Selbstverpflichtungen sind kein Königsweg!

Seit Jahren fordert die Wirtschaft anstelle weiterer ordnungsrechtlicher Vorgaben „flexiblere“ und „marktkonformere“ Instrumente wie Selbstverpflichtungen und freiwillige Vereinbarungen zur Verwirklichung politisch definierter Ziele ein. Können Selbstverpflichtungen das Ordnungsrecht und die gestaltende Politik ersetzen? --

Cosmological Impact Of Population III Binaries

We present the results of the stellar feedback from Population III (Pop III) binaries by employing improved, more realistic Pop III evolutionary stellar models. To facilitate a meaningful comparison, we consider a fixed mass of 60 M-circle dot incorporated in Pop III stars, either contained in a single star, or split up in binary stars of 30 M-circle dot each or an asymmetric case of one 45 and one 15 M-circle dot star. Whereas the sizes of the resulting H II regions are comparable across all cases, the He III regions around binary stars are significantly smaller than that of the single star. Consequently, the He+ 1640 angstrom recombination line is expected to become much weaker. Supernova (SN) feedback exhibits great variety due to the uncertainty in possible explosion pathways. If at least one of the component stars dies as a hypernova about 10 times more energetic than conventional core-collapse SNe, the gas inside the host minihalo is effectively blown out, chemically enriching the intergalactic medium (IGM) to an average metallicity of 10(-4)-10(-3) Z(circle dot), out to similar to 2 kpc. The single star, however, is more likely to collapse into a black hole, accompanied by at most very weak explosions. The effectiveness of early chemical enrichment would thus be significantly reduced, in contrast to. the lower mass binary stars, where at least one component is likely to contribute to heavy element production and dispersal. Important new feedback physics is also introduced if close binaries can form high-mass X-ray binaries, leading to the pre-heating and -ionization of the IGM beyond the extent of the stellar H II regions.IAU-Gruber FellowshipStanwood Johnston FellowshipKITP Graduate FellowshipDOE HEP Program DE-SC0010676NSF AST 0909129, AST-1009928, AST-1109394, PHY02-16783NASA Theory Program NNX14AH34GNASA NNX09AJ33GARC Future Fellowship FT120100363Monash University Larkins FellowshipDOE DE-GF02-87ER40328, DE-FC02-09ER41618Astronom

Low-energy Population III supernovae and the origin of extremely metal-poor stars

Some ancient, dim, metal-poor stars may have formed in the ashes of the first supernovae (SNe). If their chemical abundances can be reconciled with the elemental yields of specific Population III (Pop III) explosions, they could reveal the properties of primordial stars. But multidimensional simulations of such explosions are required to predict their yields because dynamical instabilities can dredge material up from deep in the ejecta that would otherwise be predicted to fall back on to the central remnant and be lost in one-dimensional (1D) models. We have performed two-dimensional (2D) numerical simulations of two low-energy Pop III SNe, a 12.4 Msun explosion and a 60 Msun explosion, and find that they produce elemental yields that are a good fit to those measured in the most iron-poor star discovered to date, SMSS J031300.36-670839.3 (J031300). Fallback on to the compact remnant in these weak explosions accounts for the lack of measurable iron in J031300 and its low iron-group abundances in general. Our 2D explosions produce higher abundances of heavy elements (atomic number Z > 20) than their 1D counterparts due to dredge-up by fluid instabilities. Since almost no Ni is ejected by these weak SNe, their low luminosities will prevent their detection in the near-infrared with the James Webb Space Telescope and future 30-m telescopes on the ground. The only evidence that they ever occurred will be in the fossil abundance record.Comment: Accepted to MNRA

Luminescent Symmetrically and Unsymmetrically Substituted Diboranes(4)

A series of 4‐(dimethylamino)phenyl and pentafluorophenyl‐substituted 1,2‐bis(dimethylamino)diboranes(4) of type A, benzo‐fused cyclic 1,4‐diaza‐2,3‐diborinanes of type B, and 1,2‐diduryldiboranes(4) of type C were synthesized and structurally characterized. Spectroscopic studies revealed that the substitution pattern is a decisive factor for the observation of fluorescence in most of the derivatives A to C. For diboranes(4) of type A, unsymmetrical substitution with electron‐donating and ‐withdrawing groups at the boron centers is crucial to invoke fluorescence, albeit weak. Substitution at the boron atoms of 1,4‐diaza‐2,3‐diborinane species B leads to a modified skeletal structure. Finally, the grafting of 4‐(dimethylamino)phenyl groups to diboranes(4) of type C results in extraordinary Stokes shifts in nonpolar solvents

