Relationship between gene expression and the accumulation of catechin during spring and autumn in tea plants (Camellia sinensis L.)

The tea plant(Camellia sinensis L.)is an important commercial crop with remarkably high catechin concentrations.Tea is popular worldwide given the plant's health benefits.Catechins are the main astringent substance in tea and are synthesized mainly via the phenylpropanoid pathway.In this study,eight cultivars of tea plants harvested both in spring and autumn were used to investigate differences in catechin concentrations by using high-performance liquid chromatography.The expression levels of genes associated with catechin biosynthesis were investigated using reverse transcription-quantitative polymerase chain reaction.The results indicated that the total catechin(TC)concentrations were significantly higher in tea plants harvested in autumn than in those harvested in spring,based on higher concentrations of epigallocatechin(EGC)in autumn tea(P<0.01).The expression of the genes phenylalanine ammonia-lyase(PAL),flavanone 3-hydroxylase(F3H),flavonoid 3′,5′-hydroxylase(F3′5′H),dihydroflavonol 4-reductase(DFR),and anthocyanidin synthase(ANS)is closely related to the TC content of tea plants in both spring and autumn.Positive correlations between PAL,cinnamate 4-hydroxylase(C4H),F3H,and DFR expression and EGC accumulation in autumn tea were identified,with correlation coefficients of 0.710,0.763,0.884,and 0.707,respectively.A negative correlation between ANS expression level and EGC concentrations in tea plants harvested in spring was noted(r=−0.732).Additionally,negative correlations between F3H and ANS expression levels and the catechin content were identified in spring tea,whereas the correlations were positive in autumn tea.Significant differences in the F3H and ANS expression levels between spring and autumn tea indicate that F3H and ANS are potentially key genes affecting catechin accumulation in tea plants.

CORRIGENDUM:Relationship between gene expression and the accumulation of catechin during spring and autumn in tea plants(Camellia sinensis L.)

Min Liu,Heng-lu Tian,Jian-Hua Wu,Ren-Rong Cao,Run-Xian Wang,Xiao-Hua Qi,Qiang Xu and Xue-Hao Chen.Horticulture Research(2015)2,15023;doi:10.1038/hortres.2015.23;published online13 May2015.Correction to:Horticulture Research(2015)2,11;doi:10.1038/hortres.2015.11;published online 13 May 2015 Since the publication of this article,the authors have noticed an error in the author list.Author“Ren-Rong Cang”should be“Ren-Rong Cao”.The authors apologize for any inconvenience it may have caused.

A Glimpse of Cultural Differences through Christmas and Spring Festival

As the two most important festivals in China and western countries, Spring Festival and Christmas Day each exempli?fies some of the core values and cultural differences in these two cultures wit which this paper is mainly concerned. By comparing the external manners such as the family reunion, shopping, exchanging New Year greetings, the paper explore the internal cultur?al differences determining those different external manners such as the collectivism, individualism, filial piety, ancestor worship and religion, etc. Through those comparisons, this paper will succeed to achieve its goal if it exhibits, as the title suggests, a glimpse of cultural differences.

Spring and autumn living coccolithophores in the Bohai Sea and Yellow Sea,China

The living coccolithophores （LCs） are an important class of calcified taxa of phytoplankton functional groups, and major producers of marine biogenic inorganic carbon, playing an important role in the marine carbon cycle. In this study, we report the two-demensional abundance, composition of LCs and its correlation with the environmental parameters in spring and autumn, in order to understand the ecological role of LCs in the Yellow Sea and the Bohai Sea. In spring, totally 9 taxa belonging to coccolithophyceae were identified using a polarized microscope at the 1 000x magnification. The dominant species were Emiliania huxleyi, Gephyrocapsa oceanica, Helicosphaera carteri, and Calcidiscus leptoporus. The abundance of coccosphores and coccoliths ranged 0-7.72 cells/mL, and 0-216.09 coccoliths/mL, with the average values of 0.21 cells/mL, and 11.36 coccoliths/mL, respectively. The Emiliania huxleyi distribution was similar to Gephyrocapsa oceanica. The highest abundance of coccoliths was observed in the east of Shandong Peninsula in northern Yellow Sea, whereas Helicosphaera carteri distributed more widely. Emiliania huxleyi and Gephyrocapsa oceanica were the two predominant species in LCs with higher abundances. The distribution of LCs was similar to that of coccoliths. In autumn, 14 taxa belonging to coccolithophyceae were identified with dominant species as Emiliania huxleyi, Gephyrocapsa oceanica, Helicosphaera carteri, Calcidiscus leptoporus and Oolithotus fragilis. The abundance of coccosphores and coccoliths ranged 0-24.69 cells/mL, and 0-507.15 coccoliths/mL, with the average values of 1.47 cells/mL, and 55.89 coccoliths/mL, respectively. The highest abundance of coccoliths was located in Qingdao coastal waters and south of the survey area. The distribution of LCs was similar to the coccoliths; in addition, LCs presented large abundance in the east of the central Yellow Sea area.

