Geolocating social media users aims to discover the real geographical locations of users from their publicly available data,which can support online location-based applications such as disaster alerts and local conten...Geolocating social media users aims to discover the real geographical locations of users from their publicly available data,which can support online location-based applications such as disaster alerts and local content recommen-dations.Social relationship-based methods represent a classical approach for geolocating social media.However,geographically proximate relationships are sparse and challenging to discern within social networks,thereby affecting the accuracy of user geolocation.To address this challenge,we propose user geolocation methods that integrate neighborhood geographical distribution and social structure influence(NGSI)to improve geolocation accuracy.Firstly,we propose a method for evaluating the homophily of locations based on the k-order neighbor-hood geographic distribution(k-NGD)similarity among users.There are notable differences in the distribution of k-NGD similarity between location-proximate and non-location-proximate users.Exploiting this distinction,we filter out non-location-proximate social relationships to enhance location homophily in the social network.To better utilize the location-proximate relationships in social networks,we propose a graph neural network algorithm based on the social structure influence.The algorithm enables us to perform a weighted aggregation of the information of users’multi-hop neighborhood,thereby mitigating the over-smoothing problem of user features and improving user geolocation performance.Experimental results on real social media dataset demonstrate that the neighborhood geographical distribution similarity metric can effectively filter out non-location-proximate social relationships.Moreover,compared with 7 existing social relationship-based user positioning methods,our proposed method can achieve multi-granularity user geolocation and improve the accuracy by 4.84%to 13.28%.展开更多
Bactrocera bryoniae and Bactrocera neohumeralis are highly destructive and major biosecurity/quarantine pests of fruit and vegetable in the tropical and subtropical regions in the South Pacific and Australia.Although ...Bactrocera bryoniae and Bactrocera neohumeralis are highly destructive and major biosecurity/quarantine pests of fruit and vegetable in the tropical and subtropical regions in the South Pacific and Australia.Although these pests have not established in China,precautions must be taken due to their highly destructive nature.Thus,we predicted the potential geographic distribution of B.bryoniae and B.neohumeralis across the world and in particular China by ecological niche modeling of the Maximum Entropy(Max Ent)model with the occurrence records of these two species.Bactrocera bryoniae and B.neohumeralis exhibit similar potential geographic distribution ranges across the world and in China,and each species was predicted to be able to distribute to over 20%of the globe.Globally,the potential geographic distribution ranges for these two fruit fly species included southern Asia,the central and the southeast coast of Africa,southern North America,northern and central South America,and Australia.While within China,most of the southern Yangtze River area was found suitable for these species.Notably,southern China was considered to have the highest risk of B.bryoniae and B.neohumeralis invasions.Our study identifies the regions at high risk for potential establishment of B.bryoniae and B.neohumeralis in the world and in particular China,and informs the development of inspection and biosecurity/quarantine measures to prevent and control their invasions.展开更多
377 isolates of Magnaporthe grisea were collected from 17 provinces in China and their geographic distribution of mating types and their fertility was tested with four standard isolates, KA3 and TH12 (Mat1.1) and Guy1...377 isolates of Magnaporthe grisea were collected from 17 provinces in China and their geographic distribution of mating types and their fertility was tested with four standard isolates, KA3 and TH12 (Mat1.1) and Guy11 and TH16 (Mat1.2) provided by CIRAD. 73 fertile isolates were tested with SCAR markers of 13 pairs of primers. Preliminary results showed that the geographic distribution of M.grisea existed among isolates collected from the same location as well as different locations and the genetic relationship between fertile isolates of the fungus in China. The existence of sexual reproduction of M .grisea was explored in the field as well.展开更多
The spatial distribution and monthly/annual variation of foggy days in China are analyzed based on the monthly mean fog data collected from 604 observational stations for the period 1961-2000. Results show that there ...The spatial distribution and monthly/annual variation of foggy days in China are analyzed based on the monthly mean fog data collected from 604 observational stations for the period 1961-2000. Results show that there are six fog regions in China： the middle reaches of the Yangtze River, coastal areas, Yunnan-Gulzhou Plateau, eastern Gansu-Shaanxi region, Huaihe River valley, Tianshan mountainous area and northern Xinjiang. On the whole the interannual variation trend of foggy days is descending, especially an obvious decline after the 1980s. The areas where the foggy days have obvious tendency present a southwest-northeast direction. The rising trend regions alternate with descending trend regions, forming a SE-NW directional wave structure. In general, the number of foggy days in autumn and winter is larger than in spring and summer over most fog regions. The monthly variation curves of foggy days are bimodal in the coastal area of the Yellow Sea and northern Xinjiang, and unimodal in other regions.展开更多
Genetic,lifestyle,and environmental factors contribute to the etiology of polycystic ovary syndrome(PCOS).Increased body mass index(BMI)exacerbates the reproductive and metabolic parameters and reduces the fecundity o...Genetic,lifestyle,and environmental factors contribute to the etiology of polycystic ovary syndrome(PCOS).Increased body mass index(BMI)exacerbates the reproductive and metabolic parameters and reduces the fecundity of women with PCOS.This is a secondary analysis of a large-sample,multicenter,randomized controlled trial conducted at 21 sites in Chinese mainland.A total of 1000 women diagnosed with PCOS were enrolled in this trial.Of these,998 women with PCOS were included in the analysis.Increased BMI was associated with more severe menstrual irregularities,elevated testosterone level,higher prevalence of metabolic syndrome,and poorer quality of life.The rates of ovulation per woman for the normal,overweight,and obese BMI groups were 83.0%,78.2%,and 63.6%,respectively(P<0.001),and the rates of live birth were 23.6%,18.1%,and 15.3%(P=0.030).Northern PCOS patients showed more severe reproductive,glucose,and lipid profiles;less exercise;and lower total ovulation rates compared with PCOS patients from Southern China(74.8%vs 81.2%,absolute difference 6.4%,95%confidence interval 1.2%–11.5%).The results show the typical phenotypic features of Han women with PCOS in Northern and Southern China.The women living in Northern China showed a higher BMI,more severe glycolipid metabolism profiles,and subsequently worse clinical outcomes by the same interventions than those living in Southern China.The difference in phenotypic features can be explained mostly by differences in BMI and the resulting difference in ovulation.展开更多
