Predicting spatiotemporal yield variability to aid arable precision agriculture in New Zealand : a case study of maize-grain crop production in the Waikato region : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Agriculture and Horticulture at Massey University, Palmerston North, New Zealand

Precision agriculture attempts to manage within-field spatial variability by applying suitable inputs at the appropriate time, place, and amount. To achieve this, delineation of field-specific management zones (MZs), representing significantly different yield potentials are required. To date, the effectiveness of utilising MZs in New Zealand has potentially been limited due to a lack of emphasis on the interactions between spatiotemporal factors such as soil texture, crop yield, and rainfall. To fill this research gap, this thesis aims to improve the process of delineating MZs by modelling spatiotemporal interactions between spatial crop yield and other complementary factors. Data was collected from five non-irrigated field sites in the Waikato region, based on the availability of several years of maize harvest data. To remove potential yield measurement errors and improve the accuracy of spatial interpolation for yield mapping, a customised filtering algorithm was developed. A supervised machine-learning approach for predicting spatial yield was then developed using several prediction models (stepwise multiple linear regression, feedforward neural network, CART decision tree, random forest, Cubist regression, and XGBoost). To provide insights into managing spatiotemporal yield variability, predictor importance analysis was conducted to identify important yield predictors. The spatial filtering method reduced the root mean squared errors of kriging interpolation for all available years (2014, 2015, 2017 and 2018) in a tested site, suggesting that the method developed in R programme was effective for improving the accuracy of the yield maps. For predicting spatial yield, random forest produced the highest prediction accuracies (R² = 0.08 - 0.50), followed by XGBoost (R² = 0.06 - 0.39). Temporal variables (solar radiation, growing degree days (GDD) and rainfall) were proven to be salient yield predictors. This research demonstrates the viability of these models to predict subfield spatial yield, using input data that is inexpensive and readily available to arable farms in New Zealand. The novel approach employed by this thesis may provide opportunities to improve arable farming input-use efficiency and reduce its environmental impact

Relationship between driver gene mutations and clinical pathological characteristics in older lung adenocarcinoma

ObjectivesLung adenocarcinoma (LUAD) is the most common newly diagnosed malignant tumor in older people. As older patients age, organ function decreases, leading to increased adverse reactions to treatment. The epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase tyrosine (ALK) tyrosine kinase inhibitors (TKIs) therapy are more effective and well-tolerated than chemotherapy, while the rate of genetic testing and subsequent targeted treatment among older patients remains relatively low, the clinical benefit limitation for those patients. This study aims to investigate the mutation characteristics of LUAD diver gene and its relationship with clinicopathological features in older LUAD.Materials and methodsA total of 275 patients were diagnosed as LUAD and were over sixty years old. We utilized next-generation sequencing technology to detect and analyze gene mutations in postoperative tissue specimens, including EGFR, KRAS, ALK, ROS1, RET, MET, BRAF, HER2, PIK3CA and NRAS.ResultsA total of 90.18% (248/275) of older LUAD patients experienced genetic mutations. The EGFR (192, 69.82%) had the highest mutation rate among ten genes, followed by KRAS (21, 7.64%), MET (21, 7.64%), ERBB2 (15, 5.45%), RET (9, 3.27%), ALK (8, 2.91%), ROS1 (8, 2.91%), PIK3CA (6, 2.18%), BRAF (5, 1.82%) and NRAS (1, 0.36%). We also found thirty patients (15.63%) with EGFR mutations also having other gene mutations. The L858R mutation and exon19 deletion were the predominant EGFR mutations, accounting for 84.90% of EGFR-mutated patients. In addition, fifty-one kinds of EGFR mutations were detected, distributed in the protein tyrosine kinase catalytic domain (43, 84.31%), cysteine enriched domain (4, 7.84%), receptor binding domain (3, 5.88%), and EGFR transmembrane domain (1,1.96%). Ten cases of gene fusion mutation were detected. Two rare partner genes, PKHD1 (P60:R34) and STK39 (R33:S11), were detected by ROS1 gene fusion. RET gene fusion revealed a rare companion gene KCND2 (R11:K2). The EGFR mutations were more prevalent in female, non-smoking patients (p < 0.05), and the KRAS mutations were more common in male and smoking patients (p < 0.01). In addition, the BRAF mutations were more likely to occur in the right lung (p < 0.05).ConclusionOlder LUAD populations exhibit diverse genetic mutations, which may also exist simultaneously. Simultaneous detection of multiple genes by NGS can accelerate and enhance targeted treatment benefits for older LUAD patients, ultimately improving their quality of life

