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Articles 14611 - 14640 of 255713

Full-Text Articles in Life Sciences

Exploring Religious Leaders’ Perspectives On Genetic Counseling, Testing, And Related Technologies, Kristina M. Wittenburg Mar 2025

Exploring Religious Leaders’ Perspectives On Genetic Counseling, Testing, And Related Technologies, Kristina M. Wittenburg

USF Tampa Graduate Theses and Dissertations

Religion significantly influences healthcare decisions, including those related to genetic testing, by shaping ethical and emotional considerations. While some religious groups provide formal stances on genetic testing, others lack clear guidelines, leaving both patients and healthcare providers without consistent resources for navigating faith-informed decisions. Understanding religious leaders’ perspectives is critical to bridging this gap and supporting diverse patient needs. This study aimed to examine religious leaders’ perspectives on genetic testing, genetic counseling, in vitro fertilization (IVF), gene therapy, stem cell research, and abortion. These topics were explored to understand the role of religious beliefs in healthcare decisions, and to develop …


Sustainable Sediment Management In Jordanian Dams: Feasibility, Economic Viability, And Agricultural Reuse Potential, Ahmed Al-Taani, Nazem El Radaideh, Wesam Al Kateeb, Fares Howari, Yousef Nazzal, Jibran Iqbal, Abeer Al Bsoul Mar 2025

Sustainable Sediment Management In Jordanian Dams: Feasibility, Economic Viability, And Agricultural Reuse Potential, Ahmed Al-Taani, Nazem El Radaideh, Wesam Al Kateeb, Fares Howari, Yousef Nazzal, Jibran Iqbal, Abeer Al Bsoul

All Works

Jordan has long faced severe water scarcity, which has significant implications for agriculture, industry, and domestic consumption. This crisis is further exacerbated by climate change, population growth, regional conflicts, and unsustainable water use. In response, Jordan has focused heavily on dam construction to secure water supplies, despite the high financial and environmental costs. However, rapid sedimentation threatens dam storage capacity and operational efficiency, reducing their lifespan and long-term sustainability. This study evaluates the feasibility of sediment removal as an alternative to constructing new dams, considering environmental, technical, agricultural, and economic factors. The research is based on case studies from King …


Precision Phenotyping For Curating Research Cohorts Of Patients With Unexplained Post-Acute Sequelae Of Covid-19, Alaleh Azhir, Jonas Hügel, Jiazi Tian, Jingya Cheng, Ingrid V Bassett, Douglas S Bell, Elmer V Bernstam, Maha R Farhat, Darren W Henderson, Emily S Lau, Michele Morris, Yevgeniy R Semenov, Virginia A Triant, Shyam Visweswaran, Zachary H Strasser, Jeffrey G Klann, Shawn N Murphy, Hossein Estiri Mar 2025

Precision Phenotyping For Curating Research Cohorts Of Patients With Unexplained Post-Acute Sequelae Of Covid-19, Alaleh Azhir, Jonas Hügel, Jiazi Tian, Jingya Cheng, Ingrid V Bassett, Douglas S Bell, Elmer V Bernstam, Maha R Farhat, Darren W Henderson, Emily S Lau, Michele Morris, Yevgeniy R Semenov, Virginia A Triant, Shyam Visweswaran, Zachary H Strasser, Jeffrey G Klann, Shawn N Murphy, Hossein Estiri

Faculty, Staff and Student Publications

BACKGROUND: Scalable identification of patients with post-acute sequelae of COVID-19 (PASC) is challenging due to a lack of reproducible precision phenotyping algorithms, which has led to suboptimal accuracy, demographic biases, and underestimation of the PASC.

METHODS: In a retrospective case-control study, we developed a precision phenotyping algorithm for identifying cohorts of patients with PASC. We used longitudinal electronic health records data from over 295,000 patients from 14 hospitals and 20 community health centers in Massachusetts. The algorithm employs an attention mechanism to simultaneously exclude sequelae that prior conditions can explain and include infection-associated chronic conditions. We performed independent chart reviews …


