In this paper, we examine the long- and short-run dynamics between electricity consumption and economic activities, using panel data of per capita electricity consumption and per capita GDP of 160 ...countries for the period of 1980–2010, accounting for the degree of electricity dependence and the level of urbanization. Furthermore, in order to capture the differences in this relationship, the full sample is divided into various subsamples based on countries' income levels, regional locations and OECD memberships. This framework is argued and found to be appropriate since the causal links and inferences arising therefrom differ considerably among the subsamples, which led us to conclude that the electricity-growth nexus is highly sensitive to regional differences, countries' income levels, urbanization rates and supply risks.
•The causal relationship between electricity consumption and GDP is investigated.•Cointegration techniques are used for 160 countries and 13 subsamples.•Urbanization and electricity trade are accounted for as additional covariates.•Causal inferences are found to be associated with panel-specific differences.•Policy issues are discussed based on the study results.
The quality attributes of jujube fruit can be directly and indirectly affected by abiotic stresses associated with climate change. Increased temperature and drought are among the most important ...factors challenging sustainable jujube production in the temperate semi-arid region in northwest China. The main objective of the present study was to understand the effects of elevated air temperature and drought stress on sugar and acid accumulation and coloration of jujube fruits. The content of soluble sugar, organic acid and pigments of traditional jujube "Linwuchangzao" under different atmospheric temperatures and drought stresses were analyzed during three different fruit ripening stages. The elevated temperature (1.5-2.5° C than normal temperature) significantly increased the fruit sugar content, sugar-acid ratio, anthocyanins, flavonoids and carotenoids content. Under the drought stress where the soil moisture was 30% -50% of the field capacity, sugar content, anthocyanin, flavonoid and carotenoid content of the fruit were significantly reduced at the same temperature, but the chlorophyll and organic acid content increased. No significant interaction of Temperature x Drought was observed for all the analyzed quality parameters. The current results showed that the fruit quality of jujube variety "Lingwuchangzao" could be improved when the atmospheric temperature increases by 2° C in this region. However, drought stress had a negative impact on the fruit's sugar-acid ratio and pigment content. The present results also showed that the synthesis and accumulation of anthocyanins in jujube fruit were positively correlated with sugar content and related enzyme activities, especially Phenylalanine Ammonia-lyase (PAL) activity. This study, therefore, provides novel information for understanding the influence of growth environment on the quality properties of jujube fruits. This knowledge will help develop appropriate crop management practices for jujube production in arid and semi-arid areas in northwest China.
A field study was carried out to analyze the short-term (2 years) effect of tillage and crop rotation on microbial community structure and enzyme activities of a clay loam soil. The experimental ...design was a split-plot arrangement of treatments, consisting of two tillage treatments—ridge tillage (RT) and no-tillage (NT)—in combination with two crop rotation treatments—corn (Zea mays L.) monoculture and a 2-year corn-soybean (Glycine max L.) rotation. Phospholipid fatty acid (PLFA) profiles were used to assess soil microbial community structure. No-tillage resulted in significantly higher total PLFAs compared to the RT treatment, which was accompanied by higher activities of protease, β-glucosaminidase, and β-glucosidase. This suggests a close link between soil microbial communities and enzyme activities in response to tillage. The increase of total microbial lipid biomass in the NT soils was due to the increase in both fungal and bacterial PLFAs. Crop rotation had little effect on soil bacterial communities and enzyme activities, but it significantly influenced soil fungal communities, particularly arbuscular mycorrhizal fungi. Soils under monoculture corn had higher fungal biomass than soils under corn-soybean rotation regardless of tillage treatment.
Zinc deficiency has a huge impact on male reproduction. The zinc transporter (ZnT) family is involved in the maintenance of zinc homeostasis and testosterone synthesis. However, the underlying ...mechanisms remain to be investigated. Therefore, in this study, we aimed to determine the effect of zinc transporter 4 (ZnT4) on testosterone synthesis in male Kunming mice and mouse Leydig cells. The results of this study showed that compared with the zinc normal diet group (Con group), the zinc-deficient diet group (ZnD group) had decreased zinc content and increased ZnT4 expression in testicular tissues, and decreased serum testosterone levels, suggesting that ZnT4 may be involved in Leydig cell injury resulting from a zinc-deficient diet. Subsequently, mouse Leydig cell line TM3 cells were used to analyze the effect of ZnT4 downregulation on TM3 cell proliferation and apoptosis, on testosterone synthesis, and its underlying mechanisms. Here, we show that knockdown of ZnT4 can induce the accumulation of zinc, inhibit the viability, and induce apoptosis in TM3 cells. In addition, knockdown of ZnT4 downregulated testosterone concentration and expression of testosterone synthesis–related proteins steroidogenic acute regulatory protein (StAR) and 3β-hydroxysteroid dehydrogenase/D5-D4 isomerase (3β-HSD) in TM3 cells, while hCG could rescue their levels. We show that it is ZnT4 that plays a role in testosterone production through a mediated PI3K/Akt/mTOR autophagy pathway, whereas mTORC1 complex inhibitor (Rapa) blocks the decrease in testosterone levels caused by ZnT4 downregulation. In conclusion, the above results indicate that ZnT4 plays an important role in regulating testosterone synthesis.
