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Articles 382441 - 382470 of 5153635
Full-Text Articles in Entire DC Network
A Comprehensive Study: Comparing Machine Learning Techniques For Breast Cancer Prediction, Tonmoy Roy
A Comprehensive Study: Comparing Machine Learning Techniques For Breast Cancer Prediction, Tonmoy Roy
Student Research Symposium
This study conducts a comparative analysis of feature selection techniques and machine learning models to improve breast cancer risk prediction using the Wisconsin Breast Cancer Dataset. Through evaluating univariate feature selection, recursive feature elimination, and principal component analysis, alongside ten machine learning models, the research aims to identify the most effective combination for accurate diagnosis.
Performance metrics such as accuracy, precision, recall, and F1 score guide the analysis.
The findings suggest that integrating specific feature selection methods with particular machine learning algorithms significantly enhances predictive accuracy, offering insights for developing more effective breast cancer detection tools and improving patient outcomes.
Impact Of Reduced Irrigation Frequency On Landscape Plants, Zirui Wang
Impact Of Reduced Irrigation Frequency On Landscape Plants, Zirui Wang
Student Research Symposium
Utah is currently facing a historic drought. Last year, 99.3% of the land in Utah was experiencing varying levels of drought (U.S. Drought Monitor, 2024).
Landscape irrigation accounts for 70% of per capita residential water use in the western United States (Hayden et al. 2015).
Evapotranspiration (ET) refers to the water loss resulting from the processes of evaporation and transpiration. Reference ET (ETo) is calculated using data from local weather stations and is employed to schedule irrigation frequency (Evans et al. 2022).
Seasonal Effects On Bovine Oocyte Quality, Harper Sjostrom
Seasonal Effects On Bovine Oocyte Quality, Harper Sjostrom
Student Research Symposium
- Bovine oocytes are impacted by the environments they grow in and the climates of those environments.
- Supplementation of melatonin or cytokine (FLI) could aid in oocyte quality and mitochondrial membrane distribution/potential.
- The aim of this study was to evaluate 1) if supplementation of melatonin/cytokine (FLI) during in vitro maturation has an impact on maturation rates in oocytes and 2) if supplementation/temperature affect mitochondrial membrane distribution/potential in bovine oocytes.
Fast Prediction Of The Trajectory And Coverage Of Aerially Delivered Fire-Retardants, Aditya Parik
Fast Prediction Of The Trajectory And Coverage Of Aerially Delivered Fire-Retardants, Aditya Parik
Student Research Symposium
Motivation & Objectives
- The utilization of aircrafts in fighting wildfires has substantially increased over the last century, as incidences of forest fires increase all over the world.
- A constant effort of various fire control agencies throughout North America (such as USDA Forest Service) has been to improve the accuracy, efficiency, and overall effectiveness of aerial retardant delivery.
- In service of this goal, we develop a model for predicting the general trajectory a retardant plume takes when it is aerially delivered to a target.
Size Variation In Bumble Bees, Mj Cantwell
Size Variation In Bumble Bees, Mj Cantwell
Student Research Symposium
Typically, a size distinction exists between queens and workers in eusocial bee species1 (Fig. 1).
Body size of workers varies throughout the season depending on time of emergence and resource availability2 (Fig. 2).
Information regarding how time of emergence impacts Bombus fervidus body size is lacking.
Cyp2d6, Autism, And Oxytocin Receptors, Ethan Dayley
Cyp2d6, Autism, And Oxytocin Receptors, Ethan Dayley
Student Research Symposium
Who cares? Differences in oxytocin receptor density have been observed in two brain regions in autism. CNVs of the CYP2D6 gene appear associated with these differences. The CYP2D6 gene has been previously associated with
Repeatability Of Fecal Egg Counts In Wild Horses, Jaron Dixon
Repeatability Of Fecal Egg Counts In Wild Horses, Jaron Dixon
Student Research Symposium
- Fecal floats are one of the most commonly used methods of quantifying parasite infections.
