Grain size is a key factor influencing grain yield and appearance quality in rice.We identified twelve quantitative trait loci(QTL)for grain length(GL),nine for grain width(GW),and nine for 1000-kernel weight(TKW)usin...Grain size is a key factor influencing grain yield and appearance quality in rice.We identified twelve quantitative trait loci(QTL)for grain length(GL),nine for grain width(GW),and nine for 1000-kernel weight(TKW)using GLU-SSSLs,which are single-segment substitution lines with Oryza glumaepatula as donor parent and Huajingxian 74(HJX74)as recipient parent.Among the QTL,qGL1-2,qGL1-4,qGL9-2,qGW2-2,qGW9-1 and qTKW9-2 contributed to high grain yield.GL9 was identified as a candidate gene for qGL9-2 by map-based cloning and sequencing,and is a novel allele of GS9.The kernel of NIL-gl9was slenderer and longer than that of HJX74,and the TKW and grain yield per plant of NIL-gl9 were higher than those of HJX74.The proportion of grain chalkiness of NIL-gl9 was much lower than that of HJX74.Thus,gl9 increased grain yield and appearance quality simultaneously.Three pyramid lines,NIL-gs3/gl9,NIL-GW7/gl9 and NIL-gw8/gl9,were developed and the kernel of each was longer than that of the corresponding recipient parent lines.The gl9 allele may be beneficial for breeding rice varieties with high grain yield and good appearance quality.展开更多
Existing technologies used to detect monosodium urate(MSU)crystals for gout diagnosis are not ideal due to their low sensitivity and complexity of operation.The purpose of this study was to explore whether aggregation...Existing technologies used to detect monosodium urate(MSU)crystals for gout diagnosis are not ideal due to their low sensitivity and complexity of operation.The purpose of this study was to explore whether aggregation-induced emission luminogens(AIEgens)can be used for highly specific imaging of MSU crystals to assist in the diagnosis of gout.First,we developed a series of luminogens(i.e.,tetraphenyl ethylene(TPE)-NH_(2),TPE-2NH_(2),TPE-4NH_(2),TPE-COOH,TPE-2COOH,TPE-4COOH,and TPE-Ketoalkyne),each of which was then evenly mixed with MSU crystals.Next,optimal fluorescence imaging of each of the luminogens was characterized by a confocal laser scanning microscope(CLSM).This approach was used for imaging standard samples of MSU,hydroxyapatite(HAP)crystals,and mixed samples with 1:1 mass ratio of MSU/HAP.We also imaged samples from mouse models of acute gouty arthritis,HAP deposition disease,and comorbidities of interest.Subsequently,CLSM imaging results were compared with those of compensated polarized light microscopy,and we assessed the biosafety of TPE-Ketoalkyne in the RAW264.7 cell line.Finally,CLSM time series and three-dimensional imaging were performed on MSU crystal samples from human gouty synovial fluid and tophi.As a promising candidate for MSU crystal labeling,TPE-Ketoalkyne was found to detect MSU crystals accurately and rapidly in standard samples,animal samples,and human samples,and could precisely distinguish gout from HAP deposition disease.This work demonstrates that TPE-Ketoalkyne is suitable for highly specific and timely imaging of MSU crystals in gouty arthritis and may facilitate future research on MSU crystal-related diseases.展开更多
The coking kinetics and reaction-regeneration on Zn/HZSM-5 （Zn/HZ） catalyst in the conversion of methanol to aromatics were investigated. The highest initial benzene, toluene and xylene （BTX） yield of ca. 67.7% wa...The coking kinetics and reaction-regeneration on Zn/HZSM-5 （Zn/HZ） catalyst in the conversion of methanol to aromatics were investigated. The highest initial benzene, toluene and xylene （BTX） yield of ca. 67.7% was obtained on fresh Zn/HZ catalyst, which showed the worst catalytic stability. The cycle of reaction-regeneration significantly modified the texture and acidity of Zn/HZ catalyst, which in turn affected its catalytic performance and coking behavior in methanol conversion to BTX. The residual carbon located on the surface of Zn/HZ catalyst led to the decrease of acid sites and the change on the acid sites distribution, which played an important roles on its activity and deactivation. It was found that the high B/L ratio and the low total acid sites concentration of the Zn/HZ catalyst favored to the high BTX yield and good catalytic stability in methanol conversion.展开更多
