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Articles 51601 - 51630 of 715038

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Long Time Behavior Of Wave And Plate Equations, Madhumita Roy Jul 2024

Long Time Behavior Of Wave And Plate Equations, Madhumita Roy

Electronic Theses and Dissertations Archive

Long time behavior of a class of nonlinear hyperbolic dynamics governed by Partial Differential Equations [PDEs] is considered in this thesis. The objective is to demonstrate that the long-term behavior can be directed towards coherent structures, such as attractors. Attractors are invariant and compact sets in the phase space that attract all trajectories. The key aspects of the dynamics that allow for these descriptions are: (i) a level of dissipation within the system and (ii) the asymptotic smoothness and regularity [compactness] of the trajectories. In this context, hyperbolic dynamics pose a notable challenge as they inherently lack both of these …

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Evaluating The Antibacterial Efficacy Of A Silver Nanocomposite Surface Coating Against Nosocomial Pathogens As An Antibiofilm Strategy To Prevent Hospital Infections, James Butler, Sian Morgan, Lewis Jones, Mathew Upton, Alexandros Besinis Jul 2024

Evaluating The Antibacterial Efficacy Of A Silver Nanocomposite Surface Coating Against Nosocomial Pathogens As An Antibiofilm Strategy To Prevent Hospital Infections, James Butler, Sian Morgan, Lewis Jones, Mathew Upton, Alexandros Besinis

School of Engineering, Computing and Mathematics

Antimicrobial nanocoatings may be a means of preventing nosocomial infections, which account for significant morbidity and mortality. The role of hospital sink traps in these infections is also increasingly appreciated. We describe the preparation, material characterization and antibacterial activity of a pipe cement-based silver nanocoating applied to unplasticized polyvinyl chloride, a material widely used in wastewater plumbing. Three-dimensional surface topography imaging and scanning electron microscopy showed increased roughness in all surface finishes versus control, with grinding producing the roughest surfaces. Silver stability within nanocoatings was >99.89% in deionized water and bacteriological media seeded with bacteria. The nanocoating exhibited potent antibiofilm …

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The Arbitrariness Of Symmetry In Mathematical Proofs, Melisa Vivanco Jul 2024

The Arbitrariness Of Symmetry In Mathematical Proofs, Melisa Vivanco

Philosophy Faculty Publications

Symmetry is not an inherent characteristic of mathematical proofs; instead, it is a property that arbitrarily manifests in different modes of presentation. This arbitrariness leads to the conclusion that symmetry cannot be part of the defining or essential properties that characterize proofs. Consequently, contrary to some authors’ claims, symmetry does not significantly contribute to the validity, accuracy, or soundness of mathematical proofs. What is more, it does not even play any critical role in heuristic aspects such as explanatory power. The examples developed in this paper constitute compelling evidence supporting these claims.

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Rfc-Berkeley Pit Wpp-2024-02, Mark Thompson, Loren Burmeister Jul 2024

Rfc-Berkeley Pit Wpp-2024-02, Mark Thompson, Loren Burmeister

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

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Synthesis Of Portions Of An Acinetobacter Baumannii Lipooligosaccharide (Los), Brandon Conrad Jul 2024

Synthesis Of Portions Of An Acinetobacter Baumannii Lipooligosaccharide (Los), Brandon Conrad

LSU Doctoral Dissertations

Glycoconjugate vaccines have become an effective strategy for protection against an array of globally persistent diseases resulting from pathogenic bacteria such as Haemophilus influenzae type b (Hib), Neisseria meningitidis, and Salmonella enterica serotype Typhi. Comprised of a carbohydrate (referred to as glycan) covalently inked to a carrier protein, these vaccines can initiate adaptive immunity by inducing B and T cell responses once in the lymphatic system. This is particularly relevant for infants two years of age and younger whose immune systems are not fully developed. A continuously emerging threat in clinical settings, Acinetobacter baumannii is a Gram-negative bacterium …

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Variable Radio Emission Of Neutron Star X-Ray Binary Ser X–1 During Its Persistent Soft State, Eli C. Pattie, Thomas J. Maccarone, Alexandra J. Tetarenko, James C. A. Miller-Jones, Manuel Pichardo Marcano, Liliana E. Rivera Sandoval Jul 2024

