305 research outputs found

    A Comparison of Drill and Broadcast Planting Methods forBiomass Production of Two Legume Cover Crops

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    The effects of drill and broadcast planting methods on cover crop biomass production depend on various environmental and operational factors. We investigated whether drilling and broadcasting result in different amounts of biomass production by crimson clover (Trifolium incarnatum L.) and hairy vetch (Vicia villosa Roth) in the upstate of South Carolina, and results vary when seeding rates are increased by 50% from the standard value (22.4 kg ha−1). Field trials were conducted during the fall–winter of 2019–2020 (season one) and 2020–2021 (season two) at the Piedmont Research and Education Center in Pendleton, SC, USA. Cover crop (hairy vetch, crimson clover), planting method (broadcast, drill), and seeding rate (standard, high) treatments were arranged as a 2 × 2 × 2 factorial in both years. Aboveground biomass was measured after 22.5 weeks from planting. At standard seeding rates, crimson clover produced a higher biomass when drilled, rather than broadcasted, whereas biomass production did not vary for hairy vetch. Even with 50% higher seeding rates, broadcasting did not always produce the same biomass as that of drilling for crimson clover. Our results suggest that the advantage of drilling over broadcasting depends upon the cover crop species, as crimson clover responds well to drilling, whereas hairy vetch does not

    Modelling Soil Degradation in Libya

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    Soil degradation is considered one of the most important factors limiting agricultural development in Libya, however little effort has been taken to identify the distribution of soil degradation occurrence and type for the country. While the soil degradation for the primary agriculture regions (PAR) has been previously determined as thirty-three percent (33%), the degradation for the rest of the country was still unknown. For this reason, polygons representing soil and climate characteristics, landscape feature and soil degradation from the PAR were converted to raster using ArcGIS (at a resolution of 1000 m2) resulting in 850 points which were then exported as a table for modelling purposes. The data set was subjected to logistic regression to model the binomial outcome of soil degradation occurrence (occurrence, no occurrence). A multinomial logistic regression was used to relate predictor variables to the type of soil degradation since there was more than two outcome options (salinization, water erosion, and wind erosion). Finally, the prediction models were used to determine the remainder of the country’s degradation occurrence and type. Results indicated that slope, texture and wind speed are the most important variables for soil degradation occurrence and type in PAR. When these models are applied to the reminder of the country, they show that salinization was the primary type of soil degradation (30 %), with water erosion and wind erosion causing 10 % and 15 % of soil degradation, respectively. The intention is for these models to assist stakeholders in identifying areas where agriculture is most likely to be successful, while also applicable to countries with similar climate and soils in North Africa. Keywords: Agriculture, GIS, Libya, Logistic regression, Soil degradation

    The Effectiveness of MyPlate and Paleolithic-based Diet Recommendations, both with and without Exercise, on Aerobic Fitness, Muscular Strength and Anaerobic Power in Young Women: A Randomized Clinical Trial

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    International Journal of Exercise Science 11(2): 921-933, 2018. The purpose of this study was to evaluate the effectiveness of recommending a MyPlate or a Paleolithic-based diet, both with and without exercise, on aerobic fitness, strength, and anaerobic power over eight weeks. Participants (n=20) were randomized to one of four groups, (1) a MyPlate diet (MP), (2) Paleolithic-based diet (PD), (3) MyPlate and exercise (MP + Ex), and (4) Paleolithic-based diet and exercise (PD + Ex). The exercise included two days of unsupervised aerobic and resistance exercise. At baseline and final, absolute and relative peak oxygen consumption (absVO2peak and relVO2peak), anaerobic power, and upper and lower body strength were determined. Data were analyzed using repeated measures two-way analysis of variance (ANOVA). The ANOVA indicated that there was no significant interaction between time point (TP)*diet (D)*exercise (Ex) for all variables except relVO2peak (p = 0.016). The MP + Ex group (Δ+4.4 ml×kg-1×min-1) had a greater change from baseline compared to the MP group (Δ-2.7 ml×kg-1×min-1, p = 0.002), and PD + Ex group (Δ-0.3 ml×kg-1×min-1, p = 0.03). The results suggest recommending a MyPlate diet with both aerobic and resistance training are effective at improving aerobic fitness when compared to PD recommendations with exercise, although these conclusions may be confounded by low compliance to exercise recommendations

    The epidemiology and etiology of adhesive capsulitis in the U.S. Medicare population

