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Purpose: A prerequisite for the successful application of phytoliths in paleoenvironmental reconstruction is the correct interpretation of their environmental significance. In this context, key questions include: What magnitude of temperature/precipitation change is required to effect significant changes in surface soil phytolith percentages? When temperature/precipitation increases by a certain amount, what is the corresponding response of the percentages and assemblages of surface soil phytoliths? Additional detailed research is required to answer these questions. Materials and methods: We analyzed the phytoliths in 90 surface soil samples collected along the isohyets corresponding to the mean annual precipitation (MAP) of 400 mm (with the mean annual temperature (MAT) range of 3.24℃) and 600 mm (with the MAT range of 8.29℃) in Northeast China. Our objective was to determine the response of phytoliths to different temperature gradients. Soil phytoliths were extracted and identified using heavy liquid separation and microscope observations. Results: The DA of the phytolith percentages enabled the separation of samples collected along the two isohyets, with a total accuracy of 94.44%. MAT was the principal factor affecting the spatial distribution of phytoliths, with an explanation rate of 46.40%. In the surface soil samples collected along the two isohyets, the percentages of ELONGATE, ACUTE BULBOSUS, and PTERIDOPHYTE-TYPE morphotypes, were significantly negatively correlated with MAT, while the percentages of SQUARE were significantly positively correlated with MAT. However, the relationship between PAPILLATE percentages and MAT varied, showing both positive and negative correlations. A temperature gradient of ~ 3℃ was insufficient to significantly affect the percentages of SADDLE, BULLIFORM FLABELLATE, and BILOBATE. The phytolith index (C/W) can be effectively used to reconstruct the palaeoclimate in Northeast China. An MAP change of 200 mm resulted in significant changes in the percentages of ELONGATE, SADDLE, BULLIFORM FLABELLATE, and TRACHEARY (with the respective rates of 39.57%, 780.77%, 179.00% and 81.25%). However, the percentages of ACUTE BULBOSUS, SQUARE, RONDEL, BILOBATE, CRENATE, PTERIDOPHYTE-TYPE, SILICIFIED STOMATA, and PAPILLATE did not change significantly. Conclusions: Our results contribute to an improved understanding of the response of various phytolith morphotypes to temperature, and they provide a modern process basis for future phytolith-based paleoclimatic reconstruction in this region. [ABSTRACT FROM AUTHOR]

In this article, we report the pathogenicity of a new strain of fungus, Rhizopus oryzae to honeybee larvae, isolated from the chalkbrood-diseased mummies of honeybee larvae and pupae collected from apiaries in China. Based on morphological observation and internal transcribed spacer (ITS) region analyses, the isolated pathogenic fungus was identified as R. oryzae. Koch's postulates were performed to determine the cause-and-effect pathogenicity of this isolate fungus. The in vitro pathogenicity of this virulent fungus in honeybees was tested by artificially inoculating worker larvae in the lab. The pathogenicity of this new fungus for honeybee larvae was both conidial-concentration and exposure-time dependent; its highly infectious and virulent effect against the larvae was observed at 1 × 105 conidia/larva in vitro after 96 h of challenge. Using probit regression analysis, the LT50 value against the larvae was 26.8 h at a conidial concentration of 1 × 105 conidia/larva, and the LC50 was 6.2 × 103 conidia/larva. These results indicate that the new isolate of R. oryzae has considerable pathogenicity in honeybee larvae. Additionally, this report suggests that pathogenic phytofungi may harm their associated pollinators. We recommend further research to quantify the levels, mechanisms, and pathways of the pathogenicity of this novel isolated pathogen for honeybee larvae at the colony level. [ABSTRACT FROM AUTHOR]

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]

Recently, endorhizospheric microbiota is realized to be able to promote the secondary metabolism in medicinal plants, but the detailed metabolic regulation metabolisms and whether the promotion is influenced by environmental factors are unclear yet. Here, the major flavonoids and endophytic bacterial communities in various Glycyrrhiza uralensis Fisch. roots collected from seven distinct places in northwest China, as well as the edaphic conditions, were characterized and analyzed. It was found that the soil moisture and temperature might modulate the secondary metabolism in G. uralensis roots partially through some endophytes. One rationally isolated endophyte Rhizobium rhizolycopersici GUH21 was proved to promote the accumulation of isoliquiritin and glycyrrhizic acid significantly in roots of the potted G. uralensis under the relatively high-level watering and low temperature. Furthermore, we did the comparative transcriptome analysis of G. uralensis seedling roots in different treatments to investigate the detailed mechanisms of the environment-endophyte-plant interactions and found that the low temperature went hand in hand with the high-level watering to activate the aglycone biosynthesis in G. uralensis, while GUH21 and the high-level watering cooperatively promoted the in planta glucosyl unit production. Our study is of significance for the development of methods to rationally promote the medicinal plant quality. Key points: • Soil temperature and moisture related to isoliquiritin contents in Glycyrrhiza uralensis Fisch. • Soil temperature and moisture related to the hosts' endophytic bacterial community structures. • The causal relation among abiotic factors—endophytes—host was proved through the pot experiment. [ABSTRACT FROM AUTHOR]

