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Clinical manifestations and the prenatal diagnosis of trisomy 7 mosaicism:Two case reports
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作者 Fei Hou Yan Li Hua Jin 《World Journal of Clinical Cases》 SCIE 2024年第8期1544-1548,共5页
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
关键词 Trisomy 7 mosaicism Copy number variation sequencing Whole-exome sequencing Karyotype analysis Prenatal diagnosis Case report
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Mosaicism of a novel variant in the ANKRD11 gene in a child with a mild KBG phenotype:A case report
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作者 Roberto Franceschi Francesca Rivieri +7 位作者 Antonio Novelli Daniele Ferretti Adriano Anesi Massimo Soffiati Giulia Porretti Evelina Maines Mafalda Mucciolo Giorgio Radetti 《World Journal of Medical Genetics》 2023年第2期21-27,共7页
BACKGROUND KBG syndrome is likely underdiagnosed because of mild and non-specific features in some affected patients especially before the upper permanent central incisors eruption at about the age of 7-8 years.Somati... BACKGROUND KBG syndrome is likely underdiagnosed because of mild and non-specific features in some affected patients especially before the upper permanent central incisors eruption at about the age of 7-8 years.Somatic mosaicisms are usually recognized in the parents only after a typically affected son is diagnosed with KBG syndrome.We describe for the first time the mosaicism of a novel variant in a child with a mild KBG phenotype.CASE SUMMARY Our patient presented at 24 mo of age with short stature,hand abnormalities,facial dysmorphism and mild developmental delay.Pituitary hypoplasia and central hypothyroidism were also detected.By next generation sequencing(NGS)analysis we found a novel deletion in the ANKRD11 gene(c.4880_4893del.),that can be classified as likely pathogenic for the syndrome,with the percentage of mutated allele of 36%.We considered this finding as causative of the mild and non-specific phenotype for KBG syndrome in our patient,as previously reported in adults.A heterozygous variant in HESX1 gene,classified as variant of uncertain significance,but suspected of causing pituitary hypoplasia and hormonal deficiency,was also found.The patient started levothyroxine and growth hormone treatment.CONCLUSION The increased use of NGS analysis may expand the phenotypic spectrum of KBG syndrome because it allows genetic diagnosis of somatic mosaicisms also in children. 展开更多
关键词 ANKRD11 KBG MOSAIC HESX1 CHILD Case report
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Cytogenetic Mechanism for the Aneuploidy and Mosaicism Foundin Tetraploid Pacific Oyster Crassostrea gigas (Thunberg) 被引量:1
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《Journal of Ocean University of China》 SCIE CAS 2014年第1期125-131,共7页
Chromosome constitution was investigated in adult tetraploid Pacific oyster produced by blocking the first polar body oftriploid eggs which were fertilized with haploid sperms. A high incidence of aneuploid and hetero... Chromosome constitution was investigated in adult tetraploid Pacific oyster produced by blocking the first polar body oftriploid eggs which were fertilized with haploid sperms. A high incidence of aneuploid and heteroploid mosaics were found amongthe offspring. Of 20 individuals identified, only 9 (45%) were eutetraploid which contained 40 chromosomes; 2 (10%) were ane-uploid (hypotetraploid), which contained 39 and 38 chromosomes, respectively; and 9 (45%) were heteroploid mosaics. One mosaicwas consisted of cells containing 40 and 39 chromosomes, respectiovely (1:1 in cell number), while the other 8 were consisted ofcells containing chromosomes varying between tetraploid and triploid. It was also interesting to note that 3 