High-grade Cocoon Filament Silkworm Chuanshan ×Shushui for Spring and Autumn Rearing

Chuanshan × Shushui is a highgrade cocoon filament silkworm variety for spring and autumn rearing bred by Nanchong Silkworm Eggs Farmthrough systematic breeding method. The characteristics of stock seed and F1 hybrid of silkworm variety Chuanshan × Shushui and their breeding technical points and precautions were introduced in the paper. Laboratory identification and rural breeding results showed that Chuanshan × Shushui wascharacterized by physical strength, high cocoon weight, good cocoon quality and superior neatness, and the cocoons produced could reel 5A6A classraw silk. The variety was suitable for breeding in silkworm areas in Sichuan, Yunnan and Shaanxi provinces. The variety was approved by Sichuansilkworm breeding committee in 2005, and more than one million boxes of silkworm eggs have been cumulatively bred in silkworm areas in Sichuan,Yunnan, Shaanxi and Hainan provinces.

Spring and Autumn of the Lü Clan and Yellow Emperor School

To which school Spring and Autumn of the Lü Clan belongs is the base of carrying out the study of its thoughts and philosophy,which has always caused controversy.This question should be answered not from the narrowperspective of a certain school,but from the perspective of academic integration. Spring and Autumn of the Lü Clan is a consummate work of YellowEmperor School. There are four reasons for this conclusion: firstly,it shares the same ideological system and basic thoughts with YellowEmperor School. Secondly,from the perspective of ideological views,it carries on the development trend of thoughts of YellowEmperor School. Thirdly,from the perspective of integration of ideological factors of various schools,it carries on the development trend of YellowEmperor School. Fourthly,it raises the banner of"YellowEmperor",and inherits many words from works of YellowEmperor School.

Temporal and Spatial Distribution and Influence Systems of Spring Thunderstorms in 2013 in Sichuan Province

Based on the lightning monitoring data, automatic and routine weather station observation data in spring （March-May） of 2013 of Sichuan Province, the corresponding relationship between the spatial distribution and the different regions, and the characteristics of atmospheric circulation and evolution of influence the sys- tem were analyzed and summarized. The results show that： the lightning and thunderstorm showed great regional differences in the spring of 2013 in Sichuan Province and the thunderstorm activity period was not the same in different areas. Because of the change of atmospheric circulation, the influence system from March to May corresponding to the thunderstorms in Sichuan tended to be volatile, also.

Two-way shape memory effect and alternating current driving characteristics of a TiNi alloy spring

Two-way shape memory effect (TWSME) was induced into the TiNi shape memoryalloys (SMAs) spring by thermomechanical training after annealing treatment, which has promisingapplication in micro-actuating fields. The TWSME spring can contract upon heating and extend uponcooling. The results show that there is an increase of the recovery ratio up to a maximum TWSME of45%. During the training procedure, transformation temperatures and hysteresis were measured bydifferent scanning calorimetry (DSC). The results show that A_s (reverse transformation starttemperature) and A_f (reverse transformation finish temperature) shift to lower temperature aftertraining. The intervals of A_fA_s and M_s-M_f (M_s and M_f are the martensite start and finishtemperatures, respectively) increase and the heat of transformation decreases after training. Theelectrothermal driving characteristics of the TWSME springs were also investigated with alternatingcurrent density of 3.2-14.7 A/mm^2. It is found that the time response and the maximum contractionratio greatly depend on the magnitude of the electrical current density.

