Miracle-dz/UniFAR-FTUs huggingface dataset:
The role of deputy principals: Perspectives of South African primary school principals and their deputies

Education leadership literature indicates that relatively little attention has been given to the specific duties and responsibilities of South African deputy principals in comparison with other leadership and management positions in schools. As a result, their roles and responsibilities remain vague. The purpose of this study was, therefore, to explore the roles of deputy principals in selected well-resourced fee-paying primary schools. Semi-structured interviews were conducted with the principal and two deputy principals of each of the five participating schools. The participating schools were selected for having a reputation of being high-performing schools and being most likely to provide rich data. The findings suggest that the sub-context of a school is an important factor influencing the role of a deputy principal. In addition, principals play a key role in determining the job description of individual deputy principals. This is often accompanied by purposeful leadership distribution and a reconfiguration of conventional management structures. In addition, deputy principals were generally viewed as ‘principals-in-training’ and their relationship with their principals characterised by shared leadership practices.
Effects of Nitrogen Form and Application Rates on the Growth of Petunia and Nitrogen Content in the Substrate

Fertigation practices have been proposed for decreasing nitrogen (N) leaching losses and for nutrient efficiency increase, including the use of nutrient solutions with low concentrations of N and the application of nitrification inhibitors with ammonium ammonium (NH4 +) N fertilizers. The effects of N form, application rates, and use of an inhibitor of nitrification [3,4- dimethylpyrazole phosphate (DMPP)] on the growth and the N percentages in leaves of Petunia × hybrida, as well as the N content in the substrate, were tested. Plants were placed in a venlo-glass greenhouse. Five treatments were established, changing N form, application rates, and with or without the inhibitor of nitrification: T1, 120 mg L−1 of N- nitrate (NO3 −); T2, 120 mg L−1 of N-NH4 +; T3, 80 mg L−1 of N-NH4 + with DMPP; T4, 120 mg L−1 of N-NH4 + with DMPP; and T5, 160 mg L−1 of N-NH4 + with DMPP. Nitrogen form did not have an effect on plant dry and fresh weight, plant height, or number of buds; however, ammonium treatments increased ammonium concentration and reduced nitrate concentration in the substrate solution. The use of DMPP achieved a significant reduction in nitrate concentrations in the substrate solution. Nitrogen percentage in leaves was not affected by N form, whereas the leaves of the plants treated with ammonium showed an increase in color, probably due to an increase in iron concentration. Ammonium fertilization increased the percentage of plants that survived in dark storage conditions.
Analysis and Takeover of the Bitcoin-Coordinated Pony Malware

Malware, like all products and services, evolves with bursts of innovation. These advances usually happen whenever security controls get ''good enough'' to significantly impact the revenue stream of malicious actors, and in the past we have seen the malware ecosystem to adopt concepts such as code obfuscation, polymorphism, domain-generation algorithms (DGAs), as well as virtual machine and sandbox evasion whenever defenses were able to perform consistent and pervasive suppression of these threats. The latest innovation step addresses one of the main Archilles' heels in malware operations: the resilient addressing of the command & control (C&C) server. As domain blacklisting and DGA reversing have become mature security practices, malware authors are now turning to the Bitcoin blockchain, and use its resilient design principle to disseminate control information that cannot be removed by defenders. In this paper, we report on the adoption of Bitcoin-based C&C addressing in the Pony malware, one of the most widely occurring malware platforms on Windows. We forensically analyze the blockchain-based C&C mechanism of the Pony malware, track the malicious operations over a period of 12 months, and report how the adversaries experimented and optimized their deployment over time. We identify a security flaw in the C&C addressing, which is used to perform a takeover of the malware's loading mechanism to quantify the volume and origin of the incoming infections.
Synthesis of Gold Nanoparticles by Leaves of Zero-Calorie Sweetener Herb (Stevia rebaudiana) and Their Nanoscopic Characterization by Spectroscopy and Microscopy

