•Ability of five rainfall products (SPPs) from the PERSIANN-family are examined.•Performance of SPPs does not particularly depend on their spatiotemporal resolution.•Algorithm includes both the cloud ...patch method and rain gauge data performs better.•PDIR-Now is superior to other SPPs on interannual, annual, and seasonal timescales.•PERSIANN-CCS-CDR is superior to other SPPs on daily and diurnal timescales.
This study evaluates the performance of five satellite precipitation products (SPPs) from the Precipitation Remotely Sensed Information using Artificial Neural Networks (PERSIANN) family for depicting precipitation changes in Taiwan over multiple timescales. Rain gauge data provided by the Central Weather Bureau (CWB) of Taiwan were used as a reference for evaluation, which focused on the wet seasons (May to October) during the period 2003–2019. All SPPs were found to have good ability in expressing the temporal phase changes over most of Taiwan on all the timescales examined, with significant temporal correlation coefficients (TCC) observed between the SPPs and the CWB data. We further evaluated the performance of the SPPs in making quantitative precipitation estimates based on the root mean square error (RMSE). For all examined timescales, the comparison between the best and worst performance shows greater normalized differences in quantitative estimates (i.e., RMSE) than in temporal phase depiction (i.e., TCC). In general, all SPPs tend to underestimate precipitation over most of Taiwan; however, two relatively new products (PDIR-Now and PERSIANN-CCS-CDR) have better RMSE performance than other SPPs on different timescales. PDIR-Now is the best product for quantitatively estimating precipitation on interannual, annual, and seasonal timescales, while PERSIANN-CCS-CDR is superior for daily and diurnal timescales. The findings also highlight that the performance of the PERSIANN-family in quantitatively estimating Taiwan precipitation does not depend primarily on the spatiotemporal resolution of SPPs, but may be related to the use of the cloud patch approach and the inclusion of weather station information in producing PDIR-Now and PERSIANN-CCS-CDR.
In March 2019, Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (IMERG)-Final v6 (hereafter IMERG6) was released, with data concerning precipitation dating back to June ...2000. The National Aeronautics and Space Administration (NASA) has suggested that researchers use IMERG6 to replace the frequently used Tropical Rainfall Measuring Mission (TRMM)-3B42 v7 (hereafter TRMM7), which is expected to cease operation in December 2019. This study aims to evaluate the performance of IMERG6 and TRMM7 in depicting the variations of summer (June, July, and August) precipitation over Taiwan during the period 2000–2017. Data used for the comparison also includes IMERG-Final v5 (hereafter IMERG5) and Global Satellite Mapping of Precipitation for Global Precipitation Measurement (GSMaP)-Gauge v7 (hereafter GSMaP7) during the summers of 2014–2017. Capabilities to apply the four satellite precipitation products (SPPs) in studying summer connective afternoon rainfall (CAR) events, which are the most frequently observed weather patterns in Taiwan, are also examined. Our analyses show that when using more than 400 local rain-gauge observations as a reference base for comparison, IMERG6 outperforms TRMM7 quantitatively and qualitatively, more accurately depicting the variations of the summer precipitation over Taiwan at multiple timescales (including mean status, daily, interannual, and diurnal). IMERG6 also performs better than TRMM7 in capturing the characteristics of CAR activities in Taiwan. These findings highlight that using IMERG6 to replace TRMM7 adds value in studying the spatial-temporal variations of summer precipitation over Taiwan. Furthermore, the analyses also indicated that IMERG6 outperforms IMERG5 and GSMaP7 in the examination of most of the features of summer precipitation over Taiwan during 2014–2017.
User authentication is a crucial service in wireless sensor networks (WSNs) that is becoming increasingly common in WSNs because wireless sensor nodes are typically deployed in an unattended ...environment, leaving them open to possible hostile network attack. Because wireless sensor nodes are limited in computing power, data storage and communication capabilities, any user authentication protocol must be designed to operate efficiently in a resource constrained environment. In this paper, we review several proposed WSN user authentication protocols, with a detailed review of the M.L Das protocol and a cryptanalysis of Das' protocol that shows several security weaknesses. Furthermore, this paper proposes an ECC-based user authentication protocol that resolves these weaknesses. According to our analysis of security of the ECC-based protocol, it is suitable for applications with higher security requirements. Finally, we present a comparison of security, computation, and communication costs and performances for the proposed protocols. The ECC-based protocol is shown to be suitable for higher security WSNs.
Lower urinary tract symptoms (LUTS) result in morbidities; however, their association with the occurrence of hip fracture is relatively unknown in the context of Asian studies. The purpose of the ...study was to investigate this link with the hip fracture risk in Taiwanese men and women aged 50 years and above.
From 2000 through 2012, a population-based retrospective cohort study was conducted; claims data of 18,976 patients diagnosed with LUTS (dysuria, urinary retention, incontinence, and increased urinary frequency and urgency) were retrieved from Taiwan's National Health Insurance Research Database. The patients were compared with 1:2 age, sex, and index year-matched controls (comparison group, n = 37,952). The incidence and hazard ratios of the hip fracture risk were calculated by the Cox proportional hazard regression models.
