Convergent journalism constitutes a systematic investigation into emergent journalistic forms,conceptual frameworks,and practices emerging within media convergence context,characterized by its inherent attributes of c...Convergent journalism constitutes a systematic investigation into emergent journalistic forms,conceptual frameworks,and practices emerging within media convergence context,characterized by its inherent attributes of convergence,datacentricity,and interactivity.Grounded in the theoretical discourse of digital narratology,this monograph crystallizes its analytical focus on the triadic conceptual constellation of"convergence""mediaticity"and"narrativity",By positioning""convergence"as the central problematique,it systematically constructs an epistemological framework for convergent journalistic narrative through three dimensions:narrative theory,narrative language,and narrative praxis,thereby elucidates the ontological foundations and operational logics intrinsic to contemporary journalism studies.展开更多
Alarm calls in bird vocalizations serve as acoustic signals announcing danger.Owing to the convergent evolution of alarm calls,some bird species can beneft from eavesdropping on certain parameters of alarm calls of ot...Alarm calls in bird vocalizations serve as acoustic signals announcing danger.Owing to the convergent evolution of alarm calls,some bird species can beneft from eavesdropping on certain parameters of alarm calls of other species.Vocal mimicry,displayed by many bird species,aids defense against predators and may help brood parasites during parasitism.In the coevolutionary dynamics between brood parasites,such as the common cuckoo(Cuculus canorus),and their hosts,female cuckoo vocalizations can induce hosts to leave the nest,increasing the probability of successful parasitism and reducing the risk of host attacks.Such cuckoo calls were thought to mimic those of the sparrowhawk.However,owing to their similarity to alarm calls,we propose a new hypothesis:Female cuckoos cheat their hosts by mimicking the parameters of the host alarm call.In this study,we tested this new hypothesis and the sparrowhawk mimicry hypothesis simultaneously by manipulating the syllable rate in male and female common cuckoo vocalizations and playing them in front of the host Oriental reed warbler(Acrocephalus orientalis)for examination.The results indicate that similar to a normal female cuckoo call,a female call with a reduced syllable rate prompted the hosts to leave their nests more frequently and rapidly than male cuckoo calls.Additionally,the male cuckoo calls with increased syllable rate did not prompt the host to leave their nests more frequently or quickly compared with the male cuckoo calls with a normal syllable rate.Our results further confrm that female common cuckoos mimic the vocalizations of Eurasian sparrowhawks(Accipiter nisus),reveal the function mechanisms underlying such mimicry,and support the theory of imperfect mimicry.展开更多
Extreme heat and chronic water scarcity present formidable challenges to large desert-dwelling mammals.In addition to camels,antelopes within the Hippotraginae and Alcelaphinae subfamilies also exhibit remarkable phys...Extreme heat and chronic water scarcity present formidable challenges to large desert-dwelling mammals.In addition to camels,antelopes within the Hippotraginae and Alcelaphinae subfamilies also exhibit remarkable physiological and genetic specializations for desert survival.Among them,the critically endangered addax(Addax nasomaculatus)represents the most desert-adapted antelope species.However,the evolutionary and molecular mechanisms underlying desert adaptations remain largely unexplored.Herein,a high-quality genome assembly of the addax was generated to investigate the molecular evolution of desert adaptation in camels and desert antelopes.Comparative genomic analyses identified 136 genes harboring convergent amino acid substitutions implicated in crucial biological processes,including water reabsorption,fat metabolism,and stress response.Notably,a convergent R146S amino acid mutation in the prostaglandin EP2 receptor gene PTGER2 significantly reduced receptor activity,potentially facilitating large-mammal adaptation to arid environments.Lineage-specific innovations were also identified in desert antelopes,including previously uncharacterized conserved non-coding elements.Functional assays revealed that several of these elements exerted significant regulatory effects in vitro,suggesting potential roles in adaptive gene expression.Additionally,signals of introgression and variation in genetic load were observed,indicating their possible influence on desert adaptation.These findings provide insights into the sequential evolutionary processes that drive physiological resilience in arid environments and highlight the importance of convergent evolution in shaping adaptive traits in large terrestrial mammals.展开更多
Mammalian scent glands mediate species-specific chemical communication,yet the mechanistic basis for convergent musk production remain incompletely understood.Forest musk deer and muskrat have independently evolved sp...Mammalian scent glands mediate species-specific chemical communication,yet the mechanistic basis for convergent musk production remain incompletely understood.Forest musk deer and muskrat have independently evolved specialized musk-secreting glands,representing a striking case of convergent evolution.Through an integrated multi-omics approach,this study identified cyclopentadecanone as a shared key metabolic precursor in musk from both forest musk deer and muskrat,although downstream metabolite profiles diverged between the two lineages.Single-cell RNA sequencing revealed that these specialized apocrine glands possessed unique secretory architecture and exhibited transcriptional profiles associated with periodic musk production,distinct from those in conventional apocrine glands.Convergent features were evident at the cellular level,where acinar,ductal,and basal epithelial subtypes showed parallel molecular signatures across both taxa.Notably,acinar cells in both species expressed common genes involved in fatty acid and glycerolipid metabolism(e.g.,ACSBG1,HSD17B12,HACD2,and HADHA),suggesting a conserved molecular framework for musk precursor biosynthesis.Metagenomic analysis of musk samples further revealed parallel microbial community structures dominated by Corynebacterium and enriched in lipid metabolic pathways.These findings suggest multi-level convergence in musk biosynthesis,from molecular pathways to microbial communities,providing novel insights into mammalian chemical signaling and artificial musk production.展开更多
On the analytic functions defined by exponential series convergent only in the right half plane, Yu Jiarong introduced the order (R) and the order (R H) and studied some exponential series, Yu Jiuman intr...On the analytic functions defined by exponential series convergent only in the right half plane, Yu Jiarong introduced the order (R) and the order (R H) and studied some exponential series, Yu Jiuman introduced the proximate zero order (R) of the functions and obtained some results. For the study of the grouth of Laplace Stieltjes transform, we introduce the order (R) and get some results similar to the case of exponential series.展开更多
