The Origin of Mesozoic A-type Granitoids,Fujian Province,Southeast China:Insights from Geochronology,Mineralogy and Geochemistry

The magma sources,origins and precise forming ages of the miarolite from Qishan and Kuiqi intrusions are still uncertain.New results reveal that,miarolites from the Qishan and Kuiqi intrusions yield crystallization ages of~101 and~98 Ma,and they have a high formation temperature(~910℃)and low oxygen fugacity value,indicating crystallization condition at low pressure in the upper crust with temperature of 678℃.The Qishan and Kuiqi miarolites are characterized by enrichment in SiO_(2) and high-K alkali,depletion in Ca and Mg,and belong to the high-K weak peraluminous rock series.The samples are enriched in HFSEs(i.e.,Ta,Zr and Hf)and LILEs(i.e.,Ba,P and Sr),depleted in Ba and Sr with the negative anomaly of Eu.In the primitive mantle normalized trace element spider diagram,the samples show a right-inclined‘seagull-type’pattern,combined the ratios of(La/Yb)_(N),10000×Al/Ga,Rb/Nb and Nb/Ta etc.,they were proved to be alkaline A-type granite.Combined the characterize of the trace elements,they were derived from clay-rich source accompanied pelite melting,and subjected to K-feldspar crystallization fractional.The values of ε_(Hf)(t)and tDM2 are distributed in the range of-2.8 to 3.3 with~1.2 Ga,and-6.0 to 4.0 with~1.2 Ga,revealing that they were generated from the Mesoproterozoic Cathaysia basement rocks.The comprehensive research reveals the Kuiqi and Qishan intrusions derived from crust-mantle mixing and partial melting of the crust,respectively,resulting from lithospheric extension generated by the Paleo-Pacific Plate subducted into the European-Asian Plate.

Deep structure of the Southeast Asian curved subduction system and its dynamic process

The deep structure,material circulation,and dynamic processes in the Southeast Asia have long been an elusive scientific puzzle due to the lack of systematic scientific observations and recognized theoretical models.Based on the deep seismic tomography using long-period natural earthquake data,in this study,the deep structure and material circulation of the curved subduction system in Southeast Asia was studied,and the dynamic processes since 100 million years ago was reconstructed.It is pointed out that challenges still exist in the precise reconstruction of deep mantle structures of the study area,the influence of multi-stage subduction on deep material exchange and shallow magma activity,as well as the spatiotemporal evolution and coupling mechanism of multi-plate convergence.Future work should focus on high-resolution land-sea joint 3-D seismic tomography imaging of the curved subduction system in the Southeast Asia,combined with geochemical analysis and geodynamic modelling works.

Characteristics of Lightning Activity in Southeast China and its Relation to the Atmospheric Background

Based on the lightning observation data from the Fengyun-4A(FY-4A)Lightning Mapping Imager(FY-4A/LMI)and the Lightning Imaging Sensor(LIS)on the International Space Station(ISS),we extract the“event”type data as the lightning detection results.These observations are then compared with the cloud-to-ground(CG)lightning observation data from the China Meteorological Administration.This study focuses on the characteristics of lightning activity in Southeast China,primarily in Jiangxi Province and its adjacent areas,from April to September,2017–2022.In addition,with the fifth-generation European Centre for Medium-Range Weather Forecasts reanalysis data,we further delved into the potential factors influencing the distribution and variations in lightning activity and their primary related factors.Our findings indicate that the lightning frequency and density of the FY-4A/LMI,ISS-LIS and CG data are higher in southern and central Jiangxi,central Fujian Province,and western and central Guangdong Province,while they tend to be lower in eastern Hunan Province.In general,the high-value areas of lightning density for the FY-4A/LMI are located in inland mountainous areas.The lower the latitude is,the higher the CG lightning density is.High-value areas of the CG lightning density are more likely to be located in eastern Fujian and southeastern Zhejiang Province.However,the high-value areas of lightning density for the ISS-LIS are more dispersed,with a scattered distribution in inland mountainous areas and along the coast of eastern Fujian.Thus,the mountainous terrain is closely related to the high-value areas of the lightning density.The locations of the high-value areas of the lightning density for the FY-4A/LMI correspond well with those for the CG observations,and the seasonal variations are also consistent.In contrast,the distribution of the high-value areas of the lightning density for the ISS-LIS is more dispersed.The positions of the peak frequency of the FY-4A/LMI lightning and CG lightning contrast with local altitudes,primarily located at lower altitudes or near mountainsides.K-index and convective available potential energy(CAPE)can better reflect the local boundary layer conditions,where the lightning density is higher and lightning seasonal variations are apparent.There are strong correlations in the annual variations between the dew-point temperature(Td)and CG lightning frequency,and the monthly variations of the dew-point temperature and CAPE are also strongly correlated with monthly variations of CG lightning,while they are weakly correlated with the lightning frequency for the FY-4A/LMI and ISS-LIS.This result reflects that the CAPE shows a remarkable effect on the CG lightning frequency during seasonal transitions.

