Response to the Lomagundi-Jatuli Event in the southwestern margin of the Yangtze Plate:Evidence from the carbon and oxygen isotopes of the Paleoproterozoic Yongjingshao Formation

The Lomagundi-Jatuli Event(LJE)refers to the significant positive carbon isotope excursion in seawater constituents that occurred immediately after the increase in atmospheric oxygen content during the Paleoproterozoic(2.22-2.06 Ga).Theδ^(13)C values of 46 dolostone samples collected from the Paleoproterozoic Yongjingshao Formation varied in the range of 0.05‰-4.95‰(V-PDB;maximum:4.95‰)in this study,which may be related to the multicellular eukaryotes in the Liangshan Formation in the Yimen Group.They are much higher than theδ^(13)C values of marine carbonates(-1.16‰on average).Theδ^(13)C values of other formations in the Paleoproterozoic Yimen Group are negative.The notable positive carbon isotope anomalies of the Yongjingshao Formation indicate the response to the LJE at the southwestern margin of the Yangtze Block,which is reported for the first time.Furthermore,they are comparable to theδ^(13)C values of carbonates in the Dashiling Formation of the Hutuo Group in the Wutaishan area in the North China Craton,the Wuzhiling Formation of the Songshan Group in the Xiong'er area,Henan Province,and the Dashiqiao Formation of the Liaohe Group in the Guanmenshan area,Liaoning Province.Therefore,it can be further concluded that the LJE is a global event.This study reveals that LJE occurred in Central Yunnan at 2.15-2.10 Ga,lasting for about 50 Ma.The macro-columnar,bean-shaped,and microfilament fossils and reticular ultramicrofossils of multicellular eukaryotes in this period were discovered in the Liangshan Formation of the Yimen Group.They are the direct cause for the LJE and are also the oldest paleontological fossils ever found.The major events successively occurring in the early stage of the Earth include the Great Oxygenation Event(first occurrence),the global Superiortype banded iron formations(BIFs),the Huronian glaciation,the Great Oxygenation Event(second occurrence),the explosion of multicellular eukaryotes,the positive carbon isotope excursion,and the global anoxic and selenium-rich sedimentary event.The authors think that the North China Craton and the Yangtze Craton were possibly in different tectonic locations of the same continental block during the Proterozoic.

大数据治理技术与央地关系的优化——基于信息政治学视角的分析

央地关系是中国国家治理的重要环节,对治理现代化的实现举足轻重。既有研究着重分析科层体系的相关因素对央地关系优化的影响,却鲜有研究系统考察信息属性的治理工具在此过程中的作用。作为一种全新的信息治理工具,大数据为国家治理带来全新机遇,相关治理技术在中国场景下应用,对央地关系有何影响?其内在作用逻辑是何?基于信息政治学,研究认为,信息不对称难题的存在使中国央地关系长期陷入“一统就死,一放就乱”的困境。而大数据具有获取更多维度、更广泛群体和内容真实信息的优势,理论上能帮助中央政府充分掌握信息、缓解信息不对称局面,从而优化中国的央地关系。大数据治理技术优化央地关系主要通过经济、技术和内容这三条路径。具体作用机制为:一是降低信息获取和运用成本,使缓解信息不对称具有可持续性,推动常态型优化;二是提升信息获取时效性,使克服信息不对称具有技术可行性,推动信息型优化;三是提升信息质量和真实性,使缓解信息不对称在内容上具有实质性,从而有助于从决策内容和质量方面实质地优化央地关系。因此,大数据治理技术发挥作用,有利于央地政府间最终实现良性互动和相互协作的新型关系模式,摆脱以往的循环怪圈。不同于既有文献,论文从信息维度出发,较为系统、深刻地揭示出央地关系内在张力的深层次逻辑,为优化央地关系提供全新的分析视角和理论解释,丰富了对大数据蕴含的相关治理意蕴的认识,同时也为实践中运用大数据技术提供政策启示。

Integrating genome-wide association and transcriptome analysis to provide molecular insights into heterophylly and eco-adaptability in woody plants