Progress in plant breeding depends on the development of genetic resources,genetic knowledge,and breeding techniques.The core of plant breeding is the use of naturally occurring variation.At the beginning of the post-...Progress in plant breeding depends on the development of genetic resources,genetic knowledge,and breeding techniques.The core of plant breeding is the use of naturally occurring variation.At the beginning of the post-genomic era,a new concept of"breeding by design"was proposed,which aims to control all allelic variation for all genes of agronomic importance.In the past two decades,we have applied a three-step strategy for research on rice breeding by design.In the first step,we constructed a singlesegment substitution line(SSSL)library using Huajingxian 74(HJX74),an elite xian(indica)rice cultivar,as the recipient in which to assemble genes from the rice AA genome.In the second step,we identified a series of desirable genes in the SSSL library.In the third step,we designed new rice lines,and achieved the breeding goals by pyramiding target genes in the HJX74-SSSL library.This review introduces the background,concept,and strategy of breeding by design,as well as our achievements in rice breeding by design using the HJX74-SSSL platform.Our practice shows that target chromosome-segment substitution is a way to breeding by design.展开更多
This study aimed to investigate the eff ect of LyPB on the intestinal microfl ora of giant pandas with indigestion,using high-throughput sequencing(HTS)technology.The species distribution and microfl oral density and ...This study aimed to investigate the eff ect of LyPB on the intestinal microfl ora of giant pandas with indigestion,using high-throughput sequencing(HTS)technology.The species distribution and microfl oral density and diversity before and after administration of the LyPB probiotic agent were analyzed.LyPB evidently has the ability to adjust the fl oral imbalance in the panda’s intestine.To test the eff ects of LyPB on the microfl ora of the panda gut,fecal samples were taken from a healthy giant panda(Anan)without administration of LyPB and from a dyspeptic giant panda Yangyang before and after LyPB administration.Compared with the sample obtained from healthy Anan(anan-c)and that obtained from dyspeptic Yangyang before LyPB administration(yangyang1),the sample taken from Yangyang(yangyang2)after LyPB administration displayed a signifi cant increase in the operational taxonomic unit index.An increase in the Chao index indicated an increase in the microfl oral richness,while an increase in the Shannon index indicated an increase in microfl oral diversity.At phylum and genus levels,a signifi cant increase was observed in the density of probiotic bacteria of phylum fi rmicutes,genus Streptococcus,while a drastic reduction in the density of Escherichia coli/Escherichia coli Shigella/bacteria of genus Shigella was observed.Data obtained in this study shows that LyPB preparations successfully improve the microbial structure within the panda’s intestinal canal by signifi cantly increasing the eff ective microbial community and decreasing the number of pathogenic microbes.展开更多
The Chinese Monal(Lophophorus thuysii)is an alpine-obligate galliform species of global conservation priority.It has been listed as a first class protected wildlife species in China,requiring conservation actions duri...The Chinese Monal(Lophophorus thuysii)is an alpine-obligate galliform species of global conservation priority.It has been listed as a first class protected wildlife species in China,requiring conservation actions during the 14 th Five-Year Plan period.However,the diet composition of Chinese Monal and its seasonal variations have rarely been studied,constraining the effective conservation of the species.Here,we investigated the plant diet composition of the Chinese Monal and its seasonal variations using a DNA metabarcoding approach on fecal samples.We collected 190 fecal samples of the Chinese Monals from the central Qionglai Mountains located in China,and analyzed the plant diet of this species using a DNA metabarcoding approach.Taxonomic profiling of higher plants in the fecal samples was performed using the second internal transcribed spacer(ITS2)amplicon.Downstream analyses,including rarefaction curves,nonmetric multidimensional scaling(NMDS)and permutational multivariate analysis of variance(PERMANOVA),were used to explore the seasonal variations in diet composition.The Chinese Monal foraged a wide range of plant recipes composed of 35 families and 83 genera throughout the year,with Brassicaceae,Apiaceae,and Poaceae as the dominant families,and Cardamine as the dominant genus.The species consumed plants from 62 genera from 28 families