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Linking leaf elemental traits to biomass across forest biomes in the Himalayas

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Science China earth Sciences 2024年第5期67卷 1518-1528页

作者： Nita DYOLA eryuan LIANG Josep peÑUeLAS J.julio CAMAReRO Shalik Ram SIGDeL Sugam ARYAL Wentao LIN Xiang LIU Yongwen LIU Xingliang XU Sergio ROSSI State Key Laboratory of Tibetan Plateau earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Laboratoire sur lesécosystèmes terrestres boréaux Département des Sciences FondamentalesUniversitédu QuébecàChicoutimi555Boulevard de l′UniversitéChicoutimi(QC)G7H2B1Canada CSIC Global Ecology Unit CREAF-CSIC-UABBellaterraE-08193 CataloniaSpain CReAF Cerdanyola del VallèsE-08193 CataloniaSpain Instituto Pirenaico de ecología(Ipe-CSIC) Avenida Montañana 1005Zaragoza 50059Spain Friedrich-Alexander-Universität erlangen-Nürnberg Institut für GeographieErlangen 91058Germany State Key Laboratory of Grassland Agro-ecosystems College of EcologyLanzhou UniversityLanzhou 730000China Key Laboratory of ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Plants require a number of essential elements in different proportions for ensuring their growth and *** elemental concentrations in leaves reflect the functions and adaptations of plants under specific environmental ***,less is known about how the spectrum of leaf elements associated with resource acquisition,photosynthesis and growth regulates forest biomass along broad elevational *** examined the influence of leaf element distribution and diversity on forest biomass by analyzing ten elements(C,N,P,K,Ca,Mg,Zn,Fe,Cu,and Mn)in tree communities situated every 100 meters along an extensive elevation gradient,ranging from the tropical forest(80 meters above sea level)to the alpine treeline(4200 meters above sea level)in the Kangchenjunga Landscape in eastern Nepal *** calculated communityweighted averages(reflecting dominant traits governing biomass,i.e.,mass-ratio effect)and functional divergence(reflecting increased trait variety,i.e.,complementarity effect)for leaf elements in a total of 1,859 trees representing 116 *** increasing mass-ratio effect and decreasing complementarity in leaf elements enhance forest biomass accumulation.A combination of elements together with elevation explains biomass(52.2%of the variance)better than individual elemental trait diversity(0.05%to 21%of the variance).elevation modulates trait diversity among plant species in biomass *** promotes biomass at lower elevations,but reduces biomass at higher elevations,demonstrating an interaction between elevation and *** interaction between elevation and mass-ratio effect produces heterogeneous effects on biomass along the elevation *** research indicates that biomass accumulation can be disproportionately affected by elevation due to interactions among trait diversities across vegetation *** higher trait variation enhances the adaptation of species to environmental changes,it reduces

关键词： ecosystem function elevational gradient Functional diversity Functional traits Leaf elements Niche complementarity

On the viability of wearing evaluation by Thin Layer Activation in the presence of non-occupationally exposed individuals

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Nuclear Science and Techniques 2022年第3期33卷 103-112页

作者： Michel de Almeida Franca julio Cezar Suita Paulo Fernando Ferreira Frutuoso e Melo Celso Marcelo Franklin Lapa Graduate Program of Nuclear engineering COPPEFederal University of Rio de JaneiroRio de JaneiroRJ 21941914Brazil Instituto de engenharia Nuclear(IeN-CNeN) Rio de Janeiro 21941614Brazil Comissao Nacional de energia Nuclear(SeASe/DRS/CNeN) Rio de Janeiro 22290040Brazil

Thin Layer Activation is a nuclear technique that has key advantages over other wear measuring techniques for mechanical systems,especially for in site experiments on equipment important to safety in nuclear ***,it incurs radioactive dose and,thus,must be proved radiologically safe before use,otherwise,the utilization of this technique may be hindered *** said technique is safe previous to any operational/monetary cost is key,providing a methodology for this early assertion is the main contribution of this work—here,only non-occupationally exposed individuals are *** work offers a methodology,through a case study,to ascertain the Thin Layer Activation parameters to obtain safe levels of radioactive dose while maintaining statistically reliable *** methodology consists of using simulations,through the Monte Carlo Method,to obtain the floors and ceilings for the previously mentioned activation parameters based on operation and work conditions on site.

