Miracle-dz/UniFAR-FTUs huggingface dataset:
Quantitative Evidence on Overlooked Aspects of Enrollment Speaker Embeddings for Target Speaker Separation

Single channel target speaker separation (TSS) aims at extracting a speaker’s voice from a mixture of multiple talkers given an enrollment utterance of that speaker. A typical deep learning TSS framework consists of an upstream model that obtains enrollment speaker embeddings and a downstream model that performs the separation conditioned on the embeddings. In this paper, we look into several important but overlooked aspects of the enrollment embeddings, including the suitability of the widely used speaker identification embeddings, the introduction of the log-mel filterbank and self-supervised embeddings, and the embeddings’ cross-dataset generalization capability. Our results show that the speaker identification embeddings could lose relevant information due to a sub-optimal metric, training objective, or common pre-processing. In contrast, both the filterbank and the self-supervised embeddings preserve the integrity of the speaker information, but the former consistently out-performs the latter in a cross-dataset evaluation. The competitive separation and generalization performance of the previously over-looked filterbank embedding is consistent across our study, which calls for future research on better upstream features.
Ferromagnetic semiconducting behavior of Mn1-xCrxTe compounds

The magnetic and electrical transport properties of ferromagnetic semiconductor Mn1�xCrxTe x = 0.04, 0.08, and 0.14 compounds have been investigated. These compounds have ferromagnetic behavior with hysteresis loops showing a coercivity of 300– 985 Oe at 5 K. The hysteresis loop is observed even at room temperature for Mn0.86Cr0.14Te. The substitution of Cr for Mn leads to a change from an antiferromagnetic state of MnTe to a ferromagnetic or ferrimagnetic state of Mn1�xCrxTe. Moreover, the incorporation of Cr into the host antiferromagnetic semiconductor MnTe lattice is confirmed by the structural characterization, which proves further that the ferromagnetic properties are not a result of the secondary phase. The typical feature of the thermally activated conduction processes for semiconductors has been verified by electrical property measurement. DOI: 10.1103/PhysRevB.72. 193308 PACS numbers: 75.50. Pp Ferromagnetic semiconductors are key materials for spin injection in electronic and optoelectronic semiconductor devices, 1 such as spin transistors, polarizing light-emitting diodes, and nonvolatile storage devices 2 that can be controlled by weak magnetic fields. Usually, ferromagnetic semiconductors are obtained by doping magnetic impurities into host non-magnetic semiconductors, such as Mn-Ge, MnSi, Cr-Ge, and Mn-CuO. 3–6 Recently, room temperature ferromagnetism was reported in Mn-GaN, Cr-GaN, Co-TiO2, and Co-ZnO. 7–10 Although the ferromagnetism in those materials was attributed to the expected ferromagnetism of the diluted magnetic semiconductors DMSs on the basis of magnetization measurements and crystallographic studies, it is still doubtful whether the ferromagnetism observed comes from the DMSs or the magnetic precipitates. 11 To obtain a real ferromagnetic semiconductor, it is important to ensure that after the doping, the same/similar crystal structure still exists with certain solid solubility between magnetic impurity and host semiconductor. On the other hand, it is interesting to detect whether any other possibilities exist for realizing a ferromagnetic semiconductor: Could the element substitution for an antiferromagnetic semiconductor induce a change from antiferromagnetic to ferromagnetic or ferrimagnetic state while maintaining its semiconductor behavior?
$\mathbf {SL_2(\bbR)}$, Exponential Herglotz Representations, and Spectral Averaging

We revisit the concept of spectral averaging and point out its origin in connection with one-parameter subgroups of $SL_2(\bbR)$ and the corresponding M\"obius transformations. In particular, we identify exponential Herglotz representations as the basic ingredient for the absolute continuity of average spectral measures with respect to Lebesgue measure and the associated spectral shift function as the corresponding density for the averaged measure. As a by-product of our investigations we unify the treatment of rank-one perturbations of self-adjoint operators and that of self-adjoint extensions of symmetric operators with deficiency indices $(1,1)$. Moreover, we derive separate averaging results for absolutely continuous, singularly continuous, and pure point measures and conclude with an averaging result of the $\kappa$-continuous part (with respect to the $\kappa$-dimensional Hausdorff measure) of singularly continuous measures.
The First Galaxy Cluster Discovered by the VISTA Variables in the Vía Láctea Survey

