An Expanded Multilocus Sequence Typing Scheme for Propionibacterium acnes: Investigation of ‘Pathogenic’, ‘Commensal’ and Antibiotic Resistant Strains

The Gram-positive bacterium Propionibacterium acnes is a member of the normal human skin microbiota and is associated with various infections and clinical conditions. There is tentative evidence to suggest that certain lineages may be associated with disease and others with health. We recently described a multilocus sequence typing scheme (MLST) for P. acnes based on seven housekeeping genes (http://pubmlst.org/pacnes). We now describe an expanded eight gene version based on six housekeeping genes and two ‘putative virulence’ genes (eMLST) that provides improved high resolution
typing (91eSTs from 285 isolates), and generates phylogenies congruent with those based on whole genome analysis. When compared with the nine gene MLST scheme developed at the University of Bath, UK, and utilised by researchers at Aarhus University, Denmark, the eMLST method offers greater resolution. Using the scheme, we examined 208 isolates from disparate clinical sources, and 77 isolates from healthy skin. Acne was predominately associated with type IA<sub>1sub> clonal complexes CC1, CC3 and CC4; with eST1 and eST3 lineages being highly represented. In contrast, type IA<sub>2sub> strains were recovered at a rate similar to type IB and II organisms. Ophthalmic infections were predominately associated with type IA<sub>1sub> and IA<sub>2sub> strains, while type IB and II were more frequently recovered from soft tissue and retrieved medical devices. Strains with rRNA mutations conferring resistance to antibiotics used in acne treatment were dominated by eST3, with some evidence for intercontinental spread. In contrast, despite its high association with acne, only a small number of resistant CC1 eSTs were identified. A number of eSTs were only recovered from healthy skin, particularly eSTs representing CC72 (type II) and CC77 (type III). Collectively our data lends support to the view that pathogenic versus truly commensal lineages of P. acnes may exist. This is likely to have important therapeutic and diagnostic implications.

NO3- transport across the plasma membrane of Arabidopsis thaliana root hairs:Kinetic control by pH and membrane voltage

High-affinity nitrate transport was examined in intact root hair cells of Arabidopsis thaliana using electrophysiological recordings to characterise the response of the plasma membrane to NO<sub>3sub>^-challenge and to quantify transport activity. The NO<sub>3sub>^--associated membrane current was determined using a three-electrode voltage clamp to bring membrane voltage under experimental control and to compensate for current dissipation along the longitudinal cell axis. Nitrate transport was evident in the roots of seedlings grown in the absence of a nitrogen source, but only 4-6 days postgermination. In 6-day-old seedlings, additions of 5-100 μm NO<sub>3sub>^-to the bathing medium resulted in membrane depolarizations of 8-43 mV, and membrane voltage (V<sub>msub>) recovered on washing NO<sub>3sub>^-from the bath. Voltage clamp measurements carried out immediately before and following NO<sub>3sub>^-additions showed that the NO<sub>3sub>^--evoked depolarizations were the consequence of an inward-directed current that appeared across the entire range of accessible voltages (-300 to +50 mV). Both membrane depolarizations and NO<sub>3sub>^--evoked currents recorded at the free-running voltage displayed quasi-Michaelian kinetics, with apparent values for K<sub>msub> of 23 ± 6 and 44 ± 11 μm, respectively and, for the current, a maximum of 5.1 ± 0.9 μA cm^-2. The NO<sub>3sub>^-current showed a pronounced voltage sensitivity within the normal physiological range between -250 and -100 mV, as could be demonstrated under voltage clamp, and increasing the bathing pH from 6.1 to 7.4-8.0 reduced the current and the associated membrane depolarizations 3- to 8-fold. Analyses showed a well-defined interaction between the kinetic variables of membrane voltage, pH<sub>osub> and [NO<sub>3sub>^-]<sub>osub>. At a constant pH<sub>osub> of 6.1, depolarization from -250 to -150 mV resulted in an approximate 3-fold reduction in the maximum current but a 10% rise in the apparent affinity for NO<sub>3sub>^-. By contrast, the same depolarization effected an approximate 20% fall in the K<sub>msub> for transport as a function in [H⁺]<sub>osub>. These, and additional characteristics of the transport current implicate a carrier cycle in which NO<sub>3sub>^-binding is kinetically isolated from the rate-limiting step of membrane charge transit, and they indicate a charge-coupling stoichiometry of 2(H⁺) per NO<sub>3sub>^-anion transported across the membrane. The results concur with previous studies showing a high-affinity NO<sub>3sub>^-transport system in Arabidopsis that is inducible following a period of nitrogen-limiting growth, but they underline the importance of voltage as a kinetic factor controlling NO<sub>3sub>^-transport at the plant plasma membrane. © 1995 Springer-Verlag New York Inc.

