The effect of 3-indoleacetic acid on the response of Lactobacillus arabinosus 17-5 to nicotinamide

Lactobacillus arabinosus 17-5 has been widely used as an assay organism for nicotinic acid (NA) since the development of the method by Snell and Wright (1). Although it has been realized that other substances present in tissue extracts may interfere with the bioassay, the nature of such substances has not been elucidated. During an investigation of tryptophan metabolism in the pea plant, we studied the possible conversion of this compound to nicotinic acid, since such a transformation has been demonstrated to occur in numerous organisms (2-4). The method involved infiltration of tissue with large quantities of tryptophan and subsequent bioassay for nicotinic acid with Lactobacillus arabinosus 17-5. Certain anomalous results led us to believe that other metabolites of tryptophan were interfering with the assay. Because 3-indoleacetic acid (IAA) is a known plant metabolite of tryptophan (5), we tested it for possible interference with the assay, and, as described below, found that such interference may occur under certain circumstances

Letter to John W. Graham & Company from E. O. Hand, June 12, 1950

Letter to John W. Graham & Company, Spokane, Washington, from E. O. Hand, Co-Chairman, Father\u27s Day Council.https://digitalcommons.whitworth.edu/fathers-day-correspondence/1105/thumbnail.jp

Water Based Soil Fluidization using a Soft Eversion Robot

Soft robotics, a form of robotics that incorporates nonrigid components, continues to grow in scope, system design, and application. A recent addition to this field is the Vine Robot platform, a bio-inspired robot designed by Stanford University in 2017. Its method of movement, known as eversion, closely resembles the way that a vine grows along a tree, giving it its name. The focus of this research was to take its proven abilities of underwater vine-like movement and soil fluidization, a process where granular materials are converted from a solid-like state to a fluid-like state, to create an underwater eversion robot capable of burrowing into sand. This was done with the goal of providing a future platform for research into soil composition studies, underwater movement using multiple eversion and fluidization tubes, and other ventures. The unique ability of this platform is extending its reach far beyond that of comparable sized systems. Specific focus was given to the measured abilities of eversion into granular substances using a combination of air and water eversion material, with the former given preference due to its accessibility in underwater environments. The resulting testing showed the capability of using the water as a fluidization material, especially in underwater environments

Resource Provisioning for Multi-Tier Virtualized Server Applications

Virtualizing the x86-based data center creates a dynamic environment for server application deployment and resource sharing. Resource management in this environment is challenging as applications are under fluctuating workloads causing diverse resource demands across their tiers. Resource allocation adaptation is essential for high performance machine utilization. This paper presents feedback controllers that dynamically adjust the CPU allocations of multi-tier applications in order to adapt to workload changes by considering the resource coupling between utilizations of application components. Our experimental evaluation on a virtualized 3-tier Rubis server application shows that our techniques work effectively

Salts and Radiation Products on the Surface of Europa

The surface of Europa could contain the compositional imprint of an underlying interior ocean, but competing hypotheses differ over whether spectral observations from the Galileo spacecraft show the signature of ocean evaporates or simply surface radiation products unrelated to the interior. Using adaptive optics at the W. M. Keck Observatory, we have obtained spatially resolved spectra of most of the disk of Europa at a spectral resolution ~40 times higher than seen by the Galileo spacecraft. These spectra show a previously undetected distinct signature of magnesium sulfate salts on Europa, but the magnesium sulfate is confined to the trailing hemisphere and spatially correlated with the presence of radiation products like sulfuric acid and SO_2. On the leading, less irradiated, hemisphere, our observations rule out the presence of many of the proposed sulfate salts, but do show the presence of distorted water ice bands. Based on the association of the potential MgSO_4 detection on the trailing side with other radiation products, we conclude that MgSO_4 is also a radiation product, rather than a constituent of a Europa ocean brine. Based on ocean chemistry models, we hypothesize that, prior to irradiation, magnesium is primarily in the form of MgCl_2, and we predict that NaCl and KCl are even more abundant, and, in fact, dominate the non-ice component of the leading hemisphere. We propose observational tests of this new hypothesis