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Vladimir P.Amalitsky and Dmitry N.Sobolev–late nineteenth/early twentieth century pioneers of modern concepts of palaeobiogeography,biosphere evolution and mass extinctions
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作者 Elena A.Jagt-Yazykova Grzegorz Racki 《Episodes》 2017年第3期189-199,共11页
The great palaeontological achievements of the Russian scientists Amalitsky and Sobolev,who worked in Russia and Poland at the turn of nineteenth and twentieth centuries,have previously been outlined in detail.However... The great palaeontological achievements of the Russian scientists Amalitsky and Sobolev,who worked in Russia and Poland at the turn of nineteenth and twentieth centuries,have previously been outlined in detail.However,their original and surprisingly modern concepts of the development of life on earth have received far less attention.Amalitsky was one of the first scholars who considered the intimate relationship between floral and faunal evolution and the interdependence between a developing biosphere and geological processes.In fact,he documented,for the first time,the existence of a single palaeobiogeographical province during the Permian Period,which we now refer to as the supercontinent Pangaea.In 1896,Amalitsky’s main idea was that there were extended periods of gradual change in topography and biosphere of the earth,but that it was orogenic activity that had a marked impact on biotic crises.His pupil at Warsaw University,Sobolev,followed up on his work,and in fact came up with the theory of neocatastrophism in 1928.Thus,Amalitsky’s model predates the concept of cyclic evolution of the biosphere in dependence on orogenic cycles,with a prime role for volcanism,which is currently well known as the“volcanic greenhouse”.Sobolev also recognised four main mass extinctions,i.e.,the late Ordovician,the late Devonian,the late Triassic and the Cretaceous/Paleogene ones,but somehow he‘missed out on’the end-Permian catastrophe. 展开更多
关键词 supercontinent Pangaea mass extinctions concepts development life earth biosphere evolution floral faunal evolution palaeontological achievements Permian period PALAEOBIOGEOGRAPHY
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Carbon-Isotope Excursions Recorded in the Cambrian System,South China:Implications for Mass Extinctions and Sea-Level Fluctuations 被引量:10
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作者 Jingxun Zuo Shanchi Peng +3 位作者 Yuping Qi Xuejian Zhu Gabriella Bagnoli Huaibin Fang 《Journal of Earth Science》 SCIE CAS CSCD 2018年第3期479-491,共13页
Cambrian carbonates with abundant fossils of agnostoid trilobites deposited on the southern slope (Jiangnan slope belt) of the Yangtze Platform and in the Jiangnan deepwater basin are well exposed in the Wangeun Sec... Cambrian carbonates with abundant fossils of agnostoid trilobites deposited on the southern slope (Jiangnan slope belt) of the Yangtze Platform and in the Jiangnan deepwater basin are well exposed in the Wangeun Section of western Hunan, South China, and in the Duibian A Section of western Zhejiang, southeastern China, respectively. To better understand the response of carbonisotope excursions to depositional environment changes, mass extinctions and eustatic events, we collected 530 carbonate samples in fresh roadcut exposures of the two measured sections for analysis of carbon and oxygen isotopic compositions. Data of δ^13C from the Wangcun Section, western Hunan, South China, demonstrate that the Cambrian carbon-isotope profile includes three remarkable positive excursions CPEwc-1, 2, 3 in the Upper Series 2, in the Lower and in the Middle Furongian Series. Three distinctive negative excursions CNEwc,-1, 2, 3 were separately tested in the Lower Terreneuvian Series, Lower Series 3 and in the Upper Furongian Series. Similarly, in the corresponding horizons in the Duibian A Section, Zhejiang Province, southeastern China, three positive excursions CPEdb-1, 2, 3 and three negative excursions CNEdb-1, 2, 3 also have been discovered. We interpret these significant carbon-isotope excursions as being associated with enhanced biogenic prodnctivity, mass extinctions and eustatic events. 展开更多
关键词 carbon-isotope excursion mass extinction sea-level change CAMBRIAN South China.
