Long noncoding RNAs(lncRNAs)are expressed in different species and different tissues,and perform different functions,but little is known about their involvement in the synthesis or secretion of follicle-stimulating ho...Long noncoding RNAs(lncRNAs)are expressed in different species and different tissues,and perform different functions,but little is known about their involvement in the synthesis or secretion of follicle-stimulating hormone(FSH).In general,we have revealed lnc RNA-micro RNA(mi RNA)-messenger RNA(m RNA)interactions that may play important roles in rat primary pituitary cells.In this study,a new lncRNA was identified for the first time.First,we analyzed the gene expression of lncRNA-m18as1 in different tissues and different stages by reverse transcription-quantitative polymerase chain reaction(RT-qPCR)and observed the localization of lncRNA-m18as1 with fluorescence in situ hybridization,which indicated that this lncRNA was distributed mainly in the cytoplasm.Next,we used RT-qPCR and enzyme-linked immunosorbent assay(ELISA)to analyze the regulation of FSH synthesis and secretion after overexpression or knockdown of lncRNA-m18as1 and found that lncRNA-m18as1 was positively correlated with FSH synthesis and secretion.In addition,mothers against decapentaplegic homolog 2(Smad2)was highly expressed in our sequencing results.We also screened miR-18a-5p from our sequencing results as a miRNA that may bind to lncRNA-m18as1 and Smad2.We used RNA immunoprecipitation-qPCR(RIP-qPCR)and/or dual luciferase assays to confirm that lncRNA-m18as1 interacted with miR-18a-5p and miR-18a-5p interacted with Smad2.Fluorescence in situ hybridization(FISH)showed that lncRNA-m18as1 and miR-18a-5p were localized mainly in the cytoplasm.Finally,we determined the relationship among lncRNA-m18as1,miR-18a-5p,and the Smad2/3 pathway.Overall,we found that lncRNA-m18as1 acts as a molecular sponge of miR-18a-5p to regulate the synthesis and secretion of FSH through the Smad2/3 pathway.展开更多
Radiotherapy is widely used in the management of advanced colorectal cancer(CRC).However,the clinical efficacy is limited by the safe irradiated dose.Sensitizing tumor cells to radiotherapy via interrupting DNA repair...Radiotherapy is widely used in the management of advanced colorectal cancer(CRC).However,the clinical efficacy is limited by the safe irradiated dose.Sensitizing tumor cells to radiotherapy via interrupting DNA repair is a promising approach to conquering the limitation.The BRCA1-BARD1 complex has been demonstrated to play a critical role in homologous recombination(HR)DSB repair,and its functions may be affected by HERC2 or BAP1.Accumulated evidence illustrates that the ubiquitination-deubiquitination balance is involved in these processes;however,the precise mechanism for the cross-talk among these proteins in HR repair following radiation hasn’t been defined.Through activity-based profiling,we identified PT33 as an active entity for HR repair suppression.Subsequently,we revealed that BAP1 serves as a novel molecular target of PT33 via a CRISPR-based deubiquitinase screen.Mechanistically,pharmacological covalent inhibition of BAP1 with PT33 recruits HERC2 to compete with BARD1 for BRCA1 interaction,interrupting HR repair.Consequently,PT33 treatment can substantially enhance the sensitivity of CRC cells to radiotherapy in vitro and in vivo.Overall,these findings provide a mechanistic basis for PT33-induced HR suppression and may guide an effective strategy to improve therapeutic gain.展开更多
In this study,eight different varieties of maize seeds were used as the research objects.Conduct 81 types of combined preprocessing on the original spectra.Through comparison,Savitzky-Golay(SG)-multivariate scattering...In this study,eight different varieties of maize seeds were used as the research objects.Conduct 81 types of combined preprocessing on the original spectra.Through comparison,Savitzky-Golay(SG)-multivariate scattering correction(MSC)-maximum-minimum normalization(MN)was identified as the optimal preprocessing technique.The competitive adaptive reweighted sampling(CARS),successive projections algorithm(SPA),and their combined methods were employed to extract feature wavelengths.Classification models based on back propagation(BP),support vector machine(SVM),random forest(RF),and partial least squares(PLS)were established using full-band data and feature wavelengths.Among all models,the(CARS-SPA)-BP model achieved the highest accuracy rate of 98.44%.This study offers novel insights and methodologies for the rapid and accurate identification of corn seeds as well as other crop seeds.展开更多
During the development of the nervous system,there is an overproduction of neurons and synapses.Hebbian competition between neighboring nerve endings and synapses performing different activity levels leads to their el...During the development of the nervous system,there is an overproduction of neurons and synapses.Hebbian competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or strengthening.We have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway,at the neuromuscular junction,in the axonal development and synapse elimination process versus the synapse consolidation.The purpose of this review is to describe the neurotrophic influence on developmental synapse elimination,in relation to other molecular pathways that we and others have found to regulate this process.In particular,we summarize our published results based on transmitter release analysis and axonal counts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors,coupled to downstream serine-threonine protein kinases A and C(PKA and PKC)and voltage-gated calcium channels,at different nerve endings in developmental competition.The dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site,influence each other,and require careful studies to individualize the mechanisms of specific endings.We describe an activity-dependent balance(related to the extent of transmitter release)between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75NTR pathways that can influence the timing and fate of the competitive interactions between the different axon terminals.The downstream displacement of the PKA/PKC activity ratio to lower values,both in competing nerve terminals and at postsynaptic sites,plays a relevant role in controlling the elimination of supernumerary synapses.Finally,calcium entry through L-and P/Q-subtypes of voltage-gated calcium channels(both channels are present,together with the N-type channel in developing nerve terminals)contributes to reduce transmitter release and promote withdrawal of the most unfavorable nerve terminals during elimination(the weakest in acetylcholine release and those that have already become silent).The main findings contribute to a better understanding of punishment-rewarding interactions between nerve endings during development.Identifying the molecular targets and signaling pathways that allow synapse consolidation or withdrawal of synapses in different situations is important for potential therapies in neurodegenerative diseases.展开更多
