Soybean mosaic virus(SMV)poses a substantial threat to the yield and quality of soybean(Glycine max(L.)Merr.),leading to significant economic losses in soybean production.However,the mining of SMVresistance loci and t...Soybean mosaic virus(SMV)poses a substantial threat to the yield and quality of soybean(Glycine max(L.)Merr.),leading to significant economic losses in soybean production.However,the mining of SMVresistance loci and the exploration of the underlying disease resistance mechanisms remain relatively limited.MicroRNAs(miRNAs)are a class of post-transcriptional regulators that play a pivotal role in modulating plant growth,development and responding to various stresses.In this study,we demonstrated the function of the “miR398c/d-GmCSDs”module between soybean resistant and susceptible varieties,focusing on its differential regulatory roles in SMV infection.Specifically,SMV infection downregulated gma-miR398c/d expression in the resistant variety(Qihuang 1,QH),while upregulated them in the susceptible variety(Nannong 1138-2,NN).Transient expression assay in N.benthamiana confirmed that gma-miR398c/d can target six superoxide dismutase(SOD)family genes,which responded to SMV infection in both varieties.Stable overexpression of Gma-MIR398c/d in soybean or inhibition of the corresponding target genes’expression via Bean pod mottle virus(BPMV)-induced gene silencing(VIGS)led to reduced H_(2)O_(2)content and thereby promoted SMV infection.Conversely,plants overexpressing the target genes exhibited the opposite phenotypes.The functions of gma-miR398c/d and their target genes were further validated in N.benthamiana through transient co-expression with SMV infectious clone(pSC7-GFP),indicating that gma-miR398c/d negatively regulated soybean resistance to SMV,while the target genes positively contributed to disease resistance.Collectively,our findings provide novel insights into the regulatory mechanisms underlying soybean resistance to SMV.展开更多
Using nine ice-tethered buoys deployed across the marginal ice zone(MIZ)and pack ice zone(PIZ)north of the Laptev Sea during the expedition of the Multidisciplinary drifting Observatory for the Study of Arctic Climate...Using nine ice-tethered buoys deployed across the marginal ice zone(MIZ)and pack ice zone(PIZ)north of the Laptev Sea during the expedition of the Multidisciplinary drifting Observatory for the Study of Arctic Climate(MOSAiC)in 2019-2020,we characterized the spatiotemporal variations in sea ice kinematics and deformation between October 2019 and July 2020 in the Transpolar Drift(TPD).From October to November,the buoys were in the upstream area of the TPD;spatial variations of deformation rates were significantly correlated with initial ice thickness(R=−0.84,P<0.05).From December 2019 to March 2020,the buoys were in the high Arctic and the ice cover was consolidated;heterogeneity in ice kinematics as measured across the buoys reduced by 65%.From April to May 2020,the buoys were in the downstream TPD;amplified spatial variations in ice kinematics were observed.This is because two buoys had drifted over the shallow waters north of Svalbard earlier;trajectory-stretching exponents derived from the data from these two buoys indicate deformation rates(10.6 d^(−1))that were about twice those in the deep basin(4.2 d^(−1)).By June 2020,a less consolidated ice pack and enhanced tidal forcing in the Fram Strait MIZ resulted in ice deformation with a semi-diurnal power spectral density of>0.25 d^(−1),which is about 1.5 times that in PIZ.Therefore,in both the upstream and downstream regions of the TPD,the transition between the MIZ and the PIZ contributes to the spatial and seasonal variations of sea ice motion and deformation.The results from this study can be used to support the characterization of the momentum balance and influencing factors during the ice advection along the TPD,which is a crucial corridor for Arctic sea ice outflow to the north Atlantic Ocean.展开更多
We focus on a modified version of the non-Hermitian Aubry-Andre-Harper(AAH)model,which has garnered significant attention due to its ability to investigate localization phenomena,metal-insulator transitions,and topolo...We focus on a modified version of the non-Hermitian Aubry-Andre-Harper(AAH)model,which has garnered significant attention due to its ability to investigate localization phenomena,metal-insulator transitions,and topological phase transitions.We have made two key modifications to the non-Hermitian AAH model:First,we introduce a mosaic structure that allows for the mixing of localized and extended states,resulting in the appearance of mobility edges,which is a feature that is not present in the original non-Hermitian AAH model.In the insulating phase,leveraging Fields Medal winner Avila's global theory,our work derives a theoretical description of the localization length,a crucial parameter previously unavailable in the non-Hermitian AAH model,and obtains the exact expression for mobility edges.We studied the variation of the energy spectrum with the amplitude and quantitatively determined the topological phase transition point within the spectrum.Furthermore,we introduced an asymmetric parameter g and calculated its corresponding localization length,the location of mobility edges,as well as the precise expressions for its extended and localized states.By quantitatively calculating the Lyapunov exponent of dual models,our work reveals an interesting fact about the robustness of localized states:within an appropriate relationship between g and the coupling potential strength,the localized states exhibit similar characteristics to those in the mosaic non-Hermitian AAH model.Our work offers a more complete and nuanced understanding of localization phenomena in disordered non-Hermitian systems,paving the way for further research in this promising field.展开更多
