441 research outputs found

    A Clustering-Based Algorithm for Data Reduction

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    Finding an efficient data reduction method for large-scale problems is an imperative task. In this paper, we propose a similarity-based self-constructing fuzzy clustering algorithm to do the sampling of instances for the classification task. Instances that are similar to each other are grouped into the same cluster. When all the instances have been fed in, a number of clusters are formed automatically. Then the statistical mean for each cluster will be regarded as representing all the instances covered in the cluster. This approach has two advantages. One is that it can be faster and uses less storage memory. The other is that the number of new representative instances need not be specified in advance by the user. Experiments on real-world datasets show that our method can run faster and obtain better reduction rate than other methods

    A simplified Bcl-2 network model reveals quantitative determinants of cell-to-cell variation in sensitivity to anti-mitotic chemotherapeutics

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    Anti-mitotic drugs constitute a major class of cytotoxic chemotherapeutics used in the clinic, killing cancer cells by inducing prolonged mitotic arrest that activates intrinsic apoptosis. Anti-mitotics-induced apoptosis is known to involve degradation of anti-apoptotic Bcl-2 proteins during mitotic arrest; however, it remains unclear how this mechanism accounts for significant heterogeneity observed in the cell death responses both within and between cancer cell types. To unravel quantitative determinants underlying variability in anti-mitotic drug response, we constructed a single-cell dynamical Bcl-2 network model describing cell death control during mitotic arrest, and constrained the model using experimental data from four representative cancer cell lines. The modeling analysis revealed that, given a variable, slowly accumulating pro-apoptotic signal arising from anti-apoptotic protein degradation, generation of a switch-like apoptotic response requires formation of pro-apoptotic Bak complexes with hundreds of subunits, suggesting a crucial role for high-order cooperativity. Moreover, we found that cell-type variation in susceptibility to drug-induced mitotic death arises primarily from differential expression of the anti-apoptotic proteins Bcl-xL and Mcl-1 relative to Bak. The dependence of anti-mitotic drug response on Bcl-xL and Mcl-1 that we derived from the modeling analysis provides a quantitative measure to predict sensitivity of distinct cancer cells to anti-mitotic drug treatment

    A simplified Bcl-2 network model reveals quantitative determinants of cell-to-cell variation in sensitivity to anti-mitotic chemotherapeutics

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    Anti-mitotic drugs constitute a major class of cytotoxic chemotherapeutics used in the clinic, killing cancer cells by inducing prolonged mitotic arrest that activates intrinsic apoptosis. Anti-mitotics-induced apoptosis is known to involve degradation of anti-apoptotic Bcl-2 proteins during mitotic arrest; however, it remains unclear how this mechanism accounts for significant heterogeneity observed in the cell death responses both within and between cancer cell types. To unravel quantitative determinants underlying variability in anti-mitotic drug response, we constructed a single-cell dynamical Bcl-2 network model describing cell death control during mitotic arrest, and constrained the model using experimental data from four representative cancer cell lines. The modeling analysis revealed that, given a variable, slowly accumulating pro-apoptotic signal arising from anti-apoptotic protein degradation, generation of a switch-like apoptotic response requires formation of pro-apoptotic Bak complexes with hundreds of subunits, suggesting a crucial role for high-order cooperativity. Moreover, we found that cell-type variation in susceptibility to drug-induced mitotic death arises primarily from differential expression of the anti-apoptotic proteins Bcl-xL and Mcl-1 relative to Bak. The dependence of anti-mitotic drug response on Bcl-xL and Mcl-1 that we derived from the modeling analysis provides a quantitative measure to predict sensitivity of distinct cancer cells to anti-mitotic drug treatment

    Quantum delayed-choice experiment with a beam splitter in a quantum superposition

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    A quantum system can behave as a wave or as a particle, depending on the experimental arrangement. When for example measuring a photon using a Mach-Zehnder interferometer, the photon acts as a wave if the second beam-splitter is inserted, but as a particle if this beam-splitter is omitted. The decision of whether or not to insert this beam-splitter can be made after the photon has entered the interferometer, as in Wheeler's famous delayed-choice thought experiment. In recent quantum versions of this experiment, this decision is controlled by a quantum ancilla, while the beam splitter is itself still a classical object. Here we propose and realize a variant of the quantum delayed-choice experiment. We configure a superconducting quantum circuit as a Ramsey interferometer, where the element that acts as the first beam-splitter can be put in a quantum superposition of its active and inactive states, as verified by the negative values of its Wigner function. We show that this enables the wave and particle aspects of the system to be observed with a single setup, without involving an ancilla that is not itself a part of the interferometer. We also study the transition of this quantum beam-splitter from a quantum to a classical object due to decoherence, as observed by monitoring the interferometer output.Comment: 9 pages, 7 figures, Accepted by Physical Review Letter

