In recent years local chiral interactions have been derived and implemented in quantum Monte Carlo methods in order to test to what extent the chiral effective field theory framework impacts our ...knowledge of few- and many-body systems. In this Letter, we present Green's function Monte Carlo calculations of light nuclei based on the family of local two-body interactions presented by our group in a previous paper in conjunction with chiral three-body interactions fitted to bound- and scattering-state observables in the three-nucleon sector. These interactions include Δ intermediate states in their two-pion-exchange components. We obtain predictions for the energy levels and level ordering of nuclei in the mass range A=4-12, accurate to ≤2% of the binding energy, in very satisfactory agreement with experimental data.
Cross sections for inclusive neutrino scattering off deuteron induced by neutral and charge-changing weak currents are calculated from threshold up to 150 MeV energies in a chiral effective field ...theory including high orders in the power counting. The contributions beyond leading order (LO) in the weak current are found to be small, and increase the cross sections obtained with the LO transition operators by a couple of percent over the whole energy range (0--150) MeV. Furthermore, the cutoff dependence is negligible, and the predicted cross sections are within ~2% of, albeit consistently larger than, corresponding predictions obtained in conventional meson-exchange frameworks.
Background
Late‐onset pain is frequent following COVID‐19, and many pathogenetic mechanisms have been proposed. Identifying the main features of patients may help in designing tailored rehabilitative ...interventions.
Methods
We enrolled post‐COVID‐19 patients with an increase in pain intensity of two points on the COVID‐19 Yorkshire Rehabilitation Scale (C19‐YRS) at 52 weeks compared to the pre‐COVID‐19 condition. All subjects were retrospectively monitored at 12, 26, and 52 weeks. A specific pain assessment was performed to determine the characteristics and mechanisms of pain. Catastrophizing, kinesiophobia, and other psychological symptoms were evaluated. The pressure pain threshold (PPT) and temporal summation (TS) were measured and compared in age‐ and sex‐matched healthy controls to analyse pain characteristics.
Results
A total of 67 patients were recruited, with 20 of them presenting an increase in pain at 52 weeks. Subjects of the two subgroups were similar in demographic and clinical characteristics at baseline; significant differences in fatigue, anxiety, mobility, ability to perform daily activities, and general health perception were recorded at 26 weeks. Fatigue significantly predicted pain onset (β = 0.54, p = 0.002). Sixteen different body regions were identified as painful, with a pain intensity of 6.0 ± 1.9. Most of the samples did not show neuropathic or nociplastic mechanisms. No differences in PPT and TS were recorded between patients and healthy controls.
Conclusions
Almost one out of three patients hospitalized for COVID‐19 developed pain 1 year later, and fatigue seems responsible for chronicity. An overlapping of conditions may explain late‐onset post‐COVID‐19 pain, and a comprehensive approach must be considered for patient management.
Significance
Late‐onset pain is frequent in post‐COVID‐19 syndrome and an overlapping of different mechanisms seems to be responsible for its development. Among many predisposing factors, fatigue in the months before seems to be one of the primary causes of pain one year following infection and its management may help to identify new strategies for prevention and treatment of late‐onset pain.
The stellar metallicity is a direct measure of the amount of metals present in a galaxy, since a large part of the metals lie in its stars. In this paper, we investigate new stellar metallicity ...indicators suitable for high-z galaxies by studying the stellar photospheric absorption lines in the rest-frame ultraviolet, hence sampling predominantly young hot stars. We defined these new indicators based on the equivalent widths (EW) of selected features using theoretical spectra created with the evolutionary population synthesis code Starburst99. We used them to compute the stellar metallicity for a sample of ultraviolet-selected galaxies at z > 3 from the AMAZE (Assessing the Mass-Abundance redshift Evolution) survey using very deep (37 h per object) VLT/FORS spectra. Moreover, we applied these new metallicity indicators to eight additional high redshift galaxies studied in literature. We then compared stellar and gas-phase metallicities measured from the emission lines for all these galaxies, finding that within the errors the two estimates are in good agreement, with possible tendency for stellar metallicities to be lower than the gas phase ones. For the first time, we study the stellar mass-stellar metallicity relation at z > 3. We find that the metallicity of young, hot stars in galaxies at z ~ 3 have similar values of the aged stars in local SDSS galaxies, in contrast to findings for the gas phase metallicity.