Variable Radio Emission Of Neutron Star X-Ray Binary Ser X–1 During Its Persistent Soft State, Eli C. Pattie, Thomas J. Maccarone, Alexandra J. Tetarenko, James C. A. Miller-Jones, Manuel Pichardo Marcano, Liliana E. Rivera Sandoval

Physics & Astronomy Faculty Publications

Ser X–1 is a low-mass neutron star X-ray binary and has been persistently accreting since its discovery in the 1960s. It has always been observed to be in a soft spectral state and has never showed substantial long-term X-ray variability. Ser X–1 has one previous radio observation in the literature in which radio emission was detected during this soft state, which is contrary to the behavior of black hole X-ray binaries. We have recently obtained 10 randomly sampled radio epochs of Ser X–1 in order to further investigate its anomalous soft-state radio emission. Out of 10 epochs, we find 8 …

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The Potential Influence Of Immune Modulatory Molecules (Tgf-Βiii And Ctla-4) In Pathogenicity Of Pcos, Mustafa Riyadh Abdullah, Hazima Mossa Alabassi Jul 2024

The Potential Influence Of Immune Modulatory Molecules (Tgf-Βiii And Ctla-4) In Pathogenicity Of Pcos, Mustafa Riyadh Abdullah, Hazima Mossa Alabassi

Karbala International Journal of Modern Science

Polycystic ovary syndrome (PCOS) is characterised by chronic anovulation, hyperandrogenism, polycystic ovaries, and immunological dysregulation. Immune homeostasis and inflammation management require immune functions. T-regulatory cells (Tregs) regulate PCOS's immune system, inflammation, insulin resistance, ovarian function, and homeostasis. Transforming growth factor βIII (TGF-βIII) and Cytotoxic-T-lymphocyte-associated-protein-4 (CTLA-4) receptors on the surfaces of Treg cells are important for controlling the immune system. The study included 68 PCOS patients and 22 non-PCOS women controls aged 20–45. The waist-hip ratio (WHR) determines obesity. We evaluated serum levels and gene expression of TGF-βIII and CTLA-4 via ELISA and real-time PCR. Women with PCOS had significantly higher …

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Enhanced Optoelectronics Performance Of Hybrid Self Power Photodetectors Go: Tio2- Ad / N-Si Heterojunctions, Mohammed J. Alsultani, Maysoon F. Alias Jul 2024

Enhanced Optoelectronics Performance Of Hybrid Self Power Photodetectors Go: Tio2- Ad / N-Si Heterojunctions, Mohammed J. Alsultani, Maysoon F. Alias

Karbala International Journal of Modern Science

A GO:TiO2/n-Si heterostructure has been submerged in an anthocyanin dye solution that extracted from the red cabbage plant creates a high responsivity, self-powered UV, and visible photodetectors fabricated by the spray pyrolysis technique. The GO concentrations are varied, whereas TiO2 is fixed. Thin films' structure, shape, and optical characteristics were examined using X-ray diffraction, field emission scanning electron microscopy, and UV-Vis spectrophotometers respectively. Island-like polycrystalline film powders with grain boundaries and granular shapes are created. Two direct energy gaps between 3.33-3.02 and 2.39-2.04 eV exist in all films. J-V characteristics were examined. The saturation current density (J …

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Uniformly Distributing Points On A Sphere, Flavio Arrigoni Jul 2024

Uniformly Distributing Points On A Sphere, Flavio Arrigoni

Rose-Hulman Undergraduate Mathematics Journal

In this paper, we are going to present and discuss different procedures for distributing points on a sphere's surface. Furthermore, we will assess their quality with three different distribution tests. The MATHEMATICA package that we created for testing and plotting the points is publicly available.

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Modeling Virus Diffusion On Social Media Networks With The Smirq Model, Justin Browning, Arnav Mazumder, Gowri Nanda Jul 2024

Modeling Virus Diffusion On Social Media Networks With The Smirq Model, Justin Browning, Arnav Mazumder, Gowri Nanda

Rose-Hulman Undergraduate Mathematics Journal

As social networking services become more complex and widespread, users become increasingly susceptible to becoming infected with malware and risk their data being compromised. In the United States, it costs the government billions of dollars annually to handle malware attacks. Additionally, computer viruses can be spread through schools, businesses, and individuals’ personal devices and accounts. Malware affecting larger groups of people causes problems with privacy, personal files, and financial security. Thus, we developed the probabilistic SMIRQ (pSMIRQ) model that shows how a virus spreads through a generated network as a way to track and prevent future viruses. Our model is …

