282 research outputs found

    Hyperfine Structure of Indium Fluoride

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    The radiofrequency spectrum of the indium fluoride molecule, 115In19F, has been measured with a high resolution molecular beam electric resonance spectrometer. We determined the hyperfine structure in the J=1 and the J=2 rotational states of several vibrational levels under conditions of very weak external electric and magnetic fields. The ∼700 MHz electric quadrupole interaction constant of the indium nucleus changes by 0.010(1) MHz between adjacent rotational states. We looked for, but did not find, an electric hexadecapole interaction of the indium nucleus; the upper limit for the (hexadecapole) interaction constant is 2 kHz.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70971/2/JCPSA6-57-10-4068-1.pd

    Hyperfine Structure of Thallium Chloride

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    The radio‐frequency spectra of TlCl at very weak electric and magnetic fields have been measured with a molecular beam electric resonance spectrometer. From these spectra the hyperfine interaction constants for the four isotopic species of the molecule were calculated. The constants for 205Tl35Cl in the J  =  2,υ  =  0J=2,υ=0 state are: eqQ  =  − 15793.32(50)kHz,cCl  =  1.38(10)kHz,cTl  =  76.35(10)kHz,c3  =  − 0.13(10)kHz,c4  =  − 1.54(10)kHz.eqQ=−15793.32(50)kHz,cCl=1.38(10)kHz,cTl=76.35(10)kHz,c3=−0.13(10)kHz,c4=−1.54(10)kHz. A test was made for the polarization of the chlorine nucleus in the electric field of the molecule by comparing the ratio of the quadrupole interaction constants for 205Tl35Cl and 205Tl37Cl to the ratio of the quadrupole interaction constants for the free chlorine atoms. The agreement of the two ratios is within their uncertainties, thus providing no evidence for a polarization effect. In addition, the dependence of the spin–rotation and spin–spin interaction constants on isotope was found to show good agreement with theory.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69724/2/JCPSA6-50-5-2086-1.pd

    Redshift and Shear Calibration: Impact on Cosmic Shear Studies and Survey Design

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    The cosmological interpretation of weak lensing by large-scale structures requires knowledge of the redshift distribution of the source galaxies. Current lensing surveys are often calibrated using external redshift samples which span a significantly smaller sky area in comparison to the lensing survey, and are thus subject to sample variance. Some future lensing surveys are expected to be calibrated in the same way, in particular the fainter galaxy populations where the entire color coverage, and hence photometric redshift estimate, could be challenging to obtain. Using N-body simulations, we study the impact of this sample variance on cosmic shear analysis and show that, to first approximation, it behaves like a shear calibration error 1+/-epsilon. Using the Hubble Deep Field as a redshift calibration survey could therefore be a problem for current lensing surveys. We discuss the impact of the redshift distribution sampling error and a shear calibration error on the design of future lensing surveys, and find that a lensing survey of area Theta square degrees and limiting magnitude m_lim}, has a minimum shear and redshift calibration accuracy requirements given by epsilon = epsilon_0 10^{beta(m_lim-24.5)} / sqrt(Theta/ 200). Above that limit, lensing surveys would not reach their full potential. Using the galaxy number counts from the Hubble Ultra-Deep Field, we find (epsilon_0,beta)=(0.015,-0.18) and (epsilon_0,beta)=(0.011,-0.23) for ground and space based surveys respectively. Lensing surveys with no or limited redshift information and/or poor shear calibration accuracy will loose their potential to analyse the cosmic shear signal in the sub-degree angular scales, and therefore complete photometric redshift coverage should be a top priority for future lensing surveys.Comment: Accepted version to Astroparticle Physic

    Urban eddy covariance measurements reveal significant missing NOx emissions in Central Europe

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    Nitrogen oxide (NOx) pollution is emerging as a primary environmental concern across Europe. While some large European metropolitan areas are already in breach of EU safety limits for NO2, this phenomenon does not seem to be only restricted to large industrialized areas anymore. Many smaller scale populated agglomerations including their surrounding rural areas are seeing frequent NO2 concentration violations. The question of a quantitative understanding of different NOx emission sources is therefore of immanent relevance for climate and air chemistry models as well as air pollution management and health. Here we report simultaneous eddy covariance flux measurements of NOx, CO2, CO and non methane volatile organic compound tracers in a city that might be considered representative for Central Europe and the greater Alpine region. Our data show that NOx fluxes are largely at variance with modelled emission projections, suggesting an appreciable underestimation of the traffic related atmospheric NOx input in Europe, comparable to the weekend-weekday effect, which locally changes ozone production rates by 40%

    The Rewiring of Ubiquitination Targets in a Pathogenic Yeast Promotes Metabolic Flexibility, Host Colonization and Virulence

