bluuebunny/crossref_metadata_2025 huggingface dataset:
Comprehensive assessment of intelligent unmanned vehicle techniques in pesticide application: A case study in pear orchard
Authors: Jiang Yulin , He Xiongkui , Song Jianli , Liu Yajia , Wang Changling , Li Tian , Qi Peng , Yu Congwei , Chen Fu
Published: August 2022

The intelligent pesticide application techniques in orchards have grown rapidly worldwide due to the decrease in agricultural populations and the increase in labor costs. However, whether and how intelligent pesticide application techniques are better than conventional pesticide application remains unclear. Here, we evaluated the performance of the unmanned aircraft vehicle (UAV) and unmanned ground vehicle (UGV) on pesticide application, ecological environment protection, and human’s health protection compared to conventional manual methods. We quantified characteristics from the aspects of working effectiveness, efficiency, environmental pollution, water saving and carbon dioxide reduction. The results showed that the UAV application has the advantages of a higher working efficiency and less environmental pollution and natural resource consumption compared to the UGV and conventional manual methods despite of its worse spray performance The UGV application techniques could improve spray performance at the cost of high environmental pollution. The conventional spray gun technique was unfriendly to environmental and resource protection although it showed a better spray performance. Thus, the balance of improving spray performance and controlling environmental pollution is the key to improve the performance of UAV and UGV technology in the future. The study could be useful in the development of intelligent pesticide application techniques and provide scientific support for the transition of intelligent management in orchards.
The lifestyle of Tuyuhun royal descendants: Identification and chemical analysis of buried plants in the Chashancun cemetery, northwest China
Authors: Lu Yongxiu , Liu Bingbing , Liu Ruiliang , Jiang Hongen , Yang Yishi , Ye Qinhan , Li Ruo , Wei Wenyu , Chen Guoke , Dong Guanghui
Published: August 2022

The Tuyuhun Kingdom (AD 313–663) was one of the most famous regimes in northwest China during the early medieval period. However, the lifestyle and spiritual pursuit of their descendants who became allied with the Tang Dynasty remain enigmatic. The excavation of the Chashancun cemetery, a Tuyuhun royal descendant (AD 691) cemetery in the Qilian Mountains in northwest China, reveals a large amount of uncharred plant remains. These remains provided a rare opportunity to explore the geographical origin of the buried crops and their social implications. In total, 253,647 crops and 12,071 weeds were identified. Foxtail millet and broomcorn millet represent 61.99 and 30.83% of the total plant remains, with the rest being barley, buckwheat, beans, and hemp. The oxygen isotope and trace elements of the crop and weed remains suggest that broomcorn millet, foxtail millet, barley, buckwheat, and hemp were sourced from different regions. The assemblage of plant remains in the Chashancun cemetery suggests that millet cultivation played an important role in the livelihoods of Tuyuhun descendants, and the location of the elite Tuyuhun cemetery and multisources of different buried crops may reflect their memory of ancestors and homelands. This case study provides a unique perspective to understand the interactions among human subsistence strategy, geopolitical patterns, and local natural environments in northwest China during the late 7th century.
How do arbuscular mycorrhizas affect reproductive functional fitness of host plants?
Authors: Wang Lei , Tang Zhanhui
Published: August 2022

Arbuscular mycorrhizal (AM) symbiosis in soil may be directly or indirectly involved in the reproductive process of sexually reproducing plants (seed plants), and affect their reproductive fitness. However, it is not clear how underground AM symbiosis affects plant reproductive function. Here, we reviewed the studies on the effects of AM symbiosis on plant reproductive fitness including both male function (pollen) and female function (seed). AM symbiosis regulates the development and function of plant sexual organs by affecting the nutrient using strategy and participating in the formation of hormone networks and secondary compounds in host plants. The nutrient supply (especially phosphorus supply) of AM symbiosis may be the main factor affecting plant's reproductive function. Moreover, the changes in hormone levels and secondary metabolite content induced by AM symbiosis can also affect host plants reproductive fitness. These effects can occur in pollen formation and transport, pollen tube growth and seed production, and seedling performance. Finally, we discuss other possible effects of AM symbiosis on the male and female functional fitness, and suggest several additional factors that may be involved in the influence of AM symbiosis on the reproductive fitness of host plants. We believe that it is necessary to accurately identify and verify the mechanisms driving the changes of reproductive fitness of host plant in symbiotic networks in the future. A more thorough understanding of the mechanism of AM symbiosis on reproductive function will help to improve our understanding of AM fungus ecological roles and may provide references for improving the productivity of natural and agricultural ecosystems.
Linkage mapping and association analysis to identify a reliable QTL for stigma exsertion rate in rice
Authors: Liu Yi , Fu Dong , Kong Deyan , Ma Xiaosong , Zhang Anning , Wang Feiming , Wang Lei , Xia Hui , Liu Guolan , Yu Xinqiao , Luo Lijun
Published: August 2022

