Miracle-dz/UniFAR-FTUs huggingface dataset:
Polymer drag reduction in surfactant-contaminated turbulent bubbly channel flows

Polymer additives are commonly utilized to manipulate bubbly flows in various applications. Here, we investigate the effects of clean and contaminated bubbles driven upwards (upflow) in Newtonian and viscoelastic turbulent channel flows. Interface-resolved direct numerical simulations are performed to examine sole and combined effects of soluble surfactant and viscoelasticity using an efficient 3D finite-difference/front-tracking method. The incompressible flow equations are solved fully coupled with the FENE-P viscoelastic model and the equations governing interfacial and bulk surfactant concentrations. The latter coupling is accomplished by a non-linear equation of state that relates the surface tension to the surfactant concentration. For Newtonian turbulent bubbly flows, the effects of Triton X-100 and 1-Pentanol surfactant are examined. It is observed that the sorption kinetics highly affect the dynamics of bubbly flow. A minute amount of Triton X-100 is found to be sufficient to prevent the formation of bubble clusters restoring the singlephase behavior while even two orders of magnitude more 1-Pentanol surfactant is not adequate to prevent the formation of layers. For viscoelastic turbulent flows, it is found that the viscoelasticity promotes formation of the bubble-wall layers and thus the polymer drag reduction is completely lost for the surfactant-free bubbly flows, while the addition of small amount of surfactant (Triton X-100) in this system restores the polymer drag reduction resulting in 25% drag reduction for the
Vision Transformer based COVID-19 Detection using Chest X-rays

COVID-19 is a global pandemic, and detecting them is a momentous task for medical professionals today due to its rapid mutations. Current methods of examining chest X-rays and CT scan requires profound knowledge and are time consuming, which suggests that it shrinks the precious time of medical practitioners when people’s lives are at stake. This study tries to assist this process by achieving state-of-the-art performance in classifying chest X-rays by fine-tuning Vision Transformer(ViT). The proposed approach uses pretrained models, fine-tuned for detecting the presence of COVID-19 disease on chest X-rays. This approach achieves an accuracy score of 97.61%, precision score of 95.34%, recall score of 93.84% and, fl-score of 94.58%. This result signifies the performance of transformer-based models on chest X-ray.
Special transition and extraordinary phase on the surface of a two-dimensional quantum Heisenberg antiferromagnet

Continuous phase transitions exhibit richer critical phenomena on the surface than in the bulk, because distinct surface universality classes can be realized at the same bulk critical point by tuning the surface interactions. The exploration of surface critical behavior provides a window looking into higher-dimensional boundary conformal field theories. In this work, we study the surface critical behavior of a two-dimensional (2D) quantum critical Heisenberg model by tuning the surface coupling strength, and discover a direct special transition on the surface from the ordinary phase into an extraordinary phase. The extraordinary phase has a long-range antiferromagnetic order on the surface, in sharp contrast to the logarithmic decaying spin correlations in the 3D classical O(3) model. The special transition point has a new set of critical exponents, y_{s}=0.86(4)ys=0.86(4) and \eta_{\parallel}=-0.33(1)η∥=−0.33(1), which are distinct from the special transition of the classical O(3) model and indicate a new surface universality class of the 3D O(3) Wilson-Fisher theory.
Towards High-fidelity Singing Voice Conversion with Acoustic Reference and Contrastive Predictive Coding

Recently, phonetic posteriorgrams (PPGs) based methods have been quite popular in non-parallel singing voice conversion systems. However, due to the lack of acoustic information in PPGs, style and naturalness of the converted singing voices are still limited. To solve these problems, in this paper, we utilize an acoustic reference encoder to implicitly model singing characteristics. We experiment with different auxiliary features, including mel spectrograms, HuBERT, and the middle hidden feature (PPG-Mid) of pretrained automatic speech recognition (ASR) model, as the input of the reference encoder, and finally find the HuBERT feature is the best choice. In addition, we use contrastive predictive coding (CPC) module to further smooth the voices by predicting future observations in latent space. Experiments show that, compared with the baseline models, our proposed model can significantly improve the naturalness of converted singing voices and the similarity with the target singer. Moreover, our proposed model can also make the speakers with just speech data sing.
NIR‐II Excitable Conjugated Polymer Dots with Bright NIR‐I Emission for Deep In Vivo Two‐Photon Brain Imaging Through Intact Skull

