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Wind-blown snow is a frequent phenomenon in high-elevation and polar regions which impacts the surface energy and mass balance of these areas. Loose surface snow gets eroded and transported by wind, which influences the snow particles' physical properties (size, shape, optical properties) that determine the characteristics of the emerging wind-impacted snowpack layer. During airborne snow transport, the governing processes happen on the micro-scale while the particles are transported over long distances. The unfolding processes and the evolution of the particles' physical properties are thus difficult to observe in situ. Here, we used cold-laboratory ring wind tunnel experiments as an interim solution to study the governing processes during airborne snow transport with stable water isotopes as tracers for these micro-scale processes. Repeated analysis of airborne-sampled snow by micro-computed tomography (µCT) documented a growing and rounding of snow particles with transport time, with a concurrent decrease in specific surface area. Stable water isotope analysis of airborne snow and water vapour allowed us to attribute this evolution to the process of airborne snow metamorphism. The changes observed in the snow isotopic composition showed a clear isotopic signature of metamorphic deposition, which requires particle–air temperature gradients. These results question the validity of the thermal-equilibrium assumption between particles and air inside the saltation layer of wind-blown snow events, where the conditions are similar to the ones found in the wind tunnel. Our results thus refine the understanding of the governing processes in the saltation layer and suggest that the snow's isotopic composition can inform on local wind-blown snow events as the original snow isotope signal gets overprinted by airborne snow metamorphism. Within transport times of 3 h, we observed changes in the isotope signal of airborne snow of up to +1.47 ‰ in δ18O, ±5.7 ‰ in δD, and −6.1 ‰ in d-excess. Thus, airborne snow metamorphism has the potential to influence the climate signal stored in snow and ice core stable water isotope records.

The evolution of the surface snow microstructure under the influence of wind during precipitation events is hardly understood but crucial for polar and alpine snowpacks. Available statistical models are solely parameterized from field data where conditions are difficult to control. Controlled experiments which exemplify the physical processes underlying the evolution of density or specific surface area (SSA) of surface snow under windy conditions are virtually non-existent. As a remedy, we conducted experiments in a cold laboratory using a ring-shaped wind tunnel with an infinite fetch to systematically investigate wind-induced microstructure modifications under controlled atmospheric, flow and snow conditions and to identify the relevant processes. Airborne snow particles are characterized by high-speed imaging, while deposited snow is characterized by density and SSA measurements. We used a single snow type (dendritic fresh snow) for simulating different precipitation intensities, varied wind speeds at a height of 0.4 m from 3 to 7 m s−1 (for fixed temperature) and varied temperatures from −24 to −2 °C (for fixed wind speed). The measured airborne impact trajectories confirm the consistency of our coefficient of restitution with large-scale saltation, rendering the setup suitable for realistically studying interactions between airborne and deposited snow. Increasing wind speeds resulted in intensified densification and stronger SSA decreases. The most drastic snow density and SSA changes in deposited snow are observed close to the melting point. Our measured densification rates as a function of wind speed show clear deviations from existing statistical models but can be re-parameterized through our data. This study, as a first of its kind, exemplifies a rich nonlinear interplay between airborne and deposited snow particles, which is discussed in view of a multitude of involved processes, i.e., airborne metamorphism, cohesion, particle separation and fragmentation.

Habitat restoration is becoming an increasingly prevalent tool in the armoury of marine conservation, particularly given the expanding interest in creating nature-based solutions to a changing climate. Seagrass restoration is a particular focus of increased numbers of projects and although there is a growing number of examples of successful seagrass restoration attempts, there remain extensive case studies of poor success or restoration failure from around the globe. To enable marine habitat restoration to happen at scale and make a genuine contribution to carbon sequestration rates globally, improved methods that are both practical and simple are required to foster higher rates of success and lower costs. Here, we present seven bottlenecks to achieving reliable seed-based seagrass restoration. In doing so, we also provide opportunities for practical and simple ways in which the knowledge gaps that underpin these bottlenecks can be filled. Seed collection needs to be easier and more efficient; the processing and storage of seeds more controlled; and germination and seedling survival more effective so that fewer seeds are required for more reliable planting. We conclude that further collaborative multidisciplinary science is required in all parts of the world to improve seagrass seed-based restoration through better incorporation of faunal and microbial ecology, more reliable modelling, improved reporting of restoration failures and a wider investigation of seed-based ecology beyond a handful of species.