The almost convergent function which was introduced by Raimi [6] and discussed by Ho [4], Das and Nanda [2, 3], is the continuous analogue of almost convergent sequences （see [5]）. In this paper, we establish the Ta...The almost convergent function which was introduced by Raimi [6] and discussed by Ho [4], Das and Nanda [2, 3], is the continuous analogue of almost convergent sequences （see [5]）. In this paper, we establish the Tauberian conditions and the Cauchy criteria for weak almost convergent functions on R2＋ .展开更多
This paper investigates a time-varying anti-disturbance formation problem for a group of quadrotor aircrafts with time-varying uncertainties and a directed interaction topology.A novel Finite-Time Convergent Extended ...This paper investigates a time-varying anti-disturbance formation problem for a group of quadrotor aircrafts with time-varying uncertainties and a directed interaction topology.A novel Finite-Time Convergent Extended State Observer(FTCESO)based fully-distributed formation control scheme is proposed to enhance the disturbance rejection and the formation tracking performances for networked quadrotors.By adopting the hierarchical control strategy,the multiquadrotor system is separated into two subsystems:the outer-loop cooperative subsystem and the inner-loop attitude subsystem.In the outer-loop subsystem,with the estimation of disturbing forces and uncertain dynamics from FTCESOs,an adaptive consensus theory based cooperative controller is exploited to ensure the multiple quadrotors form and maintain a time-varying pattern relying only on the positions of the neighboring aircrafts.In the inner-loop subsystem,the desired attitude generated by the cooperative control law is stably tracked under a FTCESO-based attitude controller in a finite time.Based on a detailed algorithm to specify the cooperative control protocol,the feasibility condition to achieve the time-varying anti-disturbance formation tracking is derived and the rigorous analysis of the whole closed-loop multi-quadrotor system is given.Some numerical examples are conducted to intuitively demonstrate the effectiveness and the improvements of the proposed control framework.展开更多
Multidisciplinary collaborative simulation （MCS） is an important area of research in the domain of multidisciplinary design optimization （MDO）.Although previous research for MCS has to some extent addressed some i...Multidisciplinary collaborative simulation （MCS） is an important area of research in the domain of multidisciplinary design optimization （MDO）.Although previous research for MCS has to some extent addressed some issues like using of multiple tools,integration stability,control of step size,data synchronization,etc,further work is still necessary to study how to achieve improved precision.A theoretical model is formulated to describe and analyze the integration process of MCS.A basic algorithm with equal major steps is proposed based on the model,along with two methods of implementation for the model,namely the serial method and the parallel method.A further algorithm based on convergent integration step is proposed,which has a more flexible strategy for run-time integration.The influence of interpolation techniques on simulation performance is studied as well.Simulations of the performance of various algorithms with different interpolation techniques are performed for both a simple numerical example and a complex mechatronic product.The novel algorithm based on convergent integration step,when used with a high-order interpolation technique,has better performance in terms of precision and efficiency.The innovation of this paper is mainly on the validation of high precision of the proposed convergent integration step algorithm.展开更多
Experiments were carried out on rats anaesthetized with uraethane. The sponta-neous discharges and nociceptive responses of convergent neurons in the right trigerninal nucleus cau-dalis(TNC) to noxious stimuli at rece...Experiments were carried out on rats anaesthetized with uraethane. The sponta-neous discharges and nociceptive responses of convergent neurons in the right trigerninal nucleus cau-dalis(TNC) to noxious stimuli at receptive field (cheek) were recorded extracellularly with glass mi-cro-electrode. Electroacupuncture (EA ) was applied at bilateral " Xiaguan" (ST 7 on face ) or "Zusanli" (ST 36 on shank) acupoint with Iow (2V) and high (18V) intensity. The noclceptive re-sponse of convergent neurons in TNC could be inhihited by low intensity EA applied at "Xiaguan" butnot "Zusanlil", showing the specificity of acupoints. High intensity EA at either "Xiaguan" or "Zusan-li" also reduced the nociceptive responses, showing the analgesic extensiveness of acupoints. We sug-gest that "the gate of control" mechanism plays a main role in low intensity EA and "diffuse noxiousinhibitory controls" (DNIC) rnechanism does so in high intensity EA.The results suggest that we should pay attention to the location of acupoints,展开更多
Hydrodynamic instabilities such as the Rayleigh–Taylor(RT)and Richtmyer–Meshkov instabilities disrupt inertial confinement fusion(ICF)implosions through the growth of 3D perturbations.Growth of these 3D imperfection...Hydrodynamic instabilities such as the Rayleigh–Taylor(RT)and Richtmyer–Meshkov instabilities disrupt inertial confinement fusion(ICF)implosions through the growth of 3D perturbations.Growth of these 3D imperfections at the interfaces of an ICF capsule during implosion lead to mixing between materials that is detrimental to performance.These instabilities have been studied extensively in planar geometry,but such experiments lack the effects of convergence in spherical implosions.While several studies have been performed in spherical geometry,these often lack a direct means to measure perturbation growth.Experiments in cylindrical geometry include convergence effects while maintaining direct diagnostic access.Although cylinders have less compression than spheres,they do provide an excellent platform to validate modeling for convergent geometries.The problem with previous cylindrical implosion experiments was that the convergence ratios were limited to∼4.With the National Ignition Facility(NIF),larger cylindrical targets can be driven to convergences of 10–15 while maintaining a large enough final diameter to measure perturbation growth.This paper reviews the design process used to both benchmark radiation hydrodynamics codes and enable 1D post-processed simulations to explore design space to separate compression effects from acceleration/deceleration RT instability.Results from 1D simulations suggest that cylindrical implosions on the NIF can produce high-convergence experiments to validate RT instability growth for ICF implosions.展开更多
The Richtmyer–Meshkov instability at the interface of solid state tin material and xenon gases under cylinder geometry is studied in this paper. The experiments were conducted at FP-1 facility in Institute of Fluid P...The Richtmyer–Meshkov instability at the interface of solid state tin material and xenon gases under cylinder geometry is studied in this paper. The experiments were conducted at FP-1 facility in Institute of Fluid Physics, China Academy of Engineering Physics(CAEP). The FP-1 facility is a pulsed power driver which could generate high amplitude magnetic field to drive metal liner imploding. Convergent shock wave was generated by impacting a magnetic-driven aluminium liner onto a inner mounted tin liner. The convergent evolution of the disturbance pre-machined onto the tin liner's inner surface was diagnosed by x-radiography. The spike amplitudes were derived from x-ray frames and were compared with linear theory.An analytical model containing material strength effect was derived and matched well to the experimental results. This sensibility of the disturbance evolution to material strength property shines light to the application of Richtmyer–Meshkov instability to infer material strength.展开更多