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Approximating Equilibria In Restricted Games, Jack W. Doyle Jul 2024

Approximating Equilibria In Restricted Games, Jack W. Doyle

Rose-Hulman Undergraduate Mathematics Journal

We consider optimal play in restricted games with linear constraints, and use ϵ-equilibria to find near-equilibrium states in these games. We present three mathematical optimization formulations -- a mixed-integer linear program (MILP), a quadratic program with linear constraints (QP), and a quadratically constrained program (QCP) -- to both approximate and identify these states. The MILP has a short runtime relative to the QP and QCP for large games (a factor 100 faster for |S|=9) and exhibits linear growth in run time, but provides only relatively weak upper bound. The QP and QCP provide a tight bound and the precise value …

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Constraining The Evolutionary Stages Of A Hypogene Karst System By Combining Morphological, Geochemical And Geochronological Data - The Example Of Carbonate Breccia-Hosted Melnička Peštera, Marjan Temovski, Zsófia Ruszkiczay-Rüdiger, Kata Molnár, László Rinyu, Alexander Wieser, Oscar Marchhart, László Palcsu Jul 2024

Constraining The Evolutionary Stages Of A Hypogene Karst System By Combining Morphological, Geochemical And Geochronological Data - The Example Of Carbonate Breccia-Hosted Melnička Peštera, Marjan Temovski, Zsófia Ruszkiczay-Rüdiger, Kata Molnár, László Rinyu, Alexander Wieser, Oscar Marchhart, László Palcsu

International Journal of Speleology

A combination of morphological observations, geochemical data from calcite minerals and geochronology by burial age dating and U-series is used to constrain the geological and geomorphological setting and the evolutionary stages of a hypogene karst system. This methodological suit is applied to Melnička Peštera, a horizontal cave developed in carbonate breccia overlying dolomite marble in Melnica locality (N. Macedonia), where hydrothermal karst development occurred in both dolomite and calcite marble. The passage morphology of the cave, having a reverse triangle, Laughöhle cross-sections, suggests development near the water table by slowly moving waters. Calcite crusts are found throughout the cave, and …

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Co2 Hypogene Speleogenesis In An Endogenic Travertine System, Mesa Del Oro, New Mexico, Usa, Victor J. Polyak, Jeffrey R. Forbes, Michael N. Spilde, Paula P. Provencio, John R. Cochran, Yemane Asmerom Jul 2024

Co2 Hypogene Speleogenesis In An Endogenic Travertine System, Mesa Del Oro, New Mexico, Usa, Victor J. Polyak, Jeffrey R. Forbes, Michael N. Spilde, Paula P. Provencio, John R. Cochran, Yemane Asmerom

International Journal of Speleology

The Mesa del Oro travertine, deposited by upwelling CO2-rich spring waters, is a large and thick mantle of calcite overlying soft Triassic Chinle Formation mudstones in western central New Mexico, USA. The travertine contains a system of small caves known as the Pronoun Cave Complex. Whut Cave is the largest known cave in the complex. While the travertine hydrologic system is no longer active, there is ample evidence that Whut Cave was formed by hypogene speleogenesis. The Whut Cave entrance is a small roughly circular shaft that descends ~four meters and intersects a linear fissure-controlled passage. Mn-oxide was …

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Resonant Solutions Of The Non-Linear Schrödinger Equation With Periodic Potential, Arein Duaibes, Yulia Karpeshina Jul 2024

Resonant Solutions Of The Non-Linear Schrödinger Equation With Periodic Potential, Arein Duaibes, Yulia Karpeshina

Mathematics Faculty Publications

The goal is construction of stationary solutions close to non-trivial combinations of two plane waves at high energies for a periodic non-linear Schrödinger Equation in dimension two. The corresponding isoenergetic surface is described for any sufficiently large energy k2. It is shown that the isoenergetic surface corresponding to k2 is essentially different from that for the zero potential even for small potentials. We use a combination of the perturbative results obtained earlier for the linear case and a method of successive approximation.