- Despite being used for over a century, each variation of the method differs in accuracy and precision.
- In this study, we quantified parasite egg counts in wild horses using a centrifugal technique and Sheather’s sucrose solution.
- Our aim was to confirm the repeatability of the technique so it may be used in additional studies.
Effects Of Nitrogen On The Nodulation Of Ceanothus Velutinus, Prakriti Nepal
Effects Of Nitrogen On The Nodulation Of Ceanothus Velutinus, Prakriti Nepal
Student Research Symposium
- Ceanothus velutinus (snowbrush ceanothus) is a nitrogen-fixing species native to North America.
- It helps improve soil fertility through nodulation, a symbiotic process with bacteria that fix atmospheric nitrogen.
- It is valued for its drought tolerance, ability to enrich soil with nitrogen, and vibrant flowers (Fig. 1).
- However, limited research has been conducted to develop C. velutinus as a specialty crop for sustainable green industry production and understand its nodulation with native Frankia bacteria.
Intentional Rest In A Musician’S Routine: A Key To Preventing Burnout And Promoting Healthy Performance, Emma Thackeray
Intentional Rest In A Musician’S Routine: A Key To Preventing Burnout And Promoting Healthy Performance, Emma Thackeray
Student Research Symposium
The Project
- Identify the trends of burnout in musicians
- Understand the role of rest in a musician’s routine
- Determine helpful habits and activities that contribute to improved performance and prevent burnout
A Model Of Changeover Behavior In Two-Alternative Choice, Matias A. Avellaneda
A Model Of Changeover Behavior In Two-Alternative Choice, Matias A. Avellaneda
Student Research Symposium
No abstract provided.
Developmental Characteristics And Renovating Pattern Of Reed Canarygrass Shoots In A Sward, M Ito, S Mizuno, T Otani, S Kobayashi
Developmental Characteristics And Renovating Pattern Of Reed Canarygrass Shoots In A Sward, M Ito, S Mizuno, T Otani, S Kobayashi
IGC Proceedings (1977-2023)
Developmental and renovating traits of shoots were investigated ecomorphologically in a reed canarygrass (Phalaris arundinacea L., cv. Palaton) sward harvested 3 times per year. Reed canarygrass shoots exhibited notably high growth rates both in the 1st and 2nd crops together with rapid leaf formation (around 7 days/leaf) and active internode elongation. Vigorously growing shoots, which regenerated soon after the 1st cutting and dominated in the 2nd crop canopy, mainly originated from the stubble formed with 3 to 4 phytomers that developed after the beginning of spring growth, thus resulting in higher shoot density than that of the 1st crop. …
Canopy Changes In Healthlands (Erica-Ulex) Grazed By Sheep Or Goats, R Celaya, K Osoro
Canopy Changes In Healthlands (Erica-Ulex) Grazed By Sheep Or Goats, R Celaya, K Osoro
IGC Proceedings (1977-2023)
The grazing effects of sheep and goats on vegetation dominated by heaths (Erica spp) and gorse (Ulex gallii) were studied for two years. Two plots were grazed from May to October 1992 by 7 ewes or 7 does and in the following year each plot was subdivided into two subplots subsequently grazed either by sheep or by goats in a factorial design. During the first grazing season both sheep and goats reduced similarly the cover percentage of shrubs since the herbaceous content was scarce, although goats reduced more the height of the shrubs than sheep. The cover …
Effect Of Nitrogen, Phosphorus, Potassium And Cutting On The Regrowth And Insect Infestation Of A Sorghum And Berseem Clover In Egypt, M B. Attia
IGC Proceedings (1977-2023)
The objective of this study was to determine the minimum quantities of phosphorus and potassium which must be applied with varying amounts of nitrogen in order to maintain maximum hay production and minimum level of insect infestation. This was more pronounced at the higher N rates and caused a significant N x K interaction during each of these years. There was no yield response to applied phosphorus at any N rate. Relation between levels of nitrogen and infestation percentage was positive but infestation rate decreased with the increase of potassium levels while there was no relation between levels of phosphorus …
An Overview Of The Physiology And Biochemistry Of N Reserves Mobilization In Forage Species, F Le Dily, A Ourry, J Boucaud
An Overview Of The Physiology And Biochemistry Of N Reserves Mobilization In Forage Species, F Le Dily, A Ourry, J Boucaud
IGC Proceedings (1977-2023)
Recent works focusing on the physiological and biochemical events associated to perennial forages sustainability (re-growth after defoliation, winter survival), provided evidence that vegetative storage proteins (VSPs, ca proteins stored in remaining organs and specifically mobilized) were key organic compounds for shoot regrowth. Attempts to elucidate environmental conditions involved in VSPs deposit ability of different species are under progress today. In contrast, mechanisms of spring- or cut-induced proteolysis are investigated at a lesser extend. This contribution is an opportunity to summarize our knowledge of N-reserves mobilization and to set the question of VSPs breakdown regulation.