during the breeding season(n=81)and 66 genera from 31 families during the non-breeding season(n=109).Further,the plant diet composition significantly varied between the breeding and non-breeding seasons,especially for the frequency of occurrence and relative read abundances at genus level.Our study analyzed the plant diet of the Chinese Monal at a high resolution for the first time,and the results revealed that the seasonal variations in its plant diet composition was adapted to plant phenology and foraging strategy.Fritillaria species,a previously confirmed important food resource for the Chinese Monal,were not detected in any fecal samples,potentially due to overharvesting of Fritillaria bulbs for Traditional Chinese Medicine.Therefore,we highly recommend further restriction of herb gathering in Chinese Monal habitats to facilitate the conservation of this endangered species.Altogether,our study enriches essential ecological information for the Chinese Monal and also provides insights into conservation management for this endangered species.展开更多
It is widely believed that various animal species can sense and respond to the geophysical stimuli that precede earthquakes,especially electromagnetic fields,although supporting field evidence is mostly anecdotal.Here...It is widely believed that various animal species can sense and respond to the geophysical stimuli that precede earthquakes,especially electromagnetic fields,although supporting field evidence is mostly anecdotal.Here we report on the reactions of four female giant pandas under observation over the three days prior to the Lushan(30.1°N,103.0°E)magnitude 7.0 earthquake that occurred in Sichuan province,China,on April 20,2013.We observed no significant generalized behavioral anomalies indicative of them perceiving an impending earthquake.We also observed no startle behaviors in the 5 s prior to tremors commencing,indicating that these pandas either did not detect or did not respond to precursor P-waves.Our findings suggest that although giant pandas have evolved in,and continue to occupy exclusively,a seismically active range in central China,they do not appear to perceive pre-earthquake geophysical warning signs.展开更多
The role that visual discriminative ability plays among giant pandas in social communication and individual discrimination has received less attention than olfactory and auditory modalities.Here,we used an eye-tracker...The role that visual discriminative ability plays among giant pandas in social communication and individual discrimination has received less attention than olfactory and auditory modalities.Here,we used an eye-tracker technology to investigate pupil fixation patterns for 8 captive male giant pandas Ailuropoda melanoleuca.We paired images(N=26)of conspecifics against:1)sympatric predators(gray wolves and tigers),and non-threatening sympatric species(golden pheasant,golden snub-nosed monkey,takin,and red panda),2)conspecifics with atypical fur colora-tion(albino and brown),and 3)zookeepers/non-zookeepers wearing either work uniform or plain clothing.For each session,we tracked the pan-da's pupil movements and measured pupil first fixation point(FFP),fixation latency,total fixation count(TFC),and duration(TFD)of attention to each image.Overall,pandas exhibited similar attention(FFPs and TFCs)to images of predators and non-threatening sympatric species.Images of golden pheasant,snub-nosed monkey,and tiger received less attention(TFD)than images of conspecifics,whereas images of takin and red panda received more attention,suggesting a greater alertness to habitat or food competitors than to potential predators.Pandas'TFCs were greater for images of black-white conspecifics than for albino or brown phenotypes,implying that familiar color elicited more interest.Pandas reacted differently to images of men versus women.For images of women only,pandas gave more attention(TFC)to familiar combinations(uniformed zookeepers and plain-clothed non-zookeepers),consistent with the familiarity hypothesis.That pandas can use visual perception to discriminate intra-specifically and inter-specifically,including details of human appearance,has applications for panda conservation and captive husbandry.展开更多
