Rural labor migration and farmers’arrangements of rice production systems in Central China:Insight from the intergenerational division of labor

Rice production is crucial for food security in China,and its relationship with rural labor migration has been studied extensively.Labor migration in rural China has taken new forms in recent years.There has been a discernible trend wherein adult children have started migrating to cities while their elderly parents return to villages to re-engage in on-farm work.The phenomenon has notably shaped the intergenerational division of labor(IDL)within households.However,it remains to be seen how farmers adjust their rice production systems in response to the IDL.The age of 60 years for employment injury insurance is the eligibility threshold for off-farm employment and is used to obtain a source of exogenous variation in the IDL.Based on a representative household survey of 1,752 rice farmers in the Hubei Province of Central China,our fuzzy regression discontinuity analysis reveals that farmers in IDL households are more likely to adopt ratoon rice(RR)than single cropping rice(SR)or double cropping rice(DR).The effect of the IDL varies under different levels of operational scales and specialized agricultural service availability.Further analysis suggests that farmers’arrangements are associated with two potential mechanisms of downward intergenerational transfer.Monetary transfer for urban housing purchases increases RR in IDL households,and time transfer for intergenerational childcare significantly promotes SR in IDL households.This study enhances the understanding of the relationship between rural labor migration and rice production in China,providing a reference for adjusting rice production systems to ensure food security.

An Energy-Saving Control Strategy on Central Air-Conditioning System

An energy-saving control strategy based on predictive control for central air-conditioning systems is proposed in this paper. The cold load model is developed to describe the dynamic characteristics of temperature control systems, and then parameters in the cold load model and in the central air-conditioning system model are estimated. Generalized predictive control (GPC) is used to establish an optimization model to minimize the consumption of energy and the control error of temperature. The simulated annealing (SA) algorithm, combined with quadratic programming, is adopted to solve the optimal problem. Contrasted with the simulation of traditional PID control, the results prove the effectiveness of this proposed strategy.

Energy performance assessment on central air-conditioning system of commercial building: A case study in China

Energy performance assessment on central air-conditioning system is essential to optimize operating, reduce operating costs, improve indoor environmental quality, and determine whether the retrofitting of the equipment is necessary. But it is difficult to evaluate it reasonably and comprehensively due to its complexity. A "holistic" approach was discussed to evaluate the energy performance of central air-conditioning system for an extra-large commercial building in a subtropical city. All procedures were described in detail, including field investigation method, field measurement instruments, data processing and data analyzing. The main factors affecting energy consumption of air-conditioning system were analyzed and the annual cooling-energy use intensity of this building was calculated and also compared with other shopping malls and other types of buildings in Guangzhou. And COP(coefficient of performance) of chiller, water transfer factor of chilled water system and cooling water system were taken into consideration. At last, the thermal comfort and indoor air quality issues were addressed. The results show that the chilled water pumps are over-sized and the indoor environmental quality should be improved. The purpose of this work is to provide reference for energy performance assessment method for air-conditioning system.

Centralized Solar PV Systems for Static Loads Using Constant Voltage Control Method

The alternative energy resources, like solar, are always complementary due to environmental changes. Energy generation with the sources such as solar and wind is gaining importance and of that photovoltaic conversion is the main focus of researches due to its promising potential as the electrical source. This paper presents the constant voltage method of control where the output of the converter is maintained constant irrespective of the variations in the irradiance with the high step-up isolated efficient single switch DC-DC converter for the solar PV systems. Constant voltage method of control uses the array of photovoltaic systems as its energy source. The output of the Solar PV systems is nonlinear and has its dependency on temperature and irradiance by which the panel voltage and current varies with the variation in irradiance. Constant voltage control method always operates in such a way that the converter voltage is tried to be maintained constantly to the reference voltage which is set by the user. The system used here utilizes high step single switch isolated DC-DC converter and monitors the voltage continuously by varying the duty cycle to maintain the converter voltage always constant. As a way of improving the performance, both the open and closed loop analysis is done where the closed loop analysis uses the PI controller for its performance. The model is implemented in MATLAB and it accepts the irradiance as the input and outputs the constant voltage from the converter and the feasibility of the proposed converter topology is confirmed with experimental results of the prototype model.