Discovery of WASP-65b and WASP-75b: Two hot Jupiters without highly inflated radii

We report the discovery of two transiting hot Jupiters, WASP-65b (M<sub>plsub> = 1.55 ± 0.16 M<sub>Jsub>; R<sub>plsub> = 1.11 ± 0.06 R<sub>Jsub>), and WASP-75b (M<sub>plsub> = 1.07 ± 0.05 M<sub>Jsub>; R<sub>plsub> = 1.27 ± 0.05 R<sub>Jsub>). They orbit their host star every ∼2.311, and ∼2.484 days, respectively. The planet host WASP-65 is a G6 star (T<sub>effsub> = 5600 K, [Fe/H] = −0.07 ± 0.07, age 8 Gyr); WASP-75 is an F9 star (T<sub>effsub> = 6100 K, [Fe/H] = 0.07 ± 0.09, age ∼ 3 Gyr). WASP-65b is one of the densest known exoplanets in the mass range 0.1 and 2.0 MJ (ρpl = 1.13 ± 0.08 ρJ), a mass range where a large fraction of planets are found to be inflated with respect to theoretical planet models. WASP-65b is one of only a handful of planets with masses of ∼1.5 MJ, a mass regime surprisingly underrepresented among the currently known hot Jupiters. The radius of WASP-75b is slightly inflated (10%) as compared to theoretical planet models with no core, and has a density similar to that of Saturn (ρpl = 0.52 ± 0.06 ρJ). Key words. planetary systems – stars: individual:

Total arsenic, inorganic arsenic, and other elements concentrations in Italian rice grain varies with origin and type

Rice is comparatively efficient at assimilating inorganic arsenic (As <sub>isub>), a class-one, non-threshold carcinogen, into its grain, being the dominant source of this element to mankind. Here it was investigated how the total arsenic (As<sub>tsub>) and As<sub>isub> content of Italian rice grain sourced from market outlets varied by geographical origin and type. Total Cr, Cd Se, Mg, K, Zn, Ni were also quantified. As<sub>tsub> concentration on a variety basis ranged from means of 0.18 mg kg^-1 to 0.28 mg kg ^-1, and from 0.11 mg kg^-1 to 0.28 mg kg^-1 by production region. For As<sub>isub> concentration, means ranged from 0.08 mg kg^-1 to 0.11 mg kg^-1 by variety and 0.10 mg kg ^-1 to 0.06 mg kg^-1 by region. There was significant geographical variation for both As<sub>tsub> and As<sub>isub>; total Se and Ni concentration; while the total concentration of Zn, Cr, Ni and K were strongly influenced by the type of rice.

Anxiolytic-like effects observed in rats exposed to the elevated zero-maze following treatment with 5-HT<sub>2sub>/5-HT<sub>3sub>/5-HT<sub>4sub> ligands

