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In this narrative review, we examined what level of research evidence is available that shift workers' sleep-wake disturbances can be minimized through ergonomie shift scheduling. We classified the pertinent studies conducted on real shift workers in field conditions by the type of shift system and study design (ie, whether the shift systems were modified or not— \"treatment\" versus \"no treatment\"). The results of the observational studies in which no changes to the shift system were made (ie, no treatment) showed that, irrespective of the shift system, night and early-morning shifts and quick returns are associated with short sleep and increases in sleepiness. The same is true for very long shifts (> 16 hours) and extremely long weekly working hours (> 55 hours). For all categories of shift systems, there were a lack of controlled intervention studies, limiting the possibility to provide solution-focused recommendations for shift scheduling. Most of the controlled intervention studies had been conducted on workers under regular 3-shift systems. These studies suggested that a change from slowly backward-rotating shifts to rapidly forward-rotating shifts is advantageous for alertness and, to some degree, sleep. We also found that a change from an 8-to 12-hour shift system does not necessarily result in impairments in the sleep-wake pattern. The level of research evidence was affected by many of the studies' frequent methodological limitations in measuring sleep and sleepiness. In all, to have reliable and solution-focused recommendations for shift scheduling, methodologically sound controlled intervention studies are required in different categories of shift systems.

Background Working time characteristics have been used to link work schedule features to health impairment; however, extant working time exposure assessments are narrow in scope. Prominent working time frameworks suggest that a broad range of schedule features should be assessed to best capture non-standard schedules. The purpose of this study was to develop a multi-dimensional scale that assesses working time exposures and test its reliability and validity for full-time workers with non-standard schedules. Methods A cross-sectional study was conducted using full-time, blue-collar worker population samples from three industries - transportation ( n  = 174), corrections ( n  = 112), and manufacturing ( n  = 99). Using a multi-phased approach including the review of scientific literature and input from an advisory panel of experts, the WorkTime Scale (WTS) was created and included multiple domains to characterize working time (length, time of day, intensity, control, predictability, and free time). Self-report surveys were distributed to workers at their workplace during company time. Following a comprehensive scale development procedure (Phase 1), exploratory factor analysis (EFA) (Phase 2) and, confirmatory factor analysis (CFA) (Phase 3; bivariate correlations were used to identify the core components of the WTS and assess the reliability and validity (Phase 4) in three samples. Results Phase 1 resulted in a preliminary set of 21 items that served as the basis for the quantitative analysis of the WTS. Phase 2 used EFA to yield a 14-item WTS measure with two subscales (“Extended and Irregular Work Days (EIWD)” and “Lack of Control (LOC)”). Phase 3 used CFA to confirm the factor structure of the WTS, and its subscales demonstrated good internal consistency: alpha coefficients were 0.88 for the EIWD factor and 0.76–0.81 for the LOC factor. Phase 4 used bivariate correlations to substantiate convergent, discriminant, and criterion (predictive) validities. Conclusions The 14-item WTS with good reliability and validity is an effective tool for assessing working time exposures in a variety of full-time jobs with non-standard schedules.

We present a comprehensive analysis of the evolution of the morphological and structural properties of a large sample of galaxies at z = 3–9 using early James Webb Space Telescope (JWST) CEERS NIRCam observations. Our sample consists of 850 galaxies at z > 3 detected in both Hubble Space Telescope (HST)/WFC3 and CEERS JWST/NIRCam images, enabling a comparison of HST and JWST morphologies. We conduct a set of visual classifications, with each galaxy in the sample classified three times. We also measure quantitative morphologies across all NIRCam filters. We find that galaxies at z > 3 have a wide diversity of morphologies. Galaxies with disks make up 60% of galaxies at z = 3, and this fraction drops to ∼30% at z = 6–9, while galaxies with spheroids make up ∼30%–40% across the redshift range, and pure spheroids with no evidence for disks or irregular features make up ∼20%. The fraction of galaxies with irregular features is roughly constant at all redshifts (∼40%–50%), while those that are purely irregular increases from ∼12% to ∼20% at z > 4.5. We note that these are apparent fractions, as many observational effects impact the visibility of morphological features at high redshift. On average, Spheroid-only galaxies have a higher Sérsic index, smaller size, and higher axis ratio than disk or irregular galaxies. Across all redshifts, smaller spheroid and disk galaxies tend to be rounder. Overall, these trends suggest that galaxies with established disks and spheroids exist across the full redshift range of this study, and further work with large samples at higher redshift is needed to quantify when these features first formed.

We present a catalog of about 25,000 images of massive (M ⋆ ≥ 109 M ⊙) galaxies at redshifts 3 ≤ z ≤ 6 from the TNG50 cosmological simulation, tailored for observations at multiple wavelengths carried out with JWST. The synthetic images were created with the SKIRT radiative transfer code, including the effects of dust attenuation and scattering. The noiseless images were processed with the mirage simulator to mimic the Near Infrared Camera (NIRCam) observational strategy (e.g., noise, dithering pattern, etc.) of the Cosmic Evolution Early Release Science (CEERS) survey. In this paper, we analyse the predictions of the TNG50 simulation for the size evolution of galaxies at 3 ≤ z ≤ 6 and the expectations for CEERS to probe that evolution. In particular, we investigate how sizes depend on the wavelength, redshift, mass, and angular resolution of the images. We find that the effective radius accurately describes the three-dimensional half-mass–radius of the TNG50 galaxies. Sizes observed at 2 μm are consistent with those measured at 3.56 μm at all redshifts and masses. At all masses, the population of higher-z galaxies is more compact than their lower-z counterparts. However, the intrinsic sizes are smaller than the mock observed sizes for the most massive galaxies, especially at z ≲ 4. This discrepancy between the mass and light distributions may point to a transition in the galaxy morphology at z = 4–5, where massive compact systems start to develop more extended stellar structures. 22 22 Data publicly released at https://www.tng-project.org/costantin22.

