342 research outputs found

    Royal jelly promotes DAF-16-mediated proteostasis to tolerate β-amyloid toxicity in C. elegans model of Alzheimer’s disease

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    Numerous studies have demonstrated that dietary intervention may promote health and help prevent Alzheimer\u27s disease (AD). We recently reported that bee products of royal jelly (RJ) and enzyme-treated royal jelly (eRJ) were potent to promote healthy aging in C. elegans. Here, we examined whether RJ/eRJ consumption may benefit to mitigate the AD symptom in the disease model of C. elegans. Our results showed that RJ/eRJ supplementation significantly delayed the body paralysis in AD worms, suggesting the β-amyloid (Aβ) toxicity attenuation effects of RJ/eRJ. Genetic analyses suggested that RJ/eRJ-mediated alleviation of Aβ toxicity in AD worms required DAF-16, rather than HSF-1 and SKN-1, in an insulin/IGF signaling dependent manner. Moreover, RJ/eRJ modulated the transactivity of DAF-16 and dramatically improved the protein solubility in aged worms. Given protein solubility is a hallmark of healthy proteostasis, our findings demonstrated that RJ/eRJ supplementation improved proteostasis, and this promotion depended on the transactivity of DAF-16. Collectively, the present study not only elucidated the possible anti-AD mechanism of RJ/eRJ, but also provided evidence from a practical point of view to shed light on the extensive correlation of proteostasis and the prevention of neurodegenerative disorders

    Reversal Effects of Probiotic Supplementation on a High Glucose Diet in Caenorhabditis elegans Model

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    TheWestern Diet refers to a diet rich in refined sugars. With an increasing glycemic index observed in Western society, it comes to no surprise that obesity, diabetes, and heart disease are on the rise. Shortened lifespan and increased susceptibility to pathogens are associated with these diseases and linked to increased consumption of foods high in sugar. Therefore, the benefits probiotics have on restoration of shortened lifespan induced by a high glucose diet, and the benefits of probiotics supplementation in combination of cranberry extracts in the model system Caenorhabditis elegans were investigated. By targeting the homologous pathways with humans, C. elegans provides an economical model system with application in humans. Here, we investigated the effects probiotics have on high glucose diet in C. elegans. Consistent with previous studies, when C. elegans was supplemented with each probiotic strain, lifespan was extended. Interestingly, the reversal of glucose induced shortened lifespan and the extension of lifespan in combination with cranberry extracts was strain dependent. The impact that probiotics have on the reversal of detrimental effects associated with a high glucose diet, including protection against known pathogens and pathway targets, is under investigation

    A Data-Driven Approach for High-Impedance Fault Localization in Distribution Systems

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    Accurate and quick identification of high-impedance faults is critical for the reliable operation of distribution systems. Unlike other faults in power grids, HIFs are very difficult to detect by conventional overcurrent relays due to the low fault current. Although HIFs can be affected by various factors, the voltage current characteristics can substantially imply how the system responds to the disturbance and thus provides opportunities to effectively localize HIFs. In this work, we propose a data-driven approach for the identification of HIF events. To tackle the nonlinearity of the voltage current trajectory, first, we formulate optimization problems to approximate the trajectory with piecewise functions. Then we collect the function features of all segments as inputs and use the support vector machine approach to efficiently identify HIFs at different locations. Numerical studies on the IEEE 123-node test feeder demonstrate the validity and accuracy of the proposed approach for real-time HIF identification

    Formin-dependent actin assembly is regulated by distinct modes of Rho signaling in yeast

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    Formins are actin filament nucleators regulated by Rho-GTPases. In budding yeast, the formins Bni1p and Bnr1p direct the assembly of actin cables, which guide polarized secretion and growth. From the six yeast Rho proteins (Cdc42p and Rho1–5p), we have determined that four participate in the regulation of formin activity. We show that the essential function of Rho3p and Rho4p is to activate the formins Bni1p and Bnr1p, and that activated alleles of either formin are able to bypass the requirement for these Rho proteins. Through a separate signaling pathway, Rho1p is necessary for formin activation at elevated temperatures, acting through protein kinase C (Pkc1p), the major effector for Rho1p signaling to the actin cytoskeleton. Although Pkc1p also activates a MAPK pathway, this pathway does not function in formin activation. Formin-dependent cable assembly does not require Cdc42p, but in the absence of Cdc42p function, cable assembly is not properly organized during initiation of bud growth. These results show that formin function is under the control of three distinct, essential Rho signaling pathways

    Characterizing stress-dependent complex and relaxation moduli of dense graded asphalt mixtures

