The dentate gyrus of the hippocampus is a plastic structure that displays modifications at different levels in response to positive stimuli as well as to negative conditions such as brain damage.The latter involves gl...The dentate gyrus of the hippocampus is a plastic structure that displays modifications at different levels in response to positive stimuli as well as to negative conditions such as brain damage.The latter involves global alterations,making understanding plastic responses triggered by local damage difficult.One key feature of the dentate gyrus is that it contains a well-defined neurogenic niche,the subgranular zone,and beyond neurogenesis,newly born granule cells may maintain a“young”phenotype throughout life,adding to the plastic nature of the structure.Here,we present a novel experimental model of local brain damage in organotypic entorhino-hippocampal cultures that results in the activation of adjacent newly born granule cells.A small piece of filter paper was placed on the surface of the granule cell layer of the dentate gyrus,which evoked a foreign body reaction of astrocytes,along with the activation of local young neurons expressing doublecortin.Forty-eight hours after foreign body placement,the number of doublecortin-immunoreactive cells increased in the subgranular zone in the direct vicinity of the foreign body,whereas overall increased doublecortin immunoreactivity was observed in the granule cell layer and molecular layer of the dentate gyrus.Foreign body placement in the pyramidal layer of the CA1 region evoked a comparable local astroglial reaction but did not lead to an increase in doublecortin-immunoreactive in either the CA1 region or the adjacent dentate gyrus.Seven days after foreign body placement in the dentate gyrus,the increase in doublecortin-immunoreactivity was no longer observed,indicating the transient activation of young cells.However,7 days after foreign body placement,the number of doublecortin-immunoreactive granule cells coimmunoreactive for calbindin was lower than that under the control conditions.As calbindin is a marker for mature granule cells,this result suggests that activated young cells remain at a more immature stage following foreign body placement.Live imaging of retrovirally green fluorescent protein-labeled newly born granule cells revealed the orientation and growth of their dendrites toward the foreign body placement.This novel experimental model of foreign body placement in organotypic entorhino-hippocampal cultures could serve as a valuable tool for studying both glial reactivity and neuronal plasticity,specifically of newly born neurons under controlled in vitro conditions.展开更多
The brain is the most complex human organ,and commonly used models,such as two-dimensional-cell cultures and animal brains,often lack the sophistication needed to accurately use in research.In this context,human cereb...The brain is the most complex human organ,and commonly used models,such as two-dimensional-cell cultures and animal brains,often lack the sophistication needed to accurately use in research.In this context,human cerebral organoids have emerged as valuable tools offering a more complex,versatile,and human-relevant system than traditional animal models,which are often unable to replicate the intricate architecture and functionality of the human brain.Since human cerebral organoids are a state-of-the-art model for the study of neurodevelopment and different pathologies affecting the brain,this field is currently under constant development,and work in this area is abundant.In this review,we give a complete overview of human cerebral organoids technology,starting from the different types of protocols that exist to generate different human cerebral organoids.We continue with the use of brain organoids for the study of brain pathologies,highlighting neurodevelopmental,psychiatric,neurodegenerative,brain tumor,and infectious diseases.Because of the potential value of human cerebral organoids,we describe their use in transplantation,drug screening,and toxicology assays.We also discuss the technologies available to study cell diversity and physiological characteristics of organoids.Finally,we summarize the limitations that currently exist in the field,such as the development of vasculature and microglia,and highlight some of the novel approaches being pursued through bioengineering.展开更多
In complex geological environments,the analysis of drill cores to determine rock strength can be challenging due to the wide variability in the degree of fracturing,leading to subjectivity in the collection of represe...In complex geological environments,the analysis of drill cores to determine rock strength can be challenging due to the wide variability in the degree of fracturing,leading to subjectivity in the collection of representative samples for uniaxial compressive strength testing.This study evaluates non-destructive techniques on calcareous rocks with different tectonic deformations,including Equotip hardness,ultrasound P-wave velocity,thin section analysis,and calcimetry,integrated with photogrammetric fracture analysis.The investigated carbonate rock samples are sourced from drill cores derived from the Umbria-Marche fold and thrust belt(northern Apennines,Italy),including a gently dipping limb of an anticline,a hinge zone of an anticline,and a fault zone associated with a thrust.Fracture intensity,quantified by the P21 parameter using photogrammetric techniques on pre-loading rock samples,is assessed alongside macroscopic identification of discontinuities(such as stylolites,veins,and joints)using marker colours to monitor failures during uniaxial compression testing.Empirical correlations depicted by single and multi-linear relationships indicate a strong dependence between the mechanical and physical properties of limestones.Both Equotip and P-wave velocity are influenced by fracture intensity,but P-wave velocity varies significantly with discontinuity orientation,especially at 45°-90°.To refine uniaxial compressive strength predictions and mitigate multicollinearity,statistical approaches,including linear and multilinear regression,Principal Component Analysis and Gaussian Process Regression,were tested.Findings improve the reliability of non-destructive techniques for assessing rock strength in structurally complex settings,with implications for geotechnical applications.展开更多
The construction industry is a significant contributor to global CO_(2) emissions,and urgent innovation is needed to mitigate its environmental impact.This paper provides a comprehensive review of scalable approaches ...The construction industry is a significant contributor to global CO_(2) emissions,and urgent innovation is needed to mitigate its environmental impact.This paper provides a comprehensive review of scalable approaches for CO_(2) uptake in construction materials,including the injection of CO_(2) into fresh concrete,the CO_(2) curing of precast concrete,and the use of ceramics as CO_(2) sinks.Among these three approaches,CO_(2) curing methods for concrete represent the most advanced and widely adopted strategies within industrial practice,with substantial research supporting their effectiveness and scalability.The comparison of carbonation mineralisation across three distinct material groups reveals that the direct injection of CO_(2) into fresh concrete mixes results in CO_(2) uptake of less than 3 kg/m3.For the precast concrete elements,the CO_(2) uptake ranges from 30 to 350 kg/m3,while ceramics can achieve uptake efficiencies up to 23 wt.%under pilot-scale conditions.Achieving efficient CO_(2) uptake in fresh and precast concrete without compromising mechanical properties relies on precise control over the CO_(2) dose,a tailored mix design,and optimised curing conditions,while avoiding excessive carbonation that could reduce alkalinity or durability.Valorisation of carbonated materials as supplementary cementitious components or aggregates is identified as an important circular solution,though further research is needed to address regeneration,performance,and standardisation.The review highlights ongoing gaps in life-cycle assessment and industrial-scale validation,and recommends future work on durability and techno-economic optimisation for robust decarbonisation in the cement and concrete industries.展开更多
The 7 ka old Qixiangzhan lava flow(QXZ,Tianchi volcano)represents the last eruptive event before the 946 CE,caldera-forming‘Millennium’eruption(ME).Petrographic,whole rock,mineral composition,Sr-Nd isotopic data on ...The 7 ka old Qixiangzhan lava flow(QXZ,Tianchi volcano)represents the last eruptive event before the 946 CE,caldera-forming‘Millennium’eruption(ME).Petrographic,whole rock,mineral composition,Sr-Nd isotopic data on QXZ show that:(a)the lava consists of two components,constituted by comenditic obsidian fragments immersed in a continuous,aphanitic component;(b)both components have the same geochemical and isotopic variations of the ME magma.The QXZ and ME comendites result from fractional crystallization and crustal assimilation processes.The temperature of the QXZ magma was about 790℃ and the depth of the magma reservoir around 7 km,the same values as estimated for ME.QXZ had a viscosity of 10^(5.5)-10^(9) Pa s and a velocity of 3-10 km/yr.The emplacement time was 0.5-1.6yr and the flow rate 0.48-1.50 m^(3)/s.These values lie within the range estimated for other rhyolitic flows worldwide.The QXZ lava originated through a mixed explosive-effusive activity with the obsidian resulting from the ascent of undercooling,degassing and the fragmentation of magma along the conduit walls,whereas the aphanitic component testifies to the less undercooled and segregated flow at the center of the conduit.The QXZ lava demonstrates the extensive history of the ME magma chamber.展开更多
