Middle Developmental Stages Research Articles

Study on Mechanism and Effect of Different Viscosity Reducing Methods on Offshore Heavy Oil

Abstract Bohai is rich in heavy oil. And its efficient development is significant. In this essay, ordinary heavy oil and extra one were selected, and the viscosity characteristics was also investigated referring to its internal composition. And so as the reducing viscosity effects of steam, oil-soluble viscosity reducer, diesel, emulsifier, flue gas and carbon dioxide. The experimental results show that resin and asphaltene content have positive effect on the viscosity of heavy oil. Compared with ordinary heavy oil, the drop is significantly greater when the temperature increases by 10°C. For ordinary heavy oil, the inflection point temperature is from 50°C to 70°C, and for extra-heavy oil, it is above 100°C. For ordinary heavy oil, its flow effect can be better improved without too high temperature, while it’s totally different for super heavy oil. For which, higher temperature and other auxiliary viscosity reduction methods are needed to achieve better flow performance. Diesel oil reduce viscosity of heavy oil by similar solubility principle, but the demand for diesel oil is large. At 50°C, the viscosity of super heavy oil with 0.5% emulsion viscosity reducer added is 36 mPa·s, but the water content needs to reach above 30%.Oil-soluble viscosity reducer reduces viscosity by dissolving asphaltenes and resins and dismantling aggregate structure of heavy oil aromatic flakes.However, the dosage should reach about 20 %, so that the viscosity of super heavy oil can be reduced to the level of dilute oil. Overall, for developing super heavy oil, steam compound with oil soluble viscosity reducer can be taken into account at the early production stage, and the emulsion viscosity reducer can be used in the middle development stage and wellbore viscosity reduction and lifting process. Finally, for ordinary heavy oil, flue gas’s viscosity reduction effects, nitrogen and carbon dioxide are investigated. It is found that the viscosity reduction effect of carbon dioxide is the best, followed by flue gas and nitrogen. Considering the offshore gas source, cost and carbon emission requirements, it is recommended to use flue gas in the field. The research provides theoretical guidance and technical reference for development of different types of offshore heavy oil.

What Attracts Green: Value Differentiation of Environmental Industry and Coagglomeration with Pollution-Intensive Industries in China

Scholars have spent decades studying how environmental (“green”) industry can promote sustainability. Few studies, however, have discussed corporate dynamics within green industry and their spatial interactions with other manufacturing and service industries. Drawing on the theoretical perspective of industrial value chain differentiation, this study unpacks the spatiotemporal dynamics of environmental enterprises by various types in China. We use the Wasserstein coagglomeration index and Poisson regression to identify the spatial coagglomeration of green and pollution-intensive (“brown”) industries. The results show that (1) China’s environmental industry is still in the early and middle stages of development with low and medium added value as the core; (2) green enterprises are mainly distributed in the eastern coastal areas and a few inland provinces with developed infrastructure; and (3) the entry and spatial distribution of equipment and engineering enterprises are highly correlated with local brown industries, whereas high-end service enterprises tend to concentrate in economically developed urban agglomerations. This research hopes to reveal the spatial characteristics of environmental industry in the regional green transition through the decomposition of its value chain and the analysis of the spatial coagglomeration effect.

Partial limitation of cellular functions and compensatory modulation of unfolded protein response pathways caused by double-knockout of ATF6α and ATF6β.

Mammalian cells have three types of endoplasmic reticulum (ER) stress-sensing molecules: ATF6, IRE1, and PERK. Among these, ATF6 is unique in that it is processed in an ER-stress-specific manner and functions as a transcription factor for the activation of anti-ER stress genes (such as BiP). ATF6 is known to have two homologues, ATF6α and ATF6β, and a greater understanding of their functions has been achieved through analyses using cultured cells. Physiological functions are also gradually being investigated in mice lacking ATF6α or ATF6β. However, little is known about the effects on mouse organisms of the deletion of both the ATF6α and ATF6β genes, since such double-knockout (DKO) mice suffer embryonic lethality at an early developmental stage. In this study, we generated and analyzed ATF6 DKO mice in which embryonic lethality was evaded by using Cre/loxP technology. Pancreatic β cell-specific ATF6 DKO mice were born normally and lived without dysregulation of blood-glucose levels but had a reduced tolerance to glucose. Islets isolated from ATF6 DKO mice also showed low production and secretion of insulin and mild enhancement of IRE1 and PERK activity. We further examined the developmental abnormalities of systemic ATF6 DKO mice. The phenotypes of ATF6α-/-; ATF6β-/- mice were similar to those previously reported, but ATF6α+/-; ATF6β-/- and ATF6α-/-; ATF6β+/- mice showed embryonic lethality at middle developmental stages, unlike those reported. Analysis of embryonic fibroblasts derived from these mice revealed that ATF6α and ATF6β have a gene-dose-dependent functional redundancy and display distinct differences in their ability to induce BiP expression. (250 words).

