bluuebunny/crossref_metadata_2025_split huggingface dataset:
Active Fractional-Order Sliding Mode Control of Flexible Spacecraft Under Actuators Saturation
Authors: alipour milad , Malekzadeh Maryam , ariaei alireza 
Published: April 2021

Abstract
In this article, a novel multi-purpose modified fractional-order nonsingular terminal sliding mode (MFONTSM) controller is designed for the flexible spacecraft attitude control and appendages passive vibration suppression, assuming the control torque saturation in the system dynamics. Furthermore, an active FONTSM controller is proposed separately to perform active vibration suppression of the flexible appendages using piezoelectric actuators. The fixed-time stability of the closed-loop system for both the passive and active controllers is analyzed and proved using the Lyapunov theorem. Finally, the performance of the proposed controllers has been tested in the presence of uncertainties, external disturbances, and the absence of the damping matrix in order to study the effectiveness of the proposed method.
Field studies analysis for new Material Handling System Design approach
Authors: Soufi Zakarya , David Pierre , Yahouni Zakaria 
Published: April 2021

Abstract
Mastering the Material Handling System (MHS) is still a crucial issue, according to Hellmann et al the costs of Material Handling activities ranges from 15–70% of total manufacturing costs depending on the kind of production [6]. The introduction of industry 4.0 technologies for Material Handling, is renewing the decisions to take in the design of MHS. The practices in MHS design and management are very diversified in industry and no consensus clearly exist on how efficiently designing such system. This paper discusses the need to understand the relation between the different aspects of Material Handling System design, and propose to identify the key challenges to be addressed. Through field studies that were conducted with five distinct companies and an analysis of the literature, five MHS aspects are examined; Material Handling Activities, Material Handling and automation, Material Handling Control System, Material Handling Equipment Selection, and Material Handling System. Based on the results of the analysis, a cross analysis is performed to identify the differences and the common patterns between the literature and the field study. As a result, research directions for new MHS design approach are proposed. It is composed of four main challenges; Material handling specifications, MHE selection, MHE deployment, and MHS analysis. Each challenge is linked to other potential subjects.
The Study on Neural Remodeling of Medullary Visceral Zone in Early Sepsis and Interfered by Cholinergic Anti-Inflammatory Pathway ​
Authors: Li H. B. , Shu ZH. G. , Pi Q. F. , Guo L. L. 
Published: April 2021

Abstract
BackgroundStudies including our own have shown that the Medullary Visceral Zone (MVZ) can effectively regulate systemic inflammation and immunity through the Cholinergic Anti-inflammatory Pathway (CAP). Sepsis usually causes neuroinflammation in the Central Nervous System (CNS), which will inevitably affect the structure and function in related brain areas such as MVZ, whether the intervention of CAP can affect the structure and function of the MVZ in sepsis needs to be further verified. Methods64 adults, specific pathogens free Sprague-Dawley male rats were used in this study. The septic models were prepared by cecum ligation and puncture (CLP) method, GTS-21 (a selective α7 nicotinic acetylcholine receptor agonist which can mimic CAP’s activation) and MLA (a powerful and selective nicotine acetylcholine receptor antagonist which can mimic CAP’s blocking) were used to interfere CAP. The pathological changes, apoptosis, the expressions of Tyrosine Hydroxylase (TH) and Choline acetyltransferase (CHAT), the expression levels of GAP-43 mRNA, Olig-2 mRNA, VEGF mRNA, GFAP mRNA, MMP-9 mRNA in MVZ were analyzed among different groups. ResultsIn this study, we found that sepsis induced apoptosis and functional suppression of catecholaminergic and cholinergic neurons and gliosis in MVZ, up-regulated key genes’ expressions such as GAP-43 mRNA，GFAP mRNA，VEGF mRNA，MMP-9 mRNA, down-regulated the expression of Olig-2 mRNA. GTS-21, a selective α7 nicotinic acetylcholine receptor agonist, obviously mitigated the above changes; whereas, methyllycaconitine (MLA), a powerful and selective nicotine acetylcholine receptor antagonist, significantly aggravated these changes. ConclusionsOur research shows that activating CAP can effectively mitigate the neural remodeling and neuronal suppression induced by early sepsis in MVZ, the mechanism may involve with its control of systemic and local inflammation. This study reveals that MVZ and CAP may be potential targets to curb the inflammatory storm in early sepsis.
Evaluation of Energy Consumption of LPWAN Technologies
Authors: Rajab Husam , Cinkler Tibor , Bouguera Taoufik 
Published: April 2021

