Land-use and plant invasion influence biodiversity.Understanding the effects of land-use types and invasive plants on the ecosystem is crucial for better management and the development of strategic plans for increasin...Land-use and plant invasion influence biodiversity.Understanding the effects of land-use types and invasive plants on the ecosystem is crucial for better management and the development of strategic plans for increasing biodiversity in Jeju Island,Korea,a designated Biosphere Reserve by the United Nations Education,Scientific,and Cultural Organization.The effect of the most dominant invasive exotic species,Hypochaeris radicata,on the four land-use types of Jeju Island was investigated.Plant composition,soil characteristics,and plant diversity among four land-use types(cropland,green space,neglected land,and residential)were compared.Among the land-use types,croplands had the most diverse plant composition and the highest richness in exotic and native plant species.Croplands,such as tangerine orchards,which are widely distributed throughout Jeju Island,showed the highest plant diversity because of medium intensity disturbance caused by weed removal.The relative cover of H.radicata did not differ between land-use types.However,H.radicata invasion was negatively related with plant species richness,making this invasive species a threat to the biodiversity of native herbs present in land-use areas.H.radicata adapts to areas with a broad range of soil properties and a variety of land-use types.Therefore,it is crucial to monitor land-use types and patterns of plant invasion to guide the implementation of consistent management and conservation strategies for maintaining ecosystem integrity of the transformed habitat in Jeju Island.展开更多
This study aims to determine the differences in leaf functional traits and phenotypic plasticity of leaf functional traits between exotic and native Compositae plant species. Leaf width of exotic plants was significan...This study aims to determine the differences in leaf functional traits and phenotypic plasticity of leaf functional traits between exotic and native Compositae plant species. Leaf width of exotic plants was significantly lower than that of native species. Leaf length, specific leaf area(SLA), single-leaf wet and dry weights, leaf moisture, and leaf thickness of exotic plants were also lower than those of native species but not significantly. The leaf shape index of exotic plants was higher than that of native species but not significantly. This implies that the relatively low leaf construction cost for exotic plants may play an important role in the success of their invasions. The higher leaf shape index and lower leaf width of exotic plants can enhance the efficiency of resource capture(especially sunlight capture) via adjustments to leaf shape and size, thereby increasing the survival of exotic plants. The plasticity indices of single-leaf wet weight and leaf thickness of exotic plants were significantly lower than those of native species. The lower phenotypic plasticity of single-leaf wet weight and leaf thickness of exotic plants may be the result of a cost to plasticity. That is, if the plasticity is too high, the fitness of plant species might be reduced sharply under unfavorable environments. Thus, lower plasticity of leaf functional traits may compensate for the negative impact of adverse environments and stabilize leaf construction costs for exotic plants. Moreover, reduced phenotypic plasticity might be one of the key competitive strategies by which exotic plants successfully invade new habitats. Overall, exotic plants did not always exhibit higher values of leaf functional traits or increased phenotypic plasticity of leaf functional traits compared with native species.展开更多
A saltmarsh has developed rapidly on the mudflat of Andong Shoal,in southern Hangzhou Bay,over the last decade since embankment.The saltmarsh vegetation changes are driven by both sediment dynamic conditions and the c...A saltmarsh has developed rapidly on the mudflat of Andong Shoal,in southern Hangzhou Bay,over the last decade since embankment.The saltmarsh vegetation changes are driven by both sediment dynamic conditions and the competition between the exotic species Spartina alterniflora(S.alterniflora) and the native species Scirpus mariqueter(S.mariqueter).This study attempted to investigate large-scale spatial variations in the exotic and native species,by analyzing and interpreting a time series(2016-2018) of high-resolution(less than 1 m) remote sensing images.The total area of the saltmarsh increased at a rate of 1.07 km^2/year,due to the accretion of the whole tidal flat.The spatial patterns revealed a new bimodal pattern for S.alterniflora invasion.S.alterniflora expanded over the upper to middle saltmarsh at a rate of1.68 km2/year.However,the S.alterniflora patches at the seaward edge expanded at a negative rate of-0.005 km^2/year,indicating a different pattern in competition:S.alterniflora had more advantages in the upper saltmarsh,while S.mariqueter had more advantages in the pioneer zone with low elevation.Consequently,S.alterniflora mainly established new habitats by invading S.mariqueter in the middle saltmarsh,but S.mariqueter occupied the bare mudflat for tradeoff.Our results aindicated that the interspecific competition result between S.alterniflora and S.mariqueter depended on elevation,and low elevation might create a favorable environment for S.mariqueter to win the competition with exotic species.This finding could be applied to future invasive species control and saltmarsh management.展开更多
Extensive exotic introgression could significantly enlarge the genetic distance of hybrid parental populations to promote strong heterosis.The goal of this study was to investigate whether genome-wide prediction can s...Extensive exotic introgression could significantly enlarge the genetic distance of hybrid parental populations to promote strong heterosis.The goal of this study was to investigate whether genome-wide prediction can support pre-breeding in populations with exotic introgressions.We evaluated seed yield,seed yield related traits and seed quality traits of 363 hybrids of Brassica napus (AACC) derived from two parental populations divergent on massive exotic introgression of related species in three environments.The hybrids presented strong heterosis on seed yield,which was much higher than other investigated traits.Five genomic best linear unbiased prediction models considering the exotic introgression and different marker effects (additive,dominance,and epistatic effects) were constructed to test the prediction ability for different traits of the hybrids.The analysis showed that the trait complexity,exotic introgression,genetic relationship between the training set and testing set,training set size,and environments affected the prediction ability.The models with best prediction ability for different traits varied.However,relatively high prediction ability (e.g.,0.728 for seed yield) was also observed when the simplest models were used,excluding the effects of the special exotic introgression and epistasis effect by5-fold cross validation,which would simplify the prediction for the trait with complex architecture for hybrids with exotic introgression.The results provide novel insights and strategies for genome-wide prediction of hybrids between genetically distinct parent groups with exotic introgressions.展开更多
