Miracle-dz/UniFAR-FTUs huggingface dataset:
The Italian depreciation suspension policy during the COVID-19 pandemic: consequences on private firms’ borrowing capacity

ABSTRACT We investigate the consequences of adopting a new accrual-based relief mechanism on private firms’ borrowing capacity. During the COVID-19 pandemic, the Italian government implemented a temporary change in accounting rules that allowed firms to suspend up to the entire amount of their depreciation and amortisation charges. Using a sample of Italian firms from 2018 to 2021 and a difference-in-differences model, we show that the depreciation and amortisation suspension policy (DASP) adopters, compared to non-adopters, access larger loans and negotiate a lower cost of debt than in the pre-DASP period. Our results are robust to additional tests for potential endogeneity and confounding factors such as earnings management and the adoption of other accounting-based relief mechanisms. We provide evidence that accrual-based relief mechanisms have real economic effects and are effective measures to support firms in managing a systemic shock.
On the influence of second order uniformly elliptic operators in nonlinear problems

The purpose of the present paper is to discuss the role of second order elliptic operators of the type L=∑i,j=1nDi(aij(x)Dj) on the existence of a positive solution for the problem involving critical exponent −Lu=un+2n−2+λuinΩ,u=0on∂Ω,where Ω is a smooth bounded domain in Rn , n≥3 , and λ is a real parameter. In particular, we show that if the function det(A(x)) has an interior global minimum point x0 such that A(x) is comparable to A(x0)+|x−x0|γIn , where A(x)=(aij(x)) and In is the identity matrix of order n, then the range of values of λ for which the problem above has a positive solution can change drastically from γ≤2 to γ>2 .
Banded chaos in power systems

This paper focuses on one aspect of ferroresonance in power systems, i.e., the appearance of a strange attractor with a band-like structure. This attractor was called a "pseudoperiodic" attractor in a previous paper where the phenomenon was first reported. It was found in this study that banded chaos arises from a sequence of period doubling bifurcations. Odd-subharmonics undergo a symmetry-breaking bifurcation before the period doubling cascade takes place. A theoretical discussion of symmetry-breaking and period doubling is given and a route to banded chaos in an actual power system is demonstrated. The Lyapunov exponents for the strange attractor were calculated.
Enhancement of Optical Gain in Two-Dimensional Photonic Crystals with Active Lattice Points

Photonic crystals with active lattice points (two-dimensional gain photonic crystals) are proposed, in which all lattice points are made of the same gain material embedded in other dissipative medium. The optical gain spectrum is found to exhibit a pronounced gain enhancement in the vicinity of the band edge of the photonic band. This gain value also shows a spatial anisotropy reflecting the symmetry of the photonic band. These gain values have a strong correlation with the variation of the group velocity of light, indicating that the marked reduction in the group velocity near the photonic band edge causes the optical gain enhancement.
Occlusive and Proliferative Properties of Different Collagen Membranes—An In Vitro Study

Different collagen barrier membranes come in various sources and crosslinking that may affect barrier function and tissue integration. This study investigated barrier function and tissue integration of the three different collagen membranes (Jason®: porcine pericardium, GENOSS: bovine tendon, and BioMend® Extend: cross-linked bovine tendon) with human gingival fibroblasts. The barrier function and tissue integration properties were determined under confocal microscopy. Morphological characteristics were observed using scanning electron microscopy. Our results showed that all collagen membranes allowed a small number of cells to migrate, and the difference in barrier function ability was not significant. The cross-linked characteristics did not improve barrier ability. The native collagen membrane surfaces allowed evenly scattered proliferation of HGF, while the cross-linked collagen membrane induced patchy proliferation. Statistically significant differences in cell proliferation were found between Jason and BioMend Extend membranes (p = 0.04). Scanning electron microscope showed a compact membrane surface at the top, while the bottom surfaces displayed interwoven collagen fibers, which were denser in the crosslinked collagen membranes. Within the limitations of this study, collagen membranes of different origins and physical properties can adequately prevent the invasion of unwanted cells. Native collagen membranes may provide a better surface for gingival cell attachment and proliferation.
QK type spaces of analytic functions