This paper reveals the travel characteristics;direct and indirect costs and travel times;users’perceptions with respect to reliability,comfort and safety;and impact of travel on the quality of academic performance fo...This paper reveals the travel characteristics;direct and indirect costs and travel times;users’perceptions with respect to reliability,comfort and safety;and impact of travel on the quality of academic performance for students in the Centro Acadêmico do Agreste of UFPE(CAA),located in Caruaru-PE(140 km from the capital)which has 3,000 students from 70 municipalities.Almost 50%of these students live in cities located within 100 km of Caruaru and commute for three hours on average(round-trip).These trips are mostly performed on non-regular intercity transportation,chartered by users or municipalities.This kind of transport,apparently inadequate in operational terms,makes access to higher education possible for a significant proportion of students,keeping them residents of their hometowns.展开更多
Climate change is altering river regimes in mountainous regions,affecting water availability and the functioning of aquatic ecosystems.In the Andes Mountains,characterizing the natural flow regime is essential for est...Climate change is altering river regimes in mountainous regions,affecting water availability and the functioning of aquatic ecosystems.In the Andes Mountains,characterizing the natural flow regime is essential for establishing operational conditions that balance multiple water uses(irrigation,supply,hydropower)with the conservation of high-elevation ecosystems in the context of increasing hydroclimatic variability.This study analyzes extreme hydrological conditions in nivoglacial rivers of the upper Mendoza River Basin(Argentina),using indicators of magnitude,frequency,duration,and timing of high(HP)and low(LP)pulses.Daily flow records from the Cuevas,Vacas,Tupungato,and Mendoza Rivers were used to define eight ecologically relevant extreme hydrological parameters over the period 1956–2023.The results reveal a reduction in the magnitude of extreme flows since 2010(−30%to–55%)and significant delays in their timing,with maximum and minimum flow shifting by 15–20 days later in recent decades.The duration of LP events increased by 120%–240%in the Cuevas,Tupungato,and Mendoza Rivers,while in the Tupungato River,HP events tended to occur less frequently but with longer durations.These changes are associated with a 0.1℃decade^(−1)rise in mean temperature and a∼25%decrease in precipitation since 2009.Such trends have major implications for water resource management and the resilience of high-Andean ecosystems under climate warming.展开更多
The Monte Desert is characterized by a great diversity of landforms created with fluvial,alluvial which the vegetation patterns are related to.The present work has the following objectives:(1) determine whether topogr...The Monte Desert is characterized by a great diversity of landforms created with fluvial,alluvial which the vegetation patterns are related to.The present work has the following objectives:(1) determine whether topographical attributes,surface characteristics,soil properties and vegetation patterns vary between alluvial landforms,and(2) define whether morphometric,soil and surface properties influence vegetation patterns along alluvial landscape.Morphometric data were obtained by processing a 5 m digital elevation model.The coverage of rock fragments,fine sediments and mulch was quantified.Observations and descriptions of the soil profiles were restricted to the uppermost 50 cm.Vegetation properties were calculated using a Point Quadrat Method.The relationship between variables was evaluated through multivariate statistical analysis.The main results show the presence of 45 plant species distributed in 19 families,where shrubs are dominant.The wind effect,topographic wetness and dissection of the landscape are limiting factors of diversity.The coverage of superficial rock fragments influence vegetation coverage through the distribution and availability of rainwater.Furthermore,the different soil textures reveal that the silt content favors an increase in vegetation coverage.The presence of V horizon could condition the installation and development of vegetation in the early stages of growth.展开更多
Unstable environments intensify the frequency of extreme disasters.Long-term climate changes can lead to agricultural and ecological degradation that threatens population sustainability.To better understand past clima...Unstable environments intensify the frequency of extreme disasters.Long-term climate changes can lead to agricultural and ecological degradation that threatens population sustainability.To better understand past climatic events and consequences,here we present a reconstruction of the self-calibrating Palmer drought severity index(scPDSI)from September to August for the desert margins of northern China,dating back to 1742.The reconstruction accounts for 42.9%of the variation of meteorological data between 1951 and 2020.Our spatial correlation analyses showed significant correlations between scPDSI,runoff,and precipitation.Over the past 279 years,the study area has undergone nine dry and eight wet periods,with the most severe climate extremes between the 1850s and 1890s.This period of prolonged drought in northeastern China coincided with the combined impacts of climatic factors and human influences,contributing to the fall of the Qing Dynasty.Analysis of periodicity and anomalies in sea surface temperatures indicate a strong association between wet and dry cycles and El Niño-Southern Oscillations.Our findings offer insights into long-term dry and wet fluctuations at the desert margins in northern China and elucidate the relationship between drought and the dynamics of civilizations.They also highlight the potential impact of extremes in climate on modern society,especially under the four projected shared socioeconomic pathways climatic scenarios,which predict worsening droughts in northern China.展开更多
Although mollusks represent Earth’s second most diverse invertebrate group,their natural history and ecology are still scarcely known.The compilation of non-traditional data,such as those from citizen science,represe...Although mollusks represent Earth’s second most diverse invertebrate group,their natural history and ecology are still scarcely known.The compilation of non-traditional data,such as those from citizen science,represents an alternative to fill these gaps,particularly on striking land snail species such as Macrocyclis peruvianus.Based on long-term citizen science,we aimed to update and describe some basic ecological aspects,such as the distribution and protected area types used by M.peruvianus.We performed pairwise comparisons to test potential changes in occurrence and occupancy among administrative regions,forest types,and protected area types using chi-squared tests.The citizen scientists were also asked to provide the number of M.peruvianus individuals observed and the tree species that dominated their habitat.Thus,we tested if the number of land snails found by citizen scientists could be related to forest and protected area types using a generalized linear mixed model.We expanded the northern distributional limit,with Nothofagus,evergreen,and mixed forests far the most frequented by M.peruvianus.Parallelly,the occurrence of M.peruvianus in official protected areas(65.73%)was significantly higher than in privately owned areas.Moreover,we did not find associations between forest and protected area types with the number of M.peruvianus recorded.Although citizen science is a helpful method for obtaining novel information regarding the ecology of neglected species such as M.peruvianus,it also introduces spatial and occurrence biases explained by the access and attractiveness of the officially protected areas compared to privately owned patches of native forest.展开更多