Prediction of potential geographic distributions is important for species protection and habitat restoration. Ulmus lamellosa is an endangered and endemic species in China for which conservation efforts are required. ...Prediction of potential geographic distributions is important for species protection and habitat restoration. Ulmus lamellosa is an endangered and endemic species in China for which conservation efforts are required. The maximum entropy （MaxEnt） model was used to predict the current and future geographic distribution （from 2030 to 2070） of U. lamellosa in China and discuss the reasons for changes in climatic suitability. The MaxEnt model provided a good fit to our data as confirmed by an AUC value of 0.948. The suitable areas for U. lamellosa were primarily projected in the northern part of China from 2030 to 2070, especially in Liaoning province. The variables ＂temperature seasonality＂, ＂precipitation of wettest month＂ and ＂precipitation of warmest quarter＂ were the most influential climatic variables in limiting the distribution of U. lamellosa. Our results clearly predict the future impacts of climate change on the geographic distribution of U. lamellosa and this can help prioritize design of localized conservation strategies in China.展开更多
In 1994, the total Chinese population in the United States were 2,017,799 which were 0.8 percent of the total US population. The Chinese population were highly concentrated by regions and among the total population. B...In 1994, the total Chinese population in the United States were 2,017,799 which were 0.8 percent of the total US population. The Chinese population were highly concentrated by regions and among the total population. By states, 42 percent of total Chinese population were found in California, 17 percent in New York. More than 80 percent total Chinese population were concentrated in 9 states. By metropolitan areas, 14.73 percent of total Chinese population were found in Los Angeles and New York respectively. Compared with the total US population, 60 percent Chinese population were found in less than 20 percent total US population and 80 percent in 50 percent. By studying the Chinese population distribution and the reason behind it, we hope to find some interesting relationships among the characteristics of this distribution and the historical, cultural, social and economic factors influencing it.展开更多
Considering a recent proposition on this journal that the endemic Xinjiang Ground Jay (Podoces biddulphi) would be expanding its range to Qinghai and Gansu, a previously overlooked statement has been found in old lite...Considering a recent proposition on this journal that the endemic Xinjiang Ground Jay (Podoces biddulphi) would be expanding its range to Qinghai and Gansu, a previously overlooked statement has been found in old literature suggesting that this species has occurred in Gansu at least since the 19th century. The phreatophytic vegetation this desert bird requires likely constrains its distribution. Therefore, although the desert expansion the current global climate warming is producing may make the Xinjiang Ground Jay expand its range, only well-preserved desert might be colonized. Future research in apparently suitable areas, at present inhabited by the Mongolian Ground Jay (P. hendersoni) instead, might make the ecology of these two mutually exclusive species better understood.展开更多
BACKGROUND Human immunodeficiency virus(HIV)infection is a major global public health concern.North African countries carry a disproportionate burden of HIV representing one of the highest rates in Africa.AIM To chara...BACKGROUND Human immunodeficiency virus(HIV)infection is a major global public health concern.North African countries carry a disproportionate burden of HIV representing one of the highest rates in Africa.AIM To characterize the epidemiological and spatial trends of HIV infection in this region.METHODS A systematic review was carried out on all the published data regarding HIV/acquired immunodeficiency syndrome in North African countries over ten years(2008-2017)following the PRISMA guidelines.We performed a comprehensive literature search using Medline PubMed,Embase,regional and international databases,and country-level reports with no language restriction.The quality,quantity,and geographic coverage of the data were assessed at both the national and regional levels.We used random-effects methods,spatial variables,and stratified results by demographic factors.Only original data on the prevalence of HIV infection were included and independently evaluated by professional epidemiologists.RESULTS A total of 721 records were identified but only 41 that met the criteria were included in the meta-analysis.There was considerable variability in the prevalence estimates of HIV within the countries of the region.The overall prevalence of HIV ranged from 0.9%[95%confidence interval(CI)0.8-1.27]to 3.8%(95%CI 1.17-6.53).The highest prevalence was associated with vulnerable groups and particularly drug abusers and sexually promiscuous individuals.The dense HIV clustering noted varied from one country to another.At least 13 HIV subtypes and recombinant forms were prevalent in the region.Subtype B was the most common variant,followed by CRF02_AG.CONCLUSION This comprehensive review indicates that HIV infection in North African countries is an increasing threat.Effective national and regional strategies are needed to improve monitoring and control of HIV transmission,with particular emphasis on geographic variability and HIV clustering.展开更多
This paper determined the abundance of General Aerobic heterotrophic Bacteria （GAB） in surficial sediments from the Chukchi Sea and the Canadian basin by using MPN and discussed their geographical distribution. The ...This paper determined the abundance of General Aerobic heterotrophic Bacteria （GAB） in surficial sediments from the Chukchi Sea and the Canadian basin by using MPN and discussed their geographical distribution. The result shows that the determination percentages of the GAB were high, even till 100 percentage. The abundance range and averages of GAB for 4℃and 25℃ were from 4.00 × 10^2 to 2.40× 10^6 , 1.71×10^6 ind.·g^-1 （wet sample ） and from 2.40 ×10^5 to 2.40×10^7 , 1.10×10^7 ind. ·g^-1 （wet sample ） respectively. Not only the abundance range but also the averages of GAB in 25℃ were higher than that in 4℃. The abundance of GAB in sediments show a tendency that it is roughly greater in the lower latitudinal area than in the higher latitudinal area. The abundance of GAB increased from east to west as for the longitudinal distribution. With the water depth increasing, the abundance of GAB at 4℃ decreased, but GBA at 25℃ is not changed obviously with water depth. It seems that warmer circumstantial temperature is more suitable for some GAB.展开更多