关键词： Thin Layer Activation Safety evaluation Simulation equipment wearing

Prefoldins 3 and 5 Play an essential Role in Arabidopsis Tolerance to Salt Stress

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Molecular Plant 2009年第3期2卷 526-534页

作者： Miguel A. Rodriguez-Milla julio Salinas Departamento de Biologfa de Plantas Centro de Investigaciones Biologicas-CSIC Ramiro de Maeztu 9 28040 Madrid Spain

During the last years, our understanding of the mechanisms that control plant response to salt stress has been steadily progressing. Pharmacological studies have allowed the suggestion that the cytoskeleton may be involved in regulating such a response. Nevertheless, genetic evidence establishing that the cytoskeleton has a role in plant tolerance to salt stress has not been reported yet. Here, we have characterized Arabidopsis T-DNA mutants for genes encoding proteins orthologous to prefoldin （PFD） subunits 3 and 5 from yeast and mammals. In these organisms, PFD subunits, also known as Genes Involved in Microtubule biogenesis （GIM）, form a heterohexameric PFD complex implicated in tubulin and actin folding. We show that, indeed, PFD3 and PFD5 can substitute for the loss of their yeast orthologs, as they are able to complement yeast gim2Δ and gim5Δ mutants, respectively. Our results indicate that pfd3 and pfd5 mutants have reduced levels of α- and β-tubulin compared to the wild-type plants when growing under both control and salt-stress conditions. In addition, pfd3 and pfd5 mutants display alterations in their developmental patterns and microtubule organization, and, more importantly, are hypersensitive to high concentrations of NaCl but not of LiCl or mannitol. These results demonstrate that the cytoskeleton plays an essential role in plant tolerance to salt stress.

关键词： Prefoldins cytoskeleton tubulin actin microtubule salt tolerance Arabidopsis

Interpe.e.rating polymers supported on microporous polypropylene membranes for the transport of chromium ions

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Chinese Journal of Chemical engineering 2017年第7期25卷 938-946页

作者： Yesid Tapiero julio Sánchez BernabéL.Rivas Polymer Department Faculty of ChemistryUniversity of ConcepdonCasilla 160-C ConcepcionChile

Modifying polypropylene membranes with interpe.e.rating polymer networks(IPNs) through the incorporation of poly(glycidyl methacrylate-N-methyl-D-glucamine)(P(GMA-NMG)) was performed by in situ synthesis via radical polymerization. The surface of the polypropylene membrane was activated by hydrophilic grafted polyelectrolyte, and then, pressure injection was used for the impregnation of the reactive solution in the *** types of pore-filled membranes were synthesized, chelating interpe.e.rating homopolymer networks of P(GMA-NMG), and chelating-ion exchange interpe.e.rating polymer networks(e.g., P(GMA-NMG)/P(AA),P(GMA-NMG)/P(AMPSA), and P(GMA-NMG)/P(Cl VBTA)). After their synthesis, the modified polypropylene membranes were characterized using techniques such as the electrokinetic potential, SeM, FT-IR, and Donnan dialysis to corroborate the chromium ion transport. The P(GMA-NMG) and complex network membranes exhibited a hydrophilic character with a water-uptake capacity between 20% and 35% and a percentage of modification between 4.0% and 7.0% in comparison with the behavior of the unmodified polypropylene *** chromium ions were efficiently transported from the food chamber at p H 9.0 when the 65.2%MTA1 P(Cl VBTA) homopolymer IPN membrane and 48.5% MTAG P(GMA-NMG)/P(Cl VBTA) IPN membrane were used. Similarly, hexavalent chromium ions were removed from the food chamber at pH 3.0 when MTAG(63.30%) and MTA1(35.68%) were used in 1 mol·L^(-1)Na Cl solution as the extraction reagent.

关键词： Polypropylene N-methyI-D-glucamine Ion exchange Donnan dialysis Interpe.e.rating polymer networks Chromium

The effect of rippling on the mechanical properties of graphene

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Nano Materials Science 2022年第1期4卷 18-26页

作者： Guillermo Lopez-Polin Cristina Gomez-Navarro julio Gomez-Herrero Instituto de Ciencia de Materiales de Madrid CSICMadrid E 28049Spain Departamento de Física de La Materia Condensada Universidad Autónoma de MadridMadridE-28049Spain IFIMAC Condensed Matter Physics Center(IFIMAC).Universidad Autónoma de Madrid MadridE-28049Spain

