Miracle-dz/UniFAR-FTUs huggingface dataset:
Relevance of DNA barcodes for biomonitoring of freshwater animals

The COI gene, colloquially named the DNA barcode, is a universal marker for species identification in the animal kingdom. Nevertheless, due to the taxonomic impediment, there are various proposals for molecular operational taxonomic units (MOTUs) because high-throughput sequencers can generate millions of sequences in one run. In the case of freshwater systems, it is possible to analyze whole communities through their DNA using only water or sediment as a sample. Using DNA barcodes with these technologies is known as metabarcoding. More than 90% of studies based on eDNA work with MOTUs without previous knowledge of the biodiversity in the habitat. Despite this problem, it has been proposed as the future for biomonitoring. All these studies are biased toward the Global North and focused on freshwater macrofaunae. Few studies include other regions of the world or other communities, such as zooplankton and phytoplankton. The future of biomonitoring should be based on a standardized gene, for example, COI, the most studied gene in animals, or another secondary consensual gene. Here, we analyzed some proposals with 28S or 12S. The studies on eDNA can focus on analyses of the whole community or a particular species. The latter can be an endangered or exotic species. Any eDNA study focused on a community study should have a well-documented DNA baseline linked to vouchered specimens. Otherwise, it will be tough to discriminate between false positives and negatives. Biomonitoring routines based on eDNA can detect a change in a community due to any perturbation of the aquatic ecosystem. Also, it can track changes along the history of an epicontinental environment through the analyses of sediments. However, their implementation will be complex in most megadiverse Neotropical countries due to the lack of these baselines. It has been demonstrated that a rapid functional construction of a DNA baseline is possible, although the curation of the species can take more time. However, there is a lack of governmental interest in this kind of research and subsequent biomonitoring.
The association between vitamin D3 deficiency and acute kidney injury in COVID-19 patients

Introduction: Vitamin D deficiency is a common clinical finding in the general population and hospitalized patients, including patients in the intensive care unit (ICU). Acute kidney injury (AKI) occurs in more than 50% in ICU admitted patients. Objectives: There are few studies regarding AKI in COVID-19 patients, therefore we investigated the relationship between vitamin D3 deficiency and the occurrence of AKI in COVID-19 patients. Patients and Methods: This cross-sectional study was conducted on 69 COVID-19 patients who were hospitalized in the ward for 12 months. Their serum vitamin D3 levels were measured in the first 24 hours of hospitalization in the ward. Patients were divided into three groups based on the serum levels of vitamin D3: >50 ng/mL as normal, 20-50 ng/mL as insufficient and <20 ng/mL as deficiency status. The patients were studied until the occurrence of acute renal injury or the occurrence of death. Results: Out of 69 hospitalized patients in the ward with COVID-19, there were 39 patients in group vitamin D3<20 ng/mL, 21 patients in group vitamin D3 of 20-50ng/mL and 9 patients in group of vitamin D3>50 ng/mL. The frequencies of AKI in groups of vitamin D3<20 ng/mL, 20-50 ng/mL, and >50 ng/mL were 46%, 28%, and 23%, respectively. A significant relationship was observed between AKI and our study groups (P=0.011). Furthermore, there was a significant association between our study groups and mortality (P=0.014), ICU admission (P=0.041) and hospital length of stay (P=0.017). In another division in patients with different levels of vitamin D3 in the presence or absence of AKI, there were significant associations between patients with vitamin D3<20 ng/mL and the presence of AKI and also with mortality (P=0.042), ICU admission (P=0.024) and additionally with hospital length of stay (P=0.027). Conclusion: Our study showed significant association between vitamin D deficiency and AKI in ICU-admitted COVID-19 patients. Moreover, there were relationships between vitamin D deficiency and mortality, ICU admission and hospital length of stay. These results suggest the correction of vitamin D deficiency may be beneficial to reduce AKI in patient with COVID-19.
Temperature‐dependent light‐output characteristics of GaInN light‐emitting diodes with different dislocation densities