The rhynchonellide brachiopod Dzieduszyckia Siemiradzki is widely distributed in the Lower Famennian strata,and exhibits a wide range of morphological variations among populations.1272 autochthonous Devonian Rongxian ...The rhynchonellide brachiopod Dzieduszyckia Siemiradzki is widely distributed in the Lower Famennian strata,and exhibits a wide range of morphological variations among populations.1272 autochthonous Devonian Rongxian Dzieduszyckia fossils were collected from three populations in South China,namely the Dazhai,Dalong,and Longmi sections.A series of quantitative morphological analyses were conducted to understand the morphological variation among populations and identify the triggers responsible for such variations.The results show that the Dazhai population differs significantly in morphospace from the Dalong and Longmi populations,while the latter two exhibit more similar morphological features,suggesting that geographic distribution may play a key role in affecting Dzieduszyckia morphology.The Longmi population shows a distinct morphospace from the Dazhai population and an overlapped morphospace with the Dalong population,indicating that habitat may not be the controlling factor.Lastly,the Dazhai and Dalong populations share some morphological similarities,but the Dazhai and Longmi populations occupy completely different morphospaces,indicating that evolution had a greater impact on phenotypic divergence than habitat.Our findings suggest that geographic distribution is the predominant factor influencing the morphological variation of Dzieduszyckia,while evolution and living habitat are less significant,the former of which might play a more important role.展开更多
Results of the analysis of taxonomic diversity and representation of different evolutionary lineages of agamid lizards(Reptilia, Sauria, Agamidae) are provided in this article. For comparison with the fauna of China, ...Results of the analysis of taxonomic diversity and representation of different evolutionary lineages of agamid lizards(Reptilia, Sauria, Agamidae) are provided in this article. For comparison with the fauna of China, the following territories were selected: North Eurasia, Iran and different countries of South and Southeast Asia. There are 49 agamid species in China, comprising 12 genera and 4 subfamilies. Annotated check-list and identification keys to genera are provided. Among the 49 species of agamids present in China, the percent of endemic species is relatively high(22 species; 45%). Endemic species refer to 4 genera with the genus Japalura having the most, 10 of 14 species, proceeded by members of Tibetan Plateau lineage of Phrynocephalus, 8 of 12 species, and Calotes with 1 species and Laudakia with 3.展开更多
There are 41 members of the CCT（CO, CO-like, and TOC1） domain-containing gene family in rice, which are divided into three subfamilies： COL（CONSTANS-like）, CMF（CCT motif family）, and PRR（pseudoresponse regula...There are 41 members of the CCT（CO, CO-like, and TOC1） domain-containing gene family in rice, which are divided into three subfamilies： COL（CONSTANS-like）, CMF（CCT motif family）, and PRR（pseudoresponse regulator）. The first flowering gene to be isolated by map-based cloning, Heading date 1（Hd1）, which is the orthologue of CO in rice, belongs to COL. The central regulator of plant development, Ghd7, belongs to CMF. The major role in controlling rice distribution to high latitudes, Ghd7.1/PRR37, belongs to PRR. Both of Hd1, Ghd7 and Ghd7.1 simultaneously control grain number, plant height, and the heading date. To date, 13 CCT family genes from these three subfamilies have been shown to regulate flowering. Some of them have pleiotropic effects on grain yield, plant height, and abiotic stresses, and others function as circadian oscillators. There are two independent photoperiod flowering pathways that are mediated by GI-Hd1-Hd3 a/RFT and GI-Ehd1-Hd3 a/RFT in rice. CCT family genes are involved in both pathways. The latest study reveals that protein interaction between Hd1 and Ghd7 integrates the two pathways. CCT family genes are rich in natural variation because rice cultivars have been subjected to natural and artificial selection for different day lengths in the process of domestication and improvement. Alleles of several crucial CCT family genes such as Hd1, Ghd7, and Ghd7.1 exhibit geographic distribution patterns and are highly associated with yield potentials. In addition, CCT family genes are probably involved in the responses to abiotic stress, which should be emphasized in future work. In general, CCT family genes play important roles in regulating flowering, plant growth, and grain yield. The functional identification and elucidation of the molecular mechanisms of CCT family genes would help construct a flowering regulatory network and maximize their contribution to rice production.展开更多
An investigation was carried out on living coccolithophores （LCs） distribution in the Yellow Sea and the East China Sea from October 17 to November 24, 2011. A total of 223 samples from different depths were col-lec...An investigation was carried out on living coccolithophores （LCs） distribution in the Yellow Sea and the East China Sea from October 17 to November 24, 2011. A total of 223 samples from different depths were col-lected at 48 stations. Totally 18 taxa belonging to coccolithophyceae were identified using a polarized micro-scope at the 1 000× magnification. The maximum species abundance was found at the outside of Transect P. The dominated species wereGephyrocapsa oceanica, Emiliania huxleyi,Helicosphaera carteri,andAlgiros-phaera robusta.The abundance of coccoliths and cells ranged 0-2 965.73 coccoliths/mL, and 0-119.16 cells/mL, with the average values of 471.00 coccoliths/mL and 23.42 cells/mL, respectively. The LCs in surface layer were mainly observed on the coastal belt and middle part of the survey area. The comparison among Transects A, F, P and E indicated lower species diversity and less abundance in the Yellow Sea than those of the East China Sea. The highest abundance of LCs was found in transect F and P. The coccolith abundance increased slightly from surface to bottom in the water column, but the highest value of the cell abundance was observed in the depth of 10-30 m. Temperature, depth and nutrient concentration were suggested as the major environmental factors controlling the distribution and species composition of LCs in the studying area based on canonical correspondence analysis （CCA）.展开更多
Amphidinium species are amongst the most abundant benthic dinoflagellates in marine intertidal sandy ecosystems.Some of them are able to produce a variety of bioactive compounds that can have both harmful effects and ...Amphidinium species are amongst the most abundant benthic dinoflagellates in marine intertidal sandy ecosystems.Some of them are able to produce a variety of bioactive compounds that can have both harmful effects and pharmaceutical potentials.The diversity of Amphidinium in shallow waters along the Chinese coast was investigated by isolating single cells from sand,coral,and macroalgal samples collected from 2012 to 2020.Their morphologies were subjected to examination using light microscopy(LM)and scanning electron microscopy(SEM).A total of 74 Amphidinium strains were morphologically identified,belonging to 11 species:A.carterae,A.gibbosum,A.operculatum,A.massartii,A.cf.massartii,A.fijiensis,A.pseudomassartii,A.steinii,A.thermaeum,A.theodori,A.tomasii,as well as an undefined species.The last seven species have not been previously reported in Chinese waters.Amphidinium carterae subcladesⅠ,Ⅱ,andⅣwere found in the South China Sea,while subcladeⅢwas only found in the Yellow Sea.Threadlike body scales were observed on the surface of subcladesⅢ and Ⅳ,supporting the idea that A.carterae might contain several different species.Large subunit ribosomal RNA(LSU rRNA)sequencesbased phylogeny revealed two groups(GroupsⅠandⅡ)within Amphidinium,which is consistent with the relative position of sulcus(in touch with cingulum or not).In addition,large differences in morphology and molecular phylogeny between A.operculatum(the type species of Amphidinium)and other species,suggest that a subdivision of Amphidinium might be needed.The pigment profiles of all available strains were analyzed by high performance liquid chromatography(HPLC).Eleven pigments,including peridinin,diadinoxanthin,diatoxanthin,pheophorbide(and pheophorbide a),antheraxanthin,β-carotene,and four different chlorophylls were detected.The high pheophorbide/pheophorbide a ratio in Amphidinium implies that it may be a good candidate as a natural source of photosensitizers,a well-known anticancer drug.展开更多
