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Articles 5281 - 5310 of 78655
Full-Text Articles in Entire DC Network
Development Of Soil Survey Methods For Urban Areas, Kohinoor Begum
Development Of Soil Survey Methods For Urban Areas, Kohinoor Begum
Dissertations, Theses, and Capstone Projects
Urban soils are the foundation of urban ecosystems and play a vital role in long-term urban sustainability and resiliency. Accurate soil surveys of urban areas should be done at higher resolution since extensive human activities often result in urban soil being highly disturbed and spatially variable. Besides heterogeneity, one of the unique and challenging aspects of urban soil is the nature and properties of its organic carbon with a significant percentage of black carbon (a particulate product of incomplete combustion), which is less biologically active. Thus, in order to determine the ability of a soil to support biological activity and …
Novel Alchemical Methodologies For Modeling Molecular Binding, Solmaz Azimi
Novel Alchemical Methodologies For Modeling Molecular Binding, Solmaz Azimi
Dissertations, Theses, and Capstone Projects
Molecular recognition is fundamental to all biological and biochemical processes. Understanding the interactions between molecules is the foundation for drug discovery and development, for understanding biological processes, and for the design of biosensors and nanomaterials. There is tremendous interest in the development of computer models to predict molecular association equilibria. In structure-based drug discovery enterprises, predicting the strength and selectivity of a small molecule to a biological target can advance target identification, aid ligand design, and accelerate high-throughput screening of drug compounds. This work focuses on free energy models, a class of computational methodologies grounded on the fundamental physical and …
Quantified Lives: Data, Bias, And The Cost Of Categorization, Colin F. Geraghty
Quantified Lives: Data, Bias, And The Cost Of Categorization, Colin F. Geraghty
Dissertations, Theses, and Capstone Projects
This project critically examines how statistical methods and data visualization have historically been used to categorize, rank, and control human populations. By exploring the works of key figures like Francis Galton, Karl Pearson, and R.A. Fisher, it traces the evolution of categorization frameworks from their eugenic roots to modern applications in artificial intelligence and global metrics like the World Happiness Report. Through interactive visualizations and historical analysis, the project invites users to question the legitimacy of these frameworks and reflect on their impact on society. At its core, this work emphasizes the need to move beyond rigid classification systems, challenging …
Chatgpt Didn’T Write This: Evaluating The Impact Of Llms With A Case Study In Grading Cuny Language Immersion Program Student Essays, Benjamin Inbar
Chatgpt Didn’T Write This: Evaluating The Impact Of Llms With A Case Study In Grading Cuny Language Immersion Program Student Essays, Benjamin Inbar
Dissertations, Theses, and Capstone Projects
This study evaluates the capabilities and limitations of large language models (LLMs), specifically OpenAI’s ChatGPT-4o, in grading essays from students in the City University of New York’s Language Immersion Program. The program serves English language learners with diverse linguistic and demographic backgrounds, offering intensive language instruction to prepare students for academic success in college. Using a dataset of 30 pre- and post-program essays scored by program instructors and ChatGPT-4o under three paradigms, this research explores the alignment between human and AI-generated scores across five rubric-based competency areas. Findings reveal that ChatGPT-4o aligns moderately with human grading, with the strongest agreement …
Assessing Vegetation Changes And Ecosystem Impacts Of Invasive Species In Florida's Water Conservation Area 3a (2004–2024) Using Landsat Data, Gideon Tandoh
Research, Papers & Creative Work
