Central South China Research Articles

Global Warming and Landscape Fragmentation Drive the Adaptive Distribution of Phyllostachys edulis in China

Global warming and landscape fragmentation significantly affect the spatial distribution pattern of bamboo forests. This study used high-resolution data and an optimized MaxEnt model to predict the distribution of Phyllostachys edulis in China under current and future climatic conditions in three climate scenarios (SSP126, SSP370, SSP585), and analyzed its land use landscape fragmentation using landscape indices. The results indicate that Phyllostachys edulis currently has potentially suitable habitats majorly distributed in East China, Southwest China, and Central South China. The precipitation of the driest month (BIO14) and the precipitation seasonality (BIO15) are the key environmental factors affecting the distribution of Phyllostachys edulis. In the next three scenarios, the adaptive distribution area of Phyllostachys edulis is generally expanding. With an increase in CO2 concentration, the adaptive distribution of Phyllostachys edulis in the 2050s migrates towards the southeast direction, and in the 2070s, the suitable habitat of Phyllostachys edulis migrates northward. In the suitable habitat area of Phyllostachys edulis, cropland and forests are the main land use types. With the passage of time, the proportion of forest area in the landscape pattern of the high-suitability area for Phyllostachys edulis continues to increase. Under SSP370 and SSP585 scenarios, the cropland in the Phyllostachys edulis high-suitability area gradually becomes fragmented, leading to a decrease in the distribution of cropland. In addition, it is expected that the landscape of high-suitability areas will become more fragmented and the quality of the landscape will decline in the future. This research provides a scientific basis for understanding the response of Phyllostachys edulis to climate change, and also provides theoretical guidance and data support for the management and planning of bamboo forest ecosystems, which will help in managing bamboo forest resources rationally and balancing carbon sequestration and biodiversity conservation.

Pregnancy complications associated with maternal near-miss in an undeveloped province in south-central China, 2012–2022

ObjectiveTo explore the relationship between pregnancy complications and maternal near-miss (MNM).MethodsData were obtained from the Maternal Near-Miss Surveillance System in Hunan Province, China, 2012–2022. The MNM ratio refers to the number of MNM per 1000 live births, and maternal mortality refers to the number of maternal deaths per 100,000 live births. Chi-square trend tests (χ2trend) were used to determine trends in proportions by year. Multivariate logistic regression analysis (method: Forward, Wald, α = 0.05) and adjusted odds ratios (aORs) were used to identify risk factors for MNM.ResultsOur study included 780,359 women with 731,185 live births, a total of 2461 MNMs, and 52 maternal deaths were identified. The MNM ratio was 3.37‰ (95%CI: 3.23–3.50), and the maternal mortality was 7.11 per 100,000 live births (95%CI: 5.18–9.04). Coagulation/hematological dysfunction was the most common cause of MNM (75.66%). From 2012 to 2022, the proportion of coagulation/hematological dysfunction among MNM increased from 49.14% in 2012 to 86.39% in 2022, which was the only cause of MNM that showed an increased trend (χ2trend = 7.43, P = 0.01). Results of multivariate logistic regression analysis showed that 10 pregnancy complications were risk factors for MNM: hemorrhage disorder (aOR = 21.50, 95%CI: 19.64–23.54), infections (aOR = 1.91, 95%CI: 1.64–2.22), hypertension (aOR = 4.50, 95%CI: 4.08–4.98), heart disease (aOR = 14.96, 95%CI: 11.51–19.44), embolic disease (aOR = 171.70, 95%CI: 94.08-313.36), liver disease (aOR = 1.54, 95%CI: 1.25–1.90), anaemia (aOR = 4.72, 95%CI: 4.29–5.19), renal disease (aOR = 5.44, 95%CI: 4.00-7.40), pulmonary disease (aOR = 14.85, 95%CI: 8.33–26.50), and connective tissue disease (aOR = 5.15, 95%CI: 3.06–8.66).ConclusionThe MNM ratio was relatively low in Hunan Province. Several pregnancy complications increased the risk of MNM. It is helpful for clinical counseling and public health policies, which may contribute to preventing MNM.

