food chain

食物链
  • 文章类型: Journal Article
    脱氧雪腐镰刀菌烯醇(DON)及其衍生物3-乙酰脱氧雪腐镰刀菌烯醇(3-Ac-DON)和15-乙酰脱氧雪腐镰刀菌烯醇(15-Ac-DON)在整个小麦加工链中的分布通过一对一进行了系统评估整个加工链的相应研究。通过液相色谱-质谱(LC-MS/MS)测定小麦籽粒和相应麦麸中的DON及其衍生物,小麦粉,以及以小麦粉为基础的半成品和成品。这项研究表明,将小麦谷物加工成小麦面粉可使DON的水平显着降低约52.7%-68.2%。以小麦粉为基础的产品的小麦粉加工使DON浓度降低了约7.0%-70.6%。在处理方法中,饼干产量下降幅度最大(70.6%)。小麦籽粒和麦麸中3-Ac-DON和15-Ac-DON含量较低的DON同时出现的频率明显高于小麦粉。对于以小麦粉为基础的产品,在使用严重污染DON的谷物制备的加工小麦粉产品中,只能观察到3-Ac-DON的分布模式。在中国,据我们所知,首次系统评价了小麦粉和小麦粉制品中DON的加工因素。小麦粉的DON平均PF为0.35,小麦粉产品的平均PF为0.37-0.84,饼干的PF最小(0.37),表明DON在饼干制作中显著减少。此外,DON的饮食暴露评估表明,中国消费者的整体健康风险可接受,在婴儿和幼儿中观察到最高的暴露。本研究为我国小麦及其各类产品DON限量的分类管理提供了重要参考。
    The distribution of deoxynivalenol (DON) and its derivatives 3-acetyldeoxynivalenol (3-Ac-DON) and 15-acetyldeoxynivalenol (15-Ac-DON) throughout the wheat processing chain were systemically evaluated by one-to-one corresponding studies of the whole processing chain. DON and its derivatives were determined by liquid chromatography-mass spectrometry (LC-MS/MS) in wheat grains and corresponding wheat bran, wheat flour, and semi-finished and finished wheat flour-based products. This investigation showed that wheat grain processing to wheat flour significantly decreased the levels of DON by approximately 52.7%-68.2%. Wheat flour processing of wheat flour-based products decreased the DON concentration by approximately 7.0%-70.6%. Among the processing methods, biscuit making showed the largest reduction (70.6%). The co-occurrence frequency of DON with low levels of 3-Ac-DON and 15-Ac-DON was significantly greater in wheat grains and wheat bran than in wheat flour. For wheat flour-based products, only the distribution pattern of 3-Ac-DON was observable in processed wheat flour products prepared using grains heavily contaminated with DON. In China, to the best of our knowledge, the processing factors (PFs) of DON in wheat flour and wheat flour-based products were systematically evaluated for the first time. The average PF of DON was 0.35 for wheat flour and the average PFs were 0.37-0.84 for wheat flour-based products, with biscuits having the smallest PF (0.37), indicating DON significantly decreasing in biscuit making. Furthermore, dietary exposure assessment of DON indicated an acceptable overall health risk in Chinese consumers, with the highest exposure being observed in infants and young children. This study provides important references for classified management of DON limits in wheat and its various products in China.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    随机食物链模型是生态学研究领域中的一个重要模型。由于现有模型难以描述交叉扩散和随机因素对物种种群演化的影响,这项工作涉及具有猎物-出租车的随机交叉扩散三物种食物链模型,其中捕食者的运动方向与猎物的梯度相反,即,更高密度的猎物。利用随机Galerkin逼近方法在Hilbert空间中建立了martingale解的存在性和唯一性。密封性标准,Jakubowski对Skorokhod定理的推广,和维塔利收敛定理。此外,研究了时间平均意义下随机交叉扩散三物种食物链模型稳态的渐近行为。最后,进行了数值模拟,以说明我们的分析结果。
