Coherent optical manipulation of electronic bandstructures via Floquet Engineering is a promising means to control quantum systems on an ultrafast time scale. However, the ultrafast switching on/off ...of the driving field comes with questions regarding the limits of the Floquet formalism (which is defined for an infinite periodic drive) through the switching process and to what extent the transient changes can be driven adiabatically. Experimentally addressing these questions has been difficult, in large part due to the absence of an established technique to measure coherent dynamics through the duration of the pulse. Here, using multidimensional coherent spectroscopy we explicitly excite, control, and probe a coherent superposition of excitons in the K and K′ valleys in monolayer WS2. With a circularly polarized, red-detuned pump pulse, the degeneracy of the K and K′ excitons can be lifted, and the phase of the coherence rotated. We directly measure phase rotations greater than π during the 100 fs driving pulse and show that this can be described by a combination of the AC-Stark shift of excitons in one valley and the Bloch–Siegert shift of excitons in the opposite valley. Despite showing a smooth evolution of the phase that directly follows the intensity envelope of the nonresonant pump pulse, the process is not perfectly adiabatic. By measuring the magnitude of the macroscopic coherence as it evolves before, during, and after the nonresonant pump pulse we show that there is additional decoherence caused by power broadening in the presence of the nonresonant pump. This nonadiabaticity arises as a result of interactions with the otherwise adiabatic Floquet states and may be a problem for many applications, such as manipulating qubits in quantum information processing; however, these measurements also suggest ways such effects can be minimized or eliminated.
Roughly 10% of occupational injuries result in permanent impairment. After initial return to work (RTW), many workers with permanent impairments face RTW interruption due to reinjury, unstable ...health, disability, and layoff. This study used open-ended survey data to: (1) explore workplace factors identified by workers as important levers for change, some of which may previously have been unrecognized; and (2) summarize workers' suggestions for workplace improvements to promote sustained RTW and prevent reinjury.
This study included data from workers' compensation claims and telephone surveys of 582 Washington State workers who had RTW after a work-related injury involving permanent impairment. The survey was conducted in 2019, about a year after claim closure. We used qualitative content analysis methods to inductively code open-ended survey responses.
The most frequent themes were: safety precautions/safer workplace (18.1%), adequate staffing/appropriate task distribution (16.2%), and safety climate (14.1%). Other frequent themes included ergonomics, rest breaks, job strain, predictability and flexibility in work scheduling practices, employer response to injury, social support, communication, and respect. Many workers reported that they were not listened to, or that their input was not sought or valued. Workers often linked communication deficiencies to preventable deficiencies in safety practices, safety climate, and RTW practices, and also to lack of respect or distrust. In counterpoint, nearly one-third of respondents reported that no change was needed to their workplace.
Policies and interventions targeting worker-suggested workplace improvements may promote safe and sustained RTW, which is essential for worker health and economic stability.
Sepsis is a common cause of death, but outcomes in individual patients are difficult to predict. Elucidating the molecular processes that differ between sepsis patients who survive and those who die ...may permit more appropriate treatments to be deployed. We examined the clinical features and the plasma metabolome and proteome of patients with and without community-acquired sepsis, upon their arrival at hospital emergency departments and 24 hours later. The metabolomes and proteomes of patients at hospital admittance who would ultimately die differed markedly from those of patients who would survive. The different profiles of proteins and metabolites clustered into the following groups: fatty acid transport and β-oxidation, gluconeogenesis, and the citric acid cycle. They differed consistently among several sets of patients, and diverged more as death approached. In contrast, the metabolomes and proteomes of surviving patients with mild sepsis did not differ from survivors with severe sepsis or septic shock. An algorithm derived from clinical features together with measurements of five metabolites predicted patient survival. This algorithm may help to guide the treatment of individual patients with sepsis.
Understanding the air stability of MnBi2Te4 thin films is crucial for the development and long-term operation of electronic devices based on magnetic topological insulators. In the present work, we ...study MnBi2Te4 thin films upon exposure to the atmosphere using a combination of synchrotron-based photoelectron spectroscopy, room-temperature electrical transport, and atomic force microscopy to determine the oxidation process. After 2 days of air exposure, a 2 nm thick oxide passivates the surface, corresponding to the oxidation of only the top two surface layers, with the underlying layers preserved. This protective oxide layer results in samples that still exhibit metallic conduction even after several days of air exposure. Furthermore, the work function decreases from 4.4 eV for pristine MnBi2Te4 to 4.0 eV after the formation of the oxide, along with only a small shift in the core levels, indicating minimal doping as a result of air exposure. With the oxide confined to the top surface layers, and the underlying layers preserved, it may be possible to explore new avenues in how to handle, prepare, and passivate future MnBi2Te4 devices.
Following a work-related permanent impairment, injured workers commonly face barriers to safe and successful return to work (RTW). Examining workers' experiences with the workers' compensation (WC) ...system could highlight opportunities to improve RTW outcomes. Objectives included summarizing workers': (1) appraisal of several WC-based RTW programs, and (2) suggestions for vocational rehabilitation and WC system improvements to promote safe and sustained RTW.