mosaics even containedsome diploid cells with 20 chromosomes. A certain number of cells of 2 tetraploids and 8 mosaics spread with 32-37 well-scatteredand some clumped chromosomes at metaphase. The percentage of aneuploid cells with chromosomes varying between triploid andtetraploid correlated significantly with that of heteroploid mosaics cells with clumping chromosomes (P〈0.05). Our findings sug-gested that reversion existed in both tetraploid and triploid oyster and chromosome clumping may underline the chromosome elimi-nation in tetraploid oyster. It seems that the reversing cells, at least some of them, continuously eliminate their chromosomes until themost stable diploid state is established. 展开更多
关键词 TETRAPLOID oyster ANEUPLOIDY mosaicism REVERSION CYTOGENETIC mechanism
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Gonadal dysgenesis in Turner syndrome with Y-chromosome mosaicism:Two case reports
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作者 Xue-Fei Leng Ke Lei +4 位作者 Yi Li Fei Tian Qin Yao Qing-Mei Zheng Zhi-Hong Chen 《World Journal of Clinical Cases》 SCIE 2020年第22期5737-5743,共7页
BACKGROUND Turner syndrome(TS)has a variety of different karyotypes,with a wide range of phenotypic features,but the specific karyotype may not always predict the phenotype.TS with Y chromosome mosaicism may have mixe... BACKGROUND Turner syndrome(TS)has a variety of different karyotypes,with a wide range of phenotypic features,but the specific karyotype may not always predict the phenotype.TS with Y chromosome mosaicism may have mixed gonadal dysgenesis,and the mosaicism is related to the potential for gonadoblastoma.CASE SUMMARY In this case report,we report two cases of TS with different karyotypes and gonadal dysgenesis.Patient 1 had obvious virilization,and was positive for the SRY gene,but her karyotype in peripheral blood lymphocytes was 45X.Patient 2 had a mosaic karyotype,45X/46X,dic(Y:Y)(p11.3:p11.2),and the proportion of Y-bearing cells was 50%in peripheral blood lymphocytes,but the patient had normal female external genitalia and streaky gonads,with no genital virilism.Different tissues in the same TS individual may exhibit different ratios of mosaicism.The gonadal determination and differentiation of mosaic TS are primarily dependent on the predominant cell line in the gonads.CONCLUSION In TS patients with virilization,it is necessary to test at least two to three tissues to search for cryptic Y material. 展开更多
关键词 Turner syndrome Gonadal dysgenesis VIRILIZATION Y chromosome mosaicism GONADOBLASTOMA Case report
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Discrepancy between non-invasive prenatal testing result and fetal karyotype caused by rare confined placental mosaicism: A case report
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作者 Zhen Li Guang-Rui Lai 《World Journal of Clinical Cases》 SCIE 2022年第24期8641-8647,共7页
BACKGROUND Confined placental mosaicism(CPM)is one of the major reasons for discrepancies between the results of non-invasive prenatal testing(NIPT)and fetal karyotype analysis.CASE SUMMARY We encountered a primiparou... BACKGROUND Confined placental mosaicism(CPM)is one of the major reasons for discrepancies between the results of non-invasive prenatal testing(NIPT)and fetal karyotype analysis.CASE SUMMARY We encountered a primiparous singleton pregnant woman with a rare CPM consisting of 47,XY,+21;47,XXY;and 46,XY,who obtained a false-positive result on NIPT with a high risk for trisomy 21.Copy-number variation sequencing on amniotic fluid cells,fetal tissue,and placental biopsies showed that the fetal karyotype was 47,XXY,while the placenta was a rare mosaic of 47,XY,+21;47,XXY;and 46,XY.CONCLUSION The patient had a rare CPM consisting of 47,XY,+21;47,XXY;and 46,XY,which caused a discrepancy between the result of NIPT and the actual fetal karyotype.It is important to remember that NIPT is a screening test,not a diagnostic test.Any positive result should be confirmed with invasive testing,and routine ultrasound examination is still necessary after a negative result. 展开更多