A two-dimensional Brans-Dicke star model with exotic matter and dark energy is studied in this paper,the field equation and balance equation are derived at finite temperature,the analytic solutions of these equations ...A two-dimensional Brans-Dicke star model with exotic matter and dark energy is studied in this paper,the field equation and balance equation are derived at finite temperature,the analytic solutions of these equations canbe used to calculate the mass of star.In addition,we find that star's mass has a minimum when matter state parameterγ→0.展开更多
The alien halophilous Artemia species, Artemia franciscana, was found in Chengkou Saltern and Yangkou Saltern of Shandong Province, P.R. China. Although the indigenous parthenogenetic Artemia is detectable, the exotic...The alien halophilous Artemia species, Artemia franciscana, was found in Chengkou Saltern and Yangkou Saltern of Shandong Province, P.R. China. Although the indigenous parthenogenetic Artemia is detectable, the exotic species is dominant in both salterns. The cross-breeding tests between the exotic A. franciscana and 5 bisexual Artemia species were conducted. The results of hybridization and morphological observations on the exotic A. franciscana are briefly presented in this short communication.展开更多
Starting from the extended tanh-function method (ETM) based on the mapping method, the variable separation solutions of the (2+1)-dimensional asymmetric Nizhnik Novikov Veselov (ANNV) system are derived. By fur...Starting from the extended tanh-function method (ETM) based on the mapping method, the variable separation solutions of the (2+1)-dimensional asymmetric Nizhnik Novikov Veselov (ANNV) system are derived. By further study, we find that these variable separation solutions are seemingly independent of but actually dependent on each other. Based on the variable separation solution and by choosing appropriate functions, some novel and interesting interactions between special solitons, such as bell-like compacton, peakon-like compacton and compacton-like semifoldon, are investigated.展开更多
The control of exotic and invasive species in areas undergoing recovery is a challenge for ecological restoration and this problem may be even greater in urbanized areas. This study evaluated the seed bank and seed ra...The control of exotic and invasive species in areas undergoing recovery is a challenge for ecological restoration and this problem may be even greater in urbanized areas. This study evaluated the seed bank and seed rain of a 5-year-old riparian forest located at the metropolitan region of Belo Horizonte in southeast Brazil, and verified changes over time in the abundance and species richness and whether planted species already were providing propagules to the site. At the forest, fifteen parcels of 100 m<sup>2</sup> were distributed randomly and soil samples were collected thrice (October 2011, March 2012 and July 2012) to evaluate the seed bank. Seed traps were installed in nine parcels to collect propagules over 1 year. Propagules were segregated and germinate at greenhouse. Species richness and abundance were estimated, and variance and similarity were quantified. In total, 86 species were recorded in the seed banks, 41.9% natives and 33.7% exotics, with the predominance of herbs (87.2%) and only 7% of trees. Species classified as weeds amounted to 52.3%. In the seed rain 642 seedlings germinated but they belonged to only 10 species, half of them were exotics. Regarding life forms, half of the species were arboreal and dominated the samples, highlighting the exotic species Melia azedarach. The species richness of the seed bank did not differ by season, unlike the seed rain which varied significantly by month. Seed bank and seed rain species had a very low floristic similarity with the list of planted species, suggesting that few planted trees had dispersed or were stocking propagules. Many non-planted species were recorded, mostly exotics and/or invasive that were probably derived from the surrounding urban matrix. These might interrupt the successional dynamics of the restoration forest and compromise the restoration process in the medium and long-terms. Our results highlight: (1) the importance of monitoring areas undergoing restoration; (2) that restoration methods and management actions directed to control exotic and invasive species are particularly important for sites in urban regions; and (3) the relevance of conserving forest fragments as sources of propagules for nearby areas.展开更多
The newly observed D^*aj family containing D^*aj(2317), Daj(2460), and Daj(2632) attracts great interests. Determining their structures may be an important task for both theorists and experimentalists. In this...The newly observed D^*aj family containing D^*aj(2317), Daj(2460), and Daj(2632) attracts great interests. Determining their structures may be an important task for both theorists and experimentalists. In this work we use a non-relativistic model (the harmonic oscillator model) to evaluate the production rate of D^*aj (2317) from the decays of ψ(4415). For a comparison, we a/so employ the widely adopted heavy quark effective theory to repeat the calculation. We lind that the rate is sizable and may be observed at BES III and CLEO, if it is a p-wave excited state of Da(1968). Unfortunately, the other two members of the family cannot be observed through decays of charmonia, because of the constraints from the final state phase space.展开更多
The idempotent semirings Rmax and Rmin play a crucial role in several areas of mathematics and their applications such as discrete mathematics, algebraic geometry, computer science, computer languages, linguistic prob...The idempotent semirings Rmax and Rmin play a crucial role in several areas of mathematics and their applications such as discrete mathematics, algebraic geometry, computer science, computer languages, linguistic problems, optimization theory, discrete event systems, fuzzy logics. In this paper we consider the expansion of the semirings Rmax and Rmin with residuals and describe how to use these expended semirings in public key cryptography.展开更多
Due to various courses of formation of zircons from kimbedites, different kinds of zircons can provide useful information about the mantle and the crystallization of kimberlites. We chose 9 typical ones out of 33 zirc...Due to various courses of formation of zircons from kimbedites, different kinds of zircons can provide useful information about the mantle and the crystallization of kimberlites. We chose 9 typical ones out of 33 zircons from the Shengli- 1 kimberlite pipe in Mengyin County, Shandong Province to study their ages and formation by means of SHRIMP, CL, Raman spectroscopy, etc. The result shows that the ^207Pb/^206Pb ages of many zircons vary from 2567±13 Ma to 2636±42 Ma, which are close to the age of Archaean granitoid (2457.3±47 Ma) in the study area. The contents of U and Th in the samples are higher than those of zircons crystallized in kimbedite and vary from 89 to 398 ppm as well as from 10 to 283 ppm. Color zones are obvious in these samples under the CL. The inclusions are composed of feldspar, quartz, apatite, etc. The above results show that the zircon samples came from the crust of the earth, which means that the kimberlite magmas are contaminated by crustal substances. The position where a great deal of volatile escapes and even explodes during rapid rise of magmas is located at the boundary of the ancient basement and the Precambrian stratum.展开更多