Abstract
Monthly unit commitment (UC) is a decision‐making process that determines the optimal generation scheduling of mid and long‐term power system, often operating as a subproblem within monthly ...electricity market operations and long‐term maintenance scheduling optimization in China. Dealing with transmission constraints in monthly security‐constrained unit commitment (SCUC) is considered to be challenging, but its simplification can be achieved through eliminating inactive security constraints. Additionally, the uncertainty associated with wind power needs to be given due consideration in monthly scheduling. Here, a three‐step watchlist construction strategy is proposed to facilitate the rapid screening of overloaded power flow constraints in monthly unit commitment, including three lists (i.e. list of risk, list of concern, and list of interest) under different conservatism. Importantly, the shift factor method is utilized to screen the potential overloaded constraints arising from the redispatch process for hedging the effects of large wind uncertainties. Results obtained from the testing of IEEE‐118 system indicates that more than 99% of active power flow constraints could be successfully screened out when wind power fluctuation is at 20%. As such, the proposed scheme provides an effective method to consider uncertainty associated with large‐scale wind power generation integrated into the power grid.
We investigated progression and interrelationships of cerebral small vessel disease (cSVD) markers. This population-based cohort study included 325 participants (age ≥ 60 years) who had repeated ...measures of cSVD markers over 6 years: white-matter hyperintensity (WMH), perivascular spaces (PVS), lacunes, and grey-matter (GM) and ventricular volumes. We found that all cSVD markers, except PVS, progressed faster with increasing age. Regional WMH progressed faster in males and less-educated people (p < 0.05). Each 10-point increment in global WMH score was associated with multi-adjusted hazard ratio of 1.78 (95% CI = 1.50‒2.10) for incident lacunes and multi-adjusted β-coefficients of 0.15 (0.08–0.22), -0.37 (-0.58‒-0.16), and 0.11 (0.03‒0.18) for annual changes of global WMH score, GM volume, and ventricular volume, respectively. The corresponding figures associated with per 10-PVS increment were 1.14 (1.01‒1.28), 0.07 (0.03‒0.11), -0.18 (-0.32‒-0.04), and 0.02 (-0.03‒0.07). Prevalent lacunes were related to multi-adjusted β-coefficients of 0.29 (0.00‒0.58), 0.22 (0.05‒0.38), 0.10 (0.01‒0.18), and -0.93 (-1.83‒-0.03) for annual changes of global, deep, and periventricular WMH scores and GM volume, respectively. These results suggest that cSVD progresses faster in older, male, and less-educated people, and that greater loads of WMH, PVS, and lacunes anticipate faster cSVD progression.
To explore the associations between dietary zinc intake and cardiovascular diseases (CVDs), including congestive heart failure (CHF), coronary heart disease (CHD), angina, heart attack, and ...cerebrovascular accident (CVA), this study was performed.
Data from the National Health and Nutrition Examination Survey (2005–2018) were used in this study. Dietary zinc intake was stratified into quartiles. Restricted cubic splines were constructed to assess nonlinear associations and identify cut-off values based on the type of nonlinearity. Binary logistic regressions were performed using the cut-offs.
Positive associations were detected between the second, third, and fourth quantiles of dietary zinc intake and decreased risks of overall CVDs (Q2: OR = 0.83, 95 % CI = 0.72–0.96; Q3: OR = 0.83, 95 % CI = 0.71–0.96; Q4: OR = 0.79, 95 % CI = 0.67–0.93). The second, third, and fourth quantiles were significantly associated with decreased risks of various CVDs (all P < 0.05), except for CHD and angina (all P > 0.05). Restricted cubic spline regression revealed significant nonlinear trends for associations of dietary zinc intake with the risk of developing CVDs and CHF (both P for nonlinear <0.05), whereas those for heart attack and CVA were marginally significant (P for nonlinear = 0.072, and 0.075, respectively).
