Michigan Technological University

About: Michigan Technological University is a education organization based out in Houghton, Michigan, United States. It is known for research contribution in the topics: Population & Volcano. The organization has 8023 authors who have published 17422 publications receiving 481780 citations. The organization is also known as: MTU & Michigan Tech.

Predicting biases in very highly educated samples: Numeracy and metacognition

Abstract: We investigated the relations between numeracy and superior judgment and decision making in two large community outreach studies in Holland (n=5408). In these very highly educated samples (e.g., 30–50% held graduate degrees), the Berlin Numeracy Test was a robust predictor of financial, medical, and metacognitive task performance (i.e., lotteries, intertemporal choice, denominator neglect, and confidence judgments), independent of education, gender, age, and another numeracy assessment. Metacognitive processes partially mediated the link between numeracy and superior performance. More numerate participants performed better because they deliberated more during decision making and more accurately evaluated their judgments (e.g., less overconfidence). Results suggest that well-designed numeracy tests tend to be robust predictors of superior judgment and decision making because they simultaneously assess (1) mathematical competency and (2) metacognitive and self-regulated learning skills.

A review on PEDOT-based counter electrodes for dye-sensitized solar cells

Abstract: SUMMARY The dye-sensitized solar cell (DSSC) is a promising alternative for the Si solar cell due to its low-cost and easy fabrication. As a novel conductive polymer, poly(3,4-ethylenedioxythiophene) (PEDOT) has attracted much attention for DSSCs. In this review article, the progress of PEDOT-based counter electrodes for DSSCs is presented. First, the properties and structure of PEDOT are briefly described, and its feasibility as a DSSC counter electrode is demonstrated. Then, the effect of various treatments on the electrical conductivity and catalytic activity of PEDOT as well as its stability is examined. Furthermore, efficient and low-cost composite counter electrodes consisting of PEDOT and other materials are deeply discussed. Finally, an outlook for PEDOT counter electrodes is provided. Copyright © 2014 John Wiley & Sons, Ltd.

The sucrose transporter family in Populus: the importance of a tonoplast PtaSUT4 to biomass and carbon partitioning

Abstract: Plasma membrane, proton-coupled Group II sucrose symporters (SUT) mediate apoplastic phloem loading and sucrose efflux from source leaves in Arabidopsis and agricultural crop species that have been studied to date. We now report that the most abundantly expressed SUT isoform in Populus tremula×alba, PtaSUT4, is a tonoplast (Group IV) symporter. PtaSUT4 transcripts were readily detected in conducting as well as mesophyll cells in stems and source leaves. In comparison, Group II orthologs PtaSUT1 and PtaSUT3 were very weakly expressed in leaves. Both Group II and Group IV SUT genes were expressed in secondary stem xylem of Populus. Transgenic poplars with RNAi-suppressed PtaSUT4 exhibited increased leaf-to-stem biomass ratios, elevated sucrose content in source leaves and stems, and altered phenylpropanoid metabolism. Transcript abundance of several carbohydrate-active enzymes and phenylalanine ammonia-lyases was also altered in transgenic source leaves. Nitrogen-limitation led to a down-regulation of vacuolar invertases in all plants, which resulted in an augmentation of sucrose pooling and hexose depletion in source leaves and secondary xylem of the transgenic plants. These results are consistent with a major role for PtaSUT4 in orchestrating the intracellular partitioning, and consequently, the efflux of sucrose from source leaves and the utilization of sucrose by lateral and terminal sinks. Our findings also support the idea that PtaSUT4 modulates sucrose efflux and utilization in concert with plant N-status.

Structural basis of eukaryotic nitrate reduction: crystal structures of the nitrate reductase active site.

Abstract: Nitrate assimilation in autotrophs provides most of the reduced nitrogen on earth. In eukaryotes, reduction of nitrate to nitrite is catalyzed by the molybdenum-containing NAD(P)H:nitrate reductase (NR; EC 1.7.1.1-3). In addition to the molybdenum center, NR contains iron-heme and flavin adenine dinucleotide as redox cofactors involved in an internal electron transport chain from NAD(P)H to nitrate. Recombinant, catalytically active Pichia angusta nitrate-reducing, molybdenum-containing fragment (NR-Mo) was expressed in P. pastoris and purified. Crystal structures for NR-Mo were determined at 1.7 and 2.6 A. These structures revealed a unique slot for binding nitrate in the active site and identified key Arg and Trp residues potentially involved in nitrate binding. Dimeric NR-Mo is similar in overall structure to sulfite oxidases, with significant differences in the active site. Sulfate bound in the active site caused conformational changes, as compared with the unbound enzyme. Four ordered water molecules located in close proximity to Mo define a nitrate binding site, a penta-coordinated reaction intermediate, and product release. Because yeast NAD(P)H:NR is representative of the family of eukaryotic NR, we propose a general mechanism for nitrate reduction catalysis.