Multi-layer light-weight protective coating and method for application

A thin, light-weight, multi-layer coating is provided for protecting metals and their alloys from environmental attack at high temperatures. A reaction barrier is applied to the metal substrate and a diffusion barrier is then applied to the reaction barrier. A sealant layer may also be applied to the diffusion barrier if desired. The reaction barrier is either non-reactive or passivating with respect to the metal substrate and the diffusion barrier. The diffusion barrier is either non-reactive or passivating with respect to the reaction barrier and the sealant layer. The sealant layer is immiscible with the diffusion barrier and has a softening point below the expected use temperature of the metal

The Eastern Belted Kingfisher, Megaceryle Alcyon Alcyon (Linnaeus), in Relation to Fish Management

The kingfisher is the most common and universally distributed bird predator of fish in Michigan. Its principal migration routes are along the Great Lakes shores. Nesting territories are established along streams and lake shores; they are usually larger in the former than in the latter. The kingfisher is diurnal in its feeding with three peaks of activity–morning, afternoon, and early evening. First feeding of fledgelings is on insects; this food is followed by crayfish, then by fish. Fish eaten average about 2.3 inches in length and at fish hatcheries are mostly the species being propagated. On natural waters the food consists mostly of non‐food and non‐game fishes and crayfish. Predation pressure varies with season and within season according to weather, nest distribution, and environmental suitabliity of waters for feeding activity. Because of their feeding proclivities, it is undesirable to have kingfishers about fish hatcheries and rearing stations. At present, general control on natural waters is not biologically justified.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142096/1/tafs0097.pd

Game of Thrones: Fully Distributed Learning for Multi-Player Bandits

We consider a multi-armed bandit game where N players compete for M arms for T turns. Each player has different expected rewards for the arms, and the instantaneous rewards are independent and identically distributed or Markovian. When two or more players choose the same arm, they all receive zero reward. Performance is measured using the expected sum of regrets, compared to optimal assignment of arms to players. We assume that each player only knows her actions and the reward she received each turn. Players cannot observe the actions of other players, and no communication between players is possible. We present a distributed algorithm and prove that it achieves an expected sum of regrets of near-O\left(\log T\right). This is the first algorithm to achieve a near order optimal regret in this fully distributed scenario. All other works have assumed that either all players have the same vector of expected rewards or that communication between players is possible.Comment: A preliminary version was accepted to NIPS 2018. This extended paper, currently under review (submitted in September 2019), improves the regret bound to near-log(T), generalizes to unbounded and Markovian rewards and has a much better convergence rat

Massive Stars in Molecular Clouds Rich in High-energy Sources: The Bridge of G332.809-0.132 and CS 78 in NGC 6334

Detections of massive stars in the direction of the H II region CS 78 in NGC 6334 and of G332.809-0.132 are here presented. The region covered by the G332.809-0.132 complex coincides with the RCW 103 stellar association. In its core (40' in radius), approximately 110 OB candidate stars (Ks < 10 mag and 0.4 < AKs < 1.6 mag) were identified using 2MASS, DENIS, and GLIMPSE data. This number of OB stars accounts for more than 50% of the observed number of Lyman continuum photons from this region. Medium-resolution K-band spectra were obtained for seven early types, including one WN 8 star and one Ofpe/WN 9 star; the latter is located near the RCW 103 remnant and its luminosity is consistent with a distance of about 3 kpc. The area analyzed encloses 9 of the 34 OB stars previously known in RCW 103, as well as IRAS 16115-5044, which we reclassify as a candidate luminous blue variable. The line of sight is particularly interesting, crossing three spiral arms; a molecular cloud at -50 (with RCW 103 in the Scutum-Crux arm) and another at -90 km s-1 (in the Norma arm) are detected, both rich in massive stars and supernova remnants. We also report the detection of a B supergiant as the main ionizing source of CS 78, 2MASS J17213513-3532415. Medium-resolution H and K band spectra display H I and He I lines, as well as Fe II lines. By assuming a distance of 1.35 kpc, we estimate a bolometric magnitude of -6.16, which is typical of supergiants.Comment: 44 pages, 15 figure

Identification of Graphene Dispersion Agents through Molecular Fingerprints

The scalable production and dispersion of 2D materials, like graphene, is critical to enable their use in commercial applications. While liquid exfoliation is commonly used, solvents such as N-methyl-pyrrolidone (NMP) are toxic and difficult to scale up. However, the search for alternative solvents is hindered by the intimidating size of the chemical space. Here, we present a computational pipeline informing the identification of effective exfoliation agents. Classical molecular dynamics simulations provide statistical sampling of interactions, enabling the identification of key molecular descriptors for a successful solvent. The statistically representative configurations from these simulations, studied with quantum mechanical calculations, allow us to gain insights onto the chemophysical interactions at the surface–solvent interface. As an exemplar, through this pipeline we identify a potential graphene exfoliation agent 2-pyrrolidone and experimentally demonstrate it to be as effective as NMP. Our workflow can be generalized to any 2D material and solvent system, enabling the screening of a wide range of compounds and solvents to identify safer and cheaper means of producing dispersions