北极气候研究多学科漂流观测计划(Multidisciplinary drifting Observatory for the Study of Arctic Climate, MOSAiC)于2019年10月至2020年9月开展,期间获得了变量完整的大气、海洋、海冰厚度及积雪厚度观测,为海冰模式的发展提供了...北极气候研究多学科漂流观测计划(Multidisciplinary drifting Observatory for the Study of Arctic Climate, MOSAiC)于2019年10月至2020年9月开展,期间获得了变量完整的大气、海洋、海冰厚度及积雪厚度观测,为海冰模式的发展提供了新的契机。本研究利用两个完整观测时段(2019年11月1日至2020年5月7日、2020年6月26日至7月27日)的大气和海洋强迫场,驱动一维海冰柱模式ICEPACK,模拟了MOSAiC期间海冰厚度的季节演变,同海冰厚度观测进行了对比,并诊断分析了海冰厚度模拟误差的原因。结果表明,在冬春季节,模式可以再现海冰厚度增长过程,但由于模式在春季高估了积雪向海冰的转化及对海冰物质平衡的贡献,模拟的春季海冰厚度偏厚。在夏季期间,2种热力学方案及3种融池方案的组合都表明模式高估了海冰表层的消融过程,导致模拟结束阶段的海冰厚度偏薄。我们的研究表明,使用变量完整的MOSAiC大气和海洋强迫场可以诊断目前海冰模式中的问题,为海冰模式的改进奠定基础。展开更多
BACKGROUND The clinical manifestations of trisomy 7 mosaicism are diverse and nonspecific,so prenatal diagnosis is very difficult.CASE SUMMARY Two pregnant women with abnormal prenatal screening results were included....BACKGROUND The clinical manifestations of trisomy 7 mosaicism are diverse and nonspecific,so prenatal diagnosis is very difficult.CASE SUMMARY Two pregnant women with abnormal prenatal screening results were included.One was a 22-year-old woman(G1P0).At 31st week of gestation,ultrasound revealed that the posterior horn of the left lateral ventricle was 10 mm and the right renal pelvis had a separation of 7 mm.The other pregnant woman was 33 years old(G2P1L1A0),and her fetus was found to have a cardiac malformation at the 24th week of gestation.Copy number variation sequencing,whole-exome sequencing and karyotype analysis were carried out after amniocentesis,and both fetuses were diagnosed with trisomy 7 mosaicism.After parental counseling,one woman continued the pregnancy,and the other woman terminated the pregnancy.CONCLUSION In trisomy 7 mosaicism,the low proportion of trisomy does not lead to abortion,but can result in abnormal fetal development,which can be detected via ultrasound.Therefore,clinicians need to pay more attention to various aspects of fetal growth and development,combining with imaging,cellular,molecular genetics and other methods to perform comprehensive evaluations of fetuses to provide more reliable genetic counseling for pregnant women.展开更多
Tobacco(Nicotiana tabacum)and tomato(Solanum lycopersicum)are two major economic crops in China.Tobacco mosaic virus(TMV;genus Tobamovirus)is the most prevalent virus infecting both crops.Currently,some widely cultiva...Tobacco(Nicotiana tabacum)and tomato(Solanum lycopersicum)are two major economic crops in China.Tobacco mosaic virus(TMV;genus Tobamovirus)is the most prevalent virus infecting both crops.Currently,some widely cultivated tobacco and tomato cultivars are susceptible to TMV and there is no effective strategy to control this virus.Cross-protection can be a safe and environmentally friendly strategy to prevent viral diseases.However,stable attenuated TMV mutants are scarce.In this study,we found that the substitutions in the replicase p126,arginine at position 196(R^(196))with aspartic acid(D),glutamic acid at position 614(E^(614))with glycine(G),serine at position 643(S^(643))with phenylalanine(F),or D at position 730(D^(730))with S,significantly reduced the virulence and replication of TMV.However,only the mutation of S^(643) to F reduced the RNA silencing suppression activity of TMV p126.A double-mutant TMV-E614G-S643F induced no visible symptom and was genetically stable through six successive passages in tobacco plants.Furthermore,our results showed that TMV-E614G-S643F double-mutant could provide effective protection against the wild-type TMV infection in tobacco and tomato plants.This study reports a promising mild mutant for cross-protection to control TMV in tobacco and tomato plants.展开更多
Genomic mosaicism describes the phenomenon where some but not all cells within a tissue harbor unique genetic mutations.Traditionally,research focused on the impact of genomic mosaicism on clinical phenotype—motivate...Genomic mosaicism describes the phenomenon where some but not all cells within a tissue harbor unique genetic mutations.Traditionally,research focused on the impact of genomic mosaicism on clinical phenotype—motivated by its involvement in cancers and overgrowth syndromes.More recently,we increasingly shifted towards the plethora of neutral mosaic variants that can act as recorders of cellular lineage and environmental exposures.Here,we summarize the current state of the field of genomic mosaicism research with a special emphasis on our current understanding of this phenomenon in brain development and homeostasis.Although the field of genomic mosaicism has a rich history,technological advances in the last decade have changed our approaches and greatly improved our knowledge.We will provide current definitions and an overview of contemporary detection approaches for genomic mosaicism.Finally,we will discuss the impact and utility of genomic mosaicism.展开更多
Three novel matrine-type alkaloids(1-3)and two unprecedented aloperine-type alkaloids(4 and 5)were isolated from the root of Sophora tonkinensis and the seeds of Sophora alopecuroides respectively.Notably,compound 1 p...Three novel matrine-type alkaloids(1-3)and two unprecedented aloperine-type alkaloids(4 and 5)were isolated from the root of Sophora tonkinensis and the seeds of Sophora alopecuroides respectively.Notably,compound 1 possessed an unprecedented 6/5/6 tricyclic skeleton,while compounds 2 and 3 characterized by rare 6/6/5/6 tetracyclic system and 6/6/6/6/6 pentacyclic system respectively.Moreover,compound 4 possessed an unprecedented 6/7/6/6 tetracyclic core,and compound 5 characterized by rare 6/6/6/6tetracyclic skeleton.Their structures were elucidated by comprehensive spectroscopic data analysis and electronic circular dichroism(ECD)calculations.Biological tests indicated that compound 5 displayed significant anti-tobacco mosaic virus(TMV)activity compared with the positive control ningnanmycin.展开更多