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SE Asian Cenozoic Larger Foraminifera:Taxonomic Questions,Apparent Radiation and Abrupt Extinctions 被引量:2
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作者 Peter Lunt Xiwu Luan 《Journal of Earth Science》 SCIE CAS CSCD 2022年第6期1378-1399,共22页
The Cenozoic larger foraminifera are important for biostratigraphy in SE Asia.This review examines the taxonomic inconsistencies of this group and especially the confusion over concepts of evolution,migration,radiatio... The Cenozoic larger foraminifera are important for biostratigraphy in SE Asia.This review examines the taxonomic inconsistencies of this group and especially the confusion over concepts of evolution,migration,radiation and extinction.It is proposed that from the Mediterranean to Indo-Pacific,Latest Eocene through Miocene,larger foraminifera populations were more homogenous than previously believed.Lineages show a slow morphological radiation interrupted by several extinctions.This pattern is superimposed on a long-term decline in larger foraminiferal abundance.The dating of the major biostratigraphic events are qualified.The main lineages of larger foraminifera can be classified by their evolutionary style.The classically“large”genera have highly peramorphic trends achieved through strong orthoselection,and these lineages were the most severely hit by a series of Mid-Eocene to Mid-Miocene extinction events.Other carbonate facies taxa that are traditionally grouped with the larger foraminifera are characterised by weak paramorphism,and these were much less affected by the extinction events.Some of these weakly peramorphic forms underwent Latest Miocene to recent radiation to and locally become rock-forming organisms.The three major and one minor larger foraminiferal extinction events since the Mid Eocene coincide with abrupt tectonic events across SE Asia.However,there are probably multiple causes for these extinctions,including global climatic changes. 展开更多
关键词 larger foraminifera evolution BIOSTRATIGRAPHY extinction
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A New View of the Mass Extinctions and the Worldwide Floods 被引量:2
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作者 Alexander N. Safronov 《International Journal of Geosciences》 2020年第4期251-287,共37页
In this study, the reasons for mass extinction in Jurassic were investigated. It was shown that galactic compression led to the activation of terrestrial nuclear reactors, which in turn led to the changes in tectonic ... In this study, the reasons for mass extinction in Jurassic were investigated. It was shown that galactic compression led to the activation of terrestrial nuclear reactors, which in turn led to the changes in tectonic activity, volcano eruptions, LIPs, MORBs, paleoclimate change, drift of continents, narrowing of the Earth, worldwide floods, tsunami, changes in mantle and core structures, in magnetic fields and in sedimentary isotopes. It was shown that the mass extinctions occurred during worldwide floods, caused by the narrowing of the Earth at the time of galactic gravitational compression. It was shown that the average statistical altitude distribution of dinosaurs has a bimodal distribution and corresponds to permanent migrations between the plains and the hills. It has been suggested that the skeletons of dinosaurs are well preserved as a result of covering the bodies of dinosaurs with mud flows of coastal sediments and the soil layers at worldwide tsunami. It was formulated the requirement to paleontology, consisting in the obligatory registration of altitudes of the actual place of the fossils found. The simple explanation of the presence of boundaries in the structure of the Earth is given: the 40K nuclear layer corresponds to the boundary between upper and lower mantle;the 137Cs layer located on the boundary between the lower mantle and the outer core;the Th-U nuclear layer is a border between outer and inner core. The previously abstract theories of subduction and continents drift have a clear and obvious physical sense. It was shown that the standard geological table is a registration book of galactic events during Paleozoic. It is proposed to restore the structure of the galactic arms by the geological deposits on the Earth. It was suggested to create the stations on elevated hills for rescue and regeneration of biological forms in the future. 展开更多
关键词 PLANET Size Milky Way Galaxy Natural Nuclear Reactor Mass EXTINCTION Sea Level WORLDWIDE FLOOD JURASSIC FOSSILS
