An ecological model of dropout intention in university students during the covid-19 pandemic

Objective: To analyse the drop out intention of university students after six months of home confinement during the covid-19 pandemic using an ecological model. Method: A non-experimental cross-sectional study with an intentional sampling of 1,011 active university students during 2020. Aged between 18 and 54 years (M = 22,6; SD = 4,8; female = 438). We evaluated them with the university dropout questionnaire for students, Depression, Anxiety and Stress Scale, Fear of covid-19 Scales, covid-19 Anxiety syndrome scale, and the Satisfaction with academic changes questionnaire. We performed a descriptive and multivariate analysis of the data. Results: The model explain 28 % of drop out intention among university students during confinement by covid-19 (sensitivity = 86,8 %). Dissatisfaction with academic changes is the main predictor of the model (OR = 0,960; IC 95 % [0,950, 0,959). Other significant predictors are positive and negative interactions (i.e., in family, social, and academic environments), negative emotional symptoms, anxiety about covid-19, being older, studying at a private university, and having a family member diagnosed with covid-19. Discussions: Macrosystem changes (i.e., home confinement and online classes) during the first six months of the covid-19 pandemic modified the students' interaction with their proximal systems and new predictors of the intention to drop out emerged (e.g., anxiety about covid-19 and having a family member diagnosed with covid-19), associated with the context of confinement.

Objetivo: Analizar la intención deserción de los estudiantes universitarios tras seis meses de confinamiento en casa durante la pandemia por covid-19 a partir de un modelo ecológico. Método: Estudio transversal no experimental con un muestreo intencional de 1011 estudiantes universitarios activos durante 2020. Con edades comprendidas entre los 18 y los 54 años (M = 22,6; DE = 4,8; mujeres = 438). Los estudiantes respondieron el cuestionario de abandono universitario para estudiantes, la Escala de Depresión, Ansiedad y Estrés, la Escala de Miedo de covid-19, la Escala de Síndrome de Ansiedad de covid-19 y el cuestionario de Satisfacción con los cambios académicos. Se realizó un análisis descriptivo y multivariante de los datos. Resultados: El modelo explica el 28 % de la varianza de la intención de deserción entre los estudiantes universitarios durante el confinamiento por covid-19 (sensibilidad = 86,8 %). La insatisfacción ante los cambios académicos es el principal predictor del modelo (OR = 0,960; IC 95 % [0,950, 0,959). Otros predictores significativos son las interacciones positivas y negativas (i.e., en el entorno familiar, social y académico), los síntomas emocionales negativos, la ansiedad ante la covid-19, ser mayor, estudiar en una universidad privada y tener un familiar diagnosticado con covid-19. Conclusiones: Los cambios en el macrosistema (i.e., el confinamiento en el hogar y las clases en línea) durante los primeros seis meses de la pandemia por covid-19 modificaron la interacción de los estudiantes con sus sistemas proximales y surgieron nuevos predictores de la intención de abandono (e.g., ansiedad ante la covid-19 y tener un familiar diagnosticado con covid-19), asociados al contexto de confinamiento.

DNA methylation diversity analysis of Lycium barbarum samples from different cultivation areas based on MSAP / 中国中药杂志

Obvious epigenetic differentiation occurred on Lycium barbarum in different cultivation areas in China. To investigate the difference and change rule of DNA methylation level and pattern of L. barbarum from different cultivation areas in China, the present study employed fluorescence-assisted methylation-sensitive amplified polymorphism(MSAP) to analyze the methylation level and polymorphism of 53 genomic DNA samples from Yinchuan Plain in Ningxia, Bayannur city in Inner Mongolia, Jingyuan county and Yumen city in Gansu, Delingha city in Qinghai, and Jinghe county in Xinjiang. The MSAP technical system suitable for the methylation analysis of L. barbarum genomic DNA was established and ten pairs of selective primers were selected. Among amplified 5'-CCGG-3' methylated sites, there were 35.85% full-methylated sites and 39.88% hemi-methylated sites, showing a high degree of epigenetic differentiation. Stoichiometric analysis showed that the ecological environment was the main factor affecting the epigenetic characteristics of L. barbarum, followed by cultivated varieties. Precipitation, air temperature, and soil pH were the main ecological factors affecting DNA methylation in different areas. This study provided a theoretical basis for the analysis of the epigenetic mechanism of L. barbarum to adapt to the diffe-rent ecological environments and research ideas for the introduction, cultivation, and germplasm traceability of L. barbarum.

