Spatial and Temporal On-Farm Risk Management - Crop Production Scheduling and Index Insurance Strategies

An agronomic crop growth model, Decision Support System for Agro-Technology Transfer (DSSAT), is used to find optimal crop management strategies for cotton production in Mitchell, Miller, and Lee Counties in Georgia during the past 10 years. Planting date and irrigation threshold are the two variables optimized to maximize farmer's expected utility. A decreasing absolute risk aversion - constant relative risk aversion (DARA-CRRA) utility function is used to examine crop management decision that can be influenced by changes in inter-temporal risk behavior. Comparison is made from management perspective - one is dynamic crop management strategy that varies each year; one is static (constant) strategy over 10 years. Based on the best crop management strategies, index insurance products are designed to help farmers further reduce production risk. The impact of geographical basis risk was assessed by comparing the risk reduction generated from index insurance contracts based on different weather stations; the impact of temporal basis risk is assessed by allowing separate contracts to be purchased for different sub-periods during the entire period.Irrigation, Planting Date, Risk Management, Weather Derivative Contract, Basis Risk, Agribusiness, Agricultural Finance, Crop Production/Industries, Farm Management, Financial Economics, Risk and Uncertainty,

Farm-Level Risk Management Using Irrigation and Weather Derivatives

An agronomic crop growth model—the Decision Support System for Agro-Technology Transfer—and a constant relative risk aversion utility function are used to examine corn irrigation strategies in Mitchell County, Georgia. Precipitation contracts are designed to help farmers manage risk. Three conclusions originate from the findings. First, the optimal irrigation strategy can greatly increase producers’ certainty-equivalent revenue. Second, changes in water pricing policy would have a limited impact on the amount of water used. And third, across levels of risk preference, the precipitation contracts are not effective in increasing certainty-equivalent revenue or reducing cumulative water use.irrigation risk management, water pricing policy, weather derivative contract, Agribusiness, Environmental Economics and Policy, Farm Management, Food Consumption/Nutrition/Food Safety, D8, G22, Q15, Q25,

Dynamic Optimization of Area Revenue Insurance and Consumption Smoothing

This study examines the interaction between insurance, credit and liquidity constraints using a stochastic dynamic model. A risk averse farmer whose objective is to manage both production and market risk is assumed to maximize the expected utility of life-time consumption by using both area revenue (AR) insurance and consumption smoothing subject to a credit constraint. The dynamic programming is coded in MATLAB using DDPSOLVE algorithm (Appendix a). DSSAT crop simulation model is used to determine optimal irrigation strategy and to simulate farm level yield. A Bayesian Model is used to estimate expected county-level revenue. The approach and results are illustrated via a numerical example using county level data from Mitchell County in Georgia. Results support the hypothesis that liquidity constraints can have a large impact on optimal insurance decisions, and that different levels of premium load, risk aversion level, and time-preferences can also affect optimal insurance decisions under liquidity constraints.Area Revenue Insurance, Consumption Smoothing, Credit Risk, Dynamic Optimization, Bayesian Modeling, Agricultural Finance, Farm Management, Financial Economics,

Spatio-vertical characterization of the BTEXS group of VOCs in Chinese agricultural soils

Ubiquitous contamination of the BTEXS (benzene, toluene, ethylbenzene, xylene, and styrene) group in soils is a significant concern for ecological safety. However, comprehensive spatio-vertical survey of the BTEXS group on a national scale is rare to date. Using a static headspace gas chromatography–mass spectrometry method (HS-GCMS), this study performed a quantitative analysis of BTEXS levels in soils from Chinese rural areas in 2013 and 2016. The median ∑BTEXS concentrations in surface soils in 2013 and 2016 were 37.5 and 34.4 ng g^(−1) dry weight, respectively. Toluene was the dominant pollutant, accounting for approximately 41.6% and 32.1% of the total levels. BTEXS contamination was higher in Shanxi province, Northeast China, and Yunnan-Guizhou Plateau compared to the other regions. Vertically, toluene, m,p′-xylene and o′-xylene concentrations were significantly higher in the top soil layer (0–15 cm) and decreased significantly with increasing soil depth (p < 0.05). Higher soil organic matter was significantly associated with higher BTEXS concentrations of sampling site. BTEXS was also enhanced at sites with higher elevations and lower temperature due to global distillation effects. The findings of this study could help decision-makers to protect against BTEXS contamination in rural areas. These findings provide a basis for further study of the mechanism of BTEXS migration and transport in large-scale environment