The Application of Big Data Technology in English Teaching Mode Innovation and Effect Analysis

Abstract Big data technology provides a detailed development of English language teaching, which is targeted through the assessment of cognitive level. In this paper, ConvSLSTM is used to describe the problem of learners’ knowledge level and build a cognitive framework. With the support of the framework, “recall rate” was introduced to quantify the English vocabulary test results, PSTM ability was adopted to reflect the acquisition of syntactic variants, and attention control was borrowed to evaluate pronunciation characteristics. Based on the initial quantification mentioned above, a hierarchical-level calculation was accomplished by combining fuzzy logic. Meanwhile, based on the estimation of different sides, a rule space model was created, and some corrections were made to achieve the cognitive diagnosis of the group level. In terms of the syntactic developmental trajectory of the girl learners, the maximum value of the range of syntactic variation of the subjects appeared in the middle and late stages. During the early stages of development, the variation range is between 10-35, and the bandwidth is 25, with very little variation. However, in the middle stage of development, it basically starts to oscillate significantly between 10-85, at which time the bandwidth increases to 75. Big data technology has created a comprehensive measurement framework for learners’ English proficiency.

Autophagy during maize endosperm development dampens oxidative stress and promotes mitochondrial clearance.

The selective turnover of macromolecules by autophagy provides a critical homeostatic mechanism for recycling cellular constituents and for removing superfluous and damaged organelles, membranes, and proteins. To better understand how autophagy impacts seed maturation and nutrient storage, we studied maize (Zea mays) endosperm in its early and middle developmental stages via an integrated multiomic approach using mutants impacting the core macroautophagy factor AUTOPHAGY (ATG)-12 required for autophagosome assembly. Surprisingly, the mutant endosperm in these developmental windows accumulated normal amounts of starch and Zein storage proteins. However, the tissue acquired a substantially altered metabolome, especially for compounds related to oxidative stress and sulfur metabolism, including increases in cystine, dehydroascorbate, cys-glutathione disulfide, glucarate, and galactarate, and decreases in peroxide and the antioxidant glutathione. While changes in the associated transcriptome were mild, the proteome was strongly altered in the atg12 endosperm, especially for increased levels of mitochondrial proteins without a concomitant increase in mRNA abundances. Although fewer mitochondria were seen cytologically, a heightened number appeared dysfunctional based on the accumulation of dilated cristae, consistent with attenuated mitophagy. Collectively, our results confirm that macroautophagy plays a minor role in the accumulation of starch and storage proteins during maize endosperm development but likely helps protect against oxidative stress and clears unneeded/dysfunctional mitochondria during tissue maturation.

Correlation and Community Stability Analysis of Herbaceous Plants in Dashiwei Tiankeng Group, China

Studying the interspecific association and stability of herbaceous communities in different developmental stages of tiankeng is helpful to understand the relationship between tiankeng vegetation and the environment, and can provide an important theoretical basis for the protection and restoration of the karst tiankeng ecosystem. In this study, the herbaceous community of the Dashiwei Tiankeng Group in Guangxi was studied to analyze the interspecific relationships and community stability of herbaceous plants in four different habitats (the earlier stage, middle stage, late stage and the external forest of tiankeng), and to explore whether the herbaceous community structure gradually stabilized with the development of tiankeng. The variance ratio (VR), X2 test, association coefficient (JI) and the Spearman rank correlation coefficient test were used to analyze the interspecific association of the main herbaceous plants in different developmental stages of tiankeng. The stability of the herbaceous community was analyzed by the stability measurement method of M. Godron. The results showed that: (1) the logarithm of the middle stage of tiankeng negatively correlated species was the highest (56.7%), and the logarithm of the later stage of tiankeng positively correlated species was the highest (57.2%). The positive and negative correlation ratio of main herbs decreased first and then increased, indicating that the middle stage of development was the period of high competition among herbs and the biggest difference in resource utilization. The ecological habits of herbaceous plants will be changed from sciophiles to hygrophytes to heliophiles and drought-enduring plants. (2) The earlier stage and middle stage of tiankeng overall relevance had a significant negative correlation, the later stage and external forest of tiankeng overall correlation were not significant positive correlation, and the X2 test and the Spearman rank correlation coefficient of different developmental stages of tiankeng most major herbaceous species were not significant correlation, suggesting that the major herbs in tiankengs had weak association and strong independence. (3) The distance from the intersection point to the stable point (20, 80) was 19.799, 17.867, 18.922 and 17.706, respectively, of the four regression models of tiankengs herb community, which further indicated that the forest herb layers were in an unstable state. The forest outside is relatively more stable than the herbaceous community inside the tiankeng.

