Cross-Lagged Relationship between Physical Activity Time,Openness and Depression Symptoms among Adolescents:Evidence from China

The relationship between physical activity time,openness and depression symptoms among adolescents is a cutting-edge research direction in the field,yet it remains unclear.This study is based on a sample of 7924 students from a nationally representative China Education Panel Survey database and examines the bidirectional relationships between physical activity time,openness and depression symptoms among Chinese adolescents.Descriptive analysis showed that during the 7th and 8th grades,the average physical activity time decreased to less than one hour per day,accompanied by a decreasing trend in openness and a slight worsening in depression symptoms.Correlation analysis showed a significant negative correlation between physical activity time and depression symptoms,a significant positive correlation between physical activity time and openness,and a significant negative correlation between depression symptoms and openness.The results from cross-lagged models indicated a bidirectional relationship between physical activity time and openness,with physical activity time significantly positively predicting openness in the following year and openness significantly positively predicting physical activity time in the following year.In addition,depression symptoms had a unidirectional negative predictive effect on openness.The conclusions provide empirical evidence for education administration and schools to promote the physical and mental health development of adolescents worldwide.

A Case-Control Study on Leisure Time Physical Activity (LTPA) during the Last Three Months of Pregnancy and Foetal Outcomes in Italy

The association between Leisure Time Physical Activity (LTPA) during pregnancy and foetal outcomes has been extensively investigated. However, epidemiological studies specifically referred to LPTA in the last months of pregnancy are scarce. We evaluated the association between LPTA and the risk of both preterm delivery and small for gestational age (SGA) during the last three months of pregnancy in Italy. A nationwide case-control study was performed in nine Italian cities. A total of 299 preterm delivery, 364 SGA and 855 controls were enrolled in the study. A self-administered questionnaire was used to assess socio-demographic variables, medical and reproductive history, life-style habits and LTPA referred to the last three months of pregnancy. Univariate and multivariate regression analyses were performed in order to estimate Odds ratios and 95% CI. LTPA during the last three months of pregnancy decreases the risk of preterm delivery (adjusted OR = 0.56;95% CI 0.39 - 0.79). Among the different types of physical activity, walking, the most frequently referred activity, appears significantly protective against preterm delivery (adjusted OR = 0.53;95% CI 0.36 - 0.81). Moreover, a small protective effect of walking was evidenced against SGA (adjusted OR = 0.72;95% CI 0.51 - 1.00). In conclusion, a mild physical activity such as walking in the last three months of pregnancy seems to reduce the risk of preterm delivery and, at a lesser extent, of SGA, confirming the beneficial effects of physical activity along the whole pregnancy.

Composite Time Concept for Quantum Mechanics and Bio-Psychology

Time has multiple aspects and is difficult to define as one unique entity, which therefore led to multiple interpretations in physics and philosophy. However, if the perception of time is considered as a composite time concept, it can be decomposed into basic invariable components for the perception of progressive and support-fixed time and into secondary components with possible association to unit-defined time or tense. Progressive time corresponds to Bergson＇s definition of duration without boundaries, which cannot be divided for measurements. Time periods are already lying in the past and fixed on different kinds of support. The human memory is the first automatic support, but any other support suitable for time registration can also be considered. The true reproduction of original time from any support requires conditions identical to the initial conditions, if not time reproduction becomes artificially modified as can be seen with a film. Time reproduction can be artificially accelerated, slowed down, extended or diminished, and also inverted from the present to the past, which only depends on the manipulation of the support, to which time is firmly linked. Tense associated to progressive and support fixed time is a psychological property directly dependent on an observer, who judges his present as immediate, his past as finished and his future as uncertain. Events can be secondarily associated to the tenses of an observer. Unit-defined time is essential for physics and normal live and is obtained by comparison of support-fixed time to systems with regular motions, like clocks. The association of time perception to time units can also be broken. Einstein＇s time units became relative, in quantum mechanics, some physicist eliminated time units, others maintained them. Nevertheless, even the complete elimination of time units is not identical to timelessness, since the psychological perception of progressive and support-fixed time still remains and cannot be ignored. It is not seizable by physical methods, but experienced by everybody in everyday life. Contemporary physics can only abandon the association of time units or tenses to the basic components in perceived time.

THE DECAY DIAGRAMS OF TWO NEW NUCLIDES ESTABLISHED BY CHINA FOR THE FIRST TIME IN THE WORLD Lanzhou Institute of Modern Physics, CAS

The decay diagrams of radioactive nuclei are the obvious indication of the main properties shown by the nuclei at low states of excitement and of the basic aspects of nuclear physics.They are extensively applied in industry’,agriculture,energy,national defense,medical science,the environment,and metrology,as well as in astronomy,archaeology,geology,biology,chemistry and other basic sciences.Therefore,they are always focuses of interest.

Prolate and Oblate Shape Coexistence in ^188Pt

A standard in-beam y-spectroscopy experiment for ^188Pt is performed via the ^176yb（^18O, 6n） reaction at beam energies of 88 and 95 MeV, and the level scheme for ^188Pt is established. Prolate and oblate shape coexistence has been demonstrated to occur in ^188Pt by applying the projected shell model. The rotation Mignment of i13/2 neutrons drives the yrast sequence changing suddenly from prolate to oblate shape at angular momentum 1Oh, indicating likely a new type of shape phase transition along the yrast fine in ^188Pt.

One Electron Atom in Special Relativity with de Sitter Space-Time Symmetry

The de Sitter invariant Special Relativity （dS-SR） is SR with constant curvature, and a natural extension of usual Einstein SR （E-SR）. In this paper, we solve the dS-SR Dirac equation of Hydrogen by means of the adiabatic approach and the quasi-stationary perturbation calculations of QM. Hydrogen atom is located in the light cone of the Universe. FRW metric and ACDM cosmological model are used to discuss this issue. To the atom, effects of de Sitter space-time geometry described by Beltrami metric are taken into account. The dS-SR Dirac equation turns out to be a time dependent quantum Hamiltonian system. We reveal that： （i） The fundamental physics constants me, h, e variate adiabatically along with cosmologic time in dS-SR QM framework. But the fine-structure constant α≡ - e^2/（hc） keeps to be invariant; （ii） （2s^1/2 - 2p^1/2）-splitting due to dS-SR QM effects： By means of perturbation theory, that splitting △E（z） are calculated analytically, which belongs to O（1/R^2）-physics of dS-SR QM. Numerically, we find that when ｜R｜ = {103 Gly, 104 Gly, 105 Gly}, and z = {1, or 2}, the AE（z） 〉〉 1 （Lamb shift）. This indicates that for these cases the hyperfine structure effects due to QED could be ignored, and the dS-SR fine structure effects are dominant. This effect could be used to determine the universal constant R in dS-SR, and be thought as a new physics beyond E-SR.