Abstract
The modern technological innovations provide small radios with ability to broadcast over vast areas with minimum energy consumption that will significantly influence the future of the Internet of Things (IoT) communications. The majority of IoT implementations demand sensor nodes run reliably for an extended time. Furthermore, the radio settings can endure a high data rate transmission while optimizing the energy-efficiency. The LoRa/LoRaWAN is one of the primary Low-Power Wide Area Network (LPWAN) technology that has highly enticed much concentration recently from the community. The energy limits is a significant issue in wireless sensor networks since battery lifetime that supplies sensor nodes have a restricted amount of energy and neither expendable nor rechargeable in most cases. A common hypothesis in previous work is that the energy consumed by sensors in sleep mode is negligible. With this hypothesis, the usual approach is to consider subsets of nodes that reach all the iterative targets. These subsets also called coverage sets, are then put in the active mode, considering the others are in the low-power or sleep mode. In this paper, we address this question by proposing an energy consumption model based on LoRa and LoRaWAN, that model optimizes the energy consumption of the sensor node for different tasks for a period of time. The proposed analytical approach permits considering the consumed power of every sensor node element; furthermore, it can be used to analyse different LoRaWAN modes to determine the most desirable sensor node design to reach its energy autonomy.
Prediction of plant-level tomato biomass and yield using machine learning with unmanned aerial vehicle imagery
Authors: Tatsumi Kenichi , Igarashi Noa , Mengxue Xiao 
Published: April 2021

Abstract
Background The objective of this study is twofold. First, ascertain the important variables that predict tomato yields from plant height (PH) and vegetation index (VI) maps. The maps were derived from images taken by unmanned aerial vehicles (UAVs). Second, examine the accuracy of predictions of tomato fresh shoot masses (SM), fruit weights (FW), and the number of fruits (FN) from multiple machine learning algorithms using selected variable sets. To realize our objective, ultra-high-resolution RGB and multispectral images were collected by a UAV on ten days in 2020’s tomato growing season. From these images, 756 total variables, including first- (e.g., average, standard deviation, skewness, range, and maximum) and second-order (e.g., gray-level co-occurrence matrix features and growth rates of PH and VIs) statistics for each plant, were extracted. Several selection algorithms (i.e., Boruta, DALEX, genetic algorithm, least absolute shrinkage and selection operator, and recursive feature elimination) were used to select the variable sets useful for predicting SM, FW, and FN. Random forests, ridge regressions, and support vector machines were used to predict the yield using the top five selected variable sets. Results First-order statistics of PH and VIs collected during the early to mid-fruit formation periods, about one month prior to harvest, were important variables for predicting SM. Similar to the case for SM, variables collected approximately one month prior to harvest were important for predicting FW and FN. Furthermore, variables related to PH were unimportant for prediction. Compared with predictions obtained using only first-order statistics, those obtained using the second-order statistics of VIs were more accurate for FW and FN. Conclusions In addition to basic statistics (e.g., average and standard deviation), we derived second-order statistics of PH and VIs at the plant level using the ultra-high resolution UAV images. Our findings indicated that our variable selection method reduced the number variables needed for tomato yield prediction, improving the efficiency of phenotypic data collection and assisting with the selection of high-yield lines within breeding programs.
Approximation-free Quantitative Prescribed Performance Control of Unknown Strict-feedback Systems
Authors: Bu Xiangwei , Qi Qiang , Jiang Baoxu 
Published: April 2021

Abstract
Prescribed performance control (PPC) has been proved to be a powerful tool which seeks transient performance for tracking errors. Unfortunately, the existing PPC schemes only can qualitatively design transient performance, while they cannot quantitatively set the convergence time and meanwhile minimize overshoot. In this article, we propose a new quantitative PPC strategy for unknown strict-feedback systems, capable of quantitatively designing convergence time and minimizing overshoot. Firstly, a new quantitative prescribed performance mechanism is proposed to impose boundary constraint on tracking errors. Then, back-stepping is used to exploit virtual controllers and actual controller based on Nussbaum Function, without requiring any prior knowledge of system unknown dynamics. Compared with the existing methodologies, the main contribution of this paper is that it can guarantee predetermined convergence time and zero overshoot for tracking errors, and meanwhile there is no need of any fuzzy/neural approximation. Finally, compared simulation results are given to validate the effectiveness and advantage.
Gender disparities in access to care for time-sensitive conditions during COVID-19 pandemic in Chile
Authors: Pacheco Jorge , Crispi Francisca , Alfaro Tania , Martinez Maria Soledad , Cuadrado Cristobal 
Published: April 2021

