Miracle-dz/UniFAR-FTUs huggingface dataset:
Quasi-two-dimensional electron gas at the epitaxial alumina/SrTiO3 interface: Control of oxygen vacancies

In this paper, we report on the highly conductive layer formed at the crystalline γ-alumina/SrTiO3 interface, which is attributed to oxygen vacancies. We describe the structure of thin γ-alumina layers deposited by molecular beam epitaxy on SrTiO3 (001) at growth temperatures in the range of 400–800 °C, as determined by reflection-high-energy electron diffraction, x-ray diffraction, and high-resolution electron microscopy. In situ x-ray photoelectron spectroscopy was used to confirm the presence of the oxygen-deficient layer. Electrical characterization indicates sheet carrier densities of ∼1013 cm−2 at room temperature for the sample deposited at 700 °C, with a maximum electron Hall mobility of 3100 cm2V−1s−1 at 3.2 K and room temperature mobility of 22 cm2V−1s−1. Annealing in oxygen is found to reduce the carrier density and turn a conductive sample into an insulator.
On the effects of solar wind dynamic pressure on the anisotropic terrestrial magnetosheath

We apply our recent three-dimensional anisotropic MHD model of magnetosheath flow [Erkaev et al., 1999] to study quantitatively effects of solar wind dynamic pressure (P d ∞) and Alfven Mach number (M a ∞) on the anisotropic magnetosheath and the plasma depletion layer (PDL) in the subsolar region. Given the wide range over which these two parameters vary, their influence on the magnetosheath structure may be significant. Our analysis is applicable to quasisteady changes in the interplanetary medium. Following our earlier work, and in general agreement with the data, we define the sunward edge of the PDL by β∥ = 1, where β∥ is the proton beta parallel to the magnetic field. We first discuss changes in P d ∞ occurring under constant M a ∞. In this case, a rescaling of the parameters yields the effects on the magnetosheath. We then study quantitatively a changing dynamic pressure through a varying Alfven Mach number. We obtain profiles of key magnetosheath parameters and the width of the PDL for Alfven Mach numbers representative of the solar wind at Earth orbit. Gradients in parameter profiles become steeper and shift toward the magnetopause as M a ∞ increases. We find that PDL width varies as 1/M a ∞ 2 even in the anisotropic magnetosheath. Using our model to study the magnetosheath location where the electromagnetic ion cyclotron wave (EICW) instability dominates over the mirror instability, we find that this location occurs well inside the PDL. In addition, we estimated the fraction of the PDL width occupied by the EICWs as a function of solar wind Alfven Mach number. We conclude that the EICW regime is contained in, but is not co-extensive with, the PDL. Examining critically this issue by changing the PDL identification criterion to others based on a density decrease relative to the bow shock value and a systematic drop toward the magnetopause, we find that this result still holds, but the region where EICWs are destabilized occupies a different fraction of the PDL thus defined. Some model results are compared with documented data from an inbound crossing of the magnetosheath made on December 24, 1994. Good agreement with model predictions are obtained.
The generation, propagation, and extinction of multiphases in the KdV zero‐dispersion limit

We study the multiphases in the KdV zero‐dispersion limit. These phases are governed by the Whitham equations, which are 2g + 1 quasi‐linear hyperbolic equations where g is the number of phases. We are interested in both the interaction of two single phases and the breaking of a single phase for general initial data. We analyze in detail how a double phase is generated from the interaction or breaking, how it propagates in space‐time, and how it collapses to a single phase in a finite time.
Small area estimation when auxiliary information is measured with error

Small area estimation methods typically combine direct estimates from a survey with predictions from a model in order to obtain estimates of population quantities with reduced mean squared error. When the auxiliary information used in the model is measured with error, using a small area estimator such as the Fay--Herriot estimator while ignoring measurement error may be worse than simply using the direct estimator. We propose a new small area estimator that accounts for sampling variability in the auxiliary information, and derive its properties, in particular showing that it is approximately unbiased. The estimator is applied to predict quantities measured in the U.S. National Health and Nutrition Examination Survey, with auxiliary information from the U.S. National Health Interview Survey. Copyright 2008, Oxford University Press.
Elucidating the effect of iron acquisition systems in Klebsiella pneumoniae on susceptibility to the novel siderophore-cephalosporin cefiderocol

