1,816 research outputs found
The use of phenyl-Sepharose for the affinity purification of proteinases
Phenyl-Sepharose is most often used as an adsorbent for hydrophobic interaction chromatography (HIC). We report on its effective use for the affinity purification of some extracellular thermostable proteinases from bacterial sources. Proteinases belonging to the serine, aspartate and metallo mechanistic classes were effective retained by the media. Purification factors in the range of 2.9â60 and enzyme activity yields in excess of 88% were obtained. In some cases homogeneous enzyme was obtained from culture supernatants in a single step. A number of other proteinases from mammalian sources were also retained. The specificity of the enzyme/support interaction was studied. Proteinases complexed with peptide inhibitors (pepstatin and chymostatin) showed reduced binding to phenyl Sepharose indicating with the active site cleft whereas modification with low molecular weight active site directed inactivators such as PMSF and DAN did not, indicating that binding may not be dependent on the catalytic site. Pepsinogen and the pro-enzyme form of the serine proteinase from the thermophilic Bacillus sp. strain Ak.1 were not retained by the media and could be resolved in an efficient manner from their active counterparts
Using an Atomic Molecular Optics Laboratory for Undergraduate Research and Mentoring of Physics Students in Georgia
Using an Atomic Molecular Optics Laboratory for Undergraduate Research and Mentoring of Physics Students in Georgia
An Atomic and Molecular Optical (AMO) Physics research lab is an excellent tool to train and mentor undergraduate students in advanced laboratory techniques. Students gain valuable basic experience in experimental designs, data acquisition techniques, working with high precision optical equipment, building electronics, and working in the machine shop. The current project is building and testing an enclosure for the diode laser to reduce sound and vibrational interference. In addition, we are developing and evaluating a new, more compact laser cavity which is 3d printed. Previously completed projects involved building a temperature controller, current supply circuit, machining the laser mount, milling the vacuum chamber mounts to support the chamber, and machining the Helmholtz coils for the chamber, which are being used to trap the atoms in a Magneto Optical Trap (MOT). This included designing, building, and baking out the vacuum chamber, constructing a trap for the Rb in the chamber, and building the lasers for a saturation-absorption system that is used to probe the 52S1/2â 52P3/2 hyperfine energy transitions of the Rb-85 atom. These energy transitions have been used to frequency-lock a diode laser to trap Rb-85 atoms and then cool them to ultra-low temperatures. The atom cooling will permit observation and measurement of the fundamental properties of atoms. This lab has mentored and supported over twelve undergraduate students in the last four years, of which one became a High School Teacher, three joined Ph.D. programs, one continued in a masterâs level engineering program, and one went to graduate school to study bioengineering
Critical Thinking as Information Literacy: A Model for the Core Curriculum?
Presentation Description
The presenters will share the history of the new critical thinking requirements adopted by Georgia Southern University, which are based upon information literacy goals. In addition, the presenters will briefly examine models for developing and measuring critical thinking skills from other USG institutions. Finally, an opportunity for input from the participants will be welcomed and facilitated through questions from the presenters that focus on assessment of critical thinking
Northern Bobwhite Habitat Modeling on a Military Installation in Relation to Red-Cockaded Woodpecker Management
The Department of Defense (DoD) manages natural resources on ~ 8 million ha of land. A top priority for much of this land is to restore and maintain native ecosystems and associated wildlife species. However, given the typical location (i.e., threatened ecosystems) and size of DoD lands, management conflicts usually occur among endangered/threatened species and game species. Military installations in the southeastern United States are commonly managed to protect red-cockaded woodpecker (Piciodes borealis) (RCW) populations and longleaf-wiregrass ecosystems. Mandated RCW management is not entirely compatible with other declining species such as northern bobwhite (Colinus virginianus). Land managers need to be equipped with spatially-explicit habitat models that can be used to make informed decisions on how to manage for particular species. Data collected on Fort Gordon Military Installation, Georgia from male bobwhite whistle counts during summer 2010 and 2011 will be used to construct competing models on the relationship between RCW management and other habitat structure metrics as it relates to bobwhite habitat suitability. These data were collected using a robust occupancy sampling design to allow open and closed population assumptions. Preliminary data suggests the RCW habitat ranking matrix is a poor predictor of bobwhite habitat suitability and, more alarmingly, RCW population performance. These models will assist natural resource managers on DoD land in making efficient decisions in the face of uncertainty