Bioclimatic classification(WBCS),which examines the relationship between vegetation distribution and climatic variables such as precipitation and temperature,is essential for understanding the ecological dynamics.This...Bioclimatic classification(WBCS),which examines the relationship between vegetation distribution and climatic variables such as precipitation and temperature,is essential for understanding the ecological dynamics.This research focuses on producing a detailed bioclimatic map of Oaxaca,Mexico,at a spatial resolution of 30 arc-seconds,using the methodology developed by Rivas-Martínez et al.(2011).Oaxaca,characterised by its complex topography and diverse climatic conditions,provides a unique opportunity to study bioclimatic patterns in a tropical region.Using high-resolution climate data from Chelsa database,we identified and mapped different bioclimates,variants,thermotypes and ombrotypes horizons and levels of continentality within the tropical macrobioclimate.Our analysis revealed a rich diversity of bioclimatic zones,reflecting the complex interplay between Oaxaca's physical geography and its bioclimates.The results,presented in high resolution maps,highlight the spatial variability and complexity of Oaxaca's bioclimatic landscape.These findings are crucial for several applications,including biodiversity conservation,agricultural planning and climate change adaptation strategies.By providing an accurate bioclimatic classification,this study makes a significant contribution to bioclimatology and could give valuable insights into climate-vegetation relationships in tropical regions.This detailed bioclimatic map improves our understanding of the current ecological status of Oaxaca and serves as a critical tool for future environmental planning and conservation efforts.Furthermore,it could be the basis for planning in national programs that consider agriculture and forests in Mexico such as Programa Sembrando Vida(PSV).展开更多
When a vehicle moves over a flexible pavement structure,it generates loading and unloading cycles that produce recoverable(resilient)and permanent(plastic)deformations in the granular base and subbase layers,which are...When a vehicle moves over a flexible pavement structure,it generates loading and unloading cycles that produce recoverable(resilient)and permanent(plastic)deformations in the granular base and subbase layers,which are made of unbound granular materials(UGMs).The primary parameter used to evaluate the resilient response of UGMs in pavements is the resilient modulus(MR).The MR is widely used in calculating stress-strain states for flexible pavement design and as a control parameter during the construction process.It is also employed to understand the progression of distresses,such as fatigue cracking and rutting.The main objective of this study was to conduct a literature review on the resilient behavior of UGMs.This manuscript presents and describes the MR and the factors that influence it.It also outlines the evolution of the mathematical equations most commonly used to estimate and predict this physical parameter.Conclusions and recommendations for future research are provided at the end of the article.Despite the large amount of research done on the subject,the resilient behavior of UGM has not yet been fully understood.This is since these materials are highly heterogeneous and show nonlinear-anisotropic behavior under different cyclic loading paths and water contents.Likewise,these materials undergo different behaviors depending on their macro and microscopic properties(gradation,density,porosity,texture,mineralogy,particle geometry and orientation,temperature,among others).On the other hand,the main limitation of the mathematical equations is that their parameters are difficult to determine experimentally and are not constants of the material(they are state variables that can change with multiple factors).Additionally,these equations do not consider the boundary conditions to which UGM in pavements are exposed.Moreover,they are obtained from repeated load triaxial(RLT)tests,which cannot simulate the three cyclic stress components(vertical,horizontal,and shear)to which UGMs are subjected in a pavement.In recent years,there has been an increase in studies evaluating the use of recycled aggregates and the effect of temperature(particularly at subzero temperatures),but more research is still needed to reach definitive conclusions.展开更多
The experiment addressed the effects of preharvest KH_(2)PO_(4)foliar spraying(20 mmol·L^(-1))on fruit quality and composition(including volatile organic compounds,VOCs)of cherry tomatoes(‘Caravaggio’,‘Sugarl...The experiment addressed the effects of preharvest KH_(2)PO_(4)foliar spraying(20 mmol·L^(-1))on fruit quality and composition(including volatile organic compounds,VOCs)of cherry tomatoes(‘Caravaggio’,‘Sugarland’and‘Top Stellina’)after 0(S0),7(S7)and 14 days(S14)of storage at 8.0°C.On the average of the 3 genotypes,the KH_(2)PO_(4)treatment improved fruit pressure firmness,total soluble solids(TSS),titratable acidity(TA),total phenols and carotenoids concentrations,along with the fruits'antioxidant capacity(by up to 17%for FRAP assay).Within the S7–S14 period,control fruits showed the highest reductions in TSS,TSS/TA ratio and total carotenoids(-17,-12 and-45,respectively),whereas treated fruits proved the strongest increase in DPPH(+12%).Sixteen out of 32 VOCs were promoted following KH_(2)PO_(4)application,including the aldehydes hexanal,(E)-2-hexenal and(Z)-3-hexenal and the apocarotenoids(E)-citral,(E)-β-ionone,geranylacetone and 6-methyl-5-hepten-2-one.Proceeding from S0 to S14,several VOCs decreased more strongly in control fruits,as for hexanal(-48%)and total aldehydes(-42%,whereas at S14 treated fruits had higher concentrations of linalool,geranylacetone and 6-methyl-5-hepten-2-one(1.06,52.50 and 79.27μg·kg^(-1),respectively).‘Caravaggio’demonstrated the strongest apocarotenoid reduction at S14,whereas‘Top Stellina’was more responsive to KH_(2)PO_(4)(mainly forβ-cyclocitral,geranylacetone and total terpenes/terpenoids),thus highlighting the central role of the genotype in responding to other experimental factors.Nonetheless,these results suggest that proper preharvest KH_(2)PO_(4)applications can preserve specific commercial,nutritional and quality traits of cold-stored cherry tomatoes.展开更多
This article aims to analyze the repercussions of food trade between China and various regions of the world to understand the dynamics of food flows and offer a novel perspective on the contemporary globalization proc...This article aims to analyze the repercussions of food trade between China and various regions of the world to understand the dynamics of food flows and offer a novel perspective on the contemporary globalization process.Understanding these flows involves analyzing the global production and commercialization of food and the effects of these movements on exporting and importing countries in economic terms and food security.The concept of unequal caloric exchange is applied to the case of China,which allows for an understanding of how its economic growth and participation in international trade have transformed its global and internal commercial dynamics by establishing links with self-sufficiency and the composition of its population’s diet.The results show that China is increasingly dependent on international markets for its food supply.From 1961 to 2021,food consumption in China has tripled in calories and experienced qualitative changes,with a reduction in high-quality carbohydrates and vegetable proteins and an increase in cereals,vegetable oils,alcohol,and vegetables.This dietary transformation is related to economic growth and greater dependence on international trade.From 1987 to 2022,China has shown a growing deficit in the food trade balance,with imports exceeding exports in volume,value,and calories,although it maintains favorable terms of trade.Food self-sufficiency has decreased from 95%in 1961 to 76%in 2022,and the diet has diversified,replacing traditional foods with products demanded in international trade.展开更多
Mountains are important reservoirs of biodiversity and endemism on a global scale, but little is known about the altitudinal configuration of this diversity and its driving factors in arid mountains. We explored varia...Mountains are important reservoirs of biodiversity and endemism on a global scale, but little is known about the altitudinal configuration of this diversity and its driving factors in arid mountains. We explored variations in composition, diversity, cover,and life forms of vascular plants along a complete altitudinal gradient(1300-4000 m a.s.l) in Sierra de Velasco, an arid mountain in northwestern Argentina.We evaluated the influence of environmental variables on plant diversity and cover. Field sampling was conducted in the northern sector of the Sa. de Velasco,on the western slope in eight 50 m wide altitudinal bands at 400 m elevation intervals. We used rectangular plots(20 × 4 m;n:10/altitudinal band) to register the vascular plants of all the growth forms, and linear transects(20 m long.;n:30/altitudinal band) to quantify the vegetation cover using the point intercept method. Diversity was calculated using hill numbers.Data analysis included non-metric multidimensional scaling(NMDS), indicator species analysis,generalized linear models(GLMs), and variance partitioning analysis. A total of 232 species from 51families and 158 genera were registered. Species composition showed greater similarity at intermediate elevations. Plant diversity and cover exhibited a unimodal distribution, peaking at intermediate elevations(2100-2500 m). In contrast, life forms' distribution showed divergent patterns. Therophytes and succulents predominated at low altitudes,phanerophytes and hemicryptophytes at medium altitudes, and chamaephytes and geophytes at high altitudes. The altitudinal patterns of plant diversity and cover were primarily driven by climatic factors.Conservation efforts in the Sierra de Velasco should focus on the middle and upper zones due to their high biodiversity and vulnerability to climate change.展开更多
