427 research outputs found
Nuclear starburst activity induced by elongated bulges in spiral galaxies
We study the effects of bulge elongation on the star formation activity in
the centers of spiral galaxies using the data from the Sloan Digital Sky Survey
Data Release 7. We construct a volume-limited sample of face-on spiral galaxies
with 19.5 mag at 0.02 0.055 by excluding barred galaxies,
where the aperture of the SDSS spectroscopic fibre covers the bulges of the
galaxies. We adopt the ellipticity of bulges measured by Simard et al. (2011)
who performed two-dimensional bulge+disc decompositions using the SDSS images
of galaxies, and identify nuclear starbursts using the fibre specific star
formation rates derived from the SDSS spectra. We find a statistically
significant correlation between bulge elongation and nuclear starbursts in the
sense that the fraction of nuclear starbursts increases with bulge elongation.
This correlation is more prominent for fainter and redder galaxies, which
exhibit higher ratios of elongated bulges. We find no significant environmental
dependence of the correlation between bulge elongation and nuclear starbursts.
These results suggest that non-axisymmetric bulges can efficiently feed the gas
into the centre of galaxies to trigger nuclear starburst activity.Comment: 9 pages, 7 figures, accepted for publication in MNRA
Freshwater and Terrestrial Algae from Ny-Ålesund and Blomstrandhalvøya Island (Svalbard)
A field survey of algae and cyanobacteria from terrestrial and freshwater habitats in the vicinity of Ny-Ålesund and on Blomstrandhalvøya Island (Svalbard) was performed in June 2009, and results were compared with data from our fieldwork in June 2006. In total, we identified 30 taxa belonging to 23 genera from the specimens collected near Ny-Ålesund (26 taxa) and on Blomstrandhalvøya Island (24 taxa). Five species previously unrecorded from this locality are depicted, including astaxanthin-containing Haematococcus sp. collected from Blomstrandhalvøya Island. This is the first report on a Haematococcus species from the High Arctic.Une étude sur le terrain portant sur les algues et les cyanobactéries d’habitats terrestres et dulçaquicoles dans les environs de Ny-Ålesund et de l’île Blomstrandhalvøya (Svalbard) a été réalisée en juin 2009, et les résultats ont été comparés aux données de notre travail sur le terrain effectué en juin 2006. En tout, nous avons identifié 30 taxons appartenant à 23 genres à partir de spécimens prélevés près de Ny-Ålesund (26 taxons) et de Blomstrandhalvøya (24 taxons). Cinq espèces qui n’avaient jamais été répertoriées dans cette localité sont illustrées, dont l’Haematococcus sp. contenant de l’astaxanthine recueillie à l’île Blomstrandhalvøya. Il s’agit de la première fois que l’espèce Haematococcus a été signalée dans l’Extrême-Arctique
Long-term Follow-up of Extensive Peri-anchor (Poly-L/D-lactic Acid) Cyst Formation after Arthroscopic Rotator Cuff Repair: A Case Report
Suture anchors are commonly used in shoulder surgeries, especially for rotator cuff tears. Peri-anchor cyst formation, however, is sometimes detected on follow-up radiologic image after surgery. The purpose of this report is to discuss the case of a patient who presented with regression of extensive peri-anchor cyst on postoperative 4-year follow-up magnetic resonance imaging and had good clinical outcome despite peri-anchor cyst formation after arthroscopic rotator cuff repair
Anticancer Efficacy of Cordyceps militaris
Cordyceps militaris is used widely as a traditional medicine in East Asia. Although a few studies have attempted to elucidate the anticancer activities of C. militaris, the precise mechanism of C. militaris therapeutic effects is not fully understood. We examined the anticancer activities of C. militaris ethanolic extract (Cm-EE) and its cellular and molecular mechanisms. For this purpose, a xenograft mouse model bearing murine T cell lymphoma (RMA) cell-derived cancers was established to investigate in vivo anticancer mechanisms. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, immunoblotting analysis, and flow cytometric assay were employed to check in vitro cytotoxicity, molecular targets, and proapoptotic action of Cm-EE. Interestingly, cancer sizes and mass were reduced in a C. militaris-administered group. Levels of the phosphorylated forms of p85 and AKT were clearly decreased in the group administered with Cm-EE. This result indicated that levels of phosphoglycogen synthase kinase 3β (p-GSK3β) and cleaved caspase-3 were increased with orally administered Cm-EE. In addition, Cm-EE directly inhibited the viability of cultured RMA cells and C6 glioma cells. The number of proapoptotic cells was significantly increased in a Cm-EE treated group compared with a control group. Our results suggested that C. militaris might be able to inhibit cancer growth through regulation of p85/AKT-dependent or GSK3β-related caspase-3-dependent apoptosis
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