In this research article,we introduce a numerical investigation through artificial neural networks(ANN)integrated with evolutionary algorithm especially Archimedean optimization algorithm(AOA)hybrid with the water cyc...In this research article,we introduce a numerical investigation through artificial neural networks(ANN)integrated with evolutionary algorithm especially Archimedean optimization algorithm(AOA)hybrid with the water cycle algorithm(WCA)to address and enhance the analysis of the non-linear magneto-hydrodynamic(MHD)Jeffery-Hamel problem,especially stretching/shrinking in convergent and divergent channel.This combined technique is referred to as ANN-AOA-WCA.The complex nonlinear magneto-hydrodynamic Jeffery-Hamel problem based partial differential equations are transformed into non-linear system of ordinary differential equations for velocity and temperature.We formulate the ANN based fitness function to find the solution of non-linear differential.Subsequently,we employ a novel hybridization of AOA and WCA(AOA-WCA)to optimize the ANN based fitness function and identify the best optimal weights and biases for ANN.To demonstrate the effectiveness and versatility of our proposed hybrid method,we explore MHD models across a range of Reynolds numbers,channel angles and stretchable boundary value leading to the development of two distinct cases.ANN-AOA-WCA numerical results closely align with reference solutions(NDSOLVE)and the absolute error between NDSOLVE and ANN-AOA-WCA is up to 3.35´10^(-8),particularly critical to the understanding of stretchable convergent and divergent channel.Furthermore,to validate the ANN-AOA-WCA technique,we conducted a statistical analysis over 150 independence runs to find the fitness value.展开更多
In the tails of dromaeosaurid dinosaurs and rhamphorhynchid pterosaurs, elongate osteological rods extend anteriorly from the chevrons and the prezygapophyses. These caudal rods are positioned in parallel and are stac...In the tails of dromaeosaurid dinosaurs and rhamphorhynchid pterosaurs, elongate osteological rods extend anteriorly from the chevrons and the prezygapophyses. These caudal rods are positioned in parallel and are stacked dorsoventrally. The fully articulated and three-dimensionally preserved caudal series of some dromaeosaurid specimens show that individually these caudal rods were flexible, not rigid as previously thought. However, examination of the arrangement of the caudal rods in cross-section indicates that the combined effect of multiple caudal rods did provide substantial rigidity in the dorsoventral, but not in the lateral, plane. The results of digital muscle reconstructions confirm that dromaeosaurids and rhamphorhynchids also shared greatly reduced caudofemoral muscles in the anterior tail region. The striking similarities between the tails of dromaeosaurids and rhamphorhynchids suggest that both evolved under similar behavioral and biomechanical pressures. Combined with recent discoveries of primitive deinonychosaurs that phylogenetically bracket the evolution of dromaeosaurid caudal rods between two arboreal gliding/flying forms, these results are evidence that the unique caudal morphologies of dromaeosaurids and rhamphorhynchids were both adaptations for an aerial lifestyle.展开更多
Although widely thought to be aggressive, solitary,and potentially cannibalistic, some spider species have evolved group-living behaviors. The distinct transition provides the framework to uncover groupliving evolutio...Although widely thought to be aggressive, solitary,and potentially cannibalistic, some spider species have evolved group-living behaviors. The distinct transition provides the framework to uncover groupliving evolution. Here, we conducted a comparative transcriptomic study and examined patterns of molecular evolution in two independently evolved group-living spiders and twelve solitary species. We report that positively selected genes among groupliving spider lineages are significantly enriched in nutrient metabolism and autophagy pathways. We also show that nutrient-related genes of group-living spiders convergently experience amino acid substitutions and accelerated relative evolutionary rates. These results indicate adaptive convergence of nutrient metabolism that may ensure energy supply in group-living spiders. The decelerated evolutionary rate of autophagy-related genes in group-living lineages is consistent with an increased constraint on energy homeostasis as would be required in a group-living environment. Together, the results show that energy metabolic pathways play an important role in the transition to group-living in spiders.展开更多
Developments of two-dimensional single-mode light/heavy interfaces driven by convergent shock waves are numerically investigated,focusing on the effect of the Atwood number on the Rayleigh-Taylor stabilization,the com...Developments of two-dimensional single-mode light/heavy interfaces driven by convergent shock waves are numerically investigated,focusing on the effect of the Atwood number on the Rayleigh-Taylor stabilization,the compressibility and the nonlinearity.Five different test gases,including C〇2,Kr,R22,R12 and SF6,are considered with air as the ambient gas.It is clarified for the first time that the unperturbed interface begins to decelerate when the shock focuses at the convergence center,and the acceleration during the deceleration phase is proportional to the Atwood number.During the first reshock,the interface moves outwards with a deceleration until it starts moving inwards.When the initial interface is weakly disturbed,a more obvious amplitude reduction is observed for the case with a larger Atwood number before the reshock,which means that the Rayleigh-Taylor stabilization is stronger.To assess the effect of the Atwood number on the compressibility and the nonlinearity,three models,including a linear incompressible model,a nonlinear incompressible model and a linear compressible model,are adopted to predict the amplitude growth before the reshock.The results show that the nonlinearity is weak,and is almost not influenced by the Atwood number before the reshock.The compressibility,however,greatly changes the amplitude growth.As the Atwood number increases,the compressibility plays a less significant role in the amplitude growth because a heavier gas is harder to be compressed.Although a gas with a larger specific heat ratio is also difficult to be compressed,the specific heat ratio plays a minor role to the compressibility relative to the Atwood number.During the reshock,the amplitude grows linearly until the nonlinearity in the cases with large Atwood numbers is strong enough to reduce the amplitude growth rate.展开更多
