Miracle-dz/UniFAR-FTUs huggingface dataset:
Modeling Precious Metal Returns through Fractional Jump-Diffusion Processes Combined with Markov Regime-Switching Stochastic Volatility

This paper is aimed at developing a stochastic volatility model that is useful to explain the dynamics of the returns of gold, silver, and platinum during the period 1994–2019. To this end, it is assumed that the precious metal returns are driven by fractional Brownian motions, combined with Poisson processes and modulated by continuous-time homogeneous Markov chains. The calibration is carried out by estimating the Jump Generalized Autoregressive Conditional Heteroscedasticity (Jump-GARCH) and Markov regime-switching models of each precious metal, as well as computing their Hurst exponents. The novelty in this research is the use of non-linear, non-normal, multi-factor, time-varying risk stochastic models, useful for an investors’ decision-making process when they intend to include precious metals in their portfolios as safe-haven assets. The main empirical results are as follows: (1) all metals stay in low volatility most of the time and have long memories, which means that past returns have an effect on current and future returns; (2) silver and platinum have the largest jump sizes; (3) silver’s negative jumps have the highest intensity; and (4) silver reacts more than gold and platinum, and it is also the most volatile, having the highest probability of intensive jumps. Gold is the least volatile, as its percentage of jumps is the lowest and the intensity of its jumps is lower than that of the other two metals. Finally, a set of recommendations is provided for the decision-making process of an average investor looking to buy and sell precious metals.
Nanoscale differentiation of surfaces and cores for olivine phosphate particles—a key characteristic of practical battery materials

We provide a review of our recent studies on the surface chemistries and electronic structures of olivine phosphate cathode materials LiMPO4 (M = Mn, Fe, Co, Ni). Li-depletion and mixed oxidation for the transition metal ions have been detected on particle surfaces, across the family of metal phosphate cathode materials. The effects of surface Li-depletion on optical properties and electronic band structures are discussed. LiFePO4 doped with metals or ions that are reported in the literature as beneficial for rate capability enhancement show more pronounced surface Li-depletion and mixed oxidation compared to undoped material. This outcome, among others, indicates that the dopant resides predominantly on, and influences, the surface of cathode materials.
Transphobic Violence in Educational Centers: Risk Factors and Consequences in the Victims’ Wellbeing and Health

School violence and bullying re worrying problems due to their growing prevalence and severe consequences for adolescent and youth health and wellbeing. Sociocultural factors can contribute to, complicate, and increase the cases of violence in classrooms and spaces related to educational centers. Transphobic violence in this article is defined as the type of violence suffered by transgender and nonbinary adolescents and youth as a manifestation of the problem of discrimination and hate against gender and sexual diversity. This work intends to study the complex sociocultural dynamics of violence detected in educational contexts affecting transgender and nonbinary adolescents and youth identified by recent high- impact studies. At the same time, we aim to fill the gap in the scientific literature on transphobic violence and articulate successful strategies to prevent and combat it. In this review, transphobic violence is defined as the violence affecting transgender adolescents and youth, continuous in time, influenced by peers, and taking place in spaces or realities related to educational centers. The reviewed studies point at the complexity of this kind of violence due to the combination of socio-personal factors and its variety in manifestations. Furthermore, we study the consequences of transphobic violence for the wellbeing and health of transgender and nonbinary adolescents and youth to deepen the knowledge of their mental health repercussions. We end by providing suggestions for how this problem can be prevented in educational environments, grounded on scientific evidence in the materialization of a transformative approach.
Volatile compounds and other indicators of quality for cold-pressed rapeseed oils obtained from peeled, whole, flaked, and roasted seeds†

Cold-pressed rapeseed oil is among the most popular virgin oils. Different processing methods yield oils varying in chemical composition and oxidative stability. The experiment aimed at identifying the differences (mostly in volatiles) between rapeseed oil obtained from peeled seeds (RO) and oils obtained by three pre-treatment methods: pressing whole seeds (WSO), flakes (FO) and roasted flakes (RFO). Volatiles were analysed using GCxGC-ToFMS and data were processed using statistical multivariate analysis. Fatty acid composition was determined using GC-FID. The oils’ oxidative stabilities were measured using peroxide value, free fatty acids’ value, absorbance at 236 and 238nm and chlorophyll content. Also, a sensory panel evaluation was performed. PCA was found to be effective tool for differentiating the oils on the basis of their volatile compounds. RO was most similar to WSO from the second pressing. Fatty acid composition analysis yielded differences between the experimental oils and RO. RO had the highest PV, p-AV and Totox values. WSO from the first pressing (WSO1) had the highest oxidative stability. Sensory analysis found that WSO1 was most similar to RO. Both oils had an intense cabbage-like and fruity odour. The study showed that the results of volatile compounds’ analysis differs from those of sensory analysis. Practical applications: The results demonstrate that the rapeseed oil obtained from whole seeds may have a volatile compounds composition that is similar to that of rapeseed oil obtained from peeled seeds. PCA makes it possible to differentiate between samples varying in pre-treatment method as well as between samples subjected to the same pre-treatment method, but obtained from a second pressing. Sensory panel performed by trained panellists may demonstrate which oils are most desirable when rated for selected attributes. The results of sensory panel may differ from those of volatile compoundanalysis performed with GCxGC-ToFMS.
A beginner’s guide to macromolecular crystallization