For a nondecreasing function K:[0,8)? [0,8) and 0<p<8, -2<q<8, we introduce QK(p,q), a QK type space of functions analytic in the unit disk and study the characterizations of QK(p,q). Necessary and sufficient conditions on K such that QK(p,q) become some known spaces are given.
Conformational Dynamics of Phytoglobin BvPgb1.2 from Beta vulgaris ssp. vulgaris

Plant hemoglobins, often referred to as phytoglobins, play important roles in abiotic stress tolerance. Several essential small physiological metabolites can be bound to these heme proteins. In addition, phytoglobins can catalyze a range of different oxidative reactions in vivo. These proteins are often oligomeric, but the degree and relevance of subunit interactions are largely unknown. In this study, we delineate which residues are involved in dimer formation of a sugar beet phytoglobin type 1.2 (BvPgb1.2) using NMR relaxation experiments. E. coli cells harboring a phytoglobin expression vector were cultivated in isotope-labeled (2H, 13C and 15N) M9 medium. The triple-labeled protein was purified to homogeneity using two chromatographic steps. Two forms of BvPgb1.2 were examined, the oxy-form and the more stable cyanide-form. Using three-dimensional triple-resonance NMR experiments, sequence-specific assignments for CN-bound BvPgb1.2 were achieved for 137 backbone amide cross-peaks in the 1H-15N TROSY spectrum, which amounts to 83% of the total number of 165 expected cross-peaks. A large proportion of the non-assigned residues are located in α-helixes G and H, which are proposed to be involved in protein dimerization. Such knowledge around dimer formation will be instrumental for developing a better understanding of phytoglobins’ roles in planta.
Settling regimes of inertial particles in isotropic turbulence

Abstract We investigate the settling speeds and root mean square (r.m.s.) velocities of inertial particles in isotropic turbulence with gravity using experiments with water droplets in air turbulence from 32 loudspeaker jets and direct numerical simulations (DNS). The dependence on particle inertia, gravity and the scales of both the smallest and largest turbulent eddies is investigated. We isolate the mechanisms of turbulence settling modification and find that the reduced settling speeds of large particles in experiments are due to nonlinear drag effects. We demonstrate using DNS that reduced settling speeds with linear drag (e.g. see Nielsen, J. Sedim. Petrol., vol. 63, 1993, pp. 835–838) only arise in artificial flows that, by design, eliminate preferential sweeping by the eddies. Gravity and inertia both reduce the particle r.m.s. velocities and falling particles are more responsive to vertical than to horizontal fluctuations. The model by Wang & Stock (J. Atmos. Sci., vol. 50, 1993, pp. 1897–1913) captures these trends.
Sources of Measurement Errors in Business Surveys

Measurement errors are commonly ascribed to four sources: the respondent, the interviewer, the instrument (the survey questionnaire), and the mode of data collection. The unique characteristics of business population and business surveys affect the survey response process and contribute to the occurrence of specific measurement errors. Several authors have already exposed the need for an additional source of measurement errors in business surveys: the records or the information system or, even more broadly, the organization. Although this addition considerably improves the usefulness of the categorization, some sources of measurement errors still lack. This paper proposes an extension of the existing categorization in order to cover all known sources of measurement errors in business surveys and elaborates on its implications for detection, reduction and prevention of measurement errors in business surveys.
Efflux from a slit in a vertical wall

A numerical solution is provided for flow of a stream of water falling under gravity after emerging from a simple slit orifice in a vertical wall. The classical free-streamline flow with contraction coefficient 0.611 applies in the absence of gravity, or as F → ∞, where F is the Froude number based on the net volume flux and the slit width. We assume here that F is finite, but find that the flow exists only for F [ges ] 0.496, with initial backflow at the upper stream surface for 0.496 [les ] F [les ] 0.578. The limiting flow at F = 0.496 has a stagnation point at the upper edge.
De Novo Assembly and Characterization of the Transcriptome of an Omnivorous Camel Cricket (Tachycines meditationis)