In the process of power scaling large-area Quantum Cascade Lasers(QCLs),challenges such as degradation of beam quality and emission of multilobed far-field modes are frequently encountered.These issues become particul...In the process of power scaling large-area Quantum Cascade Lasers(QCLs),challenges such as degradation of beam quality and emission of multilobed far-field modes are frequently encountered.These issues become particularly pronounced with an increase in ridge width,resulting in multimode problems.To tackle this,an innovative multi ridge waveguide structure based on the principle of supersymmetry(SUSY)was proposed.This structure comprises a wider main waveguide in the center and two narrower auxiliary waveguides on either side.The high-order modes of the main waveguide are coupled with the modes of the auxiliary waveguides through mode-matching design,and the optical loss of the auxiliary waveguides suppresses these modes,thereby achieving fundamental mode lasing of the wider main waveguide.This paper employs the finite difference eigenmode(FDE)method to perform detailed structural modeling and simulation optimization of the 4.6μm wavelength quantum cascade laser,successfully achieving a single transverse mode QCL with a ridge width of 10μm.In comparison to the traditional single-mode QCL(with a ridge width of about 5μm),the MRW structure has the potential to increase the gain area of the laser by 100%.This offers a novel design concept and methodology for enhancing the single-mode luminous power of mid-infrared quantum cascade lasers,which is of considerable significance.展开更多
The brain’s cellular landscape-a battleground where neurons and glial cells vie for survival-shapes cognition from infancy to old age.Researchers from the Institute of Genetics and Developmental Biology(IGDB)of the C...The brain’s cellular landscape-a battleground where neurons and glial cells vie for survival-shapes cognition from infancy to old age.Researchers from the Institute of Genetics and Developmental Biology(IGDB)of the Chinese Academy of Sciences have uncovered how neural cell competition(NCC)-a process once thought confined to early development-governs brain health across the lifespan,offering clues to combat age-related decline.展开更多
Background The mulch-free subsurface drip irrigation system demonstrated water-saving potential as an alternative to traditional mulch-based drip irrigation while also eliminating residual film pollution at source.How...Background The mulch-free subsurface drip irrigation system demonstrated water-saving potential as an alternative to traditional mulch-based drip irrigation while also eliminating residual film pollution at source.However,delayed sowing is unavoidable in mulch-free cultivation in ecological regions with a short frost-free period.Intercropping with cumin,which has a shorter growth period,served as an effective strategy to improve land use efficiency during the early growth stages of cotton.Therefore,a two-year field experiment was conducted to study the effects of intercropping cumin at the seeding rate of 2.5(ID1),3.85(ID2),and 5.2(ID3)kg・hm−2 on cotton growth,interspecies competition,fiber quality,and water use efficiency(WUE),as well as system economic benefits under subsurface drip irrigation.Monocropping cotton was used as the control(CK)treatment.Results At the initial flowering(IF)stage(the end of the co-growth period of cotton and cumin),cotton plant height in ID2 and ID3 treatments decreased by 5.93%–16.53%and 10.87%–31.11%,respectively,cotton stem diameter by 11.41%–14.25%and 3.37%–26.49%,respectively,and vegetative biomass by 14.46%–30.65%and 22.59%–49.91%,respectively,compared with CK treatment.With the increase in cumin density,the crop growth rate(CGR)and compensation effect in cotton tended to significantly decrease at the IF stage regardless of organs considered.For the non-co-growth period(after harvesting cumin),cotton reproductive organ biomass in ID2 and ID3 treatments increased by 4.09%‒14.61%at the boll opening stage,crop growth rate in reproductive organs by 20.74%and 74.26%from peak boll to boll opening stages compared with CK treatment,due to an enhancement of 19.09%and 49.30%in the compensation effect.Compared with ID1,the aggressivity treated by ID2 and ID3 decreased by 12.82%–46.34%and 17.95%–31.71%,respectively.However,owing to a greater number of green bolls in the upper canopy at the harvest stages in the ID3 treatment,the system production value(closely related to yield)treated by ID2 was 11.69%–16.89%,6.56%–20.02%,and 16.48%–59.83%greater than that of the ID1,ID3,and CK treatments,respectively.This also led to the highest WUE and net profit under the ID2 treatment.Conclusion Intercropping cumin with medium density improved the cotton biomass accumulation characteristics and increased resources such as land and water utilization efficiency and economic benefits through a stronger compensation effect after harvesting cumin under subsurface drip irrigation without mulch.This study not only provides alternatives to residual film pollution in arid cotton fields but also establishes a sustainable agro-ecological-economic planting paradigm by reducing plastic use and enhancing water and fertilizer use efficiency,holding significant implications for advancing resource-efficient agricultural systems.展开更多
Chinese companies are transitioning from“manufacturing export”to brand export and from“value-for-money competition”to“value competition”,continuously expanding their presence in Russian-speaking markets.