Background: The economic and environmental value of honeybees has been severely challenged in recent years by the collapse of their colonies worldwide, often caused by outbreaks of infectious diseases. However, our understanding of the diversity, prevalence, and transmission of honeybee viruses is largely obscure due to a lack of large-scale and longitudinal genomic surveillance on a global scale. Results: We report the meta-transcriptomic sequencing of nearly 2000 samples of the two most important economic and widely maintained honeybee species, as well as an associated ectoparasite mite, collected across China during 2016–2019. We document the natural diversity and evolution of honeybee viruses in China, providing evidence that multiple viruses commonly co-circulate within individual bee colonies. We also expanded the genomic data for 12 important honeybee viruses and revealed novel genetic variants and lineages associated with China. We identified more than 23 novel viruses from the honeybee and mite viromes, with some exhibiting ongoing replication in their respective hosts. Together, these data provide additional support to the idea that mites are an important reservoir and spill-over host for honeybee viruses. Conclusions: Our data show that honeybee viruses are more widespread, prevalent, and genetically diverse than previously realized. The information provided is important in mitigating viral infectious diseases in honeybees, in turn helping to maintain sustainable productive agriculture on a global scale. 9bxHgmASzr9JN-8jG-Ub-N Video Abstract [ABSTRACT FROM AUTHOR]

Purpose: To investigate the clinical features of infection, and associated factor for in-hospital mortality in a southern Chinese cohort with polymyositis/dermatomyositis (PM/DM). Patients and Methods: Clinical data were retrospectively reviewed from 2015 to 2022 from a tertiary hospital in southern China. Associated factors for infection and in-hospital mortality were analyzed by multivariate logistic regression analysis. Results: A total of 554 patients with PM/DM were included, and 35.6% (197/554) of them developed 404 episodes of infection. Half of the patients developed infection within 4 months after disease onset. Bacterial infection was predominant (249/404, 61.6%). Lung was the most involved (242/404, 59.9%). Gram-negative bacteria the leading pathogens (64/84, 76.2%). Patients with anti-MDA5 positive were prone to develop severe infections (35.1% vs 16.4%, P< 0.001) and had higher mortality (11.7% vs 3.4%, P=0.01). The in-hospital mortality was 6.5% (36/554). Infection was the leading cause of death (20/36, 55.6%). Older age (adjusted odds ratio (OR): 1.05, 95% confidential interval (CI): 1.02– 1.09, P=0.004), ILD (adjusted OR: 2.76, 95% CI: 1.11– 6.84, P=0.03), number of episodes of infection (adjusted OR: 1.91, 95% CI: 1.53– 2.38, P< 0.001), and elevated serum creatinine (Scr) (adjusted OR: 6.83, 95% CI: 1.77– 26.40, P=0.01) were associated with in-hospital mortality. Conclusion: Infection is an early complication in PM/DM with a high proportion of lung involvement and predominance of gram-negative bacteria. It is a major contributor to in-hospital mortality. Older age, ILD, and number of episodes of infection are associated with poor prognosis. [ABSTRACT FROM AUTHOR]

Since the completion of first‐phase projects on the eastern and middle routes of the South‐to‐North Water Diversion (SNWD), the design and implementation of water pricing mechanism have become the key factors that affect the project operation. This paper launches the evaluation of implementation effect on the water price policy of the SNWD built projects in 2018 by coordinating the consumption of transfer water, allocation of receiving‐areas' water resources, collection of water fee for transfer water, as well as the implementation of local water price policies, which mainly exerted a comprehensive and interactive influence on the water price policy. Based on a series of data statistics and analysis, the usage of water transferred from the Yangtze River, improvement of regional water resources allocation, collection of water fee, and the implementation results of local water price policies were systematically analyzed. The main conclusions and corresponding suggestions were put forward to provide useful references on the formulation of water price policies for the design, optimization, and adjustment of the subsequent water pricing mechanism in the SNWD project. [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]

Klebsiella pneumoniae carbapenemase genes (bla KPC) play an important role in carbapenem-resistant Enterobacteriaceae in China. A rapid detection method for bla KPC genes and investigations into the molecular characteristics of bla KPC positive Klebsiella pneumoniae were necessary. In this study, an easy and rapid recombinase aided amplification assay (RAA) for bla KPC was established. This protocol could be completed at 39°C in 15–20 min. The sensitivity of this assay was determined as 48 copies per reaction, and the specificity was 100%. The bla KPC RAA method could be used for clinical diagnosis and epidemiological investigation. Among 801 fecal samples from inpatients, 34 bla KPC positive isolates were identified from each sample, of which 23 isolates were K. pneumoniae. ST11 with bla KPC-2 was the most prevalent type. All these strains were multidrug resistant and carried various virulence genes. Fecal carriage of bla KPC positive carbapenem-resistant K.pneumoniae poses significant challenges for public health control. [ABSTRACT FROM AUTHOR]

High-resolution proxy-based paleoenvironmental records derived from peatlands provide important insights into climate changes over centennial to millennial timescales. In this study, we present a composite climatic index (CCI) for the Hani peatland from northeastern China, based on an innovative combination of pollen-spore, phytolith, and grain size data. We use the CCI to reconstruct variations of the East Asian summer monsoon (EASM) intensity during the Holocene. This is accomplished with complete ensemble empirical mode decomposition (CEEMD), REDFIT, and cross-wavelet coherency analysis to reveal the periodicities (frequencies) of the multi-proxy derived CCI sequences and to assess potential external forcing of the EASM. The results showed that periodicities of ca. 300–350, 475, 600, 1075, and 1875 years were present in the Hani CCI sequence. Those periodicities are consistent with previously published periodicities in East Asia, indicating they are a product of external climate controls over an extensive region, rather than random variations caused by peatland-specific factors. Cross-wavelet coherency analysis between the decomposed CCI components and past solar activity reconstructions suggests that variations of solar irradiation are most likely responsible for the cyclic characteristics at 500-year frequency. We propose a conceptual model to interpret how the sun regulates the monsoon climate via coupling with oceanic and atmospheric circulations. It seems that slight solar irradiation changes can be amplified by coupling with ENSO events, which result in a significant impact on the regional climate in the East Asian monsoon area. [ABSTRACT FROM AUTHOR]

