811 research outputs found
Research Notes : Taiwan : A spontaneous narrow-leaflet mutant
At the Asian Vegetable Research and Development Center, developing improved vegetable soybeans is one of the objectives. In accomplishing that objective, one of the crosses involved AGS 188, PI 157424 from Maturity Group IV and G 10381, cultivar \u27Kaohsiung\u27 No. 8 released by the Kaohsiung District Agricultural Improvement Station in Pingtung, Taiwan. The F1 and F2 progenies of the cross were normal
RNA polymerase V-dependent small RNAs in Arabidopsis originate from small, intergenic loci including most SINE repeats.
In plants, heterochromatin is maintained by a small RNA-based gene silencing mechanism known as RNA-directed DNA methylation (RdDM). RdDM requires the non-redundant functions of two plant-specific DNA-dependent RNA polymerases (RNAP), RNAP IV and RNAP V. RNAP IV plays a major role in siRNA biogenesis, while RNAP V may recruit DNA methylation machinery to target endogenous loci for silencing. Although small RNA-generating regions that are dependent on both RNAP IV and RNAP V have been identified previously, the genomic loci targeted by RNAP V for siRNA accumulation and silencing have not been described extensively. To characterize the RNAP V-dependent, heterochromatic siRNA-generating regions in the Arabidopsis genome, we deeply sequenced the small RNA populations of wild-type and RNAP V null mutant (nrpe1) plants. Our results showed that RNAP V-dependent siRNA-generating loci are associated predominately with short repetitive sequences in intergenic regions. Suppression of small RNA production from short repetitive sequences was also prominent in RdDM mutants including dms4, drd1, dms3 and rdm1, reflecting the known association of these RdDM effectors with RNAP V. The genomic regions targeted by RNAP V were small, with an estimated average length of 238 bp. Our results suggest that RNAP V affects siRNA production from genomic loci with features dissimilar to known RNAP IV-dependent loci. RNAP V, along with RNAP IV and DRM1/2, may target and silence a set of small, intergenic transposable elements located in dispersed genomic regions for silencing. Silencing at these loci may be actively reinforced by RdDM
Paclitaxel (Taxol)-induced Gene Expression and Cell Death Are Both Mediated by the Activation of c-Jun NH 2 -terminal Kinase (JNK/SAPK)
Paclitaxel (Taxol) is a novel anti-cancer drug that has shown efficacy toward several malignant tumors, particularly ovarian tumors. We reported previously that paclitaxel can induce interleukin (IL)-8 promoter activation in subgroups of ovarian cancer through the activation of both AP-1 and nuclear factor kappaB. Further analysis of paclitaxel analogs indicates that the degree of IL-8 induction by analysis correlates with the extent of cell death; however, IL-8 itself is not the cause of cell death. This suggests that pathways that lead to IL-8 and cell death may overlap, although IL-8 per se does not kill tumor cells. To decipher the upstream signals for paclitaxel-induced transcriptional activation and cell death, we studied the involvement of protein kinases that lead to the activation of AP-1, specifically the c-Jun NH2-terminal kinase (JNK1), p38, and the extracellular signal-regulated kinase 1 (ERK1). The role of IkappaB in paclitaxel-induced cell death was also analyzed. Paclitaxel activated JNK, and to a lesser degree p38, but not ERK1. Paclitaxel-induced IL-8 promoter activation was inhibited by dominant-inhibitory mutants of JNK, p38, and the super-repressor form of IkappaBalpha, but not by dominant-inhibitory forms of ERK1. Dominant-inhibitory mutants of JNK1 also greatly reduced paclitaxel-induced cell death, and the kinetics of JNK induction was closely followed by DNA fragmentation. These results indicate (i) that paclitaxel activates the JNK signaling pathway and (ii) that JNK activation is a common point of paclitaxel-induced gene induction and cell death
Self-assembly of a silicon-containing side-chain liquid crystalline block copolymer in bulk and in thin films: kinetic pathway of a cylinder to sphere transition
The self-assembly of a high-χ silicon-containing side-chain liquid crystalline block copolymer (LC BCP) in bulk and in thin films is reported, and the structural transition process from the hexagonally packed cylinder (HEX) to the body-centered cubic structure (BCC) in thin films was examined by both reciprocal and real space experimental methods. The block copolymer, poly(dimethylsiloxane-b-11-(4′-cyanobiphenyl-4-yloxy)undecylmethacrylate) (PDMS-b-P(4CNB11C)MA) with a molecular weight of 19.5 kg mol−1 and a volume fraction of PDMS 27% self-assembled in bulk into a hierarchical nanostructure of sub-20 nm HEX cylinders of PDMS with the P(4CNB11C)MA block exhibiting a smectic LC phase with a 1.61 nm period. The structure remained HEX as the P(4CNB11C)MA block transformed to an isotropic phase at ∼120 °C. In the thin films, the PDMS cylindrical microdomains were oriented in layers parallel to the substrate surface. The LC block formed a smectic LC phase which transformed to an isotropic phase at ∼120 °C, and the microphase-separated nanostructure transformed from HEX to BCC spheres at ∼160 °C. The hierarchical structure as well as the dynamic structural transition of the thin films were characterized using in situ grazing-incidence small-angle X-ray scattering and grazing-incidence wide-angle X-ray scattering. The transient morphologies from the HEX to BCC structure in thin films were captured by scanning electron microscopy and atomic force microscopy, and the transition pathway was described.National Science Foundation (U.S.) (DMR-1606911)National Natural Science Foundation (China) (Grant 51403132)National Natural Science Foundation (China) (Grant 51773124