Pre-reading How can a small company like DeepSeek compete with big tech giants like OpenAI and Google in the AI industry?The company DeepSeek has surprised many experts by releasing its own artificial intelligence(AI)...Pre-reading How can a small company like DeepSeek compete with big tech giants like OpenAI and Google in the AI industry?The company DeepSeek has surprised many experts by releasing its own artificial intelligence(AI)software.AI is a computer system that can learn from experience and do things that usually require human intelligence.展开更多
The“return to the Asia-Pacific”policy and the“Asia-Pacific rebalancing”policy during the Obama period marked the germination of the Indo-Pacific strategy of the United States,and since then,the Indo-Pacific strate...The“return to the Asia-Pacific”policy and the“Asia-Pacific rebalancing”policy during the Obama period marked the germination of the Indo-Pacific strategy of the United States,and since then,the Indo-Pacific strategy has been continuously strengthened by the two administrations of Trump and Biden(Ling,2023).In order to stop China from rising,the United States has been trying to draw the ten ASEAN countries which are geographically close to China to American side.However,due to the different national conditions and the different needs of the ten countries,it is difficult for the United States to keep ASEAN’s attitude towards China consistent under the frame of Indo-Pacific strategy.Therefore,this paper will analyze the different attitudes of the ten countries towards China respectively,so as to help China formulate better policies and find better ways to cope with America’s containment of China’s rise and maintain regional and world peace.展开更多
Europe’s shift toward selective protectionism,particularly targeting China,undermines its commitment to free trade,threatens its industrial competitiveness,and ultimately jeopardizes European prosperity.
Brain size varies dramatically across populations and species in anuran species.The differences in structure,function,or size of brains are linked to processing specific cognitive tasks by different behaviors.In parti...Brain size varies dramatically across populations and species in anuran species.The differences in structure,function,or size of brains are linked to processing specific cognitive tasks by different behaviors.In particular,the causes of how male-male competition promotes the increased cognitive abilities to increase brains are as yet unexplored in anurans.To evaluate the effect of male-male competition on variation in brain size in B.andrewsi,we compared the differences in relative brain size between mated males and unpaired males under natural and experimental conditions.We found that mated males had relatively larger brains than unpaired males in a natural population when controlling the effect of body size.Likewise,we also found that there were larger brains in mated males than in unpaired males in both experiment 1 where two males competed for a female and experiment 2 where three males competed for a female,suggesting that males with mating success during male-male competition possess increased brain size and cognitive abilities.When we compared difference in relative brain size in mated males between experiment2 and experiment 1 we found that males experiencing more intense competition did not display larger brains than males experiencing relatively weak competition,suggesting that low intensity competition is already enough to trigger the increase in relative brain size in B.andrewsi.展开更多
Droughts have caused tree growth decline and high tree mortality across temperate forests,however,how to manage planted forests to alleviate drought stress is still challenging.We used tree-ring and forest inventory d...Droughts have caused tree growth decline and high tree mortality across temperate forests,however,how to manage planted forests to alleviate drought stress is still challenging.We used tree-ring and forest inventory data from different density stands to investigate how competition,tree diameter at breast height(DBH),tree age,and their interactions influence drought sensitivity and resistance for three widely-distributed and planted conifer species(Larix principis-rupprechtii,Picea meyeri,and Pinus sylvestris var.mongolica).Our results showed that the drought sensitivity of the three species was influenced by competition,tree size,and their interactions.Large L.principis-rupprechtii trees were particularly sensitive to drought during the growing season in medium to high-density stands,while the growth of large P.sylvestris var.mongolica was most affected by precipitation at low to medium density stands.Drought resistance of L.principis-rupprechtii trees decreased as tree size increased.Large L.principis-rupprechtii trees had lower drought resistance than small trees in all stands.Drought resistance of large P.meyeri trees exhibited high resistance to drought only in high-density stands.However,drought resistance of P.sylvestris var.mongolica trees was affected by tree size,competition,and their interactions.These results indicated that targeted silvicultural interventions,such as thinning,can be implemented to enhance drought resistance specifically for large L.principis-rupprechtii trees and small P.sylvestris var.mongolica trees in medium and high competition stands,and small P.meyeri trees in high competition stands.Our results highlight that properly conducted thinning can in some cases enhance growth resistance to droughts,depending on stand density,tree size,and tree species.展开更多