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    Abstract Background Adhesive capsulitis (AC) of the shoulder, also known as frozen shoulder, causes substantial pain and disability. In cases of secondary AC, the inflammation and fibrosis of the synovial joint can be triggered by trauma or surgery to the joint followed by extended immobility. However, for primary AC the inciting trigger is unknown. The burden of the disorder among the elderly is also unknown leading to this age group being left out of therapeutic research studies, potentially receiving delayed diagnoses, and unknown financial costs to the Medicare system. The purpose of this analysis was to describe the epidemiology of AC in individuals over the age of 65, an age group little studied for this disorder. The second purpose was to investigate whether specific medications, co-morbidities, infections, and traumas are risk factors or triggers for primary AC in this population. Methods We used Medicare claims data from 2010–2012 to investigate the prevalence of AC and assess comorbid risk factors and seasonality. Selected medications, distal trauma, and classes of infections as potential inflammatory triggers for primary AC were investigated using a case–control study design with patients with rotator cuff tears as the comparison group. Medications were identified from National Drug codes and translated to World Health Organization ATC codes for analysis. Health conditions were identified using ICD9-CM codes. Results We found a one-year prevalence rate of AC of approximately 0.35% among adults aged 65 years and older which translates to approximately 142,000 older adults in the United States having frozen shoulder syndrome. Diabetes and Parkinson’s disease were significantly associated with the diagnosis of AC in the elderly. Cases were somewhat more common from August through December, although a clear seasonal trend was not observed. Medications, traumas, and infections were similar for cases and controls. Conclusions This investigation identified the burden of AC in the US elderly population and applied case–control methodology to identify triggers for its onset in this population. Efforts to reduce chronic health conditions such as diabetes may reduce seemingly unrelated conditions such as AC. The inciting trigger for this idiopathic condition remains elusive

    Bacteria in Construction Site Sediment Basins

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    2010 S.C. Water Resources Conference - Science and Policy Challenges for a Sustainable Futur

    Noise Reduction with Lobed Mixers: Nozzle-Length and Free-Jet Speed Effects

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    Acoustic test results are presented for 1/4th-scaled nozzles with internal lobed mixers used for reduction of subsonic jet noise of turbofan engines with bypass ratio above 5 and jet speeds up to 830 ft/s. One coaxial and three forced lobe mixers were tested with variations in lobe penetration, cut-outs in lobe-sidewall, lobe number and nozzle-length. Measured exit flow profiles and thrusts are used to assist the inferences from acoustic data. It is observed that lobed mixers reduce the low-frequency noise due to more uniformly mixed exit flow; but they may also increase the high-frequency noise at peak perceived noise (PNL) angle and angles upstream of it due to enhanced mixing inside the nozzle. Cut-outs and low lobe penetration reduce the annoying portion of the spectrum but lead to less uniform exit flow. Due to the dominance of internal duct noise in unscalloped, high-penetration mixers their noise is not reduced as much with increase in free-jet speed as that of coaxial or cut-out lobed mixers. The latter two mixers also show no change in PNL over the wide range of nozzle-lengths tested because most of their noise sources are outside the nozzle; whereas, the former show an increase in noise with decrease in nozzle-length

    B771: Long-Time Series Temperature and Precipitation Records for Maine, 1808-1978

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    The purpose of this Bulletin is to reconstruct a series of long run temperature and precipitation instrumental records for Maine (monthly means and accumulations). We hope that the data tables and graphs produced here will be of use to climatologists and other researchers and to Maine residents who are interested in the climatic history of the state. To aid in reconstruction, regional records were formed by grouping records from several geographical locations. Much of the data reproduced here have been published elsewhere in a wide variety of publications. Some are found easily in libraries while others are not readily available. A small number of records are published here for the first time. A bibliography of source materials, organized by region and then location is provided for those wishing to consult the original records.https://digitalcommons.library.umaine.edu/aes_bulletin/1132/thumbnail.jp

    HyFlex pedagogy: six strategies supported by design-based research

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    Purpose–This study investigates the following research question: What pedagogical strategies are necessary for the success of the project? The findings to this question are based in new media literacies and help to further pedagogy in an emerging HyFlex model while also grounding in needed theorization. Design/methodology/approach–This study uses design-based research(DBR) across two iterations and four doctoral, higher education courses, using mixed methods of data collection and analysis. Findings–Six pedagogical strategies influential for HyFlex research are presented, each grounded in a new media literacy skill. Originality/value–These six pedagogical strategies help practitioners grappling with the HyFlex or blended learning model merge traditional pedagogy with how this might be tailored for students entrenched in a participatory culture

    Passive Polymer Application for Turbidity Reduction

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    2012 S.C. Water Resources Conference - Exploring Opportunities for Collaborative Water Research, Policy and Managemen
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