Background Cefiderocol (CFDC) is a novel siderophore-cephalosporin, effective against multidrug-resistant Gram-negative bacteria. As it has a siderophore side chain, it can utilize iron acquisition systems for penetration of the bacterial outer membrane. We aimed to elucidate the role of siderophores and iron uptake receptors in defining Klebsiella pneumoniae susceptibility to CFDC. Methods Initially, 103 K. pneumoniae strains were characterized for susceptibility to different antibiotics including CFDC. CFDC minimum inhibitory concentrations (MIC) were determined in iron-depleted and iron-enriched conditions. Iron uptake genes including siderophores, their receptors, ferric citrate (fecA) and iron uptake (kfu) receptors were detected by PCR in all the strains. For 10 selected strains, gene expression was tested in iron-depleted media with or without CFDC treatment and compared to expression in iron-enriched conditions. Results CFDC exhibited 96.1% susceptibility, being superior to all the other antibiotics (MIC50: 0.5 and MIC90: 4 μg/ml). Only three strains (2.9%) were intermediately susceptible and a pandrug resistant strain (0.97%) was resistant to CFDC (MIC: 8 and 256 μg/ml, respectively). The presence of kfu and fecA had a significant impact on CFDC MIC, especially when co-produced, and if coupled with yersiniabactin receptor (fyuA). CFDC MICs were negatively correlated with enterobactin receptor (fepA) expression and positively correlated with expression of kfu and fecA. Thus, fepA was associated with increased susceptibility to CFDC, while kfu and fecA were associated with reduced susceptibility to CFDC. CFDC MICs increased significantly in iron-enriched media, with reduced expression of siderophore receptors, hence, causing less drug uptake. Conclusion Iron acquisition systems have a significant impact on CFDC activity, and their altered expression is a factor leading to reduced susceptibility. Iron concentration is also a major player affecting CFDC susceptibility; therefore, it is essential to explore possible ways to improve the drug activity to facilitate its use to treat infections in iron-rich sites.
Affect labeling: The role of timing and intensity

A growing number of studies have shown that labeling negative feelings can down-regulate distress. The present study aimed to test the effectiveness of affect labeling while manipulating two factors known to influence the emotion regulation process, namely timing, and emotional intensity. In Experiment 1, sixty-three participants completed a performance-based affect labeling paradigm in which they had to choose between two labels that best describe their feeling. Participants were randomly assigned to one of three experimental conditions: (1) Simultaneous labeling- the labeling occurs while watching the aversive picture. (2) Subsequent labeling- the labeling occurs immediately after watching the aversive picture. (3) Delayed labeling- the labeling occurs 10 seconds after watching the aversive picture. We found that affect labeling efficiently down-regulated distress independent of the labeling timing. In Experiment 2, seventy-nine participants utilized simultaneous labeling for aversive pictures with low and high intensity. We revealed that while affect labeling reduces distress in high-intensity aversive conditions, it increases distress in low-intensity conditions. The results question the standard advice, which calls to count to 10 before you speak in highly aversive states. In addition, it suggests that affect labeling can be beneficial in high-intensity conditions. However, it should be used with caution in low-intensity conditions.
Facilitators and barriers to colorectal cancer screening using the immunochemical faecal occult blood test among an average-risk population in semi-rural Malaysia: A qualitative study

