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Precise Point Positioning (PPP) augmentation corrections can enhance the accuracy of Global Navigation Satellite System (GNSS) positioning. Three prominent PPP augmentation services: the third generation of BeiDou Navigation Satellite System (BDS-3) PPP-B2b, Europe's Galileo High Accuracy Service (HAS) and Quasi-Zenith Satellite System (QZSS) Centimeter Level Augmentation Service (CLAS), are evaluated and compared, contributing to the optimal utilization of these services. Based on a 25-day dataset in March 2023, all the three services have made significant improvements in GPS orbit accuracy compared to the broadcast ephemeris. Galileo HAS achieved the highest three-dimension (3D) orbit accuracy for both GPS and Galileo (10.5 and 10.4 cm), followed by CLAS (48.1 and 16.3 cm) and PPP-B2b (GPS: 73.0 cm, BDS-3: 44.6 cm). This distinct performance of PPP-B2b orbits is found for the first time to be related to the large constellation rotation errors, which accounts for roughly half of the orbit errors of along and cross components. Regarding clock errors, PPP-B2b and HAS enhanced GPS clock accuracy to 0.20 ns (70 %) and 0.17 ns (74 %), respectively, over the broadcast clock (0.66 ns), while CLAS shows a much smaller improvement. Moderate correlations of 0.3–0.8 between orbit and clock errors are observed for the three augmentation corrections. For signal in space ranging error (SISRE), HAS (GPS:5.5 cm, Galileo:4.9 cm) outperforms PPP-B2b (GPS:14.3 cm, BDS-3:8.9 cm) and CLAS (GPS:23.6 cm, Galileo:13.7 cm). The 2-hourly kinematic positioning results with an accuracy of better than 20 cm (95th percentile) for the horizontal and vertical component, could be achieved for both PPP-B2b and HAS within 20 min within their service area. It is not recommended rely solely on the orbit/clock/code bias of CLAS for precise positioning, as the positioning accuracy is influenced by the SISRE. PPP-RTK of CLAS achieves horizontal 10 cm (95th percentile) and rapid convergence of mostly less than a minute by incorporating phase bias and atmospheric corrections. [ABSTRACT FROM AUTHOR]

Copyright of Jurnal Fitopatologi Indonesia is the property of IPB University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Asian citrus psyllid (ACP) Diaphorina citri Kuwayama is the leading vector of Candidatus Liberibacter asiaticus (CLas), the causative agent of citrus Huanglongbing (HLB) disease. The distribution and dynamics of CLas within ACP are critical to understanding how the transmission, spread and infection of CLas occurs within its host vector in nature. In this study, the distribution and titer changes of CLas in various tissues of ACP 5th instar nymphs and adults were examined by fluorescence in situ hybridization (FISH) and real-time quantitative PCR (qPCR) techniques. Results demonstrated that 100% of ACP 5th instar nymphs and adults were infected with CLas following feeding on infected plants, and that CLas had widespread distribution in most of the tissues of ACP. The titers of CLas within the midgut, salivary glands and hemolymph tissues were the highest in both 5th instar nymphs and adults. When compared with adults, the titers of CLas in these three tissues of 5th instar nymphs were significantly higher, while in the mycetome, ovary and testes they were significantly lower than those of adults. FISH visualization further confirmed these findings. Dynamic analysis of CLas demonstrated that it was present across all the developmental ages of ACP adults. There was a discernible upward trend in the presence of CLas with advancing age in most tissues of ACP adults, including the midgut, hemolymph, salivary glands, foot, head, cuticula and muscle. Our findings have significant implications for the comprehensive understanding of the transmission, dissemination and infestation of CLas, which is of much importance for developing novel strategies to halt the spread of CLas, and therefore contribute to the efficient prevention and control of HLB. [ABSTRACT FROM AUTHOR]

Xiaoqing Wei,1,* Junying Zhang,2,* Youwen Mei,3 Eqiong Li,4 Qianling Dai,1 Xiaoli Yang,1 Dan Luo,5 Biao Li,6 Ping Hua,7 Jian Cai,7 Hua Lai,8 Dongfeng Qi,9 Sha Lai,10 Mi Qin,11 Yonghong Lin4 1Department of Cervical Disease and Cervical Cancer Prevention and Treatment, Chengdu Women’s and Children’s Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 611731, People’s Republic of China; 2Clinical Laboratory Department, Chengdu Women’s and Children’s Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 611731, People’s Republic of China; 3Department of Reproduction and Infertility, Chengdu Women’s and Children’s Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 611731, People’s Republic of China; 4Department of Gynecology, Chengdu Women’s and Children’s Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 611731, People’s Republic of China; 5Department of Obstetrics, Chengdu Women’s and Children’s Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 611731, People’s Republic of China; 6Department of Neonatal Intensive Care Unit, Chengdu Women’ and Children’s Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 611731, People’s Republic of China; 7Department of Pathology, Chengdu Women’s and Children’s Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 611731, People’s Republic of China; 8Department of Radiation and Interventional Therapy, Chengdu Women’s and Children’s Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 611731, People’s Republic of China; 9Department of Ultrasonics, Chengdu Women’s and Children’s Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 611731, People’s Republic of China; 10Dermatology Department, Chengdu Women’s and Children’s Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 611731, People’s Republic of China; 11Department of Pediatric Surgery, Chengdu Women’s and Children’s Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 611731, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yonghong Lin; Xiaoqing Wei, Email linyhcd2011@163.com; xqcherry@163.comObjective: We report a case of Carmi Syndrome in a neonate.Aim: To share our lessons in diagnosis of the case of Carmi Syndrome.Case Report: Carmi Syndrome is an extremely rare autosomal recessive genetic disorder characterized the coexistence of pyloric atresia and junctional epidermolysis bullosa, and with aplasia cutis congenita in approximately 28% patients. In this case, a full-term male neonate was born to a G4P2+1L1 multipara through cesarean section delivery in hospital in a non-consanguineous marriage with 4000mL of II°meconium-stained amniotic fluid. He was found extensive skin loss over lower legs and other parts, with scattered blisters and bilateral microtia. Plain abdominal X-ray revealed a large gastric air bubble with no gas distally. The mother had an intrauterine fetal loss previously for reasons unknown. The dermatologist diagnosed the newborn with Bart Syndrome, while the pediatric surgeon diagnosed congenital pyloric atresia(CPA). The parents refused further treatment and the neonate passed away about 30 hours after birth.Outcome: The neonate passed away about 30 hours after birth.Conclusion: Lessons from this case:①.Rule out Carmi Syndrome in patients with PA, and differentiate Bart syndrome and Carmi Syndrome in patients with abnormal skin manifestations. ②. For rare and/or severe diseases, multidisciplinary teams(MDTs) should be establish. ③. Genetic counseling and prenatal diagnosis are necessary prior to subsequent childbearings. ④.Termination of pregnancy might be contemplated if certain indicators are revealed.Keywords: Carmi syndrome, bart syndrome, epidermolysis bullosa, EB, junctional epidermolysis bullosa, JEB, congenital pyloric atresia, CPA, aplasia cutis congenita, ACC, congenital localized absence of skin, CLAS, pyloric atresia, PA, epidermolysis bullosa with pyloric atresia, EB-PA, multidisciplinary teams, MDT