关键词 Non-invasive prenatal testing Confined placental mosaicism Copy-number variation sequencing Karyotype analysis Case report
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Pigmentary mosaicism and specific forms of phylloid hypoand hypermelanosis
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作者 Naoki Oiso Akira Kawada 《World Journal of Dermatology》 2012年第2期6-9,共4页
Pigmentary mosaicism is proposed to encompass all pigment anomalies caused by chromosomal mosaicism. The concept includes, not only pigment anomalies following the lines of Blaschko, but also pigmentary disorders with... Pigmentary mosaicism is proposed to encompass all pigment anomalies caused by chromosomal mosaicism. The concept includes, not only pigment anomalies following the lines of Blaschko, but also pigmentary disorders with phylloid, checkerboard and patchy pigmentation without midline separation. The representative disorders are hypomelanosis of Ito(pigmentary mosaicism of hypopigmented or Ito type), linear and whorled nevoid hypermelanosis(pigmentary mosaicism of hyperpigmented type), pigmentary mosaicism of hypopigmented and hyperpigmented type, and phylloid hypo- and hypermelanosis. Pigmentary mosaicism is nowadays recognized as a pigmentary disorder caused by somatic chromosomal abnormalities disrupting or accelerating the function of pigmentary genes. Affected individuals with pigmentary mosaicism commonly have multiple congenital abnormalities, developmental delays and/or mental retardation. However, the complication is not a syndrome because functional loss or acquisition due to various chromosomal abnormalities induces pigment abnormalities and specific complications. Cytogenetic abnormalities, including polyploidy, aneuploidy, deletions, insertions and translocations, are associated with almost any chromosome and tissue-limited mosaicism for chromosome abnormalities. Cytogenetic find-ings in cases with the phylloid pattern demonstrate the obvious causal relationship between phylloid hypomelanosis and mosaic trisomy 13. The pattern of cutaneous mosaicism depends on the trajectory of migration and proliferation during embryogenesis. The chromosomal regions of hot breakpoints in pigmentary mosaicism may contain pigmentation-associated genes. The accumulation of relationships between cases and chromosomal analyses may provide the opportunity to identify and understand the pigmentation-associated genes because more than 800 phenotypic alleles are known in the mice models of pigmentary anomalies and not all color loci have been identified. Here, we summarize the clinical features of pigmentary mosaicism and specific forms of phylloid hypo- and hypermelanosis. 展开更多
关键词 Pigmentary mosaicism Hypomelanosis of ITO Linear and whorled nevoid hypermelanosis Phylloid hypomelanosis Phylloid hypermelanosis The LINES of Blaschko Phylloid PATTERN
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煤矿井下无人驾驶轨道电机车障碍物识别
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作者 杨豚 郭永存 +1 位作者 王爽 马鑫 《浙江大学学报(工学版)》 EI CAS CSCD 北大核心 2024年第1期29-39,共11页
针对现有煤矿井下无人驾驶轨道电机车因巷道环境恶劣导致障碍物识别精度低的问题,提出用于无人驾驶电机车障碍物精准实时检测的PDM-YOLO模型.基于YOLOv5,将模型C3模块中的传统卷积替换为部分卷积,构建C3_P特征提取模块,有效减少模型的... 针对现有煤矿井下无人驾驶轨道电机车因巷道环境恶劣导致障碍物识别精度低的问题,提出用于无人驾驶电机车障碍物精准实时检测的PDM-YOLO模型.基于YOLOv5,将模型C3模块中的传统卷积替换为部分卷积,构建C3_P特征提取模块,有效减少模型的浮点运算量(FLOPs)与计算延迟.采用改进后的解耦头,对传统YOLOv5的预测头进行解耦,提高模型的收敛速度及对障碍物的识别精度.优化Mosaic数据增强方法,丰富训练图像的特征信息,提高模型的普适性和鲁棒性.实验结果表明,PDM-YOLO模型在自制数据集上的平均检测精度(mAP)达到96.3%,平均检测速度达到109.2帧/s,PDM-YOLO模型在PASCAL VOC公共数据集上的检测精度高于现有主流的YOLO系列模型. 展开更多
关键词 无人驾驶电机车 YOLO 障碍物识别 部分卷积 解耦头 Mosaic数据增强