Wetlands are unique ecological environments capable of harboring high biodiversity.However,urbanization can degrade,eliminate,or transformthese habitats.Although amphibians utilize habitats created by humans in urban ...Wetlands are unique ecological environments capable of harboring high biodiversity.However,urbanization can degrade,eliminate,or transformthese habitats.Although amphibians utilize habitats created by humans in urban landscapes,few studies have investigated the infuence of thehabitat quality on the life history of anurans.We assessed life history traits such as snout-vent length(SVL),body condition,and reproductiveinvestment in the South American common toad Rhinella arenarum,to determine whether urbanization is harmful or benefcial to this species.We sampled wetlands with different levels of urbanization in Río Cuarto city,Córdoba,Argentina.We recorded males with lower SVL in mediumurbanized wetlands and those with the highest SVL in both low and high urbanization categories,similar to what was found for body conditionswith males with low body conditions inhabiting wetlands with a medium degree of urbanization.In females,lower SVL was recorded in mediumurbanization and highest SVL in high and low urbanization.It is observed that females recorded in highly urbanized wetlands have a very lowbody condition.The reproductive investment parameters were not signifcantly different,but we observed an association between a greaternumber of eggs and clutch size with wetlands of low urbanization.These results show a variability of responses of R.arenarum to urbanization,which could be due to phenotypic plasticity in its life history parameters,allowing it to inhabit urban areas.Continuous monitoring of the speciesin these wetlands is needed to determine if these biological responses are temporary or persistent.展开更多
Cenozoic trachytes are characteristic of some active volcanic fields in China.In particular,the origin and mechanisms of the evolution of trachytes from the Tianchi(Changbaishan)volcano(TV,China/North Korea)are poorly...Cenozoic trachytes are characteristic of some active volcanic fields in China.In particular,the origin and mechanisms of the evolution of trachytes from the Tianchi(Changbaishan)volcano(TV,China/North Korea)are poorly known.Here,we present new geochronological,geochemical and isotopic data on two trachytic suites outcropping on the northern and southern upper slopes of TV.Detailed zircon laser ablation-multicollector-inductively coupled plasma-mass spectrometry(LA-MC-ICP-MS)U-Pb dating,Rb-Sr isochron dating of plagioclase and hornblende,^(40)Ar/^(39)Ar chronology with mineral chemistry,whole-rock element and Sr-Nd-Pb isotope data are used to explore their origins and evolutionary mechanisms during the late Middle Pleistocene.Our data indicate that the trachytes mainly consist of sanidine,orthoclase and plagioclase,with minor albite,quartz and hornblende.They formed at 0.353-0.346 Ma(lava flow from the northern slope)and 0.383-0.311 Ma(lava flow from the southern slope),respectively.The TV trachytes are characterized by high K_(2)O/Na_(2)O and AR values,with low A/CNK and Mg~#values.They are enriched in rare earth elements(REEs;except Eu),depleted in Sr and Ba,crystallizing at 742-858℃.The TV trachytes have high(^(87)Sr/^(86)Sr)_i values(0.70776-0.71195),positiveε_(Nd)(t)values(0.61-2.93)and radiogenic^(206)Pb/^(204)Pb values(17.515-17.806).These values are similar to those of the Pleistocene and Holocene TV trachytes.Geochemical data indicate that they were formed by fractional crystallization from a basaltic melt and assimilated upper crust material.The trace element pattern of the studied trachytes is consistent with an evolution from basaltic melts representative of an enriched mantle source.The vent from which the trachytic magma was erupted probably collapsed inside the caldera during the TV'Millennium'eruption(ME)in 946 AD.The contemporaneous emission of basaltic and trachytic magma during the Middle-Late Pleistocene suggests the coexistence of fissural basaltic volcanism and central-type trachytic volcanism,the latter of which was associated with a magma chamber in the upper crust during the TV cone-construction stage.展开更多
Aerosol category and its physicochemical properties are key factors influencing its climate and environmental effects.To further enhance our understanding of aerosols in the Himalayas-Tibetan Plateau region,atmospheri...Aerosol category and its physicochemical properties are key factors influencing its climate and environmental effects.To further enhance our understanding of aerosols in the Himalayas-Tibetan Plateau region,atmospheric particulate matter samples were collected at three different altitudes on Mount Qomolangma(Everest).Using an automated scanning electron microscope system,the composition,size,and morphology of 52,349 particles were analyzed.The average mass concentrations of PM_(1),PM_(2.5),and PM_(10)were 0.678,5.054,and 16.698μg/m^(3),respectively.Aluminosilicate particles dominated the samples,accounting for 71.5%to 82.8%of PM_(10)mass and 34.7%to 62.4%of the particle number.Quartz particles,carbonate particles,metal oxides,and sulfates were also observed at different periods.Carbonaceous particles made up a significant portion of aerosols,comprising 2.1%to 9.7%of PM_(10)mass and 10.4%to 45.4%of particle number,with their concentration showing an upward trend with altitude.Small amounts of tar ball particles and fly ash particles were also observed,providing direct evidence of anthropogenic influences on high-altitude regions,even at altitudes exceeding 6000 m.The size distribution and abundance of different particle categories were closely related to the transport trajectories of air masses.The morphology of different particle categories varied,with fly ash particles mainly spherical and carbonaceous particles exhibiting higher irregularity.展开更多
The tolerance of tree growth to drought in diverse mixed forests subjected to seasonal water shortage is understudied despite their ecological and economic relevance.By combining intra-and inter-annual analyses of rad...The tolerance of tree growth to drought in diverse mixed forests subjected to seasonal water shortage is understudied despite their ecological and economic relevance.By combining intra-and inter-annual analyses of radial growth responses to climate and drought at daily and monthly scales,different strategies to acclimate to hydroclimate variability of coexisting conifers and broadleaves were unveiled.We analyzed the growth patterns and responses to hydroclimate variability in two conifers(Pinus engelmannii,Juniperus deppeana)and two broadleaves(Quercus grisea,Arbutus arizonica)co-occurring in a Madrean pine-oak forest located in NW Mexico.The strongest positive response to daily precipitation was found in the two conifers,but this response peaked earlier in J.deppeana than in P.engelmannii,which presented a more delayed formation of radially-enlarging tracheids.The latest negative response to temperature was found in Q.grisea,which agrees with its more delayed xylogenesis than A.arizonica.P.engelmannii presented the highest responsiveness to water shortage,driven by lower precipitation and high maximum temperatures,responding to longer droughts ending in autumn(r=0.72),whilst A.arizonica showed the lowest responsiveness to short spring droughts(r=0.39).Growth of P.engelmannii was linked to climate-atmospheric circulation patterns over the near Pacific Ocean.Overall,P.engelmannii and A.arizonica showed high growth rates and earlier growth onset,whilst J.deppeana and Q.grisea showed slower growth rates and later growth onset.The Vaganov-Shashkin growth model evidenced that winterspring soil moisture was the key driver of growth.Under more arid conditions and more frequent and hotter droughts,pine stands could rapidly shift towards mixed pine-oak forests.展开更多
基金financial support from the PCI2023-143355 European research project,which is funded by the European Union-Agencia Estatal de Investigación,and is entitled “Mastering electrode surface to achieve ultra-high reversible capacity”(MASTER)the Regional government of “Junta de Andalucía”(group FQM288)+2 种基金excellence project no.0001020the financial support from the National Council for Scientific and Technological Development(CNPq)-Finance Code 200196/2024-3 and 403335/2023-0Coordination for the Improvement of Higher Education Personnel(CAPES)–Brazil with Finance Code 001.
