Solvable senescence model with positive mutations

We build upon our previous analytical results for the Penna model of senescence to include positive mutations. We investigate whether a small but non-zero positive mutation rate gives qualitatively different results to the traditional Penna model in which no positive mutations are considered. We find that the high-lifespan tail of the distribution is radically changed in structure, but that there is not much effect on the bulk of the population. Th e mortality plateau that we found previously for a stochastic generalization of the Penna model is stable to a small positive mutation rate.Comment: 3 figure

MicroRNAs mir‐184 and let‐7 alter Drosophila metabolism and longevity

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140032/1/acel12673.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/140032/2/acel12673-sup-0002-FigS1-S8.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/140032/3/acel12673_am.pd

A microflow electrolysis cell for laboratory synthesis on the multigram scale

A large microflow electrolysis cell for laboratory synthesis on a multigram scale is described. It is based on two circular electrodes with a diameter of 149 mm and a spiral electrolyte flow channel 2000 mm long, 5 mm wide, and 0.5 mm interelectrode gap. Using the methoxylation of N-formylpyrrolidine as a model reaction, it is demonstrated that the cell approaches 100% conversion in a single pass, and it is possible to achieve a reaction selectivity >95% and a product formation rate of >20 g h–1

Application of viscous-inviscid interaction methods to transonic turbulent flows

Two different viscous-inviscid interaction schemes were developed for the analysis of steady, turbulent, transonic, separated flows over axisymmetric bodies. The viscous and inviscid solutions are coupled through the displacement concept using a transpiration velocity approach. In the semi-inverse interaction scheme, the viscous and inviscid equations are solved in an explicitly separate manner and the displacement thickness distribution is iteratively updated by a simple coupling algorithm. In the simultaneous interaction method, local solutions of viscous and inviscid equations are treated simultaneously, and the displacement thickness is treated as an unknown and is obtained as a part of the solution through a global iteration procedure. The inviscid flow region is described by a direct finite-difference solution of a velocity potential equation in conservative form. The potential equation is solved on a numerically generated mesh by an approximate factorization (AF2) scheme in the semi-inverse interaction method and by a successive line overrelaxation (SLOR) scheme in the simultaneous interaction method. The boundary-layer equations are used for the viscous flow region. The continuity and momentum equations are solved inversely in a coupled manner using a fully implicit finite-difference scheme

Highly Regioselective Indoline Synthesis under Nickel/Photoredox Dual Catalysis

Nickel/photoredox catalysis is used to synthesize indolines in one step from iodoacetanilides and alkenes. Very high regioselectivity for 3-substituted indoline products is obtained for both aliphatic and styrenyl olefins. Mechanistic investigations indicate that oxidation to Ni(III) is necessary to perform the difficult C–N bond-forming reductive elimination, producing a Ni(I) complex, which in turn is reduced to Ni(0). This process serves to further demonstrate the utility of photoredox catalysts as controlled single electron transfer agents in multioxidation state nickel catalysis.National Institute of General Medical Sciences (U.S.) (GM63755

Electrochemical micromachining: An Introduction

Copyright © 2016 The Author(s). Electrochemical machining (ECM) is a relatively new technique, only being introduced as a commercial technique within the last 70 years (1). A lot of research was conducted in the 1960s and 1970s but research on electrical discharge machining (EDM) around the same time slowed ECM research (2). The main influence for the development of ECM came from the aerospace industry where very hard alloys were required to be machined without leaving a defective layer in order to produce a component which would behave reliably (3). ECM was primarily used for the production of gas turbine blades (2) or to machine materials into complex shapes that would be difficult to machine using conventional machining methods (4). Tool wear is high and the metal removal rate is slow when machining hard materials with conventional machining methods such as milling. This increases the cost of the machining process overall and this method creates a defective layer on the machined surface (3). Whereas with ECM there is virtually no tool wear even when machining hard materials and it does not leave a defective layer on the machined surface. This paper reviews the application of electrochemical machining with regards to micro-manufacturing and present state of the art micro ECM considering different machined materials, electrolytes and conditions used.The research reported in this article was supported by the European Commission within the project ‘Minimizing Defects in Micro-Manufacturing Applications (MIDEMMA)’ (FP7-2011-NMP-ICT-FoF-285614)