Biodiversity assessment for tree species was conducted in three forest fragments ofthe Taita Hills, southeastern Kenya to compare species diversity between and within three exotic forest plantations of pine, eucalyptu...Biodiversity assessment for tree species was conducted in three forest fragments ofthe Taita Hills, southeastern Kenya to compare species diversity between and within three exotic forest plantations of pine, eucalyptus, cypress and the indigenous forests. The study sites were: Ngangao (120 ha), Chawia (86 ha), and Mbololo (185 ha). A Y-plot design was used to sample 32 plots comprising of 65 subplots. At each subplot, all juvenile trees of 5 cm and above in diameter at breast height (DBH) were enumerated and recorded by species. Tree regeneration (seedlings and saplings) was tallied by species. The Shannon-Weiner Index was used to calculate species diversity and evenness. The derived Shannon’s indices were further converted into effective numbers to show the magnitude of differences in species biodiversities. To evaluate dif-ferences in species diversities, a one way ANOVA was conducted and to separate the means, Tukey's HSD and Duncan’s tests were used for even and uneven number of samples respectively. Jaccard’s similarity index was used to assess species similarities. There were more than 58 species whose stem densities varied between 10 and 2 000 trees per hectare.There were significant differences in species diversities between forest types and sites; the indigenous forests showed higher diversities than the exotic forests. Similarly, Chawia sites had higher species diversity than both Ngangao and Mbololo. Chawia also had a higher number of regen-erated species than the two other sites, including species such as Xymalos monospora, Rapanea melanophloeos, and Syzygium guineense, which are associated with low levels of disturbance. These findings indicate that the indigenous forest is more diverse in species as would be expected in the tropics. The high species diversity in Chawia could be accounted for by the higher levels of disturbance it underwent, unlike the two other sites. The regeneration of species associated with low levels of disturbance found in the exotic plots of Chawia show the likelihood of presence of long-term soil seed banks. The low regeneration in the exotics plots observed in Ngangao and Mbololo are likely due to the absence of seed banks since some of the plantations were established on bare land (in Ngango), or the inherent physiology (allelopathy) of some of species repelling the regeneration of others.展开更多
A projectile with exotic wraparound wings( WAW) configuration is designed to improve the finstabilized projectile shooting quality. Two fin-stabilized projectiles with the same body with and without exotic WAW configu...A projectile with exotic wraparound wings( WAW) configuration is designed to improve the finstabilized projectile shooting quality. Two fin-stabilized projectiles with the same body with and without exotic WAW configuration are simulated numerically by applying the Roe scheme. The shear-stress transport turbulence models and the lower-upper symmetric Gauss-Seidel implicit method are used to solve 3D Reynoldsaveraged Navier—Stokes equations. The differences in aerodynamic coefficients and aerodynamic characteristics of the projectiles when the Mach number varies from 0. 35 to 0. 95 are obtained,and the cause of these differences is analyzed. The calculation results indicate that the lift-to-drag ratio of the projectile significantly increases,the rolling moment decreases,and the position of the pressure center of the projectile shows relatively small changes when the exotic WAW configuration is used. Therefore,this projectile can obviously reduce rolling effect,enlarge range and improve flying stability.展开更多
The genetic diversity and relationships of seven Chinese indigenous pig breeds (Meishan, Erhualian, Hezuo, Bamei, Qingping, Tongcheng, and Huainan) and three exotic pig breeds (Large White, Landrace, and Duroc) we...The genetic diversity and relationships of seven Chinese indigenous pig breeds (Meishan, Erhualian, Hezuo, Bamei, Qingping, Tongcheng, and Huainan) and three exotic pig breeds (Large White, Landrace, and Duroc) were analyzed using the DNA differential display technique by means of eight primer combinations. A total of 123 reproducible bands were used to calculate mean Nei's gene diversity, and mean Shannon's information index for each pig population. Based on these the Nei's standard genetic identity and distance were estimated, which was used to construct a dendrogram tree for the 10 pig breeds. The experimental results obtained and the method used in this study for evaluating the genetic diversity and relationships of pigs were also discussed.展开更多
An investigation was carried out in wharves, inspection yards, processing plants in Beilun Port and the surrounding areas. Five kinds of exotic harmful weeds were discovered and collected, and they were described and ...An investigation was carried out in wharves, inspection yards, processing plants in Beilun Port and the surrounding areas. Five kinds of exotic harmful weeds were discovered and collected, and they were described and analyzed.展开更多
Kappaphycus alvarezii, a red macroalgal species native to South-East Asia, has been introduced for commercial purposes to more than 20 tropical countries. In 2000, Panama became the first Central American country to d...Kappaphycus alvarezii, a red macroalgal species native to South-East Asia, has been introduced for commercial purposes to more than 20 tropical countries. In 2000, Panama became the first Central American country to develop its cultivation following a pilot-commercial approach. Twelve years after his introduction to Panama, the species was found to the south Caribbean coast. In the present study, we report the first record of K. alvarezii collected in Costa Rican waters. Genetic identification of the sample was performed with the mitochondrial marker cox2-cox3 intergenic spacer, and phylogenetic analyses showed that the sample collected grouped into a monophyletic clade with GenBank sequences from Vietnam, Indonesia, the Philippines, Brazil and Venezuela. Here we provide further description of its position with respect to other strains of K. alvarezii collected globally. Its possible route of entry to the Caribbean coast of Costa Rica is discussed. To date, it is possible to locate K. alvarezii in different areas away from the production fields which show its dispersion, and that the species is expanding;but more studies are needed to know the phase of colonization in which it is located because it is a combination of natural factors and human exploitation that determines the invasive potential of the species.展开更多