The mean age was 66.2 ± 9.7 years, and the proportion of men was 58.1% in both study groups. Fractures occurred in 772 patients and 1,156 control subjects. The corresponding incidences were 7.0 and 5.0/1000 person-years. Compared to the control subjects, the patients with LUTS had an increased hip fracture risk adjusted hazard ratio (aHR) = 1.29; 95% confidence interval (CI): 1.17-1.42. LUTS was independently associated with an increased hip fracture risk in both men (aHR = 1.24; 95% CI: 1.08-1.42) and women (aHR = 1.34; 95% CI: 1.18-1.53) (p for interaction = 0.557). Similarly, the subgroup effect of age on hip fracture risks was not found (p for interaction = 0.665).
The study found LUTS was associated with an increased risk of hip fracture. Large-scale prospective studies in diverse populations are required to investigate causalities.
In this paper, new conditions for the delay-range-dependent stability analysis of time-varying delay systems are proposed in a Lyapunov–Krasovskii framework. Time delay is considered to be ...time-varying and has lower and upper bounds. A new method is first presented for a system with two time delays, integral inequality approach (IIA) used to express relationships among terms of Leibniz–Newton formula. Constructing a novel Lyapunov–Krasovskii functional includes information belonging to a given range; new delay-range-dependent criterion is established in term of linear matrix inequality (LMI). The advantage of that criterion lies in its simplicity and less conservative. This paper also presents a new result of stability analysis for continuous systems with two additive time-variant components representing a general class of delay with strong application background in network-based control systems. Resulting criteria are then expressed in terms of convex optimization with LMI constraints, allowing for use of efficient solvers. Finally, three numerical examples show these methods reducing conservatism and improving maximal allowable delay.
•This paper has presented an improved delay-range-dependent stability criterion for linear systems with additive time varying delays.•The advantage of the criterion lies in its simplicity and less conservatism.•Proposed criteria are computationally attractive, providing less conservative results than the existing ones.•Simulation examples are given to show efficacy and potential of developed theoretical results.
Background
Autophagy can have either beneficial or detrimental effects on various heart diseases. Pharmacological interventions improve cardiac function, which is correlated with enhanced autophagy. ...To assess whether a xanthine derivative (KMUP‐3) treatment coincides with enhanced autophagy while also providing cardio‐protection, we investigated the hypothesis that KMUP‐3 treatment activation of autophagy through PI3K/Akt/eNOS signalling offered cardioprotective properties.
Methods
The pro‐autophagic effect of KMUP‐3 was performed in a neonatal rat model targeting cardiac fibroblasts and cardiomyocytes, and by assessing the impact of KMUP‐3 treatment on cardiotoxicity, we used antimycin A‐induced cardiomyocytes.
Results
As determined by transmission electron microscopy observation, KMUP‐3 enhanced autophagosome formation in cardiac fibroblasts. Furthermore, KMUP‐3 significantly increased the expressions of autophagy‐related proteins, LC3 and Beclin‐1, both in a time‐ and dose‐dependent manner; moreover, the pro‐autophagy and nitric oxide enhancement effects of KMUP‐3 were abolished by inhibitors targeting eNOS and PI3K in cardiac fibroblasts and cardiomyocytes. Notably, KMUP‐3 ameliorated cytotoxic effects induced by antimycin A, demonstrating its protective autophagic response.
Conclusion
These findings enable the core pathway of PI3K/Akt/eNOS axis in KMUP‐3‐enhanced autophagy activation and suggest its principal role in safeguarding against cardiotoxicity.
BACKGROUNDMany natural products confer health benefits against diverse diseases through their antioxidant activities. Carbon tetrachloride (CCl4) is often used in animal experiments to study the ...effects of substances on liver injury and the related mechanisms of action, among which oxidative stress is a major pathogenic factor. AIMTo compare antioxidant and hepatoprotective activities of ten herbs and identify and quantify phytochemicals for the one with strongest hepatoprotection. METHODSThe antioxidant activity of ten medicinal herbs was determined by both ferric-reducing antioxidant power and Trolox equivalent antioxidant capacity assays. The total phenolic and flavonoid contents were determined by Folin-Ciocalteu method and aluminum chloride colorimetry, respectively. Their effects on CCl4-induced oxidative liver injury were evaluated and compared in a mouse model by administrating each water extract (0.15 g/mL, 10 mL/kg) once per day for seven consecutive days and a dose of CCl4 solution in olive oil (8%, v/v, 10 mL/kg). The herb with the strongest hepatoprotective performance was analyzed for the detailed bioactive components by using high-performance liquid chromatography-electrospray ionization source-ion trap tandem mass spectrometry. RESULTSThe results revealed that all tested herbs attenuated CCl4-induced oxidative liver injury; each resulted in significant decreases in levels of serum alanine transaminase, aspartate transaminase, alkaline phosphatase, and triacylglycerols. In addition, most herbs restored hepatic superoxide dismutase and catalase activities, glutathione levels, and reduced malondialdehyde levels. Sanguisorba officinalis (S. officinalis) L., Coptis chinensis Franch., and Pueraria lobata (Willd.) Ohwi root were the three most effective herbs, and S. officinalis L. exhibited the strongest hepatoprotective effect. Nine active components were identified in S. officinalis L. Gallic acid and (+)-catechin were quantified (7.86 ± 0.45 mg/g and 8.19 ± 0.57 mg/g dried weight, respectively). Furthermore, the tested herbs displayed a range of in vitro antioxidant activities proportional to their phenolic content; the strongest activities were also found for S. officinalis L. CONCLUSIONThis study is of value to assist the selection of more effective natural products for direct consumption and the development of nutraceuticals or therapeutics to manage oxidative stress-related diseases.
