Efficiency Of Production Systems Research Articles

Developing a Cost-Effective Surgical Scheduling System Applying Lean Thinking and Toyota's Methods for Surgery-Related Big Data for Improved Data Use in Hospitals: User-Centered Design Approach.

Surgical scheduling is pivotal in managing daily surgical sequences, impacting patient experience and hospital resources significantly. With operating rooms costing approximately US $36 per minute, efficient scheduling is vital. However, global practices in surgical scheduling vary, largely due to challenges in predicting individual surgeon times for diverse patient conditions. Inspired by the Toyota Production System's efficiency in addressing similar logistical challenges, we applied its principles as detailed in the book "Lean Thinking" by Womack and Jones, which identifies processes that do not meet customer needs as wasteful. This insight is critical in health care, where waste can compromise patient safety and medical quality. This study aims to use lean thinking and Toyota methods to develop a more efficient surgical scheduling system that better aligns with user needs without additional financial burdens. We implemented the 5 principles of the Toyota system: specifying value, identifying the value stream, enabling flow, establishing pull, and pursuing perfection. Value was defined in terms of meeting the customer's needs, which in this context involved developing a responsive and efficient scheduling system. Our approach included 2 subsystems: one handling presurgery patient data and another for intraoperative and postoperative data. We identified inefficiencies in the presurgery data subsystem and responded by creating a comprehensive value stream map of the surgical process. We developed 2 Excel (Microsoft Corporation) macros using Visual Basic for Applications. The first calculated average surgery times from intra- or postoperative historic data, while the second estimated surgery durations and generated concise, visually engaging scheduling reports from presurgery data. We assessed the effectiveness of the new system by comparing task completion times and user satisfaction between the old and new systems. The implementation of the revised scheduling system significantly reduced the overall scheduling time from 301 seconds to 261 seconds (P=.02), with significant time reductions in the revised process from 99 seconds to 62 seconds (P<.001). Despite these improvements, approximately 21% of nurses preferred the older system for its familiarity. The new system protects patient data privacy and streamlines schedule dissemination through a secure LINE group (LY Corp), ensuring seamless flow. The design of the system allows for real-time updates and has been effectively monitoring surgical durations daily for over 3 years. The "pull" principle was demonstrated when an unplanned software issue prompted immediate, user-led troubleshooting, enhancing system reliability. Continuous improvement efforts are ongoing, except for the preoperative patient confirmation step, which requires further enhancement to ensure optimal patient safety. Lean principles and Toyota's methods, combined with computer programming, can revitalize surgical scheduling processes. They offer effective solutions for surgical scheduling challenges and enable the creation of a novel surgical scheduling system without incurring additional costs.

Technological surveillance of energy efficiency in agricultural production systems: a systematic review

This document highlights Energy Efficiency (EE) in agricultural production systems through the analysis of the life-cycle of publications in Scopus database, along with the help of SigmaPlot and SciMAT software. Among the results obtained; the growth rate on publications was determined until 2019, with trends in EE research in the agricultural sector. According to the search formulas "energy efficiency" (LIMIT-TO (DOCTYPE, "ar)) and "energy efficiency AND agriculture" (LIMIT-TO (DOCTYPE," ar), which made visible the scientific projection according to the inflection point, as well as the most important motor issues, where those related to soil, water, climatic variability, crops, nitrogen and phosphorus are emphasized, being The United States the country with the greatest scientific dissemination in this regard. In addition, publications and institutions relevant to the case of Colombia were established through TAK ("energy efficiency" AND agriculture) AND (LIMIT-TO (AFFILCOUNTRY, "Colombia").