Summertime compound heat extremes change and population heat exposure distribution in China

Amid the cumulative effects of rapid urbanization and climate warming, urban residents face serious health threats posed by heat extremes. Long-term monitoring of extreme high temperatures in cities can provide a foundational framework for mitigating the urban heat environment and enhancing the livability of residents. Utilizing long-term MODIS land surface temperature (LST) data, this study examined the fluctuations of extreme high temperatures, as well as the distribution of urban populations exposed to heat extremes and the associated health risks for urban residents across 289 prefecture-level and above cities in China from 2002 to 2020, considering natural, population and economic regional scales. The results indicated that: (1) Variations in extreme high temperatures. Extreme LST thresholds exhibited an upward trend, with the nighttime growth rate being 0.24°C/decade higher than the day. Regions characterized by higher extreme LST thresholds during the day were concentrated in Northwest and North China, while nighttime were primarily found in South Central and East China. Furthermore, regions showing higher extreme LST thresholds during the day and night were situated in well-developed cities. (2) Changes in cities exposed to heat extremes. Over the past 19 years, the majority of cities have been exposed to compound extreme high temperatures, and the number of such cities increased from 230 to 256. Notably, nearly 42% of cities have been exposed to extreme high temperatures for 15 consecutive years or longer, particularly concentrated in East China and South Central China. Developed cities were more likely to endure persistent heat extremes, especially those with a population of over 5 million and a per capita GDP of over 20,000, which have almost continuously experienced heat extreme exposure for the past 19 years. (3) Urban populations exposed to compound heat extremes. The urban population heat exposure across the country was on the rise, with the fastest growth rate of 2.91 million people per year in the nighttime, and a greater escalation in East and South Central China. Moreover, cities with lower levels of population and economic development represented the primary areas for growth0, while cities with moderate development levels showcased the slowest growth rate. (4) Health risks for urban residents. The number of urban residents dying from cardiovascular and respiratory diseases increased by 522,500, with the elderly and males accounting for a greater proportion of the increase by 234,200 and 149,800, respectively. Additionally, there existed a significant positive correlation between the deaths and heat extremes during the day and night.

Impacts of tropical cyclones on extreme precipitation and flooding in a humid subtropical inland basin of China

Study regionXiangjiang basin, a humid subtropical inland region of central-south China. Study focusTropical Cyclones (TCs) usually cause extreme precipitation events (EPEs) and flooding in both coastal and inland areas, resulting in severe economic losses. However, TC impacts in inland regions were seldom investigated. This study provided a climatological view of TCs, TC-induced EPEs and flooding in the Xiangjiang basin over the past nearly 70 years, and examined their relationships with ENSO using data from 127 meteorological stations, 22 hydrological stations, and TC tracks. New hydrological insights for the regionXiangjiang basin averaged five TC visits annually, primarily between July and September, when the majority of EPEs and flooding associated with TCs occurred. Despite the relatively low frequency (less than 30 %) of TC-induced EPEs and flooding compared to coastal regions, their magnitudes were comparable to or even exceeded those in coastal regions. These influences were modulated by ENSO. In neutral years, the frequency and magnitude of TC-induced EPEs were greatest due to higher TC track density and frequency. Also, TC tracks shifted westward, increasing the likelihood of extreme TC flooding in neutral years. The southeast of the basin faced the highest risk of TC-related disasters, especially in neutral years. This paper highlights the need to strengthen monitoring and prevention for TC-induced disasters in inland regions.

Comparative analysis of the epidemiological characteristics of adenovirus, rotavirus A, and coinfection in children during 2014–2023 in Guangzhou, China