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    Funding: This work was funded by the European Research Council [http://erc.europa.eu/], AJPB (STRIFE Advanced Grant; C-2009-AdG-249793). The work was also supported by: the Wellcome Trust [www.wellcome.ac.uk], AJPB (080088, 097377); the UK Biotechnology and Biological Research Council [www.bbsrc.ac.uk], AJPB (BB/F00513X/1, BB/K017365/1); the CNPq-Brazil [http://cnpq.br], GMA (Science without Borders fellowship 202976/2014-9); and the National Centre for the Replacement, Refinement and Reduction of Animals in Research [www.nc3rs.org.uk], DMM (NC/K000306/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Acknowledgments We thank Dr. Elizabeth Johnson (Mycology Reference Laboratory, Bristol) for providing strains, and the Aberdeen Proteomics facility for the biotyping of S. cerevisiae clinical isolates, and to Euroscarf for providing S. cerevisiae strains and plasmids. We are grateful to our Microscopy Facility in the Institute of Medical Sciences for their expert help with the electron microscopy, and to our friends in the Aberdeen Fungal Group for insightful discussions.Peer reviewedPublisher PD

    Fabrication, workflow and delivery of reconstruction: Summary and consensus statements of group 4. The 6th EAO Consensus Conference 2021.

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    Objectives: To report assessments of four systematic reviews (SRs) on (i) clinical outcomes of all-ceramic implant-supported crowns (iSCs), (ii) production time, effectiveness, and costs of computer-assisted manufacturing (CAM), (iii) computer-assisted implant planning and surgery (CAIPS) time and costs, and (iv) patient-reported outcome measures (PROMS). Material and methods: An author group consisting of experienced clinicians and content experts discussed and evaluated the SRs and formulated consensus on the main findings, statements, clinical recommendations, and need for future research. Results: All four SRs were conducted and reported according to PRISMA and detailed comprehensive search strategies in at least three bibliometric databases and hand searching. The search strategies were deemed reproducible. Variation was noted regarding language restrictions and inclusion of grey literature, but the search comprehensiveness appeared persuasive. The SRs included bias risk assessments of the primary studies, and their study methodology impacted the interpretations of the extracted data. Conclusions: (i) There is limited evidence (49 NRCT) showing that veneered and monolithic all-ceramic iSCs have excellent outcomes observed up to 3 years. (ii) There is no evidence evaluating production time and effectiveness comparing subtractive and additive CAM of implant models, abutments and crowns. (iii) There is limited evidence (4 RCT) that CAIPS involves more time and costs when considering the entire workflow and for diagnostics, manufacturing, and insertion of the restoration. Time seems to be the decisive factor for higher costs. (iv) Patients' comfort increases when optical compared to conventional impressions are used for fabricating iSCs and short-span FPDs (2 RCT, 5 NRCT)

    Dyrk1A Influences Neuronal Morphogenesis Through Regulation of Cytoskeletal Dynamics in Mammalian Cortical Neurons

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    Down syndrome (DS) is the most frequent genetic cause of mental retardation. Cognitive dysfunction in these patients is correlated with reduced dendritic branching and complexity, along with fewer spines of abnormal shape that characterize the cortical neuronal profile of DS. DS phenotypes are caused by the disruptive effect of specific trisomic genes. Here, we report that overexpression of dual-specificity tyrosine phosphorylation-regulated kinase 1A, DYRK1A, is sufficient to produce the dendritic alterations observed in DS patients. Engineered changes in Dyrk1A gene dosage in vivo strongly alter the postnatal dendritic arborization processes with a similar progression than in humans. In cultured mammalian cortical neurons, we determined a reduction of neurite outgrowth and synaptogenesis. The mechanism underlying neurite dysgenesia involves changes in the dynamic reorganization of the cytoskeleton

    Oxygen matters: tissue culture oxygen levels affect mitochondrial function and structure as well as responses to HIV viroproteins

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    Mitochondrial dysfunction is implicated in a majority of neurodegenerative disorders and much study of neurodegenerative disease is done on cultured neurons. In traditional tissue culture, the oxygen level that cells experience is dramatically higher (21%) than in vivo conditions (1–11%). These differences can alter experimental results, especially, pertaining to mitochondria and oxidative metabolism. Our results show that primary neurons cultured at physiological oxygen levels found in the brain showed higher polarization, lower rates of ROS production, larger mitochondrial networks, greater cytoplasmic fractions of mitochondria and larger mitochondrial perimeters than those cultured at higher oxygen levels. Although neurons cultured in either physiological oxygen or atmospheric oxygen exhibit significant increases in mitochondrial reactive oxygen species (ROS) production when treated with the human immunodeficiency virus (HIV) virotoxin trans-activator of transcription, mitochondria of neurons cultured at physiological oxygen underwent depolarization with dramatically increased cell death, whereas those cultured at atmospheric oxygen became hyperpolarized with no increase in cell death. Studies with a second HIV virotoxin, negative regulation factor (Nef), revealed that Nef treatment also increased mitochondrial ROS production for both the oxygen conditions, but resulted in mitochondrial depolarization and increased death only in neurons cultured in physiological oxygen. These results indicate a role for oxidative metabolism in a mechanism of neurotoxicity during HIV infection and demonstrate the importance of choosing the correct, physiological, culture oxygen in mitochondrial studies performed in neurons
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