The present study examined the effects of administering selective 5-HT antagonists and agonists to rats tested in the elevated zero-maze (EZM) model of anxiety. The EZM paradigm has advantages over the elevated plus-maze (EPM) paradigm with respect to measuring anxiety, yet has been utilized less frequently. Three experiments were conducted each with a diazepam control (0.25, 0.5 and 0.75 mg/kg). In the first experiment, we administered the 5-HT<sub>2Csub> antagonist RS 102221 (0.5, 1.0, and 2.0 mg/kg) and 5-HT<sub>2Csub> agonist MK-212 (0.25, 0.5 and 0.75 mg/kg); in the second experiment, we administered the 5-HT<sub>3sub> antagonist Y-25130 (0.1, 1.0 and 3.0 mg/kg) and 5-HT<sub>3sub> agonist SR 57227A (0.1, 1.0 and 3.0 mg/kg), and in the third experiment, we administered the 5-HT<sub>4sub> antagonist RS 39604 (0.01, 0.1, 1.0 mg/kg) and 5-HT<sub>4sub> agonist RS 67333 (0.01, 0.1 and 0.5 mg/kg). The administration of 5-HT<sub>2/3/4sub> subtype antagonists all generated behavioral profiles indicative of anxiolytic-like effects in the EZM, which was apparent from examination of both traditional and ethological measures. While little effect was observed from 5-HT<sub>2sub> and 5-HT<sub>3sub> agonists, the 5-HT<sub>4sub> agonist RS 67333 was found to produce a paradoxical anxiolytic-like effect similar to that produced by the 5-HT<sub>4sub> antagonist RS 39604. We conclude by discussing the implications of these findings.

Automotive waste heat recovery: Working fluid selection and related boundary conditions

This paper presents the rational for the selection of fluids for use in a model based study of sub and supercritical Waste Heat Recovery (WHR) Organic Rankine Cycle (ORC). The study focuses on multiple vehicle heat sources and the potential of WHR ORC’s for its conversion into useful work. The work presented on fluid selection is generally applicable to any waste heat recovery system, either stationary or mobile and, with careful consideration, is also applicable to single heat sources. The fluid selection process presented reduces the number of potential fluids from over one hundred to a group of under twenty fluids for further refinement in a model based WHR ORC performance study. The selection process uses engineering judgement, legislation and, where applicable, health and safety as fluid selection or de-selection criteria. This paper also investigates and discusses the properties of specific ORC fluids with regard to their impact on the theoretical potential for delivering efficient WHR ORC work output. The paper concludes by looking at potential temperature and pressure WHR ORC limits with regard to fluid properties thereby assisting with the generation of WHR ORC simulation boundary conditions.

A randomised controlled trial of increasing fruit and vegetable intake and how this influences the carotenoid concentration and activities of PON-1 and LCAT in HDL from subjects with type 2 diabetes

Background

High density lipoproteins (HDL) have many cardioprotective roles; however, in subjects with type 2 diabetes (T2D) these cardioprotective properties are diminished. Conversely, increased fruit and vegetable (F&V) intake may reduce cardiovascular disease risk, although direct trial evidence of a mechanism by which this occurs in subjects with T2D is lacking. Therefore, the aim of this study was to examine if increased F&V consumption influenced the carotenoid content and enzymes associated with the antioxidant properties of HDL in subjects with T2D.

Eighty obese subjects with T2D were randomised to a 1- or ≥6-portion/day F&V diet for 8-weeks. Fasting serum was collected pre- and post-intervention. HDL was subfractionated into HDL<sub style="padding: 0px; margin: 0px;">2sub> and HDL<sub style="padding: 0px; margin: 0px;">3sub> by rapid ultracentrifugation. Carotenoids were measured in serum, HDL<sub style="padding: 0px; margin: 0px;">2sub> and HDL<sub style="padding: 0px; margin: 0px;">3sub> by high performance liquid chromatography. The activity of paraoxonase-1 (PON-1) was measured in serum, HDL<sub style="padding: 0px; margin: 0px;">2sub> and HDL<sub style="padding: 0px; margin: 0px;">3sub> by a spectrophotometric assay, while the activity of lecithin cholesterol acyltransferase (LCAT) was measured in serum, HDL<sub style="padding: 0px; margin: 0px;">2sub> and HDL<sub style="padding: 0px; margin: 0px;">3sub> by a fluorometric assay.