Methods for noninvasive brain imaging are highly desirable to study brain structures in neuroscience. Two‐photon fluorescence microscopy (2PFM) with near‐infrared (NIR) light excitation is a relatively noninvasive approach commonly used to study brain with high spatial resolution and large imaging depth. However, most of the current studies require cranial window implantation or skull‐thinning methods due to attenuation of excitation light. 2PFM through intact mouse skull is challenging due to strong scattering induced by skull bone. Herein, NIR‐II light excitable single‐chain conjugated polymer dots (CPdots) with bright fluorescence in NIR‐I region (peak at ≈725 nm and quantum yield of 20.6 ± 1.0%) are developed for deep in vivo two‐photon fluorescence (2PF) imaging of intact mouse brain. The synthesized CPdots exhibit good biocompatibility, high photostability, and large two‐photon absorption cross section. The CPdots allow 2PF images acquired upon excitation at 800, 1040 and 1200 nm with the highest signal‐to‐background ratio of 208 demonstrated for 1200 nm excitation. Moreover, a 3D reconstruction of the brain blood vessel network is obtained with a large vertical depth of 400 µm through intact skull. This work demonstrates great potential of bright NIR fluorophores for in vivo deep tissue imaging.
Solution‐Processed Self‐Powered Transparent Ultraviolet Photodetectors with Ultrafast Response Speed for High‐Performance Communication System

Transparent ultraviolet (UV) photodetectors are an essential component of next‐generation “see‐through” electronics. However, the current photodetectors often suffer from relatively slow response speeds and high driving voltages. Here, all‐solution‐processed UV photodetectors are reported that are facilely prepared from environmentally friendly and abundant materials. The UV photodetectors are composed of a titanium dioxide thin film as the photosensitive layer sandwiched between two different transparent electrodes to form asymmetric Schottky junctions. The photodetector with high optical transparency can operate at zero bias because of spontaneous separation of photogenerated electron–hole pairs by the built‐in electric field. The resulting self‐powered photodetector displays high sensitivity to broadband UV light (200–400 nm). In particular, an ultrafast response speed up to 44 ns is obtained, representing a significant improvement over those of the conventional transparent photodetectors. Moreover, the photodetector has been successfully applied, for the first time, in a UV communication system as the self‐powered signal receiver. This work uniquely combines the features of high optical transparency and self‐power ability into UV photodetectors and would enable a broad range of optoelectronic applications.
The impact of sugarcane filter cake on the availability of P in the rhizosphere and associated microbial community structure

This study aimed to evaluate the interaction between filter cake (FC), and phosphorus fertilizers with differing solubility on the growth and P nutrition of sugarcane. Effects of soil amendment with FC on different soil P fractions and influence on microbial community structure in the rhizosphere were also assessed. Two glasshouse experiments were conducted with completely randomized block designs. The first experiment evaluated rates of FC using a factorial design (5 × 2): 0, 2.5, 5, 10 and 15 g FC kg−1 soil applied as either broadcast in bulk soil or in the planting furrow. The second experiment used a factorial design (2 × 3): without and with FC (5 g kg−1 soil, dry basis), both without P (NP) and with P supplied as either triple superphosphate (TSP) or as rock phosphate (RP), both at the rate of 78.4 mg kg−1 based on total P. Microbial community structure was determined using TRFLP and dynamics of soil P by Hedley fractionation. Filter cake applied at increasing rates in the absence of P was effective in increasing shoot growth and P uptake by plant, particularly when applied to bulk soil as compared to furrow application. Also, FC improved P uptake and increased the availability of labile inorganic P in the rhizosphere and modified the structure of fungal and bacterial communities, whereas only bacterial and archaea communities were influenced by P fertilizer use. Filter cake was more effective when combined with RP, with increased growth and P utilization and thus can be considered as a feasible and practical option for farmer use in substitution to TSP, a more expensive source.
Homopropargyl alcohol 1,1-diphenylbut-3-yn-1-ol