Intensive High-Level Visits from Southeast Asia

Recently,senior officials from Southeast Asian countries have visited China in succession,including Indonesian Presidentelect Prabowo Subianto,Lao Deputy Prime Minister and Foreign Minister Saleumxay Kommasith,Vietnamese Foreign Minister Bui Thanh Son,Timor-Leste Foreign Minister Bendito Freitas,Vietnamese National Assembly Chairman Vuong Dinh Hue,Singaporean Deputy Prime Minister Heng Swee Keat,and Thai Princess Maha Chakri Sirinhorn.

HELLO ASEAN Visa-free policy sparks surge of Chinese tourists to Southeast Asia

As of March 1,Malaysia,Singapore,and Thailand have all implemented visa-free entry policy for Chinese citizens,allowing stays of up to 30 days.The three Southeast Asian countries have been popular destinations for Chinese outbound tourists since the late 1980s and early 1990s.The implementation of the visa-free entry policy is expected to attract more Chinese tourists,especially young people,to travel to Southeast Asia and boost the recovery of the tourism industry in the region.

Chinese Enterprises’ Investment in Southeast Asia Continues Unabated

As we all know,Southeast Asia has become a hot destination for Chinese enterprises to invest in.The latest report shows that Southeast Asia continues to attract China’s capital,within which the medical industry has become an important area for Chinese enterprises to invest in,and the investment activity has gradually warmed up despite fluctuations.

A novel seed cone of Pinus from the Miocene of coastal Southeast China indicates kinship with Southeast Asian pines

Pinus is an economically and ecologically important genus whose members are dominant components globally in low-latitude mountainous and mid-latitude temperate forests.Pinus species richness is currently concentrated in subtropical mid-low latitudes of the Northern Hemisphere,differing from the latitudinal diversity gradient mostly recognized in woody angiosperms.How the present pattern was developing in Earth's past is still poorly studied,particularly in eastern Asia.Here,a new fossil species,Pinus shengxianica sp.nov.is described based on a fossil seed cone from the Late Miocene Shengxian Formation in Zhejiang,southeast China.A co-occurring cone is recognized as a known fossil species,Pinus speciosa Li.Extensive comparison of extant and fossil members of Pinus suggests P.shengxianica shares a striking cone similarity to Pinus merkusii and Pinus latteri(subsection Pinus)from tropical Southeast Asia in having annular bulges around the umbo on the apophysis.The morphological resemblance indicates these two extant low-latitude pines probably possess a close affinity with the present newly-discovered P.shengxianica and originated from East Asian mid-low latitude ancestors during this generic re-diversification in the Miocene.This scenario is consistent with the evolutionary trajectory reflected by the pine fossil history and molecular data,marking the Miocene as a key period for the origin and evolution of most extant pines globally.The co-occurrences of diverse conifers and broadleaved angiosperms preferring diverse niches demonstrate Late Miocene eastern Zhejiang was one of the hot spots for coniferophyte diversity and hosted a needled-broadleaved mixed forest with complex vegetation structure and an altitudinal zonation.