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    The objective of this paper is to investigate the stress-dependence of the complex and relaxation moduli of dense graded asphalt mixtures. Complex modulus tests at four different confining pressures were conducted. Then, the stress dependence of the long-term equilibrium modulus of asphalt mixture based on Prony series model was modeled by Uzan model. The Maxwell components of the relaxation modulus were determined by a two-step method. Finally, the stress dependence of the relaxation modulus was quantified by relaxation spectrum of the material. The results show that for the selected dense-graded asphalt mixtures, the dynamic modulus increases, and phase angle decreases with the increasing confining pressures at relatively low reduced loading frequency. However, the stress dependence is insignificant in a relatively high-reduced loading frequency. The Uzan model coefficient of the long-term equilibrium modulus of the relaxation modulus can be determined effectively by the proposed deviatoric stress master curves. To obtain reliable and accurate Maxwell component coefficients, it is recommended that: (a) the measured loss moduli rather than the storage moduli should be used to calculate Maxwell component coefficients if collocation method is utilized, and (b) a log-scaled least squared regression minimization objective should be used as the regression objective for the coefficient determination. The relaxation spectrum of asphalt mixture can be modeled by Gaussian function, where the size of the relaxation spectrum increases but the shape and position of the relaxation spectrum remain unchanged when the confining pressure increases

    Grocery Food Taxes and U.S. County Obesity and Diabetes Rates

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    BACKGROUND: Grocery food taxes represent a stable tax revenue stream for state and municipal government during times of adverse economic shocks such as that observed under the coronavirus disease 2019 (COVID-19) pandemic. Previous research, however, suggests a possible mechanism through which grocery taxes may adversely affect health. Our objectives are to document the spatial and temporal variation in grocery taxes and to empirically examine the statistical relationship between county-level grocery taxes and obesity and diabetes. METHODS: We collect and assemble a novel national dataset of annual county and state-level grocery taxes from 2009 through 2016. We link this data to three-year, county-level estimates based on data from the Centers for Disease Control and Prevention on rates of obesity and diabetes and provide a nation-wide spatial characterization of grocery taxes and these two health outcomes. Using a county-level fixed effects estimator, we estimate the effect of grocery taxes on obesity and diabetes rates, also controlling for a subset of potential confounders that vary over time. RESULTS: We find a 1 percentage point increase in grocery taxes is associated with 0.588 and 0.215 percentage point increases in the county-level obesity and diabetes rates. CONCLUSION: Counties with grocery taxes have increased prevalence of obesity and diabetes. We estimate the economic burden of increased obesity and diabetes rates resulting from grocery taxes to be $5.9 billion. Based on this estimate, the benefit-cost ratio of removing grocery taxes across the United States only considering the effects on obesity and diabetes rates is 1.90

    Schottky Electric Field Induced Circular Photogalvanic Effect in Cd3As2 Nanobelts

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    Dirac semimetals are expected to forbid the manifestation of the circular photogalvanic effect (CPGE) because of their crystal inversion symmetry. Here, we report the observation of the CPGE in Cd3As2 nanobelt field effect transistors, when the photoexcitation is focused in the vicinity of the metal contacts up to room temperature. We attribute the CPGE to the Schottky electric field induced symmetry breaking, which results in the photocurrent modulation by circularly polarized photoexcitation via spin-momentum locking. The hypothesis is supported by a suite of experiments including spatially and angularly resolved helicity dependent photocurrent, Kelvin probe force microscopy, and gate voltage dependence. First principles calculations confirmed a topological phase transition upon field induced structural distortion. This work provides key insights on the electrically controlled helicity dependent optoelectronics in Dirac materials

    Water-soluble cranberry extract inhibits \u3ci\u3eVibrio cholerae\u3c/i\u3e biofilm formation possibly through modulating the second messenger 3’, 5’ - Cyclic diguanylate level

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    Quorum sensing (QS) and nucleotide-based second messengers are vital signaling systems that regulate bacterial physiology in response to changing environments. Disrupting bacterial signal transduction is a promising direction to combat infectious diseases, and QS and the second messengers are undoubtedly potential targets. In Vibrio cholerae, both QS and the second messenger 3’, 5’—cyclic diguanylate (c-di-GMP) play a central role in controlling motility, motile-to-sessile life transition, and virulence. In this study, we found that water-soluble extract from the North American cranberry could significantly inhibit V. cholerae biofilm formation during the development/maturation stage by reducing the biofilm matrix production and secretion. The anti-biofilm effect by water-soluble cranberry extract was possibly through modulating the intracellular c-di-GMP level and was independent of QS and the QS master regulator HapR. Our results suggest an opportunity to explore more functional foods to fight stubborn infections through interference with the bacterial signaling systems
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