885 research outputs found

    Environmental Stewardship Promotes a Sense of Place: Coral Health Monitoring on Maui

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    Environmental stewardship is an integral aspect of the Montessori curriculum. It usually includes care of the school’s setting (classrooms, grounds, gardens, eating areas, etc.) and, depending on each school’s unique situation, ideally extends into the larger environment in which the school is situated. During the 2014-15 school year, our class of Middle School students at Montessori Hale O Keiki (MHOK) were asked to select community service projects that were directly relevant to environmental and/or ecological issues on Maui. For our students, Coral Watch was the perfect project through which to integrate marine science, environmental stewardship, and community service. Through a downloadable “do-it-yourself” kit, our Middle School divers learned a simple method to “quantify bleaching and monitor coral health” (Coral Watch, 2015) by measuring small fluctuations in the color of healthy coral—key to identifying abnormal changes. Using an underwater slate, our student divers matched the color of a randomly selected coral with the colors on the slate and assigned a corresponding number. Later, back in the classroom, they uploaded this information to an online database where it was analyzed by scientists in Australia for information on coral bleaching and recovery patterns

    Contents IJE-Volume 1 (1), October 2020

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    Synthesis, X-ray Structures, Electronic Properties, and O\u3csub\u3e2\u3c/sub\u3e/NO Reactivities of Thiol Dioxygenase Active-Site Models

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    Mononuclear non-heme iron complexes that serve as structural and functional mimics of the thiol dioxygenases (TDOs), cysteine dioxygenase (CDO) and cysteamine dioxygenase (ADO), have been prepared and characterized with crystallographic, spectroscopic, kinetic, and computational methods. The high-spin Fe(II) complexes feature the facially coordinating tris(4,5-diphenyl-1-methylimidazol-2-yl)phosphine (Ph2TIP) ligand that replicates the three histidine (3His) triad of the TDO active sites. Further coordination with bidentate l-cysteine ethyl ester (CysOEt) or cysteamine (CysAm) anions yielded five-coordinate (5C) complexes that resemble the substrate-bound forms of CDO and ADO, respectively. Detailed electronic-structure descriptions of the [Fe(Ph2TIP)(LS,N)]BPh4 complexes, where LS,N = CysOEt (1) or CysAm (2), were generated through a combination of spectroscopic techniques [electronic absorption, magnetic circular dichroism (MCD)] and density functional theory (DFT). Complexes 1 and 2 decompose in the presence of O2 to yield the corresponding sulfinic acid (RSO2H) products, thereby emulating the reactivity of the TDO enzymes and related complexes. Rate constants and activation parameters for the dioxygenation reactions were measured and interpreted with the aid of DFT calculations for O2-bound intermediates. Treatment of the TDO models with nitric oxide (NO)—a well-established surrogate of O2—led to a mixture of high-spin and low-spin {FeNO}7 species at low temperature (−70 °C), as indicated by electron paramagnetic resonance (EPR) spectroscopy. At room temperature, these Fe/NO adducts convert to a common species with EPR and infrared (IR) features typical of cationic dinitrosyl iron complexes (DNICs). To complement these results, parallel spectroscopic, computational, and O2/NO reactivity studies were carried out using previously reported TDO models that feature an anionic hydrotris(3-phenyl-5-methyl-pyrazolyl)borate (Ph,MeTp–) ligand. Though the O2 reactivities of the Ph2TIP- and Ph,MeTp-based complexes are quite similar, the supporting ligand perturbs the energies of Fe 3d-based molecular orbitals and modulates Fe–S bond covalency, suggesting possible rationales for the presence of neutral 3His coordination in CDO and ADO

    Localization of [gamma]-Glutamylcysteine Synthetase and Glutathione Synthetase Activity in Maize Seedlings

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    Fresh weight, protein, cysteine, [gamma]-glutamylcysteine, glutathione, and the extractable activity of the enzymes of glutathione biosynthesis, [gamma]-glutamylcysteine synthetase (EC 6.3.2.2) and glutathione synthetase (EC 6.3.2.3), were measured in roots, scutella, endosperms, and shoots of 3-, 7-, and 11-d-old maize (Zea mays L. cv LG 9) seedlings. In 3-d-old seedlings, the scutella represented 14% of the seedling fresh weight, containing 43% of total protein and 63 and 55% of the activity of [gamma]-glutamylcysteine synthetase and glutathione synthetase, respectively; in 11-d-old seedlings, the corresponding values were 4.5% for fresh weight, 8.0% for protein content, and 14 and 20% for the enzyme activities. The highest concentrations of thiols were found for cysteine (0.27 mM) in the roots, for glutathione (4.4 mM) in the shoots, and for [gamma]-glutamylcysteine (13 [mu]M) in the scutella of 3-d-old seedlings. The enzyme activities of roots were localized in subcellular fractions after sucrose density gradient centrifugation. Nearly half of the [gamma]-glutamylcysteine synthetase activity was detected in the root proplastids of 4-d-old seedlings, whereas <10% of the glutathione synthetase activity was localized in this organelle. Our results demonstrate the importance of scutella in glutathione synthesis in the early stage of seedling development. Unlike chloroplasts, root plastids show only a small proportion of glutathione synthetase activity