Comparing regulatory processes in genome editing and autonomous vehicles: How institutional environments shape sociotechnical imaginaries

AbstractThis study compares the regulation of two emerging technologies, the CRISPR genome‐editing system and Connected and Autonomous Vehicles (CAV) in the United States. The study draws on 33 in‐depth interviews with innovation and governance experts to study the relationship between their regulatory environments and developing beliefs about these technologies. Using sociotechnical imaginaries as a framework, we explore how social actors envision technologically driven futures and the social order that enables them. These imaginaries are essential to emerging technologies, where experts build a framework of potentialities for innovation still underway. While scholarship has documented how sociotechnical imaginaries arise among policymakers, groups of scientists, state and local stakeholders, and public actors in different countries, less has been said about how regulatory organizations and their actors shape expectations around technologies that are in the early and middle stages of development. This article finds that regulatory institutions shape emerging imaginaries along three related axes: the distribution of authority, technological novelty, and risk. Interviewees negotiate these three contingencies differently based on relevant extant regulatory structures and ideologies, resulting in distinct imaginaries around each technology. CRISPR actors envision genome editing as largely diminishing biomedical harm and eventually suitable for health markets, while CAV actors diverge on whether self‐driving cars alleviate or exacerbate risk and how they may enter roads. That organizational structures and practices of regulation inform broadly held sociotechnical imaginaries bears significance for studies of innovation trajectories, suggesting regulators can take an active role in shaping how risks and benefits of emerging technology are defined.