The Green Revolution gene sd1 has been used extensively in modern rice breeding,especially in indica cultivars.However,elite sd1 alleles and related germplasm resources used for japonica rice breeding have not been id...The Green Revolution gene sd1 has been used extensively in modern rice breeding,especially in indica cultivars.However,elite sd1 alleles and related germplasm resources used for japonica rice breeding have not been identified,and extensive efforts are needed for japonica rice breeding to obtain new dwarfing sources.Data from MBKbase-Rice revealed seven sd1 haplotypes in indica and four in japonica rice.Two new sd1 alleles were identified in indica rice.In 295 japonica accessions from northeast Asia,except for the weak functional allele SD1-EQ,sd1-r was the major allele,reducing plant height in comparison with SD1-EQ.Japonica germplasm resources carrying reported sd1 alleles were identified by genotype searching and further verified by literature search,genealogical analysis,and d Caps markers.Pedigrees and geographic distribution showed that sd1-r is an excellent allele widely used in northern China and Tohoku in Japan,and sd1-j is commonly used in east China and Kyushu in Japan.Dongnong-and Xiushui-series cultivars carrying sd1-r and sd1-j,respectively,are essential branches of the backbone parents of Chinese japonica rice,Akihikari and Ce21,with the largest number of descendants and derived generations.In semi-dwarf japonica rice breeding,sd1-d was introgressed into Daohuaxiang 2(DHX2).Dwarf and semi-dwarf lines carrying sd1-d were selected and designated as 1279 and 1280,respectively,after withstanding typhoon-induced strong winds and heavy rains in 2020,and are anticipated to become useful intermediate materials for future genetic research and breeding.This work will facilitate the introduction,parental selection,and marker-assisted breeding,and provide a material basis for the next step in identifying favorable genes that selected together with the sd1 alleles in japonica backbone parents.展开更多
Integrating the theory of distributed virtual geographic environment (DVGE) and high level architecture(HLA), the architecture of DVGE based on HLA is designed. The data flow and the object models of the architecture ...Integrating the theory of distributed virtual geographic environment (DVGE) and high level architecture(HLA), the architecture of DVGE based on HLA is designed. The data flow and the object models of the architecture are also discussed. The architecture basically meets the need of DVGE in real-time communication, distribution, collaboration, reusing and interoperation, expansion, and standard.展开更多
According to this paper, the dragon-shape strategy is the optimized option of China＇s future strategy with respect to the geographic distribution of regional economy.
Drosophila lacertosa is widely distributed from northern India to Far East of Russia throughout China.We have studied geographical distributions of three kinds of chromosomal karyotypes,type D(2n=10,4 pairs of V-shape...Drosophila lacertosa is widely distributed from northern India to Far East of Russia throughout China.We have studied geographical distributions of three kinds of chromosomal karyotypes,type D(2n=10,4 pairs of V-shaped metacentric chromosomes and a pair of micro-chromosomes),type L(2n= 10,5V with a pair of large-sized heterochromatic autosomes)and type M(2n=10,5V with middle-sized ones).Type D was found exclusively in local populations of D.lacertosa distributed in Yun-Gui Plateau,southwestern China.Both type L and M have a wide range of distribution,and the former occurred in subtropical regions of China including Taiwan Island,whereas the latter in cool temperate regions of East Asia covering Far East of Russia,Korea and the Japan Islands.A strong premating isolation was detected between flies with type D and those with type L or M.These data demonstrate that genetic differentiation leading to cryptic speciation might have occurred in natural populations of Drosophila lacertosa.展开更多
The rate of climate change experienced globally in recent decades may compromise sea turtles’ survival;especially temperature increase, which is particularly fast, impacts life history characteristics, such as temper...The rate of climate change experienced globally in recent decades may compromise sea turtles’ survival;especially temperature increase, which is particularly fast, impacts life history characteristics, such as temperature-dependent sex determination (TSD), late maturity and sea turtles highly migratory nature. This review aims to identify and summarize the information that has been collected from 2009-2020 in order to aid future empirical studies that seek to fill these and other knowledge gaps, and subsequently assist conservationists in making multilevel decisions to protect sea turtle populations and species. In a summarized way the general knowledge acquired so far on the influence of environmental abiotic and biotic factors on nesting behaviour and hatching, emergence and survival successes of sea turtle hatchlings, was gathered. To accomplish this work, a search on Web of Science, Science Direct, NCBI/PubMed, and Google Scholar was carried out using the terms “sea turtles + climate change”. Published articles in the period 2009-2020 were selected, related to the nesting ecology of 5 species of sea turtles: <em>Caretta caretta</em>, <em>Eretmochelys imbricata</em>, <em>Dermochelys coriacea</em>,<em> Chelonia mydas</em>, <em>Lepidochelys olivacea</em>. Emphasis was also placed on geographical information and on population location (e.g. climatic conditions during the nesting season). These articles (N = 126) were analysed giving relevance to researcher’s data interpretations, comparisons with other researches, and the reached conclusions. An attempt was made to represent all 5 species of sea turtles when selecting articles on each of the environmental factors that influence sea turtle nesting: temperature, humidity, nesting substrate, gases, depth of the nest, sea surface temperature (SST), nest location on the beach, nesting phenology and geographic distribution of nesting habitats. The interaction between these parameters and their consequences on the terrestrial phase of reproduction are presented and discussed.展开更多
基金This work was supported by the National Key R&D Program of China(No.2022YFB3102904)the National Natural Science Foundation of China(No.62172435,U23A20305)Key Research and Development Project of Henan Province(No.221111321200).
