154 research outputs found
On the size of maximal binary codes with 2, 3, and 4 distances
We address the maximum size of binary codes and binary constant weight codes
with few distances. Previous works established a number of bounds for these
quantities as well as the exact values for a range of small code lengths. As
our main results, we determine the exact size of maximal binary codes with two
distances for all lengths as well as the exact size of maximal binary
constant weight codes with 2,3, and 4 distances for several values of the
weight and for all but small lengths.Comment: Main text 23 pp. and Appendix 17p
On the size of maximal binary codes with 2, 3, and 4 distances
We address the maximum size of binary codes and binary constant weight codes with few distances. Previous works established a number of bounds for these quantities as well as the exact values for a range of small code lengths. As our main results, we determine the exact size of maximal binary codes with two distances for all lengths n≥6 as well as the exact size of maximal binary constant weight codes with 2,3, and 4 distances for several values of the weight and for all but small lengths
Ocimum gratissimum Aqueous Extract Induces Apoptotic Signalling in Lung Adenocarcinoma Cell A549
Ocimum gratissimum (OG) is widely used as a traditional herb for its antibacterial activity in Taiwan. Recently, antitumor effect of OG on breast cancer cell is also reported; however, the effects of OG on human pulmonary adenocarcinoma cell A549 remain unclear. Therefore, we aimed to investigate whether aqueous OG extract (OGE) affects viability of A549 cells and the signals induced by OGE in A549 cells. Cell viability assays revealed that OGE significantly and dose-dependently decreased the viability of A549 cell but not that of BEAS-2B cell. Morphological examination and DAPI staining indicated that OGE induced cell shrinkage and DNA condensation for A549 cells. Further investigation showed that OGE enhanced activation of caspase-3, caspase-9 and caspase-8 and increased protein level of Apaf-1 and Bak, but diminished the level of Bcl-2. Additionally, OGE inhibited the phosphorylation of extracellular signal-regulated kinase (ERK) yet enhanced the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 MAP kinase (p38). In conclusion, our findings indicate that OGE suppressed the cell viability of A549 cells, which may result from the activation of apoptotic signaling and the inhibition of anti-apoptotic signaling, suggesting that OGE might be beneficial to lung carcinoma treatment
An in situ study on the coalescence of monolayer-protected Au-Ag nanoparticle deposits upon heating
The structural evolution of thiolate-protected nanoparticles of gold, silver, and their alloys with various Au/Ag ratios (3:1, 1:1, and 1:3) upon heating was investigated by means of in situ synchrotron radiation X-ray diffraction. The relationships between the coalescence and composition of nanoparticles, as well as the surfactant reactions, were clarified. Experimental results show that there existed a critical temperature ranging from 120°C to 164°C, above which the tiny broad X-ray diffraction peaks became sharp and strong due to particle coalescence. The coalescence temperatures for alloy nanoparticle deposits were clearly lower than those for pure metals, which can be ascribed to the rivalry between the thermodynamic effect due to alloying and the interactions between surface-assembled layers and the surface atoms of the nanoparticles. The strong affinity of thiolates to Ag and thus complex interactions give rise to a greater energy barrier for the coalescence of nanoparticles into the bulk and subsequent high coalescence temperature. The influences of particle coalescence on the optical and electrical properties of the nanoparticle deposits were also explored
Single-Image HDR Reconstruction by Learning to Reverse the Camera Pipeline
Recovering a high dynamic range (HDR) image from a single low dynamic range
(LDR) input image is challenging due to missing details in under-/over-exposed
regions caused by quantization and saturation of camera sensors. In contrast to
existing learning-based methods, our core idea is to incorporate the domain
knowledge of the LDR image formation pipeline into our model. We model the
HDRto-LDR image formation pipeline as the (1) dynamic range clipping, (2)
non-linear mapping from a camera response function, and (3) quantization. We
then propose to learn three specialized CNNs to reverse these steps. By
decomposing the problem into specific sub-tasks, we impose effective physical
constraints to facilitate the training of individual sub-networks. Finally, we
jointly fine-tune the entire model end-to-end to reduce error accumulation.
