8 research outputs found
Tl-2212 thin films annealed in a Al
Tl2Ba2CaCu2Oy(Tl-2212) thin films
were fabricated on (001) LaAlO3 substrates by a two-step technique in a
semi-closed aluminate crucible and a sealed steel container, respectively.
First, the amorphous precursor films were deposited by the pulsed laser
deposition (PLD) method, and then they were thalliated in different
containers. Almost pure phase Tl-2212 thin films can be prepared in both of
the containers. However, the as-annealed films show obvious differences in
superconducting properties and microstructure
Dating with Scambots:understanding the ecosystem of fraudulent dating applications
In this work, we are focusing on a new and yet uncovered way for malicious
apps to gain profit. They claim to be dating apps. However, their sole purpose
is to lure users into purchasing premium/VIP services to start conversations
with other (likely fake female) accounts in the app. We call these apps as
fraudulent dating apps. This paper performs a systematic study to understand
the whole ecosystem of fraudulent dating apps. Specifically, we have proposed a
three-phase method to detect them and subsequently comprehend their
characteristics via analyzing the existing account profiles. Our observation
reveals that most of the accounts are not managed by real persons, but by
chatbots based on predefined conversation templates. We also analyze the
business model of these apps and reveal that multiple parties are actually
involved in the ecosystem, including producers who develop apps, publishers who
publish apps to gain profit, and the distribution network that is responsible
for distributing apps to end users. Finally, we analyze the impact of them to
users (i.e., victims) and estimate the overall revenue. Our work is the first
systematic study on fraudulent dating apps, and the results demonstrate the
urge for a solution to protect users
De Novo Assembly of 20 Chicken Genomes Reveals the Undetectable Phenomenon for Thousands of Core Genes on Microchromosomes and Subtelomeric Regions
The gene numbers and evolutionary rates of birds were assumed to be much lower than those of mammals, which is in sharp contrast to the huge species number and morphological diversity of birds. It is, therefore, necessary to construct a complete avian genome and analyze its evolution. We constructed a chicken pan-genome from 20 de novo assembled genomes with high sequencing depth, and identified 1,335 protein-coding genes and 3,011 long noncoding RNAs not found in GRCg6a. The majority of these novel genes were detected across most individuals of the examined transcriptomes but were seldomly measured in each of the DNA sequencing data regardless of Illumina or PacBio technology. Furthermore, different from previous pan-genome models, most of these novel genes were overrepresented on chromosomal subtelomeric regions and microchromosomes, surrounded by extremely high proportions of tandem repeats, which strongly blocks DNA sequencing. These hidden genes were proved to be shared by all chicken genomes, included many housekeeping genes, and enriched in immune pathways. Comparative genomics revealed the novel genes had 3-fold elevated substitution rates than known ones, updating the knowledge about evolutionary rates in birds. Our study provides a framework for constructing a better chicken genome, which will contribute toward the understanding of avian evolution and the improvement of poultry breeding