Morphisms.

I discuss my Master of Fine Arts exhibition, Morphisms, hosted by Slocomb Galleries on the campus of East Tennessee State University March 22 through March 26, 2010. The exhibit includes works created during the artist\u27s three year study at East Tennessee State University. The exhibition consists of works that address the projection of human qualities on domesticated animals and the projection of animal qualities onto mythological deities. Discussion also includes the process involved in creating the artwork as well as artistic influences in technical concepts

In-task auditory performance-related feedback promotes cardiovascular markers of a challenge state during a pressurized task

This is the final version. Available on open access from Taylor & Francis via the DOI in this recordBackground and Objectives: Individuals evaluate the demands and resources associated with a pressurized situation, which leads to distinct patterns of cardiovascular responses. While it is accepted that cognitive evaluations are updated throughout a pressurized situation, to date, cardiovascular markers have only been recorded immediately before, or averaged across, these situations. Thus, this study examined the influence of in-task performance-related feedback on cardiovascular markers of challenge and threat to explore fluctuations in these markers.Methods and Design: Forty participants completed a pressurized visual search task while cardiovascular markers of challenge and threat were recorded. During the task, participants received either positive or negative feedback via distinct auditory tones to induce a challenge or threat state. Following task completion, cardiovascular markers were recorded during a recovery phase.Results: Participants' cardiovascular responses changed across the experimental protocol. Specifically, while participants displayed a cardiovascular response more reflective of a challenge state following in-task performance-related feedback, participants exhibited a response more akin to a threat state later during the recovery phase.Conclusions: In-task auditory performance-related feedback promoted cardiovascular markers of a challenge state. These markers fluctuated over the experiment, suggesting that they, and presumably underlying demand and resource evaluations, are relatively dynamic in nature.Experimental Psychology Societ

Precision control of thermal transport in cryogenic single-crystal silicon devices

We report on the diffusive-ballistic thermal conductance of multi-moded single-crystal silicon beams measured below 1 K. It is shown that the phonon mean-free-path $\ell$ is a strong function of the surface roughness characteristics of the beams. This effect is enhanced in diffuse beams with lengths much larger than $\ell$, even when the surface is fairly smooth, 5-10 nm rms, and the peak thermal wavelength is 0.6 $\mu$m. Resonant phonon scattering has been observed in beams with a pitted surface morphology and characteristic pit depth of 30 nm. Hence, if the surface roughness is not adequately controlled, the thermal conductance can vary significantly for diffuse beams fabricated across a wafer. In contrast, when the beam length is of order $\ell$, the conductance is dominated by ballistic transport and is effectively set by the beam area. We have demonstrated a uniformity of $\pm$8% in fractional deviation for ballistic beams, and this deviation is largely set by the thermal conductance of diffuse beams that support the micro-electro-mechanical device and electrical leads. In addition, we have found no evidence for excess specific heat in single-crystal silicon membranes. This allows for the precise control of the device heat capacity with normal metal films. We discuss the results in the context of the design and fabrication of large-format arrays of far-infrared and millimeter wavelength cryogenic detectors

Halogenases:a palette of emerging opportunities for synthetic biology–synthetic chemistry and C–H functionalisation

Authors thank ERC GenoChemetics (FP7/2007-2013/ERC consolidator grant GCGXC grant agreement no. 614779 RJMG) for funding, BBSRC Follow on Funding, Synthetic Biology Highlight award. RSE Enterprise Fellowship (SVS), China Scholarship Council and EPSRC CRITICAT EP/L016419/1 for studentship support (Y. Z. & S. M. respectively).The enzymatic generation of carbon–halogen bonds is a powerful strategy used by both nature and synthetic chemists to tune the bioactivity, bioavailability and reactivity of compounds, opening up the opportunity for selective C–H functionalisation. Genes encoding halogenase enzymes have recently been shown to transcend all kingdoms of life. These enzymes install halogen atoms into aromatic and less activated aliphatic substrates, achieving selectivities that are often challenging to accomplish using synthetic methodologies. Significant advances in both halogenase discovery and engineering have provided a toolbox of enzymes, enabling the ready use of these catalysts in biotransformations, synthetic biology, and in combination with chemical catalysis to enable late stage C–H functionalisation. With a focus on substrate scope, this review outlines the mechanisms employed by the major classes of halogenases, while in parallel, it highlights key advances in the utilisation of the combination of enzymatic halogenation and chemical catalysis for C–H activation and diversification.Publisher PDFPeer reviewe

A Mg(OH)2 coprecipitation method for determining chromium speciation and isotopic composition in seawater

Chromium (Cr) stable isotopes have emerged as a powerful tool for tracking environmental redox transfor- mations. This is because Cr isotopes are fractionated during redox reactions between Cr(III) and Cr(VI). In order to fully exploit the information recorded within Cr isotope compositions, we must be able to track changes in Cr speciation throughout the environment and, in particular, the changes in speciation between input to the ocean and eventual deposition in sediments. We must also be able to access the isotope compositions of each Cr species, rather than only total dissolved Cr. We have thus developed a magnesium hydroxide coprecipitation method that meets these objectives. This method achieves complete recovery and has a typical precision on concentration measurements of !8% (1σ). It was tested using seawater collected from Saanich Inlet, a persis- tently anoxic fjord on the Pacific coast of Canada. Chromium speciation profiles and proof-of-concept isotope ratio measurements on selected samples indicate that isotopically lighter Cr(III) can be isolated from coexisting isotopically heavier Cr(VI), effectively resolving species-specific Cr isotope compositions. While the oxygenated surface waters of Saanich Inlet follow the generally observed correlation between seawater Cr concentration and its isotopic composition, seawater from anoxic depths diverges from this array, indicating that different pro- cesses are responsible for setting the isotope composition of these deeper waters. Broader application of Mg(OH)2 coprecipitation has strong potential to yield new insights into the fractionation of Cr isotopes in the oceans and the pathways that ultimately set the Cr isotopic composition of marine sediments and sedimentary archives

Scalable background-limited polarization-sensitive detectors for mm-wave applications

We report on the status and development of polarization-sensitive detectors for millimeter-wave applications. The detectors are fabricated on single-crystal silicon, which functions as a low-loss dielectric substrate for the microwave circuitry as well as the supporting membrane for the Transition-Edge Sensor (TES) bolometers. The orthomode transducer (OMT) is realized as a symmetric structure and on-chip filters are employed to define the detection bandwidth. A hybridized integrated enclosure reduces the high-frequency THz mode set that can couple to the TES bolometers. An implementation of the detector architecture at Q-band achieves 90% efficiency in each polarization. The design is scalable in both frequency coverage, 30-300 GHz, and in number of detectors with uniform characteristics. Hence, the detectors are desirable for ground-based or space-borne instruments that require large arrays of efficient background-limited cryogenic detectors.Comment: 7 pages, 3 figures, Presented at SPIE Astronomical Telescopes and Instrumentation 2014: Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII. To be published in Proceedings of SPIE Volume 915