Three essays on water management strategies in response to climate change

Due to climate change, the amount of rainfall, and its uneven temporal and spatial distribution, affect water availability. As a result, both households and farmers need to adapt to climate change by taking appropriate actions. This dissertation incorporates insights from scholarship on both adaptation to climate change and innovation adoption. For residents, adopting drought tolerant plants (DTPs) to conserve water use is a potential adaptation to the predicted effects of climate change. Survey responses from 624 households in Missouri are analyzed using a univariate probit model. DTPs adoption is positively correlated with both low and high household incomes, homeownership, living in rural subdivisions, mowing lawns high, time spent on yardwork, pro-environmental attitudes, and concerns about droughts. Policy interventions might include subsidizing the purchase of DTPs, requirements for use of DTPs in new housing developments, and targeted educational efforts. To encourage farmers to conserve water and use water more efficiently, understanding their decision-making on adoption of enhanced irrigation systems and scientific scheduling practices is essential. Using data from the national 2013 Farm and Ranch Irrigation Survey (FRIS) conducted by USDA, this dissertation employs a mixed and multilevel approach to analyze both land- and crop-specific irrigation decisions. Three land-level equations on irrigation share, irrigation application rate, and harvest share are estimated. Results show that irrigation share, application rate and harvest share are associated with variables related to water costs, farm size, irrigation systems, barriers to improvements, information sources, etc. In addition, the adoption decisions are analyzed focusing on corn and soybean farms using multilevel models (MLMs) as they can better deal with the farm-level data embedded in states. Application of MLMs to the analysis of farmers' adoption provides new insights on the proportion of variability in each response accounted for by farm- versus state-level factors. The results suggest that, while adoption is affected by land areas, off-farm surface water, various barriers and information sources, the variability of pressure irrigation adoption is mainly accounted for by factors at the state level, while the adoption of scientific scheduling practices is mainly accounted for by farm-level variation. Controlling for farm-level factors, farmers in areas with drought conditions in 2012, i.e., lower than average rainfall and higher than average temperatures, are more likely to have adopted pressure irrigation systems and scientific scheduling practices by 2013. In addition, sustainability of water resources requires producers to take account of marginal user costs when making production decisions. Adoption of enhanced irrigation systems and higher water cost can achieve potential improvements in irrigation water use efficiency. In a multicrop production system with irrigation, farmers make decisions about land allocated to each crop, irrigation water application, and their decisions, along with growing conditions, determine crop supply. This dissertation also analyses water application to multiple crops at the farm level and the effects of influential factors on irrigation water use efficiency of specific crops. As MLMs permit the incorporation of state-level variables, they are further applied in analyzing the multicrop production decisions and irrigation water use efficiency. The results show higher water price encourages efficient water use. Moreover, adoption of pressure irrigation systems could reduce soybean water use or increase corn yield. Adoption of pressure irrigation increases the economic irrigation water use efficiency on soybean farms. The findings from MLMs show that variables representing deviations from 30 year state average climate conditions in 2012 and 2013 have fairly consistent effects. Climate risks and higher temperatures promote more efficient water use and higher yields. Higher precipitation is correlated with lower water application and higher crop yield. Federal programs and policy should not only target specific barriers and increase the effectiveness of incentives at the farm level, but also address differing priorities in each state. Implications from these analyses should benefit future policy design and improve education programs

Análisis comparativo del modelo de enseñanza del español como lengua extranjera tradicional y el asistido por ordenador en universidades chinas

[ES] El tema de esta investigación es el desarrollo de un estudio comparativo del modelo de enseñanza del español como lengua extranjera tradicional y el asistido por ordenador en universidades chinas. Con el desarrollo de la tecnología web en los últimos años, el formato del aula no se limita a la modalidad tradicional, sino que la modalidad de enseñanza asistida por ordenador también se está convirtiendo en la principal forma de enseñanza. Esta investigación principalmente toma como trasfondo el aprendizaje del español como lengua extranjera, tomando como ejemplo las universidades chinas, y compara el modelo tradicional y la modelo de enseñanza asistida por ordenador. Uno de nuestros objetivos es proponer y presentar una modalidad de enseñanza combinada, analizar su viabilidad y desarrollo futuro. Debido a que los dos modelos de enseñanza tienen sus propias ventajas y desventajas, se debe incorporar las fortalezas de cada uno y compensar sus debilidades. Uno de los objetivos, por tanto, sería presentar un nuevo modelo de enseñanza basado en la mezcla de ambos modelos comentados anteriormente. Dicho modelo no está centrado en el profesor, sino en el alumno. Además, no solo se presta atención a la enseñanza de los profesores, sino también al aprendizaje de los estudiantes, aumentando la iniciativa y la pasión tanto de los profesores como de los estudiantes.[EN] The subject of this research is the development of a comparative study of the traditional model of teaching Spanish as a foreign language and the computer-assisted one in Chinese universities. With the development of web technology in recent years, the classroom format is not limited to the traditional mode, but the computer-assisted mode of teaching is also becoming the main way of teaching. This research mainly takes as a background the learning of Spanish as a foreign language, taking Chinese universities as an example, and compares the traditional model and the computer-assisted teaching model. One of our objectives is to propose and present a combined teaching modality, analyze its viability and future development. Because the two teaching models have their own advantages and disadvantages, you must incorporate each other's strengths and compensate for their weaknesses. One of the objectives, therefore, would be to present a new teaching model based on the mixture of both models discussed above. This model is not centered on the teacher, but on the student. In addition, attention is paid not only to teachers' teaching, but also to student learning, increasing the initiative and passion of both teachers and students.Fan, Y. (2021). Análisis comparativo del modelo de enseñanza del español como lengua extranjera tradicional y el asistido por ordenador en universidades chinas. Universitat Politècnica de València. http://hdl.handle.net/10251/174834TFG