Hordeum I Genome Unlocks Adaptive Evolution And Genetic Potential For Crop Improvement, Hao Feng, Qingwei Du, Ying Jiang, Yong Jia, Tianhua He, Yibin Wang, Brett Chapman, Jiaxin Yu, Hiawen Zhang, Mengxue Gu, Mengwei Jiang, Shanshan Gao, Xinjie Zhang, Yameng Song, Vanika Garg, Rajeev K. Varshney, Jianhua Wei, Chengdao Li, Xingtan Zhang, Ruifen Li Mar 2025

Hordeum I Genome Unlocks Adaptive Evolution And Genetic Potential For Crop Improvement, Hao Feng, Qingwei Du, Ying Jiang, Yong Jia, Tianhua He, Yibin Wang, Brett Chapman, Jiaxin Yu, Hiawen Zhang, Mengxue Gu, Mengwei Jiang, Shanshan Gao, Xinjie Zhang, Yameng Song, Vanika Garg, Rajeev K. Varshney, Jianhua Wei, Chengdao Li, Xingtan Zhang, Ruifen Li

Grain and Other Field Crops Research Articles

Crop wild relatives (CWRs) are invaluable for crop improvement. Among these, Hordeum I-genome species exhibit exceptional tolerance to alkali and salt stresses. Here we present a chromosome-scale genome assembly of Hordeum brevisubulatum (II, 2n = 2x =14) and genome resequencing of 38 diploid germplasms spanning 7 I-genome species. We reveal that the adaptive evolution of the H. brevisubulatum genome is shaped by structural variations, some of which may contribute to its adaptation to high alkali and salt environments. Evolutionary duplication of the stress sensor-responder module CaBP-NRT2 and the horizontally transferred fungal gene Fhb7 were identified as novel alkaline–saline …


Tunneling Nanotube-Like Structures Regulate Distant Cellular Interactions During Heart Formation, Lianjie Miao, Yangyang Lu, Anika Nusrat, Guizhen Fan, Shaohua Zhang, Luqi Zhao, Chia-Ling Wu, Hongyan Guo, Trang Le Nu Huyen, Yi Zheng, Zhen-Chuan Fan, Weinian Shou, Robert J Schwartz, Yu Liu, Ashok Kumar, Haixin Sui, Irina I Serysheva, Alan R Burns, Leo Q Wan, Bin Zhou, Sylvia M Evans, Mingfu Wu Mar 2025

Tunneling Nanotube-Like Structures Regulate Distant Cellular Interactions During Heart Formation, Lianjie Miao, Yangyang Lu, Anika Nusrat, Guizhen Fan, Shaohua Zhang, Luqi Zhao, Chia-Ling Wu, Hongyan Guo, Trang Le Nu Huyen, Yi Zheng, Zhen-Chuan Fan, Weinian Shou, Robert J Schwartz, Yu Liu, Ashok Kumar, Haixin Sui, Irina I Serysheva, Alan R Burns, Leo Q Wan, Bin Zhou, Sylvia M Evans, Mingfu Wu

Faculty, Staff and Student Publications

In the developing mammalian heart, the endocardium and the myocardium are separated by so-called cardiac jelly. Communication between the endocardium and the myocardium is essential for cardiac morphogenesis. How membrane-localized receptors and ligands achieve interaction across the cardiac jelly is not understood. Working in developing mouse cardiac morphogenesis models, we used a variety of cellular, imaging, and genetic approaches to elucidate this question. We found that myocardium and endocardium interacted directly through microstructures termed tunneling nanotube-like structures (TNTLs). TNTLs extended from cardiomyocytes (CMs) to contact endocardial cells (ECs) directly. TNTLs transported cytoplasmic proteins, transduced signals between CMs and ECs, and …


Exploration Of Working Memory Retrieval Stage For Mild Cognitive Impairment: Time-Varying Causality Analysis Of Electroencephalogram Based On Dynamic Brain Networks, Yi Jiang, Zhiwei Guo, Xiaobo Zhou, Ning Jiang, Jiayuan He Mar 2025

Exploration Of Working Memory Retrieval Stage For Mild Cognitive Impairment: Time-Varying Causality Analysis Of Electroencephalogram Based On Dynamic Brain Networks, Yi Jiang, Zhiwei Guo, Xiaobo Zhou, Ning Jiang, Jiayuan He

Faculty, Staff and Student Publications

Background: Mild Cognitive Impairment (MCI) is an intermediate stage between the expected cognitive decline of normal aging and Alzheimer's disease (AD). Its management is crucial for it helps intervene and slow the progression of cognitive decline to AD. However, the understanding of the MCI mechanism is not completely clear. As working memory (WM) damage is a common symptom of MCI, this study focused on the core stage of WM, i.e., the memory retrieval stage, to investigate information processing and the causality relationships among brain regions based on electroencephalogram (EEG) signals.