The commercialization of hybrid rice has greatly contributed to the increase in rice yield, with the improvement of its seed production capacity having played an important role. The stigma exsertion rate (SER) is a key factor for improving the outcrossing of the sterile line and the hybrid rice seed production. We used the Zhenshan 97B × IRAT109 recombinant inbred population comprising 163 lines and a natural population of 138 accessions to decipher the genetic foundation of SER over 2 years in three environments. Additionally, we detected eight QTLs for SER on chromosomes 1, 2, and 8 via linkage mapping. We also identified seven and 19 significant associations for SER using genome-wide association study in 2016 and 2017, respectively. Interestingly, we located two lead SNPs (sf0803343504 and sf083344610) on chromosome 8 in the qTSE8 QTL region that were significantly associated with total SER. After transcriptomic analysis, quantitative real-time PCR, and haplotype analysis, we found 13 genes within this reliable region as important candidate genes. Our study results will be beneficial to molecular marker-assisted selection of rice lines with high outcrossing rate, thereby improving the efficiency of hybrid seed production.
How negative anthropomorphic message framing and nostalgia enhance pro-environmental behaviors during the COVID-19 pandemic in China: An SEM-NCA approach
Authors: Zhou Shuai , Wang Yibo
Published: August 2022

Although extensive research has been conducted on promoting pro-environmental behaviors among consumers, little is known about whether and how negative anthropomorphic message framing (NAMF) and nostalgia affect pro-environmental behavior. To provide a framework for explaining pro-environmental behavior, this study integrates protection motivation theory, the stimulus-organism-response model, and message framing. To create the model of the influences on pro-environmental behavior, NAMF was employed as the external stimulus; the sense of environmental responsibility, environmental empathy, perceived threat, and perceived vulnerability as the psychological and cognitive response factors; pro-environmental behavior as the final decision of consumers; and nostalgia as the moderating variable. An online questionnaire was distributed and 380 usable questionnaires were collected using convenience sampling and analyzed using two complementary approaches: partial least squares structural equation modeling (PLS-SEM) and necessary condition analysis (NCA). PLS-SEM results showed that pro-environmental behavior was significantly affected by NAMF (β = 0.313, t-value = 5.583), environmental responsibility (β = 0.207, t-value = 3.994), and perceived threats (β = 0.252, t-value = 4.889). Meanwhile, an increase in nostalgia increased the effect of NAMF and environmental responsibility on pro-environmental behavior. The NCA results revealed that NAMF (d = 0.108, p < 0.001) and perceived threat (d = 0.209, p < 0.001) were key factors of pro-environmental behavior. In addition, for high level of pro-environmental behavior (>80%), NAMF (12.1%) and perceived threat (39.6%) are required. Finally, we offer several suggestions based on the results of our empirical research. For example, marketing and service offerings should be tailored to the needs of masses with different nostalgic tendencies to enhance their pro-environmental behaviors.
The effectiveness of formative assessment for enhancing reading achievement in K-12 classrooms: A meta-analysis
Authors: Xuan Qianying , Cheung Alan , Sun Dan
Published: August 2022

This quantitative synthesis included 48 qualified studies with a total sample of 116,051 K-12 students. Aligned with previous meta-analyses, the findings suggested that formative assessment generally had a positive though modest effect (ES = + 0.19) on students’ reading achievement. Meta-regression results revealed that: (a) studies with 250 or less students yielded significantly larger effect size than large sample studies, (b) the effects of formative assessment embedded with differentiated instruction equated to an increase of 0.13 SD in the reading achievement score, (c) integration of teacher and student directed assessment was more effective than assessments initiated by teachers. Our subgroup analysis data indicated that the effect sizes of formative assessment intervention on reading were significantly different between Confucian-heritage culture and Anglophone culture and had divergent effective features. The result cautions against the generalization of formative assessment across different cultures without adaptation. We suggest that effect sizes could be calculated and intervention features be investigated in various cultural settings for practitioners and policymakers to implement tailored formative assessment.
The association between family relationships and depressive symptoms among pregnant women: A network analysis
Authors: Wang Jingjing , Pei Yifei , Tang Jie , Chen Qian , He Chenlu , Zhang Ying , Hou Hao , Zhang Xunbao , Wang Wei
Published: August 2022

Background

Depression of pregnant women has been a growing concern in recent years, and previous research has found that family relationships are strongly associated with depression. From a network perspective, family relationships and depression can be conceptualized as the result of interactions between individual symptoms. This research approach can elucidate the structure and mechanisms of the relationship between individual symptoms within the two groups.

Methods

A total of 990 participants were recruited from the obstetrics outpatient clinic of Maternal and Child Health Hospital in Huai'an through a randomized whole-group sampling. Respondents' depressive symptoms and family relationships were self-reported using questionnaire, and the structure of the family relationship-depressive symptoms network and related centrality indicators were examined for this sample.

Results

The results of the network analysis suggested that the most influential symptoms in the network of family relationship-depressive symptoms were worry, feeling worthless, equal status with husband and couple relationship. And equal status with husband was the most prominent bridging symptoms in this study. The whole network was robust in both stability and accuracy tests.

Limitations

Information was obtained from subjects' self-reports, which may be subject to information bias. As a cross-sectional study, no causal link between family relationships and depressive symptoms can be established.

