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
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
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
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
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
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
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 wit...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
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
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
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
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
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
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
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
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
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
The End-Permian mass extinction(EPME),Earth’s most severe biocrisis,occurred proximal to the Permian-Triassic Boundary(PTB),with marine ecosystems experiencing catastrophic collapse.This study employs stable carbon(...The End-Permian mass extinction(EPME),Earth’s most severe biocrisis,occurred proximal to the Permian-Triassic Boundary(PTB),with marine ecosystems experiencing catastrophic collapse.This study employs stable carbon(δ^(13)C)and oxygen isotopes from marine carbonates in the Haidai Section(Xuanwei,northeastern Yunnan)to decipher paleoenvironmental drivers.The well-preserved stratigraphic sequence encompasses the Upper Permian(Yangxin and Xuanwei Formations)transitioning into the Lower Triassic(Feixianguan and Jialingjiang Formations),providing a continuous marine sedimentary archive.A marked negativeδ^(13)C excursion(-9.66‰V-PDB)occurs at the PTB,initiating from+0.82‰with subsequent gradual recovery.This geochemical signature correlates with:90%reduction in primary productivity Biodiversity collapse exhibiting cluster extinction patterns Prolonged suppression of ecological recovery Concurrently,reconstructed seawater temperatures reveal extreme thermal fluctuations,surging from 23℃to 32℃at the PTB before precipitously declining to 16℃.These perturbations demonstrate coupled biogeochemical dynamics wherein:•Carbon cycle destabilization disrupted nutrient fluxes.•Temperature oscillations exceeded marine taxa thermal tolerances.•Synergistic environmental stresses amplified extinction selectivity.Theδ^(13)C-temperature covariance(r^(2)=0.085)establishes mechanistic linkages between physicochemical perturbations and biotic responses.Our findings demonstrate that the EPME was driven by positive feedback loops in which:Volcanic CO₂emissions triggered carbonate saturation decline Thermal stratification exacerbated anoxia Biogeochemical cycling perturbations suppressed primary producers This integrated geochemical record from the Haidai Section provides critical insights into environment-organism coevolution during Phanerozoic Earth’s most profound mass extinction.展开更多
Nestedness is one of the important patterns in island biogeography,community ecology and conservation biology.However,most previous nestedness studies focus on the taxonomic dimension while neglecting the functional a...Nestedness is one of the important patterns in island biogeography,community ecology and conservation biology.However,most previous nestedness studies focus on the taxonomic dimension while neglecting the functional and phylogenetic processes in generating nestedness.Moreover,few studies have examined the seasonal change of the nestedness and underlying processes.Here,we examined the seasonal nestedness of bird assemblages in taxonomic,functional,and phylogenetic dimensions,and determined the underlying processes of nestedness patterns in the Zhoushan Archipelago,China.We surveyed the occurrence, abundance,and habitats of birds on 40 islands.We calculated taxonomic,functional,and phylogenetic nestedness using WNODF and treeNODF.We determined the processes underlying nestedness by relating nestedness ranks to island characteristics and species traits.The WNODF analyses showed that bird assemblages in winter and summer were both significantly nested.The habitat-by-site matrix was also significantly nested.The nestedness of bird assemblages was significantly correlated with island area,habitat diversity,habitat specificity,minimum area requirement,habitat specificity and hand-wing index(HWI) of birds in both seasons.While the distance to the nearest mainland(DTM) exerted the influence on nestedness in summer,the distance to the nearest larger island(DTNL)affected nestedness only in winter.However,the nestedness of bird assemblages was not caused by passive sampling or human disturbance.The results of treeNODF analyses illustrated that bird assemblages were functionally and phylogenetically nested in summer and winter,but the exact mechanisms were somewhat different in these two seasons.Overall,our results supported the habitat nestedness hypothesis,selective extinction hypothesis,and selective colonization hypothesis in both seasons.From a conservation viewpoint,we should protect islands with large area and diverse habitats,islands close to the mainland,and species with large area requirement and high habitat specificity to prevent local extinction.展开更多
This research directly supported the author’s thesis work in partial fulfilment of Master of Science in biology from the University of North Texas(United States)from August 1996 to September 1997.Two sites at Lake Ra...This research directly supported the author’s thesis work in partial fulfilment of Master of Science in biology from the University of North Texas(United States)from August 1996 to September 1997.Two sites at Lake Ray Roberts,Denton County,Texas(United States)were examined and contrasted for productivity.The site located in the pelagic zone exhibited a slight,thermal gradient with no stratification,and a slightly stratified clinograde oxygen profile which is typical for summer-stratified eutrophic lakes.The site located in the shallow,littoral zone exhibited high,increasing turbidity with depth,marked by shallow light attenuation through the water column.Temperature was constant at every depth in the littoral site,with a slight,clinograde oxygen profile,typical for shallow,littoral areas subject to wind-induced mixing.Volume estimations of chlorophyll-α shows a strong presence in the euphotic zone,indicating photosynthesis occurs until approximately 2.2 m below the surface.The shallow,littoral site showed the basic signs of higher productivity than the open,pelagic site.展开更多