Quinone-dependent D-lactate dehydrogenase Dld (Cg1027) is essential for growth of Corynebacterium glutamicum on D-lactate

Kato O, Youn J-W, Stansen KC, Matsui D, Oikawa T, Wendisch VF. Quinone-dependent D-lactate dehydrogenase Dld (Cg1027) is essential for growth of Corynebacterium glutamicum on D-lactate. BMC Microbiology. 2010;10(1): 321.Background: Corynebacterium glutamicum is able to grow with lactate as sole or combined carbon and energy source. Quinone-dependent L-lactate dehydrogenase LldD is known to be essential for utilization of L-lactate by C. glutamicum. D-lactate also serves as sole carbon source for C. glutamicum ATCC 13032. Results: Here, the gene cg1027 was shown to encode the quinone-dependent D-lactate dehydrogenase (Dld) by enzymatic analysis of the protein purified from recombinant E. coli. The absorption spectrum of purified Dld indicated the presence of FAD as bound cofactor. Inactivation of dld resulted in the loss of the ability to grow with D-lactate, which could be restored by plasmid-borne expression of dld. Heterologous expression of dld from C. glutamicum ATCC 13032 in C. efficiens enabled this species to grow with D-lactate as sole carbon source. Homologs of dld of C. glutamicum ATCC 13032 are not encoded in the sequenced genomes of other corynebacteria and mycobacteria. However, the dld locus of C. glutamicum ATCC 13032 shares 2367 bp of 2372 bp identical nucleotides with the dld locus of Propionibacterium freudenreichii subsp. shermanii, a bacterium used in Swiss-type cheese making. Both loci are flanked by insertion sequences of the same family suggesting a possible event of horizontal gene transfer. Conclusions: Cg1067 encodes quinone-dependent D-lactate dehydrogenase Dld of Corynebacterium glutamicum. Dld is essential for growth with D-lactate as sole carbon source. The genomic region of dld likely has been acquired by horizontal gene transfer

Bulk nanostructured AlCoCrFeMnNi chemically complex alloy synthesized by laser-powder bed fusion process

We report the synthesis of a bulk nanostructured alloy using the laser-powder bed fusion process. The equiatomic AlCoCrFeMnNi chemically complex alloy forms a nanoscale modulated structure, which is homogeneously distributed in the as-built condition. The nanostructure consisted of Al & Ni-rich ordered (B2) and Cr & Fe-rich disordered (A2) BCC phases. The two phases form an interconnected phase-network with coherent interface boundaries. Atom-probe-tomography and aberration-corrected scanning transmission electron microscopy analysis of the spatial distribution of the modulated structure suggests the occurrence of nano-scale spinodal decomposition. These results introduce a direct synthesis of bulk nanostructured alloys with promising geometric flexibility.Comment: 21 pages, 7 Figure

Small-scale analysis of population genetics and abundance patterns of honeysuckle Lonicera periclymenum L. (Caprifoliaceae) in a North Sea island woodland system

Invasive alien plants are considered a major driving force of biodiversity loss and can deeply alter ecosystem functioning. However, invaders can also facilitate the distribution and establishment of native species, although this has been rarely documented in the literature. We observed an increase in population abundance of the liana Lonicera periclymenum L. (honeysuckle) on the north Frisian island of Amrum and hypothesized, that a surge in phorophyte availability due to the invasive neophyte Prunus serotina Ehrh. (black cherry) supported the colonization of new patches for this autochthonous liana species. Analysis of population genetics by inter-simple-sequence repeats polymerase chain reaction (ISSR-PCR) revealed high interpopulational differentiation. The genetic diversity within populations was low. The results indicated that barriers prevent small distance dispersal of seed and pollen. Further, additional results supported our hypothesis that honeysuckle may occasionally take advan-tage of the invasive neophyte black cherry

