363 research outputs found

    Algorithms for Estimating Trends in Global Temperature Volatility

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    Trends in terrestrial temperature variability are perhaps more relevant for species viability than trends in mean temperature. In this paper, we develop methodology for estimating such trends using multi-resolution climate data from polar orbiting weather satellites. We derive two novel algorithms for computation that are tailored for dense, gridded observations over both space and time. We evaluate our methods with a simulation that mimics these data's features and on a large, publicly available, global temperature dataset with the eventual goal of tracking trends in cloud reflectance temperature variability.Comment: Published in AAAI-1

    Optimation of cooled shields in insulations

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    A method to optimize the location, temperature, and heat dissipation rate of each cooled shield inside an insulation layer was developed. The method is based on the minimization of the entropy production rate which is proportional to the heat leak across the insulation. It is shown that the maximum number of shields to be used in most practical applications is three. However, cooled shields are useful only at low values of the overall, cold wall to hot wall absolute temperature ratio. The performance of the insulation system is relatively insensitive to deviations from the optimum values of the temperature and location of the cooling shields. Design curves for rapid estimates of the locations and temperatures of cooling shields in various types of insulations, and an equation for calculating the cooling loads for the shields are presented

    An extended laser flash technique for thermal diffusivity measurement of high-temperature materials

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    Knowledge of thermal diffusivity data for high-temperature materials (solids and liquids) is very important in analyzing a number of processes, among them solidification, crystal growth, and welding. However, reliable thermal diffusivity versus temperature data, particularly those for high-temperature liquids, are still far from complete. The main measurement difficulties are due to the presence of convection and the requirement for a container. Fortunately, the availability of levitation techniques has made it possible to solve the containment problem. Based on the feasibility of the levitation technology, a new laser flash technique which is applicable to both levitated liquid and solid samples is being developed. At this point, the analysis for solid samples is near completion and highlights of the technique are presented here. The levitated solid sample which is assumed to be a sphere is subjected to a very short burst of high power radiant energy. The temperature of the irradiated surface area is elevated and a transient heat transfer process takes place within the sample. This containerless process is a two-dimensional unsteady heat conduction problem. Due to the nonlinearity of the radiative plus convective boundary condition, an analytic solution cannot be obtained. Two options are available at this point. Firstly, the radiation boundary condition can be linearized, which then accommodates a closed-form analytic solution. Comparison of the analytic curves for the temperature rise at different points to the experimentally-measured values will then provide the thermal diffusivity values. Secondly, one may set up an inverse conduction problem whereby experimentally obtained surface temperature history is used as the boundary conditions. The thermal diffusivity can then be elevated by minimizing the difference between the real heat flux boundary condition (radiation plus convection) and the measurements. Status of an experimental study directed at measuring the thermal diffusivity of high-temperature solid samples of pure Nickel and Inconel 718 superalloys are presented. Preliminary measurements showing surface temperature histories are discussed

    The effect of silymarin on the expression of urotensin�ii and urotensin�ii receptor genes in the liver tissue of type 2 diabetic rats

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    BACKGROUND AND OBJECTIVE: Studies have shown that the increase in urotensin � II is associated with diabetes disorders. Considering that using herbal medicines for the treatment of diseases leads to fewer complications compared to most chemical drugs, the present study was conducted to investigate the effect of silymarin on glucose, and insulin levels and the expression of urotensin � II (U�II) and urotensin � II receptor (U�II R) genes in the liver tissue of type 2 diabetic male rats. METHODS: In this experimental study, 36 male albino Wistar rats were randomly divided into 6 groups (n=6): 1. Control group; 2 and 3. Control groups treated with 60 and 120 mg / kg / day silymarin; 4. Type 2 diabetic group which received an intraperitoneal (i.p.) injection of 60 mg / kg streptozotocin and 120 mg / kg nicotinamide; 5 and 6. Diabetic rats treated with 60 and 120 mg/kg/day silymarin. After 60 days of treatment, serum and liver tissue samples were collected. Glucose, insulin, HOMA-IR index and liver enzymes were evaluated by spectrophotometry and ELISA methods, while gene expression in liver tissue was analyzed by Real-time PCR method. FINDINGS: Insulin levels increased significantly in diabetic groups treated with silymarin (60 and 120 mg/kg) (9.6±1.11 and 9.8±0.96, respectively) in comparison with the diabetic control group (7.10±1.06) (p<0.05). Moreover, glucose level, HOMA-IR, liver enzymes, U�II and U � II R expression in diabetic group treated with silymarin significantly decreased compared to diabetic control group (p<0.05). CONCLUSION: The results of this study showed that administration of silymarin improves liver function in diabetic rats. © 2019, Babol University of Medical Sciences. All rights reserved

    Blueberries infected with the fungal pathogen Colletotrichum fioriniae release odors that repel Drosophila suzukii

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    Spotted-wing drosophila, Drosophila suzukii, is a serious pest of thin-skinned fruits. Alternative methods to control this pest are needed to reduce insecticide use, including new repellents. Previous research demonstrated that D. suzukii adults use odor cues to avoid blueberries infected with the fungal pathogen Colletotrichum fioriniae, which causes the disease anthracnose. To identify novel D. suzukii repellents, we investigated the volatile emission from experimentallyinfected fruit, which were inoculated with C. fioriniae isolates in the laboratory, and from field-collected fruit, which were naturally infected and harvested from a field. We then tested the pathogen-induced volatiles on D. suzukii adult behavior.hanks to Arthur Rudolph for his help operating the GC–MS during pandemic work restrictions, Chelsea Abegg for providing field-collected blueberry fruit infected with anthracnose, to Mustafa Wasti, Robert Holdcraft, and Vera Kyryczenko-Roth for technical assistance. Authors CCR and JJB were supported by USDA ARS CRIS 6036-224300-001-000D and CR-S and AQ were supported by USDA SCRI 2020-51181-32140, The Sridhar Polavarapu Memorial Endowment for Vaccinium Research, and USDA Sustainable Agriculture Research and Education (grant no. LNE22-455R).info:eu-repo/semantics/publishedVersio