Soybean mosaic virus(SMV),an RNA virus,is the most common and destructive pathogenic virus in soybean fields.The newly developed CRISPR/Cas immune system has provided a novel strategy for improving plant resistance to...Soybean mosaic virus(SMV),an RNA virus,is the most common and destructive pathogenic virus in soybean fields.The newly developed CRISPR/Cas immune system has provided a novel strategy for improving plant resistance to viruses;hence,this study aimed to engineer SMV resistance in soybean using this system.Specifically,multiple sgRNAs were designed to target positive-and/or negative-sense strands of the SMV HC-Pro gene.Subsequently,the corresponding CRISPR/CasRx vectors were constructed and transformed into soybeans.After inoculation with SMV,39.02%,35.77%,and 18.70%of T_(1)plants were confirmed to be highly resistant(HR),resistant(R),and mildly resistant(MR)to SMV,respectively,whereas only 6.50%were identified as susceptible(S).Additionally,qRT-PCR and DAS-ELISA showed that,both at 15 and 30 d post-inoculation(dpi),SMV accumulation significantly decreased or was even undetectable in HR and R plants,followed by MR and S plants.Additionally,the expression level of the CasRx gene varied in almost all T_(1)plants with different resistance level,both at 15 and 30 dpi.Furthermore,when SMV resistance was evaluated in the T_(2)generation,the results were similar to those recorded for the T_(1)generation.These findings provide new insights into the application of the CRISPR/CasRx system for soybean improvement and offer a promising alternative strategy for breeding for resistance to biotic stress that will contribute to the development of SMV-immune soybean germplasm to accelerate progress towards greater soybean crop productivity.展开更多
Turnip mosaic virus(TuMV)is a devastating potyvirus pathogen that infects a wide variety of both cultivated and wild Brassicaceae plants.We urgently need more information and understanding of TuMV pathogenesis and the...Turnip mosaic virus(TuMV)is a devastating potyvirus pathogen that infects a wide variety of both cultivated and wild Brassicaceae plants.We urgently need more information and understanding of TuMV pathogenesis and the host responses involved in disease development in cruciferous crops.TuMV displays great versatility in viral pathogenesis,especially in its replication and intercellular movement.Moreover,in the coevolutionary arms races between TuMV and its hosts,the virus has evolved to co-opt host factors to facilitate its infection and counter host defense responses.This review mainly focuses on recent advances in understanding the viral factors that contribute to the TuMV infection cycle and the host resistance mechanism in Brassica.Finally,we propose some future research directions on TuMV pathogenesis and control strategies to design durable TuMV-resistant Brassica crops.展开更多
With the aim of assessing floristic diversity, stand structure and vegetation ecology, the present work was carried out in the savanna mosaic forest of the locality of Ndjole (Centre Cameroon). A total of 30 floristic...With the aim of assessing floristic diversity, stand structure and vegetation ecology, the present work was carried out in the savanna mosaic forest of the locality of Ndjole (Centre Cameroon). A total of 30 floristic plots of 40 m × 40 m (1600 m<sup>2</sup>) were delineated in the different ecosystems (forest, forest-savanna contact zone and the savanna). Within each plot, all individuals with a diameter at breast height ≥ 10 cm at 1.30 m were taken into account. ANOVA was used to compare the means of the diversity indices of the different ecosystems, and the DUNCAN test at 5% significance level (XLSTAT 2016) to separate these means. A total of 85 species belonging to 67 genera and 33 families were recorded. That is, 68 species in semi-caducifolia forest, 45 in forest-savanna contact zone and 18 in savanna. Urticaceae, Combretaceae, Apocynaceae, Myristicaceae and Euphorbiaceae are the most diverse families in the forest. On the other hand, in contact zones, the Euphorbiaceae, Fabaceae, Annonaceae and Moraceae families are the most diversified, while in the savannas, the Combretaceae, Fabaceae and Annonaceae families are the most diversified. Shannon’s diversity index values (1.7 to 2.37 bits) reflect low specific diversity;Piélou’s equitability (0.86 to 0.9) shows good distribution of individuals within species. The diametric structure of woody species shows an inverted “J” shape in all plant communities. This indicates a high regeneration potential characterized by a greater number of small trees than large trees. Mesophanerophytes and megaphanerophytes are dominant in forests and forest-savanna contact zones, and microphanerophytes in the savannas. Endozoochory is the main mode of diaspore dissemination. As regards the distribution of phytogeographical types, it shows the overall dominance of Guineo-Congolese species in all plant communities. Our study provides detailed data on forest-savanna floristic and plant life traits in the mosaic and recommends further studies on the impact of environmental parameter variations on the forest encroachment into savanna.展开更多