In recent decades, the hectic lifestyle of industrialized societies has wrought its effects on the quality of sleep, and these effects are evidenced by a profusion of sleep-related disorders. Regular exposure to artificial light, coupled with social and economic pressures have shortened the time spent asleep. Otherwise, Circadian Rhythm Sleep Disorders are characterized by desynchronization between the intrinsic circadian clock and the extrinsic cycles of light/dark and social activities. This desynchronization produces excessive sleepiness and insomnia. The International Classification of Sleep Disorders describes nine sleep disorders under the category of Circadian Rhythm Sleep Disorders. Currently, this diagnosis is made based on the patient’s history, a sleep log alone, or the sleep logs and actigraphy conducted for at least 7 days. This review contains an overview of current treatment options, including chronotherapy, timed bright light exposure, and administration of exogenous melatonin.

Short range communication systems such as Bluetooth and Digital Enhanced Cordless Telecommunications require low-cost transceiver structures. Hence, the development of appropriate receiver techniques has been a major research topic. Particularly, analog limiter–discriminator with integrate and dump filtering (LDI) techniques have received considerable attention. With the availability of digital signal processing, the digital implementation of LDI techniques has become increasingly attractive. In order to make LDI receivers more accessible, zero-crossing detection was proposed. In this communication, the authors shall focus on a novel, yet promising, approach to digital zero-crossing detection in the intermediate frequency domain. Zero-crossing demodulation is an irregular sampling technique, which replaces the commonly employed regular, i.e. temporally equidistant sampling technique in the mentioned low-cost receivers. In this manuscript, a real-time capable receiver concept deploying zero-crossing demodulation shall be presented. First, the authors shall present the theoretical aspects of zero-crossing demodulation with special focus on both Bluetooth Basic Rate and Bluetooth Enhanced Data Rate. Next, the obtained performance results in terms of the bit error ratio shall be given.

New CCD observations of nearby spiral and irregular galaxies show a strong correlation between dustiness and luminosity. This correlation probably results from the well-known relation between the luminosity of a galaxy and the metallicity of its interstellar gas. The data show that the dustiness of spirals and irregulars drops precipitously below MB ≃ -18, corresponding to [Fe/H] ≃ -0.6. Little or no dust is visible in galaxies fainter than MB ≃ -16, for which [Fe/H] ≃ — 0.9. Since Galactic stars with halo kinematics have [Fe/H] ≲ — 1.0 the protoGalactic halo may have collapsed under essentially dust-free conditions. It is argued that dust probably started to form during the terminal phase of the collapse of the halo of M 31. The metallicities of stars contributing most of the light in giant ellipticals are so high that they were, almost certainly, formed in a dusty environment. It therefore seems likely that the most luminous phase in the evolution of gE galaxies occurred while these objects were shrouded in dust. Various lines of evidence suggest that many galaxies at large redshifts may be deficient in heavy elements. Such objects are therefore likely to be dust poor.

We present a detailed study of rotational asymmetry in galaxies for both morphological and physical diagnostic purposes. An unambiguous method for computing asymmetry is developed, robust for both distant and nearby galaxies. By degrading real galaxy images, we test the reliability of this asymmetry measure over a range of observational conditions, e.g. spatial resolution and signal-to-noise (S/N). Compared to previous methods, this new algorithm avoids the ambiguity associated with choosing a center by using a minimization method, and successfully corrects for variations in S/N. There is, however, a strong relationship between the rotational asymmetry and physical resolution (distance at fixed spatial resolution); objects become more symmetric when less well-resolved. We further investigate asymmetry as a function of galactic radius an rotation. We find the asymmetry index has a strong radial dependence that differs vastly between Hubble types. As a result, a meaningful asymmetry index must be specified within a well-defined radius representative of the physical galaxy scale. We enumerate several viable alternatives, which excludes the use of isophotes. Asymmetry as a function of angle (A[phi]) is also a useful indicator of ellipticity and higher-order azimuthal structure. In general, we show the power of asymmetry as a morphological parameter lies in the strong correlation with (B-V) color for galaxies undergoing normal star formation, spanning all Hubble types from ellipticals to irregular galaxies. Interacting galaxies do not fall on this asymmetry-color ``fiducial sequence,'' as these galaxies are too asymmetric for their color. We propose to use this fact to distinguish between `normal' galaxies and galaxies undergoing an interaction or merger at high redshift.

High redshift DLA systems suggest that the relative abundances of elements might be roughly solar, although with absolute abundances of more than two orders of magnitude below solar. The result comes from observations of the [SII/ZnII] ratio, which is a reliable diagnostic of the true abundance, and from DLA absorbers with small dust depletion and negligible HII contamination. In particular, in two DLA systems nitrogen is detected and at remarkably high levels (Vladilo et al. 1995, Molaro et al. 1995, Green et al. 1995, Kulkarni et al. 1996). Here we compare the predictions from chemical evolution models of galaxies of different morphological type with the abundances and abundance ratios derived for such systems. We conclude that solar ratios and relatively high nitrogen abundances can be obtained in the framework of a chemical evolution model assuming short but intense bursts of star formation, which in turn trigger enriched galactic winds, and a primary origin for nitrogen in massive stars. Such a model is the most successful in describing the chemical abundances of dwarf irregular galaxies and in particular of the peculiar galaxy IZw18. Thus, solar ratios at very low absolute abundances, if confirmed, seem to favour dwarf galaxies rather than spirals as the progenitors of at least some of the DLA systems.