ASSESSING THE DEMAND FOR WEATHER INDEX INSURANCE IN SHANDONG PROVINCE, CHINA

Shandong Province, renowned as China’s greatest agricultural province, is dominated by smallholders growing rain-fed crops and vulnerable to severe weather shocks that can increase poverty rates. Weather index insurance, an innovative agricultural risk management product, may be an effective mechanism to address vulnerability to catastrophic weather risk in rural regions of China, including Shandong. This project evaluated current household livelihood and risk management strategies and farmer interest in weather index insurance. Data from 174 participants were collected using a methodology that included focus groups, questionnaires, and personal interviews. Despite limited access to formal financial services, Shandong farmers generally employ informal, well-diversified income strategies and rely on no-interest informal loans from community members to manage adverse impacts of natural disasters, such as drought. Households sometimes rely on reducing consumption as a risk coping strategy; however, unlike many regions of the world, Shandong farmers do not tend to sell livelihood assets to manage weather shocks. A majority of interviewed participants were interested in weather index insurance after they understood its basic concept; however, participants expressed concerns regarding basis risk and program implementation

Yeast Chemical Genetics For Identifying Regulators of Late Secretory Traffic Pathways

Abstract The intracellular transport of proteins and membrane lipids to the cell surface or between organelles is a fundamental process in eukaryotic cells. This process is required for the biogenesis and maintenance of organelles, as well as for traffic to the cell surface for cell growth and proliferation. The transport routes in the late secretory pathways are branched and complex, and their regulation requires sensing and responding to environmental conditions for proper control of cell growth. Both the transport and regulatory mechanisms are robust, so that defects can be overcome by alternate mechanisms. This complexity has made it difficult to identify the late exocytic transport machinery and its regulators. The goal of my thesis work was to use a yeast chemical genetic strategy to identify components of the exocytic transport machinery, and to generate useful chemical tools that will help us to understand how the machinery functions. I analyzed the effects of small molecules that we obtained in two similar high-throughput screens of large libraries of drug-like compounds, in order to identify compounds that cause a block in the late exocytic pathway. Several of our new compounds cause exocytic defects and are selectively toxic to yeast mutants in which one of numerous transport pathways are blocked. The design of the highthroughput screen strategy was based on that of an earlier mutant screen that led to the discovery of a novel component of the transport machinery, Avl9, a conserved eukaryotic protein that has not yet been well characterized. Some of our new compounds are expected to target Avl9 or proteins with functions related to that of Avl9. In order to identify proteins and processes affected by our compounds, I screened for genes which, when overexpressed, can suppress the toxic effects of our compounds. I found that highly-expressed GTR2, which encodes a Ras-family small GTPase, can suppress the effects of one of our compounds. Gtr2 and its paralog and binding partner, Gtr1, as well as their metazoan orthologs, signal nutrient availability to regulate both traffic and the activity of TOR (target of rapamycin) kinase, a master regulator of growth. Furthermore, the gtr1Δ and gtr2Δ mutants share some phenotypes with the avl9Δ mutant. Our results indicate that our new compounds will serve as tools to help us understand how Avl9 and Gtr proteins function in cellular response to environmental conditions for proper regulation of protein and membrane transport in the late exocytic pathway

Pectin degradation by Botrytis cinerea: recognition of endopolygalacturonases by an Arabidopsis receptor and utilization of Dgalacturonic acid