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Supernova and Nova Explosion's Space Weather: Correlated Megafauna Extinctions, Antarctica Ice Melts and Biosphere Mega-disturbances-Global Warming 被引量:1
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作者 William Sokeland 《Journal of Earth Science and Engineering》 2017年第3期136-153,共18页
Correlation of megafauna extinctions and mega-biosphere disturbances with past supernova explosions has been accomplished by considering a time correction for supernova debris traveling at 88.2325 percent of light spe... Correlation of megafauna extinctions and mega-biosphere disturbances with past supernova explosions has been accomplished by considering a time correction for supernova debris traveling at 88.2325 percent of light speed.Supernova W44 is responsible for the Piora Oscillation which appears to be the biblical event of Noah's Flood.The closest supernova explosion,Vela Jr at 652 light-years,gives the beginning of the greatest historical human disaster,The Black Death.When supernova debris energy input occurs in the northern or southern hemisphere,it causes heating(global warming)in the northern or southern hemisphere,respectively.Long term cooling,the Little Ice Age,occurs in the northern hemisphere when the incoming debris of exploding stars impacts only the southern hemisphere for hundreds of years.Termination of the last ice age results due to melting of numerous supernova impacts that correlate time of impact by changing sea level and geothermal energy released for 2,800 years from the exit crater of Dr.J.Kennet's nano-diamond meteor theory and part of the process involves Dr.O'Keefe's tektite theory.Correlation of Dr Frezzotti's ice melt Antarctica data with supernova impact times over the past 800 years establishes the Global Warming model in conjunction with the November 2016 Antarctic sea ice melt. 展开更多
关键词 Warming global SUPERNOVA NOVA extinction ICE crater meteor.
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Were Late Cretaceous extinctions of gastropods selective by generic longevity?
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作者 Dmitry A.Ruban 《Geoscience Frontiers》 SCIE CAS CSCD 2013年第1期87-93,共7页
Many gastropod taxa went extinct during the Late Cretaceous.The stratigraphic ranges of 268 genera permit to establish the longevity of extinction victims for each stage of this epoch."Young"taxa(originated ... Many gastropod taxa went extinct during the Late Cretaceous.The stratigraphic ranges of 268 genera permit to establish the longevity of extinction victims for each stage of this epoch."Young"taxa(originated within B epochs before the extinction)prevailed among victims of the extinctions in all stages.The proportion of"old"taxa(originated before the Cretaceous)that went extinct was the highest in the Cenomanian,and it was the lowest in the Coniacian and the Maastrichtian.It appears that the end-Cretaceous mass extinction affected chiefly"young"taxa.However,the comparison with the earlier time intervals suggests that this pattern of selectivity by generic longevity was not specific for the noted catastrophe,but,in contrast,it was typical for the entire Late Cretaceous.The latest Cenomanian environmental perturbation(OAE2)caused a stronger extinction of"old"taxa,and thus,this biotic crisis was less selective by generic longevity.This hypothesis,however,is not proven by the statistical test. 展开更多
关键词 GASTROPODS EXTINCTION LONGEVITY SELECTIVITY Late Cretaceous
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Universal Hyperthermal Model for Mass Extinctions
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作者 Michael J.Benton 《Journal of Earth Science》 SCIE CAS CSCD 2024年第2期704-707,共4页
INTRODUCTION Earth scientists have long sought universal features of past extinction crises.It can be argued that each past extinction event was a singularity,caused by combinations of circumstances that are unique in... INTRODUCTION Earth scientists have long sought universal features of past extinction crises.It can be argued that each past extinction event was a singularity,caused by combinations of circumstances that are unique in each case,and therefore that the search for common causes is futile.However,a key feature of the uniformitarian approach to geology is that past processes are the same as modern-day processes and,with that in mind,earth scientists are keen to use their knowledge to contribute some understanding to the study of the present and future climate crisis. 展开更多