In the ≥6- vs. 1-portion post-intervention comparisons, carotenoids increased in serum, HDL<sub style="padding: 0px; margin: 0px;">2sub> and particularly HDL<sub style="padding: 0px; margin: 0px;">3sub>, (α-carotene, p = 0.008; β-cryptoxanthin, p = 0.042; lutein, p = 0.012; lycopene, p = 0.016), as did the activities of PON-1 and LCAT in HDL<sub style="padding: 0px; margin: 0px;">3sub> (p = 0.006 and 0.044, respectively).

To our knowledge, this is the first study in subjects with T2D to demonstrate that increased F&V intake augmented the carotenoid content and influenced enzymes associated with the antioxidant properties of HDL. We suggest that these changes would enhance the cardioprotective properties of this lipoprotein.

Monitoring the development of microcracks in reinforced concrete caused by sustained loading and chloride induced corrosion

Chloride-induced corrosion of steel in reinforced concrete structures is one of the main problems affecting their durability and it has been studied for decades, but most of them have focused on concrete without cracking or not subjected to any structural load. In fact, concrete structures are subjected to various types of loads, which lead to cracking when the tensile stress in concrete exceeds its tensile strength. Cracking could increase transport properties of concrete and accelerate the ingress of harmful substances (Cl ^-, O<sub>2sub>, H<sub>2sub> O, CO<sub>2sub>). This could initiate and accelerate different types of deterioration processes in concrete, including corrosion of steel reinforcement. The expansive products generated by the deterioration processes themselves can initiate cracking. The success of concrete patch repairs can also influence microcracking at the interface as well as the patch repair itself. Therefore, monitoring the development of microcracking in reinforced concrete members is extremely useful to assess the defects and deterioration in concrete structures. In this paper, concrete beams made using 4 different mixes were subjected to three levels of sustained lateral loading (0%, 50% and 100% of the load that can induce a crack with width of 0.1mmon the tension surface of beams - F <sub>0.1sub>) and weekly cycles of wetting (1 day)/drying (6 days) with chloride solution. The development of microcracking on the surface of concrete was monitored using the Autoclam Permeability System at every two weeks for 60 weeks. The ultrasonic pulse velocity of the concrete was also measured along the beam by using the indirect method during the test period. The results indicated that the Autoclam Permeability System was able to detect the development of microcracks caused by both sustained loading and chloride induced corrosion of steel in concrete. However, this was not the case with the ultrasonic method used in the work (indirect method applied along the beam); it was sensitive to microcracking caused by sustained loading but not due to corrosion. © 2014 Taylor & Francis Group.

Influence of micro and macro cracks due to sustained loading on chloride-induced corrosion of reinforced concrete beams

Chloride-induced corrosion of steel is one of the most commonly found problems affecting the durability of reinforced concrete structures in both marine environment and where de-icing salt is used in winter. As the significance of micro-cracks on chloride induced corrosion is not well documented, 24 reinforced concrete beams (4 different mixes - one containing Portland cement and another containing 35% ground granulated blastfurnace slag at 0.45 and 0.65 water-binder ratios) were subjected to three levels of sustained lateral loading (0%, 50% and 100% of the load that can induce 0.1 mm wide cracks on the tension surface of beam - F<sub>0.1sub>) in this work. The beams were then subjected to weekly cycles of wetting with 10% NaCl solution for 1 day followed by 6 days of drying at 20 (±1) °C up to an exposure period of 60 weeks. The progress of corrosion of steel was monitored using half-cell potential apparatus and linear polarisation resistance (LPR) test. These results have shown that macro-cracks (at load F<sub>0.1sub>) and micro-cracks (at 50% of F<sub>0.1sub>) greatly accelerated both the initiation and propagation stages of the corrosion of steel in the concrete beams. Lager crack widths for the F<sub>0.1sub> load cases caused higher corrosion rates initially, but after about 38 weeks of exposure, there was a decrease in the rate of corrosion. However, such trends could not be found in 50% F <sub>0.1sub> group of beams. The extent of chloride ingress also was influenced by the load level. These findings suggest that the effect of micro-cracking at lower loads are very important for deciding the service life of reinforced concrete structures in chloride exposure environments. © 2014 4th International Conference on the Durability of Concrete Structures.