In the contemporary research landscape of mental illness treatment,fear-related disorders such as post-traumatic stress disorder continue to pose significant challenges.Although exposure therapy remains a fundamental ...In the contemporary research landscape of mental illness treatment,fear-related disorders such as post-traumatic stress disorder continue to pose significant challenges.Although exposure therapy remains a fundamental component of treatment,its efficacy varies considerably among individuals.DNA methylation plays a pivotal role in the extinction of fear memories,providing a promising molecular mechanism that could enhance the success of exposure-based interventions.Extensive studies have consistently demonstrated a substantial association between DNA methylation and neuronal plasticity.While DNA methylation holds potential regulatory effects on the effectiveness of exposure therapy,the bidirectional regulatory relationship between it and neuronal activity necessitates addressing several challenges before its widespread clinical application for mental disorders.First,excessive DNA methylation may suppress neural function,and non-selective enhancement of methylation could be counterproductive.Furthermore,due to potential systemic side effects,the use of methylation-modulating agents might disrupt the physiological balance and functionality of other organs and systems.Despite the dynamic interplay between DNA methylation and neuronal activity offering novel insights into the treatment of mental disorders, the strict consideration of target specificity and an appropriate dosing window requirescautious implementation in clinical practice.展开更多
文摘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.
文摘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.
基金supported by the National Natural Science Foundation of China(Nos.41672028,41672002,41330101,41221001)
文摘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.
基金supported by the National Natural Science Foundation of China(No.92055211)the China-ASEAN Maritime Cooperation Fund Project(No.12120100500017001).
文摘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.
文摘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.
文摘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.
文摘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.
基金Supported by National Natural Science Foundation of China(61911530398,12231012)Consultancy Project by the Chinese Academy of Engineering(2022-JB-06,2023-JB-12)+3 种基金the Natural Science Foundation of Fujian Province of China(2021J01621)Special Projects of the Central Government Guiding Local Science and Technology Development(2021L3018)Royal Society of Edinburgh(RSE1832)Engineering and Physical Sciences Research Council(EP/W522521/1).
文摘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.
基金Supported by the National Natural Science Foundation of China(10671182)。
文摘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.
基金Supported by the National Key Research and Development Program of China(2022YFA1404602)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0580000)+3 种基金the National Natural Science Foundation of China(U23B2045,62305362)the Program of Shanghai Academic/Technology Research Leader(22XD1424400)the Fund of SITP Innovation Foundation(CX-461 and CX-522)Special Project to Seize the Commanding Heights of Science and Technology of Chinese Academy of Sciences,subtopic(GJ0090406-6).
文摘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.
基金supported by the National Natural Science Foundation of China(Nos.41730320,42030513)。
文摘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.
文摘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.
基金supported by the National Natural Science Foundation of China(82071498,81871046,and 32161143022)STI2030-Major Projects(2022ZD0214500).
文摘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.
文摘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.
基金supported by the National Key Research and Development Project of China(2021ZD0202800)the National Natural Science Foundation of China(U21A20418,82003727).
文摘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.
基金Supported by National Natural Science Foundation of China,No.82360231Yunnan Basic Research Program General Project,No.202401AT070075+1 种基金Dali Basic Research Program Key Project,No.202301A020021Youth Special Project for Basic Research of Local Universities in Yunnan Province,No.202301BA070001-127.
文摘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.
基金supported by the Scientific Research Fund of the Education Department of Yunnan Province(Grant Number:2019J0488).
文摘The End-Permian mass extinction(EPME),Earth’s most severe biocrisis,occurred proximal to the Permian-Triassic Boundary(PTB),with marine ecosystems experiencing catastrophic collapse.This study employs stable carbon(δ^(13)C)and oxygen isotopes from marine carbonates in the Haidai Section(Xuanwei,northeastern Yunnan)to decipher paleoenvironmental drivers.The well-preserved stratigraphic sequence encompasses the Upper Permian(Yangxin and Xuanwei Formations)transitioning into the Lower Triassic(Feixianguan and Jialingjiang Formations),providing a continuous marine sedimentary archive.A marked negativeδ^(13)C excursion(-9.66‰V-PDB)occurs at the PTB,initiating from+0.82‰with subsequent gradual recovery.This geochemical signature correlates with:90%reduction in primary productivity Biodiversity collapse exhibiting cluster extinction patterns Prolonged suppression of ecological recovery Concurrently,reconstructed seawater temperatures reveal extreme thermal fluctuations,surging from 23℃to 32℃at the PTB before precipitously declining to 16℃.These perturbations demonstrate coupled biogeochemical dynamics wherein:•Carbon cycle destabilization disrupted nutrient fluxes.•Temperature oscillations exceeded marine taxa thermal tolerances.•Synergistic environmental stresses amplified extinction selectivity.Theδ^(13)C-temperature covariance(r^(2)=0.085)establishes mechanistic linkages between physicochemical perturbations and biotic responses.Our findings demonstrate that the EPME was driven by positive feedback loops in which:Volcanic CO₂emissions triggered carbonate saturation decline Thermal stratification exacerbated anoxia Biogeochemical cycling perturbations suppressed primary producers This integrated geochemical record from the Haidai Section provides critical insights into environment-organism coevolution during Phanerozoic Earth’s most profound mass extinction.