Background Colorectal cancer (CRC) incidence in Malaysia is increasing, and most CRC patients are diagnosed at a late stage. This study investigated participant awareness of CRC and their perceptions and views about CRC screening, barriers, benefits, and facilitators towards CRC screening participation as well as health-seeking behaviour and the use of preventative health services. Method Eleven focus group discussions (FGDs) were conducted with a purposive sample of 89 participants aged > 50 from the major ethnic groups in the Segamat District, Johor State. FGDs were audiotaped, transcribed verbatim, and translated into English. Data were analysed using thematic analysis. Results We identified trust in doctors as a key reason for whether or not to seek health care. Generally, the participants had low awareness of CRC sign/symptoms and screening. Emotional and logistic concerns about sending a stool sample to a clinic emerged as the main barriers to screening. Simplified illustrated instructions about stool collection in Malay, Chinese and Tamil, free screening at health clinics and reminders to complete the iFOBT test were perceived to facilitate engagement in screening, and posited as strategies that were likely to increase iFOBT uptake. Conclusion Primary care physicians play a crucial role in terms of reducing patient’s misperceptions, recommending screening to patients, enhancing attendance, and improving uptake of CRC screening. There is a need for further research to investigate ways in which to reduce identified barriers and implement and test potential facilitative strategies as well as examine adherence by doctors to clinical guidelines about CRC screening.
Free-running 9.1-mu m distributed-feedback quantum cascade laser linewidth measurement by heterodyning with a (CO2)-O-18 laser

We report spectral linewidth measurements of a 9.1‐µm distributed-feedback quantum cascade laser (QCL). The free-running QCL beam was mixed with a waveguide isotopic C18O2 laser onto a high-speed HgCdTe photomixer, and beat notes were recorded from a radio-frequency spectral analyzer. Beating was performed at two operating conditions, first near the QCL laser threshold (beating with the C18O2R10 line) and then at a high injection current (beating with the C18O2R8 line). Overall, beat note widths of 1.3–6.5 MHz were observed, which proves that a free-running QCL can have a short-term spectral width near 1 MHz.
R-matrix calculation of eigenchannel multichannel quantum defect parameters for strontium

Within the framework of the eigenchannel R-matrix method, theoretical calculations of the multichannel quantum defect (MQDT) parameters have been performed for 1.3Po, 1.3De and 1.3Se spectra of Sr. For the singlet spectra, both discrete and autoionisation regions below the Sr+ 4d threshold are investigated, while the analysis of the triplets is restricted to the bound spectra below the Sr+ 5s threshold. Near the Sr+5s threshold, the calculated parameters are in good agreement with those previously fitted to spectroscopic data. The main improvements with respect to the empirical MQDT studies concern evidence of the large energy dependence of the parameters and identification of isolated perturbers of the 1D2 and 1S0 spectra. In addition, the energy levels and the spectral intensities are accurately reproduced and channel mixing and correlation effects in doubly excited states are analysed in detail. A close similarity is found between the 5snp-4d np 1Po mixing in Sr and the msnp-mpns 1Po mixing in the light alkaline earths Be and Mg. Such near invariance does not hold for the 1De and 1Se spectra.
Effectiveness of Sotrovimab in Preventing COVID-19-related Hospitalizations or Deaths Among U.S. Veterans

Background: Data on effectiveness of sotrovimab preventing COVID-19-related hospitalization or mortality, particularly after the emergence of the Omicron variant, are limited. Method: Determine the real-world clinical effectiveness of sotrovimab for prevention of 30-day COVID-19 related hospitalization or mortality using a retrospective cohort within the U.S. Department of Veterans Affairs (VA) healthcare system. Veterans aged [≥]18 years, diagnosed with COVID-19 between December 1, 2021, and April 4, 2022, were included. Sotrovimab recipients (n=2,816) were exactly matched to untreated controls (n=11,250) on date of diagnosis, vaccination status, and region. The primary outcome was COVID-19-related hospitalization or all-cause mortality within 30 days from diagnosis. Cox proportional hazards modeling estimated the hazard ratios (HR) and 95% Confidence Interval (CI) for the association between receipt of sotrovimab and outcomes. Results: During BA.1 dominance, compared to matched controls, sotrovimab-treated patients had a 70% lower risk hospitalization within 30 days or mortality (HR 0.30; 95%CI, 0.23-0.40), a 66% lower risk of 30-day hospitalization (HR 0.34; 95%CI, 0.25-0.46), and a 77% lower risk of 30-day all-cause mortality (HR 0.23; 95%CI, 0.14-0.38). During BA.2 dominance sotrovimab-treated patients had a 71% (HR .29; 95%CI, 0.08-0.98) lower risk of 30-day COVID-19-related- hospitalization, emergency, or urgent care. Limitations include confounding by indication. Conclusions: Using national real-world data from high risk and predominantly vaccinated Veterans, administration of sotrovimab, compared with no treatment, was associated with reduced risk of 30-day COVID-19-related hospitalization or all-cause mortality during the Omicron BA.1 period and reduced risk of progression to severe COVID-19 during the BA.2 dominant period.
The electron distribution function upstream from the Earth's bow shock

