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

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

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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

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The importance of post-cOVID condition phenotypes characterization to decipher the mechanisms underlying this post-viral syndrome

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World Journal of Pediatrics 2024年第6期20卷 633-634页

作者： Jon Izquierdo-Pujol Sara Moron-lopez Irsicaixa and Institute for Health Science Research Germans Trias i Pujol(IGTP) Can Ruti CampusBadalonaSpain Biomedicine doctoral programme Faculty of BiologyUniversity of BarcelonaBarcelonaSpain cIBERInFEc MadridSpain

The coronavirus disease-19(cOVID-19)outbreak,caused by the severe acute respiratory syndrome coronavirus 2(SARS-coV-2),was declared a global pandemic in March *** has affected over 700 million people worldwide and resulted in almost 7 million deaths,equating to a 1%mortality *** present,the majority of cOVID-19 cases are either asymptomatic or mild,typically resolving within two ***,between 1%and 10%of cOVID-19 survivors do not fully recover and experience a post-viral syndrome referred to as"long cOVID","post-acute cOVID-19 syndrome"(PASc),or"post-cOVID condition"(Pcc).This post-viral syndrome affects both adult and pediatric ***,most of the studies published to date evaluate the adult population,leaving a gap in our understanding of its impact on children and adolescents.

关键词： acute mortality respiratory

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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

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The HIF-1α/PlOD2 axis integrates extracellular matrix organization and cell metabolism leading to aberrant musculoskeletal repair

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Bone Research 2024年第2期12卷 289-301页

作者： Heeseog Kang Amy l.Strong Yuxiao Sun lei Guo conan Juan Alec c.Bancroft Ji Hae choi chase A.Pagani Aysel A.Fernandes Michael Woodard Juhoon lee Sowmya Ramesh Aaron W.James David Hudson Kevin n.Dalby lin Xu Robert J.Tower Benjamin levi center for Organogenesis Regeneration and TraumaDepartment of SurgeryUniversity of Texas SouthwesternDallasTX 75390USA Section of Plastic Surgery Department of SurgeryUniversity of MichiganAnn ArborMI 48109USA Quantitative Biomedical Research center Peter O’Donnell Jr.School of Public HealthUniversity of Texas SouthwesternDallasTX 75390USA Department of Orthopedics and Sports Medicine University of WashingtonSeattleWA 98195USA Division of chemical Biology and Medicinal chemistry College of PharmacyUniversity of Texas at AustinAustinTX 78712USA Department of Pathology Johns Hopkins UniversityBaltimoreMD 21218USA

While hypoxic signaling has been shown to play a role in many cellular processes,its role in metabolism-linked extracellular matrix(EcM)organization and downstream processes of cell fate after musculoskeletal injury remains to be ***(HO)is a debilitating condition where abnormal bone formation occurs within extra-skeletal *** andhypoxia-inducible factor 1α(HIF-1α)activation have been shown to promote ***,the underlying molecular mechanisms bywhich the HIF-1αpathway in mesenchymal progenitor cells(MPcs)contributes to pathologic bone formation remain to ***,we used a proven mouse injury-induced HO model to investigate the role of HIF-1αon aberrant cell ***-cell RnA sequencing(scRnA-seq)and spatial transcriptomics analyses of the HO site,we found that collagen EcM organizationis the most highly up-regulated biological process in *** mesenchymal cell-specific deletion of Hif1α(Hoxa11-creER^(T2);Hif1a^(fl/fl))significantly mitigated HO in ***-seq analysis of these Hoxa11-creER^(T2);Hif1a^(fl/fl)mice identified the PlOD2/lOXpathway for collagen cross-linking as downstream of the HIF-1αregulation of ***,our scRnA-seq data and mechanisticstudies further uncovered that glucose metabolism in MPcs is most highly impacted by HIF-1α*** a translational aspect,a pan-lOX inhibitor significantly decreased HO.A newly screened compound revealed that the inhibition of PlOD2 activity in MPcssignificantly decreased osteogenic differentiation and glycolytic *** suggests that the HIF-1α/PlOD2/lOX axis linked tometabolism regulates HO-forming MPc *** results suggest that the HIF-1α/PlOD2/lOX pathway represents a promisingstrategy to mitigate HO formation.