基金funded by the Alexander von Humboldt Stiftungsupported by DFG (SCH W534/6-1 to SWS)
文摘The dentate gyrus of the hippocampus is a plastic structure that displays modifications at different levels in response to positive stimuli as well as to negative conditions such as brain damage.The latter involves global alterations,making understanding plastic responses triggered by local damage difficult.One key feature of the dentate gyrus is that it contains a well-defined neurogenic niche,the subgranular zone,and beyond neurogenesis,newly born granule cells may maintain a“young”phenotype throughout life,adding to the plastic nature of the structure.Here,we present a novel experimental model of local brain damage in organotypic entorhino-hippocampal cultures that results in the activation of adjacent newly born granule cells.A small piece of filter paper was placed on the surface of the granule cell layer of the dentate gyrus,which evoked a foreign body reaction of astrocytes,along with the activation of local young neurons expressing doublecortin.Forty-eight hours after foreign body placement,the number of doublecortin-immunoreactive cells increased in the subgranular zone in the direct vicinity of the foreign body,whereas overall increased doublecortin immunoreactivity was observed in the granule cell layer and molecular layer of the dentate gyrus.Foreign body placement in the pyramidal layer of the CA1 region evoked a comparable local astroglial reaction but did not lead to an increase in doublecortin-immunoreactive in either the CA1 region or the adjacent dentate gyrus.Seven days after foreign body placement in the dentate gyrus,the increase in doublecortin-immunoreactivity was no longer observed,indicating the transient activation of young cells.However,7 days after foreign body placement,the number of doublecortin-immunoreactive granule cells coimmunoreactive for calbindin was lower than that under the control conditions.As calbindin is a marker for mature granule cells,this result suggests that activated young cells remain at a more immature stage following foreign body placement.Live imaging of retrovirally green fluorescent protein-labeled newly born granule cells revealed the orientation and growth of their dendrites toward the foreign body placement.This novel experimental model of foreign body placement in organotypic entorhino-hippocampal cultures could serve as a valuable tool for studying both glial reactivity and neuronal plasticity,specifically of newly born neurons under controlled in vitro conditions.
基金supported by the Grant PID2021-126715OB-IOO financed by MCIN/AEI/10.13039/501100011033 and"ERDFA way of making Europe"by the Grant PI22CⅢ/00055 funded by Instituto de Salud CarlosⅢ(ISCⅢ)+6 种基金the UFIECPY 398/19(PEJ2018-004965) grant to RGS funded by AEI(Spain)the UFIECPY-396/19(PEJ2018-004961)grant financed by MCIN (Spain)FI23CⅢ/00003 grant funded by ISCⅢ-PFIS Spain) to PMMthe UFIECPY 328/22 (PEJ-2021-TL/BMD-21001) grant to LM financed by CAM (Spain)the grant by CAPES (Coordination for the Improvement of Higher Education Personnel)through the PDSE program (Programa de Doutorado Sanduiche no Exterior)to VSCG financed by MEC (Brazil)
文摘The brain is the most complex human organ,and commonly used models,such as two-dimensional-cell cultures and animal brains,often lack the sophistication needed to accurately use in research.In this context,human cerebral organoids have emerged as valuable tools offering a more complex,versatile,and human-relevant system than traditional animal models,which are often unable to replicate the intricate architecture and functionality of the human brain.Since human cerebral organoids are a state-of-the-art model for the study of neurodevelopment and different pathologies affecting the brain,this field is currently under constant development,and work in this area is abundant.In this review,we give a complete overview of human cerebral organoids technology,starting from the different types of protocols that exist to generate different human cerebral organoids.We continue with the use of brain organoids for the study of brain pathologies,highlighting neurodevelopmental,psychiatric,neurodegenerative,brain tumor,and infectious diseases.Because of the potential value of human cerebral organoids,we describe their use in transplantation,drug screening,and toxicology assays.We also discuss the technologies available to study cell diversity and physiological characteristics of organoids.Finally,we summarize the limitations that currently exist in the field,such as the development of vasculature and microglia,and highlight some of the novel approaches being pursued through bioengineering.
文摘In complex geological environments,the analysis of drill cores to determine rock strength can be challenging due to the wide variability in the degree of fracturing,leading to subjectivity in the collection of representative samples for uniaxial compressive strength testing.This study evaluates non-destructive techniques on calcareous rocks with different tectonic deformations,including Equotip hardness,ultrasound P-wave velocity,thin section analysis,and calcimetry,integrated with photogrammetric fracture analysis.The investigated carbonate rock samples are sourced from drill cores derived from the Umbria-Marche fold and thrust belt(northern Apennines,Italy),including a gently dipping limb of an anticline,a hinge zone of an anticline,and a fault zone associated with a thrust.Fracture intensity,quantified by the P21 parameter using photogrammetric techniques on pre-loading rock samples,is assessed alongside macroscopic identification of discontinuities(such as stylolites,veins,and joints)using marker colours to monitor failures during uniaxial compression testing.Empirical correlations depicted by single and multi-linear relationships indicate a strong dependence between the mechanical and physical properties of limestones.Both Equotip and P-wave velocity are influenced by fracture intensity,but P-wave velocity varies significantly with discontinuity orientation,especially at 45°-90°.To refine uniaxial compressive strength predictions and mitigate multicollinearity,statistical approaches,including linear and multilinear regression,Principal Component Analysis and Gaussian Process Regression,were tested.Findings improve the reliability of non-destructive techniques for assessing rock strength in structurally complex settings,with implications for geotechnical applications.
基金funded by the Recovery and Resilience Plan(PRR)to support Collaborative Laboratories(CoLABs),Interface Mission[Notice No.01/C05-i02/2022].
文摘The construction industry is a significant contributor to global CO_(2) emissions,and urgent innovation is needed to mitigate its environmental impact.This paper provides a comprehensive review of scalable approaches for CO_(2) uptake in construction materials,including the injection of CO_(2) into fresh concrete,the CO_(2) curing of precast concrete,and the use of ceramics as CO_(2) sinks.Among these three approaches,CO_(2) curing methods for concrete represent the most advanced and widely adopted strategies within industrial practice,with substantial research supporting their effectiveness and scalability.The comparison of carbonation mineralisation across three distinct material groups reveals that the direct injection of CO_(2) into fresh concrete mixes results in CO_(2) uptake of less than 3 kg/m3.For the precast concrete elements,the CO_(2) uptake ranges from 30 to 350 kg/m3,while ceramics can achieve uptake efficiencies up to 23 wt.%under pilot-scale conditions.Achieving efficient CO_(2) uptake in fresh and precast concrete without compromising mechanical properties relies on precise control over the CO_(2) dose,a tailored mix design,and optimised curing conditions,while avoiding excessive carbonation that could reduce alkalinity or durability.Valorisation of carbonated materials as supplementary cementitious components or aggregates is identified as an important circular solution,though further research is needed to address regeneration,performance,and standardisation.The review highlights ongoing gaps in life-cycle assessment and industrial-scale validation,and recommends future work on durability and techno-economic optimisation for robust decarbonisation in the cement and concrete industries.