文摘Geolocating social media users aims to discover the real geographical locations of users from their publicly available data,which can support online location-based applications such as disaster alerts and local content recommen-dations.Social relationship-based methods represent a classical approach for geolocating social media.However,geographically proximate relationships are sparse and challenging to discern within social networks,thereby affecting the accuracy of user geolocation.To address this challenge,we propose user geolocation methods that integrate neighborhood geographical distribution and social structure influence(NGSI)to improve geolocation accuracy.Firstly,we propose a method for evaluating the homophily of locations based on the k-order neighbor-hood geographic distribution(k-NGD)similarity among users.There are notable differences in the distribution of k-NGD similarity between location-proximate and non-location-proximate users.Exploiting this distinction,we filter out non-location-proximate social relationships to enhance location homophily in the social network.To better utilize the location-proximate relationships in social networks,we propose a graph neural network algorithm based on the social structure influence.The algorithm enables us to perform a weighted aggregation of the information of users’multi-hop neighborhood,thereby mitigating the over-smoothing problem of user features and improving user geolocation performance.Experimental results on real social media dataset demonstrate that the neighborhood geographical distribution similarity metric can effectively filter out non-location-proximate social relationships.Moreover,compared with 7 existing social relationship-based user positioning methods,our proposed method can achieve multi-granularity user geolocation and improve the accuracy by 4.84%to 13.28%.
基金supported by the National Key R&D Program of China(2017YFC1200600 and 2016YFC1202104)the Innovation Team of Modern Agricultural Industry Generic Key Technology R&D of Guangdong Province,China(2019KJ134)+1 种基金the Open Fund of the Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests,China(2016-KF-3)A student scholarship was provided by the Harry Butler Institute,Murdoch University,Australia。
文摘Bactrocera bryoniae and Bactrocera neohumeralis are highly destructive and major biosecurity/quarantine pests of fruit and vegetable in the tropical and subtropical regions in the South Pacific and Australia.Although these pests have not established in China,precautions must be taken due to their highly destructive nature.Thus,we predicted the potential geographic distribution of B.bryoniae and B.neohumeralis across the world and in particular China by ecological niche modeling of the Maximum Entropy(Max Ent)model with the occurrence records of these two species.Bactrocera bryoniae and B.neohumeralis exhibit similar potential geographic distribution ranges across the world and in China,and each species was predicted to be able to distribute to over 20%of the globe.Globally,the potential geographic distribution ranges for these two fruit fly species included southern Asia,the central and the southeast coast of Africa,southern North America,northern and central South America,and Australia.While within China,most of the southern Yangtze River area was found suitable for these species.Notably,southern China was considered to have the highest risk of B.bryoniae and B.neohumeralis invasions.Our study identifies the regions at high risk for potential establishment of B.bryoniae and B.neohumeralis in the world and in particular China,and informs the development of inspection and biosecurity/quarantine measures to prevent and control their invasions.
文摘377 isolates of Magnaporthe grisea were collected from 17 provinces in China and their geographic distribution of mating types and their fertility was tested with four standard isolates, KA3 and TH12 (Mat1.1) and Guy11 and TH16 (Mat1.2) provided by CIRAD. 73 fertile isolates were tested with SCAR markers of 13 pairs of primers. Preliminary results showed that the geographic distribution of M.grisea existed among isolates collected from the same location as well as different locations and the genetic relationship between fertile isolates of the fungus in China. The existence of sexual reproduction of M .grisea was explored in the field as well.
基金The key project of Ministry of Science and Technology of China, No.2003DEA2C009-02
文摘The spatial distribution and monthly/annual variation of foggy days in China are analyzed based on the monthly mean fog data collected from 604 observational stations for the period 1961-2000. Results show that there are six fog regions in China： the middle reaches of the Yangtze River, coastal areas, Yunnan-Gulzhou Plateau, eastern Gansu-Shaanxi region, Huaihe River valley, Tianshan mountainous area and northern Xinjiang. On the whole the interannual variation trend of foggy days is descending, especially an obvious decline after the 1980s. The areas where the foggy days have obvious tendency present a southwest-northeast direction. The rising trend regions alternate with descending trend regions, forming a SE-NW directional wave structure. In general, the number of foggy days in autumn and winter is larger than in spring and summer over most fog regions. The monthly variation curves of foggy days are bimodal in the coastal area of the Yellow Sea and northern Xinjiang, and unimodal in other regions.
基金This study was supported by National Public Welfare Projects for Chinese Medicine(201507001-02)the Heilongjiang Province General Institutes of Higher Education Youth Innovative Talents Program(UNPYSCT-2017226)the Scientific Research Project of Outstanding Innovative Talents Program of Heilongjiang University of Chinese Medicine(2018RC012),Xuzhou Clinical Medical Team Talent Introduction Project—Academician Liu Yixun Integrated Chinese and Western medicine,Maternity and Reproductive Technology Innovation Team,and Academician Liu Yixun Workstation Project.
文摘Genetic,lifestyle,and environmental factors contribute to the etiology of polycystic ovary syndrome(PCOS).Increased body mass index(BMI)exacerbates the reproductive and metabolic parameters and reduces the fecundity of women with PCOS.This is a secondary analysis of a large-sample,multicenter,randomized controlled trial conducted at 21 sites in Chinese mainland.A total of 1000 women diagnosed with PCOS were enrolled in this trial.Of these,998 women with PCOS were included in the analysis.Increased BMI was associated with more severe menstrual irregularities,elevated testosterone level,higher prevalence of metabolic syndrome,and poorer quality of life.The rates of ovulation per woman for the normal,overweight,and obese BMI groups were 83.0%,78.2%,and 63.6%,respectively(P<0.001),and the rates of live birth were 23.6%,18.1%,and 15.3%(P=0.030).Northern PCOS patients showed more severe reproductive,glucose,and lipid profiles;less exercise;and lower total ovulation rates compared with PCOS patients from Southern China(74.8%vs 81.2%,absolute difference 6.4%,95%confidence interval 1.2%–11.5%).The results show the typical phenotypic features of Han women with PCOS in Northern and Southern China.The women living in Northern China showed a higher BMI,more severe glycolipid metabolism profiles,and subsequently worse clinical outcomes by the same interventions than those living in Southern China.The difference in phenotypic features can be explained mostly by differences in BMI and the resulting difference in ovulation.
