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Search Results: 1 - 10 of 215223 matches for " Robert D. Junkins "
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Autophagy Enhances Bacterial Clearance during P. aeruginosa Lung Infection
Robert D. Junkins, Ann Shen, Kirill Rosen, Craig McCormick, Tong-Jun Lin
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0072263
Abstract: Pseudomonas aeruginosa is an opportunistic bacterial pathogen which is the leading cause of morbidity and mortality among cystic fibrosis patients. Although P. aeruginosa is primarily considered an extacellular pathogen, recent reports have demonstrated that throughout the course of infection the bacterium acquires the ability to enter and reside within host cells. Normally intracellular pathogens are cleared through a process called autophagy which sequesters and degrades portions of the cytosol, including invading bacteria. However the role of autophagy in host defense against P. aeruginosa in vivo remains unknown. Understanding the role of autophagy during P. aeruginosa infection is of particular importance as mutations leading to cystic fibrosis have recently been shown to cause a blockade in the autophagy pathway, which could increase susceptibility to infection. Here we demonstrate that P. aeruginosa induces autophagy in mast cells, which have been recognized as sentinels in the host defense against bacterial infection. We further demonstrate that inhibition of autophagy through pharmacological means or protein knockdown inhibits clearance of intracellular P. aeruginosa in vitro, while pharmacologic induction of autophagy significantly increased bacterial clearance. Finally we find that pharmacological manipulation of autophagy in vivo effectively regulates bacterial clearance of P. aeruginosa from the lung. Together our results demonstrate that autophagy is required for an effective immune response against P. aeruginosa infection in vivo, and suggest that pharmacological interventions targeting the autophagy pathway could have considerable therapeutic potential in the treatment of P. aeruginosa lung infection.
Twisted gamma filtration and algebras with orthogonal involution
Caroline Junkins
Mathematics , 2012,
Abstract: For the Grothendieck group of a split simple linear algebraic group, the twisted gamma-filtration provides a useful tool for constructing torsion elements in gamma-rings of twisted flag varieties. In this paper, we construct a non-trivial torsion element in the gamma-ring of a complete flag variety twisted by means of a PGO-torsor. This generalizes the construction in the HSpin case previously obtained by Zainoulline. We use this torsion element to study algebras with orthogonal involutions.
The J-invariant and Tits algebras for groups of inner type E6
Caroline Junkins
Mathematics , 2011,
Abstract: A connection between the indices of the Tits algebras of a split linear algebraic group G and the degree one parameters of its motivic J-invariant was introduced by Queguiner-Mathieu, Semenov and Zainoulline through use of the second Chern class map in the Riemann-Roch theorem without denominators. In this paper we extend their result to higher Chern class maps and provide applications to groups of inner type E6.
Modified Chebyshev-Picard Iteration Methods for Station-Keeping of Translunar Halo Orbits
Xiaoli Bai,John L. Junkins
Mathematical Problems in Engineering , 2012, DOI: 10.1155/2012/926158
Abstract: The halo orbits around the Earth-Moon 2 libration point provide a great candidate orbit for a lunar communication satellite, where the satellite remains above the horizon on the far side of the Moon being visible from the Earth at all times. Such orbits are generally unstable, and station-keeping strategies are required to control the satellite to remain close to the reference orbit. A recently developed Modified Chebyshev-Picard Iteration method is used to compute corrective maneuvers at discrete time intervals for station-keeping of halo orbit satellite, and several key parameters affecting the mission performance are analyzed through numerical simulations. Compared with previously published results, the presented method provides a computationally efficient station-keeping approach which has a simple control structure that does not require weight turning and, most importantly, does not need state transition matrix or gradient information computation. The performance of the presented approach is shown to be comparable with published methods.