关键词 EXTINCTION SINGULARITY EXTINCTION
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Ecological Dynamics of a Logistic Population Model with Impulsive Age-selective Harvesting
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作者 DAI Xiangjun JIAO Jianjun 《应用数学》 北大核心 2026年第1期72-79,共8页
In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asy... In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asymptotic stability of the trivial solution and the positive periodic solution.Finally,numerical simulations are presented to validate our results.Our results show that age-selective harvesting is more conducive to sustainable population survival than non-age-selective harvesting. 展开更多
关键词 The logistic population model Selective harvesting Asymptotic stability EXTINCTION
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Two Asteroids, Not One,Caused Extinctions
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作者 Maggie Fox 魏黄宫 《当代外语研究》 2001年第3期1-3,共3页
科学家长期以来猜测发生在二叠纪和三叠纪期间的生物大灭绝始于彗星或陨星的撞击,但直到最近,一个美国研究小组才找到了表明彗星和陨星撞击地球的有力证据。在过去几年中,美国的科研人员研究了中、日和匈牙利的页岩和燧石,并在这些地质... 科学家长期以来猜测发生在二叠纪和三叠纪期间的生物大灭绝始于彗星或陨星的撞击,但直到最近,一个美国研究小组才找到了表明彗星和陨星撞击地球的有力证据。在过去几年中,美国的科研人员研究了中、日和匈牙利的页岩和燧石,并在这些地质样本中找到了布基球(即本文中的Buckyballs)分子,这种分子为彗星或陨星撞击地球提供了有力证据。这是因为,彗星和陨星来自恒星,通常是坍塌的恒星的“信使”,而布基球分子的形成需要非常高的压力,恒星则是布基球形成的良好场所;此外,贝克等人找到了布基球分子中含有明显的氦氩混合物,而这种混合物只存在于太空中。以上两点说明,布基球分子是撞击地球的彗星或陨星带来的。科学家认为,这一彗星直径大约13公里,足以在撞击地球时将布墓球分子稀疏地散布到整个地球。他们还推测,彗星2.5亿年前撞击地球,撞击导致90%的海洋生物灭绝,70%的陆地生物因为没有植物可食而消失。这场大灭绝是在地质年代表中二叠纪和三叠纪之间的分水岭事件,也是地球在史前遭遇的5次类似灾难中最严重的一次。 展开更多
关键词 布基球 二叠纪 有力证据 Not One Caused extinctions Two Asteroids
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Beef and cone-in-cone calcite fibrous cements associated with the end-Permian and end-Triassic mass extinctions: Reassessment of processes of formation 被引量:3
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作者 Stephen Kershaw Li Guo 《Journal of Palaeogeography》 SCIE CSCD 2016年第1期28-42,共15页
This paper reassesses published interpretation that beef and cone-in-cone (B-CIC) fibrous calcite cements were precipitated contemporaneously just below the sea floor in uncon- solidated sediment, in limestones asso... This paper reassesses published interpretation that beef and cone-in-cone (B-CIC) fibrous calcite cements were precipitated contemporaneously just below the sea floor in uncon- solidated sediment, in limestones associated with the end-Permian (P/T) and end-Triassic (T/J) mass extinctions. That interpretation introduced the concept of a sub-seafloor car- bonate factory associated with ocean acidification by raised carbon dioxide driven by volcanic eruption, coinciding with mass extinction. However, our new fieldwork and petrographic analysis, with literature comparison, reveals several problems with this concept. Two key points based on evidence in the T/J transition of the UK are: (I) that B-CIC calcite deposits form thin scattered layers and lenses at several horizons, not a distinct deposit associated with volcanic activity; and (2) B-CIC calcite is more common in Early Jurassic sediments after the extinction and after the end of the Central Atlantic Magmatic Province volcanism proposed to have supplied the carbon dioxide required. Our samples from Late Triassic, Early Jurassic and Early Cretaceous limestones in southern UK show that B-CIC calcite occurs in both marine and non-marine sediments, therefore ocean processes are not mandatory for its formation. There is no proof that fibrous calcite was formed before lithification, but our Early Jurassic samples do prove fibrous calcite formed after compaction, thus interpretation of crystal growth in uncon- solidated sediment is problematic. Furthermore, B-CIC crystals mostly grew both upwards and downwards equally, contradicting the interpretation of the novel carbonate factory that they grew preferentially upwards in soft sediment. Finally, Early Jurassic and Early Cretaceous examples are not associated with mass extinction. Three further key points derived from the literature include: (I) B-CIC calcite is wide- spread geographically and stratigraphically, not clustered around mass extinctions or the Paleocene-Eocene Thermal Maximum (PETM) event; (2) isotope signatures suggest B-CIC calcite formed under high pressure in burial at 70-120℃, incompatible with interpretation of formation of B-CIC calcite at the redox boundary below the ocean floor; and (3) B-CIC calcite reported in P/T boundary microbialites in one site in Iran is the only occurrence known despite extensive published studies of similar shallow marine settings, demon- strating its formation is localized to the Iran site. Based on the above evidence, our opinion is that B-CIC calcite is best explained as a later diagenetic feature unrelated to rapid Earth-surface environmental change associated with mass extinctions; thus a novel carbonate factory is highly unlikely. 展开更多