Caspase polymorphisms and prognosis of hepatocellular carcinoma

The aim of our study was to determine the impact of genetic polymorphisms in the caspase (CASP) genes on prognosis of hepatocellular carcinoma (HCC). We genotyped 7 potentially functional polymorphisms in CASP3, CASP7, CASP8, CASP9, CASP10 genes in 362 HCC patients of receiving surgical resection of HCC tumor. The associations of genotype and haplotype with overall survival (OS) and disease free survival (DFS) were analyzed by using the Cox proportional hazards model. We found that the CASP9 rs4645981 C allele was significantly associated with positive effect on DFS (P = 0.011 and 0.016 for CT+CC vs. TT in univariate and multivariate analysis, respectively), CT genotype was associated with a better OS of HCC than the TT genotype both in univariate and multivariate analysis (P = 0.048 and 0.041, respectively). Moreover, the CASP3 rs2705897 GT genotype showed marginally significant association with decreased OS and DFS, compared with the GG genotype. One haplotype TT/TG in CASP3 (constructed by rs12108497 T>C and rs2705897 T>G) was significantly associated with decreased OS and DFS, compared to the common haplotype TT/TT both in univariate analysis (P = 0.021 and 0.026, respectively) and multivariate analysis (P = 0.025 and 0.030, respectively). The haplotype GT/GT in CASP9 (constructed by rs4645978 A>G and rs4645981 C>T) was significantly associated with decreased DFS both in univariate and multivariate analysis (P = 0.012 and 0.010, respectively). In conclusion, the CASP9 rs4645981 polymorphism, CASP3 and CASP9 haplotypes may be useful prognosis markers for HCC patients with surgical resection of tumor

Research on the System and Control Strategy of an AC-DC Hybrid Single-Phase Electric Energy Router

With the extensive development and use of new energy sources, it has become an urgent issue to solve the problem how to effectively use such energy sources. This paper designs a single-phase electric energy router (SPEER) whose main goal is to solve the problem of optimal operation of the home power system under a high penetration rate of new energy. First, a SPEER structure is presented which has an AC-DC hybrid form to meet the power requirements of all household electrical equipment. Compared with the existing structures, its structural design is more suitable for small-capacity systems, such as home power systems. Next, a reasonable, detailed, and feasible control scheme was designed for each part of the SPEER, so that it has the functions of plug and play, power routing, island detection, and synchronous grid connection, and a seamless coordination management scheme between subsystems was designed. Complete functions make it more intelligent in response to various conditions. Finally, the correctness of the designed SPEER and control strategy was verified by experiment

Effect of Adjuvants on the Wetting Behaviors of Bifenthrin Droplets on Tea Leaves