A general analytic theory for the distribution function of particles backstreaming from an arbitrary shock in a magnetized plasma (neglecting wave-particle scattering) is presented. The theory explicitly shows that abrupt cutoffs in the parallel velocity, where ∂f/∂|v∥| > 0, arise naturally in the upstream region, irrespective of the acceleration processes active at the shock. These “cutoff” distributions may provide free energy for wave growth. Two classes of cutoff arise, escape cutoffs due to the particles requiring a characteristic speed to outrun the shock, and edge cutoffs due to the shock having an edge. Analytic expressions for the particle distribution function upstream of finite planar shocks and shocks whose two-dimensional sections are parabolic are derived. A theory for the electron distribution function upstream from the earth's bow shock and the source of free energy for the observed Langmuir waves is presented. The electron distribution has an escape cutoff in the parallel velocity. This cutoff distribution is the source of free energy for Langmuir wave growth. Distribution functions and the spatial variation of the cutoff velocity are illustrated graphically. The theory is consistent with the spatial variation in the electron beam velocity inferred from indirect observations, assuming the observed electron beams to be the wave-particle scattered remnants of cutoff distributions. An application of this theory to type II solar radio bursts is sketched.
Outcomes After Percutaneous Tracheostomy in Patients with COVID-19: A Single-Center Series of 377 Cases

Introduction: The COVID 19 pandemic was highlighted by a rise in hospital admissions secondary to respiratory decompensation. This was accompanied by an increase in ICU admissions, endotracheal intubation and mechanical ventilation. As a consequence, tracheostomies became essential in preventing complications of prolonged intubation and to facilitate weaning from sedation and mechanical ventilation. With the lack of international consensus on tracheostomy technique and optimal timing, we present our experience with 377 percutaneous tracheostomies performed on critically ill COVID 19 patients. Objective: To report the outcomes of critically ill patients with COVID 19 who underwent percutaneous tracheostomy during a period of 24 months. Methods: A retrospective single-center electronic chart review was performed on all ICU patients who underwent percutaneous tracheostomy after respiratory failure secondary to COVID 19 between March 2020 to March 2022. Results: A total of 377 percutaneous tracheostomies were performed. The mean duration between intubation and percutaneous tracheostomy was 17.4 days (3 to 61). The study included 222 males (59%) and 155 females (41%). The mean age of patients was 56.2 years (17-94), with a mean BMI was 31.3 (14 to 68). The commonest comorbidities among patients were diabetes mellitus (50%) and hypertension (48%). Complications were encountered in 85 cases (23%), with the commonest overall complication being minor bleeding. 203 patients (54%) were weaned from sedation. The mean duration between tracheostomy and weaning from sedation was 7.5 days (1 to 47 days). 156 patients (41%) were weaned from MV. The mean duration between tracheostomy and weaning from MV was 12.9 days (1 to 58 days). There was a total of 236 (63%) deaths reported during the period of this study. No deaths were attributable to the surgical procedure. Conclusion: Percutaneous tracheostomy can be safely performed in patients with COVID 19. With lack of conclusive objective data regarding the optimal timing for tracheostomy, we recommend that tracheostomy be performed as soon as possible after the 7th day endotracheal intubation. Key Words: Percutaneous tracheostomy, COVID 19, Critically ill, ICU
Wave Activity Diagnostics Applied to Baroclinic Wave Life Cycles