Ecological responses to past climate change as determined from palaeorecords offer insights into responses that may accompany future climate change. In arid and semi‐arid lands, the interactions between regional vegetation and climate change are not yet well understood, partly due to a lack of suitable palaeovegetation proxies that can provide accurate and continuous tracers for past vegetation dynamics. To gain a better understanding of long‐term vegetation dynamics, this study employs a multiproxy approach applied to sand‐palaeosol sediments of northeastern China's Songnen grasslands. Phytolith analyses and data on the stable carbon isotope composition (δ13C) of organic matter are used to reconstruct palaeovegetation composition, namely, the changing abundance of C3 and C4 species, whereas a geochemical weathering index (Fed/Fet ratios) tracks past East Asian summer monsoon (EASM) intensity. The phytolith assemblages and indices and δ13C of the soil indicate that C4 species' abundance has been increasing in the Songnen grasslands since the mid‐Holocene, although C3 vegetation is still dominant. Statistically significant negative correlations between the δ13C data and Fet/Fed ratios suggest that continuous weakening of the EASM since the mid‐Holocene may be responsible for the 13C‐enrichment of the sediments in the Songnen grasslands. Field vegetation surveys, modern topsoil phytoliths and δ13C calibration data indicate that the expansion of C4 species since the mid‐Holocene is mainly due to their ability to cope with aridity when growing season temperature is not undergoing a significant decrease. Future precipitation decreases in arid and semi‐arid lands should make C4 species more competitive in the grasslands of northeastern China. HighlightsA continuous grassland landscape history is reconstructed from a sand‐palaeosol sequence via phytolith analysis.Multiple independent approaches were used to reconstruct past EASM intensity and palaeovegetation patterns.Phytolith and δ13C analyses indicate an increase in C4 species since the mid‐Holocene.Aridification drives the increase in C4 species within the grassland ecosystem. [ABSTRACT FROM AUTHOR]

Objective. To explore the proportion and characteristic of Chinese adults meeting The Systolic Blood Pressure Intervention Trial (SPRINT) eligibility criteria and assess its generalizability. Method. Our study was based on a cross-sectional, population-based survey with a sample of 26,093 participants aged over 20 years. The SPRINT eligibility criteria were age ≥ 50 years, elevated SBP of 130 to 180 mmHg depending on the number of antihypertensive medication classes being taken, and increased cardiovascular disease (CVD) but without diabetes, history of stroke and estimated glomerular filtration rate < 20 ml / min / 1.73 m 2 , or receiving dialysis. Results. Overall, we estimated that 4,036 (15.5%) participants would meet the SPRINT eligibility criteria. They were generally older, likely to be female, lower educational level, tended to be more overweight, and had higher Framingham risk score compared with overall population or subjects aged ≥ 50 years. Of participants eligible for SPRINT, most (56.2%) of them were not treated for hypertension, and 542 (13.4%) were not previously considered to have hypertension or need for antihypertension therapy. Among the 11,637 adults with hypertension, 3,494 (30.0%) would potentially benefit from treatment intensification. The most common antihypertensive medication class being taken was diuretic agents. Conclusion. A substantial percentage of Chinese subjects meet the SPRINT eligibility criteria. Further studies are needed to assess the cost-effectiveness from treatment intensification in Chinese setting. [ABSTRACT FROM AUTHOR]

The Changbai Mountains forest ecosystem is one of the best-preserved temperate mountain forest ecosystems in Asia. Since the establishment of the reserve in 1960, extensive forest fires have been excluded as a result of strict regulation and suppression efforts and thus fuels have accumulated for several decades. Due to the lack of historical fire records in the area, the risk of fire occurrence cannot be properly estimated. In this study, we used charcoal records to reconstruct the palaeo-fire frequency in the Changbai Mountains during the last 13 000 years. The results indicate that fires were frequent during 13.0–11.0, 7.0–6.0, and 2.5–2.0 calendar (cal) kyr before present (BP) and from 1.0 cal kyr BP to the present. The fire frequencies are largely consistent with other palaeoenvironmental records from the study area and we conclude that since 13.0 cal kyr BP fires were more frequent at the regional scale during intervals of a weak summer monsoon, caused by a cold and dry climate and the abundance of flammable trees. Archaeological data from the study area since 3.0 cal kyr BP indicate increasing human activity, which dominated the occurrence of local fires. In addition, intermittent volcanic activity influenced the occurrence of fires during the past millennium. The local and regional forest fire history of the Changbai Mountains for 13 000 years was investigated using charcoal records from a peatland in north-east China. Regional fires were promoted by a cold and dry climate and vegetation changes due to a weakened East Asian Summer Monsoon. Some fire prevention policies are proposed. [ABSTRACT FROM AUTHOR]