Snow cornices growing on the leeward side of mountain ridges are common in alpine and polar regions during snow seasons. These structures may crack and fall, leading to an increase in avalanche danger. Although cornice formation has been observed in wind tunnel tests and the field, knowledge gaps still exist regarding the formation mechanism. This is particularly true with respect to wind conditions which favor cornice formation. To characterize the wind effects as the main factor for cornice growth, we carried out ring wind tunnel (RWT) experiments in a cold laboratory under various wind conditions. We quantitatively investigated the growth rate of the cornice in the horizontal and vertical direction as well as the airborne particle concentration. The results show that cornices only appear under a moderate wind speed range (1–2 times the threshold wind speed). The cornice growth rates in length and thickness are mainly determined by the combined effects of mass accumulation and erosion. The lower-limit wind speed for cornice growth is approximately equal to the threshold wind speed for snow transport. The upper limit of wind speed is when the erosion rate is higher than the deposition rate. The length growth rate of the cornices reaches a maximum for wind speeds approximately 40 % higher than the threshold wind speed. Moreover, a conceptual model for interpreting the cornice accretion mechanism is proposed based on the mass conservation and the results of the RWT experiments. The estimated suitable wind condition for cornice growth and formation are in good agreement with field observations in Gruvefjellet, Svalbard. Based on the physics of drifting snow, our results provide new insights into snow cornice formation and improve understanding of cornice processes that can influence avalanche activity. The experimental results and the conceptual model can be used in future snow cornice simulation and prediction work for cornice-induced avalanches.

More than 36 yr have passed since the discovery of the infrared excess from circumstellar dust orbiting the white dwarf G29-38, which at 17.5 pc it is the nearest and brightest of its class. The precise morphology of the orbiting dust remains only marginally constrained by existing data, subject to model-dependent inferences, and thus fundamental questions of its dynamical origin and evolution persist. This study presents a means to constrain the geometric distribution of the emitting dust using stellar pulsations measured at optical wavelengths as a variable illumination source of the dust, which reradiates primarily in the infrared. By combining optical photometry from the Whole Earth Telescope with 0.7–2.5 μ m spectroscopy obtained with SpeX at NASA’s Infrared Telescope Facility, we detect luminosity variations at all observed wavelengths, with variations at most wavelengths corresponding to the behavior of the pulsating stellar photosphere, but toward the longest wavelengths the light curves probe the corresponding time variability of the circumstellar dust. In addition to developing methodology, we find the pulsation amplitudes decrease with increasing wavelength for principal pulsation modes, yet increase beyond ≈2 μ m for nonlinear combination frequencies. We interpret these results as combination modes derived from the principal modes of identical ℓ values and discuss the implications for the morphology of the warm dust. We also draw attention to some discrepancies between our findings and theoretical expectations for the results of the nonlinearity imposed by the surface convection zone on mode–mode interactions and on the behavior of the first harmonic of the highest-amplitude pulsation mode.

To maximize the opportunities of seagrass as a nature-based solution requires restoration to occur on a large scale. New methods and knowledge are required that can solve ecological bottlenecks, improving its reliability and effectiveness. Although there is increasing interest in the use of seeds for seagrass restoration there exists a limited understanding of how best to plant them with the most knowledge on germination and seedling emergence coming from laboratory studies. Here we present the results of a novel field study on the emergence success of seeds of the seagrass Zostera marina when subjected to varied planting treatments. Seeds were planted into hessian bags according to a factorial design of three treatments (sediment type, detritus addition, and nutrient addition). By adding nutrients to natural sediment, the present study provides some evidence of seagrass shoot emergence and maximum shoot length doubling. The present study provides evidence that even in heavily nutrient-rich environments, seagrass sediments may require additional nutrients to improve seedling emergence and growth. It also highlights the highly variable nature of planting seagrass seeds in shallow coastal environments. Critically this study provides increasing levels of evidence that small subtleties in the method can have large consequences for seagrass restoration and that for restoration to scale to levels that are relevant for nature-based solutions there remain many unknowns that require consideration.