基金supported by the Shanxi Natural Science Foundation(2015011069)the University Innovation program of Science and Technology of Shanxi Province(20161109)
文摘Prediction of potential geographic distributions is important for species protection and habitat restoration. Ulmus lamellosa is an endangered and endemic species in China for which conservation efforts are required. The maximum entropy （MaxEnt） model was used to predict the current and future geographic distribution （from 2030 to 2070） of U. lamellosa in China and discuss the reasons for changes in climatic suitability. The MaxEnt model provided a good fit to our data as confirmed by an AUC value of 0.948. The suitable areas for U. lamellosa were primarily projected in the northern part of China from 2030 to 2070, especially in Liaoning province. The variables ＂temperature seasonality＂, ＂precipitation of wettest month＂ and ＂precipitation of warmest quarter＂ were the most influential climatic variables in limiting the distribution of U. lamellosa. Our results clearly predict the future impacts of climate change on the geographic distribution of U. lamellosa and this can help prioritize design of localized conservation strategies in China.
文摘In 1994, the total Chinese population in the United States were 2,017,799 which were 0.8 percent of the total US population. The Chinese population were highly concentrated by regions and among the total population. By states, 42 percent of total Chinese population were found in California, 17 percent in New York. More than 80 percent total Chinese population were concentrated in 9 states. By metropolitan areas, 14.73 percent of total Chinese population were found in Los Angeles and New York respectively. Compared with the total US population, 60 percent Chinese population were found in less than 20 percent total US population and 80 percent in 50 percent. By studying the Chinese population distribution and the reason behind it, we hope to find some interesting relationships among the characteristics of this distribution and the historical, cultural, social and economic factors influencing it.
文摘Considering a recent proposition on this journal that the endemic Xinjiang Ground Jay (Podoces biddulphi) would be expanding its range to Qinghai and Gansu, a previously overlooked statement has been found in old literature suggesting that this species has occurred in Gansu at least since the 19th century. The phreatophytic vegetation this desert bird requires likely constrains its distribution. Therefore, although the desert expansion the current global climate warming is producing may make the Xinjiang Ground Jay expand its range, only well-preserved desert might be colonized. Future research in apparently suitable areas, at present inhabited by the Mongolian Ground Jay (P. hendersoni) instead, might make the ecology of these two mutually exclusive species better understood.
文摘BACKGROUND Human immunodeficiency virus(HIV)infection is a major global public health concern.North African countries carry a disproportionate burden of HIV representing one of the highest rates in Africa.AIM To characterize the epidemiological and spatial trends of HIV infection in this region.METHODS A systematic review was carried out on all the published data regarding HIV/acquired immunodeficiency syndrome in North African countries over ten years(2008-2017)following the PRISMA guidelines.We performed a comprehensive literature search using Medline PubMed,Embase,regional and international databases,and country-level reports with no language restriction.The quality,quantity,and geographic coverage of the data were assessed at both the national and regional levels.We used random-effects methods,spatial variables,and stratified results by demographic factors.Only original data on the prevalence of HIV infection were included and independently evaluated by professional epidemiologists.RESULTS A total of 721 records were identified but only 41 that met the criteria were included in the meta-analysis.There was considerable variability in the prevalence estimates of HIV within the countries of the region.The overall prevalence of HIV ranged from 0.9%[95%confidence interval(CI)0.8-1.27]to 3.8%(95%CI 1.17-6.53).The highest prevalence was associated with vulnerable groups and particularly drug abusers and sexually promiscuous individuals.The dense HIV clustering noted varied from one country to another.At least 13 HIV subtypes and recombinant forms were prevalent in the region.Subtype B was the most common variant,followed by CRF02_AG.CONCLUSION This comprehensive review indicates that HIV infection in North African countries is an increasing threat.Effective national and regional strategies are needed to improve monitoring and control of HIV transmission,with particular emphasis on geographic variability and HIV clustering.
基金the national ministry of finance。the second Arctic research expedition（CHINARE-2003）National Natural Science Foundation of China（No.40576060, 40376017 and 40176017）.
文摘This paper determined the abundance of General Aerobic heterotrophic Bacteria （GAB） in surficial sediments from the Chukchi Sea and the Canadian basin by using MPN and discussed their geographical distribution. The result shows that the determination percentages of the GAB were high, even till 100 percentage. The abundance range and averages of GAB for 4℃and 25℃ were from 4.00 × 10^2 to 2.40× 10^6 , 1.71×10^6 ind.·g^-1 （wet sample ） and from 2.40 ×10^5 to 2.40×10^7 , 1.10×10^7 ind. ·g^-1 （wet sample ） respectively. Not only the abundance range but also the averages of GAB in 25℃ were higher than that in 4℃. The abundance of GAB in sediments show a tendency that it is roughly greater in the lower latitudinal area than in the higher latitudinal area. The abundance of GAB increased from east to west as for the longitudinal distribution. With the water depth increasing, the abundance of GAB at 4℃ decreased, but GBA at 25℃ is not changed obviously with water depth. It seems that warmer circumstantial temperature is more suitable for some GAB.
基金the National Natural Science Foundation of China(Grant Nos.41772015 and 41672334)。
文摘The rhynchonellide brachiopod Dzieduszyckia Siemiradzki is widely distributed in the Lower Famennian strata,and exhibits a wide range of morphological variations among populations.1272 autochthonous Devonian Rongxian Dzieduszyckia fossils were collected from three populations in South China,namely the Dazhai,Dalong,and Longmi sections.A series of quantitative morphological analyses were conducted to understand the morphological variation among populations and identify the triggers responsible for such variations.The results show that the Dazhai population differs significantly in morphospace from the Dalong and Longmi populations,while the latter two exhibit more similar morphological features,suggesting that geographic distribution may play a key role in affecting Dzieduszyckia morphology.The Longmi population shows a distinct morphospace from the Dazhai population and an overlapped morphospace with the Dalong population,indicating that habitat may not be the controlling factor.Lastly,the Dazhai and Dalong populations share some morphological similarities,but the Dazhai and Longmi populations occupy completely different morphospaces,indicating that evolution had a greater impact on phenotypic divergence than habitat.Our findings suggest that geographic distribution is the predominant factor influencing the morphological variation of Dzieduszyckia,while evolution and living habitat are less significant,the former of which might play a more important role.
