A developmentally retarded mutant (drm1) was identified from ethyl methanesulfonate (EMS)-mutagenized M2 seedsin Columbia (Col-0) genetic background. The drm1 flowers 109 d after sowing, with a whole life cycle of abo...A developmentally retarded mutant (drm1) was identified from ethyl methanesulfonate (EMS)-mutagenized M2 seedsin Columbia (Col-0) genetic background. The drm1 flowers 109 d after sowing, with a whole life cycle of about 160 d.It also shows a pleiotropic phenotype, e.g., slow germination and lower germination rate, lower growth rate, curlingleaves and abnormal floral organs. The drm1 mutation was a single recessive nuclear mutation, which was mapped tothe bottom of chromosome 5 and located within a region of 20-30 kb around MXK3.1. There have been no mutantswith similar phenotypes reported in the literature, suggesting that DRM1 is a novel flowering promoting locus. Thefindings that the drm1 flowered lately under all photoperiod conditions and its late flowering phenotype was significantlyrestored by vernalization treatment suggest that the drm1 is a typical late flowering mutant and most likely associatedwith the autonomous flowering pathway. The conclusion was further confirmed by the revelation that the transcriptlevel of FLC was constantly upregulated in the drm1 at all the developmental phases examined, except for a very earlystage. Moreover, the transcript levels of two other important repressors, EMF and TFL1, were also upregulated in thedrm1, implying that the two repressors, along with FLC, seems to act in parallel pathways in the drm1 to regulateflowering as well as other aspects of floral development in a negatively additive way. This helps to explain why the drm1exhibits a much more severe late-flowering phenotype than most late-flowering mutants reported. It also implies that theDRM1 might act upstream of these repressors.展开更多
[Objective] The aim of this study was to compare the drought resistance difference of the main Capsicum annuum cultivars planted in Wenshan Prefecture of Yunnan Province. [Method] The total anthocyanin, soluble sugar,...[Objective] The aim of this study was to compare the drought resistance difference of the main Capsicum annuum cultivars planted in Wenshan Prefecture of Yunnan Province. [Method] The total anthocyanin, soluble sugar, soluble protein and free proline contents of the leaves of the five main C. annuum cultivars planted in Wenshan Prefecture, i.e., ZSZ75-1, ZSZ49-1-1, 12WS-18-1, 12ZH01 and ZS130, under the drought stress simulated by PEG-6000 were studied by using spectrophotometry, and the total osmoregulation abilities of the leaves were evaluated by using subordinate function. [Result] Under the drought stress simulated by PEG-6000, the total anthocyanin contents of the veins, mesophylls and whole leaves of the five cultivars were all as: ZSZ75-1〉ZSZ49-1-1〉12WS-18-1〉12ZH01〉ZS130, the soluble sugar contents as: 12ZH01 〉12WS-18-1 〉ZS130〉ZSZ49-1-1 〉ZSZ75-1, the soluble protein contents as: ZSZ75-1〉12ZH01〉ZSZ49-1-1〉12WS-18-1〉ZS130, and the free proline contents as: ZS130〉ZSZ75-1 〉12WS-18-1 〉ZSZ49-1-1 〉12ZH01. Furthermore, the differences among the total anthocyanin contents of the veins, mesophylls and whole leaves of the five cultivars all reached the extremely significant levels, whereas the differences among the contents of the soluble sugar, soluble protein and free proline did not reach the significant levels, the correlation degrees among the contents of the total anthocyanin, soluble sugar, soluble protein and free proline of different cultivars were also inconsistent, and the total osmoregulation abilities of the five cultivar leaves were as: ZSZ75-1 〉7SZ49-1-1 〉12WS-18-1 〉ZS130〉12ZH01. [Conclusion] The anthocyanin accumulation in the specific organs of the five C. annuum cultivars in Wenshan Prefecture is beneficial to the strengthening of the leaf osmoregulation abilities under drought stress, favoring the drought tolerance of the cultivars.展开更多
In this study, 9 main traits of 774 spring wheat landraces in Tibet were investigated and analyzed. The results show that spring wheat landraces in Tibet have high plant height (with an average of 126.1 cm) and long...In this study, 9 main traits of 774 spring wheat landraces in Tibet were investigated and analyzed. The results show that spring wheat landraces in Tibet have high plant height (with an average of 126.1 cm) and long growth period (with an average of 135.2 d), with an average spike length of 9.5 cm, average effective tiller number per plant of 5.9, average spikelet number per spike of 19.9, average kernel number per spikelet of 3.5, average spikelet number per spike of 51.8, aver- age kernel weight per spike of 2.0 g, and average 1 000-grain weight of 38.1 g. Specifically, kernel number per spikelet of 2 landraces is larger than 6.0, spikelet number per spike of 2 landraces is larger than 100, kernel weight per spike of 2 landraces is larger than 4.0 g, 1 000-grain weight of 11 tandraces is larger than 50 g. There is abundant genetic diversity in those traits except in growth period, and the coefficient variation of 9 traits is in a decreasing order of effective tiller number per plant 〉 kernel weight per spike 〉 kernel number per