147 research outputs found

    Protein-mediated DNA Loop Formation and Breakdown in a Fluctuating Environment

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    Living cells provide a fluctuating, out-of-equilibrium environment in which genes must coordinate cellular function. DNA looping, which is a common means of regulating transcription, is very much a stochastic process; the loops arise from the thermal motion of the DNA and other fluctuations of the cellular environment. We present single-molecule measurements of DNA loop formation and breakdown when an artificial fluctuating force, applied to mimic a fluctuating cellular environment, is imposed on the DNA. We show that loop formation is greatly enhanced in the presence of noise of only a fraction of kBTk_B T, yet find that hypothetical regulatory schemes that employ mechanical tension in the DNA--as a sensitive switch to control transcription--can be surprisingly robust due to a fortuitous cancellation of noise effects

    Cross-Power Spectrum and Its Application on Window Functions in the WMAP data

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    Cross-power spectrum is a quadratic estimator between two maps that can provide unbiased estimate of the underlying power spectrum of the correlated signals, which is therefore used for extracting the power spectrum in the WMAP data. In this paper we discuss the limit of cross-power spectrum and derive the residual from uncorrelated signal, which is the source of error in power spectrum extraction. We employ the estimator to extract window functions by crossing pairs of extragalactic point sources. We desmonstrate its usefulness in WMAP Difference Assembly maps where the window functions are measured via Jupiter and then extract the window functions of the 5 WMAP frequency band maps.Comment: added the part of applying cross power spectrum on WMAP DA maps and frequency band maps and submitted to Ap

    Near-Field Angular Orientation of Biological Materials

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    Patient-controlled epidural Levobupicvacaine with or without Fentanyl for post-cesarean section pain relief

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    Purpose. The purpose of this study was to compare the analgesic properties of levobupivacaine with or without fentanyl for patient-controlled epidural analgesia after Cesarean section in a randomized, double-blinded study. Methods. We enrolled American Society of Anesthesiologists class I/II, full-term pregnant women at National Taiwan University Hospital who received patient-controlled epidural analgesia after Cesarean section between 2009 and 2010. Eighty women were randomly assigned into two groups. In group A, the 40 subjects received drug solutions made of 0.6 mg/ml levobupivacaine plus 2 mcg/ml fentanyl, and in group B the 40 subjects received 1 mg/ml levobupivacaine. Maintenance was self-administered boluses and a continuous background infusion. Results. There were no significant differences in the resting and dynamic pain scales and total volume of drug used between the two groups. Patient satisfaction was good in both groups. Conclusion. Our study showed that pure epidural levobupivacaine can provide comparative analgesic properties to the levobupivacaine-fentanyl combination after Cesarean section. Pure levobupivacaine may serve as an alternative pain control regimen to avoid opioid-related adverse events in parturients

    Direct measurement of the angular power spectrum of cosmic microwave background temperature anisotropies in the WMAP Data

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    Angular power spectrum of the cosmic microwave background (CMB) temperature anisotropies is one of the most important on characteristics of the Universe such as its geometry and total density. Using flat sky approximation and Fourier analysis, we estimate the angular power spectrum from an ensemble of least foreground-contaminated square patches from WMAP W and V frequency band map. This method circumvents the issue of foreground cleaning and that of breaking orthogonality in spherical harmonic analysis due to masking out the bright Galactic plane region, thereby rendering a direct measurement of the angular power spectrum. We test and confirm Gaussian statistical characteristic of the selected patches, from which the first and second acoustic peak of the power spectrum are reproduced, and the third peak is clearly visible albeit with some noise residual at the tail.Comment: 13 pages, 5 figure

    Validation of a Chinese version of disease specific quality of life scale (HFS-36) for hemifacial spasm in Taiwan

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    <p>Abstract</p> <p>Background and object</p> <p>There was no Chinese questionnaire to evaluate the health-related quality of life (HRQoL) in patients with hemifacial spasm (HFS). In this study, we aimed to validate a new disease-specific HRQoL scale for HFS (HFS-36) in Chinese version, and compared it to SF-36, a generic HRQoL scale.</p> <p>Patients and Methods</p> <p>The HFS-36 Chinese version was modified from English version of HFS-30, including subscales of mobility, activities of daily living (ADL), emotional well-being, stigma, social support, cognition, bodily discomfort, and communication. All the items were scored on the 5-point scales, ranging from 0(never) to 4(always). Patients with HFS were asked to answer HFS-36 and SF-36 questionnaires on the same day before and 6-8 weeks after Botulinum toxin (BTX) injections, respectively. The reliability and validity of HFS-36 scale were evaluated statistically.</p> <p>Results</p> <p>Totally, 103 patients (68 females; 35 males) were recruited in this study, with a mean age of 57.6 ± 11.5 years and a mean duration of HFS for 7.6 ± 5.8 years. The intra-class correlation (ICC) and Cronbach's α were over 0.7 in the majority of items. HFS-36 showed a good correlation to HFS severity before BTX treatment and a significant improvement of subscale scoring after BTX treatment. HFS-36 also had a significant correlation to the mental health of SF-36.</p> <p>Conclusions</p> <p>The Chinese version of HFS-36 demonstrated a good reliability and validity in subscales of motility, ADL, emotion well-being, stigma and bodily discomfort. The HRQoL was significantly improved after BTX treatment assessed by HFS-36 or SF-36. Compared to SF-36, HFS-36 scale was more sensitive and specific to evaluate the HRQoL in HFS.</p

    A QoS-Guaranteed Coverage Precedence Routing Algorithm for Wireless Sensor Networks

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    For mission-critical applications of wireless sensor networks (WSNs) involving extensive battlefield surveillance, medical healthcare, etc., it is crucial to have low-power, new protocols, methodologies and structures for transferring data and information in a network with full sensing coverage capability for an extended working period. The upmost mission is to ensure that the network is fully functional providing reliable transmission of the sensed data without the risk of data loss. WSNs have been applied to various types of mission-critical applications. Coverage preservation is one of the most essential functions to guarantee quality of service (QoS) in WSNs. However, a tradeoff exists between sensing coverage and network lifetime due to the limited energy supplies of sensor nodes. In this study, we propose a routing protocol to accommodate both energy-balance and coverage-preservation for sensor nodes in WSNs. The energy consumption for radio transmissions and the residual energy over the network are taken into account when the proposed protocol determines an energy-efficient route for a packet. The simulation results demonstrate that the proposed protocol is able to increase the duration of the on-duty network and provide up to 98.3% and 85.7% of extra service time with 100% sensing coverage ratio comparing with LEACH and the LEACH-Coverage-U protocols, respectively
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