Electric field effects on nematic wetting layers

We present a theoretical investigation of the temperature and electric field dependence of nematic liquid crystal wetting layers close to an aligning substrate within a confined system. Using a mesoscopic Q tensor theory coupled to Maxwell's equations for the electric field, we consider the existence and stability of homogeneous nematic wetting layers close to the substrate. Numerical results are presented showing the phase diagram for the isotropic (paranematic), nematic and wetting layer states. The effect on the isotropic-wetting transition, from first order to second order, when an electric field is applied is then investigated

The Role of Partisan Politics on Support for Public Institutions of Higher Education

Over several decades, a greater share of the expense of earning a college degree has shifted to students and their families as appropriations to public institutions of higher education have declined as a percentage of the overall cost to educate a student. Tuition has greatly outpaced inflation during this period, while inflation-adjusted household income has remained relatively flat. Despite all the benefits that accrue to both the college graduate and society as a whole, for the less affluent, a college education is becoming increasingly difficult to attain. Many decide the financial barriers are simply too great and elect not to pursue a degree. Political partisanship influences spending on higher education at the state level; Republican lawmakers, in general, are less generous toward higher education than are Democrats. This study attempted to understand whether similar correlations exist between political preferences and support for higher education among adults who may influence policymaking through their voting behavior. A survey was administered to a non-random, convenience sample of adults in four states. Analysis of the data show that overall, liberal respondents who favor the Democratic party and preferred Joe Biden in the 2020 presidential election are generally more supportive of higher education than are conservatives who support Donald Trump and the Republican party. Certain key issues, such as loan forgiveness or in-state tuition for undocumented students, were statistically correlated with level of support for higher education while other issues were not. Demographic factors such as age and hometown population also correlated with level of support. Contrary to expectations, significant differences were not seen between red states and blue states. Higher education advocates who wish to make a college education more accessible will need to craft messages that can influence voters across the political divide, especially those who remain distrustful of academia

The Role of Partisan Politics on Support for Public Institutions of Higher Education

Over several decades, a greater share of the expense of earning a college degree has shifted to students and their families as appropriations to public institutions of higher education have declined as a percentage of the overall cost to educate a student. Tuition has greatly outpaced inflation during this period, while inflation-adjusted household income has remained relatively flat. Despite all the benefits that accrue to both the college graduate and society as a whole, for the less affluent, a college education is becoming increasingly difficult to attain. Many decide the financial barriers are simply too great and elect not to pursue a degree. Political partisanship influences spending on higher education at the state level; Republican lawmakers, in general, are less generous toward higher education than are Democrats. This study attempted to understand whether similar correlations exist between political preferences and support for higher education among adults who may influence policymaking through their voting behavior. A survey was administered to a non-random, convenience sample of adults in four states. Analysis of the data show that overall, liberal respondents who favor the Democratic party and preferred Joe Biden in the 2020 presidential election are generally more supportive of higher education than are conservatives who support Donald Trump and the Republican party. Certain key issues, such as loan forgiveness or in-state tuition for undocumented students, were statistically correlated with level of support for higher education while other issues were not. Demographic factors such as age and hometown population also correlated with level of support. Contrary to expectations, significant differences were not seen between red states and blue states. Higher education advocates who wish to make a college education more accessible will need to craft messages that can influence voters across the political divide, especially those who remain distrustful of academia

Tolerance of Pseudomonas aeruginosa in in vitro biofilms to high level peracetic acid disinfection