Festivals in China and America

Festival, an occasion when people come to enjoy themselves. Every country has its own traditional festivals, celebrated by all kinds of activities. In China, the most important festival is Spring Festival, while in America, the most important festival is Christmas. Festi val differences exist between China and America. With time elapsing, festival culture changes gradually and some new cultural phenome non occurs.

Changing Spring Phenology Dates in the Three-Rivers Headwater Region of the Tibetan Plateau during 1960–2013

The variation of the vegetation growing season in the Three-Rivers Headwater Region of the Tibetan Plateau has recently become a controversial topic. One issue is that the estimated local trend in the start of the vegetation growing season(SOS)based on remote sensing data is easily affected by outliers because this data series is short. In this study, we determine that the spring minimum temperature is the most influential factor for SOS. The significant negative linear relationship between the two variables in the region is evaluated using Moderate Resolution Imaging Spectroradiometer–Normalized Difference Vegetation Index data for 2000–13. We then reconstruct the SOS time series based on the temperature data for 1960–2013.The regional mean SOS shows an advancing trend of 1.42 d(10 yr)during 1960–2013, with the SOS occurring on the 160th and 151st days in 1960 and 2013, respectively. The advancing trend enhances to 6.04 d(10 yr)during the past 14 years. The spatiotemporal variations of the reconstructed SOS data are similar to those deduced from remote sensing data during the past 14 years. The latter exhibit an even larger regional mean trend of SOS [7.98 d(10 yr)] during 2000–13. The Arctic Oscillation is found to have significantly influenced the changing SOS, especially for the eastern part of the region,during 2000–13.

The Occurrence of Migraine Auras and Possible Triggers

Our aim is to determine the cause(s) of migraine auras. Our understanding of how migraines and migraine auras originate is very imperfect. An important observation is that migraines occur more frequently in women at reproductive age than in men at a similar age. This suggests that gonadal hormones may be relevant triggers. The occurrence of classical (typical auras without headache) auras in one author (WB) has been recorded. Every aura in six years (85) has been noted, studied and analysed statistically. The auras occur predominantly in Spring and Autumn, especially in the longer reproductive season of Spring. This association is supported statistically. The results support the idea of gonadal hormones as relevant triggers, the strongest candidate being estrogen. Basic mechanisms underlying the auras are discussed, especially the phenomenon of cortical spreading depression. We also propose that both auras and migraines depend upon previous injury to the head or to the brain, giving rise to a condition of “deafferentation hypersensitivity”.

Migration routes of the endangered Oriental Stork(Ciconia boyciana)from Xingkai Lake,China,and their repeatability as revealed by GPS tracking

The Oriental Stork(Ciconia boyciana)is listed as'Endangered'on the International Union for the Conservation of Nature(IUCN)Red List of Threatened Species and is classified as a first category nationally protected bird species in China.Understanding this species'seasonal movements and migration will facilitate effective conservation to promote its population.We tagged 27 Oriental Stork nestlings at Xingkai Lake on the Sanjiang Plain in Heilongjiang Province,China,used GPS tracking to follow them over the periods of 2014-2017 and 2019-2022,and confirmed their detailed migratory routes using the spatial analysis function of ArcGIS 10.7.We discovered four migration routes during autumn migration:one common long-distance migration route in which the storks migrated along the coastline of Bohai Bay to the middle and lower reaches of the Yangtze River for wintering,one short-distance migration route in which the storks wintered in Bohai Bay and two other migration routes in which the storks crossed the Bohai Strait around the Yellow River and wintered in South Korea.There were no significant differences in the number of migration days,residence days,migration distances,number of stopovers and average number of days spent at stopover sites between the autumn and spring migrations(P>0.05).However,the storks migrated significantly faster in spring than in autumn(P=0.03).The same individuals did not exhibit a high degree of repetition in their migration timing and route selection in either autumn or spring migration.Even storks from the same nest exhibited considerable between-individual variation in their migration routes.Some important stopover sites were identified,especially in the Bohai Rim Region and on the Songnen Plain,and we further explored the current conservation status at these two important sites.Overall,our results contribute to the understanding of the annual migration,dispersal and protection status of the endangered Oriental Stork and provide a scientific basis for conservation decisions and the development of action plans for this species.

