In contrast to mainstream theories focusing on adolescent developmental deficits, the positive youth development (PYD) approach highlights adolescent developmental plasticity and potentials. There are rich empirical research and review studies showing that PYD attributes promote adolescent well-being. However, the existing literature shows several limitations. First, while there are many Western studies, Chinese studies are sparse, particularly studies in mainland China. Second, most PYD studies are cross-sectional studies with data collected at one single time point. Third, researchers in different Chinese contexts (...) seldom employed validated Chinese scales assessing different domains of PYD attributes. Fourth, few studies have examined the relationships between PYD attributes (measures of eudaimonic well-being) and life satisfaction (measure of hedonic well-being) and hopelessness (measure of negative well-being) in a single study. Finally, the role of life satisfaction or hopelessness as a mediator of the relationship between PYD attributes and psychological well-being is unclear. To explore the importance of PYD attributes to Chinese adolescent psychological well-being, we conducted a longitudinal study with two waves of data collected from junior high school students in mainland China ( N = 2,648). At both times, validated measures of PYD attributes, life satisfaction, and hopelessness were employed. Results showed that PYD attributes concurrently and longitudinally predicted life satisfaction and hopelessness with small effect sizes. Cross-lagged panel analyses showed that while Wave 2 life satisfaction did not serve as a mediator of the relationship between Wave 1 PYD attributes and Wave 2 hopelessness, Wave 2 hopelessness served as a mediator of the link from Wave 1 PYD attributes to Wave 2 life satisfaction. In view of the paucity of research findings in this area, the present findings clarify the association between PYD attributes and hedonic well-being (indexed by life satisfaction) and negative psychological well-being (indexed by hopelessness) in Chinese adolescents. (shrink)

Ribonucleotide reductase (RNR) catalyzes the rate limiting step in the production of deoxyribonucleotides needed for DNA synthesis. In addition to the well documented allosteric regulation, the synthesis of the enzyme is also tightly regulated at the level of transcription. mRNAs for both subunits are cell cycle regulated and inducible by DNA damage in all organisms examined, including E. coli, S. cerevisiae and H. sapiens. This DNA damage regulation is thought to provide a metabolic state that facilitates DNA replicational repair processes. (...) S. cerevisiae also encodes a second large subunit gene, RNR3, that is expressed only in the presence of DNA damage. Genetic analysis of the DNA damage response in S. cerevisiae has shown that RNR expression is under both positive and negative control. Among mutants constitutive for RNR expression are the general transcriptional repression genes, SSN6 and TUP1. Mutations in POL1 and POL3 also activate RNR expression, indicating that the DNA damage sensory network may respond directly to blocks in DNA synthesis. A protein kinase, Dun1, has been identified that controls inducibility of RNR1, RNR2 and RNR3 in response to DNA damage and replication blocks. This result suggests that the RNR genes in S. cerevisiae form a regulon that is coordinately regulated by protein phosphorylation in response to DNA damage. (shrink)

The signals in numerous complex systems of engineering can be regarded as nonlinear parameter trend with noise which is identically distributed random signals or deterministic stationary chaotic signals. The commonly used methods for parameter estimation of nonlinear trend in signals are mainly based on least squares. It can cause inaccurate estimation results when the noise is complex. This paper proposes a calibration method for this issue in the case of single parameter via nonstationarity measure from the perspective of the stationarity (...) of residual sequence. Some numerical studies are conducted for validation. Results of numerical studies show that the proposed calibration method performs well for various models with different noise strengths and types and can significantly improve the accuracy of initial estimates obtained by least squares method. This is the first time that the nonstationarity measure is applied to the parameter calibration. All these results will be a guide for future studies of other parameter calibrations. (shrink)

[1]. Xian Qin liang Han juan -- [2]. Wei Jin Nan Bei chao juan -- [3-4]. Sui Tang Wu dai juan -- [5-6]. Song Liao Jin Yuan juan -- [7-8]. Ming Qing juan -- [9]. Jin dai juan.