We report the first confirmed detection of the galaxy cluster VVV-J144321-611754 at very low latitudes (l = 315.°836, b = −1.°650) located in the tile d015 of the VISTA Variables in the Vía Láctea (VVV) survey. We defined the region of 30 × 30 arcmin2 centered in the brightest galaxy finding 25 galaxies. For these objects, extinction-corrected median colors of (H−Ks) = 0.34 ± 0.05 mag, (J−H) = 0.57 ± 0.08 mag, and (J−Ks) = 0.87 ± 0.06 mag; R1/2 = 1.59 ± 0. ″16; C = 3.01 ± 0.08; and Sérsic index n = 4.63 ± 0.39 were estimated. They were visually confirmed showing characteristics of early-type galaxies in the near-IR images. An automatic clustering analysis performed in the whole tile found that the concentration of galaxies VVV-J144321-611754 is a real, compact concentration of early-type galaxies. Assuming a typical galaxy cluster with low X-ray luminosity, the photometric redshift of the brightest galaxy is z = 0.196 ± 0.025. Follow-up near-IR spectroscopy with FLAMINGOS-2 at the Gemini-South telescope revealed that the two brighter cluster galaxies have typical spectra of early-type galaxies and the estimated redshift for the brightest galaxy VVV-J144321.06-611753.9 is z = 0.234 ± 0.022 and that for VVV-J144319.02-611746.1 is z = 0.232 ± 0.019. Finally, these galaxies clearly follow the cluster red sequence in the rest-frame near-IR color–magnitude diagram with a slope similar to a galaxy cluster at a redshift of 0.2. These results are consistent with the presence of a bona fide galaxy cluster beyond the Milky Way disk.
Origin and dynamics of the Primordial Magnetic field in a parity violating plasma

In this thesis, we have studied the generation and evolution of the magnetic field in the early Universe. We investigated the generation of magnetic fields in the presence of chiral symmetry and gravitational anomaly. We have used modified kinetic theory by Berry curvature and derived expressions for magnetic and vortical conductivities. We have also shown that there are two length scales: kinetic and viscous, which is one of the important results. In the latter part of the thesis, we have shown the effect of second-order viscous effects on the modes of the magnetic fields.
Study of nuclear recoils in liquid argon with monoenergetic neutrons

In the framework of developments for liquid argon dark matter detectors we assembled a laboratory setup to scatter neutrons on a small liquid argon target. The neutrons are produced mono-energetically (Ekin = 2.45 MeV) by nuclear fusion in a deuterium plasma and are collimated onto a 3" liquid argon cell operating in single-phase mode (zero electric field). Organic liquid scintillators are used to tag scattered neutrons and to provide a time-of-flight measurement. The setup is designed to study light pulse shapes and scintillation yields from nuclear and electronic recoils as well as from alpha particles at working points relevant for dark matter searches. Liquid argon offers the possibility to scrutinise scintillation yields in noble liquids with respect to the population strength of the two fundamental excimer states. Here we present experimental methods and first results from recent data towards such studies.
Bots, disinformation, and the first impeachment of U.S. President Donald Trump

Automated social media accounts, known as bots, have been shown to spread disinformation and manipulate online discussions. We study the behavior of retweet bots on Twitter during the first impeachment of U.S. President Donald Trump. We collect over 67.7 million impeachment related tweets from 3.6 million users, along with their 53.6 million edge follower network. We find although bots represent 1% of all users, they generate over 31% of all impeachment related tweets. We also find bots share more disinformation, but use less toxic language than other users. Among supporters of the Qanon conspiracy theory, a popular disinformation campaign, bots have a prevalence near 10%. The follower network of Qanon supporters exhibits a hierarchical structure, with bots acting as central hubs surrounded by isolated humans. We quantify bot impact using the generalized harmonic influence centrality measure. We find there are a greater number of pro-Trump bots, but on a per bot basis, anti-Trump and pro-Trump bots have similar impact, while Qanon bots have less impact. This lower impact is due to the homophily of the Qanon follower network, suggesting this disinformation is spread mostly within online echo-chambers.
Instability-driven interfacial dynamo in protoneutron stars