Changes in snow cover extent in the Central Taurus Mountains from 1981 to 2021 in relation to temperature, precipitation, and atmospheric teleconnections

The snow cover over the Taurus Mountains affects water supply, agriculture, and hydropower generation in the region. In this study, we analyzed the monthly Snow Cover Extent(SCE) from November to April in the Central Taurus Mountains(Bolkar, Aladaglar, Tahtali and Binboga Mountains) from 1981 to 2021. Linear trends of snow cover season(November to April) over the last 41 years showed decreases in SCE primarily at lower elevations. The downward trend in SCE was found to be more pronounced and statistically significant for only November and March. SCE in the Central Taurus Mountains has declined about-6.3% per decade for 2500-3000 m in November and about-6.0% per decade for 1000-1500 m and 3000+ m in March over the last 41 years. The loss of SCE has become evident since the 2000s, and the lowest negative anomalies in SCE have been observed in 2014, 2001, and 2007 in the last 41 years, which are consistent with an increase in air temperature and decreased precipitation. SCE was correlated with both mean temperature and precipitation, with temperature having a greater relative importance at all elevated gradients. Results showed that there is a strong linear relationship between SCE and the mean air temperature(r =-0.80) and precipitation(r = 0.44) for all elevated gradients during the snow season. The Arctic Oscillation(AO), the North Atlantic Oscillation(NAO), and the Mediterranean Oscillation(MO) winter indices were used to explain the year-to-year variability in SCE over the Central Taurus Mountains. The results showed that the inter-annual variability observed in the winter SCE on the Central Taurus Mountains was positively correlated with the phases of the winter AO, NAO and MO, especially below 2000 m elevation.

Glymphatic system:a gateway for neuroinflammation

The glymphatic system is a relatively recently identified fluid exchange and transpo rt system in the brain.Accumulating evidence indicates thatglymphatic function is impaired not only in central nervous system disorders but also in systemic diseases.Systemic diseases can trigger the inflammatory responses in the central nervous system,occasionally leading to sustained inflammation and functional disturbance of the central nervous system.This review summarizes the current knowledge on the association between glymphatic dysfunction and central nervous system inflammation.In addition,we discuss the hypothesis that disease conditions initially associated with peripheral inflammation ove rwhelm the performance of the glymphatic system,thereby triggering central nervous system dysfun ction,chronic neuroinflammation,and neurodegeneration.Future research investigating the role of the glymphatic system in neuroinflammation may offer innovative therapeutic approaches for central nervous system disorders.

Portal vein pulsatility:An important sonographic tool assessment of systemic congestion for critical ill patients

In this editorial we comment on the article by Kuwahara et al,published in the recent issue of the World Journal of Cardiology.In this interesting paper,the authors showed a correlation between portal vein pulsatility ratio,examined by bedside ultrasonography,and prognosis of hospitalized patients with acute heart failure.Systemic congestion is being notoriously underdetected in the acutely ill population with conventional methods like clinical examination,biomarkers,central venous pressure estimation and X-rays.However,congestion should be a key therapeutic target due to its deleterious effects to end organ function and subsequently patient prognosis.Doppler flow assessment of the abdominal veins is gaining popularity worldwide,as a valuable tool in estimating comprehensively congestion and giving a further insight into hemodynamics and patient management.

Central Command Architecture for High-Order Autonomous Unmanned Aerial Systems

This paper is the first in a two-part series that introduces an easy-to-implement central command architecture for high-order autonomous unmanned aerial systems. This paper discusses the development and the second paper presents the flight test results. As shown in this paper, the central command architecture consists of a central command block, an autonomous planning block, and an autonomous flight controls block. The central command block includes a staging process that converts an objective into tasks independent of the vehicle (agent). The autonomous planning block contains a non-iterative sequence of algorithms that govern routing, vehicle assignment, and deconfliction. The autonomous flight controls block employs modern controls principles, dividing the control input into a guidance part and a regulation part. A novel feature of high-order central command, as this paper shows, is the elimination of operator-directed vehicle tasking and the manner in which deconfliction is treated. A detailed example illustrates different features of the architecture.

Can the Glucose Central Control System Dysfunctions Induce Diabetes Mellitus?