    Estimating the uptake of traffic-derived NO2 from 15N abundance in Norway spruce needles

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    The 15N ratio of nitrogen oxides (NOx) emitted from vehicles, measured in the air adjacent to a highway in the Swiss Middle Land, was very high [δ15N(NO2) = +5.7‰]. This high 15N abundance was used to estimate long-term NO2 dry deposition into a forest ecosystem by measuring δ15N in the needles and the soil of potted and autochthonous spruce trees [Picea abies (L.) Karst] exposed to NO2 in a transect orthogonal to the highway. δ15N in the current-year needles of potted trees was 2.0‰ higher than that of the control after 4 months of exposure close to the highway, suggesting a 25% contribution to the N-nutrition of these needles. Needle fall into the pots was prevented by grids placed above the soil, while the continuous decomposition of needle litter below the autochthonous trees over previous years has increased δ15N values in the soil, resulting in parallel gradients of δ15N in soil and needles with distance from the highway. Estimates of NO2 uptake into needles obtained from the δ15N data were significantly correlated with the inputs calculated with a shoot gas exchange model based on a parameterisation widely used in deposition modelling. Therefore, we provide an indication of estimated N inputs to forest ecosystems via dry deposition of NO2 at the receptor level under field conditions

    Effect of glucose on assimilatory sulphate reduction in Arabidopsis thaliana roots

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    With the aim of analysing the relative importance of sugar supply and nitrogen nutrition for the regulation of sulphate assimilation, the regulation of adenosine 5′‐phosphosulphate reductase (APR), a key enzyme of sulphate reduction in plants, was studied. Glucose feeding experiments with Arabidopsis thaliana cultivated with and without a nitrogen source were performed. After a 38 h dark period, APR mRNA, protein, and enzymatic activity levels decreased dramatically in roots. The addition of 0.5% (w/v) glucose to the culture medium resulted in an increase of APR levels in roots (mRNA, protein and activity), comparable to those of plants kept under normal light conditions. Treatment of roots with d‐sorbitol or d‐mannitol did not increase APR activity, indicating that osmotic stress was not involved in APR regulation. The addition of O‐acetyl‐l‐serine (OAS) also quickly and transiently increased APR levels (mRNA, protein, and activity). Feeding plants with a combination of glucose and OAS resulted in a more than additive induction of APR activity. Contrary to nitrate reductase, APR was also increased by glucose in N‐deficient plants, indicating that this effect was independent of nitrate assimilation. [35S]‐sulphate feeding experiments showed that the addition of glucose to dark‐treated roots resulted in an increased incorporation of [35S] into thiols and proteins, which corresponded to the increased levels of APR activity. Under N‐deficient conditions, glucose also increased thiol labelling, but did not increase the incorporation of label into proteins. These results demonstrate that (i) exogenously supplied glucose can replace the function of photoassimilates in roots; (ii) APR is subject to co‐ordinated metabolic control by carbon metabolism; (iii) positive sugar signalling overrides negative signalling from nitrate assimilation in APR regulation. Furthermore, signals originating from nitrogen and carbon metabolism regulate APR synergisticall

    La Educación para el Desarrollo Sostenible aplicada a la enseñanza-aprendizaje del alemán como lengua extranjera

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    Desde la irrupción de la Agenda 2030 para el Desarrollo Sostenible, que constituye para todas las personas una oportunidad y una exigencia para responder a los desafíos del mundo, las universidades europeas dentro del espacio generado por la European Higher Education Area (EHEA) asumen su responsabilidad. El carácter integral de la Agenda 2030 permite a la Universidad la construcción de un mundo comprometido con el desarrollo sostenible e inclusivo, la justicia, la dignidad y la igualdad de las personas, dando respuesta a los desafíos que el contexto global presenta para las universidades y para la sociedad internacional en su conjunto. La Educación para el Desarrollo Sostenible (EDS), por lo tanto, concibe los espacios de educación superior como campos estratégicos de transformación-acción de manera que participen de las políticas de sostenibilidad y fomenten iniciativas que contribuyan a un mundo más sostenible y justo. En este artículo proponemos una unidad didáctica en la asignatura de “Alemán como lengua extranjera” para estudiantado matriculado en el Grado de Negocios Internacionales, la cual tematiza cuatro de los Objetivos de Desarrollo Sostenible (ODS). En este sentido, planteamos la posibilidad de vincular el aula de lengua extranjera como instrumento para el desarrollo de competencias en el ámbito de la comunicación lingüística y cultural, que favorezcan un estudiantado creativo, crítico y comprometido
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