广西大石围天坑群草本植物多样性及其生态位变化规律

PDF HTML阅读 XML下载 导出引用 引用提醒 广西大石围天坑群草本植物多样性及其生态位变化规律 DOI: 10.5846/stxb202204251137 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金（31960047）；珍稀濒危动植物生态与环境保护教育部重点实验室研究基金（ERESEP2019Z04）；广西重点研发计划项目（桂科AB21220057）；广西漓江流域景观资源保育与可持续利用重点实验室研究基金（LRCSU21Z0101） Diversity and niche characteristics of herbaceous plants in Dashiwei Tiankeng Group, Guangxi Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:研究不同发育时期天坑草本植物的多样性，能更好的理解草本层对天坑环境变化的响应机制。以广西大石围天坑群中不同发育时期天坑（初期、中期和后期）为研究对象，采用空间代替时间的方法，分析不同发育时期天坑草本植物多样性和生态位变化规律。结果表明：（1）广西大石围天坑群调查样地共记录到草本植物34科71属98种，以鳞毛蕨科、荨麻科、凤尾蕨科、菊科和禾本科为主。（2）后期天坑草本植物的Pielou's指数和Shannon-Wiener指数均显著高于初期天坑（P<0.05），表明随着天坑发育到后期，草本层物种数逐渐增多，物种分布更为均匀。（3）随着天坑的发育，草本层喜阴植物重要值下降，喜阳、半阴植物重要值上升，喜阳植物逐渐取代喜阴植物在群落中占据优势地位，草本层将经历喜阴植物-喜阴、半阴植物-喜阳植物的三个生态型转变过程。（4）各发育时期优势草本生态位相似性比例和生态位重叠平均值均<0.5，表明天坑不同发育时期对草本植物的生态位影响较小，各时期草本层总体呈现生态分化明显、种间竞争较弱的特点。（5）各发育时期优势草本生态位重叠值大、相对高度差小的种对数中，不同生态习性的种对数占比不同，中期天坑种对数远高于初期和后期天坑，表明不同发育时期中不同生态习性的草本对光能的竞争程度存在差异，中期天坑草本植物对光能竞争最为激烈。综上所述，广西大石围天坑群各发育时期草本层生态分化明显、群落结构稳定，后期天坑草本多样性最为丰富。 Abstract:Studying the diversity and niche characteristics of herbaceous plants in different developmental stages of Tiankeng can better understand the response mechanism of the herbaceous layer to the environmental changes and provide an important scientific basis for the protection of ecological environment and biodiversity resources in Tiankeng. In this study, the herbaceous in different developmental stages of Tiankeng (the earlier stage, middle stage, and later stage) were selected as the objects. We used the method of space instead of time to establish 168 herbaceous quadrates in Dashiwei Tiankeng Group, Guangxi and carried out investigations. Shannon-Wiener index, Simpson index, Pielou's index and Patrick index were used to evaluate the herb diversity at different developmental stages of the Tiankeng. The ecological niche characteristics (niche width and niche overlap) of main species in the herb layer of the different developmental stages of Tiankeng were calculated. The results showed that:(1) a total of 98 species of herbaceous plants belonging to 71 genera and 34 families were recorded in Dashiwei Tiankeng Group, Guangxi. The principal families were Dryopteridaceae, Urticaceae, Pteridaceae, Asteraceae and Poaceae. (2) Pielou's index and Shannon-Wienner index of herbs in the later development stage of Tiankeng were significantly higher than those in the earlier development stage of Tiankeng (P<0.05), indicating that with the Tiankeng developed to the later stage, the number of species in the herb layer increased and the species distribution pattern was steady. (3) With the development of Tiankeng, the importance value of sciophiles in herb layer decreased, while the importance value of heliophiles and semishade increased and the dominance was prevalent in heliophiles than sciophiles. The herb layer would go through three ecotype transition processes of sciophiles-sciophiles and semishade-heliophiles. (4) The average value of niche similarity and niche overlap of dominant herbs at each developmental stage of Tiankeng were lower than 0.5, indicating that different developmental stages of Tiankeng had a slight impact on the niche of herbs. The herbaceous layer had obviously ecological differentiation and weakly inter-specific competition. (5) In the species pairs of dominant herbs large niche overlap and small relative height at each development stage, the species pairs of different ecological habits accounted for different proportions. The species pairs of the middle development stage of Tiankeng was much higher than that of earlier and later development stages of Tiankeng. The results showed that herbaceous plants with different ecological habits at different development stages had different competition degrees for light energy. The herbs in the middle development stage of Tiankeng had the fierce competition for light. In a word, the herb layer of Dashiwei Tiankeng Group in Guangxi was obviously differentiated, the community structure was relatively stable, and the species diversity of the later development stage of Tiankeng in herb layer was rich. 参考文献 相似文献 引证文献

A Type I and a Type II Metacaspase Are Differentially Regulated during Corolla Development and in Response to Abiotic and Biotic Stresses in Petunia × hybrida

Metacaspases are structural homologs of the metazoan caspases that are found in plants, fungi, and protozoans. They are cysteine proteases that function during programmed cell death, stress, and cell proliferation. A putative metacaspase designated PhMC2 was cloned from Petunia × hybrida, and sequence alignment and phylogenetic analysis revealed that it encodes a type II metacaspase. PhMC2 cleaved protease substrates with an arginine residue at the P1 site and cysteine (iodoacetamide) and arginal (leupeptin) protease inhibitors nearly abolished this activity. The activity of PhMC2 was highest at pH 8, and the putative catalytic site cysteine residue was required for optimal activity. Quantitative PCR showed that PhMC2 transcripts were detectable in petunia corollas, styles, and ovaries. Expression patterns were not upregulated during petal senescence but were higher at the middle stages of development when flower corollas were fully open but not yet starting to wilt. PhMC1, a type I metacaspase previously identified in petunia, and PhMC2 were differentially regulated in vegetative tissues in response to biotic and abiotic stresses. PhMC2 expression was upregulated to a greater extent than PhMC1 following Botrytis cinerea infection, while PhMC1 was upregulated more by drought, salinity, and low nutrient stress. These results suggest that petunia metacaspases are involved in flower development, senescence, and stress responses.