    LncRNA RP11-19E11 is an E2F1 target required for proliferation and survival of basal breast cancer

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    Long non-coding RNAs (lncRNAs) play key roles in the regulation of breast cancer initiation and progression. LncRNAs are differentially expressed in breast cancer subtypes. Basal-like breast cancers are generally poorly differentiated tumors, are enriched in embryonic stem cell signatures, lack expression of estrogen receptor, progesterone receptor, and HER2 (triple-negative breast cancer), and show activation of proliferation-associated factors. We hypothesized that lncRNAs are key regulators of basal breast cancers. Using The Cancer Genome Atlas, we identified lncRNAs that are overexpressed in basal tumors compared to other breast cancer subtypes and expressed in at least 10% of patients. Remarkably, we identified lncRNAs whose expression correlated with patient prognosis. We then evaluated the function of a subset of lncRNA candidates in the oncogenic process in vitro. Here, we report the identification and characterization of the chromatin-associated lncRNA, RP11-19E11.1, which is upregulated in 40% of basal primary breast cancers. Gene set enrichment analysis in primary tumors and in cell lines uncovered a correlation between RP11-19E11.1 expression level and the E2F oncogenic pathway. We show that this lncRNA is chromatin-associated and an E2F1 target, and its expression is necessary for cancer cell proliferation and survival. Finally, we used lncRNA expression levels as a tool for drug discovery in vitro, identifying protein kinase C (PKC) as a potential therapeutic target for a subset of basal-like breast cancers. Our findings suggest that lncRNA overexpression is clinically relevant. Understanding deregulated lncRNA expression in basal-like breast cancer may lead to potential prognostic and therapeutic applications

    Hepatoprotective effects of silymarin on liver injury via irisin upregulation and oxidative stress reduction in rats with type 2 diabetes

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    Background: Diabetes is one of the most prevalent metabolic diseases. Irisin (FNDC5 protein) is involved in the new strategy of combating type 2 diabetes. In the liver, the antidiabetic mechanism of silymarin at the molecular level is unknown. This study investigated the effects of silymarin on irisin and the related gene expression and oxidative stress status in the liver of type 2 diabetic rats. Methods: Thirty-six rats were divided into 6 groups (n=6 each) by simple randomization: control, control+silymarin (60 mg/kg daily in normal saline orally for 60 days), control+silymarin (120 mg/kg daily in normal saline orally for 60 days), diabetic, diabetic+silymarin (60 mg/kg daily for 60 days), and diabetic+silymarin (120 mg/kg daily for 60 days). Biochemical parameters were measured by spectrophotometric and immunoassay methods, and quantitative polymerase chain reaction was used to evaluate gene expression. The data were analyzed by one-way ANOVA, followed by the Tukey test, using SPSS software, version 16.0. The results were considered statistically significant at a P value less than 0.05. Results: In the diabetic rats treated with silymarin (60 and 120 mg/kg), by comparison with the diabetic group, body weight (P=0.04 and P=0.02), insulin (P<0.001), expression of PGC-1α (P=0.04 and P=0.02), expression of FNDC5 (P=0.03 and P=0.01), and concentration of irisin in the liver (P=0.02 and P=0.01) and serum (P<0.001) were significantly increased, whereas the levels of glucose (P<0.001), HOMA-IR (P=0.03 and P=0.01), and liver injury markers (P<0.001) were significantly reduced. Oxidative stress status and histopathological changes were improved in the treated groups. Conclusion: These results suggest that silymarin because of its ability to upregulate irisin and antioxidant effects can be considered an antidiabetic agent. © 2019, Shiraz University of Medical Sciences. All rights reserved

    Carbon combustion synthesis of Janus-like particles of magnetoelectric cobalt ferrite and barium titanate

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    Carbon combustion synthesis of oxides was applied for quick and energy efficient production of multiferroic composite of cobalt ferrite and barium titanate to form Janus-like particles matrix structure. The exothermic oxidation of carbon nanoparticles with an average size of 5 nm and a specific surface area of 110 m2/g generates a self-propagating thermal wave with peak temperature of up to 1000 °C. The thermal front rapidly propagates through the mixture of solid reactants (magnetic- CoFe2O4 and ferroelectric-BaTiO3) and results in localized hot-spot sintering of magneto-electric phases to form a nanocomposite structure. Carbon is not incorporated in the product and is emitted as a gaseous CO2. Existence of discrete CoFe2O4 and BaTiO3phases in the composites nanostructures was confirmed using X-ray powder diffraction along with SEM and TEM analysis. We estimated the activation energy for the combustion synthesis of Janus-like particles to be 112 ± 3.3 kJ/mol, indicating that the barium titanate and cobalt ferrite presence decrease the activation energy barrier of carbon oxidation and facilitate the ignition process of the combustion synthesis. We observe that the as-synthesized samples show magnetoelectric coupling on multiferroic cobalt ferrite–barium titanate ceramic composites
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