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A Fresh Take: Seasonal Changes In Terrestrial Freshwater Inputs Impact Salt Marsh Hydrology And Vegetation Dynamics (Estuaries And Coasts, (2024), 10.1007/S12237-024-01392-1), Maya S. Montalvo, Emilio Grande, Anna E. Braswell, Ate Visser, Bhavna Arora, Erin C. Seybold, Corianne Tatariw, John C. Haskins, Charlie A. Endris, Fuller Gerbl Jul 2024

A Fresh Take: Seasonal Changes In Terrestrial Freshwater Inputs Impact Salt Marsh Hydrology And Vegetation Dynamics (Estuaries And Coasts, (2024), 10.1007/S12237-024-01392-1), Maya S. Montalvo, Emilio Grande, Anna E. Braswell, Ate Visser, Bhavna Arora, Erin C. Seybold, Corianne Tatariw, John C. Haskins, Charlie A. Endris, Fuller Gerbl

School of Earth & Environment Departmental Research

Salt marshes exist at the terrestrial-marine interface, providing important ecosystem services such as nutrient cycling and carbon sequestration. Tidal inputs play a dominant role in salt marsh porewater mixing, and terrestrially derived freshwater inputs are increasingly recognized as important sources of water and solutes to intertidal wetlands. However, there remains a critical gap in understanding the role of freshwater inputs on salt marsh hydrology, and how this may impact marsh subsurface salinity and plant productivity. Here, we address this knowledge gap by examining the hydrologic behavior, porewater salinity, and pickleweed (Sarcocornia pacifica also known as Salicornia pacifica) plant productivity along …

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برنامج قائم على أنماط التعلم (Vark) وأثره على تنمية مهارات التدريس باستخدام منصات التعلم التفاعلية لدى معلمي الرياضيات, عيده الرويلي Jul 2024

برنامج قائم على أنماط التعلم (Vark) وأثره على تنمية مهارات التدريس باستخدام منصات التعلم التفاعلية لدى معلمي الرياضيات, عيده الرويلي

Journal of King Abdulaziz University: Educational and Psychological Sciences

هدف البحث الحالي إلى تقصي أثر برنامج قائم على أنماط التعلم وفق نموذج VARK لأنماط التعلم وأثرها على تنمية مهارات التدريس باستخدام المنصات التفاعلية لدى معلمي الرياضيات ، ولتحقيق هدف البحث قام الباحث باستخدام المنهج التجريبي ذو المجموعات التجريبية الأربع، وتمثلت عينة البحث الحالي في معلمي الرياضيات بالمملكة العربية السعودية، والبالغ عددهم (46) معلما بالمرحلة المتوسطة، حيث تم تطبيق استبيان (VARK) لأنماط التعلم عليهم وتقسيمهم إلى أربعة مجموعات نمطية وفق نمط التعلم المفضل لكل منهم (النمط البصري – النمط السمعي – النمط القرائي/ الكتابي – النمط الحسي/ العملي)، وتم إعداد أدوات القياس والتي تمثلت في استبيان (VARK) لأنماط التعلم، واختبار …

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Effect Of Esketamine On Hypotension In Women With Preoperative Anxiety Undergoing Elective Cesarean Section: A Randomized, Double-Blind, Controlled Trial, Yu Qi, Meiyan Zhou, Yaqi Dong, Wenting Zheng, Qinyu Jiang, Yanyu Li, Xinghe Wang, Jia Sun, Hai Zhou, Zhengquan Hu, Liwei Wang Jul 2024

Effect Of Esketamine On Hypotension In Women With Preoperative Anxiety Undergoing Elective Cesarean Section: A Randomized, Double-Blind, Controlled Trial, Yu Qi, Meiyan Zhou, Yaqi Dong, Wenting Zheng, Qinyu Jiang, Yanyu Li, Xinghe Wang, Jia Sun, Hai Zhou, Zhengquan Hu, Liwei Wang