Formation and characterization of carbon-radical precursors in char steam gasification

Highly reactive radicals play an important role in high-temperature gasification processes. However, the effect of radicals on gasification has not been systematically investigated. In the present study, the formation of carbon-radical precursors using atomic radicals such as OH, O, and H and molecules such as H<sub>2sub> and O<sub>2sub> was characterized, and the effect of the precursors on the adsorption step of steam char gasification was studied using quantum chemistry methods. The results revealed that the radicals can be chemisorbed exothermically on char active sites, and the following order of reactivity was observed: O > H<sub>2sub> > H > OH > O <sub>2sub>. Moreover, hydrogen bonds are formed between steam molecules and carbon-radical complexes. Steam molecule adsorption onto carbon-O and carbon-OH complexes is easier than adsorption onto clean carbon surfaces. Alternatively, adsorption on carbon-O<sub>2sub>, carbon-H<sub>2sub>, and carbon-H complexes is at the same level with that of clean carbon surfaces; thus, OH and O radicals accelerate the physical adsorption of steam onto the char surface, H radical and O<sub>2sub> and H<sub>2sub> molecules do not have a significant effect on adsorption. © 2010 American Chemical Society.

The optimized geometric structure of the (0001) surface of α-Fe <sub>2sub>O<sub>3sub>

A tridimensional model of α-Fe<sub>2sub>O<sub>3sub> and models of (0001) and (1102) surfaces on it were built. Then the structural optimization of the (0001) surface was presented which explored the influence of the system scale and the terminal surface configuration. Four different models including two different system scale structures (MODEL□ and MODEL□) and two different terminal structures (MODEL□ and MODEL□) were analyzed in this paper. It was concluded that the boundary effect was more important in a smaller system in the structure optimization. And the Fe-terminated was more stable than the O-terminated structure which was agreed with the experiences, this structural model can be used in further work including the monatomic adsorption/desorption and the chemical reactions on this surface.

The application of Raman and anti-stokes Raman spectroscopy for in situ monitoring of structural changes in laser irradiated titanium dioxide materials

The use of Raman and anti-stokes Raman spectroscopy to investigate the effect of exposure to high power laser radiation on the crystalline phases of TiO<sub>2sub> has been investigated. Measurement of the changes, over several time integrals, in the Raman and anti-stokes Raman of TiO<sub>2sub> spectra with exposure to laser radiation is reported. Raman and anti-stokes Raman provide detail on both the structure and the kinetic process of changes in crystalline phases in the titania material. The effect of laser exposure resulted in the generation of increasing amounts of the rutile crystalline phase from the anatase crystalline phase during exposure. The Raman spectra displayed bands at 144 cm^-1 (A1g), 197 cm^-1 (Eg), 398 cm^-1 (B1g), 515 cm^-1 (A1g), and 640 cm^-1 (Eg) assigned to anatase which were replaced by bands at 143 cm^-1 (B1g), 235 cm^-1 (2 phonon process), 448 cm^-1 (Eg) and 612 cm^-1 (A1g) which were assigned to rutile. This indicated that laser irradiation of TiO<sub>2sub> changes the crystalline phase from anatase to rutile. Raman and anti-stokes Raman are highly sensitive to the crystalline forms of TiO<sub>2sub> and allow characterisation of the effect of laser irradiation upon TiO<sub>2sub>. This technique would also be applicable as an in situ method for monitoring changes during the laser irradiation process