112 Nutritional, feed safety, and environmental benefits and limitations of using soybean co-products in swine diets

Abstract Various types of soybean co-products are used in swine diets which have benefits and limitations related to protein quality, environmental impact, and feed safety. To address these concerns for sustainable pork production, methodologies have evolved. Soybean processing and storage methods affecting protein oxidation have been studied less than lipid oxidation. Protein carbonyl concentrations were measured and compared among diverse samples of soybeans and soybean meal from different regions of the US and processed by mechanical or solvent extraction. Mechanically extracted soybean meal had greater concentrations of protein carbonyls than solvent extracted soybean meal which were associated with a greater concentration of residual oil. Soybeans and their co-products also contain antioxidants that may protect against more extensive lipid and protein oxidation. Understanding the interactions between natural antioxidants and oxidation of lipid and proteins in soy co-products is important for optimizing nutritional efficiency and health in sustainable pork production systems. Because soybean meal is a major component of swine diets, its origin and environmental footprint affects the environmental impact of feed, manure, and pork production. Using a spatially explicit lifecycle assessment of feed ingredients and regional manure management programs, we compared the effect of using four feeding programs on greenhouse gas (GHG) emissions, land use, and embedded water consumption in 3 major U.S. pork production regions assuming they would provide equal growth performance and carcass composition. Although environmental impacts varied among regions, the corn-soybean meal feeding program resulted in the greatest land and water use of all grower-finisher feeding programs, and more GHG emissions than feeding low protein amino acid supplemented (LP) diets and diets containing 8% supermarket food waste, but less overall GHG emissions than the distiller’s dried grains with solubles (DDGS) feeding program. Results from a subsequent study showed that feeding corn-soybean meal diets optimized growth performance and carcass composition while simultaneously reducing impacts on climate change, marine and freshwater eutrophication, and fossil resource use compared with feeding DDGS and LP diets. Lastly, the extended survival of infectious agents such as African swine fever virus in feed ingredients has important implications for biosecurity and prevention of transboundary transmission of swine diseases. We developed a risk-free in situ surrogate non-animal assay (RISNA) to estimate survival of ASFV in various feed ingredients and conditions, and results indicate greater thermal stability than previously observed, and comparable extended survival among corn- and soybean-based ingredients. These new insights will be useful in revising feed biosecurity protocols to prevent introduction and transmission of ASFV in feed supply chains. In conclusion, holistic assessments of feed ingredients, like our evaluation of soybean co-products, are needed to achieve a more sustainable, One Health approach to pork production.

Early Beringian Traditions: Functioning and Economy of the Stone Toolkit from Swan Point CZ4b, Alaska

AbstractThe pressure knapping technique develops circa 25,000 cal BP in Northeast Asia and excels at producing highly standardized microblades. Microblade pressure knapping spreads throughout most of Northeast Asia up to the Russian Arctic, and Alaska, in areas where the human presence was unknown. Swan Point CZ4b is the earliest uncontested evidence of human occupation of Alaska, at around 14,000 cal BP. It yields a pressure microblade component produced with the Yubetsu method, which is widespread in Northeast Asia during the Late Glacial period. Through the techno-functional analysis of 634 lithic pieces from this site, this study seeks to identify the techno-economical purposes for which the Yubetsu method was implemented. Data show that the microblade production system is related to an economy based on the planning of future needs, which is visible through blanks standardization, their overproduction, their functional versatility, and the segmentation of part of the chaîne opératoire. This expresses the efficiency and economic value of the microblade production system. The flexible use of pressure microblades identified at Swan Point CZ4b is also found in Japan, Korea, Kamchatka, and the North Baikal region, suggesting that their modes of use accompany the spread of early microblade pressure knapping over an immense territory across Beringia.

Power electronics anomaly detection and diagnosis with machine learning and deep learning methods: A survey

Power electronics pertains to the conception, regulation, and utilization of electronic power circuits to proficiently administer and transform electrical energy. Power electronics play a crucial role in maintaining the reliability, efficiency, and security of complex production systems. Also, increasingly important in various applications such as renewable energy systems, electric vehicles, and industrial automation. However, modern power electronics systems are vulnerable to both cyber and physical anomalies due to the integration of information and communication technologies. So far, different methods have been used to detect abnormalities. This survey provides an overview of the state-of-the-art in anomaly detection in power electronics using machine learning and deep learning methods. It highlights the potential of these techniques in addressing the growing complexity and vulnerability of power electronics systems.