Abstract
Background: During the COVID-19 pandemic reduction on the utilization of healthcare services are reported in different contexts. Nevertheless, studies have not explored specifically gender disparities on access to healthcare in the context of covid-19. Methods: To evaluate gender disparities in access to medical in Chile we conducted an interrupted time series design using a segmented regression. The outcome variable was the number of weekly confirmed cases of a set of oncologic and cardiovascular time-sensitive conditions at a national level. The series contained data from week 1 to 39 for 2017 to 2020. Intervention period started at week 12. We selected this period because preventive interventions, such as school closures or teleworking, were implemented at this point. We estimated level effect using a dummy variable indicating the intervention period and slope effect using a continuous variable from week 12 to 39. To test heterogeneity by sex and age-group, we conducted stratified analysis. Results: We observed a sizable reduction in access to care with a slowly recovery for oncologic (level effect 0,323; 95% CI 0,291-0,359; slope effect 1,022; 95% CI 1,016-1,028) and cardiovascular diseases (level effect 0,586; 95% CI 0,564-0,609; slope effect 1,009; 95% CI 1,007-1,011). Greater reduction occurred in women compared to men, particularly marked on myocardial infarction (level effect 0,595; 95% CI 0,566-0,627 versus 0,532; 95% CI 0,502-0,564) and colorectal cancer (level effect 0,295; 95% CI 0,248-0,35 versus 0,19; 95% CI 0,159-0,228). Compared to men, a greater absolute reduction was observed in women for oncologic diseases, excluding sex-specific cancer, (1.352; 95% CI 743-1.961) and cardiovascular diseases (1.268; 95% CI 946-1.590). Conclusion: We confirmed a large drop in new diagnosis for time-sensitive conditions during the COVID-19 pandemic in Chile. This reduction was greater for women. Our findings should alert policy-makers about the urgent need to integrate a gender perspective into the pandemic response.
Determinants of prolonged hospitalization and mortality among leptospirosis patients attending tertiary care hospitals in northeastern state in Peninsular Malaysia: A cross sectional retrospective analysis
Authors: Hariri Yassin K. Al , Sulaiman Syed A.S. , Khan Amer Hayat , Adnan Azreen S. , Al-Ebrahem Sundos Q. 
Published: April 2021

Abstract
Objectives Leptospirosis is the most common anthropozoonosis worldwide and imposes a major public health problem in many tropical countries. It is a leading cause of disease burden in form of mortality, morbidity and hospital admission. Identifying patients at high risk for mortality or for prolonged hospitalization may save lives and preserve economy. The aim of the current study was to identify significant factors associated with disease mortality and prolonged hospitalization.Design Cress-sectional retrospective studySettings Tertiary care teaching hospitals in Kelantan, Peninsular Malaysia Participants Adult patients proven to have leptospirosis depending on IgM ELISA were classified into two classes depending on prolonged hospitalization (>7 days or ≤ 7 days) and mortality (fatal cases or non-fatal cases). Patients’ clinico-laboratory data were compared according to these two outcomes using the appropriate statistical test accordingly.Results Of the 525 patients enrolled, 136 (25.9%) had prolonged hospitalization. The mean length of stay was 6.77 ± 5.68 days. Logistic regression analysis identified acute kidney injury (AKI) (OR 2.3), Jaundice (OR 2.7), elevated alanine aminotransferase (ALT) (OR 2), and prolonged prothrombin time (PT) (OR 1.9) independently associated with prolonged hospitalization. Case fatality rate was 6.48% and around one third of fatal cases had prolonged hospitalization of more than seven days. Factors associated with leptospirosis mortality included age > 40 years (p<0.001), patients presented with tachypnea (p=0.002), pulmonary infiltrate (p<0.001), T-wave changes (p<0.001), atrial fibrillation (p=0.013), conducting abnormality (p<0.001), chronic kidney diseases (p<0.001), multiple organ dysfunctions (p<0.0010), respiratory failure (p<0.001), pneumonia (p<0.001), sepsis (p=0.004), low venous PH (p=0.042), AKI (P<0.001), elevated AST (p<0.001) or ALT (p=0.004), hypoalbuminemia (p<0.001), rhabdomyolysis (p<0.001), severe thrombocytopenia (p=0.042), prolonged PT (p<0.001) or prolonged aPTT (p<0.017).Conclusions Significant proportion of leptospirosis patients (25.9%) had prolonged hospital stay and less proportion died (6.48%). Early identifying patients with factors associated with prolonged hospitalization and death will positively impact practitioners’ decisions regarding the proper and fast course of management including ICU admission
Effects of soil components, solution chemical properties, and temperature on Cu(II) adsorption by alluvial acid soil: A case study in Southwest China
Authors: Ren Bangzheng , Wu Yong , Li Hongtao , Chen Zailin , Xu Junlong 
Published: April 2021

