340 research outputs found

    Visualizing chromosomal rearrangements caused by replication fork stalling in a single cell

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    Aberrant chromosome structures can promote tumors in the early stages of carcinogenesis and lead to tumor cells becoming resistant to chemotherapy, for example by changing in drug metabolism. Dicentric (containing two centromeres) and acentric (containing no centromeres) chromosomes are two abnormal chromosome structures that consider as precursors of a variety of gross chromosomal rearrangements (GCRs) generated by subsequent recombination events [1-7]. However, the mechanism of the dicentric and acentric palindromic chromosome formation and their subsequent metabolism is difficult to directly visualise. The previous results from our lab shows that replication forks stalled at a specific replication termination sequence (RTS1) can result in the formation of the dicentric and acentric palindromic chromosomes in the fission yeast Schizosaccharomyces pombe [48-52]. However, the formation of acentric and dicentric chromosomes results in a significant visability loss, due to instability and miss-segregation of the chromosomes in the yeast cells. Thus, their fate is difficult or impossible to follow. To resolve this problem, a non-essential mini-chromosome (Ch16) was developed as a novel model system in this project. The behaviour of rearranged chromosome in vivo and their subsequent fate have been visualised by integrating the lac operator (lacO) and tetracycline operator (tetO) arrays with auxotropic makers, adjacent to the RTSI locus on Ch16. The results reveal imbalanced segregation of a dicentric chromosome and subsequently undergoes a breakage event. An acentric chromosome appears to be decoupled or lost rapidly from the nucleus

    Rhythm-Flexible Voice Conversion without Parallel Data Using Cycle-GAN over Phoneme Posteriorgram Sequences

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    Speaking rate refers to the average number of phonemes within some unit time, while the rhythmic patterns refer to duration distributions for realizations of different phonemes within different phonetic structures. Both are key components of prosody in speech, which is different for different speakers. Models like cycle-consistent adversarial network (Cycle-GAN) and variational auto-encoder (VAE) have been successfully applied to voice conversion tasks without parallel data. However, due to the neural network architectures and feature vectors chosen for these approaches, the length of the predicted utterance has to be fixed to that of the input utterance, which limits the flexibility in mimicking the speaking rates and rhythmic patterns for the target speaker. On the other hand, sequence-to-sequence learning model was used to remove the above length constraint, but parallel training data are needed. In this paper, we propose an approach utilizing sequence-to-sequence model trained with unsupervised Cycle-GAN to perform the transformation between the phoneme posteriorgram sequences for different speakers. In this way, the length constraint mentioned above is removed to offer rhythm-flexible voice conversion without requiring parallel data. Preliminary evaluation on two datasets showed very encouraging results.Comment: 8 pages, 6 figures, Submitted to SLT 201

    Young women's perceptions of replaceable upper shoes before and after the upper interchange

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    This study tries to investigate the visual perception of casual and formal leather shoe uppers, by conducting semantic differential evaluations. Twelve upper design renderings were generated based on six ideations with casual uppers converted into formal leather uppers. Based on a seven-point Likert scale, twelve renderings were evaluated using fifteen Kansei adjective pairs and young women's willingness to purchase. Factor analyses were performed to analyze the differences and factors between casual and formal leather uppers. In the factor analysis of upper styles, five factors were identified for casual uppers: evaluation, attention, fashion, protection, and temperament; and five factors for formal leather uppers: attention, formality, fashion, weight, and protection. Whether a young woman is looking for formal leather uppers or casual shoe uppers, fashion plays a crucial role in her decision to purchase shoes

    Theoretical study of the ammonia nitridation rate on an Fe (100) surface: A combined density functional theory and kinetic Monte Carlo study

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    Ammonia (NH[subscript 3]) nitridation on an Fe surface was studied by combining density functional theory (DFT) and kinetic Monte Carlo (kMC) calculations. A DFT calculation was performed to obtain the energy barriers (E[subscript b]) of the relevant elementary processes. The full mechanism of the exact reaction path was divided into five steps (adsorption, dissociation, surface migration, penetration, and diffusion) on an Fe (100) surface pre-covered with nitrogen. The energy barrier (E[subscript b]) depended on the N surface coverage. The DFT results were subsequently employed as a database for the kMC simulations. We then evaluated the NH[subscript 3] nitridation rate on the N pre-covered Fe surface. To determine the conditions necessary for a rapid NH[subscript 3] nitridation rate, the eight reaction events were considered in the kMC simulations: adsorption, desorption, dissociation, reverse dissociation, surface migration, penetration, reverse penetration, and diffusion. This study provides a real-time-scale simulation of NH[subscript 3] nitridation influenced by nitrogen surface coverage that allowed us to theoretically determine a nitrogen coverage (0.56 ML) suitable for rapid NH[subscript 3] nitridation. In this way, we were able to reveal the coverage dependence of the nitridation reaction using the combined DFT and kMC simulations.Korea (South). Ministry of Education, Science and Technology (MEST) (National Research Foundation of Korea. 2011-0028612

    Eddy-Kuroshio interaction processes revealed by mooring observations off Taiwan and Luzon