spike 〉 spike length 〉 kernel number per spikelet 〉 1 000-grain weight 〉 plant height 〉 spikelet number per spike 〉 growth period. There is different relevance among different traits. Growth period is extremely significantly positively related to yield traits; grain number traits are extremely significantly positively relative to plant height and spike length, but ex- tremely significantly negatively relative to effective tiller number per plant; kernel number per spike is extremely significantly positively relative to kernel weight per spike, but extremely significantly negatively related to 1 000-grain weight; 1 000-grain weight is extremely significantly positively related to kernel weight per spike. Based on principal component analysis, these 9 traits could be included by 5 principal com- ponents (grain number, grain weight, spike length, tiller number and growth period). According to the comprehensive evaluation values of these five principal components, 50 landraces including ZM019573, ZM019849, ZM019730, ZM018745, ZM019657, ZM019891, ZM020533, ZM018508, 7M019074 and ZM020026 have good performance.展开更多
The survival chance of epiphytie orchids today not only depends on the natural site conditions required by the orchids but also on anthropogenic changes in site conditions. This study answers two questions: (1) Wha...The survival chance of epiphytie orchids today not only depends on the natural site conditions required by the orchids but also on anthropogenic changes in site conditions. This study answers two questions: (1) What is the ecological niche of the different epiphytic orchid species? (2) What are the ecological factors that threaten epiphytic orchid's population under anthropogenic disturbances? Our study area was the Kathmandu valley, Nepal, with its subtropical forest. We established 156 systematically selected sampling points in the Kathmandu area covering different types of ecosystems under human impacts such as densely populated area, agricultural land, mixed agricultural and settled area, old tree patches, and a natural forest in a national park. The ecological niche of the orchid species was analyzed with a principal component analysis (PCA). The correlations between the different site factors were statistically significant. Spearman's rank correlation matrices showed that the variables land-use intensities with altitude, and height with diameter in breast height (dbh) of host had the highest significant positive correlation coefficient (0.67 and 0.64 respectively). On the other hand, host bark pH and altitude as well as land use had a significantly strong negative correlation coefficient (-0.80 and -0.61, respectively). Different epiphytic orchid species interact differently with the given set of environmental factors: for occurrence of Vanda cristata there is no single environmental factor of special influence, while for Rhynehostylis retusa high bark pH and high light availability are important. First two axis of the PCA explained more than 50% of the total variance. Most orchid species occupy a specific, narrow niche in this ecological space. The main causes of anthropogenie influence of orchid population in the Kathmandu Valley are loss of adequate host trees (species and size) and increasing air pollution, resulting in increasing host bark pH.展开更多
The Fort Worth (Texas) exhibition/publication Poussin: The Early Years in Rome: The Origins of French Classicism (1988) proved to be a seminal event in Poussin scholarship. Over 200 works were put on display at ...The Fort Worth (Texas) exhibition/publication Poussin: The Early Years in Rome: The Origins of French Classicism (1988) proved to be a seminal event in Poussin scholarship. Over 200 works were put on display at the Kimbell Art Museum that revealed the formative years in the French painter's works. The drawings and paintings confirmed Poussin as the leading classicist in 17th century French art and expanded our appreciation of the flexibility of the artist to illustrate mythological narratives. Previous positions on the artist such as Anthony Blunt's, who viewed the painter as a strict classicist without a major interest in color, are now reevaluated after the Fort Worth show. The influence of the Venetian school, especially the work of Titian, emerged stronger into Poussin's oeuvre. It was under the classicist umbrella that the romantic verse of Ovid and the sensual color of Titian became forged into the pictures of Roman mythology. The leading source of inspiration for this work would be Ovid's Metamorphoses where figures change into flowers made timeless by the painter's brush. Just as the poet varied the structure of his narrative presentation, so too did the painter expand his approach to depicting scenes of change in a variety of formats. A key work for Poussin in these stories of change would be the Kingdom of Flora (1631) where Ovidian tales are posed as an eternal spring where the goddess distributes the flowers of the collective narrative in an olive green chitin. This paper will contribute to the position of viewing Poussin's art under a wider vision of classicism where flexible narrative design and sensuous color fit the mission to make art noble and timeless.展开更多