We have experimentally investigated the temperature dependence of optical‐output power of light‐emitting diodes (LEDs) with different threading dislocation densities (TDDs) to assess the influence of the TDD on the temperature stability of LEDs. Whereas the LED with high TDD shows a 64% decrease in optical‐output power when the ambient temperature increases from 20 to 150 °C, the LED with low TDD shows only a 54% decrease. The temperature dependence of the optical‐output power and current dependence of the characteristic temperature Tch of LEDs shows that short radiative recombination lifetime and low TDDs are essential to obtain LED characteristics that are tolerant of high temperatures.
Cavity resonance shift and bandwidth enhancement in semiconductor lasers with strong light injection

We theoretically investigated the physical mechanism of significant bandwidth enhancement in injection-locked semiconductor lasers with strong light injection. Strong light injection can increase the semiconductor laser bandwidth to several times the free-running relaxation oscillation bandwidth. We focused on the fact that an injection-locked semiconductor laser can operate at an optical frequency different from its cavity resonance condition. Resonance is shifted from solitary resonance through the carrier-induced refractive-index change due to strong optical injection. We then framed a theory in which the enhanced resonance can be generated by transient interference between the injection-locked field and the field corresponding to the shifted cavity resonance. To examine the theory, we numerically investigated the rate equations and found that the numerical and theoretical results agree well over a wide range for strong injection. A stability analysis for the rate equations revealed that there is a mode transition from relaxation oscillation to interference-induced oscillation with increased injection, and the relaxation oscillation can become suppressed for higher injection levels. We believed that negligibly small fluctuations of the carrier suppressed the relaxation oscillation and examined it numerically. We also predict that, at strong injection levels, semiconductor lasers can be lower-dimensional systems because of the possibility of adiabatic elimination of the carrier. We further conclude that such low-dimensional systems can generate a high-frequency interference beat in the laser cavity and the resultant enhanced resonance.
Multivariate discrimination methods for top quark analysis

Multivariate discrimination techniques are being considered as alternatives to many data-analysis methods conventionally used in experimental high-energy physics. In this article, the applications of four different methods—a quadratic classifier, kernel discriminant analysis, a feedforward neural network, and multivariate adaptive regression splines—are compared for the detection of the top quark. Simulated particle-collision data that correspond to two classes, a rare signal and a dominant background, are used.
Weak localization of electrons by Auger emission

The effect of the new type of weak localization of electrons scattered inelastically from disordered media on Auger emission spectra is studied. This type of weak localization leads to modification of the angular spectra and energy distributions of Auger electrons. The results obtained can be applied to the determination of the characteristics of crystal surface region. It was shown that the dependence of the scattering intensity of Auger electron on an azimuthal angle is due to coherent effects. The diagram technique allows to calculate the wave function of Auger electrons more exactly. The method in question can be used for detailed description not only particle emission measurements, but also for X-ray radiation.
Scattering by a Spherical Cap

The boundary‐value problem for plane‐wave scattering by a spherical cap is formulated in terms of either the radial velocity in the aperture or the equivalent‐vortex strength of the shell. The resulting complementary integral equations are used to construct complementary variational expressions for the scattering cross section and also are solved approximately by Galerkin's method. Numerical results are given for the scattering cross section, say σ, with special reference to the Helmholtz resonator (small aperture) and the hemispherical shell. The function σ(k), where k is the dimensionless wavenumber based on the radius of the sphere, rises initially as k4 (Rayleigh‐scattering regime) to a first peak, σ(k0), and then executes a decaying oscillation about the asymptotic value, σ∞ (twice the transverse area intercepted by the incident wave); σ(k0) = O(1/β) as the polar angle of the aperture, β, tends to zero, whilst σ(k0) = 2. 13σ∞ for the hemispherical shell.
Smoothing forecast ensembles with fitted probability distributions