Tachycines meditationis (Orthoptera: Rhaphidophoridae: Tachycines) is a widely distributed insect in eastern Asia. This species is common in urban environments, and its unique omnivorous diet may contribute to its success in various habitats. However, molecular studies on the species are scarce. Here, we obtained the first transcriptome sequence of T. meditationis and performed preliminary analyses to test whether the evolution of coding sequences fits the expectations based on the species’ ecology. We retrieved 476,495 effective transcripts and annotated 46,593 coding sequences (CDS). We analysed the codon usage and found that directional mutation pressure was the leading cause of codon usage bias in this species. This genome-wide relaxed codon usage pattern in T. meditationis is surprising, given the potentially large population size of this species. Moreover, despite the omnivorous diet, the chemosensory genes of this species do not exhibit codon usage deviating significantly from the genome-level pattern. They also do not seem to experience more gene family expansion than other cave cricket species do. A thorough search for rapidly evolved genes using the dN/dS value showed that genes associated with substance synthesis and metabolic pathways, such as retinol metabolism, aminoacyl-tRNA biosynthesis, and fatty acid metabolism, underwent species-specific positive selection. While some results seem to contradict the species ecology, our transcriptome assembly provides a valuable molecular resource for future studies on camel cricket evolution and molecular genetics for feeding ecology in insects, in general.
On approximations involved in the theory of charged particle transport in gases in electric and magnetic fields at arbitrary angles

Various approximations and computer codes for the calculation of charged particle transport in gases in electric and magnetic fields have found their may into mainstream applications of various types. Some of these codes/approximations avoid the mathematical complexity associated with an accurate solution of Boltzmann's equation, but because of assumptions of symmetry and/or near isotropy in velocity space they may be incorrect. Using an accurate multiterm solution of Boltzmann's equation for electric and magnetic fields oriented at arbitrary angles with respect to each other, we highlight the inadequacies of such assumptions. In addition we explore the validity of Tonks' theorem and the effective field approximation as applied to the more general case of arbitrary orientation angles.
Global hybrid simulation of the solar wind interaction with the dayside of Venus

The authors present a 3-dimensional global hybrid simulation of the interaction of the solar wind with the entire dayside of Venus. The model obstacle is half the size of Venus, and planetary ion mass loading is included self-consistently. Results are compared to observations as well as to results from gasdynamic convected field modeling. Magnetic field magnitudes and bulk flow speeds along the planet-Sun line are comparable in both models, but only the hybrid model reproduces the experimentally observed magnetic barrier proton density depletions. The finite gyroradius of the planetary pickup ions causes a number density asymmetry in the direction of the convective ({minus}V {times} B) electric field, as predicted and observed. Mass addition consistent with photoionization of the planetary neutral hot oxygen corona has little effect on the geometry of the shock, including the subsolar and terminator shock altitudes. Mass addition rates well in excess of likely values are required to significantly affect the model shock geometry. The hybrid model results imply that oxygen ions originating deep within the dayside Venus magnetic barrier are nearly fluidlike while oxygen ions produced higher on the dayside, at much lower densities, behave more as test particles. Gasdynamic modeling incorporating both fluid and testmore » particle mass addition reproduces the O{sup +} terminator escape flux (a few times 10{sup 24} s{sup {minus}1}) found in the hybrid model and inferred from observations, but underestimates the escape region spatial extent. The hybrid model predictions include a shock asymmetry dependent on the upstream IMF orientation, asymmetries in the magnetic barrier position and field magnitude, an asymmetry in pickup ion speed altitude profiles, and a finite gyroradius effect asymmetry in pickup ion number density caused by field draping. « less
Lyapunov stability analysis for nonlinear delay systems

Sufficient conditions ensuring that a nonlinear system with disturbances having a delay is delay independent globally asymptotically stable, are given. The proof carried out relies extensively on a characterization of the stability property in terms of the Lyapunov function. The result is applied to some biological systems and neural networks. It is also used to construct a stabilizing memoryless controller for a second order system with state-delay.
Peripheral Regional Anesthesia Using Local Anesthetics: Old Wine in New Bottles?