    The stochastic food chain model is an important model within the field of ecological research. Since existing models are difficult to describe the influence of cross-diffusion and random factors on the evolution of species populations, this work is concerned with a stochastic cross-diffusion three-species food chain model with prey-taxis, in which the direction of predators\' movement is opposite to the gradient of prey, i.e., a higher density of prey. The existence and uniqueness of martingale solutions are established in a Hilbert space by using the stochastic Galerkin approximation method, the tightness criterion, Jakubowski\'s generalization of the Skorokhod theorem, and the Vitali convergence theorem. Furthermore, asymptotic behaviors around the steady states of the stochastic cross-diffusion three-species food chain model in the time mean sense are investigated. Finally, numerical simulations are carried out to illustrate the results of our analysis.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    有机磷酸酯(OPEs)已被广泛生产和使用,而对它们在食物链中的发生和潜在来源知之甚少。在这项研究中,生牛奶,奶牛喝水,饲料是从中国各地的牧场收集的,和OPEs进行了测试,以探索OPEs在食物链中的发生和传播,并通过某些食物消费进一步评估奶牛和人类的每日OPE摄入量。原料乳中∑OPEs(15OPEs之和)的中位数水平为2140pg/mL,磷酸三(1-氯-2-丙基)酯(TCIPP)是最丰富的OPE。除磷酸三乙酯(TEP)外,水中的OPEs水平低于原奶,而饲料中大多数OPEs的水平明显高于原奶(按干重调整)。奶牛通过饲料摄入的OPEs估计为2530ng/kgbw/天,远高于水(742纳克/千克体重/天),表明饲料是更关键的暴露源。对于液态奶消费者来说,在3-17岁和成人中,∑15OPE的高暴露(第95位)估计每日摄入量(EDI)分别为20和7.11ng/kgbw/天,分别,很明显,奶牛的OPE摄入量要重得多。最后,计算的危害指数(HIs)表明,通过食用牛奶摄入OPEs不会对中国人口构成重大健康风险。
    Organophosphate esters (OPEs) have been widely produced and used, while little is known about their occurrence in the food chain and potential sources. In this study, raw cow milk, cow drinking water, and feed were collected from pastures across China, and OPEs were tested to explore the occurrence and transmission of OPEs in the food chain and to further assess daily OPE intakes for cows and humans via certain food consumption. The median level of ∑OPEs (sum of 15 OPEs) in raw milk was 2140 pg/mL, and tris(1-chloro-2-propyl) phosphate (TCIPP) was the most abundant OPE. Levels of OPEs in water were lower than those in raw milk except for triethyl phosphate (TEP), while levels of most OPEs in feed were significantly higher than those in raw milk (adjusted by dry weight). The estimated dietary intake of OPEs via feed for cows was 2530 ng/kg bw/day, which was much higher than that via water (742 ng/kg bw/day), indicating that feed was a more critical exposure source. For liquid milk consumers, the high-exposure (95th) estimated daily intakes (EDIs) of ∑15OPE were 20 and 7.11 ng/kg bw/day for 3-17 years and adults, respectively, and it is obvious that cows had much heavier OPE intake. Finally, the calculated hazard indexes (HIs) suggested that the intake of OPEs via cow milk consumption would not pose significant health risks to the Chinese population.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    土壤微生物组被认为是健康土壤的重要组成部分。土壤中的病毒也是多样和丰富的,但它们在土壤系统中的作用尚不清楚。在这里,我们主张考虑土壤微生物食物网中的病毒,并描述病毒对土壤生物地球化学的影响。土壤食物网是一系列复杂的营养水平,从自养微生物到植物和动物。每个土壤系统都包含对比和动态的物理化学条件,由颗粒组成的迷宫栖息地。条件容易发生时空变化,这种可变性可以阻碍或促进微生物和病毒的相互作用。因为病毒可以感染生命的所有领域,它们必须被视为土壤食物网动态和生物地球化学循环的关键调节剂。我们强调了未来的研究途径,这些途径将使人们能够更有力地了解病毒在土壤功能和健康中的作用。
    The soil microbiome is recognized as an essential component of healthy soils. Viruses are also diverse and abundant in soils, but their roles in soil systems remain unclear. Here we argue for the consideration of viruses in soil microbial food webs and describe the impact of viruses on soil biogeochemistry. The soil food web is an intricate series of trophic levels that span from autotrophic microorganisms to plants and animals. Each soil system encompasses contrasting and dynamic physicochemical