Based on remote sensing technique,using 1990's Landsat TM data and 2000's Landsat ETM data,the authors conducts the comparative study of mainstream area of Songhua River by means of human-computer inter-action...Based on remote sensing technique,using 1990's Landsat TM data and 2000's Landsat ETM data,the authors conducts the comparative study of mainstream area of Songhua River by means of human-computer inter-action method.The results show that the area of Songhua River mainstream was 738 102 km 2 in 1990,and was 810.451 km 2 in 2000.From 1990 to 2000,the increased area of river mainstream is up to 72.349 km2 due to soil erosion and water loss.Meanwhile,the dynamic changes of surrounding vegetation cover are also studied.It is estimated that the trend of surrounding soil erosion and water loss of Songhua River mainstream becomes worse in Jilin Province.展开更多
Oppressed by sexism from Chinese culture and racism in American society, Kingston modified the Chinese folktale image HUA Mu-lan by endowing her with strength and power. From the new image of the Swordswoman, we can s...Oppressed by sexism from Chinese culture and racism in American society, Kingston modified the Chinese folktale image HUA Mu-lan by endowing her with strength and power. From the new image of the Swordswoman, we can see the feminist ideas in the author's mind and her hatred of unfair treatment in America. This paper mainly talks about how and why Kingston modifies the image and culture integrity rather than conflict in her mind.展开更多
Giovanni Antonio Bazzi (1477-1549), also known as I1 Sodoma, was a Milanese painter who developed his mature style in Siena during the early Cinquecento. Between 1505 and 1510, under the tutelage of the Chigi and Pe...Giovanni Antonio Bazzi (1477-1549), also known as I1 Sodoma, was a Milanese painter who developed his mature style in Siena during the early Cinquecento. Between 1505 and 1510, under the tutelage of the Chigi and Petrucci families, Bazzi depicted mythological paintings focusing on the personifications of love both terrestrial and celestial. This paper looks at two such works. In one, there hangs on a sycamore tree a classical cartello with the Latin inscription Celestes, meaning celestial or heavenly, providing the title for the painting Amore Celeste (Celestial Love, Figure 3). A woman, as the personification of love, stands in front of two altars. She ignites one urn with fire and at the same time pours water over another burning fire. In the second work, a tondo with the theme of Terrestrial Love and Celestial Love, Bazzi considered the mischievousness of Venus' children Eros and Anteros (Figure 12). These paintings are mythological and poetical delights with complex symbolism, here analyzed in terms of their iconography in relation to classical influences and Renaissance Neoplatonic love or furor divinus. The paradoxical quest of Renaissance Neoplatonic love was to fuse pagan love with Christian love. For the humanists of the time (Bembo, Colonna, Poliziano, Ficino and Pico) this moral dilemma was a philosophical puzzle, but for artists (Botticelli, Nicoletto da Modena, Pinturicchio and Bazzi) the theme was a pictorial challenge.展开更多
Saffron (Crocus sativus L.) always is grown for using its flowers in nutrient industry, color industry and healthy compounds due to its flowers and specially stigmas. Because of its expensive flowers, surveying and ...Saffron (Crocus sativus L.) always is grown for using its flowers in nutrient industry, color industry and healthy compounds due to its flowers and specially stigmas. Because of its expensive flowers, surveying and recognizing on effective genes for flowering is very important and its results can help us to control rate and timing of flowering at an early stage of flowering. The gene and gene state meant Pistillata like MADS box (PIC2) were surveyed for recognizing its molecular mechanism. The molecular sequence at the genes has high similarity to members of family MADS that is a factor for controls of protein at flowering stage. PIC2 gene was studied by bioinforrnatics resources. Primers were designed for replicating the gene and DNA and RNA were extracted from saffron's leaves. The gene's eDNA was built by recopying enzyme and used such a pattern for replicating gene PIC2 at polymerase chain reactions (PCR). Segments were replicated such 900 eDNA pair-nucleotides and a segment such 2,100 of DNA's pair-nucleotides. The gene codes a protein that was composed of 210 amino acids that has MADS sequence box. Analysis of protein's molecular structure and homological modeling of the protein indicated that it has a regular structure.展开更多