The existence of a tachocline in the Sun has been proven by helioseismology. It is unknown whether a similar shear layer, widely regarded as the seat of magnetic dynamo action, also exists in a protoneutron star. Sudden jumps in magnetic diffusivity η and turbulent vorticity α, for example at the interface between the neutron-finger and convective zones, are known to be capable of enhancing mean-field dynamo effects in a protoneutron star. Here we apply the well-known, plane-parallel, MacGregorCharbonneau analysis of the Solar interfacial dynamo to the protoneutron star problem and calculate the growth rate analytically under a range of conditions. It is shown that, like the Solar dynamo, it is impossible to achieve self-sustained growth if the discontinuities in α, η, and shear are coincident and the magnetic diffusivity is isotropic. In contrast, when the jumps in η and α are situated away from the shear layer, selfsustained growth is possible for P . 49.8 ms (if the velocity shear is located at 0.3R) or P . 83.6 ms (if the velocity shear is located at 0.6R). This translates into stronger shear and/or α-effect than in the Sun. Self-sustained growth is also possible if the magnetic diffusivity if anisotropic, through the × J effect, even when the α, η, and shear discontinuities are coincident.
Vitamin D Deficiency Increases Mortality Risk in the UK Biobank

BACKGROUND Low vitamin D status is associated with increased mortality, but randomized trials on severely deficient participants are lacking. OBJECTIVE To assess genetic evidence for the causal role of low vitamin D status in mortality. DESIGN Nonlinear Mendelian randomization analyses. SETTING UK Biobank, a large-scale, prospective cohort from England, Scotland, and Wales with participants recruited between March 2006 and July 2010. PARTICIPANTS 307 601 unrelated UK Biobank participants of White European ancestry (aged 37 to 73 years at recruitment) with available measurements of 25-hydroxyvitamin D (25-(OH)D) and genetic data. MEASUREMENTS Genetically predicted 25-(OH)D was estimated using 35 confirmed variants of 25-(OH)D. All-cause and cause-specific mortality (cardiovascular disease [CVD], cancer, and respiratory) were recorded up to June 2020. RESULTS There were 18 700 deaths during the 14 years of follow-up. The association of genetically predicted 25-(OH)D with all-cause mortality was L-shaped (P for nonlinearity < 0.001), and risk for death decreased steeply with increasing concentrations until 50 nmol/L. Evidence for an association was also seen in analyses of mortality from cancer, CVD, and respiratory diseases (P ≤ 0.033 for all outcomes). Odds of all-cause mortality in the genetic analysis were estimated to increase by 25% (odds ratio, 1.25 [95% CI, 1.16 to 1.35]) for participants with a measured 25-(OH)D concentration of 25 nmol/L compared with 50 nmol/L. LIMITATIONS Analyses were restricted to a White European population. A genetic approach is best suited to providing proof of principle on causality, whereas the strength of the association is approximate. CONCLUSION Our study supports a causal relationship between vitamin D deficiency and mortality. Additional research needs to identify strategies that meet the National Academy of Medicine's guideline of greater than 50 nmol/L and that reduce the premature risk for death associated with low vitamin D levels. PRIMARY FUNDING SOURCE National Health and Medical Research Council.
Application of biochar and organic fertilizer to saline‐alkali soil in the Yellow River Delta: Effects on soil water, salinity, nutrients, and maize yield

Soil salinization is a global problem that limits agricultural productivity and sustainable development. As waste‐derived soil amendments, biochar and organic fertilizer have garnered considerable attention for their ability to improve soil physicochemical properties and contribution to agricultural waste resource recovery. However, comparable data on the effects of biochar and organic fertilizers on the physicochemical properties of saline‐alkali soils are lacking. Therefore, we applied biochar (B1: 5 t ha−1 year−1; B2: 10 t ha−1 year−1; and B3: 20 t ha−1 year−1) and organic fertilizer (OF1: 7.5 t ha−1 year−1 and OF2: 10 t ha−1 year−1) to saline‐alkali soil in the Yellow River Delta (YRD), China, continuously for 3 years. Because of the influence of their application on soil fertility and water‐salt status, maize yield increased by 55.01–62.51% and 15.01–26.67% for the biochar and organic fertilizer treated soils, respectively. Biochar and organic fertilizer increased soil water content, Ca2+, Mg2+, total phosphorus, available phosphorus, total nitrogen, NO3− ‐N, NH4+ ‐N, organic matter, and microbial biomass carbon and nitrogen, while decreasing the sodium adsorption ratio and soil pH. Compared with CK, Na+ and soil salt content were reduced by 3.83–8.16% and 2.45–12.08%, respectively, under biochar treatments and increased by 2.19–5.34% and 12.95–20.02%, respectively, under organic fertilizer treatments. Principal component analysis showed that biochar was more effective than organic fertilizer in increasing SWC and reducing salinity and Na+. Based on the evidence of this study, biochar presents an eco‐friendly agricultural strategy for improving saline‐alkali soils and increasing maize yield in the YRD.
hCOSMOS: A Dense Spectroscopic Survey of r ≤ 21.3 Galaxies in the COSMOS field

