We report the results from an optical imaging survey of proto-planetary nebula candidates using the Hubble Space Telescope (HST). The goals of the survey were to image low surface brightness optical reflection nebulosities around proto-planetary nebulae and to investigate the distribution of the circumstellar dust, which scatters the star light from the central post-asymptotic giant branch star...

The products of proto-oncogene play critical roles in the development or maintenance of multicellular societies in animals via strict regulatory systems. When these regulatory systems are disrupted, proto-oncogenes can become oncogenes, and thereby induce cell transformation and carcinogenesis. To understand the molecular basis for development of the regulatory system of proto-oncogenes during ...

Ancient (proto-) Bulgarians have long been thought of as a Turkic population. However, evidence found in the past three decades shows that this is not the case. Until now, this evidence has not included ancient mitochondrial DNA (mtDNA) analysis. To fill this void, we collected human remains from the 8th to the 10th century AD located in three necropolises in Bulgaria: Nojarevo (Silistra region...

The case is made that the intracluster medium (ICM) in spiral-rich galaxy groups today probably has undergone much slower evolution than that in elliptical-rich groups and clusters. The environments of proto-clusters and proto-groups at z > 2 are likely similar to spiral-rich group environments at lower redshift. Therefore, like the ICM in spiral-rich groups today, the ICM in proto-groups and p...

In June 2012, the Piaoshan kiln site was excavated in Huzhou, Zhejiang Province, which hitherto proved to be the earliest known Chinese proto-porcelain kiln. Judging from the decorative patterns of unearthed impressed stoneware and proto-porcelain sherds, the site was determined to date to the late Xia (c. 2070-c. 1600 BC), the first dynasty of China. Here, we report on proton-induced X-ray emi...