Background Healthcare is a complex and divergent system with uncertainty,unpredictability,and multi-layered stakeholders.The relationships among the stakeholders are multifaceted and dynamic,requiring continual interp...Background Healthcare is a complex and divergent system with uncertainty,unpredictability,and multi-layered stakeholders.The relationships among the stakeholders are multifaceted and dynamic,requiring continual interpersonal connections,networks,and co-evolution.It is pivotal to have an evidence-informed theory to explain the phenomenon,uniting the multifaceted stakeholders’efforts.Purpose To describe the development of an evidence-informed theory,the Convergent Care Theory,assembling healthcare stakeholders to work together and achieve optimal health outcomes.Methods The Convergent Care Theory was developed using a theory synthesis approach based on empirical research and literature reviews published by the theory-proposing author.The empirical evidence was categorized into:patients and families,healthcare providers,healthcare organizations,and patients’and healthcare providers’self-care.Results The Convergent Care Theory includes four concepts:all-inclusive organizational care,healthcare professional collaborative care,person-centered precision care,and patients’and healthcare providers’self-care.Achieving convergent care is a process requiring all stakeholders to work together.Six major facilitators emerged from the research evidence:competence,compassion,accountability,trusting,sharing,and engaging.Conclusion This article introduced the development process of the evidence-informed Convergent Care Theory.Healthcare systems are complex,with multiple stakeholders’needs to meet.The Convergent Care Theory strives to unite healthcare stakeholders,bond resources,and join forces to achieve optimal healthcare outcomes.The underpinning of the theory is a caring culture,which is an underlying code for organizational and team behaviors and the foundation of optimal health outcomes.展开更多
High-altitude and marine mammals inhabit distinct ecosystems but share a common challenge:hypoxia.To survive in low-oxygen environments,these species have evolved similar phenotypic pulmonary adaptations,characterized...High-altitude and marine mammals inhabit distinct ecosystems but share a common challenge:hypoxia.To survive in low-oxygen environments,these species have evolved similar phenotypic pulmonary adaptations,characterized by a high density of elastic fibers.In this study,we explored the molecular mechanisms underlying these adaptations,focusing on pulmonary fibrosis and hypoxia tolerance through comparative genomics and convergent evolution analyses.We observed significant expansions and contractions in certain gene families across both high-altitude and marine mammals,closely associated with processes involved in pulmonary fibrosis.Notably,members of the keratin gene family,such as KRT17 and KRT14,appear to be associated with the development of the dense elastic fiber phenotype observed in the lungs of hypoxia-tolerant mammals.Through selection pressure and amino acid substitution analyses,we identified multiple genes exhibiting convergent accelerated evolution,positive selection,and amino acid substitution in these species,associated with adaptation to hypoxic environments.Specifically,the convergent evolution of ZFP36L1,FN1,and NEDD9 was found to contribute to the high density of elastic fibers in the lungs of both high-altitude and marine mammals,facilitating their hypoxia tolerance.Additionally,we identified convergent amino acid substitutions and gene loss events associated with sperm development,differentiation,and spermatogenesis,such as amino acid substitutions in SLC26A3 and pseudogenization of CFAP47,as confirmed by PCR.These genetic alterations may be linked to changes in the reproductive capabilities of these animals.Overall,this study offers novel perspectives on the genetic and molecular adaptations of high-altitude and marine mammals to hypoxic environments,with a particular emphasis on pulmonary fibrosis.展开更多
The Rayleigh–Taylor instability（RTI） in cylindrical geometry is investigated analytically through a second-order weakly nonlinear（WN） theory considering the Bell–Plesset（BP） effect. The governing equations for...The Rayleigh–Taylor instability（RTI） in cylindrical geometry is investigated analytically through a second-order weakly nonlinear（WN） theory considering the Bell–Plesset（BP） effect. The governing equations for the combined perturbation growth are derived. The WN solutions for an exponentially convergent cylinder are obtained. It is found that the BP and RTI growths are strongly coupled, which results in the bubble-spike asymmetric structure in the WN stage. The large Atwood number leads to the large deformation of the convergent interface. The amplitude of the spike grows faster than that of the bubble especially for large mode number m and large Atwood number A. The averaged interface radius is small for large mode number perturbation due to the mode-coupling effect.展开更多
Dear Editor,In this letter, a finite-time convergent analysis of continuous action iterated dilemma(CAID) is proposed. In traditional evolutionary game theory, the strategy of the player is binary(cooperation or defec...Dear Editor,In this letter, a finite-time convergent analysis of continuous action iterated dilemma(CAID) is proposed. In traditional evolutionary game theory, the strategy of the player is binary(cooperation or defection), which limits the number of strategies a player can choose from.展开更多
In meandering rivers, the flow pattern is highly complex, with specific characteristics at bends that are not observed along straight paths. A numerical model can be effectively used to predict such flow fields. Since...In meandering rivers, the flow pattern is highly complex, with specific characteristics at bends that are not observed along straight paths. A numerical model can be effectively used to predict such flow fields. Since river bends are not uniform-some are divergent and others convergent-in this study, after the SSIIM 3-D model was calibrated using the result of measurements along a uniform 180° bend with a width of 0.6 m, a similar but convergent 180v bend, 0.6 m to 0.45 m wide, was simulated using the SSI1M 3-D numerical model. Flow characteristics of the convergent 180° bend, including lengthwise and vertical velocity profiles, primary and secondary flows, lengthwise and widtbwise slopes of the water surface, and the helical flow strength, were compared with those of the uniform 180° bend. The verification results of the model show that the numerical model can effectively simulate the flow field in the uniform bend. In addition, this research indicates that, in a convergent channel, the maximum velocity path at a plane near the water surface crosses the channel＇s centerline at about a 30° to 40° cross-section, while in the uniform bend, this occurs at about the 50° cross-section. The varying range of the water surface elevation is wider in the convergent channel than in the uniform one, and the strength of the helical flow is generally greater in the uniform channel than in the convergent one. Also, unlike the uniform bend, the convergent bend exhibits no rotational cell against the main direction of secondary flow rotation at the 135° cross-section.展开更多
文摘Convergent journalism constitutes a systematic investigation into emergent journalistic forms,conceptual frameworks,and practices emerging within media convergence context,characterized by its inherent attributes of convergence,datacentricity,and interactivity.Grounded in the theoretical discourse of digital narratology,this monograph crystallizes its analytical focus on the triadic conceptual constellation of"convergence""mediaticity"and"narrativity",By positioning""convergence"as the central problematique,it systematically constructs an epistemological framework for convergent journalistic narrative through three dimensions:narrative theory,narrative language,and narrative praxis,thereby elucidates the ontological foundations and operational logics intrinsic to contemporary journalism studies.