The asymmetric unit of the title compound, C16H14O, contains one molecule with a central carbon atom having a distorted tetrahedral geometry made of a propargylic fragment, a hydroxy group and two aromatic rings. Directional interactions such as unusual O—H. π contacts are observed between the molecules in the crystal.
Hyperglycaemia Lowering Effect of Kaurane Diterpenoids from the Fruits of Xylopia aethiopica (A. Dunal) Rich

Plants have been used for medicinal purposes long before recorded history in different cultures of the world (1). The World Health Organization (WHO) gave a list of about 21,000 plants used for medicinal purposes around the world (21). Plants have the ability to synthesize a wide variety of chemical compounds that possess pharmacological properties and defend against attack from predators such as insects, fungi and herbivorous animals (25,40). About 12,000 of such compounds, representing less than 10 % of the total, have been isolated. These compounds have been found to exert their effects on the human body through mechanisms that are similar to those already established in conventional drugs revealing that herbal medicines may be as effective as the latter (25,41). Furthermore, the plant kingdom is believed to hold many new drug templates; hence, the continued investigation into ethno-medicinal plants (22).
Insights into the impact on daily life of the COVID-19 pandemic and effective coping strategies from free-text analysis of people's collective experiences

There has been considerable speculation regarding how people cope during the COVID-19 pandemic; however, surveys requiring selection from prespecified answers are limited by researcher views and may overlook the most effective measures. Here, we apply an unbiased approach that learns from people's collective lived experiences through the application of natural-language processing of their free-text reports. At the peak of the first lockdown in the United Kingdom, 51 113 individuals provided free-text responses regarding self-perceived positive and negative impact of the pandemic, as well as the practical measures they had found helpful during this period. Latent Dirichlet Allocation identified, in an unconstrained data-driven manner, the most common impact and advice topics. We report that six negative topics and seven positive topics are optimal for capturing the different ways people reported being affected by the pandemic. Forty-five topics were required to optimally summarize the practical coping strategies that they recommended. General linear modelling showed that the prevalence of these topics covaried substantially with age. We propose that a wealth of coping measures may be distilled from the lived experiences of the general population. These may inform feasible individually tailored digital interventions that have relevance during and beyond the pandemic.
Complement Potentiates Immune Sensing of HIV-1 and Early Type I Interferon Responses

Importantly, our study highlights an unusual target on DCs—the α chain of complement receptor 4 (CR4) (CD11c)—for therapeutic interventions in HIV-1 treatment. Targeting CD11c on DCs mediated a potent antiviral immune response via clustering of CR4 and CCR5 and subsequent opening of an antiviral recognition pathway in DCs via MAVS. ABSTRACT Complement-opsonized HIV-1 triggers efficient antiviral type I interferon (IFN) responses in dendritic cells (DCs), which play an important role in protective responses at the earliest stages in retroviral infection. In contrast, HIV-1 suppresses or escapes sensing by STING- and MAVS-associated sensors. Here, we identified a complement receptor-mediated sensing pathway, where DCs are activated in CCR5/RLR (RIG-I/MDA5)/MAVS/TBK1-dependent fashion. Increased fusion of complement-opsonized HIV-1 via complement receptor 4 and CCR5 leads to increased incoming HIV-1 RNA in the cytoplasm, sensed by a nonredundant cooperative effect of RIG-I and MDA5. Moreover, complement-opsonized HIV-1 down-modulated the MAVS-suppressive Raf-1/PLK1 pathway, thereby opening the antiviral recognition pathway via MAVS. This in turn was followed by MAVS aggregation and subsequent TBK1/IRF3/NF-κB activation in DCs exposed to complement- but not non-opsonized HIV-1. Our data strongly suggest that complement is important in the induction of efficient antiviral immune responses by preventing HIV-1 suppressive mechanisms as well as inducing specific cytosolic sensors. IMPORTANCE Importantly, our study highlights an unusual target on DCs—the α chain of complement receptor 4 (CR4) (CD11c)—for therapeutic interventions in HIV-1 treatment. Targeting CD11c on DCs mediated a potent antiviral immune response via clustering of CR4 and CCR5 and subsequent opening of an antiviral recognition pathway in DCs via MAVS. This novel finding might provide novel tools for specifically boosting endogenous antiviral immunity via CR4, abundantly expressed on multiple DC subsets.
Institutional Blockholders and Voluntary Disclosure