Citrus Huanglongbing (HLB) caused by 'Candidatus Liberibacter asiaticus' (CLas) is the most devastating citrus disease worldwide. CLas induces systemic and chronic reactive oxygen species (ROS) production, which has been suggested to be a primary cause of cell death in phloem tissues and subsequent HLB symptoms. Mitigating oxidative stress caused by CLas using horticultural approaches has been suggested as a useful strategy to reduce HLB damages. To provide information regarding the application timing to mitigate ROS, we investigated monthly dynamics of CLas concentration, CLas-triggered ROS, and phloem cell death in the bark tissues of asymptomatic and symptomatic branches of HLB-positive Hamlin and Valencia sweet orange trees in the field. Healthy branches in the screenhouse were used as controls. CLas concentration exhibited significant variations over the course of the year, with two distinct peaks observed in Florida citrus groves--late spring/early summer and late fall. Within both Hamlin and Valencia asymptomatic tissues, CLas concentration demonstrated a negative correlation with the deviation between the monthly average mean temperature and the optimal temperature for CLas colonization in plants (25.7°C). However, such a correlation was not evident in symptomatic tissues of Hamlin or Valencia sweet oranges. ROS levels were consistently higher in symptomatic or asymptomatic branches than in healthy branches in most months. ROS concentrations were higher in symptomatic branches than in asymptomatic branches in most months. CLas triggered significant increases in ion leakage in most months for asymptomatic and symptomatic branches compared with healthy controls. In asymptomatic branches of Hamlin, a positive correlation was observed between CLas concentration and ROS concentrations, CLas concentration and ion leakage levels, as well as ROS and ion leakage. Intriguingly, such a relationship was not observed in Valencia asymptomatic branches or in the symptomatic branches of Hamlin and Valencia. This study sheds light on the pathogenicity of CLas by providing useful information on the temporal dynamics of ROS production, phloem cell death, and CLas growth, as well as provides useful information in determining the timing for application of antioxidants and antimicrobial agents to control HLB. [ABSTRACT FROM AUTHOR]

Aims Huanglongbing (citrus greening) is a plant disease putatively caused by the unculturable Gram-negative bacterium Candidatus Liberibacter asiaticus (CLas), and it has caused severe damage to citrus plantations worldwide. There are no definitive treatments for this disease, and conventional disease control techniques have shown limited efficacy. This work presents an in silico evaluation of using specifically targeting anti-microbial peptides (STAMPs) consisting of a targeting segment and an antimicrobial segment to inhibit citrus greening by inhibiting the BamA protein of CLas, which is an outer membrane protein crucial for bacterial viability. Methods and results Initially, a set of peptides with a high affinity toward BamA protein were screened and evaluated via molecular docking and molecular dynamics simulations and were verified in vitro via bio-layer interferometry (BLI). In silico studies and BLI experiments indicated that two peptides, HASP2 and HASP3, showed stable binding to BamA. Protein structures for STAMPs were created by fusing known anti-microbial peptides (AMPs) with the selected short peptides. The binding of STAMPs to BamA was assessed using molecular docking and binding energy calculations. The attachment of high-affinity short peptides significantly reduced the free energy of binding for AMPs, suggesting that it would make it easier for the STAMPs to bind to BamA. Efficacy testing in vitro using a closely related CLas surrogate bacterium showed that STAMPs had greater inhibitory activity than AMP alone. Conclusions In silico and in vitro results indicate that the STAMPs can inhibit CLas surrogate Rhizobium grahamii more effectively compared to AMPs, suggesting that STAMPs can achieve better inhibition of CLas, potentially via enhancing the site specificity of AMPs. [ABSTRACT FROM AUTHOR]

Copyright of Japanese Journal of JSCE / Doboku Gakkai Ronbunshu is the property of Japan Society of Civil Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Huanglongbing or citrus greening in Asia caused by the pathogen Candidatus Liberibacter asiaticus (CLas) is one of the most devastating citrus diseases worldwide. This disease is one of the causes of decreased citrus production in Indonesia. Symptoms of huanglongbing in citrus plants in the field and greenhouses have different levels of severity. This study was conducted to detect CLas in several types of samples based on leaf symptoms using conventional and real-time PCR (qPCR). Three pairs of primers were used in this study, a pair of Las606/LSS for conventional PCR and two pairs for qPCR, namely Las931/LSS and Lj900F/Lj900R. The results showed that blotchy mottle is the most easily detected symptom of huanglongbing and found in fields and greenhouses. The Lj900F/Lj900R primer pair is more suitable for detecting CLas pathogens using qPCR than Las606/LSS based on the melting curve and Ct value that appear. qPCR detection is more accurate and sensitive even with lower DNA concentrations. The lower limit of Ct value of healthy leaf samples is 34.08. Citrus leaves are considered positive if the Ct value is less than 34.08. Ct value based on severity or scoring between HLB symptomatic leaves from the field and greenhouse showed a significant difference, i.e. the Ct value of symptomatic samples from the field was lower than that of greenhouse samples.

Multifunctional composite structures (MFCS) have become an increasingly important field of research with the large-scale adoption of composite materials in many industrial sectors such as aerospace, automotive, sport and recreation equipment (bikes, scooters, etc.) and maritime. It is a diverse field which includes scientific areas in electromagnetics, electronics, material sciences, structures and structural augmentation, sensors, and thermal management. The paper investigates Conformal Load-bearing Smart Skins (CLSS) as a part of multifunctional composite structures specifically related to aerospace applications and focuses on the seamless incorporation and synergistic coexistence between electronic devices and composite materials. Current trends in materials and manufacturing processes, as well as measurement techniques used to validate both the electromagnetic and structural responses have been explored and discussed. Furthermore, it identifies some of the challenges and complexities associated with CLSS and explores future areas of research which still need to be addressed.