YeaNay: An Open Source Tool to Rate the Votes of Members of the United States House of Representatives and Senate  [PDF]
Eric Venlet, D. Robert Adams
Open Journal of Political Science (OJPS) , 2015, DOI: 10.4236/ojps.2015.54029
Abstract: Government transparency is typically regarded as the most viable way to strengthen its accountability to the public (Shkabatur, 2012). Even on the international stage, the right to access government information is regarded as fundamental to democracy (Bertot, Jaeger, & Grimes, 2011). In order to improve transparency, the US government made data, like bills and votes, available online (Brito, 2008b). One popular way to organize the data available to the public is through the creation of voter guides. The method an organization used for developing a voter guide was analyzed for this project. In response to the method, a web application (YeaNay) was developed to take the largely manual process and make a highly automated solution. YeaNay utilizes HTML, CSS, and JavaScript to build the user interface and ColdFusion and PL/SQL to query the data necessary for the development of a voter guide. The data are queried either from the database or from Congress API v3 (provided by the Sunlight Foundation). One user, with minimal training, is able to use YeaNay to find and score legislation within minutes for use in a voter guide. YeaNay focuses the firehose of congressional information that is now available and presents it in a manageable and usable environment.
Zion File System Simulator  [PDF]
Frederic Paladin, D. Robert Adams
Journal of Computer and Communications (JCC) , 2016, DOI: 10.4236/jcc.2016.44002
Abstract: File systems are fundamental for computers and devices with data storage units. They allow operating systems to understand and organize streams of bytes and obtain readable files from them. There are numerous file systems available in the industry, all with their own unique features. Understanding how these file systems work is essential for computer science students, but their complex nature can be difficult and challenging to grasp, especially for students at the beginning of their career. The Zion File System Simulator was designed with this in mind. Zion is a teaching and experimenting tool, in the form of a small application, built to help students understand how the I/O manager of an operating system interacts with the drive through the file system. Users can see and analyze the structure of a simple, flat file system provided with Zion, or simulate the most common structures such as FAT or NTFS. Students can also create their own implementations and run them through the simulator to analyze the different behaviors. Zion runs on Windows, and the application is provided with dynamic-link libraries that include the interfaces of a file system and a volume manager. These interfaces allow programmers to build their own file system or volume manager in Visual Studio using any .NET language (3.0 or above). Zion gives the users the power to adjust simulated architectural parameters such as volume and block size, or performance factors such as seek and transfer time. Zion runs workloads of I/O operations such as “create,” “delete,” “read,” and “write,” and analyzes the resulting metrics including I/O operations, read/write time, and disk fragmentation. Zion is a learning tool. It is not designed for measuring accurate performance of file systems and volume managers. The robustness of the application, together with its expandability, makes Zion a potential laboratory tool for computer science classes, helping students learn how file systems work and interact with an operating system.
Varying Tolerance to Glyphosate in a Population of Palmer Amaranth with Low EPSPS Gene Copy Number  [PDF]
Neal D. Teaster, Robert E. Hoagland
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.412297

A Palmer amaranth population (seeds collected in the year 2000; Washington Co., MS) suspected to be susceptible to glyphosate was examined as a population and as individual plants and found to exhibit varying tolerance or resistance to glyphosate. Whole plant spraying of glyphosate (0.84 kg·ha?1) to the population revealed that approximately 40% of this population were resistant to glyphosate and an LD50 of 0.75 kg·ha?1 was determined. Spray application of glyphosate indicated that some plants displayed varying degrees of resistance 14 days after treatment. Initial tests using leaf disc bioassays on 10 individual plants selected randomly from the population, allowed characterization of glyphosate resistance using both visual ratings of injury and quantitative measurement via chlorophyll content analysis. After initial bioassays and spray application, five plants with a range of tolerance to glyphosate were selected for cloning so that further studies could be accomplished on these individuals. Q-PCR analysis of these clones showed that resistance was not due to elevated EPSPS gene copy number. Shikimate levels were lower in the resistant and higher in the susceptible clones which correlated with varying degrees of resistance demonstrated in bioassays and spray application of glyphosate of these clones. Results demonstrate that individuals in a population can vary widely with respect to herbicide resistance and suggest that uptake, translocation, sequestration, metabolism or altered target site may contribute to the resistance in some individuals of this population.