Cowpea (Vigna unguiculata L. [Walp.]) in one of the main grain legumes contributing to food security and poverty alleviation in Sub-Saharan Africa. To control the highly damaging legume pod borer Maruca vitrata F., tr...Cowpea (Vigna unguiculata L. [Walp.]) in one of the main grain legumes contributing to food security and poverty alleviation in Sub-Saharan Africa. To control the highly damaging legume pod borer Maruca vitrata F., transgenic cowpea lines expressing the insecticidal Cry1Ab Bt protein were developed. In this study, we evaluated the impact of Cry1Ab transgene expression on the susceptibility of four cowpea lines (named IT97K-T, IT98K-T, Gourgou-T and Nafi-T) and their respective non-transgenic near isogenic lines (IT97K, IT98K, Gourgou and Nafi) to Cowpea aphid-borne mosaic virus (CABMV) in greenhouse conditions. In a preliminary quality control test by enzyme-linked immunosorbent assay, the presence of Cry1Ab protein in transgenic seed lots ranged from 59% to 72%, with no significant differences among the lines (χ2 = 3.26;p = 0.35). Upon virus inoculation, all cowpea lines exhibited mosaic symptoms with similar severity between 7- and 11-day post-inoculation. No significant differences were observed in symptom severity. Significant differences were found between cowpea lines for time of symptom onset, virus accumulation in plants and days to 50% flowering. However, while comparing pairs of transgenic lines and corresponding non-transgenic lines, virus accumulation showed not significant differences whatever the pair. Time of symptom onset and days to 50% flowering did not also differ significantly between pairs of cowpea lines except Nafi/Nafi-T in which transgenic Nafi-T showed earlier symptoms (7.4 ± 0.7 vs. 8.9 ± 0.8 days post-inoculation) and shorter flowering time (37.3 ± 0.6 vs. 42 ± 1.7 days after sowing). Overall, these findings improve our understanding of the effects of Cry1Ab gene mediated genetic modification on cowpea infection by Cowpea aphid-borne mosaic virus, with potential implications for environmental safety assessment.展开更多
45X/46XY mosaicism is a rare chromosome disease. The apparent prevalence of males and females with 45X/46XY is 5.6 and 2.1 per 100,000 liveborn males and females. We present a boy who had a developmental delay with hy...45X/46XY mosaicism is a rare chromosome disease. The apparent prevalence of males and females with 45X/46XY is 5.6 and 2.1 per 100,000 liveborn males and females. We present a boy who had a developmental delay with hypospadias. He was referred to pediatric genetics and was diagnosed with 45X/46XY mosaicism by peripheral blood chromosome examination. During serial rehabilitation programs, his speech delay was caught up. But his poor attention and hyperactivity are obvious progressively. We should pay attention to these patients, not only physical conditions but also psychological problems.展开更多
Tobacco ( Nicotiana tabacum L.) “NC89” plants were transformed with deletion mutant of cucumber mosaic virus (CMV) movement protein (MP) gene and full_length CMV MP gene, respectively. The transformed plants...Tobacco ( Nicotiana tabacum L.) “NC89” plants were transformed with deletion mutant of cucumber mosaic virus (CMV) movement protein (MP) gene and full_length CMV MP gene, respectively. The transformed plants were analyzed with polymerase chain reaction (PCR), PCR_Southern, Southern and Western blots. R 0 generation of the transgenic plants were inoculated with CMV. Five out of 10 lines of tobacco plants (BMPK) transformed with CMV MP deletion mutant gene showed high resistance to CMV infection and remained symptomless for up to 50 days post_inoculation. In contrast, tobacco plants (BMPR) transformed with full_length CMV MP gene did not show resistance to CMV infection. However, most of the infected full_length CMV MP gene transgenic plants recovered by showing none or very mild mosaic symptoms in 40 days post_inoculation. The results of R 1 generation of the BMPK transgenic plants tested under field conditions showed that all 5 lines of transgenic plants could delay the virus disease development.展开更多
With joint analysis based on the parents, F 1, F 2 and backcrosses, the authors found that the resistance of the maize inbred line Huangzaosi to the maize dwarf mosaic virus strain B was conditioned by a major gene ...With joint analysis based on the parents, F 1, F 2 and backcrosses, the authors found that the resistance of the maize inbred line Huangzaosi to the maize dwarf mosaic virus strain B was conditioned by a major gene and polygene, and identified a new major gene. Bulked segregate and microsatellite analysis of a F 2 progeny from the combination of Huangzaosi×Mo17 were used to identify the resistance gene, mdm1(t), on the long arm of chromosome 6. This new resistance gene is tightly linked to and located between the microsatellite markers loci, phi077 and bnlg391. The linkage distances between phi077-mdm1(t) and mdm1(t)-bnlg391 are 4.74 centiMorgan (cM) and 6.72 cM respectively.展开更多
近年来,Logo检测在知识产权保护和产品品牌管理等领域得到了广泛应用;针对Logo检测中的复杂背景和多尺度问题,提出了一种改进Mosaic数据增强和特征融合的Logo检测算法;将6张原始图片随机翻转、缩放和拼接构成合成图像,与单张图像和由4...近年来,Logo检测在知识产权保护和产品品牌管理等领域得到了广泛应用;针对Logo检测中的复杂背景和多尺度问题,提出了一种改进Mosaic数据增强和特征融合的Logo检测算法;将6张原始图片随机翻转、缩放和拼接构成合成图像,与单张图像和由4张原始图片合成的图像一起作为YOLOv4模型的训练输入,并确定3种输入形式的最优比例,同时使用一种新的训练策略,改进的Mosaic数据增强方法丰富了Logo对象的尺度和背景,使模型更好地学习全局和局部特征;在路径整合网络(PANet)的基础上引入跨层连接、重复堆叠、直接连接和加权特征融合等操作,改进的PANet扩大了模型感受野,增强了模型的多尺度特征表达能力;实验结果表明,提出的MP-YOLOv4算法在减小21.7%模型大小的同时,IoU(intersection of union)等于0.5时的平均精度上达到了67.4%,较YOLOv4提高了2.4%,同时在多尺度目标上的检测性能得到了改善。展开更多
基金supported by the National Key Research and Development Program of China(2022YFF1001502)Jiangsu Collaborative Innovation Center for Modern Crop Production(JCIC-MCP)Major Projects of Technological Innovation 2030(2023ZD04037).