The hydrophobic epicuticle wax on fresh leaves of tea tree (Camellia sinensis (L.) 0. Kuntze) leads to the loss of pesticide droplets, reducing efficacy. In this study, four adjuvants were selected to improve the diffusion and adhesion of bifenthrin droplets on the surface of tea leaves at different growth stages. The coupling effect of bifenthrin and adjuvants on the time-dependent and concentration-dependent wettability of droplets was investigated, and the difference in the wettability between bud and leaf was explained by observing the surface morphology. It was found that adjuvants effectively reduced the contact angle of droplets and accelerated the diffusion speed, and the above phenomenon became obvious with the increase in the adjuvant concentration. The wetting promotion of young leaves was more significant due to the reduced epicuticle wax and the greater roughness compared with fresh buds. The surface tension of the pesticide mixture was negatively correlated with the cosine of contact angle after adding the four adjuvants regardless of the growth stage of tea leaves. The contact angle of 0.2% Silwet L-77 decreased to 0° within 10 s, but the extreme wettability led to the decrease in adhesion with the increase in concentration. However, the wettability and adhesion on the surface of tea leaves were simultaneously suitable with more than 0.1% nonionic surfactant. The minimum concentration of the optimal adjuvant proposed in this study can provide an experimental basis and guide more efficient plant protection in tea gardens

Effect of Adjuvants on the Wetting Behaviors of Bifenthrin Droplets on Tea Leaves

The hydrophobic epicuticle wax on fresh leaves of tea tree (Camellia sinensis (L.) 0. Kuntze) leads to the loss of pesticide droplets, reducing efficacy. In this study, four adjuvants were selected to improve the diffusion and adhesion of bifenthrin droplets on the surface of tea leaves at different growth stages. The coupling effect of bifenthrin and adjuvants on the time-dependent and concentration-dependent wettability of droplets was investigated, and the difference in the wettability between bud and leaf was explained by observing the surface morphology. It was found that adjuvants effectively reduced the contact angle of droplets and accelerated the diffusion speed, and the above phenomenon became obvious with the increase in the adjuvant concentration. The wetting promotion of young leaves was more significant due to the reduced epicuticle wax and the greater roughness compared with fresh buds. The surface tension of the pesticide mixture was negatively correlated with the cosine of contact angle after adding the four adjuvants regardless of the growth stage of tea leaves. The contact angle of 0.2% Silwet L-77 decreased to 0° within 10 s, but the extreme wettability led to the decrease in adhesion with the increase in concentration. However, the wettability and adhesion on the surface of tea leaves were simultaneously suitable with more than 0.1% nonionic surfactant. The minimum concentration of the optimal adjuvant proposed in this study can provide an experimental basis and guide more efficient plant protection in tea gardens

GSK3β-Dzip1-Rab8 cascade regulates ciliogenesis after mitosis.

The primary cilium, which disassembles before mitotic entry and reassembles after mitosis, organizes many signal transduction pathways that are crucial for cell life and individual development. However, how ciliogenesis is regulated during the cell cycle remains largely unknown. Here we show that GSK3β, Dzip1, and Rab8 co-regulate ciliogenesis by promoting the assembly of the ciliary membrane after mitosis. Immunofluorescence and super-resolution microscopy showed that Dzip1 was localized to the periciliary diffusion barrier and enriched at the mother centriole. Knockdown of Dzip1 by short hairpin RNAs led to failed ciliary localization of Rab8, and Rab8 accumulation at the basal body. Dzip1 preferentially bound to Rab8GDP and promoted its dissociation from its inhibitor GDI2 at the pericentriolar region, as demonstrated by sucrose gradient centrifugation of purified basal bodies, immunoprecipitation, and acceptor-bleaching fluorescence resonance energy transfer assays. By means of in vitro phosphorylation, in vivo gel shift, phospho-peptide identification by mass spectrometry, and GST pulldown assays, we demonstrated that Dzip1 was phosphorylated by GSK3β at S520 in G0 phase, which increased its binding to GDI2 to promote the release of Rab8GDP at the cilium base. Moreover, ciliogenesis was inhibited by overexpression of the GSK3β-nonphosphorylatable Dzip1 mutant or by disabling of GSK3β by specific inhibitors or knockout of GSK3β in cells. Collectively, our data reveal a unique cascade consisting of GSK3β, Dzip1, and Rab8 that regulates ciliogenesis after mitosis