Forested aquatic streams depend heavily on forest canopy input. This input is a primary resource for the macroinvertebrate fauna. As a result, changes in the canopy impact the aquatic ecosystem. The focus of this stud...Forested aquatic streams depend heavily on forest canopy input. This input is a primary resource for the macroinvertebrate fauna. As a result, changes in the canopy impact the aquatic ecosystem. The focus of this study was to identify leaf degradation rates to determine resource availability for invertebrate communities. Specifically, leaf degradation rates were determined for oak, poplar, maple and kudzu. Oak, poplar, and maple are established stream canopy vegetation while kudzu is an invasive species. By comparing leaf degradation rates of native vs. exotic leaves, it provides an insight to changes in community structure. Furthermore, these changes in the plant canopy biodiversity have long-term implications for stream health.展开更多
The carbon (C) stored in the living biomass of trees is typically the largest C pool of the forest ecosystem which is directly impacted by deforestation and degradation (Ensslin et al, 2015). The relationships between...The carbon (C) stored in the living biomass of trees is typically the largest C pool of the forest ecosystem which is directly impacted by deforestation and degradation (Ensslin et al, 2015). The relationships between diversity, biomass and C stocks at varied altitudes can have crucial implications for the management and conservation of C sinks. The study was conducted at Mbeya One ward lying between Mporoto and Rungwe forest reserves in Mbeya rural district, in the Southern highlands of Tanzania. The main objective was (1) to assess the indigenous tree biomass variation between Mporoto and Rungwe forest reserves (2) to assess the exotic tree biomass variation between the two forest reserves and (3) to assess the human implication on aboveground biomass variation between the two forest reserves. The findings indicated the significant decreased in indigenous trees biomass in residential and crop land areas with a hasty increase in biomass when reaching Mporoto forest reserve indicating little human encroachment in the forest reserve. There was the same trend towards Rungwe forest reserve however in that side, there was a slight increase in indigenous tree biomass when reaching forest reserve which is the sign of human encroachment in the forest reserve. The main human activities encroaching the reserve were;timber harvesting and commercial exotic trees planting (especially the commercial trees, Pinus patula sp). However, the trend was opposite for the exotic trees especially for Pinus patula and Eucalyptus sp in the study area. Hence the study concludes that there is a significant variation between indigenous and exotic trees in the study area, hence the variation in the tree biomass (fig 2&3). There is also a massive human encroachment for indigenous trees clearance in expense of exotic trees plantations towards and in Rungwe forest reserve. Therefore, the study would like to call for an urgent intervention especially in the east side of the study area (Rungwe forest reserve) stopping exotic tree plantation penetrating into the forest reserve which intensify cutting down of indigenous trees in the forest reserves plummeting aboveground biomass and escalating carbon emissions in the atmosphere while jeopardizing the natural forest ecosystem services to the communities. Conservation education should be emphasized in the study area to local communities, exotic trees plantations owners and other relevant stakeholders.展开更多
The hematological and serum biochemical profiles of apparently healthy exotic breed of dogs in Jos, Plateau state, Nigeria was studied in this research. One hundred and seven exotic breed of dogs were examined from Oc...The hematological and serum biochemical profiles of apparently healthy exotic breed of dogs in Jos, Plateau state, Nigeria was studied in this research. One hundred and seven exotic breed of dogs were examined from October</span><span style="font-family:""> - </span><span style="font-family:"">December, 2018. The results from physical, clinical examinations and parasitological examinations were used to determine ap</span><span style="font-family:Verdana;"></span><span style="font-family:"">parently healthy exotic breed of dogs which were used in this study. The parameters measured were rectal temperature, parasitaemia, hematology which included red blood cells count, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin and hemoglobin content;total white blood cell count, including eosinophils, neutrophils, lymphocytes, monocytes, granulocytes counts, and platelets;serum biochemical parameters also included Aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total proteins, albumin, globulin, blood urea nitrogen, creatinine, cholesterol and triglyceride, using standard methods. Data generated from the study were statistically analyzed using students t</span><span style="font-family:"">-</span><span style="font-family:"">test one-way analysis of variance while the level of significance </span><span style="font-family:"">was </span><span style="font-family:"">measured at p < 0.05. From this study, hematological and serum biochemical values were comparable to and not different from those reported for dogs in available literature, but the upper and lower reference limits (minimum and maximum values) were different for most parameters. Sex-related significant difference (p < 0.05) occurred only in WBC and total protein while age-related significant difference occurred only in total protein and urea level. Breed affected the MCHC and total bilirubin level which was evident in higher MCHC level in Neapolitan mastiff than Alsatian breed while total bilirubin was higher in Alsatian breed than Bull mastiff (p < 0.05). The present study has presented preliminary information on the range of hematological and serum biochemistry profile of exotic breed of dogs in Jos, Plateau state, Nigeria which may be useful to biomedical researchers and veterinary clinicians.展开更多
Imagination of China in Western movies presented by“exoticism”is no longer the dualism of“backward and traditional Oriental”but“advanced and modern Western”.Skyfall released recently has shown on the one hand a...Imagination of China in Western movies presented by“exoticism”is no longer the dualism of“backward and traditional Oriental”but“advanced and modern Western”.Skyfall released recently has shown on the one hand a“modern”contemporary China,on the other hand,a cultural concept of“isolated relics of traditional China and ruins of modern China”.In Indiana Jones and the Temple of Doom,China is imagined to be a mixed land of the new and old,the Oriental and Western based on the comparison between China and India,which is considered to be primitive,traditional and brutal.Mission:Impossible III presents three sides of Shanghai in a mean way:“skyscraper”,“old-style apartment”and“ancient town”.Here we could see,the images of China in Western movies are comprehensive and complicated,conveying divergent cultural views.Moreover,increasing Chinese market constitutes a crucial reason why Western movies intend to hide their political bias but adopt a flattery attitude to Chinese culture.展开更多
基金This research is supported by National Research Foundation of Korea(No:2019R1I1A2A03061067).
