2,778 research outputs found
The North System for Formosa Speech Recognition Challenge 2023
This report provides a concise overview of the proposed North system, which
aims to achieve automatic word/syllable recognition for Taiwanese Hakka
(Sixian). The report outlines three key components of the system: the
acquisition, composition, and utilization of the training data; the
architecture of the model; and the hardware specifications and operational
statistics. The demonstration of the system has been made public at
https://asrvm.iis.sinica.edu.tw/hakka_sixian
Characterizing clinical isolates of Acanthamoeba castellanii with high resistance to polyhexamethylene biguanide in Taiwan
AbstractBackground/PurposeAcanthamoeba keratitis (AK), a painful infectious corneal disease, is caused by the free-living pathogenic species Acanthamoeba. The symptoms include corneal infiltrate, epithelial, and stromal destruction, and loss of vision. Current treatment generally involves an hourly application of polyhexamethylene biguanide (PHMB) over a period of several days; however, even this is not entirely effective against all strains/isolates. The aims of this study were to confirm the existence of pathogenic strains in Taiwan which are highly resistant to drugs and to characterize the behavior of these strains.MethodsAn in vitro Acanthamoeba species culture platform was established to observe the effectiveness of treatment and chart the morphological changes that occur under the effects of drugs using a light microscope and time-lapse recording. Changes in gene expression were examined using reverse transcription polymerase chain reaction (RT-PCR) and real-time PCR.ResultsOver 90% of the standard strain cells (ATCC 30010) were lysed after being treated with PHMB for 1 hour; however, clinical isolates of Acanthamoeba castellanii that differed in their susceptibility to the treatment drug were only partly lysed. Following treatment with PHMB, National Cheng Kung University Hospital isolation B (NCKH_B) transformed into a pseudocyst under the effects of drug stress; however, National Cheng Kung University Hospital isolation D (NCKH_D), an isolate with higher tolerance for PHMB, did not transform.ConclusionOur results confirm the existence of clinical isolates of A. castellanii with high resistance to PHMB in Taiwan and present the alternative drug tolerance of A. castellanii in addition to the transformation of pseudocyst/cyst
Seasonal Variation and Source Apportionment of Atmospheric Carbonyl
ABSTRACT The concentrations of 18 atmospheric carbonyls species were measured at Nan-Chie and Hsiung-Kong sites in Kaohsiung City, Taiwan, during the summer and winter of 2006. Formaldehyde and acetaldehyde were the most abundant carbonyls with respective annual mean concentrations of 17.99 g/m 3 and 13.69 g/m 3 at Nan-Chie, and 21.47 g/m 3 and 16.68 g/m 3 at Hsiung-Kong; altogether the two species accounted for approximately 56-57% of total carbonyls. In summer, the total concentrations of carbonyls were 74.06 g/m 3 and 89.99 g/m 3 at Nan-Chie and Hsiung-Kong, respectively. In winter, the concentrations were 37.14 g/m 3 and 46.50 g/m 3 at Nan-Chie and Hsiung-Kong, respectively. Measured results indicated the predominance of photolysis and photooxidation reactions of aldehydes in summer. In this study, receptor models using principal component analysis (PCA) and absolute principal component scores (APCS) suggest that the primary pollution sources at Nan-Chie in the summer were secondary emissions/vehicle exhausts (gasoline engines)/stationary emissions (food industry), stationary emissions (petrochemical)/waste treatment and restaurant emissions; the primary pollution sources at Nan-Chie in winter were vehicle exhausts (gasoline engines)/stationary emissions (petrochemical) and restaurant emissions. At Hsiung-Kong, the primary pollution sources in summer were secondary emissions/vehicle exhausts (gasoline engines and diesel engines)/stationary emissions (metal assembly), restaurant emissions and others; the primary pollution sources in winter were vehicle exhausts (gasoline engines)/restaurant emissions and vehicle exhausts (diesel engines)/stationary emissions (metal assembly)
Drumhead Surface States and Topological Nodal-Line Fermions in TlTaSe2
A topological nodal-line semimetal is a new condensed matter state with
one-dimensional bulk nodal lines and two-dimensional drumhead surface bands.
