332 research outputs found

    Nonlinearity and efficiency dynamics of foreign exchange markets: evidence from multifractality and volatility of major exchange rates

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    This study investigates the efficiencies of the exchange markets for four major currencies—the euro (EUR), the pound (GBP), the Canadian dollar (CAD) and the Japanese yen (JPY)—from 2005 to 2019 by using multifractal detrended fluctuation analysis (MFDFA). This study also investigates the causes of these efficiencies. Significant multifractal properties are demonstrated by the four markets, and long-range correlation and fat-tail distribution properties are the main causes. We calculate and compare the multifractal degrees in three subsamples, which are classified based on their temporal relation to two economic events: the 2008 financial crisis and the announcement by the Federal Reserve of its withdrawal from the quantitative easing policy in 2014. Empirical results suggest that multifractal properties exist at different levels in the subsamples, thus showing that these events affect foreign exchange market efficiencies in terms of statistics and the fractal market. The JPY exchange market has the fewest multifractal properties, thus indicating that this exchange market has the highest market efficiency among these four exchange markets. The empirical results have implications for the nonlinear mechanism and efficiency in foreign exchange markets, which may help investors effectively manage market risks and benefit a stable global economy

    A Review of Research on the Potential Value and Realistic Dilemma for Homework in Physical Education

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    Homework in physical education (PE) has become a central strategy of educational reform movements (Novak & Lynott, 2015). A Chinese policy called “the Double Reduction” provides an opportunity for the implementation of PE homework. There are abundant studies about homework in subjects like English, Math, Science, etc., but relatively few studies have been devoted specifically to PE homework. The primary purpose of this study was to analyze the value and dilemma of PE homework, with the goal of identifying the major contributions to the research knowledge base. We followed three parts to conduct the review: a) literature was searched using the following keywords: “PE homework”, OR “active homework”, AND “the value and dilemma”, AND/OR “homework in physical education” or “activity-based homework”; b) A document analysis was conducted regarding the Chinese policy related to homework in PE, including homework’s guidelines, composition system, and cultivation path, etc.; c) A total of 34 highly relevant articles were selected. The main value and dilemma of PE homework were summarized as follows: a) The PE homework appears to be an effective way of promoting policy implementation and renewal, providing a well-rounded approach to help students achieve educational goal, improving youth physical & mental health, and increasing communications with family members. b) The current PE homework has failed to realize the foregoing values due to some difficulties, including the lack of family exercise atmosphere, the absence of community organizations, and the huge amount of negative news in social media. c) Only three studies provided coping strategies to deal with the dilemma from a Social System Theory perspective, such as strengthening institutional construction, building a multivariate framework, shaping the paradigm, integrating online platform, and developing an assessment system. Most studies focused on the micro level about “the value and dilemma of homework implementation” without consideration of the other key factors from macro level. Based on the literature reviewed, a comprehensive theoretical model for PE homework is proposed to provide guidance for future research endeavors and facilitate implementation of the guidelines

    Aligning Source Visual and Target Language Domains for Unpaired Video Captioning

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    Training supervised video captioning model requires coupled video-caption pairs. However, for many targeted languages, sufficient paired data are not available. To this end, we introduce the unpaired video captioning task aiming to train models without coupled video-caption pairs in target language. To solve the task, a natural choice is to employ a two-step pipeline system: first utilizing video-to-pivot captioning model to generate captions in pivot language and then utilizing pivot-to-target translation model to translate the pivot captions to the target language. However, in such a pipeline system, 1) visual information cannot reach the translation model, generating visual irrelevant target captions; 2) the errors in the generated pivot captions will be propagated to the translation model, resulting in disfluent target captions. To address these problems, we propose the Unpaired Video Captioning with Visual Injection system (UVC-VI). UVC-VI first introduces the Visual Injection Module (VIM), which aligns source visual and target language domains to inject the source visual information into the target language domain. Meanwhile, VIM directly connects the encoder of the video-to-pivot model and the decoder of the pivot-to-target model, allowing end-to-end inference by completely skipping the generation of pivot captions. To enhance the cross-modality injection of the VIM, UVC-VI further introduces a pluggable video encoder, i.e., Multimodal Collaborative Encoder (MCE). The experiments show that UVC-VI outperforms pipeline systems and exceeds several supervised systems. Furthermore, equipping existing supervised systems with our MCE can achieve 4% and 7% relative margins on the CIDEr scores to current state-of-the-art models on the benchmark MSVD and MSR-VTT datasets, respectively.Comment: Published at IEEE Transactions on Pattern Analysis and Machine Intelligence (TPAMI

    Scutellarin Ameliorates Renal Injury via Increasing CCN1 Expression and Suppressing NLRP3 Inflammasome Activation in Hyperuricemic Mice