Understanding the fundamental drivers of large-scale species co-occurrence is a critical issue in ecology and conservation research. Here, we assessed foraging guilds, habitat type and disturbances as drivers of bird ...Understanding the fundamental drivers of large-scale species co-occurrence is a critical issue in ecology and conservation research. Here, we assessed foraging guilds, habitat type and disturbances as drivers of bird species co-occurrence in Ghana's Central Region over six months. Birds were sampled in 120 points across six different habitat types (farmland, forest reserve, urban area, coastal savannah, wetland, and mangrove), using the point-centred count technique. In total, 4060 individuals belonging to 216 species were recorded across all six habitat types. We found that co-occurring species were more similar in their foraging behaviour and habitat association. About 60% of the birds were found to co-occur randomly, 15% co-occurred negatively, and 25% co-occurred positively. Carnivores like the Black Heron (Egretta ardesiaca) and Spur-winged Lapwing (Vanellus spinosus) randomly co-occurred with other guild groups and were dominant in the mangroves and wetlands. Frugivores from forest reserves had only a 25% chance of randomly co-occurring with other birds and about a 60% chance of positively co-occurring with other birds. Our findings suggest that foraging guilds and habitat type are major factors driving bird co-occurrence and community assemblages in this West African suburban region.展开更多
Football is a popular sport all over the world,and it also has a large number of fans in China.However,in many international competitions,the Chinese team often fails to achieve the expected results.This situation mak...Football is a popular sport all over the world,and it also has a large number of fans in China.However,in many international competitions,the Chinese team often fails to achieve the expected results.This situation makes its fans very disappointed.But we should also see that the Chinese football community is making efforts to improve the situation.展开更多
The sap flow method is widely used to estimate forest transpiration.However,at the individual tree level it has spatiotemporal variations due to the impacts of environmental conditions and spatial relationships among ...The sap flow method is widely used to estimate forest transpiration.However,at the individual tree level it has spatiotemporal variations due to the impacts of environmental conditions and spatial relationships among trees.Therefore,an in-depth understanding of the coupling effects of these factors is important for designing sap flow measurement methods and performing accurate assessments of stand scale transpiration.This study is based on observations of sap flux density(SF_(d))of nine sample trees with different Hegyi’s competition indices(HCIs),soil moisture,and meteorological conditions in a pure plantation of Larix gmelinii var.principis-rupprechtii during the 2021 growing season(May to September).A multifactorial model of sap flow was developed and possible errors in the stand scale sap flow estimates associated with sample sizes were determined using model-based predictions of sap flow.Temporal variations are controlled by vapour pressure deficit(VPD),solar radiation(R),and soil moisture,and these relationships can be described by polynomial or saturated exponential functions.Spatial(individual)differences were influenced by the HCI,as shown by the decaying power function.A simple SF_(d)model at the individual tree level was developed to describe the synergistic influences of VPD,R,soil moisture,and HCI.The coefficient of variations(CV)of the sap flow estimates gradually stabilized when the sample size was>10;at least six sample trees were needed if the CV was within 10%.This study improves understanding of the mechanisms of spatiotemporal variations in sap flow at the individual tree level and provides a new methodology for determining the optimal sample size for sap flow measurements.展开更多
This study mainly investigates the influence of pore water characteristics on the adsorption properties of coalbed methane through integrated low field nuclear magnetic resonance(LF-NMR),adsorption experiments,and mol...This study mainly investigates the influence of pore water characteristics on the adsorption properties of coalbed methane through integrated low field nuclear magnetic resonance(LF-NMR),adsorption experiments,and molecular dynamics(MD)simulations.Pore water states in three coal ranks were characterized during progressive hydration.Multi-scale analysis revealed how pore water evolution regulates methane adsorption processes.During the diffusion-dominated stage(M2-M3),adsorbed water penetrates into the micropores.In the highly wettable brown coal(L1),the adsorbed water content reaches 2.12 g while in the anthracite(A1),it is only 0.29 g.During the active water injection stage(M4-M6),non-adsorbed water dominates in anthracite(over 85%of the total water content of 4.01 g),while adsorbed water remains dominant in lignite(over 60%of the total water content of 3.52 g).Water content plays a key role in methane adsorption in coal.During the water addition phase,the influence of methane adsorption on medium-to-low-rank coal is relatively weak,while the methane adsorption capacity of high-rank coal A1 shows a significant decrease during both the water diffusion and water addition phases,corresponding to a reduction in Langmuir volume of 21.22 cm^(3)/g.Molecular dynamics(MD)results further show that the free energy between molecules on the surface of hydroxyl-modified coal increases,with hydroxyl groups driving electrostatic interactions between coal and water molecules.Increased steric hindrance inhibits hydrogen bond formation and reduces the rate of hydrogen bond growth.There is a significant correlation between pore water content and coal-water molecular interaction energy,which cross-scale validates the results of LF-NMR testing and MD simulations.展开更多
