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Holocene paleoclimate reconstructions and comparisons largely rely on accurate age-depth modeling. However, uncertainties in chronology, such as those caused by sparse radiocarbon dates, will hamper inter-core comparisons and correlations, and might result in misleading "cause and consequence" conclusions. This study aimed to find a solution to increase the comparability and minimize the uncertainty of wetland chronology as much as possible. Sediment cores were recovered and radiocarbon dated from the Lianhuachi wetland located in Southeastern China. Humification degree and loss-on-ignition (LOI) were determined using colorimetric and combustion methods respectively. Our data were compared with previously published datasets obtained in the same wetland. The results show that independent humification profiles from the Lianhuachi wetland displayed high similarities. This high similarity between the humification profiles allowed us to transfer radiocarbon ages from one core to another using sequence slotting correlation. Applying the humification-based chronology refinement method to all sediment cores resulted in an improvement in the correlation coefficients between the same but independently measured proxy sequences from the wetland, which suggests both the inter- and intra-core comparability was improved. Because determining peat humification degree is easy, inexpensive, and time-saving, we suggest that humification can serve as a tool that can be used to correlate different cores and to transfer published radiocarbon ages within the same wetland (peatland) or in a comparable geological setting, to establish a more robust chronology of these comparable cores. The degree of peat humification can thus serve as a relative dating technique to refine the chronology of wetland (including peatland) records. [ABSTRACT FROM AUTHOR]

This study investigates the reliability of phytolith assemblage analysis for characterizing subtropical vegetation and explores the potential for using these modern phytolith–vegetation relationships for paleoenvironmental interpretation in southeastern China. The samples were collected from five common subtropical vegetation communities in the Daiyun Mountains, southeastern China, with the above-ground vegetation recorded at each plot. Constrained ordination analysis was used to determine the most important factor governing the variations in phytolith assemblages that could be quantitatively reconstructed with weighted averaging partial least squares regression (WAPLS). The relationship between modern phytolith assemblages and the parent vegetation, as well as production, dispersal, and taphonomic processes, was discussed. Results demonstrated that the main subtropical biomes in southeastern China could be well distinguished by soil phytolith assemblages. In particular, the overall amount of tree coverage was well represented by topsoil phytolith assemblages. Grass silica short cell phytoliths (GSSCP) tended to occur in higher proportions in open habitats (shrub-meadow) at higher elevations, whereas non-grass phytolith morphotypes attained higher frequencies under mixed and broadleaf forests at lower elevations. Human-induced deforestation might increase the frequency of GSSCP within the bulk phytolith assemblage. Our results constitute the primary phytolith reference data for the subtropical zone in southeastern Asia where vegetation change during the Holocene period, particularly forest shifts, anthropogenic deforestation, and early agriculture are poorly documented. [ABSTRACT FROM AUTHOR]

Understanding the characteristics of different human-induced coastal surface deformation will improve our understanding of recent temporal-spatial evolution trends of the coastal terrain, and help better predict the risks of coastal disasters. However, few surface deformation studies have focused on the distinction between different types of anthropogenic ground deformation. Based on Sentinel-1 Synthetic Aperture Radar (SAR) data, this study employs the hybrid multi-temporal Interferometric Synthetic Aperture Radar (InSAR) method to extract the surface deformation of Chaoshan Plain from 2015 to 2020, with a spatial resolution of 30 m × 30 m. A series of historical optical satellite images and groundwater extraction data are used to help distinguish different types of human activities that have induced surface deformation. The characteristics of ground deformation induced by different types of anthropogenic activities are explored in the space and time dimensions. Results show that InSAR ground deformation in the study area is mainly caused by three types of human activities: groundwater extraction, land reclamation, and construction. Groundwater extraction has impacted >50% of the regional surface deformation by area. The interannual variability of the surface deformation rate corresponds well to that of groundwater extraction, and the subsidence effect can last for more than five years with seasonal variability. The maximum surface subsidence rate in land reclamation areas reaches ~100 mm/year, with a linear decreasing trend against time. Without extra compaction, the reclamation area can continue to deform almost at the same rate for several years. The rapid increase of overlying loads caused by construction in the reclamation area has led to a sharp decrease in the deformation rate within 2–3 years after the completion of the construction. In areas absent of other human-induced deformation, construction activities are shown to cause surface subsidence of 10–20 mm/year in a relatively short period. In areas experiencing a combination of construction and groundwater extraction, land subsidence rates of >50 mm/year are observed. This study shows that the spatial and temporal analysis of the correlations between human activities and InSAR surface deformation is an effective way to attribute the driven factors of coastal plain deformation. • Human-induced land deformation can be interpreted by satellite time-series images. • Groundwater exploitation deformation shows the seasonal and interannual variation. • Deformation in reclaimed area largely due to surface loading and soil compaction • Construction complicates InSAR surface deformation patterns in tempo-spatially. [ABSTRACT FROM AUTHOR]