Faculty, Staff and Student Publications

To investigate the effect of low-doses esketamine on spinal anesthesia-induced hypotension in women with preoperative anxiety undergoing elective cesarean section, the randomized controlled trial enrolled 120 women aged 18-35 years who preoperative State-Trait Anxiety Inventory State scores > 40, conducted from September 2022 to August 2023 in Xuzhou Central Hospital, China. Women in the esketamine group received a single intravenous injection of 0.2 mg/kg esketamine after sensory block level achieved. The incidence of hypotension in the esketamine group was significantly lower than the control group at T2 (10% [6 of 60]; P < 0.001), T3 (5.0% [3 of 60]; P = 0.007) and T4(5.0% [3 of 60]; P = 0.004). Despite being higher in the esketamine group, the overall rates of hypertension (11.7% [7 of 60]; P = 0.186), tachycardia (23.3% [14 of 60]; P = 0.246), and bradycardia (0.0% [0 of 60]; P = 0.079) were no significantly difference between the two groups. STAI-S scores was significantly lower in the esketamine group (mean [SD] 37.52[7.14]) than in the control group (mean [SD] 41.03[9.66], P = 0.39) in postoperative day 1. Spinal anesthesia combined with intravenous low-doses esketamine infusion can significantly reduce the incidence of hypotension in women with preoperative anxiety undergoing elective cesarean section.

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The Advent Of Quantum Computer Music: Mapping The Field, Eduardo Miranda Jul 2024

The Advent Of Quantum Computer Music: Mapping The Field, Eduardo Miranda

School of Art, Design and Architecture

Quantum computing technology is developing at a fast pace. The impact of quantum computing on the music industry is inevitable. This paper maps the emerging field of quantum computer music. Quantum computer music investigates, and develops applications and methods to process music using quantum computing technology. The paper begins by contextualising the field. Then, it discusses significant examples of various approaches developed to date to leverage quantum computing to learn, process and generate music. The methods discussed range from rendering music using data from physical quantum mechanical systems and quantum mechanical simulations to computational quantum algorithms to generate music, including …

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Value Creation In A Pedagogically-Focused Faculty Online Learning Community, Fred Goldberg, Edward Price, Mo Basir, Lawrence Escalada, Steve Maier, Steven Sahyun, Tamara D. Snyder, Liang Zeng Jul 2024

Value Creation In A Pedagogically-Focused Faculty Online Learning Community, Fred Goldberg, Edward Price, Mo Basir, Lawrence Escalada, Steve Maier, Steven Sahyun, Tamara D. Snyder, Liang Zeng

Faculty Publications

Faculty online learning communities (FOLCs) can help faculty effectively adopt and persist in using research-based curricula. This paper documents faculty perspectives on the value they gained from participating in a multi-year FOLC designed to help them implement an inquiry-based physical science curriculum. Personal value narratives were collected from 11 volunteer FOLC participants. In the narratives, participants responded to prompts regarding their initial reasons for participation, activities they engaged in, and values they gained, as well as how participation impacted their profession, social connections, professional practice, and ability to influence their world as teachers. Qualitative analysis shows that the values faculty …

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The Value Of Cybersecurity Investment In Electronic Health Records (Ehrs, Ansu Katta Jul 2024

The Value Of Cybersecurity Investment In Electronic Health Records (Ehrs, Ansu Katta

Walden Dissertations and Doctoral Studies

Senior healthcare IT leaders concerned about cybersecurity in electronic health records (EHR) continue to face fundamental challenges when efficiently managing EHR cybersecurity infrastructures to fulfill business objectives. Grounded in the updated DeLone and McLean information system success model, the purpose of this quantitative multiple linear regression study was to examine relationships between information quality, system quality, service quality, and user satisfaction related to cybersecurity and cloud computing infrastructures for EHR. The participants were 161 senior healthcare IT leaders in North and South Carolina who completed a survey that used an instrument scale based on ISS. The results of the multiple …

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Calibrating The Global Network Of Gravitational Wave Observatories Via Laser Power Calibration At Nist And Ptb, Dripta Bhattacharjee, Richard Lenox Savage, Rishabh Bajpai, Joseph Betzwieser, Vladimir Bossilkov, Dan Chen, Cervane Grimaud, Shingo Hido, Sudarshan Karki, Francisco Llamas Jul 2024

Calibrating The Global Network Of Gravitational Wave Observatories Via Laser Power Calibration At Nist And Ptb, Dripta Bhattacharjee, Richard Lenox Savage, Rishabh Bajpai, Joseph Betzwieser, Vladimir Bossilkov, Dan Chen, Cervane Grimaud, Shingo Hido, Sudarshan Karki, Francisco Llamas