We studied distribution and site conditions of epiphytic orchids in a gradient of human interference in Kathmandu valley, central Nepal. The aim was to understand the recent distribution pattern of epiphytic orchids, ...We studied distribution and site conditions of epiphytic orchids in a gradient of human interference in Kathmandu valley, central Nepal. The aim was to understand the recent distribution pattern of epiphytic orchids, with respect to (i) the micro-site conditions and (ii) the type and intensity of land use. The occurrence of epiphytic orchids was recorded for a grid with 1.5 km cell size. The cells represent different types and intensities of human impact. Site factors such as bark rugosity, bark pH, diameter at breast height (dbh; 1.3 m) of host trees, exposure to wind and sunlight intensity were recorded. With regard to the species richness and abundance of epiphytic orchids, we compared different human impact categories from very strong human impact (settlement area) to very low human impact (national park). Remote sensing was used for a supervised classification of land cover. Ficus religiosa turned out to be the most important host species for orchids in urban areas, while Schima wallichii and Alnus nepalensis significantly host orchids in the other categories. Both species richness and abundance of epiphytic orchids were significantly higher under very low human impact (forest in national park) and also some remaining patches of primary forest than the other regions. Micro-climate is crucial for orchid populations. Host bark pH, bark rugosity, sunlight intensity and host exposure were significantly different for all human impact categories in order to harbour epiphytic orchid species. Habitats with a mixture of mature trees are suitable and essential for the conservation of viable populations of epiphytic orchids in settled areas. The study reveals that to improve the population size of orchids it is essential for future urban forestry to: (i) Protect old trees as carriers of existing epiphytic orchid diversity, (ii) protect medium old trees to ensure that they may become old trees, (iii) plant new host trees for the future, (iv) plant in groups instead of single isolate trees. Trees should especially be planted in areas where orchids still exist to provide more trees for orchid population enlargement (e.g. along riparian system). Native species should be favoured; the pool of such native host species is wide.展开更多
Spark discharge plasma synthetic jets(SPJs) have been used for the active flow control study on an NACA 0021 straight-wing model in a wind tunnel. The model forces and moments were measured using a six-component sting...Spark discharge plasma synthetic jets(SPJs) have been used for the active flow control study on an NACA 0021 straight-wing model in a wind tunnel. The model forces and moments were measured using a six-component sting balance at a 20 m/s wind speed. The aim was to explore the SPJ's effect on airfoil aerodynamic by examining SPJ generators' position along the chordwise and the jet flow direction about the chord. Near the wing leading edge, two SPJ generators raised the stall angle by 2° and increased the maximum lift coefficient by 9%. The drag coefficient was decreased by 33.1%, and the lift-drag ratio was increased by 104.2% at an angle of attack above 16°. The rolling-moment coefficient was modified by 0.002, and the yawing-moment coefficient was changed by 0.0007 at angles of attack in the range of 0°–16°. The results showed that SPJs can control wing aerodynamic forces at a high angle of attack and moments at a low angle of attack.展开更多
It is generally believed that physical heterogeneity in common resource or evolutionary restraint can sufficiently prevent direct conflict between host and symbionts in mutualism systems. Our data on fig/fig wasp reci...It is generally believed that physical heterogeneity in common resource or evolutionary restraint can sufficiently prevent direct conflict between host and symbionts in mutualism systems. Our data on fig/fig wasp reciprocal mutualism(Ficus racemosa), however, show that structural barriers of female flowers or genetic constraints of pollinators previously hypothesized exist, but cannot sufficiently maintain the mutualism stability. The results show that a positive relationship between seed and wasp production could be maintained in warm season, which might be because of density dependence restraint among foundresses and their low oviposition and pollination efficiency, keeping common resource(female flowers) utilization unsaturated. Whilst, a negative correlation between wasp offspring and viable seed production was also observed in cold season, which might be that the increased oviposition and pollination efficiency maximized the common resource utilization. The fitness trade-off between fig and pollinator wasps is greatly affected by environmental or ecological variations. The local stability might result from temporal low exploitation efficiency of pollinators together with interference competition among pollinators. We suggest that host repression through the active regulation of bract closure, which can create interference competition among the foundresses and prevent extra more foundresses sequential entry in fruit cavities, would help the figs avoiding the cost of over-exploitation. This essentially takes the same role as sanctioning of cheating or competitive behaviors.展开更多
