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

Digital Commons Network™

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

Physical Sciences and Mathematics

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 7411 - 7440 of 78757

Full-Text Articles in Entire DC Network

Michael Mcgraw: Profile Of The Newest Chbc Faculty Member, Danna Jaimes-Fajardo, Jeremy J. Smith, Lutishoor Salisbury Sep 2024

Michael Mcgraw: Profile Of The Newest Chbc Faculty Member, Danna Jaimes-Fajardo, Jeremy J. Smith, Lutishoor Salisbury

University Libraries Faculty Publications and Presentations

Presents the research profile of Michael McGraw, Assistant Professor, Chemistry and Biochemistry department. It highlights his research interests, education, and impact of his research.


Highly Toxic Aβ Begets More Aβ, Merc M. Kemeh, Noel Lazo Sep 2024

Highly Toxic Aβ Begets More Aβ, Merc M. Kemeh, Noel Lazo

Chemistry

No abstract provided.


Spatial Planning Offshore Wind Energy Farms In California For Mediating Fisheries And Wildlife Conservation Impacts, Crow White, Yi-Hui Wang, Ryan K. Walter, Benjamin Ruttenberg, Danny Han, Eli Newman, Ethan R. Deyle, Sucharita Gopal, Les Kaufman Sep 2024

Spatial Planning Offshore Wind Energy Farms In California For Mediating Fisheries And Wildlife Conservation Impacts, Crow White, Yi-Hui Wang, Ryan K. Walter, Benjamin Ruttenberg, Danny Han, Eli Newman, Ethan R. Deyle, Sucharita Gopal, Les Kaufman

Physics

Achieving a blue economy will require reconciling the value of emerging ocean uses with their impacts on the seascape and sectors with historical access to marine resources and areas. To meet this challenge, we developed an analytical framework for conducting marine spatial planning through tradeoff analysis, and applied it to prospective offshore wind energy development in the ∼974 km2 Morro Bay, California, USA Wind Energy Area (WEA). We generated spatial data layers estimating MW power production and impacts on fisheries value and marine wildlife conservation (seabird and cetacean populations) from wind farm development. We then quantified each sector's response to …


Image-Guided Patient-Specific Optimization Of Catheter Placement For Convection-Enhanced Nanoparticle Delivery In Recurrent Glioblastoma, Chengyue Wu, David A Hormuth, Chase D Christenson, Ryan T Woodall, Michael R A Abdelmalik, William T Phillips, Thomas J R Hughes, Andrew J Brenner, Thomas E Yankeelov Sep 2024

Image-Guided Patient-Specific Optimization Of Catheter Placement For Convection-Enhanced Nanoparticle Delivery In Recurrent Glioblastoma, Chengyue Wu, David A Hormuth, Chase D Christenson, Ryan T Woodall, Michael R A Abdelmalik, William T Phillips, Thomas J R Hughes, Andrew J Brenner, Thomas E Yankeelov

Faculty, Staff and Student Publications

Background: Proper catheter placement for convection-enhanced delivery (CED) is required to maximize tumor coverage and minimize exposure to healthy tissue. We developed an image-based model to patient-specifically optimize the catheter placement for rhenium-186 (186Re)-nanoliposomes (RNL) delivery to treat recurrent glioblastoma (rGBM).

Methods: The model consists of the 1) fluid fields generated via catheter infusion, 2) dynamic transport of RNL, and 3) transforming RNL concentration to the SPECT signal. Patient-specific tissue geometries were assigned from pre-delivery MRIs. Model parameters were personalized with either 1) individual-based calibration with longitudinal SPECT images, or 2) population-based assignment via leave-one-out cross-validation. The concordance correlation coefficient …


Imaging Photoinduced Dynamics In Gas-Phase Molecules Using Ultrafast Electron And X-Ray Diffraction, Sri Bhavya Muvva Sep 2024

Imaging Photoinduced Dynamics In Gas-Phase Molecules Using Ultrafast Electron And X-Ray Diffraction, Sri Bhavya Muvva

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

Investigating the ultrafast structural changes in photoexcited molecules provides essential information on their governing reaction mechanisms and product formation. Time-resolved electron and X-ray diffraction are crucial techniques for capturing the structural information of photoexcited molecules on femtosecond timescales. This thesis presents the investigations of photochemical reactions in gas-phase molecules using ultrafast electron and X-ray diffraction experiments.