We study afresh how the glucose control system anomalies impact the organicity of the glucose homeostasis and build up events of persistent hyperglycemia and diabetes mellitus. We have used critically the state of art literature related to the subject, in order to cross, to compare, and to organize the relevant contents to create a logical and consistent support to the finds. We show that it is consistent to assume that persistent hyperglycemia and diabetes mellitus can have precursors not only in pancreas, but also in brain, mainly induced by noxious dysfunctions of hypothalamus sensor neurons circuits and external noxious elements, causing pancreas overload, and the consequent exhaustion—overburden.

Streptococcus pneumoniae and Herpes Simplex Virus-1 Central Nervous System Co-Infection

Co-infections of the central nervous system (CNS) caused by bacterial and viral pathogens are considered to be rare. Herpes simplex virus type-1 (HSV-1) reactivation following Streptococcus pneumoniae infection is well described but most cases are related to oral or cutaneous lesions or in respiratory samples. HSV-1 CNS reactivation after Streptococcus pneumoniae meningitis is a very rare event and may have significant morbidity and mortality. In this case report, we describe a 71-year-old female patient that presented with a history of abdominal pain and confusion/disorientation that had tonic-clonic seizures while in the Emergency Department. The diagnostic work-up confirmed CNS co-infection caused by Streptococcus pneumoniae and HSV-1. Of note, beyond age, the patient had no known risk factors for both entities and recovered fully after antibiotic and antiviral therapy. This case underlines that clinicians must be aware of CNS co-infection despite being a rare diagnosis. This should be suspected particularly in patients who present an unusual clinical course of CNS infection.

SUPERSYMMETRIC INVARIANCE AND UNIVERSAL CENTRAL EXTENSIONS OF LIE SUPERTRIPLE SYSTEMS

In this article, we discuss some properties of a supersymmetric invariant bilinear form on Lie supertriple systems. In particular, a supersymmetric invariant bilinear form on Lie supertriple systems can be extended to its standard imbedding Lie superalgebras. Furthermore, we generalize Garland＇s theory of universal central extensions for Lie supertriple systems following the classical one for Lie superalgebras. We solve the problems of lifting automorphisms and lifting derivations.

The Discussion of 500kv Centralized Monitoring System For Large Operation and Large Maintenance Mode

The establishment of a centralized monitoring system is an effective means to achieve the goal that no or fewer people are on duty. The function of the current 500kV centralized monitoring system is not enough mature to meet the requirement of the large-scale operation and large-scale maintenance model proposed by the State Grid. In order to fully utilizing the function of the centralized monitoring system, an improved design scheme is presented for the current 500kV centralized monitoring of the Jiangxi Power Grid. The improved centralized monitoring system is divided into three layers: monitoring center layer, operating team layer, and substation layer, which not only has the advantages of high security, high reliability, and easy maintenance, but also realizes the management model of regional control. So it can perfectly meet anti-misoperation requirement in the large operation and large maintenance mode, which can provide reference and guidance for the design of the 500kV centralized monitoring system of Jiangxi Power Grid.

ANALYSIS OF STRUCTURAL STYLES OF THE BASIN-RANGE SYSTEMS IN THE CENTRAL CHINA OROGENIC CHAIN OF YANGTZE VALLEY AND THE DYNAMIC MECHANISM

Basin and orogenic belt belong to the same tectonic system which has close connections in spatial distribution and dynamic mechanism.Structural styles analysis of basin－ range system， not only may rebuild basin－ range coupling process and landscape evolution of orogenic belt and its adjacent basin， but also become the foundation in exploring how orogenesis controls landform,climate,resources,energy and environment etc.In the light of geodynamic mechanism,three main types of basin－ range system may be classified,namely,stretch,compression and strike－ slip.In combination with their geotectonic settings and plate movement phases, a comprehensive classification scheme may be educed for structural styles of basin－ range system.Natural disasters and geo－ ecological environment in the Yangtze Valley have been restricted and impressed by crustal movement and Qinling－ Dabie etc.orogenesis since the Mesozoic and Cenozoic.In terms of collocating relation and contacting basin prototype and orogenic belt around the basin for cause of formation, typical structural styles of basin－ range system on the central orogenic chain within the Yangtze Valley consist of coupling Tongbo－ Dabie orogenic belt and Jianghan－ Dongtin fault basin on the northern margin of the central Yangtze landmass， and coupling Qinling－ Daba mountain margin thrust－ faulted orogenic belt and Sichuan foreland basin on the northern margin of upper－ Yangtze landmass.The paper analyzes evolutionary features of two typical structural styles of basin－ range system during syn－ orogenic, late－ orogenic and post－ orogenic stages,and probes into their dynamic mechanism.It is emphasized that,in different stages of basin－ range system of different properties and basin－ mountain transformation process,different structural styles may be formed;and different associations of structural styles can form different types of natural disasters complex and eco－ environment systems.