Forecast ensembles from the European Centre for Medium‐Range Weather Forecasts Ensemble Prediction System for surface‐weather variables are smoothed by fitting Gaussian distributions. The possibility of bifurcation or other non‐Gaussian behaviours in an ensemble is allowed for by including probability mixtures of two Gaussian distributions when justified by the data. Variables that are clearly non‐Gaussian (wind speed and cloud cover) are transformed before fitting, and multivariate data with dimensions as high as four are considered. The smoothed ensembles provide more‐accurate quantile and probability estimates in a perfect‐model setting, particularly for small ensemble sizes and more‐extreme events. This advantage increases in the presence of random errors in the ensemble means, but diminishes for underdispersed ensembles. Allowing representation of ensembles as Gaussian mixtures also leads to a sharper ‘spread–skill’ relationship in the data considered. Copyright © 2002 Royal Meteorological Society.
Stabilization of time-varying pseudo-Hamiltonian systems

In this note, the problem of stability and stabilization of time-varying pseudo-Hamiltonian control systems is investigated. First, we show a stability result for time-varying pseudo-Hamiltonian dynamic systems. The relationships among the Lyapunov function, storage function and the Hamiltonian function are revealed. Roughly speaking, they are essentially equivalent. Then a new development on the stability of /spl Kscr/ + /spl Lscr/ systems is reported. Based on this new approach the stabilization problem of time-varying systems is considered. Certain results are parallel to their counterparts in time-invariant systems.
Empirical tone reproduction curve equation applied for color characterization of LCDs

An empirical function is proposed to characterize the transfer functions of the image signals to tristimulus values of twist nematic liquid crystal displays (TN LCDs). This empirical equation can be applied for color additive models and primary-shift backward model of LCDs' characterizations. A notebook PC was used to examine the fitting accuracy and color difference with different transfer functions. The main benefit of the work is that only 12 colors are required to accurately characterize the color rendering of LCDs.
Quenching processes and premixed turbulent combustion diagrams

The structure of premixed turbulent flames is a problem of fundamental interest in combustion theory. Possible flame geometries have been imagined and diagrams indicating the corresponding regimes of combustion have been constructed on the basis of essentially intuitive and dimensional considerations. A new approach to this problem is described in the present paper. An extended definition of flamelet regimes based on the existence of a continuous active (not quenched) flame front separating fresh gases and burnt products is first introduced. Direct numerical simulations of flame/vortex interactions using the full Navier–Stokes equations and a simplified chemistry model are then performed to predict flame quenching by isolated vortices. The formulation includes non-unity Lewis number, non-constant viscosity and heat losses so that the effect of stretch, curvature, transient dynamics and viscous dissipation can be accounted for. As a result, flame quenching by vortices (which is one of the key processes in premixed turbulent combustion) may be computed accurately. The effects of curvature and viscous dissipation on flame/vortex interactions may also be characterized by the same simulations. The influence of non-unity Lewis number and of thermo-diffusive processes in turbulent premixed combustion is discussed by comparing flame responses for two values of the Lewis number (Le = 0.8 and 1.2). An elementary (‘spectral’) diagram giving the response of one flame to a vortex pair is constructed. This spectral diagram is then used, along with certain assumptions, to establish a turbulent combustion diagram similar to those proposed by Borghi (1985) or Williams (1985). Results show that flame fronts are much more resistant to quenching by vortices than expected from the classical theories. A cut-off scale and a quenching scale are also obtained and compared with the characteristic scales proposed by Peters (1986). Results show that strain is not the only important parameters determining flame/vortex interaction. Heat losses, curvature, viscous dissipation and transient dynamics have significant effects, especially for small scales and they strongly influence the boundaries of the combustion regimes. It is found, for example, that the Klimov–Williams criterion which is generally advocated to limit the flamelet region, underestimates the size of this region by more than an order of magnitude.
Fractional Brownian motion and fractional Gaussian noise in subsurface hydrology: A review, presentation of fundamental properties, and extensions