Optimizing Nutrient and Energy Efficiency in a Direct-Seeded Rice Production System: A Northwestern Punjab Case Study

This study was carried out in Amritsar, Punjab, to find out how efficiently nutrients were used and how much energy was employed in direct-seeded rice (DSR) production. In this study, four levels of nitrogen (0, 40, 50, and 60 kg N ha−1) and three levels of phosphorus (0, 37.5, and 45 kg P2O5 ha−1) were tested. In a rice production system, the energy indices of various inputs and outputs were evaluated through the application of energy equivalency. The nutrient-use efficiencies in rice were assessed using different efficiency indices. The maximum grain yields of 38.9 q ha−1 and 36.9 q ha −1 were recorded at 50 kg N ha−1 and 45 kg P2O5 ha−1, respectively. On the other hand, application of nitrogen at 60 kg N ha−1 and phosphorus at 45 kg P2O5 ha−1 resulted in maximum straw yield of 57.1 q ha−1 and 51.1 q ha−1, respectively. In comparison with the control, application of 60 and 50 kg N ha−1 resulted in 161.9% and 151.0% higher grain yield, respectively. On the other hand, with applications of 45 kg P2O5 ha−1 and 37.5 kg P2O5 ha−1, an increase in the grain yield of 17.3 and 28.6%, respectively, over the control was recorded. Moving further towards nutrient-use efficiencies (NUEs), the highest values of partial factor productivity of nitrogen (PFPN), agronomic efficiency of nitrogen (AEN), partial nutrient balance of nitrogen (PNBN), and recovery efficiency of nitrogen (REN) were 89.1, 50.4, 1.78 and 0.72, respectively, which were obtained at 40 kg N ha−1, after which the values started decreasing steadily. In the case of phosphorus, the partial factor productivity (PFPP) of 88.6 was the maximum at 37.5 kg P2O5 ha−1, but partial nutrient balance (PNBP) of 0.36 and recovery efficiency (REP) of 0.08 were highest at 45 kg P2O5 ha−1. The main results revealed that the farmer field had an excessive amount of non-renewable energy inputs. The experimental field depicted greater energy-usage efficiency (EUE) of 4.5, energy productivity (EP) of 0.14, and energy profitability (EP1) of 3.5. These results were primarily ascribed to a significant drop in energy inputs under direct-seeded rice (DSR). In the case of non-renewable energy inputs, fertilizer made the maximum contribution to energy input (47.9%) in the farmer’s field. We conclude that nutrient-use efficiencies and energy-use efficiency were highest at 50 kg N and 45 kg P2O5 ha−1. This recommendation is beneficial for farmers because lower inputs and higher outputs are the main objective of every farmer.

Problems and prospects for the development and application of an algorithm for the transition to industrial digitalization

Industrial digitalization defines global prospects for increasing the efficiency of industrial production systems. Issues of industrial digitalization are accompanied by a number of complex transformation processes and preparatory procedures, the provision of which requires an integrated approach and the development of special algorithms, strategies and supporting mechanisms for industrial digitalization. The article analyzes modern problems and prospects for the development and implementation of an algorithm for the transition of enterprises to industrial digitalization. General factors are identified: limitations of industrial digitalization and prospects for transformation. A generalized algorithm is developed and the mechanisms and approaches to industrial digitalization at the micro level that support its implementation are revealed.

Scale elasticity and technical efficiency measures in two-stage network production processes: an application to the insurance sector

In performance analysis with tools such as data envelopment analysis, calculations of scale properties of the frontier points are studied using both qualitative and quantitative approaches. When the production process is a bit complicated, the calculation needs to be modified. Most existing studies are focused on a single-stage production process under the constant or variable returns to scale specification. However, some processes have two-stage structures, and, in such processes, the concepts of scale elasticity and returns to scale are inextricably related to the conditions of the stages of production. Thus, an evaluation of efficiency, scale elasticity, and returns to scale is sensitive to stages. In this study, we introduced a procedure to calculate technical efficiency and scale elasticity in a two-stage parallel-series production system. Then, our proposed technical efficiency and scale elasticity programs are applied to real data on 20 insurance companies in Iran. After applying our estimations to a real-world insurance industry, we found that, (i) overall, the total inputs of insurers in the life insurance sector should be reduced by 9%. Moreover, the inputs of nonlife insurers should be reduced by 50%. The final output in the investment sector must be increased by 48%. (ii) There are inefficiencies among all insurers in the investment sector, and to improve technical efficiency, the income from investments should be increased significantly. (iii) Finally, the efficiency and elasticity characterizations of insurers are directly subject to stages.