基金funded by the National Natural Science Foundation of China(Grant Nos.41972313 and 41790453)the Engineering Research Center of Geothermal Resources Development Technology and Equipment,Ministry of Education,Jilin University。
文摘The 7 ka old Qixiangzhan lava flow(QXZ,Tianchi volcano)represents the last eruptive event before the 946 CE,caldera-forming‘Millennium’eruption(ME).Petrographic,whole rock,mineral composition,Sr-Nd isotopic data on QXZ show that:(a)the lava consists of two components,constituted by comenditic obsidian fragments immersed in a continuous,aphanitic component;(b)both components have the same geochemical and isotopic variations of the ME magma.The QXZ and ME comendites result from fractional crystallization and crustal assimilation processes.The temperature of the QXZ magma was about 790℃ and the depth of the magma reservoir around 7 km,the same values as estimated for ME.QXZ had a viscosity of 10^(5.5)-10^(9) Pa s and a velocity of 3-10 km/yr.The emplacement time was 0.5-1.6yr and the flow rate 0.48-1.50 m^(3)/s.These values lie within the range estimated for other rhyolitic flows worldwide.The QXZ lava originated through a mixed explosive-effusive activity with the obsidian resulting from the ascent of undercooling,degassing and the fragmentation of magma along the conduit walls,whereas the aphanitic component testifies to the less undercooled and segregated flow at the center of the conduit.The QXZ lava demonstrates the extensive history of the ME magma chamber.
文摘This paper reveals the travel characteristics;direct and indirect costs and travel times;users’perceptions with respect to reliability,comfort and safety;and impact of travel on the quality of academic performance for students in the Centro Acadêmico do Agreste of UFPE(CAA),located in Caruaru-PE(140 km from the capital)which has 3,000 students from 70 municipalities.Almost 50%of these students live in cities located within 100 km of Caruaru and commute for three hours on average(round-trip).These trips are mostly performed on non-regular intercity transportation,chartered by users or municipalities.This kind of transport,apparently inadequate in operational terms,makes access to higher education possible for a significant proportion of students,keeping them residents of their hometowns.
基金National Scientific and Technical Research Council of Argentina(CONICET),Grant/Award Number:PIBAA2022-202328720210100485CO。
文摘Climate change is altering river regimes in mountainous regions,affecting water availability and the functioning of aquatic ecosystems.In the Andes Mountains,characterizing the natural flow regime is essential for establishing operational conditions that balance multiple water uses(irrigation,supply,hydropower)with the conservation of high-elevation ecosystems in the context of increasing hydroclimatic variability.This study analyzes extreme hydrological conditions in nivoglacial rivers of the upper Mendoza River Basin(Argentina),using indicators of magnitude,frequency,duration,and timing of high(HP)and low(LP)pulses.Daily flow records from the Cuevas,Vacas,Tupungato,and Mendoza Rivers were used to define eight ecologically relevant extreme hydrological parameters over the period 1956–2023.The results reveal a reduction in the magnitude of extreme flows since 2010(−30%to–55%)and significant delays in their timing,with maximum and minimum flow shifting by 15–20 days later in recent decades.The duration of LP events increased by 120%–240%in the Cuevas,Tupungato,and Mendoza Rivers,while in the Tupungato River,HP events tended to occur less frequently but with longer durations.These changes are associated with a 0.1℃decade^(−1)rise in mean temperature and a∼25%decrease in precipitation since 2009.Such trends have major implications for water resource management and the resilience of high-Andean ecosystems under climate warming.
文摘The Monte Desert is characterized by a great diversity of landforms created with fluvial,alluvial which the vegetation patterns are related to.The present work has the following objectives:(1) determine whether topographical attributes,surface characteristics,soil properties and vegetation patterns vary between alluvial landforms,and(2) define whether morphometric,soil and surface properties influence vegetation patterns along alluvial landscape.Morphometric data were obtained by processing a 5 m digital elevation model.The coverage of rock fragments,fine sediments and mulch was quantified.Observations and descriptions of the soil profiles were restricted to the uppermost 50 cm.Vegetation properties were calculated using a Point Quadrat Method.The relationship between variables was evaluated through multivariate statistical analysis.The main results show the presence of 45 plant species distributed in 19 families,where shrubs are dominant.The wind effect,topographic wetness and dissection of the landscape are limiting factors of diversity.The coverage of superficial rock fragments influence vegetation coverage through the distribution and availability of rainwater.Furthermore,the different soil textures reveal that the silt content favors an increase in vegetation coverage.The presence of V horizon could condition the installation and development of vegetation in the early stages of growth.
基金supported by the National Natural Science Foundation of China(32061123008).
文摘Unstable environments intensify the frequency of extreme disasters.Long-term climate changes can lead to agricultural and ecological degradation that threatens population sustainability.To better understand past climatic events and consequences,here we present a reconstruction of the self-calibrating Palmer drought severity index(scPDSI)from September to August for the desert margins of northern China,dating back to 1742.The reconstruction accounts for 42.9%of the variation of meteorological data between 1951 and 2020.Our spatial correlation analyses showed significant correlations between scPDSI,runoff,and precipitation.Over the past 279 years,the study area has undergone nine dry and eight wet periods,with the most severe climate extremes between the 1850s and 1890s.This period of prolonged drought in northeastern China coincided with the combined impacts of climatic factors and human influences,contributing to the fall of the Qing Dynasty.Analysis of periodicity and anomalies in sea surface temperatures indicate a strong association between wet and dry cycles and El Niño-Southern Oscillations.Our findings offer insights into long-term dry and wet fluctuations at the desert margins in northern China and elucidate the relationship between drought and the dynamics of civilizations.They also highlight the potential impact of extremes in climate on modern society,especially under the four projected shared socioeconomic pathways climatic scenarios,which predict worsening droughts in northern China.
基金supported by the Agencia Nacional de Investigacion y Desarrollo(ANID)with the ANID grant[SIA 85220045].
文摘Although mollusks represent Earth’s second most diverse invertebrate group,their natural history and ecology are still scarcely known.The compilation of non-traditional data,such as those from citizen science,represents an alternative to fill these gaps,particularly on striking land snail species such as Macrocyclis peruvianus.Based on long-term citizen science,we aimed to update and describe some basic ecological aspects,such as the distribution and protected area types used by M.peruvianus.We performed pairwise comparisons to test potential changes in occurrence and occupancy among administrative regions,forest types,and protected area types using chi-squared tests.The citizen scientists were also asked to provide the number of M.peruvianus individuals observed and the tree species that dominated their habitat.Thus,we tested if the number of land snails found by citizen scientists could be related to forest and protected area types using a generalized linear mixed model.We expanded the northern distributional limit,with Nothofagus,evergreen,and mixed forests far the most frequented by M.peruvianus.Parallelly,the occurrence of M.peruvianus in official protected areas(65.73%)was significantly higher than in privately owned areas.Moreover,we did not find associations between forest and protected area types with the number of M.peruvianus recorded.Although citizen science is a helpful method for obtaining novel information regarding the ecology of neglected species such as M.peruvianus,it also introduces spatial and occurrence biases explained by the access and attractiveness of the officially protected areas compared to privately owned patches of native forest.
基金support is acknowledged from Universidad Nacional Autónoma de México Project:DGAPA-PAPIIT IN105721,Project IN229325 DGAPAUNAM and Posdoc scholarship for Alejandro González-Pérez(UNAM-DGAPA Postdoctoral Program).
