Miracle-dz/UniFAR-FTUs huggingface dataset:
Buckling instabilities in layers of viscous liquid subjected to shearing

A theoretical and experimental investigation is reported dealing with the onset of buckling in a horizontal layer of highly viscous liquid. The layer floats on a heavier liquid with negligible viscosity, and at rest is stabilized by gravity and surface tension. When sheared at a sufficient rate, the flat configuration of the layer becomes unstable; and the aim of the investigation is to establish the relation between critical values of the shearing rate and values of the layer's thickness and other physical parameters. A primitive theory based on membrane approximations is first reviewed and its deficiencies are appreciated. Then a more reliable theory is developed, providing estimates of values taken by a dimensionless shear stress f at the threshold of instability. The values fc are found to depend primarily on a dimensionless number H proportional to the thickness of the layer. Experiments on sheared layers of silicone oil with various high viscosities are then described. Measured values of fc plotted against H over a wide range are shown to be in satisfactory agreement with the theory. Finally, discrepancies between previous experimental results and ours are discussed.
Finite-difference time-domain simulation of light scattering from multiple cells

Summary form only given. Optical properties of tissue in the near-infrared region are of great interest, stimulated primarily by successful applications of imaging techniques such as optical coherence tomography (OCT) and confocal microscopy (CM). OCT and CM provide information on physiological state of the tissue derived from the tissue scattering properties. Microscopic mechanisms of tissue scattering are fairly complex due to spatial and time varying dielectric tissue structure. Widely used for modeling of light propagation in tissue, the Monte Carlo method deals only with macroscopic tissue scattering properties. In this paper we address a more fundamental problem, namely, scattering from multiple cells at the microscopic level. To model light scattering from objects with a complex dielectric structure we use the finite-difference time-domain (FDTD) method. We apply the FDTD technique to model light scattering from multiple cell samples in two dimensions. Our results show that interactions such as multiple scattering play a significant role in tissue scattering, altering the shape of the phase function.
The influence of psychological characteristics on managers efficiency within medical institutions during the COVID-19 pandemic

This article examines the theoretical and practical aspects of the activity of medical managers, the social and psychological climate within teams, and interpersonal relations. The goal of the study was to investigate the interpersonal interaction styles and intragroup relations between team members and managers, as well as to determine the impact of managers' psycho-emotional characteristics on their effectiveness during the COVID-19 pandemic. A total of 158 medical workers participated in the study, which was conducted in 2021 using a self-developed questionnaire. The expert evaluation method and standardized psychodiagnostic methods were used. We identified negative factors that affected the management of medical institutions during the pandemic, such as deficiencies in material and economic support, low levels of managerial competence, violation of collegiality and fairness principles during duties and rewards distribution, and deficiencies in manager recruitment. The most psychologically challenging aspects of managing or working in a medical facility during a pandemic include excessive emotional tension and stress, high levels of responsibility, lack of management experience and/or competence in crisis conditions, physical overload, work outside of working hours, and lack of adequate rest. A mini-personality profile of the effective manager of medical institutions in pandemic conditions was developed. One of the psychological regularities of a manager's performance identified is the presence of self-regulative skills in negative emotional states, pronounced activity and energy, mobility, and a strong desire for action.
LOCALIZATION OF MULTIPOLE PHOTONS

multipole radiation, the local properties of the radiation field can be rigorously described in spite of the fact that photons are defined in whole space-time. In particular, the local intensity operators for the field components with different polarization can be introduced. The intensities associated with two different space-time points along the same direction can be measured together. A method of quantum measurement of correlation of polarizations at different distances based on the use of Aharonov-Bohm effect is proposed.
The Diffuse Interstellar Bands

The diffuse interstellar bands are absorption features observed in the spectra of stars seen through significant column densities of interstellar material. Of the 127 confirmed DIBs in the optical region between 0.4 and about 1.3 /Lm, only 2 have (tentatively) been identified with a specific carrier. Because DIB strengths increase roughly in proportion to color excess, they were originally suspected of being produced on or in the interstellar grains, but current evidence favors some species of free polyatomic molecules, either neutral or ionized. DIBs are conspicuously broader than the atomic interstellar lines, having widths at half-depth ranging from 0.8 to about 30 A. These widths are presumably due to unresolved rotational structure, possibly compounded by lifetime broadening of the upper state. Recent proposals that C60, some members of the PAH family, or polycarbon chains are responsible for the DIB spectrum are either not supported by observation or await better data.
High levels of fecal calprotectin and C-reactive protein in patients with colitis