关键词 End-Permian mass extinction End-Triassic mass extinctionBeefCone-in-cone calciteOcean acidification
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DNA methylation regulates the extinction of fear memory 被引量:1
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作者 Le Jiang Rui-Xue Ma +11 位作者 Er-Shu He Xiao-Ye Zheng Xin Peng Wen-Hao Ma Ying Li Han-Wei li Xue-Yan Zhang Jie-Yu Ji Yan-Jiao Li Shang-Lan Qu Li-Juan Li Zhi-Ting Gong 《World Journal of Psychiatry》 2025年第7期273-283,共11页
BACKGROUND Fear-related disorders,such as post-traumatic stress disorder(PTSD),significantly impact patients and families.Exposure therapy is a common treatment,but imp-roving its effectiveness remains a key challenge... BACKGROUND Fear-related disorders,such as post-traumatic stress disorder(PTSD),significantly impact patients and families.Exposure therapy is a common treatment,but imp-roving its effectiveness remains a key challenge.Fear conditioning and extinction in animal models offer insights into its mechanisms.Our previous research indi-cates that DNA methyltransferases play a role in fear memory renewal.AIM To investigate the role of DNA methylation in the extinction of fear memory,with the goal of identifying potential strategies to enhance the efficacy of exposure therapy for fear-related disorders.METHODS This study investigated the role of DNA methylation in fear memory extinction in mice.DNA methylation was manipulated using N-phthalyl-L-tryptophan(RG108)to reduce methylation and L-methionine injections to enhance it.Neuronal activity,and dendritic spine density was measured following extinction training.RESULTS RG108 suppressed extinction,reduced spine density,and inhibited neuronal activity.Methionine injections facilitated extinction.CONCLUSION DNA methylation is crucial for fear memory extinction.Enhancing methylation may improve the efficacy of exposure therapy,offering a potential strategy to treat fear-related disorders. 展开更多
关键词 RG108 DNA methylation Fear memory Exposure therapy EXTINCTION
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Enhanced risk assessment framework integrating distribution dynamics,genetically inferred populations,and morphological traits of Diploderma lizards 被引量:1
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作者 Qi Xiao Xiu-Dong Shi +5 位作者 Lin Shi Zhong-Yi Yao You-Hua Chen Wei-Zhao Yang Zi-Yan Liao Yin Qi 《Zoological Research》 2025年第1期15-26,共12页
Assessing the threat status of species in response to global change is critical for biodiversity monitoring and conservation efforts.However,current frameworks,even the IUCN Red List,often neglect critical factors suc... Assessing the threat status of species in response to global change is critical for biodiversity monitoring and conservation efforts.However,current frameworks,even the IUCN Red List,often neglect critical factors such as genetic diversity and the impacts of climate and land-use changes,hindering effective conservation planning.To address these limitations,we developed an enhanced extinction risk assessment framework using Diploderma lizards as a model.This framework incorporates long-term field surveys,environmental data,and land-use information to predict distributional changes for 10 recently described Diploderma species on the Qinghai-Xizang Plateau,which hold ecological significance but remain underassessed in conservation assessment.By integrating the distribution data and genetically inferred effective population sizes(Ne),we conducted scenario analyses and used a rank-sum approach to calculate Risk ranking scores(RRS)for each species.This approach revealed significant discrepancies with the IUCN Red List assessments.Notably,D.yangi and D.qilin were identified as facing the highest extinction risk.Furthermore,D.vela,D.batangense,D.flaviceps,D.dymondi,D.yulongense,and D.laeviventre,currently classified as“Least Concern”,were found to warrant reclassification as“Vulnerable”due to considerable threat from projected range contractions.Exploring the relationship between morphology and RRS revealed that traits such as snout-vent length and relative tail length could serve as potential predictors of extinction risk,offering preliminary metrics for assessing species vulnerability when comprehensive data are unavailable.This study enhances the precision of extinction risk assessment frameworks and demonstrates their capacity to refine and update risk assessments,especially for lesser-known taxa. 展开更多