Photoexcitation of conjugated diene molecules with ultraviolet (UV) laser pulses can lead to different reaction mechanisms, depending on their double bonds’ positions and molecular rigidity. Chapter 2 of this dissertation discusses the femtosecond time-resolved UV-induced excited-state structural dynamics of cis,cis-1,3-cyclooctadiene, an eight-membered cyclic conjugated …


Shifting Baselines: Visualizing Climate Change In America’S National Parks, Lee Lines Sep 2024

Shifting Baselines: Visualizing Climate Change In America’S National Parks, Lee Lines

Faculty Publications

No abstract provided.


Monocular Bev Perception Of Road Scenes Via Front-To-Top View Projection, Wenxi Liu, Qi Li, Weixiang Yang, Jiaxin Cai, Yuanhong Yu, Yuexin Ma, Shengfeng He, Jia Pan Sep 2024

Monocular Bev Perception Of Road Scenes Via Front-To-Top View Projection, Wenxi Liu, Qi Li, Weixiang Yang, Jiaxin Cai, Yuanhong Yu, Yuexin Ma, Shengfeng He, Jia Pan

Research Collection School Of Computing and Information Systems

HD map reconstruction is crucial for autonomous driving. LiDAR-based methods are limited due to expensive sensors and time-consuming computation. Camera-based methods usually need to perform road segmentation and view transformation separately, which often causes distortion and missing content. To push the limits of the technology, we present a novel framework that reconstructs a local map formed by road layout and vehicle occupancy in the bird's-eye view given a front-view monocular image only. We propose a front-to-top view projection (FTVP) module, which takes the constraint of cycle consistency between views into account and makes full use of their correlation to strengthen …


Multi-Scale Variational Autoencoder For Imputation Of Missing Values In Untargeted Metabolomics Using Whole-Genome Sequencing Data, Chen Zhao, Kuan-Jui Su, Chong Wu, Xuewei Cao, Qiuying Sha, Wu Li, Zhe Luo, Tian Qing, Chuan Qiu, Lan Juan Zhao, Anqi Liu, Lindong Jiang, Xiao Zhang, Hui Shen, Weihua Zhou, Hong-Wen Deng Sep 2024

Multi-Scale Variational Autoencoder For Imputation Of Missing Values In Untargeted Metabolomics Using Whole-Genome Sequencing Data, Chen Zhao, Kuan-Jui Su, Chong Wu, Xuewei Cao, Qiuying Sha, Wu Li, Zhe Luo, Tian Qing, Chuan Qiu, Lan Juan Zhao, Anqi Liu, Lindong Jiang, Xiao Zhang, Hui Shen, Weihua Zhou, Hong-Wen Deng

Faculty, Staff and Student Publications

Background: Missing data is a common challenge in mass spectrometry-based metabolomics, which can lead to biased and incomplete analyses. The integration of whole-genome sequencing (WGS) data with metabolomics data has emerged as a promising approach to enhance the accuracy of data imputation in metabolomics studies.

Method: In this study, we propose a novel method that leverages the information from WGS data and reference metabolites to impute unknown metabolites. Our approach utilizes a multi-scale variational autoencoder to jointly model the burden score, polygenetic risk score (PGS), and linkage disequilibrium (LD) pruned single nucleotide polymorphisms (SNPs) for feature extraction and missing metabolomics …


Numerical Simulations For Fractional Differential Equations Of Higher Order And A Wright-Type Transformation, Mariana Nacianceno, Tamer Oraby, Hansapani Rodrigo, Y. Sepulveda, Josef A. Sifuentes, Erwin Suazo, T. Stuck, J. Williams Sep 2024

Numerical Simulations For Fractional Differential Equations Of Higher Order And A Wright-Type Transformation, Mariana Nacianceno, Tamer Oraby, Hansapani Rodrigo, Y. Sepulveda, Josef A. Sifuentes, Erwin Suazo, T. Stuck, J. Williams

