Miracle-dz/UniFAR-FTUs huggingface dataset:
DOA estimation of speech source in noisy environments with weighted spatial bispectrum correlation matrix

Although the high order statistics (HOS) has promising property against the Gaussian noise, there still lack effective ways to apply the HOS to DOA estimation of the speech source. In this paper, we propose a novel HOS based DOA estimation method for speech source in strong noise conditions. A “weighted spatial bispectrum correlation matrix (WSBCM)” is formulated, which contains the spatial correlation information of bispectrum phase differences. We then propose a new DOA estimator based on the eigenvalue analysis of the WS-BCM. Besides the theoretical advantage of the bispectrum against Gaussian noises, the redundant information in the bispectrum domain is also exploited to make the WSBCM noise robust. The WSBCM enables bispectrum weighting to select the speech units in the bispectrum, which further helps to improve the performance. Experimental results demonstrate that the proposed method outperforms existing algorithms in different kinds of noisy environments.
Microglial response to N‐methyl‐D‐aspartate‐mediated excitotoxicity in the immature rat brain

The intracerebral injection of N‐methyl‐D‐aspartate (NMDA) has been proposed as a model for hypoxic‐ischemic insult in the immature brain. In this light, the aim of this study was to describe the time course of the microglial reaction in the areas undergoing primary degeneration at the site of intracortical NMDA injection as well as in areas undergoing secondary anterograde and/or retrograde degeneration. Fifty nanomoles of NMDA were injected in the sensorimotor cortex of 6‐day‐old rats. After survival times ranging from 10 hours to 28 days, cryostat sections were stained for routine histology and for the demonstration of microglial cells by means of tomato lectin histochemistry.
On the Beauty and Usability of Tag Clouds

Tag clouds are text-based visual representations of a set of tags usually depicting tag importance by font size. Recent trends in social and collaborative software have greatly increased the popularity of this type of visualization. This paper proposes a family of novel algorithms for tag cloud layout and presents evaluation results obtained from an extensive user study and a technical evaluation. The algorithms address issues found in many common approaches, for example large whitespaces, overlapping tags and restriction to specific boundaries. The layouts computed by these algorithms are compact and clear, have small whitespaces and may feature arbitrary convex polygons as boundaries. The results of the user study and the technical evaluation enable designers to devise a combination of algorithm and parameters which produces satisfying tag cloud layouts for many application scenarios.
In situ observation of graphene sublimation and multi-layer edge reconstructions

We induced sublimation of suspended few-layer graphene by in situ Joule-heating inside a transmission electron microscope. The graphene sublimation fronts consisted of mostly {1100} zigzag edges. Under appropriate conditions, a fractal-like “coastline” morphology was observed. Extensive multiple-layer reconstructions at the graphene edges led to the formation of unique carbon nanostructures, such as sp2-bonded bilayer edges (BLEs) and nanotubes connected to BLEs. Flat fullerenes/nanopods and nanotubes tunneling multiple layers of graphene sheets were also observed. Remarkably, >99% of the graphene edges observed during sublimation are BLEs rather than monolayer edges (MLEs), indicating that BLEs are the stable edges in graphene at high temperatures. We reproduced the “coastline” sublimation morphologies by kinetic Monte Carlo (kMC) simulations. The simulation revealed geometrical and topological features unique to quasi-2-dimensional (2D) graphene sublimation and reconstructions. These reconstructions were enabled by bending, which cannot occur in first-order phase transformations of 3D bulk materials. These results indicate that substrate of multiple-layer graphene can offer unique opportunities for tailoring carbon-based nanostructures and engineering novel nano-devices with complex topologies.
Atmospheric noble gases in lake sediment pore water as proxies for environmental change

Lake sediment pore water has been proposed as a noble gas archive for paleoenvironmental reconstruction, but appropriate experimental techniques have not been available until recently. Here we present noble gas concentrations measured in the sediment pore water of Lake Issyk‐Kul (Kyrgyzstan) which demonstrate for the first time the value of the sediment pore water archive for paleoclimate reconstruction. The noble gas profiles in the sediment indicate that the salinity of the lake water during the mid‐Holocene was more than twice its present value of 6.0 g/kg, implying a 200‐m lower lake level.
P-STAT1 mediates higher-order chromatin remodelling of the human MHC in response to IFNγ

