The silver-lipped pearl oyster(Pinctada maxima)is the largest and most commercially valuable pearl-producing oyster,renowned for its ability to generate large,lustrous pearls.This species is a sequential hermaphrodite...The silver-lipped pearl oyster(Pinctada maxima)is the largest and most commercially valuable pearl-producing oyster,renowned for its ability to generate large,lustrous pearls.This species is a sequential hermaphrodite,with pearl production displaying notable sexual dimorphism.Consequently,understanding the molecular mechanisms governing sex determination and differentiation is crucial for advancing breeding strategies in the pearl oyster industry.To elucidate these mechanisms,this study conducted integrative transcriptomic analyses of P.maxima gonadal tissues using isoform sequencing(Isoseq)and RNA sequencing(RNA-seq).Comparative analysis of ovarian and testicular tissues identified 2768 differentially expressed genes(DEGs).Gene coexpression network analysis delineated four key modules,including three sex-specific modules and one shared module.Key genes implicated in sex determination and maintenance were identified,including FOXL2,NANOS1,andβ-catenin,important for ovarian maintenance,and DMRT,SOX30,FEM1,and FOXJ1,crucial for testicular maintenance.These genes,widely studied in other taxa,were confirmed as hub genes in the sex-related modules of P.maxima.Interestingly,genes within the shared module were significantly enriched in the spliceosome pathway.Alternative splicing analysis highlighted its extensive role in gonadal tissues,with more pronounced activity observed in the testis compared to the ovary.Nearly half(47.83%,375)of the identified genes undergoing differential alternative splicing(DASGs)also exhibited differential transcript usage(DTUGs),while only 17%of DTUGs overlapped with DEGs.Genes associated with sex differentiation,such as DMRT,β-catenin,and U2AF2,displayed sex-specific and/or sex-biased isoforms.These findings offer novel insights into the molecular basis of sex differentiation in P.maxima,which could inform the development of targeted breeding strategies aimed at sex control,thereby enhancing pearl quality and yield in aquaculture.This study offers a robust molecular foundation for advancing breeding programs and optimizing production in the pearl oyster industry.展开更多
Motivated by some recent works on the topic of the Brown-Resnick process, we study the functional limit theorem for normalized pointwise maxima of dependent chi-processes. It is proven that the properly normalized poi...Motivated by some recent works on the topic of the Brown-Resnick process, we study the functional limit theorem for normalized pointwise maxima of dependent chi-processes. It is proven that the properly normalized pointwise maxima of those processes are attracted by the Brown-Resnick process.展开更多
Here we propose a new concept of"molecule aging":with some special treatment,a molecule could be"aged"by losing some unknown tiny particles or pieces from atoms in the molecule,Such"aging"...Here we propose a new concept of"molecule aging":with some special treatment,a molecule could be"aged"by losing some unknown tiny particles or pieces from atoms in the molecule,Such"aging"or loss of unknown tiny particles does not change apparently its molecular structure or chemical composition,but some physicochemical properties could be changed irreversibly.We further confirm such"molecule aging"via a long-term electron attacking to age water(H_(2)O)molecules.The IR spectra show no structural difference between the fresh water and the aged one,while the NMR spectra show that the electron attacking can decrease the size of water clusters.Such facts indicate that the electron attacking indeed can"affect"the structure of water molecule slightly but without damaging to its basic molecule frame.Further exploration reveals that the hydrogen evolution reaction(HER)activity of the aged water molecule is lower than the fresh water on the same Pt/C electrocatalyst.The density functional theory calculations indicate that the shortened O-H bond in H_(2)O indeed can present lower HER activity,so the observed size decrease of water clusters from NMR probably could be attributed to the shortening of O-H bond in water molecules.Such results indicate significantly that the molecule aging can produce materials with new functions for new possible applications.展开更多