Method: 21 MCI and 20 normal cognitive control (NC) participants …


Advancements In Near Real-Time Bolide Detection: Continuum Calibration, Altitude Estimation, And Velocity Approximation Using Noaa Goes Glm Data, Eric Mckinney, Ryan Frazier, John Pratt, Mike Larsen, Philip Nelson, Hans Gunther Mar 2025

Advancements In Near Real-Time Bolide Detection: Continuum Calibration, Altitude Estimation, And Velocity Approximation Using Noaa Goes Glm Data, Eric Mckinney, Ryan Frazier, John Pratt, Mike Larsen, Philip Nelson, Hans Gunther

Space Dynamics Laboratory Publications

  • Bolides, also known as fireballs, are a class of meteoroids that explosively break up and release large amounts of energy as they enter the Earth’s atmosphere

  • While inherently of scientific value, bolides that occur over populous areas can result in alarm and, on rare occasions, terrestrial damage

  • Thus, rapid bolide detection and characterization systems are advantageous for the scientific community, public interest, and political de-escalation efforts

  • Jenniskens et al. (2018) and Rumpf et al. (2019) showed that the Geostationary Lightning Mapper (GLM) sensor onboard the NOAA Geostationary Operational Environmental Satellite (GOES) satellites can detect bolide signatures

  • This presentation complements a …


More Choosy For Minor Foods: Diet, Seasonality And Food Selection In Sympatric Frugivorous And Folivorous Lemurs, Mitchell Irwin, Vololonirina Rahalinarivo, Bruno Ramorasata, Jean-Luc Raharison, Jean-Freddy Ranaivoarisoa, Chloé Gherardi, Jessica Rothman Mar 2025

More Choosy For Minor Foods: Diet, Seasonality And Food Selection In Sympatric Frugivorous And Folivorous Lemurs, Mitchell Irwin, Vololonirina Rahalinarivo, Bruno Ramorasata, Jean-Luc Raharison, Jean-Freddy Ranaivoarisoa, Chloé Gherardi, Jessica Rothman

Faculty Articles, Papers, and Other Scholarship

Despite traditional dietary categories common in primatology (folivore, frugivore, insectivore), most primates use one or more food types beyond their primary one. Among lemurs, folivores tend to have a complicated, long gastrointestinal tract with an enlarged cecum, shearing teeth, and microbiome adaptations to foliage, while frugivores have simple teeth and guts and fast gut passage. Yet frugivores often eat some leaves, and folivores eat some fruit, and little is known about the selection rules they follow within each food type. We quantified diet and food chemistry for two sympatric rainforest lemurs: a cathemeral frugivore (brown lemur, Eulemur fulvus) and a …


Genetic Counseling Student Anxiety, Self-Efficacy, And Study Strategy Use For The Genetic Counseling Board Certification Exam., Teagan E. Nunnery Mar 2025

Genetic Counseling Student Anxiety, Self-Efficacy, And Study Strategy Use For The Genetic Counseling Board Certification Exam., Teagan E. Nunnery

USF Tampa Graduate Theses and Dissertations

With a 76% pass rate for the 2024 American Board of Genetic Counseling (ABGC) certification exam, it's crucial to evaluate the study strategies used by candidates and their alignment with evidence-based practices. This study surveyed 84 genetic counseling students and graduates from 35 U.S. and Canadian training programs, focusing on demographic data, study strategy usage, anxiety, and self-efficacy. Study strategies were categorized into one of three groups: 1) active strategies, which promote recall and understanding, 2) passive strategies, and 3) hybrid, for strategies that involve both active and passive engagement as well as three metacognitive strategies: regulating learning, monitoring learning, …


Evaluating And Improving The Serious Game Life With Hereditary Cancer, Jenna K. Peterson Mar 2025

Evaluating And Improving The Serious Game Life With Hereditary Cancer, Jenna K. Peterson

