A Dynamics and Sedimentology Study of Eastern Atchafalaya Bay, Louisiana (Cluster Analysis, Estuarine).

A new Mississippi River Delta is building in Atchafalaya Bay of southcentral Louisiana as a result of a upstream natural diversion in river course. The present study focuses on several distinct but complementary aspects of the physical processes of the modern Atchafalaya River Delta. Coherence analysis reveals that the subtidal fluctuations of water stage and current velocity in the estuarine area are closely related to atmospheric forcing at different time scales. The water stage fluctuations at Morgan City had significant variance at time scale 2.5-10 days which was driven by local longitudinal (north-south) winds. There were also fluctuations at periods of 3 days which were the result of up-bay propagation of sea level fluctuations generated by longshore (west-east) winds. In winter local longitudinal winds were dominant, and in summer coastal Ekman flux driven by longshore winds became more pronounced. It is possible to estimate by a linear model the subtidal current driven by winds if enough long-term records are available. Several characteristics (e.g. annual sediment flux, seasonal variation in suspended sediment, grain size variation, abnormally large floods and sediment transport, delta growth rate, and channel geometry etc.) of sediment input from the Atchafalaya River, importance for understanding deltaic depositional processes are examined. Cluster analysis, based on grain size distribution, is applied to three sets of sediment samples totaling 563 to determine the natural grouping of the sediments in Atchafalaya Bay. Clusters produced proved to be sedimentologically meaningful and environmentally significant. Each cluster is related to certain environment(s) of deposition identified by previous studies. Based on the classification established, sediment samples from unknown environments in the study area can be objectively identified based on their grain-size distribution. Based on nonparametric statistical tests, seasonal variation in sediment grain size differs among delta lobes. This can be explained by seasonal variations of atmospheric forcings and the difference in elevation and location of delta lobes

Taxonomic reconsideration of Prunus veitchii (Rosaceae)

Prunus veitchii was published in 1912 and was treated as a synonym of P. serrulata var. pubescens. The information about this taxon is relatively scarce. When consulting specimens of Prunus L., type materials of Prunus veitchii were found to belong to three taxa and P. veitchii, P. concinna, P. japonica var. zhejiangensis, C. jingningensis and C. xueluoensis were found to be conspecific. The taxonomic status of P. veitchii is reconsidered in the present paper. Morphometric analyses were performed to evaluate the significance of differences between P. veitchii and P. serrulata var. pubescens. The results show that the leaves of P. veitchii are significantly smaller and narrower than the leaves of P. serrulata var. pubescens and the peduncle and pedicels are shorter. According to the results of morphometric analyses, P. veitchii should be treated as a separate species. To address these results, a lectotype of P. veitchii is designated here and P. concinna, Cerasus jingningensis and C. xueluoensis are here designated as synonyms of P. veitchii

Relationship between burnout and intention to leave amongst clinical nurses: the role of spiritual climate

Aim: This study aims to identify the role that spiritual climate has in reducing burnout and intentions to leave amongst clinical nurses. Background: Both shortages and the high turnover of nurses are challenging problems worldwide. Enhancing the spiritual climate amongst nurses can enhance teamwork, organisational commitment and job satisfaction and can play a role in reducing burnout and turnover intention. Methods: A total of 207 clinical nurses working at a tertiary university hospital were included in this cross-sectional, single-site study. Independent-samples t test and ANOVA, Pearson correlation analysis and hierarchical regression analysis were used to explore the relationships amongst related factors. Results: Most clinical departments showed a moderate spiritual climate (60.24±0.82) with high job burnout (33.62±0.28) and turnover intention (2.37±0.57). A good spiritual climate was correlated with high job satisfaction (r=0.412, p < 0.01), low burnout and turnover intention (r = −0.423, p < 0.01 and r = −0.292, p < 0.01, respectively). Spiritual climate could also indirectly influence nurses' job burnout and turnover intention (R2 = 10.31%).ConclusionsDifferent departments have different spiritual climates. The findings from this study indicate that spiritual climate may impact nursing burnout and turnover.Implications for nursing managementUsing a spiritual climate scale provides health care decision-makers with clear information about staff spirituality well-being. Interventions to improve spiritual climate can benefit teamwork in clinical departments

