SN 1996cr: Confirmation of a Luminous Type IIn Supernova in the Circinus Galaxy

We have recently confirmed SN 1996cr as a late-time type IIn supernova (SN) via VLT spectroscopy and isolated its explosion date to ~1 yr using archival optical imaging. We briefly touch upon here the wealth of optical, X-ray, and radio archival observations available for this enigmatic source. Due to its relative proximity (3.8 +/-0.6 Mpc), SN 1996cr ranks among the brightest X-ray and radio SNe ever detected and, as such, may offer powerful insights into the structure and composition of type IIn SNe. We also find that SN 1996cr is matched to GRB 4B 960202 at a 2-3 sigma confidence level, making it perhaps the third GRB to be significantly associated with a type II SN. We speculate on whether SN 1996cr could be an off-axis or ``failed'' GRB.Comment: 3 pages, 1 figure, poster proceeding for "Supernova 1987A: 20 Years After: Supernovae and Gamma-Ray Bursters" AIP, New York, eds. S. Immler, K.W. Weiler, and R. McCra

The second known specimen of Monodelphis unistriata (Wagner) (Mammalia: Didelphimorphia), with redescription of the species and phylogenetic analysis

Very little information exists concerning taxonomic information and phylogenetic relationships of the opossum genus Monodelphis Burnett. Of the clearly distinct named species, the least information is available for M. unistriata (Wagner), one of the world's most poorly known species of mammals. Extant specimens consist of the Brazilian holotype of a skin now without a skull and dating from almost 200 years ago, and a second specimen with skin and incomplete skull dating from over a hundred years ago and from Argentina. The most recent published notes on the holotype date from well over half a century ago and, all told, such notes, the earliest dating from 1842, add up to a highly fragmentary and contradictory picture. No observations whatsoever have ever been published for the second and more complete specimen. Also, no hypotheses have ever been made concerning the intrageneric affinities of M. unistriata and such affinities have also been obscure throughout the genus. Herein, we provide a detailed redescription of M. unistriata, the first published images of specimens, and the first account, beyond the previous few most vague and incomplete remarks, of the morphology of the skull. In an effort to ascertain the phylogenetic affinities of M. unistriata, we performed a combined molecular (cytochrome b) and nonmolecular (postcranial, cranial, integument, and karyotypic characters) parsimony analysis incorporating 27 species of didelphids, including 11 of Monodelphis. Our results strongly support the monophyly of Monodelphis, and places M. unistriata as sister group to M. iheringi, among the included species.Fil: Pine, Ronald H.. University of Kansas. Biodiversity Institute; Estados UnidosFil: Flores, David Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales; ArgentinaFil: Bauer, Kurt. Naturhistorisches Museum Wien; Austri

Veränderung des Brandsporenpotenzials von Steinbrand- (Tilletia caries) und Zwergsteinbrandsporen (T. controversa) im Boden unter Berücksichtigung verschiedener Fruchtfolgen des ökologischen Landbaus

Steinbrand und Zwergsteinbrand sind bedeutende Krankheiten im ökologischen Landbau. Starker Befall führt zu einem Anstieg des Brandsporenpotenzials im Boden. 3-jährige, randomisierte Fruchtfolgeversuche werden an drei Standorten in vier Wiederholungen auf frisch befallenen Flächen durchgeführt. Die Böden weisen dabei entweder Brandsporen von T. controversa oder von T. caries auf. Es soll im Rahmen des Versuchs überprüft werden, ob durch im ökologischen Landbau übliche Fruchtfolgen das Brandsporenpotenzial im Boden reduziert werden kann. Durch Anbau von Senf als Zwischenfrucht wird getestet, ob durch die Freisetzung von Thiocyanaten und Isothiocyanaten nach dem Mulchen und anschlieβendes Einarbeiten in den Boden eine Abnahme der Sporenzahl im Boden erfolgt. Zusätzlich wird der Einfluss von Stallmistdüngung auf die Brandsporen untersucht. Die Veränderung der Sporenzahl im Boden wird ermittelt durch die jährliche Entnahme von Bodenproben, die Extraktion der Brandsporen aus den Proben mittels Nasssiebverfahren und Sedimentationsschritten und anschlieβendes Auszählen der Sporen auf Filtern unter dem Mikroskop. Nach zwei Jahren zeigen die vorläufigen Ergebnisse eine Abnahme des Sporenpotenzials um ca. 50% auf der T. caries-Versuchsfläche, während die T. controversa-Versuchsfläche keine Veränderung aufweist. Bei den mit Stallmist gedüngten Parzellen ist eine signifikante Reduktion der Sporenzahl über alle drei Versuchsstandorte zu beobachten. Das Sporenpotenzial hat bei der Fruchtfolgevariante 3-jähriges Kleegras tendenziell stärker abgenommen als bei den anderen Fruchtfolgevarianten. Kein Unterschied kann festgestellt werden bei den Parzellen mit Anbau von Senf und denen ohne Zwischenfrucht