conditions, with labyrinthine habitats composed of particles. Conditions are prone to shifts in space and time, and this variability can obstruct or facilitate interactions of microorganisms and viruses. Because viruses can infect all domains of life, they must be considered as key regulators of soil food web dynamics and biogeochemical cycling. We highlight future research avenues that will enable a more robust understanding of the roles of viruses in soil function and health.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    重金属被定义为影响害虫生物防治效率的非生物因素。本研究构建了镉(Cd)污染的人工日粮-美国白蛾-中国白蛾食物链,以分析Cd暴露对中国紫菜控制H.cunea能力的影响。结果表明,Cd通过人工饮食通过生物放大作用转移到山葵幼虫和若虫中。以Cd积累的H.cunea幼虫为食后,中国若虫的体重减少了,死亡率增加,发育持续时间延长,和生长调节基因的表达(EX,cycE,和MER)下降。Cd激活若虫的抗氧化防御系统,伴随着H2O2和MDA含量的显着增加,中肠亚微观结构明显损伤,以及对线粒体途径/ER应激-凋亡途径至关重要的基因表达的显着诱导。Cd显著降低了总氨基酸的含量,葡萄糖,游离脂肪酸,和基因的表达(HK2,PFK,IDH1和IDH2)对于若虫的TCA循环和糖酵解至关重要。中国若虫若虫对Cd处理的H.cunea幼虫的偏好明显降低。Cd降低了搜索能力,食物摄入量,瞬时攻击率,和最大的理论每日食物摄入量,但延长若虫的摄食时间。一起来看,Cd暴露降低了中国若虫的防虫能力,并为利用天敌控制害虫的效率提供了新的挑战。研究结果对优化重金属污染区病虫害防治策略具有重要的参考价值。
    Heavy metals are defined as an abiotic factor that affects the efficiency of biological pest control. This study constructed a cadmium (Cd)-polluted artificial diets-Hyphantria cunea-Arma chinensis food chain to analyze the effects of Cd exposure on the ability of A. chinensis to control H. cunea. The results revealed that Cd was transferred through the artificial diet to H. cunea larvae and A. chinensis nymphs via a biological amplification effect. After feeding on Cd-accumulated H. cunea larvae, the body weight of A. chinensis nymphs reduced, mortality increased, developmental duration prolonged, and the expression of growth regulatory genes (EX, cycE, and MER) decreased. Cd activated the antioxidant defense system of the nymphs, accompanied by a significant enhancement in the contents of H2O2 and MDA, marked damage to the midgut sub-microstructure, and a remarkable induction in the expression of genes crucial for the mitochondrial pathway/ER stress-apoptosis pathway. Cd significantly diminished the contents of total amino acids, glucose, free fatty acids, and expression of the genes (HK2, PFK, IDH1, and IDH2) essential for the TCA cycle and glycolysis in the nymphs. The preference of the A. chinensis nymphs to Cd-treated H. cunea larvae was evidently reduced. Cd diminished the search-ability, food intake, instantaneous attack rate, and maximum theoretical daily food intake but prolonged the feeding time of the nymphs. Taken together, Cd exposure reduces the ability of A. chinensis nymphs to control H. cunea and provides a new challenge for the efficiency of insect pest control using natural enemies. These findings have important reference value for optimizing pest control strategies in heavy metal polluted areas.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    公海中的蛋白质是有机物质的重要来源,它们的轮廓反映了海洋微生物的代谢活动。这里,通过分析从太平洋收集的元蛋白质组样本,大西洋和南大洋,我们揭示了水柱中海洋微生物群蛋白质库的结构和功能的大小分级模式,特别是在黑暗的海洋(>200米)。浮游动物蛋白对深海群落蛋白质组的贡献是藻类蛋白的三倍。γ蛋白细菌在深海中表现出很高的代谢活性,贡献高达30%的细菌蛋白质。该分类单元的紧密的病毒-宿主相互作用可能解释了γ蛋白在溶解部分中的优势。硝化者中尿素酶的高表达表明它们的暗碳固定与浮游动物尿素产生之间存在联系。总之,我们的结果揭示了微生物群对海洋蛋白质库的分类学贡献,揭示蛋白质从颗粒到溶解的有机物池的通量。