基金funded by the Education Department of Hainan Province(no.HnjgY 2022-12)the National Natural Science Foundation of China(no.32260127).
文摘Alarm calls in bird vocalizations serve as acoustic signals announcing danger.Owing to the convergent evolution of alarm calls,some bird species can beneft from eavesdropping on certain parameters of alarm calls of other species.Vocal mimicry,displayed by many bird species,aids defense against predators and may help brood parasites during parasitism.In the coevolutionary dynamics between brood parasites,such as the common cuckoo(Cuculus canorus),and their hosts,female cuckoo vocalizations can induce hosts to leave the nest,increasing the probability of successful parasitism and reducing the risk of host attacks.Such cuckoo calls were thought to mimic those of the sparrowhawk.However,owing to their similarity to alarm calls,we propose a new hypothesis:Female cuckoos cheat their hosts by mimicking the parameters of the host alarm call.In this study,we tested this new hypothesis and the sparrowhawk mimicry hypothesis simultaneously by manipulating the syllable rate in male and female common cuckoo vocalizations and playing them in front of the host Oriental reed warbler(Acrocephalus orientalis)for examination.The results indicate that similar to a normal female cuckoo call,a female call with a reduced syllable rate prompted the hosts to leave their nests more frequently and rapidly than male cuckoo calls.Additionally,the male cuckoo calls with increased syllable rate did not prompt the host to leave their nests more frequently or quickly compared with the male cuckoo calls with a normal syllable rate.Our results further confrm that female common cuckoos mimic the vocalizations of Eurasian sparrowhawks(Accipiter nisus),reveal the function mechanisms underlying such mimicry,and support the theory of imperfect mimicry.
基金supported by the National Key R&D Program of China(2022YFF1000100)Shaanxi Program for Support of Top-notch Young ProfessionalsFundamental Research Funds for the Central Universities。
文摘Extreme heat and chronic water scarcity present formidable challenges to large desert-dwelling mammals.In addition to camels,antelopes within the Hippotraginae and Alcelaphinae subfamilies also exhibit remarkable physiological and genetic specializations for desert survival.Among them,the critically endangered addax(Addax nasomaculatus)represents the most desert-adapted antelope species.However,the evolutionary and molecular mechanisms underlying desert adaptations remain largely unexplored.Herein,a high-quality genome assembly of the addax was generated to investigate the molecular evolution of desert adaptation in camels and desert antelopes.Comparative genomic analyses identified 136 genes harboring convergent amino acid substitutions implicated in crucial biological processes,including water reabsorption,fat metabolism,and stress response.Notably,a convergent R146S amino acid mutation in the prostaglandin EP2 receptor gene PTGER2 significantly reduced receptor activity,potentially facilitating large-mammal adaptation to arid environments.Lineage-specific innovations were also identified in desert antelopes,including previously uncharacterized conserved non-coding elements.Functional assays revealed that several of these elements exerted significant regulatory effects in vitro,suggesting potential roles in adaptive gene expression.Additionally,signals of introgression and variation in genetic load were observed,indicating their possible influence on desert adaptation.These findings provide insights into the sequential evolutionary processes that drive physiological resilience in arid environments and highlight the importance of convergent evolution in shaping adaptive traits in large terrestrial mammals.
基金supported by the National Natural Science Foundation of China(32225009,32370452,82274046)Jilin Agricultural University High-level Talent Introduction Fund(202020218)。
文摘Mammalian scent glands mediate species-specific chemical communication,yet the mechanistic basis for convergent musk production remain incompletely understood.Forest musk deer and muskrat have independently evolved specialized musk-secreting glands,representing a striking case of convergent evolution.Through an integrated multi-omics approach,this study identified cyclopentadecanone as a shared key metabolic precursor in musk from both forest musk deer and muskrat,although downstream metabolite profiles diverged between the two lineages.Single-cell RNA sequencing revealed that these specialized apocrine glands possessed unique secretory architecture and exhibited transcriptional profiles associated with periodic musk production,distinct from those in conventional apocrine glands.Convergent features were evident at the cellular level,where acinar,ductal,and basal epithelial subtypes showed parallel molecular signatures across both taxa.Notably,acinar cells in both species expressed common genes involved in fatty acid and glycerolipid metabolism(e.g.,ACSBG1,HSD17B12,HACD2,and HADHA),suggesting a conserved molecular framework for musk precursor biosynthesis.Metagenomic analysis of musk samples further revealed parallel microbial community structures dominated by Corynebacterium and enriched in lipid metabolic pathways.These findings suggest multi-level convergence in musk biosynthesis,from molecular pathways to microbial communities,providing novel insights into mammalian chemical signaling and artificial musk production.
