Miracle-dz/UniFAR-FTUs huggingface dataset:
Optimization of the Extraction of Antioxidant Compounds from Roselle Hibiscus Calyxes (Hibiscus sabdariffa), as a Source of Nutraceutical Beverages

Secondary metabolites from Hibiscus sabdariffa have been used to prevent different diseases. Roselle Hibiscus is known for being rich in phenolic bioactive compounds. The extraction conditions are directly related to the chemical composition and then to the overall bioactivity of the extract. In this study, a Box-Behnken experimental design has been used to optimize the antioxidant activity, considering four variables: ethanol:water ratio, temperature, extraction time, and solvent:solid ratio. The experiment comprises 27 experiments and 3 repetitions at the central point. The results are described by surface response analysis and a second-degree polynomial equation. The model explains 87% of the variation in the response. The maximum antioxidant activity is yielded when 1% solids are extracted in 35.5% ethanol at 60 °C for 33 min. Finally, a nutritional functional supplement of 495 µmol Trolox Equivalent (TE) antioxidant capacity was prepared with the optimized extract.
Multi-Level Optimization and Strategies in Microbial Biotransformation of Nature Products

Continuously growing demand for natural products with pharmacological activities has promoted the development of microbial transformation techniques, thereby facilitating the efficient production of natural products and the mining of new active compounds. Furthermore, due to the shortcomings and defects of microbial transformation, it is an important scientific issue of social and economic value to improve and optimize microbial transformation technology in increasing the yield and activity of transformed products. In this review, the aspects regarding the optimization of fermentation and the cross-disciplinary strategy, leading to the microbial transformation of increased levels of the high-efficiency process from natural products of a plant or microbial origin, were discussed. Additionally, due to the increasing craving for targeted and efficient methods for detecting transformed metabolites, analytical methods based on multiomics were also discussed. Such strategies can be well exploited and applied to the production of more efficient and more natural products from microbial resources.
A survey of handling and transportation of UK farmed deer

Studies on the transport of deer (Cervidae), in the UK, were published > 15 years ago. A more recent study of deer transport is required to allow for assessments and improvements to the transport of farmed deer. Sixteen deer farmers participated in a survey describing their management practices related to transport. Their responses showed that most vehicles used to transport deer were designed for other livestock. Participating farmers estimated journey times to slaughter as 1–8 h, with an arithmetic mean of 4.8 (± 2.38) h. Specific concerns raised by the respondents, relating to the transport of deer, included a need for deer-specific vehicles, stop-off areas for long journeys, market locations and haulier experience. Furthermore, data were collected from two abattoirs between July 2019 and June 2020 comprising journey times, slaughter times, bruising, location of origin, vehicle type and the number of animals. In total, 4,922 deer were transported across 133 journeys (from farm to abattoir) from 61 farms. Median and range for journey length were 3.2 (0.4–9.8) h and 154.2 (7.1–462.2) km, whereas group size and time spent in the lairage were 24 (1–121) and 17.8 (10.2–68.9) h, respectively. Group size was found to be significantly associated with both the presence of bruising in a group and the amount of bruising per deer. This study provides a much-needed update on the transport of farmed deer in the UK and highlights key areas for future research including the welfare impact of transport in larger groups and for longer durations.
Stabilized nodal‐based finite element methods for the magnetic induction problem

We consider the time‐dependent magnetic induction model as a step towards the resistive magnetohydrodynamics model in incompressible media. Conforming nodal‐based finite element approximations of the induction model with inf‐sup stable finite elements for the magnetic field and the magnetic pseudo‐pressure are investigated. Based on a residual‐based stabilization technique proposed by Badia and Codina, SIAM J. Numer. Anal. 50 (2012), pp. 398–417, we consider a stabilized nodal‐based finite element method for the numerical solution. Error estimates are given for the semi‐discrete model in space. Finally, we present some examples, for example, for the magnetic flux expulsion problem, Shercliff's test case and singular solutions of the Maxwell problem. Copyright © 2015 John Wiley & Sons, Ltd.
Wave propagation across fluid—solid interfaces: a grid method approach