Analysis on the Ecological and Climatic Advantages of Tea Production in Western Guizhou

The ecological and climatic conditions in the main tea areas of western Guizhou were analyzed,and the comparison with Meitan,Duyun and Leishan tea areas in Guizhou Province was conducted. The results showed that spring,summer and autumn tea can be picked in western Guizhou Province;spring tea can be picked for about 100 d,and summer and autumn tea can be picked for about 50 d. The average content of amino acids in tea from western Guizhou was 0.9%-2.9% higher than the national average,and the average content of polyphenols was 10.9% lower than the national average maximum,while the average content of caffeine was 1.4% lower than the national average maximum. In the first ten days of February,the temperature in the western tea area began to rise,which was earlier than Meitan,Duyun,Leishan tea areas and had a larger warming range,which was conducive to the germination of tea trees. The average temperature of ten days in the western tea area from middle May to early July was lower than that of Meitan,Duyun and Leishan tea areas,and the temperature rise was not violent,which was conducive to the growth of summer shoots and vigorous growth of tea buds. The ten-day average temperature of the western tea area from the first ten days of August to the last ten days of September was lower than Meitan,Duyun and Leishan tea areas,and its precipitation was more than Meitan,Duyun and Leishan tea areas,and the number of rainy and foggy days was more. The climate conditions are favorable for the formation of tea quality.

Wave propagation across fluid-solid interfaces with LBM-LSM coupling schemes

Seismic wave propagation in fluid-solid coupled media is currently a popular topic. However, traditional wave equation-based simulation methods have to consider complex boundary conditions at the fluid-solid interface. To address this challenge, we propose a novel numerical scheme that integrates the lattice Boltzmann method(LBM) and lattice spring model(LSM). In this scheme, LBM simulates viscoacoustic wave propagation in the fluid area and LSM simulates elastic wave propagation in the solid area. We also introduce three different LBM-LSM coupling strategies, a standard bounce back scheme, a specular reflection scheme, and a hybrid scheme, to describe wave propagation across fluid-solid boundaries. To demonstrate the accuracy of these LBM-LSM coupling schemes, we simulate wave propagation in a two-layer model containing a fluid-solid interface. We place excitation sources in the fluid layer and the solid layer respectively, to observe the wave phenomena when seismic waves propagate to interface from different sides. The simulated results by LBM-LSM are compared with the reference wavefields obtained by the finite difference method(FDM) and the analytical solution(ANA).Our LBM-LSM coupling scheme was verified effective, as the relative errors between the LBM-LSM solutions and reference solutions were within an acceptable range, sometimes around 1.00%. The coupled LBM-LSM scheme is further used to model seismic wavefields across a more realistic rugged seabed,which reveals the potential applications of the coupled LBM-LSM scheme in marine seismic imaging techniques, such as reverse-time migration and full-waveform inversion. The method also has potential applications in simulating wave propagation in complex two-and multi-phase media.

金牡丹不同茶类夏秋茶香气品质差异分析

以‘金牡丹’品种夏、秋季嫩梢为原料,分别加工成绿茶、黄茶、白茶、乌龙茶及红茶,采用顶空固相微萃取-气相色谱-质谱联用技术对夏、秋季的5类茶中的挥发性代谢物进行测定和分析。结果表明,夏茶中鉴定出522种挥发性代谢物,以萜类、酯类及醇类为主;秋茶中鉴定出502种挥发性代谢物,以萜类、酯类和杂环化合物为主。香气活性值分析表明,β-紫罗兰酮、α-紫罗兰酮、癸醛、苯甲酸甲酯、香叶醇等是金牡丹绿茶的关键呈香物质;β-紫罗兰酮、2-乙氧基-3-甲基吡嗪、癸醛、苯甲酸甲酯、香叶醇等是金牡丹黄茶的关键呈香物质;香叶醇、苯乙醛、水杨酸甲酯、(E)-芳樟醇氧化物、2-乙氧基-3-甲基吡嗪等是金牡丹白茶的关键呈香物质;吲哚、苯甲酸甲酯、苯乙醛、香叶醇、(E)-芳樟醇氧化物等是金牡丹乌龙茶的关键呈香物质;香叶醇、芳樟醇、苯乙醛、苯甲酸甲酯、水杨酸甲酯等是金牡丹红茶的关键呈香物质。秋茶中呈香物质的贡献、种类与数量均多于夏茶,其中,香叶醇、水杨酸甲酯、苯乙醇等42种关键呈香物质在秋季样品中香气活性值均高于夏季。整体而言,金牡丹茶以花香类为主要香型,秋茶香气品质显著优于夏茶,香叶醇、芳樟醇、2-乙氧基-3-甲基吡嗪、苯甲酸甲酯等14种挥发性代谢物为金牡丹茶品种的关键香气物质。