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基于改进YOLOv5m的电动车骑行者头盔与车牌检测方法 被引量:1
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作者 庄建军 叶振兴 《南京信息工程大学学报(自然科学版)》 CAS 北大核心 2024年第1期1-10,共10页
电动车上路必须佩戴安全头盔已成为交管部门的强制性规定.为了能自动检测出电动车骑行者的头盔佩戴情况,提出一种基于改进的YOLOv5m模型的头盔与车牌检测方法,在检测出骑行者未佩戴头盔的同时还能检测出电动车车牌.模型使用自建电动车... 电动车上路必须佩戴安全头盔已成为交管部门的强制性规定.为了能自动检测出电动车骑行者的头盔佩戴情况,提出一种基于改进的YOLOv5m模型的头盔与车牌检测方法,在检测出骑行者未佩戴头盔的同时还能检测出电动车车牌.模型使用自建电动车骑行者头盔与车牌检测数据集进行训练,用DIOU损失函数代替GIOU损失函数,DIOU_NMS代替加权NMS,增强模型对密集骑行场景的识别能力.在Backone部位与预测中小目标的Neck部位加入ECA注意力机制,使得模型对中小目标的识别率有所提高;用K-means算法对锚框尺寸重新进行聚类.最后,改进Mosaic数据增强方式.实验结果表明:改进的YOLOv5m电动车骑行者头盔与车牌检测模型的mAP为92.7%,较原YOLOv5m模型提高2.15个百分点,较YOLOv4-tiny、Faster RCNN模型分别提高5.7个百分点与6.9个百分点.改进后的YOLOv5m模型能有效提高对头盔与车牌的识别率. 展开更多
关键词 头盔检测 车牌检测 YOLOv5m 注意力机制 DIOU K-MEANS算法 改进Mosaic数据增强
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基于改进的Faster RCNN的仪表自动识别方法
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作者 王欣然 张斌 +1 位作者 湛敏 赵成龙 《机电工程》 CAS 北大核心 2024年第3期532-539,共8页
在环境复杂的工业场景中,仪表盘存在类别多、相似性高等问题,导致检测的识别效果较差、准确率不高。针对这一问题,提出了一种基于改进的更快速的区域卷积神经网络(Faster RCNN)的仪表自动识别方法。首先,采用残差网络(Resnet)101代替视... 在环境复杂的工业场景中,仪表盘存在类别多、相似性高等问题,导致检测的识别效果较差、准确率不高。针对这一问题,提出了一种基于改进的更快速的区域卷积神经网络(Faster RCNN)的仪表自动识别方法。首先,采用残差网络(Resnet)101代替视觉几何群网络(VGG)16,进行了网络结构简化;然后,引入了特征金字塔网络(FPN),并将其改进为递归特征金字塔网络后进行了迭代融合,输出了特征图;接着,引入了注意力机制模块,根据特征的重要程度,完成了对输出通道权值的重新分配,增强了Faster RCNN对目标的运算能力;提出了改进非极大值抑制算法(Softer-NMS),通过降低置信度来确定准确的目标候选框;最后,采用Mosaic数据增强技术对可视对象类(VOC)2007数据集进行了扩充,对改进后的Faster RCNN模型进行了仪表自动识别的实验。研究结果表明:在相同工业环境下,与传统的Faster RCNN算法模型相比,改进后的Faster RCNN模型准确率为93.5%,较原模型提高了3.8%,mAP值为92.6%,较原模型提高了3.7%,可见该方法在实际生产中具有较强的鲁棒性与泛化能力,可满足工业上对智能检测的要求。 展开更多
关键词 仪表识别 更快速的区域卷积神经网络 递归特征金字塔网络 注意力机制 非极大值抑制算法 Mosaic数据增强技术
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Floristic Diversity, Stand Structure and Plant Life Traits in the Forest-Savanna Mosaic at Ndjole (Centre Cameroon)
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作者 Djeuguen Vanessa Tchaleu Solefack Marie Caroline Momo +3 位作者 Mateso Aimé Kambale Ndondjeu Charles Tafen Yanick Borel Kamga Victor François Nguetsop 《Open Journal of Ecology》 2024年第4期309-330,共22页
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
关键词 MOSAIC COMMUNITIES DISSEMINATION Regeneration Diversity
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iDEAL-CIO: Instant Digital Express Advocated “Magic Lamp” for Cloud Intelligence Outlet
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作者 Sheldon Liang Paul Anthony Miller +1 位作者 Brendan Shane Rowe Alexis Rainbow 《Intelligent Information Management》 2024年第1期35-63,共29页
Instant Digital Express iDEAL-CIO The “Magic Lamp” for Cloud Intelligence Outlet, which has been recommended, combines innovations to satisfy modern users’ needs and efficiently sift through the ever-expanding amou... Instant Digital Express iDEAL-CIO The “Magic Lamp” for Cloud Intelligence Outlet, which has been recommended, combines innovations to satisfy modern users’ needs and efficiently sift through the ever-expanding amount of intelligent content stored in the cloud. One such innovation introduces a ground-breaking concept to remove superfluous and outdated sequential search patterns that overwhelm the user and computer in order to better serve the user in an eclectic & elastic and multidimensional approach to finding, grouping, assimilation, organizing, and delivering archival content. The cloud intelligence outlet (CIO) is presented in this article as the perfect magic lamp option for quick digital express advocacy. The grouping, indexing, folding, and targeting (GIFT) method of multidimensional online synthetic/analytical intelligent content (MOSAIC) for adaptive intelligence is the fundamental intelligent aggregation and automated process of the Magic Lamp. Three perspectives above this new ideal framework are available to observe: The Magic