基金supported by the Russian Foundation for Basic Research(Project Nos.09-04-00132-а,RFBR-China 05-04-39003 and 10-04-91152,11-04-93981-INIS)the Scientific School Support Program(Project No.NSh-4724.2010.4)+1 种基金the NSFC-RFBR Project(31011120088)NSFC(31071892)
文摘Results of the analysis of taxonomic diversity and representation of different evolutionary lineages of agamid lizards(Reptilia, Sauria, Agamidae) are provided in this article. For comparison with the fauna of China, the following territories were selected: North Eurasia, Iran and different countries of South and Southeast Asia. There are 49 agamid species in China, comprising 12 genera and 4 subfamilies. Annotated check-list and identification keys to genera are provided. Among the 49 species of agamids present in China, the percent of endemic species is relatively high(22 species; 45%). Endemic species refer to 4 genera with the genus Japalura having the most, 10 of 14 species, proceeded by members of Tibetan Plateau lineage of Phrynocephalus, 8 of 12 species, and Calotes with 1 species and Laudakia with 3.
基金supported by the National Key Research and Development Program of China (2016YFD0100301)
文摘There are 41 members of the CCT（CO, CO-like, and TOC1） domain-containing gene family in rice, which are divided into three subfamilies： COL（CONSTANS-like）, CMF（CCT motif family）, and PRR（pseudoresponse regulator）. The first flowering gene to be isolated by map-based cloning, Heading date 1（Hd1）, which is the orthologue of CO in rice, belongs to COL. The central regulator of plant development, Ghd7, belongs to CMF. The major role in controlling rice distribution to high latitudes, Ghd7.1/PRR37, belongs to PRR. Both of Hd1, Ghd7 and Ghd7.1 simultaneously control grain number, plant height, and the heading date. To date, 13 CCT family genes from these three subfamilies have been shown to regulate flowering. Some of them have pleiotropic effects on grain yield, plant height, and abiotic stresses, and others function as circadian oscillators. There are two independent photoperiod flowering pathways that are mediated by GI-Hd1-Hd3 a/RFT and GI-Ehd1-Hd3 a/RFT in rice. CCT family genes are involved in both pathways. The latest study reveals that protein interaction between Hd1 and Ghd7 integrates the two pathways. CCT family genes are rich in natural variation because rice cultivars have been subjected to natural and artificial selection for different day lengths in the process of domestication and improvement. Alleles of several crucial CCT family genes such as Hd1, Ghd7, and Ghd7.1 exhibit geographic distribution patterns and are highly associated with yield potentials. In addition, CCT family genes are probably involved in the responses to abiotic stress, which should be emphasized in future work. In general, CCT family genes play important roles in regulating flowering, plant growth, and grain yield. The functional identification and elucidation of the molecular mechanisms of CCT family genes would help construct a flowering regulatory network and maximize their contribution to rice production.
基金The National Program on Key Basic Research Project of China under contract Nos 2010CB428900 and 2009CB421202the National Natural Science Foundation of China under contract Nos 41176136,40776093,41276124,41050110436 and 41306118
文摘An investigation was carried out on living coccolithophores （LCs） distribution in the Yellow Sea and the East China Sea from October 17 to November 24, 2011. A total of 223 samples from different depths were col-lected at 48 stations. Totally 18 taxa belonging to coccolithophyceae were identified using a polarized micro-scope at the 1 000× magnification. The maximum species abundance was found at the outside of Transect P. The dominated species wereGephyrocapsa oceanica, Emiliania huxleyi,Helicosphaera carteri,andAlgiros-phaera robusta.The abundance of coccoliths and cells ranged 0-2 965.73 coccoliths/mL, and 0-119.16 cells/mL, with the average values of 471.00 coccoliths/mL and 23.42 cells/mL, respectively. The LCs in surface layer were mainly observed on the coastal belt and middle part of the survey area. The comparison among Transects A, F, P and E indicated lower species diversity and less abundance in the Yellow Sea than those of the East China Sea. The highest abundance of LCs was found in transect F and P. The coccolith abundance increased slightly from surface to bottom in the water column, but the highest value of the cell abundance was observed in the depth of 10-30 m. Temperature, depth and nutrient concentration were suggested as the major environmental factors controlling the distribution and species composition of LCs in the studying area based on canonical correspondence analysis （CCA）.