Transcriptional activation of the major histocompatibility complex (MHC) by IFNγ is a key step in cell-mediated immunity. At an early stage of IFNγ induction, chromatin carrying the entire MHC locus loops out from the chromosome 6 territory. We show here that JAK/STAT signalling triggers this higher-order chromatin remodelling and the entire MHC locus becomes decondensed prior to transcriptional activation of the classical HLA class II genes. A single point mutation of STAT1 that prevents phosphorylation is sufficient to abolish chromatin remodelling, thus establishing a direct link between the JAK/STAT signalling pathway and human chromatin architecture. The onset of chromatin remodelling corresponds with the binding of activated STAT1 and the chromatin remodelling enzyme BRG1 at specific sites within the MHC, and is followed by RNA-polymerase recruitment and histone hyperacetylation. We propose that the higher-order chromatin remodelling of the MHC locus is an essential step to generate a transcriptionally permissive chromatin environment for subsequent activation of classical HLA genes.
Illumination transition image: Parameter-based illumination estimation and re-rendering

Varying illumination condition is a challenging problem for face recognition and synthesis. The illumination re-rendering technique allows aligning the illumination effects of facial images or relighting them as expected. In this paper, we propose an improved illumination re-rendering method based on more accurate mapping of facial images in the parametric illumination space. This will make the parameter-based illumination alignment more reliable. A clustering-based criterion is designed to evaluate its parameter estimation precision. To guide the image re-rendering between any a parameter pair, an intermediate image called the illumination transition image (ITI) is defined to represent both the illumination variation information and the person-specific facial shape features. The extensive experimental results verify the proposed method outperforms the quotient image approach on both parameter precision and rendering quality.
Serotonin Modulation of Inferior Olivary Oscillations and Synchronicity: A Multiple‐electrode Study in the Rat Cerebellum

Simultaneous recording of complex spikes from multiple Purkinje cells (up to 44) in the rat cerebellum was used to examine the effects of 5‐hydroxytryptamine (serotonin, 5‐HT) on olivocerebellar function. Microinjection into the inferior olive was found to increase the average firing rate of inferior olivary neurons while slowing their oscillation frequency and increasing the coherence of their oscillations. Indeed, while the normal rostrocaudal band of synchronous activity remained unchanged, the degree of synchrony between Purkinje cell complex spikes within this band was enhanced following the 5‐HT injections. Multiple‐electrode recordings obtained from crus Ha and vermal lobule Vlb yielded qualitatively similar results; however, the effects on vermal activity were more pronounced. The effects of the 5‐HT microinjection decayed with a time course of 75 min. The half‐maximum effective concentration of 5‐HT was between 10 and 100 μM. Injections of various 5‐HT agonists and antagonists demonstrated that a 5‐HT type‐2A (5‐HT2A) receptor is the main mediator for the 5‐HT effect, which was very similar to the effect produced by injections of harmaline. However, 5‐HT and harmaline appear to have independent mechanisms since the action of harmaline was not blocked by the 5‐HT2A antagonist LY53857. A possible role for 5‐HT, as a physiological enhancer of the timing of motor function of the olivocerebellar system, is discussed.
Attracted to open access journals: a bibliometric author analysis in the field of biology

Purpose – Scholars from developing countries have limited access to research publications due to expensive subscription costs. However, the open access movement is challenging the constraint to access. Consequently, researchers in developing countries are often mentioned as major recipients of the benefits when advocating open access (OA). One of the implications of that argument is that authors from developing countries are more likely to perceive open access positively than authors from developed countries. The present study aims to investigate the use of open access by researchers from developing countries and is thus a supplement to the existing author surveys and interviews.Design/methodology/approach – Bibliometric analyses of both publishing behaviour and citing behaviour in relation to OA publishing provides evidence of the impact of open access on developing countries.Findings – The results of the multivariate linear regression show that open access journals are not characterised by a different c.
Discovering potential user browsing behaviors using custom-built apriori algorithm