关键词 LIZARD Extinction Risk Assessment IUCN Red List Conservation Status Effective Population Size Morphological Traits
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Dynamics of a Stochastic Epidemic Model with Age-group
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作者 LAN Xiaomin CHEN Guangmin +5 位作者 ZHOU Ruiyang ZHENG Kuicheng CAI Shaojian WEI Fengying JIN Zhen MAO Xuerong 《应用数学》 北大核心 2025年第1期294-307,共14页
A stochastic epidemic model with two age groups is established in this study,in which the susceptible(S),the exposed(E),the infected(I),the hospitalized(H)and the recovered(R)are involved within the total population,t... A stochastic epidemic model with two age groups is established in this study,in which the susceptible(S),the exposed(E),the infected(I),the hospitalized(H)and the recovered(R)are involved within the total population,the aging rates between two age groups are set to be constant.The existence-and-uniqueness of global positive solution is firstly showed.Then,by constructing several appropriate Lyapunov functions and using the high-dimensional Itô’s formula,the sufficient conditions for the stochastic extinction and stochastic persistence of the exposed individuals and the infected individuals are obtained.The stochastic extinction indicator and the stochastic persistence indicator are less-valued expressions compared with the basic reproduction number.Meanwhile,the main results of this study are modified into multi-age groups.Furthermore,by using the surveillance data for Fujian Provincial Center for Disease Control and Prevention,Fuzhou COVID-19 epidemic is chosen to carry out the numerical simulations,which show that the age group of the population plays the vital role when studying infectious diseases. 展开更多
关键词 Epidemic model Age groups PERSISTENCE EXTINCTION
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Stochastic Periodic Solutions for Two Populations Game Models with Impulses
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作者 HOU Meiting QIU Xiaoling 《应用数学》 北大核心 2025年第2期453-467,共15页
The article studies the evolutionary dynamics of two-population two-strategy game models with and without impulses. First, the payment matrix is given and two evolutionary dynamics models are established by adding sto... The article studies the evolutionary dynamics of two-population two-strategy game models with and without impulses. First, the payment matrix is given and two evolutionary dynamics models are established by adding stochastic and impulse. For the stochastic model without impulses, the existence and uniqueness of solution, and the existence of positive periodic solutions are proved, and a sufficient condition for strategy extinction is given. For the stochastic model with impulses, the existence of positive periodic solutions is proved. Numerical results show that noise and impulses directly affect the model, but the periodicity of the model does not change. 展开更多
关键词 Periodic solution Stochastic game IMPULSES Strategy extinct
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Advances in integrated polarization detectors with innovative features
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作者 BU Yong-Hao ZHOU Jing +8 位作者 DENG Jie WANG Ruo-Wen YE Tao SHI Meng-Die HUANG Jun-Wei ZHANG Yu-Jie NING Jun LU Wei CHEN Xiao-Shuang 《红外与毫米波学报》 北大核心 2025年第3期371-383,共13页
The polarization properties of light are widely applied in imaging,communications,materials analy⁃sis,and life sciences.Various methods have been developed that can measure the polarization information of a target.How... The polarization properties of light are widely applied in imaging,communications,materials analy⁃sis,and life sciences.Various methods have been developed that can measure the polarization information of a target.However,conventional polarization detection systems are often bulky and complex,limiting their poten⁃tial for broader applications.To address the challenges of miniaturization,integrated polarization detectors have been extensively explored in recent years,achieving significant advancements in performance and functionality.In this review,we focus mainly on integrated polarization detectors with innovative features,including infinitely high polarization discrimination,ultrahigh sensitivity to polarization state change,full Stokes parameters measure⁃ment,and simultaneous perception of polarization and other key properties of light.Lastly,we discuss the oppor⁃tunities and challenges for the future development of integrated polarization photodetectors. 展开更多