Intraspecific Competition In Lucerne And Relationships With Reserve Availability, Jean Christophe Avice, Alain Ourry, Gilles Lemaire, Jeffrey J. Volenec, Jean Boucaud
Intraspecific Competition In Lucerne And Relationships With Reserve Availability, Jean Christophe Avice, Alain Ourry, Gilles Lemaire, Jeffrey J. Volenec, Jean Boucaud
IGC Proceedings (1977-2023)
Below-ground reserves are thought to provide an indication of a forage potential for shoot regrowth after defoliation. The aim of this work was to re-evaluate the causal relationships existing between organic reserves (non-structural carbohydrates and N reserves) and shoot regrowth of alfalfa. The variations brought about by cultivar differences (cv Lodi or Europe), length of the previous regrowth period (30 or 45 d), or by intraspecific competition for light within a dense canopy, were studied. Field grown plants were harvested at weekly intervals, and separated as dominant, intermediate and suppressed plants. Shoot regrowth yield was determined and taproot were analyzed …
Seasonal Fluctuations Of Vegetative Storage Proteins And Starch Concentrations In Stolons Of Trifolium Repens L., V Bouchart, A Ourry, J C. Simon, J Boucaud
Seasonal Fluctuations Of Vegetative Storage Proteins And Starch Concentrations In Stolons Of Trifolium Repens L., V Bouchart, A Ourry, J C. Simon, J Boucaud
IGC Proceedings (1977-2023)
The seasonal pattern of nitrogen, starch and vegetative storage protein (VSP) concentrations was studied in the stolons of two Trifolium repens L. genotypes (cv Aran and Rivendel). Maximum concentrations of starch were found in summer months; its hydrolysis occurred in winter, at the time, where VSP and nitrogen were accumulated. The decrease of nitrogen and VSP concentrations occurred during spring, and an inverse relationship was found between VSP concentrations in stolons and mean temperatures. The causal implications of starch and VSP availability on spring regrowth potential are discussed in relation with regulatory mechanism inducing VSP synthesis.
Cynodon Dactylon Control In Conservation Tillage Systems, A Rios, J M. Sanz
Cynodon Dactylon Control In Conservation Tillage Systems, A Rios, J M. Sanz
IGC Proceedings (1977-2023)
Bermudagrass (Cynodon dactylon L. PERS.) is the most important weed in Uruguay. With the development of conservation tillage systems, chemical control of bermudagrass becomes essential. The objective of this research was to evaluate, in a long term integrated program, bermudagrass chemical control during the first year of a pasture. Application of glyphosate and no-tillage seeding of the pasture took place during fall. A 70% reduction of underground part of the weed was detected. The chemical control, together with a conservation tillage system and an adequate pasture management allowed an important reduction in bermudagrass level for the first year pasture. …
Legume Seedling Development In No Till Pasture Establishment, J L. Rossi, V A. Deregibus
Legume Seedling Development In No Till Pasture Establishment, J L. Rossi, V A. Deregibus
IGC Proceedings (1977-2023)
The objective of this study was to compare no-till and conventional seeding of pasture and their effects on legume establishment. The presence of residue cover reduced legume seedling establishment and weed population under no-till seeding. The reduction in establishment was associated with the physical impediment of the residue cover and the decay of seedling vigor when passing through that cover.