Infant call structure should have evolved to elicit maximum maternal attention and investment.Neonates of giant pandas produce three types of vocalizations reported to be vitally important in the context of mother–in...Infant call structure should have evolved to elicit maximum maternal attention and investment.Neonates of giant pandas produce three types of vocalizations reported to be vitally important in the context of mother–infant communications.However,how cubs,0–15 days old,communicate with their mothers to elicit maternal care remains unknown.We analyzed 12 different call parameters of 3475 squawks,1355 squalls,and 491 croaks from 11 captive giant panda(Ailuropoda melanoleuca)neonates from age 0 to 15 days.In playback experiments,we also tested whether mothers could detect ultrasound.Our results show that neonates use broadband calls with ultrasonic frequencies up to 65 kHz to convey information about their physiological needs and to attract maternal care.In playback experiments,we tested if mothers reacted differently to broadband calls(BBC)than to artificially altered calls that included only frequencies<20 kHz(AUDC)or calls that included only frequencies>20 kHz(USC).Playback confirmed that,although adult females responded significantly less often to USC,BBC than to or AUDC,they could detect USC,BBC and generally made appropriate behavioral responses,indicating a potential benefit for neonates to utilize ultrasonic and broadband frequencies.Our findings provide a new insight into mother–infant communication in giant pandas and will be helpful for reducing the mortality of cubs,younger than 1 month old,in captivity.展开更多
Organic light-emitting materials have attracted considerable attention because of their promising applications in diverse areas.Most fluorophores emit brightly in either dilute solutions or aggregate states;the former...Organic light-emitting materials have attracted considerable attention because of their promising applications in diverse areas.Most fluorophores emit brightly in either dilute solutions or aggregate states;the former generally suffer from aggregation-caused quenching problem,and the latter encounter intensity loss at low concentrations.Herein,we propose a new strategy to overcome these dilemmas by balancing the planar and distorted structures of terphenyl-based luminogens and obtain three luminogens,2PB-AC,2Me2PB-AC,and 2T2PB-AC,with bright emission in both solution and aggregate states.Among them,2PB-AC shows absolute photoluminescence quantum yields(ФPL)higher than 90%in both tetrahydrofuran solution(90.2%)and aggregate states(92.7%for powder and 95.3%for crystal).Thus,2PB-AC could be an efficient probe to realize dual-channel explosive detection in both solution and aggregate states.Moreover,it could be used to image live-cell lipid droplets at a wide range of concentrations.In addition,benefiting from its thermodynamically favorable intersystem crossing process,2Me2PB-AC could be doped in polymethyl methacrylate matrix to provide efficient room-temperature phosphorescence.Thus,this work provides a feasible strategy for the design of luminogens with highly efficient emission in both solution and aggregate states,greatly facilitating and broadening their practical applications.展开更多
Grain size is an important determinant of grain weight and yield in rice.Although several genes related to grain size have been identified,natural variations in these genes that affect grain size are poorly characteri...Grain size is an important determinant of grain weight and yield in rice.Although several genes related to grain size have been identified,natural variations in these genes that affect grain size are poorly characterized.Here,we describe the grain length QTL GL10,encoding MADS56,which positively regulates grain length and grain weight.A natural allelic variation of NIL-gl10,containing an~1.0-kb deletion in the first exon that abolishes its transcription,results in shorter grain length,lower grain weight and delayed flowering in gl10 plants.The knockout of GL10 in the HJX74 background leads to grain phenotypes similar to that of NIL-gl10,while overexpression of GL10 results in increased grain length and weight and earlier heading date.GL10 regulates grain length by promoting greater longitudinal cell growth in the grain glume.Additionally,GL10 participates in the regulation of gibberellic acid(GA)signaling pathway genes in young panicle tissues.Analysis of GL10 haplotypes shows obvious divergence between the japonica and indica lineages.Our findings reveal an allelic variation of GL10 that may explain differences in grain length among modern cultivars and could be used to breed rice varieties with optimized grain shape.展开更多
