Maximum Gene-Support Tree

Genomes and genes diversify during evolution; however, it is unclear to what extent genes still retain the relationship among species. Model species for molecular phylogenetic studies include yeasts and viruses whose genomes were sequenced as well as plants that have the fossil-supported true phylogenetic trees available. In this study, we generated single gene trees of seven yeast species as well as single gene trees of nine baculovirus species using all the orthologous genes among the species compared. Homologous genes among seven known plants were used for validation of the finding. Four algorithms—maximum parsimony (MP), minimum evolution (ME), maximum likelihood (ML), and neighbor-joining (NJ)—were used. Trees were reconstructed before and after weighting the DNA and protein sequence lengths among genes. Rarely a gene can always generate the “true tree” by all the four algorithms. However, the most frequent gene tree, termed “maximum gene-support tree” (MGS tree, or WMGS tree for the weighted one), in yeasts, baculoviruses, or plants was consistently found to be the “true tree” among the species. The results provide insights into the overall degree of divergence of orthologous genes of the genomes analyzed and suggest the following: 1) The true tree relationship among the species studied is still maintained by the largest group of orthologous genes; 2) There are usually more orthologous genes with higher similarities between genetically closer species than between genetically more distant ones; and 3) The maximum gene-support tree reflects the phylogenetic relationship among species in comparison

Phoebe's orbit from ground-based and space-based observations

The ephemeris of Phoebe, the ninth satellite of Saturn, is not very accurate. Previous dynamical models were usually too simplified, the astrometry is heterogeneous and, the Saturn's ephemeris itself is an additionnal source of error. The aim is to improve Phoebe's ephemeris by using a large set of observations, correcting some systematic errors and updating the dynamical model. The dynamical model makes use of the most recent ephemeris of planets and Saturnian satellites. The astrometry of Phoebe is improved by using a compilation of ground-based and space-based observations and by correcting the bias in stellar catalogues used for the reduction. We present an accurate ephemeris of Phoebe with residuals of 0.45 arcsec and with an estimated accuracy of Phoebe's position of less that 100 km on 1990-2020 period.Comment: 10 pages, 9 figures, accepted by A&

Surface Rebound of Relativistic Dislocations Directly and Efficiently Initiates Deformation Twinning

Under ultrahigh stresses (e.g., under high strain rates or in small-volume metals) deformation twinning (DT) initiates on a very short time scale, indicating strong spatial-temporal correlations in dislocation dynamics. Using atomistic simulations, here we demonstrate that surface rebound of relativistic dislocations directly and efficiently triggers DT under a wide range of laboratory experimental conditions. Because of its stronger temporal correlation, surface rebound sustained relay of partial dislocations is shown to be dominant over the conventional mechanism of thermally activated nucleation of twinning dislocations.National Science Foundation (U.S.) (Grant DMR-1410636

An integrated approach for remanufacturing job shop scheduling with routing alternatives.

Remanufacturing is a practice of growing importance due to increasing environmental awareness and regulations. However, the stochastic natures inherent in the remanufacturing processes complicate its scheduling. This paper undertakes the challenge and presents a remanufacturing job shop scheduling approach by integrating alternative routing assignment and machine resource dispatching. A colored timed Petri net is introduced to model the dynamics of remanufacturing process, such as various process routings, uncertain operation times for cores, and machine resource conflicts. With the color attributes in Petri nets, two types of decision points, recovery routing selection and resource dispatching, are introduced and linked with places in CTPN model. With time attributes in Petri nets, the temporal aspect of recovery operations for cores as well as the evolution dynamics in cores\u27 operational stages is mathematically analyzed. A hybrid meta-heuristic algorithm embedded scheduling strategy over CTPN is proposed to search for the optimal recovery routings for worn cores and their recovery operation sequences on workstations, in minimizing the total production cost. The approach is demonstrated through the remanufacturing of used machine tool and its effectiveness is compared against another two cases: baseline case with fixed recovery process routings and case 2 using standard SA/MST

Application of Poly (vinylbutyral) Nanocomposites in Environment Design

This text passed an adoption to totally mix a method to lead to make even PVB/SiO2 compound material into the nano SiO2 grain son in gather the PVB material.. With the UV-VIS, FT-IR, XRD, SEM etc. modern tested means token tiny view facial look, structure and optics function of material. Result enunciation:because the lead of the nano SiO2 grain son go into and make the compound material of the PVB/SiO2 have good ultraviolet rays to shield function; Meanwhile, the tenacity of material gets an obvious exaltation, it splits an elongation rate is 8 times than the for pure PVB material. Key words: nanocomposite; mixing process; nanometer silica; environment desig

A Community of Practice Approach to Integrating Professional Skills Training with Graduate Thesis Research

Background. It is well recognized that current graduate education is too narrowly focused on thesis research. Graduate students have a strong desire to gain skills for their future career success beyond thesis research. This obvious gap in professional skill training in current graduate study also leads to the common student perception that professional skills beyond academic knowledge should only be gained after completion of thesis research. Purpose. A new program is being developed to rigorously integrate professional skills training with thesis research. The approach is to establish learning communities of Graduates for Advancing Professional Skills (GAPS) to incorporate project management skill training from industry into academic research. The GAPS program seeks to address two fundamental education research questions: How can project management skill training be integrated with thesis research in graduate education? What is the role/value of learning communities in enhancing the training and retention of professional skills and the effectiveness of thesis research? Our proposed solution is that graduate student learning communities engaging in a blended online and classroom approach will promote learning of professional skills such as project and time management in thesis research activities. The purpose of this session is to establish the connection between project management and thesis research, and demonstrate the beginning progress of the GAPS program towards. Methodology/approach. The following progress is being made to establish GAPS learning communities through which to teach and practice professional skills. A website has been developed to introduce the program, recruit participants, provide information on the online modules, and survey results of participants’ current levels of knowledge and skills related to project management. A new course, “Introduction of Project Management for Thesis Research”, has been added to the course catalog and open to enrollment for students from different majors. In addition, learning modules including project charter, scheduling, communication, teamwork, critical path method, and lean concept are developed. Case studies and examples have been developed to help students learn how to utilize project management skills in their thesis research. Conclusions. The concept of integrating professional skills training with thesis research through learning communities has been demonstrated. There are multiple advantages of this approach, including efficient utilization of the current resources, and faculty buy-in. Preliminary data from the first cohort are being collected and analyzed to identify students’ needs, benefits of the program, and areas of improvement for future cohort iterations. Implications. The GAPS program will improve professional skill training for graduate students through communities of practice. This new learning model has the potential to fundamentally change the culture of graduate education. We believe the method demonstrated here can be broadly applied to different engineering majors, and even broadly to all thesis research