The necrotrophic fungal plant pathogenBotrytis cinerea is able to infect over 200 host plants and cause severe damage to crops, both pre- and post-harvest. B. cinerea often penetrates host leaf tissue at the anticlinal cell wall and subsequently grows into and through the middle lamella, which consists mostly of low-methylesterified pectin. Effective pectin degradation thus is important for virulence of B. cinerea. Chapter 1 describes the chemical structures of plant cell wall polysaccharides, the cell wall-associated mechanisms that confer resistance against pathogens, and the microbial enzymes involved in cell wall decomposition. It then discusses the plant cell wall degrading enzymes of pathogenic fungi and illustrates with case studies the process of pectin decomposition by B. cinerea. Chapter 2describes the molecular identification and functional characterization of a novel MAMP receptor RBPG1, a Leucine-Rich Repeat Receptor-Like Protein (LRR-RLP), that recognizes fungal endo-polygalacturonases (endo-PGs), in particular the B. cinerea protein BcPG3. Infiltration of the BcPG3 protein into Arabidopsis thaliana accession Col-0 induced a necrotic response. Heat-inactivated protein and a catalytically inactive mutant protein retained the ability to induce necrosis. An 11-amino acid peptide stretch was identified that is conserved among many fungal but not plant endo-PGs. A synthetic peptide comprising this sequence was unable to induce necrosis. A map-based cloning strategy, combined with comparative and functional genomics, led to the identification of the RBPG1 gene, which is required for responsiveness of A. thaliana to the BcPG3 protein. Co-immunoprecipitation experiments demonstrated that RBPG1 and BcPG3 form a complex inNicotiana benthamiana, which also involves the A. thaliana LRR-RLK SOBIR1. The sobir1 mutant plants no longer respond to BcPG3. Furthermore, overexpression of RBPG1 in the BcPG3-non-responsive accession Br-0 did not enhance resistance to a number of microbial pathogens. Chapter 3describes the functional, biochemical and genetic characterization of the D-galacturonic acid catabolic pathway in B. cinerea. The B. cinerea genome contains two non-homologous galacturonate reductase genes (Bcgar1 and Bcgar2), a galactonate dehydratase gene (Bclgd1), and a 2-keto-3-deoxy-L-galactonate aldolase gene (Bclga1). Targeted gene replacement of all four genes in B. cinerea, either separately or in combinations, yielded mutants that were affected in growth on D-galacturonic acid, pectate, or pectin as the sole carbon source. The extent of growth reduction of the mutants on pectic substrates was positively correlated to the proportion of D-galacturonic acid present in the pectic substrate. The virulence of these mutants on different host plants is discussed in Chapter 4. These mutants showed reduced virulence on N. benthamiana and A. thaliana leaves, but not on tomato leaves. The cell walls of N. benthamiana and A. thaliana leaves have a higher D-galacturonic acid content as compared to tomato. Additional in vitro growth assays with the knockout mutants suggested that the reduced virulence of D-galacturonic acid catabolism-deficient mutants on N. benthamiana and A. thaliana is not only due to the inability of the mutants to utilize an abundant carbon source as nutrient, but also due to the growth inhibition by catabolic intermediates. In Chapter 5, the functional characterization of two putative D-galacturonic acid transporters is presented. Bchxt15 is highly and specifically induced by D-galacturonic acid, whereas Bchxt13 is highly expressed in the presence of all carbon sources tested except for glucose. Subcellular localization of BcHXT13-GFP and BcHXT15-GFP fusion proteins expressed under their native promoter suggests that the fusion proteins are localized in plasma membranes and intracellular vesicles. Knockout mutants in the Bchxt13 and Bchxt15 genes, respectively, were neither affected in their growth on D-galacturonic acid as the sole carbon source, nor in their virulence on tomato and N. benthamiana leaves. Chapter 6describes the genome-wide transcriptome analysis in B. cinerea grown in media containing glucose and pectate as sole carbon sources. Genes were identified that are significantly altered in their expression during growth on these two carbon sources. Conserved sequence motifs were identified in the promoters of genes involved in pectate decomposition and D-galacturonic acid utilization. The role of these motifs in regulating D-galacturonic acid-induced expression was functionally analysed in thepromoter of the Bclga1 gene, which encodes one of the key enzymes in the D-galacturonic acid catabolic pathway. The regulation by D-galacturonic acid required the presence of sequences encompassing the GAE1 motif and a binding motif for the pH-dependent transcriptional regulator PacC. Chapter 7 provides a general discussion of the results presented in this thesis. A model of the concerted action of pectin degradation and subsequent monosaccharide consumption and co-regulation of gene expression is proposed.</p

Research on vibration characteristics of gear-coupled multi-shaft rotor-bearing systems under the excitation of unbalance

