Adenovirus-based phospholamban antisense expression as a novel approach to improve cardiac contractile dysfunction: comparison of a constitutive viral versus an endothelin-1-responsive cardiac promoter

BACKGROUND: A decrease in sarcoplasmic reticulum Ca(2+) pump (SERCA2) activity is believed to play a role in the impairment of diastolic function of the failing heart. Because the expression ratio of phospholamban (PL) to SERCA2 may be a target to improve contractile dysfunction, a PL antisense RNA strategy was developed under the control of either a constitutive cytomegalovirus (CMV) or an inducible atrial natriuretic factor (ANF) promoter. The latter is upregulated in hypertrophied and failing heart, allowing "induction-by-disease" gene therapy. METHODS AND RESULTS: Part of the PL cDNA was cloned in antisense and sense directions into adenovectors under the control of either a CMV (Ad5CMVPLas and Ad5CMVPLs, respectively) or ANF (Ad5ANFPLas and Ad5ANFPLs, respectively) promoter. Infection of cultured rat neonatal cardiomyocytes with Ad5CMVPLas reduced PL mRNA to 30+/-7% of baseline and PL protein to 24+/-3% within 48 and 72 hours, respectively. The effects were vector dose dependent. Ad5CMVPLas increased the Ca(2+) sensitivity of SERCA2 and reduced the time to 50% recovery of the Ca(2+) transient. A decrease of PL protein was also achieved by infection with Ad5ANFPLas, and the presence of the hypertrophic stimulus, endothelin-1, led to enhanced downregulation of PL. The adenovectors expressing PL sense RNA had no effect on any of the tested parameters. CONCLUSIONS: Vector-mediated PL antisense RNA expression may become a feasible approach to modulate myocyte Ca(2+) homeostasis in the failing heart. The inducible ANF promoter for the first time offers the perspective for induction-by-disease gene therapy, ie, selective expression of therapeutic genes in hypertrophied and failing cardiomyocytes

On the relative Contribution of high-redshift Galaxies and Active Galactic Nuclei to Reionization

In this paper we discuss the contribution of different astrophysical sources to the ionization of neutral hydrogen at different redshifts. We critically revise the arguments in favour/against a substantial contribution of Active Galactic Nuclei (AGNs) and/or Lyman Break Galaxies (LBGs) to the reionization of the Universe at z>5. We consider extrapolations of the high-z QSO and LBG luminosity functions and their redshift evolution as well as indirect constraints on the space density of lower luminosity Active Galactic Nuclei based on the galaxy stellar mass function. Since the hypothesis of a reionization due to LBGs alone requires a significant contribution of faint dwarf galaxies and a LyC photon escape fraction (f_esc) of the order of ~20%, in tension with present observational constraints, we examine under which hypothesis AGNs and LBGs may provide a combined relevant contribution to the reionization. We show that a relatively steep faint-end of the AGN luminosity function, consistent with present constraints, provides a relevant (although sub-dominant) contribution, thus allowing us to recover the required ionizing photon rates with f_esc~5% up to z~7. At higher redshifts, we test the case for a luminosity-dependent f_esc scenario and we conclude that, if the observed LBGs are indeed characterized by very low f_esc, values of the order of f_esc~70% are needed for objects below our detection threshold, for this galaxy population to provide a substantial contribution to reionization. Clearly, the study of the properties of faint sources (both AGNs and LBGs) is crucial.Comment: 9 pages, 7 figures, MNRAS accepte

DOGS: Reaction-Driven de novo Design of Bioactive Compounds

We present a computational method for the reaction-based de novo design of drug-like molecules. The software DOGS (Design of Genuine Structures) features a ligand-based strategy for automated ‘in silico’ assembly of potentially novel bioactive compounds. The quality of the designed compounds is assessed by a graph kernel method measuring their similarity to known bioactive reference ligands in terms of structural and pharmacophoric features. We implemented a deterministic compound construction procedure that explicitly considers compound synthesizability, based on a compilation of 25'144 readily available synthetic building blocks and 58 established reaction principles. This enables the software to suggest a synthesis route for each designed compound. Two prospective case studies are presented together with details on the algorithm and its implementation. De novo designed ligand candidates for the human histamine H4 receptor and γ-secretase were synthesized as suggested by the software. The computational approach proved to be suitable for scaffold-hopping from known ligands to novel chemotypes, and for generating bioactive molecules with drug-like properties

A High Yield of New Sightlines for the Study of Intergalactic Helium: Far-UV-Bright Quasars from SDSS, GALEX, and HST

