1,343 research outputs found
Towards Runtime Verification via Event Stream Processing in Cloud Computing Infrastructures
Software bugs in cloud management systems often cause erratic behavior, hindering detection, and recovery of failures. As a consequence, the failures are not timely detected and notified, and can silently propagate through the system. To face these issues, we propose a lightweight approach to runtime verification, for monitoring and failure detection of cloud computing systems. We performed a preliminary evaluation of the proposed approach in the OpenStack cloud management platform, an “off-the-shelf” distributed system, showing that the approach can be applied with high failure detection coverage
Hot and cold spots counts as probes of non-Gaussianity in the CMB
We introduce the numbers of hot and cold spots, and , of excursion
sets of the CMB temperature anisotropy maps as statistical observables that can
discriminate different non-Gaussian models. We numerically compute them from
simulations of non-Gaussian CMB temperature fluctuation maps. The first kind of
non-Gaussian model we study is the local type primordial non-Gaussianity. The
second kind of models have some specific form of the probability distribution
function from which the temperature fluctuation value at each pixel is drawn,
obtained using HEALPIX. We find the characteristic non-Gaussian deviation
shapes of and , which is distinct for each of the models under
consideration. We further demonstrate that and carry additional
information compared to the genus, which is just their linear combination,
making them valuable additions to the Minkowski Functionals in constraining
non-Gaussianity.Comment: 17 pages, accepted for publication in Ap
The Prognostic Significance of the Preoperative Full Blood Count after Resection of Colorectal Liver Metastases
Introduction. Increased preoperative platelet and neutrophil counts are risk factors for decreased survival in several different malignancies. Our aim was to investigate the relationship between overall or disease-free survival after resection of CRLM and the preoperative haematological parameters.
Methods. We reviewed a cohort of 140 patients who underwent resection of CRLM with curative intent, utilising prospectively maintained databases. Patient demographics, operative details, FBC, CRP, INR, histopathology results, and survival data were examined. Kaplan-Meier survival and Cox regression analyses were used to determine the impact of all variables on survival.
Results. 140 patients (96 males) with a median age of 67 years (range 33–82 years) underwent resection of CRLM. A significant correlation was exhibited between preoperative platelet count and neutrophil count (rho = 0.186, P = .028). When modelled as continuous covariates in a Cox regression hazards, an increased preoperative platelet (P = .02) and neutrophil counts (P ≤ .001) were significantly associated with overall survival. Of the haematological parameters assessed only preoperative platelet count showed a strong trend of association with disease free survival; however this failed to reach statistical significance (P = .076). Conclusions. Increased preoperative platelet and neutrophil counts are independent risk factors for decreased survival in patients undergoing resection of CRLM in our series of patients. These findings require validation in larger studies to determine their relationship with survival. Further research into the role of these cell types in tumour progression, particularly in the development and inhibition of angiogenesis, is warranted
Fock Representations of Quantum Fields with Generalized Statistic
We develop a rigorous framework for constructing Fock representations of
quantum fields obeying generalized statistics associated with certain solutions
of the spectral quantum Yang-Baxter equation. The main features of these
representations are investigated. Various aspects of the underlying
mathematical structure are illustrated by means of explicit examples.Comment: 26 pages, Te
Probing quantum coherence in qubit arrays
We discuss how the observation of population localization effects in
periodically driven systems can be used to quantify the presence of quantum
coherence in interacting qubit arrays. Essential for our proposal is the fact
that these localization effects persist beyond tight-binding Hamiltonian
models. This result is of special practical relevance in those situations where
direct system probing using tomographic schemes becomes infeasible beyond a
very small number of qubits. As a proof of principle, we study analytically a
Hamiltonian system consisting of a chain of superconducting flux qubits under
the effect of a periodic driving. We provide extensive numerical support of our
results in the simple case of a two-qubits chain. For this system we also study
the robustness of the scheme against different types of noise and disorder. We
show that localization effects underpinned by quantum coherent interactions
should be observable within realistic parameter regimes in chains with a larger
number o
Screening of fungal strains for cellulolytic and xylanolytic activities production and evaluation of brewers’ spent grain as substrate for enzyme production by selected fungi
Brewer’s spent grain (BSG), the solid residue of beer production, is attracting significant
attention as raw material for the production of added value substances, since until recently it was
mainly used as animal feed or deposited in landfills, causing serious environmental problems.