The blue sheep is an endemic species to the Qinghai‐Tibet Plateau and surrounding regions. It has been regarded as having 2 subspecies: Pseudois nayaur nayaur and P. n. szechuanensis. However, such a classification remains controversial. Herein, we analyze 10 microsatellite loci and part of the mitochondrial control region for clarification in such taxonomic debates. We use samples from 168 individuals from 6 geographic populations covering almost all the distribution areas of the species in China to carry out comparisons. Phylogenetic trees derived from both the microsatellite and mitochondrial markers combined with the discriminant analysis of principal components (DAPC) and the STRUCTURE analysis reveal that the individuals in the Helan Mountains are well grouped with a distinct evolutionary lineage and are significantly different from the other populations of P. n. szechuanensis according to Fst values, implying that this isolated population should be categorized as a valid subspecies; namely, Pseudois nayaur alashanicus. The isolation‐by‐distance (IBD) analysis shows a significant positive relationship between genetic and geographical distances among the populations. [ABSTRACT FROM AUTHOR]

Phytoliths are a reliable paleovegetation proxy and have made an important contribution to paleoclimatic studies. However, little is known about the depositional processes affecting soil phytoliths, which limits their use for paleoclimate and paleovegetation reconstructions. Here, we present the results of a study of the vertical translocation characteristics of phytoliths in 40 natural soil profiles in Northeast China. The results show that phytolith concentration decreases within the humic horizon of the soil profiles and that ∼22% of the phytoliths are translocated below the surface of the studied soils. In addition, we find that the translocation rate of phytoliths varies markedly with phytolith type and that phytolith size and aspect ratio also have a significant effect. Phytoliths with length >30 μm and with aspect ratio >2 and those with length <20 μm and aspect ratio <2 are preferentially translocated compared to those with length >25 μm and aspect ratio <2. Our results demonstrate that differential translocation of phytoliths within soil profiles should be considered when using soil phytoliths for paleoclimate and paleovegetation reconstruction. [ABSTRACT FROM AUTHOR]

The assessment and calibration of representational bias in modern soil phytolith assemblages provide the basis for improving interpretation of fossil phytolith assemblages. We studied soil phytolith representation by comparing phytoliths from living plant communities with those from paired surface soils, representing 39 plant communities in Northeast China. Together with the use of representation indices, the 34 and 30 soil morphotypes observed in forest and grassland samples, respectively, were both classified into the following four groups: “Associated types” were similarly represented in soils and in the corresponding species inventory data; “Over-represented types” and “Under-represented types” were respectively over- and under-represented in soils compared to the inventory data; and, in the case of “Special types,” the relationship with the parent plants was unclear. In addition, the diagnostic types exhibited different degrees of representation, while the most common morphotypes were equally represented between grassland samples and forest samples. On this basis, a comparison between the original and corrected soil phytolith indices of the additional 29 soil samples was conducted. The soil phytoliths frequencies corrected by R-values differed between plots with differing plant compositions, and were moderately consistent with actual plant richness in the plot inventory data. We therefore confirmed that R-values are a promising means of correcting soil phytoliths for representational bias in temperate regions. The corrected soil phytoliths can be used to reliably reflect vegetation variability. Overall, our study provides an improved understanding of soil phytolith representation and offers a potential method for improving the accuracy of paleovegetation reconstruction. [ABSTRACT FROM AUTHOR]

To provide a basis for tracing changes in vegetation and tree cover density, we studied the phytoliths of 129 common temperate plant species, and extracted the phytoliths from 75 surface soil samples from sites in grassland, forest−grassland ecotone and forest habitats in northeast China. From the analysis of shapes and morphological parameters of the plant samples, we developed a reference data set of herbaceous and woody phytoliths, and subsequently identified 21 herbaceous and 13 woody phytolith types in the surface soil samples. To test the reliability of soil phytolith analysis for distinguishing forest, grassland and the forest−grassland ecotone, we used principal components analysis (PCA) and discriminant analysis (DA) to summarize the soil phytolith assemblage characteristics of the different ecosystems. The results show that the grassland and forest samples are characterized by abundant herbaceous and woody phytoliths, respectively; and that forest−grassland ecotone habitats are characterized by low abundances of blocky polyhedral, multifaceted epidermal and sclereid phytoliths. In general, the surface soil phytolith assemblages can reliably differentiate samples from forest, grassland and the forest−grassland ecotone, with up to 92% of the samples classified correctly. We also tested the reliability of phytolith indices (W/G (1), W/G (2), W/G (3)) for discriminating different vegetation types in our study area, and found that W/G (2) was the most reliable index and corresponded well with the species inventory data. The W/G values for grassland ranged from 0 to 0.3, from 0.3 to 0.6 for the forest−grassland ecotone, and exceeded 0.6 for forest. We conclude that our study provides reliable analogues for phytolith assemblages from palaeoecological contexts, which can be used to reconstruct shifts in forest−grassland ecotones and vegetation succession in temperate areas. [ABSTRACT FROM AUTHOR]