Propelled by the synergy of policy,technology,and market demand,the low-altitude economy has emerged as a powerful driver of high-quality development in China.This burgeoning sector is reshaping traditional industries...Propelled by the synergy of policy,technology,and market demand,the low-altitude economy has emerged as a powerful driver of high-quality development in China.This burgeoning sector is reshaping traditional industries while forging new strategic pathways for China to excel in the global competitive arena.展开更多
基金the National Natural Science Foundation of China(No.31872349)。
文摘Long noncoding RNAs(lncRNAs)are expressed in different species and different tissues,and perform different functions,but little is known about their involvement in the synthesis or secretion of follicle-stimulating hormone(FSH).In general,we have revealed lnc RNA-micro RNA(mi RNA)-messenger RNA(m RNA)interactions that may play important roles in rat primary pituitary cells.In this study,a new lncRNA was identified for the first time.First,we analyzed the gene expression of lncRNA-m18as1 in different tissues and different stages by reverse transcription-quantitative polymerase chain reaction(RT-qPCR)and observed the localization of lncRNA-m18as1 with fluorescence in situ hybridization,which indicated that this lncRNA was distributed mainly in the cytoplasm.Next,we used RT-qPCR and enzyme-linked immunosorbent assay(ELISA)to analyze the regulation of FSH synthesis and secretion after overexpression or knockdown of lncRNA-m18as1 and found that lncRNA-m18as1 was positively correlated with FSH synthesis and secretion.In addition,mothers against decapentaplegic homolog 2(Smad2)was highly expressed in our sequencing results.We also screened miR-18a-5p from our sequencing results as a miRNA that may bind to lncRNA-m18as1 and Smad2.We used RNA immunoprecipitation-qPCR(RIP-qPCR)and/or dual luciferase assays to confirm that lncRNA-m18as1 interacted with miR-18a-5p and miR-18a-5p interacted with Smad2.Fluorescence in situ hybridization(FISH)showed that lncRNA-m18as1 and miR-18a-5p were localized mainly in the cytoplasm.Finally,we determined the relationship among lncRNA-m18as1,miR-18a-5p,and the Smad2/3 pathway.Overall,we found that lncRNA-m18as1 acts as a molecular sponge of miR-18a-5p to regulate the synthesis and secretion of FSH through the Smad2/3 pathway.
基金supported by the National Natural Science Foundation of China(NSFC)(No.82272743 to Xin Yue(82172812)of NSFC to Ran-yi Liu+4 种基金81871996 to Ran-yi Liu82003218 to Xuecen Wang82072029 to Zhenwei Peng and 81973174 to Xianzhang Bu)Guangdong Basic and Applied Basic Research Foundation(No.2021A1515012496 to Xin Yue and 2022A1515012221 to Xianzhang Bu)Basic Scientific Research Operation of Sun Yat-sen University(No.19ykpy192 to Xin Yue)。
文摘Radiotherapy is widely used in the management of advanced colorectal cancer(CRC).However,the clinical efficacy is limited by the safe irradiated dose.Sensitizing tumor cells to radiotherapy via interrupting DNA repair is a promising approach to conquering the limitation.The BRCA1-BARD1 complex has been demonstrated to play a critical role in homologous recombination(HR)DSB repair,and its functions may be affected by HERC2 or BAP1.Accumulated evidence illustrates that the ubiquitination-deubiquitination balance is involved in these processes;however,the precise mechanism for the cross-talk among these proteins in HR repair following radiation hasn’t been defined.Through activity-based profiling,we identified PT33 as an active entity for HR repair suppression.Subsequently,we revealed that BAP1 serves as a novel molecular target of PT33 via a CRISPR-based deubiquitinase screen.Mechanistically,pharmacological covalent inhibition of BAP1 with PT33 recruits HERC2 to compete with BARD1 for BRCA1 interaction,interrupting HR repair.Consequently,PT33 treatment can substantially enhance the sensitivity of CRC cells to radiotherapy in vitro and in vivo.Overall,these findings provide a mechanistic basis for PT33-induced HR suppression and may guide an effective strategy to improve therapeutic gain.
基金supported by the Science and Technology Development Plan Project of Jilin Provincial Department of Science and Technology (No.20220203112S)the Jilin Provincial Department of Education Science and Technology Research Project (No.JJKH20210039KJ)。
文摘In this study,eight different varieties of maize seeds were used as the research objects.Conduct 81 types of combined preprocessing on the original spectra.Through comparison,Savitzky-Golay(SG)-multivariate scattering correction(MSC)-maximum-minimum normalization(MN)was identified as the optimal preprocessing technique.The competitive adaptive reweighted sampling(CARS),successive projections algorithm(SPA),and their combined methods were employed to extract feature wavelengths.Classification models based on back propagation(BP),support vector machine(SVM),random forest(RF),and partial least squares(PLS)were established using full-band data and feature wavelengths.Among all models,the(CARS-SPA)-BP model achieved the highest accuracy rate of 98.44%.This study offers novel insights and methodologies for the rapid and accurate identification of corn seeds as well as other crop seeds.