Stone Pine(Pinus pinea L.)is currently the pine species with the highest commercial value with edible seeds.In this respect,this study introduces a new methodology for extracting Stone Pine trees from Digital Surface ...Stone Pine(Pinus pinea L.)is currently the pine species with the highest commercial value with edible seeds.In this respect,this study introduces a new methodology for extracting Stone Pine trees from Digital Surface Models(DSMs)generated through an Unmanned Aerial Vehicle(UAV)mission.We developed a novel enhanced probability map of local maxima that facilitates the computation of the orientation symmetry by means of new probabilistic local minima information.Four test sites are used to evaluate our automated framework within one of the most important Stone Pine forest areas in Antalya,Turkey.A Hand-held Mobile Laser Scanner(HMLS)was utilized to collect the reference point cloud dataset.Our findings confirm that the proposed methodology,which uses a single DSM as an input,secures overall pixel-based and object-based F1-scores of 88.3%and 97.7%,respectively.The overall median Euclidean distance revealed between the automatically extracted stem locations and the manually extracted ones is computed to be 36 cm(less than 4 pixels),demonstrating the effectiveness and robustness of the proposed methodology.Finally,the comparison with the state-of-the-art reveals that the outcomes of the proposed methodology outperform the results of six previous studies in this context.展开更多
2008～2010年，在广西涠洲岛进行了大珠母贝（Pinctada maxima Jameson）游离珍珠培育实验。实验过程中采用解剖法优选植核核位、几种术前处理方法和低温处理小片贝制备外套膜小片等技术，旨在提高育珠贝留核率、成珠率和优珠率。结果...2008～2010年，在广西涠洲岛进行了大珠母贝（Pinctada maxima Jameson）游离珍珠培育实验。实验过程中采用解剖法优选植核核位、几种术前处理方法和低温处理小片贝制备外套膜小片等技术，旨在提高育珠贝留核率、成珠率和优珠率。结果表明，在大珠母贝内脏囊缩足肌左右两侧各有一个适合培育游离珍珠的核位，分别称为左袋和右袋，实际操作中只有左袋可以植入珠核培育游离珍珠；不同术前处理实验组的植核贝休养期成活率差异不显著（P〉0．05），但留核率、成珠率显著差异（P〈0．05），其中采用传统术前处理和低温处理相结合的综合术前处理方法可有效提高留核率、成珠率平均达78．2％和80．1％；低温处理小片贝与传统方法制备的大珠母贝外套膜小片的育珠效果（成珠率、优珠率、正圆珠比例）存在显著差异（P〈0．05），且在实验温度范围内，成珠率、优珠率、正圆珠比例随处理温度的降低而增高，在4～8℃达到最好育珠效果，成珠率、优珠率和正圆珠比例分别达到98％、53％和30％左右；在术后休养期，植核贝吐核高峰出现植核后5-t5d，手术伤口愈合时间为15-20d，育殊贝的死亡高峰出现在术后的第20～30天。在水温25～30℃条件下，珠核表面形成珍珠层的时间为45d左右。展开更多
基金supported by the Hainan Province Science and Technology Talent Innovation Project(KJRC2023A02)Project of Sanya Yazhouwan Science and Technology City Management Foundation(SKJC-KJ-2019KY01)Sanya Science and Technology Special Fund(2022KJCX91)。
文摘The silver-lipped pearl oyster(Pinctada maxima)is the largest and most commercially valuable pearl-producing oyster,renowned for its ability to generate large,lustrous pearls.This species is a sequential hermaphrodite,with pearl production displaying notable sexual dimorphism.Consequently,understanding the molecular mechanisms governing sex determination and differentiation is crucial for advancing breeding strategies in the pearl oyster industry.To elucidate these mechanisms,this study conducted integrative transcriptomic analyses of P.maxima gonadal tissues using isoform sequencing(Isoseq)and RNA sequencing(RNA-seq).Comparative analysis of ovarian and testicular tissues identified 2768 differentially expressed genes(DEGs).Gene coexpression network analysis delineated four key modules,including three sex-specific modules and one shared module.Key genes implicated in sex determination and maintenance were identified,including FOXL2,NANOS1,andβ-catenin,important for ovarian maintenance,and DMRT,SOX30,FEM1,and FOXJ1,crucial for testicular maintenance.These genes,widely studied in other taxa,were confirmed as hub genes in the sex-related modules of P.maxima.Interestingly,genes within the shared module were significantly enriched in the spliceosome pathway.Alternative splicing analysis highlighted its extensive role in gonadal tissues,with more pronounced activity observed in the testis compared to the ovary.Nearly half(47.83%,375)of the identified genes undergoing differential alternative splicing(DASGs)also exhibited differential transcript usage(DTUGs),while only 17%of DTUGs overlapped with DEGs.Genes associated with sex differentiation,such as DMRT,β-catenin,and U2AF2,displayed sex-specific and/or sex-biased isoforms.These findings offer novel insights into the molecular basis of sex differentiation in P.maxima,which could inform the development of targeted breeding strategies aimed at sex control,thereby enhancing pearl quality and yield in aquaculture.This study offers a robust molecular foundation for advancing breeding programs and optimizing production in the pearl oyster industry.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(LY18A010020)the Innovation of Jiaxing City:A Program to Support the Talented Persons.