Conclusion

Worry, feeling worthless, equal status with husband and couple relationship are central symptoms of the family relationship-depressive symptoms network structure in pregnant women. Timely and systematic multilevel interventions targeting the central symptoms may be effective in alleviating the onset of depressive symptoms in women during this period.
Epidemiology of childhood trauma and its association with insomnia and psychotic-like experiences in Chinese Zhuang adolescents
Authors: Wei Qiaoyue , Pan Yuli , Zhang Shengjie , Yin Wenwen , Lin Qinghong , Pan Shuibo , Dai Chenyangzi , Zhou Linhua , Wu Junduan
Published: August 2022

Background

Adolescents who have experienced childhood trauma are more likely to have insomnia and psychotic-like experiences (PLEs) than adolescents from other ethnic groups. However, little is known about the youth of ethnic minorities. This study aimed to investigate the epidemiology of childhood trauma and its relationship with insomnia and PLEs in Chinese Zhuang adolescents, focusing on the role of a specific type of trauma and accumulation.

Methods

A questionnaire of Childhood Trauma Questionnaire-Short Form (CTQ-SF), Athens Insomnia Scale (AIS), and Chinese Version Community assessment psychic experiences-8 (CCAPE- 8) were all completed by 1,493 Chinese Zhuang adolescents. Chi-square and multivariate logistic regression analyses examined the association between childhood trauma and insomnia/PLEs.

Results

The incidences of emotional abuse (EA), physical abuse (PA), sexual abuse (SA), emotional neglect (EN), and physical neglect (PN) occurred at rates of 5.63, 5.02, 6.56, 23.98, and 33.15%, respectively. EA, SA, EN, and PN were all positively related to insomnia (OR: 1.314–7.720, all p < 0.05). EA and SA were positively associated with PLEs (OR: 2.131–3.202, all p < 0.001). Adolescents who had experienced three or more types of traumas were more likely to have insomnia (OR = 6.961, p < 0.001) and PLEs (OR = 3.558, p < 0.001).

Conclusion

The most common type of childhood trauma is PN. Childhood trauma has the primary effect on insomnia/PLE. A significant dose-response relationship was found between Childhood trauma and insomnia/ PLEs. This association varied depending on the type and accumulation of exposure.
Integrated co-expression network analysis uncovers novel tissue-specific genes in major depressive disorder and bipolar disorder
Authors: Han Mengyao , Yuan Liyun , Huang Yuwei , Wang Guiying , Du Changsheng , Wang Qingzhong , Zhang Guoqing
Published: August 2022

Tissue-specific gene expression has been found to be associated with multiple complex diseases including cancer, metabolic disease, aging, etc. However, few studies of brain-tissue-specific gene expression patterns have been reported, especially in psychiatric disorders. In this study, we performed joint analysis on large-scale transcriptome multi-tissue data to investigate tissue-specific expression patterns in major depressive disorder (MDD) and bipolar disorder (BP). We established the strategies of identifying tissues-specific modules, annotated pathways for elucidating biological functions of tissues, and tissue-specific genes based on weighted gene co-expression network analysis (WGCNA) and robust rank aggregation (RRA) with transcriptional profiling data from different human tissues and genome wide association study (GWAS) data, which have been expanded into overlapping tissue-specific modules and genes sharing with MDD and BP. Nine tissue-specific modules were identified and distributed across the four tissues in the MDD and six modules in the BP. In general, the annotated biological functions of differentially expressed genes (DEGs) in blood were mainly involved in MDD and BP progression through immune response, while those in the brain were in neuron and neuroendocrine response. Tissue-specific genes of the prefrontal cortex (PFC) in MDD-, such as IGFBP2 and HTR1A, were involved in disease-related functions, such as response to glucocorticoid, taste transduction, and tissue-specific genes of PFC in BP-, such as CHRM5 and LTB4R2, were involved in neuroactive ligand-receptor interaction. We also found PFC tissue-specific genes including SST and CRHBP were shared in MDD-BP, SST was enriched in neuroactive ligand-receptor interaction, and CRHBP shown was related to the regulation of hormone secretion and hormone transport.
A core framework of “mountain management–water management–moist city” for sponge city special planning: The case of northwestern China
Authors: Wu Ran , Yang Ye , He Junchao , Zhu Jiang
Published: August 2022

Sponge city special planning represents a basis for sponge city construction in China. It has a leading role in problem-oriented, effect-centered comprehensive, and coordinated construction. In accordance with the Interim Provisions on the Formulation of Sponge City Special Planning, China has gradually established a standardized method for formulating sponge city special planning based on the “four-water” framework. While this method emphasizes the normalization of planning contents, it has limitations when dealing with regional characteristics. The present paper clarifies the purposes and demands of formulating sponge city special planning for semi-arid valley cities in northwestern China. It furthermore highlights the limitations of the standard method and suggests a three-level optimization, i.e., problem identification, target indicators, and system construction. Based on the framework of “mountain management–water management–moist city,” this paper proposes a set of ideas for formulating sponge city special planning. In this regard, the discussions are based on the formulation practice of Xining.
Direct Robotic Extrusion of Photopolymers (DREPP): Influence of microgravity on an in-space manufacturing method
Authors: Kringer Michael , Böhrer Christoph , Frey Moritz , Pimpi Jannik , Pietras Markus
Published: August 2022