Lamp proposes contextual and multiple analytical tracks to improve cloud intelligence services conceptually. Technically speaking, MOSAIC combines domain-specific services for a wide range of international users, and through the usage of Cloud Intelligence Outlet, GIFT operationally activates grouping, indexing, folding, and targeting to promote decent experience and in-depth research on target for users’ wants. Because of this, iDEAL-CIO works in tandem with cloud extraction, digital transformation, and archival loading to provide improved service through the readily accessible cloud intelligence outlet. 展开更多
关键词 iDEAL-CIO MOSAIC Multidimensional Online Synthetic/Analytical Intelligent Content
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Single-cell Sequencing Reveals Clearance of Blastula Chromosomal Mosaicism in In Vitro Fertilization Babies
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作者 Yuan Gao Jinning Zhang +10 位作者 Zhenyu Liu Shuyue Qi Xinmeng Guo Hui Wang Yanfei Cheng Shuang Tian Minyue Ma Hongmei Peng Lu Wen Fuchou Tang Yuanqing Yao 《Genomics, Proteomics & Bioinformatics》 SCIE CAS CSCD 2022年第6期1224-1231,共8页
Although chromosomal mosaic embryos detected by trophectoderm(TE)biopsy offer healthy embryos available for transfer,high-resolution postnatal karyotyping and chromosome testing of the transferred embryos are insuffic... Although chromosomal mosaic embryos detected by trophectoderm(TE)biopsy offer healthy embryos available for transfer,high-resolution postnatal karyotyping and chromosome testing of the transferred embryos are insufficient.Here,we applied single-cell multi-omics sequencing for seven infants with blastula chromosomal mosaicism detected by TE biopsy.The chromosome ploidy was examined by single-cell genome analysis,with the cellular identity being identified by single-cell transcriptome analysis.A total of 1616 peripheral leukocytes from seven infants with embryonic chromosomal mosaicism and three control ones with euploid TE biopsy were analyzed.A small number of blood cells showed copy number alterations(CNAs)on seemingly random locations at a frequency of 0%-2.5%per infant.However,none of the cells showed CNAs that were the same as those of the corresponding TE biopsies.The blastula chromosomal mosaicism may be fully self-corrected,probably through the selective loss of the aneuploid cells during development,and the transferred embryos can be born as euploid infants without mosaic CNAs corresponding to the TE biopsies.The results provide a new reference for the evaluations of transferring chromosomal mosaic embryos in certain situations. 展开更多
关键词 mosaicism Pre-implantation genetic testing for aneuploidy Next-generation sequencing Single-cell multi-omics sequencing Mosaic embryo transfer
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注意力机制优化SSD的戴口罩人脸快速检测研究
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作者 苏海涛 张守棋 《电脑知识与技术》 2023年第19期30-34,38,共6页
MobileNet-SSD算法在目标检测领域具有速度快、参数少的优点。尤其在大目标检测方面,准确率、召回率、AP值较高,但对于小目标检测,检测速度快但存在准确率、召回率及AP值偏低等问题。鉴于此,本文通过添加Mosaic数据增强算法增加小物体... MobileNet-SSD算法在目标检测领域具有速度快、参数少的优点。尤其在大目标检测方面,准确率、召回率、AP值较高,但对于小目标检测,检测速度快但存在准确率、召回率及AP值偏低等问题。鉴于此,本文通过添加Mosaic数据增强算法增加小物体图片扩充数据集,选用Focal Loss取代Softmax Loss分类损失函数,通过整体修改特征提取网络并添加修改过后SE通道注意力构建一种新特征提取网络(DynaNet),并基于此网络实现SSD算法,实现对戴口罩人脸的检测。实验证明,相较于MobileNet-SSD算法,DynaNet-SSD针对小目标戴口罩人脸,检测准确率提高了6.9%、召回率提高了4.3%,mAP值提高了6.82%,检测速度快于RetinaNet和YoloV5。 展开更多
关键词 DynaNet-SSD SE注意力机制 小目标检测 人脸检测 Focal Loss MOSAIC
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改进型YOLOv4-tiny的轻量级目标检测算法 被引量:1
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作者 郭明镇 汪威 +3 位作者 申红婷 候红涛 刘宽 罗子江 《计算机工程与应用》 CSCD 北大核心 2023年第23期145-153,共9页