Most of the organizations put information on the web because they want it to be seen by the world. Their goal is to have visitors come to the site, feel comfortable and stay a while and try to know completely about the running organization. As educational system increasingly requires data mining, the opportunity arises to mine the resulting large amounts of student information for hidden useful information (patterns like rule, clustering, and classification, etc). The education domain offers ground for many interesting and challenging data mining applications like astronomy, chemistry, engineering, climate studies, geology, oceanography, ecology, physics, biology, health sciences and computer science. Collecting the interesting patterns using the required interestingness measures, which help us in discovering the sophisticated patterns that are ultimately used for developing the site. We study the application of data mining to educational log data collected from Guru Nanak Institute of Technology, Ibrahimpatnam, India. We have proposed a custom-built apriori algorithm to find the effective pattern analysis. Finally, analyzing web logs for usage and access trends can not only provide important information to web site developers and administrators, but also help in creating adaptive web sites.
Stability metric based routing protocol for low-power and lossy networks

To design a routing protocol for applications over low-power and lossy networks (LLNs), the IETF ROLL Working Group standardized the IPv6 Routing Protocol for LLNs (RPL), which organizes nodes in a LLN into a tree-like topology called Destination Oriented Directed Acyclic Graph (DODAG). RPL shows good scalability and fast network setup. However, it may suffer from severe unreliability due to the selection of suboptimal routes with low quality links. To optimize the reliability of RPL routes, this paper proposes a stability metric based routing protocol named sRPL for reliable routing and data collection in LLNs. We introduce a new routing metric for RPL called stability index (SI), which exploits stability characteristics of RPL nodes to select more stable routes. In addition, we present a passive and lightweight network layer technique to measure the bi-directional expected transmission count (ETX) for wireless links in LLNs. As a use case of SI, we combine SI metric with ETX metric to make routing decisions. Simulation results show that sRPL can improve packet delivery rate of RPL routing protocol by 20%.
Subpixel edge localization and the interpolation of still images

In this paper, we present a nonlinear interpolation scheme for still image resolution enhancement. The algorithm is based on a source model emphasizing the visual integrity of detected edges and incorporates a novel edge fitting operator that has been developed for this application. A small neighborhood about each pixel in the low-resolution image is first mapped to a best-fit continuous space step edge. The bilevel approximation serves as a local template on which the higher resolution sampling grid can then be superimposed (where disputed values in regions of local window overlap are averaged to smooth errors). The result is an image of increased resolution with noticeably sharper edges and, in all tried cases, lower mean-squared reconstruction error than that produced by linear techniques.
What Do Deep Statistical Analyses on Gaming Motivation and Game Characteristics Clusters Reveal About Targeting Demographics when Designing Gamified Contents ?

This paper presents the comprehensive results of the study of a cohort of college graduate and undergraduate students who participated in playing a Massively Multiplayer Online Role Playing Game (MMORPG) as a gameplay rich with social interaction as well as intellectual and aesthetic features. We present the full results of the study in the form of inferential statistics and a review of our descriptive statistics previously reported in [46]. Separate one-way independent-measures multivariate analysis of variance (MANOVA)'s were used to analyze the data from several instruments to determine if there were statistically significant differences first by gender, then by age group, and then by degree. Moreover, a one-way repeated-measures analysis of variance (ANOVA) was used to determine if there was a statistically significant difference between the clusters in the 5 gaming clusters on the Game Characteristic Survey. Follow-up paired samples t-tests were used to see if there was a statistically significant difference between each of the 10 possible combinations of paired clusters. Our results support the hypotheses and outline the features that may need to be taken into account in support of tailoring gamified educational content targeting a certain demographic. Sections 1, 2, and 3 below from our pervious study [46] are included because this is the second part of the two-part study.
The Relation between Price Changes and Trading Volume: A Study in Indian Stock Market