    9-(Dimethoxy­meth­yl)anthracene

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    In the title compound, C17H16O2, a dimethyl acetal of 9-anthraldehyde, the anthracene skeleton is planar and the two meth­oxy groups attached to the C atom at position 9 of the aromatic ring system are located above and below the ring system

    The diagnostic value of elastography and ultrasound contrast in papillary thyroid microcarcinoma

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    目的 评估弹性成像与超声造影(CEUS)两种检查技术对鉴别诊断甲状腺微小乳头状癌(TMC)的价值。方法  对常规超声检测出且定性困难的73例80个甲状腺微小结节进行弹性成像及CEUS检查,所有结节均经手术病理证实。比较两种检查方法的准确性。结果 80个结节中CEUS诊断正确率为85.0%(68/80),其中6例TMC误诊为良性病变,6例良性结节误诊为TMC;弹性成像5分法诊断正确率为92.5%(74/80),其中3例TMC误诊为良性结节,3例良性结节误诊为TMC。性成像诊断甲状腺微小癌的敏感性94.0%,特异性90.0%,准确性92.5%;CEUS诊断甲状腺微小癌的敏感性88.0%,特异性80.0%,准确性85.0%。结论 CEUS和弹性成像对于诊断TMC方面均有价值,但弹性评分≥3作为诊断TMC的敏感性、特异性及准确性均高于CEUS。Objective: To assess the value of elastic imaging and CEUS two inspection techniques for differential diagnosis of thyroid papillary carcinoma (TMC). Method: To do elastic imaging and CEUS checks to 73 cases of 80 thyroid nodules which was tested by conventional ultrasonic and difficult to quantify. All nodules were confirmed by surgery and pathologic examination. Comparing the accuracy of both detection methods. Result: Of the 80 nodules, the accuracy of CEUS diagnosis was 85.0%(68/80),  of which 6 cases were misdiagnosed as benign lesions, and 6cases of benign nodules were misdiagnosed as TMC: the accuracy of 5-point scale criteria of elastography was 92.5%(74/80), of which 3 TMC were misdiagnosed as benign nodules: and 3 benign nodules were misdiagnosed as TMC. The application of elastography in the diagnosis of thyroid microcarcinoma displayed a sensitivity of 94.0%, a specificity of 90.0% and an accuracy of 92.5%. Elastography detection was more advantagerous than CEUS in the diagnosis of thyroid microcarcinoma, and compared to CEUS , the differences were statistically significant(P <0.05).Conclusion: Elastography and Ultrasound Contrast have highly practical value to diagnosis of TMC.  The sensitivity specificity and accuracy of using elastic score ≥3 as criteria of diagnosis of TMC was higher than that of CEUS

    Global Epidemiological Features of Human Monkeypox Cases and Their Associations With Social-Economic Level and International Travel Arrivals: A Systematic Review and Ecological Study

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    Objectives: We aimed to evaluate global epidemiological features of human monkeypox (mpox) cases and their associations with social-economic level and international travel arrivals.Methods: We estimated the pooled value by random-effects models. Then, we conducted an ecological study to evaluate the relationship of confirmed cases with social-economic indices and international travel arrivals using correlation analyses.Results: The average age (2022: 35.52, 95% CI [28.09, 42.94] vs. before 2022: 18.38, 95% CI [14.74, 22.02]) and comorbidity rate (2022: 15.7%, 95% CI [8.9%, 22.4%] vs. before 2022: 14.9%, 95% CI [8.5%, 21.3%]) of mpox cases in the 2022 human mpox outbreak were significantly higher than those of cases before 2022. During the 2022 mpox outbreak, the proportion of men who have sex with men (MSM) was high (79.8%, 95% CI [65.5%, 94.2%]). The number of confirmed mpox cases in 2022 significantly correlated with high social-economic levels and international travel arrivals (all p < 0.05).Conclusion: Our findings highlighted the importance of early surveillance and timely detection in high-risk populations, including older people, MSM, and travelers, which is crucial to curb the wide transmission of mpox