The destructive citrus disease, Huanglongbing (HLB) or citrus greening, continues to devastate Florida's citrus industry. A hemipteran insect, the Asian citrus psyllid (ACP), disperses Candidatus Liberibacter asiaticus, one of the putative bacterial pathogens of HLB. This study builds upon ongoing research utilizing high-throughput sequencing to analyze the virome of ACP populations collected from citrus groves throughout Florida. Following the widespread detection of sequences aligning to the genome of citrus tristeza virus (CTV) across consecutive years in the Florida ACP virome, we continued to detect a pervasive amount of CTV in Florida ACPs during subsequent years. Simultaneously, we also detected mixed infections of CTV strains in pooled ACPs from different Florida regions. Predating the HLB epidemic, CTV has been present in Florida for many years and our results confirm its widespread and diverse persistence in Florida citrus groves through a unique lens, the ACP. CTV presence in the ACP likely results from feeding on CTV-infected citrus trees in Florida citrus groves, which may help to understand an overlapping presence of CTV and HLB, both endemic citrus pathosystems in the state, and their role in future integrated pest management strategies.

Citrus Huanglongbing (HLB) is the most destructive citrus disease worldwide, mainly caused by ‘Candidatus Liberibacter asiaticus’ (CLas). It encodes a large number of Sec-dependent effectors that contribute to HLB progression. In this study, an elicitor triggering ROS burst and cell death in Nicotiana benthamiana, CLIBASIA_04425 (CLas4425), was identified. Of particular interest, its cell deathinducing activity is associated with its subcellular localization and the cytoplasmic receptor Botrytis-induced kinase 1 (BIK1). Compared with CLas infected psyllids, CLas4425 showed higher expression level in planta. The transient expression of CLas4425 in N. benthamiana and its overexpression in Citrus sinensis enhanced plant susceptibility to Pseudomonas syringae pv. tomato DC3000 DhopQ1-1 and CLas, respectively. Furthermore, the salicylic acid (SA) level along with the expression of genes NPR1/EDS1/NDR1/PRs in SA signal transduction was repressed in CLas4425 transgenic citrus plants. Taken together, CLas4425 is a virulence factor that promotes CLas proliferation, likely by interfering with SA-mediated plant immunity. The results obtained facilitate our understanding of CLas pathogenesis. [ABSTRACT FROM AUTHOR]

Huanglongbing (HLB), referred to as citrus greening disease, is a bacterial disease impacting citrus production worldwide and is fatal to young trees and mature trees of certain varieties. In some areas, the disease is devastating the citrus industry. A successful solution to HLB will be measured in economics: citrus growers need treatments that improve tree health, fruit production, and most importantly, economic yield. The profitability of citrus groves is the ultimate metric that truly matters when searching for solutions to HLB. Scientific approaches used in the laboratory, greenhouse, or field trials are critical to the discovery of those solutions and to estimate the likelihood of success of a treatment aimed at commercialization. Researchers and the citrus industry use a number of proxy evaluations of potential HLB solutions; understanding the strengths and limitations of each assay, as well as how best to compare different assays, is critical for decision-making to advance therapies into field trials and commercialization. This perspective aims to help the reader compare and understand the limitations of different proxy evaluation systems based on the treatment and evaluation under consideration. The researcher must determine the suitability of one or more of these metrics to identify treatments and predict the usefulness of these treatments in having an eventual impact on citrus production and HLB mitigation. As therapies advance to field trials in the next few years, a reevaluation of these metrics will be useful to guide future research efforts on strategies to mitigate HLB and vascular bacteria] pathogens in other perennial crops. [ABSTRACT FROM AUTHOR]

Plant microbiomes are critical components to plant health and can influence disease outcomes. We provide empirical data describing disease-induced shifts within the citrus microbiome at different levels of huanglongbing (HLB) disease severity. HLB is associated with an invasive phloem-limited bacterium, ‘Candidatus Liberibacter asiaticus’, that is introduced into the aerial portions of the tree by an insect vector. Disease manifests as aboveground foliar and fruit symptoms and significant root decline belowground. During the early phase of disease, there were depletions of putative keystone taxa in leaves and roots, followed by enrichments of putative beneficial taxa, suggesting a microbially derived immune response involved in plant protection that is ancillary to immune components encoded in the plant’s genome. In the late phase of disease, we observed enrichments of parasitic and saprophytic microorganisms, particularly in the roots. The community shifts within the root compartment are emblematic of a disease-induced dysbiosis where pathogens other than ‘Ca. L. asiaticus’ begin to dominate the community. Furthermore, we define key taxa enriched in trees with a slower rate of disease development, referred to as survivor trees, that are hallmarks of those found in trees in the early phase of disease that may be drivers of the survivor tree phenotype. We propose a disease ecology model that illustrates the relationship between the pathogen, the microbiome, and the host plant that highlights microorganisms that may serve as disease facilitators or antagonists.

Having bacteria grown in pure culture has been the foundation of bacteriology, by allowing a wide range of microbiological studies towards understanding the functionality of a specific bacterium. However, most bacteria have not been axenically cultured to date, thus hindering the understanding of their role in the context of their host or environment. One of these unculturable bacteria are the recently emergent plant pathogens ‘Candidatus Liberibacter spp.’. This group is comprised by dynamic psyllid-vectored, phloem-limited plant pathogens and endophytes that harm a wide range of economically important crops worldwide. ‘Candidatus Liberibacter asiaticus’ (CLas) is associated with Huanglongbing (HLB) in most of the main citrus-producing areas globally, a disease causing severe economic damages. Although the establishment of axenic cultures of CLas remains a major scientific challenge, many research groups have devoted efforts to culture this bacterium to aid in elucidating its virulence mechanism and contribute towards effective HLB management. This led to the development of innovative systems to culture and grow CLas, however different authors have approached the concepts of bacterial culture and axenic culture in different manners, leading to confusion in the terminology used. In this review, we provide the scientific definitions of important terms in bacteriology, while critically reviewing the contribution of each of these important CLas culturing studies.