We study how institutional blockholdings affect firm voluntary disclosure. We document that concentrated institutional ownership reduces firms’ voluntary disclosure measured by the propensity to issue management forecasts, comprehensiveness of guidance, propensity to engage in conference calls, and the number of 8-K filings. We identify two channels through which institutional blockholders affect firms’ voluntary disclosure. First, blockholders have easier access to managers and substitute private for public information acquisition. Second, a higher proportion of non-monitoring blockholders with low demand for voluntary disclosure, such as passive blockholders, reduces the firm’s incentive to provide voluntary disclosure. The results are robust to endogeneity and reverse causality concerns. Our study identifies an important effect that concentrated ownership has on firm corporate disclosure.
A Taxonomy of Major Premises and Implications for Falsification and Verification

ABSTRACT Both naïve and sophisticated falsification arguments depend upon using the logic of modus tollens to employ empirical defeats to conclude that the theory is not true (naïve falsification) or that the conjunction of theory and auxiliary assumptions is not true (sophisticated falsification). However, both types of modus tollens syllogisms depend strongly on the precise form of the major premise. The present goal is to introduce a taxonomy of four types of major premises: positive frame, negative frame, positive-negative frame, and negative-positive frame. For two frames, falsification really is logically superior to verification, but for two other frames, verification is logically superior to falsification. Thus, there is no overall logical basis for preferring falsification to verification or for preferring verification to falsification. Nor are there convincing arguments from Bayesian statistical, frequentist statistical, or empirical standpoints. Thus, the attraction of falsification, whether naïve or sophisticated, comes down, in the end, to something other than an objective philosophical account.
Information Sharing in Procurement Contracting with Multiple Suppliers and Input Interdependencies

This paper analyzes a procurement situation where a manufacturer decides on sharing proprietary information with suppliers of complementary components when these components are commonly used for several products. I find that the interdependencies have profound impact on the manufacturer's information sharing strategy. The manufacturer may engage in selective information sharing, making demand or cost information accessible to one supplier but concurrently withholding the same information from a second, complementary input supplier. Information sharing to the second supplier is intermediate whereas concealment is two-tailed. Selective information sharing arises because in light of component interdependencies the disclosure strategy causes two competing forces – lowering one component's costs versus increasing the other's costs.
New Documentary of Acid-Stable Glutaminase Production by an Efficient Acidophilic Aspergillus niger CPGM 1439

Samples for isolation were taken from natural spoiled salted foods. All acidophilic isolates were subjected under comparison for finding the most potent glutaminase producing one. Optimization of the produced enzyme was done in the light of seven environmental and five nutritional factors including incubation time, temperature, pH, buffer system, static and different shaking speeds conditions, dark and light conditions, different inoculum size, additional carbon sources, additional nitrogen sources, heavy metals, vitamins, amino acids. Five fungal isolates have been selected and were tested for their ability to grow on L- glutamine containing medium at pH 3 and 2. Only 5 fungal isolates (F1.a, F2.a, F3.a, F4.a and F5.a) were able to grow efficiently on pH3, two of them were able to grow also on pH2. The activity of enzyme was measured extracellularly and intracellularly for each isolate and were 20.34, (2.68), 17.8, (0.423), 5.77, (5.77), 10.27, (1.39), 2.28 and (0.071) U/mL respectively. The highest enzyme activity producing isolate (F1.a) was selected and identified genetically. It was found to be closely related to Aspergillus niger strain CPGM 1439 with 93% homology and accession number DQ196192.1. The yield was quiet high after optimization reached 49.59 U/mL extracellularly which is essential advantage for such production method. The maximum yield was obtained at 35°C, pH1.8, 100 ppm Mn+2, addition of iso- leucine 3.59% for 7 days incubation in dark condition and shaking speed 100 rpm. Glutaminase enzyme was produced efficiently by the finally selected acidophilic Aspergillus niger isolate and optimization lead to higher enzyme activity which was measured by U/mL in each step.
The Controls of Iron and Oxygen on Hydroxyl Radical (•OH) Production in Soils