Inflammatory bowel disease (IBD) with a poor prognosis may be due to persistent colitis. According to the latest guidelines, monitoring has become a part of the treatment process for colitis. Adequate monitoring of the patient's condition is necessary to determine the course of the disease to prevent the worsening of the condition and suppress the subclinical inflammatory process. This analytical study with a cross-sectional design was conducted to evaluate the activity of colitis using the results of C-reactive protein (CRP) and fecal calprotectin (FC) assays. FC levels were analyzed by ELISA, while CRP levels were analyzed using Siemens Flex particle-enhanced turbidimetric immunoassay. In 30 subjects with endoscopy and biopsy of colitis, 16 men and 14 women had a median age of 52.5 (18–70) years. The median FC value increased by 67 (7.3–722 g/g) and was positive (≥50 g/g) in 20 subjects (66.7%), and the mean CRP value was 13.64 mg/L, positive (10–15 mg/L) in 13 subjects (43.33%), and negative (<10 mg/L) in 17 subjects (56.67%). This study demonstrated that FC had a significant relationship with CRP (r=0.57; p<0.001) in patients with colitis. Assessing the levels of FC and CRP among patients with colitis can be useful to assess the worsening of symptoms early and reduce mortality and morbidity.
Philopatry yields higher fitness than dispersal in a cooperative breeder with sex-specific life history trajectories

Social evolution is tightly linked to dispersal decisions, but the ecological and social factors selecting for philopatry or dispersal often remain obscure. Elucidating selection mechanisms underlying alternative life histories requires measurement of fitness effects in the wild. We report on a long-term field study of 496 individually marked cooperatively breeding fish, showing that philopatry is beneficial as it increases breeding tenure and lifetime reproductive success in both sexes. Dispersers predominantly join established groups and end up in smaller groups when they ascend to dominance. Life history trajectories are sex specific, with males growing faster, dying earlier, and dispersing more, whereas females more likely inherit a breeding position. Increased male dispersal does not seem to reflect an adaptive preference but rather sex-specific differences in intrasexual competition. Cooperative groups may thus be maintained because of inherent benefits of philopatry, of which females seem to get the greater share in social cichlids.
The Role of Major Biomarkers of Stress in Atrial Fibrillation: A Literature Review

Numerous studies have reported that physical or emotional stress can provoke atrial fibrillation (AF) or vice versa, which suggests a potential link between exposure to external stressors and AF. This review article sought to describe in detail the relationship between major stress biomarkers and the pathogenesis of AF and presents up-to-date knowledge on the role of physiological and psychological stress in AF patients. For this purpose, this review article contends that plasma cortisol is linked to a greater risk of AF. A previous study has investigated the association between increased copeptin levels and paroxysmal AF (PAF) in rheumatic mitral stenosis and reported that copeptin concentration was not independently associated with AF duration. Reduced levels of chromogranin were measured in patients with AF. Furthermore, the dynamic activity of antioxidant enzymes, including catalase as well as superoxide dismutase, was examined in PAF patients during a period of <48 h. Malondialdehyde activity, serum high-sensitivity C-reactive protein, and high mobility group box 1 protein concentrations were significantly greater in patients with persistent AF or PAF compared to controls. Pooled data from 13 studies confirmed a significant reduction in the risk of AF related to the administration of vasopressin. Other studies have revealed the mechanism of action of heat shock proteins (HSPs) in preventing AF and also discussed the therapeutic potential of HSP-inducing compounds in clinical AF. More research is required to detect other biomarkers of stress, which have not been reported in the pathogenesis of AF. Further studies are required to identify their mechanism of action and drugs to manage these biomarkers of stress in AF patients, which might help to reduce the prevalence of AF globally.
Suboptimal control of singularly perturbed systems and periodic optimization

A traditional approach to singularly perturbed optimal control problems is based on an approximation of these problems by some reduced problems. The reduced problems are obtained via the formal replacement of the fast variables by the states of equilibrium of the fast subsystems considered with frozen slow variables and controls. It is shown that such as approximation may not be valid, and that it is valid if and only if certain families of periodic optimization problems admit steady-state solutions. It is also shown how the solutions of these problems can be used to construct suboptimal controls for singularly perturbed problems when the approximation by the reduced problems is not possible. <<ETX>>
Assessment of Dentoalveolar Changes Following Leveling and Alignment of Severely Crowded Upper Anterior Teeth Using Self-Ligating Brackets Alone or With Flapless Piezocision Compared to Traditional Brackets: A Randomized Controlled Clinical Trial