Modelling and forecasting wind-driven redistribution of snow in mountainous regions with its implications on avalanche danger, mountain hydrology or flood hazard is still a challenging task often lacking in essential details. Measurements of drifting and blowing snow for improving process understanding and model validation are typically limited to point measurements at meteorological stations, providing no information on the spatial variability of horizontal mass fluxes or even the vertically integrated mass flux. We present a promising application of a compact and low-cost radar system for measuring and characterizing larger-scale (hundreds of metres) snow redistribution processes, specifically blowing snow off a mountain ridge. These measurements provide valuable information of blowing snow velocities, frequency of occurrence, travel distances and turbulence characteristics. Three blowing snow events are investigated, two in the absence of precipitation and one with concurrent precipitation. Blowing snow velocities measured with the radar are validated by comparison against wind velocities measured with a 3D ultra-sonic anemometer. A minimal blowing snow travel distance of 60–120 m is reached 10–20 % of the time during a snow storm, depending on the strength of the storm event. The relative frequency of transport distances decreases exponentially above the minimal travel distance, with a maximum measured distance of 280 m. In a first-order approximation, the travel distance increases linearly with the wind velocity, allowing for an estimate of a threshold wind velocity for snow particle entrainment and transport of 7.5–8.8 m s−1, most likely depending on the prevailing snow cover properties. Turbulence statistics did not allow a conclusion to be drawn on whether low-level, low-turbulence jets or highly turbulent gusts are more effective in transporting blowing snow over longer distances, but highly turbulent flows are more likely to bring particles to greater heights and thus influence cloud processes. Drone-based photogrammetry measurements of the spatial snow height distribution revealed that increased snow accumulation in the lee of the ridge is the result of the measured local blowing snow conditions.

Phosphors the ceramic materials should able to work in tough environment surrounded and bombarded by high energy Vacuum Ultra Violet (VUV), UV or electron beam radiations in any discharge tube. The plasma display panel (PDP) is increasingly gaining attention over conventional cathode ray tube (CRT)-based TVs as a medium of large format (60+”) television (TV), particularly high definition TVs (HDTVs). Improvements have been made not only in size but also in other areas such as resolution, luminescence efficiency, brightness, contrast ratio, power consumption, and cost reduction. The formation of a phosphor host and doping process by solid solution is critical and is highly dependent on the reaction temperature and conditions. Since the purity of starting chemicals is very important to the synthesis of phosphors, the starting chemicals are typically 99.9%, 99.999% in purity. Required amounts of starting ingredients are mixed in the presence of an appropriate flux (if necessary) and fired at high temperatures (1200 °C) in air or in a controlled atmosphere (N2, C, CO, or N2 with 2-5% of H2). The present paper reports the synthesis and luminescence characteristics of different ceramic materials (phosphors) for display applications.

The present paper reports the Photoluminescence (PL) of the Sr2CeO4 phosphor, singly doped with Erbium rare-earth ion with different concentrations (0.01, 0.1, 0.2, 0.5 and 1%).The phosphor samples were synthesized using the standard solid state reaction technique. The effect of Er dopant on the structural, morphological, and Photoluminescent properties of the samples are studied with X-ray diffraction (XRD), PL and SEM analysis. The PL emission of undoped Sr2CeO4 phosphor was observed at 470 nm with high intensity followed by the primary Er emissions with good intensity at 525, 530, 549, 557 and 565 nm.

Abstract Background Studying functional divergences between paralogs that originated from genome duplication is a significant topic in investigating molecular evolution. Genes that exhibit basal level cyclic expression patterns including circadian and light responsive genes are important physiological regulators. Temporal shifts in basal gene expression patterns are important factors to be considered when studying genetic functions. However, adequate efforts have not been applied to studying basal gene expression variation on a global scale to establish transcriptional activity baselines for each organ. Furthermore, the investigation of cyclic expression pattern comparisons between genome duplication created paralogs, and potential functional divergence between them has been neglected. To address these questions, we utilized a teleost fish species, Xiphophorus maculatus, and profiled gene expression within 9 organs at 3-h intervals throughout a 24-h diurnal period. Results Our results showed 1.3–21.9% of genes in different organs exhibited cyclic expression patterns, with eye showing the highest fraction of cycling genes while gonads yielded the lowest. A majority of the duplicated gene pairs exhibited divergences in their basal level expression patterns wherein only one paralog exhibited an oscillating expression pattern, or both paralogs exhibit oscillating expression patterns, but each gene duplicate showed a different peak expression time, and/or in different organs. Conclusions These observations suggest cyclic genes experienced significant sub-, neo-, or non-functionalization following the teleost genome duplication event. In addition, we developed a customized, web-accessible, gene expression browser to facilitate data mining and data visualization for the scientific community.