文摘Land-use and plant invasion influence biodiversity.Understanding the effects of land-use types and invasive plants on the ecosystem is crucial for better management and the development of strategic plans for increasing biodiversity in Jeju Island,Korea,a designated Biosphere Reserve by the United Nations Education,Scientific,and Cultural Organization.The effect of the most dominant invasive exotic species,Hypochaeris radicata,on the four land-use types of Jeju Island was investigated.Plant composition,soil characteristics,and plant diversity among four land-use types(cropland,green space,neglected land,and residential)were compared.Among the land-use types,croplands had the most diverse plant composition and the highest richness in exotic and native plant species.Croplands,such as tangerine orchards,which are widely distributed throughout Jeju Island,showed the highest plant diversity because of medium intensity disturbance caused by weed removal.The relative cover of H.radicata did not differ between land-use types.However,H.radicata invasion was negatively related with plant species richness,making this invasive species a threat to the biodiversity of native herbs present in land-use areas.H.radicata adapts to areas with a broad range of soil properties and a variety of land-use types.Therefore,it is crucial to monitor land-use types and patterns of plant invasion to guide the implementation of consistent management and conservation strategies for maintaining ecosystem integrity of the transformed habitat in Jeju Island.
基金Project(31300343)supported by the National Natural Science Foundation of ChinaProject(Y20160023)supported by Open Science Research Fund of State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Chinasupported by Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment,China
文摘This study aims to determine the differences in leaf functional traits and phenotypic plasticity of leaf functional traits between exotic and native Compositae plant species. Leaf width of exotic plants was significantly lower than that of native species. Leaf length, specific leaf area(SLA), single-leaf wet and dry weights, leaf moisture, and leaf thickness of exotic plants were also lower than those of native species but not significantly. The leaf shape index of exotic plants was higher than that of native species but not significantly. This implies that the relatively low leaf construction cost for exotic plants may play an important role in the success of their invasions. The higher leaf shape index and lower leaf width of exotic plants can enhance the efficiency of resource capture(especially sunlight capture) via adjustments to leaf shape and size, thereby increasing the survival of exotic plants. The plasticity indices of single-leaf wet weight and leaf thickness of exotic plants were significantly lower than those of native species. The lower phenotypic plasticity of single-leaf wet weight and leaf thickness of exotic plants may be the result of a cost to plasticity. That is, if the plasticity is too high, the fitness of plant species might be reduced sharply under unfavorable environments. Thus, lower plasticity of leaf functional traits may compensate for the negative impact of adverse environments and stabilize leaf construction costs for exotic plants. Moreover, reduced phenotypic plasticity might be one of the key competitive strategies by which exotic plants successfully invade new habitats. Overall, exotic plants did not always exhibit higher values of leaf functional traits or increased phenotypic plasticity of leaf functional traits compared with native species.
基金supported by the National Natural Science Foundation of China(Grant No.41776096).
文摘A saltmarsh has developed rapidly on the mudflat of Andong Shoal,in southern Hangzhou Bay,over the last decade since embankment.The saltmarsh vegetation changes are driven by both sediment dynamic conditions and the competition between the exotic species Spartina alterniflora(S.alterniflora) and the native species Scirpus mariqueter(S.mariqueter).This study attempted to investigate large-scale spatial variations in the exotic and native species,by analyzing and interpreting a time series(2016-2018) of high-resolution(less than 1 m) remote sensing images.The total area of the saltmarsh increased at a rate of 1.07 km^2/year,due to the accretion of the whole tidal flat.The spatial patterns revealed a new bimodal pattern for S.alterniflora invasion.S.alterniflora expanded over the upper to middle saltmarsh at a rate of1.68 km2/year.However,the S.alterniflora patches at the seaward edge expanded at a negative rate of-0.005 km^2/year,indicating a different pattern in competition:S.alterniflora had more advantages in the upper saltmarsh,while S.mariqueter had more advantages in the pioneer zone with low elevation.Consequently,S.alterniflora mainly established new habitats by invading S.mariqueter in the middle saltmarsh,but S.mariqueter occupied the bare mudflat for tradeoff.Our results aindicated that the interspecific competition result between S.alterniflora and S.mariqueter depended on elevation,and low elevation might create a favorable environment for S.mariqueter to win the competition with exotic species.This finding could be applied to future invasive species control and saltmarsh management.
