584 research outputs found

    A Triangular Personalized Recommendation Algorithm for Improving Diversity

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    Recommendation systems are used when searching online databases. As such they are very important tools because they provide users with predictions of the outcomes of different potential choices and help users to avoid information overload. They can be used on e-commerce websites and have attracted considerable attention in the scientific community. To date, many personalized recommendation algorithms have aimed to improve recommendation accuracy from the perspective of vertex similarities, such as collaborative filtering and mass diffusion. However, diversity is also an important evaluation index in the recommendation algorithm. In order to study both the accuracy and diversity of a recommendation algorithm at the same time, this study introduced a “third dimension” to the commonly used user/product two-dimensional recommendation, and a recommendation algorithm is proposed that is based on a triangular area (TR algorithm). The proposed algorithm combines the Markov chain and collaborative filtering method to make recommendations for users by building a triangle model, making use of the triangulated area. Additionally, recommendation algorithms based on a triangulated area are parameter-free and are more suitable for applications in real environments. Furthermore, the experimental results showed that the TR algorithm had better performance on diversity and novelty for real datasets of MovieLens-100K and MovieLens-1M than did the other benchmark methods

    VlincRNAs controlled by retroviral elements are a hallmark of pluripotency and cancer

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    Background The function of the non-coding portion of the human genome remains one of the most important questions of our time. Its vast complexity is exemplified by the recent identification of an unusual and notable component of the transcriptome - very long intergenic non-coding RNAs, termed vlincRNAs. Results Here we identify 2,147 vlincRNAs covering 10 percent of our genome. We show they are present not only in cancerous cells, but also in primary cells and normal human tissues, and are controlled by canonical promoters. Furthermore, vlincRNA promoters frequently originate from within endogenous retroviral sequences. Strikingly, the number of vlincRNAs expressed from endogenous retroviral promoters strongly correlates with pluripotency or the degree of malignant transformation. These results suggest a previously unknown connection between the pluripotent state and cancer via retroviral repeat-driven expression of vlincRNAs. Finally, we show that vlincRNAs can be syntenically conserved in humans and mouse and their depletion using RNAi can cause apoptosis in cancerous cells. Conclusions These intriguing observations suggest that vlincRNAs could create a framework that combines many existing short ESTs and lincRNAs into a landscape of very long transcripts functioning in the regulation of gene expression in the nucleus. Certain types of vlincRNAs participate at specific stages of normal development and, based on analysis of a limited set of cancerous and primary cell lines, they appear to be co-opted by cancer-associated transcriptional programs. This provides additional understanding of transcriptome regulation during the malignant state, and could lead to additional targets and options for its reversal

    Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

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    Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≀0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

    Ultralight vector dark matter search using data from the KAGRA O3GK run

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    Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

    Observation of gravitational waves from the coalescence of a 2.5−4.5 M⊙ compact object and a neutron star

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    Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

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    Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

    Age and gender differences in expressive flexibility and the association with depressive symptoms in adolescents

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    ObjectiveThis study investigated age and gender differences in the ability to flexibly enhance and suppress facial expressions according to situational demands, known as expressive flexibility (EF), as well as its relationship with depressive symptoms in adolescents.MethodsThe participants included 766 Chinese high school students aged between 12 and 18 years (mean age = 14.96 years, standard deviation = 2.04; 52.2% female). Data on EF and depressive symptoms were collected using self-report questionnaires.ResultsGirls scored higher on enhancement abilities than boys, but with no significant gender difference in suppression abilities. There were also no significant age-related differences in enhancement and suppression abilities. Only enhancement ability was negatively associated with depressive symptoms.ConclusionThe development of EF abilities was stable among adolescents, with varying effects in terms of gender, and the importance of EF and enhancement abilities in reducing depressive symptoms in adolescents was highlighted

    Emotion regulation as a mediator on the relationship between emotional awareness and depression in elementary school students

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    As a cognitive skill, emotional awareness plays a fundamental role in emotional intelligence and significant effect on the development of individuals’ social adaptation. However, the role of emotional awareness in children’s social adaptation, especially emotional development, remains unclear, the current study sought to determine the significant influence of emotional awareness in children’s emotional development. By using cross-sectional and longitudinal study designs, the current study explored the relationship between emotional awareness and children’s depression, as well as the mediation effect of emotion regulation on this relationship. The sample comprised 166 Chinese elementary school students (89 girls and 77 boys) ranging from 8 to 12 years old. After adjusting for demographic variables (gender, grade, etc.), the results showed that children with high emotional awareness were less likely to adopt expressive suppression as an emotion regulation strategy and had lower depression levels currently and in the future. In contrast, children with low emotional awareness were more likely to use suppression strategies and showed higher depression levels. Thus, the results indicated that emotional awareness could predict children’s current and future depression status. Meanwhile, emotional regulation strategies are an important mediating variable explaining the relationship between emotional awareness and children’s depression. Implications and limitations were also discussed

    Can Farmers’ Satisfaction with Green Production Policies Be Explained by Policy Structure and Policy Implementation? Evidence from China

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    The implementation of green production policies (GPPs) is an important guarantee to improve the utilization of agricultural resources and adapt to climate change and plays an important role in supporting and guiding farmers. The overall goal of this study is to explore the mechanisms of the impacts of policy structure and implementation on the satisfaction of farmers with GPPs. Data analysis was based on 1180 observations collected from a field survey in Anhui Province, China, in 2021. The results revealed that the satisfaction of farmers with GPPs is not high. Policy structure affects the satisfaction of farmers with GPPs, and there are differences in the impacts of agricultural service, financial, technical, subsidy, and supervision policies. The results also showed that a positive evaluation of policy implementation by farmers can significantly improve their satisfaction with GPPs, and there are differences in the effectiveness of evaluating the support intensity, degree of promotion, policy sustainability, and implementation effect. Further analysis revealed that the impact of policy structure on the satisfaction of farmers with GPPs is transmitted through policy implementation evaluation. The impacts of policy structure and policy implementation on the satisfaction of farmers with GPPs are heterogeneous in terms of gender, age, and education. Finally, some policy recommendations are proposed to construct GPPs for farmers across the entire industrial chain, increase policy promotion efforts, ensure the sustainability of policy formulation and implementation, and consider farmers’ subjective evaluations of policy implementation effects. The results of this study and the related policy recommendations can provide support for the formulation and optimization of agricultural GPPs in China and other countries

    Age-Related Differences in the Late Positive Potential during Emotion Regulation between Adolescents and Adults

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    Abstract The late positive potential (LPP) has been well documented in predicting the effect of emotion regulation in previous developmental literature. However, few studies have examined age-related changes in emotion regulation from adolescence to adulthood using this biomarker. To test this, Reactivity and Regulation-Image Task was used to test 18 young adolescents and 22 adults to examine the modulation of LPP during emotion regulation. Results revealed that (a) on the behavioral level, adults reported higher intensity of emotional experience than adolescents when they were asked to use up-regulation. Down-regulation showed no age effect for self-reported rating; (b) adolescents showed higher amplitudes of LPP than adults when using different regulatory strategies in all windows; (c) In late time window, regulation effect was larger when using up-regulation strategy than down-regulation strategy for adolescents, while the difference between the two strategies was negligible for adults. (d) In early time window, reactivity effect was larger in negative conditions than in positive conditions for adolescents, while the difference between the two conditions was again negligible for adults. Differences in the amplitudes and time courses of LPP during emotion regulation between adolescents and adults suggested that age-related changes in emotion regulation may occur during adolescence
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