Water Relations In Berseem Cultivars Under Drought Stress, A Iannucci, A Rascio, M Russo, P Martiniello
Water Relations In Berseem Cultivars Under Drought Stress, A Iannucci, A Rascio, M Russo, P Martiniello
IGC Proceedings (1977-2023)
Berseem clover (Trifolium alexandrinum L.) is a crop of particular interest in semi-arid regions, used for herbage and hay productions. However, its seed yield is reduced by drought stress that occurs during seed filling. In this study five cultivars (Axi, Big Bee, Lilibeo, Sacromonte and Saniros) subjected to four irrigation frequencies in controlled environment, were compared for their physiological responses to subsequent water stress period (3 days). Some parameters (leaf water potential (), osmotic potential (þ), relative water content (RWC) and gravimetric soil water content (GSWC)) related to plant water status were recorded. Plants subjected to previous periods of …
Modelling The Effect Of A Variable Light Extinction Coefficient And Leaf Dispersion On Light Partitioning Between Species In A Grass-Clover Mixture, M Nassiri, A Elgersma
Modelling The Effect Of A Variable Light Extinction Coefficient And Leaf Dispersion On Light Partitioning Between Species In A Grass-Clover Mixture, M Nassiri, A Elgersma
IGC Proceedings (1977-2023)
Light partitioning in a grass-clover mixture was studied using a general competition model. The model assumes a fixed extinction coefficient (k) and no leaf dispersion. This was compared with modelling the effect of different k of both species over height as well as the effect of type of leaf dispersion. These new assumptions led to a better estimation of the light partitioning between both species. For grass the effect of variable k and leaf dispersion was similar and in both cases the total absorbed light was lower than under default conditions. For clover the new assumptions led to a higher …
Ecotypic Adaptation Of Medicago Polymorpha Along A Gradient In Central Chile: Growth And Seed Production, A Del Pozo, C Ovalle, J Avendano
Ecotypic Adaptation Of Medicago Polymorpha Along A Gradient In Central Chile: Growth And Seed Production, A Del Pozo, C Ovalle, J Avendano
IGC Proceedings (1977-2023)
Relative growth rate, total dry weight and seed yield on 19 accessions of burr medic (Medicago polymorpha L.) from different bioclimatic conditions, were assessed at Cauquenes (35°58’;72°17’W) in the subhumid mediterranean region. The accessions were sown in microplots over raised beds during two years (1991 and 1992), and swards cut periodically at 2, 6 and 10 cm height. There were significant differences between accessions in both total dry weight and seed yield (P < 0.001, Table 1), but the interaction between accessions and height of cutting was not significant (P > 0.05). Total dry weight was positive correlated with days to flowering (r2 = 0.81; P > 0.01).
