5,225 research outputs found

    Observation of higher-order topological states on a quantum computer

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    Programmable quantum simulators such as superconducting quantum processors and ultracold atomic lattices represent rapidly developing emergent technology that may one day qualitatively outperform existing classical computers. Yet, apart from a few breakthroughs, the range of viable computational applications with current-day noisy intermediate-scale quantum (NISQ) devices is still significantly limited by gate errors, quantum decoherence, and the number of high-quality qubits. In this work, we develop an approach that places NISQ hardware as a particularly suitable platform for simulating multi-dimensional condensed matter systems, including lattices beyond three dimensions which are difficult to realize or probe in other settings. By fully exploiting the exponentially large Hilbert space of a quantum chain, we encoded a high-dimensional model in terms of non-local many-body interactions that can further be systematically transcribed into quantum gates. We demonstrate the power of our approach by realizing, on IBM transmon-based quantum computers, higher-order topological states in up to four dimensions, which are exotic phases that have never been realized in any quantum setting. With the aid of in-house circuit compression and error mitigation techniques, we measured the topological state dynamics and their protected mid-gap spectra to a high degree of accuracy, as benchmarked by reference exact diagonalization data. The time and memory needed with our approach scale favorably with system size and dimensionality compared to exact diagonalization on classical computers.Comment: 21 pages, 8 figures in main text; 4 pages, 2 tables in supplementary informatio

    An Analogue Front-End System with a Low-Power On-Chip Filter and ADC for Portable ECG Detection Devices

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    Medical diagnostic instruments can be made into portable devices for the purpose of home care, such as the diagnosis of heart disease. These assisting devices are not only used to monitor patients but are also beneficial as handy and convenient medical instruments. Hence, for reasons of both portability and durability, designers should reduce the power consumption of assistant devices as much as possible to extend their battery lifetime. However, achieving the low power requirement of the ECG sensing and the processing board for the ECG with commercial discrete components (A21-0003) is difficult because the low power consumer electronics for ECG acquisition systems are not yet available. With the help of the integrated circuit technology, the power-saving requirement of portable and durable equipment gives circuit designers the impetus to reduce the power consumption of analogue front-end circuits in ECG acquisition systems. In addition, the analogue front-end circuits, which are the interface between physical signals and the digital processor, must be operated at a low-supply voltage to be integrated into the low-voltage system-on-a-chip (SOC) system (Eshraghian, 2006). Therefore, the chapter will present two design examples of low-voltage (1 V) and low-power (<1 ļ­W) on-chip circuits including a low-pass filter (LPF) and an analogue-to-digital converter (ADC) to demonstrate the possibility of developing the low-voltage low-power ECG acquisition SO

    Increasing ā€œObject-Substitutionā€ Symbolic Play in Young Children with Autism Spectrum Disorders

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    Children with autism spectrum disorders (ASD) may not develop symbolic play skills so such skills need to be taught specifically. We report an experiment regarding a procedure targeting ā€œobject-substitutionā€ symbolic play skills. The ā€œobject-substitutionā€ symbolic play behavior occurred when the child labeled a common object with the name of a substitute and used the object to perform a play action (e.g., As she put a bowl on her head, she called it a hat). A multiple probe across behaviors design was employed with five children (four boys and one girl, aged 3 to 6) with ASD. All children had verbal communication and demonstrated functional play and generalized imitation, but no symbolic play skills prior to the study. The instruction consisted of intraverbal training, picture prompts, and modeling of play actions. All children demonstrated object-substitution symbolic play skills after the instruction. The occurrences of response generalization were also discussed

    An Emotional Skills Intervention for Elementary Children with Autism in China: A Pilot Study

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    The purpose of this pilot study was to examine the effects of an emotional skills intervention on behavioral and emotional competence, as well as on communication for children with autism in China. Eight children (seven boys and one girl), aged 7 to 8, participated in this study. We used a pre and posttest group design. The intervention consisted of 10 group sessions and four individual sessions. Each group session had two or three children. The intervention curriculum consisted of emotion recognition, emotion recognition within context, self-expression of emotions, seeking help when encountering problems, and techniques for emotion regulation. Results indicated that the intervention significantly improved childrenā€™s emotional skills, behavioral and emotional competence, and communication. The potential implications of this study for elementary children with autism in China are also discussed