An Assessment Capability for LNG Leaks in Complex Environments  [PDF]
Sydney D. Ryan, Robert C. Ripley
Journal of Geoscience and Environment Protection (GEP) , 2018, DOI: 10.4236/gep.2018.66005
Abstract: Pollutants may be introduced into urban or marine settings by various means and could result in an adverse impact to public safety and the environment. Therefore, it is important for emergency management personnel to understand the potential risks and physical extents of a leaked substance, whether it is toxic, flammable or explosive. Traditional tools for predicting the atmospheric dispersion of leaked substances are quick and simple to use, but may not adequately consider the effects of the built environment that includes complex urban and terrain geometries. Alternatively, CFD methods have been increasing in application; although, their superior accuracy is met with commensurate manual effort. The All Hazards Planner is a fast, accurate gas dispersion modelling tool for city and port environments, which employs a full-physics CFD approach but automates the intensive manual effort. In this work, a credible LNG leak from a 12-mm-diameter hole is modelled for two hypothetical case studies: adjacent to an LNG tanker and between a cruise ship and pier during bunkering. The LNG vapour flammability extents are compared to an empirical model in the absence of geometry effects and are contrasted with geometry effects to highlight the importance of the real environment. The free-field extents are invariant, whereas the inclusion of geometry is shown to reduce the flammability extents by spreading at the ground-level and forcing the plume upwards.
Temporal Lobe Epilepsy Semiology
Robert D. G. Blair
Epilepsy Research and Treatment , 2012, DOI: 10.1155/2012/751510
Abstract: Epilepsy represents a multifaceted group of disorders divided into two broad categories, partial and generalized, based on the seizure onset zone. The identification of the neuroanatomic site of seizure onset depends on delineation of seizure semiology by a careful history together with video-EEG, and a variety of neuroimaging technologies such as MRI, fMRI, FDG-PET, MEG, or invasive intracranial EEG recording. Temporal lobe epilepsy (TLE) is the commonest form of focal epilepsy and represents almost 2/3 of cases of intractable epilepsy managed surgically. A history of febrile seizures (especially complex febrile seizures) is common in TLE and is frequently associated with mesial temporal sclerosis (the commonest form of TLE). Seizure auras occur in many TLE patients and often exhibit features that are relatively specific for TLE but few are of lateralizing value. Automatisms, however, often have lateralizing significance. Careful study of seizure semiology remains invaluable in addressing the search for the seizure onset zone. 1. Introduction Epilepsy has been recognized since antiquity. It affects millions of people worldwide and remains one of the most common and frightening neurological conditions. The word is derived from the Greek word which means to “seize” or “take hold of.” Epilepsy encompasses a heterogeneous group of disorders with various manifestations including seizures in addition to other signs, symptoms, and features that define a phenotype. The taxonomy and terminology of epilepsy has undergone a number of changes over the years. An early classification system generated confusion and heated discussion over equating the term “complex partial seizures” (CPSs) and “temporal lobe epilepsy” (TLE) [1]. The 1981 classification of epileptic seizures represented a consensus at that time [2]. A further revision was the Classification of Epilepsies and Epileptic Syndromes accepted in 1989 [3]. Yet another modification and change in philosophy was initiated by the Executive Committee of the International League Against Epilepsy (ILAE) which took office in 1997. The ILAE task force published the Revised Terminology and Concepts for Organization of the Epilepsies in 2010 [4]. Temporal lobe seizures are the most frequent site of origin of partial seizures. They represent approximately two thirds of the intractable seizure population coming to surgical management. Jackson in the 19th Century [5] was the first to link seizures characterized by a “dreamy state” to lesions near the uncus in the temporal lobe (hence the term “uncinate fits”). Gibbs and
Long-Term Monitoring of Brain Dopamine Metabolism In Vivo with Carbon Paste Electrodes
Robert D. O’Neill
Sensors , 2005, DOI: 10.3390/s5060317
Abstract: This review focuses on the stability of voltammetric signals recorded overperiods of months with carbon paste electrodes (CPEs) implanted in the brain. The keyinteraction underlying this stability is between the pasting oil and brain lipids that arecapable of inhibiting the fouling caused by proteins. In brain regions receiving a significantdopaminergic input, a peak due to the methylated metabolites of dopamine, principallyhomovanillic acid (HVA), is clearly resolved using slow sweep voltammetry. Although anumber of factors limit the time resolution for monitoring brain HVA concentrationdynamics, the stability of CPEs allows investigations of long-term effects of drugs, as wellas behavioral studies, not possible using other in-vivo monitoring techniques.
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