Medical Morbidity Profile of Adults in a Rural Community in Enugu, Southeast Nigeria: A Cross Sectional Survey

Introduction: People in rural communities are exposed to the risk factors for non-communicable disease as those in urban areas. Correct interpretation and management of symptoms are important in primary care especially in rural communities where diagnostic facilities are not readily available. Materials and Methods: This was a cross-sectional study carried out in a village in Enugu South Local Government area of Enugu State. Thorough medical history was taken from all eligible participants who gave their consent. Data were analyzed using SPSS version 26. Results: Data from a total of 1019 (64.7%) out of 1576 participants were analysed. Fever was by far the most common presenting complaint 580 (56.9%) of all participants and 67.9% of medical complaints seen in the clinic. This was followed remotely by musculoskeletal problems and neurological problems 15.6% and 3.8% of the participants respectively. Across all age groups, febrile illness was more than non-febrile illness except in those 65 years. Generalized body pains 74 (7.3%), back pains 55 (5.1), headache 33 (3.2%) and abdominal pains 24 (2.4%) were the commonest symptoms presented by the participants. About 15 (1.5%) of the population surveyed had had trauma/surgery in the past. This was twice the number who presented to the clinic with symptoms related to injury and trauma 7 (0.7%). Conclusions: Fever and musculoskeletal pains are the dominant medical complaints presented by adults in a rural community clinic. This may be related to the season of the year and the occupation of the population studied.

Alteration of intestinal microbiota is associated with diabetic retinopathy and its severity:Samples collected from southeast coast Chinese

BACKGROUND Current approaches for the therapy of diabetic retinopathy(DR),which was one of leading causes of visual impairment,have their limitations.Animal experiments revealed that restructuring of intestinal microbiota can prevent retinopathy.AIM To explore the relationship between intestinal microbiota and DR among patients in the southeast coast of China,and provide clues for novel ways to prevention and treatment methods of DR.METHODS The fecal samples of non-diabetics(Group C,n=15)and diabetics(Group DM,n=30),including 15 samples with DR(Group DR)and 15 samples without DR(Group D),were analyzed by 16S rRNA sequencing.Intestinal microbiota compositions were compared between Group C and Group DM,Group DR and Group D,as well as patients with proliferative diabetic retinopathy(PDR)(Group PDR,n=8)and patients without PDR(Group NPDR,n=7).Spearman correlation analyses were performed to explore the associations between intestinal microbiota and clinical indicators.RESULTS The alpha and beta diversity did not differ significantly between Group DR and Group D as well as Group PDR and Group NPDR.At the family level,Fusobacteriaceae,Desulfovibrionaceae and Pseudomonadaceae were significantly increased in Group DR than in Group D(P<0.05,respectively).At the genera level,Fusobacterium,Pseudomonas,and Adlercreutzia were increased in Group DR than Group D while Senegalimassilia was decreased(P<0.05,respectively).Pseudomonas was negatively correlated with NK cell count(r=-0.39,P=0.03).Further,the abundance of genera Eubacterium(P<0.01),Peptococcus,Desulfovibrio,Acetanaerobacterium and Negativibacillus(P<0.05,respectively)were higher in Group PDR compared to Group NPDR,while Pseudomonas,Alloprevotella and Tyzzerella(P<0.05,respectively)were lower.Acetanaerobacterium and Desulfovibrio were positively correlated with fasting insulin(r=0.53 and 0.61,respectively,P<0.05),when Negativibacillus was negatively correlated with B cell count(r=-0.67,P<0.01).CONCLUSION Our findings indicated that the alteration of gut microbiota was associated with DR and its severity among patients in the southeast coast of China,probably by multiple mechanisms such as producing short-chain fatty acids,influencing permeability of blood vessels,affecting levels of vascular cell adhesion molecule-1,hypoxia-inducible factor-1,B cell and insulin.Modulating gut microbiota composition might be a novel strategy for prevention of DR,particularly PDR in population above.

Are scorpion stings the new public health threat for southeast Turkey and northern Syria after the earthquakes?An emphasis on Leiurus quinquestriatus

In tropical countries,scorpion sting is a significant cause of disease,leading to severe localized cutaneous reactions,neurologic impairments,and respiratory distress,as well as myocarditis[1].The world’s most poisonous scorpion species,Leiurus quinquestriatus,is found in southern Turkey and is a threat to the public’s health in all of the provinces,particularly in Adiyaman and its surrounding areas,which were hit by the recent Turkey and Syria earthquake[1].

