Polynomial-Chaos-based Kriging

Computer simulation has become the standard tool in many engineering fields for designing and optimizing systems, as well as for assessing their reliability. To cope with demanding analysis such as optimization and reliability, surrogate models (a.k.a meta-models) have been increasingly investigated in the last decade. Polynomial Chaos Expansions (PCE) and Kriging are two popular non-intrusive meta-modelling techniques. PCE surrogates the computational model with a series of orthonormal polynomials in the input variables where polynomials are chosen in coherency with the probability distributions of those input variables. On the other hand, Kriging assumes that the computer model behaves as a realization of a Gaussian random process whose parameters are estimated from the available computer runs, i.e. input vectors and response values. These two techniques have been developed more or less in parallel so far with little interaction between the researchers in the two fields. In this paper, PC-Kriging is derived as a new non-intrusive meta-modeling approach combining PCE and Kriging. A sparse set of orthonormal polynomials (PCE) approximates the global behavior of the computational model whereas Kriging manages the local variability of the model output. An adaptive algorithm similar to the least angle regression algorithm determines the optimal sparse set of polynomials. PC-Kriging is validated on various benchmark analytical functions which are easy to sample for reference results. From the numerical investigations it is concluded that PC-Kriging performs better than or at least as good as the two distinct meta-modeling techniques. A larger gain in accuracy is obtained when the experimental design has a limited size, which is an asset when dealing with demanding computational models

Goniothalamus Species: A Source of Drugs for the Treatment of Cancers and Bacterial Infections?

Irrespective of the presence of cytotoxic acetogenins and styryl-lactones in the genus Goniothalamus, only 22 species in the genus Goniothalamus, out of 160 species (13.7%) have so far been investigated. In an effort to promote further research on the genus Goniothalamus which could represent a source of drugs for the treatment of cancers and bacterial infections, this work offers a broad analysis of current knowledge on Goniothalamus species. Therefore, it includes (i) taxonomy (ii) botanical description (iii) traditional medicinal uses and (iv) phytochemical and pharmacological studies. We discuss the molecular mechanisms of actions of acetogenins and styryl-lactones, with some emphasis on the possible involvement of protein kinase, Bax and TRAIL receptors in the cytotoxic effects of styryl-lactones. We also report (v) the growth inhibition of several nosocomial bacteria by Goniothalamus. scortechinii. The crude methanol extract of G. scortechinii showed a good and broad spectrum of antibacterial activity against both Gram-negative and Gram-positive bacteria

Imagining the Body in Pacific Francophone Literature

This article deals with the central position of the body in Polynesian and Kanak imaginary, ancestral myths, and language. In the collective imagination, the body is akin to a particle of the cosmos. The author probes into major primordial images in order to understand the peculiar role of the body in the Oceanic "anthropological structures of the imaginary" (Gilbert Durand’s term) and asks whether the vision proposed by archaic myths finds its way into modern autochthonous Polynesian and Kanak indigenous literature, especially in the writings of Déwé Gorodé, Chantal Spitz, Flora Devatine, and Moetai Brotherson. Indeed, in keeping with the theories of Michel Foucault, the Oceanic body as it appears in modern poetic or novelistic narrations bears witness in its maimed flesh to a collective history and bears the scars of colonialism. Through its transhistorical dimension as well, this brand of francophone literature constitutes an original way to introduce some sort of counter-discourse into narrative strategies shaped by Western colonial history. In reclaiming the body, these writers are also reviving an ancestral voice

Evaluation of Recovery in Female Swimmers During a Competitive Season

Objective: To monitor the stress and recovery of college swimmers throughout a competitive season. The priori hypothesis was that RESTQ-SPORT scores will change with changes in training load through the season Patients or Other Participants: 23 female swimmers (mean age = 19.48±1.16, mean height = 168.6 cm ± 5.5, mean weight = 65.91kg ± 7.78) that were members of a southeastern Division I intercollegiate swim team. Interventions: The training load was measured using session rate of perceived exertion (RPE). RPE uses a 0-10 Borg scale to define effort. Each individual\u27s daily score was multiplied by practice duration to give a training load. The RESTQ-SPORT 76 was given monthly. The data was then placed into the RESTQ-SPORT computer program to calculate scores. Main Outcome Measures: RESTQ-SPORT 76 mean scores for recovery-stress state, global stress, and global recovery were recorded to two decimal places. A repeated measures ANOVA was run on each mean and significance was set at p=0.05. Results: There was a significant time effect for scores over the season (F5=4.67; P\u3c.001) for RESTQ total. A simple contrast using the initial RESTQ-Sport as a baseline (M=9.85 ± 10.34) showed the RESTQ total was significantly less at time point 2 (F1=9.55, M=4.14 ± 10.06 P=.006) and time point 4 (F1=5.88, M=11.65 P=.026). There was no significance for global recovery. Global stress showed a significant time effect for scores over the season (F5=9.85, P\u3c.001). There was no group effect or interaction. A simple contrast using the initial RESTQ-Sport as a baseline (M=19.60 ± 5.71) showed that time point 2 (F1=21.23, M=24.00 ± 6.80 P\u3c.001), time point 4 (F1=20.96, M=26.08 ± 7.72 P\u3c.001), and time point 5 (F1=4.54, M=22.89 ± 7.68 P=.047) were significantly less than baseline. The highest training loads were seen at time points 2 and 4. Conclusions: The study shows that as training load increases through a season, the internal stress increases. This can lead to an increased risk of underrecovery. Swimmers need to be taught better strategies for recovery to gain the intended training effects and improve performance

Evidence of the El Niño/La Niña Climatic Events in New Zealand Over the Last Century

We investigate interrelations between the mean sea level, sea surface temperature, atmospheric temperature and pressure at four tide gauges in New Zealand (Auckland, Wellington, Lyttelton, and Dunedin) with records available for over a century. The least-squares linear regression analysis is applied to estimate linear (secular) trends in the seasonally-adjusted time series. The detrended annual data are then used to analyze the influence of (quasi)periodical climatic cycles on the variability of these recorded data. In particular, we assess the presence of climatic signals attributed to: (i) the inter-annual El Niño Southern Oscillation (ENSO) cycle of El Niño/La Niña events (described by the Southern Oscillation Index - SOI) and (ii) the Inter-decadal Pacific Oscillation (IPO) of the long-term climate cycle occurring over whole Pacific Ocean with a typical period of about 15-30 years. The correlation analysis reveals the presence of significant signal of the SOI and IPO in the mean sea level data in Auckland. The signature of the SOI and IPO attenuates towards higher geographical latitudes. The SOI and IPO also significantly modulate sea surface temperature and atmospheric temperature variations, while the signatures of these climatic cycles are much less pronounced in atmospheric pressure fluctuations