SUMMARY This paper presents a new numerical technique for modelling wave propagation in media with both fluid (acoustic) and solid (elastic) regions, as found for instance in a marine seismic case. The scheme can correctly satisfy the fluid‐solid interface conditions and accurately models the arbitrary interface topography. This work is an extension of the grid method, which is able to model wave propagation in heterogeneous solid (elastic) media with arbitrary surface topography and irregular interfaces. The scheme is developed by formulating the problem in terms of displacements in elastic regions and pressure in acoustic regions with an explicit boundary between them. The fluid‐solid interface conditions on this explicit boundary are implemented by introducing an integral approach to the fluid‐solid interface conditions. The solution in terms of pressure in acoustic regions together with this integral approach means that no extra computational cost is needed to implement the fluid‐solid interface conditions for a complex geometry, instead of resulting in additional computations as with the spectralelement, finite-element or finite-difference methods. In this paper an acoustic grid method is developed to solve the acoustic problem inside the fluid, and the (elastic) grid method, which is improved based on a parsimonious staggered-grid scheme, is used to solve the elastic problem inside the solid. The numerical dispersion and stability criteria for the acoustic grid method are discussed in detail. Comparison with an analytical solution demonstrates that the proposed scheme handles the fluid‐solid interface conditions correctly. Examples of wave propagation in a mixed fluid/solid model with both weak and strong sinusoidal fluid‐solid interfaces illustrate the suitability of the proposed scheme for modelling wave propagation across fluid‐solid interfaces with complex geometries.
Gaussian Process Regression with Heteroscedastic Residuals and Fast MCMC Methods

Gaussian Process Regression with Heteroscedastic Residuals and Fast MCMC Methods Chunyi Wang Doctor of Philosophy Graduate Department of Statistics University of Toronto 2014 Gaussian Process (GP) regression models typically assume that residuals are Gaussian and have the same variance for all observations. However, applications with inputdependent noise (heteroscedastic residuals) frequently arise in practice, as do applications in which the residuals do not have a Gaussian distribution. In this thesis, we propose a GP regression model with a latent variable that serves as an additional unobserved covariate for the regression. This model (which we call GPLC) allows for heteroscedasticity since it allows the function to have a changing partial derivative with respect to this unobserved covariate. With a suitable covariance function, our GPLC model can handle (a) Gaussian residuals with input-dependent variance, or (b) non-Gaussian residuals with input-dependent variance, or (c) Gaussian residuals with constant variance. We compare our model, using synthetic datasets, with a model proposed by Goldberg, Williams and Bishop (1998), which we refer to as GPLV, which only deals with case (a), as well as a standard GP model which can handle only case (c). Markov Chain Monte Carlo methods are developed for the GPLC and GPLV models. Experiments show that when the data is heteroscedastic, both GPLC and GPLV give better results (smaller mean squared error and smaller negative log-probability density) than standard GP regression. In addition, if we do not assume Gaussian residuals, our GPLC model (as in case (b) above) is still generally nearly as good as GPLV when the residuals are in fact Gaussian. When the residuals are non-Gaussian, our GPLC model is better than GPLV.
Construction of the cryogen-free 23 T hybrid magnet

In order to settle problems requiring a large amount of liquid helium and limiting the operation time for a wide bore superconducting magnet of a hybrid magnet, a cryogen-free 23 T hybrid magnet is being constructed at the High Field Laboratory for Superconducting Materials for the first time. An outer compact superconducting magnet is wound with highly strengthened CuNb/Nb/sub 3/Sn multifilamentary wires and is refrigerated conductively by GM-cryocoolers. The maximum stress value of 210 MPa was designed for the CuNb/Nb/sub 3/Sn coil. The cryogen-free superconducting magnet will be operated using dual power supplies independently, and has potential to generate central fields of 4.59 T at 198 A for the outer section NbTi coil and 3.41 T at 145 A for the inner section CuNb/Nb/sub 3/Sn coil. When the cryogen-free 7.5 T superconducting magnet with a 360 mm room temperature bore is combined with an inner 15.5 T water-cooled resistive magnet, a cryogen-free hybrid magnet will achieve 23.0 T in a 52 mm room temperature experimental bore.
Experimental studies on the performance of magnetic shields under different magnetization conditions

In recent decades, magnetic shields have provided basic experimental environments for the measurements of extremely weak magnetic fields represented by the biological magnetic signal. Excellent shielding performances, including the low residual field and high shielding factor (SF), are necessary to ensure the quality of these weak magnetic signals and avoid the interference of external magnetic fields. The magnetic shielding performance of the same device can be affected by different degaussing and test conditions, which remains to be systematically studied. In this paper, experiments with variable magnetization conditions, including different degaussing orders, test fields and environmental fields, are established in a nearly zero-field space to simulate the different situations during measurement. The residual field and SF of the cubic shielding device are tested in these cases. Meanwhile, these shielding performances are analyzed from the perspective of the magnetization state and calculated based on the magnetic properties which are tested and fitted by the Jiles–Atherton model. The results show the influence of these different conditions on the shielding performances of the cubic device, consistent with the numerical calculation. Under the same environmental field, the different degaussing order and test field lead to completely different residual field and shielding performance, respectively. The influence of the Earth’s magnetic field on the SF can be ignored due to its tiny equivalent bias field determined by the anhysteretic magnetization curve.
Exploring the cognitive apprenticeship approach in teacher education: a case study of an early childhood practicum experience