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    Considerable evidences have indicated that elevated uric acid (UA) was involved in renal tubular injury leading to hyperuricemic nephropathy (HN). Scutellarin is a biologically active flavonoid derived from the Chinese traditional herb Erigeron breviscapus Hand-Mazz, which has been widely used in the treatment of cardiovascular and cerebrovascular diseases. In the present study, we analyzed the effect of scutellarin on HN, by using C57BL/6 mice and human renal tubular epithelial cell line HK-2 which was subjected to adenine/potassium oxonate and UA to mimic a HN injury. The HN mice showed a significant decrease in renal function with the increased SCr and blood urea nitrogen (BUN) (p < 0.05). Hematoxylin-eosin staining results showed a histological injury in HN mice kidney tissues with severe tubular damage. Scutellarin dose dependently alleviated the renal injury of the HN model (p < 0.05), and a dose of 20 mg/kg/day remarkably reduced the Scr level (26.10 +/- 3.23 mu mol/ml vs. 48.39 +/- 7.51 mu mol/ml, p < 0.05) and BUN (151.12 +/- 30.24 mmol/L vs. 210.43 +/- 45.67 mmol/L, p < 0.05) compared with the HN model group. Similarly, scutellarin decreased NGAL, Kim-1, cystatin C, and IL-18 protein expression levels in HN mouse (p < 0.05). Overexpressed CCN1 could not induce NLRP3 inflammasome activation, with no change of mRNA and protein expression levels of NLRP3, ASC, and pro-caspase-1 compared with the control HK-2. However, HK-2 showed a significant NLRP3 inflammasome activation and apoptosis. Importantly, knockdown of CCN1 not only aggravated NLRP3 inflammasome activation and apoptosis but also abrogated the protective effect of scutellarin in UA-induced HK-2 injury. Thus, scutellarin might alleviate HN progression via a mechanism involved in CCN1 regulation on NLRP3 inflammasome activation

    MiR-181d-5p Targets KLF6 to Improve Ischemia/Reperfusion-Induced AKI Through Effects on Renal Function, Apoptosis, and Inflammation

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    Renal tubular epithelial cell (RTEC) death and renal interstitial inflammation are the most crucial pathophysiological changes in acute kidney ischemia/reperfusion injury (IRI). The microRNA (miR)-181d family plays diverse roles in cell proliferation, apoptosis and inflammation, but its renal target and potential role in IRI are unknown. Here, we showed that the expression of miR-181d-5p decreased and Krueppel-like factor 6 (KLF6) increased in a renal cell (HK-2) model of hypoxia/reoxygenation (H/R) injury and a mouse model of renal IRI. They were mainly distributed in the renal tubules. After renal IRI, miR-181d-5p overexpression significantly inhibited inflammatory mediators, reduced apoptosis and further improved renal function. KLF6 exacerbated RTEC damage and acted as a NF-κB co-activator to aggravate the renal IRI inflammatory response. Mechanistically, KLF6 was predicted as a new potential target gene of miR-181d-5p through bioinformatic analysis and luciferase reporter assay verification. After overexpressing miR-181d-5p and inhibiting KLF6, the role of miR-181d-5p was weakened on the renal damage improvement. In conclusion, miR-181d-5p upregulation produced protective antiapoptotic and anti-inflammatory effects against IRI in kidneys in vivo and H/R injury in HK-2 cells in vitro, and these effects were achieved by targeted inhibition of KLF6. Thus, our results provide novel insights into the molecular mechanisms associated with IRI and a potential novel therapeutic target

    An assessment of hepatitis E virus (HEV) in US blood donors and recipients: No detectable HEV RNA in 1939 donors tested and no evidence for HEV transmission to 362 prospectively followed recipients.

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    BACKGROUND: Hepatitis E virus (HEV) infection has become relevant to blood transfusion practice because isolated cases of blood transmission have been reported and because HEV has been found to cause chronic infection and severe liver disease in immunocompromised patients. STUDY DESIGN AND METHODS: We tested for immunoglobulin (Ig)G and IgM antibodies to the HEV and for HEV RNA in 1939 unselected volunteer US blood donors. Subsequently, we tested the same variables in pre- and serial posttransfusion samples from 362 prospectively followed blood recipients to assess transfusion risk. RESULTS: IgG anti-HEV seroprevalence in the total 1939 donations was 18.8%: 916 of these donations were made in 2006 at which time the seroprevalence was 21.8% and the remaining 1023 donations were in 2012 when the seroprevalence had decreased to 16.0% (p \u3c 0.01). A significant (p \u3c 0.001) stepwise increase in anti-HEV seroprevalence was seen with increasing age. Eight of 1939 donations (0.4%) tested anti-HEV IgM positive; no donation was HEV RNA positive. Two recipients had an apparent anti-HEV seroconversion, but temporal relationships and linked donor testing showed that these were not transfusion-transmitted HEV infections. CONCLUSION: No transfusion-transmitted HEV infections were observed in 362 prospectively followed blood recipients despite an anti-HEV seroprevalence among donations exceeding 16%