为解决部署在嵌入式设备上的目标检测中特征提取速度较慢、检测实时性不足和算法移植性较差的问题,以YOLOv4-tiny为基准网络,提出一种基于CSPRDWConv(cross stage partial residual depthwise convolution)模块的轻量级网络YOLOv4-tiny-... 为解决部署在嵌入式设备上的目标检测中特征提取速度较慢、检测实时性不足和算法移植性较差的问题,以YOLOv4-tiny为基准网络,提出一种基于CSPRDWConv(cross stage partial residual depthwise convolution)模块的轻量级网络YOLOv4-tiny-CSPRDWConv,并使用改进的Mosaic数据增强来提升检测模型精度。CSPRDWConv模块中适当缩减算力规模,使得整个模块在保持精度的同时大幅提升推理速度;改进的Mosaic数据增强方法,节省数据增强进程的时间,充分利用每个图像块,并且过滤掉物体过小的目标,使得模型更易于训练。在此基础之上,主干网络的卷积层全部选用小卷积核,只在最后一次压缩特征图时使用5×5的深度可分离卷积,以确保模型低延迟和高准确度的特性;在Neck中引入弱SPP模块,利用局部特征和全局特征来提高目标检测的精度;通过NEON指令对训练后的检测模型进行优化,将卷积层与BN层融合,加快模型的推理进程。改进的YOLOv4-tiny算法在1080Ti的硬件上达到1 308 FPS的实时检测速度,在RK3288开发板上的推理速度约为8 FPS,检测速度约为YOLOv4-tiny基准网络的4倍;mAP达到22.31%,相比于基准网络提升0.61个百分点。实验结果表明,改进的YOLOv4-tiny算法在嵌入式设备上的检测效果更为流畅和高效。 展开更多
关键词 目标检测 YOLOv4-tiny 嵌入式系统 CSPRDWConv模块 Mosaic数据增强
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MEB-YOLO: An Efficient Vehicle Detection Method in Complex Traffic Road Scenes 被引量:3
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作者 Yingkun Song Shunhe Hong +4 位作者 Chentao Hu Pingan He Lingbing Tao Zhixin Tie Chengfu Ding 《Computers, Materials & Continua》 SCIE EI 2023年第6期5761-5784,共24页
Rapid and precise vehicle recognition and classification are essential for intelligent transportation systems,and road target detection is one of the most difficult tasks in the field of computer vision.The challenge ... Rapid and precise vehicle recognition and classification are essential for intelligent transportation systems,and road target detection is one of the most difficult tasks in the field of computer vision.The challenge in real-time road target detection is the ability to properly pinpoint relatively small vehicles in complicated environments.However,because road targets are prone to complicated backgrounds and sparse features,it is challenging to detect and identify vehicle kinds fast and reliably.We suggest a new vehicle detection model called MEB-YOLO,which combines Mosaic and MixUp data augmentation,Efficient Channel Attention(ECA)attention mechanism,Bidirectional Feature Pyramid Network(BiFPN)with You Only Look Once(YOLO)model,to overcome this problem.Four sections make up this model:Input,Backbone,Neck,and Prediction.First,to improve the detection dataset and strengthen the network,MixUp and Mosaic data improvement are used during the picture processing step.Second,an attention mechanism is introduced to the backbone network,which is Cross Stage Par-tial Darknet(CSPDarknet),to reduce the influence of irrelevant features in images.Third,to achieve more sophisticated feature fusion without increasing computing cost,the BiFPN structure is utilized to build the Neck network of the model.The final prediction results are then obtained using Decoupled Head.Experiments demonstrate that the proposed model outperforms several already available detection methods and delivers good detection results on the University at Albany DEtection and TRACking(UA-DETRAC)public dataset.It also enables effective vehicle detection on real traffic monitoring data.As a result,this technique is efficient for detecting road targets. 展开更多
关键词 Target detection YOLO ECA attention mechanism MOSAIC MixUp BiFPN
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基于Faster-RCNN的自然环境下苹果识别
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作者 石展鲲 杨风 +2 位作者 韩建宁 郭鑫 曹尚斌 《计算机与现代化》 2023年第2期62-65,共4页
针对苹果园中存在的果实相互重叠、枝叶干扰以及复杂背景等问题,本文提出Faster-RCNN一种改进的模型。该模型通过增强Mosaic数据,使得识别小物体目标果实能力得到提升,同时,对Faster-RCNN结构中的锚框进行优化,优化后的锚框能更好地检... 针对苹果园中存在的果实相互重叠、枝叶干扰以及复杂背景等问题,本文提出Faster-RCNN一种改进的模型。该模型通过增强Mosaic数据,使得识别小物体目标果实能力得到提升,同时,对Faster-RCNN结构中的锚框进行优化,优化后的锚框能更好地检测出距离相机较远的目标果实,以及使用Soft NMS算法对密集区域的识别效果进一步得到改进。通过对300幅未参与识别的自然环境下的苹果图像进行验证,验证结果表明:召回率为91.44%,准确率为93.35%,F1值为92.38%,每幅图像的检测可在0.2 s内完成。改进后的算法鲁棒性得到增强,能够满足在自然环境下对苹果果实的识别工作。 展开更多
关键词 Faster-RCNN Mosaic数据增强 目标识别 Soft NMS算法
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Effect of light and nutrients on interspecific interactions between submerged macrophytes:implications for restoration of multispecies aquatic vegetation in eutrophic lakes
