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Post-fire recovery of Puya raimondii, vegetation and birds in the puna of Huascarán National Park, Perú

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Journal of Mountain Science 2024年第1期21卷 20-32页

作者： Mery l.SUNI Giovana P.VADIllO césar ARANA Enoc JARA-PENA letty SAlINAS M.Estela PONcE Paul M.RAMSAY Plant Physiology laboratory Faculty of Biological SciencesUniversidad Nacional Mayor de San MarcosLima 15081Peru Natural History Museum Universidad Nacional Mayor de San MarcosLima 15072Peru Applied Phytology laboratory Faculty of Biological SciencesUniversidad Nacional Mayor de San MarcosLima 15081Peru Department of Statistics Faculty of Mathematical SciencesUniversidad Nacional Mayor de San MarcosLima 15081Peru Department of chemical and Biological Sciences Universidad de las Américas PueblaSan Andrés Cholula CP Cholula CP 72810Mexico

A large fire of 233 ha in Huascarán National Park in Peru provided an opportunity to compare plant and bird responses in burned and nearby unburned zones of the puna. Heights and live diameters of flagship Puya raimondii rosettes(assigned to four broad developmental phases), plant communities(66 species in 24 families and nine growth forms) and bird communities(77 species in six trophic guilds) were monitored after the fire. Although no mortality was observed, Puya raimondii plants were affected by the fire, losing approximately 60% of their photosynthetic area across all developmental phases, but recovered quickly during the first two years after fire. The comparison of Puya rosette recovery after fire was complicated by the changes in live rosette diameter for unburned plants, which showed plasticity of photosynthetic area linked to seasonal and annual fluctuations in precipitation in this relatively dry environment(decreased by 26% for mature adult plants over the study period). Fire caused an immediate change in the density, biomass and composition of vegetation. Although the species present remained similar, their abundances changed significantly immediately after the fire, with notable reductions in dominant tussock grasses. This provided opportunities for other plants, resulting in higher postfire diversity of plant species, genera, families and growth forms. In turn, the changes in vegetation after fire affected the composition of birds according to their trophic guild. Granivores largely disappeared,generalists were mostly unaffected, and other guilds showed a more complex response. As the vegetation recovered, most displaced birds returned within approximately one year.

关键词： Burning Plant biomass Trophic guilds Andes Giant rosette plants

On the functions of astrocyte-mediated neuronal slow inward currents

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Neural Regeneration Research 2024年第12期19卷 2602-2612页

作者： Balázs Pál Department of Physiology Faculty of MedicineUniversity of DebrecenDebrecenHungary

Slow inward currents are known as neuronal excitatory currents mediated by glutamate release and activation of neuronal extra synaptic N-met hyl-D-aspartate receptors with the contribution of *** events are significantly slower than the excitatory postsynaptic *** of slow inward currents are determined by seve ral factors including the mechanisms of astrocytic activation and glutamate release,as well as the diffusion pathways from the release site towards the extra synaptic recepto *** are stimulated by neuronal network activity,which in turn excite neurons,forming an astrocyte-neuron feedback *** as a consequence of brain edema,astrocytic swelling can also induce slow inward currents under pathological *** is a growing body of evidence on the roles of slow inward currents on a single neuron or local network *** events often occur in synchro ny on neurons located in the same astrocytic *** synchronization of neuronal excitability,slow inward currents also set synaptic strength via eliciting timing-dependent synaptic *** addition,slow inward currents are also subject to non-synaptic plasticity triggered by long-la sting stimulation of the excitatory *** note,there might be important regionspecific differences in the roles and actions triggering slow inward *** greater networks,the pathophysiological roles of slow inward currents can be better understood than physiological *** inward currents are identified in the pathophysiological background of autism,as slow inward currents drive early hypersynchrony of the neural *** inward currents are significant contributors to paroxysmal depolarizational shifts/interictal *** events are related to epilepsy,but also found in Alzheimer's disease,Parkinson's disease,and stroke,leading to the decline of cognitive *** with features overlapping with slow inward currents(excitatory,N-methyl-Dasp

关键词： astrocyte cortical spreading depolarization gliotransmission glutamate neural synchronization NMDA receptor paroxysmal depolarizational shift slow inward current

Degradation and resynthesis of chlorophyll during increased oxidative stress and prolonged darkness differ between annual and perennial flax(linum l.)