ABSTRACT In this research work, gold nanostructures with different shapes, such as octahedrons, hexagons and triangles, have been synthesized within 20 min by reducing gold chloride (HAuCl4) with dried, powdered Stevia rebaudiana, leaves, previously not exploited for the synthesis of gold nanoparticles. The nanoparticles were characterized and investigated by ultraviolet-visible (UV-Vis) spectrophotometry, high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray (EDX) spectroscopy, and X-ray diffraction (XRD). The UV-Vis spectrum of the aqueous medium containing gold nanostructures showed a peak at 539 nm corresponding to the surface plasmon resonance band (SPR) of gold nanoparticles. HR-TEM micrograph showed the formation of well-dispersed octahedral gold nanoparticles of size 8–20 nm. XRD spectrum of the gold nanoparticles “exhibited Bragg's pattern of reflection. ”
The TolTEC camera: an overview of the instrument and in-lab testing results

TolTEC is a three-band imaging polarimeter for the Large Millimeter Telescope. Simultaneously observing with passbands at 1.1mm, 1.4mm and 2.0mm, TolTEC has diffraction-limited beams with FWHM of 5, 7, and 11 arcsec, respectively. Over the coming decade, TolTEC will perform a combination of PI-led and Open-access Legacy Survey projects. Herein we provide an overview of the instrument and give the first quantitative measures of its performance in the lab prior to shipping to the telescope in 2021.
A supervised machine learning approach for the optimisation of the assembly line feeding mode selection

The Line Feeding Problem (LFP) involves the delivery of components to the production area. Previous models minimise the delivery costs and optimally assign each component to a line feeding mode between line stocking, kitting, and sequencing but cannot provide easily comprehensible guidelines. We use the Classification And Regression Tree (CART) algorithm to develop, in a supervised way, a decision tree based on problems that are solved with a Mixed Integer Programming (MIP) model for training purposes. Based on selected attributes of the components and the manufacturing environment, the decision tree suggests a line feeding mode for every component. For a synthetically determined training and evaluation data set, we find that the classification tree can predict the line feeding mode with an average classification accuracy of 78.49%. After the decision tree is implemented and a line feeding mode is selected for each component, an infeasible solution might occur. We develop a repair approach that solves this problem with an average cost deviation from the optimal solution of 0.38%.
Tissue-Engineered Anterior Segment Eye Cultures Maintain Intraocular Pressure within a Normal Range

Glaucoma is a blinding disease largely caused by increased resistance to drainage of fluid from the eye’s anterior chamber, resulting in elevated intraocular pressure (IOP). A major site of fluid outflow regulation and pathology is the trabecular meshwork (TM) at the entrance of the eye’s drainage system. We aimed to characterize the structural and functional properties of a newly developed tissue-engineered anterior segment eye culture model. We hypothesized that repopulation of a decellularized TM with non-native TM cells could restore aspects of normal TM. The decellularization protocol removed all cells and debris while preserving the ECM. Seeded cells localized to the TM region and progressively infiltrated the meshwork ECM. Cells reached a distribution comparable to control TM after four days of perfusion culture. After a perfusion rate increase challenge, tissue-engineered cultures reestablished normal IOPs (reseeded = 13.7±0.4 mmHg, decellularized = 35.2±2.2 mmHg, p < 0.0001). eGFP expressing CrFK control cells caused a high and unstable IOP (27.0±6.2 mmHg). In conclusion, we describe a readily available, storable, and biocompatible scaffold for anterior segment perfusion culture of non-native cells. Tissue-engineered organs demonstrated similarities to native tissues and may reduce the need for scarce donor globes in outflow research.
Simulation of a Ground Water Recirculation Well with a Dual‐Column Laboratory Setup

