Dispersion curves in ocean environments are accurately estimated from received signals through the extraction of instantaneous modal frequencies and corresponding arrival times for long-range propagation. The ultimate goal is to estimate sediment sound speed using the extracted dispersion pattern. The approach extends work previously conducted in dispersion tracking with sequential filtering, improving on the latter technique. The sequential state-space method that is developed for the extraction of time-frequency information from specific time instances relies on a representation of those as a sum of elemental pulses, resulting from analysis of the received field. The method is tested on synthetic noisy data with different noise levels. After dispersion probability density functions are estimated via a particle filter, they are subsequently employed for sound speed inversion. Correct mode identification is a challenge impacting inversion; this is demonstrated through two examples and a way to remedy the problem is discussed.
Advanced time series models have been intensively developed and used to predict in financial data such as foreign exchange data (forex). In this paper, we implement the random compression method to reduce a large dimensional forex data into much smaller matrix form. Then, Bayesian inferences on vector autoregression are used to obtain all interesting parameters. Subsequently, the models are able to perform out-of-sample prediction up to 14 days ahead of forecast. For empirical works, 30 forex pairs are used in this paper. The results show that Bayesian compressed vector autoregression (BCVAR) and timevarying BCVAR (TVP-BCVAR) deliver excellent forecasting on AUD-JPY, CAD-CHF, CAD-JPY, EUR-DKK, EUR-MXN, and EUR-TRY forex datasets according to mean square forecasting error, outperforming the traditional benchmark Bayesian Autoregression. INDEX TERMS Bayesian methods, compression algorithms, finance, autoregressive processes, forecasting, Bayesian model averaging, dymamic model averaging, Kalman filter.
The effect of Perilla frutescens L. leaves extract (PFLE) on melanogenesis regulation in B16F10 cells was investigated. The extract had a significant inhibitory effect on melanogenesis in a dose-dependent manner without cytotoxicity at concentrations between 2.5 and 10 μg/mL. The PFLE was formulated as an underarm serum (PL serum) and evaluated for skin irritation and its skin whitening efficacy on 30 Thai women twice daily for 4 weeks. Changes in skin melanin and erythema index, L* a* values were studied. A gradual decrease in melanin index from 37.94±0.66 to 35.90±0.64 (5.38%), and a significant decrease in erythema index from 11.32±0.79 to 10.21±0.11 (9.80%) could be observed during a 4-week period. Therefore, the efficacy of PL serum in improving skin was demonstrated by a significant decrease in melanin and erythema index compared with initial values and skin tone was improved without skin irritation. Extract from Perilla frutescens L. leaves can be used as a novel whitening cosmeceutical ingredient.
In previous studies, Perilla frutescens pomace was shown to contain bioactive phenolic compounds and good anti-oxidative activity. However, reports about collagenase activity and melanogenesis inhibitory effects of P. frutescens pomace are limited. This study aimed to evaluate the bioactivity of P. frutescens pomace extract and incorporate the extract into a cosmetic formulation for evaluating its effects on collagenase and melanogenesis inhibition on human skin. The P. frutescens seeds after an oil pressing process were extracted with ethanol (70% v/v) in order to examine the remaining phytochemical compounds, the bioactivity in pomace perilla, and its efficacy as a skincare product. In this study, total phenolic and total flavonoid contents of P. frutescens seed extract (PFSE) were determined using spectrophotometry. The free radical scavenging activity was determined with 2, 2′-diphenyl-1-picrylhydrazyl (DPPH) radicals and 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) ABTS radicals. Additionally, the effects on collagenase activity, melanin content, and alpha-Melanocyte stimulating hormone (α-MSH) on the viability of cultured B16F10 melanoma cells were investigated. Skin irritation and efficacy of PFSE cream for skin elasticity and skin color were also clinically evaluated. The total phenolic content with gallic acid equivalents (GAE) value and total flavonoids content with catechin equivalents (CE) value were, respectively, 92.79 ± 1.19 and 56.02 ± 2.83 mg/g. Furthermore, PFSE significantly inhibited the collagenase activity (p < 0.001) at the concentration of 400 µg/mL (82 ± 3.23%). These results clearly demonstrated the anti-melanogenic effects on B16F10 cells without causing any cytotoxicity or death. Although there was a slight improvement in skin elasticity in the 4th week compared to the previous week, the 4th week melanin content of the skin significantly decreased from the beginning (p < 0.05) without any irritations. In conclusion, PFSE could be cosmetically considered as a key ingredient that effectively lessens the effects of skin aging and skin hyperpigmentation disorders.
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