This study investigates the dynamic relationship between stock return and trading volume of Indian stock Market by using Bivariate Regression model, VECM Model, VAR, IRF and Johansen’s Co integration test. The study shows that there is a bi-directional causality between trading volume and stock return volatility. Again the study used Variance Decomposition technique to compare the degree of explanatory power of the trading volume over stock return and the evidence supports the influential role of the trading volume in the Indian stock market. Further Johansen’s co integration analysis demonstrates that stock return is co integrated with the trading volume indicating long-run equilibrium relationship. The study concludes that stock price changes in any direction have information content for upcoming trading activities.
Growth Factor-mediated Signaling and Growth-negative MCF-7 Cells Restores both Estrogen and Insulin-like α in Estrogen Receptor α Re-expression of Estrogen Receptor Updated

Estrogen can increase insulin-like growth factor-I receptor (IGF-IR) and insulin receptor substrate-1 (IRS-1) expression, two key components of IGF-I-mediated signaling. The result is sensitization of breast cancer cells to IGF-I and synergistic growth in the presence of estrogen and IGF-I. We hypothesized that loss of estrogen receptora (ERa) would result in reduced IGF-mediated signaling and growth. To test this hypothesis, we examined IGF-I effects in MCF-7 breast cancer cell sublines that have been selected for loss of ER a (C4 and C4-12 cells are ERa-negative) by long-term estrogen withdrawal. C4 and C4-12 cells had reduced IGF-IR and IRS-1 mRNA and protein expression (compared with MCF-7 cells) that was not inducible by estrogen. Furthermore, C4 and C4-12 cells showed reduced IGF-I signaling and failed to show any growth response to either estrogen or IGF-I. To prove that loss of IGF and estrogenmediated signaling and growth was a consequence of loss of ER a, we re-expressed ERa in C4-12 cells by stable transfection with HA-tagged ERa. Three independent C4-12 ERa-HA clones expressed a functional ERa that (a) was down-regulated by estrogen, (b) conferred estrogeninduction of cyclin D1 expression, and (c) caused estrogen-mediated increase in the number of cells in S phase. All of the effects were completely blocked by antiestrogens. Interestingly, ERa-HA expression in C4-12 cells did not restore estrogen induction of progesterone receptor expression. However, ERa-positive C4-12 cells now exhibited estrogen-induction of IGF-IR and IRS-1 levels and responded mitogenically to both estrogen and IGF-I. These data show that ERa is a critical requirement for IGF signaling, and to our knowledge this is the first report of functional ERa expression that confers estrogen-mediated growth of an ER-negative breast cancer cell line.
Differential Post-Surgical Metastasis and Survival in SCID, NOD-SCID and NOD-SCID-IL-2Rγnull Mice with Parental and Subline Variants of Human Breast Cancer: Implications for Host Defense Mechanisms Regulating Metastasis

We compare for the first time, the metastatic aggressiveness of the parental MDA-MB-231 breast cancer cell line and two luciferase-tagged in vivo-derived and selected pro-metastatic variants (LM2-4/luc+ and 164/8-1B/luc+) in SCID, NOD-SCID and NOD-SCID-IL-2Rγnull (NSG) mice following orthotopic implantation and primary tumour resection. The variants are known to be more aggressively metastatic in SCID mice, compared to the parental line which has limited spontaneous metastatic competence in these mice. When 2×106 cells were injected into the mammary fat pad, the growth of the resultant primary tumours was identical for the various cell lines in the three strains of mice. However, metastatic spread of all three cell lines, including the MDA-MB-231 parental cell line, was strikingly more aggressive in the highly immunocompromised NSG mice compared to both NOD-SCID and SCID mice, resulting in extensive multi-organ metastases and a significant reduction in overall survival. While these studies were facilitated by monitoring post-surgical spontaneous metastases using whole body bioluminescence imaging, we observed that the luciferase-tagged parental line showed altered growth and diminished metastatic properties compared to its untagged counterpart. Our results are the first to show that host immunity can have a profound impact on the spread of spontaneous visceral metastases and survival following resection of a primary tumour in circumstances where the growth of primary tumours is not similarly affected; as such they highlight the importance of immunity in the metastatic process, and by extension, suggest certain therapeutic strategies that may have a significant impact on reducing metastasis.
Constraining the Evolution of the Ionizing Background and the Epoch of Reionization with z ∼ 6 Quasars. II. A Sample of 19 Quasars