基金supported by the major science and technology research projects of Guangdong Laboratory for Lingnan Modern Agriculture(NT2021001)the Key Projects of Basic Research and Applied Basic Research of Guangdong Province(2019B030302006)+1 种基金the National Natural Science Foundation of China(32072040,31622041)the National Innovation and Entrepreneurship Training Program for College Students(202110564045)。
文摘Grain size is a key factor influencing grain yield and appearance quality in rice.We identified twelve quantitative trait loci(QTL)for grain length(GL),nine for grain width(GW),and nine for 1000-kernel weight(TKW)using GLU-SSSLs,which are single-segment substitution lines with Oryza glumaepatula as donor parent and Huajingxian 74(HJX74)as recipient parent.Among the QTL,qGL1-2,qGL1-4,qGL9-2,qGW2-2,qGW9-1 and qTKW9-2 contributed to high grain yield.GL9 was identified as a candidate gene for qGL9-2 by map-based cloning and sequencing,and is a novel allele of GS9.The kernel of NIL-gl9was slenderer and longer than that of HJX74,and the TKW and grain yield per plant of NIL-gl9 were higher than those of HJX74.The proportion of grain chalkiness of NIL-gl9 was much lower than that of HJX74.Thus,gl9 increased grain yield and appearance quality simultaneously.Three pyramid lines,NIL-gs3/gl9,NIL-GW7/gl9 and NIL-gw8/gl9,were developed and the kernel of each was longer than that of the corresponding recipient parent lines.The gl9 allele may be beneficial for breeding rice varieties with high grain yield and good appearance quality.
基金Thisworkwas supported by the Shanghai Science and Technology Committee(No.22dz1204700)the NationalKeyR&D Program of China(Nos.2020YFA0803800 and 2017YFE0132200)+2 种基金the National Natural Science Foundation of China(Nos.82072510,21907034,21788102,21525417,and 51620105009)the Natural Science Foundation of Guangdong Province(Nos.2019B030301003 and 2016A030312002)the Innovation and Technology Commission of Hong Kong(No.ITC-CNERC14S01).
文摘Existing technologies used to detect monosodium urate(MSU)crystals for gout diagnosis are not ideal due to their low sensitivity and complexity of operation.The purpose of this study was to explore whether aggregation-induced emission luminogens(AIEgens)can be used for highly specific imaging of MSU crystals to assist in the diagnosis of gout.First,we developed a series of luminogens(i.e.,tetraphenyl ethylene(TPE)-NH_(2),TPE-2NH_(2),TPE-4NH_(2),TPE-COOH,TPE-2COOH,TPE-4COOH,and TPE-Ketoalkyne),each of which was then evenly mixed with MSU crystals.Next,optimal fluorescence imaging of each of the luminogens was characterized by a confocal laser scanning microscope(CLSM).This approach was used for imaging standard samples of MSU,hydroxyapatite(HAP)crystals,and mixed samples with 1:1 mass ratio of MSU/HAP.We also imaged samples from mouse models of acute gouty arthritis,HAP deposition disease,and comorbidities of interest.Subsequently,CLSM imaging results were compared with those of compensated polarized light microscopy,and we assessed the biosafety of TPE-Ketoalkyne in the RAW264.7 cell line.Finally,CLSM time series and three-dimensional imaging were performed on MSU crystal samples from human gouty synovial fluid and tophi.As a promising candidate for MSU crystal labeling,TPE-Ketoalkyne was found to detect MSU crystals accurately and rapidly in standard samples,animal samples,and human samples,and could precisely distinguish gout from HAP deposition disease.This work demonstrates that TPE-Ketoalkyne is suitable for highly specific and timely imaging of MSU crystals in gouty arthritis and may facilitate future research on MSU crystal-related diseases.
基金supported by the National Ministry of Education(NCET-10-878)Shaanxi"13115"Innovation Project(2009ZDKJ-70)Shaanxi Key Innovation Project(2011ZKC4-08)
文摘The coking kinetics and reaction-regeneration on Zn/HZSM-5 （Zn/HZ） catalyst in the conversion of methanol to aromatics were investigated. The highest initial benzene, toluene and xylene （BTX） yield of ca. 67.7% was obtained on fresh Zn/HZ catalyst, which showed the worst catalytic stability. The cycle of reaction-regeneration significantly modified the texture and acidity of Zn/HZ catalyst, which in turn affected its catalytic performance and coking behavior in methanol conversion to BTX. The residual carbon located on the surface of Zn/HZ catalyst led to the decrease of acid sites and the change on the acid sites distribution, which played an important roles on its activity and deactivation. It was found that the high B/L ratio and the low total acid sites concentration of the Zn/HZ catalyst favored to the high BTX yield and good catalytic stability in methanol conversion.