Hydroxyl radical (•OH) is produced in soils from oxidation of reduced iron (Fe(II)) by dissolved oxygen (O2) and can oxidize dissolved organic carbon (DOC) to carbon dioxide (CO2). Understanding the role of •OH on CO2 production in soils requires knowing whether Fe(II) production or O2 supply to soils limits •OH production. To test the relative importance of Fe(II) production versus O2 supply, we measured changes in Fe(II) and O2 and in situ •OH production during simulated precipitation events and during common, waterlogged conditions in mesocosms from two landscape ages and the two dominant vegetation types of the Arctic. The balance of Fe(II) production and consumption controlled •OH production during precipitation events that supplied O2 to the soils. During static, waterlogged conditions, •OH production was controlled by O2 supply because Fe(II) production was higher than its consumption (oxidation) by O2. An average precipitation event (4 mm) resulted in 200 µmol •OH m−2 per day produced compared to 60 µmol •OH m−2 per day produced during waterlogged conditions. These findings suggest that the oxidation of DOC to CO2 by •OH in arctic soils, a process potentially as important as microbial respiration of DOC in arctic surface waters, will depend on the patterns and amounts of rainfall that oxygenate the soil.
Visiting The Past: A Case Study of Experiential Learning with Young People at Historic Sites

Abstract Learning about the past is becoming a complex issue due to the increasing need to ensure the approaches consider not only the facts, but also the implications for increasingly diverse future societies. This paper studies how experiential visits to memorial sites contribute to young people’s understanding of history from a wider and more inclusive perspective. The article presents a case study of two educational activities carried out at two memory sites related to the Spanish Civil War (1936–39) involving various qualitative techniques such as participant- and non-participant observation, expert interviews and focus groups with young people. The results show that an experiential approach to the past that works with emotions, empathy and dialogue with secondary students (17 years old) and older young people (15–25 years old) is a very effective means of offering a touching interpretation of the past and learning opportunity for youth, regardless of level of previous knowledge. Other findings show that the content needs to be reconsidered so new generations can interact with it. Young people’s worlds are shaped by cultural diversity, globalisation and the need to connect knowledge with the social environment, which enables them to engage in a critical re-appropriation of the past. This may be a new perspective that could be incorporated into the school curricula, and these types of visits could prove very useful for teachers and historical institutions such as museums or memorial sites interested in including young people’s experiences when planning their activities.
Human Health Effects of Heavy Metal Pollution in the Cross-Border Area of Romania and Serbia: A Review

Abstract This review illustrates the state of air, water and soil pollution with heavy metals resulting from mining activities in the cross-border area of Romania and the Republic of Serbia. It also emphasizes the possible human health effects that certain heavy metals can cause. The heavy metals that were identified as polluting the air, water, and/or soil in the area of interest are: As, Cd, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, and Zn. Acute or chronic exposure to these heavy metals may cause numerous human health effects as they affect numerous organs and tissues (gastrointestinal tract, liver, lungs, kidneys, bladder, central nervous system, reproductive system, etc.). The review shows that the pollution produced by both abandoned and active mines cannot be neglected and underlines the necessity of changes in the current mining practices so that mining operations will assure better protection for the environment and human health.