This paper describes a dual‐column laboratory setup consisting of a glass column and a stainless‐steel column filled with aquifer material. The setup was used to replicate a ground water recirculation well that serves as an in situ reactor and a combined injection/withdrawal well. The treatment solution consisted of a buffered titanium (III) citrate/vitamin B12 mixture. The first column, representing the well, was made of glass, allowing for visual inspection of the mixing. The stainless‐steel column was instrumented with redox (Eh) probes to monitor the changes in redox conditions. The redox measurement showed that, although the sand contained large quantities of iron oxides, the oxidation rate was relatively slow and the titanium solution would remain reduced for some time in the aquifer, continuing to react with the contaminants. This laboratory setup was used to optimize the reagent concentrations and rate of delivery for field implementation. It was found that 4 mM titanium citrate and 3 mg/L vitamin B12 were sufficient to degrade 1,1,2,2‐tetrachloroethane and carbon tetrachloride within one day, but not trichloroethylene, which required five days with 10 mM titanium citrate and 5 mg/L vitamin B12.
The Perils of Laundering Control through Customers: A Study of Control and Resistance in the Ride-hail Industry

Customer abuse of frontline service workers is widespread. Yet despite growing recognition of this problem, we know very little about the role that service companies play in potentially enabling customers’ abusive behaviors. This phenomenon deserves attention because one of the recent trends in service management is giving customers a direct role in managing and evaluating workers’ performance. In this article, the author explores how granting customers direct access to organizational power over workers, what the author develops conceptually as “laundering control through customers,” explains how customer abuse emerges. Drawing on a sample of 486 Uber and Lyft drivers, the author examines how the companies’ use of the “five-star” evaluation system enables customers to engage in a range of different forms of abuse and how workers resist this configuration of control. This study contributes to the customer triangle literature by bringing in evidence from the gig economy and uncovers new implications for the “dark side” of customer service work.
Imaging temozolomide-induced changes in the myeloid glioma microenvironment

Rationale: The heterogeneous nature of gliomas makes the development and application of novel treatments challenging. In particular, infiltrating myeloid cells play a role in tumor progression and therapy resistance. Hence, a detailed understanding of the dynamic interplay of tumor cells and immune cells in vivo is necessary. To investigate the complex interaction between tumor progression and therapy-induced changes in the myeloid immune component of the tumor microenvironment, we used a combination of [18F]FET (amino acid metabolism) and [18F]DPA-714 (TSPO, GAMMs, tumor cells, astrocytes, endothelial cells) PET/MRI together with immune-phenotyping. The aim of the study was to monitor temozolomide (TMZ) treatment response and therapy-induced changes in the inflammatory tumor microenvironment (TME). Methods: Eighteen NMRInu/nu mice orthotopically implanted with Gli36dEGFR cells underwent MRI and PET/CT scans before and after treatment with TMZ or DMSO (vehicle). Tumor-to-background (striatum) uptake ratios were calculated and areas of unique tracer uptake (FET vs. DPA) were determined using an atlas-based volumetric approach. Results: TMZ therapy significantly modified the spatial distribution and uptake of both tracers. [18F]FET uptake was significantly reduced after therapy (-53 ± 84%) accompanied by a significant decrease of tumor volume (-17 ± 6%). In contrast, a significant increase (61 ± 33%) of [18F]DPA-714 uptake was detected by TSPO imaging in specific areas of the tumor. Immunohistochemistry (IHC) validated the reduction in tumor volumes and further revealed the presence of reactive TSPO-expressing glioma-associated microglia/macrophages (GAMMs) in the TME. Conclusion: We confirm the efficiency of [18F]FET-PET for monitoring TMZ-treatment response and demonstrate that in vivo TSPO-PET performed with [18F]DPA-714 can be used to identify specific reactive areas of myeloid cell infiltration in the TME.
Chemical Reaction Sequence in the Formation of Water-Blown, Urethane Foam

Water-blown urethane foaming is a process which leads in a matter of minutes to the production of highly &dquo;engineered,&dquo; supramolecular architecture of foam from a mixture of relatively low molecular weight components. This making of urethane foam is one of the few industrial processes in which rapid polymerization occurs in such a controlled way that polymerization and supramolecular structure are achieved almost simultaneously. In order to understand this remarkable transformation, it is necessary to define the chemical species present and the order in which these species react. By inference from the highly involved structure produced, the order and timing of these reactions is critical. In this paper, this sequence of reactions is defined and related to the physical stages of foaming evident from rise-profile and &dquo;gel-profile&dquo; measurements. From these studies, a clearer understanding is possible of the measurement of &dquo;gel-profile. &dquo;
Cadmium Sorption and Transport in Variable Charge Soils: A Review