We study the evolution of the ionization state of the intergalactic medium (IGM) at the end of the reionization epoch using moderate-resolution spectra of a sample of 19 quasars at 5.74 < zem < 6.42 discovered in the Sloan Digital Sky Survey. Three methods are used to trace IGM properties: (1) the evolution of the Gunn-Peterson (GP) optical depth in the Lyα, Lyβ, and Lyγ transitions; (2) the distribution of lengths of dark absorption gaps; and (3) the size of H II regions around luminous quasars. Using this large sample, we find that the evolution of the ionization state of the IGM accelerated at z > 5.7: the GP optical depth evolution changes from τ ∼ (1 + z)4.3 to (1 + z)≳11, and the average length of dark gaps with τ > 3.5 increases from <10 to >80 comoving Mpc. The dispersion of IGM properties along different lines of sight also increases rapidly, implying fluctuations by a factor of ≳4 in the UV background at z > 6, when the mean free path of UV photons is comparable to the correlation length of the star-forming galaxies that are thought to have caused reionization. The mean length of dark gaps shows the most dramatic increase at z ∼ 6, as well as the largest line-of-sight variations. We suggest using dark gap statistics as a powerful probe of the ionization state of the IGM at yet higher redshift. The sizes of H II regions around luminous quasars decrease rapidly toward higher redshift, suggesting that the neutral fraction of the IGM has increased by a factor of ≳10 from z = 5.7 to 6.4, consistent with the value derived from the GP optical depth. The mass-averaged neutral fraction is 1%-4% at z ∼ 6.2 based on the GP optical depth and H II region size measurements. The observations suggest that z ∼ 6 is the end of the overlapping stage of reionization and are inconsistent with a mostly neutral IGM at z ∼ 6, as indicated by the finite length of the dark absorption gaps.
A Kinetic Perspective on k-ε Turbulence Model and Corresponding Entropy Production

In this paper, we present an alternative derivation of the entropy production in turbulent flows, based on a formal analogy with the kinetic theory of rarefied gas. This analogy allows for proving that the celebrated \(k - \epsilon\) model for turbulent flows is nothing more than a set of coupled BGK (Bhatnagar–Gross–Krook)-like equations with a proper forcing. This opens a novel perspective on this model, which may help in sorting out the heuristic assumptions essential for its derivation, such as the balance between turbulent kinetic energy production and dissipation. The entropy production is an essential condition for the design and optimization of devices where turbulent flows are involved.
An Overview of Conventional and Emerging Analytical Methods for the Determination of Mycotoxins

Mycotoxins are a group of compounds produced by various fungi and excreted into the matrices on which they grow, often food intended for human consumption or animal feed. The high toxicity and carcinogenicity of these compounds and their ability to cause various pathological conditions has led to widespread screening of foods and feeds potentially polluted with them. Maximum permissible levels in different matrices have also been established for some toxins. As these are quite low, analytical methods for determination of mycotoxins have to be both sensitive and specific. In addition, an appropriate sample preparation and pre-concentration method is needed to isolate analytes from rather complicated samples. In this article, an overview of methods for analysis and sample preparation published in the last ten years is given for the most often encountered mycotoxins in different samples, mainly in food. Special emphasis is on liquid chromatography with fluorescence and mass spectrometric detection, while in the field of sample preparation various solid-phase extraction approaches are discussed. However, an overview of other analytical and sample preparation methods less often used is also given. Finally, different matrices where mycotoxins have to be determined are discussed with the emphasis on their specific characteristics important for the analysis (human food and beverages, animal feed, biological samples, environmental samples). Various issues important for accurate qualitative and quantitative analyses are critically discussed: sampling and choice of representative sample, sample preparation and possible bias associated with it, specificity of the analytical method and critical evaluation of results.