In telephone interviews, 582 Washington State workers with work-related permanent impairments were asked whether participation in specified WC-based RTW programs helped them RTW and/or stay at work. Suggestions for program and system improvements were solicited using open-ended questions; qualitative content analysis methods were used to inductively code responses.
Most respondents reported positive impacts from RTW program participation; for example, 62.5% of vocational rehabilitation participants reported it helped them RTW, and 51.7% reported it helped them stay at work. Among 582 respondents, 28.0% reported that no change was needed to the WC system, while 57.6% provided suggestions or critiques. Reduce delays/simplify process/improve efficiency was the most frequent WC system theme-mentioned by 34.9%. Among 120 vocational rehabilitation participants, 35.8% reported that no change was needed to vocational rehabilitation, while 46.7% (N = 56) provided suggestions or critiques. More worker choice/input into the vocational retraining plan was the most frequent vocational rehabilitation theme-mentioned by 33.9%.
This study's findings suggest that there is substantial room for improvement in workers' experience with the WC system. In addition, injured workers' feedback may reflect opportunities to reduce administrative burden and to improve worker health and RTW outcomes.
Coherent optical manipulation of electronic bandstructures via Floquet Engineering is a promising means to control quantum systems on an ultrafast time scale. However, the ultrafast switching on/off ...of the driving field comes with questions regarding the limits of the Floquet formalism (which is defined for an infinite periodic drive) through the switching process and to what extent the transient changes can be driven adiabatically. Experimentally addressing these questions has been difficult, in large part due to the absence of an established technique to measure coherent dynamics through the duration of the pulse. Here, using multidimensional coherent spectroscopy we explicitly excite, control, and probe a coherent superposition of excitons in the
and
' valleys in monolayer WS
. With a circularly polarized, red-detuned pump pulse, the degeneracy of the
and
' excitons can be lifted, and the phase of the coherence rotated. We directly measure phase rotations greater than π during the 100 fs driving pulse and show that this can be described by a combination of the AC-Stark shift of excitons in one valley and the Bloch-Siegert shift of excitons in the opposite valley. Despite showing a smooth evolution of the phase that directly follows the intensity envelope of the nonresonant pump pulse, the process is not perfectly adiabatic. By measuring the magnitude of the macroscopic coherence as it evolves before, during, and after the nonresonant pump pulse we show that there is additional decoherence caused by power broadening in the presence of the nonresonant pump. This nonadiabaticity arises as a result of interactions with the otherwise adiabatic Floquet states and may be a problem for many applications, such as manipulating qubits in quantum information processing; however, these measurements also suggest ways such effects can be minimized or eliminated.
Intimate partner violence (IPV) is a serious public health problem in the United States with adverse consequences for affected individuals and families. Recent reviews of the literature suggest that ...economic policies should be further investigated as part of comprehensive strategies to address IPV. The Earned Income Tax Credit (EITC) is the nation’s largest anti-poverty program for working parents, and especially benefits low-income women with children, who experience an elevated risk of IPV. The EITC may prevent IPV by offering financial resources; such resources may help individuals experiencing IPV leave abusive relationships or address IPV risk factors, thereby preventing entry into abusive relationships. However, the association between EITC generosity and IPV has not been previously examined. We used state-level and individual-level datasets to examine the association between EITC generosity and IPV. Our state-level data source was the nationally representative National Crime Victimization Survey (NCVS; N = ~ 95,000 households per year). For NCVS, we used a difference-in-difference approach to investigate the relationship between state EITC generosity and IPV rates. We also used individual-level longitudinal data from the Fragile Families and Child Well-being Study (n = 13,422 person-waves). Using this cohort of US families at higher risk for IPV, we evaluated associations between estimated EITC benefits based on the mother’s state of residence and number of children and self-reported IPV. In both state- and individual-level analyses, no significant association between state EITC benefits and IPV was found. Factors that may account for these null findings include program ineligibility for individuals who separate from abusive spouses. Future research efforts should more closely examine EITC policy implementation processes and the lived experience of participating in anti-poverty programs for people experiencing IPV.
Na3Bi has attracted significant interest in both bulk form as a three-dimensional topological Dirac semimetal and ultrathin form as a wide-band gap two-dimensional topological insulator. Its extreme ...air sensitivity has limited experimental efforts on thin and ultrathin films grown via molecular beam epitaxy to ultrahigh vacuum environments. Here, we demonstrate air-stable Na3Bi thin films passivated with magnesium difluoride (MgF2) or silicon (Si) capping layers. Electrical measurements show that deposition of MgF2 or Si has minimal impact on the transport properties of Na3Bi while in ultrahigh vacuum. Importantly, the MgF2-passivated Na3Bi films are air-stable and remain metallic for over 100 h after exposure to air, as compared to near instantaneous degradation when they are unpassivated. Air stability enables transfer of films to a conventional high-magnetic field cryostat, enabling quantum transport measurements, which verify that the Dirac semimetal character of Na3Bi films is retained after air exposure.
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