The spread of invasive species is a concrete problem, threatening biodiversity, ecosystem integrity, and the functional status of wetlands. As these species continue to advance, it is crucial to assess their spread as well as management success through the more sophisticated invasive monitoring methodologies. This research examines the change in vegetation communities and the spread of invasive plants in the Water Conservation Area 3A (WCA-3A) using Object-Based Image Analysis (OBIA) and Support Vector Machine (SVM) classifiers on time series Landsat images. Unlike traditional pixel-based methods, OBIA enhances classification accuracy by incorporating spatial, spectral, and contextual information, enabling precise differentiation between …
Analysis Of 26 Studies Of The Impact Of Coconut Oil On Lipid Parameters: Beyond Total And Ldl Cholesterol, Mary T. Newport, Fabian M. Dayrit
Analysis Of 26 Studies Of The Impact Of Coconut Oil On Lipid Parameters: Beyond Total And Ldl Cholesterol, Mary T. Newport, Fabian M. Dayrit
Chemistry Faculty Publications
Coconut oil (CNO) is often characterized as an “artery-clogging fat” because it is a predominantly saturated fat that ostensibly raises total cholesterol (TChol) and LDL cholesterol (LDL-C). Whereas previous analyses assessed CNO based on the relative effects on lipid parameters against other fats and oils, this analysis focuses on the effects of CNO itself. Here, we review the literature on CNO and analyze 984 lipid profile data sets from 26 CNO studies conducted over the past 40 years. This analysis shows considerable heterogeneity among CNO studies regarding participant selection, the amount consumed, and the study duration. The analysis reveals that, …
Project Title: Maximizing The Volume Of A Cardboard Box To Save Trees– An Application Of Polynomial Functions To Address Global Issues [Mathematics], Lucie Mingla
Open Educational Resources
MAT 115 College Algebra & Trigonometry/Precalculus
Project Title: Maximizing the Volume of a Cardboard Box to Save Trees– An Application of Polynomial Functions to Address Global Issues
Reflective Narrative:
This project was inspired by my participation in the "Designing and Implementation of STEM Co-Curricular Activities" CTL seminar in Spring 2023. I am grateful to Drs. Bukurie Gjoci, Daniel Gertner, Ingrid Veras, and Midas Tsai, along with fellow participants, for their invaluable feedback that helped shape its development. The project was implemented in two College Algebra and Trigonometry courses. I participated in two seminars to further develop this project. The Community …
Investigating Dna Damage Caused By Reactive Oxygen And Nitrogen Species Via Guided-Ion-Beam Scattering And Computational Techniques, Jonathan Benny
Investigating Dna Damage Caused By Reactive Oxygen And Nitrogen Species Via Guided-Ion-Beam Scattering And Computational Techniques, Jonathan Benny
Dissertations, Theses, and Capstone Projects
Among DNA nucleobases, guanine (G) is the primary target for one-electron ionization and oxidation, generating G●+ through various processes, including photooxidation, electrocatalytic oxidation, DNA-binding transition metals, ionizing radiation, and photolysis. This is due to the low adiabatic ionization potential and oxidation potential of guanine. Electron holes from other nucleobases can move to guanine, proving that G●+ production traps oxidative DNA damage. G●+ formation can exacerbate DNA damages and cause secondary reactions from reactive oxygen species (ROS) and reactive nitrogen species (RNS) during pathological processes. The following three projects were conducted using a customized electrospray ionization (ESI) guided-ion-beam tandem mass spectrometer, …
Solvation Thermodynamic Mapping Approaches For Computer-Aided Drug Discovery, Vjay Molino
Solvation Thermodynamic Mapping Approaches For Computer-Aided Drug Discovery, Vjay Molino
Dissertations, Theses, and Capstone Projects
The drug discovery process is inherently long and costly, prompting the development and integration of computational tools to mitigate these challenges. One of area explored in computer-aided drug discovery is to understand the role of solvation in protein-drug binding and to develop computational tools and methods that can be integrated in the drug discovery process. Grid Inhomogeneous Solvation Theory (GIST) is a tool that provides a framework for mapping solvation thermodynamiproperties of water molecules on the protein surface.This thesis explores the use of GIST in generating pharmacophore models and elucidates the role of solvation in protein structural fluctuations.