Socio-ecological determinants of dengue prevention practices: A cross-sectional study among wet market traders in a selected district in Perak, Malaysia

Objective: To determine the level of dengue prevention practices among wet market traders in a Malaysian district and their associated socio-ecological factors including individual, relationships, community and societal factors. Methods: A cross-sectional study involving 246 wet market traders was conducted in a district in Perak state in northwest Malaysia between September 2018 to June 2019. Participants were selected through stratified sampling from four wet markets in Hilir Perak district. Data on dengue prevention practices and associated socio-ecological characteristics were collected using a validated interview-based questionnaire. The data were analyzed using SPSS version 25. Multiple logistic regression was performed to identify socio-ecological determinants of dengue prevention practices among wet market traders in Hilir Perak District. Results: From the total number of respondents, 78% had high dengue prevention practices. Higher dengue prevention practices were associated with owners of wet market shoplots compared to employed workers (adjusted OR 4.18, 95% CI 1.78, 9.85), high perceived susceptibility (adjusted OR 6.93, 95% CI 3.02, 15.92), high familial support (adjusted OR 3.65, 95% CI 1.25, 10.64), and high perceived dengue prevention and control laws and regulations (adjusted OR 3.24, 95% CI 1.44, 7.32). Conclusions: Dengue prevention practices were associated not only with individual determinants but also with other determinants from relationships to societal level which must be considered in planning or evaluating current dengue control programs.

Effects of ecological factors on shape and ginsenoside of Panax ginseng / 中国中药杂志

The ecological environment is closely related to the growth and quality of authentic medicinal materials. Ginseng is very strict with its natural environment and grows mostly in the damp valleys of forests, and the appearance and chemical composition of ginseng under different growth environments are very different. This article reviews the effects of different ecological factors(including light, temperature, altitude, moisture, soil factors, etc.)on the appearance and chemical composition(mainly ginsenosides) of ginseng. Through systematic review, it is found that soil physical factors are the most important ecological factors that affect the appea-rance of ginseng, and soil bulk density plays a key role; temperature affects ginsenosides in ginseng medicinal materials The dominant ecological factors for the accumulation of chemical ingredents; strong light, high altitude, high soil moisture, low soil nutrient and strong acid soil can influence the accumulation of secondary metabolites in ginseng. Environmental stress can also stimulate the formation and accumulation of secondary metabolites in medicinal plants. Appropriate low temperature stress, high or low water stress, acid or alkali stress can also promote the accumulation of ginsenosides. This article systematically reviews the ecological factors that affect the appearance and chemical composition of ginseng, and clarifies the dominant ecological factors and limiting factors for the formation of ginseng's appearance and quality, as well as beneficial environmental stress factors, in order to provide a theoretical basis for ginseng ecological planting and ginseng quality improvement.

Correlation of Chemical Components in Periploca forrestii with Ecological and Soil Factors / 中国实验方剂学杂志

Objective:To study the correlation of eight chemical components in Miao medicine <italic>Periploca forrestii</italic> from different producing areas with the ecological and soil factors. Method:The contents of neochlorogenic acid， chlorogenic acid， cryptochlorogenic acid， isochlorogenic acid B， isochlorogenic acid A， isochlorogenic acid C， procyanidin A₂， and periplocin were simultaneously determined by ultra-performance liquid chromatography （UPLC）. The root soil samples from various producing areas were collected for testing various soil factors， followed by climate data extraction with ArcGIS and topographic data recording using GPS. SPSS 24.0 was employed to conduct the bivariate analysis and stepwise regression analysis of the eight chemical components in <italic>P. forrestii</italic> from different producing areas with the ecological and soil factors. Result:Stepwise regression equations of the content of eight chemical components against ecological and soil factors were established. The findings demonstrated that neochlorogenic acid was negatively correlated with precipitation in the coldest season and chlorogenic acid negatively correlated with precipitation in the driest month. Cryptochlorogenic acid was negatively correlated with precipitation in the coldest season and average temperature in the warmest season， but positively with selenium. Isochlorogenic acid B was mainly affected by soil factors. Specifically， it was positively correlated with available iron and molybdenum but negatively with total phosphorus and available phosphorus. Isochlorogenic acid A was positively correlated with molybdenum but negatively with the coefficient of variation of precipitation. Isochlorogenic acid C showed a positive correlation with exchangeable magnesium. Procyanidin A₂ exhibited a positive correlation with molybdenum and a negative correlation with available potassium. Periplocin was negatively correlated with the coefficient of variation of precipitation. Conclusion:The correlation between the eight chemical components of <italic>P. forrestii</italic> and the ecological and soil factors has been clarified， which will provide reference for the introduction， cultivation， and standardized planting of <italic>P. forrestii </italic>and also a theoretical basis for further research on its ecological and soil factors and quality formation mechanism.