Largely tunable band structures of few-layer InSe by uniaxial strain

Due to the strong quantum confinement effect, few-layer {\gamma}-InSe exhibits a layer-dependent bandgap, spanning the visible and near infrared regions, and thus recently draws tremendous attention. As a two-dimensional material, the mechanical flexibility provides an additional tuning knob for the electronic structure. Here, for the first time, we engineer the band structures of few-layer and bulk-like InSe by uniaxial tensile strain, and observe salient shift of photoluminescence (PL) peaks. The shift rate of the optical gap is approximately 90-100 meV per 1% strain for 4- to 8-layer samples, which is much larger than that for the widely studied MoS2 monolayer. Density functional calculations well reproduce the observed layer-dependent bandgaps and the strain effect, and reveal that the shift rate decreases with increasing layer number for few-layer InSe. Our study demonstrates that InSe is a very versatile 2D electronic and optoelectronic material, which is suitable for tunable light emitters, photo-detectors and other optoelectronic devices.Comment: submitte

Positive spiritual climate supports transformational leadership as means to reduce nursing burnout and intent to leave

AimTo explore the relationship between spiritual climate and transformational leadership, and examine their impact on nurses perceived emotional exhaustion and intentions to quit.BackgroundTransformational leadership is known to have a significant positive effect on work environment and job satisfaction. Additionally, promoting spiritual climate amongst staff can benefit workers by increasing self‐worth. The relationship between the two is unknown.MethodsNurse clinicians from 2 sites in the Jiangsu Province of China completed self‐report questionnaires based on spiritual climate, emotional exhaustion, clinical leadership and Turnover Intention Scales. Mediation analysis was applied to evaluate impact of spiritual climate.ResultsPerceived positive spirituality amongst nurse clinicians reinforces transformational leadership to reduce emotional exhaustion (indirect effect of −0.089, p < .01). Burnout and intention to leave showed significantly positive correlation with lower levels of perceived spirituality (r = .545, p < .01).ConclusionTransformational leadership in the workplace can reduce nurses' burnout, and a positive spiritual climate increases meaningfulness in their work. This may help in nurse retention.Implications for Nursing ManagementHealth care leaders must look beyond transformational leadership to maintain a positive and supportive clinical climate, and this may involve acknowledgement of nurses' spiritual needs

Structure constrained controller design for power plants and EV aggregator in frequency regulation considering time delays

Frequency control is the major concern for the integration of renewable energy into power systems. Electric vehicles (EV) are suggested to mitigate the system frequency deviation due to its vehicle-to-grid (V2G) capability and quick response characteristic. In this paper, the EVs are modeled by an EV aggregator and responded to the measureable states, such as system frequency, outputs of power plants and EV aggregator. Thus, a structure constrained feedback controller for the power plants and the EV aggregator is designed. However, the time delays during the transmission of control signal and state variable are inevitable. To deal with the time delays in the input and state variables, the Pade approximation is applied to construct the state space equations for the time delays. An equivalent augmented system without time delay is derived, in which the linear quadratic regulator (LQR) method is applied to derive the structure constrained feedback controller. Effectiveness and correctness of the proposed method are validated by a simple Great Britain power system in 2020

Gapless surface Dirac cone in antiferromagnetic topological insulator MnBi2_2Te4_4

The recent discovered antiferromagnetic topological insulators in Mn-Bi-Te family with intrinsic magnetic ordering have rapidly drawn broad interest since its cleaved surface state is believed to be gapped, hosting the unprecedented axion states with half-integer quantum Hall effect. Here, however, we show unambiguously by using high-resolution angle-resolved photoemission spectroscopy that a gapless Dirac cone at the (0001) surface of MnBi$_2$Te$_4$ exists between the bulk band gap. Such unexpected surface state remains unchanged across the bulk N\'eel temperature, and is even robust against severe surface degradation, indicating additional topological protection. Through symmetry analysis and $\textit{ab}$-$\textit{initio}$ calculations we consider different types of surface reconstruction of the magnetic moments as possible origins giving rise to such linear dispersion. Our results reveal that the intrinsic magnetic topological insulator hosts a rich platform to realize various topological phases such as topological crystalline insulator and time-reversal-preserved topological insulator, by tuning the magnetic configurations.Comment: 9 pages, 4 figures. To appear in Phys. Rev. X. See Version 1 for the supplementary fil