A field and reactive transport model study of arsenic in a basaltic rock aquifer

The use of geothermal energy as a source for electricity and district heating has increased over recent decades. Dissolved As can be an important constituent of the geothermal fluids brought to the Earth's surface. Here the field application of laboratory measured adsorption coefficients of aqueous As species on basaltic glass surfaces is discussed. The mobility of As species in the basaltic aquifer in the Nesjavellir geothermal system, Iceland was modelled by the one-dimensional (1D) reactive transport model PHREEQC ver. 2, constrained by a long time series of field measurements with the chemical composition of geothermal effluent fluids, pH, Eh and, occasionally, Fe- and As-dissolved species measurements. Di-, tri- and tetrathioarsenic species (As(OH)S22-, AsS<sub>3sub>H^2-, AsS33- and As(SH)4-) were the dominant form of dissolved As in geothermal waters exiting the power plant (2.556μM total As) but converted to some extent to arsenite (H<sub>3sub>AsO<sub>3sub>) and arsenate HAsO42- oxyanions coinciding with rapid oxidation of S2- to S2O32- and finally to SO42- during surface runoff before feeding into a basaltic lava field with a total As concentration of 0.882μM following dilution with other surface waters. A continuous 25-a data set monitoring groundwater chemistry along a cross section of warm springs on the Lake Thingvallavatn shoreline allowed calibration of the 1D model. Furthermore, a series of ground water wells located in the basaltic lava field, provided access along the line of flow of the geothermal effluent waters towards the lake. The conservative ion Cl^- moved through the basaltic lava field (4100m) in less than10a but As was retarded considerably due to surface reactions and has entered a groundwater well 850m down the flow path as arsenate in accordance to the prediction of the 1D model. The 1D model predicted a complete breakthrough of arsenate in the year 2100. In a reduced system arsenite should be retained for about 1ka. © 2011 Elsevier Ltd.

Arsenic-glutathione complexes - Their stability in solution and during separation by different HPLC modes

Complexes of arsenic compounds and glutathione are believed to play an essential part in the metabolism and transport of inorganic arsenic and its methylated species. Up to now, the evidence of their presence is mostly indirect. We studied the stability and Chromatographic behaviour of glutathione complexes with trivalent arsenic: i.e. As^III(GS)<sub>3sub>, MA ^III(GS)<sub>2sub> and DMA^III(GS) under different conditions. Standard ion chromatography using PRP X-100 and carbonate or formic acid buffer disintegrated the complexes, while all three complexes are stable and separable by reversed phase chromatography (0.1% formic acid/acetonitrile gradient). As^III(GS)<sub>3sub> and MA^III(GS)<sub>2sub> were more stable than DMA^III(GS), which even under optimal conditions tended to degrade on the column at 25 °C. Chromatography at 6 °C can retain the integrity of the samples. These results shed more light on the interpretation of a vast number of previously published arsenic speciation studies, which have used Chromatographic separation techniques with the assumption that the integrity of the arsenic species is guaranteed. © The Royal Society of Chemistry 2004.

Biomarkers reveal the effects of hydrography on the sources and fate of marine and terrestrial organic matter in the western Irish Sea

A suite of lipid biomarkers were investigated from surface sediments and particulate matter across hydrographically distinct zones associated with the western Irish Sea gyre and the seasonal bloom. The aim was to assess the variation of organic matter (OM) composition, production, distribution and fate associated with coastal and southern mixed regions and also the summer stratified region. Based on the distribution of a suite of diagnostic biomarkers, including phospholipid fatty acids, source-specific sterols, wax esters and C<sub>25sub> highly branched isoprenoids, diatoms, dinoflagellates and green algae were identified as major contributors of marine organic matter (MOM) in this setting. The distribution of cholesterol, wax esters and C<sub>20sub> and C<sub>22sub> polyunsaturated fatty acids indicate that copepod grazing represents an important process for mineralising this primary production. Net tow data from 2010 revealed much greater phytoplankton and zooplankton biomass in well-mixed waters compared to stratified waters. This appears to be largely reflected in MOM input to surface sediments. Terrestrial organic matter (TOM), derived from higher plants, was identified as a major source of OM regionally, but was concentrated in proximity to major riverine input at the Boyne Estuary and Dundalk Bay. Near-bottom residual circulation and the seasonal gyre also likely play a role in the fate of TOM in the western Irish Sea.