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.

Ptr-miR397a is a negative regulator of laccase genes affecting lignin content in Populus trichocarpa.

Abstract: Laccases, as early as 1959, were proposed to catalyze the oxidative polymerization of monolignols. Genetic evidence in support of this hypothesis has been elusive due to functional redundancy of laccase genes. An Arabidopsis double mutant demonstrated the involvement of laccases in lignin biosynthesis. We previously identified a subset of laccase genes to be targets of a microRNA (miRNA) ptr-miR397a in Populus trichocarpa. To elucidate the roles of ptr-miR397a and its targets, we characterized the laccase gene family and identified 49 laccase gene models, of which 29 were predicted to be targets of ptr-miR397a. We overexpressed Ptr-MIR397a in transgenic P. trichocarpa. In each of all nine transgenic lines tested, 17 PtrLACs were down-regulated as analyzed by RNA-seq. Transgenic lines with severe reduction in the expression of these laccase genes resulted in an ∼40% decrease in the total laccase activity. Overexpression of Ptr-MIR397a in these transgenic lines also reduced lignin content, whereas levels of all monolignol biosynthetic gene transcripts remained unchanged. A hierarchical genetic regulatory network (GRN) built by a bottom-up graphic Gaussian model algorithm provides additional support for a role of ptr-miR397a as a negative regulator of laccases for lignin biosynthesis. Full transcriptome–based differential gene expression in the overexpressed transgenics and protein domain analyses implicate previously unidentified transcription factors and their targets in an extended hierarchical GRN including ptr-miR397a and laccases that coregulate lignin biosynthesis in wood formation. Ptr-miR397a, laccases, and other regulatory components of this network may provide additional strategies for genetic manipulation of lignin content.

Consequences of Cultural Practices for Entrepreneurial Behaviors

Abstract: Although national culture is an important regulator of entrepreneurship, there is a dearth of studies that (i) explore the effects of national cultural practices on entrepreneurial behaviors by individuals; (ii) use appropriate multi-level research designs; (iii) consider the effects of culture on different entrepreneurial behaviors such as entry and post-entry growth aspirations. We combined Global Entrepreneurship Monitor (GEM) and Global Leadership and Organizational Behavior Effectiveness (GLOBE) data from 42 countries for 2005-2008 to address these gaps using a multi-level design. We found societal institutional collectivism practices negatively associated with entrepreneurial entry but positively associated with entrepreneurial growth aspirations. Uncertainty avoidance practices were negatively associated with entry but not with growth aspirations, while performance orientation practices were positively associated with entry. Our analysis highlights the differential effects of cultural practices on entrepreneurial entry and growth aspirations and demonstrates the value of multi-level techniques in analyzing the effect of culture on entrepreneurship.

Physisorption of nucleobases on graphene : Density-functional calculations

Abstract: We report the results of our first-principles investigation on the interaction of the nucleobases adenine (A), cytosine (C), guanine (G), thymine (T), and uracil (U) with graphene, carried out within the density-functional theory framework, with additional calculations utilizing Hartree-Fock plus second-order M\o{}ller-Plesset perturbation theory. The calculated binding energy of the nucleobases shows the following hierarchy: $\mathrm{G}g\mathrm{A}\ensuremath{\approx}\mathrm{T}\ensuremath{\approx}\mathrm{C}g\mathrm{U}$, with the equilibrium configuration being rather similar for all five of them. Our results clearly demonstrate that the nucleobases exhibit significantly different interaction strengths when physisorbed on graphene. The stabilizing factor in the interaction between the base molecule and graphene sheet is dominated by the molecular polarizability that allows a weakly attractive dispersion force to be induced between them. The present study represents a significant step toward a first-principles understanding of how the base sequence of DNA can affect its interaction with carbon nanotubes, as observed experimentally.

The Development and Assessment of a Course for Enhancing the 3‐D Spatial Visualization Skills of First Year Engineering Students

Abstract: In January 1993, we received NSF funding to develop a pre-graphics course for freshman engineering majors who are weak in 3-D spatial visualization skills. A text and computer lab exercises utilizing I-DEAS software were written specifically for this course. The course is 3-credits (quarter system) with two hours of lecture and two hours of computer lab each week. It was offered at Michigan Technological University (MTU) for the first time during the 1993 Fall term and has been offered each fall since that time. The objective of the course is to provide the prerequisite spatial skills needed by students to succeed in their subsequent engineering graphics courses. Assessment for the course has been continuous. Recently, a six-year longitudinal study was conducted to determine the overall success of this project. This paper will describe the project and the assessment findings from the longitudinal study.

The potential of agrivoltaic systems

Abstract: In order to meet global energy demands with clean renewable energy such as with solar photovoltaic (PV) systems, large surface areas are needed because of the relatively diffuse nature of solar energy. Much of this demand can be matched with aggressive building integrated PV and rooftop PV, but the remainder can be met with land-based PV farms. Using large tracts of land for solar farms will increase competition for land resources as food production demand and energy demand are both growing and vie for the limited land resources. This land competition is exacerbated by the increasing population. These coupled land challenges can be ameliorated using the concept of agrivoltaics or co-developing the same area of land for both solar PV power as well as for conventional agriculture. In this paper, the agrivoltaic experiments to date are reviewed and summarized. A coupled simulation model is developed for both PV production (PVSyst) and agricultural production (Simulateur mulTIdisciplinaire les Cultures Standard (STICS) crop model), to gauge the technical potential of scaling agrivoltaic systems. The results showed that the value of solar generated electricity coupled to shade-tolerant crop production created an over 30% increase in economic value from farms deploying agrivoltaic systems instead of conventional agriculture. Utilizing shade tolerant crops enables crop yield losses to be minimized and thus maintain crop price stability. In addition, this dual use of agricultural land can have a significant effect on national PV production. The results showed an increase in PV power between over 40 and 70 GW if lettuce cultivation alone is converted to agrivoltaic systems in the U.S. It is clear, further work is warranted in this area and that the outputs for different crops and geographic areas should be explored to ascertain the potential of agrivoltaic farming throughout the globe.