Obtaining diffraction-quality crystals is currently the rate-limiting step in macromolecular X-ray crystallography of proteins, DNA, RNA or their complexes, in the vast majority of cases. Since each sample has different and specific characteristics – which is the reason for wanting to study every single one of them in the first place – crystallization conditions cannot be predicted. Hence, researchers must enable crystal nucleation and growth through experimentation and screening. The size, shape and surface of the sample or complexes of interest are often altered through genetic and biochemical manipulation to facilitate crystallization, based on bioinformatics analyses and trial and error. Pure samples are trialled against a very broad range of crystallization conditions. The currently predominant method to achieve crystallization is sitting drop vapour diffusion with nanolitre-class robotic liquid handlers. Once initial screening yields crystals, further optimization experiments are usually required to obtain larger and diffraction-quality crystals.
Coupled D33 Mode-Based High Performing Bio-Inspired Piezoelectric MEMS Directional Microphone

Microelectromechanical system (MEMS) directional microphones have been identified as having use in multi-projected virtual reality applications such as virtual meetings for projecting cameras. In these applications, the acoustic sensitivity plays a vital role as it biases the directional sensing, signal-to-noise ratio (SNR) and self-noise. The acoustic sensitivity is the multiplied outcome of the mechanical sensitivity and the electrical sensitivity. As the dimensions are limited in MEMS technology, the improvement of the acoustic sensitivity by reflecting the mechanical as well as electrical domains is a challenge. This paper reports on a new formation of the D33 mode, the coupled D33 mode, based on piezoelectric sensing to improve the acoustic functionalities. The unique advancement of the proposed D33 mode is that it allows multiple spans of the regular D33 mode to perform together, despite this increasing the diaphragm’s dimensions. At a reduced diaphragm size, the orientation of the coupled D33 mode realizes the maximum conversion of the mechanical deflection into electrical sensitivity. The significance of the proposed D33 mode in comparison to the regular D33 mode is simulated using COMSOL Multiphysics. Then, for a proof–of–concept, the experimental validation is carried out using a piezoelectric MEMS directional microphone inspired by the ears of the fly Ormia ochracea. In both ways, the results are found to be substantially improved in comparison with the regular approach of the D33 mode, showing the novelty of this work.
The Short-Term Impact of COVID-19 on Global Stock Market Indices

The COVID-19 pandemic, declared on March 11, 2020 by the World Health Organisation (WHO), has had a severe economic and financial impact on every economy around the world. This paper aims to analyze the short-term impact of COVID-19 on global financial stock market indices. We study the impact of six different WHO announcements regarding COVID-19 on five different sectors (Pharma, Healthcare, Information Technology, Hotel & Airline) based on the indices of three different economies (World, Developed and Emerging economy). We also study the movement of stock prices and volume of nine different global stock market indices (classified as developed & emerging) based on the number of new cases and deaths due to COVID-19. The study’s findings suggest that there is a significant effect of COVID-19 on global financial stock markets. However, the effect is varied for developed and emerging economies.
A Systematic Review of Literature on Organizational Unlearning and Forgetting

Purpose – Unlearning has been one of the interesting and debatable construct emerged in studies of organizational behaviour. Discussion on this phenomenon precedes from interdisciplinary realms ranging from psychology to pedagogy approaching towards arena of business studies. Studies often question the applicability of its existence and practical applications. Starting from the base of unlearning this paper attempts to enfolds the multi-foci perspectives associated with unlearning. Aiming to analyse the construct, this paper provides an insight to definitional notions, account of existing stream of work, its unit of analysis at individual and organizational level and finally discussion of routines structured on unlearning perspective. Design/methodology/approach – A systematic analysis and review is proposed in order to study streams of literature existing on phenomenon existing on unlearning. This systematic review will help in stating various definitional notions of unlearning, identifying the theoretical lenses applied, processes underlying the unlearning mechanism and extent of quantitative and qualitative studies carried out. Originality/value – As the study is conceptual in its nature, therefore it aims to contribute towards identifying and enhancing the literature of unlearningby identifying gaps and future avenues. Enlightening the applicability of unlearning in multiple sectors it enhances its dimensionality. Practical implications – Study can be helpful for managers and organizations, as unlearning is rooting from change management, which would provide new revelations for organization as useful tools. Review provides insights to areas which can be useful for future studies.
Molecular Docking Evaluation of Syzygium aromaticum Isolated Compounds Against Exo-β-(1,3)-glucanases of Candida albicans