A simple statistical speech recognition of mandarin monosyllables
Abstract Each mandarin syllable is represented by a sequence of vectors of linear predict coding cepstra (LPCC). Since all syllables have a simple phonetic structure, in our speech recognition, we partition the sequence of LPCC vectors of all syllables into equal segments and average the LPCC vectors in each segment. The mean vector of LPCC is used as the feature of a syllable. Our simple feature does not need any time consuming and complicated nonlinear contraction and expansion as adopted by the dynamic time-warping. We propose several probability distributions for the feature values. A simplified Bayes decision rule is used for classification of mandarin syllables. For the speaker-independent mandarin digits, the recognition rate is 98.6% if a normal distribution is used for feature values and the rate is 98.1% if an exponential distribution is used for the absolute values of the features. The feature proposed in this paper to represent a syllable is the simplest one, much easier to be extracted than any other known features. The computation for feature extraction and classification is much faster and more accurate than using the HMM method or any other known techniques
Ranking Enhanced Dialogue Generation
How to effectively utilize the dialogue history is a crucial problem in
multi-turn dialogue generation. Previous works usually employ various neural
network architectures (e.g., recurrent neural networks, attention mechanisms,
and hierarchical structures) to model the history. However, a recent empirical
study by Sankar et al. has shown that these architectures lack the ability of
understanding and modeling the dynamics of the dialogue history. For example,
the widely used architectures are insensitive to perturbations of the dialogue
history, such as words shuffling, utterances missing, and utterances
reordering. To tackle this problem, we propose a Ranking Enhanced Dialogue
generation framework in this paper. Despite the traditional representation
encoder and response generation modules, an additional ranking module is
introduced to model the ranking relation between the former utterance and
consecutive utterances. Specifically, the former utterance and consecutive
utterances are treated as query and corresponding documents, and both local and
global ranking losses are designed in the learning process. In this way, the
dynamics in the dialogue history can be explicitly captured. To evaluate our
proposed models, we conduct extensive experiments on three public datasets,
i.e., bAbI, PersonaChat, and JDC. Experimental results show that our models
produce better responses in terms of both quantitative measures and human
judgments, as compared with the state-of-the-art dialogue generation models.
Furthermore, we give some detailed experimental analysis to show where and how
the improvements come from.Comment: Accepted at CIKM 202
The experience and attitude of TMU faculty and researchers toward predatory journals and research productivity
A questionnaire related to journal submission was sent to researchers for a 2-week period to investigate the submission status as well as the problems faced by Taipei Medical University faculties and researchers. This study has two major findings including the Experience of predatory journal and Calculations of academic performance point and discuss about users’ cognition and their needs from the library and the university, as well as the library policy and services related to predatory journals. It is authors’ hope that the research results can serve as reference for other medical libraries planning to provide relevant services
Quantum key distribution without alternative measurements and rotations
A quantum key distribution protocol based on entanglement swapping is
proposed. Through choosing particles by twos from the sequence and performing
Bell measurements, two communicators can detect eavesdropping and obtain the
secure key. Because the two particles measured together are selected out
randomly, we need neither alternative measurements nor rotations of the Bell
states to obtain security.Comment: 11 pages, no figures, a modified version of quant-ph/0412014, add a
security proof and delete the identification par
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