Magnetar-powered supernovae in two dimensions. II. Broad-line supernovae Ic

Nascent neutron stars with millisecond periods and magnetic fields in excess of $10^{16}$ Gauss can drive highly energetic and asymmetric explosions known as magnetar-powered supernovae. These exotic explosions are one theoretical interpretation for supernovae Ic-BL which are sometimes associated with long gamma-ray bursts. Twisted magnetic field lines extract the rotational energy of the neutron star and release it as a disk wind or a jet with energies greater than 10$^{52}$ erg over $\sim 20$ sec. What fractions of the energy of the central engine go into the wind and the jet remain unclear. We have performed two-dimensional hydrodynamical simulations of magnetar-powered supernovae (SNe) driven by disk winds and jets with the CASTRO code to investigate the effect of the central engine on nucleosynthetic yields, mixing, and light curves. We find that these explosions synthesize less than 0.05 Msun of Ni and that this mass is not very sensitive to central engine type. The morphology of the explosion can provide a powerful diagnostic of the properties of the central engine. In the absence of a circumstellar medium these events are not very luminous, with peak bolometric magnitudes $M_b \sim -16.5$ due to low Ni production.Comment: Accepted to Ap

Candidatus Borrelia kalaharica Detected from a Febrile Traveller Returning to Germany from Vacation in Southern Africa

A 26 year-old female patient presented to the Tropical Medicine outpatient unit of the Ludwig Maximilians-University in Munich with febrile illness after returning from Southern Africa, where she contracted a bite by a large mite-like arthropod, most likely a soft-tick. Spirochetes were detected in Giemsa stained blood smears and treatment was started with doxycycline for suspected tick-borne relapsing fever. The patient eventually recovered after developing a slight Jarisch-Herxheimer reaction during therapy. PCR reactions performed from EDTA-blood revealed a 16S rRNA sequence with 99.4% similarity to both, Borrelia duttonii, and B. parkeri. Further sequences obtained from the flagellin gene (flaB) demonstrated genetic distances of 0.066 and 0.097 to B. parkeri and B. duttonii, respectively. Fragments of the uvrA gene revealed genetic distance of 0.086 to B. hermsii in genetic analysis and only distant relations with classic Old World relapsing fever species. This revealed the presence of a novel species of tick-borne relapsing fever spirochetes that we propose to name "Candidatus Borrelia kalaharica", as it was contracted from an arthropod bite in the Kalahari Desert belonging to both, Botswana and Namibia, a region where to our knowledge no relapsing fever has been described so far. Interestingly, the novel species shows more homology to New World relapsing fever Borrelia such as B. parkeri or B. hermsii than to known Old World species such as B. duttonii or B. crocidurae

The DNA-polymorphism rs849142 is associated with skin toxicity induced by targeted anti-EGFR therapy using cetuximab

Skin toxicity (ST) is a frequent adverse effect (AE) in anti-epidermal growth factor receptor (EGFR)-targeted treatment of metastatic colorectal cancer (mCRC) resulting in decreased quality of life and problems in clinical management. We wanted to identify biomarkers predicting ST in this setting and focused on 70 DNA polymorphisms associated with acne, the (immunoglobulin fragment crystallizable region) Fcγ-receptor pathway, and systemic lupus erythematosus (SLE) applying next-generation-sequencing (NGS). For the analysis patients with mCRC treated with cetuximab were selected from the FIRE-3 study. A training group consisting of the phenotypes low (1) - and high-grade (3) ST (n = 16) and a validation group (n = 55) representing also the intermediate grade (2) were genotyped and investigated in a genotype-phenotype association analysis. The single nucleotide polymorphism (SNP) rs849142 significantly associated with ST in both the training- (p < 0.01) and validation-group (p = 0.04). rs849142 is located in an intron of the juxtaposed with another zinc finger protein 1 (JAZF1) gene. Haplotype analysis demonstrated significant linkage disequilibrium of rs849142 with JAZF1. Thus, rs849142 might be a predictive biomarker for ST in anti-EGFR treated mCRC patients. Its value in the clinical management of AE has to be validated in larger cohorts