基金supported by Catalan Government,Nos.2014SGR344(to JT),2017SGR704(to JT),2021SGR01214(to MAL)MCIN/AEI/10.13039/501100011033/by“ERDF A way of making Europe,”Nos.SAF2015-67143(to JT),PID2019-106332GB-I00(to JT and MAL)and PID2022-141252NB-I00(to MAL).
文摘During the development of the nervous system,there is an overproduction of neurons and synapses.Hebbian competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or strengthening.We have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway,at the neuromuscular junction,in the axonal development and synapse elimination process versus the synapse consolidation.The purpose of this review is to describe the neurotrophic influence on developmental synapse elimination,in relation to other molecular pathways that we and others have found to regulate this process.In particular,we summarize our published results based on transmitter release analysis and axonal counts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors,coupled to downstream serine-threonine protein kinases A and C(PKA and PKC)and voltage-gated calcium channels,at different nerve endings in developmental competition.The dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site,influence each other,and require careful studies to individualize the mechanisms of specific endings.We describe an activity-dependent balance(related to the extent of transmitter release)between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75NTR pathways that can influence the timing and fate of the competitive interactions between the different axon terminals.The downstream displacement of the PKA/PKC activity ratio to lower values,both in competing nerve terminals and at postsynaptic sites,plays a relevant role in controlling the elimination of supernumerary synapses.Finally,calcium entry through L-and P/Q-subtypes of voltage-gated calcium channels(both channels are present,together with the N-type channel in developing nerve terminals)contributes to reduce transmitter release and promote withdrawal of the most unfavorable nerve terminals during elimination(the weakest in acetylcholine release and those that have already become silent).The main findings contribute to a better understanding of punishment-rewarding interactions between nerve endings during development.Identifying the molecular targets and signaling pathways that allow synapse consolidation or withdrawal of synapses in different situations is important for potential therapies in neurodegenerative diseases.
基金Supported by the National Natural Science Foundation of China(62105039)。
文摘In the process of power scaling large-area Quantum Cascade Lasers(QCLs),challenges such as degradation of beam quality and emission of multilobed far-field modes are frequently encountered.These issues become particularly pronounced with an increase in ridge width,resulting in multimode problems.To tackle this,an innovative multi ridge waveguide structure based on the principle of supersymmetry(SUSY)was proposed.This structure comprises a wider main waveguide in the center and two narrower auxiliary waveguides on either side.The high-order modes of the main waveguide are coupled with the modes of the auxiliary waveguides through mode-matching design,and the optical loss of the auxiliary waveguides suppresses these modes,thereby achieving fundamental mode lasing of the wider main waveguide.This paper employs the finite difference eigenmode(FDE)method to perform detailed structural modeling and simulation optimization of the 4.6μm wavelength quantum cascade laser,successfully achieving a single transverse mode QCL with a ridge width of 10μm.In comparison to the traditional single-mode QCL(with a ridge width of about 5μm),the MRW structure has the potential to increase the gain area of the laser by 100%.This offers a novel design concept and methodology for enhancing the single-mode luminous power of mid-infrared quantum cascade lasers,which is of considerable significance.
文摘The brain’s cellular landscape-a battleground where neurons and glial cells vie for survival-shapes cognition from infancy to old age.Researchers from the Institute of Genetics and Developmental Biology(IGDB)of the Chinese Academy of Sciences have uncovered how neural cell competition(NCC)-a process once thought confined to early development-governs brain health across the lifespan,offering clues to combat age-related decline.
基金supported by the National Natural Science Foundation of China(31250512).
文摘Background The mulch-free subsurface drip irrigation system demonstrated water-saving potential as an alternative to traditional mulch-based drip irrigation while also eliminating residual film pollution at source.However,delayed sowing is unavoidable in mulch-free cultivation in ecological regions with a short frost-free period.Intercropping with cumin,which has a shorter growth period,served as an effective strategy to improve land use efficiency during the early growth stages of cotton.Therefore,a two-year field experiment was conducted to study the effects of intercropping cumin at the seeding rate of 2.5(ID1),3.85(ID2),and 5.2(ID3)kg・hm−2 on cotton growth,interspecies competition,fiber quality,and water use efficiency(WUE),as well as system economic benefits under subsurface drip irrigation.Monocropping cotton was used as the control(CK)treatment.Results At the initial flowering(IF)stage(the end of the co-growth period of cotton and cumin),cotton plant height in ID2 and ID3 treatments decreased by 5.93%–16.53%and 10.87%–31.11%,respectively,cotton stem diameter by 11.41%–14.25%and 3.37%–26.49%,respectively,and vegetative biomass by 14.46%–30.65%and 22.59%–49.91%,respectively,compared with CK treatment.With the increase in cumin density,the crop growth rate(CGR)and compensation effect in cotton tended to significantly decrease at the IF stage regardless of organs considered.For the non-co-growth period(after harvesting cumin),cotton reproductive organ biomass in ID2 and ID3 treatments increased by 4.09%‒14.61%at the boll opening stage,crop growth rate in reproductive organs by 20.74%and 74.26%from peak boll to boll opening stages compared with CK treatment,due to an enhancement of 19.09%and 49.30%in the compensation effect.Compared with ID1,the aggressivity treated by ID2 and ID3 decreased by 12.82%–46.34%and 17.95%–31.71%,respectively.However,owing to a greater number of green bolls in the upper canopy at the harvest stages in the ID3 treatment,the system production value(closely related to yield)treated by ID2 was 11.69%–16.89%,6.56%–20.02%,and 16.48%–59.83%greater than that of the ID1,ID3,and CK treatments,respectively.This also led to the highest WUE and net profit under the ID2 treatment.Conclusion Intercropping cumin with medium density improved the cotton biomass accumulation characteristics and increased resources such as land and water utilization efficiency and economic benefits through a stronger compensation effect after harvesting cumin under subsurface drip irrigation without mulch.This study not only provides alternatives to residual film pollution in arid cotton fields but also establishes a sustainable agro-ecological-economic planting paradigm by reducing plastic use and enhancing water and fertilizer use efficiency,holding significant implications for advancing resource-efficient agricultural systems.