USF Tampa Graduate Theses and Dissertations

Hereditary cancer syndromes increase cancer risks for individuals with pathogenic variants and their family members, yet many at-risk individuals do not pursue genetic testing due to barriers in family communication. Serious games—interactive tools designed to educate through gameplay—offer a promising approach to addressing these barriers by engaging users and creating supportive learning environments. LIFE with Hereditary Cancer is a serious game designed to improve genetic literacy, promote informed decision-making, and encourage family conversations about hereditary cancer risks and genetic testing. This evaluation used a mixed-methods approach to assess participant emotions, perceptions, and experiences with LIFE with Hereditary Cancer and identify …


Salmon As An Ecological Pathway Of Contaminants Into Alaskan Food Webs, Miranda Brohman, Gretchen Roffler, Dimitri G. Giarikos, David Kerstetter, Amy C. Hirons Mar 2025

Salmon As An Ecological Pathway Of Contaminants Into Alaskan Food Webs, Miranda Brohman, Gretchen Roffler, Dimitri G. Giarikos, David Kerstetter, Amy C. Hirons

SECLER Data

Salmon are important fish taxa for humans and animals in hemiboreal and subarctic ecosystems. Trace elements and their marine food web bioaccumulation raises biomagnification and potential human health risk concerns. Sixteen trace element concentrations and their health risk assessments were determined in seven different tissues of two Southeast Alaska salmon species (chum, Oncorhynchus keta and pink, Oncorhynchus gorbuscha). Chum tissues had overall higher trace element concentrations compared to pink, which may be attributed to a difference of diets, generally longer-lived and spending more time in the open ocean. All kidney and liver samples exceeded the tolerable daily intake for …


Identifying Racial Disparities In Patient Activation Outcomes In Genetic Counseling Sessions, Moriah M. Melhado Mar 2025

Identifying Racial Disparities In Patient Activation Outcomes In Genetic Counseling Sessions, Moriah M. Melhado

USF Tampa Graduate Theses and Dissertations

Patient empowerment and activation are critical determinants of health outcomes, fostering patients’ confidence, knowledge, and engagement in their care. While the influence of race and ethnicity on patient activation has been extensively studied with other healthcare providers such as physicians and nurses, limited research has explored this dynamic within genetic counseling (GC). This study combines a systematic literature review, following PRISMA guidelines, a secondary data analysis , and an exploratory qualitative analysis of patient interviews post-session to examine relationships between race, ethnicity, and patient activation or empowerment in GC. Search terms identified 536 peer-reviewed articles, of which 44 met inclusion …


Efficacy And Safety Of Venetoclax Plus Azacitidine For Patients With Treatment-Naive High-Risk Myelodysplastic Syndromes, Jacqueline S Garcia, Uwe Platzbecker, Olatoyosi Odenike, Shaun Fleming, Chun Yew Fong, Uma Borate, Meagan A Jacoby, Daniel Nowak, Maria R Baer, Pierre Peterlin, Brenda Chyla, Huipei Wang, Grace Ku, David Hoffman, Jalaja Potluri, Guillermo Garcia-Manero Mar 2025

Efficacy And Safety Of Venetoclax Plus Azacitidine For Patients With Treatment-Naive High-Risk Myelodysplastic Syndromes, Jacqueline S Garcia, Uwe Platzbecker, Olatoyosi Odenike, Shaun Fleming, Chun Yew Fong, Uma Borate, Meagan A Jacoby, Daniel Nowak, Maria R Baer, Pierre Peterlin, Brenda Chyla, Huipei Wang, Grace Ku, David Hoffman, Jalaja Potluri, Guillermo Garcia-Manero

Faculty, Staff and Student Publications

Outcomes are poor in patients with higher-risk myelodysplastic syndromes (HR MDS) and frontline treatment options are limited. This phase 1b study investigated safety and efficacy of venetoclax, a selective B-cell lymphoma 2 inhibitor, at the recommended phase 2 dose (RP2D; 400 mg for 14 days per 28-day cycle), in combination with azacitidine (75 mg/m2 for 7 days per 28-day cycle) for treatment-naive HR MDS. Safety was the primary outcome, and complete remission (CR) rate was the primary efficacy outcome. Secondary outcomes included rates of modified overall response (mOR), hematologic improvement (HI), overall survival (OS), and time to next treatment (TTNT). …