Two New Species of Fire-Bellied Newts (Caudata, Salamandridae, Cynops) from Southeastern China

The fire-bellied newt genus Cynops contains ten known species distributed in China and Japan in East Asia.In this work,two new Cynops species are described,namely Cynops jiaoren sp.nov.distributed in northern Guangdong and Cynops maguae sp.nov.distributed in eastern Jiangxi.The two new species can be distinctly distinguished from their congeners by the independent phylogenetic placements and a combination of morphological characteristics.The discovery of these two new species in the Southeast Chinese Hilly Area,where half of congeners occur,increases the known diversity of Cynops,and indicates unresolved relationships among the species in southeastern China.Further discussions on the taxonomic status of Cynops cyanurus are also provided.

China's E-commerce Enterprises Tap Southeast Asian

Driven by geographical and encouraging policy factors,Chinese e-commerce enterprises have always regarded Southeast Asia as the first stop of taking their business overseas.Although the Indonesian subsidiary of JD.com announced that it would stop services on March 31,and JD.com Thailand had announced that it would be closed,the Chinese e-commerce platform Alibaba,and cross-border e-commerce operation platform TikTok Shop,said they would continue to expand businesses in Southeast Asia.

Southeast Asia Embraces TCM

Traditional Chinese medicine(TCM),a gem in the treasure trove of Chinese culture,offers crucial insights into the time-honored Oriental civilization.As early as the Qin Dynasty(221-206 BC),increased trade and cultural interactions between China and neighboring Southeast Asian countries had already brought the Chinese medical therapies to the region as optional treatments.

Influence of Diversity of Prototypical Ethnic Culture in Diversity of Glutinous Rice in Southeast of Guizhou

There were quite abundant prototypical ethnic cultures and plant diversity in Qiandongnan （ Southeast of Guizhou） ,where the primitive natural ecology was also perfectly conserved. It was honored by World Native Culture Fund as One of the Eighteen Ecological and Cultural Conservations in the World. The prototypical ethnic culture of Southeast of Guizhou, as a stable life-style and economic culture type of the local people, came into being in the process of the local minorities＇ communicating, blending and struggling against the natural environment in the long course of history. It could be seen from this research that there were our preliminary research that there are quite abundant resources in Southeast of Guizhou in terms of prototypical ethnic cultures and genetic diversity of glutinous rice. A full reflection of the culture of Glutinous Rice could be seen in the local minority people＇s daily life, production, custom, religious belief, etc. These showed that the formation and great vitality of the genetic diversity of glutinous rice was not only determined by the diversity of local prototypical ethnic cultures but also to its own biotic condition and its adaptation to natural ecology. It was showed that prototypical ethnic cultures had positive impact on the conservation and utilization of Glutinous Rice diversity.

Characteristics of Soil Seed Bank and Natural Regenerations in Pinus densata Natural Forest of Southeast Tibet

Pinusdensata is one of the main constructive species for coniferous forests in southeast Tibet. P. densata forests are important water conservation forests in the drainage basins of the middle and lower reaches of Yalu Tsangpo River, Nyang River and Parlung Zangbo River. In this study, with P. densata forest distributed in southeast Tibet as research object, the seed rain, soil seed bank, seed germination and natural regeneration of P. densata were monitored and ana- lyzed by field investigation, located monitoring and indoor experimental analysis. The results showed that the average intensity of the seed rain of P. densata was 249.30±78.42 seeds/m2, in which the intensity of full seeds was 168.09±56.36 seeds/m2, the intensity of seeds damaged by worms was 41.11±20.25 seeds/m2, and the intensity of empty seeds was 40.10±21.04 seeds/m2. The intensity of the seed rain exhibited a single-peak trend of increasing at first and decreasing then over time. The spatial distribution patterns in the whole seed falling process and at different seed falling time all exhibited clumping distribution, and within in certain range, with the distance from the seed tree increasing, the diffusion intensity of the seed rain was weakened, exhibiting approximately normal distribution. In average density of P. densata seeds in the soil seed bank of P. densata was 231 seeds/m2, in which 62.77% of seeds were distributed in the litter layer, and 37.23% of seeds were distributed in the soil layer, and about 8% of seeds were lost during the pro- cess from seed rain to soil seed bank. Field sowing observation showed that the accumulated germination rate curve of P. densata fitted with Logistics equation y= 91.404/（1＋e66194.449）. The height structure, basal diameter structure and age structure of seedlings and young trees of P. densata were all of reverse ＂J＂ type, indicating good natural regeneration of P. densata. This study would provide a science basis for protection and resource management of P. densata, and further enrich the eval- uation content of national ecological safety curtain of the Tibet plateau.