BackgroundInfection is the cause of diarrhoea, and rotaviruses and adenoviruses are important pathogens in children.MethodsA retrospective study was conducted on 144,067 children with diarrhoea between 2014 and 2023 in China. We used the colloidal gold method to detect intestinal adenovirus and rotavirus A antigens in faeces. The epidemiological characteristics of these viruses and the impact of meteorological factors on them were analysed before and after coronavirus disease 2019 (COVID-19) pandemic.ResultsDuring this decade, the positive rate of adenovirus infection was 6.41%, while the positive rate of rotavirus A infection was 11.81%, higher than that of adenovirus infection. The positive rate of adenovirus and rotavirus A coinfection was 1.92%. The positive rates of adenovirus, rotavirus A and coinfection showed a fluctuating trend, and suddenly decreased in 2020. There was an apparent decrease of positive rate of rotavirus A, with a decrease of 57.27%, during 2020–2023. Surprisingly, the positive rate of adenovirus infection exceeded that of rotavirus A infection in 2021 and 2023. During the COVID-19 pandemic, the proportion of female patients and children over two years of age infected with adenovirus or rotavirus A increased, while the proportion of cases in winter decreased. In addition, we found that the positive rate of rotavirus A infection was related to average temperature and sunshine, and the positive rate of adenovirus and rotavirus A coinfection was only related to sunshine. However, these correlations disappeared during the COVID-19 pandemic.ConclusionsThis study revealed the recent prevalence of adenovirus and rotavirus A infections in children with diarrhoea in south-central China and provided a theoretical basis for the prevention and control of viral diarrhoea.

The impact of the COVID-19 pandemic on RSV outbreaks in children: A multicenter study from China

ObjectiveThe aim of the study is to describe the season of RSV prevalence in China during the COVID-19 pandemic. MethodsThis multicenter retrospective study analyzed the epidemiology of pediatric RSV infections and the possible factors contributing to its variations in China from January 1, 2019, to October 31, 2022. ResultsA total of 872,565 children were included. During the pandemic, RSV detection rate increased across various regions, including South China, East China, Central China, and Northeast China. From 2019 to 2021, the detection rates of RSV showed an increasing trend among children aged <1 year, 1–2 years, and 3–5 years, but decreased in 2022. Among those tested positive for RSV, the proportion of children under 1 year old significantly decreased during the pandemic. The spring season of RSV in China in 2020 was shortened, and most regions experienced a summer season of RSV in 2021. This shift led to a year-round RSV outbreak throughout 2021. After April 2022, RSV positive rate significantly decreased, and no clear seasonal pattern was observed. ConclusionOur study found that the COVID-19 pandemic has disrupted the seasonal pattern of RSV outbreaks in China, leading to increased RSV positive rate and off-season outbreaks.

Complete chloroplast genome sequence of Artemisia littoricola (Asteraceae) from Dokdo Island Korea: genome structure, phylogenetic analysis, and biogeography study.

The Asteraceae family, particularly the Artemisia genus, presents taxonomic challenges due to limited morphological characteristics and frequent natural hybridization. Molecular tools, such as chloroplast genome analysis, offer solutions for accurate species identification. In this study, we sequenced and annotated the chloroplast genome of Artemisia littoricola sourced from Dokdo Island, employing comparative analyses across six diverse Artemisia species. Our findings reveal conserved genome structures with variations in repeat sequences and junction boundaries. Notably, the chloroplast genome of A. littoricola spans 150,985bp, consistent with other Artemisia species, and comprises 131 genes, including 86 protein-coding, 37 tRNA, and 8 rRNA genes. Among these genes, 16 possess a single intron, while clpP and ycf3 exhibit two introns each. Furthermore, 18 genes display duplicated copies within the IR regions. Moreover, the genome possesses 42 Simple Sequence Repeats (SSRs), predominantly abundant in A/T content and located within intergenic spacer regions. The analysis of codon usage revealed that the codons for leucine were the most frequent, with a preference for ending with A/U. While the chloroplast genome exhibited conservation overall, non-coding regions showed lower conservation compared to coding regions, with the Inverted Repeat (IR) region displaying higher conservation than single-copy regions. Phylogenetic analyses position A. littoricola within subgenus Dracunculus, indicating a close relationship with A. scoparia and A. desertorum. Additionally, biogeographic reconstructions suggest ancestral origins in East Asia, emphasizing Mongolia, China (North East and North Central and South Central China), and Korea. This study underscores the importance of chloroplast genomics in understanding Artemisia diversity and evolution, offering valuable insights into taxonomy, evolutionary patterns, and biogeographic history. These findings not only enhance our understanding of Artemisia's intricate biology but also contribute to conservation efforts and facilitate the development of molecular markers for further research and applications in medicine and agriculture.

