Genome size variation within species of Chinese jujube (Ziziphus jujuba Mill.) and its wild ancestor sour jujube (Z. acidojujuba Cheng et Liu)

One of the most important attributes of a genome is genome size, which can to a large extent reflect the evolutionary history and diversity of a plant species. However, studies on genome size diversity within a species are still very limited. This study aims to clarify the variation in genome sizes of Chinese jujube and sour jujube, and to characterize if there exists an association between genome sizes and geographical variation. We measured the genome sizes of 301 cultivars of Chinese jujube and 81 genotypes of sour jujube by flow cytometry. Ten fruit traits, including weight, vertical diameter, horizontal diameter, size, total acids, total sugar, monosaccharide, disaccharide, soluble solids, and ascorbic acid were measured in 243 cultivars of Chinese jujube. The estimated genome sizes of Chinese jujube cultivars ranged from 300.77 Mb to 640.94 Mb, with an average of 408.54 Mb, with the highest number of cultivars (20.93%) falling in the range of 334.787 to 368.804 Mb. The genome size is somewhat different with geographical distribution. The results showed weakly significant positive correlation (p \u3c 0.05) between genome size and fruit size, vertical diameter, horizontal diameter, and weight in the Chinese jujube. The estimated sour jujube genome sizes ranged from 346.93 Mb to 489.44 Mb, with the highest number of genotypes (24.69%) falling in the range of 418.185 to 432.436 Mb. The average genome size of sour jujube genotypes is 423.55 Mb, 15 Mb larger than that of Chinese jujube. There exists a high level of variation in genome sizes within both Chinese jujube cultivars and sour jujube genotypes. Genome contraction may have been occurred during the domestication of Chinese jujube. This study is the first large-scale investigation of genome size variation in both Chinese jujube and sour jujube, which has provided useful resources and data for the characterization of genome evolution within a species and during domestication in plants

Coherence of ion cyclotron resonance for damping ion cyclotron waves in space plasmas

Ion cyclotron resonance is one of the fundamental energy conversion processes through field-particle interaction in collisionless plasmas. However, the key evidence for ion cyclotron resonance (i.e., the coherence between electromagnetic fields and the ion phase space density) and the resulting damping of ion cyclotron waves (ICWs) has not yet been directly observed. Investigating the high-quality measurements of space plasmas by the Magnetospheric Multiscale (MMS) satellites, we find that both the wave electromagnetic field vectors and the bulk velocity of the disturbed ion velocity distribution rotate around the background magnetic field. Moreover, we find that the absolute gyro-phase angle difference between the center of the fluctuations in the ion velocity distribution functions and the wave electric field vectors falls in the range of (0, 90) degrees, consistent with the ongoing energy conversion from wave-fields to particles. By invoking plasma kinetic theory, we demonstrate that the field-particle correlation for the damping ion cyclotron waves in our theoretical model matches well with our observations. Furthermore, the wave electric field vectors ($\delta \mathbf{E'}_{\mathrm {wave,\perp}}$), the ion current density ($\delta \mathbf{J}_\mathrm {i,\perp}$) and the energy transfer rate ($\delta \mathbf{J}_\mathrm {i,\perp}\cdot \delta \mathbf{E'}_{\mathrm {wave,\perp}}$) exhibit quasi-periodic oscillations, and the integrated work done by the electromagnetic field on the ions are positive, indicates that ions are mainly energized by the perpendicular component of the electric field via cyclotron resonance. Therefore, our combined analysis of MMS observations and kinetic theory provides direct, thorough, and comprehensive evidence for ICW damping in space plasmas

Statistical Study of Anisotropic Proton Heating in Interplanetary Magnetic Switchbacks Measured by Parker Solar Probe

Magnetic switchbacks, which are large angular deflections of the interplanetary magnetic field, are frequently observed by Parker Solar Probe (PSP) in the inner heliosphere. Magnetic switchbacks are believed to play an important role in the heating of the solar corona and the solar wind as well as the acceleration of the solar wind in the inner heliosphere. Here, we analyze magnetic field data and plasma data measured by PSP during its second and fourth encounters, and select 71 switchback events with reversals of the radial component of the magnetic field at times of unchanged electron-strahl pitch angles. We investigate the anisotropic thermal kinetic properties of plasma during switchbacks in a statistical study of the measured proton temperatures in the parallel and perpendicular directions as well as proton density and specific proton fluid entropy. We apply the “genetic algorithm” method to directly fit the measured velocity distribution functions in field-aligned coordinates using a two-component bi-Maxwellian distribution function. We find that the protons in most switchback events are hotter than the ambient plasma outside the switchbacks, with characteristics of parallel and perpendicular heating. Specifically, significant parallel and perpendicular temperature increases are seen for 45 and 62 of the 71 events, respectively. We find that the density of most switchback events decreases rather than increases, which indicates that proton heating inside the switchbacks is not caused by adiabatic compression, but is probably generated by nonadiabatic heating caused by field–particle interactions. Accordingly, the proton fluid entropy is greater inside the switchbacks than in the ambient solar wind