School of Mathematical & Statistical Sciences Faculty Publications

In this work, a new relationship is established between the solutions of higher order fractional differential equations and a Wright-type transformation. Solutions could be interpreted as expected values of functions in a random time process. As applications, we solve the fractional beam equation, fractional electric circuits with special functions as external sources, derive d’Alembert’s formula and show the existence of explicit solutions for a general fractional wave equation with variable coefficients. Due to this relationship, we present two methods for simulating solutions of fractional differential equations. The two approaches use the interpretation of the Caputo derivative of a function as …


Fractional Derivative-Based Analysis Of The Heat Transfer Properties Of Fluid Flow Over A Contracting Permeable Infinite-Length Cylinder, Anas Saeb Alhasan Sep 2024

Fractional Derivative-Based Analysis Of The Heat Transfer Properties Of Fluid Flow Over A Contracting Permeable Infinite-Length Cylinder, Anas Saeb Alhasan

Theses

Understanding the complex interplay between the contracting behavior of the cylinder and the fluid flow dynamics has implications for the design of porous structures for heat exchange and filtration systems. In this study, we investigate the dynamics and thermal behavior of fluid flow past a contracting permeable infinite cylinder. First, we developed a mathematical model based on the Navier-Stokes equations to describe the fluid dynamics around the contracting permeable infinite cylinder. A new simple well-behaved definition of fractional derivative called conformable fractional derivative introduced by authors Khalil et al. [3] is employed to generalize the PDE’s of momentum and energy. …


Diabetes Technology Meeting 2023, Tiffany Tian, Rachel E Aaron, Ashley Y Dunova, Johan H Jendle, David Kerr, Eda Cengiz, Andjela Drincic, John C Pickup, Kong Y Chen, Naomi Schwartz, Douglas B Muchmore, Halis K Akturk, Carol J Levy, Signe Schmidt, Riccardo Bellazzi, Alan H B Wu, Elias K Spanakis, Bijan Najafi, James Geoffrey Chase, Jane Jeffrie Seley, David C Klonoff Sep 2024

Diabetes Technology Meeting 2023, Tiffany Tian, Rachel E Aaron, Ashley Y Dunova, Johan H Jendle, David Kerr, Eda Cengiz, Andjela Drincic, John C Pickup, Kong Y Chen, Naomi Schwartz, Douglas B Muchmore, Halis K Akturk, Carol J Levy, Signe Schmidt, Riccardo Bellazzi, Alan H B Wu, Elias K Spanakis, Bijan Najafi, James Geoffrey Chase, Jane Jeffrie Seley, David C Klonoff

Center on Aging Staff Publications

Diabetes Technology Society hosted its annual Diabetes Technology Meeting from November 1 to November 4, 2023. Meeting topics included digital health; metrics of glycemia; the integration of glucose and insulin data into the electronic health record; technologies for insulin pumps, blood glucose monitors, and continuous glucose monitors; diabetes drugs and analytes; skin physiology; regulation of diabetes devices and drugs; and data science, artificial intelligence, and machine learning. A live demonstration of a personalized carbohydrate dispenser for people with diabetes was presented.


Enhancing Community Flood Resilience By Incorporating Landscape Hydrological Sensitivity And Connectivity, Wenlong Feng Aug 2024

Enhancing Community Flood Resilience By Incorporating Landscape Hydrological Sensitivity And Connectivity, Wenlong Feng

Dissertations

Rapid urban expansion and dramatic climate change have significantly increased the intensity and frequency of floods worldwide. With rising flood risks, conventional flood defense strategies that rely on structural measures become ineffective. The present designations for flood-prone areas, such as FEMA's flood maps, are becoming unreliable. Flood risk management is shifting toward enhancing community flood resilience, highlighting the importance of non-structural approaches. Landscape resilience has become a foundation of community flood resilience. However, past urban development typically undermined natural hydro-ecological functions and landscape resilience because of poor recognition of landscapes' ecological role, hydrological sensitivity, and hydrological connections. This study aims …


Microwave Catalysis-Enabled Membrane Processes For Microbial Inactivation, Fangzhou Liu Aug 2024

