149 research outputs found

    The relationship between sleep quality and occupational well-being in employees: The mediating role of occupational self-efficacy

    Get PDF
    ObjectiveThis study aimed to examine the impact of sleep quality on occupational well-being in employees by primarily focusing on the mediating role of occupational self-efficacy.MethodsA total of 487 junior staff completed a set of questionnaires comprised Pittsburgh Sleep Quality Index scale, Occupational Self-efficacy Scale, and occupational well-being measurements.ResultsThe results revealed that both sleep quality and occupational self-efficacy were significantly correlated with occupational well-being. The structural equation modeling analysis and the bootstrap test indicated that occupational self-efficacy partially mediated the effect of poor sleep quality on occupational well-being.DiscussionThese findings expand upon existing research on the relationship between sleep quality and well-being among occupational workers, shed light on the correlation of poor sleep quality with occupational well-being, and are valuable in promoting the occupational well-being of employees

    Efficient simulation of open quantum systems coupled to a reservoir through multiple channels

    Full text link
    The simulation of open quantum systems coupled to a reservoir through multiple channels remains a substantial challenge. This kind of open quantum system arises when considering the radiationless decay of excited states that are coupled to molecular vibrations, for example. We use the chain mapping strategy in the interaction picture to study systems linearly coupled to a harmonic bath through multiple interaction channels. In the interaction picture, the bare bath Hamiltonian is removed by a unitary transformation (the system-bath interactions remain), and a chain mapping transforms the bath modes to a new basis. The transformed Hamiltonian contains time-dependent local system-bath couplings. The open quantum system is coupled to a limited number of (transformed) bath modes in the new basis. As such, the entanglement generated by the system-bath interactions is local, making efficient dynamical simulations possible with matrix product states. We use this approach to simulate singlet fission, using a generalized spin-boson Hamiltonian. The electronic states are coupled to a vibrational bath both diagonally and off-diagonally. This approach generalizes the chain mapping scheme to the case of multi-channel system-bath couplings, enabling the efficient simulation of this class of open quantum systems using matrix product states.Comment: 6 pages, 4 figure

    Why are gainers more risk seeking

    Get PDF
    The phenomenon that prior gains may increase people’s willingness to accept risky gambles is named as the house money effect (Thaler and Johnson, 1990). Many studies have shown that the “house money effect” is a robust phenomenon but few scholars explain the mechanism of it well. We suppose the reason for the house money effect is that the ante (starting amount) is from the prior gambling profits, and its potential loss has relatively low psychological value. To test this hypothesis, we designed a series of studies using two-stage gambles. A total of 915 university students participated. In Study 1, in addition to a standard condition (which replicated the basic effect), we test how people respond to “prospect theory, with memory” frame, a “concreteness” frame and “quasi-hedonic” editing. None of these types of frames result in a significant house money effect. In Study 2, we certify the reference point shift to 100 Yuan in the second-stage gamble, thus the house money effect can be regarded as the absence of loss aversion; Study 3, consisting of 3 sub-experiments, indicated that gambling profits and normal income will open different mental accounts which are spent quite differently. The pain of losing 100 Yuan allowance is more serious than that of losing 100 Yuan gambling wins. People will typically reject the gamble of 50/50 chance to gain or lose 100 Yuan if the ante is from the “normal income account”, but accept if the ante is from the “windfall account”. The results of the series of experiments prove the accuracy of our hypothesis mostly

    Reconfigurable multi-component micromachines driven by optoelectronic tweezers

    Get PDF
    There is great interest in the development of micromotors which can convert energy to motion in sub-millimeter dimensions. Micromachines take the micromotor concept a step further, comprising complex systems in which multiple components work in concert to effectively realize complex mechanical tasks. Here we introduce light-driven micromotors and micromachines that rely on optoelectronic tweezers (OET). Using a circular micro-gear as a unit component, we demonstrate a range of new functionalities, including a touchless micro-feed-roller that allows the programming of precise three-dimensional particle trajectories, multi-component micro-gear trains that serve as torque- or velocity-amplifiers, and micro-rack-and-pinion systems that serve as microfluidic valves. These sophisticated systems suggest great potential for complex micromachines in the future, for application in microrobotics, micromanipulation, microfluidics, and beyond