关键词： metabolism skeletal aberrant

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深冷循环热处理下锆基金属玻璃的回春行为调控

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Transactions of nonferrous Metals Society of china 2024年第2期34卷 582-591页

作者：郭威余圣丁俊吕书林吴树森赵觅华中科技大学材料科学与工程学院材料成形与模具技术全国重点实验室武汉430074 深圳华中科技大学研究院深圳518057 西安交通大学金属材料强度国家重点实验室材料创新设计中心西安710049 华中科技大学航空航天学院武汉430074

研究Zr_(55)cu_(30)ni_(5)Al_(10)(摩尔分数,%)金属玻璃在深冷循环处理过程中的回春行为。实验发现,随着循环次数的增加,样品的回春程度更高,表现为更高的弛豫焓与更低的密度。回春程度经200次循环后逐渐饱和,这可能与非晶结构中有限的... 详细信息

研究Zr_(55)cu_(30)ni_(5)Al_(10)(摩尔分数,%)金属玻璃在深冷循环处理过程中的回春行为。实验发现,随着循环次数的增加,样品的回春程度更高,表现为更高的弛豫焓与更低的密度。回春程度经200次循环后逐渐饱和,这可能与非晶结构中有限的自由体积含量有关。同时,高循环次数下的样品硬度更低,塑性更好,这与其剪切转变区体积增大有关。此时,更低的剪切面形成能有利于多重剪切带的形成。此外,还发现自由体积含量与样品塑性应变及剪切转变区体积呈线性关系。分子动力学模拟结果还表明,在高冷速下回春程度高的样品会发生原子体积的饱和。

关键词：金属玻璃回春深冷循环热处理循环次数塑性

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Polyelectrolyte complexes between Hyperbranched and linear Polysaccharides: Fucoidan/chitosan

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chinese Journal of Polymer Science 2024年第4期42卷 468-479页

作者： Ekaterina R.Gasilova Daria n.Poshina Aleksandra O.Sitnikova natalia n.Saprykina Yury A.Skorik Institute of Macromolecular compounds of the Russian Academy of Sciences Bolshoi VO 31St.Petersburg199004Russian Federation

Polyelectrolyte complexes(PEcs)of hyperbranched(HB)and linear polysaccharides are promising as more effective encapsulation agents compared to PEcs formed by linear *** investigated the PEcs between the HB anionic polysaccharide fucoidan(FUc)and the cationic linear polysaccharide chitosan(cS).The FUc had a molecular weight(MW)of 30×*** PEcs were prepared in three solvents(water,0.01 and 0.1 mol/l acetic acid)with cS of MW of 15,110 and 170 kDa,and deacetylation degrees(DDA)of 70%and 97%.The structures of the PEcs and the initial FUc were investigated by multi-angle static and dynamic light *** the FUc contained 18 wt%of—OSO3 groups and 5 wt%of uronic acid units,it was a“strong-weak”copolyanion,so the HB macromolecules of the FUc formed nanogel particles in 0.1 mol/l AcOH and open branched structures in water,as confirmed by the Kratky *** mixing the solutions of original components,the PEc structures underwent an equilibration period,the duration of which increased with the MW of *** the charge stoichiometry was approached,the PEcs shrank;the fractal dimension approached unity,indicating the side-by-side packing of adjacent FUc branches with the help of *** aggregation in the vicinity of the charge compensation was hardly observed,as it occurred in a very narrow *** PEc content at theζ-potential inversion depended on solvents’pH and the DDA of *** the extreme case of core-shell PEcs in 0.1 mol/l AcOH,obtained by mixing FUc nanogels with the solutions of high MW cS of 97%DDA,the protruding tails of cS formed a positively charged shell in the whole range of FUc content(10 wt%ccanning electron microscopy and atomic force microscopy images of dried samples were discussed in relation to the light scattering results.