文摘Bioclimatic classification(WBCS),which examines the relationship between vegetation distribution and climatic variables such as precipitation and temperature,is essential for understanding the ecological dynamics.This research focuses on producing a detailed bioclimatic map of Oaxaca,Mexico,at a spatial resolution of 30 arc-seconds,using the methodology developed by Rivas-Martínez et al.(2011).Oaxaca,characterised by its complex topography and diverse climatic conditions,provides a unique opportunity to study bioclimatic patterns in a tropical region.Using high-resolution climate data from Chelsa database,we identified and mapped different bioclimates,variants,thermotypes and ombrotypes horizons and levels of continentality within the tropical macrobioclimate.Our analysis revealed a rich diversity of bioclimatic zones,reflecting the complex interplay between Oaxaca's physical geography and its bioclimates.The results,presented in high resolution maps,highlight the spatial variability and complexity of Oaxaca's bioclimatic landscape.These findings are crucial for several applications,including biodiversity conservation,agricultural planning and climate change adaptation strategies.By providing an accurate bioclimatic classification,this study makes a significant contribution to bioclimatology and could give valuable insights into climate-vegetation relationships in tropical regions.This detailed bioclimatic map improves our understanding of the current ecological status of Oaxaca and serves as a critical tool for future environmental planning and conservation efforts.Furthermore,it could be the basis for planning in national programs that consider agriculture and forests in Mexico such as Programa Sembrando Vida(PSV).
文摘When a vehicle moves over a flexible pavement structure,it generates loading and unloading cycles that produce recoverable(resilient)and permanent(plastic)deformations in the granular base and subbase layers,which are made of unbound granular materials(UGMs).The primary parameter used to evaluate the resilient response of UGMs in pavements is the resilient modulus(MR).The MR is widely used in calculating stress-strain states for flexible pavement design and as a control parameter during the construction process.It is also employed to understand the progression of distresses,such as fatigue cracking and rutting.The main objective of this study was to conduct a literature review on the resilient behavior of UGMs.This manuscript presents and describes the MR and the factors that influence it.It also outlines the evolution of the mathematical equations most commonly used to estimate and predict this physical parameter.Conclusions and recommendations for future research are provided at the end of the article.Despite the large amount of research done on the subject,the resilient behavior of UGM has not yet been fully understood.This is since these materials are highly heterogeneous and show nonlinear-anisotropic behavior under different cyclic loading paths and water contents.Likewise,these materials undergo different behaviors depending on their macro and microscopic properties(gradation,density,porosity,texture,mineralogy,particle geometry and orientation,temperature,among others).On the other hand,the main limitation of the mathematical equations is that their parameters are difficult to determine experimentally and are not constants of the material(they are state variables that can change with multiple factors).Additionally,these equations do not consider the boundary conditions to which UGM in pavements are exposed.Moreover,they are obtained from repeated load triaxial(RLT)tests,which cannot simulate the three cyclic stress components(vertical,horizontal,and shear)to which UGMs are subjected in a pavement.In recent years,there has been an increase in studies evaluating the use of recycled aggregates and the effect of temperature(particularly at subzero temperatures),but more research is still needed to reach definitive conclusions.
基金funded by the National Recovery and Resilience Plan(NRRP),Mission 4 Component 2 Investment 1.3—Call for proposals No.341 of 15 March 2022 of Italian Ministry of University and Research funded by the European Union—NextGenerationEU,Award Number:Project code PE00000003Concession Decree No.1550 of 11 October 2022 adopted by the Italian Ministry of University and Research,CUP E63C22002060006+1 种基金Project title“ON Foods—Research and innovation network on food and nutrition Sustainability,Safety and Security—Working ON Foodsfunded by the Italian Ministry of University and Research(MUR)under the project“Conservabilità,qualitàe sicurezza dei prodotti ortofrutticoli ad alto contenuto di servizio-ARS01_00640–POFACS”(Grant Nos.D.D.1211/2020 and 1104/2021).
文摘The experiment addressed the effects of preharvest KH_(2)PO_(4)foliar spraying(20 mmol·L^(-1))on fruit quality and composition(including volatile organic compounds,VOCs)of cherry tomatoes(‘Caravaggio’,‘Sugarland’and‘Top Stellina’)after 0(S0),7(S7)and 14 days(S14)of storage at 8.0°C.On the average of the 3 genotypes,the KH_(2)PO_(4)treatment improved fruit pressure firmness,total soluble solids(TSS),titratable acidity(TA),total phenols and carotenoids concentrations,along with the fruits'antioxidant capacity(by up to 17%for FRAP assay).Within the S7–S14 period,control fruits showed the highest reductions in TSS,TSS/TA ratio and total carotenoids(-17,-12 and-45,respectively),whereas treated fruits proved the strongest increase in DPPH(+12%).Sixteen out of 32 VOCs were promoted following KH_(2)PO_(4)application,including the aldehydes hexanal,(E)-2-hexenal and(Z)-3-hexenal and the apocarotenoids(E)-citral,(E)-β-ionone,geranylacetone and 6-methyl-5-hepten-2-one.Proceeding from S0 to S14,several VOCs decreased more strongly in control fruits,as for hexanal(-48%)and total aldehydes(-42%,whereas at S14 treated fruits had higher concentrations of linalool,geranylacetone and 6-methyl-5-hepten-2-one(1.06,52.50 and 79.27μg·kg^(-1),respectively).‘Caravaggio’demonstrated the strongest apocarotenoid reduction at S14,whereas‘Top Stellina’was more responsive to KH_(2)PO_(4)(mainly forβ-cyclocitral,geranylacetone and total terpenes/terpenoids),thus highlighting the central role of the genotype in responding to other experimental factors.Nonetheless,these results suggest that proper preharvest KH_(2)PO_(4)applications can preserve specific commercial,nutritional and quality traits of cold-stored cherry tomatoes.
基金supported by the Government of Catalonia,and the ETOS project(TED2021-132032A-I00)supported by the Spanish Ministry of Science and Innovation.
文摘This article aims to analyze the repercussions of food trade between China and various regions of the world to understand the dynamics of food flows and offer a novel perspective on the contemporary globalization process.Understanding these flows involves analyzing the global production and commercialization of food and the effects of these movements on exporting and importing countries in economic terms and food security.The concept of unequal caloric exchange is applied to the case of China,which allows for an understanding of how its economic growth and participation in international trade have transformed its global and internal commercial dynamics by establishing links with self-sufficiency and the composition of its population’s diet.The results show that China is increasingly dependent on international markets for its food supply.From 1961 to 2021,food consumption in China has tripled in calories and experienced qualitative changes,with a reduction in high-quality carbohydrates and vegetable proteins and an increase in cereals,vegetable oils,alcohol,and vegetables.This dietary transformation is related to economic growth and greater dependence on international trade.From 1987 to 2022,China has shown a growing deficit in the food trade balance,with imports exceeding exports in volume,value,and calories,although it maintains favorable terms of trade.Food self-sufficiency has decreased from 95%in 1961 to 76%in 2022,and the diet has diversified,replacing traditional foods with products demanded in international trade.
文摘Mountains are important reservoirs of biodiversity and endemism on a global scale, but little is known about the altitudinal configuration of this diversity and its driving factors in arid mountains. We explored variations in composition, diversity, cover,and life forms of vascular plants along a complete altitudinal gradient(1300-4000 m a.s.l) in Sierra de Velasco, an arid mountain in northwestern Argentina.We evaluated the influence of environmental variables on plant diversity and cover. Field sampling was conducted in the northern sector of the Sa. de Velasco,on the western slope in eight 50 m wide altitudinal bands at 400 m elevation intervals. We used rectangular plots(20 × 4 m;n:10/altitudinal band) to register the vascular plants of all the growth forms, and linear transects(20 m long.;n:30/altitudinal band) to quantify the vegetation cover using the point intercept method. Diversity was calculated using hill numbers.Data analysis included non-metric multidimensional scaling(NMDS), indicator species analysis,generalized linear models(GLMs), and variance partitioning analysis. A total of 232 species from 51families and 158 genera were registered. Species composition showed greater similarity at intermediate elevations. Plant diversity and cover exhibited a unimodal distribution, peaking at intermediate elevations(2100-2500 m). In contrast, life forms' distribution showed divergent patterns. Therophytes and succulents predominated at low altitudes,phanerophytes and hemicryptophytes at medium altitudes, and chamaephytes and geophytes at high altitudes. The altitudinal patterns of plant diversity and cover were primarily driven by climatic factors.Conservation efforts in the Sierra de Velasco should focus on the middle and upper zones due to their high biodiversity and vulnerability to climate change.
