Miracle-dz/UniFAR-FTUs huggingface dataset:
Field reversals in electrically asymmetric capacitively coupled radio-frequency discharges in hydrogen

In this paper, we present a simulation study of electrically asymmetric capacitively coupled radio-frequency hydrogen discharges using the hybrid plasma equipment model operated at the combined frequencies of 10 and 20 MHz. We find that, in such discharges, field reversals cause ionization near the electrodes during the sheath collapse. In the case of the investigated asymmetric voltage waveforms, the field reversals are asymmetrically distributed over the sheaths, which causes asymmetric ionization and density profiles. The asymmetry of these profiles can be controlled by the phase angle between the two frequencies. As a result, the possibility to control the ion energy independently from the ion flux via the electrical asymmetry effect (EAE) is reduced in discharges displaying strong field reversals, as the asymmetric field reversals compensate the electrically induced asymmetry. The reason for this is understood by an analytical model. Furthermore, we demonstrate, that the EAE can be restored by the addition of specific gases to a pure hydrogen discharge.
Time for Reset? Covid-19 and Tourism Resilience

As a rapidly evolving global pandemic, COVID-19 provides several opportunities for tourism researchers to study the resilience of the tourism industry from a socioecological system perspective. Pandemics are not new and, similar to other crises and disasters, can have lasting impacts on individuals, businesses, communities, and nations. This article offers ways to explore how COVID-19 could affect different aspects of tourism resilience, adopting a three-level approach (macro, meso, and micro). While recognizing that these three levels are not necessarily mutually exclusive, interactions between them can be a worthy area of research in itself. This article proposes a research agenda on COVID-19 and tourism system resilience and contributes to further understanding of scale of change (temporal and spatial), impacts, and resilience. The article identifies, for example, resilience of destinations, organizations, and tourists as important areas of future research in relation to the pandemic. However, theoretical advancements and managerial implications of such research should not be sacrificed at the expense of the opportunities that the context of COVID-19 presents. It is time for reset not only for the tourism industry but also for tourism researchers.
How do firms' and individuals' incentives to invest in human capital vary across groups?

Past research shows that training opportunities are unequally distributed across workers, with workers who are already in a better position in the labour market having more opportunities to acquire new skills. We decompose the downstream training market in order to trace the extent to which differences in the provision of employer-sponsored training across groups of workers are due to demand (by employees) or supply (by employers). The empirical results suggest that employers tend to exclude women, immigrants, young employees, involuntary part-time and temporary workers, workers in low-skilled occupations and workers with low literacy, when selecting which employees to train. By contrast, lower demand appears to account for lower training participation of older and less educated workers. In the case of older workers, labour market imperfections affecting the distribution of training benefits and the length of employers' and employees' pay-back periods are likely to be behind this pattern. In the case of less educated workers, credit constraints and/or training market imperfections – due to lack of training information and contractibility between employers and employees – may partially explain this finding. However, noneconomic factors, such as lesser motivation or bad pedagogical experiences, must also be taken into account. Finally, demand does not appear to vary with firm size or sector. However, supply rises with firm size, perhaps due to lower unit costs of training, larger benefits, and greater access to credit and information for large firms.
Rice Cooking Quality and Physico-Chemical Characteristics: a Comparative Analysis of Selected Local and Newly Introduced Rice Varieties in Ebonyi State, Nigeria