Preparing DARIAH
In this paper, a preparatory project for an integrated European research infrastructure in the humanities is presented. This project, Preparing for the construction of the Digital Research Infrastructure for the Arts and Humanities - or Preparing DARIAH for short, is part of the ESFRI e-infrastructures programme and supports the emergence of a new collaborative framework in which researchers are able to maximise the impact of their work on the international stage and aims at providing the foundations for the timely construction of the infrastructure requisite for the arts, humanities and cultural heritage communities in the digital age. DARIAH uses an interdisciplinary approach and involves tackling a number of interrelated issues such as strategic, organisational, financial, technical and conceptual in order to facilitate long-term access to and use of all European humanities and cultural heritage information for the purposes of enhancing and expanding research, thereby increasing our knowledge and understanding of our histories, heritage, languages and cultures. The DARIAH network will act as a place where the incubation of new ideas and ways of working can be facilitated and developed, and then transitioned into established organisations thus ensuring long-term sustainability and stability and the integration of these methods and techniques into everyday research practice. DARIAH will support research practitioners at all stages in the research process, and at differing levels of sophistication, from beginners through to those employing advanced techniques and methodologies
Scripts, Stigma, and Disability in Fiction
This research aims to bring disability studies to light in the works of Flowers for Algernon by Daniel Keyes and The Curious Incident of the Dog in the Night-Time by Mark Haddon. I aim to examine how the neurotypical modes of genre script uphold stereotypes of the protagonists of each novel, using David Hermanâs theory about genre scripts and Erving Goffmanâs sociological theories of phantom acceptance and phantom normalcy. Using Hermanâs literary theory with Goffmanâs sociological theory, I then, use disability studies as a lens to examine how these theories point to the stark stereotypes that are highlighted in each novel
Fullerol ionic fluids
http://pubs.rsc.org/en/Content/ArticlePDF/2010/NR/C0NR00307G/2010-06-08?page=SearchWe report for the first time an ionic fluid based on hydroxylated fullerenes (fullerols). The ionic fluid was synthesized by neutralizing the fully protonated fullerol with an amine terminated polyethylene/polypropylene oxide oligomer (Jeffamine(R)). The ionic fluid was compared to a control synthesized by mixing the parially protonated from (sodium form) of hte fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol). In the fullerol fluid the ionic bonding significantly perturbs the thermal transitions and melting/crystallization behavior of the amine. In contrast, both the normalized heat of fusion and crystallization of the amine in the control are similar to those of the neat amine consistent with a physical mixture of the fullerols/amine with minimal interactions. In addition to differences in thermal behavior, the fullerol ionic fluid exhibits a complex viscoelastic behavior intermediate between the neat Jeffamine (R) (liquid-like) and the control (solid-like).This publication is based on work supported in part by Award No. KUS-C1-018-02 made by King Abdullah University of Science and Technology (KAUST)
Manufacturing of 100mm diameter GaSb substrates for advanced space based applications
Engineered substrates such as large diameter (100mm) GaSb wafers need to be ready years in advance of any major shift in DoD and commercial technology, and typically before much of the rest of the materials and equipment for fabricating next generation devices. Antimony based III-V semiconductors are of significant interest for advanced applications in optoelectronics, high speed transistors, microwave devices, and photovoltaics. GaSb demand is increasing due to its lattice parameter matching of various ternary and quaternary III-V compounds, as their bandgaps can be engineered to cover a wide spectral range. For these stealth and spaced based applications, larger format IRFPAs benefit clearly from next generation starting substrates. In this study, we have manufactured and tested 100mm GaSb substrates. This paper describes the characterization process that provides the best possible GaSb material for advanced IRFPA and SLS epi growth. The analysis of substrate by AFM surface roughness, particles, haze, GaSb oxide character and desorption using XPS, flatness measurements, and SLS based epitaxy quality are shown. By implementing subtle changes in our substrate processing, we show that a Sb-oxide rich surface is routinely provided for rapid desorption. Post-MBE CBIRD structures on the 100mm ULD GaSb were examined and reveals a high intensity, 6.6nm periodicity, low (15.48 arcsec) FWHM peak distribution that suggests low surface strain and excellent lattice matching. The Ra for GaSb is a consistent ~0.2-4nm, with average batch wafer warp of ~4 ÎŒm to provide a clean, flat GaSb template critical for next generation epi growth
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