Microwave Catalysis-Enabled Membrane Processes For Microbial Inactivation, Fangzhou Liu

Dissertations

The COVID-19 pandemic has highlighted the urgent need for advanced technologies to combat virus transmission. Traditional membrane filtration technologies primarily serve as physical barriers, capturing pollutants but failing to inactivate microbial agents such as bacteria and viruses. These membranes typically target larger particles but are ineffective against sub-micrometer viral particles. Thus, there's a critical demand for membrane filtration processes that combine robust filtration with antifouling and reaction -enabled functions for efficient pathogen disinfection. This research explores a novel microwave-assisted membrane filtration process incorporating catalytic reactions to enhance microbial disinfection and prevent membrane fouling, offering a groundbreaking solution to global challenges …


Large Deviation Theory In Stochastic Processes: Applications To Biological Modeling, Moshe C. Silverstein Aug 2024

Large Deviation Theory In Stochastic Processes: Applications To Biological Modeling, Moshe C. Silverstein

Dissertations

This dissertation delves into developing and applying stochastic models to analyze complex biological systems. It leverages Large Deviation Theory (LDT) to gain insights into these systems, focusing on two key examples: neural networks and calcium signaling dynamics. Traditional deterministic methods frequently fail to capture biological processes' randomness and inherent variability. Meanwhile, many stochastic approaches struggle to be mathematically tractable or provide accessible insights. The approach introduced in this study provides rigorous mathematical frameworks to enhance understanding of these stochastic behaviors while remaining tractable and insightful.

A stochastic model for a random biological neural network is constructed that addresses the dependencies …


Investigations On V2o5 And Its Derivative Nanocomposites For Photocatalytic Textile Organic Dye Degradation, Jenifer A Aug 2024

Investigations On V2o5 And Its Derivative Nanocomposites For Photocatalytic Textile Organic Dye Degradation, Jenifer A

Theses and Dissertations

In recent times, organic dyes from industrial sludge become one of the significant causes of water contamination due to their utility in textile and paper manufacturing industries. These organic dyes are highly toxic and carcinogenic. Fortunately, the photocatalytic degradation process is a practical tool for decomposing toxic organic matter in wastewater by utilizing light. The photodegradation process can be performed using semiconductor materials to purify wastewater. Thus, semiconductor photocatalysis is a desirable alternative technique for decolorizing various organic pollutants.

In this context, the present work reports the preparation and characterization of V2O5 nanocomposites by facile methods and tests them against …


Emergence Of Extreme Events In Nonlinear Oscillators Due To Parametric And External Excitations, Kaviya B Aug 2024

Emergence Of Extreme Events In Nonlinear Oscillators Due To Parametric And External Excitations, Kaviya B

Theses and Dissertations

This comprehensive PhD thesis immerses itself in the intricate world of dynamical systems, aiming to understand, characterize, and develop innovative mitigation strategies for rare and extreme events occurring within diverse nonlinear oscillatory models. The term "events" spans a broad array of occurrences within defined systems, with "rare events" standing out as infrequent outliers or deviations from the norm.

Rare events span various disciplines such as oceanography, climate studies, biology, economics, ecology, encompassing phenomena like rogue waves, floods, cyclones, earthquakes, and financial crises. Recognized for their potential to cause substantial harm to both society and the environment, these events are widely …


Monitoring Marine Animal Interactions With Open Ocean Aquaculture And The Potential For Measuring Impacts, Ryan Richard Yont Aug 2024

Monitoring Marine Animal Interactions With Open Ocean Aquaculture And The Potential For Measuring Impacts, Ryan Richard Yont

Theses

Aquaculture, the farming of water-based organisms, is one of the fastest growing industries in the food production sector globally. Aquaculture farms, regardless of type, are categorized as either coastal or offshore marine aquaculture and are generalized into three categories: fed (e.g., finfish), unfed (e.g., filter-feeding bivalves), and autotrophic (e.g. kelp). Viewed as an agricultural industry, marine aquaculture is tightly regulated, particularly in the U.S. Despite this, an area of concern for the public and management alike is the potential for marine life interactions with aquaculture gear. Even the best-run farms represent a change in the physical and biological characteristics of …