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Oil crop Science 2024年第2期9卷 121-130页

作者： Kenyon J. Nisbett Abida Alokozai Su Hyun Elizabeth Ko G. Adam Mott Jason c.l. Browna Department of Biological Sciences University of Toronto ScarboroughTorontoONCanada Department of cell&Systems Biology University of TorontoTorontoONCanada centre for the Analysis of Genome Evolution&Function University of TorontoTorontoONCanada

Among plants,there is considerable variation in lifespan:annuals live less than one year,whereas perennials live for several years,with the longest-living perennial having survived 43,600 *** proposed by the Disposable Soma Theory,this lifespan variation among plants likely reflects differential investment of limited energy and nutrient resources,with perennials investing more energy and nutrients into biomolecular maintenance compared to annuals in order to ensure persistence over multiple *** differential investment may be particularly important during periods of exogenous stress,which are known to accelerate biomolecular *** present study evaluated this hypothesis using annual and perennial flax(linum l.)subjected to two exogenous stressors—increased oxidative stress(i.e.,foliar H2O2spraying)and complete prolonged *** chlorophyll has been shown to exhibit degradation in response to changes in environmental conditions,we utilized changes in chlorophyll levels during and after periods of exogenous stress to evaluate our *** predicted that i)perennials would exhibit a slower rate of chlorophyll degradation during exposure to exogenous stressors compared to annuals,and ii)perennials would exhibit a faster rate of chlorophyll resynthesis following such exposure compared to *** levels before,during,and after exposure to both exogenous stressors were measured in two separate trails,once using image colour analysis and once using *** chlorophyll degradation rates in response to oxidative stress did not differ between annuals and perennials,contrary to our predictions,chlorophyll resynthesis rates following such exposure were significantly higher in perennials,as *** plants were subjected to complete prolonged darkness,chlorophyll degradation rates were significantly lower in perennials than annuals,as predicted;however,when plants were subsequently reintroduced to natural photoperiod,ch

关键词： Ageing life history Maximum lifespan Oxidative stress Somatic maintenance

A Practical Predefined-Time Stability criterion and Its Application to Uncertain Nonlinear Systems

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Journal of Systems Science & complexity 2024年

作者： XU Hao YU Dengxiu SUI Shuai XU Bowen cHEN c.l.Philip Unmanned System Research Institute Northwestern Polytechnical University college of Science Liaoning University of Technology School of Artificial Intelligence Optics and Electronics Northwestern Polytechnical University School of computer Science and Engineering South China University of Technology and Pazhou Lab

In this paper, the singularity-free predefined-time fuzzy adaptive tracking control problem is studied for non-strict feedback(NSF) nonlinear systems considering mismatched external disturbances. An innovative practical predefined-time stability(PPTS) criterion is proposed to provide the theoretical basis for subsequent control design. compared to the existing predefined-time stability(PTS) criterion, this criterion has a broader application range and can solve the control design issues of nonlinear systems with system uncertainties. Fuzzy logic systems(FlSs) are employed to identify unknown nonlinear functions. Based on the backstepping control technology, a singularity-free predefined-time control(PTc) design method is proposed, in which the hyperbolic tangent function is utilized to avoid the singular problem, and the nature of fuzzy basis function is adopted to resolve the algebraic loop problem. The PPTS of the closed-loop NSF nonlinear system is proven with the lyapunov theory and the proposed PPTS criterion. Ultimately, the efficiency of the presented PTc design method is verified by several sets of simulations on a single link manipulator system.

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Harnessing the power of complex light propagation in multimode fibers for spatially resolved sensing

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Photonics Research 2024年第3期12卷 411-422页

作者： DARcY l.SMITH lINH V.NGUYEN MOHAMMAD I.REJA ERIK P.ScHARTNER HEIKE EBENDORFF-HEIDEPRIEM DAVID J.OTTAWAY STEPHEN c.WARREN-SMITH Institute for Photonics and Advanced Sensing and School of Physics Chemistry and Earth SciencesThe University of AdelaideAdelaideSA 5005Australia Australian Research council centre of Excellence for Gravitational Wave Discovery(OzGrav) AdelaideSAAustralia Future Industries Institute University of South AustraliaMawson LakesSA 5095Australia laser Physics and Photonics Devices laboratory University of South AustraliaMawson LakesSA 5095Australia

The propagation of coherent light in multimode optical fibers results in a speckled output that is both complex and sensitive to environmental *** properties can be a powerful tool for sensing,as small perturbations lead to significant changes in the output of the ***,the mechanism to encode spatially resolved sensing information into the speckle pattern and the ability to extract this information are thus far *** this paper,we demonstrate that spatially dependent mode coupling is crucial to achieving spatially resolved *** leverage machine learning to quantitatively extract the spatially resolved sensing information from three fiber types with dramatically different characteristics and demonstrate that the fiber with the highest degree of spatially dependent mode coupling provides the greatest accuracy.