Heterophylly is regard as an important adaptive mechanism in response to different environments within plants.However,the genetic mechanisms responsible for heterophylly in woody plants are still poorly understood.Herein,the divergence of heterophyllous leaves was investigated at morphogenesis and using microdissection and physiological indexes in paper mulberry,and the genetic basis of heterophylly was further revealed combined with genome-wide association study(GWAS),transcriptome analysis and weighted gene coexpression network analysis(WGCNA).Our results revealed that the flavonoid content and antioxidant activity increased gradually from the entire leaf to the palmatisect leaf,while the hormone content and net photosynthetic rate decreased.Through GWAS and transcriptome analysis,a total of 98 candidate genes and 2338 differentially expressed genes associated with heterophylly were identified.Importantly,we uncovered critical variations in the candidate genes Bp07g0981(WOX)and Bp07g0920(HHO),along with significant differences in haplotypes and expression levels among heterophyllous leaves.Our results also suggested that the genes involved in hormone signaling pathways,antioxidant activity,and f lavonoid metabolism might be closely related to the heterophylly of paper mulberry,which could account for the physiological data.Indeed,CR-wox mutant lines showed significant changes in leaf phenotypes,and differential expression profile analysis also highlighted the expression of genes related to phytohormones and transcription factors.Together,the genetic variations and candidate genes detected in this study provide novel insights into the genetic mechanism of heterophylly,and would improve the understanding of eco-adaptability in heterophyllous woody plants.

碳化硼增强铝基复合材料的摩擦磨损性能

为了比较两种含量不同的碳化硼颗粒增强铝基复合材料的摩擦学性能,将其加工成销试样,在多功能摩擦磨损试验机上分别与钢盘试样进行对比摩擦磨损试验,重点研究了接触载荷和相对滑动速度对两种复合材料摩擦磨损性能的影响。结果表明:碳化硼增强铝基复合材料的磨损量随载荷与相对滑动速度的增大而增大,而摩擦因数随载荷与相对滑动速度的增大而减小,较高碳化硼含量的复合材料的耐磨性能比较低含量的复合材料好。

聚己内酯对左旋聚乳酸结晶行为的影响

采用端羟基聚己内酯(PCL)并控制丙交酯(L-LA)的质量合成不同嵌段长度的PLLA-PCL-PLLA三嵌段共聚物;使用相对分子质量相近的左旋聚乳酸(PLLA)与PCL均聚物共混得到PLLA/PCL共混物。红外光谱测试和核磁共振氢谱测试确定了共聚物结构。差示扫描量热(DSC)测试结果表明,PCL的引入有效提高了PLLA嵌段共聚物和PLLA均聚物的结晶速率。利用DSC考察总结晶速率,热台偏光显微镜考察生长速率,结果表明当共聚物中PLLA嵌段相对分子质量与共混物中PLLA均聚物相对分子质量相当时,PLLA嵌段与PLLA均聚物结晶速率相当。PCL的加入使得PLLA最大结晶速率所对应的温度降低,其加入方式对PLLA的结晶形貌有一定的影响,无论以共聚或共混的方式引入PCL均对PLLA结晶速率的提高有积极作用。

IN VIVO ~1 H MAGNETIC RESONANCE SPECTROSCOPY IN EVALUATION OF HEPATOCELLULAR CARCINOMA AND ITS EARLY RESPONSE TO TRANSCATHETER ARTERIAL CHEMOEMBOLIZATION

Objective To investigate the value of in vivo proton magnetic resonance spectroscopy （MRS） in the assessment of hepatocelhilar carcinoma （HCC） and monitor its metabolic change shortly after transcatheter arterial chemoembolization （TACE）. Mothoda In this prospective study, 28 consecutive patients with large HCC （ ≥3 cm in diameter） confirmed by fine needle aspiration biopsy were recruited. The ^1H MRS of all hepatic lesions and some uninvolved liver parenchyma were performed with 1.5T whole body MR scanner. Among them, 15 cases were evaluated again about one week after TACE. The main metabolites such as choline and lipid before and after interventional therapy were measured to assess the early response of the tumor. The technical success rate of IH MRS in liver was high （33/41, 80% ）, closely related to breath motion, location of lesion, and size of voxeL In spectra, the choline compound peak of HCC elevated compared with uninvolved liver parenchyma. After TACE, both the amplitude and the area of choline resonance peak significantly descended （ choline-to-lipid ratios from 0.352±0. 080 to 0. 167±0. 030, P = 0. 026; from 0. 205±0. 060 to 0. 070±0. 020, P = 0. 042, respectively ） ; yet lipid resonance peak ascended. Conclusions In vivo tH MRS is technically feasible for the evaluation of large focal hepatic lesions, however, the reproducibility and stability are not as good as routine MR scan. IH MRS can monitor the early stage metabolic changes of HCC after TACE but limitation like quantification still exists.