Background: Patients with breast cancer (BC) show strong interest in complementary and alternative medicine (CAM), particularly for adverse effects of adjuvant endocrine treatment — e.g., with letrozole. Letrozole often induces myalgia/limb pain and arthralgia, with potential noncompliance and treatment termination. This analysis investigated whether CAM before aromatase inhibitor (AI) therapy is associated with pain development and the intensity of AI-induced musculoskeletal syndrome (AIMSS) during the first year of treatment. Patients and methods: The multicenter phase IV PreFace study evaluated letrozole therapy in postmenopausal, hormone receptor–positive patients with early BC. Patients were asked about CAM use before, 6 months after, and 12 months after treatment started. They recorded pain every month for 1 year in a diary including questions about pain and numeric pain rating scales. Data were analyzed for patients who provided pain information for all time points. Results: Of 1396 patients included, 901 (64.5%) had used CAM before AI treatment. Throughout the observation period, patients with CAM before AI treatment had higher pain values, for both myalgia/limb pain and arthralgia, than non-users. Pain increased significantly in both groups over time, with the largest increase during the first 6 months. No significant difference of pain increase was noted regarding CAM use. Conclusions: CAM use does not prevent or improve the development of AIMSS. Pain intensity was generally greater in the CAM group. Therefore, because of the risk of non-compliance and treatment discontinuation due to the development of higher pain levels, special attention must be paid to patient education and aftercare in these patients.

Abstract Fluorescent light (FL) has been shown to induce a cellular immune and inflammatory response that is conserved over 450 MY of evolutionary divergence and among vertebrates having drastically different lifestyles such as Mus musculus, Danio rerio, Oryzias latipes and Xiphophorus maculatus. This surprising finding of an inflammation and immune response to FL not only holds for direct light receiving organs (skin) but is also observed within internal organs (brain and liver). Light responsive genetic circuitry initiated by the IL1B regulator induces a highly conserved acute phase response in each organ assessed for all of biological models surveyed to date; however, the specific light wavelengths triggering this response have yet to be determined so investigation of mechanisms and/or light specific molecule(s) leading to this response are difficult to assess. To understand how specific light wavelengths are received in both external and internal organs, zebrafish were exposed to specific 50 nm light wavebands spanning the visible spectrum from 300–600 nm and the genetic responses to each waveband exposure were assessed. Surprisingly, the induced cellular stress response previously observed following FL exposure is not triggered by the lower “damaging” wavelengths of light (UVB and UVA from 300–400 nm) but instead is maximally induced by higher wavelengths ranging from 450–500 nm in skin to 500–600 nm in both brain and liver).

Measurable residual disease (MRD) quantified by multiparameter flow cytometry (MFC) is a strong and independent prognostic factor in acute myeloid leukemia (AML). However, several technical factors may affect the final read-out of the assay. Experts from the MRD Working Party of the European LeukemiaNet evaluated which aspects are crucial for accurate MFC-MRD measurement. Here, we report on the agreement, obtained via a combination of a cross-sectional questionnaire, live discussions, and a Delphi poll. The recommendations consist of several key issues from bone marrow sampling to final laboratory reporting to ensure quality and reproducibility of results. Furthermore, the experiences were tested by comparing two 8-color MRD panels in multiple laboratories. The results presented here underscore the feasibility and the utility of a harmonized theoretical and practical MFC-MRD assessment and are a next step toward further harmonization.