Efficacy And Safety Of Venetoclax Plus Azacitidine For Patients With Treatment-Naive High-Risk Myelodysplastic Syndromes, Jacqueline S Garcia, Uwe Platzbecker, Olatoyosi Odenike, Shaun Fleming, Chun Yew Fong, Uma Borate, Meagan A Jacoby, Daniel Nowak, Maria R Baer, Pierre Peterlin, Brenda Chyla, Huipei Wang, Grace Ku, David Hoffman, Jalaja Potluri, Guillermo Garcia-Manero Mar 2025

Efficacy And Safety Of Venetoclax Plus Azacitidine For Patients With Treatment-Naive High-Risk Myelodysplastic Syndromes, Jacqueline S Garcia, Uwe Platzbecker, Olatoyosi Odenike, Shaun Fleming, Chun Yew Fong, Uma Borate, Meagan A Jacoby, Daniel Nowak, Maria R Baer, Pierre Peterlin, Brenda Chyla, Huipei Wang, Grace Ku, David Hoffman, Jalaja Potluri, Guillermo Garcia-Manero

Faculty, Staff and Student Publications

Outcomes are poor in patients with higher-risk myelodysplastic syndromes (HR MDS) and frontline treatment options are limited. This phase 1b study investigated safety and efficacy of venetoclax, a selective B-cell lymphoma 2 inhibitor, at the recommended phase 2 dose (RP2D; 400 mg for 14 days per 28-day cycle), in combination with azacitidine (75 mg/m2 for 7 days per 28-day cycle) for treatment-naive HR MDS. Safety was the primary outcome, and complete remission (CR) rate was the primary efficacy outcome. Secondary outcomes included rates of modified overall response (mOR), hematologic improvement (HI), overall survival (OS), and time to next treatment (TTNT). …


Impact Of Crack Location, Crack Initial Length, And Crosshead Speed On Fracture Toughness Of Polypropylene And Glass Fiber-Reinforced Polypropylene Pipes, R. Singer, A. Koriem, A. M. Ollick, M. Elhadary Mar 2025

Impact Of Crack Location, Crack Initial Length, And Crosshead Speed On Fracture Toughness Of Polypropylene And Glass Fiber-Reinforced Polypropylene Pipes, R. Singer, A. Koriem, A. M. Ollick, M. Elhadary

Mansoura Engineering Journal

Fracture toughness (KIC) is a critical parameter for evaluating the performance of materials, particularly in engineering applications where structural integrity is crucial. The objective of this study is to investigate the fracture toughness characteristics of polypropylene (PP) and glass fiber-reinforced polypropylene (GFPP) pipes. Specifically, evaluating the influence of crosshead speed, crack location, and initial crack length on the KIC of these materials under both tensile loading (Mode I fracture) and bending conditions. Tensile tests were conducted on both materials using two specimen configurations and varied notch lengths to simulate Mode I fracture conditions. Additionally, three-point bending tests …


Deep Learning Models Based On Pretreatment Mri And Clinicopathological Data To Predict Responses To Neoadjuvant Systemic Therapy In Triple-Negative Breast Cancer, Zhan Xu, Zijian Zhou, Jong Bum Son, Haonan Feng, Beatriz E Adrada, Tanya W Moseley, Rosalind P Candelaria, Mary S Guirguis, Miral M Patel, Gary J Whitman, Jessica W T Leung, Huong T C Le-Petross, Rania M Mohamed, Bikash Panthi, Deanna L Lane, Huiqin Chen, Peng Wei, Debu Tripathy, Jennifer K Litton, Vicente Valero, Lei Huo, Kelly K Hunt, Anil Korkut, Alastair Thompson, Wei Yang, Clinton Yam, Gaiane M Rauch, Jingfei Ma Mar 2025

Deep Learning Models Based On Pretreatment Mri And Clinicopathological Data To Predict Responses To Neoadjuvant Systemic Therapy In Triple-Negative Breast Cancer, Zhan Xu, Zijian Zhou, Jong Bum Son, Haonan Feng, Beatriz E Adrada, Tanya W Moseley, Rosalind P Candelaria, Mary S Guirguis, Miral M Patel, Gary J Whitman, Jessica W T Leung, Huong T C Le-Petross, Rania M Mohamed, Bikash Panthi, Deanna L Lane, Huiqin Chen, Peng Wei, Debu Tripathy, Jennifer K Litton, Vicente Valero, Lei Huo, Kelly K Hunt, Anil Korkut, Alastair Thompson, Wei Yang, Clinton Yam, Gaiane M Rauch, Jingfei Ma

Faculty, Staff and Student Publications

Purpose: To develop deep learning models for predicting the pathologic complete response (pCR) to neoadjuvant systemic therapy (NAST) in patients with triple-negative breast cancer (TNBC) based on pretreatment multiparametric breast MRI and clinicopathological data.