基金supported by the National Natural Science Foundation of China (NSFC-DFG, 31861133016NSFC, 31970564)。
文摘Extensive exotic introgression could significantly enlarge the genetic distance of hybrid parental populations to promote strong heterosis.The goal of this study was to investigate whether genome-wide prediction can support pre-breeding in populations with exotic introgressions.We evaluated seed yield,seed yield related traits and seed quality traits of 363 hybrids of Brassica napus (AACC) derived from two parental populations divergent on massive exotic introgression of related species in three environments.The hybrids presented strong heterosis on seed yield,which was much higher than other investigated traits.Five genomic best linear unbiased prediction models considering the exotic introgression and different marker effects (additive,dominance,and epistatic effects) were constructed to test the prediction ability for different traits of the hybrids.The analysis showed that the trait complexity,exotic introgression,genetic relationship between the training set and testing set,training set size,and environments affected the prediction ability.The models with best prediction ability for different traits varied.However,relatively high prediction ability (e.g.,0.728 for seed yield) was also observed when the simplest models were used,excluding the effects of the special exotic introgression and epistasis effect by5-fold cross validation,which would simplify the prediction for the trait with complex architecture for hybrids with exotic introgression.The results provide novel insights and strategies for genome-wide prediction of hybrids between genetically distinct parent groups with exotic introgressions.
基金Supported by the Natural Science Foundation of Sichuan Education Committee under Grant No.08ZA038
文摘A two-dimensional Brans-Dicke star model with exotic matter and dark energy is studied in this paper,the field equation and balance equation are derived at finite temperature,the analytic solutions of these equations canbe used to calculate the mass of star.In addition,we find that star's mass has a minimum when matter state parameterγ→0.
文摘The alien halophilous Artemia species, Artemia franciscana, was found in Chengkou Saltern and Yangkou Saltern of Shandong Province, P.R. China. Although the indigenous parthenogenetic Artemia is detectable, the exotic species is dominant in both salterns. The cross-breeding tests between the exotic A. franciscana and 5 bisexual Artemia species were conducted. The results of hybridization and morphological observations on the exotic A. franciscana are briefly presented in this short communication.
基金Project supported by the National Natural Science Foundation of China (Grant No 10672147) and Natural Science Foundation of Zhejiang Forestry University, China (Grant No 2006FR035). Acknowledgments The authors are indebted to Professor Zhang J F for his helpful suggestions and fruitful discussions, and also express their sincere thanks to the editors and the anonymous referees for their constructive suggestions and kind help.
文摘Starting from the extended tanh-function method (ETM) based on the mapping method, the variable separation solutions of the (2+1)-dimensional asymmetric Nizhnik Novikov Veselov (ANNV) system are derived. By further study, we find that these variable separation solutions are seemingly independent of but actually dependent on each other. Based on the variable separation solution and by choosing appropriate functions, some novel and interesting interactions between special solitons, such as bell-like compacton, peakon-like compacton and compacton-like semifoldon, are investigated.
基金supported by Coordination for the Improvement of Higher Educational Personnel(CAPES)
文摘The control of exotic and invasive species in areas undergoing recovery is a challenge for ecological restoration and this problem may be even greater in urbanized areas. This study evaluated the seed bank and seed rain of a 5-year-old riparian forest located at the metropolitan region of Belo Horizonte in southeast Brazil, and verified changes over time in the abundance and species richness and whether planted species already were providing propagules to the site. At the forest, fifteen parcels of 100 m<sup>2</sup> were distributed randomly and soil samples were collected thrice (October 2011, March 2012 and July 2012) to evaluate the seed bank. Seed traps were installed in nine parcels to collect propagules over 1 year. Propagules were segregated and germinate at greenhouse. Species richness and abundance were estimated, and variance and similarity were quantified. In total, 86 species were recorded in the seed banks, 41.9% natives and 33.7% exotics, with the predominance of herbs (87.2%) and only 7% of trees. Species classified as weeds amounted to 52.3%. In the seed rain 642 seedlings germinated but they belonged to only 10 species, half of them were exotics. Regarding life forms, half of the species were arboreal and dominated the samples, highlighting the exotic species Melia azedarach. The species richness of the seed bank did not differ by season, unlike the seed rain which varied significantly by month. Seed bank and seed rain species had a very low floristic similarity with the list of planted species, suggesting that few planted trees had dispersed or were stocking propagules. Many non-planted species were recorded, mostly exotics and/or invasive that were probably derived from the surrounding urban matrix. These might interrupt the successional dynamics of the restoration forest and compromise the restoration process in the medium and long-terms. Our results highlight: (1) the importance of monitoring areas undergoing restoration; (2) that restoration methods and management actions directed to control exotic and invasive species are particularly important for sites in urban regions; and (3) the relevance of conserving forest fragments as sources of propagules for nearby areas.
基金The project supported by National Natural Science Foundation of China and the Special Research Fund for Doctor Programs of the Chinese Universities
文摘The newly observed D^*aj family containing D^*aj(2317), Daj(2460), and Daj(2632) attracts great interests. Determining their structures may be an important task for both theorists and experimentalists. In this work we use a non-relativistic model (the harmonic oscillator model) to evaluate the production rate of D^*aj (2317) from the decays of ψ(4415). For a comparison, we a/so employ the widely adopted heavy quark effective theory to repeat the calculation. We lind that the rate is sizable and may be observed at BES III and CLEO, if it is a p-wave excited state of Da(1968). Unfortunately, the other two members of the family cannot be observed through decays of charmonia, because of the constraints from the final state phase space.
文摘The idempotent semirings Rmax and Rmin play a crucial role in several areas of mathematics and their applications such as discrete mathematics, algebraic geometry, computer science, computer languages, linguistic problems, optimization theory, discrete event systems, fuzzy logics. In this paper we consider the expansion of the semirings Rmax and Rmin with residuals and describe how to use these expended semirings in public key cryptography.