Graphene is the stiffest material known so far but, due to its one-atom thickness, it is also very ***, free-standing graphene exhibit ripples that has major effects on its elastic properties. Here we will summarize three experiments where the influence of rippling is essential to address the results. Firstly, we observed that atomic vacancies lessen the negative thermal expansion coefficient(TeC) of free-standing *** also observed an increase of the Young's modulus with global applied strain and with the introduction of small density defects that we attributed to the decrease of rippling. Here, we will focus on a surprising feature observed in the data: the experiments consistently indicate that only the rippling with wavelengths between 5 and 10 nm influences the mechanics of graphene. The rippling responsible of the negative TeC and anomalous elasticity is thought to be dynamic, i.e. flexural phonons. However, flexural phonons with these wavelengths should have minor effects on the mechanics of graphene, therefore other mechanisms must be considered to address our observations. We propose static ripples as one of the key elements to correctly understand the thermomechanics of graphene and suggest that rippling arises naturally due to a competition of symmetry breaking and anharmonic fluctuations.

关键词： Graphene Mechanical properties Atomic force microscopy Defects Ripples Stmain

Using dung beetles to evaluate the effects of urbanization on Atlantic Forest biodiversity

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Insect Science 2013年第3期20卷 393-406页

作者： Vanesca Korasaki Jose Lopes George Gardner Brown julio Louzada Departamento de Agronomia Departamento de Biologia Animal e Vegetal Universidade Estadual de Londrina Londrina-PR empresa Brasileira de pesquisa Agropecu~ria Embrapa Florestas Colombo-PR Departamento de Biologia Setor de Ecologia Universidade Federal de Lavras Lavras Minas Gerais Brazil

We used dung beetles to evaluate the impact of urbanization on insect biodi- versity in three Atlantic Forest fragments in Londrina, Parana, Brazil. This study provides the first empirical evidence of the impact of urbanization on richness, abundance, compo- sition and guild structure of dung beetle communities from the Brazilian Atlantic Forest. We evaluated the community aspects （abundance, richness, composition and food guilds） of dung beetles in fragments with different degrees of immersion in the urban matrix using pitfall traps with four alternative baits （rotten meat, rotten fish, pig dung and decaying ba- nana）. A total of 1 719 individuals were collected, belonging to 29 species from 11 genera and six Scarabaeinae tribes. The most urban-immersed fragment showed a higher species dominance and the beetle community captured on dung presented the greatest evenness. The beetle communities were distinct with respect to the fragments and feeding habits. except for the dung beetle assemblage in the most urbanized forest fragment, all others exhibited contrasting differences in species composition attracted to each bait type. Our results clearly show that the degree of urbanization affects Atlantic Forest dung beetle communities and that the preservation of forest fragments inside the cities, even small ones, can provide refuges for Scarabaeinae.

关键词： bioindicator coprophagous beetles food preference fragmentation habitat loss urban matrix

Attosecond twisted beams from high-order harmonicgeneration driven by optical vortices

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High Power Laser Science and engineering 2017年第1期5卷 12-19页

作者： Carlos Hernandez-Garcia Laura Rego julio San Roman Antonio Picon Luis Plaja Grupo de Investigacion en Aplicaciones del Laser y Fotonica Departamento de Fisica AplicadaUniversity of SalamancaE-37008SalamancaSpain Argonne National Laboratory Argonne1L 60439USA

Optical vortices are structures of the electromagnetic field with a spiral phase ramp about a point-phase singularity,carrying orbital angular momentum(OAM). Recently, OAM has been imprinted to short-wavelength radiation through high-order harmonic generation(HHG), leading to the emission of attosecond twisted beams in the extreme-ultraviolet(XUV) regime. We explore the details of the mapping of the driving vortex to its harmonic spectrum. In particular, we show that the geometry of the harmonic vortices is convoluted, arising from the superposition of the contribution from the short and long quantum paths responsible of HHG. Finally, we show how to take advantage of transverse phase-matching to select twisted attosecond beams with different spatiotemporal properties.