Alfisols, Entisols, Inceptisols, Ultisols, Vertisols, and Oxisols are all commonly found in tropical and subtropical regions receiving more than 500 mm mean annual rainfall. Landscapes throughout the tropics and subtropics are, however, dominated by Oxisols and Ultisols occupying extensive areas of potentially highly productive soils. The mineral fractions of these soils consist primarily of low-activity clays having variable surface charge that differs from high activity clays in the origin of that charge. Low activity clays are dominated by iron (Fe) and aluminium (Al) oxyhydroxides and 1:1 layer silicates (kaolin). Much research has been conducted on the effects of pH, organic matter (OM), and cation composition of the soil solution on the surface charge characteristics of variable charge soils from the tropics. In general, net negative surface charge increases with increasing soil pH and OM content. Adsorption of metal ions by variable charge soils and minerals also increases as their pH, clay, and OM contents increase. Although the precise mechanisms for the change in net negative charge of soil and mineral surfaces with increasing pH are not fully understood, the generation of negative charge either through dissociation of H + ions from surfaces or consumption of OH - ions by soils is generally accepted. In soils dominated by permanent charge surfaces, heavy metals are not mobile but in variable charge soils, the low surface charge density creates conditions conducive to increased mobility. Consequently, the adsorption of heavy metals, in particular, cadmium (Cd) by strongly weathered soils in relation to the effects of inorganic and organic ligands and the implications for metal transport are reviewed.
The Budgetary Implications of Being an Organic Consumer

Abstract It has repeatedly been shown that consumers consider the higher price of organic produce to be a barrier to buying organic food products. The present paper therefore asks whether organic consumption affects consumers’ actual total food expenditures. Food purchase data for a panel of Danish households during 2006–2014 were used to compare the total food expenditures of different organic household segments. A fixed effects model and a cross-section model both indicated that although food expenditures rose slightly with organic consumption, the increase was considerably less than had been suggested by organic price premiums at product level.
An investigation on improving the homogeneity of plasma generated by linear microwave plasma source with a length of 1550 mm

To develop a larger in-line plasma enhanced chemical vapor deposition (PECVD) device, the length of the linear microwave plasma source needs to be increased to 1550 mm. This paper proposes a solution to the problem of plasma inhomogeneity caused by increasing device length. Based on the COMSOL Multiphysics, a multi-physics field coupling model for in-line PECVD device is developed and validated. The effects of microwave power, chamber pressure, and magnetic flux density on the plasma distribution are investigated, respectively, and their corresponding optimized values are obtained. This paper also presents a new strategy to optimize the wafer position to achieve the balance between deposition rate and film quality. Numerical results have indicated that increasing microwave power and magnetic flux density or decreasing chamber pressure all play positive roles in improving plasma homogeneity, and among them, the microwave power is the most decisive influencing factor. It is found that the plasma homogeneity is optimal under the condition of microwave power at 2000 W, chamber pressure at 15 Pa, and magnetic field strength at 45 mT. The relative deviation is within −3.7% to 3.9%, which fully satisfies the process requirements of the equipment. The best position for the wafer is 88 mm from the copper antenna. The results are very valuable for improving the quality of the in-line PECVD device.
Distributed Generation: A Review on Current Energy Status, Grid-Interconnected PQ Issues, and Implementation Constraints of DG in Malaysia