Energy-use efficiency of organic and conventional plant production systems in Germany

Sustainable and efficient energy use in agriculture helps tackle climate change by reducing fossil energy use. We evaluated German farming systems by analysing energy input and output. Data from 30 organic and 30 conventional farms (12 arable, 18 dairy farms each) between 2009 and 2011 was used. Energy input, output, and the influence of farm type, farm structure, and management intensity on energy-use efficiency (EUE) were analysed for crop production using the farm management system REPRO. Conventional farms (CF) always had higher energy input. The energy input for organic farms (OF) was 7.2 GJ ha−1 and for CF 14.0 GJ ha−1. The energy output of CF was also higher. Reductions were higher in energy input than in energy output. In 73.3% of the farm pairs, OF were more energy efficient than CF. The EUE was comparable with CF on 10% of OF and for 16.7% of CF the EUE was higher suggesting better fossil energy utilization. EUE can be increased when reducing fossil energy inputs through more efficient machinery, reduction of agrochemicals, precision farming, the use of renewable energy or energy retention, and by increasing yields. A reduction of inputs is urgently required to lower the (political) dependence on fossil energy.

Enhancing economic efficiency in modular production systems through deep reinforcement learning

In times of increasingly complex production processes and volatile customer demands, the production adaptability is crucial for a company's profitability and competitiveness. The ability to cope with rapidly changing customer requirements and unexpected internal and external events guarantees robust and efficient production processes, requiring a dedicated control concept at the shop floor level. Yet in today's practice, conventional control approaches remain in use, which may not keep up with the dynamic behaviour due to their scenario-specific and rigid properties. To address this challenge, deep learning methods were increasingly deployed due to their optimization and scalability properties. However, these approaches were often tested in specific operational applications and focused on technical performance indicators such as order tardiness or total throughput. In this paper, we propose a deep reinforcement learning based production control to optimize combined techno-financial performance measures. Based on pre-defined manufacturing modules that are supplied and operated by multiple agents, positive effects were observed in terms of increased revenue and reduced penalties due to lower throughput times and fewer delayed products. The combined modular and multi-staged approach as well as the distributed decision-making further leverage scalability and transferability to other scenarios.

Design of cost-effective and highly efficient systems for protonic ceramic fuel cells based on techno-economic analysis

Theoretically, protonic ceramic fuel cells (PCFCs) are considered to achieve higher energy conversion efficiencies than conventional solid oxide fuel cells. However, doped barium-based perovskite oxide, a typical electrolyte material, has a significant leakage current derived from hole conduction. Therefore, it is still unclear whether the actual performance of whole PCFC systems can reach the expected high efficiency. In this study, two strategies to suppress the leakage current, namely, low-temperature operation and a bilayer electrolyte cell using a high-ion and low-hole conductor, were discussed. The effects of these approaches on production costs and system efficiency were investigated from an economic perspective for social implementation. Moreover, the following technological options were discussed to comprehensively investigate the effects of cell, manufacturing process, and system designs on the system efficiencies and system costs; (1) cell design: examining a high-performance electrode; (2) module production process design: examining the annual production rate, co-sintering of electrode and electrolyte layers, and fabrication of an electrolyte layer with vapor-phase deposition; and (3) system design: examining a methane-fueled system, a multi-stage PCFC operation, a membrane for hydrogen separation, and lower oxygen utilization. Here, we focused on a residential 5 kW alternating current (AC) class system. Consequently, system efficiency and module production cost were calculated as 57 % based on the lower heating value (LHV) in a direct current (DC) and 4,650 USD/system adopting a monolayer electrolyte cell using BaZr0.8Y0.2O3-δ (BZY20) at 600 °C, assuming hydrogen as fuel under the annual production rate of 50 k/year. However, it was suggested that the system efficiency could be improved to 63 % in case of a lower temperature operation at 550 °C and 69 % adopting a bilayer electrolyte cell at 600 °C. Furthermore, technological options resulted in a system efficiency of 71 % and a production cost of 4,480 USD/system in the case of the bilayer cell, assuming a high-performance cathode when fabricated using the co-sintering method. Finally, the electricity cost was calculated to investigate the system lifetime and fuel cost requirements to achieve the present baseload electricity cost. From an economic and performance perspectives, this study could contribute to the widespread use of PCFC devices by exploring new technological options.