Recent studies have shown that fractional Brownian motion (fBm) and fractional Gaussian noise (fGn) are useful in characterizing subsurface heterogeneities in addition to geophysical time series. Although these studies have led to a fairly good understanding of some aspects of fBm/fGn, a comprehensive introduction to these stochastic, fractal functions is still lacking in the subsurface hydrology literature. In this paper, efforts have been made to define fBm/fGn and present a development of their mathematical properties in a direct yet rigorous manner. Use of the spectral representation theorem allows one to derive spectral representations for fBm/fGn even though these functions do not have classical Fourier transforms. The discrete and truncated forms of these representations have served as a basis for synthetic generation of fBm/fGn. The discrete spectral representations are developed and various implications discussed. In particular, it is shown that a discrete form of the fBm spectral representation is equivalent to the well known Weierstrass‐Mandelbrot random fractal function. Although the full implications are beyond the scope of the present paper, it is observed that discrete spectral representations of fBm constitute stationary processes even though fBm is nonstationary. A new and general spectral density function is introduced for construction of complicated, anisotropic, (3‐D) fractals, including those characterized by vertical fGn and horizontal fBm. Such fractals are useful for modeling anisotropic subsurface heterogeneities but cannot be generated with existing schemes. Finally, some basic properties of fractional Lévy motion and concepts of universal multifractals, which can be considered as generalizations of fBm/fGn, are reviewed briefly.
A complete neural network approach to solving a class of combinatorial problems

Summary form only given. The concept of the Hopfield neural network (NN) has been generalized where discrete neurons, called quantrons (Q'trons, a shorthand for quantum neurons), are exploited. Unlike the conventional neuron in a Hopfield NN, a Q'tron may have multiple (usually more than two) output levels. A system energy, referred to as Lyapunov energy, is embedded in the NN and is shown to possess monotonically decreasing property. Therefore, a combinatorial problem can be solved using this Q'tron NN by first reformulating the problem into one which minimizes a Lyapunov energy function, on the basis of which the NN is then built. As a result, when the NN gets to settle on a stable state, the original combinatorial problem is solved. Remarkable features of this approach are: (1) a solution to the problem, if it exists, will always be reached with probability one; and (2) no false solution will ever be reported. <<ETX>>
Existence of Nonabelian Free Subgroups in the Maximal Subgroups of GLn(D)

Given a non-commutative finite dimensional F-central division algebra D, we study conditions under which every non-abelian maximal subgroup M of GLn(D) contains a non-cyclic free subgroup. In general, it is shown that either M contains a non-cyclic free subgroup or there exists a unique maximal subfield K of Mn(D) such that NGLn(D)(K*)=M, K* ◁ M, K/F is Galois with Gal(K/F) ≅ M/K*, and F[M]=Mn(D). In particular, when F is global or local, it is proved that if ([D:F],Char(F))=1, then every non-abelian maximal subgroup of GL1(D) contains a non-cyclic free subgroup. Furthermore, it is also shown that GLn(F) contains no solvable maximal subgroups provided that F is local or global and n ≥ 5.
Determination of the complex dielectric tensor of triclinic crystals: theory

Theoretical expressions are derived for normal-incidence reflectances at three faces of a cube, cut from a triclinic crystal, for any desired orientation of crystallographic axes relative to the cube edges. The reflectances are expressed in terms of the components of the complex dielectric tensor of the crystal referred to the cube axes. Also presented is a suitable dispersion formula in which each component of the dielectric tensor, referred to the fixed cube axes, is given as a sum of the contributions of all crystal oscillators, each multiplied by products of the direction cosines of the oscillator axis relative to the cube axes. A least-squares-fitting procedure, based on the variation of the oscillator parameters and the direction cosines, can be used to obtain the best match of the measured and calculated reflectances, over a wide frequency range, and thereby to determine the dielectric tensor as a function of frequency.
Surface electromagnetic waves supported by the interface of two semi-infinite rugate filters with sinusoidal refractive-index profiles