文摘Soybean mosaic virus(SMV)poses a substantial threat to the yield and quality of soybean(Glycine max(L.)Merr.),leading to significant economic losses in soybean production.However,the mining of SMVresistance loci and the exploration of the underlying disease resistance mechanisms remain relatively limited.MicroRNAs(miRNAs)are a class of post-transcriptional regulators that play a pivotal role in modulating plant growth,development and responding to various stresses.In this study,we demonstrated the function of the “miR398c/d-GmCSDs”module between soybean resistant and susceptible varieties,focusing on its differential regulatory roles in SMV infection.Specifically,SMV infection downregulated gma-miR398c/d expression in the resistant variety(Qihuang 1,QH),while upregulated them in the susceptible variety(Nannong 1138-2,NN).Transient expression assay in N.benthamiana confirmed that gma-miR398c/d can target six superoxide dismutase(SOD)family genes,which responded to SMV infection in both varieties.Stable overexpression of Gma-MIR398c/d in soybean or inhibition of the corresponding target genes’expression via Bean pod mottle virus(BPMV)-induced gene silencing(VIGS)led to reduced H_(2)O_(2)content and thereby promoted SMV infection.Conversely,plants overexpressing the target genes exhibited the opposite phenotypes.The functions of gma-miR398c/d and their target genes were further validated in N.benthamiana through transient co-expression with SMV infectious clone(pSC7-GFP),indicating that gma-miR398c/d negatively regulated soybean resistance to SMV,while the target genes positively contributed to disease resistance.Collectively,our findings provide novel insights into the regulatory mechanisms underlying soybean resistance to SMV.
基金supported by the National Key Research and Development Program of China(Grant no.2021YFC2803304)the National Natural Science Foundation of China(Grant nos.52192691 and 52192690)the Program of Shanghai Academic/Technology Research Leader(Grant no.22XD1403600).
文摘Using nine ice-tethered buoys deployed across the marginal ice zone(MIZ)and pack ice zone(PIZ)north of the Laptev Sea during the expedition of the Multidisciplinary drifting Observatory for the Study of Arctic Climate(MOSAiC)in 2019-2020,we characterized the spatiotemporal variations in sea ice kinematics and deformation between October 2019 and July 2020 in the Transpolar Drift(TPD).From October to November,the buoys were in the upstream area of the TPD;spatial variations of deformation rates were significantly correlated with initial ice thickness(R=−0.84,P<0.05).From December 2019 to March 2020,the buoys were in the high Arctic and the ice cover was consolidated;heterogeneity in ice kinematics as measured across the buoys reduced by 65%.From April to May 2020,the buoys were in the downstream TPD;amplified spatial variations in ice kinematics were observed.This is because two buoys had drifted over the shallow waters north of Svalbard earlier;trajectory-stretching exponents derived from the data from these two buoys indicate deformation rates(10.6 d^(−1))that were about twice those in the deep basin(4.2 d^(−1)).By June 2020,a less consolidated ice pack and enhanced tidal forcing in the Fram Strait MIZ resulted in ice deformation with a semi-diurnal power spectral density of>0.25 d^(−1),which is about 1.5 times that in PIZ.Therefore,in both the upstream and downstream regions of the TPD,the transition between the MIZ and the PIZ contributes to the spatial and seasonal variations of sea ice motion and deformation.The results from this study can be used to support the characterization of the momentum balance and influencing factors during the ice advection along the TPD,which is a crucial corridor for Arctic sea ice outflow to the north Atlantic Ocean.
基金Project supported by the National Natural Science Foundation of China(Grant No.12301218)。
文摘We focus on a modified version of the non-Hermitian Aubry-Andre-Harper(AAH)model,which has garnered significant attention due to its ability to investigate localization phenomena,metal-insulator transitions,and topological phase transitions.We have made two key modifications to the non-Hermitian AAH model:First,we introduce a mosaic structure that allows for the mixing of localized and extended states,resulting in the appearance of mobility edges,which is a feature that is not present in the original non-Hermitian AAH model.In the insulating phase,leveraging Fields Medal winner Avila's global theory,our work derives a theoretical description of the localization length,a crucial parameter previously unavailable in the non-Hermitian AAH model,and obtains the exact expression for mobility edges.We studied the variation of the energy spectrum with the amplitude and quantitatively determined the topological phase transition point within the spectrum.Furthermore,we introduced an asymmetric parameter g and calculated its corresponding localization length,the location of mobility edges,as well as the precise expressions for its extended and localized states.By quantitatively calculating the Lyapunov exponent of dual models,our work reveals an interesting fact about the robustness of localized states:within an appropriate relationship between g and the coupling potential strength,the localized states exhibit similar characteristics to those in the mosaic non-Hermitian AAH model.Our work offers a more complete and nuanced understanding of localization phenomena in disordered non-Hermitian systems,paving the way for further research in this promising field.