Currently, smart homes rely heavily on wireless sensor networks (WSNs), which typically consist of wireless sensor nodes with limited resources and are scattered throughout the network. This topology makes them vulnerable to packet sniffing, spoofing, and other malicious attacks, which can result in the leakage of private data collected by devices. Additionally, managing the device key for the entire system becomes difficult as more devices are added. Moreover, the centralization of current cloud service management in smart home systems poses a serious single-point-of-failure problem, and the private data of cloud outsourcing cannot receive strict privacy supervision, ultimately relying entirely on the trust of enterprises. To address these issues, this paper proposes using a consortium blockchain and InterPlanetary File System (IPFS) instead of the existing centralized structure. An improved pairing-free certificateless aggregated signature(CLAS) scheme ensures the security of message authentication and solves the device key management problem. Our scheme reduces the computational and communication overheads at the device side by 50% and 25%, respectively, compared with existing schemes in WSNs. The overall computational overhead is also reduced by 28.6%, making it more suitable for smart home scenarios. Additionally, we use an auditing method based on Merkle root hash verification to ensure the reliability of data storage in IPFS.

Huanglongbing (HLB) is a global devastating citrus disease that is mainly caused by "Candidatus Liberibacter asiaticus" (CLas). It is mostly transmitted by the insect Asian citrus psyllid (ACP, Diaphorina citri) in a persistent and proliferative manner. CLas traverses multiple barriers to complete an infection cycle and is likely involved in multiple interactions with D. citri. However, the protein-protein interactions between CLas and D. citri are largely unknown. Here, we report on a vitellogenin-like protein (Vg_VWD) in D. citri that interacts with a CLas flagellum (flaA) protein. We found that Vg_VWD was upregulated in CLas-infected D. citri. Silencing of Vg_VWD in D. citri via RNAi silencing significantly increased the CLas titer, suggesting that Vg_VWD plays an important role in the CLas-D. citri interaction. Agrobacterium-mediated transient expression assays indicated that Vg_VWD inhibits BAX- and INF1-triggered necrosis and suppresses the callose deposition induced by flaA in Nicotiana benthamiana. These findings provide new insights into the molecular interaction between CLas and D. citri. [ABSTRACT FROM AUTHOR]

Citrus huanglongbing (HLB), associated with the unculturable phloem‐limited bacterium "Candidatus Liberibacter asiaticus" (CLas), is the most devastating disease in the citrus industry worldwide. However, the pathogenicity of CLas remains poorly understood. In this study, we show that AGH17488, a secreted protein encoded by the prophage region of the CLas genome, suppresses plant immunity via targeting the host ASCORBATE PEROXIDASE6 (APX6) protein in Nicotiana benthamiana and Citrus sinensis. The transient expression of AGH17488 reduced the chloroplast localization of APX6 and its enzyme activity, inhibited the accumulation of reactive oxygen species (H2O2 and O2−) and the lipid oxidation endproduct malondialdehyde in plants, and promoted the proliferation of Pseudomonas syringae pv. tomato DC3000 and Xanthomonas citri subsp. citri. This study reveals a novel mechanism underlying how CLas uses a prophage‐encoded effector, AGH17488, to target a reactive oxygen species accumulation‐related gene, APX6, in the host to facilitate its infection. [ABSTRACT FROM AUTHOR]

Introduction: Huanglonbing (HLB) is the most serious disease of citrus in the world, associated with three non-cultivable phloem-restricted bacteria Candidatus Liberibacter asiaticus (CLas), Ca L. africanus (CLaf) and Ca L. americanus (CLam). CLas is transmitted by the Asian citrus psyllid Diaphorina citri, and has spread to several countries. The African psyllid Trioza erytreae, the vector of CLaf occurs in Africa and neighbouring islands. Only two major citrusgrowing regions - Australia/New Zealand and the Mediterranean Basin - are still HLB-free in the world. However, T. erytreae has recently been introduced into continental Europe (Portugal and Spain) and has become a potential threat to citrus production. The transmission of CLas by T. erytreae had been postulated but never tested. To evaluate the risk of T. erytreae transmitting CLas, comparative transmissions of CLas by T. erytreae and D. citri were assessed. Methods: Transmission tests were performed on excised leaves and seedlings of Citrus volkameriana with different inoculation access periods (in series) for both insect species. Quantifications of bacterial titers were made in excised leaves, seedlings three and six months after inoculation and on individual insects. Results: Our results showed that T. erytreae was able to efficiently acquire CLas. Furthermore, T. erytreae carried significantly higher bacterial titers than D. citri, and was able to efficiently transmit the bacteria to seedlings at a similar rate that D. citri highlighting the high risk of spread of the most aggressive variant of HLB (CLas) by T. erytreae in Europe. Discussion: Thus, extreme precautions to prevent any entry of CLas into Europe should be adopted. [ABSTRACT FROM AUTHOR]

Improving nutrient uptake and tree health play an important role in managing Huanglongbing (HLB)-affected citrus trees in Florida. A greenhouse experiment was conducted to evaluate the effect of increasing rates of manganese (Mn) on growth and development of sweet orange [Citrus sinensis (L.) Osbeck] trees at the University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center in Lake Alfred, FL. Half the trees were graft-inoculated with the HLB pathogen and the remainder were used as the HLB-free (non HLB) control trees. Four rates of Mn (0.0 kg·ha−1 Mn (Control), 5.6 kg·ha−1 Mn (1x—standard rate), 11.2 kg·ha−1 Mn (2x—standard rate), and 22.4 kg·ha−1 Mn (4x—standard rate) were split applied quarterly to both sets of the trees in a completely randomized design. There were seven single tree replicates for each treatment. Response variables measured were trunk diameter, tree height, leaf Mn concentration, plus above- and belowground biomass. The accumulated Mn in leaf tissues significantly increased trunk diameter but did not affect tree height for both HLB-affected and non-HLB trees, the 2x rate had the maximum value for trunk diameter relative to the 4x rate. This study established a positive correlation between soil available Mn with Fe and Cu, but negative correlation with B and Zn. A strong correlation of −0.76, −0.69, and 0.65 was observed between soil Mn and B, Zn, and Cu, respectively, as compared with 0.49 with Mn and Fe. Among HLB-affected trees, the 2x rate gave the most belowground dry matter, which was 3% greater than the control and 5% greater than 4x. Aboveground dry matter had at least 30% more biomass than belowground matter among all treatments within HLB-affected trees. For small and medium roots, Mn accumulation increased with Mn application until 2x rate and decreased thereafter for HLB-affected trees. The results from our study showed an Mn rate of 8.9–11.5 kg·ha−1 Mn, as the optimum Mn level for young ‘Valencia’ HLB-affected trees in Florida.

