1,045 research outputs found
A Survey of the Content of Some Heavy Metals in Soil and Corn Grain in the Pond and Lower Green River Bottoms
Corn is intensively grown along the Green and Pond Rivers in McLean, Hopkins, and Webster Counties, Kentucky, representing a major source of income to producers in those areas. However, producers in McLean County have experienced poorer corn production than expected for many years. This has been observed more on the Pond River bottoms and the Green River bottoms below the confluence of the Pond than upstream on the Green above the Pond. Some producers have speculated that their poor production may be associated with chemical pollution from the Pond River and/or nearby industrial sources. On this basis, an assumption was made that if chemical pollution did occur, it would be most noticeable in fields which commonly overflow with water originating upstream on the Green or Pond Rivers. Further, a second assumption was made that bottom land sites which less frequently overflow, would have lower concentrations of chemical pollutants
PsrA controls the synthesis of the Pseudomonas aeruginosa quinolone signal via repression of the FadE homolog, PA0506
Pseudomonas aeruginosa is a ubiquitous, Gram-negative opportunistic pathogen that can cause disease in various sites within the human body. This bacterium is a major source of nosocomial infections that are often difficult to treat due to high intrinsic antibiotic resistance and coordinated virulence factor production. P. aeruginosa utilizes three cell-to-cell signal- ing systems to regulate numerous genes in response to cell density. One of these systems utilizes the small molecule 2-heptyl-3-hydroxy-4-quinolone (Pseudomonas quinolone signal [PQS]) as a signal that acts as a co-inducer for the transcriptional regulator PqsR. Quinolone signaling is required for virulence in multiple infection models, and PQS is produced during human infections, making this system an attractive target for potential drug development. In this study we have examined the role of a TetR-type transcriptional regulator, PsrA, in the regulation of PQS production by P. aeruginosa. Previous studies showed that PsrA regu- lates genes of the fatty acid β-oxidation pathway, including PA0506, which encodes a FadE homolog. In this report, we show that deletion of psrA resulted in a large decrease in PQS production and that co-deletion of PA0506 allowed PQS production to be restored to a wild type level. We also found that PQS production could be restored to the psrA mutant by the addition of oleic or octanoic acid. Taken together, our data suggest that psrA positively affects PQS production by repressing the transcription of PA0506, which leads to a decrease in the conversion of acyl-CoA compounds to enoyl-CoA compounds, thereby allowing some octanoyl-CoA to escape the ß-oxidation pathway and serve as a PQS precursor
Prospectus, September 28, 1977
COMMUNITY COLLEGE GRADS SUCCESSFUL AT 4-YEAR SCHOOLS; Canteen must go by contract, lower prices; Parkland Events; New budget OK\u27d by Board: salaries and benefits are 70%; Activities Day; Kites, volleyball, music…: Students gather for fun; Women\u27s theatre group to perform; Dancer to appear; Cleveland Armory; Harry\u27s brother a hit: Johnson, Chapin charm loud Auditorium crowd; Health topics start Tuesday; IM football to start Tuesday at Centennial; Classifieds; Record no. entrants: Holland wins Freddy; X-Country team finishes sixth: Sugar Grove; Tennis meeting is tomorrow; Cobras place 14th in Lincoln Trail Golf Invitationalhttps://spark.parkland.edu/prospectus_1977/1011/thumbnail.jp
Online Payment Gateways Used to Facilitate E-Commerce Transactions and Improve Risk Management
As online transactions continue to increase and become a significant part of the global economy, the ability to accept payments online becomes more important for businesses. This paper evaluates the literature and provides current information for IS researchers and instructors focusing on electronic commerce. In this paper, we explore the components of e-credit providers (conventional, person-to-person, and third-party) and explain how each system processes a single transaction. We then analyze several market leaders in each segment and summarize the strengths and weaknesses of each company. We provide guidelines for selecting an e-credit provider and highlight the options that apply best to online businesses. Finally, we outline potential areas of future research and provide a simple tutorial on creating a business account with PayPal website Payments Standard as an example of an online payment provider
A Reduced–Cost Mechanized System for Handling and Curing Mechanically–Harvested Burley Tobacco
An experimental system was tested in which mechanically harvested burley tobacco plants placed onto steel slotted receivers were retrieved from a field, transported to a field curing structure, and placed onto the structure for air curing by a single worker. The system consisted of a tractor–towed, trailer mechanism that engaged and hoisted loads of approximately 360 burley plants of approximately 1 Mg mass. Ten slotted steel rails, 3.05 m long, holding 36 notched plants were placed onto parallel wooden beams suspended at a height of 2.13 m by wooden posts set in the ground. Burley tobacco was cured in this configuration covered by polyethylene.