基金supported by the National Natural Science Foundation of China(40272021)the Outstanding Young Teachers Project of China University of Geosciences(CUGQNL0319).
文摘Due to various courses of formation of zircons from kimbedites, different kinds of zircons can provide useful information about the mantle and the crystallization of kimberlites. We chose 9 typical ones out of 33 zircons from the Shengli- 1 kimberlite pipe in Mengyin County, Shandong Province to study their ages and formation by means of SHRIMP, CL, Raman spectroscopy, etc. The result shows that the ^207Pb/^206Pb ages of many zircons vary from 2567±13 Ma to 2636±42 Ma, which are close to the age of Archaean granitoid (2457.3±47 Ma) in the study area. The contents of U and Th in the samples are higher than those of zircons crystallized in kimbedite and vary from 89 to 398 ppm as well as from 10 to 283 ppm. Color zones are obvious in these samples under the CL. The inclusions are composed of feldspar, quartz, apatite, etc. The above results show that the zircon samples came from the crust of the earth, which means that the kimberlite magmas are contaminated by crustal substances. The position where a great deal of volatile escapes and even explodes during rapid rise of magmas is located at the boundary of the ancient basement and the Precambrian stratum.
基金supported by the Academy of Finland for the funding of the TAITATOO project
文摘Biodiversity assessment for tree species was conducted in three forest fragments ofthe Taita Hills, southeastern Kenya to compare species diversity between and within three exotic forest plantations of pine, eucalyptus, cypress and the indigenous forests. The study sites were: Ngangao (120 ha), Chawia (86 ha), and Mbololo (185 ha). A Y-plot design was used to sample 32 plots comprising of 65 subplots. At each subplot, all juvenile trees of 5 cm and above in diameter at breast height (DBH) were enumerated and recorded by species. Tree regeneration (seedlings and saplings) was tallied by species. The Shannon-Weiner Index was used to calculate species diversity and evenness. The derived Shannon’s indices were further converted into effective numbers to show the magnitude of differences in species biodiversities. To evaluate dif-ferences in species diversities, a one way ANOVA was conducted and to separate the means, Tukey's HSD and Duncan’s tests were used for even and uneven number of samples respectively. Jaccard’s similarity index was used to assess species similarities. There were more than 58 species whose stem densities varied between 10 and 2 000 trees per hectare.There were significant differences in species diversities between forest types and sites; the indigenous forests showed higher diversities than the exotic forests. Similarly, Chawia sites had higher species diversity than both Ngangao and Mbololo. Chawia also had a higher number of regen-erated species than the two other sites, including species such as Xymalos monospora, Rapanea melanophloeos, and Syzygium guineense, which are associated with low levels of disturbance. These findings indicate that the indigenous forest is more diverse in species as would be expected in the tropics. The high species diversity in Chawia could be accounted for by the higher levels of disturbance it underwent, unlike the two other sites. The regeneration of species associated with low levels of disturbance found in the exotic plots of Chawia show the likelihood of presence of long-term soil seed banks. The low regeneration in the exotics plots observed in Ngangao and Mbololo are likely due to the absence of seed banks since some of the plantations were established on bare land (in Ngango), or the inherent physiology (allelopathy) of some of species repelling the regeneration of others.
基金Sponsored by the National Natural Science Foundation of China(Grant No.51076066)
文摘A projectile with exotic wraparound wings( WAW) configuration is designed to improve the finstabilized projectile shooting quality. Two fin-stabilized projectiles with the same body with and without exotic WAW configuration are simulated numerically by applying the Roe scheme. The shear-stress transport turbulence models and the lower-upper symmetric Gauss-Seidel implicit method are used to solve 3D Reynoldsaveraged Navier—Stokes equations. The differences in aerodynamic coefficients and aerodynamic characteristics of the projectiles when the Mach number varies from 0. 35 to 0. 95 are obtained,and the cause of these differences is analyzed. The calculation results indicate that the lift-to-drag ratio of the projectile significantly increases,the rolling moment decreases,and the position of the pressure center of the projectile shows relatively small changes when the exotic WAW configuration is used. Therefore,this projectile can obviously reduce rolling effect,enlarge range and improve flying stability.
文摘The genetic diversity and relationships of seven Chinese indigenous pig breeds (Meishan, Erhualian, Hezuo, Bamei, Qingping, Tongcheng, and Huainan) and three exotic pig breeds (Large White, Landrace, and Duroc) were analyzed using the DNA differential display technique by means of eight primer combinations. A total of 123 reproducible bands were used to calculate mean Nei's gene diversity, and mean Shannon's information index for each pig population. Based on these the Nei's standard genetic identity and distance were estimated, which was used to construct a dendrogram tree for the 10 pig breeds. The experimental results obtained and the method used in this study for evaluating the genetic diversity and relationships of pigs were also discussed.
基金Supported by Ningbo Natural Science Foundation(2017A610074)
文摘An investigation was carried out in wharves, inspection yards, processing plants in Beilun Port and the surrounding areas. Five kinds of exotic harmful weeds were discovered and collected, and they were described and analyzed.