文摘北极气候研究多学科漂流观测计划(Multidisciplinary drifting Observatory for the Study of Arctic Climate, MOSAiC)于2019年10月至2020年9月开展,期间获得了变量完整的大气、海洋、海冰厚度及积雪厚度观测,为海冰模式的发展提供了新的契机。本研究利用两个完整观测时段(2019年11月1日至2020年5月7日、2020年6月26日至7月27日)的大气和海洋强迫场,驱动一维海冰柱模式ICEPACK,模拟了MOSAiC期间海冰厚度的季节演变,同海冰厚度观测进行了对比,并诊断分析了海冰厚度模拟误差的原因。结果表明,在冬春季节,模式可以再现海冰厚度增长过程,但由于模式在春季高估了积雪向海冰的转化及对海冰物质平衡的贡献,模拟的春季海冰厚度偏厚。在夏季期间,2种热力学方案及3种融池方案的组合都表明模式高估了海冰表层的消融过程,导致模拟结束阶段的海冰厚度偏薄。我们的研究表明,使用变量完整的MOSAiC大气和海洋强迫场可以诊断目前海冰模式中的问题,为海冰模式的改进奠定基础。
文摘BACKGROUND The clinical manifestations of trisomy 7 mosaicism are diverse and nonspecific,so prenatal diagnosis is very difficult.CASE SUMMARY Two pregnant women with abnormal prenatal screening results were included.One was a 22-year-old woman(G1P0).At 31st week of gestation,ultrasound revealed that the posterior horn of the left lateral ventricle was 10 mm and the right renal pelvis had a separation of 7 mm.The other pregnant woman was 33 years old(G2P1L1A0),and her fetus was found to have a cardiac malformation at the 24th week of gestation.Copy number variation sequencing,whole-exome sequencing and karyotype analysis were carried out after amniocentesis,and both fetuses were diagnosed with trisomy 7 mosaicism.After parental counseling,one woman continued the pregnancy,and the other woman terminated the pregnancy.CONCLUSION In trisomy 7 mosaicism,the low proportion of trisomy does not lead to abortion,but can result in abnormal fetal development,which can be detected via ultrasound.Therefore,clinicians need to pay more attention to various aspects of fetal growth and development,combining with imaging,cellular,molecular genetics and other methods to perform comprehensive evaluations of fetuses to provide more reliable genetic counseling for pregnant women.
基金supported by funds from‘Taishan Scholar’Construction Project,China(TS2022-028 and 202101KN275)。
文摘Tobacco(Nicotiana tabacum)and tomato(Solanum lycopersicum)are two major economic crops in China.Tobacco mosaic virus(TMV;genus Tobamovirus)is the most prevalent virus infecting both crops.Currently,some widely cultivated tobacco and tomato cultivars are susceptible to TMV and there is no effective strategy to control this virus.Cross-protection can be a safe and environmentally friendly strategy to prevent viral diseases.However,stable attenuated TMV mutants are scarce.In this study,we found that the substitutions in the replicase p126,arginine at position 196(R^(196))with aspartic acid(D),glutamic acid at position 614(E^(614))with glycine(G),serine at position 643(S^(643))with phenylalanine(F),or D at position 730(D^(730))with S,significantly reduced the virulence and replication of TMV.However,only the mutation of S^(643) to F reduced the RNA silencing suppression activity of TMV p126.A double-mutant TMV-E614G-S643F induced no visible symptom and was genetically stable through six successive passages in tobacco plants.Furthermore,our results showed that TMV-E614G-S643F double-mutant could provide effective protection against the wild-type TMV infection in tobacco and tomato plants.This study reports a promising mild mutant for cross-protection to control TMV in tobacco and tomato plants.
基金support from the Boettcher Foundation and the National Institutes of Health(1K99HD111686).
文摘Genomic mosaicism describes the phenomenon where some but not all cells within a tissue harbor unique genetic mutations.Traditionally,research focused on the impact of genomic mosaicism on clinical phenotype—motivated by its involvement in cancers and overgrowth syndromes.More recently,we increasingly shifted towards the plethora of neutral mosaic variants that can act as recorders of cellular lineage and environmental exposures.Here,we summarize the current state of the field of genomic mosaicism research with a special emphasis on our current understanding of this phenomenon in brain development and homeostasis.Although the field of genomic mosaicism has a rich history,technological advances in the last decade have changed our approaches and greatly improved our knowledge.We will provide current definitions and an overview of contemporary detection approaches for genomic mosaicism.Finally,we will discuss the impact and utility of genomic mosaicism.
