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In this article, we discuss Micro Assignment Guided Inquiry and Collaboration (MAGIC), an active learning method that draws on the merits of inquiry-based learning in STEM courses. We describe the use of Micro Assignments (MAs) consisting of a series of short, instructive guiding questions that scaffold the course material. Students work through these questions and present solutions to the class. The instructor facilitates learning as well as collaboration among the students during face-to-face interactions, providing the Guided Inquiry and Collaboration (GIC). We present a qualitative discussion about this active learning approach that achieves some of the documented benefits, such as deep student engagement with the material and familiarity with communicating arguments. This method also helps students develop the skills they need as they move from lower- to upper-level courses, such as collaborating, active reading, and breaking down involved assignments and problems into manageable steps. Through GIC and use of the MAs, the instructor guides students to become more abstract thinkers who desire evidence, evaluate arguments, and no longer follow step-by-step formulas but rather produce logical thought processes.

Sulfur (S) is an essential macronutrient and important component of the earth’s crust, and its cycling has critical impacts on trace metal mobility, water quality, and human health. Pyrite weathering is the primary pathway by which sulfur enters surface waters. However, biogeochemical cycling of sulfur in soils and the river corridor mediates sulfate exports. In this study, we identified the major forms of sulfur across multiple compartments and scales in a pristine mountainous watershed, including shale bedrock weathering profiles, hillslope soils, and alluvial floodplain sediments, in order to provide insight into biogeochemical sulfur cycling in a hydrologically variable alpine system. X-ray absorption near-edge spectroscopy (XANES) analysis of shale weathering profiles showed clear evidence of pyrite oxidation to sulfate, with large accumulations of intermediate S(0) (20%–53%). Micro-scale XANES showed evidence of reprecipitation of pyrite at fracture surfaces within the permanently saturated zone. Organic sulfur dominated S speciation in shallow hillslope soil and floodplain sediment, with little evidence of reduced inorganic S. However, mackinawite formation, representing active sulfate reduction, was observed in saturated oxbow sediments and saturated weathered shale underlying floodplain sediments. Further evidence of sulfate reduction from aqueous sulfur isotopic analysis was observed in shallow groundwater transects across an Fe-reducing meander, whereas increases in pore water sulfate concentrations implied sulfur oxidation at other locations. The data present an integrated picture of sulfur cycling in a shale-dominated watershed, where riverine sulfate exports are mediated by biological cycling, particularly in redox-stratified and temporally dynamic hyporheic zone sediments.

La question de la prise en charge éducative des enfants soldats démobilisés nous a préoccupée dans cette étude. A bien considérer les choses, nous nous trouvons face au défi de donner accès à l'école à tous les enfants de notre pays, sans distinction de leurs conditions. C'est le prix à payer pour la démocratisation de l'éducation, une ambition partagée pour tout le monde, et exprimée à travers l'objectif du millénaire relatif à l'éducation pour tous. Et, les situations particulières que traversent des milliers d'enfants dans notre pays doivent attirer l'attention, non seulement des décideurs, mais aussi des chercheurs. Ceux-ci ont le devoir de donner la juste mesure des conditions de ces enfants et de proposer des solutions adaptées. Dans cette étude, nous partons du constat selon lequel l'abandon des classes est l'une des graves conséquences qui s'aggrave avec des conflits armés qui dérangent le pays, surtout dans sa partie orientale. Et la cessation des hostilités entre belligérants est une opportunité que saisissent les États et les organisations s'occupant de la scolarisation pour faire récupérer aux enfants leur formation scolaire. Les cas des enfants soldats démobilisés est spécial par le fait de leur statut d'enfants qui ont connu une expérience particulière dans le conflit. Dans cette étude, nous essayons de déceler les problèmes que rencontrent les écoles de Kindu qui ont admis les anciens enfants soldats démobilisés.

