58 research outputs found

    Personal control of the indoor environment in offices: Relations with building characteristics, influence on occupant perception and reported symptoms related to the building-the officair project

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    Personal control over various indoor environment parameters, especially in the last decades, appear to have a significant role on occupants' comfort, health and productivity. To reveal this complex relationship, 7441 occupants of 167 recently built or retrofitted office buildings in eight European countries participated in an online survey about personal/health/work data as well as physical/psycho-social information. The relationship between the types of control available over indoor environments and the perceived personal control of the occupants was examined, as well as the combined effect of the control parameters on the perceived comfort using multilevel statistical models. The results indicated that most of the occupants have no or low control on noise. Half of the occupants declared no or low control on ventilation and temperature conditions. Almost one-third of them remarked that they do not have satisfactory levels of control for lighting and shading from sun conditions. The presence of operable windows was shown to influence occupants' control perception over temperature, ventilation, light and noise. General building characteristics, such as floor number and floor area, office type, etc., helped occupants associate freedom positively with control perception. Combined controlling parameters seem to have a strong relation with overall comfort, as well as with perception regarding amount of privacy, office layout and decoration satisfaction. The results also indicated that occupants with more personal control may have less building-related symptoms. Noise control parameter had the highest impact on the occupants' overall comfort

    Intra- and Interspecies Genomic Transfer of the Enterococcus faecalis Pathogenicity Island

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    Enterococci are the third leading cause of hospital associated infections and have gained increased importance due to their fast adaptation to the clinical environment by acquisition of antibiotic resistance and pathogenicity traits. Enterococcus faecalis harbours a pathogenicity island (PAI) of 153 kb containing several virulence factors including the enterococcal surface protein (esp). Until now only internal fragments of the PAI or larger chromosomal regions containing it have been transfered. Here we demonstrate precise excision, circularization and horizontal transfer of the entire PAI element from the chromosome of E. faecalis strain UW3114. This PAI (ca. 200 kb) contained some deletions and insertions as compared to the PAI of the reference strain MMH594, transferred precisely and integrated site-specifically into the chromosome of E. faecalis (intergenic region) and Enterococcus faecium (tRNAlys). The internal PAI structure was maintained after transfer. We assessed phenotypic changes accompanying acquisition of the PAI and expression of some of its determinants. The esp gene is expressed on the surface of donor and both transconjugants. Biofilm formation and cytolytic activity were enhanced in E. faecalis transconjugants after acquisition of the PAI. No differences in pathogenicity of E. faecalis were detected using a mouse bacteraemia and a mouse peritonitis models (tail vein and intraperitoneal injection). A 66 kb conjugative pheromone-responsive plasmid encoding erm(B) (pLG2) that was transferred in parallel with the PAI was sequenced. pLG2 is a pheromone responsive plasmid that probably promotes the PAI horizontal transfer, encodes antibiotic resistance features and contains complete replication and conjugation modules of enterococcal origin in a mosaic-like composition. The E. faecalis PAI can undergo precise intra- and interspecies transfer probably with the help of conjugative elements like conjugative resistance plasmids, supporting the role of horizontal gene transfer and antibiotic selective pressure in the successful establishment of certain enterococci as nosocomial pathogens

    Amyloids - A functional coat for microorganisms

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    Amyloids are filamentous protein structures ~10 nm wide and 0.1–10 µm long that share a structural motif, the cross-β structure. These fibrils are usually associated with degenerative diseases in mammals. However, recent research has shown that these proteins are also expressed on bacterial and fungal cell surfaces. Microbial amyloids are important in mediating mechanical invasion of abiotic and biotic substrates. In animal hosts, evidence indicates that these protein structures also contribute to colonization by activating host proteases that are involved in haemostasis, inflammation and remodelling of the extracellular matrix. Activation of proteases by amyloids is also implicated in modulating blood coagulation, resulting in potentially life-threatening complications.