During the past decade, numerous efforts were undertaken aiming at prolonging the analgesic effect of regional anesthesia. With the development of extended-release formulations and enhanced selectivity for nociceptive sensory neurons, a very promising contribution to the development of pain medications has been achieved. At present, liposomal bupivacaine is the most popular, non-opioid, controlled drug delivery system, but its duration of action, which is still controversially discussed, and its expensiveness have decreased initial enthusiasm. Continuous techniques can be seen as an elegant alternative for providing a prolonged duration of analgesia, but for logistic or anatomical reasons, they are not always the best choice. Therefore, focus has been directed towards the perineural and/or intravenous addition of old and established substances. As for perineural application, most of these so-called ‘adjuvants’ are used outside their indication, and their pharmacological efficacy is often not or only poorly understood. This review aims to summarize the recent developments for prolonging the duration of regional anesthesia. It will also discuss the potential harmful interactions and side effects of frequently used analgesic mixtures.
Uniform exponential stability for families of linear time-varying systems

We present sufficient conditions for uniform exponential stability of families of linear time varying (LTV) systems. That is, LTV systems characterized by certain parameters. Our conditions are in the form of classical concepts in adaptive control, such as persistency of excitation. However, our proofs are based on modern tools which can be interpreted as an "integral" version of Lyapunov theorems; rather than on the concept of uniform complete observability which is most common in the literature. Uniformity is established in both, the initial conditions of the system, and the parameter which characterizes each system of the "family".
Deuterated as a probe of isotope fractionation in star-forming regions

Observations of molecular D/H ratios in the interstellar medium are used to probe the physical conditions, such as temperature, ionization fraction and the importance of gas–grain reactions. In cold, dense regions, such as cores which are collapsing to form stars, the level of deuterium fractionation depends on the conversion of into its deuterated isotopologues (H2D+, D2H+ and ). The relative abundances of these molecules uniquely probe the centres of these cores where other, heavier, species have frozen onto dust grains. We present models of the deuterium chemistry close to the centre of a pre-stellar core, in the last stage before the star forms, showing the dependence of the observable molecular D/H ratios on the physical parameters and rate coefficients that are assumed. We compare model predictions with the latest observations of these regions.
SAT3D: Slot Attention Transformer for 3D Point Cloud Semantic Segmentation

Semantic segmentation of 3D point cloud is a key task in numerous intelligent transportation system applications, e.g., self-driving vehicles, traffic monitoring. Due to the sparsity and varying density of points in the outdoor point clouds, it becomes particularly challenging to extract object-centric features from data. This leads to poor semantic segmentation, especially for the rare object classes. To address that, we introduce the first-ever Slot Attention Transformer based technique to effectively model object-centric features in point cloud data. Our method uses cylindrical splits of space for voxelization and computes channel-wise positional embeddings before repetitively encoding the point cloud with slot attentions. Our second major contribution is a Large-Scale Outdoor Point Cloud dataset (SWAN), collected in a dense urban environment, driving 150km distance. It provides 16 billion points in more than 200K frames. The dataset also provides annotations for 10K frames for 24 classes. We also contribute a data augmentation scheme to handle rare object classes in real-world point clouds. Besides benchmarking popular existing methods on SWAN for the first time, we thoroughly evaluate our technique on the existing large-scale datasets, Semantic KITTI and nuScenes. Our results demonstrate a consistent performance gain for our technique, and verify the need of the more challenging SWAN dataset.
Numerical Modeling of Ice Deposition

