1,534 research outputs found

    Acetic and formic acids emitted from wood samples and their effect on selected materials in museum environments

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    The concentrations of acetic acid and formic acid vapours emitted by a number of wood samples held in sealed environments were measured to assess differences between hardwood and softwood species. Three cases studies are reported where sodium formate, lead formate and acetate-based efflorescences were identified on glass, lead and calcareous artefacts held in heritage environments with elevated acetic acid and formic acid vapours. Simulated experiments were undertaken to assess the affect of formic acid vapour on limestone, egg shell, copper, lead and brass coupons and it was confirmed that porous limestone preferentially scavenged formic acid vapours from air

    Modelling aromatisation of (BN)nH2n azabora-annulenes

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    Despite a long tradition of descriptions of borazine as an ‘inorganic benzene’, this molecule is a non-aromatic species according to the magnetic (ring-current) criterion. Borazine, borazocine, and the larger neutral (BN)nH2n azabora-annulene heterocycles in planar conformations, although π-isoelectronic with [2n]annulenes, support only localized induced currents in perpendicular magnetic fields. The π-current maps of these systems comprise superpositions of separate ‘lone-pair’ circulations on all nitrogen centres. For the systems with n > 4, planarity must be enforced by a constraint. Qualitative orbital analysis based on the ipsocentric approach to calculation of induced current density suggests that global induced currents could be produced through strategic changes to the π electron count. In ab initio calculations, azabora-annulenes with rings of size [8]- and larger were indeed found to support global diatropic ring currents in both anionic and cationic forms with (4N + 2) π electron counts. The planar conformation of the charged ring typically occupies a stationary point of higher order on the potential energy surface, rather than a minimum. However, the borazocine dianion, [B4N4H8]2−, occupies a planar minimum, supports a diatropic ring current of strength comparable to that in benzene, and is predicted to participate in sandwich compounds; it is therefore a good candidate for an aromatised azabora-annulene

    Circulating microRNA changes in patients with impaired glucose regulation

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    © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. We analysed if levels of four miRNAs would change after a lifestyle intervention involving dietary and exercises in prediabetes. MiRNAs previously shown to be associated with diabetes (Let-7a, Let-7e, miR-144 and miR-92a) were extracted from serum pre- and post-intervention. mRNA was extracted from fat-tissue for gene expression analyses. The intervention resulted in increased Let-7a and miR-92a. We found correlations between miRNAs and clinical variables (triglycerides, cholesterol, insulin, weight and BMI). We also found correlations between miRNAs and target genes, revealing a link between miR-92a and IGF system. A lifestyle intervention resulted in marked changes in miRNAs. The association of miRNAs with insulin and the IGF system (both receptors and binding proteins) may represent a mechanism of regulating IGFs metabolic actions

    A Process and Outcome Evaluation of a Shelter for Homeless Young Women

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    To evaluate the processes and outcomes of a short-term shelter, both quantitative and qualitative data were gathered via participant observation, focus group interviews with shelter staff and residents, and individual interviews with a sample of 40 young women who had been homeless prior to using the shelter. The process evaluation showed that the shelter staff strived to utilize an empowerment philosophy in their relationships with residents, but that there were many challenges to implementing this philosophy. The outcome evaluation showed that, at a 3-month follow-up, the participants reported significant improvements in housing, income, independence, and life satisfaction, but most continued to experience poverty and a number of other difficulties. The results were discussed in terms of the implications for future research and the value and limitations of shelters for dealing with homeless youth. The need for more sustained and comprehensive program interventions and supportive social policies was underscored

    Evaluating genetic association between fusarium and pythium root rots resistances in the bean genotype RWR 719

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    Resistance to Fusarium root rot ( Fusarium solani f.s.p phaseoli ) has been reported in common bean ( Phaseolus vulgaris L.) sources and is usually associated with Pythium root rot resistance. Pythium root rot ( Pythium ultimum var ultimum ) resistance is controlled by a single dominant gene, marked by a SCAR marker PYAA19800 . It remains unclear whether the inheritance to resistance of these two bean root rots is genetically independent. We evaluated the association of Fusarium root rot resistance with the Pythium root rots resistance gene and/or the molecular marker PYAA19800 in genotype RWR 719. Two populations; F2 and F2:3 lines, generated from RWR 719 (resistant) 7 K132 (susceptible) were respectively screened with Fusarium solani and Pythium ultimum isolates, and root damages were scored based on the CIAT 1 \u2013 9 scale. Additionally, the F2:3 lines were screened with PYAA19800. The F2 segregation ratio deviated from a single gene model for reaction to Fusarium solani. The F2:3 lines fit the model for a single dominant gene that confers resistance to Pythium ultimum. Fusarium solani and Pythium ultimum resistances were inherited independently. There was lack of association between PYAA19800 and Fusarium solani resistance, but the PYAA19800 was strongly associated with Pythium ultimum resistance. This contradicts the assertion of linkage of the two resistances that was deduced based on the joint occurrence of both resistances in the available donor genotypes.La r\ue9sistance \ue0 la porriture racinaire par suite du Fusarium solani f.s.p Phaseoli a \ue9t\ue9 signal\ue9e dans les sources du haricot commun ( Phaseolus vulgaris L.) et commun\ue9ment associ\ue9e \ue0 la r\ue9sistance de la pourriture racinaire due au Pythium . La r\ue9sistance \ue0 la pourriture racinaire due au pithium ( Pythium ultimum var ultimum ) est control\ue9e par un unique g\ue8ne dominant marqu\ue9 par un marquer SCAR PYAA19800. Il demeure incertain si l\u2019h\ue9ritage de la r\ue9sistance \ue0 ces deux types de pourriture racinaire du haricot est g\ue9n\ue9tiquement ind\ue9pendant. Nous avons \ue9valu\ue9 l\u2019association des g\ue8nes de r\ue9sistance \ue0 la pourriture racinaire due au Fusarium solani et au Pythium ultimum et/ou le marqueur mol\ue9culaire PYAA19800 dans le g\ue9notype RWR 719. Deux populations, F2 et F2:3 issues du croisement entre 719 (r\ue9sistant) 7 K132 (sensible) ont \ue9t\ue9 respectivement test\ue9es avec des isolats de Fusarium solani et Pythium ultimum, et les d\ue9g\ue2ts \ue9taient mesur\ue9s sur base de l\u2019\ue9chelle de cotation de 1 \ue0 9 du CIAT. Additionnellement, F2:3 \ue9taient test\ue9es avec PYAA19800. Le rapport de s\ue9gr\ue9gation de F2 a d\ue9vi\ue9 du mod\ue8le unique pour la r\ue9action au Fusarium solani. Les lign\ue9es F2:3 se sont adapt\ue9es au mod\ue8le de l\u2019unique g\ue8ne dominant qui conf\ue8re la r\ue9sistance au Pythium ultimum. Les r\ue9sistances au Fusarium solani et au Pythium ultimum \ue9taient ind\ue9pendamment h\ue9rit\ue9es. Il n\u2019y avait aucune association entre PYAA 19800 et la r\ue9sistance au Fusarium solani, mais le PYAA19800 \ue9tait un g\ue8ne unique dominant avec r\ue9sistance au Pythium ultimum. Ceci contr\ue9dit l\u2019assertion du lien de ces deux r\ue9sistances d\ue9duit sur base de l\u2019occurrence combin\ue9e de toutes les deux resistances dans les g\ue9notypes donneurs disponibles