Wave activity diagnostics are calculated for four different baroclinic wave life cycles, including the LC1 and LC2 cases studied by Thorncroft, Hoskins, and McIntyre. The wave activity is a measure of the disturbance relative to some zonally symmetric, time-independent basic state, which need not be the initial zonally averaged state and which satisfies a finite-amplitude conservation relation. The wave activity density and fluxes may be calculated in terms of Eulerian variables provided that the potential vorticity is a monotonic function of latitude on isentropic surfaces in the basic state. The LC1 and LC2 experiments used initial states in which the potential vorticity (PV) did not satisfy this monotonicity condition. Therefore two approaches are taken. The first is to define a basic state that is not the initial state and use this to calculate the wave activity diagnostics. The second is to carry out new LC1- and LC2-type experiments on initial states in which the monotonicity condition is satisfied. New basic states are generated by PV rearrangement and inversion. The results allow quantification of the difference between LC1- and LC2-type life cycles. They also show that LC1- and LC2-type behavior occurs for different initial states other than those used by Thorncroft, Hoskins, and McIntyre and that the classification is therefore robust in terms of the potential vorticity field and wave activity diagnostics. If one were to consider only eddy kinetic energy, the distinction is no longer clear. In fact, in the evolution of eddy kinetic energy the modified LC1-type life cycle resembles LC2 and the modified LC2 more than it resembles LC1. The results also shed new light on the role of wave propagation in baroclinic life cycles. In particular, it is found that during the later stages of the life cycle the pattern of equatorward wave activity flux that has often been interpreted as associated with equatorward wave propagation in the subtropical upper troposphere is in fact associated primarily with advective transport of wave activity. New finite-amplitude expressions are presented for the wave activity associated with potential temperature gradients on the lower boundary. Problems with using PV rearrangement techniques are discussed.
The recombination-induced temperature change of non-equilibrium charge carriers

A novel mechanism changing the temperature of a non-equilibrium gas of charge carriers is shown to exist: recombination of a proportion of the carriers. The rate of temperature change thus induced is proportional to the recombination probability 1/ tau . If recombination heating occurs it can compensate carrier-acoustic-phonon-mediated energy relaxation. For density- and time-independent recombination probabilities the minimum temperature Tmin that carriers can reach is defined. The sign, size and temperature dependence of the 'recombination heating' depend on the type of statistics obeyed by the carriers and on the details of the energy dependence of the recombination probability. For Maxwell-Boltzmann statistics heating, nothing or cooling occurs if the recombination probability decreases with, does not depend on or increases with energy, respectively. If the Fermi statistics applies to an electron-hole plasma the remaining carriers always heat upon recombination. The results of this theory are compared with experimental findings on the temperature relaxation of free electrons trapped by impurities, excitons in quantum wells and electron-hole drops.
Errors in Estimating Mean Weight and other Statistics from Mean Length

Abstract Computer simulations of length-weight data indicated that the error incurred by estimating mean weight from mean length is a function of the exponent in the length-weight relationship and the coefficient of variation in the length-frequency distribution. Errors were less than 10% for exponents up to 4.0 if the coefficient of variation were less than 0.1, but error increased to near 90% of actual mean weight for large exponents and coefficients of variation. Similar errors arise for other exponential relationships, such as length-fecundity, that commonly are developed in fisheries work.
Collaborative construction of the closet (in and out): The affordance of interactivity and gay and lesbian employees’ identity work online

For LGBQ employees, the disclosure and management of sexual identity in the workplace are likely to cause additional identity work. In this paper, we explore how such identity work is undertaken collectively by gays and lesbians on internet forums. Drawing on the literature on discursive identity work and social media affordances, we conduct a netnographic study of two internet forums, and analyse the ways in which these forums enable gay and lesbian employees’ identity work and guide their identity management processes. Overall, our study advances knowledge on sexual identity disclosure and management in three main ways. First, by shifting the focus from the identity disclosure accounts of individual gay and lesbian employees to online peer discussions around the topic, it sheds light on the broader context of identity management beyond the workplace. Second, our findings elucidate particular types of collaborative identity work – consulting, legitimating and questioning identity work – enabled by the affordance of interactivity of internet forums that inform and guide gays and lesbians’ identity management practices in organisations. Third, we identify and elaborate on specific discursive identity threats – the ‘falsehood’, ‘incoherence’, ‘exaggeration’ and ‘outdatedness’ of identity – which gay and lesbian employees are likely to encounter when reflecting on and performing specific identity management strategies, such as concealing or revealing their sexual orientation at work.