Abstract A method of computing the rate of growth of ice crystals by deposition is described. Predictions of growth characteristics over the temperature range of −1 through −35C are shown and compared with meager experimental data available within this temperature range. The growth rate equations are based on Fick's law of diffusion. In applying this law to nonspherical ice crystals, the analogy between an electrostatic potential field surrounding a charged body and the vapor-density field surrounding a similarly shaped ice crystal is utilized. Allowances are made for effects of forced convection caused by the movement of the crystal through the air and the change in shape and bulk density of the ice crystal; these effects are predicted to be of significant importance. A simple, empirical equation using two temperature-dependent parameters was found to describe the crystal growth rate as a, function of mass. For many cases where only the rate of mass conversion from vapor to solid is required, the simple .
Outcomes of Transcatheter Aortic Valve Implantation Comparing Medtronic’s Evolut PRO and Evolut R: A Systematic Review and Meta-Analysis of Observational Studies

Background: Transcatheter aortic valve implantation (TAVI) has become a broadly acceptable alternative to AV surgery in patients with aortic stenosis (AS). New valve designs are becoming available to address the shortcomings of their predecessors and improve clinical outcomes. Methods: A systematic review and meta-analysis was carried out to compare Medtronic’s Evolut PRO, a new valve, with the previous Evolut R design. Procedural, functional and clinical endpoints according to the VARC-2 criteria were assessed. Results: Eleven observational studies involving N = 12,363 patients were included. Evolut PRO patients differed regarding age (p < 0.001), sex (p < 0.001) and STS–PROM estimated risk. There was no difference between the two devices in terms of TAVI-related early complications and clinical endpoints. A 35% reduction of the risk of moderate-to-severe paravalvular leak (PVL) favoring the Evolut PRO was observed (RR 0.66, 95%CI, [0.52, 0.86] p = 0.002; I2 = 0%). Similarly, Evolut PRO-treated patients demonstrated a reduction of over 35% in the risk of serious bleeding as compared with the Evolut R (RR 0.63, 95%CI, [0.41, 0.96]; p = 0.03; I2 = 39%), without differences in major vascular complications. Conclusions: The evidence shows good short-term outcomes of both the Evolut PRO and Evolut R prostheses, with no differences in clinical and procedural endpoints. The Evolut PRO was associated with a lower rate of moderate-to-severe PVL and major bleeding.
Accurate approximation of fields and spectral response functions for perpendicular recording heads

Solutions for the magnetic potential in rectangular regions with simple boundary conditions are used to approximate the two-dimensional potential in the head face plane of a recording head. This method of approximation can be applied to any recording head with rectangular corners, in the presence of an underlayer. The slot approximation is demonstrated for ring heads and shielded (magnetoresistive) pole heads. The quarter plane approximation is given for application to finite-length heads. Estimates of the field components and the spectral response function are derived from the approximate potential. The simple slot approximation is shown to be at least as accurate as other, often more complicated, methods of approximation. Most significantly, both the slot and the quarter-plane approximations are easy to apply and need no prior knowledge of the head field of the particular geometry under consideration.
The psychological impact of COVID-19 lockdown on the wellbeing, learning efficacy and sleeping behaviors of Romanian medical students

Background and aims The COVID-19 lockdowns are reported to have negatively influenced the wellbeing and learning efficacy of students. In this context, we analyzed the psychological impact of the COVID-19 quarantine on healthcare students, a subpopulation experiencing high stress levels. Methods Our survey-based, cross-sectional study assessed wellbeing indicators, lifestyle and learning behaviors before and during the quarantine for 388 Romanian healthcare students. Results Our findings included the increase in phone and social media use, at the expense of formal and independent study time; deteriorations in mood, self-organization capacity and learning efficacy, and increased procrastination behaviors. Unexpectedly, our study identified an improvement in sleep quality and duration. The increase in social media use was less severe among rural students. We identified correlations between study time, online activities (including social media), wellbeing indicators and procrastination. Conclusion Our study draws attention to quarantine-induced deteriorations of wellbeing and learning capacity in an important category of students.