One of …
Leveraging Collective Impact To Characterize And Identify Solutions To Cultural Challenges Within Scientific Societies, Taylor Lightner, Simone B. Soso, Candice M. Etson, Robin Mc C. Greenler, Mercy Mugo, Verónica A. Segarra
Leveraging Collective Impact To Characterize And Identify Solutions To Cultural Challenges Within Scientific Societies, Taylor Lightner, Simone B. Soso, Candice M. Etson, Robin Mc C. Greenler, Mercy Mugo, Verónica A. Segarra
Physics: Faculty Publications
A consortium of scientific societies recently identified challenges to inclusivity within the biology communities they represent. Specifically, societies encounter difficulties collecting member demographic data effectively, integrating scientists at transitional career stages, and diversifying their leadership. In response, the Leveraging, Enhancing, and Developing Biology (LED-BIO) research coordination network (NSF 2134725) organized two meetings at the Marine Biological Laboratory in Woods Hole, MA to gather stakeholders and employ top-down and bottom-up organizational approaches to address these challenges. These meetings included Town Hall and Think Tank events to facilitate open dialogue and gather feedback on policies and programs from national organizations in attendance. …
Analytical Method For Solving Systems Of Fractional Initial Value Problems Using The Modified Atangana-Baleanu Derivative, Lana Mohammad Aref
Analytical Method For Solving Systems Of Fractional Initial Value Problems Using The Modified Atangana-Baleanu Derivative, Lana Mohammad Aref
Theses
This thesis presents an analytical method to solve systems of fractional initial value problems using the Modified Atangana-Baleanu Fractional Derivative. The proposed approach leverages an improved operational matrix method, incorporating an iterative, direct computation technique to simplify the solution process and reduce computational costs. Foundational concepts in fractional calculus and block pulse functions are introduced, followed by the derivation of operational matrices tailored for fractional systems. Theoretical analysis establishes the existence and uniqueness of solutions, along with uniform convergence and error estimates. Practical examples and applications are presented that demonstrate the efficiency, accuracy, and versatility of the method in solving …
Vaxbot-Hpv: A Gpt-Based Chatbot For Answering Hpv Vaccine-Related Questions, Yiming Li, Jianfu Li, Manqi Li, Evan Yu, Danniel Rhee, Muhammad Amith, Lu Tang, Lara S Savas, Licong Cui, Cui Tao
Vaxbot-Hpv: A Gpt-Based Chatbot For Answering Hpv Vaccine-Related Questions, Yiming Li, Jianfu Li, Manqi Li, Evan Yu, Danniel Rhee, Muhammad Amith, Lu Tang, Lara S Savas, Licong Cui, Cui Tao
Faculty, Staff and Student Publications
OBJECTIVE: Human Papillomavirus (HPV) vaccine is an effective measure to prevent and control the diseases caused by HPV. However, widespread misinformation and vaccine hesitancy remain significant barriers to its uptake. This study focuses on the development of VaxBot-HPV, a chatbot aimed at improving health literacy and promoting vaccination uptake by providing information and answering questions about the HPV vaccine.
METHODS: We constructed the knowledge base (KB) for VaxBot-HPV, which consists of 451 documents from biomedical literature and web sources on the HPV vaccine. We extracted 202 question-answer pairs from the KB and 39 questions generated by GPT-4 for training and …
Dft Study Of The Mechanism Of Selective Hydrogenation Of Acetylene By Rhodium Single-Atom Catalyst Supported On Hy Zeolite, Melisa Su Yordanlı, Roberto Escobar, Jessica Meza, Deniz Akgül, Yuxin Zhao, Alper Uzun, Fatma Ahu Akin, Viktorya Aviyente, Abdurrahman Cagri Atesin, Tülay A. Ateşin