Investigations of He II Ly-alpha (304 A rest) absorption toward a half-dozen quasars at z~3-4 have demonstrated the great potential of helium studies of the IGM, but the current critically small sample size of clean sightlines for the He II Gunn-Peterson test limits confidence in cosmological inferences, and a larger sample is required. Although the unobscured quasar sightlines to high redshift are extremely rare, SDSS DR6 provides thousands of z>2.8 quasars. We have cross-correlated these SDSS quasars with GALEX GR2/GR3 to establish a catalog of 200 higher-confidence (~70% secure) cases of quasars at z=2.8-5.1 potentially having surviving far-UV (restframe) flux. We also catalog another 112 likely far-UV-bright quasars from GALEX cross-correlation with other (non-SDSS) quasar compilations. Reconnaissance UV prism observations with HST of 24 of our SDSS/GALEX candidates confirm 12 as detected in the far-UV, with at least 9 having flux extending to very near the He II break; with refinements our success rate is even higher. Our SDSS/GALEX selection approach is thereby confirmed to be an order of magnitude more efficient than previous He II quasar searches, more than doubles the number of spectroscopically confirmed clean sightlines to high redshift, and provides a resource list of hundreds of high-confidence sightlines for upcoming He II and other far-UV studies from HST. Our reconnaissance HST prism spectra suggest some far-UV diversity, confirming the need to obtain a large sample of independent quasar sightlines across a broad redshift range to assess such issues as the epoch(s) of helium reionization, while averaging over individual-object pathology and/or cosmic variance.Comment: 32 pages, 7 figures, accepted by Ap

The line-of-sight proximity effect in individual quasar spectra

We exploit a set of high signal-to-noise (~70), low-resolution (R~800) quasar spectra to search for the signature of the so-called proximity effect in the HI Ly alpha forest. Our sample consists of 17 bright quasars in the redshift range 2.7<z<4.1. Analysing the spectra with the flux transmission technique, we detect the proximity effect in the sample at high significance. We use this to estimate the average intensity of the metagalactic UV background, assuming it to be constant over this redshift range. We obtain a value of J = (9+-4)x10^{-22}ergcm^{-2}s^{-1}Hz^{-1}sr^{-1}, in good agreement with previous measurements at similar z. We then apply the same procedure to individual lines of sight, finding a significant deficit in the effective optical depth close to the emission redshift in every single object except one (which by a different line of evidence does nevertheless show a noticeable proximity effect). Thus, we clearly see the proximity effect as a universal phenomenon associated with individual quasars. Using extensive Monte-Carlo simulations to quantify the error budget, we assess the expected statistical scatter in the strength of the proximity effect due to shot noise (cosmic variance). The observed scatter is larger than the predicted one, so that additional sources of scatter are required. We rule out a dispersion of spectral slopes as a significant contributor. Possible effects are long time-scale variability of the quasars and/or gravitational clustering of Ly alpha forest lines. We speculate on the possibility of using the proximity effect as a tool to constrain individual quasar ages, finding that ages between ~10^6 and ~10^8 yrs might produce a characteristic signature in the optical depth profile towards the QSO. We identify one possible candidate for this effect in our sample.Comment: A&A accepted for publication, 14 pages, 24 figures (including 17 online figures

The stellar content of the Hamburg/ESO survey. V. The metallicity distribution function of the Galactic halo

We determine the metallicity distribution function (MDF) of the Galactic halo by means of a sample of 1638 metal-poor stars selected from the Hamburg/ESO objective-prism survey (HES). The sample was corrected for minor biases introduced by the strategy for spectroscopic follow-up observations of the metal-poor candidates, namely "best and brightest stars first". [...] We determined the selection function of the HES, which must be taken into account for a proper comparison between the HES MDF with MDFs of other stellar populations or those predicted by models of Galactic chemical evolution. The latter show a reasonable agreement with the overall shape of the HES MDF for [Fe/H] > -3.6, but only a model of Salvadori et al. (2007) with a critical metallicity for low-mass star formation of Z_cr = 10^{-3.4} * Z_Sun reproduces the sharp drop at [Fe/H] ~-3.6 present in the HES MDF. [...] A comparison of the MDF of Galactic globular clusters and of dSph satellites to the Galaxy shows qualitative agreement with the halo MDF, derived from the HES, once the selection function of the latter is included. However, statistical tests show that the differences between these are still highly significant. [ABSTRACT ABRIDGED]Comment: Accepted for publication in A&

SecurePLUGandWORK – Abschlussbericht

Industrie 4.0 umfasst unter anderem intelligente Anlagenkomponenten, Maschinen und Anlagen sowie IT-Systeme, die miteinander vernetzt und über die relevanten ‚Partner\u27 mit ihren Fähigkeiten informiert sind. Bei einem Neuaufbau oder Umbau von Anlagen, Maschinen und Komponenten können alle Partner auf die Veränderung entsprechend reagieren. Änderungen sind beispielsweise in der eingebetteten Software der Feldgeräte, im Programmcode der Steuerungen, aber auch in überlagerten IT-Systemen wie bspw. MES nötig