Distinguishing communal narcissism from agentic narcissism: A behavior genetics analysis on the agency-communion model of narcissism

This article examined the genetic and environmental bases of the newly proposed agency communion model of narcissism. The model distinguishes between agentic narcissism and communal narcissism. The sample comprised 304 pairs of twins. Genes explained 47% and 25% of the variance in agentic and communal narcissism, respectively; shared environments contributed 0% and 15%, respectively, to agentic and communal narcissism, with non-shared environments accounting for the remaining portions. Although some common genes and environments influenced agentic and communal narcissism simultaneously, most genetic (68%) and environmental (94%) influences on agentic and communal narcissism were unique. These findings provide novel evidence for the theoretical plausibility of communal narcissism as well as its relatedness to and distinctiveness from agentic narcissism, supporting the agency communion narcissism model. (C) 2014 Elsevier Inc. All rights reserved

Fast Quantification of Phosphorus in Crude Soybean Oil by Near-Infrared Spectroscopy

The existing methods for the determination of phosphorus content are unable to regulate the addition of acid and base in the refining process of crude soybean oil through real-time monitoring. Therefore, a novel rapid method for determining the phosphorus content of crude soybean oil based on near-infrared spectroscopy was proposed in this study. It was found that standard normal variate transformation was more effective than two other spectral preprocessing methods evaluated for denoising the spectral data indicative of the phosphorus content in soybean crude oil. The characteristic absorption band of phosphorus was optimized by synergy interval partial least squares (SiPLS). A back propagation (BP) neural network prediction model of the phosphorus content in crude soybean oil was established with learning efficiency of 0.005 and 108 training cycles. The determination coefficient (R2), root mean square error (RMSE) and relative standard deviation (RSD) for the correction set were 0.979 7, 0.859 3 and 1.89%, respectively. The R2, RMSE and RSD for the validation set were 0.978 5, 0.963 8 and 2.15%, respectively. The above results showed that NIR spectroscopy can achieve rapid, accurate and non-destructive detection of the phosphorus content in, and provide a feasible method for the refining of crude soybean oil

Relationship between occupational stress and job burnout among rural-to-urban migrant workers in Dongguan, China: a cross-sectional study

Objectives: In China, there have been an increasing number of migrant workers from rural to urban areas, and migrant workers have the highest incidence of occupational diseases. However, few studies have examined the impact of occupational stress on job burnout in these migrant workers. This study aimed to investigate the relationship between occupational stress and job burnout among migrant workers. Design: This study used a cross-sectional survey. Setting: This investigation was conducted in Dongguan city, Guangdong Province, China. Participants: 3806 migrant workers, aged 18–60 years, were randomly selected using multistage sampling procedures. Primary and secondary outcome measures: Multistage sampling procedures were used to examine demographic characteristics, behaviour customs and jobrelated data. Hierarchical linear regression and logistic regression models were constructed to explore the relationship between occupational stress and burnout. Results: Demographics, behaviour customs and jobrelated characteristics significantly affected on burnout. After adjusting for the control variable, a high level of emotional exhaustion was associated with high role overload, high role insufficiency, high role boundary, high physical environment, high psychological strain, high physical strain, low role ambiguity, low responsibility and low vocational strain. A high level of depersonalisation was associated with high role overload, high role ambiguity, high role boundary, high interpersonal strain, high recreation, low physical environment and low social support. A low level of personal accomplishment was associated with high role boundary, high role insufficiency, low responsibility, low social support, low physical environment, low self-care and low interpersonal strain. Compared to the personal resources, the job strain and personal strain were more likely to explain the burnout of rural-to-urban migrant workers in our study. Conclusions: The migrant workers have increased job burnouts in relation to occupational stress. Relieving occupational stress and maintaining an appropriate quantity and quality of work could be important measures for preventing job burnout among these workers

Global Solutions to an initial boundary problem for the compressible 3-D MHD equations with Navier-slip and perfectly conducting boundary conditions in exterior domains

An initial boundary value problem for compressible Magnetohydrodynamics (MHD) is considered on an exterior domain (with the first Betti number vanishes) in $R^3$ in this paper. The global existence of smooth solutions near a given constant state for compressible MHD with the boundary conditions of Navier-slip for the velocity filed and perfect conduction for the magnetic field is established. Moreover the explicit decay rate is given. In particular, the results obtained in this paper also imply the global existence of classical solutions for the full compressible Navier-Stokes equations with Navier-slip boundary conditions on exterior domains in three dimensions, which is not available in literature, to the best of knowledge of the authors'