Firefly algorithm with chaos Gandomi, A.H.; Yang, X.-S.; Talatahari, S. ...
Communications in nonlinear science & numerical simulation,
January 2013, 2013-1-00, 20130101, Letnik:
18, Številka:
1
Journal Article
Recenzirano
► Novel Chaotic Improved Firefly Algorithms (CFAs) are presented for global optimization. ► Twelve different chaotic maps are utilized to improve the attraction term of the algorithm. ► Comparing the ...new chaotic algorithms with the standard FA demonstrates superiority of the CFAs for the benchmark functions.
A recently developed metaheuristic optimization algorithm, firefly algorithm (FA), mimics the social behavior of fireflies based on the flashing and attraction characteristics of fireflies. In the present study, we will introduce chaos into FA so as to increase its global search mobility for robust global optimization. Detailed studies are carried out on benchmark problems with different chaotic maps. Here, 12 different chaotic maps are utilized to tune the attractive movement of the fireflies in the algorithm. The results show that some chaotic FAs can clearly outperform the standard FA.
Summary
The diagnosis of primary sclerosing cholangitis (PSC) is difficult due to the lack of sensitive and specific biomarkers, as is the early diagnosis of cholangiocarcinoma (CC), a complication ...of PSC. The aim of this study was to identify specific serum miRNAs as diagnostic biomarkers for PSC and CC. The levels of 667 miRNAs were evaluated in 90 human serum samples (30 PSC, 30 CC and 30 control subjects) to identify disease‐associated candidate miRNAs (discovery phase). The deregulated miRNAs were validated in an independent cohort of 140 samples 40 PSC, 40 CC, 20 primary biliary cirrhosis (PBC) and 40 controls. Receiver operating characteristic (ROC) curves were established and only miRNAs with an area under the curve (AUC) > 0·70 were considered useful as biomarkers. In the discovery phase we identified the following: 21 miRNAs expressed differentially in PSC, 33 in CC and 26 in both in comparison to control subjects as well as 24 miRNAs expressed differentially between PSC and CC. After the validation phase, miR‐200c was found to be expressed differentially in PSC versus controls, whereas miR‐483‐5p and miR‐194 showed deregulated expression in CC compared with controls. We also demonstrate a difference in the expression of miR‐222 and miR‐483‐5p in CC versus PSC. Combination of these specific miRNAs further improved the specificity and accuracy of diagnosis. This study provides a basis for the use of miRNAs as biomarkers for the diagnosis of PSC and CC.
AIMS: The influence of bacterial species/strains in agitated culture was investigated on the morphology and structure characteristics of bacterial cellulose. METHODS AND RESULTS: Komagataeibacter ...nataicola Y19 and Gluconacetobacter entanii ACCC10215 were inoculated in Hestrin–Schramm (HS) medium and subjected to agitated cultivation. Different kinds of BCs were obtained including flocky asterisk‐like BC by G. entanii ACCC10215 and solid sphere‐like BC by K. nataicola Y19. The SEM results showed that the asterisk‐like BC had larger pores than the solid sphere‐like BC. The FT‐IR and X‐ray diffraction results showed the asterisk‐like BC had lower crystallinity (81·43%), higher cellulose Iα mass fraction (79·74%) and smaller crystallite size. CONCLUSIONS: The different species/strains can influence the morphology and structure characteristics of BC in agitated culture. SIGNIFICANCE AND IMPACT OF THE STUDY: We examined the influence of different species/strains on the morphology, macro‐ and microstructure of BCs produced in agitated culture for the first time, which suggest that different BCs with potential applications could be obtained by choosing different species or strains and fermentation method.
To explore the value of quantitative image features of gadoxetic acid-enhanced magnetic resonance imaging (MRI) for predicting Gglypican-3 (GPC3) expression of single hepatocellular carcinoma (HCC) ...≤3 cm.
One hundred and forty-nine patients with histopathologically confirmed HCC were included retrospectively. Quantitative image features and clinicopathological parameters were analysed. The significant predictors for GPC3 expression were identified using multivariate logistic regression analyses. Nomograms were constructed from the prediction model and the progression-free survival (PFS) rate was evaluated by the Kaplan–Meier method.
The tumour-to-liver signal intensity (SI) ratio on the hepatobiliary phase (HBP; odds ratio OR = 0.004; p=0.001), serum alpha-fetoprotein (AFP) > 20 ng/ml (OR=6.175; p<0.001), and non-smooth tumour margin (OR=4.866; p=0.002) were independent significant factors for GPC3 expression. When the three factors were combined, the diagnostic specificity was 97.7% (42/43). The nomogram based on the predictive model performed satisfactorily (C-index: 0.852). Kaplan–Meier curves showed that patients with GPC3-positive HCCs have lower PFS rates than patients with GPC3-negative HCCs (Log-rank test, p=0.006).