基金supported by the National Natural Science Foundation of China (32271734)。
文摘Nestedness is one of the important patterns in island biogeography,community ecology and conservation biology.However,most previous nestedness studies focus on the taxonomic dimension while neglecting the functional and phylogenetic processes in generating nestedness.Moreover,few studies have examined the seasonal change of the nestedness and underlying processes.Here,we examined the seasonal nestedness of bird assemblages in taxonomic,functional,and phylogenetic dimensions,and determined the underlying processes of nestedness patterns in the Zhoushan Archipelago,China.We surveyed the occurrence, abundance,and habitats of birds on 40 islands.We calculated taxonomic,functional,and phylogenetic nestedness using WNODF and treeNODF.We determined the processes underlying nestedness by relating nestedness ranks to island characteristics and species traits.The WNODF analyses showed that bird assemblages in winter and summer were both significantly nested.The habitat-by-site matrix was also significantly nested.The nestedness of bird assemblages was significantly correlated with island area,habitat diversity,habitat specificity,minimum area requirement,habitat specificity and hand-wing index(HWI) of birds in both seasons.While the distance to the nearest mainland(DTM) exerted the influence on nestedness in summer,the distance to the nearest larger island(DTNL)affected nestedness only in winter.However,the nestedness of bird assemblages was not caused by passive sampling or human disturbance.The results of treeNODF analyses illustrated that bird assemblages were functionally and phylogenetically nested in summer and winter,but the exact mechanisms were somewhat different in these two seasons.Overall,our results supported the habitat nestedness hypothesis,selective extinction hypothesis,and selective colonization hypothesis in both seasons.From a conservation viewpoint,we should protect islands with large area and diverse habitats,islands close to the mainland,and species with large area requirement and high habitat specificity to prevent local extinction.
文摘This research directly supported the author’s thesis work in partial fulfilment of Master of Science in biology from the University of North Texas(United States)from August 1996 to September 1997.Two sites at Lake Ray Roberts,Denton County,Texas(United States)were examined and contrasted for productivity.The site located in the pelagic zone exhibited a slight,thermal gradient with no stratification,and a slightly stratified clinograde oxygen profile which is typical for summer-stratified eutrophic lakes.The site located in the shallow,littoral zone exhibited high,increasing turbidity with depth,marked by shallow light attenuation through the water column.Temperature was constant at every depth in the littoral site,with a slight,clinograde oxygen profile,typical for shallow,littoral areas subject to wind-induced mixing.Volume estimations of chlorophyll-α shows a strong presence in the euphotic zone,indicating photosynthesis occurs until approximately 2.2 m below the surface.The shallow,littoral site showed the basic signs of higher productivity than the open,pelagic site.
基金Supported by the General Program of the Joint Fund Project Under the Liaoning Provincial Science and Technology Plan,No.2024-MSLH-104Research Project Plan of the Qingpu Branch of Zhongshan Hospital,No.QYT2023-02Research Topic of the Shanghai Qingpu District Health Commission,No.QWJ2024-10.
文摘In the contemporary research landscape of mental illness treatment,fear-related disorders such as post-traumatic stress disorder continue to pose significant challenges.Although exposure therapy remains a fundamental component of treatment,its efficacy varies considerably among individuals.DNA methylation plays a pivotal role in the extinction of fear memories,providing a promising molecular mechanism that could enhance the success of exposure-based interventions.Extensive studies have consistently demonstrated a substantial association between DNA methylation and neuronal plasticity.While DNA methylation holds potential regulatory effects on the effectiveness of exposure therapy,the bidirectional regulatory relationship between it and neuronal activity necessitates addressing several challenges before its widespread clinical application for mental disorders.First,excessive DNA methylation may suppress neural function,and non-selective enhancement of methylation could be counterproductive.Furthermore,due to potential systemic side effects,the use of methylation-modulating agents might disrupt the physiological balance and functionality of other organs and systems.Despite the dynamic interplay between DNA methylation and neuronal activity offering novel insights into the treatment of mental disorders, the strict consideration of target specificity and an appropriate dosing window requirescautious implementation in clinical practice.
