149 research outputs found

    Design and Control Using Stochastic Models of Deposition Reactors

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    The financial feasibility of the creation of a start-up company to sell software developed for the optimization and in-line control of thin film growth in deposition processes was investigated. An analysis of the current marketplace revealed potential for a small start-up company to be competitive with this novel product. The investigation concluded an IRR of 20% for a five year period before possible sale of the company. The kinetic Monte Carlo method was employed as the basis for all simulations in this work. This method retains atomic scale information while enabling simulation of process relevant features such as roughness, growth rate and efficiency. A model predictive controller was designed to reproducibly generate thin films with desired properties under a variety of initial condition disturbances for both single component and multi component systems. The substrate temperature and gas flux were employed as control variables. The control algorithms were investigated using a sensitivity analysis and shown to be robust under a wide range of conditions

    A Quadruple Knockout of lasIR and rhlIR of Pseudomonas aeruginosa PAO1 That Retains Wild-Type Twitching Motility Has Equivalent Infectivity and Persistence to PAO1 in a Mouse Model of Lung Infection

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    It has been widely reported that quorum-sensing incapable strains of Pseudomonas aeruginosa are less virulent than wild type strains. However, quorum sensing mutants of P. aeruginosa have been shown to develop other spontaneous mutations under prolonged culture conditions, and one of the phenotypes of P. aeruginosa that is frequently affected by this phenomenon is type IV pili-dependent motility, referred to as twitching motility. As twitching motility has been reported to be important for adhesion and colonisation, we aimed to generate a quorum-sensing knockout for which the heritage was recorded and the virulence factor production in areas unrelated to quorum sensing was known to be intact. We created a lasIRrhlIR quadruple knockout in PAO1 using a published technique that allows for the deletion of antibiotic resistance cartridges following mutagenesis, to create an unmarked QS knockout of PAO1, thereby avoiding the need for use of antibiotics in culturing, which can have subtle effects on bacterial phenotype. We phenotyped this mutant demonstrating that it produced reduced levels of protease and elastase, barely detectable levels of pyoverdin and undetectable levels of the quorum sensing signal molecules N-3-oxododecanoly-L-homoserine lactone and N-butyryl homoserine lactone, but retained full twitching motility. We then used a mouse model of acute lung infection with P. aeruginosa to demonstrate that the lasIRrhlIR knockout strain showed equal persistence to wild type parental PAO1, induced equal or greater neutrophil infiltration to the lungs, and induced similar levels of expression of inflammatory cytokines in the lungs and similar antibody responses, both in terms of magnitude and isotype. Our results suggest, in contrast to previous reports, that lack of quorum sensing alone does not significantly affect the immunogenicity, infectiveness and persistence of P. aeruginosa in a mouse model of acute lung infection. © 2013 Lazenby et al

    The effect of exercise on innate mucosal immunity

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    METHODS The authors conducted a prospective observational study comparing salivary lactoferrin and lysozyme concentration over 5 months (chronic changes) in elite rowers (n=17, mean age 24.3+/-4.0 years) with sedentary individuals (controls) (n=18, mean age=27.2+/-7.1 years) and a graded exercise test to exhaustion (acute changes) with a cohort of elite rowers (n=11, mean age 24.7+/-4.1). RESULTS Magnitudes of differences and changes were interpreted as a standardised (Cohen's) effect size (ES). Lactoferrin concentration in the observational study was approximately 60% lower in rowers than control subjects at baseline (7.9+/-1.2 microg/ml mean+/-SEM, 19.4+/-5.6 microg/ml, p=0.05, ES=0.68, 'moderate') and at the midpoint of the season (6.4+/-1.4 microg/ml mean +/- SEM, 21.5+/-4.2 microg/ml, p=0.001, ES=0.89, 'moderate'). The concentration of lactoferrin at the end of the study was not statistically significant (p=0.1) between the groups. There was no significant difference between rowers and control subjects in lysozyme concentration during the study. There was a 50% increase in the concentration of lactoferrin (p=0.05, ES=1.04, 'moderate') and a 55% increase in lysozyme (p=0.01, ES=3.0, 'very large') from pre-exercise to exhaustion in the graded exercise session. CONCLUSION Lower concentrations of these proteins may be indicative of an impairment of innate protection of the upper respiratory tract. Increased salivary lactoferrin and lysozyme concentration following exhaustive exercise may be due to a transient activation response that increases protection in the immediate postexercise period

    Law, politics and the governance of English and Scottish joint-stock companies 1600-1850

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    This article examines the impact of law on corporate governance by means of a case study of joint-stock enterprise in England and Scotland before 1850. Based on a dataset of over 450 company constitutions together with qualitative information on governance practice, it finds little evidence to support the hypothesis that common-law regimes such as England were more supportive of economic growth than civil-law jurisdictions such as Scotland: indeed, levels of shareholder protection were slightly stronger in the civil-law zone. Other factors, such as local political institutions, played a bigger role in shaping organisational forms and business practice