Electric supply is listed as one of the basic amenities of sustainable development in Malaysia. Under this key contributing factor, the sustainable development goal aims to ensure universal access to an affordable, clean, and reliable energy service. To support the generation capacity in years to come, distributed generation is conceptualized through stages upon its implementation in the power system network. However, the rapid establishment growth of distributed generation technology in Malaysia will invoke power quality problems in the current power system network. In order to prevent this, the current government is committed to embark on the development of renewable technologies with the assurance of maintaining the quality of power delivered to consumers. Therefore, this research paper will focus on the review of the energy prospect of both fossil fuel and renewable energy generation in Malaysia and other countries, followed by power quality issues and compensation device under a high renewable penetration distribution network. The issues and challenges of distributed generation are presented, with a comprehensive discussion and insightful recommendation on future work of the distributed generation. In accordance with the addressed highlights in this paper, it would serve as the criterion on upcoming revolution of distributed generation integrated along with the traditional network in Malaysia.
PROTEIN INTERACTIONS WITH POLY(ETHYLENE GLYCOL) SELF-ASSEMBLED MONOLAYERS ON GLASS SUBSTRATES : DIFFUSION AND ADSORPTION

Hydrophilic polymer chains, poly(ethylene glycol) (PEG), are attached to glass surfaces by silylation of the silanol groups on glass surfaces with (ω-methoxy-terminated PEG)trimethoxysilanes. We consider these tethered polymer chains to resemble self-assembled monolayers (SAMs) of PEG since the grafting process is entirely spontaneous. They are shown to exhibit excellent biocompatibility and represent a model system for studying the interactions of proteins with polymer surfaces. The PEG SAMs are prepared with two different molecular weight polymers (MW = 750 and 5000) and characterized with the techniques of angular-dependent X-ray photoelectron spectroscopy and atomic force microscopy. For the low molecular weight sample, the polymer chains tend to extend, forming a brush-like monolayer, whereas for the large molecular weight sample, the longer polymer chains tend to interpenetrate each other, forming a mushroom-like PEG monolayer on the surface. Interactions between a plasma protein, bovine serum album.
COMMD1 upregulation is involved in copper efflux from ischemic hearts

Copper depletion is associated with myocardial ischemic infarction, in which copper metabolism MURR domain 1 (COMMD1) is increased. The present study was undertaken to test the hypothesis that the elevated COMMD1 is responsible for copper loss from the ischemic myocardium, thus worsening myocardial ischemic injury. Mice (C57BL/6J) were subjected to left anterior descending coronary artery permanent ligation to induce myocardial ischemic infarction. In the ischemic myocardium, copper reduction was associated with a significant increase in the protein level of COMMD1. A tamoxifen-inducible, cardiomyocyte -specific Commd1 knockout mouse (C57BL/6J) model (COMMD1CMC▲/▲) was generated using the Cre-LoxP recombination system. COMMD1CMC▲/▲ and wild-type littermates were subjected to the same permanent ligation of left anterior descending coronary artery. At the 7th day after ischemic insult, COMMD1 deficiency suppressed copper loss in the heart, along with preservation of vascular endothelial growth factor and vascular endothelial growth factor receptor 1 expression and the integrity of the vascular system in the ischemic myocardium. Corresponding to this change, infarct size of ischemic heart was reduced and myocardial contractile function was well preserved in COMMD1CMC▲/▲ mice. These results thus demonstrate that upregulation of COMMD1 is at least partially responsible for copper efflux from the ischemic heart. Cardiomyocyte-specific deletion of COMMD1 helps preserve the availability of copper for angiogenesis, thus suppressing myocardial ischemic dysfunction.
Study on the emission spiral patterns by changing the sidewall of the discharge system

In this work, a rich variety of emission spiral patterns have been obtained in dielectric argon/air barrier discharge (DBD) system with a special designed water electrodes setup. We investigate the characteristics of spiral patterns with two kinds of different sidewall materials. By analyzing the image and the light signals of the patterns, it is found that spiral patterns with different sidewall material have different characteristics. The profile of the intensity distribution curve under the glass sidewall appears as a sinusoidal oscillation, while displays in relaxation oscillation mode under plastic sidewall. The space frequency spectrum of spirals under glass sidewall contains only one order spectrum, while the space spectrum of spirals under plastic sidewall contains more than two orders of space frequency spectrum. The experiment results indicate that the sidewall material may affect the excited property of the discharge system.