Teacher Candidate Book Introductions

The purpose of this descriptive multi-case study was to explore teacher candidates\u27 book introductions during their field-based studies in elementary classrooms. The participants were 11 undergraduate students (also teacher candidates) enrolled in a field-based reading course at a South Texas regional university. The lessons occurred in the teacher candidates\u27 cooperating teachers\u27 elementary classrooms. Five sources of data were analyzed using both a priori and open coding to determine themes. The book introductions included information related to the meaning of the text and helping students make connections to text; however, little to no syntactical or visual cue information was included. The findings have implications for reading course instructors to ensure that teacher candidates have many opportunities to see and practice the delivery of book introductions during guided reading instruction

Comparison of the Spinels Co3O4 and NiCo2O4 as Bifunctional Oxygen Catalysts in Alkaline Media

Data from experiments with both rotating disc electrodes (RDEs) and gas diffusion electrodes (GDEs) are used to investigate the properties of the spinels, Co3O4 and NiCo2O4, as bifunctional oxygen electrocatalysts. Emphasis is placed on catalyst compositions and electrode structures free of carbon. Oxygen evolution and reduction occur at surfaces where the transition metals are in different oxidation states but the surface can be repeatedly cycled between these two states without significant change. It is shown that carbon-free, NiCo2O4 catalysed GDEs can be fabricated using structures based on stainless steel cloth or nickel foam. Those based on nickel foam can be cycled extensively and allow both O2 evolution and reduction at current densities up to 100 mA cm−2.European Commission (Theme 2010.7.3.1) Energy Storage Systems for Power Distribution NetworksMinistry of National Education, Republic of Turke

Semi-Autonomous Rodent Habitat for Deep Space Exploration

NASA has flown animals to space as part of trailblazing missions and to understand the biological responses to spaceflight. Mice traveled in the Lunar Module with the Apollo 17 astronauts and now mice are frequent research subjects in LEO on the ISS. The ISS rodent missions have focused on unravelling biological mechanisms, better understanding risks to astronaut health, and testing candidate countermeasures. A critical barrier for longer-duration animal missions is the need for humans-in-the-loop to perform animal husbandry and perform routine tasks during a mission. Using autonomous or telerobotic systems to alleviate some of these tasks would enable longer-duration missions to be performed at the Deep Space Gateway. Rodent missions performed using the Gateway as a platform could address a number of critical risks identified by the Human Research Program (HRP), as well as Space Biology Program questions identified by NRC Decadal Survey on Biological and Physical Sciences in Space, (2011). HRP risk areas of potentially greatest relevance that the Gateway rodent missions can address include those related to visual impairment (VIIP) and radiation risks to central nervous system, cardiovascular disease, as well as countermeasure testing. Space Biology focus areas addressed by the Gateway rodent missions include mechanisms and combinatorial effects of microgravity and radiation. The objectives of the work proposed here are to 1) develop capability for semi-autonomous rodent research in cis-lunar orbit, 2) conduct key experiments for testing countermeasures against low gravity and space radiation. The hardware and operations system developed will enable experiments at least one month in duration, which potentially could be extended to one year in duration. To gain novel insights into the health risks to crew of deep space travel (i.e., exposure to space radiation), results obtained from Gateway flight rodents can be compared to ground control groups and separate groups of mice exposed to simulated Galactic Cosmic Radiation (at the NASA Space Radiation Lab). Results can then be compared to identical experiments conducted on the ISS. Together results from Gateway, ground-based, and ISS rodent experiments will provide novel insight into the effects of space radiation