16,992 research outputs found

    Decision support for personalized cloud service selection through multi-attribute trustworthiness evaluation

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    Facing a customer market with rising demands for cloud service dependability and security, trustworthiness evaluation techniques are becoming essential to cloud service selection. But these methods are out of the reach to most customers as they require considerable expertise. Additionally, since the cloud service evaluation is often a costly and time-consuming process, it is not practical to measure trustworthy attributes of all candidates for each customer. Many existing models cannot easily deal with cloud services which have very few historical records. In this paper, we propose a novel service selection approach in which the missing value prediction and the multi-attribute trustworthiness evaluation are commonly taken into account. By simply collecting limited historical records, the current approach is able to support the personalized trustworthy service selection. The experimental results also show that our approach performs much better than other competing ones with respect to the customer preference and expectation in trustworthiness assessment. © 2014 Ding et al

    In vivo manganese-enhanced MRI and diffusion tensor imaging of developing and impaired visual brains

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    This study explored the feasibility of high-resolution Mn-enhanced MRI (MEMRI) and diffusion tensor imaging (DTI) for in vivo assessments of the development and reorganization of retinal and visual callosal pathways in normal neonatal rodent brains and after early postnatal visual impairments. Using MEMRI, intravitreal Mn 2+ injection into one eye resulted in maximal T1-weighted hyperintensity in neonatal contralateral superior colliculus (SC) 8 hours after administration, whereas in adult contralateral SC signal increase continued at 1 day post-injection. Notably, mild but significant Mn 2+ enhancement was observed in the ipsilateral SC in normal neonatal rats, and in adult rats after neonatal monocular enucleation (ME) but not in normal adult rats. Upon intracortical Mn 2+ injection to the visual cortex, neonatal binocularly-enucleated (BE) rats showed an enhancement of a larger projection area, via the splenium of corpus callosum to the V1/V2 transition zone of the contralateral hemisphere in comparison to normal rats. For DTI, the retinal pathways projected from the enucleated eyes possessed lower fractional anisotropy (FA) 6 weeks after BE and ME. Interestingly, in the optic nerve projected from the remaining eye in ME rats a significantly higher FA was observed compared to normal rats. The results of this study are potentially important for understanding the axonal transport, microstructural reorganization and functional activities in the living visual brain during early postnatal development and plasticity in a global and longitudinal setting. © 2011 IEEE.published_or_final_versionThe 33rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC 2011), Boston, MA., 30 August-3 September 2011. In IEEE Engineering in Medicine and Biology Society Conference Proceedings, 2011, p. 7005-700

    Electrospinning of poly(methyl methacrylate) nanofibers in a pump-free process

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    The effects of processing parameters, including solution concentration, viscosity, nozzle diameter, voltage bias and the nozzle to collector distance, on the morpho logy and diameters of poly(methyl methacrylate) (PMMA) fibers have been systematically investigated, using a unique pump-free electrospinning method. For PMMA solution concentrations less than the critical entanglement concentration, c e, prolate spheroidshaped droplets or beads with fibers were formed, whereas at concentrations above c e, good quality beadfree fibers were formed. Quantitative analysis revealed a linear dependence between the solution viscosity and fiber diameter. Larger fiber diameters were achieved by increasing the nozzle diameter and voltage bias. Increasing the bias voltage has the additional effect of broadening the diameter distribution, as a result of splaying and splitting. By contrast, when the strength of the electrical field was reduced by increasing the distance between the nozzle and collector, the overall fiber dia meter was reduced

    Noninvasive fMRI investigation of interaural level difference processing the rat auditory subcortex

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    A Self-Reference False Memory Effect in the DRM Paradigm: Evidence from Eastern and Western Samples

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    It is well established that processing information in relation to oneself (i.e., selfreferencing) leads to better memory for that information than processing that same information in relation to others (i.e., other-referencing). However, it is unknown whether self-referencing also leads to more false memories than other-referencing. In the current two experiments with European and East Asian samples, we presented participants the Deese-Roediger/McDermott (DRM) lists together with their own name or other people’s name (i.e., “Trump” in Experiment 1 and “Li Ming” in Experiment 2). We found consistent results across the two experiments; that is, in the self-reference condition, participants had higher true and false memory rates compared to those in the other-reference condition. Moreover, we found that selfreferencing did not exhibit superior mnemonic advantage in terms of net accuracy compared to other-referencing and neutral conditions. These findings are discussed in terms of theoretical frameworks such as spreading activation theories and the fuzzytrace theory. We propose that our results reflect the adaptive nature of memory in the sense that cognitive processes that increase mnemonic efficiency may also increase susceptibility to associative false memories

    Nodal dynamics, not degree distributions, determine the structural controllability of complex networks