The tumour-to-liver SI ratio on the HBP combined with serum AFP >20 ng/ml and non-smooth tumour margin are potential predictive factors for GPC3 expression of small HCC ≤3cm. GPC3 expression is correlated with a poor prognosis in HCC patients.
•The combinational model could predict GPC3 expression of small HCC.•GPC3 was associated with recurrence in HCC patients after surgical resection.•This model could help clinicians in the preoperative management of small HCC.
Quercetin (3,3′,4′,5,7-pentahydroxyflavone, Qu) is a promising cancer chemo-preventive agent for various cancers because it inhibits disease progression and promotes apoptotic cell death. In our ...previous study, we demonstrated that Qu could evoke ER stress to enhance drug cytotoxicity in ovarian cancer (OC). However, Qu-induced ER stress in OC is still poorly understood. Here, we demonstrated that Qu evoked ER stress to involve in mitochondria apoptosis pathway via the p-STAT3/Bcl-2 axis in OC cell lines and in primary OC cells. Unexpectedly, inhibition of ER stress did not reverse Qu-induced cell death. Further functional studies revealed that Qu-induced ER stress could activate protective autophagy concomitantly by activating the p-STAT3/Bcl-2 axis in this process. Moreover, the autophagy scavenger 3-MA was shown to enhance Qu’s anticancer effects in an ovarian cancer mice xenograft model. These findings revealed a novel role of ER stress as a “double edge sword” participating in Qu-induced apoptosis of OC and might provide a new angle to consider in clinical studies of biological modifiers that may circumvent drug resistance in patients by targeting protective autophagy pathways.
The debate on the relationship between corporate or industrial environmental performance (EP) and financial performance (FP) has yet to be resolved, and studies need to examine the possible ...moderating effects on the EP-FP link. We argue that industrial EP has a positive effect on FP and that industrial munificence and resource slack can moderate the EP-FP link. Using a dataset from Chinese industrial firms, we examine the direct effect of industrial EP on FP and the indirect effects of industrial munificence and resource slack on the EP-FP link. Our results show that improving corporate or industrial-level EP significantly influences FP and that slack resources play a significant role on the EP-FP link. However, we found no significant moderating effect of industrial munificence on the link.
•Industrial environmental performance has a significant influence on financial performance.•Resource slack plays a moderating role on environmental performance.•Resource slack plays a moderating role on financial performance.
Mg-based materials are promising candidates for high capacity hydrogen storage. However, their poor hydrogenation/dehydrogenation kinetics and high desorption temperature are the main obstacles to ...their applications. This paper reports a method for in situ formation of cycle stable CeH2.73-MgH2-Ni nanocomposites, from the hydrogenation of as-melt Mg80Ce18Ni2 alloy, with excellent hydrogen storage performance. The nanocomposites demonstrate reversible hydrogen storage capacity of more than 4.0 wt %, at a low desorption temperature with fast kinetics and long cycle life. The temperature for the full hydrogenation/dehydrogenation cycle of the composites is significantly decreased to 505 K, which is about 100 K lower than that for pure Mg. The hydrogen desorption activation energy is 63 ± 3 kJ/mol H2 for the composites, which is significantly lower than those of Mg3Ce alloy and pure Mg (104 ± 7 and 158 ± 2 kJ/mol H2, respectively). X-ray diffraction and transmission electron microscopy have been used to reveal the mechanism that delivers this excellent cycle stability and fast hydriding/dehydriding kinetics. It is found that the hydriding/dehydriding process is catalyzed by the combination of in situ formed extremely fine CeH2/CeH2.73 and Ni to Mg/MgH2. In addition, this nanocomposite structure can effectively suppress Mg/MgH2 grain growth and enable the material to maintain its high performance for more than 500 hydrogenation dehydrogenation cycles.
We present a clear case study on the occurrence of two successive X-class flares, including a decade-class flare (X9.3) and two coronal mass ejections (CMEs) triggered by shearing motion and sunspot ...rotation in active region NOAA 12673 on 2017 September 6. A shearing motion between the main sunspots with opposite polarities began on September 5 and lasted even after the second X-class flare on September 6. Moreover, the main sunspot with negative polarity rotated around its umbral center, and another main sunspot with positive polarity also exhibited a slow rotation. The sunspot with negative polarity at the northwest of the active region also began to rotate counterclockwise before the onset of the first X-class flare, which is related to the formation of the second S-shaped structure. The successive formation and eruption of two S-shaped structures were closely related to the counterclockwise rotation of the three sunspots. The existence of a flux rope is found prior to the onset of two flares by using nonlinear force-free field extrapolation based on the vector magnetograms observed by Solar Dynamics Observatory/Helioseismic and Magnetic Image. The first flux rope corresponds to the first S-shaped structures mentioned above. The second S-shaped structure was formed after the eruption of the first flux rope. These results suggest that a shearing motion and sunspot rotation play an important role in the buildup of the free energy and the formation of flux ropes in the corona that produces solar flares and CMEs.
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