Numerical Simulations of Magnetic Effects on Zonal Flows in Giant Planets

Jupiter and Saturn exhibit alternating east-west jet streams as seen from surface. The origin of these zonal flows has been debated for decades. The high-precision gravity measurements by Juno mission and the grand finale of Cassini mission have revealed that the zonal flows observed at the surface may extend several thousand kilometres deep and stop around the transition region from molecular to metallic hydrogen, suggesting the magnetic braking effect on zonal flows. In this study, we perform a set of magnetohydrodynamic simulations in a spherical shell with radially variable electrical conductivity to investigate the interaction between magnetic fields and zonal flows. A key feature of our numerical models is that we impose a background dipole magnetic field on the anelastic rotating convection. By varying the strength of the imposed magnetic field and the vigor of convection, we investigate how the magnetic field interacts with the convective motions and the convection-driven zonal flows. Our simulations reveal that the magnetic field tends to destroy zonal flows in the metallic hydrogen and suppress zonal flows in the molecular envelope, while the magnetic field may enhance the radial convective motions. We extract a quantitative relation between the magnetic field strength and the amplitude of zonal flows at the surface through our simulations, which roughly matches the observed magnetic field and zonal wind speed of Jupiter and Saturn. This discovery provides support from a new perspective for the scenario of deep convection-driven zonal winds which are confined to the molecular hydrogen layers in giant planets.Comment: accepted for publication in JGR:planet

NF-kappa B mediated Up-regulation of CCCTC-binding factor in pediatric acute lymphoblastic leukemia

BACKGROUND: Acute lymphoblastic leukemia (ALL) is the most frequently occurring malignant neoplasm in children. Despite advances in treatment and outcomes for ALL patients, the pathogenesis of the disease remains unclear. Microarray analysis of samples from 100 Chinese children with ALL revealed the up-regulation of CTCF (CCCTC binding factor). CTCF is a highly conserved 11-zinc finger protein that is involved in many human cancers; however, the biological function of CTCF in pediatric ALL is unknown. METHODS: The expression patterns of CTCF were evaluated in matched newly diagnosed (ND), complete remission (CR), and relapsed (RE) bone marrow samples from 28 patients. The potential oncogenic mechanism of CTCF and related pathways in leukemogenesis were investigated in leukemia cell lines. RESULTS: We identified significant up-regulation of CTCF in the ND samples. Importantly, the expression of CTCF returned to normal levels after CR but rebounded in the RE samples. In the pre-B ALL cell line Nalm-6, siRNA-mediated silencing of CTCF expression promoted cell apoptosis and reduced cell proliferation; accordingly, over-expression of a cDNA encoding full-length CTCF protected cells from apoptosis and enhanced cell proliferation. Furthermore, inhibition or activation of the nuclear factor-kappa B (NF-κB) pathway resulted in marked variations in the levels of CTCF mRNA and protein in leukemic cells, indicating that CTCF may be involved downstream of the NF-κB pathway. Moreover, inhibition of the NF-κB pathway increased cell apoptosis, which was partially rescued by ectopic over-expression of CTCF, suggesting that CTCF may play a significant role in the anti-apoptotic pathway mediated by NF-κB. CONCLUSIONS: Our results indicate that CTCF serves as both an anti-apoptotic factor and a proliferative factor in leukemic cells. It potentially contributes to leukemogenesis through the NF-κB pathway in pediatric ALL patients

Population transcriptomes reveal synergistic responses of DNA polymorphism and RNA expression to extreme environments on the Qinghai-Tibetan Plateau in a predatory bird

Low oxygen and temperature pose key physiological challenges for endotherms living on the Qinghai–Tibetan Plateau (QTP). Molecular adaptations to high‐altitude living have been detected in the genomes of Tibetans, their domesticated animals and a few wild species, but the contribution of transcriptional variation to altitudinal adaptation remains to be determined. Here we studied a top QTP predator, the saker falcon, and analysed how the transcriptome has become modified to cope with the stresses of hypoxia and hypothermia. Using a hierarchical design to study saker populations inhabiting grassland, steppe/desert and highland across Eurasia, we found that the QTP population is already distinct despite having colonized the Plateau <2000 years ago. Selection signals are limited at the cDNA level, but of only seventeen genes identified, three function in hypoxia and four in immune response. Our results show a significant role for RNA transcription: 50% of upregulated transcription factors were related to hypoxia responses, differentiated modules were significantly enriched for oxygen transport, and importantly, divergent EPAS1 functional variants with a refined co‐expression network were identified. Conservative gene expression and relaxed immune gene variation may further reflect adaptation to hypothermia. Our results exemplify synergistic responses between DNA polymorphism and RNA expression diversity in coping with common stresses, underpinning the successful rapid colonization of a top predator onto the QTP. Importantly, molecular mechanisms underpinning highland adaptation involve relatively few genes, but are nonetheless more complex than previously thought and involve fine‐tuned transcriptional responses and genomic adaptation

Towards More Authentic Heritage Destination Experiences

Heritage destinations have a significant responsibility to visitors. In countries like China, where heritage plays a significant role in a person\u27s identity, such destinations offer visitors an opportunity to develop a deeper sense of self. For this reason, they need to be authentic, but so do the visitors. UCF Rosen College of Hospitality Management researcher Dr. Xiaoxiao Fu joined a team of experts based in China to identify how the perceived authenticity of two of China\u27s most revered heritage sites affects visitors\u27 personal sense of authenticity, their wellbeing, and how memorable they found their visits