Effect of b value on monitoring therapeutic response by diffusion-weighted imaging

AIM： To explore the diffusion gradient b-factor that optimizes both apparent diffusion coefficient （ADC） measurement and contrast-to-noise （CNR） for assessing tumor response to transarterial chemoembolization （TACE） in a rabbit model. METHODS： Twelve New Zealand white rabbits bearing VX2 tumors in the liver were treated with TACE. Diffusion-weighted imaging （DWI） with various b values was performed using the same protocol before and 3 d after treatment with TACE. ADC values and CNR of each tumor pre- and post-treatment with different b factors were analyzed. Correlation between ADC values and extent of necrosis in histological specimens was analyzed by a Pearson＇s correlation test.RESULTS： The quality of diffusion-weighted images diminished as the b value increased. A substantial decrease in the mean lesion-to-liver CNR was observed on both pre- and post-treatment DW images, the largest difference in CNR pre- and post-treatment was manifested at a b value of 1000 s/mm^2 （P = 0.036 ）. The effect of therapy on diffusion early after treatment was shown by a significant increase in ADCs （P = 0.007）, especially with large b factors （≥ 600 s/mm^2）. The mean percentage of necrotic cells present within the tumor was 76.3%-97.5%. A significant positive correlation was found between ADC values and the extent of necrosis with all b values except for b200, a higher relative coefficient between ADC values and percentage of necrosis was found on DWI with bl000 and b2000 （P = 0.002 and 0.006, respectively）. CONCLUSION： An increasing b value of up to 600 s/mm^2 would increase ADC contrast pre- and post-treatment, but decrease image quality. Taking into account both CNR and ADC measurement, diffusion-weighted imaging obtained with a b value of 1000 s/mm^2 is recommended for monitoring early hepatic tumor response to TACE.

“内外有别”:政治参与何以影响公众的获得感?

随着中国特色社会主义进入新时代,提升公众获得感已成为以人民为中心发展理念的题中应有之义。因此,获得感的影响机制是一个极具理论和现实意义的话题。既有研究主要从实实在在的物质“成果”(即政府施政的结果)来解析公众获得感的差异,然而,系统地考察机会享有(即政治过程的参与)对获得感的影响还鲜有其人。事实上,政治参与是现代政治的基本特征,也是中国特色社会主义政治文明发展的重要内容。那么,公众的政治参与是否影响获得感?具体有何作用?此外,政治参与存在不同类型,体制内参与和体制外参与对获得感的影响是否完全相同?上述困惑尚未得到学界的系统讨论和实证分析,存在较大的学理探讨空间。鉴于此,论文在具体研究中将政治参与分为体制内参与和体制外参与,利用中国社会状况调查(CSS)的混合截面数据,对获得感进行实证分析。研究发现,体制外参与(包括网络参与和线下参与)不论是行为还是意愿程度的提高,都会显著降低公众获得感;相反,体制内参与(基层选举)的行为和意愿程度的提高,都会显著提升公众获得感;另外,公众参与行为和参与意愿对获得感的影响在作用方向上存在一致性。论文紧扣中国国家治理的时代主线,进一步揭示出获得感的影响机制,从过程性视角重塑了对获得感生成逻辑的既有认知。据此,在未来的国家治理实践中,应更为重视政治参与的作用,不断健全和完善公众通过制度化方式参与公共生活的途径,减少和降低公众试图在体制外寻求参与的行为和意愿。

Assessment of hemodynamics in precancerous lesion of hepatocellular carcinoma:Evaluation with MR perfusion

AIM: To investigate the hemodynamic changes in a precancerous lesion model of hepatocellular carcinoma (HCC). METHODS: Hemodynamic changes in 18 Wistar rats were studied with non-invasive magnetic resonance (MR) perfusion. The changes induced by diethylnitrosamine (DEN) developed into liver nodular lesions due to hepatic cirrhosis during the progression of carcinogenesis. The MR perfusion data [positive enhancement integral (PEI)] were compared between the nodular lesions corresponding well with MR images and pathology and their surrounding hepatic parenchyma. RESULTS: A total of 46 nodules were located by MR imaging and autopsy, including 22 dysplastic nodules (DN), 9 regenerative nodules (RN), 10 early HCCs and 5 overt HCCs. Among the 22 DNs, 6 were low-grade DN (lGDN) and 16 were high-grade DN (HGDN). The average PEI of RN, DN, early and overt HCC was 205.67 ± 31.17, 161.94 ± 20.74, 226.09 ± 34.83, 491.86 ± 44.61 respectively, and their liver parenchyma nearby was 204.84 ± 70.19. Comparison of the blood perfusion index between each RN and its surrounding hepatic parenchyma showed no statistically significant difference (P = 0.06). There were significant differences in DN (P = 0.02). During the late hepatic arterial phase, the perfusion curve in DN declined. DN had an iso-signal intensity at the early hepatic arterial phase and a low signal intensity at the portal venous phase. Of the 10early HCCs, 4 demonstrated less blood perfusion and 6 displayed minimally increased blood flow compared to the surrounding parenchyma. Five HCCs showed significantly increased blood supply compared to the surrounding parenchyma (P = 0.02). CONCLUSION: Non-invasive MR perfusion can detect changes in blood supply of precancerous lesions.

