Flaherty, J Drelich Jr Jun 2024

The Use Of Grasslands To Improve Water Quality In The New York City Watershed, D J. Flaherty, J Drelich Jr

IGC Proceedings (1977-2023)

The purpose of this paper is to demonstrate how grasslands are used in the New York City (NYC) Watershed to improve water quality. A Watershed Agricultural Program was established to voluntarily implement Pollution Prevention Best Management Practices on watershed farms. Grasslands have been used in Whole Farm Plans to reduce nutrients, sediments and other toxic materials reaching New York City’s water supply. Rotational grazing has been used to limit access to streams and stream banks and improve nutrient distribution on pastures. Improved grassland management also helps correct the nutrient balance on the farm and facilitates better nutrient management. Brush removal …


Objective Indicators For Monitoring Drought In Grasslands, D H. White, S M. Howden Jun 2024

Objective Indicators For Monitoring Drought In Grasslands, D H. White, S M. Howden

IGC Proceedings (1977-2023)

Australia’s National Drought Policy was ratified by the Commonwealth (Federal), State and Territory governments in 1992. However, a sequence of El Niño-based events that started in Queensland in 1991 culminated in much of Australia experiencing abnormally low rainfall throughout 1994 and into 1995. Many farmers experienced substantial loss of income. The Commonwealth government therefore devised measures to determine which areas had been exposed to exceptional drought so that financial assistance could be directed as effectively as possible. In this paper we discuss progress in developing regionally-sensitive indicators and methodologies to aid in future assessments of drought exceptional circumstances.


Are We Ignoring Science In Our Quest For Simplicity In Range Management?, W A. Laycock Jun 2024

Are We Ignoring Science In Our Quest For Simplicity In Range Management?, W A. Laycock

IGC Proceedings (1977-2023)

Accurate determination of range condition and trend is essential for proper range management. In the United States, the range condition model currently used is not based on up-to-date ecological knowledge. It assumes a single stable state (climax) and linear pathways. Multiple stable state models more accurately depict community dynamics but have not been widely accepted. U.S. Federal land management agencies are using surrogates, such as qualitative “instant trend” measures and substitution of utilization for measured condition and trend to guide management. Most of these short cuts are not based on science. Attacks on livestock grazing by environmentalists are based on …


Socio-Economic And Climate Change In Mongolia - Effects On Grassland Ecosystems, C Opp Jun 2024

Socio-Economic And Climate Change In Mongolia - Effects On Grassland Ecosystems, C Opp

IGC Proceedings (1977-2023)

In Mongolia, in combination with strong changes of the whole society during the past 76 years, from the feudal system to socialism and from the socialist system of planned development to the market economy, there are a lot of changes in the use of natural resources all over the country. In consequence of this a lot of effects on grassland ecosystems, caused by socio-economic and climate driving factors, were observed and studied in different scales: zonal, regional, local.


Integrating Biophysical And Economic Models For Assessing Impacts Of Change On Grazingland Ecosystems, J De Souza Neto, J R. Conner, J W. Stuth, W T. Hamilton, J W. Richardson Jun 2024

Integrating Biophysical And Economic Models For Assessing Impacts Of Change On Grazingland Ecosystems, J De Souza Neto, J R. Conner, J W. Stuth, W T. Hamilton, J W. Richardson

IGC Proceedings (1977-2023)

PHYGROW, a hydrologic-based forage simulation model, was parameterized to represent a typical South Texas ranch engaged in the production of cattle and meat goats with an indigenous population of white-tailed deer. Forage production and associated stocking rates for two cattle: goat ratios were simulated for 20 years. Two, ten-year weather scenarios, one representing normal conditions (30% drought years) and one representing dryer weather conditions (50% drought years) were analyzed. Management decision rules were developed for the region to produce estimates of annual animal production and operating cost for the enterprises in each of the four scenarios. These performance and cost …


Linear And Community-Based Processes Of Ethical Decision Making For Grassland Workers, Gary W. Fick Jun 2024

Linear And Community-Based Processes Of Ethical Decision Making For Grassland Workers, Gary W. Fick

IGC Proceedings (1977-2023)

Grasslands are basic elements in sustainable development, but few grassland workers are familiar with concepts of ethical decision making useful in integrating ecological, economic, and sociological components of sustainability. Most published procedures for ethical decision making are based on linear models for individualized social systems with modern technologies. In the context of sustainable agriculture, nonlinear community-based procedures may be more appropriate. In this paper, a nonlinear model from the Haudenosaunee (Iroquois) Indians is compared to more conventional linear procedures. After identification of a problem, linear models often leave the solution of the ethical dilemma (ranking ethical goals when they conflict) …


Policy Options For Decreasing N And P2o5 Losses From Grassland Based Dairy Farms, P.B M. Berentsen, G.W J. Giesen Jun 2024

Policy Options For Decreasing N And P2o5 Losses From Grassland Based Dairy Farms, P.B M. Berentsen, G.W J. Giesen

IGC Proceedings (1977-2023)

Policy instruments for reducing nutrient losses include extension and education, research, financial incentives such as subsidies and levies, and regulations. The potential of these instruments for reducing nitrogen (N), phosphate (P2O5), and ammonia (NH3) losses is examined for Dutch specialized dairy farms on sandy soils. A linear programming model is used to estimate policy impacts. Results indicate that efficiency improvements through extension, education, and research alone have the potential to decrease total N losses to government target levels in 2005 and to erase 92% of the gap between base and target P2O5 losses, but only 24% of the corresponding NH3 …


Production V Conservation: A Policy Dilemma In The Tree Clearing Debate In Queensland, Australia, J C. Scanlan, E J. Turner Jun 2024

Production V Conservation: A Policy Dilemma In The Tree Clearing Debate In Queensland, Australia, J C. Scanlan, E J. Turner

IGC Proceedings (1977-2023)

A process for developing policy for tree clearing that meets the competing goals of conservation and production has been followed. There were two levels at which policy was developed. An overall Statewide policy outlined general targets to meet commitments of the Queensland Government. Local guidelines were developed by a large number of groups containing representatives of government and interested conservation movement and industry representatives. The policy and the local guidelines are an important part of the process used to assess applications for permits to clear woody vegetation.


Forage Production And Performance Of Beef Yearlings Grazing Diploid And Tetraploid Crested Wheatgrass, J D. Bruynooghe, R.D H. Cohen, N W. Holt, P G. Jefferson Jun 2024

Forage Production And Performance Of Beef Yearlings Grazing Diploid And Tetraploid Crested Wheatgrass, J D. Bruynooghe, R.D H. Cohen, N W. Holt, P G. Jefferson

IGC Proceedings (1977-2023)

A series of experiments were conducted during 1994 and 1995 at Swift Current, Saskatchewan, Canada to evaluate forage production and animal performance on tetraploid Kirk (Agropyron cristatum (L.) Gaertn.) and diploid Fairway (Agropyron cristatum (L.) Gaertn.) crested wheatgrass pastures under grazing conditions imposed by beef (Bos taurus) yearling steers at four stock density levels (3, 4, 6 and 8 steers ha-1). Total ungrazed forage production for Kirk was greater (<0.05) than Fairway (6302 kg ha-1 vs. 5235 kg ha-1) in 1994 but less (P<0.05) than Fairway in 1995 (3709 kg ha-1 vs. 4633 kg ha-1). Animal performance (average daily gain, animal grazing days and total animal production) did not differ (P>0.05) for steers grazing either Kirk or Fairway pastures. Plant vigour and available energy reserves following one season of grazing were evaluated through etiolated growth with …