La qualité de l’environnement dans laquelle évolue l’homme est l’un des paramètres déterminants tant pour son épanouissement que pour un meilleur rendement des activités qu’il exerce dans son milieu. La constitution congolaise protège par ailleurs cette prérogative en ces termes : « toute personne a droit à un environnement sain et propice à son épanouissement » (article 53, alinéa 1er) et l’État veille à la protection de l’environnement et à la santé des populations (article 53, alinéa 3). Ce qui explique l’obligation pour le pouvoir public et des individus de la prise en charge des campagnes de la lutte contre la pollution, la destruction de l’écosystème et toutes les autres formes d’altération environnementale dans le cadre d’une politique environnementale programmée et planifiée. La République Démocratique du Congo (RDC) semble malheureusement faire peu cas de l'ère dans sa politique de gestion de l'environnement et de conservation de la nature. L'école étant le milieu d'apprentissage et de socialisation par excellence, notre étude s'est donnée la tâche d'explorer le milieu scolaire de pool de Lemba dans la ville province de Kinshasa en vue de cerner les problèmes qui empêchent les élèves de s’impliquer aux travaux de maintien de la propreté de leur environnement scolaire.

Stratigraphy is a fundamental component of floodplain heterogeneity and hydraulic conductivity and connectivity of alluvial aquifers, which affect hydrologic processes such as groundwater flow and hyporheic exchange. Watershed-scale hydrological models commonly simplify the sedimentology and stratigraphy of floodplains, neglecting natural floodplain heterogeneity and anisotropy. This study, conducted in the upper reach of the East River in the East River Basin, Colorado, USA, combines point-, meander-, and floodplain-scale data to determine key features of alluvial aquifers important for estimating hydrologic processes. We compare stratigraphy of two meanders with disparate geometries to explore floodplain heterogeneity and connectivity controls on flow and transport. Meander shape, orientation, and internal stratigraphy affected residence time estimates of laterally exchanged hyporheic water. Although the two meanders share a sediment source, vegetation, and climate, their divergent river migration histories resulted in contrasting meander hydrofacies. In turn, the extent and orientation of these elements controlled the effective hydraulic conductivity and, ultimately, estimates of groundwater transport and hyporheic residence times. Additionally, the meanders’ orientation relative to the valley gradient impacted the hydraulic gradient across the meanders—a key control of groundwater velocity. Lastly, we combine our field data with remotely sensed data and introduce a potential approach to estimate key hydrostratigraphic packages across floodplains. Prospective applications include contaminant transport studies, hyporheic models, and watershed models. © 2019 John Wiley & Sons, Ltd.

Introduction: Large scale, Earth processes and bulk rock properties are influenced by underpinning, dynamic, microstructures within rocks and geomaterials. Traditionally, the amount of porosity has been considered the primary control on important bulk rock properties like seismic wave velocities (Vp and Vs) and permeability. However, in tight rocks, velocity and permeability (k) can change substantially despite small changes in the amount of porosity during cracking. Therefore, other microstructural features inherent to given lithologies, such as heterogeneity and anisotropy in mineral properties are considered as factors controlling these bulk rock properties. Understanding which microstructural features control Vp, Vs, and permeability in tight rocks is useful in applications like enhanced geothermal systems (EGS), where thermal shocking is used to increase permeability. Thermal shocking involves injecting surface water into the subsurface to cool mineral crystals, induce contraction of crystals, and cause thermal cracking.Methods: We tested three tight lithologies with unique microstructures; granodiorite (SWG), basalt (PTB), and carbonate (MSA). We simulated thermal shocking by slowly heating samples to 350°C and then quenching them. We chose a temperature of 350°C because thermal shocking at this temperature is not well documented in literature, and this temperature is relevant to EGS. Using time-lapse microimaging, we assessed how thermal cracking occurs in each lithology and explored how thermal cracks influence connected porosity, Vp, Vs, and k.Results: Microimaging shows extensive cracking in the SWG and MSA lithologies, and little to no cracking in PTB with thermal shocking treatment. Vp and Vs became more pressure sensitive, and elastic moduli decreased with treatment for all lithologies. This may be caused by reduced stiffness between mineral crystal boundaries with treatment.Discussion: Lithologies with minerals that have anisotropy of or a wide range in thermal conductivity and/or thermal expansion coefficients can have increased thermal cracking. In thermally shocked SWG and MSA, Vp and Vs are good indicators of thermal cracking and k increases, but less so in PTB. Lithologies like PTB may require multiple thermal shock stimulations to increase permeability. Our results highlight how micro-scale changes influence bulk rock properties and when we can monitor permeability increases and microscale thermal cracking with Vp and Vs.