    User Satisfaction with Virtual Social Community: The Case of Bulletin Board Systems

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    Building upon expectation confirmation theory and elaboration likelihood model, this study proposed and empirically tested a research model of user satisfaction with virtual social community. An online questionnaire was posted in the Bulletin Board Systems of a local university in Mainland China. A total of 240 online questionnaires were collected, and the data was analyzed using partial least squares. The research model provided over 70 percent of variance explained in user satisfaction with virtual social community. Relevance and comprehensiveness of messages, and disconfirmations of relevance and accuracy of messages are found statistically significant. The dimensions of perceived source credibility (including source expertise and source trustworthiness) are not found significant, but their disconfirmations are found statistically significant. Implications of this study are noteworthy for both researchers and practitioners

    Lack of spontaneous ocular neovascularization and attenuated laser-induced choroidal neovascularization in IGF-I overexpression transgenic mice

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    Robust IGF-I overexpression induces ocular angiogenesis in mice. To investigate the effect of subtle IGF-I overexpression, we examined the ocular phenotype of IGF-II promoter-driven IGF-I transgenic mice. Despite 2.5-fold elevation of IGF-I mRNA in the retina and 29 and 52% increase of IGF-I protein in the retina and aqueous humor, respectively, no ocular abnormality was observed in these transgenics. This was correlated with unaltered VEGF mRNA levels in the transgenic retina. The transgene was also associated with an attenuated laser-induced choroidal neovascularization. Differential expression levels and pattern of IGF-I gene may underlie the different retinal phenotypes in different transgenic lines

    Understanding Status Update in Microblog: A Perspective on Media Needs

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    Microblog has grown popularly as a seminal social medium for timely information seeking and sharing. However, the reason why individuals update real-time information in microblog has not been well understood, and empirical research to address this specific information behavior is hardly available. As a felt urge can be conceptualized as a precursor of real-time updating in the microblog, we attempt to capture the underlying mechanism in causing this less reflective behavior urge. We apply the media needs theory to investigate how the individualsā€™ media needs spark their urge to update personal status in the microblog. In particular, we conceptualize the cognitive needs as related to information uniqueness, personal integrative needs as related to connectivity, social integrative needs as a unidirectional relationship, affective needs as positive emotions and tension release needs as negative emotions. An online survey was employed to validate the proposed model within 523 microblog users in China. The results suggest that the usersā€™ behavior urge is significantly influenced by information uniqueness, connectivity, unidirectional relationship and positive emotions. Furthermore, among the five media needs, the affective and social integrative related factors strongly determine the personal real-time status update in microblog. The theoretical and practical implications are discussed in this paper

    Comparative Investigations of Social Context-Dependent Dominance in Captive Chimpanzees (Pan troglodytes) and Wild Tibetan Macaques (Macaca thibetana)

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    Theoretical definitions of dominance, how dominance is structured and organized in nature, and how dominance is measured have varied as investigators seek to classify and organize social systems in gregarious species. Given the variability in behavioral measures and statistical methods used to derive dominance rankings, we conducted a comparative analysis of dominance using existing statistical techniques to analyze dominance ranks, social context-dependent dominance structures, the reliability of statistical analyses, and rank predictability of dominance structures on other social behaviors. We investigated these topics using behavioral data from captive chimpanzees (Pan troglodytes) and wild Tibetan macaques (Macaca thibetana). We used a combination of all-occurrence, focal-animal, and instantaneous scan sampling to collect social, agonistic, and associative data from both species. We analyzed our data to derive dominance ranks, test rank reliability, and assess cross-context predictability using various statistical analyses. Our results indicate context-dependent dominance and individual social roles in the captive chimpanzee group, one broadly defined dominance structure in the Tibetan macaque group, and high within-context analysis reliability but little cross-context predictability. Overall, we suggest this approach is preferable over investigations of dominance where only a few behavioral metrics and statistical analyses are utilized with little consideration of rank reliability or cross-context predictability