Based on first-principles calculations and our effective k . p model, we
propose the existence of topological nodal-line fermions in the ternary
transition- metal chalcogenide TlTaSe2. The noncentrosymmetric structure and
strong spin-orbit coupling give rise to spinful nodal-line bulk states which
are protected by a mirror reflection symmetry of this compound. This is
remarkably distinguished from other proposed nodal-line semimetals such as
Cu3NPb(Zn) in which nodal lines exist only in the limit of vanishing spin-orbit
coupling. We show that the drumhead surface states in TlTaSe2, which are
associated with the topological nodal lines, exhibit an unconventional chiral
spin texture and an exotic Lifshitz transition as a consequence of the linkage
among multiple drumhead surface-state pockets.Comment: Related papers at
http://physics.princeton.edu/zahidhasangroup/index.htm
Post-translational regulation enables robust p53 regulation
The tumor suppressor protein p53 plays important roles in DNA damage repair, cell cycle arrest and apoptosis. Due to its critical functions, the level of p53 is tightly regulated by a negative feedback mechanism to increase its tolerance towards fluctuations and disturbances. Interestingly, the p53 level is controlled by post-translational regulation rather than transcriptional regulation in this feedback mechanism
Scallop hull and its offset
A linear-time algorithm that computes the envelope of the offset of a monotone chain is presented. The scallop hull, an extended notion of the convex hull, of the monotone chain is first computed by using an approach similar to that of the convex-hull construction algorithm. The offset of the scallop hull, which yields the desired envelope, can then be computed in linear time from the scallop hull, giving a tool path.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31482/1/0000404.pd
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Human papillomavirus 16 E6 induces FoxM1B in oral keratinocytes through GRHL2
High-risk human papillomavirus (HPV) is a major risk factor for oral and pharyngeal cancers (OPCs), yet the detailed mechanisms by which HPV promotes OPCs are not understood. Forkhead box M1B (FoxM1B) is an oncogene essential for cell cycle progression and tumorigenesis, and it is aberrantly overexpressed in many tumors. We previously showed that FoxM1B was the putative target of an epithelial-specific transcription factor, Grainyhead-like 2 (GRHL2). In the current study, we demonstrate that HPV type 16 (HPV-16) E6 induces FoxM1B in human oral keratinocytes (HOKs) and tonsillar epithelial cells (TECs) in part through GRHL2. FoxM1B was barely detectable in cultured normal human oral keratinocytes (NHOKs) and progressively increased in immortalized HOKs harboring HPV-16 genome (HOK-16B) and tumorigenic HOK-16B/BaP-T cells. Retroviral expression of HPV-16 E6 and/or E7 in NHOKs, TECs, and hypopharyngeal carcinoma cells (FaDu) revealed induction of FoxM1B and GRHL2 by the E6 protein but not E7. Both GRHL2 and FoxM1B were strongly induced in the epidermis of HPV-16 E6 transgenic mice and HPVoral squamous cell carcinomas. Ectopic expression of FoxM1B led to acquisition of transformed phenotype in HOK-16B cells. Loss of FoxM1B by lentiviral short hairpin RNA vector or chemical inhibitor led to elimination of tumorigenic characteristics of HOK-16B/BaP-T cells. Luciferase reporter assay revealed that GRHL2 directly bound and regulated the FoxM1B gene promoter activity. Using epithelial-specific Grhl2 conditional knockout mice, we exposed wild-type (WT) and Grhl2 KO mice to 4-nitroquinolin 1-oxide (4-NQO), which led to induction of FoxM1B in the tongue tissues and rampant oral tumor development in the WT mice. However, 4-NQO exposure failed to induce tongue tumors or induction of FoxM1B expression in Grhl2 KO mice. Collectively, these results indicate that HPV-16 induces FoxM1B in part through GRHL2 transcriptional activity and that elevated FoxM1B level is required for oropharyngeal cancer development
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