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    Structural controllability has been proposed as an analytical framework for making predictions regarding the control of complex networks across myriad disciplines in the physical and life sciences (Liu et al., Nature:473(7346):167-173, 2011). Although the integration of control theory and network analysis is important, we argue that the application of the structural controllability framework to most if not all real-world networks leads to the conclusion that a single control input, applied to the power dominating set (PDS), is all that is needed for structural controllability. This result is consistent with the well-known fact that controllability and its dual observability are generic properties of systems. We argue that more important than issues of structural controllability are the questions of whether a system is almost uncontrollable, whether it is almost unobservable, and whether it possesses almost pole-zero cancellations.Comment: 1 Figures, 6 page

    Resting-state fMRI using passband balanced steady-state free precession

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    OBJECTIVE: Resting-state functional MRI (rsfMRI) has been increasingly used for understanding brain functional architecture. To date, most rsfMRI studies have exploited blood oxygenation level-dependent (BOLD) contrast using gradient-echo (GE) echo planar imaging (EPI), which can suffer from image distortion and signal dropout due to magnetic susceptibility and inherent long echo time. In this study, the feasibility of passband balanced steady-state free precession (bSSFP) imaging for distortion-free and high-resolution rsfMRI was investigated. METHODS: rsfMRI was performed in humans at 3 T and in rats at 7 T using bSSFP with short repetition time (TR = 4/2.5 ms respectively) in comparison with conventional GE-EPI. Resting-state networks (RSNs) were detected using independent component analysis. RESULTS AND SIGNIFICANCE: RSNs derived from bSSFP images were shown to be spatially and spectrally comparable to those derived from GE-EPI images with considerable intra- and inter-subject reproducibility. High-resolution bSSFP images corresponded well to the anatomical images, with RSNs exquisitely co-localized to the gray matter. Furthermore, RSNs at areas of severe susceptibility such as human anterior prefrontal cortex and rat piriform cortex were proved accessible. These findings demonstrated for the first time that passband bSSFP approach can be a promising alternative to GE-EPI for rsfMRI. It offers distortion-free and high-resolution RSNs and is potentially suited for high field studies.published_or_final_versio

    Androgen receptor phosphorylation at serine 515 by Cdk1 predicts biochemical relapse in prostate cancer patients

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    <br>Background:Prostate cancer cell growth is dependent upon androgen receptor (AR) activation, which is regulated by specific kinases. The aim of the current study is to establish if AR phosphorylation by Cdk1 or ERK1/2 is of prognostic significance.</br> <br>Methods: Scansite 2.0 was utilised to predict which AR sites are phosphorylated by Cdk1 and ERK1/2. Immunohistochemistry for these sites was then performed on 90 hormone-naive prostate cancer specimens. The interaction between Cdk1/ERK1/2 and AR phosphorylation was investigated in vitro using LNCaP cells.</br><br>Results:Phosphorylation of AR at serine 515 (pAR(S515)) and PSA at diagnosis were independently associated with decreased time to biochemical relapse. Cdk1 and pCdk1(161), but not ERK1/2, correlated with pAR(S515). High expression of pAR(S515) in patients with a PSA at diagnosis of ≤20 ng ml(-1) was associated with shorter time to biochemical relapse (P=0.019). This translated into a reduction in disease-specific survival (10-year survival, 38.1% vs 100%, P<0.001). In vitro studies demonstrated that treatment with Roscovitine (a Cdk inhibitor) caused a reduction in pCdk1(161) expression, pAR(S515)expression and cellular proliferation.</br> <br>Conclusion: In prostate cancer patients with PSA at diagnosis of ≤20 ng ml(-1), phosphorylation of AR at serine 515 by Cdk1 may be an independent prognostic marker.</br&gt

    Testing supersymmetry at the LHC through gluon-fusion production of a slepton pair

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    Renormalizable quartic couplings among new particles are typical of supersymmetric models. Their detection could provide a test for supersymmetry, discriminating it from other extensions of the Standard Model. Quartic couplings among squarks and sleptons, together with the SU(3) gauge couplings for squarks, allow a new realization of the gluon-fusion mechanism for pair-production of sleptons at the one-loop level. The corresponding production cross section, however, is at most of O(1){\cal O}(1) fb for slepton and squark masses of O(100){\cal O}(100) GeV. We then extend our investigation to the gluon-fusion production of sleptons through the exchange of Higgs bosons. The cross section is even smaller, of O(0.1){\cal O}(0.1) fb, if the exchanged Higgs boson is considerably below the slepton-pair threshold, but it is enhanced when it is resonant. It can reach O(10){\cal O}(10) fb for the production of sleptons of same-chirality, exceeding these values for τ~\widetilde{\tau}'s of opposite-chirality, even when chirality-mixing terms in the squark sector are vanishing. The cross section can be further enhanced if these mixing terms are nonnegligible, providing a potentially interesting probe of the Higgs sector, in particular of parameters such as AA, μ\mu, and tanβ\tan\beta.Comment: 28 pages, 11 figure
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