Huanglongbing (HLB) is one of the most destructive diseases of citrus worldwide. The disease keeps spreading in several citrus-growing areas of southern Iran. The potential of (GTG)5-rep marker in revealing the genetic diversity of geographic isolates of Candidatus Liberibacter asiaticus was evaluated in the present study. Twenty-one HLB-infected samples collected from the Hormozgan and Sistan and Baluchestan provinces were used in the trial. PCR with the (GTG)5 primer produced 16 scorable bands, of which nearly 100% were polymorphic among or within the populations. The most observed variation resided within (80.56, P < 0.10) and a substantially less (19.44, P < 0.10) between the populations. The isolates were distributed in two main (A and B) clusters, each consisting of several subgroups. Group A included Sistan and Baluchestan and Hormozgan isolates and the group B embraced Hormozgan isolates. Based on pairwise genetic differences, the Haji Abad and Hashtbandi populations exhibited the highest between-population variation, and the Siahoo, Hashtbandi, Nikshahr, Haji Abad, and Sarbaz showed the greatest within-population variation. The first three coordinates of the principal coordinate analysis explained more than 72.39% of the variation among or within the populations. The first two coordinates explained 58.20% of band variation in plotting, and the first and third coordinates explained 55.54% of band variation. These results may be inferred that the Hormozgan populations might have diverged from the Sistan populations, or both might have originated separately from an initial or parental population possessing a high genetic diversity.

IntroductionHuanglonbing (HLB) is the most serious disease of citrus in the world, associated with three non-cultivable phloem-restricted bacteria Candidatus Liberibacter asiaticus (CLas), Ca L. africanus (CLaf) and Ca L. americanus (CLam). CLas is transmitted by the Asian citrus psyllid Diaphorina citri, and has spread to several countries. The African psyllid Trioza erytreae, the vector of CLaf occurs in Africa and neighbouring islands. Only two major citrus-growing regions - Australia/New Zealand and the Mediterranean Basin - are still HLB-free in the world. However, T. erytreae has recently been introduced into continental Europe (Portugal and Spain) and has become a potential threat to citrus production. The transmission of CLas by T. erytreae had been postulated but never tested. To evaluate the risk of T. erytreae transmitting CLas, comparative transmissions of CLas by T. erytreae and D. citri were assessed.MethodsTransmission tests were performed on excised leaves and seedlings of Citrus volkameriana with different inoculation access periods (in series) for both insect species. Quantifications of bacterial titers were made in excised leaves, seedlings three and six months after inoculation and on individual insects.ResultsOur results showed that T. erytreae was able to efficiently acquire CLas. Furthermore, T. erytreae carried significantly higher bacterial titers than D. citri, and was able to efficiently transmit the bacteria to seedlings at a similar rate that D. citri highlighting the high risk of spread of the most aggressive variant of HLB (CLas) by T. erytreae in Europe.DiscussionThus, extreme precautions to prevent any entry of CLas into Europe should be adopted.

Research related to the authentication schemes in vehicular ad hoc networks (VANETs) has received significant attention recently. They substantially impact the security and privacy aspects of the message dissemination process in the road environment. Some authentication schemes with certificateless aggregate signature (CLAS) in VANETs have been published since the first related article emerged in 2015. This paper comprehensively reviews most of them regarding their main feature, contributions, security, and performance efficiency, as the state-of-the-art of all CLAS mechanisms in VANETs. Finally, the conclusion and some open issues on the CLAS authentication scheme in VANETs are provided in this survey. [ABSTRACT FROM AUTHOR]

Citrus Huanglongbing (HLB), known as the most economically devastating disease in citrus industry, is mainly caused by phloem-restricted Gramnegative bacterium "Candidatus Liberibacter asiaticus" (CLas). To date, CLas is still unculturable in vitro, which has been dramatically delaying the research on its pathogenesis, and only few Sec-dependent effectors (SDEs) have been identified to elucidate the pathogenesis of CLas. Here, we confirmed that a CLas-secreted Sec-dependent polypeptide, namely SECP8 (CLIBASIA_05330), localized in nucleus, cytoplasm and cytoplasmic membrane, and showed remarkably higher transcript abundance in citrus than in psyllids. Potato virus X (PVX)-mediated transient expression assays indicated that mSECP8 (the mature form of SECP8) suppressed proapoptotic mouse protein BAX and Phytophthora infestans elicitin INF1-triggered hypersensitive response (HR) associated phenotypes, including cell death, H2O2 accumulation and callose deposition. Intriguingly, mSECP8 also inhibited SDE1 (CLIBASIA_05315)-induced water-soaked and dwarfing symptoms in Nicotiana benthamiana. In addition, mSECP8 can promote the susceptibility of transgenic Wanjincheng orange (Citrus sinensis) to CLas invasion and further HLB symptom development, and it contributes to the proliferation of Xanthomonas citri subsp. citri (Xcc). Moreover, the expression of ten immunity-related genes were significantly down-regulated in mSECP8 transgenic citrus than those in wide-type (WT) plants. Overall, we propose that mSECP8 may serve as a novel broad-spectrum suppressor of plant immunity, and provide the first evidence counteractive effect among CLas effectors. This study will enrich and provide new evidences for elucidating the pathogenic mechanisms of CLas in citrus host. [ABSTRACT FROM AUTHOR]

Huanglongbing (HLB), associated with "Candidatus Liberibacter asiaticus" (CLas), is a globally devastating plant disease. The highly reduced genome of CLas encodes a number of secretory proteins. The conserved prophage‐encoded protein AGH17470 is herein identified as a nonclassical secretory protein. We confirmed that the N‐terminal and C‐terminal sequences jointly determine the secretion of AGH17470. The transient expression of AGH17470 protein in Nicotiana benthamiana caused hypersensitive response (HR) cell death in infiltrated leaves and systemically infected leaves as well as the dwarfing of the entire plant, suggesting that AGH17470 is involved in the plant immune response, growth, and development. Overexpression of AGH17470 in N. benthamiana and citrus plants up‐regulated the transcription of pathogenesis‐related and salicylic acid (SA)‐signalling pathway genes and promoted SA accumulation. Furthermore, transient expression of AGH17470 enhanced the resistance of sweet orange to Xanthomonas citri subsp. citri. To our knowledge, AGH17470 is the first prophage‐encoded secretory protein demonstrated to elicit an HR and induce a strong plant immune response. The findings have increased our understanding of prophage‐encoded secretory protein genes, and the results provide clues as to the plant defence response against CLas. [ABSTRACT FROM AUTHOR]