    Deja Vu: Contextual Sparsity for Efficient LLMs at Inference Time

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    Large language models (LLMs) with hundreds of billions of parameters have sparked a new wave of exciting AI applications. However, they are computationally expensive at inference time. Sparsity is a natural approach to reduce this cost, but existing methods either require costly retraining, have to forgo LLM's in-context learning ability, or do not yield wall-clock time speedup on modern hardware. We hypothesize that contextual sparsity, which are small, input-dependent sets of attention heads and MLP parameters that yield approximately the same output as the dense model for a given input, can address these issues. We show that contextual sparsity exists, that it can be accurately predicted, and that we can exploit it to speed up LLM inference in wall-clock time without compromising LLM's quality or in-context learning ability. Based on these insights, we propose DejaVu, a system that uses a low-cost algorithm to predict contextual sparsity on the fly given inputs to each layer, along with an asynchronous and hardware-aware implementation that speeds up LLM inference. We validate that DejaVu can reduce the inference latency of OPT-175B by over 2X compared to the state-of-the-art FasterTransformer, and over 6X compared to the widely used Hugging Face implementation, without compromising model quality. The code is available at https://github.com/FMInference/DejaVu

    Effects of ambient temperature and relative humidity on preterm birth during early pregnancy and before parturition in China from 2010 to 2018: a population-based large-sample cohort study

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    BackgroundThe progression of global warming and increase in instances of extreme weather have received considerable attention. We conducted a cohort study on women of childbearing age in Yunnan Province, examined the association between ambient temperature and humidity on preterm birth and evaluated the effects of extreme weather during early pregnancy and before parturition on preterm birth.MethodsWe conducted a population-based cohort study on women of childbearing age 18–49 years who participated in National Free Preconception Health Examination Project (NFPHEP) in Yunnan Province from January 1, 2010, to December 31, 2018. Meteorological data, namely daily average temperature (°C) and daily average relative humidity (%), were obtained from China National Meteorological Information Center. Four exposure windows were explored: 1 week of pregnancy, 4 weeks of pregnancy, 4 weeks before delivery, and 1 week before delivery. We used a Cox proportional hazards model and adjusted the potential risk factors for preterm birth to obtain the effects of exposure to temperature and humidity on preterm birth among the stages of pregnancy.ResultsAt 1 week of pregnancy and at 4 weeks of pregnancy, the association between temperature and preterm birth was U-shaped. The correlation between relative humidity and the risk of preterm birth was n-type at 1 week of pregnancy. The correlation between preterm birth and temperature and relative humidity at 4 weeks before delivery and at 1 week before delivery is J-shaped. Low temperature and low humidity were protective factors against preterm birth, whereas high temperature and high humidity were risk factors for preterm birth.The effects of high temperature and extremely high temperature were the strongest at 4 weeks before delivery, with HRs of 1.417 (95% CI: 1.362–1.474) and 1.627 (95% CI: 1.537–1.722), respectively. The effects of extremely low humidity and low humidity were strongest at 1 week before delivery, with HRs of 0.681 (95% CI: 0.609–0.761) and 0.696 (95% CI: 0.627–0.771), respectively.ConclusionTemperature and relative humidity affect preterm birth differently for each pregnancy stage. The effects of meteorological factors on pregnancy outcomes such as premature birth should not be ignored

    A Diffie-Hellman quantum session key establishment protocol without entanglement

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    In 2016 and 2017, Shi et al first proposed two protocols for the communication parties to establish a quantum session key. Both work by rotating the angle of one communicator’s private key on the other party\u27s quantum public key. In their approaches, the session key shared by each pair of communicators is fixed after the key generation phase. Thereafter, the key used in each communication does not change, but for security consideration, the session key should be changed in every time usage. In other words, those key agreement protocols do not satisfy the requirement of key security. In view of this, this paper develops a quantum session key establishment based on the Diffie-Hermann style key exchange to produce different quantum session keys in each communications. After analysis, we confirm that our method can resist various attacks and is therefore secure
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