ABSTRACT High quality field or practicum experiences are important for preparing preservice teachers for the profession. Studies suggest preservice teachers rate their practicum experiences more favourably when their cooperating teachers mentor them using apprenticeship-type practices. There is scant research on how such an approach is used in early childhood practicum settings. Using a case study design, the researcher investigated how the teaching methods of the cognitive apprenticeship (CA) could be used to support a year-long early childhood practicum. Twenty junior year practicum students and two cooperating teachers participated in the study. Data were collected from interviews, focus groups, and observations. Findings indicate the methods of the CA approach supported teaching and learning at the practicum site because of intentional support for shared practice among participants, gradual release of support from cooperating teachers, and because the practicum was nested in a community where relationships and collaboration were prioritized.
Recent progress toward a nanoslot modulator: polymer poling experiments

Modulators using silicon waveguides with a small (~100 nm) slot in the center of the waveguide filled with an electro-optic polymer can have very low switching voltage. A variety of challenges, including difficulty poling the polymer and difficulty achieving high-speed operation, have so far prevented successful demonstration. Problems poling the polymer may be electrical, such as nonuniform poling fields or too much polymer conductivity compared to the silicon electrodes, or they may be more fundamental. This paper discusses research into one possible improvement in the polymer poling method, which is illumination of the device with an 800-nm-wavelength laser during poling to improve conductivity between the external voltage source and the polymer in the slot.
Conservation of energy in random media, with application to the theory of sound absorption by an inhomogeneous flexible plate

This paper discusses the linear theory of wave propagation through conservative random media. By means of a simple illustrative example taken from acoustics it is verified that, at least uniformly to second order in an expansion parameter associated with the random fluctuations, the net flow of energy is from the mean, or coherent, wave field to the random component of the wave field (in accordance with the second law of thermodynamics). A general formula is derived for the distribution of the random modes of the system responsible for the power flux into the random field. These are demonstrated unambiguously (without recourse to the use of far field asymptotics) to be precisely those propagating modes which satisfy the homogeneous, non-random dispersion relation. The extension of the theory to a wider class of wave propagation problems is then outlined using an approach involving a Lagrangian density of wide generality. Finally the discussion is extended further to cover the case of coupled systems of wave-bearing media. An important analytical feature of such cases is the occurrence of ‘branch-cut’ integrals in the power flux formula. The situation is illustrated by an investigation of the power extracted from a plane sound wave incident on a flexible plate whose mass density is a random function of position. The division of the scattered power between the acoustic and plate bending modes is obtained, and comparison made with a heuristic argument leading to the same result.
Synthesis Design of Multiband Bandpass Filters Employing Multimode Bandstop Resonators With Star-Like Topology

Multimode resonators (MMRs) can be utilized to build multiband bandpass filters (MBPFs). Each individual mode serves as the operating mode for one of the passbands in a well-known coupling topology. However, several difficulties are involved with the classical design method. In this article, we present a novel star-like topology to design MBPFs based on MMRs. Differently from the classical use, in the proposed novel topology, they are so regarded as bandstop resonators and provide multiple controllable transmission zeros. To explain the proposed concept and the implementation method, two bandstop MMRs – a classical dual-mode stub loaded resonator (DSLR) and a new tri-mode dual-stub loaded resonator (TDSR) – are investigated with detailed design formulas and diagrams. Then, a tri-band MBPF with equal individual sub-bands, a quad-band and two quint-band MBPFs with unequal individual sub-bands are synthesized and designed using the proposed bandstop MMRs. Additionally, simulations and experiments are used to verify the efficiency of all prototypes. Good agreements with the theoretical calculations are observed for all the MBPFs.
Excitation of VLF waves by an electron beam injected into the ionosphere

We propose a scenario for radiation of electromagnetic whistlers as a result of the injections of a modulated electron beam into the ionosphere. We show that for plasma parameters typical of the ionosphere and electron beam parameters typical of electron guns carried into space aboard rockets or spacecraft, the interaction can result in the instability of electrostatic waves driven by Cherenkov resonance between the waves and the beam. A linear stability analysis was carried out for two limiting cases: a wide and a narrow electron beam; the wave excitation is shown to develop at typical distances of the order of 1 km. Nonlinear evolution of the instability was investigated by a combination of analytical and numerical methods. Electron beam energy is efficiently transformed into the electrostatic mode. The mechanism of electromagnetic mode generation is then dipole radiation from the electron beam, which is strongly bunched as a result of the electrostatic instability. The efficiency of radiation is a strong function of the ratio of the electron beam velocity to electron Alfven velocity (v{sub ae} = cw{sub ce}/w{sub pe}); the possibility of increasing the efficiency of radiation is discussed. 34 refs., 9 figs.
Security Attacks and Countermeasures in Smart Homes