Large slow oscillations (SO, 0.5–2 Hz) characterise slow-wave sleep and are crucial to memory consolidation and other physiological functions. Manipulating slow oscillations may enhance sleep and memory, as well as benefitting the immune system. Closed-loop auditory stimulation (CLAS) has been demonstrated to increase the SO amplitude and to boost fast sleep spindle activity (11–16 Hz). Nevertheless, not all such stimuli are effective in evoking SOs, even when they are precisely phase locked. Here, we studied what factors of the ongoing activity patterns may help to determine what oscillations to stimulate to effectively enhance SOs or SO-locked spindle activity. Hence, we trained classifiers using the morphological characteristics of the ongoing SO, as measured by electroencephalography (EEG), to predict whether stimulation would lead to a benefit in terms of the resulting SO and spindle amplitude. Separate classifiers were trained using trials from spontaneous control and stimulated datasets, and we evaluated their performance by applying them to held-out data both within and across conditions. We were able to predict both when large SOs occurred spontaneously, and whether a phase-locked auditory click effectively enlarged them with good accuracy for predicting the SO trough (∼70%) and SO peak values (∼80%). Also, we were able to predict when stimulation would elicit spindle activity with an accuracy of ∼60%. Finally, we evaluate the importance of the various SO features used to make these predictions. Our results offer new insight into SO and spindle dynamics and may suggest techniques for developing future methods for online optimization of stimulation.

Improving nutrient uptake and tree health play an important role in managing Huanglongbing (HLB)-affected citrus trees in Florida. A greenhouse experiment was conducted to evaluate the effect of increasing rates of manganese (Mn) on growth and development of sweet orange [Citrus sinensis (L.) Osbeck] trees at the University of Florida's Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center in Lake Alfred, FL. Half the trees were graft-inoculated with the HLB pathogen and the remainder were used as the HLB-free (non HLB) control trees. Four rates of Mn (0.0 kg·ha-1 Mn (Control), 5.6 kg·ha-1 Mn (1x--standard rate), 11.2 kg·ha-1 Mn (2x--standard rate), and 22.4 kg·ha-1 Mn (4x--standard rate) were split applied quarterly to both sets of the trees in a completely randomized design. There were seven single tree replicates for each treatment. Response variables measured were trunk diameter, tree height, leaf Mn concentration, plus above- and belowground biomass. The accumulated Mn in leaf tissues significantly increased trunk diameter but did not affect tree height for both HLB-affected and non-HLB trees, the 2x rate had the maximum value for trunk diameter relative to the 4x rate. This study established a positive correlation between soil available Mn with Fe and Cu, but negative correlation with B and Zn. A strong correlation of -0.76, -0.69, and 0.65 was observed between soil Mn and B, Zn, and Cu, respectively, as compared with 0.49 with Mn and Fe. Among HLB-affected trees, the 2x rate gave the most belowground dry matter, which was 3% greater than the control and 5% greater than 4x. Aboveground dry matter had at least 30% more biomass than belowground matter among all treatments within HLB-affected trees. For small and medium roots, Mn accumulation increased with Mn application until 2x rate and decreased thereafter for HLB-affected trees. The results from our study showed an Mn rate of 8.9-11.5 kg·ha-1 Mn, as the optimum Mn level for young 'Valencia' HLB-affected trees in Florida. [ABSTRACT FROM AUTHOR]

Citrus Huanglongbing (HLB) or citrus greening, is the most destructive disease for citrus worldwide. It is caused by the psyllid-transmitted, phloem-limited bacteria “Candidatus Liberibacter asiaticus” (CLas). To date, there are still no effective practical strategies for curing citrus HLB. Understanding the mechanisms against CLas can contribute to the development of effective approaches for combatting HLB. However, the unculturable nature of CLas has hindered elucidating mechanisms against CLas. In this review, we summarize the main aspects that contribute to the understanding about the mechanisms against CLas, including (1) CLas virulence targets, focusing on inhibition of virulence genes; (2) activation of citrus host defense genes and metabolites of HLB-tolerant citrus triggered by CLas, and by agents; and (3) we also review the role of citrus microbiome in combatting CLas. Finally, we discuss novel strategies to continue studying mechanisms against CLas and the relationship of above aspects.

Huanglongbing [HLB (Candidatus Liberibacter asiaticus)] is one of the most devastating diseases in citrus (Citrus sp.). Field observations in Florida have shown that citrus groves with high soil and irrigation water pH decline rapidly under HLB-prevalent conditions. It is worth noting that irrigation water pH has always been high in Florida; however, neither tree decline nor low productivity under such conditions has been an issue for citrus before HLB. Therefore, there is a need to determine if HLB increases citrus tree sensitivity to high-pH irrigation water. The objective of this research was to evaluate the molecular and physiological responses of healthy and HLB-affected citrus trees irrigated with water at pH levels of 5.8, 7.0, and 8.0. The results demonstrated that soil pH is positively correlated with irrigation water pH. Overall, regardless of disease occurrence, tree performance decreased as pH increased. HLB-affected trees at pH 8.0 had the greatest mortality (40%) and leaf drop (87%) and the lowest height growth (

Abstract Huanglongbing (HLB), a bacterial disease, is one of the most destructive citrus diseases. For many decades, it has been known that using heat/high temperatures (thermotherapy) is effective in suppressing plant diseases, particularly the suppression of Candidatus Liberibacter (CLas, casual agent for HLB) when the treated plants are grown in pots (allowing treatment of roots) under controlled conditions. However, in-field thermotherapy has yielded inconsistent results: the tree shows vigorous and symptomless growth for a brief period and then relapses with HLB symptoms. To understand why, this 2-year study was conducted to evaluate the efficacy of in-field thermotherapy and its comparison with defoliation. A significant reduction in visible tree health, foliage, and yield was observed over time in all the treatments. The quantitative real-time polymerase chain reaction (qRT-PCR) results showed that in-field thermotherapy and other treatments were not effective in reducing CLas titer. Interestingly, the performance of thermotherapy and partial defoliated trees were comparable throughout the course of the experiment, indicating that the short-term effects and vigorous growth after thermotherapy are likely an artifact of defoliation and should not be confused with or considered recovery from disease. In an in-depth molecular and biochemical analysis, we found a few subtle transient (up to 15 days) differences occurring in the in-field thermotherapy trees. Genes associated with stress and plant defense response were observed to be altered by in-field thermotherapy. Overall, our results indicate that in-field thermotherapy is not an effective and reliable strategy for mitigating HLB in commercial citrus production and that its efficacy within in-field conditions is similar to manual defoliation. It is critical that any strategy aimed at mitigating HLB should target the whole plant, including the roots, as the CLas colonizes in shoots and the root system; therefore, it can possibly translocate within the entire plant with the bulk phloem flow.