Antioxidant, Photoprotective, And Cytotoxic Activities Of Tristaniopsis Merguensis Leaf Fractions With Molecular Docking Study Of Potential Fraction, Boima Situmeang, Respati Tri Swasono, Tri Joko Raharjo Aug 2024

Antioxidant, Photoprotective, And Cytotoxic Activities Of Tristaniopsis Merguensis Leaf Fractions With Molecular Docking Study Of Potential Fraction, Boima Situmeang, Respati Tri Swasono, Tri Joko Raharjo

Karbala International Journal of Modern Science

Through experimental along with molecular docking techniques of potential fraction, this study intended to evaluate the essential phytochemical elements of Tristaniopsis merguensis leaflets as well as potential antioxidant, photoprotective, along with cytotoxic activities. The DPPH and ABTS tests were used to evaluate the antioxidant efficacy of the n-hexane (HPF), ethyl acetate (EPF), and methanol (MPF) fractions. Using an in-vitro solar protection factor (SPF) assessment, the photoprotective ability of T. merguensis components against UV damage was examined. Subsequently, invitro cytotoxic research were carried out against MCF-7 cell line (breast cancer line) assay. This was followed by molecular docking stimulation testing against …


Far-Right Ecological Extremism: The Synthesis Of Violence, Hate, And The Environment On /Pol/., Hannah Claire Dunleavy Aug 2024

Far-Right Ecological Extremism: The Synthesis Of Violence, Hate, And The Environment On /Pol/., Hannah Claire Dunleavy

Environmental Studies Senior Theses

American far-right ecologism incorporates the American far-right’s antidemocratic and exclusionary tendencies, fears of existential threats and conspiracies, apocalyptic fantasies, and commitment to racial hierarchies. There are many shades of far-right ecologisms – including authoritarian deep ecology, eco-fascism, and exclusionary eco-nationalism – but all threaten the United States’ democratic ideals, multiculturalism, and pluralistic society. This thesis examines the rise of far-right ecologism in the U.S. by analyzing posts from 4chan’s /pol/ board (2015–2020) with a mixed-methods that blends a literature review, quantitative analysis, and descriptive case study. From 2015 to 2019, far-right ecology posts increased by 410%, and violent rhetoric in …


Special Supplement Issue On Quality Assurance And Enrichment Of Biological And Biomedical Ontologies And Terminologies, Licong Cui, Ankur Agrawal Aug 2024

Special Supplement Issue On Quality Assurance And Enrichment Of Biological And Biomedical Ontologies And Terminologies, Licong Cui, Ankur Agrawal

Faculty, Staff and Student Publications

Ontologies and terminologies serve as the backbone of knowledge representation in biomedical domains, facilitating data integration, interoperability, and semantic understanding across diverse applications. However, the quality assurance and enrichment of these resources remain an ongoing challenge due to the dynamic nature of biomedical knowledge. In this editorial, we provide an introductory summary of seven articles included in this special supplement issue for quality assurance and enrichment of biological and biomedical ontologies and terminologies. These articles span a spectrum of topics, such as development of automated quality assessment frameworks for Resource Description Framework (RDF) resources, identification of missing concepts in SNOMED …


A Step By Step Shoreline Attribute Analysis For Selected Waterbodies In The Gulf Of Mexico To Promote The Use Of Living Shorelines, Christoper Boyd, Xutong Niu, Taylor R. Horn Aug 2024

A Step By Step Shoreline Attribute Analysis For Selected Waterbodies In The Gulf Of Mexico To Promote The Use Of Living Shorelines, Christoper Boyd, Xutong Niu, Taylor R. Horn

Journal of Extension

Living Shorelines are being promoted by coastal extension professionals as a more resilient nature-based solution to control shoreline erosion. The Virginia Institute of Marine Sciences Living Shorelines Suitability Model was run in selected waterbodies within the Gulf of Mexico.

The locations of the selected water bodies, coastal data sets used, and shoreline protection recommendations generated by the Model are presented. A step-by-step statistical analysis conducted through ArcGIS Pro from these selected coastal shorelines will illustrate how extension professionals with novice GIS experience can use the model output to promote living shorelines to coastal property owners, city managers, and developers.


