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Investigation of Multiple Recognitions Used for EFL Writing in Authentic Contexts
Recognition technologies had been prevailing and widely used for EFL learning. We investigated the different recognitions used for EFL writing based on image-to-text, translated speech-to-text, and location-to-text recognitions – ITR, TSTR, and LTR. A quasi-experiment was implemented for 12 weeks in a vocational high school with experimental and control groups in two stages. Pre-test, posttests 1 and 2, questionnaires, and interviews were conducted and analyzed. Experimental learners, who wrote writing based on ITR and TSTR, outperformed control learners who wrote that based on TSTR only. Also, the experimental learners, who wore writing based on ITR, TSTR, and LTR, outperformed the control learners who wrote that based on ITR and TSTR. Particularly, LTR was beneficial for identifying controlling ideas and addressing the writing topics. ITR was beneficial for brainstorming and generating more ideas. TSTR was beneficial for yielding and transferring writing contents into words. The multiple recognitions were beneficial for most EFL writers, especially for low-ability language writers. Most writers were interested in describing based on authentic context learning. However, they complained about the low accuracy of LTR and TSTR and the difficulty of ITR texts when writing. Accordingly, the LTR database with various categories of places, the generation of ITR based on the language abilities of learners, and the higher accuracy of TSTR should be strictly considered when applying multiple recognitions for EFL writing
On Vague Computers
Vagueness is something everyone is familiar with. In fact, most people think
that vagueness is closely related to language and exists only there. However,
vagueness is a property of the physical world. Quantum computers harness
superposition and entanglement to perform their computational tasks. Both
superposition and entanglement are vague processes. Thus quantum computers,
which process exact data without "exploiting" vagueness, are actually vague
computers
Hacking commercial quantum cryptography systems by tailored bright illumination
The peculiar properties of quantum mechanics allow two remote parties to
communicate a private, secret key, which is protected from eavesdropping by the
laws of physics. So-called quantum key distribution (QKD) implementations
always rely on detectors to measure the relevant quantum property of single
photons. Here we demonstrate experimentally that the detectors in two
commercially available QKD systems can be fully remote-controlled using
specially tailored bright illumination. This makes it possible to tracelessly
acquire the full secret key; we propose an eavesdropping apparatus built of
off-the-shelf components. The loophole is likely to be present in most QKD
systems using avalanche photodiodes to detect single photons. We believe that
our findings are crucial for strengthening the security of practical QKD, by
identifying and patching technological deficiencies.Comment: Revised version, rewritten for clarity. 5 pages, 5 figures. To
download the Supplementary information (which is in open access), go to the
journal web site at http://dx.doi.org/10.1038/nphoton.2010.21
From Practice to Theory: The "Bright Illumination" Attack on Quantum Key Distribution Systems
The "Bright Illumination" attack [Lydersen et al., Nat. Photon. 4, 686-689
(2010)] is a practical attack, fully implementable against quantum key
distribution systems. In contrast to almost all developments in quantum
information processing (for example, Shor's factorization algorithm, quantum
teleportation, Bennett-Brassard (BB84) quantum key distribution, the
"Photon-Number Splitting" attack, and many other examples), for which theory
has been proposed decades before a proper implementation, the "Bright
Illumination" attack preceded any sign or hint of a theoretical prediction.
Here we explain how the "Reversed-Space" methodology of attacks, complementary
to the notion of "quantum side-channel attacks" (which is analogous to a
similar term in "classical" - namely, non-quantum - computer security), has
missed the opportunity of predicting the "Bright Illumination" attack.Comment: 17 page
Linear, Deterministic, and Order-Invariant Initialization Methods for the K-Means Clustering Algorithm
Over the past five decades, k-means has become the clustering algorithm of
choice in many application domains primarily due to its simplicity, time/space
efficiency, and invariance to the ordering of the data points. Unfortunately,
the algorithm's sensitivity to the initial selection of the cluster centers
remains to be its most serious drawback. Numerous initialization methods have
been proposed to address this drawback. Many of these methods, however, have
time complexity superlinear in the number of data points, which makes them
impractical for large data sets. On the other hand, linear methods are often
random and/or sensitive to the ordering of the data points. These methods are
generally unreliable in that the quality of their results is unpredictable.