We describe the hCOSMOS redshift survey of the COSMOS field conducted with the Hectospec spectrograph on the MMT. In the central 1 deg2, the hCOS20.6 subset of the survey is complete to a limiting magnitude r = 20.6. The hCOSMOS survey includes 1701 new redshifts in the COSMOS field. We also use the total of 4362 new and remeasured objects to derive the age-sensitive index over the entire redshift interval . For 85% of the quiescent galaxies in hCOS20.6, we measure the central line-of-sight velocity dispersion. To explore potential uses of this survey, we combine previously measured galaxy sizes, profiles, and stellar masses with the spectroscopy. The comparison reveals the known relations among structural, kinematic, and stellar population properties. We also compare redshift and distributions of hCOS20.6 galaxies with SHELS; a complete spectroscopic survey of 4 deg2 observed to the same depth. The redshift distributions in the two fields are very different, but the distribution is remarkably similar. The relation between velocity dispersion and stellar mass for massive hCOS20.6 galaxies is consistent with the local relation from the Sloan Digital Sky Survey. Using measured velocity dispersions, we test a photometric proxy calibrated to galaxies in the local universe. The systematic differences between the measured and photometric proxy velocity dispersions are correlated with galaxy dynamical and stellar population properties highlighting the importance of direct spectroscopic measurements.
Precision Distances to Dwarf Galaxies and Globular Clusters from Pan-STARRS1 3π RR Lyrae

We present new spatial models and distance estimates for globular clusters and dwarf spheroidals orbiting our Galaxy based on RR Lyrae (RRab) stars in the Pan-STARRS1 (PS1) 3π survey. Using the PS1 sample of RRab stars from Sesar et al. in 16 globular clusters and 5 dwarf galaxies, we fit structural models in (l, b, D) space; for 13 globular clusters and 6 dwarf galaxies, we give only their mean heliocentric distance D. We verify the accuracy of the period–luminosity relations used in Sesar et al. to constrain the distance to those stars, and compare them to period–luminosity–metallicity relations using metallicities from Carretta et al. We compare our Sesar et al. distances to the parallax-based Gaia DR2 distance estimates from Bailer-Jones et al. and find our distances to be consistent and considerably more precise.
Random Geometric Graphs

Random geometric graphs are built by first sampling a set of points from some underlying distribution, and then connecting each point to its k nearest neighbors. In this project we investigated the behavior of distance functions on random geometric graphs when the sample size n goes to infinity (and the connectivity parameter k scales appropriately). It is well known that in graphs where the edges are suitably weighted according to their Euclidean lengths, the shortest path distance converges to the underlying Euclidean distance. However, it turned out this is not the case for unweighted kNN graphs [461]. In this case, the shortest path distance converges to a distance function that is weighted by the underlying density and takes wide detours to avoid high density regions (see left figure above). In machine learning applications, this behavior of the shortest path distance can be highly misleading. As an example, consider the Isomap algorithm and the data set shown in the middle figure. If we build an unweighted kNN graph based on this data and apply Isomap to recover the point configuration, we get the figure on the right. Obviously, it is grossly distorted and cannot serve as a faithful representation of the original data. The commute distance (aka resistance distance) between vertex u and v is defined as the expected time it takes the natural random walk starting in vertex u to travel to vertex v and back. It is widely used in machine learning because it supposedly satisfies the following, highly desirable property: Vertices in the same cluster of the graph have a small commute distance, whereas vertices in different clusters of the graph have a large commute distance to each other. We studied the behavior of the commute distance as the number of vertices in the graph tends to infinity [599], proving that the commute distance between two points converges to a trivial quantity that only takes into account the degree of the two vertices. Hence, all information about cluster structure gets lost when the graph is large enough. To alleviate this shortcoming, we proposed the family of p-resistances [497]. For p = 1 it reduces to the shortest path distance, for p = 2 it coincides with the resistance distance, and for p → ∞ it is related to the minimal s-t-cut in the graph. The family shows an interesting phase transition: there exist two critical thresholds p∗ and p∗∗ such that if p < p∗, then the p-resistance depends on meaningful global properties of the graph, whereas if p > p∗∗, it only depends on trivial local quantities and does not convey any useful information. In particular, the p-resistance for p = p∗ nicely reveals the cluster structure.
Angular Correlation Function of Fmnt Galaxies