Energetic and Monetary Analysis of Efficiency in Family-Owned Dairy Goat Production Systems in Andalusia (Southern Spain).

The family-owned dairy goat sector in Andalusia presents great diversity. Taking into account the particularities of their economic strategies, which are focused on generating net value added and a stable long-term remuneration for family labor, this work aims to expand the scarce existing knowledge on the energetic and economic profiles of the different caprine management systems in a context of climate and energy crisis. For this purpose, twenty-one farms, representatives of the four typologies of the Andalusian dairy goat system, were monitored for one year: pastoral systems, grazing systems with high feed supply, indoor systems with associated crops, and indoor systems without associated crops. Technical-economic information was obtained that allowed the calculation of energy and economic indicators. In terms of socialized output, the differences found were due to the energy derived from milk sales, which was clearly lower in pastoral systems. The higher proportion of energy output obtained from manure with respect to edible products (milk and meat) highlights the importance of the former in energetic terms. High values for external inputs are found in the intensive group (111.22 GJ LSU-1), while the lowest results correspond to the pastoral group (36.96 GJ LSU-1). The main external input is the energy proceeding from purchased feed, which accounts for over 79% of the total external energy input in all four groups. The highest energy efficiency corresponds to the pastoral group, which is also the most efficient one in the use of non-renewable energy to produce milk and meat. Additionally, the level of eco-efficiency is higher in pastoral systems. Common Agricultural Policy funds contribute to increasing the remuneration of family work in pastoral systems, assimilating it to the rest of the systems. Therefore, intensification does not imply an absolute monetary advantage in all cases, while extensification can be remunerative for family-owned dairy farming.

Large-Scale Hydrogen Production Systems Using Marine Renewable Energies: State-of-the-Art

To achieve a more ecologically friendly energy transition by the year 2050 under the European “green” accord, hydrogen has recently gained significant scientific interest due to its efficiency as an energy carrier. This paper focuses on large-scale hydrogen production systems based on marine renewable-energy-based wind turbines and tidal turbines. The paper reviews the different technologies of hydrogen production using water electrolyzers, energy storage unit base hydrogen vectors, and fuel cells (FC). The focus is on large-scale hydrogen production systems using marine renewable energies. This study compares electrolyzers, energy storage units, and FC technologies, with the main factors considered being cost, sustainability, and efficiency. Furthermore, a review of aging models of electrolyzers and FCs based on electrical circuit models is drawn from the literature and presented, including characterization methods of the model components and the parameters extraction methods, using a dynamic current profile. In addition, industrial projects for producing hydrogen from renewable energies that have already been completed or are now in progress are examined. The paper is concluded through a summary of recent hydrogen production and energy storage advances, as well as some applications. Perspectives on enhancing the sustainability and efficiency of hydrogen production systems are also proposed and discussed. This paper provides a review of behavioral aging models of electrolyzers and FCs when integrated into hydrogen production systems, as this is crucial for their successful deployment in an ever-changing energy context. We also review the EU’s potential for renewable energy analysis. In summary, this study provides valuable information for research and industry stakeholders aiming to promote a sustainable and environmentally friendly energy transition.