关键词 integrated polarization detector infinite polarization extinction ratio polarization state change detection full-Stokes multidimensional detection
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Gastropod Fauna of the Zuodeng Permian-Triassic Boundary Section in the Nanpanjiang Basin and Its Geometric-Based Morphological Disparity Analysis
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作者 Xin Sun Li Tian +5 位作者 Xincheng Qiu Kaiping Guan Erik Tihelka Haijun Song Jinnan Tong Hao Yang 《Journal of Earth Science》 2025年第1期89-101,共13页
Gastropods,as one of the most common invertebrates in shallow marine environments,were heavily impacted by the Permian–Triassic mass extinction(PTME),with severe loss of diversity and remarkable dwarfism of body size... Gastropods,as one of the most common invertebrates in shallow marine environments,were heavily impacted by the Permian–Triassic mass extinction(PTME),with severe loss of diversity and remarkable dwarfism of body size.Here,we report a new gastropod fauna from the Permian-Triassic carbonates of Zuodeng,Guangxi Province,South China.Five species belonging to five genera and two indeterminate taxa are identified.The Zuodeng fauna is dominated by Paleozoic holdover taxa,including Holopea teres,Protostylus sp.,and Wannerispira shangganensis although most of them are found in the basal Triassic microbialites.Three gastropod communities have been recognized by cluster analysis.Further morphological analyses show that the changing pattern of disparity,with diversity decreasing from communityⅡtoⅢ,fits the interior-reduction model.In addition,the morphospace of community in microbialites is higher than those in non-microbialite bearing beds at Zuodeng,shedding new light on the ecological role of microbialites during the Permian–Triassic environmental stress. 展开更多
关键词 molluscs MORPHOSPACE MICROBIALITE mass extinction SURVIVAL
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The silent crisis of freshwater species
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作者 谭荷英 《疯狂英语(新读写)》 2025年第7期41-43,77,共4页
Nearly a quarter of animals living in rivers,lakes and other freshwater sources are threatened with extinction,according to new research published on Wednesday.“Huge rivers like the Amazon River can appear mighty,but... Nearly a quarter of animals living in rivers,lakes and other freshwater sources are threatened with extinction,according to new research published on Wednesday.“Huge rivers like the Amazon River can appear mighty,but at the same time,freshwater environments are very weak,”said the study's co⁃author Patricia Charvet,a biologist at Brazil's Federal University of Ceará. 展开更多
关键词 biodiversity freshwater species environmental vulnerability EXTINCTION RIVERS LAKES
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Memory Reconsolidation Updating in Substance Addiction: Applications, Mechanisms, and Future Prospects for Clinical Therapeutics
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作者 Shihao Huang Xiaoxing Liu +6 位作者 Zhonghao Li Yue Si Liping Yang Jiahui Deng Yixiao Luo Yan-Xue Xue Lin Lu 《Neuroscience Bulletin》 2025年第2期289-304,共16页
Persistent and maladaptive drug-related memories represent a key component in drug addiction.Converging evidence from both preclinical and clinical studies has demonstrated the potential efficacy of the memory reconso... Persistent and maladaptive drug-related memories represent a key component in drug addiction.Converging evidence from both preclinical and clinical studies has demonstrated the potential efficacy of the memory reconsolidation updating procedure(MRUP),a non-pharmacological strategy intertwining two distinct memory processes:reconsolidation and extinction—alternatively termed“the memory retrieval-extinction procedure”.This procedure presents a promising approach to attenuate,if not erase,entrenched drug memories and prevent relapse.The present review delineates the applications,molecular underpinnings,and operational boundaries of MRUP in the context of various forms of substance dependence.Furthermore,we critically examine the methodological limitations of MRUP,postulating potential refinement to optimize its therapeutic efficacy.In addition,we also look at the potential integration of MRUP and neurostimulation treatments in the domain of substance addiction.Overall,existing studies underscore the significant potential of MRUP,suggesting that interventions predicated on it could herald a promising avenue to enhance clinical outcomes in substance addiction therapy. 展开更多