Exploration of population ecological factors related to the spatial heterogeneity of dengue fever cases diagnosed through a national network of laboratories in India, 2017

Background & objectives: Dengue virus (DENV) transmission is known to be influenced by the environmental conditions. During 2017, the Viral Research and Diagnostic Laboratories (VRDLs) tested 78,744 suspected dengue fever (DF) patients, of whom, 21,260 were laboratory confirmed. The objectives of the study were to evaluate the hypothesis that spatial heterogeneity existed for DF patients and to identify significant determinants of DENV transmission in various districts across the Indian States during 2017. Methods: Laboratory confirmed DF cases were analysed from 402 districts spread across the Indian States. The determinants for DF transmission included in the model were population density, proportion of population living in rural areas, proportion o f forest cover area to the total geographical area, proportion of persons not able to read and write and who were aged greater than seven years; the climatic variables considered were minimum, maximum and average temperature, precipitation and cumulative rainfall. The spatial heterogeneity was assessed using spatial regression analysis. Results: DF cases showed strong spatial dependency, with Moran's I=4.44 (P <0.001). The robust measure for spatial lag (6.55; P=0.01) was found to be the best model fit for the data set. Minimum temperature and cumulative rainfall were significant predictors. Interpretation & conclusions: A significant increase in the number of dengue cases has occurred when the minimum temperature was 23.0-25.8癈 and the cumulative rainfall 118.14-611.64 mm across the Indian districts. Further in-depth investigations incorporating more number of demographic, ecological and socio-economic factors would be needed for robust conclusions.

Ecological Factors and the Prevalence of Trypanosome Infections and Its Economic Implications for Livestock Industry in Simanjiro, Tanzania: A Review

Aims: Trypanosomosis is among one of the tropical neglected diseases which have impactedonhuman, livestock and wildlife. Different factors have been discussed by various researchers butecological factors being considered in nutshell. This paper aimed at reviewing details on how the ecological factors influence the prevalence of trypanosome.Study Design:Literature review where various literatures have been reviewed and the information synthesized. This paper has placed focus on: habitat type, wildlife management type, wildlife abundance and diversity, fire incidenceand human activities.Place and Duration of Study:This literature review work focused in Tanzania mainland and specifically on Simanjiro district for economic implication of trypanosomiasis for the period of 2011-2013 years.ReviewArticleNgongolo et al. Methodology:Literature Searching was done usingkey words in the following search engines Research gate, (https://www.researchgate.net), Google scholar,(https://scholar.google.com/), and PubMed. Manual search in printed documents were done in reports from government, poster, proceedings and publications which were not available in the internet.Results:Variation of habitat types was observed to have impacts on spatial and temporal distribution of various tsetse flies and wildlife species which are vector and reservoirs of the diseases respectively. Incidence of fire affected the distribution of tsetse flies, wildlife and prevalence of trypanosome. For the interval of three years (2011-2013) a loss of more than 1million USDassociated with trypanosomiasis is estimated in Simanjiro district. More money is used by pastoralists in treatment of animalsthan in spraying pesticides.Conclusion:It is recommended that, more work to be doneon the impact of ecological factors on trypanosomiasis. Also more effort is required in controlling the disease through collaboration ofdifferent stakeholders such as livestock officers, ecologists, veterinariansand otherrelevant agencies.