Introduction Dental crowding is one of the most common types of malocclusions. It can be treated with or without extraction, depending on the severity of the crowding. Extraction-based orthodontic treatments are the preferred treatment option in cases of severe crowding, but they take longer than non-extraction cases. Objective This study aimed to evaluate the dentoalveolar changes following the orthodontic treatment of severely crowded maxillary anterior teeth in adults using self-ligating brackets alone or combined with flapless piezocision. Materials and methods The participants in this study were 63 patients (46 females and 17 males; mean age SD: 19.71 ± 2.74 years) who attended the Department of Orthodontics at the University of Damascus from January 2020 to December 2021. The participants were divided into three groups at random: Group (1): traditional brackets group, Group (2): self-ligating brackets group; and Group (3): self-ligating brackets with flapless piezocision group. Little's Irregularity Index (LII) was measured at five assessment times: before the onset of orthodontic treatment (T0), after one month (T1), after two months (T2), after three months (T3), and at the end of the leveling and alignment phase (T4). The intercanine width (lingual), the intercanine width (cusp), and the canine rotation angle were measured at two assessment times: before the onset of orthodontic treatment (T0) and at the end of the leveling and alignment phase (T4). Results The three studied groups had statistically significant differences in terms of LII during the first three months, and the most significant improvement of LII was in the self-ligating brackets with the piezocision group (P < 0.001). In addition, the intercanine width (cusp) at the end of the leveling and aligning phase revealed greater mean values in both self-ligating brackets groups compared to the traditional brackets group, and the differences were statistically significant (P < 0.001). Otherwise, no statistically significant differences were found at the end of the leveling and aligning phase in the intercanine width (lingual) or the canine rotation angle between the three studied groups (P > 0.05). Conclusion Using self-ligating brackets with flapless piezocision revealed more significant results concerning LII as compared to other groups. Thus, combining these two acceleration methods could get more effective results in aligning severely crowded teeth. Self-ligating brackets, whether used alone or with flapless piezocision, resulted in greater intercanine width at the cusp level. The type of brackets (traditional or self-ligating) did not affect the canine rotation angle.
Zonal-detached-eddy simulation of the flow around a high-lift configuration

A zonal hybrid Reynolds-averaged Navier-Stokes large-eddy simulation (RANS/LES) approach, called zonal-DES, used to handle a two-dimensional high-lift configuration with deployed slat and flap is presented. This method allows to reduce significantly the cost of an accurate numerical prediction of the unsteady flow around wings compared to a complete LES. Some issues concerning grid generation as well as the use of zonal-detached-eddy simulation for a multi-element airfoil are discussed. The basic planar grid has 250,000 points and the finest spanwise grid has 31 points with Az/c = 0.002. The effort is geared toward detailed comparison of the numerical results with the Europiv2 experimental particle image velocimetry data including both mean and fluctuating properties of the velocity field (Arnott and al)
On the boundedness of solutions of nonlinear integral equations

Sufficient conditions are presented for the boundedness of the solutions of a vector nonlinear Volterra integral equation of the second kind that frequently arises in the study of automatic control systems containing an arbitrary finite number of time-varying nonlinear elements. Similar conditions are given for the boundedness of the solutions of the discrete analog of the integral equation. A direct application of the results yields a Nyquist-like frequency-domain condition for the “bounded-input implies bounded-output stability” of a large class of feedback systems containing a single time-varying nonlinear element.
The behavior of solar magnetic plages measured from Mt. Wilson observations between 1915-1984

We describe the digitization and reduction of the daily solar chromospheric spectroheliograms obtained in the K-line of Ca II between 1915-1984 at Mt. Wilson Observatory. Our results provide the first reliable information on the behavior of solar magnetic plage area prior to 1947, thus extending by almost 70% the length of the primary data base needed to model past total, UV and EUV solar irradiances. Comparison with other solar activity indices confirms the remarkably linear relation between plage areas, and sunspot number and area, found in the post-1947 data. Our analysis also shows a markedly non-linear relation between the areas of chromospheric plage, and of photospheric white-light faculae. We provide an explanation of this surprising nonlinearity between measurements of two magnetic structures that are known to be closely related in the sun's atmosphere.
ABRUPT BORON PROFILES BY SILICON-MBE

Surface segregation and diffusion are the dominant mechanisms for profile smearing. However in the low temperature regime below 600°C diffusion is negligible. We investigated the dopant profile during silicon molecular beam epitaxy (MBE) in silicon (100). A method for measurement of the adlayer density of segregating dopant atoms is suggested. We utilize the results of this experiment to generate very sharp boron profiles. For the doping we use the pre-build up method with constant boron flux.
Reasons for ineligibility for clinical trials of patients with medication‐resistant epilepsy

