Biosurfactant production and surface translocation are regulated by PlcR in Bacillus cereus ATCC 14579 under low nutrient conditions

Bacillus cereus ATCC 14579 can respond to nutrient changes by adopting different forms of surface translocation. The B. cereus ATCC 14579 DeltaplcR mutant, but not the wild type, formed dendritic (branched) patterns on EPS [a low-nutrient medium that contains 7.0 g K(2)HPO(4), 3.0 g KH(2)PO(4), 0.1 g MgSO(4).7H(2)O, 0.1 g (NH(4))(2)SO(4), 0.01 g CaCl(2), 0.001 g FeSO(4), 0.1 g NaCl, 1.0 g glucose, and 125 mg yeast extract per liter] containing 0.7% agar. The dendritic patterns formed by sliding translocation of nonflagellated cells are enhanced under low-nutrient conditions and require sufficient production of a biosurfactant, which appears to be repressed by PlcR. The wild-type and complemented strains failed to slide on the surface of EPS agar because of the production of low levels of biosurfactant. Precoating EPS agar surfaces with surfactin (a biosurfactant produced by Bacillus subtilis) or biosurfactant purified from the DeltaplcR mutant rescued the ability of the wild-type and complemented strains to slide. When grown on a nutrient-rich medium like Luria-Bertani agar, both the wild-type and DeltaplcR mutant strains produced flagella. The wild type was hyperflagellated and elongated and exhibited swarming behavior, while the DeltaplcR mutant was multiflagellated and the cells often formed long chains but did not swarm. Thin-layer chromatography and mass spectrometry analyses suggested that the biosurfactant purified from the DeltaplcR mutant was a lipopeptide and had a mass of 1,278.1722 (m/z). This biosurfactant has hemolytic activity and inhibited the growth of several gram-positive bacteria

RE^(III) 3-Furoate Complexes: Synthesis, Structure, and Corrosion Inhibiting Properties

In this study, two types of Rare Earth (RE) 3-furoate complexes were synthesized by metathesis reactions between RE chlorides or nitrates and preformed sodium 3-furoate. Two different structural motifs were identified as Type 1RE and Type 2RE. The Type 1RE monometallic complexes form 2D polymeric networks with the composition [RE(3fur)3(H2O)2]n (1RE = 1La, 1Ce, 1Pr, 1Nd, 1Gd, 1Dy, 1Ho, 1Y; 3furH = 3-furoic acid) while Type 2RE bimetallic complexes form 3D polymeric systems [NaRE(3fur)4]n (2RE = 2Ho, 2Y, 2Er, 2Yb, 2Lu). The stoichiometric mole ratio used (RE: Na(3fur) = 1:3 or 1:4) in the metathesis reaction determines whether 1RE or 2RE (RE = Ho or Y) is formed, but 2RE (RE = Er, Yb, Lu) were obtained regardless of the ratio. The corrosion inhibition behaviour of the compounds has been examined using immersion studies and electrochemical measurements on AS1020 mild steel surfaces by a 0.01 M NaCl medium. Immersion test results revealed that [Y(3fur)3(H2O)2]n has the highest corrosion inhibition capability with 90% resistance after 168 h of immersion. Potentiodynamic polarisation (PP) measurements also indicate the dominant behaviour of the 1Y compound, and the PP curves show that these rare earth carboxylate compounds act predominantly as anodic inhibitors

Outdoor ventures: Tracking Eastern Box Turtles

This project was designed to engage middle-grade students in an authentic task involving the study of an endangered species, the eastern box turtle (Terrapene carolina carolina). It emphasizes learning by doing and promotes character growth, teamwork, reflection, and literacy. This article describes the process of coming together under these theories to study a population of eastern box turtles. The project's goals are to: * bring together the middle school, university, and community to educate students about the environment and the importance of stewardship; * integrate math, science, reading, computer literacy, and scientific field techniques in a science classroom and interdisciplinary project; and * produce documents that will provide a model for other schools interested in establishing hands-on science with conservation implications

The box turtle connection : building a legacy

In 2006, we wrote The Box Turtle Connection: A Passageway into the Natural World, a guide forresource managers, herpetologists, nature center directors, and citizen scientists that would help directtheir work on this (once) common organism. The book was resoundingly successful. Scientists andagency personnel working with box turtles and other species of turtles have adopted and adapted ourpractices. The book has been reproduced hundreds of times and put directly into the hands of teachersand environmental educators who are working to keep box turtles common across their native ranges.Ten years later, we offer a revised version: The Box Turtle Connection: Building a Legacy. This editionmodifies and standardizes our research protocols and portrays how the Box Turtle Connection projectin North Carolina is building a long-term research study that will exceed 100 years and leave a legacyfor others to follow, be inspired by, and build upon. We have not surrendered our mission to connectothers to the natural world through box turtles, but now turn our focus towards the quality of theresearch that informs us about box turtle populations’ present and future status. By reflecting upon ourprotocols and introducing new techniques, we hope curators, naturalists, educators, and students willengage in carefully designed box turtle research studies with a commitment to scientific validity