基金supported by the Major Program of Transgenic New Variety Breeding of China(2009ZX08009005)the National Natural Science Foundation of China(91435207 and 91735304)。
文摘Progress in plant breeding depends on the development of genetic resources,genetic knowledge,and breeding techniques.The core of plant breeding is the use of naturally occurring variation.At the beginning of the post-genomic era,a new concept of"breeding by design"was proposed,which aims to control all allelic variation for all genes of agronomic importance.In the past two decades,we have applied a three-step strategy for research on rice breeding by design.In the first step,we constructed a singlesegment substitution line(SSSL)library using Huajingxian 74(HJX74),an elite xian(indica)rice cultivar,as the recipient in which to assemble genes from the rice AA genome.In the second step,we identified a series of desirable genes in the SSSL library.In the third step,we designed new rice lines,and achieved the breeding goals by pyramiding target genes in the HJX74-SSSL library.This review introduces the background,concept,and strategy of breeding by design,as well as our achievements in rice breeding by design using the HJX74-SSSL platform.Our practice shows that target chromosome-segment substitution is a way to breeding by design.
文摘This study aimed to investigate the eff ect of LyPB on the intestinal microfl ora of giant pandas with indigestion,using high-throughput sequencing(HTS)technology.The species distribution and microfl oral density and diversity before and after administration of the LyPB probiotic agent were analyzed.LyPB evidently has the ability to adjust the fl oral imbalance in the panda’s intestine.To test the eff ects of LyPB on the microfl ora of the panda gut,fecal samples were taken from a healthy giant panda(Anan)without administration of LyPB and from a dyspeptic giant panda Yangyang before and after LyPB administration.Compared with the sample obtained from healthy Anan(anan-c)and that obtained from dyspeptic Yangyang before LyPB administration(yangyang1),the sample taken from Yangyang(yangyang2)after LyPB administration displayed a signifi cant increase in the operational taxonomic unit index.An increase in the Chao index indicated an increase in the microfl oral richness,while an increase in the Shannon index indicated an increase in microfl oral diversity.At phylum and genus levels,a signifi cant increase was observed in the density of probiotic bacteria of phylum fi rmicutes,genus Streptococcus,while a drastic reduction in the density of Escherichia coli/Escherichia coli Shigella/bacteria of genus Shigella was observed.Data obtained in this study shows that LyPB preparations successfully improve the microbial structure within the panda’s intestinal canal by signifi cantly increasing the eff ective microbial community and decreasing the number of pathogenic microbes.