    Keep up production and save grain

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    The Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311

    Transcutaneous immunization as preventative and therapeutic regimens to protect against experimental otitis media due to nontypeable Haemophilus influenzae

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    We have developed three nontypeable Haemophilus influenzae (NTHI) adhesin-derived immunogens that are significantly efficacious against experimental otitis media (OM) due to NTHI when delivered parenterally. We now expanded our preventative immunization strategies to include transcutaneous immunization (TCI) as a less invasive, but potentially equally efficacious, regimen to prevent OM due to NTHI. Additionally, we examined the potential of TCI as a therapeutic immunization regimen to resolve ongoing experimental OM. Preventative immunization with NTHI outer membrane protein (OMP) P5- and type IV pilus-targeted immunogens, delivered with the adjuvant LT(R192G-L211A), induced significantly earlier clearance of NTHI from the nasopharynges and middle ears of challenged chinchillas compared with receipt of immunogen or adjuvant alone. Moreover, therapeutic immunization resulted in significant resolution of established NTHI biofilms from the middle ear space of animals compared with controls. These data advocate TCI with the adhesin-directed immunogens as an efficacious regimen for prevention and resolution of experimental NTHI-induced OM

    Fantastic voyage: the journey of intestinal microbiota-derived microvesicles through the body

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    As part of their life cycle, Gram-negative bacteria produce and release microvesicles (outer membrane vesicles, OMVs) consisting of spherical protrusions of the outer membrane that encapsulate periplasmic contents. OMVs produced by commensal bacteria in the gastrointestinal (GI) tract of animals are dispersed within the gut lumen with their cargo and enzymes being distributed across and throughout the GI tract. Their ultimate destination and fate is unclear although they can interact with and cross the intestinal epithelium using different entry pathways and access underlying immune cells in the lamina propria. OMVs have also been found in the bloodstream from which they can access various tissues and possibly the brain. The nanosize and non-replicative status of OMVs together with their resistance to enzyme degradation and low pH, alongside their ability to interact with the host, make them ideal candidates for delivering biologics to mucosal sites, such as the GI and the respiratory tract. In this mini-review, we discuss the fate of OMVs produced in the GI tract of animals with a focus on vesicles released by Bacteroides species and the use of OMVs as vaccine delivery vehicles and other potential applications

    Dorsal hippocampal involvement in conditioned-response timing and maintenance of temporal information in the absence of the CS

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    Involvement of the dorsal hippocampus (DHPC) in conditioned-response timing and maintaining temporal information across time gaps was examined in an appetitive Pavlovian conditioning task, in which rats with sham and DHPC lesions were first conditioned to a 15-s visual cue. After acquisition, the subjects received a series of non-reinforced test trials, on which the visual cue was extended (45 s) and gaps of different duration, 0.5, 2.5, and 7.5 s, interrupted the early portion of the cue. Dorsal hippocampal-lesioned subjects underestimated the target duration of 15 s and showed broader response distributions than the control subjects on the no-gap trials in the first few blocks of test, but the accuracy and precision of their timing reached the level of that of the control subjects by the last block. On the gap trials, the DHPC-lesioned subjects showed greater rightward shifts in response distributions than the control subjects. We discussed these lesion effects in terms of temporal versus non-temporal processing (response inhibition, generalisation decrement, and inhibitory conditioning)

    Non-typeable Haemophilus Influenzae detection in the lower airways of patients with lung cancer and chronic obstructive pulmonary disease

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    Background: Chronic airway inflammation and hypersensitivity to bacterial infection may contribute to lung cancer pathogenesis. Previous studies have demonstrated that nontypeable Haemophilus influenzae (NTHi) is the most common colonizing bacteria in the lower airways of patients with COPD. The objective of this study was to determine the presence of NTHi and immunoglobulin concentrations in patients with lung cancer, COPD and controls. Methods: Serum and bronchial wash samples were collected from patients undergoing diagnostic bronchoscopy. Total IgE, IgG and specific NTHi IgG were measured by enzyme linked immunosorbent assay. Bronchial wash samples were examined for the presence of NTHi via PCR. Results: Out of the 60 patients: 20 had confirmed Lung Cancer, 27 had COPD only and 13 were used as Controls. NTHi was detected in the lower airways of all three groups (Lung Cancer 20%; COPD 22% and Controls 15%). Total IgE was highest in Lung Cancer subjects followed by COPD and control subjects (mean ± SD: 870 ± 944, 381 ± 442, 159 ± 115). Likewise total IgG was higher in Lung cancer (Mean ± SD: 6.99 ± 1.8) patients compared to COPD (Mean ± SD: 5.43 ± 2). Conclusions: The lack of difference in NTHi and specific antibodies between the three groups makes it less likely that NTHi has an important pathogenetic role in subjects with Lung Cancer. However the detection of higher IgE antibody in Lung Cancer subjects identifies a possible mechanism for carcinogenesis in these subjects and warrants further study.Griffith Health, School of MedicineFull Tex
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