文摘On the analytic functions defined by exponential series convergent only in the right half plane, Yu Jiarong introduced the order (R) and the order (R H) and studied some exponential series, Yu Jiuman introduced the proximate zero order (R) of the functions and obtained some results. For the study of the grouth of Laplace Stieltjes transform, we introduce the order (R) and get some results similar to the case of exponential series.
文摘The almost convergent function which was introduced by Raimi [6] and discussed by Ho [4], Das and Nanda [2, 3], is the continuous analogue of almost convergent sequences （see [5]）. In this paper, we establish the Tauberian conditions and the Cauchy criteria for weak almost convergent functions on R2＋ .
文摘This paper investigates a time-varying anti-disturbance formation problem for a group of quadrotor aircrafts with time-varying uncertainties and a directed interaction topology.A novel Finite-Time Convergent Extended State Observer(FTCESO)based fully-distributed formation control scheme is proposed to enhance the disturbance rejection and the formation tracking performances for networked quadrotors.By adopting the hierarchical control strategy,the multiquadrotor system is separated into two subsystems:the outer-loop cooperative subsystem and the inner-loop attitude subsystem.In the outer-loop subsystem,with the estimation of disturbing forces and uncertain dynamics from FTCESOs,an adaptive consensus theory based cooperative controller is exploited to ensure the multiple quadrotors form and maintain a time-varying pattern relying only on the positions of the neighboring aircrafts.In the inner-loop subsystem,the desired attitude generated by the cooperative control law is stably tracked under a FTCESO-based attitude controller in a finite time.Based on a detailed algorithm to specify the cooperative control protocol,the feasibility condition to achieve the time-varying anti-disturbance formation tracking is derived and the rigorous analysis of the whole closed-loop multi-quadrotor system is given.Some numerical examples are conducted to intuitively demonstrate the effectiveness and the improvements of the proposed control framework.
基金supported by National Natural Science Foundation of China (Grant No. 61074110)National Defense Pre-Research Foundation of China (Grant No. B0420060524)
文摘Multidisciplinary collaborative simulation （MCS） is an important area of research in the domain of multidisciplinary design optimization （MDO）.Although previous research for MCS has to some extent addressed some issues like using of multiple tools,integration stability,control of step size,data synchronization,etc,further work is still necessary to study how to achieve improved precision.A theoretical model is formulated to describe and analyze the integration process of MCS.A basic algorithm with equal major steps is proposed based on the model,along with two methods of implementation for the model,namely the serial method and the parallel method.A further algorithm based on convergent integration step is proposed,which has a more flexible strategy for run-time integration.The influence of interpolation techniques on simulation performance is studied as well.Simulations of the performance of various algorithms with different interpolation techniques are performed for both a simple numerical example and a complex mechatronic product.The novel algorithm based on convergent integration step,when used with a high-order interpolation technique,has better performance in terms of precision and efficiency.The innovation of this paper is mainly on the validation of high precision of the proposed convergent integration step algorithm.
文摘Experiments were carried out on rats anaesthetized with uraethane. The sponta-neous discharges and nociceptive responses of convergent neurons in the right trigerninal nucleus cau-dalis(TNC) to noxious stimuli at receptive field (cheek) were recorded extracellularly with glass mi-cro-electrode. Electroacupuncture (EA ) was applied at bilateral " Xiaguan" (ST 7 on face ) or "Zusanli" (ST 36 on shank) acupoint with Iow (2V) and high (18V) intensity. The noclceptive re-sponse of convergent neurons in TNC could be inhihited by low intensity EA applied at "Xiaguan" butnot "Zusanlil", showing the specificity of acupoints. High intensity EA at either "Xiaguan" or "Zusan-li" also reduced the nociceptive responses, showing the analgesic extensiveness of acupoints. We sug-gest that "the gate of control" mechanism plays a main role in low intensity EA and "diffuse noxiousinhibitory controls" (DNIC) rnechanism does so in high intensity EA.The results suggest that we should pay attention to the location of acupoints,
基金This work used resources provided by Los Alamos National Laboratory,supported by the U.S Department of Energy National Nuclear Security Administration,operated by Los Alamos National Security,LLC(Contract No.DE-AC52-06NA25396)until November 2018and currently operated by Triad National Security,LLC(Contract No.89233218CNA000001).
文摘Hydrodynamic instabilities such as the Rayleigh–Taylor(RT)and Richtmyer–Meshkov instabilities disrupt inertial confinement fusion(ICF)implosions through the growth of 3D perturbations.Growth of these 3D imperfections at the interfaces of an ICF capsule during implosion lead to mixing between materials that is detrimental to performance.These instabilities have been studied extensively in planar geometry,but such experiments lack the effects of convergence in spherical implosions.While several studies have been performed in spherical geometry,these often lack a direct means to measure perturbation growth.Experiments in cylindrical geometry include convergence effects while maintaining direct diagnostic access.Although cylinders have less compression than spheres,they do provide an excellent platform to validate modeling for convergent geometries.The problem with previous cylindrical implosion experiments was that the convergence ratios were limited to∼4.With the National Ignition Facility(NIF),larger cylindrical targets can be driven to convergences of 10–15 while maintaining a large enough final diameter to measure perturbation growth.This paper reviews the design process used to both benchmark radiation hydrodynamics codes and enable 1D post-processed simulations to explore design space to separate compression effects from acceleration/deceleration RT instability.Results from 1D simulations suggest that cylindrical implosions on the NIF can produce high-convergence experiments to validate RT instability growth for ICF implosions.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11605183 and 11502254)
文摘The Richtmyer–Meshkov instability at the interface of solid state tin material and xenon gases under cylinder geometry is studied in this paper. The experiments were conducted at FP-1 facility in Institute of Fluid Physics, China Academy of Engineering Physics(CAEP). The FP-1 facility is a pulsed power driver which could generate high amplitude magnetic field to drive metal liner imploding. Convergent shock wave was generated by impacting a magnetic-driven aluminium liner onto a inner mounted tin liner. The convergent evolution of the disturbance pre-machined onto the tin liner's inner surface was diagnosed by x-radiography. The spike amplitudes were derived from x-ray frames and were compared with linear theory.An analytical model containing material strength effect was derived and matched well to the experimental results. This sensibility of the disturbance evolution to material strength property shines light to the application of Richtmyer–Meshkov instability to infer material strength.