Evaluation of Rice Germplasm from Southeast Asia

Totaling 662 rice germplasms were collected from Southeast Asia,including 120 wild species and 542 cultivated rice plants.An information database of the collections was constructed after phenotype identification.Based on evaluation of cultivated rice,some germplasm resources were found to have good characteristics,including 58 accessions resistant to brown planthopper,nine accessions resistant to rice blast,eleven accessions resistant to bacterial blight,and twelve accessions with salt-tolerance.The introduced rice resources broaden genetic basis of rice and enrich rice genbank in China,which would play an active role in rice genetic research and rice breeding.

Tourist Products Design of National Village Based on Experience——A Case Study of Minority Villages of Southeast Guizhou,China

On the basis of resources features of minority villages in Southeast Guizhou and tourists' experience needs,the paper proposed that national villages would increasingly be the ideal destination of cultural experience tourism under the background of experience economy,and products design centering on experience need was the common problem confronted tourism development of national villages.Through analyzing four aspects of tourist resources which were natural ecology and pastoral scenery,tangible national culture,process and event national culture,and intangible culture,the paper proposed a general method for design of tourist products of national villages.The design should be conducted by following steps of "theme extraction—image shaping—scene design—atmosphere creation—program arrangement—implication design—publicity marketing".It should establish brand image of tourist products of national villages,so as to help tourists realize "image establishment—purchasing impulse—participation into interaction—profound experience—expectation achievement",and to constantly increase the attraction power of tourist products of national villages and comprehensive economic benefit of tourism.

Impact of El Nino on Large-scale Circulation of Southeast Asian Summer Monsoon

Multi-year SST and NCEP/NCAR reanalyzed wind data were employed to study the impacts of El Nio on the Southeast Asian summer monsoon (SEASM). It was found that the impacts of El Nio on the SEASM differed distinctly from those on the East Asian summer monsoon (EASM) and the Indian summer monsoon (ISM). Composite analysis indicated that the "gear point" of coupling between the Indo-monsoon circulation and the Pacific-Walker circulation was located in the western margins of Southeast Asia when the developing stage of El Nio events covered the boreal summer. The anomalous circulations in the lower and upper troposphere and divergent circulation are all favorable for the strengthening of the SEASM during this period. Following the evolution of El Nio, the "gear point" of the two cells shifted eastward to the central Pacific when the mature or decaying period of El Nio events covered the boreal summer. The anomalous circulations are favorable for the weakening of the SEASM. The anomalous indexes of intensity of SEASM accord well with the above results. Additionally, the difference of SSTA patterns in the tropical Indo-Pacific Ocean between the two stages of the El Nio may play an important role.

Space Pattern of Rural Leisure Tourism Development in Southwest Minority Area——A Case Study of Ethnic Minority Area in Southeast Chongqing

On the basis of analysis of current research documents on rural leisure tourism, taking ethnic minority area of Southeast Chongqing for example, the paper expounded ecology, culture, authenticity and uniqueness of rural leisure tourist resources in ethnic minority area, and city-dependent, scenic area-dependent, traffic route-dependent and remote characteristic village type of space pattern.

Review and prospects: in celebration of the 20th anniversary of Journal of Southeast University (English Edition)

The twenty years history of Journal of Southeast University (English Edition) and its significant achievements are briefly reviewed. Based on the experiences accumulated over its twenty years, some suggestions for improving the quality of this English-language academic journal are proposed, including focusing on the report of the excellent disciplines of its sponsoring university, attracting high-level papers by giving the priority of publication, publishing special issues for experts and scholars at home and abroad, shortening publication period, and realizing the internationalization of the members of the editorial committee, etc.