文摘Motivated by some recent works on the topic of the Brown-Resnick process, we study the functional limit theorem for normalized pointwise maxima of dependent chi-processes. It is proven that the properly normalized pointwise maxima of those processes are attracted by the Brown-Resnick process.
基金funded by the Key Research and Development Program sponsored by the Ministry of Science and Technology(MOST)(2022YFA1203400)National Natural Science Foundation of China(21925205,22072145,21372155,22005294,and 22102172)。
文摘Here we propose a new concept of"molecule aging":with some special treatment,a molecule could be"aged"by losing some unknown tiny particles or pieces from atoms in the molecule,Such"aging"or loss of unknown tiny particles does not change apparently its molecular structure or chemical composition,but some physicochemical properties could be changed irreversibly.We further confirm such"molecule aging"via a long-term electron attacking to age water(H_(2)O)molecules.The IR spectra show no structural difference between the fresh water and the aged one,while the NMR spectra show that the electron attacking can decrease the size of water clusters.Such facts indicate that the electron attacking indeed can"affect"the structure of water molecule slightly but without damaging to its basic molecule frame.Further exploration reveals that the hydrogen evolution reaction(HER)activity of the aged water molecule is lower than the fresh water on the same Pt/C electrocatalyst.The density functional theory calculations indicate that the shortened O-H bond in H_(2)O indeed can present lower HER activity,so the observed size decrease of water clusters from NMR probably could be attributed to the shortening of O-H bond in water molecules.Such results indicate significantly that the molecule aging can produce materials with new functions for new possible applications.
基金supported by the Projects of Scientific Investigation(BAP)of Ankara Haci Bayram Veli University[Grant No.01/2019-32].
文摘Stone Pine(Pinus pinea L.)is currently the pine species with the highest commercial value with edible seeds.In this respect,this study introduces a new methodology for extracting Stone Pine trees from Digital Surface Models(DSMs)generated through an Unmanned Aerial Vehicle(UAV)mission.We developed a novel enhanced probability map of local maxima that facilitates the computation of the orientation symmetry by means of new probabilistic local minima information.Four test sites are used to evaluate our automated framework within one of the most important Stone Pine forest areas in Antalya,Turkey.A Hand-held Mobile Laser Scanner(HMLS)was utilized to collect the reference point cloud dataset.Our findings confirm that the proposed methodology,which uses a single DSM as an input,secures overall pixel-based and object-based F1-scores of 88.3%and 97.7%,respectively.The overall median Euclidean distance revealed between the automatically extracted stem locations and the manually extracted ones is computed to be 36 cm(less than 4 pixels),demonstrating the effectiveness and robustness of the proposed methodology.Finally,the comparison with the state-of-the-art reveals that the outcomes of the proposed methodology outperform the results of six previous studies in this context.
文摘2008～2010年，在广西涠洲岛进行了大珠母贝（Pinctada maxima Jameson）游离珍珠培育实验。实验过程中采用解剖法优选植核核位、几种术前处理方法和低温处理小片贝制备外套膜小片等技术，旨在提高育珠贝留核率、成珠率和优珠率。结果表明，在大珠母贝内脏囊缩足肌左右两侧各有一个适合培育游离珍珠的核位，分别称为左袋和右袋，实际操作中只有左袋可以植入珠核培育游离珍珠；不同术前处理实验组的植核贝休养期成活率差异不显著（P〉0．05），但留核率、成珠率显著差异（P〈0．05），其中采用传统术前处理和低温处理相结合的综合术前处理方法可有效提高留核率、成珠率平均达78．2％和80．1％；低温处理小片贝与传统方法制备的大珠母贝外套膜小片的育珠效果（成珠率、优珠率、正圆珠比例）存在显著差异（P〈0．05），且在实验温度范围内，成珠率、优珠率、正圆珠比例随处理温度的降低而增高，在4～8℃达到最好育珠效果，成珠率、优珠率和正圆珠比例分别达到98％、53％和30％左右；在术后休养期，植核贝吐核高峰出现植核后5-t5d，手术伤口愈合时间为15-20d，育殊贝的死亡高峰出现在术后的第20～30天。在水温25～30℃条件下，珠核表面形成珍珠层的时间为45d左右。