Dft Study Of The Mechanism Of Selective Hydrogenation Of Acetylene By Rhodium Single-Atom Catalyst Supported On Hy Zeolite, Melisa Su Yordanlı, Roberto Escobar, Jessica Meza, Deniz Akgül, Yuxin Zhao, Alper Uzun, Fatma Ahu Akin, Viktorya Aviyente, Abdurrahman Cagri Atesin, Tülay A. Ateşin
School of Earth, Environmental, & Marine Sciences Faculty Publications
The selectivity of acetylene hydrogenation by the Rh single-atom catalyst (SAC) supported on HY zeolite was investigated using density functional theory (DFT) and a 5/83T quantum mechanics/molecular mechanics (QM/MM) embedded cluster model. The calculated activation barrier (ΔG‡) for the oxidative addition of dihydrogen to the Rh metal center (15.9 kcal/mol) is lower in energy than that for the σ-bond metathesis of dihydrogen to the Rh—C bond (22.7 kcal/mol) and the Rh—O bond (28.4 kcal/mol). The activation barriers of the oxidative addition of subsequent dihydrogen molecules are significantly higher than that of the oxidative addition of the first dihydrogen molecule. These …
Offshore Wind Farms Could Impact Coastal Marine Heatwaves In Eastern Boundary Upwelling Systems, Michael Dalsin, Ryan K. Walter, Piero L.F. Mazzini
Offshore Wind Farms Could Impact Coastal Marine Heatwaves In Eastern Boundary Upwelling Systems, Michael Dalsin, Ryan K. Walter, Piero L.F. Mazzini
Physics
Analysis of ecosystem impacts from offshore wind (OSW) farm development has primarily focused on localized effects. However, in Eastern Boundary Current Upwelling Systems (EBUS) like the California Current, OSW farms can modify the intensity and spatial structure of wind-driven upwelling, inducing non-local (tens of kms away) changes to seawater temperature. Recent numerical modeling research determined that a hypothetical upper bound full buildout of OSW farms in central California could warm coastal waters through a reduction in upwelling. Here, we examine the sensitivity of coastal marine heatwaves (MHWs), which are prolonged extreme seawater temperatures that are among the greatest threats to …
A Statistical Framework For Multi-Trait Rare Variant Analysis In Large-Scale Whole-Genome Sequencing Studies, Xihao Li, Han Chen, Margaret Sunitha Selvaraj, Eric Van Buren, Hufeng Zhou, Yuxuan Wang, Ryan Sun, Zachary R Mccaw, Zhi Yu, Min-Zhi Jiang, Daniel Dicorpo, Sheila M Gaynor, Rounak Dey, Donna K Arnett, Emelia J Benjamin, Joshua C Bis, John Blangero, Eric Boerwinkle, Donald W Bowden, Jennifer A Brody, Brian E Cade, April P Carson, Jenna C Carlson, Nathalie Chami, Yii-Der Ida Chen, Joanne E Curran, Paul S De Vries, Myriam Fornage, Nora Franceschini, Barry I Freedman, Charles Gu, Nancy L Heard-Costa, Jiang He, Lifang Hou, Yi-Jen Hung, Marguerite R Irvin, Robert C Kaplan, Sharon L R Kardia, Tanika N Kelly, Iain Konigsberg, Charles Kooperberg, Brian G Kral, Changwei Li, Yun Li, Honghuang Lin, Ching-Ti Liu, Ruth J F Loos, Michael C Mahaney, Lisa W Martin, Rasika A Mathias, Braxton D Mitchell, May E Montasser, Alanna C Morrison, Take Naseri, Kari E North, Nicholette D Palmer, Patricia A Peyser, Bruce M Psaty, Susan Redline, Alexander P Reiner, Stephen S Rich, Colleen M Sitlani, Jennifer A Smith, Kent D Taylor, Hemant K Tiwari, Ramachandran S Vasan, Satupa'itea Viali, Zhe Wang, Jennifer Wessel, Lisa R Yanek, Bing Yu, Nhlbi Trans-Omics For Precision Medicine (Topmed) Consortium, Josée Dupuis, James B Meigs, Paul L Auer, Laura M Raffield, Alisa K Manning, Kenneth M Rice, Jerome I Rotter, Gina M Peloso, Pradeep Natarajan, Zilin Li, Zhonghua Liu, Xihong Lin