The Choice of rice varieties by farmers and consumers and the rate at which farmers in Ebonyi state go for new rice varieties at the expense of indigenous varieties have become a source of worry to scientists in Nigeria. We assessed the cooking quality and physico-chemical characteristics of 15 selected indigenous and five newly introduced hybrid rice varieties grown in Ebonyi State, Nigeria. Significant variation (P<0.05) was detected among the 20 rice varieties for all the traits evaluated. The results showed that all the five newly introduced hybrid rice varieties do not swell appreciably during cooking. The grains of Cv. “China” had the highest elongation values of 3.2 ± 0.00 mm. “E4197” has the best physical appearance but easily dissolves in water during cooking. Most of the physico-chemical characteristic such as amylose, amylopectin, gel consistency and gelatinization temperature were significantly correlated (positively or negatively) with some of the cooking quality traits (elongation during cooking, solids in cooking water and optimum cooking time), indicating that efforts aimed at selecting rice varieties with improved cooking quality traits would warrant a consideration of the physico-chemical attributes of the rice grain. The overall cooking quality and physico-chemical attributes of some of the indigenous rice varieties were even relatively better than the newly introduced hybrid varieties. Farmers should, therefore, be critical in accepting new varieties that may not be comparably outstanding in cooking quality and physico-chemical characteristics, in order to preserve the integrity of the all-cherished indigenous rice varieties of Ebonyi State, Nigeria.
Optogenetic delivery of trophic signals in a genetic model of Parkinson’s disease

Optogenetics has been harnessed to shed new mechanistic light on current therapies and to develop future treatment strategies. This has been to date achieved by the correction of electrical signals in neuronal cells and neural circuits that are affected by disease. In contrast, the optogenetic delivery of trophic biochemical signals, which support cell survival and thereby may modify progression of degenerative disorders, has never been demonstrated in an animal disease model. Here, we reengineered the human and Drosophila melanogaster REarranged during Transfection (hRET and dRET) receptors to be activated by light, creating one-component optogenetic tools termed Opto-hRET and Opto-dRET. Upon blue light stimulation, these receptors robustly induced the MAPK/ERK proliferative signaling pathway in cultured cells. In PINK1B9 flies that exhibit loss of PTEN-induced putative kinase 1 (PINK1), a kinase associated with familial Parkinson’s disease (PD), light activation of Opto-dRET suppressed mitochondrial defects, tissue degeneration and behavioral deficits. In human cells with PINK1 loss-of-function, mitochondrial fragmentation was rescued using Opto-dRET via the PI3K/NF-кB pathway. Our results demonstrate that a light-activated receptor can ameliorate disease hallmarks in a genetic model of PD. The optogenetic delivery of trophic signals is cell type-specific and reversible and thus has the potential to overcome limitations of current strategies towards a spatio-temporal regulation of tissue repair. Significance Statement The death of physiologically important cell populations underlies of a wide range of degenerative disorders, including Parkinson’s disease (PD). Two major strategies to counter cell degeneration, soluble growth factor injection and growth factor gene therapy, can lead to the undesired activation of bystander cells and non-natural permanent signaling responses. Here, we employed optogenetics to deliver cell type-specific pro-survival signals in a genetic model of PD. In Drosophila and human cells exhibiting loss of the PINK1 kinase, akin to autosomal recessive PD, we efficiently suppressed disease phenotypes using a light-activated tyrosine kinase receptor. This work demonstrates a spatio-temporally precise strategy to interfere with degeneration and may open new avenues towards tissue repair in disease models.
Effect of Intra-Articular Injection of Chondrocytes Differentiated from Mesenchymal Stem Cells in Monosodium iodoacetate Induced Osteoarthritis in Male Rats

Abstract Osteoarthritis [OA] is a chronic, prevalent, debilitating joint disease characterized by progressive cartilage degradation, subchondral bone remodeling, bone marrow lesions, meniscal damage, and synovitis. Joint diseases are very difficult to be treated with traditional line therapy. Hence the importance of developing new therapeutic methods such as stem cell therapy. Mesenchymal Stem Cells [MSCs] isolated from multiple tissues as bone marrow, adipose tissue, dental pulp, placenta and umbilical cord. They possess ability of self-renewal and multilineage differentiation which is a hoping tool for treatment of multiple diseases. The aim of this study is to assess the ability of stem cells to differentiate into chondrocytes and the ability of those chondrocytes to induce cartilage repair and suppresses cartilage degeneration in Monosodium iodoacetate [MIA] induced osteoarthritis in rats' model. In this experimental study Wharton jelly separated from umbilical cord was used to isolate MSCs then differentiated to chondrocytes and injected into MIA induced osteoarthritis in rat's model. The rats divided into three groups; control group, MIA-treated group and MIA- Chondrocytes treated group. Results: MIA- Chondrocytes treated group appeared healthy with no signs of inflammation. On microscopic examination: the articular cartilage of injected limbs showed observable restoration of surface continuity, chondrocytes density, boundaries between layers and matrix basophilia. Conclusion: Intra-articular injection of chondrocytes improves, inhibits the progression of degeneration of the affected cartilage and induces cartilage repair.
THE NON-LINEAR EFFECTS OF OWNERSHIP STRUCTURE ON CORPORATE PERFORMANCE: EVIDENCE FROM EMERGING MARKET