Encroachment order and spatial patterns of broad-leaf tree species in the naturalization of a Cunninghamia lanceolata plantation

The aim of this study was to understand the encroachment order, spatial patterns, interspecific associations, and species diversity of a Cunninghamia lanceolata plantation and to provide context for how to improve the spatial structure of C. lanceolata plantations. We investigated a Guanshan (C. lanceolata) Plantation in the Jiangxi Province. The C. lanceolata plantation was divided into three developmental stages (early, middle and late), with a space-for-time substitution method, according to their diameter at breast height (DBH) measurements. Across these plots, we analyzed encroachment patterns of the species and their interspecific associations with C. lanceolata according to the coordinates of trees in the plot, as well as the variation of species diversity after the encroachment of broad-leaf tree species. Our results show that the encroachment of broad-leaf trees into the C. lanceolata plantation followed a clear successional sequence of tree community assembly: intolerant tree species encroachment first, such as Alniphyllum fortunei and Liquidambar formosana, encroached; neutral tree species then encroachment, such as Daphniphyllum oldhamii and Schima superba, and shade-tolerant tree species encroachment last, such as Castanopsis eyrei and Castanopsis tibetana. Further, the spatial pattern of species establishment differed based upon when they encroached on the plantation. Intolerant and neutral tree species of early and middle developmental stages were distributed randomly. However, intolerant and some shade-tolerant tree species of the late developmental stage were aggregated on a scale of about 0–3 m. In addition, the interspecific associations between broad-leaf species encroachment into the C. lanceolata plantation were mainly negative, among which the most competitive ones were A. fortunei, D. oldhamii and Machilus thunbergii. However, with the development of the community, some species with negative correlations changed to having no correlation with C. lanceolata. We found that species diversity in the plantation gradually increased by nearly-five times from the early to the late developmental stage. Based on our collective results, we conclude that the encroachment and assembly of tree species show obvious order and pattern, which has a strong competitive effect with C. lanceolata in the naturalized plantation. Additionally, the community biodiversity has been significantly improved. Therefore, this successional process is important in the transformation of the C lanceolata plantation and different tree species should be replanted according to C. lanceolata plantation developmental stages with priority given to competitive species, such as A. fortunei, D. oldhamii, and M. thunbergii, so as to promote the C. lanceolata plantation change to C. lanceolata and broadleaf mixed forest.

Prevalence of Ranavirus Infection in Three Anuran Species across South Korea.

To cope with amphibian die-offs caused by ranavirus, it is important to know the underlying ranavirus prevalence in a region. We studied the ranavirus prevalence in tadpoles of two native and one introduced anuran species inhabiting agricultural and surrounding areas at 49 locations across eight provinces of South Korea by applying qPCR. The local ranavirus prevalence and the individual infection rates at infected locations were 32.6% and 16.1%, respectively, for Dryophytes japonicus (Japanese tree frog); 25.6% and 26.1% for Pelophylax nigromaculatus (Black-spotted pond frog); and 30.5% and 50.0% for Lithobates catesbeianus (American bullfrog). The individual infection rate of L. catesbeianus was significantly greater than that of D. japonicus. The individual infection rate of P. nigromaculatus was related to the site-specific precipitation and air temperature. The individual infection rate gradually increased from Gosner development stage 39, and intermittent infection was confirmed in the early and middle developmental stages. Our results show that ranavirus is widespread among wild amphibians living in agricultural areas of South Korea, and mass die-offs by ranavirus could occur at any time.

Aggregation pheromone 4-vinylanisole promotes the synchrony of sexual maturation in female locusts.

Reproductive synchrony generally occurs in various group-living animals. However, the underlying mechanisms remain largely unexplored. The migratory locust, Locusta migratoria, a worldwide agricultural pest species, displays synchronous maturation and oviposition when forms huge swarm. The reproductive synchrony among group members is critical for the maintenance of locust swarms and population density of next generation. Here, we showed that gregarious female locusts displayed more synchronous sexual maturation and oviposition than solitarious females and olfactory deficiency mutants. Only the presence of gregarious male adults can stimulate sexual maturation synchrony of female adults. Of the volatiles emitted abundantly by gregarious male adults, the aggregation pheromone, 4-vinylanisole, was identified to play key role in inducing female sexual maturation synchrony. This maturation-accelerating effect of 4-vinylanisole disappeared in the females of Or35-/- lines, the mutants of 4-vinylanisole receptor. Interestingly, 4-vinylanisole displayed a time window action by which mainly accelerates oocyte maturation of young females aged at middle developmental stages (3-4 days post adult eclosion). We further revealed that juvenile hormone/vitellogenin pathway mediated female sexual maturation triggered by 4-vinylanisole. Our results highlight a 'catch-up' strategy by which gregarious females synchronize their oocyte maturation and oviposition by time-dependent endocrinal response to 4-vinylanisole, and provide insight into reproductive synchrony induced by olfactory signal released by heterosexual conspecifics in a given group.

Association of bud and anther morphology with developmental stages of the male gametophyte of melon (Cucumis melo L.).

