Policy in Support of Pedagogy: Collaboration Among Scientists, Science Educators, and Engineers in Preparing Qualified K-8 STEM Teachers

Teachers with knowledge of science and science teach-ing pedagogy are essential to teaching science in K-12 schools. We present collaborative efforts among science and science education faculty members that build a sci-ence teacher program with an overarching objective of training qualified science teachers. Our Foundational Level General Science program goes beyond increasing science content knowledge. Its design fosters a sustained collaboration for faculty in science and education to in-tegrate inquiry-based pedagogy into curricula with the goal of recruiting and retaining STEM teachers. Our ex-perience suggests that certain policies within the higher education infrastructure are necessary to sustain these efforts

Potential of plant genetic engineering for phytoremediation of toxic trace elements

Developed under the Auspices of the UNESCO [http://www.eolss.net]info:eu-repo/semantics/publishe

The Keys to Success in K-6 Next Generation Science Standards Implementation III: Learning Through Scientific and Engineering Practices

The scientific and engineering practices in the Next Generation Science Standards (NGSS) focus on the central practices used by scientists and engineers. These include asking questions and defining problems, modeling, investigating, analyzing and interpreting data, using mathematics, developing explanations, engaging in augmentation, and evaluating information.The presenters describe approaches for preparing current and future teachers to advance their students' understanding of the NGSS scientific and engineering practices. They also talk about engaging experiences that directly involve students in using the practices.Who Will BenefitThe series is aimed at a broad group of stakeholders in education—university faculty, district administrators, and STEM coordinators.Other Webinars in This SeriesThe Keys to Success in K-6 NGSS Implementation I: Well-Prepared Teachers, Excellent Programs [Archived]The Keys to Success in NGSS Implementation II: Cross-Cutting Concepts and CCSS Alignmen

Two Poplar Hybrid Clones Differ in Phenolic Antioxidant Levels and Polyphenol Oxidase Activity in Response to High Salt and Boron Irrigation

Poplar hybrids can be used for selenium (Se) and boron (B) phytoremediation under saline conditions. The phenolic antioxidant stress response of two salt and B tolerant poplar hybrids of parentage Populus trichocarpa × <i>nigra</i> × <i>deltoides</i> was studied using high-performance liquid chromatography (HPLC) and absorption-based assays to determine the antioxidant capacity, total phenolic content, hydroxycinnamic acid levels, and the enzyme activity of l-phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), phenol peroxidase (POD), and laccase. Most remarkable was the contrasting response of the two poplar clones for PPO activity and phenolic levels to irrigation with high salt/B water. To cope with stressful growing conditions, only one clone increased its phenolic antioxidant level, and each clone displayed different PPO isoform patterns. Our study shows that poplar hybrids of the same parentage can differ in their salt/B stress coping mechanism

Complexation of Hg with phytochelatins is important for plant Hg tolerance

14 Pag., 3 Tabl., 5 Fig. The definitive version is available at: www3.interscience.wiley.comThree-week-old alfalfa (Medicago sativa), barley (Hordeum vulgare) and maize (Zea mays) were exposed for 7 d to 30 µm of mercury (HgCl2) to characterize the Hg speciation in root, with no symptoms of being poisoned. The largest pool (99%) was associated with the particulate fraction, whereas the soluble fraction (SF) accounted for a minor proportion (<1%). Liquid chromatography coupled with electro-spray/time of flight mass spectrometry showed that Hg was bound to an array of phytochelatins (PCs) in root SF, which was particularly varied in alfalfa (eight ligands and five stoichiometries), a species that also accumulated homophytochelatins. Spatial localization of Hg in alfalfa roots by microprobe synchrotron X-ray fluorescence spectroscopy showed that most of the Hg co-localized with sulphur in the vascular cylinder. Extended X-ray Absorption Fine Structure (EXAFS) fingerprint fitting revealed that Hg was bound in vivo to organic-S compounds, i.e. biomolecules containing cysteine. Albeit a minor proportion of total Hg, Hg–PCs complexes in the SF might be important for tolerance to Hg, as was found with Arabidopsis thaliana mutants cad2-1 (with low glutathione content) and cad1-3 (unable to synthesize PCs) in comparison with wild type plants. Interestingly, high-performance liquid chromatography-electrospray ionization-time of flight analysis showed that none of these mutants accumulated Hg–biothiol complexes.This work was supported by Fundación Ramón Areces (http://www.fundacionareces.es), the Spanish Ministry of Science and Innovation (AGL2010-15151-PROBIOMET and AGL2007-61948), Comunidad de Madrid (EIADES S2009/AMB-1478), Junta Comunidades Castilla-La Mancha (FITOALMA, PBI07-0091-3644) and the Aragón Government (Group A03). The HPLC-ESI-TOFMS equipment was co-financed with EU FEDER funds. Portions of this research were carried out at the Stanford Synchrotron Radiation Lightsource, through the Structural Molecular Biology Program supported by the Department of Energy, Office of Biological and Environmental Research, and by the National Institute of Health, National Centre for Research Resources, Biomedical Technology Program.Peer reviewe

Mercury Localization and Speciation in Plants Grown Hydroponically or in a Natural Environment

Better understanding of mercury (Hg) accumulation, distribution, and speciation in plants is required to evaluate potential risks for the environment and to optimize phytostabilization strategies for Hg-contaminated soils. The behavior of Hg in alfalfa (<i>Medicago sativa</i>) plants grown under controlled conditions in a hydroponic system (30 μM HgCl₂) was compared with that of naturally occurring Horehound (<i>Marrubium vulgare</i>) plants collected from a mining soil polluted with Hg (Almadenejos, Spain) to characterize common mechanisms of tolerance. Synchrotron X-ray Fluorescence microprobe (μ-SXRF) showed that Hg accumulated at the root apex of alfalfa and was distributed through the vascular system to the leaves. Transmission electron microscopy (TEM) implied association of Hg with cell walls, accompanied by their structural changes, in alfalfa roots. Extended X-ray absorption fine structure (EXAFS) determined that Hg was principally bound to biothiols and/or proteins in <i>M. sativa</i> roots, stems, and leaves. However, the major fraction of Hg detected in <i>M. vulgare</i> plants consisted of mineral species, possibly associated with soil components. Interestingly, the fraction of Hg bound to biothiols/proteins (i.e., metabolically processed Hg) in leaves of both plants (alfalfa and <i>M. vulgare</i>) was similar, in spite of the big difference in Hg accumulation in roots, suggesting that some tolerance mechanisms might be shared