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作者 Yiping WANG Xiaoguang XU +5 位作者 Dujun LI Yongjun LU Xinhou ZHANG Chuyao YANG Qiu JIN Guoxiang WANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第5期1821-1833,共13页
Constructing multispecies submerged vegetation systems and maintaining stable seasonal succession is crucial for restoring shallow eutrophic lakes.However,little is known about the interactions between successional an... Constructing multispecies submerged vegetation systems and maintaining stable seasonal succession is crucial for restoring shallow eutrophic lakes.However,little is known about the interactions between successional and existing species of different growth forms,particularly under the low light and high nutrient conditions of eutrophic lakes.We measured the functional traits of mature Vallisneria natans(Lour.)Hara plants and Potamogeton crispus L.shoots in monoculture and mosaic patterns under different light and nutrient conditions.The effect of light on functional traits of the submerged macrophyte species was more significant than that of nutrients,but the reverse was true for P.crispus biomass allocation.Moreover,interspecific interactions affected only the submerged macrophytes under the low light condition and varied with species.Specifically,the interaction of P.crispus to V.natans was biased towards competition,while the interaction of V.natans to P.crispus was converted from facilitation to competition by eutrophication,particularly in the homogenous mosaic growth pattern.This study demonstrates that sufficient light is a prerequisite and patch planting is an effective means to form a multispecies submerged vegetation system.In addition,we emphasize that the coexistence of eutrophication and low light will likely result in a competition between submerged macrophytes thus simplifying the vegetation,even if their growth forms and growing seasons are different.These findings help explain the collapse of multispecies submerged vegetation and guide the restoration of aquatic plants in eutrophic lakes. 展开更多
关键词 submerged macrophyte LIGHT NUTRIENT MONOCULTURE MOSAIC interspecific interaction
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An image mosaic technique with non-overlapping regions based on microscopic vision in precision assembly
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作者 Yawei Li Xiaodong Wang +1 位作者 Tao Wang Yi Luo 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2023年第4期66-74,共9页
Microscopic vision has been widely applied in precision assembly.To achieve sufficiently high resolution in measurements for precision assembly when the sizes of the parts involved exceed the field of view of the visi... Microscopic vision has been widely applied in precision assembly.To achieve sufficiently high resolution in measurements for precision assembly when the sizes of the parts involved exceed the field of view of the vision system,an image mosaic technique must be used.In this paper,a method for constructing an image mosaic with non-overlapping areas with enhanced efficiency is proposed.First,an image mosaic model for the part is created using a geometric model of the measurement system installed on a X-Y-Z precision stages with high repeatability,and a path for image acquisition is established.Second,images are captured along the same path for a specified calibration plate,and an entire image is formed based on the given model.The measurement results obtained from the specified calibration plate are utilized to identify mosaic errors and apply compensation for the part requiring measurement.Experimental results show that the maximum error is less than 4μm for a camera with pixel equivalent 2.46μm,thereby demonstrating the accuracy of the proposed method.This image mosaic technique with non-overlapping regions can simplify image acquisition and reduce the workload involved in constructing an image mosaic. 展开更多