Correlations between the morphological features of f lower buds and the developmental stages of the male gametophyte are of great practical interest as a reliable marker that accelerates and simplif ies the selection of appropriate plant material for isolated microspore culture. Microspore culture enables one to quickly obtain many pure lines of different vegetable crops, but it has not yet been widely applied in the melon (Cucumis melo L.). To successfully apply this technique in a new culture, one has to optimize many of its elements: f irst, f ind the biological markers for selecting the f lower buds containing the microspores of certain development stages. The paper presents the results of research estimating the correlations between the length and diameter of the f lower buds, the length of the visual part of the corolla, the length of the anthers and the development stages of the male gametophyte in the F1 hybrid of the Kim Hong Ngoc melon. The strongest correlation (CC = 0.885) was found for the f lower bed diameter and a strong correlation (CC = 0.880), for the bud length. The corolla’s visual part was a less reliable morphological feature, and the anther’s length should not be used as a parameter to predict the developmental stages of the melon’s male gametophyte. It was also found that one anther could contain the microspores and pollen grains of different developmental stages. In the f lower buds less than 4 mm in length and 1.51 ± 0.02 mm in diameter prevailed tetrads, and in the buds 4.0–4.9 mm in length and 2.30 ± 0.02 mm in diameter, early microspores. The microspores of a middle stage of development prevailed in the f lower buds 5.0–5.9 mm in length and 2.32 ± 0.00 mm in diameter; mid and late vacuolated microspores, in the buds 6.0–8.9 mm in length and 2.96 ± 0.37 mm in diameter; and two-celled pollen, in the buds more than 9 mm in length and more than 3.97 ± 0.34 mm in diameter

Critical metabolic pathways and genes cooperate for epoxy fatty acid-enriched oil production in developing seeds of Vernonia galamensis, an industrial oleaginous plant

BackgroundVernonia galamensis native to Africa is an annual oleaginous plant of Asteraceae family. As a newly established industrial oil crop, this plant produces high level (> 70%) of vernolic acid (cis-12-epoxyoctadeca-cis-9-enoic acid), which is an unusual epoxy fatty acid (EFA) with multiple industrial applications. Here, transcriptome analysis and fatty acid profiling from developing V. galamensis seeds were integrated to uncover the critical metabolic pathways responsible for high EFA accumulation, aiming to identify the target genes that could be used in the biotechnological production of high-value oils.ResultsBased on oil accumulation dynamics of V. galamensis seeds, we harvested seed samples from three stages (17, 38, and 45 days after pollination, DAP) representing the initial, fast and final EFA accumulation phases, and one mixed sample from different tissues for RNA-sequencing, with three biological replicates for each sample. Using Illumina platform, we have generated a total of 265 million raw cDNA reads. After filtering process, de novo assembly of clean reads yielded 67,114 unigenes with an N50 length of 1316 nt. Functional annotation resulted in the identification of almost all genes involved in diverse lipid-metabolic pathways, including the novel fatty acid desaturase/epoxygenase, diacylglycerol acyltransferases, and phospholipid:diacylglycerol acyltransferases. Expression profiling revealed that various genes associated with acyl editing, fatty acid β-oxidation, triacylglycerol assembly and oil-body formation had greater expression levels at middle developmental stage (38 DAP), which were consistent with the fast accumulation of EFA in V. galamensis developing seed, these genes were detected to play fundamental roles in EFA production. In addition, we isolated some transcription factors (such as WRI1, FUS3 and ABI4), which putatively regulated the production of V. galamensis seed oils. The transient expression of the selected genes resulted in a synergistic increase of EFA-enriched TAG accumulation in tobacco leaves. Transcriptome data were further confirmed by quantitative real-time PCR for twelve key genes in EFA biosynthesis. Finally, a comprehensive network for high EFA accumulation in V. galamensis seed was established.ConclusionsOur findings provide new insights into molecular mechanisms underlying the natural epoxy oil production in V. galamensis. A set of genes identified here could be used as the targets to develop other oilseeds highly accumulating valued epoxy oils for commercial production.