Geriatric pharmacotherapy : optimisation through integrated approach in the hospital setting

Since older patients are more vulnerable to adverse drug-related events, there is a need to ensure appropriate prescribing in these patients in order to prevent misuse, overuse and underuse of drugs. Different tools and strategies have been developed to reduce inappropriate prescribing; the available measures can be divided into medication assessment tools, and specific interventions to reduce inappropriate prescribing. Implicit criteria of inappropriate prescribing focus on appropriate dosing, search for drug-drug interactions, and increase adherence. Explicit criteria are consensus-based standards focusing on drugs and diseases and include lists of drugs to avoid in general or lists combining drugs with clinical data. These criteria take into consideration differences between patients, and stand for a medication review, by using a systematic approach. Different types of interventions exist in order to reduce inappropriate prescribing in older patients, such as: educational interventions, computerized decision support systems, pharmacist-based interventions, and geriatric assessment. The effects of these interventions have been studied, sometimes in a multifaceted approach combining different techniques, and all types seem to have positive effects on appropriateness of prescribing. Interdisciplinary teamwork within the integrative pharmaceutical care is important for improving of outcomes and safety of drug therapy. The pharmaceutical care process consists offour steps, which are cyclic for an individual patient. These steps are pharmaceutical anamnesis, medication review, design and follow-up of a pharmaceutical care plan. A standardized approach is necessary for the adequate detection and evaluation of drug-related problems. Furthermore, it is clear that drug therapy should be reviewed in-depth, by having full access to medical records, laboratory values and nursing notes. Although clinical pharmacists perform the pharmaceutical care process to manage the patient’s drug therapy in every day clinical practice, the physician takes the ultimate responsibility for the care of the patient in close collaboration with nurses

Dual function of rare earth carboxylate compounds on the barrier properties and active corrosion inhibition of epoxy coatings on mild steel

In this work, two rare earth carboxylate compounds, lanthanum 4-hydroxycinnamate (La(4-OHcin)3) and yttrium 3-(4-methylbenzoyl)propanoate (Y(mbp)3), were incorporated into bisphenol-based epoxy resin to investigate their effectiveness in coating barrier properties and active corrosion inhibition. EIS results showed that the incorporation of rare earth carboxylate inhibitors significantly improved corrosion resistance compared to the inhibitor free coating, with the global impedance modulus remaining at a level higher than 1 GΩ cm2 after 219 days immersion. Following EIS experiments, cross-sectional views of the coatings exhibited a pore-plugging behavior by rare earth containing precipitates, which reinforced the coating barrier properties and delayed the electrolyte diffusion process. These effects were also reflected from the electrochemical parameters extracted from breakpoint frequency analysis and equivalent circuit modelling. Filiform corrosion experiments for artificially scratched coatings suggest that the addition of rare earth carboxylates effectively suppressed the initiation and growth of filaments as well as the development of the coating delamination front. The active corrosion inhibition is possibly related to the formation of a surface protective film consisting of bimetallic complexes and rare earth metal rich precipitates. The electrochemical measurements and surface analyses evidence the dual function of rare earth carboxylate species for enhancing coating barrier properties against electrolyte penetration and providing active corrosion inhibition for the underlying AS1020 mild steel

Generalized Boltzmann Equation for Lattice Gas Automata

In this paper, for the first time a theory is formulated that predicts velocity and spatial correlations between occupation numbers that occur in lattice gas automata violating semi-detailed balance. Starting from a coupled BBGKY hierarchy for the $n$-particle distribution functions, cluster expansion techniques are used to derive approximate kinetic equations. In zeroth approximation the standard nonlinear Boltzmann equation is obtained; the next approximation yields the ring kinetic equation, similar to that for hard sphere systems, describing the time evolution of pair correlations. As a quantitative test we calculate equal time correlation functions in equilibrium for two models that violate semi-detailed balance. One is a model of interacting random walkers on a line, the other one is a two-dimensional fluid type model on a triangular lattice. The numerical predictions agree very well with computer simulations.Comment: 31 pages LaTeX, 12 uuencoded tar-compressed Encapsulated PostScript figures (`psfig' macro), hardcopies available on request, 78kb + 52k