基金supported by Department of Wildlife Conservation,National Forestry and Grassland Administration of Chinathe National Natural Science Foundation of China(32000354)+1 种基金the Special Foundation for National Science and Technology Basic Research Program of China(2018FY100701)the Sichuan Science and Technology Program。
文摘The Chinese Monal(Lophophorus thuysii)is an alpine-obligate galliform species of global conservation priority.It has been listed as a first class protected wildlife species in China,requiring conservation actions during the 14 th Five-Year Plan period.However,the diet composition of Chinese Monal and its seasonal variations have rarely been studied,constraining the effective conservation of the species.Here,we investigated the plant diet composition of the Chinese Monal and its seasonal variations using a DNA metabarcoding approach on fecal samples.We collected 190 fecal samples of the Chinese Monals from the central Qionglai Mountains located in China,and analyzed the plant diet of this species using a DNA metabarcoding approach.Taxonomic profiling of higher plants in the fecal samples was performed using the second internal transcribed spacer(ITS2)amplicon.Downstream analyses,including rarefaction curves,nonmetric multidimensional scaling(NMDS)and permutational multivariate analysis of variance(PERMANOVA),were used to explore the seasonal variations in diet composition.The Chinese Monal foraged a wide range of plant recipes composed of 35 families and 83 genera throughout the year,with Brassicaceae,Apiaceae,and Poaceae as the dominant families,and Cardamine as the dominant genus.The species consumed plants from 62 genera from 28 families during the breeding season(n=81)and 66 genera from 31 families during the non-breeding season(n=109).Further,the plant diet composition significantly varied between the breeding and non-breeding seasons,especially for the frequency of occurrence and relative read abundances at genus level.Our study analyzed the plant diet of the Chinese Monal at a high resolution for the first time,and the results revealed that the seasonal variations in its plant diet composition was adapted to plant phenology and foraging strategy.Fritillaria species,a previously confirmed important food resource for the Chinese Monal,were not detected in any fecal samples,potentially due to overharvesting of Fritillaria bulbs for Traditional Chinese Medicine.Therefore,we highly recommend further restriction of herb gathering in Chinese Monal habitats to facilitate the conservation of this endangered species.Altogether,our study enriches essential ecological information for the Chinese Monal and also provides insights into conservation management for this endangered species.
基金supported by National Natureal Science Foundation of China(Nos.31172097,31472009 and 31772466)International Collaborative Giant Panda Project(No.2012-018).
文摘It is widely believed that various animal species can sense and respond to the geophysical stimuli that precede earthquakes,especially electromagnetic fields,although supporting field evidence is mostly anecdotal.Here we report on the reactions of four female giant pandas under observation over the three days prior to the Lushan(30.1°N,103.0°E)magnitude 7.0 earthquake that occurred in Sichuan province,China,on April 20,2013.We observed no significant generalized behavioral anomalies indicative of them perceiving an impending earthquake.We also observed no startle behaviors in the 5 s prior to tremors commencing,indicating that these pandas either did not detect or did not respond to precursor P-waves.Our findings suggest that although giant pandas have evolved in,and continue to occupy exclusively,a seismically active range in central China,they do not appear to perceive pre-earthquake geophysical warning signs.
基金supported by grants from International Collaborative Project on The Conservation for the Giant Panda(Grant#2017-127 G.Zhang and 2017-115 to D.Liu)National Natural Science Foundation of China(Grant#31772466).
文摘The role that visual discriminative ability plays among giant pandas in social communication and individual discrimination has received less attention than olfactory and auditory modalities.Here,we used an eye-tracker technology to investigate pupil fixation patterns for 8 captive male giant pandas Ailuropoda melanoleuca.We paired images(N=26)of conspecifics against:1)sympatric predators(gray wolves and tigers),and non-threatening sympatric species(golden pheasant,golden snub-nosed monkey,takin,and red panda),2)conspecifics with atypical fur colora-tion(albino and brown),and 3)zookeepers/non-zookeepers wearing either work uniform or plain clothing.For each session,we tracked the pan-da's pupil movements and measured pupil first fixation point(FFP),fixation latency,total fixation count(TFC),and duration(TFD)of attention to each image.Overall,pandas exhibited similar attention(FFPs and TFCs)to images of predators and non-threatening sympatric species.Images of golden pheasant,snub-nosed monkey,and tiger received less attention(TFD)than images of conspecifics,whereas images of takin and red panda received more attention,suggesting a greater alertness to habitat or food competitors than to potential predators.Pandas'TFCs were greater for images of black-white conspecifics than for albino or brown phenotypes,implying that familiar color elicited more interest.Pandas reacted differently to images of men versus women.For images of women only,pandas gave more attention(TFC)to familiar combinations(uniformed zookeepers and plain-clothed non-zookeepers),consistent with the familiarity hypothesis.That pandas can use visual perception to discriminate intra-specifically and inter-specifically,including details of human appearance,has applications for panda conservation and captive husbandry.
基金This work was financially supported by the National Natural Science Foundation of China(grant#31772466)funding from CCRCGP(grant#CCRCGP181914 to Hemin Zhang and Dingzhen Liu)the International Collaborative Project of the Giant Panda(2017-115).