A Climate-Sensitive Mixed-Effects Individual Tree Mortality Model for Masson Pine in Hunan Province, South–Central China

Accurately assessing tree mortality probability in the context of global climate changes is important for formulating scientific and reasonable forest management scenarios. In this study, we developed a climate-sensitive individual tree mortality model for Masson pine using data from the seventh (2004), eighth (2009), and ninth (2014) Chinese National Forest Inventory (CNFI) in Hunan Province, South–Central China. A generalized linear mixed-effects model with plots as random effects based on logistic regression was applied. Additionally, a hierarchical partitioning analysis was used to disentangle the relative contributions of the variables. Among the various candidate predictors, the diameter (DBH), Gini coefficient (GC), sum of basal area for all trees larger than the subject tree (BAL), mean coldest monthly temperature (MCMT), and mean summer (May–September) precipitation (MSP) contributed significantly to changes in Masson pine mortality. The relative contribution of climate variables (MCMT and MSP) was 44.78%, larger than tree size (DBH, 32.74%), competition (BAL, 16.09%), and structure variables (GC, 6.39%). The model validation results based on independent data showed that the model performed well and suggested an influencing mechanism of tree mortality, which could improve the accuracy of forest management decisions under a changing climate.

Scaling the Diurnal Mixing/Mixed Layer Depth in the Tropical Ocean: A Case Study in the South China Sea

AbstractThe diurnal cycling of the surface mixing/mixed layer (ML) depth, air‐sea heat flux, and vertical profiles of the temperature and turbulent kinetic energy dissipation rate in the tropical central South China Sea was observed in summer (June 2017) and winter (January 2018). In the daytime, solar heating warmed and stabilized the ML, and the thickness of the ML can be well characterized by the Zilitinkevich scale as noted in previous studies. By contrast, in the nighttime the ML was deepened by convective turbulence generated by surface cooling. Guided by these observations, we have derived a simple scaling for the nighttime deepening of the ML by simplifying the classic Kraus‐Turner type model. We show that the variation of the ML depth can be scaled by a function of the wind speed, air‐sea heat flux and the temporal variation of the sea surface temperature, all of which are observable variables at the sea surface. It is found that the scaling works well in reproducing observed variations of the ML depth from hydrographic data. As such, this study advances our understanding of the response of the upper ocean to atmospheric forcing and provides a simple way for predicting the ML depth with solely surface observations.

What Are the Variation Patterns of Vegetation and Its Influencing Factors in China from 2000–2020 from the Partition Perspective?

China’s vegetation ecosystem has undergone profound changes, and there is an urgent need to explore the mechanisms behind vegetation changes in different ecological sub-regions and historical periods across China. Based on NDVI (normalized difference vegetation index) data, this study analyzed the spatial and temporal evolution patterns and driving mechanisms of six ecological sub-regions in China. The results showed that: (1) over the past 20 years, the vegetation coverage in mainland China showed a decreasing trend from east to west. (2) Over the past 20 years, the vegetation coverage of the six ecological sub-regions showed an increasing trend, with the highest increase in Central Southern China (0.0039) and the lowest increase in East China (0.002). (3) The gravity center of Northeast China showed a trend of migration to the northwest. The gravity center of North China, East China, and Central South China showed a trend of migration to the southwest, while that of Northwest and Southwest China showed a trend of migration to the southeast. (4) During the period from 2000 to 2020, vegetation cover levels showed an upward trend. (5) The lag time of vegetation types in different regions was different. (6) Precipitation was the dominant influencing factor in the evolution of vegetation in Northeast China, North China, Northwest China, and Southwest China. The dominant influencing factors of vegetation evolution in East China were land use and GDP (gross domestic product), while the dominant influencing factors of vegetation evolution in Central South China were precipitation and land use.

The genus Nemoura (Plecoptera: Nemouridae) from Shennongjia National Park of Hubei, China.

Two new species of nemourid stonefly genus Nemoura, N. liuqifeii sp. nov. and N. shennongjia sp. nov., are described from Shennongjia National Park, Hubei Province of south-central China. The relationships between the new species and similar species in the genus are discussed. Three females of an undetermined Nemoura are also described from the park, however, they were not successfully associated with the new species or previously barcoded species.

Analysis of epidemiological characteristics of extrapulmonary tuberculosis from South-Central China.