Effects Of Nitrogen On The Growth Of Hyparrhenia Diplandra, J Nkandza
Effects Of Nitrogen On The Growth Of Hyparrhenia Diplandra, J Nkandza
IGC Proceedings (1977-2023)
The nitrogen effects on Hyparrhenia diplandra were studied. Plants were grown on nutrient solutions of variable concentrations in nitrogen. The supplied nitrogen increased tillering, leaf production, lamina area, total dry matter accumulation and total nitrogen accumulation in lamina. A detailed examination showed that the effect on tillering was the main cause of the differences observed in dry weights between different treatments. The nitrogen supply elongated significantly the lamina and nitrogen deficiency increased its thickness; but this was not enough to compensate the loss of weight in lower nitrogen treatment. The lamina area as well as nitrogen accumulation in the lamina …
Biochemical And Isoenzyme Analysis Of Seven Pennisetum Purpureum (Schum.) Cultivars, E E. Bach, V B.G. Alacantara, P B. Alcntara, E A. Veasey
Biochemical And Isoenzyme Analysis Of Seven Pennisetum Purpureum (Schum.) Cultivars, E E. Bach, V B.G. Alacantara, P B. Alcntara, E A. Veasey
IGC Proceedings (1977-2023)
This study characterized seven Pennisetum purpureum cultivars, namely cv. Anão, Bajra, Cameroon, Guaçu, Roxo, Taiwan A-144 and Uruckwami, through biochemical analysis, including protein, glucose and fructose contents, and polyacrylamide gel electrophoresis using the esterase system, by sampling 30, 60, 90, 120 and 150 dayold leaves. Cultivar Taiwan A-144 presented the highest number of nodes per stem and percentage of emerging buds. Protein concentration decreased gradually after 60 days for all cultivars, except for Anão. Cultivar Guaçu presented the highest level of glucose in 90 day old plants, whereas Cameroon presented the highest levels at 120 and 150 days. The esterase …
Effect Of Phosphorous Fertiliser On The Competition Between Two Tropical Grasses And Two Tropical Legumes, F D. Hu, R J. Jones
Effect Of Phosphorous Fertiliser On The Competition Between Two Tropical Grasses And Two Tropical Legumes, F D. Hu, R J. Jones
IGC Proceedings (1977-2023)
The effect of P fertiliser on the competition between grass and legume in four grass-legume mixtures : Urochloa mosambicensis cv. Nixon/ Stylosanthes hamata cv. Verano; Nixon/S.scabra cv. Seca; Bothriochloa pertusa cv. Bowen/Verano and Bowen/Seca were studied. Each mixture was grown in a low P, low N soil, in pots. A standard replacement series design with two P levels (0 and 10 kg/ ha equivalent) and 3 replicates were used. Seventy days after sowing, Nixon mixtures outyielded Bowen mixtures, and Verano mixtures outyielded Seca mixtures. P increased top and root yields of all mixtures but there was no significant (p …
Selection And Agronomic Characterization Of Leucaena Spp. Genotypes For Cold Tolerance. I. Dry Matter Yield., M C. Goldfarb, J F. Casco
Selection And Agronomic Characterization Of Leucaena Spp. Genotypes For Cold Tolerance. I. Dry Matter Yield., M C. Goldfarb, J F. Casco
IGC Proceedings (1977-2023)
Biotypes of Leucaena spp (56) were evaluated in order to identify those with tolerance to low temperature and with desirable characteristics as a forage crop. Selection was done at two phases. Phase I: 92 days old seedlings (n=2800) were subjected at two temperatures treatments during 14 hours: T1= -8 °C and T2= -3 °C. Selection criteria was established as 50% of live leaves remained after treatments were applied. Phase II: Plants that survived phase I were planted at field conditions and agronomic characteristics were measured. Seventeen plants were selected from eleven different biotypes, resulting one from T1 and the rest …
Effect Of Snowtrapping And Fertilization On Production Of Crested Wheatgrass And Native Pastures In Southwest Saskatchewan, M P. Schellenberg, J Waddington
Effect Of Snowtrapping And Fertilization On Production Of Crested Wheatgrass And Native Pastures In Southwest Saskatchewan, M P. Schellenberg, J Waddington
IGC Proceedings (1977-2023)
