Development of a nucleic acid lateral flow immunoassay for simultaneous detection of Listeria spp. and Listeriamonocytogenes in food

We present a new nucleic acid lateral flow immunoassay (NALFIA) for the assessment of listeria contamination. The detection procedure starts with enrichment of sample in Half Fraser broth (24 h). Following isolation of DNA, a duplex PCR is performed with two labelled primer sets, one generic and directed to a specific sequence of the gene encoding 16S rRNA from Listeria spp. and the other specific and directed to a part of the prfA gene encoding the central virulence gene regulator from the food pathogen Listeria monocytogenes (3.5 h). The PCR solution is directly added to the one-step assay device and the appearance of a grey/black line is indicative of the presence of specific amplicons (max 15 min). In all tests performed, the method correctly identified L. monocytogenes and strains of Listeria spp. PCR material of over 20 food samples was tested by NALFIA. The method proved to be useful for the detection of L. monocytogenes in different kinds of food sample

Minimal Uncertainty in Momentum: The Effects of IR Gravity on Quantum Mechanics

The effects of the IR aspects of gravity on quantum mechanics is investigated. At large distances where due to gravity the space-time is curved, there appears nonzero minimal uncertainty $\Delta p_{0}$ in the momentum of a quantum mechanical particle. We apply the minimal uncertainty momentum to some quantum mechanical interferometry examples and show that the phase shift depends on the area surrounded by the path of the test particle . We also put some limits on the related parameters. This prediction may be tested through future experiments. The assumption of minimal uncertainty in momentum can also explain the anomalous excess of the mass of the Cooper pair in a rotating thin superconductor ring.Comment: 8 pages, revised version accepted by PR

High-precision Atomic Physics Laboratories in Space: White Dwarfs and Subdwarfs

The 21st European Workshop on White Dwarfs was held in Austin, TX from July 23rd to 27th of 2018Stellar atmospheres are prime laboratories to determine atomic properties of highly ionized species. Reliable opacities are crucial ingredients for the calculation of stellar atmospheres of white dwarfs and subdwarfs. A detailed investigation on the precision of many iron-group oscillator strengths is still outstanding. To make progress, we used the Hubble Space Telescope Imaging Spectrograph to measure high-resolution spectra of three hot subdwarfs that exhibit extremely high iron-group abundances. The predicted relative strengths of the identified lines are compared with the observations to judge the quality of Kurucz’s line data and to determine correction factors for abundance determinations of the respective elements.Astronom

Stationary problems for equation of the KdV type and dynamical rr-matrices.

We study a quite general family of dynamical $r$-matrices for an auxiliary loop algebra ${\cal L}({su(2)})$ related to restricted flows for equations of the KdV type. This underlying $r$-matrix structure allows to reconstruct Lax representations and to find variables of separation for a wide set of the integrable natural Hamiltonian systems. As an example, we discuss the Henon-Heiles system and a quartic system of two degrees of freedom in detail.Comment: 25pp, LaTe

Force-Free Gravitational Redshift: Proposed Gravitational Aharonov-Bohm experiment

We propose a feasible laboratory interferometry experiment with matter waves in a gravitational potential caused by a pair of artificial field-generating masses. It will demonstrate that the presence of these masses (and, for moving atoms, time dilation) induces a phase shift, even if it does not cause any classical force. The phase shift is identical to that produced by the gravitational redshift (or time dilation) of clocks ticking at the atom's Compton frequency. In analogy to the Aharonov-Bohm effect in electromagnetism, the quantum mechanical phase is a function of the gravitational potential and not the classical forces.Comment: Updated to published versio

Wachstumsstörungen als Leitsymptom

Zusammenfassung: Kleinwuchs als Leitsymptom stellt eine häufige Fragestellung sowohl in der humangenetischen als auch in der pädiatrischen Sprechstunde dar. Definiert ist Kleinwuchs als eine Körperhöhe unter der 3.Perzentile der Norm bzw. unter −2Standardabweichungen. Diese macht sich bemerkbar durch Änderungen der Wachstumsgeschwindigkeit oder des Wachstumsverlaufs, welche grundsätzlich genetisch determiniert, jedoch auch von sekundären Faktoren beeinflussbar sind. Das Spektrum der zugrunde liegenden genetischen Ursachen reicht von Störungen der Wachstumshormonsekretion und -wirkung über Skelettdysplasien bis hin zu komplexen Fehlbildungssyndromen. Die genetische Abklärung stellt somit einen Grundpfeiler zur Beurteilung der Prognose und einer möglichen therapeutischen Intervention dar. Es werden die grundlegenden diagnostischen Überlegungen anhand häufiger Differenzialdiagnosen, deren genetischen Grundlagen und Behandlungsmöglichkeiten aufgeführt: Ullrich-Turner-Syndrom, Léri-Weill-Syndrom, Silver-Russell-Syndrom, Noonan-Syndrom und Achondroplasi

Fractal geometry of critical Potts clusters

Numerical simulations on the total mass, the numbers of bonds on the hull, external perimeter, singly connected bonds and gates into large fjords of the Fortuin-Kasteleyn clusters for two-dimensional q-state Potts models at criticality are presented. The data are found consistent with the recently derived corrections-to-scaling theory. However, the approach to the asymptotic region is slow, and the present range of the data does not allow a unique identification of the exact correction exponentsComment: 7 pages, 8 figures, Late

The Distribution of Metallicity in the IGM at z~2.5: OVI and CIV Absorption in the Spectra of 7 QSOs

We present a direct measurement of the metallicity distribution function for the high redshift intergalactic medium. We determine the shape of this function using survival statistics, which account for both detections and non-detections of OVI and CIV associated with HI absorption in quasar spectra. Our OVI sample probes the metal content of ~50% of all baryons at z~2.5. We find a median intergalactic abundance of [O,C/H]=-2.82; the differential abundance distribution is approximately lognormal with mean ~-2.85 and \sigma=0.75 dex. Some 60-70% the Lya forest lines are enriched to observable levels ([O,C/H]>-3.5) while the remaining ~30% of the lines have even lower abundances. Thus we have not detected a universal metallicity floor as has been suggested for some Population III enrichment scenaria. In fact, we argue that the bulk of the intergalactic metals formed later than the first stars that are thought to have triggered reionization. We do not observe a significant trend of decreasing metallicity toward the lower density IGM, at least within regions that would be characterized as filaments in numerical simulations. However, an [O/H] enhancement may be present at somewhat high densities. We estimate that roughly half of all baryons at these redshifts have been enriched to [O/H]>=-3.5. We develop a simple model for the metallicity evolution of the IGM, to estimate the chemical yield of galaxies formed prior to z~2.5. We find that the typical galaxy recycled 0.1-0.4% of its mass back into the IGM as heavy elements in the first 3 Gyr after the Big Bang.Comment: 23 pages in emulateapj, 19 figures. Accepted to ApJ, pending review of new changes. Revised comparison between our results and Schaye et al (2003