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An examination of predictive markers for successful sperm extraction procedures:a linear model and systematic review

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Asian Journal of Andrology 2023年第1期25卷 38-42页

作者： Nicholas Major K Russ Edwards Kit Simpson Marc rogers Department of Urology Medical University of South CarolinaCharlestonSC 29425USA Department of Healthcare Leadership and Management Medical University of South CarolinaCharlestonSC 29425USA Department of Urology University of North CarolinaChapel HillNC 27514USA

The authors performed a comprehensive review of current literature to create a model comparing commonly evaluated variables in male factor infertility,for example,follicle-stimulating hormone(FSH),testicular volume(TV),and testosterone(T),to better predict sperm retrieval rate(SRR).Twenty-nine studies were included,9 with data on conventional testicular sperm extraction(cTESE)for a total of 1227 patients and 20 studies including data on microdissection testicular sperm extraction(mTESE)for a total of 4760 patients.A weighted-means value of SRR,FSH,T,and TV was created,and a weighted linear regression was then used to describe associations among SRR,type of procedure,FSH,T,and *** this study,weighted-means values demonstrated mTESE to be superior to cTESE with an SRR of 51.9%vs 40.1%.Multiple weighted linear regressions were created to describe associations among SRR,procedure type,FSH,T,and *** models showed that for every 1.19 mIU ml^(−1)increase in FSH,there would be a significant decrease in SRR by 1.0%.Seeking to create a more clinically relevant model,FSH values were then divided into normal,moderate elevation,and significant elevation categories(FSH20 mIU ml^(−1),respectively).For an index patient undergoing cTESE,the retrieval rates would be 57.1%,44.3%,and 31.2%for values normal,moderately elevated,and significantly elevated,*** conclusion,in a large meta-analysis,mTESE was shown to be more successful than cTESE for sperm *** has an inverse relationship to SRR in retrieval techniques and can alone be predictive of cTESE SRR.

关键词： follicle-stimulating hormone meta-analysis microtesticular sperm extraction nonobstructive azoospermia testicular sperm retrieval

Development of a Portable Electro-Mechanical Educational Model for Variable Rate Center Pivot Irrigation Technology

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Journal of Water Resource and Protection 2016年第4期8卷 449-458页

作者： Young J. Han Ahmad Khalilian Jose Payero Nicholas rogers Department of Agricultural and Environmental sciences Clemson University Clemson SC USA Edisto Research and Education Center Department of Agricultural and Environmental Sciences Clemson University Blackville SC USA

Center pivot irrigation systems usually apply a relatively uniform amount of water to fields that are often inherently variable, which could lead to significant waste of water and energy. To address this issue, our team is now developing an Intelligent Center Pivot (ICP) by integrating sensor-based irrigation scheduling with variable rate irrigation technology. However, before this technology can be applied in commercial production, it is necessary to educate growers about its practicality and potential benefits. The objective of this study was to develop a portable tabletop intelligent center pivot model (ICPDemo) to demonstrate and promote adoption of the ICP technology. This paper describes an ICPDemo constructed in 2014, including the design specifications, electro-mechanical design, control strategy, and performance. The ICPDemo has performed according to design specifications and is successfully being used to demonstrate the benefits and effectiveness of ICP technology for irrigation scheduling.

关键词： Irrigation Center Pivot Irrigation Electro-Mechanical Model Sensors Control Variable Rate Irrigation

An Electro-Mechanical Controller for Adjusting Piston Pump Stroke On-the-Go for Site-Specific Application of Crop Nutrients

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Agricultural sciences 2017年第9期8卷 949-959页

作者： Ali Mirzakhani Nafchi Joe Mari Maja Ahmad Khalilian Young Han Nicholas rogers Jose O. Payero Michael W. Marshall Phillip B. Williams Jonathan Fox Department of Agricultural sciences Clemson University Clemson SC USA Edisto Research and Education Center Clemson University Blackville SC USA

Nutrient application systems are designed to apply a relatively uniform amount of a fertilizer to agricultural fields. However, considerable variation in soil texture and other characteristics often occurs within and across production fields, which could have a major impact on fertilizer management strategies. Therefore, uniform application of a fertilizer over the entire field can be both costly and environmentally unsound. Due to their rugged and fool-proof design, crankshaft type piston pumps are widely used in agriculture. The on-the-go outlet flow of these pumps can only be varied by changing the drive shaft speed for each pump stroke setting. But only a limited range of flow rates can be achieved by changing the drive shaft speed. There is a need for an electronic controller, which can adjust the pump stroke on-the-go, for real-time, variable-rate application of crop nutrients. The Clemson “Electro-me-chanical controller for adjusting pump stroke on-the-go” was designed to replace the current manual stroke adjustment system on positive displacement piston pumps. This affordable system can be retrofitted on most John Blue - piston pumps for real-time adjustment of the pump stroke and can be controlled using pre-described position sequences (map-based) or real-time sensor commands (such as optical, pressure, and flow sensors) combined with fertilizer calculation algorithms. In addition, it can adjust pump stroke manually, using an eclectic dial from the tractor’s cab.