Farmers’ Adoption and Perceived Benefits of Diversified Crop Rotations in the Margins of U.S. Corn Belt

Monoculture and simplified two-crop rotation systems compromise the ecosystem services essential to crop production, diminish agricultural productivity, and cause detrimental effects on the environment. In contrast to the simplified two-crop rotation, diversified crop rotation (DCR) refers to rotation systems that contain three or more crops. Despite multiple benefits generated by DCR, its usage has dwindled over the past several decades. This paper examined determinants of farmers\u27 adoption decisions and perceived benefits of DCR in the west margins of the U.S. Corn Belt where crop diversity has declined. We analyzed 708 farmer responses from a farmer survey conducted in the eastern South Dakota in 2018, accounting for county-level climate variables, as well as cropland data, soil and topographic variables in close proximity of the farm. Our findings indicated that farmers were more likely to utilize DCR as an adaptive strategy to cope with water deficit and reduce soil erosion on marginal land. Additionally, livestock integration and organic farming helped necessitate DCR adoption and magnify its benefits. Producer concerns towards lack of equipment and new crop profitability diluted producers’ interests in DCR practice and compromised its benefits. Enhanced technical and policy support, along with infrastructure and market development, could help producers fully utilize DCR benefits and expand DCR usage to more regions

Acetylome analyses provide novel insights into the effects of chronic intermittent hypoxia on hippocampus-dependent cognitive impairment

IntroductionChronic intermittent hypoxia (CIH) can negatively affect hippocampal function through various molecular mechanisms. Protein acetylation, a frequently occurring modification, plays crucial roles in synaptic plasticity and cognitive processes. However, the global protein acetylation induced by CIH in the hippocampus and its specific effects on hippocampal function and behavior remain poorly understood.MethodsTo address this gap, we conducted a study using liquid chromatography-tandem mass spectrometry to analyze the lysine acetylome and proteome of the hippocampus in healthy adult mice exposed to intermittent hypoxia for 4 weeks (as a CIH model) compared to normoxic mice (as a control).ResultsWe identified and quantified a total of 2,184 lysine acetylation sites in 1,007 proteins. Analysis of these acetylated proteins revealed disturbances primarily in oxidative phosphorylation, the tricarboxylic acid (TCA) cycle, and glycolysis, all of which are localized exclusively to mitochondria. Additionally, we observed significant changes in the abundance of 21 proteins, some of which are known to be associated with cognitive impairments.DiscussionThis study helps to elucidate the molecular mechanisms underlying CIH-induced changes in protein acetylation in the hippocampus. By providing valuable insights into the pathophysiological processes associated with CIH and their impacts on hippocampal function, our findings contribute to a better understanding of the consequences of CIH-induced changes in protein acetylation in the hippocampus and the potential role of CIH in cognitive impairment

Triphenylphosphine-Based Covalent Organic Frameworks and Heterogeneous Rh-P-COFs Catalysts

The synthesis of phosphine-based functional covalent organic frameworks (COFs) has attracted great attention recently. Herein, we present two examples of triphenylphosphine-based COFs (termed P-COFs) with well-defined crystalline structures, high specific surface areas, and good thermal stability. Furthermore, rhodium catalysts with these P-COFs as support material show high turnover frequency for the hydroformylation of olefins, as well as excellent recycling performance. This work not only extends the phosphine-based COF family, but also demonstrates their application in immobilizing homogeneous metal-based (e.g., Rh-phosphine) catalysts for application in heterogeneous catalysis

Folate-deficiency induced acyl-CoA synthetase short-chain family member 2 increases lysine crotonylome involved in neural tube defects