New Class Function In Dual Soft Topological Space, Maryam Adnan Al-Ethary, Maryam Sabbeh Al-Rubaiea, Mohammed H. O. Ajam Aug 2024

New Class Function In Dual Soft Topological Space, Maryam Adnan Al-Ethary, Maryam Sabbeh Al-Rubaiea, Mohammed H. O. Ajam

Al-Bahir

In this paper we introduce a new class of maps in the dual Soft topological space and study some of its basic properties and relations among them, then we study and mapping.


How Much Green To Keep The Garden Clean? An Analysis Of The Willingness To Pay (Wtp) Of Home Gardeners For Biowrap Technology, Gengchen Cai, Kanij Fatema, Karina A. Schoengold Aug 2024

How Much Green To Keep The Garden Clean? An Analysis Of The Willingness To Pay (Wtp) Of Home Gardeners For Biowrap Technology, Gengchen Cai, Kanij Fatema, Karina A. Schoengold

Cornhusker Economics

A research team from the University of Nebraska-Lincoln, Kansas State University, and South Dakota School of Mines are working on creating an alternative product that would use locally available materials to create a spray-on, biodegradable polymer that can suppress weeds and will biodegrade in a timeframe that is amenable to crop production. We broadly refer to this technology as BioWRAP (Bioplastics with Regenerative Agricultural Properties).

Our results show that the home garden market is potentially a significant one for a BioWRAP product. Continued work in the development of the BioWRAP technology is necessary to determine what the cost of a …


A Dft Comparison Of C–C Reductive Coupling From Terminal Cyanido And Cyaphido Complexes Of Nickel, Roberto Escobar, Jessica Meza, Javier Pena, Abdurrahman Atesin, William D. Jones, Christian Müller, Tülay A. Ateşin Aug 2024

A Dft Comparison Of C–C Reductive Coupling From Terminal Cyanido And Cyaphido Complexes Of Nickel, Roberto Escobar, Jessica Meza, Javier Pena, Abdurrahman Atesin, William D. Jones, Christian Müller, Tülay A. Ateşin

School of Integrative Biological & Chemical Sciences Faculty Publications

The density functional theory study of the thermal C–C reductive coupling from terminal cyanido and hypothetical cyaphido complexes of [Ni(dmpe)] (dmpe = 1,2-bis(dimethylphosphino)ethane) revealed the key reaction intermediate in the reductive C–CP coupling being a σ-CC complex unlike an η2-aryl complex in the Ni C–CN system, as already observed in our previous studies. The reaction in THF is endothermic by 4.9 kcal/mol for cyanido with a 32.0 kcal/mol activation barrier and exothermic by 28.5 kcal/mol for cyaphido with an 11.3 kcal/mol activation barrier. To compare our results with the existing experimental data, we chose mesityl as the aryl group and …


Dynamic Optimization With Timing Risk, Erin Cottle Hunt, Frank N. Caliendo Aug 2024

Dynamic Optimization With Timing Risk, Erin Cottle Hunt, Frank N. Caliendo

Economics and Finance Faculty Publications

Timing risk refers to a situation in which the timing of an economically important event is unknown (risky) from the perspective of an economic decision maker. While this special class of dynamic stochastic control problems has many applications in economics, the methods used to solve them are not easily accessible within a single, comprehensive survey. We provide a survey of dynamic optimization methods under comprehensive assumptions about the nature of timing risk. We also relax the assumption of full information and summarize optimization with limited information, ambiguity, imperfect hedging, and dynamic inconsistency. Our goal is to provide a concise user …


Experimental Realization Of Supergrowing Fields, Sethuraj K. R., Tathagata Karmakar, S. A. Wadood, Andrew N. Jordan, A. Nick Vamivakas Aug 2024

Experimental Realization Of Supergrowing Fields, Sethuraj K. R., Tathagata Karmakar, S. A. Wadood, Andrew N. Jordan, A. Nick Vamivakas

Mathematics, Physics, and Computer Science Faculty Articles and Research

Supergrowth refers to the local amplitude growth rate of a signal being faster than its fastest Fourier mode. In contrast, superoscillation pertains to the variation of the phase. Compared to the latter, supergrowth can have exponentially higher intensities and promises improvement over superoscillation-based superresolution imaging. Here, we demonstrate the experimental synthesis of controlled supergrowing fields with a maximum growth rate of ∼19.07 times the system bandlimit. Our work is an essential step toward realizing supergrowth-based far-field superresolution imaging.


