THE BIOECONOMICS OF SHADE-GROWN COFFEE PRODUCTION UNDER CLIMATE AND PRICE RISKS IN PUERTO RICO

Coffee production is severely affected by global climate change. One of the important impacts comes from the increasing infestation and distribution of coffee berry borer (CBB), the most damaging coffee pest worldwide. Shade-grown coffee (SGC) systems can alleviate the impacts and increase the resilience of coffee farms by providing non-market and market ecosystem services. From an ecological perspective, SGC systems can provide many non-market ecosystem services such as pest risk mitigation, soil water retention, soil fertility, and pollination, which are all critical factors affecting coffee yields. From a financial perspective, SGC systems can benefit farmers by increasing the prices through shade-grown certification price premiums or quality price premiums, reducing price risks faced by farmers by providing alternative sources of income such as shade, and reducing the production risks by allowing more steady year-to-year coffee production. However, SGC systems can be more labor-intensive and often produce lower yields either due to lower per-shrub yields or due to lower coffee shrub density, or both, which can decrease farmers’ profits. Although farmers might agree that environmental conservation is an important goal of SGC systems, planting decisions are likely to be driven by farm production costs and revenues. The existence of trade-offs between ecosystem service provision and coffee production calls for an integrated bioeconomic analysis of SGC systems before recommendations can be made to farmers, with the net value of ecosystem service provision and the risk effects taken into consideration. In this thesis, we construct an integrated bioeconomic model, including a cellular automata model, a coffee yield model, and an economic model, to incorporate the ecosystem services and risk preferences into a farmer’s decision-making and find the optimal amount of shade on a coffee farm for risk-neutral and risk-averse farmers. Results show that, for risk-neutral farmers, the shade-grown systems generate higher net present values (NPVs) than sun-grown systems within shading levels of 12% - 37%. The optimal shading level is 24% and the optimal NPV is about $24,593 /0.5ha over 25 years. For moderately risk-averse farmers, shade-grown systems generate higher utility than a sun-grown system at any shading level, and the optimal shading level is 30%. Higher risk aversion leads to higher shading level selection. In the United States, the CBB is a new threat to the domestic production in Puerto Rico and Hawaii. Results of this thesis can inform policy discussions on the economic argument for shade-grown coffee systems that, under optimal shade levels, can maximize farm profits while to protecting farmers from temperature and price risks

Optimization of Coastal Cruise Lines in China

The paper analyzes the current state of the Chinese cruise market and presents the idea of building a business model of coastal cruising. The cruise demand of middle-income families, which includes the desired travel days, ports of call, is surveyed. The data of the previous non-cruise travels and the data of future cruises of middle-income families are used to develop a model designed to identify the maximum passenger volume with minimum operating costs while taking cruise itineraries and schedules into account. A matrix coding genetic algorithm was designed to solve the model. The case study found that a voyage of 4.79 days results in equilibrium, that the annual demand is 200,840 passengers, and that the daily voyage cost is 0.843 million Yuan

High resolution object detection algorithm based on parallel

With the continuous development and improvement of the aviation information warfare system, target detection technology has also become a key part of the airborne system to perceive the environment. Traditional target detection technology is now difficult to meet the requirements of high precision and high real-time performance in airborne scenarios. With the continuous development of deep learning technology, neural network has become the latest method to deal with object detection task, which greatly improves its accuracy and processing efficiency. However, due to the different targets detected in airborne scenes, the scale of data needed to be processed by using neural networks to process target detection tasks also expands dramatically, and the computing resources provided by single chip are already difficult to meet the needs of target detection algorithm execution in airborne environment. This paper proposes a set of high-precision target detection algorithms based on parallelism, which greatly improves the precision and processing efficiency of the target detection algorithm in airborne scenarios

Indian Summer Monsoon variations and competing influences between hemispheres since ~35 ka recorded in Tengchongqinghai Lake, southwest China