基金financially supported by the National Natural Science Foundation of China(Nos.32160103 and U1812403)the Science and Technology Department of Guizhou Province(Nos.QKH ZC-[2021]-YB181,QKH CXTD-[2022]-007 and QKH ZYD-[2022]-4015)Guizhou Provincial Engineering Research Center for Natural Drugs。
文摘Three novel matrine-type alkaloids(1-3)and two unprecedented aloperine-type alkaloids(4 and 5)were isolated from the root of Sophora tonkinensis and the seeds of Sophora alopecuroides respectively.Notably,compound 1 possessed an unprecedented 6/5/6 tricyclic skeleton,while compounds 2 and 3 characterized by rare 6/6/5/6 tetracyclic system and 6/6/6/6/6 pentacyclic system respectively.Moreover,compound 4 possessed an unprecedented 6/7/6/6 tetracyclic core,and compound 5 characterized by rare 6/6/6/6tetracyclic skeleton.Their structures were elucidated by comprehensive spectroscopic data analysis and electronic circular dichroism(ECD)calculations.Biological tests indicated that compound 5 displayed significant anti-tobacco mosaic virus(TMV)activity compared with the positive control ningnanmycin.
基金supported by grants from National Natural Science Foundation of China(32001571)R&D Program of Beijing Municipal Education Commission(KM202212448003,KM202312448004)+4 种基金Science and Technology Innovation Project of Beijing Vocational College of Agriculture(XY-YF-22-02)Zhongshan Biological Breeding Laboratory(ZSBBL-KY2023-03)China Agriculture Research System of MOF and MARA(CARS-04)Jiangsu Collaborative Innovation Center for Modern Crop Production(JCICMCP)Collaborative Innovation Center for Modern Crop Production co-sponsored by Province and Ministry(CIC-MCP).
文摘Soybean mosaic virus(SMV),an RNA virus,is the most common and destructive pathogenic virus in soybean fields.The newly developed CRISPR/Cas immune system has provided a novel strategy for improving plant resistance to viruses;hence,this study aimed to engineer SMV resistance in soybean using this system.Specifically,multiple sgRNAs were designed to target positive-and/or negative-sense strands of the SMV HC-Pro gene.Subsequently,the corresponding CRISPR/CasRx vectors were constructed and transformed into soybeans.After inoculation with SMV,39.02%,35.77%,and 18.70%of T_(1)plants were confirmed to be highly resistant(HR),resistant(R),and mildly resistant(MR)to SMV,respectively,whereas only 6.50%were identified as susceptible(S).Additionally,qRT-PCR and DAS-ELISA showed that,both at 15 and 30 d post-inoculation(dpi),SMV accumulation significantly decreased or was even undetectable in HR and R plants,followed by MR and S plants.Additionally,the expression level of the CasRx gene varied in almost all T_(1)plants with different resistance level,both at 15 and 30 dpi.Furthermore,when SMV resistance was evaluated in the T_(2)generation,the results were similar to those recorded for the T_(1)generation.These findings provide new insights into the application of the CRISPR/CasRx system for soybean improvement and offer a promising alternative strategy for breeding for resistance to biotic stress that will contribute to the development of SMV-immune soybean germplasm to accelerate progress towards greater soybean crop productivity.
基金supported by a grant from Chinese Agriculture Research System of MOF and MARA (Grant No.CARS-24-C-04)Zhejiang Provincial Natural Science Foundation (Grant No.LZ24C140001)+1 种基金National Natural Science Foundation of China (Grant Nos.32370144,32070165)the K.C.Wong Magna Fund in Ningbo University。
文摘Turnip mosaic virus(TuMV)is a devastating potyvirus pathogen that infects a wide variety of both cultivated and wild Brassicaceae plants.We urgently need more information and understanding of TuMV pathogenesis and the host responses involved in disease development in cruciferous crops.TuMV displays great versatility in viral pathogenesis,especially in its replication and intercellular movement.Moreover,in the coevolutionary arms races between TuMV and its hosts,the virus has evolved to co-opt host factors to facilitate its infection and counter host defense responses.This review mainly focuses on recent advances in understanding the viral factors that contribute to the TuMV infection cycle and the host resistance mechanism in Brassica.Finally,we propose some future research directions on TuMV pathogenesis and control strategies to design durable TuMV-resistant Brassica crops.
文摘With the aim of assessing floristic diversity, stand structure and vegetation ecology, the present work was carried out in the savanna mosaic forest of the locality of Ndjole (Centre Cameroon). A total of 30 floristic plots of 40 m × 40 m (1600 m<sup>2</sup>) were delineated in the different ecosystems (forest, forest-savanna contact zone and the savanna). Within each plot, all individuals with a diameter at breast height ≥ 10 cm at 1.30 m were taken into account. ANOVA was used to compare the means of the diversity indices of the different ecosystems, and the DUNCAN test at 5% significance level (XLSTAT 2016) to separate these means. A total of 85 species belonging to 67 genera and 33 families were recorded. That is, 68 species in semi-caducifolia forest, 45 in forest-savanna contact zone and 18 in savanna. Urticaceae, Combretaceae, Apocynaceae, Myristicaceae and Euphorbiaceae are the most diverse families in the forest. On the other hand, in contact zones, the Euphorbiaceae, Fabaceae, Annonaceae and Moraceae families are the most diversified, while in the savannas, the Combretaceae, Fabaceae and Annonaceae families are the most diversified. Shannon’s diversity index values (1.7 to 2.37 bits) reflect low specific diversity;Piélou’s equitability (0.86 to 0.9) shows good distribution of individuals within species. The diametric structure of woody species shows an inverted “J” shape in all plant communities. This indicates a high regeneration potential characterized by a greater number of small trees than large trees. Mesophanerophytes and megaphanerophytes are dominant in forests and forest-savanna contact zones, and microphanerophytes in the savannas. Endozoochory is the main mode of diaspore dissemination. As regards the distribution of phytogeographical types, it shows the overall dominance of Guineo-Congolese species in all plant communities. Our study provides detailed data on forest-savanna floristic and plant life traits in the mosaic and recommends further studies on the impact of environmental parameter variations on the forest encroachment into savanna.