Background: This study aimed to assess ethnic differences in health-related quality of life (HRQoL) among the rural elderly, and to examine the influence of ethnic culture, residential segregation and socioeconomic development on HRQoL.Methods: A total of 6,511 rural elderly aged 60 years and older from 5,541 households in 116 villages across eight ethnic groups in Guangxi Zhuang Autonomous region were selected and assessed for HRQoL. The EQ-5D index values were calculated based on the Chinese Time Trade-Off values set. The EQ-5D descriptive system scores, visual analogue scale scores, and index values were described by ethnic group. The EQ-5D index was modeled against ethnic culture, residential segregation and socioeconomic development using villages as random effects.Results: The median (IQR) of HRQoL among all the ethnic groups was 0.88 (0.80, 0.96). Pain/discomfort was the most prevalent problem, followed by anxiety/depression. After controlling for sociodemographic characteristics, a significant difference in HRQoL among ethnic groups persisted, but this was not true for residential segregation.Conclusion: Social welfare and health policies designed to improve the health of the rural elderly should focus more on older, female, less-educated, Yao minority individuals as well as lower-income households. [ABSTRACT FROM AUTHOR]

Aiming to gain a better understanding of the response of sediment-starved coastal systems to the climate-driven sea level change, this study examines the Holocene evolution history of Qing'ao Embayment, southern China, as a case study. Results suggest three distinct stages of the evolution history: Stage 1 (8400–6000 cal yr BP) records an initial sedimentation phase associated with the early Holocene marine transgression into the embayment. Stage 2 (6000–3000 cal yr BP) records early sediment deposition under relatively strong hydrodynamic inshore/open-bay environment during early marine regression. Stage 3 (3000 cal yr BP to present) records two substages: Stage 3a relates to the semi-enclosed bay, intertidal and lagoonal salt marsh facies between 3000 and 1300 cal yr BP, and Stage 3b records the final infilling of the embayment into a lagoonal plain. This evolution model suggests that the rates of sea level change and sediment accretion are the two major controlling factors for the Holocene geomorphological evolution of sediment-starving coastal systems. Comparison of the evolution of Qing'ao embayment with sediment-supply rich large-river estuary/deltas reveals unique features in the response to Holocene sea level change of this sediment-starved embayment: During the early Holocene marine transgression, sediment starts to accumulate in the small embayment around 8400 cal yr BP, hundreds of years later than in large river estuaries. During 8400–6000 cal yr BP, sediment accretion rate remains dramatically lower than sea level rise rate, which results in the quick growth of sediment accommodation space during this stage. Around 6000 cal yr BP, though sea level has remained relatively stable and large-river deltas have been growing for about 1000 years, the sediment-starved embayment was still under shallow marine and/or open bay conditions. At 3000 cal yr BP, shoreline started to prograde in sediment-starved embayment, which is about 3000 years later than large river deltas. Finally, agricultural activity started around 1300 cal yr BP in the embayment, thousands of years later than large river deltas. Limited or minimal fluvial sediment supply to the small embayment has constrained the land expansion during the sea level stabilization since mid-Holocene, and the limited living space might result in the much later agricultural activity in such coastal system. Due to the different balances between sea level change and sediment flux, sediment-starved coasts are expected to be under higher risks than large river deltas. However, earlier and more extensive human activities in large river basins have resulted in the reduction of sediment discharge that heighten the risks of large river deltas against future sea level rise. Thus, more attention should be paid to the coastal sediment supply budgets in the context of the background of rising sea level. • Holocene evolution history of a sediment-starved embayment has been reconstructed. • Early-Holocene rapid sea level rise results in a basin-wide marine inundation. • Low sedimentation rate within the embayment since mid-Holocene SL stabilization. • Limited habitation land results in later-than-delta human cultivation development. • Sediment-starved coastal systems are sensitive to climate-driven sea level change. [ABSTRACT FROM AUTHOR]