To find out the effect of eccentricity of a gear wheel on inherent characteristics of a gear-rotor system, this paper establishes a pair of general transverse-rotational-axial-swinging multi degrees of freedom coupling helical gear meshing dynamic model based on the finite element method (FEM). Considering the influence of the azimuth, the meshing angle, the helix angle and the rotation direction of driving shaft on mesh stiffness matrix, it analyzes the effect of mesh stiffness and mesh damping on the inherent characteristics and the transient response of the system. It obtains the displacement response curve and the dynamic meshing force curve of all nodes responding to the incentives of static transmission error and unbalance while considering mesh damping. It concludes that the effects of gear coupling and eccentricity of gear wheel should be taken into account in a multi-parallel-shaft gear meshing rotor system

Evaluating the Influence of Spatial Resampling for Motion Correction in Resting-State Functional MRI

Head motion is one of major concerns in current resting-state functional MRI studies. Image realignment including motion estimation and spatial resampling is often applied to achieve rigid-body motion correction. While the accurate estimation of motion parameters has been addressed in most studies, spatial resampling could also produce spurious variance, and lead to unexpected errors on the amplitude of BOLD signal. In this study, two simulation experiments were designed to characterize these variance related with spatial resampling. The fluctuation amplitude of spurious variance was first investigated using a set of simulated images with estimated motion parameters from a real dataset, and regions more likely to be affected by spatial resampling were found around the peripheral regions of the cortex. The other simulation was designed with three typical types of motion parameters to represent different extents of motion. It was found that areas with significant correlation between spurious variance and head motion scattered all over the brain and varied greatly from one motion type to another. In the last part of this study, four popular motion regression approaches were applied respectively and their performance in reducing spurious variance was compared. Among them, Friston 24 and Voxel-specific 12 model (Friston et al., 1996), were found to have the best outcomes. By separating related effects during fMRI analysis, this study provides a better understanding of the characteristics of spatial resampling and the interpretation of motion-BOLD relationship

Novel Self-Healable Thermosets and Their Carbon Fiber Reinforced Polymer (CFRP) Composites

Intrinsically self-healing polymers allow repeatable damage repair of a fracture located within materials without the need for external additives. Self-healing polymers possess promising potential for numerous structural applications, such as the construction, automobile, and aerospace industries, due to their capability to reduce system maintenance requirements and increase the longevity and safety of the composite structures. The healing capacity of the polymers is derived from the formation of covalent bonds between reactive components at the fracture spot. These reactive components are typically varied in their chemical structures and are dependent on the employed healing chemistry, therefore a variety of new chemistries have been reported. However, current self-healing polymers either 1) undergo significant thermal degradation at elevated temperatures, or 2) lose their mechanical strength and stiffness above their typically low glass transition temperature and are thus limited by the healing chemistry. Developing a new healing chemistry which exhibits thermal stability and maintains mechanical properties and mechanical stability at a higher temperature range is of great importance for the development of high-performance self-healing materials for structural applications and has been a long lasting challenge in the composites research field. This dissertation details the discovery of a novel healing chemistry with stability at high temperature, based on which new self-healing materials with significantly improved high-temperature performance and mechanical stability have been developed. Initially, this new healing chemistry of isocyanurate-to-oxazolidone transformation is studied both in model compounds and in the polymer network, where the instability of isocyanurate in the presence of epoxide is confirmed. The isocyanurate-to-oxazolidone transformation is then embedded in isocyanurate-oxazolidone (ISOX) polymers and the polymerization mechanism of the ISOX polymers, including the initiation, cross-linking, and network propagation is further investigated. Based on the understanding of the polymerization mechanism, a two-step curing procedure is designed for the ISOX polymers to ensure the presence of a large amount of two reactive components, isocyanurate and epoxide, for the isocyanurate-to-oxazolidone transformation within the polymers. Combined chemical characterization through Fourier-transform infrared (FTIR) spectroscopy and carbon nuclear magnetic resonance (NMR) spectroscopy is performed in order to quantify the chemical composition of the ISOX polymers, including the isocyanurate fraction which can be controlled through both the nucleophilicity of the polymerization catalyst and the duration of the post-cure of the polymers. Secondly, the developed ISOX polymers are evaluated and shown to achieve damage repair in the presence of a macroscopic crack, yielding considerable recovery of polymer strength after thermal annealing which is repeatable over multiple damage-repair cycles. The study on structure-property relationship of the ISOX polymers shows that the material properties of the polymers are uncompromised with the addition of the self-healing functionality, as their excellent mechanical properties and high-temperature performance remain comparable to that of an engineering grade epoxy. Lastly, self-healing carbon fiber reinforced polymer (CFRP) composites are developed using the ISOX polymers as the matrix material. After multiple delamination events, repeatable strength recovery of the composites has been demonstrated with a first healing efficiency of up to 85% after thermal treatment. The strength and stiffness of the composites are comparable to those of engineering grade polymer matrix composites typically used in aerospace applications, while their thermal stability places them in the polybismaleimide performance region. This dissertation details the development of novel self-healing materials which have great potential for advanced structural applications in extreme environments.PHDMacromolecular Science & EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/155070/1/zhalisha_1.pd