Host-mediated effects on hemiparasitic mistletoes were hypothesized to contribute to mistletoes reproductive phenological asynchrony,thus providing a longer period of food supply to its mutualistic pollinators and dis...Host-mediated effects on hemiparasitic mistletoes were hypothesized to contribute to mistletoes reproductive phenological asynchrony,thus providing a longer period of food supply to its mutualistic pollinators and dispersers.However,studies with empirical data interrogating this hypothesis are lacking.Weekly monitoring of flowering and fruiting patterns on a generalist mistletoe Dendrophthoe pentandra(Loranthaceae)was conducted for two consecutive years in tropical Xishuangbanna,Southwest China.We examined whether flowering and fruiting patterns were seasonal,quantified the degree of stagger within D.pentandra populations and determined the factors influencing the first flowering date(FFD)of D.pentandra.Furthermore,the effect of change in the number of host species on reproductive phenological asynchrony of mistletoe was examined.We found that(i)both flowering and fruiting exhibited unimodal peaks in the two consecutive years of the study;(ii)the FFD was significantly influenced by crown area of mistletoe and light,such that clump with larger crown and more light exposure had an earlier FFD and longer flowering and fruiting durations;(iii)different host species had a significant impact on the phenology of mistletoes.However,contrary to our hypothesis,the number of host species did not significantly change the asynchrony of reproductive phenology of mistletoe.Therefore,these results suggest that alternative hypotheses are needed to interpret the ecological significance of the number of host species and phenological asynchrony of generalist mistletoes.展开更多
文摘A developmentally retarded mutant (drm1) was identified from ethyl methanesulfonate (EMS)-mutagenized M2 seedsin Columbia (Col-0) genetic background. The drm1 flowers 109 d after sowing, with a whole life cycle of about 160 d.It also shows a pleiotropic phenotype, e.g., slow germination and lower germination rate, lower growth rate, curlingleaves and abnormal floral organs. The drm1 mutation was a single recessive nuclear mutation, which was mapped tothe bottom of chromosome 5 and located within a region of 20-30 kb around MXK3.1. There have been no mutantswith similar phenotypes reported in the literature, suggesting that DRM1 is a novel flowering promoting locus. Thefindings that the drm1 flowered lately under all photoperiod conditions and its late flowering phenotype was significantlyrestored by vernalization treatment suggest that the drm1 is a typical late flowering mutant and most likely associatedwith the autonomous flowering pathway. The conclusion was further confirmed by the revelation that the transcriptlevel of FLC was constantly upregulated in the drm1 at all the developmental phases examined, except for a very earlystage. Moreover, the transcript levels of two other important repressors, EMF and TFL1, were also upregulated in thedrm1, implying that the two repressors, along with FLC, seems to act in parallel pathways in the drm1 to regulateflowering as well as other aspects of floral development in a negatively additive way. This helps to explain why the drm1exhibits a much more severe late-flowering phenotype than most late-flowering mutants reported. It also implies that theDRM1 might act upstream of these repressors.
基金Supported by Foreign Cooperation Project of Science and Technology of Yunnan Province(2015IC057)Province-strengthening Project via Science and Technology Innovation of Yunnan(2015AB011)Fund of Wenshan Academy of Agricultural Sciences(HZ2015-01)~~
文摘[Objective] The aim of this study was to compare the drought resistance difference of the main Capsicum annuum cultivars planted in Wenshan Prefecture of Yunnan Province. [Method] The total anthocyanin, soluble sugar, soluble protein and free proline contents of the leaves of the five main C. annuum cultivars planted in Wenshan Prefecture, i.e., ZSZ75-1, ZSZ49-1-1, 12WS-18-1, 12ZH01 and ZS130, under the drought stress simulated by PEG-6000 were studied by using spectrophotometry, and the total osmoregulation abilities of the leaves were evaluated by using subordinate function. [Result] Under the drought stress simulated by PEG-6000, the total anthocyanin contents of the veins, mesophylls and whole leaves of the five cultivars were all as: ZSZ75-1〉ZSZ49-1-1〉12WS-18-1〉12ZH01〉ZS130, the soluble sugar contents as: 12ZH01 〉12WS-18-1 〉ZS130〉ZSZ49-1-1 〉ZSZ75-1, the soluble protein contents as: ZSZ75-1〉12ZH01〉ZSZ49-1-1〉12WS-18-1〉ZS130, and the free proline contents as: ZS130〉ZSZ75-1 〉12WS-18-1 〉ZSZ49-1-1 〉12ZH01. Furthermore, the differences among the total anthocyanin contents of the veins, mesophylls and whole leaves of the five cultivars all reached the extremely significant levels, whereas the differences among the contents of the soluble sugar, soluble protein and free proline did not reach the significant levels, the correlation degrees among the contents of the total anthocyanin, soluble sugar, soluble protein and free proline of different cultivars were also inconsistent, and the total osmoregulation abilities of the five cultivar leaves were as: ZSZ75-1 〉7SZ49-1-1 〉12WS-18-1 〉ZS130〉12ZH01. [Conclusion] The anthocyanin accumulation in the specific organs of the five C. annuum cultivars in Wenshan Prefecture is beneficial to the strengthening of the leaf osmoregulation abilities under drought stress, favoring the drought tolerance of the cultivars.