关键词 Image mosaic Microscopic vision Visual measurement Precision assembly
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High-temperature annealing of(201)β-Ga_(2)O_(3) substrates for reducing structural defects after diamond sawing
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作者 Pavel Butenko Michael Boiko +5 位作者 Mikhail Sharkov Aleksei Almaev Aleksnder Kitsay Vladimir Krymov Anton Zarichny Vladimir Nikolaev 《Journal of Semiconductors》 EI CAS CSCD 2023年第12期125-132,共8页
A commercial epi-ready(201)β-Ga_(2)O_(3) wafer was investigated upon diamond sawing into pieces measuring 2.5×3 mm^(2).The defect structure and crystallinity in the cut samples has been studied by X-ray diffract... A commercial epi-ready(201)β-Ga_(2)O_(3) wafer was investigated upon diamond sawing into pieces measuring 2.5×3 mm^(2).The defect structure and crystallinity in the cut samples has been studied by X-ray diffraction and a selective wet etching technique.The density of defects was estimated from the average value of etch pits calculated,including near-edge regions,and was obtained close to 109 cm^(-2).Blocks with lattice orientation deviated by angles of 1-3 arcmin,as well as non-stoichiometric fractions with a relative strain about(1.0-1.5)×10^(-4)in the[201]direction,were found.Crystal perfection was shown to decrease significantly towards the cutting lines of the samples.To reduce the number of structural defects and increase the crystal perfection of the samples via increasing defect motion mobility,the thermal annealing was employed.Polygonization and formation of a mosaic structure coupled with dislocation wall appearance upon 3 h of annealing at 1100℃ was observed.The fractions characterized by non-stoichiometry phases and the block deviation disappeared.The annealing for 11 h improved the homogeneity and perfection in the crystals.The average density of the etch pits dropped down significantly to 8×10^(6) cm^(-2). 展开更多
关键词 gallium oxide epi-ready substrate etch pits crystal defect mosaic structure crystal perfection
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General mapping of one-dimensional non-Hermitian mosaic models to non-mosaic counterparts:Mobility edges and Lyapunov exponents
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作者 蒋盛莲 刘彦霞 郎利君 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第9期79-86,共8页
We establish a general mapping from one-dimensional non-Hermitian mosaic models to their non-mosaic counterparts.This mapping can give rise to mobility edges and even Lyapunov exponents in the mosaic models if critica... We establish a general mapping from one-dimensional non-Hermitian mosaic models to their non-mosaic counterparts.This mapping can give rise to mobility edges and even Lyapunov exponents in the mosaic models if critical points of localization or Lyapunov exponents of localized states in the corresponding non-mosaic models have already been analytically solved.To demonstrate the validity of this mapping,we apply it to two non-Hermitian localization models:an Aubry-Andre-like model with nonreciprocal hopping and complex quasiperiodic potentials,and the Ganeshan-Pixley-Das Sarma model with nonreciprocal hopping.We successfully obtain the mobility edges and Lyapunov exponents in their mosaic models.This general mapping may catalyze further studies on mobility edges,Lyapunov exponents,and other significant quantities pertaining to localization in non-Hermitian mosaic models. 展开更多
关键词 non-Hermitian mosaic model mosaic-to-non-mosaic mapping mobility edge Lyapunov exponent
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