Effects of ecological factors and gene expression of key enzymes on synthesis of major medicinal ingredients of Scutellaria baicalensis in autumn / 中草药

Objective:To study the dynamic changes of the pharmacodynamic components of Scutellaria baicalensis in the harvest period and the effects of ecological factors and key enzyme expression on it. Methods :The artificial cultivated annual S. baicalensis was studied and the expression of nine key enzyme genes (PAL, C4H, 4CL, CHS, CHI, FNS, F6H, UBGAT, and GUS) in the roots of S. baicalensis were determined by real-time quantitative PCR. The content of four main flavonoids (baicalin, wogonoside, baicalein, and wogonin) in the roots was determined by HPLC. The meteorological data of S. baicalensis were collected by the ecological meteorological station. SPSS statistical software and DPS statistical software were used for data analysis. Results: The content of flavonoids of four monomers of annual S. baicalensis decreased slowly in autumn, so the best harvest time of S. baicalensis was in early September. The results of grey correlation analysis showed that the ecological factors affecting the four flavonoids were SWC, Max Ta, RH, and PAR. The expression of C4H and UBGAT genes had an important effect on the accumulation of flavonoids in the roots of S. baicalensis in autumn. Maximum rainfall intensity may indirectly affect the accumulation of the pharmacodynamic components of S. baicalensis by affecting the gene expression of key enzymes. Conclusion: The dynamic changes of four main flavonoids of annual S. baicalensis in autumn and the expression of key enzyme genes of S. baicalensis annual are clarified, providing the theoretical basis for the clarification of the physiological and ecological mechanism of the biosynthesis of S. baicalensis and the improvement of the quality of S. baicalensis.

Genetic diversity of Forsythia suspensa based on ISSR / 中草药

Objective: To investigate the genetic diversity of Forsythia suspensa from different populations. Methods: ISSR markers were used to analyze the genetic diversity of 25 populations of F. suspensa. Percentage of species level polymorphic bands (P), Nei’s genetic diversity index (H), and Shannon’s information index (I) of genetic information were calculated by POPGEN 32. UPGMA relationship dendrogram was clustered by NTSYS. Results: Thirteen primers produced 353 bands and P was 100%. H and I were 0.252 3 and 0.394 0, and genetic differentiation coefficient (Gst) and gene flow (Nm) were 0.331 8 and 1.007 0 within the population levels. The genetic distance varied from 0.031 0 to 0.155 5. NTSYSpc software was used to cluster the system. A total of 25 clusters were divided into two categories and seven groups. Cluster analysis was conducted among Forsythia individuals. A total of 195 samples were divided into two categories and five groups. Conclusion: The genetic diversity among the populations of F. suspensa is at higher level. However, the genetic distance among the Forsythia population is not related to the geographical distance, which is mainly dependent on the ecological factors and the growth environment.

Correlation Between Chemical Constituents and Ecological Factors of Tibetan Medicine Swertia mussotii / 中国实验方剂学杂志

Objective:The HPLC fingerprinting of Swertia mussotii was established to study the correlation between chemical components and ecological factors in different areas. Method:The fingerprint of S. mussotii was established by high performance liquid chromatography (HPLC),and the evaluation and analysis were made based on the " Chinese Medicine Chromatographic Fingerprint Similarity Evaluation System 2004A Edition" promulgated by the National Pharmacopoeia Commission. The analysis was carried out on a Wondasil C18 column(4.6 mm×250 mm,5 μm), with methanol-0.2%phosphoric acid as the mobile phase for gradient elution,and the column temperature was set at 30℃. The flow rate was 1.0 mL·min-1, and the detection wavelength was set at 245 nm. And data on ecological factors in each sample habitat, such as climate and soil, were collected. The gray correlation and bivariate analysis were carried out on the chemical constituents and ecological factors of medicinal materials in different areas using DPS data processing system and SPSS 21.0 statistical software. Result:The HPLC fingerprint of S. mussotii was established,a total of 12 common fingerprint peaks were marked, and the chemical constituent of the seven peaks were determined. The chemical constituents, such as swertiamain and mangiferin of S. mussotii, were significantly correlated with ecological factors. Moreover,the chemical constituents were obviously affected by the monthly average temperature range,annual precipitation,precipitation seasonality in the climatic factors,the soil organic carbon ratio and soil pH in the soil factors. Conclusion:The chemical constituents of S. mussotii have a correlation with the external ecological factors,the findings could provide a basis for the artificial planting of the medicinal material and the scientific connotation of the " environment-based" theory for Tibetan medicines.