Colorectal neoplasm:Magnetic resonance colonography with fat enema-initial clinical experience

AIM： To assess Magnetic resonance colonography with fat enema as a method for detection of colorectal neoplasm.METHODS： Consecutive twenty-two patients underwent MR colonography with fat enema before colonoscopy. Tl-weighted three-dimensional fast spoiled gradient- echo with inversion recovery sequence was acquired with the patient in the supine position before and 75 s after Gadopentetate Dimelumine administration. Where by, pre and post MR coronal images were obtained with a single breath hold for about 20 s to cover the entire colon. The quality of MR colonographs and patients＇ tolerance to fat contrast medium was investigated. Colorectal neoplasms identified by MR colonography were compared with those identified on colonoscopy and sensitivity of detecting the lesions was calculated accordingly.RESULTS： MR colonography with fat enema was well tolerated without sedation and analgesia. 120 out of 132 （90.9%） colonic segments were well distended and only 1 （0.8%） colonic segment was poor distension. After contrast enhancement scan, mean contrast-to-noise ratio （CNR） value between the normal colonic wall and lumen was 18.5 ± 2.9 while mean CNR value between colorectal neoplasm and lumen was 20.2± 3.1. By Magnetic resonance colonography, 26 of 35 neoplasms （sensitivity 74.3%） were detected. However, sensitivity of MRC was 95.5% （21 of 22） for neoplasm larger than 10 mm and 55.6% （5 of 9） for 5-10 mm neoplasm.CONCLUSION： MR colonography with fat enema and Tl-weighted three-dimensional fast spoiled gradientecho with inversion recovery sequence is feasible in detecting colorectal neoplasm larger than 10 mm.

Protoconodont fossils for refining the Cambrian bottom and the contribution to shale gas formation along the southwest margin of Yangtze Block

It has been an intense debate on the exact boundary between Ediacaran and Cambrian in the southwest Yangtze Block.The calibration of this critical boundary has a remarkable influence on the further investigation of the break-up of the Rodinia Supercontinent,the early life evolution,and the mechanism of the phosphorite deposit.Ediacaran and Cambrian strata and fossils are widely distributed in Anning,Yunnan Province in China.In recent years,the Xiaowaitoushan Member from the Lower Yuhucun Formation has been studied.Through this interval with continuous collections,the first appearance datums(FADs)of the protoconodont(Fomitchella cf.inchoate Yang et He,Protohertzina cf.anabarica Missarzhevsky)and globular embryos fossil(Olivooides sp.)earlier than these in the Lower Cambrian strata of the Meishucun Formation were discovered.This discovery indicates that the Xiaowaitoushan Member has included more FADs than the previously discovered single FAD of Anabarites primitivus Qian et Jiang,and the Ediacaran–Cambrian boundary in southwest China should be replaced below the Point“A”of the Meishucun Formation in Yunnan Province.The Point“B”of the Meishucun Formation is younger than the suggested age 541 Ma of the Ediacaran–Cambrian boundary and can no longer reference the Global Boundary Stratotype Section and Point(GSSP)correlation in southwest China.It can be suggested based on the previous stratigraphy and palaeontology studies from northern Sichuan and southern Shaanxi and the FAD of the globular embryos fossils that the Ediacaran‒Cambrian boundary in the southwest Yangtze Block should be placed at the base of the Xiaowaitoushan Member;other phosphorite strata refer to Xiaowaitoushan Member.The discovery of the FADs of the shelly fossils in the Xiaowaitoushan Member provides new evidence for the global correlation of the Ediacaran–Cambrian boundary in the southwest Yangtze Block.The conodont discoloration index(CAI)of the specimens in Anning is between 2 and 3,which indicates that the organic matter in Xiaowaitoushan Member is matured and has high potential to form a shale gas reservoir.