关键词： fiber spatially resolved

A multi-shot target wheel assembly for high-repetition-rate, laser-driven proton acceleration

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High Power laser Science and Engineering 2024年第2期12卷 87-94页

作者： J.Penas A.Bembibre D.cortina-Gil l.Martin A.Reija c.Ruiz M.Seimetz A.Alejo J.Benlliure Instituto Galego de Fisica de Altas Enerxias Universidade de Santiago de CompostelaSantiago de CompostelaSpain laboratorio laser de Aceleracion y Aplicaciones RIAIDTUniversidade de Santiago de CompostelaSantiago de CompostelaSpain Instituto Universitario de Física Fundamental y Matematicas y Dpto.de Didactica de la Matematica y de las ciencias Experimentales Universidad de SalamancaSalamancaSpain Instituto de Instrumentación para Imagen Molecular(I3M) CSIC-Universitat Politecnica de ValenciaValenciaSpain

A multi-shot target assembly and automatic alignment procedure for laser–plasma proton acceleration at high repetition rate are *** assembly is based on a multi-target rotating wheel capable of hosting more than 5000 targets,mounted on a 3D motorized stage to allow rapid replenishment and alignment of the target material between laser *** automatic alignment procedure consists of a detailed mapping of the impact positions at the target surface prior to the irradiation that ensures stable operation of the target,which alongside the purpose-built design of the target wheel,enables operation at rates up to 10 *** and continuous laser-driven proton acceleration at 10 Hz is demonstrated,with observed cut-off energy stability about 15%.

关键词： high repetition rate laser-plasma acceleration multi-shot operation proton source target assembly

Quantum vortices get stretched

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Frontiers of physics 2024年第3期19卷 225-227页

作者： Emanuel A.l.Henn São carlos Institute of Physics University of São Paulo-PO Box 36913560-970São CarlosBrazil

Since its discovery, superfluidity [1,2] remains one of the most remarkable phenomena in quantum physics. The onset of the quantum regime in liquid helium is visually striking, when the fluid flows without dissipation or detaches from a rotating bucket, remaining still upon soft rotations. The same phenomenon is present in the context of ultracold bosonic quantum gases where, most of the time, superfluidity walks hand-in-hand with the transition to Bose−Einstein condensation [3].

关键词： quantum rotating rotation

Time-inconsistent stochastic linear-quadratic control problem with indefinite control weight costs

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Science china Mathematics 2024年第1期67卷 211-236页

作者： Qi lü Bowen Ma School of Mathematics Sichuan UniversityChengdu 610064China

A time-inconsistent linear-quadratic optimal control problem for stochastic differential equations is *** introduce conditions where the control cost weighting matrix is possibly *** such conditions,we obtain a family of closed-loop equilibrium strategies via multi-person differential *** result extends Yong’s work(2017) in the case of stochastic differential equations,where a unique closed-loop equilibrium strategy can be derived under standard conditions(namely,the control cost weighting matrix is uniformly positive definite,and the other weighting coefficients are positive semidefinite).

关键词： linear-quadratic optimal control problem time-inconsistent cost functional generalized Riccati equation indefinite control weight cost closed-loop equilibrium strategy

Rogue wave solutions and rogue-breather solutions to the focusing nonlinear Schr?dinger equation

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communications in Theoretical Physics 2024年第3期76卷 33-41页

作者： Si-Jia chen Xing lü college of Science Tianjin University of TechnologyTianjin 300384People's Republic of China Department of Mathematics Beijing Jiaotong UniversityBeijing 100044People's Republic of China Beijing laboratory of National Economic Security Early-warning Engineering Beijing Jiaotong UniversityBeijing 100044People's Republic of China

Based on the long wave limit method,the general form of the second-order and third-order rogue wave solutions to the focusing nonlinear Schr?dinger equation are given by introducing some arbitrary *** interaction solutions between the first-order rogue wave and one-breather wave are constructed by taking a long wave limit on the two-breather *** applying the same method to the three-breather solutions,two types of interaction solutions are obtained,namely the first-order rogue wave and two breather waves,the second-order rogue wave and one-breather wave,*** influence of the parameters related to the phase on the interaction phenomena is graphically *** occur among the rogue waves and breather *** the collisions,the shape of them remains *** abundant interaction phenomena in this paper will contribute to a better understanding of the propagation and control of nonlinear waves.

关键词： nonlinear Schrodinger equation rogue wave solutions interaction solutions