This study aimed to investigate the epidemiological and drug resistance (DR) characteristics of extrapulmonary tuberculosis (EPTB) in South-Central China. EPTB inpatients who were culture-positive for Mycobacterium tuberculosis were retrospectively included in a study at a provincial TB hospital in Hunan, a province in South-Central China, from January 2013 to December 2021. Demographic, clinical, and drug susceptibility data were retrieved from TB treatment records. Descriptive statistical methods and a Chi-squared test were used to analyze the epidemiological and DR characteristics of EPTB patients. A logistic regression model was used to explore the risk factors of rifampicin-resistant/multidrug-resistant (RR/MDR)-EPTB. A total of 1,324 cases were included. The majority of EPTB patients were in the age range of 20-29 years, were predominantly men (male-to-female ratio: 2.03), and were farmers (65.63%). Most EPTB cases were found in 2013 and 2017 from 2013 to 2021. The most prevalent subtypes of EPTB were lymphatic TB (29.83%, 395/1,324), multiple EPTB (20.85%, 276/1,324), and musculoskeletal TB (14.65%, 194/1,324). Musculoskeletal TB and genitourinary TB predominantly presented as exclusive EPTB forms, while lymphatic TB and pharyngeal/laryngeal TB often co-occurred with pulmonary TB (PTB). Drug susceptibility testing results showed that total DR rates (resistance to any of RFP, isoniazid [INH], streptomycin [STR], and/or ethambutol [EMB]) and RR/MDR rates in EPTB were 25.23% and 12.39%, respectively. Musculoskeletal TB exhibited the highest rates of total DR (31.40%), INH resistance (28.90%), STR resistance (20.10%), EMB resistance (6.20%), MDR (13.90%), and poly-DR (6.70%). The multivariable logistic regression model showed that patients aged from 20 to 59 years (compared to those aged 10 years), workers (compared to retirees), and EPTB patients from the south and west of Hunan (compared to those from the east of Hunan) were at an increased risk of developing RR/MDR EPTB (all OR values > 1). Our study provided a detailed account of the epidemiological and DR characteristics of EPTB in Hunan province, China. The significant DR rates, particularly in musculoskeletal TB cases, highlight the need for timely diagnosis, effective drug susceptibility testing, and the development of more effective treatment regimens for EPTB, especially targeting musculoskeletal TB treatments.

Influence of the atmospheric environment on spatial variation of lung cancer incidence in China.

Conducting this research contributes to a deeper understanding of the correlation between atmospheric environmental quality and lung cancer incidence, and provides the scientific basis for formulating effective environmental protection and lung cancer prevention and control strategies. Lung cancer incidence in China has strong spatial variation. However, few studies have systematically revealed the characteristics of the spatial variation in lung cancer incidence, and have explained the causes of this spatial variation in lung cancer incidence from the perspectives of multiple components of the atmospheric environment to explain this spatial variation in lung cancer incidence. To address research limitations, we first analyze the spatial variation and spatial correlation characteristics of lung cancer incidence in China. Then, we build a spatial regression model using GeoDa software with lung cancer incidence as the dependent variable, five atmospheric environment factors-particulate matter 2.5 (PM2.5) concentration, temperature, atmospheric pressure, and elevation as explanatory variables, and four socio-economic characteristics as control variables to systematically analyze the influence and intensity of these factors on lung cancer incidence. The results show that lung cancer incidence in China has apparent changes in geographical and spatial unevenness, and spatial autocorrelation characteristics. In China, the lung cancer incidence is relatively high in Northeast China, while some areas of high lung cancer incidence still exist in Central China, Southwest China and South China, although the overall lung cancer incidence is relatively low. The atmospheric environment significantly affects lung cancer incidence. Different elements of the atmospheric environment vary in the direction and extent of their influence on the development of lung cancer. A 1% increase in PM2.5 concentration is associated with a level of 0.002975 increase in lung cancer incidence. Atmospheric pressure positively affects lung cancer incidence, and an increase in atmospheric pressure by 1% increases lung cancer incidence by a level of 0.026061. Conversely, a 1% increase in temperature is linked to a level of 0.006443 decreases in lung cancer incidence, and a negative correlation exists between elevation and lung cancer incidence, where an increase in elevation by 1% correlates with a decrease in lung cancer incidence by a level of 0.000934. The core influencing factors of lung cancer incidence in the seven geographical divisions of China exhibit variations. This study facilitates our understanding of the spatial variation characteristics of lung cancer incidence in China on a finer scale, while also offering a more diverse perspective on the impact of the atmospheric environment on lung cancer incidence.