文摘Chinese companies are transitioning from“manufacturing export”to brand export and from“value-for-money competition”to“value competition”,continuously expanding their presence in Russian-speaking markets.
文摘Pre-reading How can a small company like DeepSeek compete with big tech giants like OpenAI and Google in the AI industry?The company DeepSeek has surprised many experts by releasing its own artificial intelligence(AI)software.AI is a computer system that can learn from experience and do things that usually require human intelligence.
文摘The“return to the Asia-Pacific”policy and the“Asia-Pacific rebalancing”policy during the Obama period marked the germination of the Indo-Pacific strategy of the United States,and since then,the Indo-Pacific strategy has been continuously strengthened by the two administrations of Trump and Biden(Ling,2023).In order to stop China from rising,the United States has been trying to draw the ten ASEAN countries which are geographically close to China to American side.However,due to the different national conditions and the different needs of the ten countries,it is difficult for the United States to keep ASEAN’s attitude towards China consistent under the frame of Indo-Pacific strategy.Therefore,this paper will analyze the different attitudes of the ten countries towards China respectively,so as to help China formulate better policies and find better ways to cope with America’s containment of China’s rise and maintain regional and world peace.
文摘Europe’s shift toward selective protectionism,particularly targeting China,undermines its commitment to free trade,threatens its industrial competitiveness,and ultimately jeopardizes European prosperity.
基金funded by the National Natural Science Foundation of China (32370456)the Key Project of Natural Sciences Foundation of Sichuan Province (22NSFSC0011)。
文摘Brain size varies dramatically across populations and species in anuran species.The differences in structure,function,or size of brains are linked to processing specific cognitive tasks by different behaviors.In particular,the causes of how male-male competition promotes the increased cognitive abilities to increase brains are as yet unexplored in anurans.To evaluate the effect of male-male competition on variation in brain size in B.andrewsi,we compared the differences in relative brain size between mated males and unpaired males under natural and experimental conditions.We found that mated males had relatively larger brains than unpaired males in a natural population when controlling the effect of body size.Likewise,we also found that there were larger brains in mated males than in unpaired males in both experiment 1 where two males competed for a female and experiment 2 where three males competed for a female,suggesting that males with mating success during male-male competition possess increased brain size and cognitive abilities.When we compared difference in relative brain size in mated males between experiment2 and experiment 1 we found that males experiencing more intense competition did not display larger brains than males experiencing relatively weak competition,suggesting that low intensity competition is already enough to trigger the increase in relative brain size in B.andrewsi.
基金funded by State Key Research and Development Program of China(No.2023YFD2200401)S&T Program of Hebei(Nos.226Z6801G,22326807D)Talent Introduction Program in Hebei Agricultural University(No.YJ201918).
文摘Droughts have caused tree growth decline and high tree mortality across temperate forests,however,how to manage planted forests to alleviate drought stress is still challenging.We used tree-ring and forest inventory data from different density stands to investigate how competition,tree diameter at breast height(DBH),tree age,and their interactions influence drought sensitivity and resistance for three widely-distributed and planted conifer species(Larix principis-rupprechtii,Picea meyeri,and Pinus sylvestris var.mongolica).Our results showed that the drought sensitivity of the three species was influenced by competition,tree size,and their interactions.Large L.principis-rupprechtii trees were particularly sensitive to drought during the growing season in medium to high-density stands,while the growth of large P.sylvestris var.mongolica was most affected by precipitation at low to medium density stands.Drought resistance of L.principis-rupprechtii trees decreased as tree size increased.Large L.principis-rupprechtii trees had lower drought resistance than small trees in all stands.Drought resistance of large P.meyeri trees exhibited high resistance to drought only in high-density stands.However,drought resistance of P.sylvestris var.mongolica trees was affected by tree size,competition,and their interactions.These results indicated that targeted silvicultural interventions,such as thinning,can be implemented to enhance drought resistance specifically for large L.principis-rupprechtii trees and small P.sylvestris var.mongolica trees in medium and high competition stands,and small P.meyeri trees in high competition stands.Our results highlight that properly conducted thinning can in some cases enhance growth resistance to droughts,depending on stand density,tree size,and tree species.