Abstract
The specific soil components such as soil organic matter, Fe and Mn oxides exert a significant influence on Cu(II) adsorption in soil. In the present study, clay fraction was separated from an alluvial acid soil, Then the selective chemical extraction method was used to remove the specific components in the bulk soil and clay fraction. Adsorption experiments showed that the adsorption capacity of the clay fraction of Cu(II) is greater than that of the bulk soil, regardless of whether it is treated by selective chemical extraction or not. Compared with untreated soil samples, after the removal of organic matter by H2O2, Kd decreased by a maximum of 82.8% for the bulk soil and 73.5% for the clay fraction. After the removal of manganese oxides by NH2OH·HCl, Kd decreased by a maximum of 68.1% for the bulk soil and 73.2% for the clay fraction. However, after the removal of free iron oxides by dithionite-citrate-bicarbonate, Kd increased by a maximum of 422% for the bulk soil and 195.5% for the clay fraction. Kd increased by 4263.3% when the initial pH increased from 2 to 3.5 and, then, increased to 6. The amount of Cu(II) adsorbed did not change significantly. Within a range greater than 6, the increased Cu(II) adsorption may be due to the precipitation of Cu(II). When the concentration of NaNO3 changes from 0.01 to 0.1 M, the adsorption capacity decreased by a maximum of 36%, Kd decreased by a maximum of 84.3%. The presence of foreign ions decreased Cu(II) adsorption; their order of effect on Cu(II) adsorption is Na+ < K+ < Mg2+ < Ca2+ for cations and NO3− < SO42− ≈ Cl− for anions. The adsorption of Cu(II) was an endothermic and spontaneous process under the experimental conditions.
Design and Preliminary Evaluation of a Wearable Passive Cam-Based Shoulder Exoskeleton
Authors: Asgari Morteza , Phillips Elizabeth A. , Dalton Britt M. , Rudl Jennifer L. , Crouch Dustin L. 
Published: April 2021

Abstract
BackgroundMechanically passive (i.e. spring-powered) exoskeletons may be a practical and affordable solution to meet a growing clinical need for continuous, home-based movement assistance. We designed, fabricated, and preliminarily evaluated the performance of a wearable, passive, cam-driven shoulder exoskeleton (WPCSE) prototype. MethodsThe novel feature of the WPCSE is a modular spring-cam-wheel module, which generates an assistive force that can be customized to compensate for any proportion of the shoulder elevation moment due to gravity. We performed a benchtop experiment to validate the mechanical output of the WPCSE against our theoretical model. We also conducted a pilot biomechanics study (four able-bodied subjects) to quantify the effect of a WPCSE prototype on muscle activity and shoulder kinematics during three one-degree-of-freedom shoulder movements. ResultsThe shoulder elevation moment produced by the spring-cam-wheel module alone closely matched the desired, theoretical moment. However, when measured from the full WPCSE prototype, the moment was lower (up to 30%) during positive shoulder elevation and higher (up to 120%) during negative shoulder elevation compared to the theoretical moment, due primarily to friction. Even so, a WPCSE prototype, compensating for about 25% of the shoulder elevation moment due to gravity, showed a trend of reducing root mean square (up to 50%) and peak (up to 53%) electromyogram magnitudes of several muscles crossing the shoulder during shoulder elevation and horizontal adduction/abduction movements. Subjects verbally reported that the WPCSE did not physically constrain them during the tested movements. ConclusionThe results provide proof-of-concept evidence that our WPCSE can potentially assist shoulder movements. The proposed WPCSE, once refined, could provide clinical and home-based rehabilitation for patients with shoulder disability.
Effects of Indoor Air Pollution on Household Health: Evidence from Turkey
Authors: ipek özlem , İpek Egemen 
Published: April 2021