文摘Cowpea (Vigna unguiculata L. [Walp.]) in one of the main grain legumes contributing to food security and poverty alleviation in Sub-Saharan Africa. To control the highly damaging legume pod borer Maruca vitrata F., transgenic cowpea lines expressing the insecticidal Cry1Ab Bt protein were developed. In this study, we evaluated the impact of Cry1Ab transgene expression on the susceptibility of four cowpea lines (named IT97K-T, IT98K-T, Gourgou-T and Nafi-T) and their respective non-transgenic near isogenic lines (IT97K, IT98K, Gourgou and Nafi) to Cowpea aphid-borne mosaic virus (CABMV) in greenhouse conditions. In a preliminary quality control test by enzyme-linked immunosorbent assay, the presence of Cry1Ab protein in transgenic seed lots ranged from 59% to 72%, with no significant differences among the lines (χ2 = 3.26;p = 0.35). Upon virus inoculation, all cowpea lines exhibited mosaic symptoms with similar severity between 7- and 11-day post-inoculation. No significant differences were observed in symptom severity. Significant differences were found between cowpea lines for time of symptom onset, virus accumulation in plants and days to 50% flowering. However, while comparing pairs of transgenic lines and corresponding non-transgenic lines, virus accumulation showed not significant differences whatever the pair. Time of symptom onset and days to 50% flowering did not also differ significantly between pairs of cowpea lines except Nafi/Nafi-T in which transgenic Nafi-T showed earlier symptoms (7.4 ± 0.7 vs. 8.9 ± 0.8 days post-inoculation) and shorter flowering time (37.3 ± 0.6 vs. 42 ± 1.7 days after sowing). Overall, these findings improve our understanding of the effects of Cry1Ab gene mediated genetic modification on cowpea infection by Cowpea aphid-borne mosaic virus, with potential implications for environmental safety assessment.
文摘45X/46XY mosaicism is a rare chromosome disease. The apparent prevalence of males and females with 45X/46XY is 5.6 and 2.1 per 100,000 liveborn males and females. We present a boy who had a developmental delay with hypospadias. He was referred to pediatric genetics and was diagnosed with 45X/46XY mosaicism by peripheral blood chromosome examination. During serial rehabilitation programs, his speech delay was caught up. But his poor attention and hyperactivity are obvious progressively. We should pay attention to these patients, not only physical conditions but also psychological problems.
文摘Tobacco ( Nicotiana tabacum L.) “NC89” plants were transformed with deletion mutant of cucumber mosaic virus (CMV) movement protein (MP) gene and full_length CMV MP gene, respectively. The transformed plants were analyzed with polymerase chain reaction (PCR), PCR_Southern, Southern and Western blots. R 0 generation of the transgenic plants were inoculated with CMV. Five out of 10 lines of tobacco plants (BMPK) transformed with CMV MP deletion mutant gene showed high resistance to CMV infection and remained symptomless for up to 50 days post_inoculation. In contrast, tobacco plants (BMPR) transformed with full_length CMV MP gene did not show resistance to CMV infection. However, most of the infected full_length CMV MP gene transgenic plants recovered by showing none or very mild mosaic symptoms in 40 days post_inoculation. The results of R 1 generation of the BMPK transgenic plants tested under field conditions showed that all 5 lines of transgenic plants could delay the virus disease development.
文摘With joint analysis based on the parents, F 1, F 2 and backcrosses, the authors found that the resistance of the maize inbred line Huangzaosi to the maize dwarf mosaic virus strain B was conditioned by a major gene and polygene, and identified a new major gene. Bulked segregate and microsatellite analysis of a F 2 progeny from the combination of Huangzaosi×Mo17 were used to identify the resistance gene, mdm1(t), on the long arm of chromosome 6. This new resistance gene is tightly linked to and located between the microsatellite markers loci, phi077 and bnlg391. The linkage distances between phi077-mdm1(t) and mdm1(t)-bnlg391 are 4.74 centiMorgan (cM) and 6.72 cM respectively.
文摘近年来,Logo检测在知识产权保护和产品品牌管理等领域得到了广泛应用;针对Logo检测中的复杂背景和多尺度问题,提出了一种改进Mosaic数据增强和特征融合的Logo检测算法;将6张原始图片随机翻转、缩放和拼接构成合成图像,与单张图像和由4张原始图片合成的图像一起作为YOLOv4模型的训练输入,并确定3种输入形式的最优比例,同时使用一种新的训练策略,改进的Mosaic数据增强方法丰富了Logo对象的尺度和背景,使模型更好地学习全局和局部特征;在路径整合网络(PANet)的基础上引入跨层连接、重复堆叠、直接连接和加权特征融合等操作,改进的PANet扩大了模型感受野,增强了模型的多尺度特征表达能力;实验结果表明,提出的MP-YOLOv4算法在减小21.7%模型大小的同时,IoU(intersection of union)等于0.5时的平均精度上达到了67.4%,较YOLOv4提高了2.4%,同时在多尺度目标上的检测性能得到了改善。