A Steady State Voltage Stability Analysis of Wind Power Centralized System

It is significant to research the voltage stability of the wind power centralized system (WPCS) for the effective development of the large scale clustering wind energy resources. A steady state voltage stability analysis of the WPCS by employing the PV curve and model analysis is proposed to reveal the voltage stability influence from different aspects. The PV curve is utilized to trace and indicate the voltage collapse point of the WPCS when the small disturbance of wind power is increased gradually. Then the steady state voltage instability modes of the WPCS are analyzed by calculating the bus participation factors of the minimum eigenvalue model at the collapse point. The simulation results of an actual WPCS in North China show that the static state voltage instability mode of the WPCS is closely related to the operating features and control strategies of different reactive power sources. In addition, the implementation of the doubly-fed induction generator wind turbine generator voltage control is beneficial to improve the WPCS voltage stability.

《Information Systems Research》1998~2017文献计量分析—基于Citespace可视图谱

本文运用Citespace文献计量分析软件,以《Information Systems Research》(简称ISR)期刊在1998年至2017年近20年收录的747篇文献为研究对象,从文献产出分析、国家合作网络分析、机构合作网络分析和引文网络聚类分析四个方面进行研究,研究结果表明:1) 根据文献产出分析,ISR期刊的文献产出量呈现波动性增长;2) 根据国家合作网络分析,美国在国家合作网络中是核心节点,中国需要加强国际合作,提高自身影响力;3) 在研究机构合作网络中,文献产出量前五所高校均位于美国,同时根据合作网络中心性分析,中心性在0.1以上的12所机构中,9所位于美国,中国只有香港城市大学列于其中,另外,德克萨斯大学达拉斯分校、佐治亚理工学院、新加坡国立大学和德克萨斯大学奥斯汀分校,在信息系统领域研究潜力巨大;4) 根据引文网络聚类分析,研究热点的演变可分为三个阶段:1998年至2001年期间信息系统领域研究的重心在信息系统的企业应用,2002年至2011年期间研究重心由传统的组织转移到虚拟组织的测量指标、信任和影响因素,2012年至2017年期间由电子口碑研究转向在线知识社区中的知识扩散研究。

Differential Diagnostic Value of Texture Feature Analysis of Magnetic Resonance T2 Weighted Imaging between Glioblastoma and Primary Central Neural System Lymphoma

Objective To investigate the difference in tumor conventional imaging findings and texture features on T2 weighted images between glioblastoma and primary central neural system(CNS) lymphoma. Methods The pre-operative MRI data of 81 patients with glioblastoma and 28 patients with primary CNS lymphoma admitted to the Chinese PLA General Hospital and Hainan Hospital of Chinese PLA General Hospital were retrospectively collected. All patients underwent plain MR imaging and enhanced T1 weighted imaging to visualize imaging features of lesions. Texture analysis of T2 weighted imaging(T2 WI) was performed by use of GLCM texture plugin of ImageJ software, and the texture parameters including Angular Second Moment(ASM), Contrast, Correlation, Inverse Difference Moment(IDM), and Entropy were measured. Independent sample t-test and Mann-Whitney U test were performed for the between-group comparisons, regression model was established by Binary Logistic regression analysis, and receiver operating characteristic(ROC) curve was plotted to compare the diagnostic efficacy. Results The conventional imaging features including cystic and necrosis changes(P = 0.000), ‘Rosette' changes(P = 0.000) and ‘incision sign'(P = 0.000), except ‘flame-like edema'(P = 0.635), presented significantly statistical difference between glioblastoma and primary CNS lymphoma. The texture features, ASM, Contrast, Correlation, IDM and Entropy, showed significant differences between glioblastoma and primary CNS lympoma(P = 0.006,0.000, 0.002, 0.000, and 0.015 respectively). The area under the ROC curve was 0.671, 0.752, 0.695, 0.720 and 0.646 respectively, and the area under the ROC curve was 0.917 for the combined texture variables(Contrast, cystic and necrosis, ‘Rosette' changes, and ‘incision sign') in the model of Logistic regression. Binary Logistic regression analysis demonstrated that cystic and necrosis changes, ‘Rosette' changes and ‘incision sign' and texture Contrast could be considered as the specific texture variables for the differential diagnosis of glioblastoma and primary CNS lymphoma. Conclusion The texture features of T2 WI and conventional imaging findings may be used to distinguish glioblastoma from primary CNS lymphoma.