    Parity-Violating Interaction Effects I: the Longitudinal Asymmetry in pp Elastic Scattering

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    The proton-proton parity-violating longitudinal asymmetry is calculated in the lab-energy range 0--350 MeV, using a number of different, latest-generation strong-interaction potentials--Argonne V18, Bonn-2000, and Nijmegen-I--in combination with a weak-interaction potential consisting of rho- and omega-meson exchanges--the model known as DDH. The complete scattering problem in the presence of parity-conserving, including Coulomb, and parity-violating potentials is solved in both configuration- and momentum-space. The predicted parity-violating asymmetries are found to be only weakly dependent upon the input strong-interaction potential adopted in the calculation. Values for the rho- and omega-meson weak coupling constants hρpph^{pp}_\rho and hωpph^{pp}_\omega are determined by reproducing the measured asymmetries at 13.6 MeV, 45 MeV, and 221 MeV.Comment: 24 pages, 8 figures, submitted to Physical Review

    Raman Deuterium Isotope Probing Reveals Microbial Metabolism at the Single-Cell Level

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    We illustrate that single-cell Raman microspectroscopy, coupled with deuterium isotope probing (Raman-DIP), provides a culture-independent and nondestructive approach to probe metabolic pathways of carbon substrates at the single-cell level. We found a distinguishable C-D vibration band at 2070-2300 cm-1 in single-cell Raman spectra (SCRS) when Escherichia coli used deuterated glucose and Pseudomonas sp. used deuterated naphthalene as sole carbon sources. The intensity of the C-D band is proportional to the extent of deuteration in the carbon source, and as little as 5% deuteration can be distinguished by analysis of SCRS. It suggests that Raman-DIP could be used to semiquantitatively and sensitively indicate the metabolism of deuterated carbon source in microbes. A lower lipid conversion rate of deuterated naphthalene compared to that of deuterated glucose was observed, presumably owing to different anabolic pathways and membrane alteration. Apart from the C-D band shift from C-H, SCRS also reveal several isotopic shifts of the phenylalanine band, of which the positions correlate well with a computational model. A reduction in phenylalanine deuteration in Pseudomonas sp. compared to that in E. coli is due to the dilution effect of different pathways of phenylalanine biosynthesis in Pseudomonas sp. Collectively, we demonstrate that Raman-DIP can not only indicate metabolic activity using deuterated carbon sources but also reveal different metabolic pathways by analyzing SCRS. By harnessing such low-cost and versatile deuterated substrates, Raman-DIP has the potential to probe a wide range of metabolic pathways and functions at the single-cell level

    Epistemic and Ontic Quantum Realities

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    Quantum theory has provoked intense discussions about its interpretation since its pioneer days. One of the few scientists who have been continuously engaged in this development from both physical and philosophical perspectives is Carl Friedrich von Weizsaecker. The questions he posed were and are inspiring for many, including the authors of this contribution. Weizsaecker developed Bohr's view of quantum theory as a theory of knowledge. We show that such an epistemic perspective can be consistently complemented by Einstein's ontically oriented position

    The hyperon-nucleon interaction: conventional versus effective field theory approach

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    Hyperon-nucleon interactions are presented that are derived either in the conventional meson-exchange picture or within leading order chiral effective field theory. The chiral potential consists of one-pseudoscalar-meson exchanges and non-derivative four-baryon contact terms. With regard to meson-exchange hyperon-nucleon models we focus on the new potential of the Juelich group, whose most salient feature is that the contributions in the scalar--isoscalar (\sigma) and vector--isovector (\rho) exchange channels are constrained by a microscopic model of correlated \pi\pi and KKbar exchange.Comment: 28 pages, 8 figures, submitted to Lecture Notes in Physic
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