This paper examines the non-linear effects of ownership structure (variables) on corporate performance. The data used in this study are derived from 167 publicly traded companies quoted on the Amman Stock Exchange (ASE), over the period 1989-2006. The ownership structure is measured by the percentage of shares held by each type of owner (state, institution, foreign concentrated owners, and individuals). Results in this study confirm earlier findings of a curvilinear relationship reported for larger markets. The results also show that the relationship between government ownership and ROA and MBVR is a hump-shaped curve. The value of a firm increases when government ownership is low, but the value of a firm decreases when it is high. As the government reduces its stake in a privatised company to below a specific point, perhaps market monitoring become ineffective and this increases the agency costs. The results also document that the relation between institutional ownership and ROA and Tobin’s Q is a hump-shaped curve. When institutional ownership increases above a specific point, institutional shareholders negatively influence a firm’s activities. Findings in this study contribute to the growing body of international evidence that the non-linear cubic relationship between ownership structure and corporate performance is robust to differences in governance structures across markets.
Democracy, Autocracy, and Emergency Threats: Lessons for COVID-19 From the Last Thousand Years

Abstract Our experience with COVID-19 has yet to show that either democracies or autocracies are unambiguously better at dealing with this threat. What the pandemic has instead demonstrated is that these two forms of government each have specific strengths and weaknesses when it comes to dealing with external emergencies. In autocracies centralization of power allows for decisive action, but their ability to maintain secrecy means that they can also suppress information and ignore a problem. In a democracy greater transparency makes it hard to cover up a threat, but the decentralization of power that is inherent to a democracy can lead to a slow and potentially ineffective response. Using both current and historical comparisons between China and western countries, I show that these different patterns have deep roots, dating back a thousand years or more. I then consider three alternative proposals for democracies to be able to act more decisively: allowing for rule by decree, devolving responsibility to localities, and investing in preventative state capacity. History shows that the latter of these three is the safest and most effective strategy, but for it to work voters must reward politicians for investing in prevention. Unfortunately, this reward cannot be assumed.
Electromagnetic transients as triggers in searches for gravitational waves from compact binary mergers

The detection of an electromagnetic transient which may originate from a binary neutron star merger can increase the probability that a given segment of data from the LIGO-Virgo ground-based gravitational-wave detector network contains a signal from a binary coalescence. Additional information contained in the electromagnetic signal, such as the sky location or distance to the source, can help rule out false alarms, and thus lower the necessary threshold for a detection. Here, we develop a framework for determining how much sensitivity is added to a gravitational-wave search by triggering on an electromagnetic transient. We apply this framework to a variety of relevant electromagnetic transients, from short GRBs to signatures of r-process heating to optical and radio orphan afterglows. We compute the expected rates of multi-messenger observations in the Advanced detector era, and find that searches triggered on short GRBs --- with current high-energy instruments, such as Fermi --- and nucleosynthetic `kilonovae' --- with future optical surveys, like LSST --- can boost the number of multi-messenger detections by 15% and 40%, respectively, for a binary neutron star progenitor model. Short GRB triggers offer precise merger timing, but suffer from detection rates decreased by beaming and the high a priori probability that the source is outside the LIGO-Virgo sensitive volume. Isotropic kilonovae, on the other hand, could be commonly observed within the LIGO-Virgo sensitive volume with an instrument roughly an order of magnitude more sensitive than current optical surveys. We propose that the most productive strategy for making multi-messenger gravitational-wave observations is using triggers from future deep, optical all-sky surveys, with characteristics comparable to LSST, which could make as many as ten such coincident observations a year.
A Synoptic Examination of Causes of Land Loss in Southern Louisiana as Related to the Exploitation of Subsurface Geologic Resources