Supply Chain for Regional Centralized Purchasing: An Application Model

In Europe Health Organizations are progressively modifying their management models to rationalize expenditure in order to assure better levels of effectiveness and efficiency: many countries are going to centralize the management of goods and services supply. In this paper a specific model of centralized purchasing is proposed;it is particularly suitable in cases of severe economy suffering at regional level (e.g. Campania, Lazio, Calabria in Italy) or at national level (e.g. Greece, Ireland, Italy), that means in all those cases where the scale economies, obtainable by supply centralization, would be partly or totally compromised by the extra charges induced by the missing of contractual commitments. This work aims either to analyse such specific approach for centralized purchasing or to propose a simulation model based on Petri net, which could be useful for designing and managing similar case studies.

Expression of Nogo-A mRNA after injury of the rat central nervous system

BACKGROUND： Nogo protein has been identified as an inhibitor of axonal growth, which was highly expressed in central nervous system; however, there are only a few studies on changes of Nogo-A expression following central nervous system injury. OBJECTIVE： To investigate the dynamic expression of Nogo-A mRNA after rat central nervous system injury. DESIGN： Randomized controlled animal study. MATERIALS： Thirty-five rats were randomly divided into two groups, normal animal group （n = 5） and model group （n = 30）. The model group was then divided into six subgroups at six time points： 12, 24 hours and 3, 9, 15, and 21 days post-injury, with five rats in each subgroup. METHODS： The left parietal lobe of rats was contused by free-fall strike, and total RNA was extracted from the entire brain tissue. Semi-quantitative RT-PCR was used to detect Nogo-A mRNA expression, and the ratio between expression of the target gene and glyceraldehyde phosphate dehydrogenase was used to determine the relative expression level. MAIN OUTCOME MEASURES： To determine whether Nogo-A mRNA expression was higher than usual following brain injury. RESULTS： The level of Nogo-A mRNA started to increase 12 hours after injury （P 〈 0.05） and decreased slightly by 24 hours post-injury. Expression increased again on day 3 and reached a peak on day 9. Nogo-A mRNA expression started to decrease on day 15, and then decreased to normal levels at days 21 （P 〉 0.05）. CONCLUSION： After injury of the central nervous system, Nogo-A may play a pivotal role in obstructing regeneration of the nerve.

Expression of c-fos in Rat Brain as a Prelude Marker of Central Nervous System Injury in Response to Methylmercury-stimulation

Objective To probe into the prelude marker of central nervous system injury in response to methyl mercury chloride （MMC） stimulation and the signal transduction molecular mechanism of injury in rat brain induced by MMC. Methods The expression of c-fos mRNA in brain and the expression of c-FOS protein in cortex, hippocampus and ependyma were observed using reverse transcription polymerase chain reaction （RT-PCR） and immunocytochemical methods. The control group was injected with physiological saline of 0.9%, while the concentrations for the exposure groups were 0.05 and 0.5, 5 mg/kg MMC respectively, and the sampling times points were 20, 60, 240, 1440 min. Results The expression of c-FOS protein in cortex and hippocampus increased significantly, the accumulation of mercury in the brain induced by 0.05 mg/Kg MMC for 20 min had no significant difference compared with the control group. The mean value was 0.0044 mg/Kg, while the protein c-FOS expression had significant difference compared with the control group （P〈0.01）. More sensitive expression occurred in hippocampus and cortex, but not in ependyma. Conclusion The expression of c-FOS protein in cortex and hippocampus can predict the neurotoxicity of MMC in the early time, and immediately early gene （lEG） c-fos participates in the process of brain injury induced by MMC.