Innovative tools for risk management of the production activities of agricultural enterprises in an institutional environment

The security of agricultural sector development is increasingly becoming a relevant issue in modern conditions, as the agricultural sector determines the sustainability of the economy and ensures the country’s food security. Growing risks, such as climate change, economic difficulties and geopolitical conflicts, highlight the need to improve the security of agricultural production systems, which makes the study relevant. The study aimed to conduct a systematic analysis of innovative tools for managing the risks of production activities of agricultural enterprises and their impact on the formation of secure development in the agricultural sector of Ukraine. To achieve this goal, the method of analysis and modelling was used. Study results indicate that innovative approaches to risk management have a decisive impact on the sustainability and efficiency of agricultural production systems. To achieve a stable level of safe development of agricultural enterprises, it is necessary to focus on the implementation of key areas, such as maintaining the food base at a level sufficient to ensure a healthy diet, ensuring an adequate level of effective demand for the population and eliminating dependence on imports, aimed at protecting the interests of domestic producers of agricultural raw materials. The study demonstrated that institutional factors of risk management form an integrated system, where efficiency depends on the implementation of specific strategies for the development of agricultural institutions aimed at introducing innovative tools into the production cycle of agricultural enterprises. Furthermore, due to the accumulation of large amounts of production, financial, logistical and innovative potential of agricultural enterprises in the Forest-Steppe and Polissia regions, the level of safe development of agricultural enterprises is significantly increasing. This indicates their high capacity for sustainable reproduction of production and making a significant contribution to the agricultural sector of Ukraine. The study is of practical importance for agricultural enterprises, research institutions and government agencies, which can use the results to improve risk management strategies and increase the level of security of agricultural sector development

Efficiency of implementation of Smart Farms: economic assessment

The goal is to study the mechanism for increasing the efficiency of production systems when fattening beef cattle. An example of the use of Smart Technology is given to determine and influence the quality of genetic selection of meat animals, which in turn contributes to high average daily gain and increased profitability of farms. The object of research - methods of keeping and feeding cattle, digital technologies and technical means, results of fundamental, theoretical, forecasting and search and applied scientific developments. Methods – comparative analysis, expert assessments, experience in applying promising trends and innovative technology of the Intergado system. Results – it is shown that the use of such nanotechnologies makes it possible, depending on the “key feature,” to automatically generate databases of production processes through which the weight and condition of the livestock is monitored. Based on information about changes in the weight of cattle, timely adjustments are made to the animals’ diet, which helps improve their health and optimize the genetic algorithm. Weighing cattle (BW) is an important tool in herd management since increasing body weight affects productivity, productivity and, as a result, readiness for speedy sale and savings in feed costs. Conclusions – digital solutions have been proposed to improve the effectiveness of regulation of agricultural production with a large flow of information and technological operations; model parameters make it possible to automatically transfer farm animals from one production group to another by tracking the “live weight” indicator for culling.

Combined mechanistic and genetic modelling to benchmark body reserve traits as proxies of dairy cows’ lifetime efficiency in grass-based production systems

Improving lifetime lactation efficiency of dairy cows by selection is difficult due to the complexity of this trait and the existence of genotype-by-environment interactions. This study aimed at assessing the relevance of traits derived from body reserves as lifetime efficiency indicators under contrasting nutritional environments. Given the absence of large-scale datasets covering a panel of feeding regimes, phenotypes were simulated for populations of 20 000 dairy cows using a mechanistic bioenergetic model. Ten phenotypes were computed for third-lactation cows. Analysed phenotypes comprised total milk production, lactation efficiency, BW at calving (BWcalv), DM intake (DMI) and interval between first insemination and conception. Five traits described levels and changes of body reserves at different periods during lactation. Lifetime lactation efficiency was computed for all cows (Life_Eff). Three nutritional environments were defined considering a grass-based production system with seasonal calving: a high non-limiting scenario (HS) mimicking ad libitum access to feed and two limiting environments with moderate (MS) and low (LS) feed offer. Variance components were estimated for all traits within and between environments using REML. Heritabilities estimated for milk production, lactation efficiency, BWcalv and DMI were moderate in the different environments (0.27–0.35 ± 0.04). The heritability of body reserve levels and dynamics were moderate in the HS and MS scenarios (0.23–0.30 ± 0.03) and lower in the LS scenario (0.14–0.25 ± 0.03). The heritability of Life_Eff was low in the HS environment (0.07 ± 0.01) and slightly increased in the limiting environments. All genetic correlations estimated between environments were moderate to high (≥0.66 ± 0.07), suggesting low to moderate genotype-by-environment interactions. Estimated genetic correlations were moderate between Life_Eff and body reserve levels (from 0.39 to 0.51 ± 0.08) and moderate but negative between Life_Eff and change in body reserves traits (−0.27 to −0.37 ± 0.09) in the HS environment. The genetic correlations between Life_Eff and body reserve levels increased to higher values in the limiting environments. In contrast, genetic correlations between Life_Eff and the changes in body reserves were closer to zero. In conclusion, this study showed that body reserve levels were relevant proxies of lifetime irrespective of the environment. In contrast, changes in body reserves that reflected energy mobilisation in early lactation were less informative about lifetime efficiency in environments with severe feed restrictions.