Abstract: Research on response of phytolith assembles in Phragmites communis to two treatments is a new idea for studying global change. As P. communis is an important dominant species in the Songnen Grassland and widely distributed in sampling area and produce abundant phytoliths. P. communis was selected as the material and target to find a link between the phytolith variety and elevated CO2 concentration. An OTC (open top chamber) was used to elevate the concentration of CO2, and the phytoliths in P. communis were investigated to identify the effects. The phytolith record reveals the elevation of CO2 concentration can change the ratio of different types and size of phytoliths significantly. The number of silicified stomata and Saddle decreased while hair cell increased after elevated CO2 treatment. Moreover, after the measurement using a particle-size analyzer and under a microscope, phytoliths grow smaller after elevated CO2 treatment. Research on relationship between phytolith and CO2 concentration renews the traditional understanding. This study introduces a different way to study the influence of global change, and the use of common reed could provide basic data for other studies to make regional contrast with the same species. [Copyright &y& Elsevier]

An improved understanding of past interactions between terrestrial vegetation and various forcings, such as climate change, human impact, and paleofire, is crucial for assessing impacts of future global change on terrestrial ecosystems. This study seeks to find the key factor or factors that have driven Holocene vegetation change along the East Asian monsoon margin. Several high-resolution pollen records are reviewed and new phytolith-based paleovegetation reconstructions and physical geochemical datasets are presented from a peatland in northeastern China. Using 108 modern topsoil samples as a training set, canopy cover and vegetation composition are estimated for the period since 5100 cal. yr BP. Variation partitioning analysis (VPA) is used to determine the relative importance of climate change, human impacts, and paleofire disturbance. The generalized dynamic vegetation model LPJ-GUESS is forced with climate anomaly output from an atmospheric general circulation model to simulate vegetation dynamics during the mid-Holocene and the pre-industrial era. The proxy-based estimates are compared to modelling output. Results indicate that regional tree cover varied from 10% to 40% during the past five millennia. The single-core, phytolith-based reconstructions are generally consistent with stacked tree pollen z-scores calculated from different records along the East Asian monsoon margin, implying that mid-Holocene tree cover decrease was persistent and almost synchronous over extensive areas. VPA demonstrates that long-term monsoon marginal vegetation successions were mainly caused by climate effects. Numerical modelling suggests that since the mid-Holocene the retreat of forests along the monsoon margin was primarily associated with precipitation deficits. Our investigation highlights that the precipitation associated with the East Asian monsoon system has exerted a stronger influence than the westerlies on the monsoon margin climate and vegetation change. With ongoing global change, close attention to variations in precipitation patterns and amounts should be especially helpful in efforts aimed at ecological monitoring, change prediction, and restoration. • Phytoliths provide complementary paleovegetation evidence to pollen for the monsoon margin area in northeastern China. • Phytolith-based quantitative tree coverage reconstructions suggest persistent forest cover since the mid-Holocene. • Vegetation dynamics within the monsoon margin area is strongly associated with East Asian monsoon variability. • DGVMs modelling suggests the dominant role of precipitation in regulating vegetation change. [ABSTRACT FROM AUTHOR]

Abstract: This study is aiming to assess the primary energy consumption, and the energy-related carbon dioxide (CO2) emissions in vehicle cycle for a China passenger car powered by internal combustion engine. Meanwhile, this analysis concerns about the share of coal demand in the total primary energy use. The results show that the vehicle cycle energy consumption and CO2 emissions of a China passenger car are about 91.13 GJ and 11.13 ton per vehicle, respectively. And coal accounting for about 84.5% of the vehicle cycle primary energy consumption is the key contributor to the CO2 emissions in China. The processes of material production and vehicle assembly account for most of the vehicle cycle energy use and CO2 emissions. There are four ways to reduce vehicle cycle environmental impacts: use clean energy, lower the weight of the vehicle under the condition of ensuring vehicle performance, adopt low energy-intensive and low emission-intensive materials in vehicle, and develop advanced vehicle propulsion systems. [Copyright &y& Elsevier]

Although early-onset Parkinson's disease (EOPD) has a more penetrant genetic etiology, the genetic architecture of EOPD remains unclear. The objectives of this study were to assess the genetic and clinical features of EOPD among ethnic Chinese from mainland China. Using whole-exome sequencing, we performed genetic analyses of 240 participants including 193 with sporadic and 47 with familial EOPD (age of onset <50 years). In total, 18 patients (7.5%) harbored pathogenic or likely pathogenic variants in known PD genes. Among these variants, biallelic variants in Parkin and PINK1 were responsible for 4.2% of cases, and rare likely pathogenic variants in LRRK2 (1.7%) also appeared to be a relatively common cause of EOPD. Notably, 7.5% of patients carried risk variants in either LRRK2 or GBA , which should also be considered for EOPD. Nevertheless, 41 patients (17.1%) had rare variants of unknown significance. In conclusion, our findings provide a better understanding of the genetic architecture of PD among ethnic Chinese, and the pathogenicity of numerous rare variants should be further investigated. • 18 patients (7.5%) carried pathogenic or likely pathogenic variants in known PD genes. • (Likely) pathogenic variants in Parkin and PINK1 were responsible for 4.2% of the patients. • Rare likely pathogenic variants in LRRK2 (1.7%) also appeared to be a relatively common cause of EOPD. • 7.5% of patients carried risk variants in either LRRK2 or GBA. [ABSTRACT FROM AUTHOR]