The southeastern China coast is a region of special interest in the study of past and present relative sea-level change, given its distal location from giant ice sheets (far-field regions). During the past decades, a large number of biological, geological, and archaeological sea-level indicators have been retrieved from the Fujian coastal region which allows for recalibration and recalculation of sea-level index points (SLIPs). This study constructs a database of Holocene relative sea-level (RSL) observations for the Fujian coast, southeastern China. The database contains 59 quality-controlled SLIPs which show that RSL for the Fujian coast did not exceed present (0 m) during the Holocene, except potentially during 7.5–5.5 cal. kyr BP and 1.8–0.7 cal. kyr BP. Rates of RSL change were highest during the early Holocene and have decreased over time, due to the diminishing response of the Earth's mantle to glacial isostatic adjustment (GIA) and reduction of meltwater input. A series of sea-level oscillations were recorded in our SLIPs-based reconstructions which might correspond to global climate warming or cooling events. We assessed the spatial variability of RSL histories and compared these with the ICE-6G_C and ANU-ICE GIA model predictions. Substantial misfits between GIA predictions and regional RSL reconstructions were recognized: (1) the deceleration of the early-Holocene sea-level rise ended about one millennia earlier in the ICE-6G_C model than in the SLIPs-based reconstructions; (2) GIA model predictions show a mid-Holocene sea-level highstand of 1–3 m which is absent from our SLIPs-based reconstructions; and (3) all GIA model predicted a gradual RSL fall to 0 m since the middle Holocene, while our reconstruction displays significant RSL oscillations. It is presently unknown whether these misfits are caused by uncertainties in regional tectonic movement estimation or parameters used in the GIA models. Future applications of spatiotemporal statistical techniques are required to better quantify the gradient of the isostatic contribution and to provide improved context for the assessment of the ongoing acceleration of sea-level rise. • Holocene sea level index points (SLIPs) for the Fujian coast have been standardized. • SLIPs-based relative sea level (RSL) reconstructions are compared to model predictions. • Early-Holocene rapid RSL rise terminates earlier in models than in reconstructions. • Mid-Holocene highstands are captured in models but not obvious in the reconstruction. • Local tectonic and modelling parameter selection might have resulted in the misfits. [ABSTRACT FROM AUTHOR]

Indices based on branched glycerol dialkyl glycerol tetraethers (brGDGTs) have been useful in paleo-environmental reconstructions, although their applicability in river-estuarine sediments remains unclear. This study aims to investigate the correlation between brGDGT-based indices and modern environmental parameters, and to discuss possible impact factors. In this study, we discussed the applicability of several brGDGT-based indices, with specific interests on the IR x' (the relative abundance of 6- vs. 5-methylated brGDGTs) and CBT' (cyclization index of branched tetraethers based on the separation of 5- and 6-methylated brGDGTs) for pH reconstruction, and MBT' 5ME (the methylation index of branched tetraethers based on the separation of 5- and 6-methylated brGDGTs) for MAAT (mean annual air temperature) reconstruction. From the Jiulong River (JLR) catchment, we have analyzed both riverbank soil samples and riverbed surface sediment samples for brGDGTs, with the following main findings: Firstly, for pH reconstruction, the indices CBT' and IR x' are useful in soil and fluvial sedimentary settings. Secondly, for MAAT reconstruction, the MBT' 5ME index is sensitive to the air temperature, and the BayMBT 0 model performs relatively better than other global or regional calibrations in the study area; By employing the BayMBT 0 model, MAAT reconstructed from soils are higher than the measured MAAT, but are generally lower than the measured MAAT when reconstructed from riverbed surface sediments. Thirdly, the disagreement between the reconstructed results from the two sedimentary archives suggests that: Signatures of brGDGTs in the aquatic environment are under strong impacts of in situ produced brGDGTs; Impacts of upper-reach brGDGTs input might have resulted in the increasingly negative offset for the reconstructed MAAT downstream; And influences of complex aquatic biogeochemical conditions on sedimentary brGDGT signals are site-dependent in this area. Finally, brGDGT-based indices are sensitive to the source of brGDGTs, e.g., soil vs aquatic in situ brGDGTs; And terrigenous brGDGTs have been exposed to a range of complex biogeochemical processes before their deposition in the estuary. Based on these findings, we suggest that at least the above impact factors need to be taken into consideration when interpreting the brGDGT signals from estuarine archives, and thus, multi-proxy studies are encouraged. The findings of this study provide a better understanding of the correlation between brGDGT-based indices and modern environmental parameters in subtropical river systems, and provide useful information for interpreting the paleo-environmental signals based on brGDGTs from fluvial-estuarine archives. • BrGDGTs are useful for soil pH and mean annual air temperature (MAAT) prediction. • Predicted pH in soil and fluvial sediment is close to soil pH. • BayMBT 0 Model performs well for the MAAT prediction in the study region. • Predicted MAAT for soil (fluvial sediment) is slightly higher (lower) than measured. • In situ production of brGDGTs impact the MAAT prediction from riverine sediments. [ABSTRACT FROM AUTHOR]