A Statistical Framework For Multi-Trait Rare Variant Analysis In Large-Scale Whole-Genome Sequencing Studies, Xihao Li, Han Chen, Margaret Sunitha Selvaraj, Eric Van Buren, Hufeng Zhou, Yuxuan Wang, Ryan Sun, Zachary R Mccaw, Zhi Yu, Min-Zhi Jiang, Daniel Dicorpo, Sheila M Gaynor, Rounak Dey, Donna K Arnett, Emelia J Benjamin, Joshua C Bis, John Blangero, Eric Boerwinkle, Donald W Bowden, Jennifer A Brody, Brian E Cade, April P Carson, Jenna C Carlson, Nathalie Chami, Yii-Der Ida Chen, Joanne E Curran, Paul S De Vries, Myriam Fornage, Nora Franceschini, Barry I Freedman, Charles Gu, Nancy L Heard-Costa, Jiang He, Lifang Hou, Yi-Jen Hung, Marguerite R Irvin, Robert C Kaplan, Sharon L R Kardia, Tanika N Kelly, Iain Konigsberg, Charles Kooperberg, Brian G Kral, Changwei Li, Yun Li, Honghuang Lin, Ching-Ti Liu, Ruth J F Loos, Michael C Mahaney, Lisa W Martin, Rasika A Mathias, Braxton D Mitchell, May E Montasser, Alanna C Morrison, Take Naseri, Kari E North, Nicholette D Palmer, Patricia A Peyser, Bruce M Psaty, Susan Redline, Alexander P Reiner, Stephen S Rich, Colleen M Sitlani, Jennifer A Smith, Kent D Taylor, Hemant K Tiwari, Ramachandran S Vasan, Satupa'itea Viali, Zhe Wang, Jennifer Wessel, Lisa R Yanek, Bing Yu, Nhlbi Trans-Omics For Precision Medicine (Topmed) Consortium, Josée Dupuis, James B Meigs, Paul L Auer, Laura M Raffield, Alisa K Manning, Kenneth M Rice, Jerome I Rotter, Gina M Peloso, Pradeep Natarajan, Zilin Li, Zhonghua Liu, Xihong Lin
Faculty, Staff and Student Publications
Large-scale whole-genome sequencing (WGS) studies have improved our understanding of the contributions of coding and noncoding rare variants to complex human traits. Leveraging association effect sizes across multiple traits in WGS rare variant association analysis can improve statistical power over single-trait analysis, and also detect pleiotropic genes and regions. Existing multi-trait methods have limited ability to perform rare variant analysis of large-scale WGS data. We propose MultiSTAAR, a statistical framework and computationally scalable analytical pipeline for functionally informed multi-trait rare variant analysis in large-scale WGS studies. MultiSTAAR accounts for relatedness, population structure and correlation among phenotypes by jointly analyzing multiple …
Exploring Key Factors Influencing Depressive Symptoms Among Middle-Aged And Elderly Adult Population: A Machine Learning-Based Method, Ngoc Doan Thu Tran, Yi Zhen Tan, Sapphire Lin, Fang Zhao, Yee Sien Ng, Dong Ma, Jeonggil Ko, Rajesh Krishna Balan
Exploring Key Factors Influencing Depressive Symptoms Among Middle-Aged And Elderly Adult Population: A Machine Learning-Based Method, Ngoc Doan Thu Tran, Yi Zhen Tan, Sapphire Lin, Fang Zhao, Yee Sien Ng, Dong Ma, Jeonggil Ko, Rajesh Krishna Balan
Research Collection School Of Computing and Information Systems
Objective: This paper aims to investigate the key factors, including demographics, socioeconomics, physical wellbeing, lifestyle, daily activities and loneliness that can impact depressive symptoms in the middle-aged and elderly population using machine learning techniques. By identifying the most important predictors of depressive symptoms through the analysis, the findings can have important implications for early depression detection and intervention. Participants: For our cross-sectional study, we recruited a total of 976 volunteers, with a specific focus on individuals aged 50 and above. Each participant was requested to provide their demographic, socioeconomic information and undergo several physical health tests. Additionally, they were asked …
Geometry, Art, And Technology: Islamic Geometric Patterns In The Classroom, Rebin Muhammad, Mona Hajghassem, Mais Alraee
Geometry, Art, And Technology: Islamic Geometric Patterns In The Classroom, Rebin Muhammad, Mona Hajghassem, Mais Alraee
Journal of Humanistic Mathematics
In this paper, we share our experiences developing and implementing three Desmos activities. These activities aim to introduce geometric concepts such as transformation, symmetry, and geometric construction by using examples from Islamic Geometric Patterns (IGP). Our target audience for these activities is future elementary school teachers. In addition to leveraging technology, we enrich the learning process by incorporating hands-on exploration with physical IGP examples.