89 Physiological Mechanisms Related to Feed Efficiency of Beef Cattle

Abstract Improving feed efficiency is essential for the sustainability of the US beef production system. However, achieving this goal is challenging due to various factors such as diet types, genetics, environments, and industry segmentation. To address these difficulties, it is critical to have a fundamental understanding of what contributes to efficient nutrient utilization and feed resources, which can guide future genetic selection and production practices. Despite recent progress, the regulation of feed intake in growing and finishing cattle remains incompletely understood, hindering advances in feed efficiency. Recent research has aimed to advance the hepatic oxidation theory to growing and finishing cattle fed high-concentrate diets and explored the control of appetite by gut peptide hormones. Other factors contributing to variation in feed efficiency include nutrient metabolism and hormonal control of metabolism. Previous research is limited by a lack of in-depth analysis of metabolism due to the inability to time sample collection relative to feed consumption and account for correlations among metabolites. The role of fat metabolism in the rumen has been associated with epithelial inflammation, while inflammation of the gut has been identified as a contributing factor to inefficiencies in nutrient utilization. However, there is still a need to further understand the role of fatty acid metabolism in the induction of inflammation. An issue that limits the further understanding of efficiency is that a wide variety of feedstuffs are utilized by the industry and small changes in the nutrient composition of a diet can have large impacts on efficiency. Therefore, it is important to consider the utilization efficiency of specific nutrients rather than general feed efficiency. Nitrogen utilization efficiency is becoming increasingly important due to the significant economic and environmental ramifications of inefficiencies in nitrogen utilization. There is growing evidence that precision feeding of protein to match requirements can reduce nitrogen excretion without compromising growth and efficiency. In conclusion, a better understanding of the underlying biology contributing to nutrient utilization is crucial for improving feed utilization efficiency in the US beef production system, which will enhance the sustainability of the US beef production system.

180 Differences in Gene Expression in Granulosa Cells Harvested from Fertile and Sub-Fertile Beef Heifers

Abstract Infertility in beef replacement heifers is one of the leading contributors to economic losses in the cow-calf sector of the beef production industry. Successful reproduction is complex, involving multiple tissues and biological systems. This complexity makes identifying the leading causes of subfertility difficult. One potential source of fertility issues is poor oocyte health. As developing oocytes are dependent on granulosa cells (GCs) and physically coupled with GCs, we hypothesized that the gene expression profile would be different between the GCs from fertile heifers and those from sub-fertile heifers. The objective of this study was to identify differences in gene expression in GCs collected from beef heifers of differing fertility status, either fertile or sub-fertile. To gather this information, Angus-Simmental crossbred heifers underwent an estrus synchronization and fixed-time artificial insemination (AI) protocol (7-Day CO-synch + CIDR). At 41 days post-AI, heifers were pregnancy checked through ultrasound and palpation. Heifers pregnant to AI were classified as fertile (n = 8). Any heifers that remained non-pregnant following AI were exposed to bulls of proven fertility for 61 days. Bull-exposed heifers were evaluated for pregnancy 34 days after the bulls were removed. The non-pregnant heifers following both AI and natural service were classified as sub-fertile (n = 5). Pregnancies were terminated in fertile heifers, and heifers from both groups were allowed to resume normal cyclicity before GCs being harvested. RNA was extracted from GCs and quality was checked for each sample. Total RNA from GCs of 13 heifers was subjected to the library preparation and sequencing on the Nova-Seq platform. Through the application of DESeq2, 79 genes were identified as significantly differentially expressed genes (DEGs) with P-value &amp;lt; 0.05 and absolute (log2 fold change) &amp;gt; 0.5 including DNER, HOXD10, CD52, CXCL12, and HOXD11. DEGs, along with co-expressed genes, were over-represented in pathways associated with the regulation of MAP kinase activity, regulation of serine/threonine kinase activity, MHC protein binding, and plasma membrane signaling receptor complex. Through the pursuit of knowledge regarding the function of top DEGs, increased sample size, and more diverse sample collection time points, we may improve our understanding of the causation of heifer fertility issues. Improving our knowledge of heifer infertility has the potential to develop therapeutic options, and in turn, increase the efficiency and sustainability of cow-calf production systems.