文摘Understanding the fundamental drivers of large-scale species co-occurrence is a critical issue in ecology and conservation research. Here, we assessed foraging guilds, habitat type and disturbances as drivers of bird species co-occurrence in Ghana's Central Region over six months. Birds were sampled in 120 points across six different habitat types (farmland, forest reserve, urban area, coastal savannah, wetland, and mangrove), using the point-centred count technique. In total, 4060 individuals belonging to 216 species were recorded across all six habitat types. We found that co-occurring species were more similar in their foraging behaviour and habitat association. About 60% of the birds were found to co-occur randomly, 15% co-occurred negatively, and 25% co-occurred positively. Carnivores like the Black Heron (Egretta ardesiaca) and Spur-winged Lapwing (Vanellus spinosus) randomly co-occurred with other guild groups and were dominant in the mangroves and wetlands. Frugivores from forest reserves had only a 25% chance of randomly co-occurring with other birds and about a 60% chance of positively co-occurring with other birds. Our findings suggest that foraging guilds and habitat type are major factors driving bird co-occurrence and community assemblages in this West African suburban region.
文摘Football is a popular sport all over the world,and it also has a large number of fans in China.However,in many international competitions,the Chinese team often fails to achieve the expected results.This situation makes its fans very disappointed.But we should also see that the Chinese football community is making efforts to improve the situation.
基金supported by the Fundamental Research Funds of the Chinese Academy of Forestry(CAFYBB2020QB004)the National Natural Science Foundation of China(41971038,32171559,U20A2085,and U21A2005).
文摘The sap flow method is widely used to estimate forest transpiration.However,at the individual tree level it has spatiotemporal variations due to the impacts of environmental conditions and spatial relationships among trees.Therefore,an in-depth understanding of the coupling effects of these factors is important for designing sap flow measurement methods and performing accurate assessments of stand scale transpiration.This study is based on observations of sap flux density(SF_(d))of nine sample trees with different Hegyi’s competition indices(HCIs),soil moisture,and meteorological conditions in a pure plantation of Larix gmelinii var.principis-rupprechtii during the 2021 growing season(May to September).A multifactorial model of sap flow was developed and possible errors in the stand scale sap flow estimates associated with sample sizes were determined using model-based predictions of sap flow.Temporal variations are controlled by vapour pressure deficit(VPD),solar radiation(R),and soil moisture,and these relationships can be described by polynomial or saturated exponential functions.Spatial(individual)differences were influenced by the HCI,as shown by the decaying power function.A simple SF_(d)model at the individual tree level was developed to describe the synergistic influences of VPD,R,soil moisture,and HCI.The coefficient of variations(CV)of the sap flow estimates gradually stabilized when the sample size was>10;at least six sample trees were needed if the CV was within 10%.This study improves understanding of the mechanisms of spatiotemporal variations in sap flow at the individual tree level and provides a new methodology for determining the optimal sample size for sap flow measurements.
基金supported by the National Science Fund for Distinguished Young Scholars(No.51925404)the National Natural Science Foundation of China(Nos.52104233,52104228 and 52404261)the Fundamental Research Funds for the Central Universities(No.2023ZDPY05).
文摘This study mainly investigates the influence of pore water characteristics on the adsorption properties of coalbed methane through integrated low field nuclear magnetic resonance(LF-NMR),adsorption experiments,and molecular dynamics(MD)simulations.Pore water states in three coal ranks were characterized during progressive hydration.Multi-scale analysis revealed how pore water evolution regulates methane adsorption processes.During the diffusion-dominated stage(M2-M3),adsorbed water penetrates into the micropores.In the highly wettable brown coal(L1),the adsorbed water content reaches 2.12 g while in the anthracite(A1),it is only 0.29 g.During the active water injection stage(M4-M6),non-adsorbed water dominates in anthracite(over 85%of the total water content of 4.01 g),while adsorbed water remains dominant in lignite(over 60%of the total water content of 3.52 g).Water content plays a key role in methane adsorption in coal.During the water addition phase,the influence of methane adsorption on medium-to-low-rank coal is relatively weak,while the methane adsorption capacity of high-rank coal A1 shows a significant decrease during both the water diffusion and water addition phases,corresponding to a reduction in Langmuir volume of 21.22 cm^(3)/g.Molecular dynamics(MD)results further show that the free energy between molecules on the surface of hydroxyl-modified coal increases,with hydroxyl groups driving electrostatic interactions between coal and water molecules.Increased steric hindrance inhibits hydrogen bond formation and reduces the rate of hydrogen bond growth.There is a significant correlation between pore water content and coal-water molecular interaction energy,which cross-scale validates the results of LF-NMR testing and MD simulations.
文摘Propelled by the synergy of policy,technology,and market demand,the low-altitude economy has emerged as a powerful driver of high-quality development in China.This burgeoning sector is reshaping traditional industries while forging new strategic pathways for China to excel in the global competitive arena.