    The creatine kinase system and pleiotropic effects of creatine

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    The pleiotropic effects of creatine (Cr) are based mostly on the functions of the enzyme creatine kinase (CK) and its high-energy product phosphocreatine (PCr). Multidisciplinary studies have established molecular, cellular, organ and somatic functions of the CK/PCr system, in particular for cells and tissues with high and intermittent energy fluctuations. These studies include tissue-specific expression and subcellular localization of CK isoforms, high-resolution molecular structures and structure–function relationships, transgenic CK abrogation and reverse genetic approaches. Three energy-related physiological principles emerge, namely that the CK/PCr systems functions as (a) an immediately available temporal energy buffer, (b) a spatial energy buffer or intracellular energy transport system (the CK/PCr energy shuttle or circuit) and (c) a metabolic regulator. The CK/PCr energy shuttle connects sites of ATP production (glycolysis and mitochondrial oxidative phosphorylation) with subcellular sites of ATP utilization (ATPases). Thus, diffusion limitations of ADP and ATP are overcome by PCr/Cr shuttling, as most clearly seen in polar cells such as spermatozoa, retina photoreceptor cells and sensory hair bundles of the inner ear. The CK/PCr system relies on the close exchange of substrates and products between CK isoforms and ATP-generating or -consuming processes. Mitochondrial CK in the mitochondrial outer compartment, for example, is tightly coupled to ATP export via adenine nucleotide transporter or carrier (ANT) and thus ATP-synthesis and respiratory chain activity, releasing PCr into the cytosol. This coupling also reduces formation of reactive oxygen species (ROS) and inhibits mitochondrial permeability transition, an early event in apoptosis. Cr itself may also act as a direct and/or indirect anti-oxidant, while PCr can interact with and protect cellular membranes. Collectively, these factors may well explain the beneficial effects of Cr supplementation. The stimulating effects of Cr for muscle and bone growth and maintenance, and especially in neuroprotection, are now recognized and the first clinical studies are underway. Novel socio-economically relevant applications of Cr supplementation are emerging, e.g. for senior people, intensive care units and dialysis patients, who are notoriously Cr-depleted. Also, Cr will likely be beneficial for the healthy development of premature infants, who after separation from the placenta depend on external Cr. Cr supplementation of pregnant and lactating women, as well as of babies and infants are likely to be of benefit for child development. Last but not least, Cr harbours a global ecological potential as an additive for animal feed, replacing meat- and fish meal for animal (poultry and swine) and fish aqua farming. This may help to alleviate human starvation and at the same time prevent over-fishing of oceans

    Geochemical and geochronological constraints on the formation of shear-zone hosted Cu-Au-Bi-Te mineralization in the Stanos area, Chalkidiki, northern Greece

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    Copper-gold-bismuth-tellurium mineralization in the Stanos area, Chalkidiki Peninsula, Greece, occurs in the Proterozoic- to Silurian-aged Serbomacedonian Massif, which tectonically borders the Mesozoic Circum-Rhodope metamorphic belt to the west and crystalline rocks of the Rhodope Massif to the east. This area contains the Paliomylos, Chalkoma, and Karambogia prospects, which are spatially related to regional NW-SE trending shear zones and hosted by marble, amphibolite gneiss, metagabbro, and various muscovite-biotite-chlorite-actinolite-feldspar-quartz schists of the Silurian Vertiskos Unit. Metallic minerals occur as disseminated to massive aggregates along foliation planes and in boudinaged quartz veins. Iron-bearing sulfides (pyrite, arsenopyrite, and pyrrhotite) formed prior to a copper-bearing stage that contains chalcopyrite along with galena, sphalerite, molybdenite, and various minerals in the system Bi-Cu-Pb-Au-Ag-Te. Fluid inclusion homogenization temperatures of primary aqueous liquid-vapor inclusions in stage I quartz veins range from 170.1°C to 349.6°C (peak at ~230°C), with salinities of 4.5 to 13.1wt.% NaCl equiv. Calculated isochores intersect P-T conditions associated with the upper greenschist facies caused by local overpressures during late-stage tectonic movement along the shear zone in the Eocene, which produced stretching and unroofing of rocks in the region. Values of δ34S for sulfides in the Stanos shear zone range from 2.42 to 10.19‰ and suggest a magmatic sulfur source with a partially reduced seawater contribution. For fluids in equilibrium with quartz, δ18O at 480°C varies from 5.76 to 9.21‰ but does not allow for a distinction between a metamorphic and a magmatic fluid.A 187Re-187Os isochron of 19.2±2.1Ma for pyrite in the Paliomylos prospect overlaps ages obtained previously from intrusive rocks spatially-related to the Skouries porphyry Cu-Au, the Asimotrypes Au, and the intrusion-related Palea Kavala Bi-Te-Pb-Sb±Au deposits in northern Greece, as well as alteration minerals in the carbonate-replacement Madem Lakkos Pb-Zn deposit. Ore-forming components of deposits in the Stanos area were likely derived from magmatic rocks at shallow depth that intruded an extensional shear environment at ~19Ma. © 2014 Elsevier B.V

    Fabrication of piezoelectric micro-cantilevers in domain-engineered LiNbO<sub>3</sub> single crystals

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    We report on a novel route for fabrication of micro-cantilevers in ferroelectric single-crystal lithium niobate (LiNbO3). Using the sequential techniques of photolithographic patterning, electric field poling, direct bonding and domain-oriented differential etching, free-standing cantilevers of dimensions 50µm × 50µm × 5 mm in the x, z and y crystallographic directions, respectively, have been fabricated