Physics & Astronomy Faculty Publications

Current gravitational wave (GW) observatories rely on photon calibrators that use laser radiation pressure to generate displacement fiducials used to calibrate detector output signals. Reducing calibration uncertainty enables optimal extraction of astrophysical information such as source distance and sky position from detected signals. For the ongoing O4 observing run that started on 24 May 2023, the global GW detector network is employing a new calibration scheme with transfer standards calibrated at both the National Institute of Standards and Technology (NIST) and the Physikalisch-Technische Bundesanstalt (PTB). These transfer standards will circulate between the observatories and the metrology institutes to provide laser …

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Quantum Classical Algorithm For Solving The Hubbard Model Via Dynamical Mean-Field Theory, Anshumitra Baul Jul 2024

Quantum Classical Algorithm For Solving The Hubbard Model Via Dynamical Mean-Field Theory, Anshumitra Baul

LSU Doctoral Dissertations

Modeling many-body quantum systems is widely regarded as one of the most promising applications for near-term noisy quantum computers. However, in the near term, system size limitation will remain a severe barrier for applications in materials science or strongly correlated systems. A promising avenue of research is to combine many-body physics with machine learning for the classification of distinct phases. I present a workflow that synergizes quantum computing, many-body theory, and quantum machine learning (QML) for studying strongly correlated systems. In particular, it can capture a putative quantum phase transition of the stereotypical strongly correlated system, the Hubbard model. Following …

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Autumn Grass Growth- The Effect Of Rest Interval, R Neilan, E G. O'Riordan, G Keane Jul 2024

Autumn Grass Growth- The Effect Of Rest Interval, R Neilan, E G. O'Riordan, G Keane

IGC Proceedings (1977-2023)

The effect of closing dates (Experiment 1: August 1, August 14 and September 18) and grass regrowth interval (Experiment 2) on herbage yield in the autumn/winter and in the following spring were investigated on a previously grazed Lolium perenne sward. In Experiment 1, similar yields were obtained for the August 1 and August 14 closing. Yields decreased and the proportion of dead material increased from 0.19 to 0.61 between mid-October and late- December. In Experiment 2, dry matter yield increased linearly (P < 0.05) with rest interval up to 7 wks in swards closed in September. There was no significant yield advantage for rest intervals greater than 5-6 wks. It is concluded that accumulated autumn and spring yields showed increased DM production with the shorter regrowth intervals.

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Improving Pasture Composition Increases Wool Returns In Eucalypt Woodlands, T J. Hall, R G. Silcock, J J. Sevil, J R. Van Der Meulen Jul 2024

Improving Pasture Composition Increases Wool Returns In Eucalypt Woodlands, T J. Hall, R G. Silcock, J J. Sevil, J R. Van Der Meulen

IGC Proceedings (1977-2023)

A sheep grazing experiment in red earth Eucalypt country on semiarid pastures dominated by either Gayndah buffel grass (Cenchrus ciliaris) or wiregrass (Aristida jerichoensis) quantified liveweight, wool production and quality, and financial returns. Wethers were grazed at 0.32 and 0.6 ha/sheep. In year 1 there was no significant effect of either stocking rate or pasture type on liveweight or wool growth rate. Vegetable fault was greater in the fleeces from the wiregrass. The sheep grazing buffel grew better than those on wiregrass when stocking rates were doubled in year 2, while pasture yields remained high. The …

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Responses Of Artemisia Herba-Alba Asso. And Its Associated Species To Grazing Frequency (Midelt, Morocco), M Mejjati Alami, O Berkat, C Bensalem Jul 2024

Responses Of Artemisia Herba-Alba Asso. And Its Associated Species To Grazing Frequency (Midelt, Morocco), M Mejjati Alami, O Berkat, C Bensalem

IGC Proceedings (1977-2023)

The objective of this study (conducted in 1994) was to assess the effects of season and grazing frequency (control, continuous, intermittent during 2 days per week) on vegetation attributes, and animal feeding behavior. Mean standing crop, for which Artemisia herba alba contributed 72%, attained 533 for the control while it was maintained at 394 and 322 Kg DM/ha, for the continuous and the intermittent grazing, respectively. Mean productivity of Artemisia herba alba varied according to treatment and had values of 5.3, 3.0 and 2.5 Kg DM/ha/day, under the ungrazed control, the continuous and the intermittent grazing regimes, respectively. Percent utilization …

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Grazing Management Of An Italian Ryegrass Sward With Dairy Sheep In The Mediterranean Environment, M Sitzia, P P. Roggero, N Fois, G Molle Jul 2024