Enigmatic ribbon-like fossil from Early Cambrian of Yunnan, China

During the Late Neoproterozoic and Early Cambrian,a series of paleogeographic and paleoecological events occurred associated with deglaciations and the evolution of life.The appearance of fossils representing diverse phyla,novel body plans and complex ecologies in Ediacaran and Cambrian sedimentary successions has sparked diverse hypotheses about potential drivers for the radiation of early animals during this interval.Recently,new macroscopic fossils of carbonaceous compressions with unique features have been found in Anning,Yunnan,China.The fossils’bodies are ribbon-shaped and bilaterally symmetric,with dense longitudinal features and transversal features.The fossils occur 0.68 m below a bentonite interlayer which has been dated 535.2±1.7 Ma by Ri-xiang Zhu and his team in 2009.The relatively simply morphology of these fossils,coupled with a lack of preserved internal structures challenge efforts taxonomically identify the precursor organism and definitively ally it to a living group.However,the symmetry and unusual features of the body are analogous to members of Platyzoa.The presence of ribbon-shaped fossils in the Zhongyicun Member in Anning indicates that these organisms were at least a locally significant component of Cambrian seafloor ecosystems,and may hold important implications for our understanding of the early evolution of Bilateria.

Convection effect on an arc plasma evolution process in a two parallel contact system

A low voltage circuit breaker(LVCB)is an important piece of protection equipment which will switch off the fault current in a power system.The moving contact of a low voltage circuit breaker with a higher rated current consists of two parallel contacts.Therefore,the convection effect on the air arc evolution process in a two parallel contact system is analyzed.A threedimensional(3 D)magneto–hydro–dynamic(MHD)model of arc simulation is built.In this model,the anode consists of two parallel contacts and a bonding conductor.A nonlinear voltage–current density characteristic is employed to represent the near-anode and near-cathode voltage.The current density,arc voltage and currents through every contact are obtained.The influence of convection and conduction on the arc evolution process are quantitatively calculated.The displacements of the arc roots are obtained and the asymmetry of the arc root motion is analyzed.The arc evolution process of a two parallel contact system is preliminarily revealed.

Design of an all-dielectric long-wave infrared wide-angle metalens

Optical metasurfaces are two-dimensional arrays of nano-scatterers that modify optical wavefronts at subwavelength spatial resolution.They achieve the effect of focusing through phase control under a subwavelength scale,and are called metalenses.They are poised to revolutionize optics by enabling complex low-cost systems.However,there are severe monochromatic aberrations in the metasurfaces.In this paper,the coma of the long-wave infrared optical system is eliminated through a single-layer metasurface.By changing the phase function,this metalens has a numerical aperture of 0.89,a focal length of 150μm and a field of view of 120°(0.4@60 line pairs/mm)that enables diffraction-limited monochromatic imaging along the focal plane at a wavelength of 10.6μm.The designed metasurface maintains a favorable value of the modulation transfer function at different angles.This equipment can be widely used in imaging and industrial processing.

Quantum noise of a harmonic oscillator under classical feedback control

Quantum sensing has been receiving researcher's attention these years due to its ultrahigh sensitivity and precision. However, the bandwidth of the sensors may be low, thus limiting the scope of their practical applications. The low-bandwidth problem is conquered by feedback control methods, which are widely utilized in classic control fields. Based on a quantum harmonic oscillator model operating near the resonant point, the bandwidth and sensitivity of the quantum sensor are analyzed. The results give two important conclusions: (a) the bandwidth and sensitivity are two incompatible performance parameters of the sensor, so there must be a trade-off between bandwidth and sensitivity in practical applications;(b) the quantum white noise affects the signal to be detected in a non-white form due to the feedback control.

Temperature-responded tunable metalenses based on phase transition materials

Once the metalenses are fabricated,the functions of most metalenses are invariable.The tunability and reconfigurability are useful and cost-saving for metalenses in realistic applications.We demonstrate this tunability here via a novel hybrid metalens with the strategic placement of an ultra-thin VO;layer.The hybrid metalens is capable of dynamically modulating the focusing intensity of transmitted light at a wavelength of 1550 nm,and demonstrate a 42.28%focusing efficiency of the incident light and 70.01%modulation efficiency.The hybrid metalens’optothermal simulations show an optothermal conversion process of dynamic focusing,and a maximum laser density of 1.76×10^(3)W/cm^(2) can be handled at an ambient temperature lower than 330 K.The hybrid metalens proposed in this work,a light-dose sensitive tunable smart metalens that can protect other instruments/systems or materials from being damaged,has its specific applications such as in anti-satellite blinding,bio-imaging,etc.