White Horses In The Sky: Or The Magical Place Where Topology Meets Poetry, Sanziana Caraman, Lorelei Caraman
White Horses In The Sky: Or The Magical Place Where Topology Meets Poetry, Sanziana Caraman, Lorelei Caraman
Journal of Humanistic Mathematics
What do Shakespearean words, doughnuts, cups of tea, and horses in the sky all have in common with a famous theorem? To discover the answer, we take you on a journey in a strange, enchanted land: the land where mathematics meets poetry. Here we explore how a fundamental literary trope, metaphor, and a fundamental result in topology, Brouver's Fixed Point Theorem, touch and illuminate one another. Delving into the symmetry of this transdisciplinary embrace, we find that it reveals, not only the beauty of poetry and mathematics, but that of life itself: the beauty hidden in ordinary things like a …
The Swaying Equations: An Exhibition Of Mathematical And Algorithmic Art, Awansika Nimuthumana, Anuradha Mahasinghe
The Swaying Equations: An Exhibition Of Mathematical And Algorithmic Art, Awansika Nimuthumana, Anuradha Mahasinghe
Journal of Humanistic Mathematics
An exhibition of mathematical and algorithmic art took place on 30th September and 01st October 2023 at the Lionel Wendt art gallery in Colombo, Sri Lanka. To our knowledge, this is the first-ever mathematical art exhibition in Sri Lanka. This report contains a brief overview of the artworks and some highlights of the exhibition.
Recurrent Selection For Partial Resistance To Anthracnose Disease In Shrubby Stylo (Stylosanthes Scabra), D F. Cameron, R A. Boland, S Chakraborty, B Jamieson, J.A G. Irwin
Recurrent Selection For Partial Resistance To Anthracnose Disease In Shrubby Stylo (Stylosanthes Scabra), D F. Cameron, R A. Boland, S Chakraborty, B Jamieson, J.A G. Irwin
IGC Proceedings (1977-2023)
Three cycles of crossing have been completed in a recurrent selection programme for partial resistance to anthracnose disease of shrubby stylo (Stylosanthes scabra) In a field study of a subset of 40 F2 populations from the first cycle, highly significant differences (P<0.001) in anthracnose resistance were found for both male and female effects and for the female x male interaction, In a subsequent F3 progeny test of 99 families selected for disease resistance and yield, 92 of the families were resistant to highly resistant with leaf damage <1% (cf, >50% damage for the susceptible cultivar, Fitzroy). Strong discrimination for resistance was also obtained in a second subset of 23 F2 populations using combined glasshouse and field selection for resistance. Further improvement in anthracnose resistance was achieved in the second and third cycles of recurrent selection. The broadly based resistance of selections from the third cycle …0.001)>
Calliandra Calothyrsus - A Potential New Shrub Legume For Tropical Animal Production?, B Palmer, R A. Bray, T M. Ibrahim
Calliandra Calothyrsus - A Potential New Shrub Legume For Tropical Animal Production?, B Palmer, R A. Bray, T M. Ibrahim
IGC Proceedings (1977-2023)
Calliandra calothyrsus outyielded leucaena in cutting experiments at 2 sites in northern Australia and I in Indonesia. Drying significantly depressed the voluntary intake and digestibility of leaf, possibly due to the presence of tannin. Calliandra has the potential as a supplement for the low quality grass common to the tropics both ln grazing and cut-and-carry systems.