Optimizing Nitrogen Fertilization to Enhance Productivity and Profitability of Upland Rice Using CSM-CERES-Rice.

Nitrogen (N) deficiency can limit rice productivity, whereas the over- and underapplication of N results in agronomic and economic losses. Process-based crop models are useful tools and could assist in optimizing N management, enhancing the production efficiency and profitability of upland rice production systems. The study evaluated the ability of CSM-CERES-Rice to determine optimal N fertilization rate for different sowing dates of upland rice. Field experimental data from two growing seasons (2018-2019 and 2019-2020) were used to simulate rice responses to four N fertilization rates (N30, N60, N90 and a control-N0) applied under three different sowing windows (SD1, SD2 and SD3). Cultivar coefficients were calibrated with data from N90 under all sowing windows in both seasons and the remaining treatments were used for model validation. Following model validation, simulations were extended up to N240 to identify the sowing date's specific economic optimum N fertilization rate (EONFR). Results indicated that CSM-CERES-Rice performed well both in calibration and validation, in simulating rice performance under different N fertilization rates. The d-index and nRMSE values for grain yield (0.90 and 16%), aboveground dry matter (0.93 and 13%), harvest index (0.86 and 7%), grain N contents (0.95 and 18%), total crop N uptake (0.97 and 15%) and N use efficiencies (0.94-0.97 and 11-15%) during model validation indicated good agreement between simulated and observed data. Extended simulations indicated that upland rice yield was responsive to N fertilization up to 180 kg N ha-1 (N180), where the yield plateau was observed. Fertilization rates of 140, 170 and 130 kg N ha-1 were identified as the EONFR for SD1, SD2 and SD3, respectively, based on the computed profitability, marginal net returns and N utilization. The model results suggested that N fertilization rate should be adjusted for different sowing windows rather than recommending a uniform N rate across sowing windows. In summary, CSM-CERES-Rice can be used as a decision support tool for determining EONFR for seasonal sowing windows to maximize the productivity and profitability of upland rice production.

Shielding factors for a fission-powered mars exploration rover

Background: With the advances in compact fission power systems and Stirling converters, the efficiency and portability of electrical energy production systems has increased substantially thanks to NASA’s Kilopower project. These 1-10 kWe-class reactors are compact enough to be transportable by pressurized rovers, allowing an extended human reach across the surface of Mars to produce scientific data at a rate that greatly surpasses the rate of robotic rover data collection. If rovers were to harness fission power while mobile, it is possible for near-limitless range. This capability could allow one crew on Mars for under a “Conjunction” class mission as outlined in NASA’s Mars Design Reference Architecture (DRA) 5.0 to visit many geological sites of interest instead of requiring additional landings to explore distant features of the Martian surface. This study explored the parameters that affected the mass of the shielding required to protect the crew against a fission reactor embedded in the chassis of a pressurized rover. Methods: An analytical approach was devised to estimate the required mass of a hypothetical solid tungsten shield under various conditions. Results: Power levels below 3.4 kWe were found to be impractical for rover applications. Between 3.4 kWe and 10 kWe would be able to recharge the rover without returning to base camp. The increase in shielding mass from a 3.4 kWe reactor and a 10 kWe reactor was 6%. The reduction between a 10 kWe reactor at 3 m and 6 m was 7%. Varying the shield thickness in accordance with astronaut activities resulted in a 19% reduction. Powering the reactor off before exiting the vehicle resulted in an additional 65% reduction. Conclusions: Knowledge of the crew activities and locations had the greatest impact on the required shielding mass and the mission activities should be well-understood before finalizing a shield design.