Foraging Strategies Of Ruminant Livestock On Intensively Managed Grasslands: Potential And Constraints, I J. Gordon, C Lascano Aug 2024

Foraging Strategies Of Ruminant Livestock On Intensively Managed Grasslands: Potential And Constraints, I J. Gordon, C Lascano

IGC Proceedings (1977-2023)

All grazed swards exhibit heterogeneity in the spatial (horizontal and vertical) dispersion of species/biomass. A herbivore foraging at random within such a heterogeneous environment would ingest less nutrients than wou Id one which exploited the heterogeneity on offer through selective grazing. The suite of decision-making processes involved in the selective grazing we observe is termed the animal's foraging strategy. On first observation, intensively managed sown swards appear to offer little opportunity for a herbivore to exhibit a foraging strategy; however, opporlunities do exist and there is empirical evidence that herbivores foraging on sown swards tend to have a diet higher …


Comparative Foraging Strategies Of Grazing Ungulates In African Savanna Grasslands, N Owen-Smith, D H.M Cumming Aug 2024

Comparative Foraging Strategies Of Grazing Ungulates In African Savanna Grasslands, N Owen-Smith, D H.M Cumming

IGC Proceedings (1977-2023)

We review the evolutionary (species-specific) and ecological (individual behavioural) strategies of African grazing ungulates. The contexts considered are free-ranging wild ungulates, traditional livestock pastoralism and extensive commercial ranching. Particularly successful are (1) buffalo, able to digest grass fibre effectively in mesic grasslands; (2) wildebeest, exploiting semi-arid grasslands through migration; (3) megaherbivores (elephant, hippopotamus and white rhinoceros) utilising a wide range of vegetation components. Species-specific adaptations include body size and metabolic rate, digestive efficiency and passage rate, oral and dental anatomy, water dependence and detoxification capacity. Species overlap in grass species se'lected, with dietary differences apparent in grass height favoured, and …


Comparison Of Animal Gains Using Perennial Pastures Exclusively Or Combined With Chicory-Oats-Clover Temporary Winter Pastures, J A. Josifovich Aug 2024

Comparison Of Animal Gains Using Perennial Pastures Exclusively Or Combined With Chicory-Oats-Clover Temporary Winter Pastures, J A. Josifovich

IGC Proceedings (1977-2023)

The increment of winter forage availability using short-rotation pastures could be an interesting way to increase winter carrying capacity. The producer could make good use of higher spring grass production. Sowing oats, rye or chicory alone is quite common in the Argentine Pampa. to evaluate the efficiency of these short-rotation winter pastures a 3 year trial was carried out at Pergamino Experiment Station. The treatments were: a) perennial pastures, 100% of the surface, b) perennial pastures 75%, and chicory-clover 25%, with 2 replications of 3 ha each. The pastures were, for. class II soils, fescue (Festrlca aru11dinacea Schreb.) cv. El …


Influence Of Climatic Factors On Animal Production In The Humid Pampa Of Argentina, J D. Josifovich, E Frutos Aug 2024

Influence Of Climatic Factors On Animal Production In The Humid Pampa Of Argentina, J D. Josifovich, E Frutos

IGC Proceedings (1977-2023)

For any' pasture grazing area it is important lo know the relationship among the climatic parameters, rainfall and temperature, with carrying capacity and minimal gains. The availability of pasture to adjust stocking rates and make provisions for hay or supplementary feed needed for periods of shortage can be estimated from these data. Seven years of monthly rainfall and medium average temperature; and 25 years of forage digestibility and average daily gains were related to cattle i: carrying capacity; Analysis was made using the stepwise regression method. Carrying capacity was evaluated considering animal units (AU) for a 400 kg head gaining …