    Bismuthinite derivatives, lillianite homologues, and bismuth sulfotellurides as indicators of gold mineralization in the stanos shear-zone related deposit, Chalkidiki, Northern Greece

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    Arsenic-copper-gold-bismuth mineralization in the Stanos area is hosted by a km-long, NW-SE trending ductile to brittle shear zone within Silurian orthogneisses of the Vertiskos terrane of the Servomacedonian Massif, Chalkidiki Peninsula, northern Greece. Shearing was accompanied by iron-potassic alteration of the gneisses including biotite, muscovite, chlorite, apatite, zircon, quartz, and minor rare-earth element phosphates. Metallic minerals form disseminated to massive aggregates along foliation planes, asymmetric crenulation cleavages, and S-C&apos; fabrics. Detailed textural investigation of the ore assemblages revealed two stages of hydrothermal mineralization during shearing. An initial introduction of iron sulfides (pyrite, arsenopyrite, and pyrrhotite) was followed by a copper-bearing stage that is associated with the formation of chalcopyrite, minor sulfides (galena, sphalerite, and molybdenite), and Bi-Cu-Pb-Au-Ag-Te minerals. The stage II metallic mineral association consists mainly of Bi sulfosalts (bismuthinite derivatives, lillianite homologues, matildite), native elements (bismuth, electrum), and bismuth chalcogenides (joséite-A, joséite-B, ikunolite, and unnamed Bi-Pb-bearing sulfotellurides). The bismuthinite derivatives are mainly bismuthinite (including cuprian varieties), gladite-krupkaite, paarite, salzburgite, and an unnamed CuPbBi7S12 phase. The ikunolite is Se-free, corresponding to the formula Bi4S3, and is the first known occurrence in Greece. Most stage II minerals exist in two-, three-, and, more rarely, four-component blebs or patches generally with curvilinear boundaries, suggesting the possibility that they were precipitated in a molten form. Phase relationships among minerals in the system Au-Bi-Te-Pb-Ag-Cu indicate that they formed by successive hydrothermal pulses from fluids that penetrated the shear zone at different times contemporaneous with ductile deformation. These pulses deposited the following assemblages in paragenetic order: molybdenite + cosalite + native bismuth + galenobismutite → gustavite/lillianite + native gold + native bismuth + bismuth sulfotellurides → bismuthinite-aikinite solid solution series→ matildite + native bismuth + galena → chalcopyrite + bornite. The observed association suggests that the system evolved under fluctuating f(S2) and f(O2) conditions and precious metals may have been scavenged by composite Bi-Te-Pb-S melts at temperatures well above 350 °C. The enrichment of Bi, Mo, Pb likely indicates a magmatic contribution to the ore-forming fluid

    Detection of a phylogenetically distinct imp-type metallo-blactamase, imp-35, in a cc235 pseudomonas aeruginosa from the dutch-german border region (euregio)

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    To characterize a highly divergent IMP-type metallo-b-lactamase (MBL) variant detected in a multidrug-resistant Pseudomonas aeruginosa clinical isolate. Methods: P. aeruginosa isolate 1876 was recovered from an anal swab of an inpatient at a German hospital in the Dutch-German border region (Euregio), where cross-border patient healthcare occurs. MICs were determined by agar dilution and phenotypic screening for MBL production by Etest MBL. Typing was performed by multilocus sequence typing (MLST). PCR assays and nucleotide sequencing were employed for identification of bla gene types. The class 1 integron carrying the blaIMP-type gene was characterized by PCR mapping and sequencing using a set of specific primers. A phylogenetic tree was constructed for the new blaIMP variant. Results: Isolate 1876 was phenotypically positive for MBL production, exhibited resistance to carbapenems and harboured a new blaIMP-type gene, blaIMP-35. MLST showed that the allelic profile corresponded to ST622, which belongs to the prevalent international clonal complex CC235. The blaIMP-35 gene was located in a class 1 integron as the first gene cassette, followed by blaOXA-35, aacA6, qacED1 and sul1, suggesting its recent integration. IMP-35 was highly divergent, possessing 33/246 (13.4%) different amino acid residues from its closest IMP variants (IMP-8 and IMP-12) and was phylogenetically distinct, representing a separate group in the phylogenetic tree of IMP proteins. Conclusions: The identification of this phylogenetically distinct IMP-type variant in a CC235 P. aeruginosa suggests the ongoing spread of new IMP-type carbapenemases as well as the potential of the blaIMP-35 gene to evolve in the hospital environment. ©The Author 2013
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