Research progress on factors affecting accumulation of volatile oil from Atractylodes Macrocephala / 中草药

Atractylodes macrocephala, belonging to Compositae family, whose dry rhizome as its medicinal parts, is a famous traditional Chinese medicine, with the function of tonifying spleen, aesthetic improvements and so on. Its main medicinal ingredient is volatile oil, which has obviously effect of antitumor. Recently, the market demand of this herb gradually increased, while its quality has not been guaranteed. This paper concluded the process of biosynthesis and transformation of sesquiterpenoids, an important secondary metabolite in violate oil; And firstly reviewed the factors affecting the accumulation of volatile oil in A. macrocephala in the aspects of inheritance and ecology. It is expected to provide a reference for the further study of the biosynthesis and biotransformation of sesquiterpenoids in A. macrocephala and help to improve the yield and quality of the volatile oil.

Analysis on ecological factors and active components content of wild Dipsacus asper in Chongqing Wulong district / 中国中药杂志

An HPLC method was developed for the determination of iridoid glycosides (loganin acid, loganin, sweroside) and saponins (asperosaponin Ⅵ) in the wild Dipsacus asper. A total of 108 samples consecutive growing 12 month were collected in 9 plots in Wulong district of Chongqing. Subsequent analysis of the content of loganin acid, loganin, sweroside and asperosaponin Ⅵ was performed by HPLC to evaluate the quality. In addition, 20 climate data provided by the world climate database (http://www.worldclim.org/) was analyzed to deduce the correlation between the growing environment factors and the active ingredient content accumulation of D. asperoides and choose the apposite growing environment for D. asper. The range of active ingredient content in wild D. asper were 0.01%-3.80%(loganin acid), 0.08%-0.62%(loganin), 0.12%-0.78%(sweroside), 0.64%-5.26%(asperosaponin Ⅵ). The highest content of these active ingredients was concentrated from February to April, with 2.64% of loganin acid, 0.36% of loganin), 0.57% of sweroside, and 3.09% of asperosaponin Ⅵ. The method used for determination of the active ingredient content in D. asper was simple and convenient with accurate result. The selection of the quadrats is scientific and reasonable and can be used for the analysis of the contents of the wild D. asper, thus provide a reference for quality evaluation of D. asper and protection of D. asper resources.

Effects of ecological factors on ginsenosides synthesis and its key enzyme genes expression / 中草药

Objective To explore the effect of ecological factors and the expression of key enzyme genes on the synthesis and accumulation of ginsenosides. Methods Cultivated four-year-old ginseng were used as test materials, the expression of key enzyme genes (HMGR, FPS, SS, SE, DS, β-AS, CYP82D47, CYP716A47) in the biosynthesis of ginsenosides of roots in different growth periods was determined by real-time quantitative PCR, determination of the content of eight ginsenosides (ginsenoside Rg1, Re, Rf, Rb1, Rb2, Rb3, Rc, Rd) in roots by HPLC, the meteorological data were collected by a small weather station, correlation analysis was performed with SPSS. Results The expression of key enzyme genes in the period of flowering to fruit ripening was higher than the root growing after fruit period and the withering period, the expression of key enzyme genes involved in the synthesis of ginsenosides was influenced by each other, and the expression of key enzyme genes in ginseng roots showed a positive correlation with the accumulation of ginsenosides; The contents of ginsenoside Rg1, Rb1, Re, and Rc were higher in the roots of ginseng, eight kinds of monomer ginsenosides content dynamic changes trend is different; Temperature, photosynthetically active radiation, soil water potential are important ecological factors for ginsenosides synthesis in roots, temperature was significantly negatively correlated with ginsenoside Rb1 and Rd (P < 0.05), PAR can significantly promote the formation of ginsenoside Rg1 (P < 0.05), soil water potential was significantly negatively correlated with ginsenoside Rb1 (P < 0.05); Grey correlation analysis results showed that the major ecological factors that influenced ginsenosides content in ginseng roots were temperature, PAR and relative humidity, the grey correlation between the expression of the key enzyme genes with the content of ginsenosides is less than ecological factors with the content of ginsenosides, under the guidance of ecological factors, the expression of the key enzyme genes regulate the synthesis and accumulation of ginsenosides. Conclusion The dynamic changes of the expression of key enzyme genes and the content of ginsenosides in ginseng were determined, it provides a theoretical basis for elucidating the physiological and ecological mechanism of ginsenoside synthesis and the quality control of Radix Ginseng.