Selection criteria for clinical trials for medication‐resistant epilepsy are used to limit variability and to ensure safety. However, it has become more challenging to recruit subjects for trials. This study investigated the impact of each inclusion and exclusion criterion on medication‐resistant epilepsy clinical trial recruitment at a large academic epilepsy center. We retrospectively identified all patients with medication‐resistant focal or generalized onset epilepsy who attended an outpatient clinic over a consecutive 3‐month period. We assessed each patient's eligibility for trials with commonly required inclusion and exclusion criteria to evaluate the proportion of eligible patients and the most common reasons for exclusion. Among 212 patients with medication‐resistant epilepsy, 144 and 28 patients met the criteria for focal or generalized onset epilepsy, respectively. Overall, 9.4% (n = 20) patients were eligible for trials (19 focal onset and one generalized onset). Most patients were excluded from the study due to insufficient seizure frequency (58% of focal onset, 55% of generalized onset). A small proportion of patients with medication‐resistant epilepsy were eligible for trials based on common selection criteria. These eligible patients may not be representative of the general population of patients with medication‐resistant epilepsy. Insufficient seizure frequency was the most common reason for exclusion.
Disparate population and holobiont structure of pocilloporid corals across the Red Sea gradient demonstrate species‐specific evolutionary trajectories

Global habitat degradation heightens the need to better understand patterns of genetic connectivity and diversity of marine biota across geographical ranges to guide conservation efforts. Corals across the Red Sea are subject to pronounced environmental differences, but studies so far suggest that animal populations are largely connected, excepting evidence for a genetic break between the northern‐central and southern regions. Here, we investigated population structure and holobiont assemblage of two common pocilloporid corals, Pocillopora verrucosa and Stylophora pistillata, across the Red Sea. We found little evidence for population differentiation in P. verrucosa, except for the southernmost site. Conversely, S. pistillata exhibited a complex population structure with evidence for within‐reef and regional genetic differentiation, in line with differences in their reproductive mode (P. verrucosa is a broadcast spawner and S. pistillata is a brooder). Analysis for genomic loci under positive selection identified 85 sites (18 of which were in coding sequences) that distinguished the southern P. verrucosa population from the remainder of the Red Sea population. By comparison, we found 128 loci (24 of which were residing in coding sequences) in S. pistillata with evidence for local adaptation at various sites. Functional annotation of the underlying proteins revealed putative roles in the response to stress, lipid metabolism, transport, cytoskeletal rearrangement, and ciliary function (among others). Microbial assemblages of both coral species showed pervasive association with microalgal symbionts from the genus Symbiodinium (former clade A) and bacteria from the genus Endozoicomonas that exhibited significant differences according to host genotype and environment. The disparity of population genetic and holobiont assemblage patterns even between closely related species (family Pocilloporidae) highlights the need for multispecies investigations to better understand the role of the environment in shaping evolutionary trajectories. It further emphasizes the importance of networks of reef reserves to achieve conservation of genetic variants critical to the future survival of coral ecosystems.
Gulp1 deficiency augments bone mass in male mice by affecting osteoclasts due to elevated 17β‐estradiol levels

The engulfment adaptor phosphotyrosine‐binding domain containing 1 (GULP1) is an adaptor protein involved in the engulfment of apoptotic cells via phagocytosis. Gulp1 was first found to promote the phagocytosis of apoptotic cells by macrophages, and its role in various tissues, including neurons and ovaries, has been well studied. However, the expression and function of GULP1 in bone tissue are poorly understood. Consequently, to determine whether GULP1 plays a role in the regulation of bone remodeling in vitro and in vivo, we generated Gulp1 knockout (KO) mice. Gulp1 was expressed in bone tissue, mainly in osteoblasts, while its expression is very low in osteoclasts. Microcomputed tomography and histomorphometry analysis in 8‐week‐old male Gulp1 KO mice revealed a high bone mass in comparison with male wild‐type (WT) mice. This was a result of decreased osteoclast differentiation and function in vivo and in vitro as confirmed by a reduced actin ring and microtubule formation in osteoclasts. Gas chromatography‐mass spectrometry analysis further showed that both 17β‐estradiol (E2) and 2‐hydroxyestradiol levels, and the E2/testosterone metabolic ratio, reflecting aromatase activity, were also higher in the bone marrow of male Gulp1 KO mice than in male WT mice. Consistent with mass spectrometry analysis, aromatase enzymatic activity was significantly higher in the bone marrow of male Gulp1 KO mice. Altogether, our results suggest that GULP1 deficiency decreases the differentiation and function of osteoclasts themselves and increases sex steroid hormone‐mediated inhibition of osteoclast differentiation and function, rather than affecting osteoblasts, resulting in a high bone mass in male mice. To the best of our knowledge, this is the first study to explore the direct and indirect roles of GULP1 in bone remodeling, providing new insights into its regulation.