文摘Kappaphycus alvarezii, a red macroalgal species native to South-East Asia, has been introduced for commercial purposes to more than 20 tropical countries. In 2000, Panama became the first Central American country to develop its cultivation following a pilot-commercial approach. Twelve years after his introduction to Panama, the species was found to the south Caribbean coast. In the present study, we report the first record of K. alvarezii collected in Costa Rican waters. Genetic identification of the sample was performed with the mitochondrial marker cox2-cox3 intergenic spacer, and phylogenetic analyses showed that the sample collected grouped into a monophyletic clade with GenBank sequences from Vietnam, Indonesia, the Philippines, Brazil and Venezuela. Here we provide further description of its position with respect to other strains of K. alvarezii collected globally. Its possible route of entry to the Caribbean coast of Costa Rica is discussed. To date, it is possible to locate K. alvarezii in different areas away from the production fields which show its dispersion, and that the species is expanding;but more studies are needed to know the phase of colonization in which it is located because it is a combination of natural factors and human exploitation that determines the invasive potential of the species.
文摘Forested aquatic streams depend heavily on forest canopy input. This input is a primary resource for the macroinvertebrate fauna. As a result, changes in the canopy impact the aquatic ecosystem. The focus of this study was to identify leaf degradation rates to determine resource availability for invertebrate communities. Specifically, leaf degradation rates were determined for oak, poplar, maple and kudzu. Oak, poplar, and maple are established stream canopy vegetation while kudzu is an invasive species. By comparing leaf degradation rates of native vs. exotic leaves, it provides an insight to changes in community structure. Furthermore, these changes in the plant canopy biodiversity have long-term implications for stream health.
文摘The carbon (C) stored in the living biomass of trees is typically the largest C pool of the forest ecosystem which is directly impacted by deforestation and degradation (Ensslin et al, 2015). The relationships between diversity, biomass and C stocks at varied altitudes can have crucial implications for the management and conservation of C sinks. The study was conducted at Mbeya One ward lying between Mporoto and Rungwe forest reserves in Mbeya rural district, in the Southern highlands of Tanzania. The main objective was (1) to assess the indigenous tree biomass variation between Mporoto and Rungwe forest reserves (2) to assess the exotic tree biomass variation between the two forest reserves and (3) to assess the human implication on aboveground biomass variation between the two forest reserves. The findings indicated the significant decreased in indigenous trees biomass in residential and crop land areas with a hasty increase in biomass when reaching Mporoto forest reserve indicating little human encroachment in the forest reserve. There was the same trend towards Rungwe forest reserve however in that side, there was a slight increase in indigenous tree biomass when reaching forest reserve which is the sign of human encroachment in the forest reserve. The main human activities encroaching the reserve were;timber harvesting and commercial exotic trees planting (especially the commercial trees, Pinus patula sp). However, the trend was opposite for the exotic trees especially for Pinus patula and Eucalyptus sp in the study area. Hence the study concludes that there is a significant variation between indigenous and exotic trees in the study area, hence the variation in the tree biomass (fig 2&3). There is also a massive human encroachment for indigenous trees clearance in expense of exotic trees plantations towards and in Rungwe forest reserve. Therefore, the study would like to call for an urgent intervention especially in the east side of the study area (Rungwe forest reserve) stopping exotic tree plantation penetrating into the forest reserve which intensify cutting down of indigenous trees in the forest reserves plummeting aboveground biomass and escalating carbon emissions in the atmosphere while jeopardizing the natural forest ecosystem services to the communities. Conservation education should be emphasized in the study area to local communities, exotic trees plantations owners and other relevant stakeholders.
文摘The hematological and serum biochemical profiles of apparently healthy exotic breed of dogs in Jos, Plateau state, Nigeria was studied in this research. One hundred and seven exotic breed of dogs were examined from October</span><span style="font-family:""> - </span><span style="font-family:"">December, 2018. The results from physical, clinical examinations and parasitological examinations were used to determine ap</span><span style="font-family:Verdana;"></span><span style="font-family:"">parently healthy exotic breed of dogs which were used in this study. The parameters measured were rectal temperature, parasitaemia, hematology which included red blood cells count, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin and hemoglobin content;total white blood cell count, including eosinophils, neutrophils, lymphocytes, monocytes, granulocytes counts, and platelets;serum biochemical parameters also included Aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total proteins, albumin, globulin, blood urea nitrogen, creatinine, cholesterol and triglyceride, using standard methods. Data generated from the study were statistically analyzed using students t</span><span style="font-family:"">-</span><span style="font-family:"">test one-way analysis of variance while the level of significance </span><span style="font-family:"">was </span><span style="font-family:"">measured at p < 0.05. From this study, hematological and serum biochemical values were comparable to and not different from those reported for dogs in available literature, but the upper and lower reference limits (minimum and maximum values) were different for most parameters. Sex-related significant difference (p < 0.05) occurred only in WBC and total protein while age-related significant difference occurred only in total protein and urea level. Breed affected the MCHC and total bilirubin level which was evident in higher MCHC level in Neapolitan mastiff than Alsatian breed while total bilirubin was higher in Alsatian breed than Bull mastiff (p < 0.05). The present study has presented preliminary information on the range of hematological and serum biochemistry profile of exotic breed of dogs in Jos, Plateau state, Nigeria which may be useful to biomedical researchers and veterinary clinicians.
文摘Imagination of China in Western movies presented by“exoticism”is no longer the dualism of“backward and traditional Oriental”but“advanced and modern Western”.Skyfall released recently has shown on the one hand a“modern”contemporary China,on the other hand,a cultural concept of“isolated relics of traditional China and ruins of modern China”.In Indiana Jones and the Temple of Doom,China is imagined to be a mixed land of the new and old,the Oriental and Western based on the comparison between China and India,which is considered to be primitive,traditional and brutal.Mission:Impossible III presents three sides of Shanghai in a mean way:“skyscraper”,“old-style apartment”and“ancient town”.Here we could see,the images of China in Western movies are comprehensive and complicated,conveying divergent cultural views.Moreover,increasing Chinese market constitutes a crucial reason why Western movies intend to hide their political bias but adopt a flattery attitude to Chinese culture.