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In near-field remote sensing, noncontact methods (radars) that measure stage and surface water velocity have the potential to supplement traditional bridge scour monitoring tools because they are safer to access and are less likely to be damaged compared with in-stream sensors. The objective of this study was to evaluate the use of radars for monitoring the hydraulic conditions that contribute to bridge–pier scour in gravel-bed channels. Measurements collected with a radar were also leveraged along with minimal field measurements to evaluate whether time-integrated stream power per unit area (Ω) was correlated with observed scour depth at a scour-critical bridge in Colorado. The results of this study showed that (1) there was close agreement between radar-based and U.S. Geological Survey streamgage-based measurements of stage and discharge, indicating that radars may be viable tools for monitoring flow conditions that lead to bridge pier scour; (2) Ω and pier scour depth were correlated, indicating that radar-derived Ω measurements may be used to estimate scour depth in real time and predict scour depth based on the measured trajectory of Ω. The approach presented in this study is intended to supplement, rather than replace, existing high-fidelity scour monitoring techniques and provide data quickly in information-poor areas.

L-ascorbate (L-ASC) is a widely-known dietary nutrient which holds promising potential in cancer therapy when given parenterally at high doses. The anticancer effects of L-ASC involve its autoxidation and generation of H2O2, which is selectively toxic to malignant cells. Here we present that thioredoxin antioxidant system plays a key role in the scavenging of extracellularly-generated H2O2 in malignant B-cells. We show that inhibition of peroxiredoxin 1, the enzyme that removes H2O2 in a thioredoxin system-dependent manner, increases the sensitivity of malignant B-cells to L-ASC. Moreover, we demonstrate that auranofin (AUR), the inhibitor of the thioredoxin system that is used as an antirheumatic drug, diminishes the H2O2-scavenging capacity of malignant B-cells and potentiates pharmacological ascorbate anticancer activity in vitro and in vivo. The addition of AUR to L-ASC-treated cells triggers the accumulation of H2O2 in the cells, which results in iron-dependent cytotoxicity. Importantly, the synergistic effects are observed at as low as 200 µM L-ASC concentrations. In conclusion, we observed strong, synergistic, cancer-selective interaction between L-ASC and auranofin. Since both of these agents are available in clinical practice, our findings support further investigations of the efficacy of pharmacological ascorbate in combination with auranofin in preclinical and clinical settings.

Statins, HMG-CoA reductase inhibitors, are used in the prevention and treatment of cardiovascular diseases owing to their lipid-lowering effects. Previous studies revealed that, by modulating membrane cholesterol content, statins could induce conformational changes in cluster of differentiation 20 (CD20) tetraspanin. The aim of the presented study was to investigate the influence of statins on glucose transporter 1 (GLUT1)-mediated glucose uptake in tumor cells. We observed a significant concentration- and time-dependent decrease in glucose analogs' uptake in several tumor cell lines incubated with statins. This effect was reversible with restitution of cholesterol synthesis pathway with mevalonic acid as well as with supplementation of plasma membrane with exogenous cholesterol. Statins did not change overall GLUT1 expression at neither transcriptional nor protein levels. An exploratory clinical trial revealed that statin treatment decreased glucose uptake in peripheral blood leukocytes and lowered 18F-fluorodeoxyglucose (18F-FDG) uptake by tumor masses in a mantle cell lymphoma patient. A bioinformatics analysis was used to predict the structure of human GLUT1 and to identify putative cholesterol-binding motifs in its juxtamembrane fragment. Altogether, the influence of statins on glucose uptake seems to be of clinical significance. By inhibiting 18F-FDG uptake, statins can negatively affect the sensitivity of positron emission tomography, a diagnostic procedure frequently used in oncology.

We present experimentally determined potential energy curves for the 10(0+)[43Π0] electronic state of NaCs. The 10(0+)[43Π0] state exhibits a double-minimum structure, resulting in a distinctive bound-free fluorescence signature. The perturbation facilitated optical-optical double resonance method was used to obtain Doppler-free excitation spectra corresponding to rovibrational transitions to the 10(0+)[43Π0] state. Spectroscopic constants were determined to summarize data belonging to inner well, outer well, and above the barrier regions of the electronic state. The Rydberg-Klein-Rees and inverted perturbation approach methods were used to construct a potential which reproduces the experimental rovibrational energies within a root-mean-square deviation of 2.33 cm−1. An alternative to the pointwise potential approach was also used to determine the potential energy curve by directly fitting an expanded Morse oscillator functional form. Advantages between the two approaches as they apply to double minimum wells are discussed. [ABSTRACT FROM AUTHOR]