Methods: The prospective institutional review board-approved study [NCT02276443] included 282 patients with stage I-III TNBC who had multiparametric breast MRI at baseline and underwent NAST and surgery during 2016-2021. Dynamic contrast-enhanced MRI (DCE), diffusion-weighted imaging (DWI), and clinicopathological data were used for the model development and internal testing. Data from the I-SPY 2 trial (2010-2016) were used for external testing. Four variables with a …


Cranial Radiation Disrupts Dopaminergic Signaling And Connectivity In The Mammalian Brain, Die Zhang, Riya Thomas, Thanh Thai Lam, Ines Veselinovic, David R Grosshans Mar 2025

Cranial Radiation Disrupts Dopaminergic Signaling And Connectivity In The Mammalian Brain, Die Zhang, Riya Thomas, Thanh Thai Lam, Ines Veselinovic, David R Grosshans

Faculty, Staff and Student Publications

Cognitive impairment is a common and challenging side effect of cranial radiation therapy for brain tumors, though its precise mechanisms remain unclear. The mesocortical dopaminergic pathway, known to play a key role in cognitive function, is implicated in several neuropsychiatric disorders, yet its involvement in radiation-induced cognitive dysfunction is unexplored. Here, with using in vivo multi-electrode array recordings of both anesthetized and free-moving rats to monitor the firing activities of dopamine neurons in the ventral tegmental area (VTA) and local field potentials in both the prefrontal cortex (PFC) and VTA, as well as the immunofluorescence assays and western blotting, we …


Closing Ceremony Speech, S. Ray Smith Mar 2025

Closing Ceremony Speech, S. Ray Smith

IGC Proceedings (1977-2023)

No abstract provided.


Soil Compaction And Novel Traffic Systems In Ryegrass Grown For Silage: Effects On Herbage Yield, Quality And Nitrogen Uptake, J T. Douglas, C E. Crawford Mar 2025

Soil Compaction And Novel Traffic Systems In Ryegrass Grown For Silage: Effects On Herbage Yield, Quality And Nitrogen Uptake, J T. Douglas, C E. Crawford

IGC Proceedings (1977-2023)

Grassland soils, on which the crop is managed for conser­vation as silage, receive large amounts of vehicle and machinery traffic : rolling and multiple slurry and fertilizers applications, plus multiple harvests, are all activities which are potentially damaging to soil and sward. A number of short-term studies in the UK (Frame, 1987 and Frost, 1988) and elsewhere (Luten and Roozeboom, 1976, and Rasmussen and M¢ller, 1981) have indicated that dry matter yield can be reduced as a consequence of stress imparted to soil by agricultural tyres. Nevertheless, there is a general lack of information on the influence of soil compaction …


Contribution Of Red Clover To Maize Grain Yields, K D. Johnson, D K. Greene, J H. Cherney Mar 2025

Contribution Of Red Clover To Maize Grain Yields, K D. Johnson, D K. Greene, J H. Cherney

IGC Proceedings (1977-2023)

Renewed emphasis has been placed on crop rotation systems that include a perennial legume. Reasons for this interest include protection of soil from erosion, protection of ground water from nitrate contamination, reduction of soil compac­tion, and potential for fewer inputs which could reduce costs of grain production. Barnes et al. (1985) reported that a nondormant alfalfa (Medicago sativa L.) selected for increased Nin the root and crown had similar summer herbage yield as adapted dormant cultivars, but provided 62 % more symbiotically fixed N for a following crop than dormant cultivars. If most benefit is to be derived from cultivars …


Analysis Of The Effect On N Nutrition On Dry Matter Yield Of A Sward By Reference To Potential Yield And Optimum N Content, G Lemaire, F Gastal, J Salette Mar 2025

Analysis Of The Effect On N Nutrition On Dry Matter Yield Of A Sward By Reference To Potential Yield And Optimum N Content, G Lemaire, F Gastal, J Salette