    Impact of ENSO events on meteorological drought in the Weihe River basin, China

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    El Niño–Southern Oscillation (ENSO) events influence elements of the terrestrial water cycle such as precipitation and temperature, which in turn have a significant impact on drought. This work assessed the impact of El Niño and La Niña on droughts from 1970 to 2020 in the Weihe River basin (WRB) in China. This study used a standardized precipitation index (SPI) to characterize meteorological drought. The regional drought response to extreme events in El Niño/La Niña was analyzed using principal component analysis (PCA), Wilcoxon and Mann–Whitney tests, and other methods. The results showed that, based on PCA, the WRB is divided into two regions, with the northwest region (67%) comprising more area than the southeast region (33%). El Niño/La Niña significantly impacted drought in the WRB. Droughts mainly occurred in the El Niño year and the year following La Niña. El Niño had the highest number of drought years (44%), followed by the year following La Niña (43%). The number of droughts was lowest in the year following El Niño (22%). At 1-, 3-, and 6-month timescales, significant droughts mainly occurred from July to December in El Niño years and the summer following La Niña. On a 12-month timescale, significant droughts mainly occurred from January to April in El Niño years, while no droughts occurred in La Niña years. The longer the timescale of the SPI, the more months of significant drought in El Niño years; however, the intensity of drought in the basin was reduced. In the year following La Niña, summer droughts intensified on a 6-month timescale compared to a 3-month timescale. El Niño and La Niña had greater impacts on the drought index in the northwest region of the WRB. In the northwest region, 60% of the months showed significant drought, compared to only 2% of the months in the southeast region. The drought intensity was higher in the northwest region. The results of this study provide a reference for drought management and early warning systems in the WRB and support solutions to water shortage

    Inhibition and Production of Anger Cost More: Evidence From an ERP Study on the Production and Switch of Voluntary Facial Emotional Expression

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    Humans need to flexibly produce or switch different facial emotional expressions to meet social communication need. However, little is known about the control of voluntary facial emotional expression. We investigated the production and switch of facial expressions of happiness and anger in a response-priming task of 23 Chinese female university students and recorded electroencephalographic (EEG) signals. Results revealed that a frontal-central P2 component demonstrated greater positivity in the invalidly cued condition compared with the validly cued condition. Comparing the two facial emotional expressions, data from the contingent negative variation (CNV) component revealed that happiness and anger did not differ in the motor preparation phase. While data from N2 and P3 showed that switching from anger to happiness elicited larger N2 amplitudes than switching from happiness to anger and switching from happiness to anger elicited larger P3 than switching from anger to happiness. The results revealed that in invalidly cued condition, the inhibition (N2) and reprogramming (P3) cost of anger was greater than that of happiness. The findings indicated that during the switching process, both the inhibition and the reprogramming of anger cost more processing resources than those of happiness

    Exploring a Multi-Layer Coupled Network Propagation Model Based on Information Diffusion and Bounded Trust

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    Objective: To explore the law of opinion dissemination and individual opinion evolution at the micro level, this paper analyzes the influence of variation and oyster on communication from the perspective of network structure.Methods: In this paper, we introduce the concepts of “variation” and “oyster”, build a multi-layer coupled network environment combined with the ISOVR model, and conduct simulation experiments of network information dissemination based on the bounded trust model.Results: The experimental results reveal that the extent and scope of variation’s spread in the network are more dependent on the trust of nodes themselves, and decreasing the trust of nodes significantly reduces the rate and peak value of variation. Changing the silence coefficient of variation does not effectively change the direction of rumor propagation, which indicates that rumor has a strong propagation ability after mutation.Conclusion: The insights of this paper on the dissemination of public opinions include: 1) pay attention to people with high trust levels, such as opinion leaders; 2) clarify the misinformation in time to prevent further spread of rumors

    Are We Ready to Embrace Generative AI for Software Q&A?

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    Stack Overflow, the world's largest software Q&A (SQA) website, is facing a significant traffic drop due to the emergence of generative AI techniques. ChatGPT is banned by Stack Overflow after only 6 days from its release. The main reason provided by the official Stack Overflow is that the answers generated by ChatGPT are of low quality. To verify this, we conduct a comparative evaluation of human-written and ChatGPT-generated answers. Our methodology employs both automatic comparison and a manual study. Our results suggest that human-written and ChatGPT-generated answers are semantically similar, however, human-written answers outperform ChatGPT-generated ones consistently across multiple aspects, specifically by 10% on the overall score. We release the data, analysis scripts, and detailed results at https://anonymous.4open.science/r/GAI4SQA-FD5C.Comment: Accepted by the New Ideas and Emerging Results (NIER) track at The IEEE/ACM Automated Software Engineering (ASE) Conferenc
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