基金Financial support was provided by Secretaría de Cienciay Técnica-Universidad Nacional de Río Cuarto(SECyTUNRC,Grant PPI 18/C416)Fondo para la Investigación Científca y Tecnológica(FONCyT,Grant PICT BIDPICT 0981-20182530-2019).
文摘Wetlands are unique ecological environments capable of harboring high biodiversity.However,urbanization can degrade,eliminate,or transformthese habitats.Although amphibians utilize habitats created by humans in urban landscapes,few studies have investigated the infuence of thehabitat quality on the life history of anurans.We assessed life history traits such as snout-vent length(SVL),body condition,and reproductiveinvestment in the South American common toad Rhinella arenarum,to determine whether urbanization is harmful or benefcial to this species.We sampled wetlands with different levels of urbanization in Río Cuarto city,Córdoba,Argentina.We recorded males with lower SVL in mediumurbanized wetlands and those with the highest SVL in both low and high urbanization categories,similar to what was found for body conditionswith males with low body conditions inhabiting wetlands with a medium degree of urbanization.In females,lower SVL was recorded in mediumurbanization and highest SVL in high and low urbanization.It is observed that females recorded in highly urbanized wetlands have a very lowbody condition.The reproductive investment parameters were not signifcantly different,but we observed an association between a greaternumber of eggs and clutch size with wetlands of low urbanization.These results show a variability of responses of R.arenarum to urbanization,which could be due to phenotypic plasticity in its life history parameters,allowing it to inhabit urban areas.Continuous monitoring of the speciesin these wetlands is needed to determine if these biological responses are temporary or persistent.
基金financially supported by the project of the National Observation and Research Station of the Institute of Geology,China Earthquake Administration(Grant No.NORSCBS22-06)the Youth Science and Technology Development Project of the Jilin Earthquake Agency(Grant No.JZQ-202402)+1 种基金the Earthquake Science and Technology Spark Project(Grant No.XH23013B)the China Scholarship Council(Grant No.202104190014)。
文摘Cenozoic trachytes are characteristic of some active volcanic fields in China.In particular,the origin and mechanisms of the evolution of trachytes from the Tianchi(Changbaishan)volcano(TV,China/North Korea)are poorly known.Here,we present new geochronological,geochemical and isotopic data on two trachytic suites outcropping on the northern and southern upper slopes of TV.Detailed zircon laser ablation-multicollector-inductively coupled plasma-mass spectrometry(LA-MC-ICP-MS)U-Pb dating,Rb-Sr isochron dating of plagioclase and hornblende,^(40)Ar/^(39)Ar chronology with mineral chemistry,whole-rock element and Sr-Nd-Pb isotope data are used to explore their origins and evolutionary mechanisms during the late Middle Pleistocene.Our data indicate that the trachytes mainly consist of sanidine,orthoclase and plagioclase,with minor albite,quartz and hornblende.They formed at 0.353-0.346 Ma(lava flow from the northern slope)and 0.383-0.311 Ma(lava flow from the southern slope),respectively.The TV trachytes are characterized by high K_(2)O/Na_(2)O and AR values,with low A/CNK and Mg~#values.They are enriched in rare earth elements(REEs;except Eu),depleted in Sr and Ba,crystallizing at 742-858℃.The TV trachytes have high(^(87)Sr/^(86)Sr)_i values(0.70776-0.71195),positiveε_(Nd)(t)values(0.61-2.93)and radiogenic^(206)Pb/^(204)Pb values(17.515-17.806).These values are similar to those of the Pleistocene and Holocene TV trachytes.Geochemical data indicate that they were formed by fractional crystallization from a basaltic melt and assimilated upper crust material.The trace element pattern of the studied trachytes is consistent with an evolution from basaltic melts representative of an enriched mantle source.The vent from which the trachytic magma was erupted probably collapsed inside the caldera during the TV'Millennium'eruption(ME)in 946 AD.The contemporaneous emission of basaltic and trachytic magma during the Middle-Late Pleistocene suggests the coexistence of fissural basaltic volcanism and central-type trachytic volcanism,the latter of which was associated with a magma chamber in the upper crust during the TV cone-construction stage.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(No.2019QZKK0106)the Basic Research Fund of CAMS(Nos.2023Z004 and 2023Z015).
文摘Aerosol category and its physicochemical properties are key factors influencing its climate and environmental effects.To further enhance our understanding of aerosols in the Himalayas-Tibetan Plateau region,atmospheric particulate matter samples were collected at three different altitudes on Mount Qomolangma(Everest).Using an automated scanning electron microscope system,the composition,size,and morphology of 52,349 particles were analyzed.The average mass concentrations of PM_(1),PM_(2.5),and PM_(10)were 0.678,5.054,and 16.698μg/m^(3),respectively.Aluminosilicate particles dominated the samples,accounting for 71.5%to 82.8%of PM_(10)mass and 34.7%to 62.4%of the particle number.Quartz particles,carbonate particles,metal oxides,and sulfates were also observed at different periods.Carbonaceous particles made up a significant portion of aerosols,comprising 2.1%to 9.7%of PM_(10)mass and 10.4%to 45.4%of particle number,with their concentration showing an upward trend with altitude.Small amounts of tar ball particles and fly ash particles were also observed,providing direct evidence of anthropogenic influences on high-altitude regions,even at altitudes exceeding 6000 m.The size distribution and abundance of different particle categories were closely related to the transport trajectories of air masses.The morphology of different particle categories varied,with fly ash particles mainly spherical and carbonaceous particles exhibiting higher irregularity.
基金funding by the Science and Innovation Ministry(projects PID2021-123675OB-C43 and TED2021-129770B-C21).
文摘The tolerance of tree growth to drought in diverse mixed forests subjected to seasonal water shortage is understudied despite their ecological and economic relevance.By combining intra-and inter-annual analyses of radial growth responses to climate and drought at daily and monthly scales,different strategies to acclimate to hydroclimate variability of coexisting conifers and broadleaves were unveiled.We analyzed the growth patterns and responses to hydroclimate variability in two conifers(Pinus engelmannii,Juniperus deppeana)and two broadleaves(Quercus grisea,Arbutus arizonica)co-occurring in a Madrean pine-oak forest located in NW Mexico.The strongest positive response to daily precipitation was found in the two conifers,but this response peaked earlier in J.deppeana than in P.engelmannii,which presented a more delayed formation of radially-enlarging tracheids.The latest negative response to temperature was found in Q.grisea,which agrees with its more delayed xylogenesis than A.arizonica.P.engelmannii presented the highest responsiveness to water shortage,driven by lower precipitation and high maximum temperatures,responding to longer droughts ending in autumn(r=0.72),whilst A.arizonica showed the lowest responsiveness to short spring droughts(r=0.39).Growth of P.engelmannii was linked to climate-atmospheric circulation patterns over the near Pacific Ocean.Overall,P.engelmannii and A.arizonica showed high growth rates and earlier growth onset,whilst J.deppeana and Q.grisea showed slower growth rates and later growth onset.The Vaganov-Shashkin growth model evidenced that winterspring soil moisture was the key driver of growth.Under more arid conditions and more frequent and hotter droughts,pine stands could rapidly shift towards mixed pine-oak forests.