Abstract
Indoor air pollution caused by use of biomass energy in heating and cooking affects the health status of household members adversely. In Turkey, despite with the rapid economic growth in the last decade, biomass has been among the most preferred type of energy by households for heating and cooking due to inadequate infrastructure, dependence on foreign energy, and high energy prices. This study aims to provide empirical evidence from Turkey to the literature on indoor air pollution caused by households’ energy choice and health status. This study is analyzed these effects with the random effects panel discrete ordered models using the Income Living Conditions Micro Longitudinal Data Set for the period 2014-2017. As a result of the analysis, we found that age, being a woman, having dependent children, and indoor air pollution have adverse effects on the health status. However, education level, and income level affect the health status positively. The most important result obtained from this study is that even if households have high-income, the inability to access clean energy resources affects their health adversely.
Do Higher Education Research and Development Expenditures affect Environmental Sustainability? New Evidence from Thirty-One Chinese Provinces
Authors: Yawen Sun , Jiang Qingquan , Khattak Shoukat Iqbal , Ahmad Manzoor , Li Hui 
Published: April 2021

Abstract
Higher education R&D expenditures (HEEXP) are one of the important determinants of economic growth that facilitates science, technology, new ideas, and innovation, but its effect on environmental sustainability remains unexplored. This paper examines the nexus between HEEXP and carbon dioxide emissions (CO2e), followed by control variables such as electricity consumption, foreign direct investment, gross domestic product, and total population for the period 2000Q1-2019Q4. Some of the key results are as follows. First, the present findings confirmed the long-run cointegration among variables. Second, the finding showed significant long-term negative nexus between HEEXP and CO2e. Third, the findings indicated that electricity consumption, foreign direct investment, gross domestic product, and total population are the important factors that intensify the overall situation of CO2e. Fourth, the results indicated that there exist a bi-directional causality between EC and CO2e; FDI and CO2e; GDP and CO2e; POP and CO2e and HEEXP, and CO2e.
Simulated Space Environmental Factors of Weightlessness, Noise and Low Air Pressure Differentially Affect the Circadian Rhythm and Gut Microbiome
Authors: Ma Huan , Gan Xihui , Zhao Jianwei , Zhang Yin , Li Silin , Kan Guanghan , Wang Bo , Zhang Peng , Ma Xiaohong , Tian Hongni , Liao Meimei , Ju Dapeng , Xu Shuihong , Chang Lulin , Chen Xiaoping , Guo Jinhu 
Published: April 2021

Abstract
Backgroundhe circadian clock extensively regulates physiology and behavior. In space, the astronauts encounter many environmental factors that are dramatically different from those on earth, however, the effects of these factors on circadian rhythms and the mechanisms remain largely unknown. The present study aimed to investigate the changes in the mouse circadian rhythm and gut microbiome under simulated space capsule conditions, including microgravity, noise and low atmospheric pressure.ResultsNoise and low atmospheric pressure were loaded in the capsule while the conditions in the animal room remained constant. The mice in the capsule showed disturbed locomotor rhythms and faster adaptation to a 6-h phase advance. RNA sequencing of hypothalamus samples revealed that microgravity simulated by hind limb unloading (HU) and exposure to noise and low atmospheric pressure led to decreases in the quantities of differentially expressed genes (DEGs), including circadian clock genes. Changes in the rhythmicity of genes implicated in pathways of cardiovascular deconditioning and more concentrated circadian phases were found under HU or noise and low atmospheric pressure. Furthermore, 16S rRNA sequencing revealed dysbiosis in the gut microbiome, and noise and low atmospheric pressure may repress the temporal discrepancy in the microbiome community structure induced by microgravity. Changes in diel oscillation were observed in a number of gut bacteria with critical physiological consequences in metabolism and immunodefense.ConclusionsOur data demonstrate that in addition to microgravity, exposure to noise and low atmospheric pressure affect the robustness of circadian rhythms and the community structure of the gut microbiome, and these factors may interfere with each other in their adaptation to respective conditions. These findings are important to further our understanding of the alteration of circadian rhythms in the space complex environment.