A method using Direct Robotic Extrusion of Photopolymers (DREPP) to manufacture structures in space in a cost- and power-efficient way is presented in this article. The DREPP technology has the potential to outperform conventional deployable structures, which generally suffer from severe limitations: long and high-cost development phases, dimensioning driven by launch loads instead of operational loads, mechanical complexity as well as constraints to the maximum structure size due to volume limitations on the spacecraft. In-Space Manufacturing (ISM) and especially AM offer a solution to circumvent these limitations. Fundamental investigations on AM in space have already been carried out on the International Space Station (ISS). Numerous test prints have shown that Fused Filament Fabrication (FFF) provide satisfactory results under microgravity and controlled environmental conditions. With the investigated manufacturing process, a photoreactive resin is robotically extruded through a nozzle and directly cured by UV-light. Unlike most conventional Additive Manufacturing (AM) methods, which manufacture layer-by-layer, the DREPP technology is able to create three-dimensional structural elements in one continuous movement. To investigate the feasibility under microgravity conditions, multiple experiments were performed on parabolic flights, where it was shown that different geometries can be successfully manufactured under microgravity conditions. When examining the printing process at zero-gravity and under 1 g conditions, differences in the printing behaviour can be observed, which are investigated in detail. In addition, the evaluation shows that a large curing zone – the transition area between the liquid and cured state of the extruded resin – is easier to handle in zero-gravity than under 1 g conditions. This contributes to an increased overall process stability and enables new ways for controlling the process. This article provides details on the ground, zero and altered gravity testing, process quality evaluation and gives an outlook on future investigations of the DREPP approach and preparations for experiments in microgravity and vacuum on a sounding rocket.
Quantifying the pollutant load into the Southern California Bight from Mexican sewage discharges from 2011 to 2020
Authors: Arreola-Serrano Ana S. , Mendoza-Espinosa Leopoldo G. , Hernández-Cruz Astrid , Daesslé Luis W. , Villada-Canela Mariana
Published: August 2022

Sewage discharges into the ocean are one of the main sources of pollutant load on the coasts, resulting in health risks and ecological deterioration. The Southern California Bight runs from Point Conception in California (USA) to Punta Colonet in Baja California (Mexico). The impact of U.S. sewage discharges on the bay is well-documented, much less exist about the Mexican discharges. Official wastewater quality results for 17 wastewater treatment plants (WWTP) in Tijuana-Rosarito, Baja California from 2011 to 2020 are presented for the first time. The average wastewater flow during these years was 3,421 L s−1, covering the discharge of 2,049,413 people. Water quality was compared with the current Mexican Norm for the discharge of wastewater to the ocean. It was found that only 53% of the samples complied with all the normed parameters, while 88% complied specifically with trace metal concentrations. Among the parameters above the norm were fecal coliforms, total suspended solids, and chemical and biochemical oxygen demand (COD and BOD). The San Antonio de Los Buenos WWTP accounts for the discharge of 80% of the BOD for all Tijuana-Rosarito WWTPs, 76% of COD, 84% of total suspended solids (TSS), 54% of total nitrogen (TN), and 55% of total phosphorous (TP) to the ocean. These represent mean yearly discharges from 2011 to 2020 of 150 tons of TN, 27 tons of TP, 528 tons of TSS, 401 tons of BOD and 1,191 tons of COD. Immediate action is needed to stop these high loads into the Pacific coast.
The characteristics of the breaststroke pullout in elite swimming
Authors: McCabe Carla , Mosscrop Emma , Hodierne Ryan , Tor Elaine
Published: August 2022

Since the rule change permitting the inclusion of one dolphin kick during the underwater breaststroke pullout phase following a swim start or turn, there has been an emergence of several different pullout techniques adopted by elite swimmers. The aim of this study was to characterize the underwater breaststroke pullout technique trends and to assess the effectiveness of each technique as utilized by elite male and female swimmers. The sample included 60 swimmers (n = 26 male, n = 34 female) competing across the 50, 100, and 200 m long-course breaststroke final races from the World Championships 2015, 2017, 2019 and Olympic Games 2016. An above-water camera was used to identify and measure the different phases of the underwater pullout techniques, which was found to be a highly accurate methodological approach (ICC = 0.97). From the 150 trials analyzed, three different pullout techniques were identified: the Fly-Kick First technique, the Combined technique and the Pull-Down First technique. Although the most common underwater pullout technique utilized by elite competitive breaststroke swimmers was the Combined technique (n = 71), followed by the Fly-Kick First technique (n = 65) and the Pull-Down First technique (n = 14), it was observed that technical selection deviates according to gender. This indicates that male and female swimmers should not be coached adhering to the same technical model. This study found no significant difference in terms of performance outcome with respect to each of these techniques, indicating that technique selection should be guided by one's individual preference. It was concluded that the results of this study will serve as an up-to-date resource for coaches and swimmers working with elite breaststroke swimmers and as a useful insight to current underwater pullout trends.
Combined intra- and extra-endoscopic techniques for endoscopic intraventricular surgery with a new mini-tubular port
Authors: Liu Xi , Qiu Yan'kai , Zhang Fan , Wei Xiaoming , Zhou Zhisong , Zhang Feng , Xue Yiteng , Ma Zhaoru , Wang Xiaosong , Shen Hong , Lin Zhiguo , Shi Huaizhang , Liu Li
Published: August 2022

Objective

Intraoperative hemorrhage represents a major risk during endoscopic intraventricular surgery. There are very few publications describing the maintenance of hemostasis during conventional endoscopic intraventricular surgery. Here, we designed a new mini-tubular port to combine intra- and extra-endoscopic techniques for endoscopic intraventricular surgery. With this new methodology, complicated techniques can be performed more efficiently with improved bleeding control.