Biofilm has been suggested as a cause of disinfection failures in flexible endoscopes where no lapses in the decontamination procedure can be identified. To test this theory, the activity of peracetic acid (PAA), one of the commonly used disinfectants in the reprocessing of flexible endoscopes, was evaluated against both planktonic and sessile communities of Pseudomonas aeruginosa. To investigate the ability of P. aeruginosa biofilm to survive high level PAA disinfection. The susceptibility of planktonic cells of P. aeruginosa and biofilms 24, 48, 96 and 192 h old to PAA was evaluated by estimating their viability using resazurin viability and plate count methods. The biomass of the P. aeruginosa biofilms was also quantified using crystal violet assay. Planktonic cells of P. aeruginosa were treated with 5 - 30 ppm concentration of PAA in the presence of 3.0 g/L of Bovine serum albumin (BSA) for 5 min. Biofilms of P. aeruginosa were also treated with various PAA concentrations (100 - 3000 ppm) for 5 min. Planktonic cells of P. aeruginosa were eradicated by 20 ppm of PAA, whereas biofilms showed an age dependent tolerance to PAA, and 96 h old biofilm was only eradicated at PAA concentration of 2500 ppm. 96 h old P. aeruginosa biofilm survives 5 min treatment with 2000 ppm of PAA, which is the working concentration used in some endoscope washer disinfectors. This implies that disinfection failure of flexible endoscopes could occur when biofilms are allowed to build up in the lumens of endoscopes

The Porphyromonas gingivalis hemagglutinins HagB and HagC are major mediators of adhesion and biofilm formation

Porphyromonas gingivalis is a bacterium associated with chronic periodontitis that possesses a family of genes encoding hemagglutinins required for heme acquisition. In this study we generated ΔhagB and ΔhagC mutants in strain W83 and demonstrate that both hagB and hagC are required for adherence to oral epithelial cells. Unexpectedly, a double ΔhagB/ΔhagC mutant had less severe adherence defects than either of the single mutants, but was found to exhibit increased expression of the gingipain-encoding genes rgpA and kgp, suggesting that a ΔhagB/ΔhagC mutant is only viable in populations of cells that exhibit increased expression of genes involved in heme acquisition. Disruption of hagB in the fimbriated strain ATCC33277 demonstrated that HagB is also required for stable attachment of fimbriated bacteria to oral epithelial cells. Mutants of hagC were also found to form defective single and multi-species biofilms that had reduced biomass relative to biofilms formed by the wild-type strain. This study highlights the hitherto unappreciated importance of these genes in oral colonization and biofilm formation

Systems thinkers think About systems education under the April 2010 (volcanic ash) clouds of Austria

The fragmented nature of systems education with multiple traditions expressed in very different ways at different institutions with ultimate confusing effects on the community of learners (students, managers, policy makers, etc), led to a group of Systems Thinkers to discuss and create generic curricula for education and learning about systems for the generalist and specialist tracks. An active network of systems educators and stakeholders who can benefit from enhanced systems education in having to deal with complex issues, was also explored. In this presentation some guidelines for designing introductory and advanced courses will be discussed. The Introduction to Systemic Thinking and Practice course is intended as an introductory course for students from all disciplines. The Advanced Systemic Thinking and Practice course is intended as a more advanced course for students who are faced with complex issues that require a trans-disciplinary and integrated approach. The designs contain a set of key systems concepts and frameworks relevant to the appropriate level, along with some indicative tools and methods which will enable students to explore the concepts. The value of a Global Network of Systems Educators will also be discussed and how this network could help to fulfil the needs of managers, policy makers and society in general. An example will be given of how the integration of this network with the UQ-UNESCO/MAB Global Learning Laboratories NET could lead to more people (decision-and policy makers in Governments, managers, businesses, etc.) having the ability to practice systems thinking – all of these contributing to Systems Thinking becoming a more mainstream part of a sustainable society

Aspergillus fumigatus enhances elastase production in pseudomonas aeruginosaco-cultures