ABSTRACT Olea, R.A. and Coleman, J.L. , Jr., 2014. A synoptic examination of causes of land loss in southern Louisiana as related to the exploitation of subsurface geologic resources. During the last 80 years, Louisiana has been losing wetlands at an average rate of 62 km2/y (24 mi2/y) for an accumulated loss of approximately 4900 km2 (1900 mi2). The loss seems to be the combined result of natural and anthropogenic causes that are behind primarily land subsidence averaging about 10 mm/y (0.4 in/y) coinciding with a sea level rise now at 3 mm/y (0.1 in/y), both contributing to coastal inundation. Upon completing extensive review of often controversial and conflicting views only synoptically reported here, conclusions reached by applying Monte Carlo simulation include: (1) geodetic measurements are consistent with independently postulated causes of regional subsidence; (2) ranking of subsidence factors shows that the main contributor to the regional subsidence is adjustment to sediment load in the form of lithosphere flexure followed by normal faulting dipping basinward, which combined, account on average for 70% of the subsidence, with compaction accounting for another 23%; and (3) production of oil and gas plays a tertiary role. The literature supports the historical view that before experiencing engineering modifications across the catchment area, sedimentation from the Mississippi River system was able to build a prograding coastline by overcoming subsidence rates of similar magnitude with more generous sediment loads of coarser particle size. Sea level rise will become an increasingly dominant factor in land loss only if the acceleration predicted by simulation model scenarios materializes. Wetland losses most likely will continue for as long as there is no compensation to counterbalance the negative effects of land subsidence and sea level rise, with the latter determining the pace of future losses.
Carbon nanodots revised: the thermal citric acid/urea reaction†

Luminescent compounds obtained from the thermal reaction of citric acid and urea have been studied and utilized in different applications in the past few years. The identified reaction products range from carbon nitrides over graphitic carbon to distinct molecular fluorophores. On the other hand, the solid, non-fluorescent reaction product produced at higher temperatures has been found to be a valuable precursor for the CO2-laser-assisted carbonization reaction in carbon laser-patterning. This work addresses the question of structural identification of both, the fluorescent and non-fluorescent reaction products obtained in the thermal reaction of citric acid and urea. The reaction products produced during autoclave–microwave reactions in the melt were thoroughly investigated as a function of the reaction temperature and the reaction products were subsequently separated by a series of solvent extractions and column chromatography. The evolution of a green molecular fluorophore, namely HPPT, was confirmed and a full characterization study on its structure and photophysical properties was conducted. The additional blue fluorescence is attributed to oligomeric ureas, which was confirmed by complementary optical and structural characterization. These two components form strong hydrogen-bond networks which eventually react to form solid, semi-crystalline particles with a size of ∼7 nm and an elemental composition of 46% C, 22% N, and 29% O. The structural features and properties of all three main components were investigated in a comprehensive characterization study.
Cornea In Vivo Prediction of Air-Puff Induced Corneal Deformation Using LASIK , SMILE , and PRK Finite Element Simulations

Mathew Francis, Pooja Khamar, Rohit Shetty, Kanchan Sainani, Rudy M. M. A. Nuijts, Bart Haex, and Abhijit Sinha Roy Imaging, Biomechanics and Mathematical Modeling Solutions Lab, Narayana Nethralaya Foundation, Bangalore, India Department of Cornea and Refractive Surgery, Narayana Nethralaya, Bangalore, India University Eye Clinic Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands Director of Research Policy, Maastricht University, Maastricht, The Netherlands
A comparison of transient and conventional approaches to AMT