采收季节对鹅绒委陵菜(Potentilla anserina L.)块根总黄酮含量的影响

通过紫外可见光光度法测定了不同季节采收的鹅绒委陵菜块根———蕨麻以及野生蕨麻中的总黄酮含量,结果表明,栽培种和野生种总黄酮含量几乎没有差别;春蕨麻和秋蕨麻的总黄酮含量有较大差异,秋蕨麻的总黄酮含量比春蕨麻高25 8%,从而为蕨麻的最佳收获时间提供了理论依据.

Orbit determination and prediction for Beidou GEO satellites at the time of the spring/autumn equinox

Geostationary(GEO) satellites form an indispensable component of the constellation of Beidou navigation system(BDS). The ephemerides, or predicted orbits of these GEO satellites(GEOs), are broadcast to positioning, navigation, and timing users. User equivalent ranging error(UERE) based on broadcast message is better than 1.5 m(root formal errors: RMS) for GEO satellites. However, monitoring of UERE indicates that the orbital prediction precision is significantly degraded when the Sun is close to the Earth's equatorial plane(or near spring or autumn Equinox). Error source analysis shows that the complicated solar radiation pressure on satellite buses and the simple box-wing model maybe the major contributor to the deterioration of orbital precision. With the aid of BDS' two-way frequency and time transfer between the GEOs and Beidou time(BDT, that is maintained at the master control station), we propose a new orbit determination strategy, namely three-step approach of the multi-satellite precise orbit determination(MPOD). Pseudo-range(carrier phase) data are transformed to geometric range(biased geometric range) data without clock offsets; and reasonable empirical acceleration parameters are estimated along with orbital elements to account for the error in solar radiation pressure modeling. Experiments with Beidou data show that using the proposed approach, the GEOs' UERE when near the autumn Equinox of 2012 can be improved to 1.3 m from 2.5 m(RMS), and the probability of user equivalent range error(UERE)<2.0 m can be improved from 50% to above 85%.

Is bi-seasonal germination an optimal choice for an ephemeral plant living in a cold desert?

Research on germination strategies has been proposed as a tool for understanding the evolutionary patterns of plant species living in extreme climate conditions. Previous research has concentrated on spring-germinated plants, while there has been little investigation on the ecological significance of ephemeral plants that germinate in both autumn and spring. The biological characteristics and life history strategies of autumn-and spring-germinated plants of Hypecoum erectum L. that belongs to Hypecoum in Papaveraceae family in the southern part of the Gurbantunggut Desert, China, were investigated from 2016 to 2017. Results showed that:(1) the interval from seedling emergence to the end of the life cycle in autumn-germinated plants(202–208 d) was significantly longer than that in spring-germinated plants(53–65 d);(2) the height, crown, principal axis and the number of leaves of autumn-germinated plants were much greater than those of spring-germinated plants;(3) allocation of dry mass to reproduction was 30.24%(±2.41%) and 10.12%(±0.68%) in autumn-and spring-germinated plants, respectively. Autumn-germinated seedlings of H. erectum had an advantage in avoiding the competition between annual and perennial herbs that had longer periods of vegetative growth.Spring-germinated seedlings need to ensure the survival of population when only a fewer autumn-germinated seedlings successfully overwinter. In an unpredictable environment, the germination strategy of bet hedging not only utilizes the resources and reduces the competition intensity in offspring,but also ensures the survival of the plant population.

基于Origin的弹簧振子实验数据处理方法

用Origin软件对弹簧振子实验的数据进行线性拟合与作图处理,拟合结果与逐差法、图解法进行数据处理的结果作对比。结果表明:Origin线性拟合可以得到符合实验需求的光滑曲线,使得实验数据处理更加快捷、准确、直观。