    Proteins in the open ocean represent a significant source of organic matter, and their profiles reflect the metabolic activities of marine microorganisms. Here, by analyzing metaproteomic samples collected from the Pacific, Atlantic and Southern Ocean, we reveal size-fractionated patterns of the structure and function of the marine microbiota protein pool in the water column, particularly in the dark ocean (>200 m). Zooplankton proteins contributed three times more than algal proteins to the deep-sea community metaproteome. Gammaproteobacteria exhibited high metabolic activity in the deep-sea, contributing up to 30% of bacterial proteins. Close virus-host interactions of this taxon might explain the dominance of gammaproteobacterial proteins in the dissolved fraction. A high urease expression in nitrifiers suggested links between their dark carbon fixation and zooplankton urea production. In summary, our results uncover the taxonomic contribution of the microbiota to the oceanic protein pool, revealing protein fluxes from particles to the dissolved organic matter pool.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    长江江豚(YFP,新毛白鲸)是在中国发现的唯一淡水鲸目动物。然而,YFP中的全氟烷基物质和多氟烷基物质(PFASs)风险尚不清楚。在这项研究中,遗留PFAS,它们的前体和替代品,在YFP肌肉中测定(n=32),肝脏(n=29),肾(n=24),皮肤(n=5),2017年至2023年从鄱阳湖(PL)和长江(YR)收集的鲸脂(n=25)。全氟辛烷磺酸(PFOS)是所有YFP组织中主要的PFAS,肝脏浓度中位数为1700ng/g湿重,高于全球其他江豚。全氟辛烷磺酸,氯化多氟醚磺酸盐(Cl-PFESA),来自PL的YFP肝脏中的全氟烷烃磺胺类药物浓度显着高于来自YR的水平(p<0.05);但是,对于六氟环氧丙烷酸观察到相反的情况。生物放大和营养放大因子(BMF和TMF,分别)YFP食物网中大多数PFAS>1。全氟庚烷磺酸具有最高的BMF值(99),其次是6:2Cl-PFESA(94)和全氟辛烷磺酸(81)。总PFAS的TMFmuscum和TMFliver值分别为3.4和6.6,与氟化碳链长度呈极显著正相关(p<0.01)。此外,高达62%的6:2Cl-PFESA的危险商数>1,高于全氟辛烷磺酸(48%),提示6:2Cl-PFESA对YFP的高肝毒性。遗留物和新兴替代品在水生生物中的生物累积和生物毒性仍然是一个令人关切的问题,特别是强调长寿和濒危物种的脆弱性。
    The Yangtze finless porpoise (YFP, Neophocaena asiaeorientalis asiaeorientalis) is the only freshwater cetacean found in China. However, per- and polyfluoroalkyl substances (PFASs) risks in YFPs remain unclear. In this study, legacy PFASs, their precursors and alternatives, were determined in YFP muscles (n = 32), liver (n = 29), kidney (n = 24), skin (n = 5), and blubbers (n = 25) collected from Poyang Lake (PL) and Yangtze River (YR) between 2017 and 2023. Perfluorooctane sulfonic acid (PFOS) was the predominant PFAS in all YFP tissues, with a median hepatic concentration of 1700 ng/g wet weight, which is higher than that in other finless porpoises worldwide. PFOS, chlorinated polyfluorinated ether sulfonates (Cl-PFESAs), and perfluoroalkane sulfonamides concentrations in YFP livers from PL were significantly higher than those from YR (p < 0.05); however, the opposite was observed for hexafluoropropylene oxide acids. Biomagnification and trophic magnification factors (BMF and TMF, respectively) of most PFASs in the YFP food web were > 1. Perfluoroheptane sulfonic acid had the highest BMF value (99), followed by 6:2 Cl-PFESA (94) and PFOS (81). The TMFmuscle and TMFliver values of the total PFASs were 3.4 and 6.6, respectively, and were significantly positively correlated with the fluorinated carbon chain length (p < 0.01). In addition, up to 62 % of the hazard quotients for 6:2 Cl-PFESA were > 1, which was higher than that of PFOS (48 %), suggesting a high hepatotoxicity of 6:2 Cl-PFESA to YFPs. Bioaccumulation and biotoxicity of legacy and emerging alternatives in aquatic organisms continue to be a concern, especially for underscoring the vulnerability of the long-lived and endangered species.