IGC Proceedings (1977-2023)

Previous work has shown that the N content of a sward could be related to the dry matter accumulation during the course of the regrowth by the following equation : N % = a(Wtb, where W is the weight of aboveground biomass and N % the N concentration of dry matter (Salette & Lemaire, 1981). The coefficient a represents the N % for an aerial biomass of I t/ha, and b characterizes the degree of dilution of N during the regrowth. When b = 0, N % remains constant during the regrowth. If b = I, there is an increase …


Nitrogen Fixation In Mixed Pastures Under Two Grazing Intensities, R O. Refi, C A. Navarro, C J. Escuder Mar 2025

Nitrogen Fixation In Mixed Pastures Under Two Grazing Intensities, R O. Refi, C A. Navarro, C J. Escuder

IGC Proceedings (1977-2023)

In the Humid Pampa, 10 millions of ha present intrazonal hydromorphic alkaline soils with low P assimilable content and cyclic floods and droughts. Gramineous native ranges utilized for extensive cattle raising with low productivity levels occupy 70 % of the area. The lack of adapted legume and grass genotypes and little information about grazing management makes it difficult to increase production through implanted pastures due to their low persistence (Darwich and Gonzalez, 1982). To modify this situation an interdisciplinary study of four forage mixtures integrated by promising germplasm for that conditions was carried out. This paper is part of that …


Strategies Of Fertilizer Nitrogen Applications To Grassland For Beef: Effects On Production And Soil Mineral Nitrogen, N M. Titchen, R J. Wilkins, L Philipps, D Scholefield Mar 2025

Strategies Of Fertilizer Nitrogen Applications To Grassland For Beef: Effects On Production And Soil Mineral Nitrogen, N M. Titchen, R J. Wilkins, L Philipps, D Scholefield

IGC Proceedings (1977-2023)

Experiments in Britain have shown beef production increases with fertilizer-N application to grazed grassland up to at least 300 kg N/ha (Wilkins et al., 1987; Baker and Mayne, 1988). However in view of the small offtake of N in the animal products (c.30 kg/ha) there is increased concern on the fate of the applied N, particularly in relation to loss of nitrate by leaching (Garwood and Ryden, 1986). This paper reports a 3-year experiment which examined the impact on production and on N movements of different strategies of fertilizer-N appli­cation and of the effects of removing grazing livestock at the …


Biomass Production And Nitrogen Transfer In Mixed Cropping With Glycine Max (L) Merr. And Sorghum Biocolor Moench, S Ogata, K Kuwata, H Saneoka, K Fujita Mar 2025

Biomass Production And Nitrogen Transfer In Mixed Cropping With Glycine Max (L) Merr. And Sorghum Biocolor Moench, S Ogata, K Kuwata, H Saneoka, K Fujita

IGC Proceedings (1977-2023)

It is well known that the mixed-cropping of legumes and grasses benefits the productivity and management of pastures (Ogata et al., 1986; Kawamoto et al., 1983). However, the effect of mixed-croppings on forage biomass production, and how to transfer N fixed to the associated gramineous plants in fields of low N fertility, is less well known (Simpson, 1965). The N accumulation and the transference ofN fixed in mix­tures of forage type soybean and sorghum were studied as a model system.


Changes In Vegetation Of Various Meadows Under Differential Mineral Fertilization, S Benedycki, S Grzegorczyk, M Mlynarczyk, K Grabowski Mar 2025

Changes In Vegetation Of Various Meadows Under Differential Mineral Fertilization, S Benedycki, S Grzegorczyk, M Mlynarczyk, K Grabowski

IGC Proceedings (1977-2023)

Permanent meadows and pastures occurring in the Mazurian Lake District (North-eastern part of Poland) constitute 32 % of arable lands. Most meadows are situated on peat soils (Olkowski, 1972). Continuous and successive changes take place in such populations. The moment some species decline, the number of others increases which are better adjusted to site conditions or human activity such as fertilization and the way of land use. These changes occur with different intensity depen­ding on fertilizer doses, land use and site conditions which have not been well recognized with regard to permanent meadows (Olkowski and Olesinski, 1976, Eilart, 1986). Determination …


Developing Effective Nutrient Seed Coatings For Grasses And Legumes, J M. Scott Mar 2025