• Assessments are presented of three different methods for quantifying carbon content of aeolian sediments. • The loss-on-ignition method significantly overestimated TOC content for aeolian sediments. • The general wet-oxidation method did not overestimate the TOC content. • Consistent measurements among different methods enable further trend comparisons. • Comparison of different quantification methods for other specific sediment types is proposed. Total organic carbon (TOC) and inorganic carbon (carbonates) are important soil factors and paleoenvironmental proxies used worldwide. During past decades, several different methods have been proposed for determining these parameters from various sediment archives. Although the automatic elemental analyzer is gradually replacing the traditional quantification methods, it is critical to assess the reliability of all currently used methods to ensure accurate regional comparisons, carbon stock estimations and long-term carbon-cycle dynamics modelling. In this study, three most commonly used methods for determining TOC and carbonate content are compared using sediment samples from a sand-paleosol sequence located in northeastern China. Pearson's correlation between results of the different TOC and carbonate quantification methods produced high correlation coefficients, confirming substantial consistency among them. The automatic carbon analyzer yielded more accurate values with smaller uncertainties, while results of the general chemical method and loss-on-ignition (LOI) produced relatively reliable values with more data variability. Meanwhile, combustion at 500 °C to quantify the TOC content yielded significantly higher values than the automatic carbon analyzer and chemical methods, indicating that LOI method is not as reliable as previously thought. We attribute the overestimation to unsuitable SOM to TOC conversion factors and/or the presence of volatile minerals in the samples. In contrast with other studies, chemical wet oxidation of the sand-paleosol sediments did not significantly overestimate TOC, which commonly occurs in modern soils and lacustrine sediments. Our results suggest that the reliability of different methods for measuring carbon content could be affected by the sediment's origin and environment. Assessment of the results of the different TOC and carbonate quantification methods on additional types of sediment is needed so that researchers can use the most appropriate method for their study and make appropriate paleoenvironmental reconstructions given the sediments and methods used. [ABSTRACT FROM AUTHOR]

Modern process research on phytoliths, including on the characteristics and spatial distribution of phytoliths assemblages and their relationship with environmental factors, is the basis of the use of phytoliths in paleoenvironmental reconstruction. We collected 54 surface soil samples along the isohyet of 600 mm in Northeast China in order to determine the relationship between modern phytoliths distributions and temperature. These were comprised by 20 samples from Xiaoxing'an Mountains, 32 samples from Songliao Plain, and 2 samples from Liaoxi Hills. The main phytoliths types were elongate and lanceolate, followed by short cell phytoliths, blocky, tabular and cuneiform; the percentages of the other types were all less than 1% and only occurred sporadically. There were significant differences in phytoliths assemblages among Xiaoxing'an Mountains, Songliao Plain, and Liaoxi Hills. Discriminant analysis was conducted using phytoiths assemblages, the samples from these three regions could be separated with a total accuracy of 96.30%. Elongate, lanceolate and pteridophyte‒type on average made up the largest proportion in Xiaoxing'an Mountains and the smallest in Liaoxi Hills, whereas saddle, bilobate and papillae showed the inverse trend; the proportions of blocky, tabular and cuneiform were the largest in Songliao Plain. The percentages of these types abovementioned were significantly different among the three regions. Correlation analysis revealed a significant negative correlation between the percentages of elongate, lanceolate and pteridophyte‒type and mean annual temperature (MAT), while there was a significant positive correlation between the percentages of blocky, tabular, cuneiform, saddle, bilobate, papillae and MAT. There was no significant relationship between rondel, trapeziform sinuate, conduit, carinate, sclereid, silicified stomata and MAT. A phytoliths index (C/W) based on the common phytoliths types in the surface soil samples which had a significant correlation with MAT was built. C/W = (elongate + lanceolate)/(elongate + lanceolate + blocky + tabular + cuneiform + saddle + bilobate). The values of C/W in Northeast China varied from 0.14 to 0.91, with an average of 0.67. The accuracy of the C/W index indicating climatic trends was significantly higher than the previously established Ic (climate index) and Iw (warm index). Overall, our results contribute to an improved understanding on the environmental significance of various phytoliths morphotypes, and provide a modern process foundation for phytoliths–based paleoclimatic reconstruction in the study region. [ABSTRACT FROM AUTHOR]

Increasing use is being made of phytoliths for quantitative palaeovegetation and palaeoclimatic reconstruction, and consequently studies of phytolith transport are attracting increasing attention. In this context, we conducted a detailed study of factors affecting the soil phytolith transport in six representative natural soil types in Northeast China. We define a phytolith transport index (T) which indicates that transport rates are the lowest in chernozem and chestnut soils, intermediate in dark brown and albic soils, and obviously higher in black and alluvial soils. Additionally, there are differences in the vertical transport of different phytolith types in the soils; however, the transport characteristics are essentially the same among the different soil types. Transport rates are lowest for tabular and blocky phytoliths, followed by bulliform phytolith. By contrast, the rates for short cell, lanceolate and elongate phytoliths are significantly higher, and, notably, these phytolith types have different size and aspect ratios. The transport of phytoliths is also mainly influenced by mean annual precipitation (MAP), soil pH and soil clay content. Climatic factors, especially MAP, are a more significant factor for phytolith transport than phytolith size and aspect ratio. Overall, our findings are significant for the palaeoenvironmental interpretation of soil phytolith assemblages in topsoils. [ABSTRACT FROM AUTHOR]