文摘In this research article,we introduce a numerical investigation through artificial neural networks(ANN)integrated with evolutionary algorithm especially Archimedean optimization algorithm(AOA)hybrid with the water cycle algorithm(WCA)to address and enhance the analysis of the non-linear magneto-hydrodynamic(MHD)Jeffery-Hamel problem,especially stretching/shrinking in convergent and divergent channel.This combined technique is referred to as ANN-AOA-WCA.The complex nonlinear magneto-hydrodynamic Jeffery-Hamel problem based partial differential equations are transformed into non-linear system of ordinary differential equations for velocity and temperature.We formulate the ANN based fitness function to find the solution of non-linear differential.Subsequently,we employ a novel hybridization of AOA and WCA(AOA-WCA)to optimize the ANN based fitness function and identify the best optimal weights and biases for ANN.To demonstrate the effectiveness and versatility of our proposed hybrid method,we explore MHD models across a range of Reynolds numbers,channel angles and stretchable boundary value leading to the development of two distinct cases.ANN-AOA-WCA numerical results closely align with reference solutions(NDSOLVE)and the absolute error between NDSOLVE and ANN-AOA-WCA is up to 3.35´10^(-8),particularly critical to the understanding of stretchable convergent and divergent channel.Furthermore,to validate the ANN-AOA-WCA technique,we conducted a statistical analysis over 150 independence runs to find the fitness value.
基金the financial support of the Dinosaur Research Institute and the University of Alberta China Institute
文摘In the tails of dromaeosaurid dinosaurs and rhamphorhynchid pterosaurs, elongate osteological rods extend anteriorly from the chevrons and the prezygapophyses. These caudal rods are positioned in parallel and are stacked dorsoventrally. The fully articulated and three-dimensionally preserved caudal series of some dromaeosaurid specimens show that individually these caudal rods were flexible, not rigid as previously thought. However, examination of the arrangement of the caudal rods in cross-section indicates that the combined effect of multiple caudal rods did provide substantial rigidity in the dorsoventral, but not in the lateral, plane. The results of digital muscle reconstructions confirm that dromaeosaurids and rhamphorhynchids also shared greatly reduced caudofemoral muscles in the anterior tail region. The striking similarities between the tails of dromaeosaurids and rhamphorhynchids suggest that both evolved under similar behavioral and biomechanical pressures. Combined with recent discoveries of primitive deinonychosaurs that phylogenetically bracket the evolution of dromaeosaurid caudal rods between two arboreal gliding/flying forms, these results are evidence that the unique caudal morphologies of dromaeosaurids and rhamphorhynchids were both adaptations for an aerial lifestyle.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB31000000) to S.Q.L。
文摘Although widely thought to be aggressive, solitary,and potentially cannibalistic, some spider species have evolved group-living behaviors. The distinct transition provides the framework to uncover groupliving evolution. Here, we conducted a comparative transcriptomic study and examined patterns of molecular evolution in two independently evolved group-living spiders and twelve solitary species. We report that positively selected genes among groupliving spider lineages are significantly enriched in nutrient metabolism and autophagy pathways. We also show that nutrient-related genes of group-living spiders convergently experience amino acid substitutions and accelerated relative evolutionary rates. These results indicate adaptive convergence of nutrient metabolism that may ensure energy supply in group-living spiders. The decelerated evolutionary rate of autophagy-related genes in group-living lineages is consistent with an increased constraint on energy homeostasis as would be required in a group-living environment. Together, the results show that energy metabolic pathways play an important role in the transition to group-living in spiders.
基金This work was supported by the National Natural Science Foundation of China(Grants 11772329 and 11625211).
文摘Developments of two-dimensional single-mode light/heavy interfaces driven by convergent shock waves are numerically investigated,focusing on the effect of the Atwood number on the Rayleigh-Taylor stabilization,the compressibility and the nonlinearity.Five different test gases,including C〇2,Kr,R22,R12 and SF6,are considered with air as the ambient gas.It is clarified for the first time that the unperturbed interface begins to decelerate when the shock focuses at the convergence center,and the acceleration during the deceleration phase is proportional to the Atwood number.During the first reshock,the interface moves outwards with a deceleration until it starts moving inwards.When the initial interface is weakly disturbed,a more obvious amplitude reduction is observed for the case with a larger Atwood number before the reshock,which means that the Rayleigh-Taylor stabilization is stronger.To assess the effect of the Atwood number on the compressibility and the nonlinearity,three models,including a linear incompressible model,a nonlinear incompressible model and a linear compressible model,are adopted to predict the amplitude growth before the reshock.The results show that the nonlinearity is weak,and is almost not influenced by the Atwood number before the reshock.The compressibility,however,greatly changes the amplitude growth.As the Atwood number increases,the compressibility plays a less significant role in the amplitude growth because a heavier gas is harder to be compressed.Although a gas with a larger specific heat ratio is also difficult to be compressed,the specific heat ratio plays a minor role to the compressibility relative to the Atwood number.During the reshock,the amplitude grows linearly until the nonlinearity in the cases with large Atwood numbers is strong enough to reduce the amplitude growth rate.