This study revealed that high dietary zinc intake is associated with reduced risks of developing CVDs, CHF, heart attack, and CVA, but not CHD or angina.
A high-fat diet (HFD) is associated with adipose inflammation, which contributes to key components of metabolic syndrome, including obesity and insulin resistance. The increased visceral adipose ...tissue mass associated with obesity is the result of hyperplasia and hypertrophy of adipocytes. To investigate the effects of exercise on HFD-induced metabolic disorders, male C57BL/6 mice were divided into four groups: SED (sedentary)-ND (normal diet), EX (exercise)-ND, SED-HFD, and EX-HFD. Exercise was performed on a motorized treadmill at 15 m/min, 40 min/day, and 5 day/wk for 8 wk. Exercise resulted in a decrease in abdominal fat contents and inflammation, improvements in glucose tolerance and insulin resistance, and enhancement of vascular constriction and relaxation responses. Exercise with or without HFD increased putative brown adipocyte progenitor cells in brown adipose tissue compared with groups with the same diet, with an increase in brown adipocyte-specific gene expression in brown and white adipose tissue. Exercise training enhanced in vitro differentiation of the preadipocytes from brown adipose depots into brown adipocytes and enhanced the expression of uncoupling protein 1. These findings suggest that exercise ameliorates high-fat diet-induced metabolic disorders and vascular dysfunction, and increases adipose progenitor cell population in brown adipose tissue, which might thereby contribute to enhanced functional brown adipose.
Mitogen-activated protein kinase (MAPK) cascades play important roles in the stress response in both plants and microorganisms. The mycorrhizal symbiosis established between arbuscular mycorrhizal ...fungi (AMF) and plants can enhance plant drought tolerance, which might be closely related to the fungal MAPK response and the molecular dialogue between fungal and soybean MAPK cascades. To verify the above hypothesis, germinal Glomus intraradices (syn. Rhizophagus irregularis) spores and potted experiments were conducted. The results showed that AMF GiMAPKs with high homology with MAPKs from Saccharomyces cerevisiae had different gene expression patterns under different conditions (nitrogen starvation, abscisic acid treatment, and drought). Drought stress upregulated the levels of fungi and soybean MAPK transcripts in mycorrhizal soybean roots, indicating the possibility of a molecular dialogue between the two symbiotic sides of symbiosis and suggesting that they might cooperate to regulate the mycorrhizal soybean drought-stress response. Meanwhile, the changes in hydrogen peroxide, soluble sugar, and proline levels in mycorrhizal soybean as well as in the accelerated exchange of carbon and nitrogen in the symbionts were contributable to drought adaptation of the host plants. Thus, it can be preliminarily inferred that the interactions of MAPK signals on both sides, symbiotic fungus and plant, might regulate the response of symbiosis and, thus, improve the resistance of mycorrhizal soybean to drought stress.
We sought to identify the optimal cut-off of glycated hemoglobin (HbA1c) for defining diabetes and to assess the agreements of fasting plasma glucose (FPG), fasting serum glucose (FSG), and HbA1c in ...defining diabetes among rural older adults in China.
This population-based cross-sectional study included 3547 participants (age ≥61 years, 57.8% women) from the Multidomain Interventions to Delay Dementia and Disability in Rural China from 2018-2019; of these, 3122 had no previously diagnosed diabetes. We identified the optimal cut-off of HbA1c against FPG ≥7.0 mmol/L for defining diabetes by using receiver operating characteristic curve and Youden index. The agreements of FPG, FSG, and HbA1c in defining diabetes were assessed using kappa statistics.
Among participants without previously diagnosed diabetes (n = 3122), the optimal HbA1c cut-off for defining diabetes was 6.5% (48 mmol/mol), with the sensitivity of 88.9%, specificity of 93.7%, and Youden index of 0.825. The correlation coefficients were 0.845 between FPG and FSG, 0.574 between FPG and HbA1c, and 0.529 between FSG and HbA1c in the total sample (n = 3547). The kappa statistic for defining diabetes was 0.962 between FSG and FPG, and 0.812 between HbA1c and FPG.
The optimal cut-off of HbA1c for diagnosing diabetes against FPG >7.0 mmol/L is ≥6.5% in Chinese rural-dwelling older adults. The agreement in defining diabetes using FPG, FSG, and HbA1c is nearly perfect. These results have relevant implications for diabetes research and clinical practice among older adults in China.
The protocol of MIND-China was registered in the Chinese Clinical Trial Registry (ChiCTR, www.chictr.org.cn; registration no.: ChiCTR1800017758).
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