• GDGTs could indicate organic-matter (OM) sources in a small river-estuary system. • The GDGT-0/cren and bGDGTs indicated anthropogenic-induced water eutrophication. • The BIT estimated well the soil vs marine OM inputs in the estuary. • Estuarine OM distribution was influenced by OM sources and preservation processes. Recently, glycerol dialkyl glycerol tetraethers (GDGTs) have been successfully used to identify different sources for organic-matter in the offshore and open ocean areas, while their applicability in the coastal areas remains unclear. This study was carried out to investigate the behavior of GDGTs and their applicability as indicators for organic-matter sources in a small subtropical river-estuary system, the Jiulong River-Estuary system (JRES), southeastern China. In 2018, three groups of samples including riverbank soils, riverbed surface sediments, and estuarine surface sediments were collected and analyzed. The results supported three main findings: 1) The abundances of GDGTs and crenarchaeol, and the ratios of iGDGTs/bGDGTs, GDGT-0/crenarchaeol (GDGT-0/cren), crenarchaeol isomer / (crenarchaeol + crenarchaeol isomer) and the IIIa/IIa, were good indicators for organic-matter sources; 2) At the middle and lower reaches of West River, the abnormally high values of GDGT-0/cren ratio and bGDGT abundance might indicate anthropogenic-induced water eutrophication; and 3) The branched and isoprenoid tetraether index (BIT) was especially sensitive in indicating of the soil- vs marine-organic matter contribution to the total organic matter of estuarine sediments. The high BIT values at the estuary turbidity maximum zone (TMZ) and the mid estuary suggested that TMZ filtering effect, preservation conditions and extra sources of soils have impacted the organic-matter distribution. Understanding the behavior and application of GDGTs in such a system helps to improve research on organic carbon cycling in the coastal system. [ABSTRACT FROM AUTHOR]

Purpose: The objective of this study was to validate the reliability and validity of the safety attitudes questionnaire (SAQ) in Heilongjiang province, northern China., Methods: The SAQ was distributed to 27 public hospitals in five cities across Heilongjiang province. The Cronbach's α, item-dimension and dimension-dimension correlations were calculated. Descriptive analyses and confirmatory factor analysis were also performed., Results: The recovery rate of the questionnaire was 84.45%. The validity and reliability measures of the SAQ were acceptable. The goodness-of-fit index from the confirmatory factor analysis showed a reasonable model fit (CFI = 0.93, GFI = 0.91, RMSEA = 0.05). The Cronbach's α value for the scale was 0.91 and ranged from 0.66 to 0.91 for each of the scales. The SAQ showed good internal consistency reliability., Conclusion: The SAQ had satisfactory psychometric properties and could be a useful tool to measure safety attitudes in public hospitals in Heilongjiang province in China.