文摘Background Healthcare is a complex and divergent system with uncertainty,unpredictability,and multi-layered stakeholders.The relationships among the stakeholders are multifaceted and dynamic,requiring continual interpersonal connections,networks,and co-evolution.It is pivotal to have an evidence-informed theory to explain the phenomenon,uniting the multifaceted stakeholders’efforts.Purpose To describe the development of an evidence-informed theory,the Convergent Care Theory,assembling healthcare stakeholders to work together and achieve optimal health outcomes.Methods The Convergent Care Theory was developed using a theory synthesis approach based on empirical research and literature reviews published by the theory-proposing author.The empirical evidence was categorized into:patients and families,healthcare providers,healthcare organizations,and patients’and healthcare providers’self-care.Results The Convergent Care Theory includes four concepts:all-inclusive organizational care,healthcare professional collaborative care,person-centered precision care,and patients’and healthcare providers’self-care.Achieving convergent care is a process requiring all stakeholders to work together.Six major facilitators emerged from the research evidence:competence,compassion,accountability,trusting,sharing,and engaging.Conclusion This article introduced the development process of the evidence-informed Convergent Care Theory.Healthcare systems are complex,with multiple stakeholders’needs to meet.The Convergent Care Theory strives to unite healthcare stakeholders,bond resources,and join forces to achieve optimal healthcare outcomes.The underpinning of the theory is a caring culture,which is an underlying code for organizational and team behaviors and the foundation of optimal health outcomes.
基金supported by the National Natural Science Foundation of China(32270442,31872219,31370401,32030011,31630071,31772448)National Key Research and Development Program of China(2022YFF1301602)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX23_1747,KYCX23_1740)。
文摘High-altitude and marine mammals inhabit distinct ecosystems but share a common challenge:hypoxia.To survive in low-oxygen environments,these species have evolved similar phenotypic pulmonary adaptations,characterized by a high density of elastic fibers.In this study,we explored the molecular mechanisms underlying these adaptations,focusing on pulmonary fibrosis and hypoxia tolerance through comparative genomics and convergent evolution analyses.We observed significant expansions and contractions in certain gene families across both high-altitude and marine mammals,closely associated with processes involved in pulmonary fibrosis.Notably,members of the keratin gene family,such as KRT17 and KRT14,appear to be associated with the development of the dense elastic fiber phenotype observed in the lungs of hypoxia-tolerant mammals.Through selection pressure and amino acid substitution analyses,we identified multiple genes exhibiting convergent accelerated evolution,positive selection,and amino acid substitution in these species,associated with adaptation to hypoxic environments.Specifically,the convergent evolution of ZFP36L1,FN1,and NEDD9 was found to contribute to the high density of elastic fibers in the lungs of both high-altitude and marine mammals,facilitating their hypoxia tolerance.Additionally,we identified convergent amino acid substitutions and gene loss events associated with sperm development,differentiation,and spermatogenesis,such as amino acid substitutions in SLC26A3 and pseudogenization of CFAP47,as confirmed by PCR.These genetic alterations may be linked to changes in the reproductive capabilities of these animals.Overall,this study offers novel perspectives on the genetic and molecular adaptations of high-altitude and marine mammals to hypoxic environments,with a particular emphasis on pulmonary fibrosis.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11275031,11475034,11575033 and 11274026the National Basic Research Program of China under Grant No 2013CB834100
文摘The Rayleigh–Taylor instability（RTI） in cylindrical geometry is investigated analytically through a second-order weakly nonlinear（WN） theory considering the Bell–Plesset（BP） effect. The governing equations for the combined perturbation growth are derived. The WN solutions for an exponentially convergent cylinder are obtained. It is found that the BP and RTI growths are strongly coupled, which results in the bubble-spike asymmetric structure in the WN stage. The large Atwood number leads to the large deformation of the convergent interface. The amplitude of the spike grows faster than that of the bubble especially for large mode number m and large Atwood number A. The averaged interface radius is small for large mode number perturbation due to the mode-coupling effect.
基金supported in part by the National Science Fund for Distinguished Young Scholarship of China (62025602)the National Natural Science Foundation of China (11931915, U22B2036)+2 种基金Fok Ying-Tong Education Foundationm China (171105)Technological lmnovation Team of Shaanxi Province (2020TD013)the Tencent Foundation and XPLORER PRIZE。
文摘Dear Editor,In this letter, a finite-time convergent analysis of continuous action iterated dilemma(CAID) is proposed. In traditional evolutionary game theory, the strategy of the player is binary(cooperation or defection), which limits the number of strategies a player can choose from.
文摘In meandering rivers, the flow pattern is highly complex, with specific characteristics at bends that are not observed along straight paths. A numerical model can be effectively used to predict such flow fields. Since river bends are not uniform-some are divergent and others convergent-in this study, after the SSIIM 3-D model was calibrated using the result of measurements along a uniform 180° bend with a width of 0.6 m, a similar but convergent 180v bend, 0.6 m to 0.45 m wide, was simulated using the SSI1M 3-D numerical model. Flow characteristics of the convergent 180° bend, including lengthwise and vertical velocity profiles, primary and secondary flows, lengthwise and widtbwise slopes of the water surface, and the helical flow strength, were compared with those of the uniform 180° bend. The verification results of the model show that the numerical model can effectively simulate the flow field in the uniform bend. In addition, this research indicates that, in a convergent channel, the maximum velocity path at a plane near the water surface crosses the channel＇s centerline at about a 30° to 40° cross-section, while in the uniform bend, this occurs at about the 50° cross-section. The varying range of the water surface elevation is wider in the convergent channel than in the uniform one, and the strength of the helical flow is generally greater in the uniform channel than in the convergent one. Also, unlike the uniform bend, the convergent bend exhibits no rotational cell against the main direction of secondary flow rotation at the 135° cross-section.