Methods

The new mini-tubular port consists of an outer sheath and an obturator. The sheath is a thin-walled transparent cylinder that is 0.35 mm thick, 10 mm in diameter, and 90 mm in length. In this report, we describe the use of the mini-tubular port on 36 patients receiving endoscopic intraventricular surgery.

Results

The study enrolled 36 patients, with a median age of 45 years (range: 0–72 years), of which 19 were male and 17 were female. Pure ETV (endoscopic third ventriculostomy) was performed in 20 patients and pure biopsy was performed in 2. ETV and biopsy were performed in five patients, ETV and the removal of cysticerci were performed in five, cyst fenestration was performed in one, ETV and cyst fenestration were performed in two, and ETV and shunt removal were performed in one patient. Two patients received microscopic surgery following endoscopic surgery during the same operation. A total of 17 patients (47%) underwent extra-endoscopic techniques. The median Karnofsky Performance Status (KPS) score of the patients prior to surgery was 50, while the median KPS score of the patients after one month of surgery was 80; these scores were significantly different (P < 0.05), as determined by Wilcoxon's test. In total, 27 patients had a KPS score ≥70% and 75% of patients had a favorable prognosis one month after surgery. None of the patients experienced seizure.

Conclusion

The new mini-tubular port can conveniently combine intra- and extra-endoscopic techniques for endoscopic intraventricular surgery. The application of these techniques can efficiently control bleeding during surgery, help improve the confidence of the surgeons involved, and provide a highly efficient approach for performing complicated procedures.
Effects of dietary supplement with a Chinese herbal mixture on growth performance, antioxidant capacity, and gut microbiota in weaned pigs
Authors: Xu Qinglei , Cheng Meng , Jiang Rong , Zhao Xianle , Zhu Jianjin , Liu Mingzheng , Chao Xiaohuan , Zhang Chunlei , Zhou Bo
Published: August 2022

Weaning stress decreases the growth performance of piglets and is one of the main concerns of pig industries. Traditional Chinese herbal medicines have been used to reduce the adverse effects of weaning stress as both nutritional supplements and antibiotic substitutes. This study aimed to evaluate the effects of a Chinese herbal mixture (Kangtaile, which contained Paeonia lactiflora, licorice, dandelion, and tea polyphenols) on the growth performances, immune response, antioxidant capacity, and intestinal microbiota of weaned pigs. A total of 400 weaned pigs [Duroc × (Landrace × Yorkshire)] were randomly allocated into one of four treatments: the CON group, fed with basic diet; the HM1 group, fed with basal diet supplemented with 0.5 g herbal mixture/kg diet; the HM2 group, fed with basal diet supplemented with 1.0 g herbal mixture/kg diet; or the HM3 group, fed with basal diet supplemented with 1.5 g herbal mixture/kg diet. The results revealed that dietary supplementation with the herbal mixture for 28 days improved average daily gain and feed conversion ratio, while decreased the diarrhea rate of weaned pigs. Moreover, dietary supple-mentation with the herbal mixture improved the antioxidant capacity through increasing the activity of catalase (CAT) and the total antioxidant capacity (T-AOC) level, while decreasing the concentration of malondialdehyde (MDA) in the serum. Pigs supplemented with herbal mixture presented an increased serum immunoglobulin (Ig)M level on day 14 compared with control pigs. The herbal mixture altered the composition of intestinal microbiota by influencing the relative abundances of Firmicutes and Bacteroidetes at the phylum level. The relative abundances of the Firmicutes and Bacteroidetes were significantly related to the body weight gain of pigs. In conclusion, supplementation of herbal mixture to the diet improved growth performance, immunity, and antioxidant capacity and modified the composition of intestinal microbiota in weaning pigs. This study provided new insights into the nutritional regulation effects of the herbal mixtures on weaned pigs.
QFC: A Parallel Software Tool for Feature Construction, Based on Grammatical Evolution
Authors: Tsoulos Ioannis G.
Published: August 2022

This paper presents and analyzes a programming tool that implements a method for classification and function regression problems. This method builds new features from existing ones with the assistance of a hybrid algorithm that makes use of artificial neural networks and grammatical evolution. The implemented software exploits modern multi-core computing units for faster execution. The method has been applied to a variety of classification and function regression problems, and an extensive comparison with other methods of computational intelligence is made.
High-Rate, High-Precision Wing Twist Actuation for Drone, Missile, and Munition Flight Control
Authors: Barrett-Gonzalez Ronald , Wolf Nathan
Published: August 2022