The southwestern Yunnan Province of China, which is located at the southeastern margin of the Tibetan Plateau and close to Bay of Bengal, is significantly influenced by the Indian Summer Monsoon (ISM). In this study, we reconstruct proxies for the ISM from 35 to 1 ka through detailed analysis of grain-size distribution, geochemical composition and environmental magnetism from a 7.96 m sediment core from Tengchongqinghai Lake, Yunnan Province, China. Globally recognized, abrupt climatic events, including Heinrich Events 0–3 (H0−H3) and the Bølling-Allerød (B/A) warm period are identified in most of our proxies, and the long-term trend is consistent with other published records such as stalagmite oxygen isotopes (δ18O) from Sangxing Cave. Northern Hemisphere (NH) temperature, which is influenced by NH solar insolation, is commonly suggested to play a dominant role in controlling the ISM. A comparison of our record with the δ18O variations of ice cores from Greenland and Antarctica, a sea surface temperature (SST) record from the Bay of Bengal, and summer solar insolation at 25°N latitude demonstrates that the general pattern of ISM change does follow variations in summer insolation; however, the ISM lags summer insolation by thousands of years. While the ISM fluctuations are highly correlated with NH temperature on shorter timescales (centennial-millennial), the gradually weakened ISM from 22.5 ka until the Last Glacial Maximum (LGM) indicates a close relationship with the rise of Southern Hemisphere (SH) temperature and the relatively cold background of the SH. Our record expands on the findings of ISM records from Heqing paleolake basin in southwestern China and the Arabian Sea sediments, suggesting that the NH and SH have a competitive influence on ISM by controlling the cross-equatorial pressure gradient. This relationship means that when NH temperatures are relatively high, it has a stronger influence on the ISM than SH influences. In contrast, when the SH temperature is relatively low, it has a dominant influence on ISM. In addition, we speculate that the change of SH temperature not only influences the cross-equatorial pressure gradient directly, but also likely modulates the circulation system of ocean energy by influencing the Atlantic Meridional Overturning Circulation (AMOC)

Mediating effect of sleep quality on the association between job stress and health-related productivity loss among workers in R&D enterprises in Shanghai

BackgroundPast research indicates that occupational stress negatively predicts health-related productivity. Simultaneously, sleep problem among workers may stem from job stress, subsequently leading to a decline in sleep quality and resulting in reduced health productivity. Therefore, this study aims to idenitify whether the sleep quality of employees functions as a mediator in the process through which job stress impacts health productivity.ObjectivesThis study aimed to assess the status and analyze differences in quality of sleep, job stress, and health-related productivity loss (HRPL) among workers in research and development (R&D) enterprises in Minhang District, Shanghai. We also assessed the mediating effect of sleep quality on the relationship between job stress and HRPL.MethodsA total of 3,216 workers in R&D firms aged between 18 and 60 years participated in this study (mean age 35.15 years; standard deviation 8.44; male-to-female ratio≈2:1). The Nakata Insomnia Questionnaire, the Chinese version of the Brief Job Stress Questionnaire revised edition, and the Chinese version of the Work Productivity and Activity Impairment Questionnaire were used in this study. And the Kruskal–Wallis test, Hierarchical Multiple Regression Analysis, and Path Analysis were utilized for data analysis in this study.ResultsThere were significant differences in the positive detection rate of insomnia among participants according to age, educational level, marital status, position, length of service, and level of financial difficulties (all P < 0.05). We also found significant differences in the positive detection rate of HRPL among participants according to age, marital status, length of service, and level of financial difficulties (all P < 0.05); participants with insomnia scored higher for HRPL than those without insomnia (6.00 vs. 4.20, P < 0.001). Additionally, participants with job stress problems had higher HRPL than those without these issues (7.00 vs. 4.20, P < 0.001). Our findings suggest that sleep quality plays a mediating role between job stress and HRPL (all P < 0.05).ConclusionsOccupational health professionals must pay particular attention to job stress, sleep quality, and their influencing factors to positively influence the wellbeing of workers while improving productivity