Introduction: Coccidioidomycosis is a fungal infection endemic in the southwestern United States (US). Primary pulmonary coccidioidomycosis (PPC) is a leading cause of community-acquired pneumonia (CAP) in this region, although its diagnosis is often delayed, leading to lag in antifungal treatment and subsequent morbidity. The impact of early empiric antifungal therapy as part of treatment for CAP in endemic areas on clinical outcomes is unknown. Methods: Phase IV randomized, double-blind, placebo-controlled trial in individuals aged 18 years or older with CAP who met all eligibility criteria in Coccidioides endemic regions in the US. Eligible participants with CAP were randomized to receive either fluconazole (400 mg daily) or matching placebo for 42 days and were subsequently monitored for clinical resolution of their illness. Objectives: The primary objective was to assess the clinical response of early empiric antifungal therapy with fluconazole through Day 22 in subjects with PPC who were adherent to the study intervention. Secondary objectives included: assessments of the impact of early empiric antifungal therapy with fluconazole through Day 22 and 43 in subjects with PPC regardless of adherence, comparisons of the clinical response and its individual components over time by treatment group in subjects with PPC, assessments of days lost from work or school, hospitalization, and all-cause mortality. Discussion: This trial was halted early due to slow enrollment (72 participants in one year, 33 received fluconazole and 39 received placebo). Of those enrolled, eight (11%) met the study definition of PPC. The study design and challenges are discussed.

OBJECTIVES:. We sought to validate prognostic scores in coronavirus disease 2019 including National Early Warning Score, Modified Early Warning Score, and age-based modifications, and define their performance characteristics. DESIGN:. We analyzed prospectively collected data from the Adaptive COVID-19 Treatment Trial. National Early Warning Score was collected daily during the trial, Modified Early Warning Score was calculated, and age applied to both scores. We assessed prognostic value for the end points of recovery, mechanical ventilation, and death for score at enrollment, average, and slope of score over the first 48 hours. SETTING:. A multisite international inpatient trial. PATIENTS:. A total of 1,062 adult nonpregnant inpatients with severe coronavirus disease 2019 pneumonia. INTERVENTIONS:. Adaptive COVID-19 Treatment Trial 1 randomized participants to receive remdesivir or placebo. The prognostic value of predictive scores was evaluated in both groups separately to assess for differential performance in the setting of remdesivir treatment. MEASUREMENTS AND MAIN RESULTS:. For mortality, baseline National Early Warning Score and Modified Early Warning Score were weakly to moderately prognostic (c-index, 0.60–0.68), and improved with addition of age (c-index, 0.66–0.74). For recovery, baseline National Early Warning Score and Modified Early Warning Score demonstrated somewhat better prognostic ability (c-index, 0.65–0.69); however, National Early Warning Score+age and Modified Early Warning Score+age further improved performance (c-index, 0.68–0.71). For deterioration, baseline National Early Warning Score and Modified Early Warning Score were weakly to moderately prognostic (c-index, 0.59–0.69) and improved with addition of age (c-index, 0.63–0.70). All prognostic performance improvements due to addition of age were significant (p < 0.05). CONCLUSIONS:. In the Adaptive COVID-19 Treatment Trial 1 cohort, National Early Warning Score and Modified Early Warning Score demonstrated moderate prognostic performance in patients with severe coronavirus disease 2019, with improvement in predictive ability for National Early Warning Score+age and Modified Early Warning Score+age. Area under receiver operating curve for National Early Warning Score and Modified Early Warning Score improved in patients receiving remdesivir versus placebo early in the pandemic for recovery and mortality. Although these scores are simple and readily obtainable in myriad settings, in our data set, they were insufficiently predictive to completely replace clinical judgment in coronavirus disease 2019 and may serve best as an adjunct to triage, disposition, and resourcing decisions.

Fish have a high diversity of sex-determining systems, but the mechanisms responsible for this are not well understood. Here, Franchini et al. show how hybridization and backcrossing have led to the evolution of a new sex chromosome in swordtail fish during 30 years of experimental evolution.