In the cystic fibrosis (CF) lung the presence of bacteria and fungi in the airways promotes an inflammatory response causing progressive lung damage, ultimately leading to high rates of morbidity and mortality. We hypothesized that polymicrobial interactions play an important role in promoting airway pathogenesis. We therefore examined the interplay between the most commonly isolated bacterial CF pathogen, Pseudomonas aeruginosa, and the most prevalent filamentous fungi, Aspergillus fumigatus, to test this. Co-culture experiments showed that in the presence of A. fumigatus the production of P. aeruginosa elastase was enhanced. This was confirmed by the presence of zones of clearance on Elastin-Congo Red (ECR) agar, which was identified as elastase by mass spectrometry. When P. aeruginosa were grown in a co-culture model with mature A. fumigatus biofilms, 60% of isolates produced significantly more elastase in the presence of the filamentous fungi than in its absence (P < .05). The expression of lasB also increased when P. aeruginosa isolates PA01 and PA14 were grown in co-culture with A. fumigatus. Supernatants from co-culture experiments were also significantly toxic to a human lung epithelial cell line (19–38% cell cytotoxicity) in comparison to supernatants from P. aeruginosa only cultures (P < .0001). Here we report that P. aeruginosa cytotoxic elastase is enhanced in the presence of the filamentous fungi A. fumigatus, suggesting that this may have a role to play in the damaging pathology associated with the lung tissue in this disease. This indicates that patients who have a co-colonisation with these two organisms may have a poorer prognosis

UK utility data integration: overcoming schematic heterogeneity

In this paper we discuss syntactic, semantic and schematic issues which inhibit the integration of utility data in the UK. We then focus on the techniques employed within the VISTA project to overcome schematic heterogeneity. A Global Schema based architecture is employed. Although automated approaches to Global Schema definition were attempted the heterogeneities of the sector were too great. A manual approach to Global Schema definition was employed. The techniques used to define and subsequently map source utility data models to this schema are discussed in detail. In order to ensure a coherent integrated model, sub and cross domain validation issues are then highlighted. Finally the proposed framework and data flow for schematic integration is introduced

Surface disinfection challenges for Candida auris: an in-vitro study

The emerging pathogenic multidrug-resistant yeast Candida auris is an important source of healthcare-associated infections and of growing global clinical concern. The ability of this organism to survive on surfaces and withstand environmental stressors creates a challenge for eradicating it from hospitals. A panel of C. auris clinical isolates was evaluated on different surface environments against the standard disinfectant sodium hypochlorite and high-level disinfectant peracetic acid. C. auris was shown to selectively tolerate clinically relevant concentrations of sodium hypochlorite and peracetic acid in a surface-dependent manner, which may explain its ability to successfully persist within the hospital environment

Hsp90 governs dispersion and drug resistance of fungal biofilms

Fungal biofilms are a major cause of human mortality and are recalcitrant to most treatments due to intrinsic drug resistance. These complex communities of multiple cell types form on indwelling medical devices and their eradication often requires surgical removal of infected devices. Here we implicate the molecular chaperone Hsp90 as a key regulator of biofilm dispersion and drug resistance. We previously established that in the leading human fungal pathogen, Candida albicans, Hsp90 enables the emergence and maintenance of drug resistance in planktonic conditions by stabilizing the protein phosphatase calcineurin and MAPK Mkc1. Hsp90 also regulates temperature-dependent C. albicans morphogenesis through repression of cAMP-PKA signalling. Here we demonstrate that genetic depletion of Hsp90 reduced C. albicans biofilm growth and maturation in vitro and impaired dispersal of biofilm cells. Further, compromising Hsp90 function in vitro abrogated resistance of C. albicans biofilms to the most widely deployed class of antifungal drugs, the azoles. Depletion of Hsp90 led to reduction of calcineurin and Mkc1 in planktonic but not biofilm conditions, suggesting that Hsp90 regulates drug resistance through different mechanisms in these distinct cellular states. Reduction of Hsp90 levels led to a marked decrease in matrix glucan levels, providing a compelling mechanism through which Hsp90 might regulate biofilm azole resistance. Impairment of Hsp90 function genetically or pharmacologically transformed fluconazole from ineffectual to highly effective in eradicating biofilms in a rat venous catheter infection model. Finally, inhibition of Hsp90 reduced resistance of biofilms of the most lethal mould, Aspergillus fumigatus, to the newest class of antifungals to reach the clinic, the echinocandins. Thus, we establish a novel mechanism regulating biofilm drug resistance and dispersion and that targeting Hsp90 provides a much-needed strategy for improving clinical outcome in the treatment of biofilm infections