Seventeen compounds from Syzygium aromaticum are selected for exo-β-(1,3)-glucanases inhibitory activity by using molecular docking study. The compounds are uploaded from the PubChem database and molecular docking with AutoDock 1.5. 6 tools is carried out. The molecular docking scores indicate that stigmasterol and campesterol are of the highest potentials, and approximately have similar binding affinities with Candida albicans' active site (3N9K, 3O6A). The hydroxyl moiety has played an important role in the antifungal potentiality of all studied compounds. Original Research Article Shalayel et al.; JPRI, 32(46): 34-44, 2020; Article no.JPRI . 64925 35
A Method to Measure Flame Index in Turbulent Partially-Premixed Flames

A Method to Measure Flame Index in Turbulent Partially-Premixed Flames by David Ari Rosenberg Chair: James F. Driscoll This dissertation describes the development of a diagnostic technique and data processing routine to measure the flame index in partially-premixed flames, called the Flame Index Measurement Method. Many modern combustion applications involve conditions in which the fuel and oxidizer are only partially mixed prior to entering the flame. These partially-premixed flames contain some regions of premixed and some regions of non-premixed flamelets. New computational approaches use the flame index concept: premixed regions are identified and a premixed model is applied; non-premixed regions are also identified and a non-premixed model is applied. The flame index is defined as the normalized dot product of the gradients of the fuel and oxidizer mass fractions; it is +1 in premixed flamelets and is −1 in non-premixed flamelets. Previously there had been no experimentally measured values of flame index available to assess the modeling approaches. A new method has been developed to measure the flame index using Planar Laser-Induced Fluorescence tracers to indicate the sign and direction of the fuel and oxygen gradients. Through the modeling of premixed and non-premixed flamelets, acetone was selected as a fuel tracer and nitrogen dioxide was
Development of risk assessment tool using damaging energy and argumentation theory for evaluating construction occupational safety and health risks

PurposeThe purpose of this paper is to describe the development of a risk assessment model to assess the occupational safety and health (OSH) risks presented by different construction approaches, namely traditional and industrialised building system (IBS). The development process applies the concept of argumentation theory, which helps construction designers integrate the management of OSH risk into the design process. In addition, an energy damage model is used as an underpinning framework for developing the model.Design/methodology/approachDevelopment of the model was achieved through two phases. Phase I involved collection of data on the activities involved in the construction process and their associated OSH risks, derived from five different case studies, field observation and interviews. Knowledge of design aspects that have the potential to impact on OSH was obtained from document analysis. Using the knowledge obtained in phase I, a model was developed in the form of argument trees (Phase II), which represent a reasoning template with regard to options available to designers when they make judgements about aspects of their designs. Inferences from these aspects eventually determined the magnitude of the damaging energies for every activity involved. Finally, the model was validated by panels of experts, and revisions and amendments were made to the model accordingly.FindingsThe risk assessment model development revealed that the concept of argumentation theory and energy damage model is suitable to represent design safety risk knowledge and effectively address the designer's role in making decisions in their designs and further illuminate the level of OSH risk their designs pose.Practical implicationsThe developed model provides best-practice reasoning support for construction designers, which help them to understand the impact of their designs decisions on worker's safety and health, and thereby assist them to further mitigate the risk to an acceptable level.Originality/valueThis study departs from the existing tool in that the model was developed based upon the combination of argumentation theory and energy damage model. The significance of the model is discussed.
Computer Insight into the Molecular Level of Heart Failure. What is the Role of NCX

Though congestive heart failure is a leading cause of death in our population, the pathophysiological mechanisms at molecular level remain to be elucidated. This paper discusses the contribution of NCX to the pathological pattern of intracellular calcium regulation and contraction on the basis of computer simulations of a virtual cell. The model comprises calcium handling mechanisms, troponin control and acto-myosin interactions. The contribution of NCX was studied by changing its activity and turning it off for some simulations. It was found that NCX helps to support diastolic function by reducing the Ca2 level during the diastole. At the same time there is a reduction in peak Cai and hence contraction. However, increased NCX activity does not seem to improve calcium handling and contraction crucially, as has been suggested by some authors.
Evaluating Convective Initiation in High-Resolution Numerical Weather Prediction Models Using GOES-16 Infrared Brightness Temperatures