The vertical distribution and temporal occurrence of three types of rice planthoppers in Shanghai

AbstractIn this study, we investigated the dynamic occurrence and vertical distribution of three types of rice planthoppers (Nilaparvata lugens, Sogatella furcifera, and Laodelphax striatellus) in Shanghai, China. Our results showed that S. furcifera and L. striatellus infested the lower part of rice plants in the early development stage, S. furcifera and L. striatellus inhabited every part of rice in the middle development stage, and L. striatellus and N. lugens formicated in the upper part of the rice plant in the posterior development stage. The populations of rice planthoppers were larger in July and September, Where more than 600 adult and nymphal planthoppers, per a hundred hills of rice, were found in late July, and out of the 600, the majority were the nymphs of S. furcifera and L. striatellus. S. furcifera was mainly found from July to October, L. striatellus during the rice development, and N. lugens after September, during which their maximal individual number, per a hundred hills of rice, was 480, 220, less than 50, respectively. In addition, our results showed that adult rice planthoppers were mostly observed from late August to mid‐October with the highest population being found during mid to late September. The adult S. furcifera, L. striatellus, and N. lugens were mostly observed in August and September, from August to October, and past mid‐September, respectively. Moreover, the number of adult L. striatellus that were sticking to yellow sticky card was significantly higher than that of S. furcifera and N. lugens.

Assessing the Viability of American Horseshoe Crab (Limulus polyphemus) Embryos in Salt Marsh and Sandy Beach Habitats.

AbstractFor animal embryos that develop externally, the physio-chemical environment can substantially affect offspring viability. In the case of the American horseshoe crab (Limulus polyphemus), sediment conditions along estuarine shorelines influence development rates and embryonic viability. Sandy beach habitats are considered to have optimal conditions for horseshoe crab embryonic development; however, spawning is often observed outside of these optimal habitats, in areas such as salt marshes, where reduced oxygen availability is thought to decrease the viability of eggs laid in these sediments. We excavated horseshoe crab eggs, embryos, and trilobites laid naturally in marsh and beach sediments in South Carolina to compare their development and viability between habitats. We found all developmental stages in both marsh and beach habitats. For two of three sampling areas, trilobites were more likely to be found at beaches than at marshes. Multivariate analyses demonstrate that the prevalence of early and middle developmental stages was similar between habitats but that beaches had a greater proportion of late-stage trilobites than marshes. The lower likelihood of finding trilobites at some marshes may reflect differences in spawning phenology between habitats or reduced rates of embryonic development in marshes compared to beaches, leading to potentially different developmental timelines rather than a true reduction in viability. Nevertheless, the substantial proportions of eggs laid in salt marshes that survive to the trilobite stage indicate that spawning in this habitat could represent a previously underappreciated source of recruitment for horseshoe crab populations that may need to be incorporated into population assessments.

Dynamic transcriptome analysis identifies genes related to fatty acid biosynthesis in the seeds of Prunus pedunculata Pall

BackgroundPrunus pedunculata Pall, the deciduous shrub of Amygdalus subgenus in Rosaceae, is a new kind of desert oil-bearing tree. It has a long story of being planted in the West and North of China for sand fixation and desert control. In addition, the seeds of P. pedunculata are rich of oil, especially the monounsaturated fatty acid and polyunsaturated fatty acid. However, little is known about the molecular mechanisms of oil accumulation during the seed development of P. pedunculata.ResultsThe seeds of P. pedunculata from three independent plants at 10, 18, 24, 31, 39, 45, 59 and 73 days after flowering (DAF) were obtained and the oil compositions were evaluated. It showed that oleic acid was the dominant type of oil content in the mature seeds (from 32.724% at 10DAF to 72.06% at 73DAF). Next, transcriptome sequencing for the developing seeds produced 988.795 million high quality reads and TRINITY assembled 326,271 genes for the first transcriptome for P. pedunculata. After the assembled transcriptome was evaluated by BUSCO with 85.9% completeness, we identified 195,342, 109,850 and 121,897 P. pedunculata genes aligned to NR, GO and KEGG pathway databases, respectively. Then, we predicted 23,229 likely proteins from the assembled transcriptome and identified 1917 signal peptides and 5512 transmembrane related proteins. In the developing seeds we detected 91,362 genes (average FPKM > 5) and correlation analysis indicated three possible development stages – early (10 ~ 24DAF), middle (31 ~ 45DAF) and late (59 ~ 73DAF). We next analyzed the differentially expressed genes (DEGs) in the developing seeds. Interestingly, compared to 10DAF the number of DEGs was increased from 4406 in 18DAF to 27,623 in 73DAF. Based on the gene annotation, we identified 753, 33, 8 and 645 DEGs related to the fatty acid biosynthesis, lipid biosynthesis, oil body and transcription factors. Notably, GPAT, DGD1, LACS2, UBC and RINO were highly expressed at the early development stage, ω6-FAD, SAD, ACP, ACCA and AHG1 were highly expressed at the middle development stage, and LACS6, DGD1, ACAT1, AGPAT, WSD1, EGY2 and oleosin genes were highly expressed at the late development stage.ConclusionsThis is the first time to study the developing seed transcriptome of P. pedunculata and our findings will provide a valuable resource for future studies. More importantly, it will improve our understanding of molecular mechanisms of oil accumulation in P. pedunculata.