关键词 RECONSOLIDATION EXTINCTION Memory reconsolidation updating Retrieval-extinction Drug addiction
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The Abundance of the Remaining Mammalian Fauna and the Impacts of Hunting in a Biodiversity Hotspot’s Hotspot in the Atlantic Forest of North-Eastern Brazil
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作者 Éverton Renan de Andrade Melo José Ramon Gadelha +1 位作者 Leandro Ricardo Rodrigues de Lucena Antonio Rossano Mendes Pontes 《Open Journal of Ecology》 2025年第1期65-91,共27页
Although hunting in the north-eastern Atlantic forest of Brazil began more than 500 years ago, no study to date has evaluated its impacts on the region’s mammalian fauna. For one year we carried out diurnal and noctu... Although hunting in the north-eastern Atlantic forest of Brazil began more than 500 years ago, no study to date has evaluated its impacts on the region’s mammalian fauna. For one year we carried out diurnal and nocturnal surveys using the Line Transect method in seven forest fragments varying from 7.32 ha to 469.76 ha, within a 4000 ha forest island archipelago, in Pernambuco State, Atlantic forest of northeastern Brazil. We calculated species density, population size, biomass and synergetic biomass, and recorded direct and indirect human impacts along the study transects. We recorded 44 mammalian species, of which 45.5% (n = 20) went extinct through hunting. The smallest forest fragment had the lowest richness, diversity, population size, and total biomass. It also had no synergetic biomass. The largest fragment had the highest richness, total density, and population size. There was a statistically significant relationship between fragment area and number of gunshots heard and suspended hunting platforms found;between population size and gunshots heard, suspended hunting platforms, free-roaming and feral dogs, and between total density and free-roaming and feral dogs. After more than 500 years of colonization hunting is still devastating, with larger fragments being linked to more hunters. Higher mammal abundances attracted more free-roaming and feral dogs, which have adapted to hunt wildlife on their own. Unless we protect every single forest fragment and create sustainable landscapes, we will not be able to save this hotspot’s hotspot. 展开更多
关键词 Atlantic Forest MAMMALS ABUNDANCE Human Impact Extinction
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How Fear Memory is Updated:From Reconsolidation to Extinction?
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作者 Jiahui Chen Zhuowen Fang +2 位作者 Xiaolan Zhang Yanrong Zheng Zhong Chen 《Neuroscience Bulletin》 2025年第6期1054-1084,共31页
Post-traumatic stress disorder(PTSD)is a psychiatric disorder caused by traumatic past experiences,rooted in the neurocircuits of fear memory formation.Memory processes include encoding,storing,and recalling to forget... Post-traumatic stress disorder(PTSD)is a psychiatric disorder caused by traumatic past experiences,rooted in the neurocircuits of fear memory formation.Memory processes include encoding,storing,and recalling to forgetting,suggesting the potential to erase fear memories through timely interventions.Conventional strategies such as medications or electroconvulsive therapy often fail to provide permanent relief and come with significant side-effects.This review explores how fear memory may be erased,particularly focusing on the mnemonic phases of reconsolidation and extinction.Reconsolidation strengthens memory,while extinction weakens it.Interfering with memory reconsolidation could diminish the fear response.Alternatively,the extinction of acquired memory could reduce the fear memory response.This review summarizes experimental animal models of PTSD,examines the nature and epidemiology of reconsolidation to extinction,and discusses current behavioral therapy aimed at transforming fear memories to treat PTSD.In sum,understanding how fear memory updates holds significant promise for PTSD treatment. 展开更多
关键词 Post-traumatic stress disorder Fear memory RECONSOLIDATION EXTINCTION Engram
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