A dynamical measure of the black hole mass in a quasar 11 billion years ago.

Tight relationships exist in the local Universe between the central stellar properties of galaxies and the mass of their supermassive black hole (SMBH)1-3. These suggest that galaxies and black holes co-evolve, with the main regulation mechanism being energetic feedback from accretion onto the black hole during its quasar phase4-6. A crucial question is how the relationship between black holes and galaxies evolves with time; a key epoch to examine this relationship is at the peaks of star formation and black hole growth 8-12 billion years ago (redshifts 1-3)7. Here we report a dynamical measurement of the mass of the black hole in a luminous quasar at a redshift of 2, with a look back in time of 11 billion years, by spatially resolving the broad-line region (BLR). We detect a 40-µas (0.31-pc) spatial offset between the red and blue photocentres of the Hα line that traces the velocity gradient of a rotating BLR. The flux and differential phase spectra are well reproduced by a thick, moderately inclined disk of gas clouds within the sphere of influence of a central black hole with a mass of 3.2 × 108 solar masses. Molecular gas data reveal a dynamical mass for the host galaxy of 6 × 1011 solar masses, which indicates an undermassive black hole accreting at a super-Eddington rate. This suggests a host galaxy that grew faster than the SMBH, indicating a delay between galaxy and black hole formation for some systems.

First Report of Ilyonectria macrodidyma Associated with Black Foot Disease of Grapevine in Brazil.

Cultivated grapevine (Vitis labrusca and V. vinifera) is of considerable economic importance to the Brazilian fruit industry for both fresh market consumption and for the production of wines, sparkling beverages, and juices. Black foot disease is caused by fungi of the genera Ilyonectria P. Chaverri & C. Salgado (anamorph: Cylindrocarpon Wollew.), Campylocarpon Halleen, Schroers & Crous, and Cylindrocladiella Boesew. In 2012, 4- to 40-year-old grapevines (Vitis spp.) showing reduced vigor, vascular lesions, necrotic root lesions, delayed budding, vine decline, and death were collected from seven locations at Rio Grande do Sul state, Brazil. Fungal isolations were made from root fragments and crown lesions (at least 2 cm above the bottom) on potato dextrose agar (PDA) medium added with 0.5 g L-1 streptomycin sulfate. Eight isolates were obtained and identified on the basis of morphological features and multi-gene analysis (rDNA-ITS, ß-tubulin, and histone H3) as Ilyonectria macrodidyma (Halleen, Schroers & Crous) P. Chaverri & C. Salgado. One representative isolate (Cy5UFSM) was used for more detailed morphological and molecular characterization, and pathogenicity confirmation. When incubated in the dark at 20°C for 7 to 10 days, colonies of felty straw-colored mycelium (3) 4.79 cm diameter on average were observed. No sporodochia or other fruiting bodies were produced on carnation leaf agar (CLA) medium after 30 days. Microconidia that were produced after 5 weeks on spezieller nährstoffarmer agar (SNA) medium with addition of two pieces of 1 cm2 filter paper showed ovoid and ellipsoid shape (6.4 × 3.6 µm) and one-septate macroconidia (17.3 × 4.1 µm). To confirm the species, primer pairs ITS1 and ITS4 (4); Bt2a and Bt2b; and H3-1a and H3-1b (2) were used to amplify the ITS1-5.8S rRNA-ITS2, part of the ß-tubulin and histone H3 genes, respectively. Sequences of these three regions showed 99, 100, and 100% of homology with I. macrodidyma, respectively. To confirm pathogenicity, 4-month-old rooted cuttings of V. labrusca cv. Bordô were inoculated by immersing them in a conidial suspension of the isolate (106 conidia ml-1) for 60 min (1). Thirty days later, inoculation was performed again by drenching the crown with 40 ml of 106 conidia ml-1 suspension to ensure infection of the roots. In the control treatment, plants were inoculated with sterile distilled water. Plants inoculated with I. macrodidyma showed necrosis of the leaf ribs, reduction in root mass, root and crown necrosis, browning of vessels, drying of shoots, and death. I. macrodidyma was re-isolated from the crown necrosis and vascular lesions, confirming Koch's postulates. To our knowledge, this is the first report of I. macrodidyma associated with black foot disease of grapevine in Brazil, which poses considerable threat to the industry unless management options are realized. References: (1) A. Cabral et al. Phytopathol. Mediterr. 51:340, 2012. (2) N. L. Glass et al. Appl. Environ. Microbiol. 61:1323, 1995. (3) R. W. Rayner. A Mycological Colour Chart. Commonwealth Mycological Institute and British Mycological Society, 1970. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.

Energy transfer, volumetric expansion, and removal of oral biofilms by non-contact brushing.

Non-contact removal of oral biofilms offers advantages beyond the reach of bristles, but it is unknown how energy transfer for removal from brush-to-biofilm occurs. In the present study we evaluated non-contact, oral biofilm removal by oscillating-rotating and sonic toothbrushes, and their acoustic output up to 6 mm distance. Whereas some brushes removed biofilm when used at a distance of up to 6 mm, others lost efficacy at a distance of 2-4 mm from the biofilm. Loss of efficacy was accompanied with high standard deviations and volumetric biofilm expansion. Both sonic and oscillating-rotating brushes caused fluid flows and the inclusion of air-bubbles, while non-contact acoustic energy-transfer was demonstrated to decay with distance for both types of brushes. We put forward the following mechanism for non-contact removal: (i) brush energy is absorbed by biofilm, resulting in the visco-elastic expansion of the biofilm; (ii) if the energy absorbed is sufficient and deformation is beyond the yield point, biofilm removal occurs; and (iii) if deformation is in the plastic range but below the yield point (i.e. at the limiting distance for non-contact removal), biofilm is expanded but not removed.

Staphylococcal septicemia in children with atopic dermatitis.

Atopic dermatitis (AD) is frequently complicated by minor bacterial superinfections. Invasive infections such as osteomyelitis have rarely been reported. We describe two children with staphylococcal septicemia during an exacerbation of their AD. Cellulitis and underlying congenital heart disease, respectively, were considered predisposing factors for the development of bacteremia. Identical strains were isolated from the skin, and there was a significant increase in antibodies against Staphylococcus aureus capsular polysaccharide in one child. Our cases demonstrate the potential severity of bacterial skin infections in AD, especially when associated with an underlying condition that increases vulnerability to bacteremia. While their true incidence in children with AD is currently unknown, it is conceivable that systemic staphylococcal infections may be more common than previously thought. Staphylococcal bacteremia has to be considered in the differential diagnosis of fever in children with severe AD. Conversely, episodes of staphylococcal bacteremia should prompt a search for underlying predisposing factors.