Therefore, it is common practice to perform multiple runs of such methods and
take the output of the run that produces the best results. Such a practice,
however, greatly increases the computational requirements of the otherwise
highly efficient k-means algorithm. In this chapter, we investigate the
empirical performance of six linear, deterministic (non-random), and
order-invariant k-means initialization methods on a large and diverse
collection of data sets from the UCI Machine Learning Repository. The results
demonstrate that two relatively unknown hierarchical initialization methods due
to Su and Dy outperform the remaining four methods with respect to two
objective effectiveness criteria. In addition, a recent method due to Erisoglu
et al. performs surprisingly poorly.Comment: 21 pages, 2 figures, 5 tables, Partitional Clustering Algorithms
(Springer, 2014). arXiv admin note: substantial text overlap with
arXiv:1304.7465, arXiv:1209.196
Phenotype instability of hepatocyte-like cells produced by direct reprogramming of mesenchymal stromal cells
Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2020-05-20T13:36:52Z
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Previous issue date: 2020Fundação de Amparo à Pesquisa do Estado da Bahia (FAPESB), Conselho
Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil.MRC Centre for Regenerative Medicine. Edinburgh, UK.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil / D’Or Institute for Research and Education. Rio de Janeiro, RJ, Brazil.Universidade Federal da Bahia. Institute of Health Sciences. Salvador, BA, Brasil.MRC Centre for Regenerative Medicine. Edinburgh, UK.São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil / D’Or Institute for Research and Education. Rio de Janeiro, RJ, Brazil.São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil / D’Or Institute for Research and Education. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / National Institute of Science and Technology for Regenerative Medicine. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil.MRC Centre for Regenerative Medicine. Edinburgh, UK.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / National Institute of Science and Technology for Regenerative Medicine. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil / D’Or Institute for Research and Education. Rio de Janeiro, RJ, Brazil / National Institute of Science and Technology for Regenerative Medicine. Rio de Janeiro, RJ, Brazil /Hepatocyte-like cells (iHEPs) generated by transcription factor-mediated direct reprogramming of somatic cells have been studied as potential cell sources for the development of novel therapies targeting liver diseases. The mechanisms involved in direct reprogramming, stability after long-term in vitro expansion, and safety profile of reprogrammed cells in different experimental models, however, still require further investigation. Methods: iHEPs were generated by forced expression of Foxa2/Hnf4a in mouse mesenchymal stromal cells and
characterized their phenotype stability by in vitro and in vivo analyses.
Results: The iHEPs expressed mixed hepatocyte and liver progenitor cell markers, were highly proliferative, and
presented metabolic activities in functional assays. A progressive loss of hepatic phenotype, however, was observed
after several passages, leading to an increase in alpha-SMA+ fibroblast-like cells, which could be distinguished and
sorted from iHEPs by differential mitochondrial content. The resulting purified iHEPs proliferated, maintained liver
progenitor cell markers, and, upon stimulation with lineage maturation media, increased expression of either biliary
or hepatocyte markers. In vivo functionality was assessed in independent pre-clinical mouse models. Minimal
engraftment was observed following transplantation in mice with acute acetaminophen-induced liver injury. In
contrast, upon transplantation in a transgenic mouse model presenting host hepatocyte senescence, widespread
engraftment and uncontrolled proliferation of iHEPs was observed, forming islands of epithelial-like cells, adipocytelike
cells, or cells presenting both morphologies.
Conclusion: The results have significant implications for cell reprogramming, suggesting that iHEPs generated by
Foxa2/Hnf4a expression have an unstable phenotype and depend on transgene expression for maintenance of
hepatocyte-like characteristics, showing a tendency to return to the mesenchymal phenotype of origin and a
compromised safety profil
CAS9 transcriptional activators for target specificity screening and paired nickases for cooperative genome engineering
Prokaryotic type II CRISPR-Cas systems can be adapted to enable targeted genome modifications across a range of eukaryotes.1–7. Here we engineer this system to enable RNA-guided genome regulation in human cells by tethering transcriptional activation domains either directly to a nuclease-null Cas9 protein or to an aptamer-modified single guide RNA (sgRNA). Using this functionality we developed a novel transcriptional activation–based assay to determine the landscape of off-target binding of sgRNA:Cas9 complexes and compared it with the off-target activity of transcription activator–like (TAL) effector proteins8, 9. Our results reveal that specificity profiles are sgRNA dependent, and that sgRNA:Cas9 complexes and 18-mer TAL effector proteins can potentially tolerate 1–3 and 1–2 target mismatches, respectively. By engineering a requirement for cooperativity through offset nicking for genome editing or through multiple synergistic sgRNAs for robust transcriptional activation, we suggest methods to mitigate off-target phenomena. Our results expand the versatility of the sgRNA:Cas9 tool and highlight the critical need to engineer improved specificity
A CRISPR-Cas9 gene drive system targeting female reproduction in the malaria mosquito vector Anopheles gambiae.
Gene drive systems that enable super-Mendelian inheritance of a transgene have the potential to modify insect populations over a timeframe of a few years. We describe CRISPR-Cas9 endonuclease constructs that function as gene drive systems in Anopheles gambiae, the main vector for malaria. We identified three genes (AGAP005958, AGAP011377 and AGAP007280) that confer a recessive female-sterility phenotype upon disruption, and inserted into each locus CRISPR-Cas9 gene drive constructs designed to target and edit each gene. For each targeted locus we observed a strong gene drive at the molecular level, with transmission rates to progeny of 91.4 to 99.6%. Population modeling and cage experiments indicate that a CRISPR-Cas9 construct targeting one of these loci, AGAP007280, meets the minimum requirement for a gene drive targeting female reproduction in an insect population. These findings could expedite the development of gene drives to suppress mosquito populations to levels that do not support malaria transmission
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