Risk factors for maternal near-miss in an undeveloped province in south-central China, 2012–2022

ObjectiveTo explore the risk factors for maternal near-miss (MNM) using the WHO near-miss approach.MethodsData were obtained from the Maternal Near-Miss Surveillance System in Hunan Province, China, 2012–2022. Multivariate logistic regression analysis (method: Forward, Wald, α = 0.05) and adjusted odds ratios (aORs) were used to identify risk factors for MNM.ResultsOur study included 780,359 women with 731,185 live births, a total of 2461 (0.32%) MNMs, 777,846 (99.68%) non-MNMs, and 52 (0.006%) maternal deaths were identified. The MNM ratio was 3.37‰ (95%CI: 3.23–3.50). Coagulation/hematological dysfunction was the most common cause of MNM (75.66%). Results of multivariate logistic regression analysis showed risk factors for MNM: maternal age > = 30 years old (aOR > 1, P < 0.05), unmarried women (aOR = 2.21, 95%CI: 1.71–2.85), number of pregnancies > = 2 (aOR > 1, P < 0.05), nulliparity (aOR = 1.51, 95%CI: 1.32–1.72) or parity > = 3 (aOR = 1.95, 95%CI: 1.50–2.55), prenatal examinations < 5 times (aOR = 1.13, 95%CI: 1.01–1.27), and number of cesarean sections was 1 (aOR = 1.83, 95%CI: 1.64–2.04) or > = 2 (aOR = 2.48, 95%CI: 1.99–3.09).ConclusionThe MNM ratio was relatively low in Hunan Province. Advanced maternal age, unmarried status, a high number of pregnancies, nulliparity or high parity, a low number of prenatal examinations, and cesarean sections were risk factors for MNM. Our study is essential for improving the quality of maternal health care and preventing MNM.

Forecasting the Expansion of Bactrocera tsuneonis (Miyake) (Diptera: Tephritidae) in China Using the MaxEnt Model.

The invasive pest, Bactrocera tsuneonis (Miyake), has become a significant threat to China's citrus industry. Predicting the area of potentially suitable habitats for B. tsuneonis is essential for optimizing pest control strategies that mitigate its impact on the citrus industry. Here, existing distribution data for B. tsuneonis, as well as current climate data and projections for four future periods (2021-2040, 2041-2060, 2061-2080, and 2081-2100) from the Coupled Model Intercomparison Project Phase 6 (CMIP6) were obtained. The distribution of B. tsuneonis under current and different climate change scenarios in China was predicted using the optimized MaxEnt model, ArcGIS, and the ENMeval data package. Model accuracy was assessed using ROC curves, and the primary environmental factors influencing the distribution of the pest were identified based on the percent contribution. When the regularization multiplier (RM) was set to 1.5 and the feature combination (FC) was set to LQH, a model with lower complexity was obtained. Under these parameter settings, the mean training AUC was 0.9916, and the mean testing AUC was 0.9854, indicating high predictive performance. The most influential environmental variables limiting the distribution of B. tsuneonis were the Precipitation of Warmest Quarter (Bio18) and Temperature Seasonality (standard deviation ×100) (Bio4). Under current climatic conditions, potentially suitable habitat for B. tsuneonis in China covered an area of 215.9 × 104 km2, accounting for 22.49% of the country's land area. Potentially suitable habitat was primarily concentrated in Central China, South China, and East China. However, under future climatic projections, the area of suitable habitat for B. tsuneonis exhibited varying degrees of expansion. Furthermore, the centroid of the total suitable habitat for this pest gradually shifted westward and northward. These findings suggest that B. tsuneonis will spread to northern and western regions of China under future climate changes. The results of our study indicate that climate change will have a major effect on the invasion of B. tsuneonis and have implications for the development of strategies to control the spread of B. tsuneonis in China.