The benefits of increasing soil water with snow management and fertilizer for annual and perennial crops have been demonstrated for semiarid environments. We examined the combined effect of snow management and fertilizer on forage production. In 1985, vertical wood slat or slotted plastic snow fencing (0.7m high) were erected on crested wheatgrass (Agropyron cristatum) pasture. In 1986, five rates of fertilizer: 400, 200, 100, 50, 0 kg ha-1 nitrogen each with 50 kg ha-1 phosphorous and a sixth treatment with no fertilizer were applied to each side and type of the snowfence. A second site was selected on …
Light Quality Effects On Grass Seedling Growth And Development, P G. Jefferson, R Muri
Light Quality Effects On Grass Seedling Growth And Development, P G. Jefferson, R Muri
IGC Proceedings (1977-2023)
The poor establishment success of Russian wildrye (Psathyrostachys juncea Fisch. Nevski) limits its use. Our hypothesis was that Russian wildrye (RWR) was more sensitive to light competition than crested wheatgrass (Agropyron desertorum Fischer ex Link) or Dahurian wildrye (Elymus dahuricus Turcz. Ex Grieseb.). Seedlings were grown under plastic filters that altered both quantity and quality of light. Tiller counts, leaf counts, leaf area, light intensity and red:farred light ratio (above and beside each seedling) were recorded each week for four weeks after planting. Seedling dry weights were determined at four weeks. Low light intensity significantly reduced tiller …
Morphogenesis And Growth Analysis Of Panicum Maximum Cultivars, A Gomide, C A.M Gomide
Morphogenesis And Growth Analysis Of Panicum Maximum Cultivars, A Gomide, C A.M Gomide
IGC Proceedings (1977-2023)
Four cultivars of Panicum maximum, grown in pots, were evaluated regarding their leaf appearance and elongation rates, tillering appearance rate, as well as growth indices. Differences among cultivars were found as to leaf appearance and elongation rates and tillering rates. Main tiller leaf appearance was higher relative to primary tiller in the seedling growth, only. Primary tiller showed higher leaf elongation rate in the aftermath growth. No difference among cultivars was found for drymatter yield after 52 d growth period, leaf mortality, net assimilation rate, leaf area ratio and relative growth rate.
Competitive Interactions Between Palatable And Unpalatable Grasses: Effects Of Selective Defoliations Of The Palatable Grasses, R A. Distel, A S. Moretto
Competitive Interactions Between Palatable And Unpalatable Grasses: Effects Of Selective Defoliations Of The Palatable Grasses, R A. Distel, A S. Moretto
IGC Proceedings (1977-2023)
Selective herbivory of the palatable species appears to be a dominant mechanisms contributing to species competitive replacement in grasslands. Selective herbivory of the palatable species allows unpalatable species to realize a competitive advantage within the community. To test this hypothesis we compare the competitive ability of the unpalatable grasses Stipa trichotoma or S. gyneriodes in the presence of nondefoliated and defoliated plants of the palatable grass S. clarazii. The three species are native to a temperate semiarid grassland of Argentina. The response variables estimated in S.trichotoma and S.gynerioides, at both plant and tiller levels, were higher (P < 0.05) in the presence of defoliated than in the presence of undefoliated plants of S.clarazii. These results support the hypothesis that selective herbivory of the palatable species confers unpalatable species a competitive advantages, contributing to species competitive replacement within the community.
Allelopathic Interactions Among Forage Grasses And Legumes, A P.S Souza Filho, T De J.D. Rodrigues, L.R. De A. Rodrigues, R A. Reis
Allelopathic Interactions Among Forage Grasses And Legumes, A P.S Souza Filho, T De J.D. Rodrigues, L.R. De A. Rodrigues, R A. Reis
IGC Proceedings (1977-2023)
Aqueous extracts at 10% were prepared with the shoots of the grasses Brachiaria brizantha cv. Marandú, B. decumbens, B. humidicola, and of the legumes Calopogonium mucunoides, Leucaena leucocephala, Stylosanthes guianensis cv. Mineirão. The effects of the extracts were evaluated on the germination and on the radicleelongation of the forages. The pH, the electric conductivity and the osmotic potential of the extracts were determined. The germination and radicle biossays were conducted in germination chambers, with controlled temperature and photoperiod. The pH and the presence of ions did not contribute to the effects observed. The extracts of the legumes tended …