Maternal folate deficiency increases the risk of neural tube defects (NTDs), but the mechanism remains unclear. Here, we established a mouse model of NTDs via low folate diets combined with MTX-induced conditions. We found that a significant increase in butyrate acid was observed in mouse NTDs brains. In addition, aberrant key crotonyl-CoA-producing enzymes acyl-CoA synthetase short-chain family member 2 (ACSS2) levels and lysine crotonylation (Kcr) were elevated high in corresponding low folate content maternal serum samples from mouse NTD model. Next, proteomic analysis revealed that folate deficiency led to global proteomic modulation, especially in key crotonyl-CoA-producing enzymes, and dramatic ultrastructural changes in mouse embryonic stem cells (mESCs). Furthermore, we determined that folate deficiency induced ACSS2 and Kcr in mESCs. Surprisingly, folic acid supplementation restored level of ACSS2 and Kcr. We also investigated overall protein post-translational Kcr under folate deficiency, revealing the key regulation of Kcr in glycolysis/gluconeogenesis, and the citric acid cycle. Our findings suggest folate deficiency leads to the occurrence of NTDs by altering ACSS2. Protein crotonylation may be the molecular basis for NTDs remodeling by folate deficiency

Rural Households’ Willingness to Pay for Improving Environmental Quality in China: A Double-Hurdle Approach

Introduction and hypothesis Economic growth and welfare increase motivate people’s willingness to improve environmental quality including rural residents in China. Rural households have been active in implementing Rural Revitalization Strategy promoted as a national development initiative since 2017. Along with the urbanization strategy, the new initiative will direct and dominate rural development for the coming decades with immense policy and financial support from both central and provincial governments (Wang and Zhuo, 2018). Implementation and effectiveness of government policies have been limited, and participatory approaches have been promoted focusing on self-governance of communities and stakeholders. In addition to the policy and financial support, rural households can greatly increase the success of the national rural development initiative with their active participation and investment. While government finance typically focuses on municipal infrastructures, individual households may be willing to invest in improving surrounding environments including trash disposal, sewerage treatment, greening, etc. Moreover, the willingness to pay (WTP) for environmental quality may be affected by people’s awareness of and attitude to environmental quality problems. While most previous literature have documented WTP for ecosystem services, the WTP for environmental quality improvement is still understudied, in particular, from the perspective of Chinese rural households. The primary objective of this study is to investigate the WTP of rural households for improving living environment and examine effects of influential factors on WTP using a double-hurdle model accounting for heteroscedasticity concerning separate decisions. We used a conceptual model to link awareness of environmental problems with rural households’ WTP for improving environmental quality. Households’ WTP decisions can be associated with factors in four categories: 1) household characteristics, 2) living conditions and health status, 3) attitudes to environmental problems, and 4) information sources. Based on the literature, the following variables were hypothesized to affect WTP decisions: age (−), higher education (+), household size (+), senior or youth (+), higher household income (+), higher household expenditure (−), adopting sustainable farming practices (+), satisfaction and happiness with current living conditions (+), better health status (+), better air quality (−), better housing condition (+), poor awareness of environmental protection (+), pesticide and fertilizers causing environmental problems (+), and more information from government, TV, internet, and neighbors (+). Data and methods We used data from a rural households survey conducted in December 2018. The data were collected from Fujian, Henan, and Sichuan provinces, representing eastern, middle, and western regions of China. The questionnaire includes detailed information on individual and household-level characteristics, agricultural production and marketing, household members’ health and living conditions, attitude to air quality change, living environment change, housing condition change, awareness of environmental problems, decisions and willingness to pay for environmental quality improvement, information sources, etc. The survey focused on rural households with agricultural production, while excluding city residents, because we are more interested in how rural households make decisions to complement the national initiative for rural development. We employed a double-hurdle model to account for the separate decision making of rural households. Two steps were considered: an individual decides whether to pay for environmental improvement and the amount of payment he/she would like to make. The command churdle exponential in Stata software allowed us to jointly estimate a participation decision (Yes=1, No=0) with a payment decision (continuous variable) with the het option to account for selection variance. Marginal effects were estimated and interpreted for each of the independent variables. Results Among the 820 respondents, about 61% would like to pay for environmental improvement with an average payment of 261 yuan (7 yuan ≈ 1 USD). Regarding the participation, people who are more happy with current living, having better health status, better environment condition, aware of poor environmental planning, and living in eastern region are more likely to participate in the public investment in environmental improvements. People who have better education, higher household income, better health condition, more information from government and internet are more likely to pay more for the environmental improvement

Adoption of Pressure Irrigation Systems and Scientific Irrigation Scheduling Practices by U.S. Farmers: An Application of Multilevel Models

Water scarcity is becoming more acute, necessitating better understanding of farmer adoption of improved irrigation technologies. Using data from the national 2013 Farm and Ranch Irrigation Survey, this study employs a multilevel modeling approach to analyze irrigation decisions. The variation in pressure irrigation adoption is mainly accounted for by state-level factors, while adoption of scientific scheduling practices is more associated with farm-level factors. Adoption increases with larger acreage, groundwater use, information sources other than neighbors, and recent higher temperatures. Adoption is negatively associated with on-farm surface water and barriers related to increased costs, management time, and time horizon