This paper covers a new actuation and deflection controller configuration for high-aspect-ratio wings used on subsonic drones, missiles, and munitions. Current approaches to the flight control of these aircraft have unearthed challenges with friction, stiction, slop, bandwidth, and thick boundary layer nonlinearities, which degrade flight control accuracy—especially in terminal flight phases. The approach described in this paper uses directionally attached piezoelectric (DAP) actuators to actively twist a high-aspect-ratio wing for flight control. The DAP actuators were modeled analytically and computationally using linear finite element modeling. A 3″ (7.62 cm) chord × 15″ (38.1 cm) semispan rectangular wing with an NACA 0012 profile was built and structurally tested, demonstrating excellent agreement between theory and experiment. New actuation methods were used to overdrive the PZT-5H piezoelectric elements deep into the repoling range. This overdrive actuation rejuvenated the actuator elements and allowed for dramatically improved deflections with respect to configurations in previous years. Static testing demonstrated deflections in excess of ±1.6° in root-to-tip twist. Dynamic testing showed corner frequencies greater than 310 Hz. A series of wind tunnel tests at up to 180 ft/s (55 m/s, 123 mph, 107 kts, 198 kph) demonstrated excellent roll control authority, rapid manipulation of Clδ, and lift manipulation using quasi-static deflections. The paper concludes with a summary of implications for terminal guidance for drone, missile, and munition flight control in real atmospheres.
Fault-Tolerant Control of Linear Systems with Unmatched Uncertainties Based on Integral Sliding Mode Technique
Authors: Hao Li-Ying , Zhou Lian-Sheng
Published: August 2022

This paper proposes a novel fault-tolerant control method based on the integral sliding mode technique for unmatched uncertain linear systems with external perturbations. Differently from the existing works, the uncertainties under consideration have an unmatched norm-bounded form in the system and input matrix. Based on linear matrix inequalities, the existence conditions of the sliding mode surface are presented. The unknown fault information is then estimated by some adaptive laws. On the grounds of that, an integral sliding mode controller is also obtained to guarantee the disturbance attenuation and fault tolerance for linear uncertain systems with unmatched uncertainties and actuator faults from the initial time. Finally, the comparative simulation results verify the effectiveness of our presented scheme.
Study of the Impact of Traffic Flows on the ATC Actions
Authors: Gutiérrez Teuler Guillermo , Arnaldo Valdés Rosa María , Gómez Comendador Victor Fernando , López de Frutos Patricia María , Rodríguez Rodríguez Rubén
Published: August 2022

It has always been a topic of great interest in air transport management to be able to estimate controller workload. So far, research has not had the opportunity to make use of real data on the controller’s actions. We have enough data to be able to use machine learning methods. The aim of this work is to predict the controller’s actions to know his workload. Several machine learning models were tested to try different combinations of features and the selected algorithms and two models were finally chosen. The predictions provided by the models are good enough to be used when a first approximation of the workload in a sector is to be obtained. Finally, explainability techniques were employed to discover the patterns found by the AI in the machine learning models. Thanks to these techniques, we can build a profile of the critical flights that increase the workload the most.
Influence of Spray Control Parameters on the Performance of an Air-Blast Sprayer
Authors: Hu Yaohua , Yang Huanbo , Hou Bingru , Xi Ziting , Yang Zidong
Published: August 2022

Orchard plant protection machinery in China still has a low application efficiency. Air-blast sprayers represent the primary development direction of pesticide applications in orchards. The spray control parameters have to be matched to the tree canopy status to achieve precise results. In this study, a vertical patternator was used to determine the accuracy of spraying fruit trees. The influences of three control parameters (blower speed, spray angle, and spray distance) on the spray performance of the air-blast sprayer were analyzed, and the volume of the spray was measured in collection plates at different heights. The quantitative relationship between the overall collection volume and the critical height collection volume was obtained for different parameter values, and the combined effects of any two control parameters on the collection performance and the position of the optimum collection area were obtained. The regression model describing the relationship between the collection volume in the critical height range and the three factors was established, and the main effects of the control parameters were determined. The results showed that if one parameter remained constant, the correlation between the other two parameters was non-significant. The collection volume in the critical height range increased initially and then decreased as the spray distance increased. The maximum collection volume was obtained at a spray distance of 1.762 m. The regression model can be used to obtain the optimum values of the parameters.
Effect of Water Deficit on Growth and Photoassimilate Partitioning in Leersia hexandra and Luziola peruviana
Authors: Silva Renan Souza , Scherner Ananda , Da-Silva Cristiane Jovelina , Camargo Edinalvo Rabaioli , Palacios-Zuñiga Roque Mauricio , Schreiber Fabio , Amarante Luciano do , Parfitt José Maria Barbat , Avila Luis Antonio de
Published: August 2022