The evolution of model-based cloud-top brightness temperatures (BT) associated with convective initiation (CI) is assessed for three bulk cloud microphysics schemes in the Weather Research and Forecasting Model. Using a composite-based analysis, cloud objects derived from high-resolution (500 m) model simulations are compared to 5-min GOES-16 imagery for a case study day located near the Alabama–Mississippi border. Observed and simulated cloud characteristics for clouds reaching CI are examined by utilizing infrared BTs commonly used in satellite-based CI nowcasting methods. The results demonstrate the ability of object-based verification methods with satellite observations to evaluate the evolution of model cloud characteristics, and the BT comparison provides insight into a known issue of model simulations producing too many convective cells reaching CI. The timing of CI from the different microphysical schemes is dependent on the production of ice in the upper levels of the cloud, which typically occurs near the time of maximum cloud growth. In particular, large differences in precipitation formation drive differences in the amount of cloud water able to reach upper layers of the cloud, which impacts cloud-top glaciation. Larger cloud mixing ratios are found in clouds with sustained growth leading to more cloud water lofted to the upper levels of the cloud and the formation of ice. Clouds unable to sustain growth lack the necessary cloud water needed to form ice and grow into cumulonimbus. Clouds with slower growth rates display similar BT trends as clouds exhibiting growth, which suggests that forecasting CI using geostationary satellites might require additional information beyond those derived at cloud top.
DUALCOR: a phylogenetic comparative method to evaluate phylogenetic correlation between a character and a non‐evolving external variable

A new phylogenetic comparative method called DUALCOR is presented to evaluate the evolutionary response of a character to non‐evolving external factors, such as environmental variables. The method treats the character as a typical evolving feature of an organism that is reconstructed on a given tree, whereas the external factor is treated as unrelated to the phylogeny. DUALCOR first calculates the correlation/regression between the observed values of the character and the external factor; then it maps the character onto the phylogeny, shuffles the changes among branches, and re‐evolves the character to yield new terminal values uncorrelated with the observed values of the external factor, allowing users to examine whether the observed degree of correlation can be attained at random. This is repeated n (say, 999) times, thereby using the dual nature of characters to construct a permutation test that is shown to satisfy requirements of Generalized Monte Carlo procedures. In addition, we provide an empirical example with a reverse test where the external variable (features determined largely by non‐heritable factors) is the dependent variable.
Design and analysis of the variable-axis structure before and after the large magnetic block of the charging and discharging magnetic adsorption robot

The new type of magnetic adsorption robot for charging and discharging the outer surface of ships has unique advantages in derusting the outer surface of ships. Due to the relatively large volume of the charging and discharging magnetic block, it is difficult to rotate around the bearings at the front and rear ends through the track. This paper designs a variable axis structure for large magnetic blocks before and after walking. Use NX to complete the construction of the 3D model, and import the 3D model into ANSYS for structural analysis through the association with ANSYS-Workbench. The deformation and stress analysis of parts provide theoretical support for the safety and stability of the Variable axis structure.
A study on the use of mobile computing technologies for improving the mobility of Windhoek residents

The aim of this study was to investigate the use of mobile computing technologies for improving the mobility of Windhoek residents, through exploring the perceptions and attitudes of Windhoek taxi drivers and passengers subjected to a real time experiment of an existing mobile taxi hailing and dispatcher system, Taxi StartApp. The study used the Experience Sampling Method (ESM) where users simulated a taxi hailing service that included a pick and drop in real time and then assessed their perceptions of the location-based technology and its service. The research further deployed a widely used System Usability Scale to evaluate the Taxi StartApp system usability, as a combination of effectiveness, efficiency and satisfaction. This research employed qualitative analysis through the adoption of ESM. Eighty samples were selected randomly among taxi drivers and passengers within the town (Windhoek) vicinity. The research falls in the technology adoption research category and the lessons learned from the ESM will help developers to come up with demographically appropriate applications that will address the transportation and mobility challenges in Windhoek.
Concepção em casais heterossexuais sorodiscordantes para o Vírus da imunodeficiência humana: scoping review

Objective: To identify the care related to the conception process and reproductive plans of HIV serodiscordant hetrossexual couples. Methods: For conducting the study it was chosen six methodological steps from the scoping review:(1) identifying the research question, (2) identifying relevant studies (search for relevant studies), (3) study selection, (4) charting the data, (5) collating, summarizing and (6) reporting the results. Results: A summary was carried out according to the method’s nature, to which it was classified as follows: TARV acquicense with suppressed viral load and PrEP for the seronegative partner, natural methods, non-natural methods, safe PLHIV conception counseling skills from professionals. Final considerations: There has been a high investment in research and improvement in recent years in relation to the health care of PLHIV and their serodiscordant partnerships, however, they are slow to reach this audience, as one of the biggest barriers to the implementation of safe design methods are the difficulties of professionals for these knowledge.