肝癌外泌体在肿瘤微环境细胞间通讯中的作用

肝细胞肝癌(hepatocellular carcinoma,HCC)是世界上最致命的癌症之一。由于HCC发病隐匿、进展迅速且缺乏有效的治疗方法,预后极差,其5年平均生存率低于10%。肿瘤微环境是HCC发生发展所处的内环境,可调节HCC的起源、发展、侵袭和转移。肝癌细胞在癌症进展过程中可以通过释放含有特异信号的外泌体调控肿瘤微环境中的肿瘤细胞、癌相关成纤维细胞、癌相关免疫细胞等不同细胞的生物学行为,进而促进癌症进展。然而,外泌体在这些过程中对具体细胞调控的确切分子机制和作用仍不清楚。本综述首先介绍了HCC微环境的组成和肿瘤微环境中外泌体的来源和特征以及力学因素对外泌体的影响。其次,本综述重点讨论了HCC外泌体对微环境中不同类型细胞的作用。我们看到,在包括肝癌在内的临床癌症治疗中使用外泌体作为载体仍然有许多必须克服的困难。首先,外泌体的同质性很难得到保证。其次,外泌体主要通过皮下注射给药,虽然这种方法简单易行,但吸收效率并不理想。第三,外泌体提取方法有限且效率低,因此难以大量制备外泌体。特别是对于外泌体介导的肿瘤免疫治疗,确保使用的外泌体数量足以引发有效的肿瘤免疫反应非常重要。随着鉴定、分离和纯化技术的改进,外泌体有望成功运用于早期HCC的临床诊断和肝癌的临床治疗中。

Determination of the Range of Magnetic Interactions from the Relations between Magnon Eigenvalues at High-Symmetry k Points

Magnetic exchange interactions(MEIs) define networks of coupled magnetic moments and lead to a surprisingly rich variety of their magnetic properties. Typically MEIs can be estimated by fitting experimental results.Unfortunately, how many MEIs need to be included in the fitting process for a material is unclear a priori,which limits the results obtained by these conventional methods. Based on linear spin-wave theory but without performing matrix diagonalization, we show that for a general quadratic spin Hamiltonian, there is a simple relation between the Fourier transform of MEIs and the sum of square of magnon energies(SSME). We further show that according to the real-space distance range within which MEIs are considered relevant, one can obtain the corresponding relationships between SSME in momentum space. By directly utilizing these characteristics and the experimental magnon energies at only a few high-symmetry k points in the Brillouin zone, one can obtain strong constraints about the range of exchange path beyond which MEIs can be safely neglected. Our methodology is also generally applicable for other Hamiltonian with quadratic Fermi or Boson operators.

Morphological reconstruction of the Ediacaran macroalga Gesinella from South China

Macroalga Gesinella,a carbonaceous compression,is found in the upper part of Doushantuo Formation(Ediacaran)in the Yangtze Platform of South China.Morphologically,it is composed of a thallus(including an oval or oblong lamina and a short-rod-like stipe)and a holdfast(including a cone-shaped rhizome and many filamentous rhizoids).The cone-shaped rhizome connects with the stipe and the long rhizoids grew on the rhizome,meaning that the rhizome grew downwards and inserted into the sediment,while the rhizoids grew in the gaps between the sediment grains to anchor its body on the seafloor.On the lamina,branching and/or unbranching filaments are regularly distributed,so that the oval or oblong lamina can be interpreted as a sac-like body that has been compressed.The filaments on the lamina extend from the three-dimensionally preserved stipe,suggesting that the short-rod-like stipe may have been flexible to support the sac-like body in the water column.With tissue and organ differentiations,Gesinella can be regarded as a eukaryotic macroalga and a high-level metaphyte.Based on measurement and analysis of 108 specimens,the Ediacaran macroalga Gesinella from South China can be divided into three stages:juvenile stage(<3 mm maximum width)identified with difficulty,adult stage(3e10 mm maximum width)interpreted to have grown upwards for sunlight,and senescent stage(>10 mm maximum width)that grew sideways.