Minimum tillage in rice production is increasing in southern Brazil, reaching 60% of the total planted area. Compared to conventional tillage, in this system there is an increase in the occurrence of perennial weeds, such as Luziola peruviana and Leersia hexandra, which are amphibious plants, as they can occur in both flooded environments and aerobic conditions. These weeds are controlled in burn-down before rice planting by glyphosate applications, the efficacy of which depends on the soil moisture. This study aimed to evaluate the effect of different soil moisture regimes in L. hexandra and L. peruviana growth and photoassimilate partitioning. Both species were assessed under soil moisture regimes of flooded, saturated, 7 kPa, 15 kPa, 40 kPa, and 100 kPa (experiment 1) and flooded, saturated, and 7 kPa (experiment 2). Plants were sampled immediately after drainage (3 months after transplant) and 1 and 2 weeks after drainage. The results showed that as soil moisture levels decreased, growth and development parameters were negatively affected in both species. Photoassimilate partitioning was affected by water regime and differences were observed between species. The total soluble sugars and starch content decreased in the leaves, and sucrose concentration increased in the roots following drainage. Soil drainage affects the growth and alters carbohydrate partitioning of these weeds, increasing the sugar storage in roots. The agronomic impact of these findings is that this behavior may affect herbicide transport in phloem and may affect herbicide efficacy.
Estimation of Maize LAI Using Ensemble Learning and UAV Multispectral Imagery under Different Water and Fertilizer Treatments
Authors: Cheng Qian , Xu Honggang , Fei Shuaipeng , Li Zongpeng , Chen Zhen
Published: August 2022

The leaf area index (LAI), commonly used as an indicator of crop growth and physiological development, is mainly influenced by the degree of water and fertilizer stress. Accurate assessment of the LAI can help to understand the state of crop water and fertilizer deficit, which is important for crop management and the precision agriculture. The objective of this study is to evaluate the unmanned aerial vehicle (UAV)-based multispectral imaging to estimate the LAI of maize under different water and fertilizer stress conditions. For this, multispectral imagery of the field was conducted at different growth stages (jointing, trumpet, silking and flowering) of maize under three water treatments and five fertilizer treatments. Subsequently, a stacking ensemble learning model was built with Gaussian process regression (GPR), support vector regression (SVR), random forest (RF), least absolute shrinkage and selection operator (Lasso) and cubist regression as primary learners to predict the LAI using UAV-based vegetation indices (VIs) and ground truth data. Results showed that the LAI was influenced significantly by water and fertilizer stress in both years’ experiments. Multispectral VIs were significantly correlated with maize LAI at multiple growth stages. The Pearson correlation coefficients between UAV-based VIs and ground truth LAI ranged from 0.64 to 0.89. Furthermore, the fusion of multiple stage data showed that the correlations were significantly higher between ground truth LAI and UAV-based VIs than that of single growth stage data. The ensemble learning algorithm with MLR as the secondary learner outperformed as a single machine learning algorithm with high prediction accuracy R2 = 0.967 and RMSE = 0.198 in 2020, and R2 = 0.897 and RMSE = 0.220 in 2021. We believe that the ensemble learning algorithm based on stacking is preferable to the single machine learning algorithm to build the LAI prediction model. This study can provide certain theoretical guidance for the rapid and precise management of water and fertilizer for large experimental fields.
Hierarchical Linkage between the Basic Characteristics of Smallholders and Technology Awareness Determines Small-Holders’ Willingness to Adopt Green Production Technology
Authors: Cui Shilei , Li Yajuan , Jiao Xiaoqiang , Zhang Dong
Published: August 2022

As a collection of technologies that match the carrying capacity of resources and the environment, harmonize ecology and life, and balance the quantity and quality of agricultural products in agricultural production, green production technologies are regarded as an important means to help promote sustainable agricultural production. It includes scientific fertilization technology, water-saving irrigation technology, biological control technology, and conservation tillage technology. However, the smallholders’ low level of awareness and application of green production technology has become a key factor limiting the sustainable development of Chinese agriculture. Several technological innovations have been implemented to address these problems while many studies have been conducted on the smallholders’ willingness to adopt the technology. However, the correlation and the hierarchical structure among different factors are not clear. Therefore, to clarify these issues, we used the logit model and interpretative structural modeling (ISM) to analyze the factors influencing the adoption of green production technologies by smallholders and the hierarchical linkage between them based on a sample of 709 from 16 provinces in China. Our results revealed that scientific fertilization and biological control technology were most preferred by smallholders. Compared with wheat (38.8%, 43.2%) and maize (29.3%, 39.4%), rice smallholders (66.7%, 82.5%) were more willing to adopt the two technologies. In addition, the technology awareness and technology benefits were expected to significantly affect the smallholders’ willingness to adopt the technology directly. Household characteristics and land characteristics are the root factors affecting the smallholders’ willingness to adopt green production technology. Family characteristics and land characteristics also changed the willingness of smallholders to adopt green production technologies by changing their awareness of production technology and the technological benefits expected. Therefore, accelerating the promotion of green production technologies through the implementation of policies such as increasing the promotion of high-value-added agricultural products and cultivation techniques, increasing out-of-school knowledge education, and enhancing the construction of agricultural production infrastructure can be potentially viable ways to promote green transformation in agriculture. This study provides case support for increasing the smallholders’ adoption of green production technology.
The Impacts of Rapid Urbanization on Farmland Marginalization: A Case Study of the Yangtze River Delta, China
Authors: Liu Junna , Zeng Siyan , Ma Jing , Chang Yuanyuan , Sun Yan , Chen Fu
Published: August 2022