The canonical problem of surface-wave propagation guided by the interface of two semi-infinite rugate filters made of isotropic dielectric materials was formulated and solved. Numerical studies showed that multiple Tamm waves—with different phase speeds, polarization states, and degrees of localization—can be guided by the interface of a homogeneous dielectric material and a rugate filter. Multiple Tamm waves and optical Tamm states are supported by a phase-defect interface in a rugate filter. A sudden change of either the mean refractive index or the amplitude of the sinusoidal variation of the refractive index also creates an interface that can guide multiple Tamm waves, as can the interface of two distinct rugate filters. Whereas the Tamm waves can be either p or s polarized, all optical Tamm states were found to be p polarized.
TIDALLY INDUCED STAR FORMATION IN ABELL 1367

Our principal aim is to compare global star formation rates between cluster galaxies and field galaxies in order to clarify environmental influence on star formation. We use an objective prism technique to survey over 200 Zwicky catalogue (CGCG) galaxies within ∼ 2°. 5 of Abell 1367 for Hα emission. After a brief discussion of the survey characteristics, we consider first the dependence of Hα detection on Hubble type, galaxy disturbance and the presence of a bar. As expected, we rarely detect early-type galaxies and consequently restrict further discussion to spirals (type S0/a and later), of which we detect ∼ 35 per cent in Hα. We find that an extremely valuable distinction to make is between galaxies with diffuse Hα and galaxies with compact Hα. There is a very significant tendency for galaxies with compact Hα emission to be disturbed, and there may be a weak tendency for them to be barred. Neither of these tendencies is found for galaxies with diffuse Hα emission. We infer that compact emission results from tidally induced star formation, while diffuse emission results from more normal disc star formation. After considering field contamination, we adopt as a ‘predominantly cluster’ sample the spiral population inside 0.5 rA; a ‘predominantly field’ sample outside 0.5 rA; and a ‘pure field’ sample outside 1.5 rA. We consistently find a much larger fraction of spirals detected with compact Hα in the cluster sample compared to the field samples (e.g. 38 versus 0 per cent detected in cluster and ‘pure field’ samples, χ2 significance 3.6 σ). This increased fraction detected in the cluster is found for early-, mid- and late-type spirals separately. No such cluster/field differences are found for galaxies with diffuse Hα emission. We conclude that tidal perturbations are more common in the cluster than in the field, leading to a higher incidence of compact tidally triggered star formation. By combining information on galaxy disturbance, galaxy companions, and the location of galaxies within the cluster, we have tried to identify the origin of the tidal perturbations. We find strong evidence that near-neighbour interaction plays a significant role in triggering star formation. However, we also find candidate objects near the cluster core which may be perturbed by the overall cluster tidal field, and candidate objects which may be influenced by a higher speed ‘harassment’ interaction between galaxies.
Continuous and discrete state estimation with error covariance assignment

A novel method of state estimator design is presented for linear continuous and discrete-time systems with white noise inputs. This method provides a closed-form solution for directly assigning the steady-state estimation error covariance. The assignability conditions are interpreted using system theoretical concepts. A robustness property of such estimators is also pointed out. <<ETX>>
Spectra and minimum distances of repeat multiple accumulate codes

In this paper we consider ensembles of codes, denoted RAm, obtained by a serial concatenation of a repetition code and m accumulate codes through uniform random inter-leavers. We analyze their average spectrum functions for each m showing that they are equal to 0 below a threshold distance isinm and positive beyond it. One of our main results is to prove that these average spectrum functions form a not-increasing sequence in m converging uniformly to a limit spectrum function which is equal to the maximum between the average spectrum function of the classical linear random ensemble and 0. As a consequence the sequence isinm converges to the Gilbert-Varshamov distance. A further analysis allows to conclude that the threshold distance isinm is indeed the typical distance of the ensemble RAm when the interleaver length goes to infinity. Combining the two results we are able to conclude that the typical distance of the ensembles RAm converges to the Gilbert-Varshamov bound.