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    Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 42 (2015): 8098–8105, doi:10.1002/2015GL065814.The influence and fate of westward propagating eddies that impinge on the Kuroshio were observed with pressure sensor-equipped inverted echo sounders (PIESs) deployed east of Taiwan and northeast of Luzon. Zero lag correlations between PIES-measured acoustic travel times and satellite-measured sea surface height anomalies (SSHa), which are normally negative, have lower magnitude toward the west, suggesting the eddy-influence is weakened across the Kuroshio. The observational data reveal that impinging eddies lead to seesaw-like SSHa and pycnocline depth changes across the Kuroshio east of Taiwan, whereas analogous responses are not found in the Kuroshio northeast of Luzon. Anticyclones intensify sea surface and pycnocline slopes across the Kuroshio, while cyclones weaken these slopes, particularly east of Taiwan. During the 6 month period of overlap between the two PIES arrays, only one anticyclone affected the pycnocline depth first at the array northeast of Luzon and 21 days later in the downstream Kuroshio east of Taiwan.Ministry of Science and Technology (MOST) of Taiwan Grant Number: NSC-101-2611-M-002-018-MY3; US Office of Naval Research (ONR) Grant Number: N00014-12-1-0445; MA Grant Number: N00014-15-1-2593; ONR Grant Numbers: N00014-10-1-0397, N00014-10-1-0308, N00014-10-1-04682016-03-0

    New Attenuation Relationship for Peak Ground and Pseudo-Spectral Acceleration of Normal-Faulting Earthquakes in Offshore Northeast Taiwan

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    Ground motions from normal-faulting earthquakes are generally considered to be smaller than those of strike-slip and thrust events. On 11 April 2011 a crustal normal-faulting earthquake [the Fukushima earthquake (Mw 6.6)] occurred in Eastern Japan. The peak ground acceleration (PGA) observed was considerably higher than the predictions of several ground-motion prediction equations (GMPEs), which were derived mainly from thrust or strike-slip earthquakes. In northeast Taiwan, the tectonic structure of the Ryukyu Arc and the Okinawa Trough typically entail normal-faulting earthquakes. Because of the normal-faulting earthquakes relevance to ground motions and nuclear power plant sites in northeast Taiwan, we evaluated the impact of the ground motion of normal-faulting earthquakes in offshore northeast Taiwan using a newly constructed attenuation relationship for PGA and pseudo-spectral acceleration (Sa). We collected 832 records from 13 normal-faulting earthquakes with focal depths of less than 50 km. The moment magnitude (Mw) of the 13 events was between 4 - 6. The Sa and PGA of normal-faulting earthquakes offshore northeast Taiwan determined with the newly constructed attenuation relationship were higher and lower, respectively, than those obtained using attenuation equations commonly used in the Taiwan subduction zone

    Utilization of Inertial Measurement Units for Determining the Sequential Chain of Baseball Strike Posture

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    The purpose of this study was to employ inertial measurement units (IMU) with an eyetracking device to investigate different swing strategies between two levels of batters. The participants were 20 healthy males aged 20 to 30 years old, with ten professional and ten amateur batters. Eye gaze position, head, shoulder, trunk, and pelvis angular velocity, and ground reaction forces were recorded. The results showed that professional batters rotated segments more rhythmically and efficiently than the amateur group. Firstly, the professional group spent less time in the preparation stages. Secondly, the maximum angular velocity timing of each segment of the professional group was centralized in the swing cycle. Thirdly, the amateur group had significantly earlier gaze timing of the maximum angular velocity than the professional group. Moreover, the maximum angular velocity timing of the gaze was the earliest parameter among the five segments, and significantly earlier (at least 16.32% of cycle time) than the maximum angular velocity of the head, shoulder, trunk, and pelvis within the amateur group. The visual-motor coordination strategies were different between the two groups, which could successfully be determined by wearable instruments of IMU

    REG3A overexpression functions as a negative predictive and prognostic biomarker in rectal cancer patients receiving CCRT

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    Background. Concurrent chemoradiotherapy (CCRT) is suggested before resection surgery in the control of rectal cancer. Unfortunately, treatment outcomes are widely variable and highly patientspecific. Notably, rectal cancer patients with distant metastasis generally have a much lower survival rate. Accordingly, a better understanding of the genetic background of patient cohorts can aid in predicting CCRT efficacy and clinical outcomes for rectal cancer before distant metastasis. Methods. A published transcriptome dataset (GSE35452) (n=46) was utilized to distinguish prospective genes concerning the response to CCRT. We recruited 172 rectal cancer patients, and the samples were collected during surgical resection after CCRT. Immunohistochemical (IHC) staining was performed to evaluate the expression level of regenerating family member 3 alpha (REG3A). Pearson's chi-squared test appraised the relevance of REG3A protein expression to clinicopathological parameters. The Kaplan-Meier method was utilized to generate survival curves, and the log-rank test was performed to compare the survival distributions between two given groups. Results. Employing a transcriptome dataset (GSE35452) and focusing on the inflammatory response (GO: 0006954), we recognized that REG3A is the most significantly upregulated gene among CCRT nonresponders (log2 ratio=1.2472, p=0.0079). Following IHC validation, high immunoexpression of REG3A was considerably linked to advanced post-CCRT tumor status (p<0.001), post-CCRT lymph node metastasis (p=0.042), vascular invasion (p=0.028), and low-grade tumor regression (p=0.009). In the multivariate analysis, high immunoexpression of REG3A was independently correlated with poor disease-specific survival (DSS) (p=0.004) and metastasis-free survival (MeFS) (p=0.045). The results of the bioinformatic analysis also supported the idea that REG3A overexpression is implicated in rectal carcinogenesis. Conclusion. In the current study, we demonstrated that REG3A overexpression is correlated with poor CCRT effectiveness and inferior patient survival in rectal cancer. The predictive and prognostic utility of REG3A expression may direct patient stratification and decisionmaking more accurately for those patients
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