Glycine Latifolia- A Potentially Useful Native Legume For Clay Soils In Tropical And Subtropical Australia, M C. Rees, R M. Jones, A.H D. Brown, J N. Coote
Glycine Latifolia- A Potentially Useful Native Legume For Clay Soils In Tropical And Subtropical Australia, M C. Rees, R M. Jones, A.H D. Brown, J N. Coote
IGC Proceedings (1977-2023)
In tropical and subtropical Australia, more than 5 million ha of heavy-textured soils receive adequate rainfall for cropping or pasture improvement. Glycine latifolla, a perennial legume native to these areas, shows promise for permanent pastures or long term leys. It occurs from latitudes 22"8 to 31 •s on heavy textured soils in the 500-1200 mm rainfall zone. It is a prostrate plant that roots from stolons and sets seed under grazing, It is drought tolerant, frost resistant, and produces dry matter yields comparable to those from the introduced legumes Desmanthus virgatus and Indigofera schimperi, There is a need to …
Development Of Rhizoma Peanut For Forage In Lower South, Usa, Gordon M. Prine, Edwin C. French
Development Of Rhizoma Peanut For Forage In Lower South, Usa, Gordon M. Prine, Edwin C. French
IGC Proceedings (1977-2023)
Rhizoma (perennial) peanut (Arachiis glabrata Benth.) (RP) is n perennial, warm-season legume, adapted to well-drained soils of humid tropics and subtropics. It is grown in Florida and warmer portions of the south-eastern USA up to about 32°N. Cultivar Florigraze was released in 1978 and cv. Arbrook in 1986. Commercial hectarage of RP has increased about 40% annually to approximately 2000 ha in 1992. Propagated vegetatively from rhizomes, RP Is slow to establish. Rhizoma peanut is drought-tolerant, persistent, grows well on droughty, low-fertility soils, requires moderate to excessive soil drainage and requires no N and usually no P fertiliser. It …
Effects Of Cutting Heights And Cutting Frequencies On The Annual Yield Of Leucaena And Calliandra Hedges, O Ncamihigo, P Brandelard
Effects Of Cutting Heights And Cutting Frequencies On The Annual Yield Of Leucaena And Calliandra Hedges, O Ncamihigo, P Brandelard
IGC Proceedings (1977-2023)
A 3-year study was conducted in Burundi to examine the effects of 3 cutting heights (0, 50 and 100 cm) and 3 cutting frequencies (3, 4 and 6 months) on the total annual biomass yield and leaf production of 3 shrub legumes, Leucaena diverslfolia cv, Buitenzorg, L. leucocephala cv, Peruvian and Calliandra calothyrsus. Highest annual biomass and leaf production were obtained at the 100 cm cutting hejght, There was no significant effect of cutting interval on L. leucocephala but for Calliandra calothyrsus, leaf production was highest at the 4- month cutting frequency. Both biomass production and leaf production …
Performance Of Desmanthus Virgatus Accessions In The Caribbean, M B. Adjei, K Albrecht
Performance Of Desmanthus Virgatus Accessions In The Caribbean, M B. Adjei, K Albrecht
IGC Proceedings (1977-2023)
Twenty-three Desmanthus virgatus accessions, established on a mildly alkaline clay soil (Typic Rendoll Mollisol), were repeatedly harvested to 10 cm stubble over a 2-year period whenever regrowths reached the early-pod stage of maturity to determine forage yield, leaf/stem proportions, forage quality and stand persistence. Differences were observed in seasonal growth distribution and annual forage yield of accessions. Collections from Venezeula and Mexico were among the most productive (8-11 t dry matter/ha/year) and from the Dominican Republic, the least productive (<6 t/ha/year) accessions. Most accessions perissted well under the lenient garvesting regime imposed. The proportion of leaf in dry forage ranged from 34 to 43% with average leaf crude protein (CP) content in vitro organic matter digestibility (IVOMD) of 19.2% and 83.4%, respectively. The average stem CP and IVOMD were 7.4% and 48.9%, respectively, and were not affected by accessions. Leaf samples of all Desmanthus accessions contained high levels of tannins (26-31 g tannic acid equivalent s/kg DM). However, unlike fibre fractions, leaf IVOMD was only weakly correlated with leaf tannin content (r-0.38).