关键词： Polyelectrolyte complexes chitosan Hyperbranched fucoidan light scattering

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Boosting Adaptive Weighted Broad learning System for Multi-label learning

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IEEE/cAA Journal of Automatica Sinica 2024年第11期11卷 2204-2219页

作者： Yuanxin lin Zhiwen Yu Kaixiang Yang Ziwei Fan c.l.Philip chen the School of computer Science and Engineering in South china university of Technology IEEE the Pengcheng laboratory

Multi-label classification is a challenging problem that has attracted significant attention from researchers, particularly in the domain of image and text attribute annotation. However, multi-label datasets are prone to serious intra-class and inter-class imbalance problems, which can significantly degrade the classification performance. To address the above issues, we propose the multi-label weighted broad learning system(MlW-BlS) from the perspective of label imbalance weighting and label correlation mining. Further, we propose the multi-label adaptive weighted broad learning system(MlAW-BlS) to adaptively adjust the specific weights and values of labels of MlW-BlS and construct an efficient imbalanced classifier set. Extensive experiments are conducted on various datasets to evaluate the effectiveness of the proposed model, and the results demonstrate its superiority over other advanced approaches.

关键词： learning systems Adaptation models correlation Adaptive systems Annotations Boosting classification algorithms Broad learning system label correlation mining label imbalance weighting multi-label imbalance clASSIFIcATIOn EnSEMBlE

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liquid crystal immunosensors for the selective detection of Escherichia coli with a fast analysis tool

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Photonics Research 2024年第7期12卷 1564-1573页

作者： SAnDRO c.OlIVEIRA MARIA S.SOARES BÁRBARA V.GOnÇAlVES AnDREIA c.M.RODRIGUES AMADEU M.V.M.SOARES RITA G.SOBRAl nunO F.SAnTOS JAn nEDOMA PEDRO l.AlMEIDA cARlOS MARQUES cIcEcO-Aveiro Institute of Materials Physics DepartmentUniversity of Aveiro3810-193 AveiroPortugal i3n Physics DepartmentUniversity of Aveiro3810-193 AveiroPortugal Associate laboratory i4HB-Institute for Health and Bioeconomy School of Sciences and TechnologyNOVA University of Lisbon1099-085 LisbonPortugal cESAM-centre for Environmental and Marine Studies and Department of Biology University of Aveiro3810-193 AveiroPortugal Department of Telecommunications VSB-Technical University of OstravaOstrava 70800Czech Republic i3n-cEnIMAT School of Sciences and TechnologyNOVA University of Lisbon1099-085 LisbonPortugal unIRE ISELPolytechnic Institute of Lisbon1549-020 LisbonPortugal Department of Physics VSB-Technical University of OstravaOstrava 70800Czech Republic

The consumption of contaminated food may cause serious illnesses,and traditional methods to detect Escherichia coli are still associated with long waiting times and high costs given the necessity to transport samples to specialized *** is a need to develop new technologies that allow cheap,fast,and direct monitoring at the site of ***,in this work,we developed optical immunosensors for the selective detection of ***,based on liquid crystal technology,whose molecules can align in different manners depending on the boundary conditions (such as substrates) as well as the environment that they *** glass substrate was functionalized with *** antibody using cysteamine as an intermediate,and a vertical alignment was imposed on the liquid crystal molecules by using DMOAP during *** presence of bacteria disrupts the alignment of the liquid crystal molecules,changing the intensity of light emerging between cross polarizers,measured using a polarized optical microscope and a *** was possible to detect *** in suspensions in the concentration range from 2.8 cells/ml to 2.8×10^(9) cells∕*** was also evaluated,and the sensors were used to analyze contaminated water samples.A prototype was developed to allow faster,in-situ,and easier analysis avoiding bulky instruments.

关键词： crystal alignment analysis

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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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