Developing Effective Nutrient Seed Coatings For Grasses And Legumes, J M. Scott

IGC Proceedings (1977-2023)

Seed coatings provide a unique opportunity to supply developing seedlings with a source of nutrients to which each sown seedling has preferential access compared to neighbour­ing weeds, thus providing the seedlings with a competitive advantage during pasture establishment. A study of commer­cially prepared nutrient coatings (containing nitrogen [NJ, phosphorus [P] and sulfur [SJ) applied to seeds of perennial rye­grass showed that whilst the S component of the coating was effective, the P component was only partially effective, and the N component was ineffective in alleviating the respective soil nutrient deficiencies (Scott et al., 1985). The successful development of nutrient seed …


The Impact Of Renovation And Phosphate Fertilization On The Productivity Of Pastures In Uruguay, J A. Garcia Mar 2025

The Impact Of Renovation And Phosphate Fertilization On The Productivity Of Pastures In Uruguay, J A. Garcia

IGC Proceedings (1977-2023)

Natural grasslands in Uruguay produce low yields of poor quality herbage and therefore intensive farming is based upon sown pastures of temperate species. Although quite productive, these pastures show high instability and after reaching a peak in the second year, herbage yields rapidly go down due to a consistent legume decline. They usually end up in the fourth year in a low producing grassy sward dominated by perennial grasses like tall fescue or by bermudagrass which is endemic in the cropping/pasture area. Thee lack of persistence is also common to other countries of the region and although the effects of …


Sur Les Teneurs En Molybedne Des Plantes Fourrageres Des Sols Liasiques Du Bassigny - Consequences Zootechniques, L Duval Mar 2025

Sur Les Teneurs En Molybedne Des Plantes Fourrageres Des Sols Liasiques Du Bassigny - Consequences Zootechniques, L Duval

IGC Proceedings (1977-2023)

En 1943, Ferguson et ses collaborateurs mirent en evidence que la teneur elevee en molybdene des plantes fourrageres est la cause d'une maladie des ruminants appelee scouring ou teartness et observee par Clarke (1855) sur les sols liasiques du Somerset (Grande-Bretagne); ils montrerent aussi que cette • intoxication molybdique ou molybdenose est prevenue et guerie par !'ingestion de cuivre (Ferguson et al., 1943). En France, c'est aussi sur des sols liasiques que des cas aigus de molybdenose ont ete identifies par Fretet (1959), a Is-en­Bassigny (Haute-Marne). Des determinations, effectuees par Flon (1968), confirmerent !'existence de teneurs elevees en molybdene clans …


Effects Of Changes In Fertilizer Use On The Composition And Productivity Of Permanent Grassland In Relation To Agricultural Production And Floristic Diversity, R J. Wilkins, A Hopkins, F W. Kirkham, C Sargent, O Mountford, C Dibb, J Gilbey Mar 2025

Effects Of Changes In Fertilizer Use On The Composition And Productivity Of Permanent Grassland In Relation To Agricultural Production And Floristic Diversity, R J. Wilkins, A Hopkins, F W. Kirkham, C Sargent, O Mountford, C Dibb, J Gilbey

IGC Proceedings (1977-2023)

More than 50 % of enclosed grassland in Britain comprises swards older than 20 years. There is much variation both in fer­tiliser inputs and in stocking rates, with the trend for increased intensity in use over the last 40 years now being succeeded by increased concern for nature conservation and the protection of the environment. In some areas financial incentives are given for the adoption of management practices intended to increase sward botanical diversity, but there is little information on the rates of change in botanical diversity and production as the management of an old sward is changed with either …


Phosphorus Requirement For Establishment Of Tropical Forage Grasses And Legumes, J A. Gomide Mar 2025

Phosphorus Requirement For Establishment Of Tropical Forage Grasses And Legumes, J A. Gomide

IGC Proceedings (1977-2023)

Soil phosphorus level is a limiting factor for successfull for­age establishment which, in turn, determines pasture pro­ductivity. Recommendations of P fertilization should not only be based on the available PO4 but should consider the soil P04 buffer capacity and the P critical value for the crop to be grown (Novais and Kamprath, 1979). This study aimed at the determ­inations of P critical doses and levels for the establishment of four species of Brachiaria and four tropical legumes, in five soils.