关键词： Electro-Mechanical Controller Metering Piston Pumps Nutrient Management Precision Agriculture Pump Stroke

Investigation of Wave-Structure Interaction Using State of the Art CFD Techniques

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Open Journal of Fluid Dynamics 2014年第1期4卷 18-43页

作者： Jan Westphalen Deborah M. Greaves Alison Raby Zheng Zheng Hu Derek M. Causon Clive G. Mingham Pourya Omidvar Peter K. Stansby Benedict D. rogers school of Computing Mathematics and Digital Technology Manchester Metropolitan University Manchester UK school of Marine science and Engineering Marine Institute University of Plymouth Plymouth UK school of Mechanical Aerospace and Civil Engineering University of Manchester Manchester UK

The suitability of computational fluid dynamics (CFD) for marine renewable energy research and development and in particular for simulating extreme wave interaction with a wave energy converter (WEC) is considered. Fully nonlinear time domain CFD is often considered to be an expensive and computationally intensive option for marine hydrodynamics and frequency-based methods are traditionally preferred by the industry. However, CFD models capture more of the physics of wave-structure interaction, and whereas traditional frequency domain approaches are restricted to linear motions, fully nonlinear CFD can simulate wave breaking and overtopping. Furthermore, with continuing advances in computing power and speed and the development of new algorithms for CFD, it is becoming a more popular option for design applications in the marine environment. In this work, different CFD approaches of increasing novelty are assessed: two commercial CFD packages incorporating recent advances in high resolution free surface flow simulation;a finite volume based Euler equation model with a shock capturing technique for the free surface;and meshless Smoothed Particle Hydrodynamics (SPH) method. These different approaches to fully nonlinear time domain simulation of free surface flow and wave structure interaction are applied to test cases of increasing complexity and the results compared with experimental data. Results are presented for regular wave interaction with a fixed horizontal cylinder, wave generation by a cone in driven vertical motion at the free surface and extreme wave interaction with a bobbing float (The Manchester Bobber WEC). The numerical results generally show good agreement with the physical experiments and simulate the wave-structure interaction and wave loading satisfactorily. The grid-based methods are shown to be generally less able than the meshless SPH to capture jet formation at the face of the cone, the resolution of the jet being grid dependent.

关键词： Wave Loading Wave Energy Wave-Structure Interaction Manchester Bobber CFD Physical Experiments FV CV-FE SPH Cartesian-Cut-Cell SPHysics AMAZON sc STAR CCM+ CFX

Sensor-Based Algorithm for Mid-Season Nitrogen Application in Corn

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Open Journal of Soil science 2017年第10期7卷 278-287页

作者： Ahmad Khalilian Nicholas G. rogers Phillip B. Williams Young J. Han Ali Mirzakhani Nafchi Joe Mari Maja Michael W. Marshall Jose O. Payero Department of Agricultural sciences Clemson University Clemson SC USA Edisto Research and Education Center Clemson University Blackville SC USA

Applying insufficient nitrogen (N) in a highly responsive crop, such as corn, results in lower grain yield, quality, and profits. On the other hand, when nitrogen is applied in excess of crop needs, profit is reduced and negative environmental consequences are likely. The objective of this study was to develop and employ a sensor-based algorithm to determine the mid-season N requirements for deficit-irrigated corn in Coastal Plain soils. The algorithm was developed using varied prescription rate N plot on two soil types. The test plots received nine different rates of N fertilizer, replicated 5 times in plots of each soil type using a Randomized Complete Block design. A 6-row GreenSeeker optical sensor was used to measure plant NDVI, between the V6 to V8 growth stages. The sensor readings were used to develop an algorithm to be used in the estimation of side-dress N application in corn. The NDVI sensor readings were collected at the V6 to V8 growth stage during the 2015 and 2016 growing seasons correlated with actual corn yields (R2 > 0.68, p < 0.001). In-Season Estimated yield (INSEY) was used along with the actual yield to produce a yield potential for each growing season for deficit-irrigated corn crop. In summary, the algorithm developed from the NDVI readings reduced N application rates by 21% and 34% in soil types 1 and 2, respectively, compared to the normal grower practice (226 kg N/ha) with no reduction in corn yields.

关键词： Algorithms Corn Nutrient Management Precision Agriculture Normalized Difference Vegetation Index (NDVI) Sensors