Deposit formation from the gasoline autoxidation process has attracted more and more attention since the emergence of new systems operating at a higher pressure range and higher temperatures, ...imposing new fuel constraints and so favoring the appearance of deposits on different engine parts in contact with the fuel (e.g., injection systems, valves, pumps, and pistons). This study aims to evaluate the oxidation stability of a non-additized standard European gasoline SP95 Euro 6 containing 10% v/v ethanol (SP95E6E10) complying with the EN228 standard and the impact of additives such as methylcyclopentadienyl manganese tricarbonyle (MMT) and dimethyl disulfide (DMDS) on deposit formation to mimic other world market fuels such as Africa or China. The stability of these fuels was compared to that of a commercial Nigerian gasoline which has a higher sulfur content (800 mg/kg) to evaluate the sulfur effect on deposit formation. The fuel degradation tendencies induction period (IP) obtained from a PetroOxy apparatus and an Autoclave reactor were compared to the real engine tendencies to form deposits. The deposits targeted are those created on the injector nozzle of a VW EA111 engine (direct injection) and on the valve using an M102E engine (indirect injection). PetroOxy results show the negative impact of DMDS and MMT on the IP of the gasoline, SP95 E10 ULG Euro 6: an IP decrease of up to 30%. Comparison of the IP results in PetroOxy and Autoclave with the results of the direct injection (VW EA111) and indirect injection (M102E) engine tests suggests that the PetroOxy results follow the trend of the mass of deposits formed on the valves of the indirect injection, M102E, engine tests, with the IP decreasing as the valve deposit mass increases. On the contrary, the Autoclave results appear to follow the trend of the results of the direct injection, VW EA111 engine tests: IP decreases when the injection time increases. These features could allow us to identify fuel tendencies to form deposits on specific spare parts based only on laboratory-scale methods, helping to optimize and to target the maintenance operation and preventing failures or damages on real engine systems.
Internet overuse is an emerging public health emergency, especially for college students in the United States. The purpose of this study was to assess college students’ internet usage and interest in ...learning healthy internet usage skills as part of a college curriculum.
Participants completed an online anonymous questionnaire which included the short version of the Internet Addiction Test, a modified Youth Health Movement survey, and questions regarding their interest in healthy internet use coursework.
A total of 402 participants were recruited via an email LISTSERV of current undergraduates and recent graduates who had taken at least one class within a child and adolescent mental health studies minor while enrolled in a large university.
Overall, 70% of participants reported that they use the internet excessively, and a majority of participants reported that internet use has negatively affected their sleep and increased their anxiety. Seventy percent of participants reported that they would benefit from instruction on healthy internet usage via formal courses for credit or online modules.
Students are aware of the difficulty in managing their internet use in college and are motivated to engage in novel courses on healthy internet usage. Academic institutions should consider developing courses or modules on healthy internet use.
Abstract
Modern engines require continuous and detailed monitoring in order to minimize variations in performance and emissions during their operation. To this aim, the engine thermodynamic cycle ...must be brought into focus, with special emphasis on the combustion process.
The in-cylinder pressure is the parameter that is most directly associated with the engine thermodynamic cycle. Direct measurements by means of dynamic pressure sensors are commonly used for research and development purpose. Currently, however, the cost and intrusiveness of such sensors, together with the harsh operating conditions that limits their lifetime, make direct measurements of the in-cylinder pressure not yet suitable for mass production applications. As a consequence, there’s great interest in developing cost-effective and reliable alternative solutions to extract pressure trace and combustion indicators such as the indicated mean effective pressure (IMEP).
The paper presents a technique for reconstructing the pressure cycle of each cylinder of a multi-cylinder engine by combining the instantaneous crankshaft speed information and a 0D thermodynamic model. Crankshaft position, angular velocity and angular acceleration, coupled with the engine inertia, are used to estimate the effective torque oscillation. The average indicated torque and the combustion torque contribution of each cylinder are then evaluated by coupling the information coming from engine speed and the 0D model. Eventually, through the kinematic relationship between the effective torque and the indicated pressure, the in-cylinder pressure trace is reconstructed.
The methodology proposed by the authors allows to evaluate the indicated pressure of each cylinder: this is especially useful for detecting cylinder-to-cylinder variations and misfiring events. Data from a 1D calibrated numerical model of a four-cylinder engine is used for preliminary validation at different engine speeds and loads.
A power-efficient charge pump is proposed. The use of low-voltage transistors and of a simple two-phase clocking scheme permits the use of higher operating frequencies compared to conventional ...solutions, thus obtaining high current, high efficiency, and small area. Measurements show good results for frequencies around 100 MHz. Two test patterns have been fabricated, one with three stages and one with five stages, in a 1.8-V 0.18-/spl mu/m triple-well standard CMOS digital process (six metals). High-voltage capacitors have been implemented using metal to metal parasitic capacitance.
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