基金Supported by Special Foundation for Biological Germplasm Resources Innovation&Functional Gene Discovery and Utilization of Xinjiang Production and Construction Corps(2012BB047)"12th Five-Year"Breeding Project of Xinjiang Production and Construction Corps(2011BA002)Fund from Key Laboratory for Cereal Quality Research and Genetic Improvement of Xinjiang Production and Construction Corps(CQG2012-XJ01)
文摘In this study, 9 main traits of 774 spring wheat landraces in Tibet were investigated and analyzed. The results show that spring wheat landraces in Tibet have high plant height (with an average of 126.1 cm) and long growth period (with an average of 135.2 d), with an average spike length of 9.5 cm, average effective tiller number per plant of 5.9, average spikelet number per spike of 19.9, average kernel number per spikelet of 3.5, average spikelet number per spike of 51.8, aver- age kernel weight per spike of 2.0 g, and average 1 000-grain weight of 38.1 g. Specifically, kernel number per spikelet of 2 landraces is larger than 6.0, spikelet number per spike of 2 landraces is larger than 100, kernel weight per spike of 2 landraces is larger than 4.0 g, 1 000-grain weight of 11 tandraces is larger than 50 g. There is abundant genetic diversity in those traits except in growth period, and the coefficient variation of 9 traits is in a decreasing order of effective tiller number per plant 〉 kernel weight per spike 〉 kernel number per spike 〉 spike length 〉 kernel number per spikelet 〉 1 000-grain weight 〉 plant height 〉 spikelet number per spike 〉 growth period. There is different relevance among different traits. Growth period is extremely significantly positively related to yield traits; grain number traits are extremely significantly positively relative to plant height and spike length, but ex- tremely significantly negatively relative to effective tiller number per plant; kernel number per spike is extremely significantly positively relative to kernel weight per spike, but extremely significantly negatively related to 1 000-grain weight; 1 000-grain weight is extremely significantly positively related to kernel weight per spike. Based on principal component analysis, these 9 traits could be included by 5 principal com- ponents (grain number, grain weight, spike length, tiller number and growth period). According to the comprehensive evaluation values of these five principal components, 50 landraces including ZM019573, ZM019849, ZM019730, ZM018745, ZM019657, ZM019891, ZM020533, ZM018508, 7M019074 and ZM020026 have good performance.
文摘The survival chance of epiphytie orchids today not only depends on the natural site conditions required by the orchids but also on anthropogenic changes in site conditions. This study answers two questions: (1) What is the ecological niche of the different epiphytic orchid species? (2) What are the ecological factors that threaten epiphytic orchid's population under anthropogenic disturbances? Our study area was the Kathmandu valley, Nepal, with its subtropical forest. We established 156 systematically selected sampling points in the Kathmandu area covering different types of ecosystems under human impacts such as densely populated area, agricultural land, mixed agricultural and settled area, old tree patches, and a natural forest in a national park. The ecological niche of the orchid species was analyzed with a principal component analysis (PCA). The correlations between the different site factors were statistically significant. Spearman's rank correlation matrices showed that the variables land-use intensities with altitude, and height with diameter in breast height (dbh) of host had the highest significant positive correlation coefficient (0.67 and 0.64 respectively). On the other hand, host bark pH and altitude as well as land use had a significantly strong negative correlation coefficient (-0.80 and -0.61, respectively). Different epiphytic orchid species interact differently with the given set of environmental factors: for occurrence of Vanda cristata there is no single environmental factor of special influence, while for Rhynehostylis retusa high bark pH and high light availability are important. First two axis of the PCA explained more than 50% of the total variance. Most orchid species occupy a specific, narrow niche in this ecological space. The main causes of anthropogenie influence of orchid population in the Kathmandu Valley are loss of adequate host trees (species and size) and increasing air pollution, resulting in increasing host bark pH.
文摘The Fort Worth (Texas) exhibition/publication Poussin: The Early Years in Rome: The Origins of French Classicism (1988) proved to be a seminal event in Poussin scholarship. Over 200 works were put on display at the Kimbell Art Museum that revealed the formative years in the French painter's works. The drawings and paintings confirmed Poussin as the leading classicist in 17th century French art and expanded our appreciation of the flexibility of the artist to illustrate mythological narratives. Previous positions on the artist such as Anthony Blunt's, who viewed the painter as a strict classicist without a major interest in color, are now reevaluated after the Fort Worth show. The influence of the Venetian school, especially the work of Titian, emerged stronger into Poussin's oeuvre. It was under the classicist umbrella that the romantic verse of Ovid and the sensual color of Titian became forged into the pictures of Roman mythology. The leading source of inspiration for this work would be Ovid's Metamorphoses where figures change into flowers made timeless by the painter's brush. Just as the poet varied the structure of his narrative presentation, so too did the painter expand his approach to depicting scenes of change in a variety of formats. A key work for Poussin in these stories of change would be the Kingdom of Flora (1631) where Ovidian tales are posed as an eternal spring where the goddess distributes the flowers of the collective narrative in an olive green chitin. This paper will contribute to the position of viewing Poussin's art under a wider vision of classicism where flexible narrative design and sensuous color fit the mission to make art noble and timeless.