Response of chlorophyll-a to rainfall event in the basin of the South China sea: Statistical analysis

Chlorophyll-a (Chl-a) is an essential ecological indicator, and affected by processes such as typhoons, mesoscale eddies, and Rossby waves. However, the impact of more frequent and widespread precipitation events on Chl-a seems to be overlooked. This study utilized remote sensing data and reanalysis data to investigate the response of Chl-a to 240 precipitation events in the central South China Sea from 2005 to 2019. The results indicate that precipitation events have a significant impact on Chl-a concentration. Following a precipitation event in 2019, the Chl-a concentration in the affected area increased by approximately 0.22 mg m−³ from the 3rd to the 7th day. The reasons for the increase in Chl-a concentration were the vertical mixing induced by wind stirring and the upwelling caused by wind stress curl, which transported nutrients to the euphotic zone, lowering the sea surface temperature and triggering a proliferation of phytoplankton. Additionally, dissolved nutrients in precipitation provided a nutrient source for Chl-a growth. The contributions of nutrient supply, wind speed, and wind stress curl to the increase in Chl-a concentration during precipitation events were 18%, 37%, and 45%, respectively. Precipitation events enhanced marine primary productivity, playing a crucial role in deepening our understanding of ocean-atmosphere interactions and their impact on marine ecosystem.

A Pilot Study on the Diel Vertical Migration Pattern of Mesopelagic Fishes in the Southern and Central South China Sea

The diel vertical migration of mesopelagic fishes in the southern (S-May station and S-Nov station) and central (C-Jun station and C-Dec station) South China Sea was investigated through a series of continuous field surveys conducted in May, June, November, and December 2017. These surveys employed a combination of mid-water trawl and acoustics techniques. The diel migration process, vertical distribution, acoustic migration proportion, and migration pattern of mesopelagic fishes were analyzed. The results revealed that mesopelagic fishes initiated an upward migration before sunset, with the process concluding within 30–120 min after dark. Subsequently, they commenced a downward migration before dawn, which terminated within 10–50 min after sunrise. The mesopelagic deep-sea layers of mesopelagic fishes at the S-May, S-Nov, C-Jun, and C-Dec stations ranged from 360 to 700 m, 350 to 680 m, 350 to 520 m, and 300 to 700 m, respectively. The acoustic migration proportions of mesopelagic fishes at the corresponding stations were found to be approximately 44.5%, 25.7%, 29.8%, and 58.0%, respectively. There were seasonal and regional differences in the vertical migration and distribution patterns of mesopelagic fishes in the South China Sea. A total of 228 species were identified, including 203 fish species, 23 cephalopod species, and 2 shark species. Among these, a subset of 43 fish and cephalopod species exhibited extensive diel vertical migrating behavior. Specifically, this subset comprised 23 lanternfish species, 8 cephalopod species, and 12 other fish species. Lanternfishes were the predominant diel vertical migratory species, while cephalopods also played a significant role in diel vertical migration. The diel migration behavior was found to be slight for Diaphus lucidus, Melamphaes microps, Argyropelecus affinis, and six other fish species. Non-migratory behavior was observed in Sternoptyx obscura, Argyropelecus sladeni, Sternoptyx diaphana, and 13 other fish species. The diel migration habits of 178 additional species of fish, cephalopods, and sharks could not be definitively determined.

Genotype-phenotype correlations of AR-CMT2S in a cohort of axonal Charcot-Marie-Tooth patients from Central South China.

This study aimed to report nine Charcot-Marie-Tooth disease (CMT) families with six novel IGHMBP2 mutations in our CMT2 cohort and to summarize the genetic and clinical features of all AR-CMT2S patients reported worldwide. General information, clinical and neurophysiological data of 275 axonal CMT families were collected. Genetic screening was performed by inherited peripheral neuropathy related genes panel or whole exome sequencing. The published papers reporting AR-CMT2S from 2014 to 2023 were searched in Pubmed and Wanfang databases. In our CMT2 cohort, we detected 17 AR-CMT2S families carrying IGHMBP2 mutations and eight were published previously. Among these, c.743 T > A (p.Val248Glu), c.884A > G (p.Asp295Gly), c.1256C > A (p.Ser419*), c.2598_2599delGA (p.Lys868Sfs*16), c.1694_1696delATG (p.Asp565del) and c.2509A > T (p.Arg837*) were firstly reported. These patients prominently presented with early-onset typical axonal neuropathy and without respiratory dysfunction. So far, 56 AR-CMT2S patients and 57 different mutations coming from 43 families have been reported in the world. Twenty-nine of 32 missense mutations were clustered in helicase domain and ATPase region. The age at onset ranged from 0.11to 20 years (Mean ± SD: 3.43 ± 3.88 years) and the majority was infantile-onset (<2 years). The initial symptoms included weakness of limbs (19, 29.7%), delayed milestones (12, 18.8%), gait disturbance (11, 17.2%), feet deformity (8, 12.5%), feet drop (8, 12.5%), etc. INTERPRETATION: AR-CMT2S accounted for 6.2% in our CMT2 cohort. We firstly reported six novel IGHMBP2 mutations which expanded the genotypic spectrum of AR-CMT2S. Furthermore, 17 AR-CMT2S families could provide more resources for natural history study, drug research and development.