Time–and–motion experiments showed that the system could retrieve tobacco from the field and place it onto a curing structure adjacent to the field at the rate of 0.1 to 0.18 ha/h. Replicated experiments also showed that the system operated with negligible leaf loss due to handling. Finally, experimental results showed that leaf grade index decreased with time that filled tobacco rails were left lying on the ground after being harvested and prior to being retrieved. This study further indicated that the estimated cost of the proposed harvesting system compares favorably with systems that require several manual laborers
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CDR Data Management Plan: Data Survey and System Design
The University of Texas at Austin Center for Space Research (UT-CSR) final report to address topics and questions raised by the General Land Office (GLO) concerning concepts underlying the Texas Disaster Information System (TDIS).Texas General Land Office through GLO Contract No. 18-229-000-B854Center for Space Researc
Simulating Cardiac Fluid Dynamics in the Human Heart
Cardiac fluid dynamics fundamentally involves interactions between complex
blood flows and the structural deformations of the muscular heart walls and the
thin, flexible valve leaflets. There has been longstanding scientific,
engineering, and medical interest in creating mathematical models of the heart
that capture, explain, and predict these fluid-structure interactions. However,
existing computational models that account for interactions among the blood,
the actively contracting myocardium, and the cardiac valves are limited in
their abilities to predict valve performance, resolve fine-scale flow features,
or use realistic descriptions of tissue biomechanics. Here we introduce and
benchmark a comprehensive mathematical model of cardiac fluid dynamics in the
human heart. A unique feature of our model is that it incorporates
biomechanically detailed descriptions of all major cardiac structures that are
calibrated using tensile tests of human tissue specimens to reflect the heart's
microstructure. Further, it is the first fluid-structure interaction model of
the heart that provides anatomically and physiologically detailed
representations of all four cardiac valves. We demonstrate that this
integrative model generates physiologic dynamics, including realistic
pressure-volume loops that automatically capture isovolumetric contraction and
relaxation, and predicts fine-scale flow features. None of these outputs are
prescribed; instead, they emerge from interactions within our comprehensive
description of cardiac physiology. Such models can serve as tools for
predicting the impacts of medical devices or clinical interventions. They also
can serve as platforms for mechanistic studies of cardiac pathophysiology and
dysfunction, including congenital defects, cardiomyopathies, and heart failure,
that are difficult or impossible to perform in patients
Acinetobacter baumannii Regulates Its Stress Responses via the BfmRS Two-Component Regulatory System
Acinetobacter baumannii is a common nosocomial pathogen that utilizes numerous mechanisms to aid its survival in both the environment and the host. Coordination of such mechanisms requires an intricate regulatory network. We report here that A. baumannii can directly regulate several stress-related pathways via the two-component regulatory system BfmRS. Similar to previous studies, results from transcriptomic analysis showed that mutation of the BfmR response regulator causes dysregulation of genes required for the oxidative stress response, the osmotic stress response, the misfolded protein/heat shock response, Csu pilus/fimbria production, and capsular polysaccharide biosynthesis. We also found that the BfmRS system is involved in controlling siderophore biosynthesis and transport, and type IV pili production. We provide evidence that BfmR binds to various stress-related promoter regions and show that BfmR alone can directly activate transcription of some stress-related genes. Additionally, we show that the BfmS sensor kinase acts as a BfmR phosphatase to negatively regulate BfmR activity. This work highlights the importance of the BfmRS system in promoting survival of A. baumannii. IMPORTANCE Acinetobacter baumannii is a nosocomial pathogen that has extremely high rates of multidrug resistance. This organism’s ability to endure stressful conditions is a key part of its ability to spread in the hospital environment and cause infections. Unlike other members of the gammaproteobacteria, A. baumannii does not encode a homolog of the RpoS sigma factor to coordinate its stress response. Here, we demonstrate that the BfmRS two-component system directly controls the expression of multiple stress resistance genes. Our findings suggest that BfmRS is central to a unique scheme of general stress response regulation by A. baumannii
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