Bromatological Analysis and Characterization of Phenolics in Snow Mountain Garlic

The remarkable properties of garlic A. sativum L. have been described, but little is known about Snow mountain garlic. Understanding general aspects of this garlic composition, including the presence of phenolics, will establish its possible use for health or infer which compounds can contribute to improving it. This study aimed to determine the ash content, lipid profile, and characterization of phenolics in Snow mountain garlic. The organic content was obtained by common techniques (oven drying, calcination, Kjeldahl method, etc.). The quantitative analysis of the ashes was made by Inductively Coupled Plasma Emission Spectrometry. The fatty acid profile was determined by Gas Chromatography. The presence of phenolics was determined by foam, Libermann–Burchard, Dragendorff, Salkowski, ferric chloride, vanillin, catechin, Constantinescu, and Shinoda reactions. The total phenolic content was determined via the Folin–Ciocalteu method, and antioxidant activity was determined using the DPPH radical method. The bromatological analysis showed a 51.1% humidity, and the main organic compounds were carbohydrates (46.7%). Ash analysis showed 287.46 g/kg of potassium. The fatty acid profile showed 75.61% of polyunsaturated fatty acid. Phenolics like saponins, alkaloids, triterpenes, tannins, and flavonoids were present. Antioxidant activity was found by radical DPPH of 25.64 (±0.78) µmol TE/1 g dw. Snow mountain garlic shares a composition similar to those found in other garlic.     

Applying the Horizontal Visibility Graph Method to Study Irreversibility of Electromagnetic Turbulence in Non-Thermal Plasmas

One of the fundamental open questions in plasma physics is the role of non-thermal particles distributions in poorly collisional plasma environments, a system that is commonly found throughout the Universe, e.g., the solar wind and the Earth’s magnetosphere correspond to natural plasma physics laboratories in which turbulent phenomena can be studied. Our study perspective is born from the method of Horizontal Visibility Graph (HVG) that has been developed in the last years to analyze time series avoiding the tedium and the high computational cost that other methods offer. Here, we build a complex network based on directed HVG technique applied to magnetic field fluctuations time series obtained from Particle In Cell (PIC) simulations of a magnetized collisionless plasma to distinguish the degree distributions and calculate the Kullback–Leibler Divergence (KLD) as a measure of relative entropy of data sets produced by processes that are not in equilibrium. First, we analyze the connectivity probability distribution for the undirected version of HVG finding how the Kappa distribution for low values of κ tends to be an uncorrelated time series, while the Maxwell–Boltzmann distribution shows a correlated stochastic processes behavior. Subsequently, we investigate the degree of temporary irreversibility of magnetic fluctuations that are self-generated by the plasma, comparing the case of a thermal plasma (described by a Maxwell–Botzmann velocity distribution function) with non-thermal Kappa distributions. We have shown that the KLD associated to the HVG is able to distinguish the level of reversibility that is associated to the thermal equilibrium in the plasma, because the dissipative degree of the system increases as the value of κ parameter decreases and the distribution function departs from the Maxwell–Boltzmann equilibrium.     

Acylation of dimethyl maleate photocatalyzed by decatungstate anion: insights into the hydrogen atom transfer reaction mechanism

Research on Chemical Intermediates - Polyoxometalates arise as significant catalysts in the field of organic chemistry due to their diverse properties and functions. Recent progress based on...     

Transient magnetoviscosity of dilute ferrofluids

The magnetic field induced change in the viscosity of a ferrofluid, commonly known as the magnetoviscous effect and parameterized through the magnetoviscosity, is one of the most interesting and practically relevant aspects of ferrofluid phenomena. Although the steady state behavior of ferrofluids under conditions of applied constant magnetic fields has received considerable attention, comparatively little attention has been given to the transient response of the magnetoviscosity to changes in the applied magnetic field or rate of shear deformation. Such transient response can provide further insight into the dynamics of ferrofluids and find practical application in the design of devices that take advantage of the magnetoviscous effect and inevitably must deal with changes in the applied magnetic field and deformation. In this contribution Brownian dynamics simulations and a simple model based on the ferrohydrodynamics equations are applied to explore the dependence of the transient magnetoviscosity for two cases: (I) a ferrofluid in a constant shear flow wherein the magnetic field is suddenly turned on, and (II) a ferrofluid in a constant magnetic field wherein the shear flow is suddenly started. Both simulations and analysis show that the transient approach to a steady state magnetoviscosity can be either monotonic or oscillatory depending on the relative magnitudes of the applied magnetic field and shear rate.     