The Internet of Things (IoT) application is visible in all aspects of humans’ day-to-day affairs. The demand for IoT is growing at an unprecedented rate, from wearable wristwatches to autopilot cars. The smart home has also seen significant advancements to improve the quality of lifestyle. However, the security and privacy of IoT devices have become primary concerns as data is shared among intelligent devices and over the internet in a smart home network. There are several attacks - node capturing attack, sniffing attack, malware attack, boot phase attack, etc., which are conducted by adversaries to breach the security of smart homes. The security breach has a negative impact on the tenants' privacy and prevents the availability of smart home services. This article presents smart homes' most common security attacks and mitigation techniques.
Characterization of the Endometrial Microbiome in Patients with Recurrent Implantation Failure

An abnormal endometrial microbiota has been associated with implantation failure; therefore, it may be important to evaluate it in order to improve reproductive outcomes in infertile patients. The main objective of our study was to compare the endometrial microbiome of patients with recurrent implantation failure (RIF) and control patients undergoing assisted reproduction treatment (ART). A prospective cohort study including forty-five patients with their own or donated gametes. The endometrial microbiome was analysed by massive sequencing of the bacterial 16S rRNA gene. Different bacterial communities were detected in RIF and control patients. Lactobacillus stands out as the most frequent genus, with 92.27% in RIF patients and 97.96% in control patients, and significant differences were reported between the two groups (p = 0.002). No significant differences were found regarding alpha diversity index. In beta diversity analysis, a significant trend was observed in the separation of the bacterial community between established groups (p < 0.07). Relative abundance analysis identified genera Prevotella (p < 0.001), Streptococcus (p < 0.001), Bifidobacterium (p = 0.002), Lactobacillus (p = 0.002) and Dialister (p = 0.003). Our results demonstrated the existence of an endometrial microbiota characteristic of RIF patients and showed that there might be a relationship between population of the endometrial microbiome and embryo implantation failure, providing us the possibility to improve clinical results in this patients.
Restoration techniques of millimeter-wave images

A non-linear image restoration method has been developed by combining the advantages of the existing Lorentzian and Wiener filter techniques. It sharpens edges without introducing Gibbs ringing and restores the background without flattening it. An image is separated into features and background regions, the features are restored using the Lorentzian method and the background is sharpened using a Wiener filter. The Wiener filter is applied to the second derivative of the background to avoid ringing introduced by discontinuities where feature shave been removed. Also three pre-processing techniques are described that suppress fixed pattern noise, temporal noise and scan-lines from video data. The fixed pattern noise is suppressed by subtracting one frame of a moving image from another. Then the difference image is deconvoled with a function based on the translation of the image between each frame. Temporal noise is suppressed by calculating the displacement between frames and averaging the frames in their displaced position. Scan- lines are suppress by blurring the image in a direction perpendicular to the scan-lines and fitting the original image to the blurred image by adjusting gains and offsets. Examples of each method are provided.
Comment on "On the logical consistency of special relativity theory and non-Euclidean geometries: Platonism versus formalism"

The Lorentz transformations in the theory of special relativity~(SR) lead to a little-investigated phenomenon called relativistic determinism. When two relatively moving inertial observers A and B coincide in space at a given instant, it is possible that a particular distant event is in the future of one of the observers~(B), but is in the present or even in the past of the other~(A); this is a well-known consequence of the relativity of simultaneity. Hence B's future at the instant of coincidence with A is determined by the fact that A had already seen it at that instant. In this paper, it is argued that Platonism is inherent in relativistic determinism and from the point of view of formalism, a logical inconsistency can be deduced in SR, as formalized in classical first-order predicate logic~(FOPL). Similarly, it is argued that Platonism is inherent in non-Euclidean geometries~(NEG) and that formalism demands that Euclid's fifth postulate~(EP) be provable in plane neutral geometry~(NG) consisting of Tarski's axioms (as formalized in FOPL). The essential argument here is that models of NEG can only be constructed by assuming that the postulates of Euclidean geometry~(EG) are metamathematically or Platonically `true'. Formalism demands however that such Platonic truths do not exist and so one concludes that formally, the provability of EP follows from its truth in every model of NG. The classical argument for `interpreting' NEG within EG must be formally rejected as amounting to assuming the Platonic/metamathematical truth of the Euclidean postulates. So from the point of view of formalism, this argument does not really prove the relative consistency of NEG with respect to EG. An argument for provability of EP in NG is presented in the non-Aristotelian finitary logic~(NAFL) proposed by the author.