The associations of fatty acids related dietary patterns with overweight and obesity among Chinese children

BackgroundChildhood overweight and obesity is becoming an emerging face of malnutrition. The aims of this study were to develop fatty acid (FAs) related dietary patterns and explored the associations of FAs related dietary patterns with overweight and obesity among Chinese children.MethodsAn observational study was conducted on 435 children aged 4 to 7 years old in South Central China. Erythrocyte FAs composition was analyzed by gas chromatography-mass spectrometry. Diet was collected by food frequency questionnaires and dietary patterns were evaluated by reduced rank regression. The logistic regression analysis was used to exploring the association of dietary patterns with overweight and obesity.ResultsThe prevalence of overweight, obesity, and overweight or obesity were 6.52, 4.59, and 11.11% in Chinese children, respectively. Twenty five types of FAs were detected in erythrocyte of children and four FAs related dietary patterns were identified. The dietary pattern positively correlated with n-3 PUFAs, but negatively with SFAs,was characterized by high intake of fish, shrimp, crab and shellfish, leaf-off vegetable, nuts, and tubers, which have a significantly decreased overweight risk (OR = 0.580, 95%CI: 0.375 ∼ 0.895, P = 0.014).The pattern positively strong associated with n-6 PUFAs, but negatively strong with n-3 PUFAs, had high intake of snacks, leaf-off vegetable, fresh beans, and coarse cereals, which have a significantly decreased obesity risk (OR = 0.518, 95%CI: 0.325 ∼ 0.827, P = 0.006).ConclusionFour FAs related dietary patterns were identified. The dietary pattern with high intake of fish, shrimp, crab and shellfish decreased overweight risk by increasing n-3 PUFAs, and decreasing SFAs. The dietary pattern with high intake of plant food, decreased obesity risk by providing an balanced n-6/n-3 PUFAs ratio.

Ensemble model-based analysis of the effects of environmental factors on the distribution and chemical composition of Asparagus cochinchinensis (Lour.) Merr.

Asparagus cochinchinensis (Lour.) Merr., is a traditional Chinese herbal medicine with pharmacological effects such as cough and asthma suppression, anti-inflammation, and immunity enhancement. Currently, as a wild resource it is scarce and its distribution has not been well defined. Especially in the context of climate change, the effect of the environment on its chemical composition is also unknown. In this study, we constructed an ensemble model of species distribution for A. cochinchinensis to predict its current and future potential suitable habitat areas, and explored the relationship between its chemical composition and key environmental factor using statistical analysis. The results showed that the Mean Diurnal Range (Bio2) contributed 67.74% to the model and was the key environmental factor influencing the distribution of A. cochinchinensis. The current habitat of A. cochinchinensis was mainly distributed in south-central and southeastern China, such as Sichuan, Chongqing, Guangxi, Guangdong and Fujian. Under the influence of climate change, its potential habitat would gradually decrease, especially in highly suitable areas. The results of chemical analysis showed that the quality of A. cochinchinensis was higher in Neijiang than other locations, which might be related to the fact that Bio2 in Neijiang was most suitable for growth. In addition, the correlation results showed that 12 out of 36 chemical indicators had significant correlation with Bio2, and all of them except protein and Tyr had significantly negative correlation with Bio2, indicating that the environment affected the biosynthesis of chemical composition of A. cochinchinensis. The results of the study provide theoretical guidance for the cultivation, management, and sustainable use of A. cochinchinensis resources, as well as a theoretical basis for their quality improvement.