Farmland is the most precious natural resource and the primary source of food for human beings. Urbanization not only occupies a large amount of farmland spatially, but also economically squeezes agricultural production, resulting in farmland marginalization and causing serious threats to food security. However, the manner in which rapid urbanization drives farmland marginalization in surrounding areas and the factors that might play a dominant role in this process remain elusive. Therefore, the present study considered rapidly urbanized regions of 128 county-level units in the Yangtze River Delta (YRD) of China from 2000 to 2020 as the study area. Methods such as spatial autocorrelation analysis, hotspot analysis, and multiple linear regression analysis were used to explore the spatiotemporal evolution characteristics and the driving factors of farmland marginalization. The results showed that: (i) the marginalization ratio of farmland in YRD from 2000 to 2020 was 31.34%, with a distinctly increasing trend, generally high in the central and southern and low in the north areas; (ii) marginalization exhibited different spatial agglomeration under different influencing factors: the economy-induced marginalization ratio was 23.19%, playing a dominant role, in general, distributed as high in the middle and low on the sides, while the nature-induced marginalization ratio was 8.15%, and in general, the spatial pattern shifted from discrete- to a clear- distribution of high in the south and low in the north; and, (iii) farmland area per capita, total power of agricultural machinery, GDP per capita and government farmland subsidies were the main factors driving farmland marginalization. In addition, nature-induced marginalization was primarily driven by economic level and topographical conditions, whereas economy-induced marginalization was primarily driven by production conditions. We suggest that in the future, corresponding policies and measures should be established to reduce farmland marginalization in rapidly urbanized areas and to ensure food security.
Identification and Characterization of Copy Number Variations Regions in West African Taurine Cattle
Authors: Goyache Félix , Pérez-Pardal Lucía , Fernández Iván , Traoré Amadou , Menéndez-Arias Nuria A. , Arias Katherine D. , Álvarez Isabel
Published: August 2022

A total of 106 West African taurine cattle belonging to the Lagunaire breed of Benin (33), the N’Dama population of Burkina Faso (48), and N’Dama cattle sampled in Congo (25) were analyzed for Copy Number Variations (CNVs) using the BovineHDBeadChip of Illumina and two different CNV calling programs: PennCNV and QuantiSNP. Furthermore, 89 West African zebu samples (Bororo cattle of Mali and Zebu Peul sampled in Benin and Burkina Faso) were used as an outgroup to ensure that analyses reflect the taurine cattle genomic background. Analyses identified 307 taurine-specific CNV regions (CNVRs), covering about 56 Mb on all bovine autosomes. Gene annotation enrichment analysis identified a total of 840 candidate genes on 168 taurine-specific CNVRs. Three different statistically significant functional term annotation clusters (from ACt1 to ACt3) involved in the immune function were identified: ACt1 includes genes encoding lipocalins, proteins involved in the modulation of immune response and allergy; ACt2 includes genes encoding coding B-box-type zinc finger proteins and butyrophilins, involved in innate immune processes; and Act3 includes genes encoding lectin receptors, involved in the inflammatory responses to pathogens and B- and T-cell differentiation. The overlap between taurine-specific CNVRs and QTL regions associated with trypanotolerant response and tick-resistance was relatively low, suggesting that the mechanisms underlying such traits may not be determined by CNV alterations. However, four taurine-specific CNVRs overlapped with QTL regions associated with both traits on BTA23, therefore suggesting that CNV alterations in major histocompatibility complex (MHC) genes can partially explain the existence of genetic mechanisms shared between trypanotolerance and tick resistance in cattle. This research contributes to the understanding of the genomic features of West African taurine cattle.
Physiology and Proteomic Basis of Lung Adaptation to High-Altitude Hypoxia in Tibetan Sheep
Authors: Zhao Pengfei , Li Shaobin , He Zhaohua , Zhao Fangfang , Wang Jiqing , Liu Xiu , Li Mingna , Hu Jiang , Zhao Zhidong , Luo Yuzhu
Published: August 2022

The Tibetan sheep is an indigenous animal of the Tibetan plateau, and after a long period of adaptation have adapted to high-altitude hypoxia. Many physiological changes occur in Tibetan sheep as they adapt to high-altitude hypoxia, especially in the lungs. To reveal the physiological changes and their molecular mechanisms in the lungs of Tibetan sheep during adaptation to high altitudes, we selected Tibetan sheep from three altitudes (2500 m, 3500 m, and 4500 m) and measured blood-gas indicators, observed lung structures, and compared lung proteome changes. The results showed that the Tibetan sheep increased their O2-carrying capacity by increasing the hemoglobin (Hb) concentration and Hematocrit (Hct) at an altitude of 3500 m. While at altitude of 4500 m, Tibetan sheep decreased their Hb concentration and Hct to avoid pulmonary hypertension and increased the efficiency of air-blood exchange and O2 transfer by increasing the surface area of gas exchange and half-saturation oxygen partial pressure. Besides these, some important proteins and pathways related to gas transport, oxidative stress, and angiogenesis identified by proteome sequencing further support these physiology findings, including HBB, PRDX2, GPX1, GSTA1, COL14A1, and LTBP4, etc. In conclusion, the lungs of Tibetan sheep are adapted to different altitudes by different strategies; these findings are valuable for understanding the basis of hypoxic adaptation in Tibetan sheep.