基金Supported by the Scientifi c Research Foundation of Third Institute of Oceanography,MNR(No.2017023)the National Natural Science Foundation of China(Nos.41806154,41876173,42076144)+1 种基金the Special Foundation for National Science and Technology Basic Research Program of China(Nos.2018FY100200,2018FY100100)the Project of Southern Marine Science and Engineering Guangdong Laboratory(No.311021004)。
文摘Amphidinium species are amongst the most abundant benthic dinoflagellates in marine intertidal sandy ecosystems.Some of them are able to produce a variety of bioactive compounds that can have both harmful effects and pharmaceutical potentials.The diversity of Amphidinium in shallow waters along the Chinese coast was investigated by isolating single cells from sand,coral,and macroalgal samples collected from 2012 to 2020.Their morphologies were subjected to examination using light microscopy(LM)and scanning electron microscopy(SEM).A total of 74 Amphidinium strains were morphologically identified,belonging to 11 species:A.carterae,A.gibbosum,A.operculatum,A.massartii,A.cf.massartii,A.fijiensis,A.pseudomassartii,A.steinii,A.thermaeum,A.theodori,A.tomasii,as well as an undefined species.The last seven species have not been previously reported in Chinese waters.Amphidinium carterae subcladesⅠ,Ⅱ,andⅣwere found in the South China Sea,while subcladeⅢwas only found in the Yellow Sea.Threadlike body scales were observed on the surface of subcladesⅢ and Ⅳ,supporting the idea that A.carterae might contain several different species.Large subunit ribosomal RNA(LSU rRNA)sequencesbased phylogeny revealed two groups(GroupsⅠandⅡ)within Amphidinium,which is consistent with the relative position of sulcus(in touch with cingulum or not).In addition,large differences in morphology and molecular phylogeny between A.operculatum(the type species of Amphidinium)and other species,suggest that a subdivision of Amphidinium might be needed.The pigment profiles of all available strains were analyzed by high performance liquid chromatography(HPLC).Eleven pigments,including peridinin,diadinoxanthin,diatoxanthin,pheophorbide(and pheophorbide a),antheraxanthin,β-carotene,and four different chlorophylls were detected.The high pheophorbide/pheophorbide a ratio in Amphidinium implies that it may be a good candidate as a natural source of photosensitizers,a well-known anticancer drug.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA24020301)Young Scientists Fund(CN)(31900423)+1 种基金Excellent Youth Foundation for Heilongjiang Scientific Committee(JC2017009)Cooperative Innovation Extension System of Rice Modern Agricultural Industrial Technology in Heilongjiang province。
文摘The Green Revolution gene sd1 has been used extensively in modern rice breeding,especially in indica cultivars.However,elite sd1 alleles and related germplasm resources used for japonica rice breeding have not been identified,and extensive efforts are needed for japonica rice breeding to obtain new dwarfing sources.Data from MBKbase-Rice revealed seven sd1 haplotypes in indica and four in japonica rice.Two new sd1 alleles were identified in indica rice.In 295 japonica accessions from northeast Asia,except for the weak functional allele SD1-EQ,sd1-r was the major allele,reducing plant height in comparison with SD1-EQ.Japonica germplasm resources carrying reported sd1 alleles were identified by genotype searching and further verified by literature search,genealogical analysis,and d Caps markers.Pedigrees and geographic distribution showed that sd1-r is an excellent allele widely used in northern China and Tohoku in Japan,and sd1-j is commonly used in east China and Kyushu in Japan.Dongnong-and Xiushui-series cultivars carrying sd1-r and sd1-j,respectively,are essential branches of the backbone parents of Chinese japonica rice,Akihikari and Ce21,with the largest number of descendants and derived generations.In semi-dwarf japonica rice breeding,sd1-d was introgressed into Daohuaxiang 2(DHX2).Dwarf and semi-dwarf lines carrying sd1-d were selected and designated as 1279 and 1280,respectively,after withstanding typhoon-induced strong winds and heavy rains in 2020,and are anticipated to become useful intermediate materials for future genetic research and breeding.This work will facilitate the introduction,parental selection,and marker-assisted breeding,and provide a material basis for the next step in identifying favorable genes that selected together with the sd1 alleles in japonica backbone parents.
基金Funded by the National Natural Science Foundation of China (No.40341011) and the National 863 Program of China(No.2002AA135230)
文摘Integrating the theory of distributed virtual geographic environment (DVGE) and high level architecture(HLA), the architecture of DVGE based on HLA is designed. The data flow and the object models of the architecture are also discussed. The architecture basically meets the need of DVGE in real-time communication, distribution, collaboration, reusing and interoperation, expansion, and standard.
文摘According to this paper, the dragon-shape strategy is the optimized option of China＇s future strategy with respect to the geographic distribution of regional economy.
基金supported by National Natural Science Foudation of China,(No.39930100,30024004)Chinese Academy of Science(No.KSCX2-1-05)Japan Society for the Promotion of Science(No.12375002)
文摘Drosophila lacertosa is widely distributed from northern India to Far East of Russia throughout China.We have studied geographical distributions of three kinds of chromosomal karyotypes,type D(2n=10,4 pairs of V-shaped metacentric chromosomes and a pair of micro-chromosomes),type L(2n= 10,5V with a pair of large-sized heterochromatic autosomes)and type M(2n=10,5V with middle-sized ones).Type D was found exclusively in local populations of D.lacertosa distributed in Yun-Gui Plateau,southwestern China.Both type L and M have a wide range of distribution,and the former occurred in subtropical regions of China including Taiwan Island,whereas the latter in cool temperate regions of East Asia covering Far East of Russia,Korea and the Japan Islands.A strong premating isolation was detected between flies with type D and those with type L or M.These data demonstrate that genetic differentiation leading to cryptic speciation might have occurred in natural populations of Drosophila lacertosa.
文摘The rate of climate change experienced globally in recent decades may compromise sea turtles’ survival;especially temperature increase, which is particularly fast, impacts life history characteristics, such as temperature-dependent sex determination (TSD), late maturity and sea turtles highly migratory nature. This review aims to identify and summarize the information that has been collected from 2009-2020 in order to aid future empirical studies that seek to fill these and other knowledge gaps, and subsequently assist conservationists in making multilevel decisions to protect sea turtle populations and species. In a summarized way the general knowledge acquired so far on the influence of environmental abiotic and biotic factors on nesting behaviour and hatching, emergence and survival successes of sea turtle hatchlings, was gathered. To accomplish this work, a search on Web of Science, Science Direct, NCBI/PubMed, and Google Scholar was carried out using the terms “sea turtles + climate change”. Published articles in the period 2009-2020 were selected, related to the nesting ecology of 5 species of sea turtles: <em>Caretta caretta</em>, <em>Eretmochelys imbricata</em>, <em>Dermochelys coriacea</em>,<em> Chelonia mydas</em>, <em>Lepidochelys olivacea</em>. Emphasis was also placed on geographical information and on population location (e.g. climatic conditions during the nesting season). These articles (N = 126) were analysed giving relevance to researcher’s data interpretations, comparisons with other researches, and the reached conclusions. An attempt was made to represent all 5 species of sea turtles when selecting articles on each of the environmental factors that influence sea turtle nesting: temperature, humidity, nesting substrate, gases, depth of the nest, sea surface temperature (SST), nest location on the beach, nesting phenology and geographic distribution of nesting habitats. The interaction between these parameters and their consequences on the terrestrial phase of reproduction are presented and discussed.