    Bee venom attenuates neuroinflammatory events and extends survival in amyotrophic lateral sclerosis models

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    <p>Abstract</p> <p>Background</p> <p>Amyotrophic lateral sclerosis (ALS) is a disease affecting the central nervous system that is either sporadic or familial origin and causing the death of motor neurons. One of the genetic factors contributing to the etiology of ALS is mutant SOD1 (mtSOD1), which induces vulnerability of motor neurons through protein misfolding, mitochondrial dysfunction, oxidative damage, cytoskeletal abnormalities, defective axonal transport, glutamate excitotoxicity, inadequate growth factor signaling, and neuroinflammation. Bee venom has been used in the practice of Oriental medicine and evidence from the literature indicates that BV plays an anti-inflammatory or anti-nociceptive role against inflammatory reactions associated with arthritis and other inflammatory diseases. The purpose of the present study was to determine whether bee venom suppresses motor neuron loss and microglial cell activation in hSOD1<sup>G93A </sup>mutant mice.</p> <p>Methods</p> <p>Bee venom (BV) was bilaterally injected (subcutaneously) into a 14-week-old (98 day old) male hSOD1<sup>G93A </sup>animal model at the Zusanli (ST36) acupoint, which is known to mediate an anti-inflammatory effect. For measurement of motor activity, rotarod test was performed and survival statistics were analyzed by Kaplan-Meier survival curves. The effects of BV treatment on anti-neuroinflammation of hSOD1<sup>G93A </sup>mice were assessed via immunoreactions using Iba 1 as a microglia marker and TNF-Ī± antibody. Activation of ERK, Akt, p38 MAP Kinase (MAPK), and caspase 3 proteins was evaluated by western blotting.</p> <p>Results</p> <p>BV-treated mutant hSOD1 transgenic mice showed a decrease in the expression levels of microglia marker and phospho-p38 MAPK in the spinal cord and brainstem. Interestingly, treatment of BV in symptomatic ALS animals improved motor activity and the median survival of the BV-treated group (139 Ā± 3.5 days) was 18% greater than control group (117 Ā± 3.1 days). Furthermore, we found that BV suppressed caspase-3 activity and blocked the defects of mitochondrial structure and cristae morphology in the lumbar spinal cord of hSOD1<sup>G93A </sup>mice at the symptomatic stage.</p> <p>Conclusion</p> <p>From these findings, our research suggests BV could be a potential therapeutic agent for anti-neuroinflammatory effects in an animal model of ALS.</p

    CWCL: Cross-Modal Transfer with Continuously Weighted Contrastive Loss

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    This paper considers contrastive training for cross-modal 0-shot transfer wherein a pre-trained model in one modality is used for representation learning in another domain using pairwise data. The learnt models in the latter domain can then be used for a diverse set of tasks in a zero-shot way, similar to ``Contrastive Language-Image Pre-training (CLIP)'' and ``Locked-image Tuning (LiT)'' that have recently gained considerable attention. Most existing works for cross-modal representation alignment (including CLIP and LiT) use the standard contrastive training objective, which employs sets of positive and negative examples to align similar and repel dissimilar training data samples. However, similarity amongst training examples has a more continuous nature, thus calling for a more `non-binary' treatment. To address this, we propose a novel loss function called Continuously Weighted Contrastive Loss (CWCL) that employs a continuous measure of similarity. With CWCL, we seek to align the embedding space of one modality with another. Owing to the continuous nature of similarity in the proposed loss function, these models outperform existing methods for 0-shot transfer across multiple models, datasets and modalities. Particularly, we consider the modality pairs of image-text and speech-text and our models achieve 5-8% (absolute) improvement over previous state-of-the-art methods in 0-shot image classification and 20-30% (absolute) improvement in 0-shot speech-to-intent classification and keyword classification.Comment: Accepted to Neural Information Processing Systems (NeurIPS) 2023 conferenc
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