Background: Physical activity(PA) during pregnancy provides physical and psychological benefits for mother and child. U.S. guidelines recommend ≥30 min of moderate exercise for healthy pregnant women most days of the...Background: Physical activity(PA) during pregnancy provides physical and psychological benefits for mother and child. U.S. guidelines recommend ≥30 min of moderate exercise for healthy pregnant women most days of the week; however, most women do not meet these recommendations. Theory assists in identifying salient determinants of health behavior to guide health promotion interventions; however, the application of theory to examine PA among pregnant women has not been examined cohesively among multiple levels of influence(e.g.,intrapersonal, interpersonal, neighborhood/environmental, and organizational/political). Subsequently, this systematic review aims to identify and evaluate the use of health behavior theory in studies that examine PA during pregnancy.Methods: Articles published before July 2014 were obtained from Pub Med and Web of Science. Inclusion criteria applied were:(1) empiricallybased;(2) peer-reviewed;(3) measured factors related to PA;(4) comprised a pregnant sample; and(5) applied theory. Fourteen studies were included. Each study's application of theory and theoretical constructs were evaluated.Results: Various theories were utilized to explain and predict PA during pregnancy; yet, the majority of these studies only focused on intrapersonal level determinants. Five theoretical frameworks were applied across the studies—all but one at the intrapersonal level. Few determinants identified were from the interpersonal, neighborhood/environmental, or organizational/political levels.Conclusion: This systematic review synthesized the literature on theoretical constructs related to PA during pregnancy. Interpersonal, community,and societal levels remain understudied. Future research should employ theory-driven multi-level determinants of PA to reflect the interacting factors influencing PA during this critical period in the life course.展开更多
In the warming world, tropical Pacific sea surface temperature （SST） variation has received considerable attention because of its enormous influence on global climate change, particularly the El Nino-Southern Oscill...In the warming world, tropical Pacific sea surface temperature （SST） variation has received considerable attention because of its enormous influence on global climate change, particularly the El Nino-Southern Oscillation process. Here, we provide new high-resolution proxy records of the magnesium/ calcium ratio and the oxygen isotope in foraminifera from a core on the Ontong-Java Plateau to reconstruct the SST and hydrological variation in the center of the Western Pacific Warm Pool （WPWP） over the last 360 000 years. In comparison with other Mg/Ca-derived SST and δ18O records, the results suggested that in a relatively stable condition, e.g., the last glacial maximum （LGM） and other glacial periods, the tropical Pacific would adopt a La Nifia-like state, and the Walker and Hadley cycles would be synchronously enhanced. Conversely, El Nino-like conditions could have occurred in the tropical Pacific during fast- changing periods, e.g., the termination and rapidly cooling stages of interglacial periods. In the light of the sensitivity of the Eastern Pacific Cold Tongue （EPCT） and the inertia of the WPWP, we hypothesize an inter-restricted relationship between the WPWP and EPCT, which could control the zonal gradient variation of SST and affect climate change.展开更多
文摘Background: Physical activity(PA) during pregnancy provides physical and psychological benefits for mother and child. U.S. guidelines recommend ≥30 min of moderate exercise for healthy pregnant women most days of the week; however, most women do not meet these recommendations. Theory assists in identifying salient determinants of health behavior to guide health promotion interventions; however, the application of theory to examine PA among pregnant women has not been examined cohesively among multiple levels of influence(e.g.,intrapersonal, interpersonal, neighborhood/environmental, and organizational/political). Subsequently, this systematic review aims to identify and evaluate the use of health behavior theory in studies that examine PA during pregnancy.Methods: Articles published before July 2014 were obtained from Pub Med and Web of Science. Inclusion criteria applied were:(1) empiricallybased;(2) peer-reviewed;(3) measured factors related to PA;(4) comprised a pregnant sample; and(5) applied theory. Fourteen studies were included. Each study's application of theory and theoretical constructs were evaluated.Results: Various theories were utilized to explain and predict PA during pregnancy; yet, the majority of these studies only focused on intrapersonal level determinants. Five theoretical frameworks were applied across the studies—all but one at the intrapersonal level. Few determinants identified were from the interpersonal, neighborhood/environmental, or organizational/political levels.Conclusion: This systematic review synthesized the literature on theoretical constructs related to PA during pregnancy. Interpersonal, community,and societal levels remain understudied. Future research should employ theory-driven multi-level determinants of PA to reflect the interacting factors influencing PA during this critical period in the life course.
基金Supported by the Knowledge Innovation Engineering Project of Chinese Academy of Sciences(No.XDA10010305)the National Special Project for‘Global Change and Air-Sea Interaction’(No.GASI-04-01-02)the National Natural Science Foundation of China(Nos.41230959,41076030,41576051)
文摘In the warming world, tropical Pacific sea surface temperature （SST） variation has received considerable attention because of its enormous influence on global climate change, particularly the El Nino-Southern Oscillation process. Here, we provide new high-resolution proxy records of the magnesium/ calcium ratio and the oxygen isotope in foraminifera from a core on the Ontong-Java Plateau to reconstruct the SST and hydrological variation in the center of the Western Pacific Warm Pool （WPWP） over the last 360 000 years. In comparison with other Mg/Ca-derived SST and δ18O records, the results suggested that in a relatively stable condition, e.g., the last glacial maximum （LGM） and other glacial periods, the tropical Pacific would adopt a La Nifia-like state, and the Walker and Hadley cycles would be synchronously enhanced. Conversely, El Nino-like conditions could have occurred in the tropical Pacific during fast- changing periods, e.g., the termination and rapidly cooling stages of interglacial periods. In the light of the sensitivity of the Eastern Pacific Cold Tongue （EPCT） and the inertia of the WPWP, we hypothesize an inter-restricted relationship between the WPWP and EPCT, which could control the zonal gradient variation of SST and affect climate change.