Associations of pre-hospital statin treatment with in-hospital outcomes and severity of coronary artery disease in patients with first acute coronary syndrome-findings from the CCC-ACS project

BackgroundThe current burden of dyslipidemia, the pre-hospital application of statins and the association of pre-hospital statins with the severity of coronary artery disease (CAD) and in-hospital outcomes in Chinese patients with first acute coronary syndrome (ACS) are very significant and remain unclear.MethodsA total of 41,183 patients who underwent coronary angiography and were diagnosed with ACS for the first time from a nationwide registry study (CCC-ACS) were enrolled. The severity of CAD was assessed using the CAD prognostic index (CADPI). The patients were classified into statin and non-statin groups according to their pre-hospital statin treatment status. Clinical characteristics, CADPI and in-hospital outcomes were compared, and a logistic regression analysis was performed to determine whether pre-hospital statin therapy is associated with in-hospital outcomes and CADPI. A sensitivity analysis was used to further explore the issues above.ResultsThe non-statin group had more in-hospital all-cause deaths (1.2 vs. 0.8%, P = 0.010). However, no association exists between statin pretreatment and in-hospital major adverse cardiovascular events (MACEs) or all-cause deaths in the entire population and subgroups (all P &gt; 0.05). Surprisingly, statin pretreatment was associated with an 8.9% higher risk of severely obstructive CAD (CADPI ≥ 37) (OR, 1.089; 95% CI, 1.010–1.175, P = 0.028), and similar results were observed in subgroups of females, those aged 50 to 75 years, and patients with hypertension.ConclusionStatin pretreatment was not related to MACEs or all-cause death during hospital stay, but it was associated with a higher risk of increased angiographic severity in patients with first ACS

Myricetin promotes peripheral nerve regeneration in rat model of sciatic nerve injury via regulation of BDNFAkt/ GSK-3β/mTOR signalling pathway

Purpose: To investigate the effects of myricetin on peripheral nerve regeneration in sciatic nerve crush injury model.Methods: Separate groups of rats were administered myricetin at 25, 50 or 100 mg/kg body weight/day for 2 weeks. Functional recovery following sciatic nerve injury was assessed by foot position and walking track analyses, measurement of mechanical hyperalgesia, and withdrawal reflex latency (WRL).Results: Myricetin treatment resulted in significantly enhanced recovery of sensorimotor functions as evidenced by increased scores in functional analysis tests. Myricetin treatment remarkably elevated brain derived neurotrophic factor (BDNF) expression, and also enhanced activation of Akt and mTORc1, reflecting up-regulation of PI3K/Akt/mTORC1 signalling involved in nerve regeneration.Conclusion: Myricetin enhances functional recovery and nerve regeneration in rats. These findings suggest that myricetin is a potent neuroprotective agent with potential for the management of peripheral nerve injury.Keywords: Glycogen synthase kinase 3β, Mammalian target of rapamycin (mTOR), Myricetin, Nerve regeneratio