Objective: To study the feasibility of a randomized controlled trial (RCT) comparing intrauterine insemination (IUI) with and without letrozole in couples with unexplained or mild male factor infertility STUDY DESIGN: We performed a randomized pilot study including 100 couples with unexplained or mild male factor infertility in the Reproductive Medicine Centre of Peking University Third Hospital in China. The couples scheduled for IUI were randomized to IUI with or without ovarian stimulation (letrozole) for up to 3 cycles within a time horizon of 4 months. Women in the letrozole group received 5 mg oral letrozole daily starting from cycle day 3-5 for 5 days. Women in the natural cycle IUI group did not receive any ovarian stimulation before IUI. The primary outcome is ongoing pregnancy leading to live birth. The study was registered under trial number NCT03455426 RESULTS: Between March 2018 and January 2019, 158 couples were eligible to participate after initial screening and 100 (63.3 %) couples agreed to participate. Of the 100 recruited couples, 50 were randomly allocated to IUI with letrozole and 50 to natural cycle IUI. Live birth occurred in 12 women (24.0 %) in the letrozole group and 10 women (20.0 %) in the natural cycle group (RR 1.20 (95 % CI 0.57-2.52)). Clinical pregnancy rates were 28 % and 26 % in the letrozole group and natural cycle group respectively (RR 1.08 (95 % CI 0.56-2.05). There were no multiple pregnancies in both groups. Patients were willing to be randomized and useful information was gained to plan a definitive trial.Conclusions: We showed that an RCT comparing IUI with letrozole versus natural cycle IUI in couples with unexplained or mild male factor infertility is feasible and acceptable. [ABSTRACT FROM AUTHOR]

Many prehistoric cultural sites with distinctive regional characteristics have been discovered on fixed aeolian dunes in Nenjiang River Basin, Northeast China. The rise and decline of these cultures was substantially influenced by the regional environmental evolution. To elucidate how human activity responded to environmental changes, we conducted analyses of phytoliths, grain-size and organic content of a natural sediment profile at Honghe Neolithic site. The phytolith analysis shows that the vegetation was dominated by C3 Pooideae, and the grain-size analysis shows that the site was strongly affected by the winter monsoon and that the sediment source was regionally-derived aeolian sand from Songnen Sandy Land. The environment of Nenjiang River Basin experienced several periods of sand dune mobilization and stabilization: During 7024-4233 cal yr BP, 3414-2433 cal yr BP and 1700-1000 cal yr BP the dunes of Songnen Sandy Land were stable and the environment was warm and wet. During 4233-3,414 cal yr BP, 2433-1,700 cal yr BP and 1000 cal yr BP-present the dunes were mobile and the climate was cold and dry. In addition, the global 4.2 ka cold climatic event is recorded in the section. Correspondingly, the human history can be divided into three periods: (I) Neolithic Age (7024-4, 233 cal yr BP) when the winter monsoon was weak, the sand dunes were stable and the environment was warm and wet. Human activity was relatively intense during this period, manifested by the Angangxi Culture in the middle reaches of Nenjiang River, a representative of the 'Fishing-Hunting Neolithic Culture'. However, only a small number of tombs post-dating 4200 cal yr BP have been found in the Angangxi district (II) Bronze Age (4233-2, 433 cal yr BP). The Xiaolaha Cultural sites in the lower reaches of Nenjiang River, which inherited the characteristics of the Angangxi Culture, flourished during 3800-3260 cal yr BP, and after a transitional period it gradually evolved into the Baijinbao Culture (2800-2,500 cal yr BP). This pattern of evolution shows that human activity diminished in the middle reaches of Nenjiang River after 4233 cal yr BP, in response to the colder and drier environment. (III) Post-Warring States period (2 433 cal yr BP - present). The Hanshu II culture prospered during 2380-2067 cal yr BP, and the Hongmashan Culture was the dominant culture during 2000-1700 cal yr BP. Historical documents and archaeological evidence revealed that frequent wars interrupted the continuity of human cultural development after 2000 cal yr BP in the Nenjiang River Basin. [ABSTRACT FROM AUTHOR]

Abstract Phytolith records have provided a new perspective on the reconstruction and interpretation of palaeovegetation in forested regions. However, the reliability of phytolith records for vegetation reconstruction in northern temperate forest regions has not been fully determined, and it needs to be assessed before they can be used in palaeoecological contexts. To address this issue, we analyzed surface soil phytolith assemblages at 108 sites and established a modern soil phytolith reference database for five dominant vegetation communities in Northeast China. The phytolith reference dataset was then used to analyze a stratigraphic sequence of fossil phytolith assemblages from the same region to confirm the reliability of the phytolith-based paleovegetation reconstruction. The results demonstrate that both the phytolith assemblages of surface soils and the phytolith indices (Iw, Ic, Iph and W/G) vary substantially in different temperate forest habitats, and the indices are also well correlated with the vegetation inventory data. Thus, we conclude that modern soil phytoliths are reliable analogues for reconstructing paleovegetation. The modern phytolith reference-based paleovegetation reconstruction indicates that the study area has experienced substantial vegetation change since the late-glacial. The vegetation types ranged from open Larix mixed forest to open woodland, to closed broadleaf forest, and finally to closed Pinus koraiensis mixed forest. The phytolith-based vegetation types since the late-glacial are consistent with those reconstructed by a pollen record from the same stratigraphic profile, and thus our study confirms the reliability of phytolith analysis for interpreting both the entire vegetation landscape and vegetation changes in the northern temperate forest region. Moreover, fossil phytoliths also provide additional information - including the composition of grasses in the understory, changes in the proportions of C3/C4 plants, Larix abundance and tree cover density - which complements that provided by pollen analysis. Our study provides new perspectives on the reliability of phytoliths for reconstructing vegetation dynamics in the northern temperate forest region, and it provides a robust foundation for the application of phytolith analysis in the region. Highlights • Surface soil phytolith reference was established for NE China to identify different temperate forest types. • Based on the modern phytolith dataset we reconstructed the paleovegetation of a peat profile since the late-glacial. • Our work confirmed the reliability of phytolith-based paleovegetation reconstruction in the northern temperate forest region. [ABSTRACT FROM AUTHOR]