Breeding For Rust Resistance In Marcoptilium Atropurpureum, R A. Bray
Breeding For Rust Resistance In Marcoptilium Atropurpureum, R A. Bray
IGC Proceedings (1977-2023)
Rust in Macroptilium atropurpurewn cv. Siratro is an important disease, reducing both yield and quality, Resistance to the disease is conditioned by several genetic mechanisms, including single dominant. genes, multiple dominant genes, single major genes together with genes of lesser effect, and single recessive genes. Near-isogenic lines have been developed by backcrossing dominant genes into Slratro background, and these lines used to demonstrate pathogenic specialisation in Mexican collections of the rust organism. No variation In virulence is apparent in S Australian isolates of the fungus, Pour of the backcross populations, with resistance genes from geographically diverse origins, have been mixed …
Phenological Development Of Line 8400 Stylo And Alyeclover Planted At Two Dates In Subtropical Florida, M J. Williams, C G. Chambliss, J B. Brolmann
Phenological Development Of Line 8400 Stylo And Alyeclover Planted At Two Dates In Subtropical Florida, M J. Williams, C G. Chambliss, J B. Brolmann
IGC Proceedings (1977-2023)
Line 8400 slylo (Stylosathes guianensis) remains vegetative later in the autumn than many tropical annual legumes. The objective of our study was lo determine the effect of planting dale (April or June) on the phenological development of Line 8400 stylo compared with alyceclover (Alysicarpus vaginalis). Root/shoot ratio of Line 8400 stylo (0.16) was not affected by planting date and was similar to April-planted alyceclover (0.15), but was lower (P<0.05) than Juneplanted alyceclover (0,21). Legume leaf/stem ratio was not affected by planting date, declined (P=0.0001) from an average of 2.79 at 4 weeks to 0.55 by 16 weeks post-planting, and was higher (P=0.03) for Line 8400 stylo (1.76) than alyceclover (1.29). Maximum dry mailer yield was 10.1 and 5.0 Mg/ha for April- and 7.2 and 5.6 Mg/ ha for June-planted Line 8400 stylo and alyceclover, respectively.
Selection Of Sylosanthes Spp. For The Cerrados Of Brazil, B Grof, A.T F. Fernandes, C D. Fernandez
Selection Of Sylosanthes Spp. For The Cerrados Of Brazil, B Grof, A.T F. Fernandes, C D. Fernandez
IGC Proceedings (1977-2023)
Improved seed yield and leaf retention during the dry season coupled with anthracnose resistance were recorded among mid-season flowering progenies of intervarietal hybrids of Stylosantheses guianensis var. vulgaris x var. panciflora. Mineirao, a late-flowering accession of S. g11ia11e11sis var. vulgaris, displayed similar agronomic traits, but produced lower seed yields. Venezuelan accessions of S. capitata, and a binary mixture of S. capitata-S. ,nacrocepllala showed field resistance to anthracnose. Inter- and intraspecific variation for resistance to anthracnose disease was demonstrated by inoculation with virulent local and introduced pathotypes of Colletotrichum gloeosporioides. The development from these heterogeneous populations of cultivars …
Meeting The Challenge Of Adapting Leucaena Leucocephala To The Acid Oxisols And Utisolds Of South America And South-East Asia, E M. Hutton, Chin Peng Chen
Meeting The Challenge Of Adapting Leucaena Leucocephala To The Acid Oxisols And Utisolds Of South America And South-East Asia, E M. Hutton, Chin Peng Chen
IGC Proceedings (1977-2023)
Shtteen lines from 2 families of Leucaena leucocephala-L. diversifolia hybrids selected for acid-soil tolerance in Brazil were reselected in the Kuala Linggi acid-sulphate soil and Serdang oxisol in Malaysia. In the K. Linggi soil with 81 % Al saturation, highly acid-tolerant hybrids were selected with 35-79% more growth than the intolerant cv. Cunningham. At Serdang the oxisol had ·a mean 68% Al saturation and hybrids were selected with 19-49% more growth than Cunningham which lacked intolerance symptoms due to annual dolomite application. In a severe psyllid infestation at K. Linggi, 5 of the 14 hybrids from one family had …
Evaluation Of Wild Nut-Producing Arachis Species For Forage, A E. Kretschmer Jr, C E. Simpson, T C. Wilson, W D. Pitman
Evaluation Of Wild Nut-Producing Arachis Species For Forage, A E. Kretschmer Jr, C E. Simpson, T C. Wilson, W D. Pitman
IGC Proceedings (1977-2023)
Fourteen nut-producing wild peanut (Arachis spp,) accessions were evaluated in single-plant plots and in ranchers' fields under grazing. Transplants were used for initial and some secondary planting, Agronomic characteristics and persistence were measured. The cv. Amarillo (4222) and a selection previously evaluated (2273) were used as controls. Plant yield, leaf and stem weights, nut production and other attributes varied among the accessions. Accession 2273 was one of the earliest and most prolific flowering and nut producers, while 4222 was the most persistent under initial grazing evaluation,