Grazing Management Of An Italian Ryegrass Sward With Dairy Sheep In The Mediterranean Environment, M Sitzia, P P. Roggero, N Fois, G Molle

IGC Proceedings (1977-2023)

A grazing experiment was conducted in North-West Sardinia with the aim of testing the sward height as a mean to set up an efficient spring management of Italian ryegrass (Lolium multiflorum Lam.). Three fields were continuously grazed during spring 1992 by three groups of 12 dairy Sarda ewes, at three different sward heights (SH): 30 - 60 - 90 mm. The target sward height was obtained by continuously adjusting the field sizes. The results showed that the different grazing managements influenced the above ground biomass production and partitioning of the Italian ryegrass and the animal performances. During the vegetative …

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Estimation Of Herbage Intake Of High Producing Milking Cows Under Intensive Grazing With A Supplementary Feeding Method In Northern Japan, K Ohiai, K Sudo, T Ikeda, T Honma Jul 2024

Estimation Of Herbage Intake Of High Producing Milking Cows Under Intensive Grazing With A Supplementary Feeding Method In Northern Japan, K Ohiai, K Sudo, T Ikeda, T Honma

IGC Proceedings (1977-2023)

The objective of this study was to estimate the herbage intake and to assess a supplementary feeding method for high producing milk cows under intensive grazing. Eight high producing milking cows were grazed rotationally on perennial ryegrass (Lolium perenne L) dominant mixed pasture and on meadow fescue (Festuca elatior L) dominant mixed pasture, changing rotation period and grazing area ccording to seasonal pasture growth rate. Pasture intakes were estimated to be about 2% of body weight by TDN requirements estimation of animals. A supplementary feeding method is examined to be proper for high producing milking cows under …

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Palatability Of Grasses And Grazing On Hungarian Grassland, Z Barcsak, I Kertesz, L Szeman Jul 2024

Palatability Of Grasses And Grazing On Hungarian Grassland, Z Barcsak, I Kertesz, L Szeman

IGC Proceedings (1977-2023)

Grasslands provide the most basic and cheapest forage diet for cattle. The palatability studies were carried out on pure and mixed swards sown in 1990 on the GATE experimental farm. The studies involved the following 12 species: Lolium perenne, Trifolium repens, Festuca arundinacea, Festuca rubra, Poa pratensis, Festuca pratensis, Bromus inermis, Phalaris arundinacea, Lotus corniculatus, Agropyron crystatum, Dactylis glomerata and a mixed sward. During the study the morning and afternoon grazings were investigated with the involvement of 60 Limousin cattle. The following observations were made: 1. On the basis of our ethological observations regarding the bite rates the animals found …

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Selective Sheep Grazing In An Heterogeneous Wheatgrass Dominated Pasture Related To Stocking Rate, G L. Siffredi, M A. Brizuela, M S. Cid, C Cangiano Jul 2024

Selective Sheep Grazing In An Heterogeneous Wheatgrass Dominated Pasture Related To Stocking Rate, G L. Siffredi, M A. Brizuela, M S. Cid, C Cangiano

IGC Proceedings (1977-2023)

It has been hypothesized that patch and community selection are driven by forage quality and/or quantity. We assess the relationship between vegetation characteristics and community and patch selection by sheep under continuous grazing at different stocking rates in an heterogeneous pasture. Our results suggest that when communities strongly differed in nutritive value sheep recurrently select the higher quality community in spite of its low biomass. However, sheep do not completely exclude the poorer quality community, generating a patchy vegetation pattern.

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Grazing Management Of Elephant-Grass For Milk Production, F Deresz, L L. Matos Jul 2024

Grazing Management Of Elephant-Grass For Milk Production, F Deresz, L L. Matos

IGC Proceedings (1977-2023)

The objectives of these experiments were to study the effects of three resting periods (RP) of elephant-grass pasture on milk production and composition of Holstein-Zebu cows. These trials were carried out during two consecutive rainy seasons (December to May) using 24 cows in each year. They were randomly assigned by blocks according to milk yield and live weight (LW) to four treatments: 30- day RP with no concentrate (30N), 30-day RP with concentrate (30C), 36 and 45-day RP with C (36C and 45C) in the first year. In the second year the treatments were: 30C, 30N, 36N and 45N. Concentrate …

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