文摘Based on remote sensing technique,using 1990's Landsat TM data and 2000's Landsat ETM data,the authors conducts the comparative study of mainstream area of Songhua River by means of human-computer inter-action method.The results show that the area of Songhua River mainstream was 738 102 km 2 in 1990,and was 810.451 km 2 in 2000.From 1990 to 2000,the increased area of river mainstream is up to 72.349 km2 due to soil erosion and water loss.Meanwhile,the dynamic changes of surrounding vegetation cover are also studied.It is estimated that the trend of surrounding soil erosion and water loss of Songhua River mainstream becomes worse in Jilin Province.
文摘Oppressed by sexism from Chinese culture and racism in American society, Kingston modified the Chinese folktale image HUA Mu-lan by endowing her with strength and power. From the new image of the Swordswoman, we can see the feminist ideas in the author's mind and her hatred of unfair treatment in America. This paper mainly talks about how and why Kingston modifies the image and culture integrity rather than conflict in her mind.
文摘Giovanni Antonio Bazzi (1477-1549), also known as I1 Sodoma, was a Milanese painter who developed his mature style in Siena during the early Cinquecento. Between 1505 and 1510, under the tutelage of the Chigi and Petrucci families, Bazzi depicted mythological paintings focusing on the personifications of love both terrestrial and celestial. This paper looks at two such works. In one, there hangs on a sycamore tree a classical cartello with the Latin inscription Celestes, meaning celestial or heavenly, providing the title for the painting Amore Celeste (Celestial Love, Figure 3). A woman, as the personification of love, stands in front of two altars. She ignites one urn with fire and at the same time pours water over another burning fire. In the second work, a tondo with the theme of Terrestrial Love and Celestial Love, Bazzi considered the mischievousness of Venus' children Eros and Anteros (Figure 12). These paintings are mythological and poetical delights with complex symbolism, here analyzed in terms of their iconography in relation to classical influences and Renaissance Neoplatonic love or furor divinus. The paradoxical quest of Renaissance Neoplatonic love was to fuse pagan love with Christian love. For the humanists of the time (Bembo, Colonna, Poliziano, Ficino and Pico) this moral dilemma was a philosophical puzzle, but for artists (Botticelli, Nicoletto da Modena, Pinturicchio and Bazzi) the theme was a pictorial challenge.
文摘Saffron (Crocus sativus L.) always is grown for using its flowers in nutrient industry, color industry and healthy compounds due to its flowers and specially stigmas. Because of its expensive flowers, surveying and recognizing on effective genes for flowering is very important and its results can help us to control rate and timing of flowering at an early stage of flowering. The gene and gene state meant Pistillata like MADS box (PIC2) were surveyed for recognizing its molecular mechanism. The molecular sequence at the genes has high similarity to members of family MADS that is a factor for controls of protein at flowering stage. PIC2 gene was studied by bioinforrnatics resources. Primers were designed for replicating the gene and DNA and RNA were extracted from saffron's leaves. The gene's eDNA was built by recopying enzyme and used such a pattern for replicating gene PIC2 at polymerase chain reactions (PCR). Segments were replicated such 900 eDNA pair-nucleotides and a segment such 2,100 of DNA's pair-nucleotides. The gene codes a protein that was composed of 210 amino acids that has MADS sequence box. Analysis of protein's molecular structure and homological modeling of the protein indicated that it has a regular structure.