Research on suitable distribution of Paris yunnanensis based on remote sensing and GIS / 中国中药杂志

Paris yunnanensis is a kind of rare medicinal herb, having a very high medicinal value. Studying its suitable ecological condition can provide a basis for its rational exploitation, artificial cultivation, and sustainable utilization. A practicable method in this paper has been proposed to research the suitable regional distribution of P. yunnanensis in Sichuan province. By the case study of P. yunnanensis in Sichuan province, and according to related literatures, the suitable ecological condition of P. yunnanensis such as altitude, mean annual temperature (MAT), annual precipitation, regional slope, slope ranges, vegetative cover, and soil types was analyzed following remote sensing (RS) and GIS.The appropriate distribution regionof P. yunnanensis and its area were extracted based on RS and GIS technology,combing with the information of the field validation data. The results showed that the concentrated distribution regions in counties of Sichuan province were, Liangshan prefecture, Aba prefecture, Sertar county of Ganzi prefecture, Panzhihua city, Ya'an city, Chengdu city, Meishan city, Leshan city, Yibin city, Neijiang city, Luzhou city, Bazhong city, Nanchong city, Guangyuan city and other cities and counties area.The suitable distribution area in Sichuan is about 7 338 km², accounting for 3.02% of the total study regional area. The analysis result has high consistency with the filed validation data, and the research method for P. yunnanensis distribution region based onspatial overlay analysis and the extracted the information of land usage and ecological factors following the RS and GIS is reliable.

Predictive distribution and planting GAP of Cyathula officinalis in China based on 3S technology and MaxEnt modelling / 中国中药杂志

Research on predictive distribution and planting GAP of Cyathula officinalis in China is helpful to provide scientific basis for its protection and planting popularization. According to the data in 63 distribution sites and 49 ecological variables, using MaxEnt ecological niche model and 3S technology, we performed a quantitative analysis of suitable distribution and planting GAP of C. officinalis in China. Our results show that: ① the area of suitable distribution of C. officinalis is about 634 385.80 km² in total, and mainly in Northeastern and Southeastern Sichuan, Northern and Southeastern Yunnan, Western and Southwestern Guizhou, Southwestern and Northeastern Chongqing, Southwestern Shaanxi, Southeastern Gansu, Western Guangxi, Southeastern Tibet. ② The main ecological factors determining the potential distribution are precipitation, altitude, minimum temperature of coldest month, soil type, monthly mean temperature. ③ The planting GAP region are mainly in Guangyuan, Mianyang, Ya'an, Leshan, Liangshan, Panzhihua of Sichuan province, Hanzhong of Shaanxi province, Dali, Nujiang, Chuxiong, Baoshan, Qujing, Wenshan of Yunnan province, southwestern autonomous prefecture in Guizhou province. The results are of great significance for realizing the growth environment, predicting the potential distribution and promoting planting popularization for C. officinalis.

Study on ecological suitability regionalization of Corni Fructus based on Maxent and ArcGIS model / 中国中药杂志

Through planting regionalization the scientific basis for planting area of high-quality medicinal materials was predicted. Through interview investigation and field survey, the distribution information of Corni Fructus in China was collected,and 89 sampling point from 14 producing areas were collected. Climate and topography of Corni Fructus were analyzed, the ecological adaptability of study was conducted based on ArcGIS and Maxent. Different suitability grade at potential areas and regionalization map were formulated. There are nine ecological factors affecting the growth of Corni Fructus, for example precipitation in November and March and vegetation type. The results showed that the most suitable habitats are Henan, Shaanxi, Zhejiang, Chongqing, Hubei, Sichuan, Anhui, Hunan and Shandong province. Using the spatial analysis method,the study not only illustrates the most suitable for the surroundings of Corni Fructus,but also provides a scientific reference for wild resource tending, introduction and cultivation, and artificial planting base and directing production layout.