With extensive quantitative and qualitative experiments on diverse image
datasets, we demonstrate that the proposed method performs favorably against
state-of-the-art single-image HDR reconstruction algorithms.Comment: CVPR 2020. Project page:
https://www.cmlab.csie.ntu.edu.tw/~yulunliu/SingleHDR Code:
https://github.com/alex04072000/SingleHD
Maximizing Science Outreach on Facebook: An Analysis of Scientists’ Communication Strategies in Taiwan
The internet, and especially social media platforms, offer scientists new opportunities to connect with a broader public. While many studies have focused on science communication on Twitter, surprisingly few have analyzed how scientists use Facebook, even though it is an essential platform for the general public in many countries. A possible explanation for this lack of research is that scientists keep their Facebook profiles separate from their work life and are more active on Twitter in their professional roles. Our study challenges this assumption by focusing on Taiwan as a peculiar case. Due to the local culture, Twitter is less popular there, and scientists are more active on Facebook, even in their professional roles. In our study, we analyzed 35 public pages of scientists on Facebook and assessed the factors explaining the reach of their communication using content analysis in combination with a multilevel model that allowed us to test predictors on the page level, such as the number of fans, in combination with predictors on the post level, such as the complexity of the language used. Our study shows that Facebook can play an influential role in science outreach. To effectively communicate with the audience on Facebook, it is best to use strategies that appeal to new and existing followers. Posts that address current issues and include opinions are likely to be shared widely, while humor or personal self-disclosure is likely to engage the existing audience. Our study contributes to the current debate about alternatives to Twitter in science communication
Improved support vector machine classification for imbalanced medical datasets by novel hybrid sampling combining modified mega-trend-diffusion and bagging extreme learning machine model
To handle imbalanced datasets in machine learning or deep learning models, some studies suggest sampling techniques to generate virtual examples of minority classes to improve the models' prediction accuracy. However, for kernel-based support vector machines (SVM), some sampling methods suggest generating synthetic examples in an original data space rather than in a high-dimensional feature space. This may be ineffective in improving SVM classification for imbalanced datasets. To address this problem, we propose a novel hybrid sampling technique termed modified mega-trend-diffusion-extreme learning machine (MMTD-ELM) to effectively move the SVM decision boundary toward a region of the majority class. By this movement, the prediction of SVM for minority class examples can be improved. The proposed method combines α-cut fuzzy number method for screening representative examples of majority class and MMTD method for creating new examples of the minority class. Furthermore, we construct a bagging ELM model to monitor the similarity between new examples and original data. In this paper, four datasets are used to test the efficiency of the proposed MMTD-ELM method in imbalanced data prediction. Additionally, we deployed two SVM models to compare prediction performance of the proposed MMTD-ELM method with three state-of-the-art sampling techniques in terms of geometric mean (G-mean), F-measure (F1), index of balanced accuracy (IBA) and area under curve (AUC) metrics. Furthermore, paired t-test is used to elucidate whether the suggested method has statistically significant differences from the other sampling techniques in terms of the four evaluation metrics. The experimental results demonstrated that the proposed method achieves the best average values in terms of G-mean, F1, IBA and AUC. Overall, the suggested MMTD-ELM method outperforms these sampling methods for imbalanced datasets
Melatonin acts synergistically with pazopanib against renal cell carcinoma cells through p38 mitogen-activated protein kinase-mediated mitochondrial and autophagic apoptosis
Background Mounting evidence indicates that melatonin has possible activity against different tumors. Pazopanib is an anticancer drug used to treat renal cell carcinoma (RCC). This study tested the anticancer activity of melatonin combined with pazopanib on RCC cells and explored the underlying mechanistic pathways of its action. Methods The 786-O and A-498 human RCC cell lines were used as cell models. Cell viability and tumorigenesis were detected with the MTT and colony formation assays, respectively. Apoptosis and autophagy were assessed using TUNEL, annexin V/propidium iodide, and acridine orange staining with flow cytometry. The expression of cellular signaling proteins was investigated with western blotting. The in vivo growth of tumors derived from RCC cells was evaluated using a xenograft mouse model. Results Together, melatonin and pazopanib reduced cell viability and colony formation and promoted the apoptosis of RCC cells. Furthermore, the combination of melatonin and pazopanib triggered more mitochondrial, caspase-mediated, and LC3-II-mediated autophagic apoptosis than melatonin or pazopanib alone. The combination also induced higher activation of the p38 mitogen-activated protein kinase (p38MAPK) in the promotion of autophagy and apoptosis by RCC cells than melatonin or pazopanib alone. Finally, tumor xenograft experiments confirmed that melatonin and pazopanib cooperatively inhibited RCC growth in vivo and predicted a possible interaction between melatonin/pazopanib and LC3-II. Conclusion The combination of melatonin and pazopanib inhibits the growth of RCC cells by inducing p38MAPK-mediated mitochondrial and autophagic apoptosis. Therefore, melatonin might be a potential adjuvant that could act synergistically with pazopanib for RCC treatment
Influence of pain location and hand dominance on scapular kinematics and EMG activities: an exploratory study
<p>Abstract</p> <p>Background</p> <p>Assessment of three-dimensional kinematics and electromyography (EMG) activities is common in patients with chronic neck pain. However, the effect of hand dominance and neck pain location on the measurement of movement and EMG characteristics is still unclear. Therefore, the purpose of this study was to investigate the effect of neck pain location and arm dominance on the scapular kinematics and muscle EMG activities in patients with chronic neck pain.</p> <p>Methods</p> <p>Thirty subjects (10 males, 20 females; mean age (sd): 38 (11.9) years) with chronic neck pain for more than 3 months were recruited. The scapular kinematics and EMG activity of the upper trapezius and sternocleidomastoid muscles were measured during the bilateral arm elevation task. The three-way repeated measures ANOVA was used to examine the effect of neck pain location and hand dominance on the measurement of kinematics and EMG muscle activities.</p> <p>Results</p> <p>The movement of scapular posterior tilt was significantly influenced by arm dominance (P = 0.001) and by the interaction of arm dominance and elevation angle (P = 0.002). The movement of scapular upward/downward rotation was affected by the interaction of arm dominance and elevation angle (P = 0.02). The location of pain did not show any significant influence on the scapular movement and muscle activities.</p> <p>Conclusions</p> <p>Hand dominance could have an influence on the scapular kinematics, which should be taken into consideration when describing and comparing neuromuscular characteristics in individuals with chronic neck pain.</p
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