文摘We studied distribution and site conditions of epiphytic orchids in a gradient of human interference in Kathmandu valley, central Nepal. The aim was to understand the recent distribution pattern of epiphytic orchids, with respect to (i) the micro-site conditions and (ii) the type and intensity of land use. The occurrence of epiphytic orchids was recorded for a grid with 1.5 km cell size. The cells represent different types and intensities of human impact. Site factors such as bark rugosity, bark pH, diameter at breast height (dbh; 1.3 m) of host trees, exposure to wind and sunlight intensity were recorded. With regard to the species richness and abundance of epiphytic orchids, we compared different human impact categories from very strong human impact (settlement area) to very low human impact (national park). Remote sensing was used for a supervised classification of land cover. Ficus religiosa turned out to be the most important host species for orchids in urban areas, while Schima wallichii and Alnus nepalensis significantly host orchids in the other categories. Both species richness and abundance of epiphytic orchids were significantly higher under very low human impact (forest in national park) and also some remaining patches of primary forest than the other regions. Micro-climate is crucial for orchid populations. Host bark pH, bark rugosity, sunlight intensity and host exposure were significantly different for all human impact categories in order to harbour epiphytic orchid species. Habitats with a mixture of mature trees are suitable and essential for the conservation of viable populations of epiphytic orchids in settled areas. The study reveals that to improve the population size of orchids it is essential for future urban forestry to: (i) Protect old trees as carriers of existing epiphytic orchid diversity, (ii) protect medium old trees to ensure that they may become old trees, (iii) plant new host trees for the future, (iv) plant in groups instead of single isolate trees. Trees should especially be planted in areas where orchids still exist to provide more trees for orchid population enlargement (e.g. along riparian system). Native species should be favoured; the pool of such native host species is wide.
文摘Spark discharge plasma synthetic jets(SPJs) have been used for the active flow control study on an NACA 0021 straight-wing model in a wind tunnel. The model forces and moments were measured using a six-component sting balance at a 20 m/s wind speed. The aim was to explore the SPJ's effect on airfoil aerodynamic by examining SPJ generators' position along the chordwise and the jet flow direction about the chord. Near the wing leading edge, two SPJ generators raised the stall angle by 2° and increased the maximum lift coefficient by 9%. The drag coefficient was decreased by 33.1%, and the lift-drag ratio was increased by 104.2% at an angle of attack above 16°. The rolling-moment coefficient was modified by 0.002, and the yawing-moment coefficient was changed by 0.0007 at angles of attack in the range of 0°–16°. The results showed that SPJs can control wing aerodynamic forces at a high angle of attack and moments at a low angle of attack.
基金supported by the National Natural Science Foundation of China (31170408, 31270433, 31370408)the National Science Fund for Distinguished Young Scholars (31325005)+1 种基金NSFC-Yunnan United Fund (U1302267)the West Light Foundation of the Chinese Academy of Sciences
文摘It is generally believed that physical heterogeneity in common resource or evolutionary restraint can sufficiently prevent direct conflict between host and symbionts in mutualism systems. Our data on fig/fig wasp reciprocal mutualism(Ficus racemosa), however, show that structural barriers of female flowers or genetic constraints of pollinators previously hypothesized exist, but cannot sufficiently maintain the mutualism stability. The results show that a positive relationship between seed and wasp production could be maintained in warm season, which might be because of density dependence restraint among foundresses and their low oviposition and pollination efficiency, keeping common resource(female flowers) utilization unsaturated. Whilst, a negative correlation between wasp offspring and viable seed production was also observed in cold season, which might be that the increased oviposition and pollination efficiency maximized the common resource utilization. The fitness trade-off between fig and pollinator wasps is greatly affected by environmental or ecological variations. The local stability might result from temporal low exploitation efficiency of pollinators together with interference competition among pollinators. We suggest that host repression through the active regulation of bract closure, which can create interference competition among the foundresses and prevent extra more foundresses sequential entry in fruit cavities, would help the figs avoiding the cost of over-exploitation. This essentially takes the same role as sanctioning of cheating or competitive behaviors.
基金supported by the National Natural Science Foundation of China(31670393)to L.Z.
文摘Host-mediated effects on hemiparasitic mistletoes were hypothesized to contribute to mistletoes reproductive phenological asynchrony,thus providing a longer period of food supply to its mutualistic pollinators and dispersers.However,studies with empirical data interrogating this hypothesis are lacking.Weekly monitoring of flowering and fruiting patterns on a generalist mistletoe Dendrophthoe pentandra(Loranthaceae)was conducted for two consecutive years in tropical Xishuangbanna,Southwest China.We examined whether flowering and fruiting patterns were seasonal,quantified the degree of stagger within D.pentandra populations and determined the factors influencing the first flowering date(FFD)of D.pentandra.Furthermore,the effect of change in the number of host species on reproductive phenological asynchrony of mistletoe was examined.We found that(i)both flowering and fruiting exhibited unimodal peaks in the two consecutive years of the study;(ii)the FFD was significantly influenced by crown area of mistletoe and light,such that clump with larger crown and more light exposure had an earlier FFD and longer flowering and fruiting durations;(iii)different host species had a significant impact on the phenology of mistletoes.However,contrary to our hypothesis,the number of host species did not significantly change the asynchrony of reproductive phenology of mistletoe.Therefore,these results suggest that alternative hypotheses are needed to interpret the ecological significance of the number of host species and phenological asynchrony of generalist mistletoes.