Asian citrus psyllid (Diaphorina citri) transmits the bacterial pathogen Candidatus Liberibacter asiaticus (CLas), the putative causative agent of citrus Huanglongbing disease (HLB). Insect-specific viruses can act against insects as their natural enemies, and recently, several D. citri-associated viruses were discovered. The insect gut plays an important role as not only a pool for diverse microbes but also as a physical barrier to prevent the spread of pathogens such as CLas. However, there is little evidence of the presence of D. citri-associated viruses in the gut and of the interaction between them and CLas. Here, we dissected psyllid guts collected from five growing regions in Florida, and the gut virome was analyzed by high throughput sequencing. Four insect viruses, including D. citri-associated C virus (DcACV), D. citri densovirus (DcDV), D. citri reovirus (DcRV), and D. citri flavi-like virus (DcFLV), were identified, and their presence in the gut, including an additional D. citri cimodo-like virus (DcCLV), were confirmed with PCR-based assays. Microscopic analysis showed that DcFLV infection leads to morphological abnormalities in the nuclear structure in the infected psyllid gut cells. The complex and diverse composition of microbiota in the psyllid gut suggests a possible interaction and dynamics between CLas and the D. citri-associated viruses. Our study identified various D. citri-associated viruses that localized in the psyllid gut and provided more information that helps to evaluate the potential vectors for manipulating CLas in the psyllid gut.

The plant rhizosphere microbiome is known to play a vital role in plant health by competing with pathogens or inducing plant resistance. This study aims to investigate rhizosphere microorganisms responsive to a devastating citrus disease caused by ‘Candidatus Liberibacter asiaticus’ (CLas) infection, by using 16S rRNA sequencing and metagenome technologies. The results show that 30 rhizosphere and 14 root bacterial genera were significantly affected by CLas infection, including 9 plant resistance-associated bacterial genera. Among these, Amycolatopsis, Sphingopyxis, Chryseobacterium, Flavobacterium, Ralstonia, Stenotrophomonas, Duganella, and Streptacidiphilus were considerably enriched in CLas-infected roots, while Rhizobium was significantly decreased. Metagenome analysis revealed that the abundance of genes involved in carbohydrate metabolism, such as glycolysis, starch and sucrose metabolism, amino sugar and nucleotide sugar metabolism, was significantly reduced in the CLas-infected citrus rhizosphere microbial community. Likewise, the abundance of genes involved in phosphoinositide signaling and phosphoinositide metabolism, which play important roles in energy metabolism (such as carbohydrate metabolism and lipid metabolism), was also decreased in the CLas-infected samples. Taken together, our results indicate that CLas infection could affect the resistance potential and energy metabolism of the citrus rhizosphere microbial community, which may help us to understand the rhizosphere responses to plant disease and thus facilitate the development and application of antagonistic microorganism products in citrus industry. [ABSTRACT FROM AUTHOR]

BackgroundTranscranial Doppler (TCD) can detect a right-to-left shunt (RLS) with high sensitivity but has a 5% chance of a false negative study. TCD is usually performed with injection of agitated saline into an arm vein. We compared the sensitivity of TCD performed from the brachial versus femoral veins.MethodsPatients presenting to the cardiac catheterization laboratory for percutaneous closure of a patent foramen ovale (PFO) were enrolled. Power M-mode Transcranial Doppler (Terumo 150 PMD) was conducted. After injection of a mixture of 8 cc of agitated saline, 0.5 cc of air, and 1 cc of blood into the brachial vein, embolic tracks were counted over the middle cerebral arteries. The degree of RLS was evaluated by TCD at rest, and with Valsalva at 40 mmHg aided by visual feedback with a manometer device. The test was repeated using femoral venous injections.ResultsSixty five patients were enrolled, mean age 52, 43% male. TCD grades were significantly higher with femoral injections compared to brachial injections at rest (p

In 2019, citrus production in Florida declined by more than 70%, mostly because of Huanglongbing (HLB), which is caused by the bacterium 'Candidatus Liberibacter asiaticus' (CLas). Thermotherapy for HLB-affected trees was proposed as a short-term management solution to maintain field productivity. It was hypothesized that thermotherapy could eliminate HLB from affected branches; therefore, the study objectives were to show which time-temperature combinations eliminated CLas from woody tissues. Hardening, rounded Valencia twigs collected from HLB-affected field trees were treated in a steam chamber at different time-temperature combinations (50°C for 60 s; 55°C for 0, 30, 60, 90, and 120 s; 60°C for 30 s; and an untreated control). Three independent repetitions of 13 branches per treatment were grafted onto healthy rootstocks and tested to detect CLas after 6, 9, and 12 months. For the RNA-based CLas viability assay, three branches per treatment were treated and bark samples were peeled for RNA extraction and subsequent gene expression analyses. During the grafting study, at 12 months after grafting, a very low frequency of trees grafted with twigs treated at 55%#176;C for 90 s and 55°C for 120 s had detectable CLas DNA. In the few individuals with CLas, titers were significantly lower (P < 0.0001) and could have been remnants of degrading DNA. Additionally, there was a significant decrease (P > 0.0001) in CLas 16S rRNA expression at 55°C for 90 s, 55°C for 120 s, and 60°C for 30 s (3.4-fold change, 3.4-fold change, and 2.3-fold change, respectively) in samples 5 days after treatment. Heat injury, not total CLas kill, could explain the limited changes in transcriptional activity; however, failed recovery and eventual death of CLas resulted in no CLas detection in most of the grafted trees treated with the highest temperatures or longest durations. [ABSTRACT FROM AUTHOR]