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    水母在食物网的物质循环和能量流动中起着重要作用,大量聚集可能对当地渔业产生有害后果;然而,水母花对沿海渔业的营养影响的理论框架尚不清楚。为了解决这个知识差距,我们通过稳定同位素分析评估了中国沿海水域(CWC)中同时发生的水母与优势鱼群(杂食性鱼类和食鱼)之间的营养相互作用;随后,我们讨论了水母水华如何影响沿海生态系统的能量流。我们的结果表明,水母和小型杂食性鱼类(<10厘米)之间存在相当程度的营养重叠(平均比例>65%),突出了喂养习惯的相似性,而重叠率下降到<55%的大型杂食性鱼群(>10厘米)。在水母生物量较高的生态系统中发现了相对较高的营养水平和较小的大型杂食性鱼类重叠,这表明它们可能会加强个体发育的营养转移模式,以减轻在水母爆炸条件下与水母进行资源竞争的潜力。最小的营养重叠(<20%)强调了水母和食鱼之间的强烈营养差异。此外,我们的研究表明,水母的大量聚集会对浮游动物产生负面影响,但可能无法有效地进一步传递能量,暗示CWC生态系统中水母与上层营养水平之间的营养耦合较弱。因此,我们推测,水母在塑造食物网能量转移的途径中起着重要作用,大量的水华可能会通过自下而上的控制影响猎物的可用性而对渔业产生负面影响。总的来说,这些结果对进一步加深对水母和鱼类种群之间营养相互作用的理解具有很强的潜力。此外,这项研究为预测水母开花对生态系统的影响提供了有价值的数据,对于基于生态系统的沿海渔业管理至关重要。
    Jellyfish play an important role in the material cycling and energy flow of food webs, and massive aggregations may have deleterious consequences for local fisheries; yet a theoretical framework of the trophic effects of jellyfish blooms on coastal fisheries is unclear. To address this knowledge gap, we assessed the trophic interactions between cooccurring bloom jellyfish and dominant fish groups (omnivorous fish and piscivorous fish) in the coastal waters of China (CWC) via stable isotope analysis; we subsequently discussed how jellyfish blooms may affect energy flow through coastal ecosystems. Our results indicate a considerable degree of trophic overlap (mean ratio > 65 %) between jellyfish and small omnivorous fish (< 10 cm), highlighting a similarity in feeding habits, while the overlap ratio decreased to <55 % of the large omnivorous fish group (> 10 cm). Relatively higher trophic levels and smaller overlaps of large omnivorous fish were found in the ecosystem with high jellyfish biomass, which suggested that they may reinforce the ontogenetic trophic shift pattern to alleviate the potential for resource competition with jellyfish under conditions of jellyfish explosion. The smallest trophic overlap (< 20 %) highlighted the strong trophic differentiation between jellyfish and piscivorous fish. Additionally, our study suggested that a massive aggregation of jellyfish can negatively influence zooplankton but may not transfer energy further up efficiently, implying a weak trophic coupling between jellyfish and upper-trophic levels in CWC ecosystems. Thus, we speculate that jellyfish play an important role in shaping pathways involved in the energy transfer of food webs and that large blooms may negatively affect fisheries through bottom-up control affecting prey availability. In general, these results hold strong potential to further improve the understanding of the trophic interactions between jellyfish and fish populations. Furthermore, this study provides valuable data for predicting the consequences of jellyfish blooms on ecosystems, and is crucial for ecosystem-based management of coastal fisheries.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    海底荒漠化日益凸显了海底栖息地恢复的重要性。战略工程人工鱼礁在实现恢复目标方面至关重要。然而,尚未认识到基础物种对不同人工鱼礁中生物成分和生态系统属性的重大影响。本研究整理了黄渤海沿岸人工鱼礁及其相应的自然控制生态系统的20个Ecopath模型,中国,根据基础物种的生物量和生产力,将它们分为五种不同的系统类型。我们的结果表明,无量纲指数,而不是实际的系统值,被认为是为了促进相互比较分析。比较分析揭示了生物量分布的差异,能源利用,以及五种生态系统类型的营养结构。所有人工鱼礁系统共同提高了初级生产的利用率。基础物种组件构成了系统功能的基石,通过调节能量流动力学显著影响生态系统的稳定性。观察到贝类和大型藻类的不同影响;前者增加了碎屑食物链,而后者加强了放牧的食物链。因此,基于模型的综合分析能够对不同类型的人工鱼礁生态系统进行稳健比较,并证实促进基础物种的定殖是人工鱼礁设计和部署过程中不可忽视的因素.