Enzymatic engineering of the porcine genome with transposons and recombinases

<p>Abstract</p> <p>Background</p> <p>Swine is an important agricultural commodity and biomedical model. Manipulation of the pig genome provides opportunity to improve production efficiency, enhance disease resistance, and add value to swine products. Genetic engineering can also expand the utility of pigs for modeling human disease, developing clinical treatment methodologies, or donating tissues for xenotransplantation. Realizing the full potential of pig genetic engineering requires translation of the complete repertoire of genetic tools currently employed in smaller model organisms to practical use in pigs.</p> <p>Results</p> <p>Application of transposon and recombinase technologies for manipulation of the swine genome requires characterization of their activity in pig cells. We tested four transposon systems- <it>Sleeping Beauty</it>, <it>Tol2</it>, <it>piggyBac</it>, and <it>Passport </it>in cultured porcine cells. Transposons increased the efficiency of DNA integration up to 28-fold above background and provided for precise delivery of 1 to 15 transgenes per cell. Both Cre and Flp recombinase were functional in pig cells as measured by their ability to remove a positive-negative selection cassette from 16 independent clones and over 20 independent genomic locations. We also demonstrated a Cre-dependent genetic switch capable of eliminating an intervening positive-negative selection cassette and activating GFP expression from episomal and genome-resident transposons.</p> <p>Conclusion</p> <p>We have demonstrated for the first time that transposons and recombinases are capable of mobilizing DNA into and out of the porcine genome in a precise and efficient manner. This study provides the basis for developing transposon and recombinase based tools for genetic engineering of the swine genome.</p

The Quest for the Missing Dust: II -- Two Orders of Magnitude of Evolution in the Dust-to-Gas Ratio Resolved Within Local Group Galaxies

We explore evolution in the dust-to-gas ratio with density within four well-resolved Local Group galaxies - the LMC, SMC, M31, and M33. We do this using new ${\it Herschel}$ maps, which restore extended emission that was missed by previous ${\it Herschel}$ reductions. This improved data allows us to probe the dust-to-gas ratio across 2.5 orders of magnitude in ISM surface density. We find significant evolution in the dust-to-gas ratio, with dust-to-gas varying with density within each galaxy by up to a factor 22.4. We explore several possible reasons for this, and our favored explanation is dust grain growth in denser regions of ISM. We find that the evolution of the dust-to-gas ratio with ISM surface density is very similar between M31 and M33, despite their large differences in mass, metallicity, and star formation rate; conversely, we find M33 and the LMC to have very different dust-to-gas evolution profiles, despite their close similarity in those properties. Our dust-to-gas ratios address previous disagreement between UV- and FIR-based dust-to-gas estimates for the Magellanic Clouds, removing the disagreement for the LMC, and considerably reducing it for the SMC - with our new dust-to-gas measurements being factors of 2.4 and 2.0 greater than the previous far-infrared estimates, respectively. We also observe that the dust-to-gas ratio appears to fall at the highest densities for the LMC, M31, and M33; this is unlikely to be an actual physical phenomenon, and we posit that it may be due to a combined effect of dark gas, and changing dust mass opacity.Comment: Accepted for publication in the Astrophysical Journa

Conditional gene expression in the mouse using a Sleeping Beauty gene-trap transposon

BACKGROUND: Insertional mutagenesis techniques with transposable elements have been popular among geneticists studying model organisms from E. coli to Drosophila and, more recently, the mouse. One such element is the Sleeping Beauty (SB) transposon that has been shown in several studies to be an effective insertional mutagen in the mouse germline. SB transposon vector studies have employed different functional elements and reporter molecules to disrupt and report the expression of endogenous mouse genes. We sought to generate a transposon system that would be capable of reporting the expression pattern of a mouse gene while allowing for conditional expression of a gene of interest in a tissue- or temporal-specific pattern. RESULTS: Here we report the systematic development and testing of a transposon-based gene-trap system incorporating the doxycycline-repressible Tet-Off (tTA) system that is capable of activating the expression of genes under control of a Tet response element (TRE) promoter. We demonstrate that the gene trap system is fully functional in vitro by introducing the "gene-trap tTA" vector into human cells by transposition and identifying clones that activate expression of a TRE-luciferase transgene in a doxycycline-dependent manner. In transgenic mice, we mobilize gene-trap tTA vectors, discover parameters that can affect germline mobilization rates, and identify candidate gene insertions to demonstrate the in vivo functionality of the vector system. We further demonstrate that the gene-trap can act as a reporter of endogenous gene expression and it can be coupled with bioluminescent imaging to identify genes with tissue-specific expression patterns. CONCLUSION: Akin to the GAL4/UAS system used in the fly, we have made progress developing a tool for mutating and revealing the expression of mouse genes by generating the tTA transactivator in the presence of a secondary TRE-regulated reporter molecule. A vector like the gene-trap tTA could provide a means for both annotating mouse genes and creating a resource of mice that express a regulable transcription factor in temporally- and tissue-specific patterns for conditional gene expression studies. These mice would be a valuable resource to the mouse genetics community for purpose of dissecting mammalian gene function