Xiphophorus interspecies hybrids represent a valuable model system to study heritable tumorigenesis, and the only model system that exhibits both spontaneous and inducible tumors. Types of tumorigenesis depend on the specific pedigree of the parental species, X. maculatus, utilized to produce interspecies hybrids. Although the ancestors of the two currently used X. maculatus parental lines, Jp163 A and Jp163 B, were originally siblings produced by the same mother, backcross interspecies hybrid progeny between X. hellerii and X. maculatus Jp163 A develop spontaneous melanoma initiating at the dorsal fin due to segregation of an oncogene and a regulator encoded by the X. maculatus genome, while the backcross hybrid progeny with X. hellerii or X. couchianus and Jp163 B exhibit melanoma on the flanks of their bodies, especially after treatment with ultraviolet light. Therefore, dissecting the genetic differences between these two closely related lines may lead to better understanding of functional molecular differences associated with tumorigenic mechanisms. For this purpose, comparative genomic analyses were undertaken to establish genetic variants between these two X. maculatus lines. Surprisingly, given the heritage of these two fish lines, we found genetic variants are clustered together in select chromosomal regions. Among these variants are non-synonymous mutations located in 381 genes. The non-random distribution of genetic variants between these two may highlight ancestral chromosomal recombination patterns that became fixed during subsequent inbreeding. Employing comparative transcriptomics, we also determined differences in the skin transcriptional landscape between the two lines. The genetic differences observed are associated with pathways highlighting fundamental cellular functions including inter-cellular and microenvironment-cellular interactions, and DNA repair. These results collectively lead to the conclusion that diverged functional genetic baselines are present between Jp163 A and B strains. Further, disruption of these fixed genetic baselines in the hybrids may give rise to spontaneous or inducible mechanisms of tumorigenesis.

Abstract Background Evolution occurred exclusively under the full spectrum of sunlight. Conscription of narrow regions of the solar spectrum by specific photoreceptors suggests a common strategy for regulation of genetic pathways. Fluorescent light (FL) does not possess the complexity of the solar spectrum and has only been in service for about 60 years. If vertebrates evolved specific genetic responses regulated by light wavelengths representing the entire solar spectrum, there may be genetic consequences to reducing the spectral complexity of light. Results We utilized RNA-Seq to assess changes in the transcriptional profiles of Xiphophorus maculatus skin after exposure to FL (“cool white”), or narrow wavelength regions of light between 350 and 600 nm (i.e., 50 nm or 10 nm regions, herein termed “wavebands”). Exposure to each 50 nm waveband identified sets of genes representing discrete pathways that showed waveband specific transcriptional modulation. For example, 350–400 or 450–500 nm waveband exposures resulted in opposite regulation of gene sets marking necrosis and apoptosis (i.e., 350–400 nm; necrosis suppression, apoptosis activation, while 450–500 nm; apoptosis suppression, necrosis activation). Further investigation of specific transcriptional modulation employing successive 10 nm waveband exposures between 500 and 550 nm showed; (a) greater numbers of genes may be transcriptionally modulated after 10 nm exposures, than observed for 50 nm or FL exposures, (b) the 10 nm wavebands induced gene sets showing greater functional specificity than 50 nm or FL exposures, and (c) the genetic effects of FL are primarily due to 30 nm between 500 and 530 nm. Interestingly, many genetic pathways exhibited completely opposite transcriptional effects after different waveband exposures. For example, the epidermal growth factor (EGF) pathway exhibits transcriptional suppression after FL exposure, becomes highly active after 450–500 nm waveband exposure, and again, exhibits strong transcriptional suppression after exposure to the 520–530 nm waveband. Conclusions Collectively, these results suggest one may manipulate transcription of specific genetic pathways in skin by exposure of the intact animal to specific wavebands of light. In addition, we identify genes transcriptionally modulated in a predictable manner by specific waveband exposures. Such genes, and their regulatory elements, may represent valuable tools for genetic engineering and gene therapy protocols.

Background. Maternal GBS colonization is associated with early-onset neonatal sepsis and extensive efforts are directed to preventing this complication. Less is known about maternal risks of GBS colonization. We seek to provide a modern estimate of the incidence and impact of maternal GBS colonization and invasive GBS disease. Methods. A single center historical cohort study of all births between 2003 and 2015 was performed. Data was collected via electronic health record abstraction using an institutional specific tool. Descriptive statistics were performed regarding GBS status. Inferential statistics were performed comparing risk of adverse pregnancy outcomes in cohorts with and without GBS colonization as well as cohorts with GBS colonization and invasive GBS disease. Results. A total of 60,029 deliveries were included for analysis. Overall, 21.6% of the population was GBS colonized and 0.1% had invasive GBS disease. GBS colonization was associated with younger maternal age, Black race, non-Hispanic ethnicity, chronic hypertension, preexisting diabetes, and tobacco use (p