Accuracy of paleovegetation reconstruction and understanding of phytolith formation would both be improved by further study of phytolith size in the Phragmites australis under different environmental conditions. Leaves of P. australis were collected from 11 sampling sites in northeast China with differences in temperature, precipitation and habitat. Principal component analysis of environmental factors (climatic and edaphic) indicated that the annual averages of temperature and precipitation were the main factors influencing phytolith size. Moreover, three-way analyses of variance (ANOVAs) further showed that phytolith size differed significantly under conditions of different temperature or precipitation gradients, whereas habitat differences had little effect. The changes in phytolith size with temperature differed in the humid, semi-humid and semi-arid areas of northeast China. In the humid and semi-humid areas, moving from the temperate to the warm temperate zone, increasing temperature reduced phytolith size; whereas in the semi-arid area, phytolith became larger with increasing temperature. In the warm temperate and temperate zones, the changes of phytolith size with precipitation showed the same trend—moving from the semi-arid to semi-humid to humid areas, as precipitation increased, phytolith grew larger. Finally, ANOVA revealed that phytoliths were also sensitive to habitat. These findings demonstrated that the size of P . australis phytoliths was sensitive to environmental factors: for regional research, the annual averages of temperature and precipitation were the major factors influencing size, but in the same climate district, habitat differences seemed to also have a significant impact on phytolith size. Consequently, phytolith analysis has potential utility in the study of global climate change, palaeoenvironment reconstruction, and environmental conservation and restoration. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi (AMF) could improve crop yield by nutrient uptake from soil. However, how AMF of topsoil and subsoil respond to long-term differential application of mineral and organic fertilizers and how they are influenced in presence of different crops and growth stages have never been assessed together. Next generation sequencing was applied to profile soil AMF communities in both topsoil and subsoil from a typical arable soil (Eutric Regosol) in the Sichuan Base, southwest China. Soils were collected at anthesis and harvest of winter wheat and maize after 15-years of differential fertilization of an annual maize-wheat rotation (same inputs of nitrogen, N; but different in carbon, C; phosphorus, P; and potassium, K): (i) no-fertilization control (CT), (ii) 100% mineral NPK fertilizer (NPK), (iii) 60% mineral N and 100% mineral PK plus 40% N as crop residues (NPKCR); and (iv) 60% mineral N and 100% mineral PK plus 40% N as pig (organic) manure (NPKOM). Compared to CT, AMF diversity significantly decreased in topsoil, but increased in subsoil for both wheat and maize under NPK, NPKCR and NPKOM. The AMF community composition differed between NPK and CT in both topsoil and subsoil of maize and wheat. Both distance-based redundancy analysis (db-RDA) and structural equation modeling (SEM) suggested that AMF communities in topsoil and subsoil of maize and wheat responded in differences in soil available P, soil organic carbon, fertilization and climate (temperature and/or rainfall). Fertilization and available N, not AMF community, had significantly positive effects on wheat and maize aboveground dry matter and grain yield. Results from the present study shed light on how AMF communities in topsoil and subsoil respond to different soil fertility management over the long-term. Insights of this study are valuable in managing an important part of biological soil fertility. • AMF communities differed between fertilization regimes and soil depths. • AMF communities correlated with available phosphorus in topsoil and nitrogen in subsoil. • Soil organic carbon and rainfall correlated with AMF community Chao1 index and diversity. • Fertilization, but not AMF Chao1 index, determined plant biomass and grain yield. • AMF communities in subsoil were influenced by N fertilization. [ABSTRACT FROM AUTHOR]

Understanding local-scale paleoecological processes and their driving mechanisms is a major challenge in plant community ecology. However, phytolith records have the potential to retrieve localized signals of the evolution and patterns of past ecosystems. As a case study, we selected a forested region in Northeast China. We first established a modern phytolith reference dataset which enabled numerical estimates to be made of various aspects of the plant community. We then apply the dataset to a phytolith record from a sedimentary profile (HN) from the Changbai mountain region in order to quantitatively reconstruct the evolution of the vegetation since the last deglaciation. The results of partial least squares regression were used demonstrate that modern phytoliths can quantitatively estimate plant community coverage, species diversity and dry weight ratio; three numerical estimates respectively explained 62.3%, 50.3% and 49.5% of the variance. These quantitative relationships can provide reliable modern phytolith analogues for paleoecological reconstructions. The modern phytolith-based vegetation reconstruction indicates that the Changbai mountain region was dominated by forest communities since the late glacial period. The temporal development of the vegetation can be summarized as follows: boreal or coniferous forest, sparse and species-poor → mixed broadleaf-conifer forest, relatively dense and species-rich → mixed broadleaf-conifer forest, dense and species-rich. The phytolith-inferred changes in plant community coverage, dry weight ratio and species diversity correspond well with climatic changes. This supports the view that the environmental background mainly dominates ecosystem evolution, and it also confirms the utility of phytolith records to resolve local paleovegetation patterns and evolution. [ABSTRACT FROM AUTHOR]