关键词： attosecond science extreme-ultraviolet vortices high harmonic generation orbital angular momentum twisted beams vortexbeams

Contrasting climate drivers of seasonal growth in western vs. eastern Mexican mountain conifer forests

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Forest ecosystems 2023年第1期10卷 64-72页

作者： Marin Pompa-Garcia J.julio Camarero eduardo DVivar-Vivar Laboratorio de Dendroecologia Facultad de Ciencias Forestales y AmbientalesUniversidad Juarez del Estado de DurangoRio Papaloapan y Blvd.Durango s/n Col.Valle del SurDurango34120Mexico Instituto Pirenaico de ecologia(Ipe-CSIC) Avda.Montanana 100550192ZaragozaSpain

Hydroclimate affects the radial growth responses of trees, but the drivers of their spatial and population variability are not sufficiently understood. We addressed this issue by sampling several conifer populations located at the same latitude, but at different longitude and elevation in western(W) and eastern(e) Mexican regions. We used dendroecology to disentangle how earlywood width(eW), latewood width(LW) and adjusted LW(LWadj),i.e. the residuals after removing eW influences on LW, responded to climate variables(temperature and precipitation), climate indices(Southern Oscillation Index, SOI, Nino 3.4, Pacific Decadal Oscillation, PDO) and a drought index(Standardised Precipitation-evapotranspiration Index, SpeI). The W species(Pinus herrerae Martinez, Pinus durangensis Martinez, Abies durangensis Martínez and Cupressus lusitanica Mill.) showed lower growth rates than the e species(Pinus hartwegii Lindl., Picea mexicana Martinez, Pseudotsuga menziesii(Mirb.) Franco and Abies vejari Martinez). Growth in W benefits mostly from high precipitation in the prior winter and current spring and it is limited by high temperatures in spring, whereas growth in the e showed similar but weaker ***, positive(negative) correlations were found in radial growth with the Nino 3.4(SOI) and the PDO from the prior to current autumns, which were again stronger in absolute terms in the W than in the e regions,excepting SOI in summer. In the W, P. durangensis and C. lusitanica were the least and most responsive species to spring drought, respectively;whilst P. menziesii and A. vejari were very responsive to spring drought compared to P. hartwegii in the e. Our results suggest greater responsiveness to hydroclimate and atmospheric patterns in the W than in the e region. These findings allow better interpretations of future changes in growth and composition in Mexican conifer forests, considering that climate models forecast warmer spring conditions and increased water s

关键词： Drought earlywood el Nino-Oscillation Latewood

environmental Factors that Affect Primary Plant Succession Trajectories on Lahars(Popocatépetl Volcano,Mexico)

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Journal of Mountain Science 2015年第5期12卷 1254-1266页

作者： GARCIA-ROMeRO Arturo ALANIS-ANAYA Rocío Marisol MUNOZ-JIMeNeZ julio Departamento de Geografía Física Instituto de GeografíaUniversidad Nacional Autónoma de México.Circuitoexterior s/nCiudad Universitaria04510 MexicoDistrito FederalMexico Laboratorio de Análisis Geoespacial Instituto de GeografíaUniversidad Nacional Autónoma de México.Circuitoexterior s/nCiudad Universitaria04510 MexicoDistrito FederalMexico Departamento de A.G.R.y Geografía Física Facultad de Geografía e HistoriaUniversidad Complutense de Madrid.Calle Profesor Aranguren s/nCiudad Universitaria28040MadridSpain

The earliest stages of plant succession on severely disturbed sites usually follow highly unpredictable trajectories. However, in the Popocatépetl volcano area(50 km Se of Mexico City),the development of physiognomically distinct primary plant communities suggests the occurrence of various successional trajectories only 10 years after the onset of colonization of a temperate forest on lahars. To characterize plant communities and determine the environmental factors that drive the differences observed between plant communities and their successional trajectories, we monitored 64 circular sample plots(3.14 m2) from 2002 to 2011. We examined the plant communities' composition and structure in terms of their species richness and abundance, plant cover, and maximum stem height,and recorded 13 environmental factors related to the volcanic deposit characteristics, microclimate, soil,flow dynamics and gravitational processes. A cluster analysis of the species abundance data showed that,by 2011, six plant community types(CT's) had established, including grasslands, and open, dense and very dense shrub lands. As these communities developed over the same period of time and within the same overall ecosystem, then these plant community types were interpreted as different stages of the same successional trajectory. Two sequential main stages that drive regeneration were identified from this successional trajectory: a) the first four years are characterized by a steady increase in species richness and physiognomic development(plant size and coverage), mostly dominated by Baccharis conferta, eupatorium glabratum and Senecio barbajohannis; b) from the sixth year onwards, a continued increase in the abundance of those same species led to the development of the dense shrubland *** in the availability of soil resources and disturbances linked to recent lahar flows were the main factors accounting for such differences.

关键词： ecosystem regeneration Plantcolonization Primary succession Temperate forest Light exposure elevation Soil Slope aspect