The natural electromagnetic field in the frequency range above 1 Hz is predominantly due to lightning discharges. The random, incoherent sum of globally distributed sources gives rise to a low level quasicontinuous component which is, in general, elliptically polarized. The effects of discrete events related to individual lightning discharges from either relatively nearby and/or very large current moment discharges are superimposed on this continuous component. ‘Nearby’ in this context is defined relative to the scale of global waveguide attenuation, which at 100 Hz is of the order of 5000 km whilst at 5000 Hz it is perhaps more like 1500 km. The transient event signals can be much larger amplitude than the background component, but they are also strongly linearly polarized. The diversity of the polarization affects the stability with which Earth response curves can be estimated. A ‘transient’ approach to AMT involves the time localized recording of linearly polarized transient event signals. Although not widely adopted, this is not a new approach, having been used previously by many others, including Don Hoover of the USGS in the 1970's, Keeva Vozoff, Ken Paulson and Andreas Tzanis in the 1980's, and Stephen Garner in the late 1990's. The use of linearly polarized transients with conventional estimation procedures such as remote reference (RR) produces a bias that is additional to that caused by finite signal-to-noise ratio (SNR) and sample size. To improve the transient approach, we have developed a data processing algorithm called Adaptive Polarization Stacking (APS) that is specifically designed to work with linearly polarized transients. This new method produces results which properly reflect the polarization diversity, SNR and sample size in the final Earth response curves and error bars. We have shown that our APS algorithm has a higher order bias convergence than RR when applied to transients with typical polarization characteristics. In this paper, we compare results obtained with conventional and ‘transient’ AMT data collected on the same seismic line by survey crews that were in the survey area at the same time. Despite our first generation coils being at least four times noisier at low frequency and ten times noisier at high frequency than those used by our conventional survey colleagues, and that our 12 bit analog-to-digital-converter (ADC) (c/f the 24 bit ADC used in the conventional survey) had a software bug that required the removal of all of our pre-trigger data, we believe that our impedance data turned out as good as our colleague's in terms of curve smoothness and width of dead-band, and that our tipper data is demonstrably better.
CD 147 mediates transforming growth factor ‐ β 1 ‐ induced epithelial ‐ mesenchymal transition and cell invasion in squamous cell carcinoma of the tongue

Epithelial-mesenchymal transition (EMT) is a physiological process in which epithelial cells attain the motile and invasive characteristics of mesenchymal cells, which results in the development of increased migratory and invasive cell behavior, serving as a vital mechanism of cancer progression. Hence, controlling the EMT for cancer treatment, including head and neck squamous cell carcinoma (HNSCC), is imperative. Among EMT-associated factors, transforming growth factor-β (TGF-β) is a well-established potent inducer. Recent research has revealed that CD147, a member of the immunoglobulin superfamily, promotes the EMT. However, the role of CD147 in the EMT and the following tumorigenicity in HNSCC has not been completely elucidated. This study aims to investigate the role of CD147 in the EMT and related tumorigenicity in HNSCC. The present study used two HNSCC cell lines, SAS and FaDu, for in vitro studies. In HNSCC cells, TGF-β1 induced spindle-shaped morphological changes, and western blot analysis revealed that TGF-β1 induced changes in EMT markers, downregulation of vimentin, and upregulation of E-cadherin, yet increased CD147. In addition, TGF-β1 increased cell migration in HNSCC cells. However, a TGF-β1-induced alteration in EMT makers was attenuated with CD147 silencing by small interfering RNA (siRNA) in SAS cells. In addition, the TGF-β1-induced cell invasion of SAS was attenuated with CD147 silencing. In conclusion, the present study suggests that CD147 mediates TGF-β1-induced EMT and tumorigenicity in HNSCC. Hence, CD147 may serve as a vital therapeutic target in HNSCC.