Comparative study of floral developments and its systematic importance in the genus Astragalus L. and Oxytropis DC. (Fabaceae, Leguminosae: Papilionoideae)

The initiation pattern of the floral organs of the Astragalus species displays uniqueness at the initial stages of ontogeny. However, its most common way is unidirectional initiation, which occurs from the abaxial to the adaxial sides. The overlapping of organs and the emergence of common primordia shortens the time of development and is of an evolutionary advantage to the genus. Astragalus species are constantly evolving, and they are bestowed with unique floral ontogeny that offers various advantages to these plants to survive and adapt to changing environmental conditions. The morphological features of the floral organ production of four Astragalus species were identical in the early and middle stages of development. During the middle and the late stages, some unique features such as rolled petals, sticky keel tips, diadelphous androecium were observed. Semi-circular receptacular nectaries were found in Astragalus henryi. Comparison of the inflorescence development between A. henryi and A. membranaceus revealed that A. membranaceus formed one terminal inflorescence, which developed into a raceme while A. henryi formed a variety of terminal inflorescences, branched by racemes to form panicles. Development of common primordia and organ overlap was also observed in both Oxytropis ochrocephala and Astragalus species. However, the most significant difference was observed in the keel petals of O. ochrocephala, which developed a beak at the later stages of development. The study unravels interesting relationships between four species of Astragalus and one species of Oxytropis. Study of floral ontogeny through series of sections using various microscopic techniques provided insights into the understudied floral traits of the genera. Such studies also need to be corroborated with other empirical evidence and analyses.

Kargopol ceramics: a separate type or a variety of pit-comb ceramics (on the example of materials from the settlements of Karelia)?

The purpose of this study is to consider the phenomenon of Kargopol ceramics in Karelia, which is manifested in its bright originality, sharp difference from other types of Neolithic ware and the vastness of the area-from Lake Onega in the west to the Pechora River in the east and from the Southern White Sea in the north to the southern limits of the Vologda Region in the south. There are 20 known settlements in Karelia, the complexes of which contain Kargopol ceramics with a total number of 275 vessels. The center of this layer of antiquities is Lake Vodlozero, located near the border of Karelia with the Arkhangelsk Region. Most Kargopol vessels have a straight flat-cut corolla with short and shallow notches applied from the outer and inner edges, below there is a horizontal belt of pits or punctures. There are six variants of ornamentation, three of which include elements of pit-comb and comb dishes. The authors think that the concentration of Kargopol vessels on the monuments of eastern Karelia, mainly in the complexes with pit-comb ceramics of the middle stage of development in the lake basin Vodlozera, and its almost complete absence in other areas of Karelia indicates the penetration of a similar ceramic tradition from the Eastern Prionezh Region, where it was first isolated. Based on the available modern data, it is still difficult to talk about the independent existence of Kargopol ceramics in the Neolithic of Karelia.

Population Characteristics of Loess Gully System in the Loess Plateau of China

Gullies in the Loess Plateau of China vary in developmental stages and morphologic sizes. In this case study, in Linjialian watershed in the loess hilly region, we introduced some perspectives from population ecology to explore the population characteristics of the loess gully system. Different types of gullies were extracted based on the digital elevation model and imagery data. Population analysis was then carried out from three aspects, namely, quantity, structure, and distribution. Results showed that in terms of the quantity, hillslope ephemeral gullies (187 numbers/km2 in number density) and bank gullies (8.3 km/km2 in length density) are the most active gullies in this area with an exponential growth trend, and the hillslope ephemeral gully is the dominant type. Along with age structure analysis, the pyramid-shaped age structure indicated that the gully system is at its early or middle stages of development. The spatial distribution of hillslope ephemeral gullies has a clear aspect asymmetry pattern, and the bank gully distribution is symmetrical. A hierarchical structure (hillslope ephemeral gully–bank gully–valley gully in upslope–shoulder line–bottom area) in an elevation distribution is presented. These preliminary results are helpful for further understanding the organized, systematic development, and evolution of the gully system.