Study on Temperature Feedback Effect of Supercritical CO2–Cooled Reactor

As a potential new-type reactor, the supercritical CO2 (S-CO2)–cooled reactor has several advantages, such as being a simple system, having high thermal efficiency, having a small size, and being lightweight. Due to the poor neutronics moderation performance, the S-CO2–cooled reactor shows the disadvantage of a weak temperature feedback effect on reactivity. In this article, the neutronics performance of the reactor has been focused on, and the effects of temperature feedback on fuel, coolant, and moderator studied and the method to improve temperature feedback of the S-CO2 reactor proposed.

Crosstalk between SUMOylated PPARγ1 and FOXO1 Exerts a Positive-feedback Effect on Vascular Endothelial Insulin Resistance

Background: PPARγ and FOXO1 are key regulators of transcription factors that mediate insulin sensitivity. We previously showed that a small ubiquitin-related modifier of PPARγ1 at K77 (SUMOylation) favors endothelial insulin resistance (IR) induced by high-fat/high-glucose (HF/HG) administration. However, whether and how the crosstalk between SUMOylated PPARγ1 and FOXO1 mediates the development of IR remains unclear. Here, we place emphasis on elucidating how PPARγ1-K77 SUMOylation interacts with FOXO1 and participates in the development of endothelial IR.Methods: Adenovirus or adeno-associated virus carrying a truncated PPARγ1 containing AF1 and DBD domains fused with SUMO-1 (PPARγ1[1-182 aa]-SUMO-1 fusion protein) was utilized to simulate PPARγ1-K77 SUMOylation. Furthermore, we carried out PPARγ1-K77 SUMOylation imitating-IR and worsening-IR experiments in vitro and in vivo. The vascular diastolic function and levels of p-IKK, IKK, p-PI3K, PI3K, p-Akt, Akt, p-eNOS, and eNOS were measured. To elucidate the underlying mechanism, the interaction of PPARγ1-K77 SUMOylation and FOXO1 was examined by co-immunoprecipitation. The recruitment of PPARγ1 or FOXO1 to PPRE was analyzed by chromatin immunoprecipitation, followed by measuring the PPARγ1 transcriptional activity and translocation of FOXO1.Results: Our results show that like HF/HG, PPARγ1-K77 SUMOylation imitates endothelial IR and dysfunction, presenting decreased NO levels and elevated ET-1 levels, with PI3K/Akt/eNOS pathway inhibited, and endothelium-dependent vasodilation function impaired. Moreover, combination of HF/HG and PPARγ1-K77 SUMOylation exhibits a synergistic worsening effect on endothelial IR. Mechanistically, the results reveal that PPARγ1-K77 SUMOylation readily interacts with FOXO1, and the PPRE binding site of PI3K is competitively blocked by FOXO1, which represses PPARγ1 transcriptional activity and downregulates the PI3K-Akt pathway. Inhibition of the PI3K-Akt pathway promotes the nuclear accumulation of FOXO1, which interacts with SUMOylated PPARγ1 in the nucleus, exerting a positive feedback effect on IR pathogenesis.Conclusion: These results reveal a novel association between PPARγ1-K77 SUMOylation and FOXO1, which inhibits PPARγ1 transcriptional activity and contributes to vascular endothelial IR. These findings will be beneficial for better understanding the pathogenesis of endothelial IR and providing novel pharmacological targets for diabetic angiopathy.

Short.Term Reactivity Change: Local.Parameter Reactivity Feedback

A change in power for an operating reactor generally alters local parameters in the reactor such as the temperatures of the fuel, moderator, and coolant. A change in any of these local parameters causes a change in reactivity that, in turn, affects reactor operation (a feedback effect). Local parameters help to understand the feedback reactivity components related to the core evolution. For the CANDU reactor, the most important local parameters are the following:

SELF-MIXING LASER VIBROMETER WITHE RESOLUTION IN THE MICRO AND NANO METERS SCALE

We present the development of an interferometer capable of making contactless measurements of vibrations. The resultsshow the we achieve micro- and/or nano-metric measurements without the stabilization of the laser. While there aremultiple techniques to achieve this objective, in this case we use a method whose main virtue is the low componentcount and the self-alignment capacity. The method is based on the optical feedback effect in a laser diode which relieson the use of an internal reference for calibration.

Feedback effects of economic growth on innovation: a country-level empirical study

Purpose The purpose of this paper is to understand the nature of the feedback effects of economic growth on innovation. The question is whether the economies with higher levels of endowments have a declining feedback effect of income on innovation and contribute to the development of effective innovation policies are raised. Design/methodology/approach This study hypothesizes that innovation input’s response to economic growth in terms of income is an inverted “U” shaped path, whereas the innovation output’s response to income is positive and asymptotic. This paper uses the global innovation index data of 154 countries over the period 2013–2017 on innovation and gross domestic product for the analysis using the fixed-effect regression models. Findings The results confirmed the inverted U shaped relationship in the line of Kuznets’s curve for innovation input and that of negative slope and asymptotic behaviour for innovation output. Research limitations/implications In this study, the analysis performed using the global innovation index 2013–2017 data. This study can be extended at each factor level to understand this phenomenon in depth with more data and to help in improving the innovation policies for the betterment of the economic growth. Practical implications This study suggests that developed countries need to guard against complacency in their innovation efforts because of the asymptotic nature exhibited through the effective development of innovation policies. The developing economies can look forward to establishing themselves in the domains of innovation input through imitation of technologies. Originality/value This paper extends the study of feedback effects of economic growth on innovation. This study brings out the nature of feedback effects of economic growth on input innovation and output innovation activities. The results show a declining feedback effect of income on innovation in economies with a higher level of endowments and highlight the inclusion of feedback effects of economic activities on the innovation while designing the innovation and economic policies of a country.

Spatio-Temporal Variation Characteristics of Snow Depth and Snow Cover Days over the Tibetan Plateau

Changes in snow cover over the Tibetan Plateau (TP) have a significant impact on agriculture, hydrology, and ecological environment of surrounding areas. This study investigates the spatio-temporal pattern of snow depth (SD) and snow cover days (SCD), as well as the impact of temperature and precipitation on snow cover over TP from 1979 to 2018 by using the ERA5 reanalysis dataset, and uses the Mann–Kendall test for significance. The results indicate that (1) the average annual SD and SCD in the southern and western edge areas of TP are relatively high, reaching 10 cm and 120 d or more, respectively. (2) In the past 40 years, SD (s = 0.04 cm decade−1, p = 0.81) and SCD (s = −2.3 d decade−1, p = 0.10) over TP did not change significantly. (3) The positive feedback effect of precipitation is the main factor affecting SD, while the negative feedback effect of temperature is the main factor affecting SCD. This study improves the understanding of snow cover change and is conducive to the further study of climate change on TP.