Therefore, this work aimed at developing a bioprocess using BSG as a substrate for the production of
cellulases and xylanases for waste saccharification and bioenergy production. Different fungi were
analyzed for their cellulolytic and xylanolytic abilities, through a first screening on solid media by
assessment of fungal growth and enzyme production on agar containing carboxylmethylcellulose or
xylan as the sole carbon source, respectively. The best cellulase and xylanase producers were subjected
to quantitative evaluation of enzyme production in liquid cultures. Aspergillus niger LPB-334 was
selected for its ability to produce cellulase and xylanase at high levels and it was cultivated on BSG
by solid state fermentation. The cellulase production reached a maximum of 118.04 8.4 U/g of dry
substrate after 10 days of fermentation, while a maximum xylanase production of 1315.15 37.5 U/g
of dry substrate was reached after 4 days. Preliminary characterization of cellulase and xylanase
activities and identification of the enzymes responsible were carried out
Ethical Issues in the Use of Animal Models for Tissue Engineering:Reflections on Legal Aspects, Moral Theory, Three Rs Strategies, and Harm-Benefit Analysis
Animal experimentation requires a solid and rational moral foundation. Objective and emphatic decision-making and protocol evaluation by researchers and ethics committees remain a difficult and sensitive matter. This article presents three perspectives that facilitate a consideration of the minimally acceptable standard for animal experiments, in particular, in tissue engineering (TE) and regenerative medicine. First, we review the boundaries provided by law and public opinion in America and Europe. Second, we review contemporary moral theory to introduce the Neo-Rawlsian contractarian theory to objectively evaluate the ethics of animal experiments. Third, we introduce the importance of available reduction, replacement, and refinement strategies, which should be accounted for in moral decision-making and protocol evaluation of animal experiments. The three perspectives are integrated into an algorithmic and graphic harm-benefit analysis tool based on the most relevant aspects of animal models in TE. We conclude with a consideration of future avenues to improve animal experiments
Gold Coast diagnostic criteria increase sensitivity in amyotrophic lateral sclerosis
Objective: This study evaluates diagnostic accuracy of the proposed ‘Gold Coast’ (GC) diagnostic criteria for amyotrophic lateral sclerosis (ALS). Methods: Five European centres retrospectively sampled consecutive patients referred for electromyography on suspicion of ALS. Patients were classified according to the GC criteria, the revised El Escorial (rEE) criteria and the Awaji (AW) criteria without and with the ‘Possible’ category (+ Poss). Reference standard was ALS confirmed by disease progression at follow-up. Results: Of 404 eligible patients 272 were diagnosed as ALS, 94 had mimicking disorders, 35 were lost for follow-up, and three had insufficient data. Sensitivity for the GC criteria was 88.2% (95% CI: 83.8-91.8%), which was higher than for previous criteria, of which the AW + Poss criteria reached the highest sensitivity of 77.6% (95% CI: 72.2–82.4%) (p < 0.001). Specificity was high for all criteria. The increase in sensitivity for the GC criteria was mainly due to the inclusion of 28 patients with progressive muscular atrophy (PMA). Conclusions: The simpler GC criteria increase the sensitivity, primarily due to considering PMA as a form of ALS with high specificity preserved. Significance: This validation study supports that GC criteria should be used in clinical practice and may be used for inclusion in trials
Searching for non Gaussian signals in the BOOMERanG 2003 CMB maps
We analyze the BOOMERanG 2003 (B03) 145 GHz temperature map to constrain the
amplitude of a non Gaussian, primordial contribution to CMB fluctuations. We
perform a pixel space analysis restricted to a portion of the map chosen in
view of high sensitivity, very low foreground contamination and tight control
of systematic effects. We set up an estimator based on the three Minkowski
functionals which relies on high quality simulated data, including non Gaussian
CMB maps. We find good agreement with the Gaussian hypothesis and derive the
first limits based on BOOMERanG data for the non linear coupling parameter f_NL
as -300<f_NL<650 at 68% CL and -800<f_NL<1050 at 95% CL.Comment: accepted for publication in ApJ. Letter
MicroRNA 199b-5p delivery through stable nucleic acid lipid particles (SNALPs) in tumorigenic cell lines
MicroRNA (miR)-199b-5p has been shown to regulate Hes-1, a downstream effector of the canonical Notch and noncanonical SHH pathways, whereby it impairs medulloblastoma (MB) cancer stem cells (CSCs) through a decrease in the CD133+/CD15+ cell population. Here, we have developed stable nucleic acid lipid particles (SNALPs) that encapsulate miR-199b-5p. The efficacy of the miR- 199b-5p delivery by these SNALPs is demonstrated by significant impairment of Hes-1 levels and CSC markers in a range of different tumorigenic cell lines: colon (HT- 29, CaCo-2, and SW480), breast (MDA-MB231T and MCF-7), prostate (PC-3), glioblastoma (U-87), and MB(Daoy, ONS-76, and UW-228). After treatment with SNALP miR-199b-5p, there is also impairment of cell pro- liferation and no signs of apoptosis, as measured by cas- pases 3/7 activity and annexin V fluorescence cell sorter analyses. These data strengthen the importance of such carriers for miRNA delivery, which show no cytotoxic effects and provide optimal uptake into cells. Thus, efficient target downregulation in different tumorigenic cell lines will be the basis for future preclinical studies
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