The impact of industry-wide and target market environmental hostility on entrepreneurial leadership in mergers and acquisitions

Based on survey data from 115 acquisitions completed between 2008 and 2011 by European acquirers from German-speaking countries, we find evidence that entrepreneurial leadership is a strong predictor of exploration and a weaker but significant driver of exploitation outcomes following M&A. Industry-wide environmental hostility negatively impacts the influence of entrepreneurial leadership on exploitation. Target market environmental hostility negatively impacts the influence of entrepreneurial leadership on exploration. Thus, while entrepreneurial leadership is a key success factor of M&A performance by increasing both, post-merger exploration and exploitation, acquirers need to take environmental conditions at the industry and market level into account

Perspiration and inspiration:Grit and innovativeness as antecedents of entrepreneurial success

Venture success has been related to numerous characteristics of entrepreneurs including their enduring personality traits. Separately, recent scholarship has elucidated trait “Grit” comprising two dimensions, “Consistency of Interests” (or “Passion”) and “Perseverance of Effort”, and validated Grit as a predictor of success in areas such as education, military training, and income. We report a study with a sample of Austrian entrepreneurs relating Grit as well as firm-level Innovativeness to entrepreneurial success. We show that both Grit and Innovativeness predict success; Grit affects success directly and in effects that are mediated by Innovativeness

Structural and Mechanistic Analysis of the Choline Sulfatase from Sinorhizobium melliloti: A Class I Sulfatase Specific for an Alkyl Sulfate Ester.

Hydrolysis of organic sulfate esters proceeds by two distinct mechanisms, water attacking at either sulfur (S-O bond cleavage) or carbon (C-O bond cleavage). In primary and secondary alkyl sulfates, attack at carbon is favored, whereas in aromatic sulfates and sulfated sugars, attack at sulfur is preferred. This mechanistic distinction is mirrored in the classification of enzymes that catalyze sulfate ester hydrolysis: arylsulfatases (ASs) catalyze S-O cleavage in sulfate sugars and arylsulfates, and alkyl sulfatases break the C-O bond of alkyl sulfates. Sinorhizobium meliloti choline sulfatase (SmCS) efficiently catalyzes the hydrolysis of alkyl sulfate choline-O-sulfate (kcat/KM=4.8×103s-1M-1) as well as arylsulfate 4-nitrophenyl sulfate (kcat/KM=12s-1M-1). Its 2.8-Å resolution X-ray structure shows a buried, largely hydrophobic active site in which a conserved glutamate (Glu386) plays a role in recognition of the quaternary ammonium group of the choline substrate. SmCS structurally resembles members of the alkaline phosphatase superfamily, being most closely related to dimeric ASs and tetrameric phosphonate monoester hydrolases. Although >70% of the amino acids between protomers align structurally (RMSDs 1.79-1.99Å), the oligomeric structures show distinctly different packing and protomer-protomer interfaces. The latter also play an important role in active site formation. Mutagenesis of the conserved active site residues typical for ASs, H218O-labeling studies and the observation of catalytically promiscuous behavior toward phosphoesters confirm the close relation to alkaline phosphatase superfamily members and suggest that SmCS is an AS that catalyzes S-O cleavage in alkyl sulfate esters with extreme catalytic proficiency