    The seabed desertification has increasingly highlighted the importance of benthic habitat restoration. Strategically engineered artificial reefs emerges as pivotal in achieving restoration objectives. However, the significant influence of foundation species on biotic components and ecosystem attributes within diverse artificial reefs has been underrecognized. This study collated twenty Ecopath models of artificial reefs and their corresponding natural control ecosystems along the coasts of the Yellow Sea and Bohai Sea, China, categorizing them into five distinct system types predicated on the biomass and productivity of foundational species. Our results suggest that dimensionless indices, rather than actual system values, were posited to facilitate inter-comparative analysis. The comparative analysis revealed differences in biomass distribution, energy utilization, and trophic structure across the five ecosystem types. All the artificial reef systems collectively enhanced the utilization of primary production. Foundation species components formed the cornerstone of system functionality, significantly impacting ecosystem stability through modulation of energy flow dynamics. Distinct impacts were observed from shellfish and macroalgae; the former augmenting the detrital food chain, while the latter bolstering the grazing food chain. Consequently, the model-based integrated analysis enabled a robust comparison among various types of artificial reef ecosystems and confirmed that promoting the colonization of foundation species was a non-negligible factor in the design and deployment of artificial reefs.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    本文旨在建立平流环境中空间生态流行病学捕食者-食饵系统连接不同均衡的行波解的存在性。应用行波坐标后,这些解对应于相空间中的异斜轨道。我们使用射击方法研究了从边界平衡到共存平衡的行波解的存在性。与黄介绍的技术不同,我们通过构造一个特殊的有界集,直接证明了解对共存均衡的收敛性。此外,我们构造的Lyapunov型函数不需要下面的有界条件。我们的方法提供了一种不同的方法来研究关于共存平衡的行波解的存在性。利用定性理论和几何奇异摄动理论证明了共存均衡之间行波解的存在性。本文还讨论了其他一些感兴趣的悬而未决的问题。
    This paper aims to establish the existence of traveling wave solutions connecting different equilibria for a spatial eco-epidemiological predator-prey system in advective environments. After applying the traveling wave coordinates, these solutions correspond to heteroclinic orbits in phase space. We investigate the existence of the traveling wave solution connecting from a boundary equilibrium to a co-existence equilibrium by using a shooting method. Different from the techniques introduced by Huang, we directly prove the convergence of the solution to a co-existence equilibrium by constructing a special bounded set. Furthermore, the Lyapunov-type function we constructed does not need the condition of bounded below. Our approach provides a different way to study the existence of traveling wave solutions about the co-existence equilibrium. The existence of traveling wave solutions between co-existence equilibria are proved by utilizing the qualitative theory and the geometric singular perturbation theory. Some other open questions of interest are also discussed in the paper.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

公众号