Finite data-size scaling of clustering in earthquake networks

An earthquake network is known to be of the small-world type. The values of the network’s characteristics, however, depend not only on the cell size (i.e., the scale of coarse graining needed for constructing the network) but also on the size of a seismic data set. Here, discovery of a scaling law for the clustering coefficient in terms of the data size, which is referred to here as finite data-size scaling, is reported. Its universality is shown to be supported by the detailed analysis of the data taken from California, Japan and Iran. Effects of setting a threshold of magnitude are also discussed.     

The same geometry textbook does not mean the same classroom enactment

Textbooks are often used in classroom instruction in quite different ways, leading to potential differences in students’ opportunities to learn. This paper explores the enactment of the topic of congruence by 12 teachers using the same geometry textbook. We highlight variations in the number and nature of lessons taught or skipped, in expectations for homework, and in instructional style. For instance, teachers taught between 60 and 100 % of the lessons on congruence but often skipped content focused on unique applications. The number of minutes of homework assigned varied from 16–30 min per night to 46–60 min per night. Ten of the 12 teachers spent at least 50 % of class time each week in whole-class instruction. Only one-third used dynamic geometry software and one used no calculator or computer technology in the congruence chapters. The results provide detailed insights into differences in upper secondary teachers’ use of textbooks, an area where less research exists than at elementary or lower secondary levels.     

Researching the enacted mathematics curriculum: learning from various perspectives on enactment

This issue of ZDM focuses on research related to the enacted curriculum from various perspectives within the context of the US educational system. In this editorial, we describe the broad view of curriculum enactment taken in this issue, highlighting that we mean more than just how instruction plays out within a classroom. For instance, enactment can occur at a national level as educational goals are enacted into a set of national objectives or standards. Enactment can occur as goals or standards are embedded into written curriculum materials or textbooks, both in terms of teacher guides and materials for students. Enactment can occur as teachers make decisions about how to use their written curriculum materials. Finally, enactment can occur as teachers and students engage and interact with written materials during classroom instruction. We elaborate briefly on these views and then outline the structure of this ZDM issue.     

Assessments accompanying published textbooks: the extent to which mathematical processes are evident

Assessments accompanying published textbooks are often used by teachers in the USA as a primary means to evaluate students’ mathematical knowledge. In addition to assessing content knowledge, assessments should provide insight into students’ ability to engage with mathematical processes such as reasoning, communication, connections, and representations. We report here an analysis of the extent to which the assessments accompanying published textbooks in the USA at the elementary, middle grades, and high school levels provide opportunities for students to engage with these mathematical processes. Results indicate that in elementary grades, communication, connections, and graphics are not consistently emphasized across grade levels and publishers. In middle grades, students are rarely asked to record their reasoning or translate among representational forms of a concept. In high school geometry, students are given many opportunities to interpret and create graphics, but the same is not true for algebra. With the exception of connections, the results suggest that inconsistent emphasis is placed on the mathematical processes within assessments accompanying commercial textbooks in the USA.     

PEROXIDASE MEDIATED CHEMILUMINESCENCE WITH PHENOL DERIVATIVES. PHYSICO-CHEMICAL PARAMETERS AND USES IN BIOLOGICAL ASSAYS

Abstract— The influence of pH and concentration of reagents on the chemiluminescence emitted during peroxidase mediated oxidation of phenol derivatives was studied. Maximal light emission was determined under conditions where chemiluminescence due to auto-oxidation was negligible. With phloroglucinol and purpurogallin as substrates, a direct proportionality was obtained between the concentration of peroxidase and the maximal light emission. p-Phenylenediamine enhances 8-fold the light emitted with purpurogallin. With resorcinol as substrate the relation between concentration of enzyme and maximal light emission gives an S-shaped curve. With pyrogallol the light emitted is proportional to the square of the concentration of peroxidase.