文摘Infant call structure should have evolved to elicit maximum maternal attention and investment.Neonates of giant pandas produce three types of vocalizations reported to be vitally important in the context of mother–infant communications.However,how cubs,0–15 days old,communicate with their mothers to elicit maternal care remains unknown.We analyzed 12 different call parameters of 3475 squawks,1355 squalls,and 491 croaks from 11 captive giant panda(Ailuropoda melanoleuca)neonates from age 0 to 15 days.In playback experiments,we also tested whether mothers could detect ultrasound.Our results show that neonates use broadband calls with ultrasonic frequencies up to 65 kHz to convey information about their physiological needs and to attract maternal care.In playback experiments,we tested if mothers reacted differently to broadband calls(BBC)than to artificially altered calls that included only frequencies<20 kHz(AUDC)or calls that included only frequencies>20 kHz(USC).Playback confirmed that,although adult females responded significantly less often to USC,BBC than to or AUDC,they could detect USC,BBC and generally made appropriate behavioral responses,indicating a potential benefit for neonates to utilize ultrasonic and broadband frequencies.Our findings provide a new insight into mother–infant communication in giant pandas and will be helpful for reducing the mortality of cubs,younger than 1 month old,in captivity.
基金This work was financially supported by the National Natural Science Foundation of China(grant no.21788102)the Natural Science Foundation of Guangdong Province(grant nos.2019B030301003 and 2016A030312002)the Innovation and Technology Commission of Hong Kong(grant no.ITC-CNERC14S01).
文摘Organic light-emitting materials have attracted considerable attention because of their promising applications in diverse areas.Most fluorophores emit brightly in either dilute solutions or aggregate states;the former generally suffer from aggregation-caused quenching problem,and the latter encounter intensity loss at low concentrations.Herein,we propose a new strategy to overcome these dilemmas by balancing the planar and distorted structures of terphenyl-based luminogens and obtain three luminogens,2PB-AC,2Me2PB-AC,and 2T2PB-AC,with bright emission in both solution and aggregate states.Among them,2PB-AC shows absolute photoluminescence quantum yields(ФPL)higher than 90%in both tetrahydrofuran solution(90.2%)and aggregate states(92.7%for powder and 95.3%for crystal).Thus,2PB-AC could be an efficient probe to realize dual-channel explosive detection in both solution and aggregate states.Moreover,it could be used to image live-cell lipid droplets at a wide range of concentrations.In addition,benefiting from its thermodynamically favorable intersystem crossing process,2Me2PB-AC could be doped in polymethyl methacrylate matrix to provide efficient room-temperature phosphorescence.Thus,this work provides a feasible strategy for the design of luminogens with highly efficient emission in both solution and aggregate states,greatly facilitating and broadening their practical applications.
基金supported by the National Natural Science Foundation of China (32072040, 31622041)the Key Projects of Basic Research and Applied Basic Research of Guangdong Province(2019B030302006)
文摘Grain size is an important determinant of grain weight and yield in rice.Although several genes related to grain size have been identified,natural variations in these genes that affect grain size are poorly characterized.Here,we describe the grain length QTL GL10,encoding MADS56,which positively regulates grain length and grain weight.A natural allelic variation of NIL-gl10,containing an~1.0-kb deletion in the first exon that abolishes its transcription,results in shorter grain length,lower grain weight and delayed flowering in gl10 plants.The knockout of GL10 in the HJX74 background leads to grain phenotypes similar to that of NIL-gl10,while overexpression of GL10 results in increased grain length and weight and earlier heading date.GL10 regulates grain length by promoting greater longitudinal cell growth in the grain glume.Additionally,GL10 participates in the regulation of gibberellic acid(GA)signaling pathway genes in young panicle tissues.Analysis of GL10 haplotypes shows obvious divergence between the japonica and indica lineages.Our findings reveal an allelic variation of GL10 that may explain differences in grain length among modern cultivars and could be used to breed rice varieties with optimized grain shape.