    Heat Shock Protein 40 (HSP40) in Pacific White Shrimp (Litopenaeus vannamei): Molecular Cloning, Tissue Distribution and Ontogeny, Response to Temperature, Acidity/Alkalinity and Salinity Stresses, and Potential Role in Ovarian Development

    Get PDF
    Heat shock proteins (HSPs), a family of conserved proteins that are produced by cells in response to stresses, are known as molecular chaperones with a range of housekeeping and cellular protective functions. The 40 kD heat shock protein (HSP40) is a co-chaperone for HSP70 in the regulation of ATP hydrolysis. Unlike its well-documented cofactor HSP70, little is currently known regarding the biological functions of HSP40 in crustacean species such as penaeid shrimp. In the present study, the cDNA encoding HSP40 (Lv-HSP40) was identified from the Pacific white shrimp Litopenaeus vannamei, a highly significant commercial culture species. The structural organization indicates that Lv-HSP40 belongs to the type-I HSP40s. The muscle, gill, and hepatopancreas are the main sites of Lv-HSP40 transcript expression. Within these tissues, Lv-HSP40 mRNA were predominantly exhibited in the myocytes, epithelial cells and hepatopancreatic cells, respectively. Under acute thermal stress in the culture environment, Lv-HSP40 transcript levels are significantly induced in these three tissues, while low pH stress only upregulates Lv-HSP40 mRNA in the hepatopancreas and gill. During ontogenesis, Lv-HSP40 transcript levels are high at early embryonic stages and drop sharply at late embryonic and early larval stages. The ovary is another major organ of Lv-HSP40 mRNA expression in female shrimp, and Lv-HSP40 transcripts were mainly presented in the follicle cells but only weekly detected in the oocytes. Ovarian Lv-HSP40 mRNA levels increase continuously during gonadal development. Silencing of the Lv-HSP40 gene by RNA interference may effectively delay ovarian maturation after unilateral eyestalk ablation. The roles of Lv-HSP40 in ovarian development are speculated to be independent of its cofactor HSP70, and the vitellogenesis factor vitellogenin (Vg) and vitellogenin receptor (VgR). Our study, as a whole, provides new insights into the roles of HSP40 in multiple physiological processes in L. vannamei: (1) HSP40 is a responding factor during stressful conditions; and (2) HSP40 participates in embryonic and ovarian development

    Persistent sulfate formation from London Fog to Chinese haze

    Get PDF
    Sulfate aerosols exert profound impacts on human and ecosystem health, weather, and climate, but their formation mechanism remains uncertain. Atmospheric models consistently underpredict sulfate levels under diverse environmental conditions. From atmospheric measurements in two Chinese megacities and complementary laboratory experiments, we show that the aqueous oxidation of SO2 by NO2 is key to efficient sulfate formation but is only feasible under two atmospheric conditions: on fine aerosols with high relative humidity and NH3 neutralization or under cloud conditions. Under polluted environments, this SO2 oxidation process leads to large sulfate production rates and promotes formation of nitrate and organic matter on aqueous particles, exacerbating severe haze development. Effective haze mitigation is achievable by intervening in the sulfate formation process with enforced NH3 and NO2 control measures. In addition to explaining the polluted episodes currently occurring in China and during the 1952 London Fog, this sulfate production mechanism is widespread, and our results suggest a way to tackle this growing problem in China and much of the developing world

    Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

    Full text link
    Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30MM_{\odot} for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

    Robust estimation of bacterial cell count from optical density

    Get PDF
    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
    corecore