The angular correlation function has been computed for a two-color survey of faint galaxies (J < 24, F < 23) covering a ∼2.4 deg 2 area near the North Galactic Pole. Faint galaxies are found to belong to a population that is more weakly clustered than luminous nearby galaxies, by a factor ≥ 2 at J = 22 and ≥ 4 at J = 24. Objects selected in the F (red) band are closer to model predictions than those observed in the J band. These observations are interpreted in terms of models in which (weakly clustered) bursting dwarf galaxies comprise the bulk of the number counts at faint magnitudes
Chandra Detection of the First X-Ray Forest along the Line of Sight to Markarian 421

We present the first ≥3.5 (conservative) or ≥5.8 σ (sum-of-lines significance) detection of two warm-hot intergalactic medium (WHIM) filaments at z > 0, which we find along the line of sight to the blazar Mrk 421. These systems are detected through highly ionized resonant metal absorption in high-quality Chandra ACIS and HRC Low Energy Transmission Grating (LETG) spectra of Mrk 421, obtained following our two Target of Opportunity requests during two outburst phases (F0.5-2 keV = 40 and 60 mcrab; 1 crab = 2 × 10-8 ergs s-1 cm-2). Columns of He-like oxygen and H-like nitrogen can be detected in the co-added LETG spectrum of Mrk 421 down to a sensitivity of N ≥ 8 × 1014 cm-2 and N ≥ 1015 cm-2, respectively, at a significance ≥3 σ. The two intervening WHIM systems that we detect have O VII and N VII columns of N = (1.0 ± 0.3) × 1015 cm-2, N = (0.8 ± 0.4) × 1015 cm-2 and N = (0.7 ± 0.3) × 1015 cm-2, N = (1.4 ± 0.5) × 1015 cm-2, respectively. We identify the closest of these two systems with an intervening WHIM filament at cz = 3300 ± 300 km s-1. The second system, instead, at cz = 8090 ± 300 km s-1, is identified with an intervening WHIM filament located ~13 Mpc from the blazar. The filament at cz = 3300 ± 300 lies ≲5 Mpc from a known H I Lyα system at cz = 3046 ± 12 km s-1 (Shull and coworkers) whose 3 σ maximal H I kinetic temperature, as derived from the observed line FWHM, is T ≤ 1.2 × 105 K. This temperature is inconsistent with the temperature measured for the X-ray filament, so if the systems are related, a multiphase WHIM is required. Combining UV and far-ultraviolet (FUV) upper limits on the H I Lyα and the O VI2s→2p transitions with our measurements in the X-rays, we show that, for both filaments, equilibrium collisional ionization (with residual photoionization by both the diffuse UV and X-ray background and the beamed emission of Mrk 421 along our line of sight) provides acceptable solutions. These solutions define ranges of temperatures, metallicity ratios, and equivalent H column densities, which are in good agreement with the predictions of hydrodynamical simulations for the formation of large-scale structures in the universe. From the detected number of WHIM filaments along this line of sight we can estimate the number of O VII filaments per unit redshift with columns larger than 7 × 1014 cm-2, d𝒩/dz(N ≥ 7 × 1014) = 67, consistent, within the large 1 σ errors, with the hydrodynamical simulation predictions of d𝒩/dz(N ≥ 7 × 1014) = 30. Finally, we measure a cosmological mass density of X-ray WHIM filaments Ωb = 0.027 × 10, consistent with both model predictions and the estimated number of "missing" baryons at low redshift.
Gauge invariance and the interpretation of inter- and intraband processes in high-order harmonic generation from bulk solids

A theoretical model for high-order harmonic generation (HHG) in bulk solids is considered. Our approach treats laser-induced interand intraband currents on an equal footing. The sum of these currents is the source of the high-order harmonic radiation, and does not depend on the particular electromagnetic gauge we choose to describe the process. On the other hand, as it is shown using analytic and numerical calculations, the distinction between intraand interband dynamics is gauge dependent, implying that the interpretation of the process of HHG using these terms requires carefulness.