Ecology suitability study of Ephedra intermedia / 中国中药杂志

The study aims at predicting ecological suitability of Ephedra intermedia in China by using maximum entropy Maxent model combined with GIS, and finding the main ecological factors affecting the distribution of E. intermedia suitability in appropriate growth area. Thirty-eight collected samples of E. intermedia and E. intermedia and 116 distribution information from CVH information using ArcGIS technology were analyzed. MaxEnt model was applied to forecast the E. intermedia in our country's ecology. E. intermedia MaxEnt ROC curve model training data and testing data sets the AUC value was 0.986 and 0.958, respectively, which were greater than 0.9, tending to be 1.The calculated E. intermedia habitat suitability by the model showed a high accuracy and credibility, which indicated that MaxEnt model could well predict the potential distribution area of E. intermedia in China.

Correlation between flavonoids contents in Hippophae rhamnoides subsp. inensis leaf and ecological factors, and ecological suitability analysis of H. rhamnoides subsp. sinensis / 中国中药杂志

The study aims at providing a new suitable way to promote artificial cultivation, solving the problem of resources increasingly endangered wild medicine, and protecting the wild resources of Tibetan medicine. The content of quercetin,kaempferol and isorhamnetin was determined by HPLC. The correlation between flavonoids components and ecological factors was analyzed using partial least-squares regression (PLSR). Based on Maxent model combining using ArcGIS software, suitable regionalization for H.rhamnoides subsp. sinensis was studied.The results showed that the difference of quercetin,kaempferol and isorhamnetin content in samples from different regions were obvious. The main factors effecting quercetin content accumulation were the altitude andthe average monthly precipitation in January and August. The main factors effecting kaempferol accumulation were the altitude andthe average monthly precipitation in the coldest quarter and December. The main factors effecting isorhamnetin accumulation were the average monthly precipitation in August, January and the coldest quarter.The regional distribution suitability index for H.rhamnoides subsp. sinensis was 0-0.708. The suitable area 590 500 km², accounting for 6.13% of the total area. The preferably suitable area was 552 500 km², accounting for 5.73% of the total area.The methods used in the study is simple and feasible, the result is reliable which provide a new approach for Tibetan medicine resources sustainable exploitation and utilization.

Potential distribution of Rhodiola crenulata in Tibetan Plateau based on Maxent model / 中国中药杂志

Wildlife tending and artificial cultivation is an important way to protect the wild resources of Rhodiola crenulata. It is a study hotspot at present. The distribution information of R. crenulata was collected by query data and field survey, the ecological suitability regionalization was conducted based on maximum entropy model combine with ecological factors, including climate, soil and altitude. To provide the reference for production layout, suitable planting area and the selection of artificial planting base by studying the ecological suitability regionalization of R. crenulata. The potential distribution areas mainly concentrated in the easen Tibet, western Sichuan, southern Qinghai, and Gansu Gannan Tibetan Autonomous Prefecture, Yunnan Diqing Tibetan Autonomous Prefecture. There were 5 major environmental factors to have obvious influence on ecology suitability distributions of R. crenulata, including altitude (contribution rate of 61.8%), precipitation of warmest quarter (contribution rate of 19%), the coefficient of variation of precipitation seasonality (contribution rate of 4.7%), the SD of temperature seasonality (contribution rate of 4%), mean temperature of driest quarter (contribution rate of 2.5%). The AUCs of ROC curve were both above 0.9, indicating that the predictive results with the Maxent model were highly precise. The study of the ecological suitability regionalization of R. crenulata based on Maxent can provide a scientific basis for the selection of artificial planting base.

Study on ecological suitability of Gardenia jasminoides based on ArcGIS and Maxent model / 中国中药杂志

The application of ArcGIS and Maxent modelto analyze the ecological suitability of Gardenia jasminoides.Taking 85 batches of Gardenia as the basis of analysis, the selection of ecological factors for the growth of Gardenia. The results showed that the average precipitation in April, the average precipitation in November and the average precipitation in August were the most important factors affecting the growth of Gardenia. The relative concentration of Gardenia suitable growth region,north to the south of Shaanxi province, south of Henan, central Anhui, south to the north of Hainan province, west to central Sichuan province, east of Zhejiang coastal area, northeast of Taiwan.