The destructive citrus disease, Huanglongbing (HLB) or citrus greening, continues to devastate Florida’s citrus industry. A hemipteran insect, the Asian citrus psyllid (ACP), disperses Candidatus Liberibacter asiaticus, one of the putative bacterial pathogens of HLB. This study builds upon ongoing research utilizing high-throughput sequencing to analyze the virome of ACP populations collected from citrus groves throughout Florida. Following the widespread detection of sequences aligning to the genome of citrus tristeza virus (CTV) across consecutive years in the Florida ACP virome, we continued to detect a pervasive amount of CTV in Florida ACPs during subsequent years. Simultaneously, we also detected mixed infections of CTV strains in pooled ACPs from different Florida regions. Predating the HLB epidemic, CTV has been present in Florida for many years and our results confirm its widespread and diverse persistence in Florida citrus groves through a unique lens, the ACP. CTV presence in the ACP likely results from feeding on CTV-infected citrus trees in Florida citrus groves, which may help to understand an overlapping presence of CTV and HLB, both endemic citrus pathosystems in the state, and their role in future integrated pest management strategies.

One of the important functions of antennas is to facilitate wireless communication. The IEEE 802.11 is part of the IEEE802 set of local area network technical standards, and specifies the media access control and physical layer protocols for implementing wireless local area network computer communication. The network physical layer protocol with a centre frequency of 2.4 GHz has a bandwidth of 22 MHz. A conformal load-bearing antenna structure (CLAS) facilitating this communication band that is tuned to 2.4 GHz must remain within this bandwidth. The aim of this paper is to investigate the effects of mechanical loading imposed on a load-bearing patch antenna with respect to its ability to remain within the specified bandwidth. The mechanical loading configurations considered include tensile, biaxial, and twisting. This paper will also report on the response of the antenna patch to the presence of a disbond between the metallised antenna and its substrate, which can arise due to fabrication anomalies and operational usage. This numerical work will assist in the design of experimental testing of the mechanical and electromagnetic properties of an embedded CLAS, which will ultimately be used to inform selection of appropriate regions to place patch antennas on load-bearing deformable surfaces.

The aim of this article is to increase awareness of language practices in the deaf community that affect communication needs and health outcomes, focusing particularly on the prevalence of bilingualism among deaf adults. Language deprivation and poor health outcomes in the deaf population are risks that cannot be addressed solely by hearing intervention. We propose that bilingualism acts as a protective measure to minimize the health risks faced by deaf individuals. Provision of culturally and linguistically appropriate services to deaf stakeholders, and particularly hearing families of deaf children, requires familiarity with the developmental and social ramifications of bilingualism. [ABSTRACT FROM AUTHOR]

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Huanglongbing (HLB), a bacterial disease, is one of the most destructive citrus diseases. For many decades, it has been known that using heat/high temperatures (thermotherapy) is effective in suppressing plant diseases, particularly the suppression of Candidatus Liberibacter (CLas, casual agent for HLB) when the treated plants are grown in pots (allowing treatment of roots) under controlled conditions. However, in-field thermotherapy has yielded inconsistent results: the tree shows vigorous and symptomless growth for a brief period and then relapses with HLB symptoms. To understand why, this 2-year study was conducted to evaluate the efficacy of in-field thermotherapy and its comparison with defoliation. A significant reduction in visible tree health, foliage, and yield was observed over time in all the treatments. The quantitative real-time polymerase chain reaction (qRT-PCR) results showed that in-field thermotherapy and other treatments were not effective in reducing CLas titer. Interestingly, the performance of thermotherapy and partial defoliated trees were comparable throughout the course of the experiment, indicating that the short-term effects and vigorous growth after thermotherapy are likely an artifact of defoliation and should not be confused with or considered recovery from disease. In an in-depth molecular and biochemical analysis, we found a few subtle transient (up to 15 days) differences occurring in the in-field thermotherapy trees. Genes associated with stress and plant defense response were observed to be altered by in-field thermotherapy. Overall, our results indicate that in- field thermotherapy is not an effective and reliable strategy for mitigating HLB in commercial citrus production and that its efficacy within in-field conditions is similar to manual defoliation. It is critical that any strategy aimed at mitigating HLB should target the whole plant, including the roots, as the CLas colonizes in shoots and the root system; therefore, it can possibly translocate within the entire plant with the bulk phloem flow. [ABSTRACT FROM AUTHOR]

The purpose of this study is to evaluate the performance of a robot combine harvester by comparing the Centimeter Level Augmentation Service (CLAS) and the Multi-Global Navigation Satellite System (GNSS) Advanced Demonstration tool for Orbit and Clock Analysis (MADOCA) from the Quasi-Zenith Satellite System (QZSS) by using the Real Time Kinematic (RTK) positioning technique as a reference. The first section of this study evaluates the availability and the precision under static conditions by measuring the activation time, the reconnection time, and obtaining a Twice Distance Root Mean Square (2DRMS) of 0.04 m and 0.10 m, a Circular Error Probability (CEP) of 0.03 m and 0.08 m, and a Root Mean Square Error (RMSE) of 0.57 m and 0.54 m for the CLAS and MADOCA, respectively. The second section evaluates the accuracy under dynamic conditions by using a GNSS navigation-based combine harvester running in an experimental field. The results show that the RMSE of the lateral deviation is between 0.04 m and 0.69 m for MADOCA and between 0.03 m and 0.31 m for CLAS; which suggest that the CLAS positioning augmentation system can be utilized for the robot combine harvester if the user considers these accuracy and dynamic characteristics.

Investigations on Ti, Pr, and Dy substitution and Ti co-substitution with La, Ce, Pr, Nd, and Dy in Y site were carried out. The XRD patterns indicate that the solubility limit for Ti is 5%. The solubility limit for Dy is 100%. Impurities will form if the substituting proportion surpasses the solubility limit for the substituting ion. For the phase composition of all co-substitution samples, only Ti and Dy substituted one is essentially single phase. The largest oxygen content δ reached 1.054, 1.188 and 1.070 for Y0.95Ti0.05BaCo4O7+δ, DyBaCo4O7+δ, Y0.2Ti0.05Dy0.75BaCo4O7+δ, respectively. The largest oxygen content δ reached was 0.900 for Y0.25Pr0.75BaCo2O5+δ. [ABSTRACT FROM AUTHOR]