: Chronic cigarette smoking is a major risk factor for many serious diseases. While complete cessation of smoking is the best option to reduce harm from smoking, adverse impacts of smoking on health ...could persist for several years after cessation. Therefore, Biomarkers of Potential Harm (BoPH) are useful in interim evaluations of the beneficial effects of smoking cessation or switching to potentially lower-risk tobacco products. A 14-day smoking abstinence study was conducted under clinical confinement conditions and enrolled 70 subjects into younger (24-34 years,
= 33) and older (35-60 years,
= 37) age cohorts. Biomarkers of Exposure (BoE), which indicate exposure to nicotine and other toxicants, were measured at baseline, 7 and 14 days. Several BoPH including previously identified eicosanoids (leukotriene 4 (LTE4) and 2,3-dinor thromboxane
(2,3-d-TXB
) and others were evaluated. Significant declines in BoE, LTE
2,3-d-TXB
, neutrophils, WBC and select RBC, and arterial blood gas parameters were observed in both age cohorts at Days 7 and 14 compared to baseline, while other BoPH (e.g., FeNO) showed age-related effects. Rapid and reproducible reductions in LTE
, 2,3-d-TXB
WBC, and neutrophil counts were consistently detected following smoking abstinence, indicating the value of these markers as useful BoPH.
In this paper, the problem of delay-derivative-dependent stability analysis for generalized neural networks with interval time-varying delays is considered. First, we divide the whole delay interval ...into two segmentations with an unequal width and checking the variation of the Lyapunov–Krasovskii functional (LKF) for each subinterval of delay, where the information on the lower and upper bounds of time delay and its derivative are fully exploited. Second, a new delay-derivative-dependent stability condition for time-varying delay systems with interval time-varying delays, which expressed in terms of quadratic forms of linear matrix inequalities (LMIs), and has been derived by constructing the LKF from the delayed-decomposition approach and integral inequality approach. Third, all the conditions are presented in terms of LMIs can be easily calculated by using Matlab LMI control toolbox. Fourth, the computational complexity of newly obtained stability conditions is reduced because fewer variables are involved. Finally, four numerical examples are provided to verify the effectiveness of the proposed criteria.
Since March 2014, the Global Precipitation Measurement (GPM) Integrated Multi-satellitE Retrievals for GPM (IMERG) has provided satellite precipitation estimates across the globe. Using gridded ...surface precipitation data derived from local rain gauges as a reference, this study evaluated the performance of IMERG in depicting the spatial-temporal characteristics of precipitation variations over Taiwan at multiple (including annual, seasonal, intraseasonal, diurnal and semidiurnal) timescales. The analysis focused on the period of March 2014–February 2017. Our results show that, quantitatively, IMERG underestimated the magnitude of precipitation over most of Taiwan for all the examined timescales; spatially, the bias in variability was larger over the mountainous areas than over the plain areas; temporally, the bias in variability was larger in the warm seasons than in the cold seasons. Despite the magnitude differences, IMERG was capable of qualitatively depicting several distinct features of Taiwan precipitation changes, listed as follows: (1) a bimodal pattern, with a peak in May and another peak in September, in the annual evolution of precipitation area averaged over Taiwan; (2) a seasonal counterclockwise rotation feature, with the precipitation maximum located over northern Taiwan in the winter, over northwestern Taiwan in the spring, over southwest Taiwan in the summer and over eastern Taiwan in the autumn; (3) a 10-to-35-day intraseasonal oscillation feature, with a transition of variations from smaller amplitudes in the cold seasons to larger amplitudes in the warm seasons, occurring around mid-May (i.e., the so-called Meiyu onset in Taiwan); and (4) a roughly out-of-phase feature, with a morning precipitation maximum in the winter and an afternoon precipitation maximum in the other seasons, for the diurnal evolution of the area-averaged precipitation over Taiwan. In addition, IMERG was capable of qualitatively depicting the phase evolution of semidiurnal precipitation over Taiwan in most seasons, except for the winter season. These findings highlight the potential use of IMERG to qualitatively represent changes in precipitation over Taiwan at multiple timescales.
•IMERG is able to qualitatively depict many features of the changes in Taiwan rainfall•IMERG depicts the temporal bimodal peaks for the annual evolution of Taiwan rainfall•IMERG depicts the seasonal anticlockwise rotation of the rainfall maxima location•IMERG depicts the 10-to-35 day intraseasonal oscillation signal of Taiwan rainfall•IMERG depicts the seasonal differences in the diurnal evolution of Taiwan rainfall
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