主流媒体短视频传播中的国家形象建构研究——以中国网短视频节目《中国三分钟(China Mosaic)》为例

以中国网账号发布在境外社交媒体平台Facebook上的节目《中国三分钟(China Mosaic)》为例,使用Python工具软件抓取得到评论数据样本,能很好地分析海外受众对主题类型的关注偏向和态度取向。从整体上看,海外受众对我国国家形象呈现出积极认可的态度,主要表现为:高度肯定我国的经济实力和科教发展成果,赞许我大国外交所起到的作用和经济建设成就,向往中华优秀传统文化等。但由于意识形态、东西方认知的差异,在海外受众的评论中也存在一些杂音,需要我们理性对待、主动消弭。在对外传播中,要用海外受众乐于接受的话语表达方式、共通的符号,从大处着眼、小处入手讲述中国故事,掌握议题设置的主动权,传播好中国声音。

MOSAiC现场观测期间海冰厚度季节变化模拟误差分析

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。

Development of a stable attenuated double-mutant of tobacco mosaic virus for cross-protection

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.

Floristic Diversity, Stand Structure and Plant Life Traits in the Forest-Savanna Mosaic at Ndjole (Centre Cameroon)

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 m2) 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.

CRISPR/CasRx-mediated resistance to Soybean mosaic virus in soybean

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.

Turnip mosaic virus pathogenesis and host resistance mechanisms in Brassica

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.

Reactions of Maruca Resistant Transgenic Cowpea to Cowpea Aphid-Borne Mosaic Virus

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.

Clinical manifestations and the prenatal diagnosis of trisomy 7 mosaicism:Two case reports

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.

建筑机械加工轴承表面缺陷光学识别模型

建筑机械加工轴承表面缺陷识别技术的表面缺陷识别效果不佳,影响工业生产的安全性。为了解决这一问题,提出建筑机械加工轴承表面缺陷光学识别模型构建方法。获取多角度机械加工轴承表面图像,将建筑机械加工轴承表面展开,再进行二维图像拼接,获得建筑机械加工轴承表面没有重复且完整的二维图像;通过局部与全部相结合的平滑策略构建光流误差轨迹模型,在光流求解策略的基础上,构建建筑机械加工轴承表面缺陷光学识别模型,计算建筑机械加工轴承表面二维图像的光流值,根据计算结果对建筑机械加工轴承表面缺陷情况进行判定,实现建筑机械加工轴承表面缺陷的识别。实验结果表明,所提方法的轴承表面缺陷识别率高、识别用时明显提升。

空气源热泵毛细管地板辐射供暖系统实验研究

空气源热泵毛细管地板辐射供暖系统以制冷剂为热工质直接加热地板,具有系统简单、传热效果好的优点。搭建了空气源热泵毛细管地板辐射供暖实验装置,在不同室外环境温度下对平行布置的毛细管地板辐射末端进行供暖实验研究。实验结果表明:室外温度越低,毛细管地板辐射末端温度稳定所需时间越长,当室外温度为-5℃时,稳定时间为120 min;同一根毛细管壁面上排气入口端与凝液出口端温差较大,可达到6.40℃,2 cm厚水泥地板表面温差可达4.20℃;从毛细管壁至水泥地板表面竖向温差较小,不超过0.40℃,地板竖向传热效果良好;不同毛细管的同一位置处温差在0.80℃以内,温度均匀性良好;室外温度为-5℃时,机组稳定运行制热COP可达4.61,性能良好。

女性盆底功能障碍患者对生殖道激光微创治疗的认知现状与治疗决策意向的关系

目的调查女性盆底功能障碍患者对生殖道激光微创治疗的认知,并分析其决策意向的影响因素,为盆底功能障碍患者的早期治疗及生殖健康管理的持续发展提供依据。方法采用便利抽样,选取2023年6月至2024年8月在东莞市妇幼保健院盆底康复中心就诊的164例女性盆底功能障碍患者,采用女性性功能指数量表、尿失禁生活质量问卷及家庭支持自评量表进行调查,应用二元logistic逐步回归分析患者进行生殖道激光微创治疗的影响因素。结果164例女性患者中共143例(87.2%)有治疗意向,对生殖道激光微创治疗相对了解者占22.6%。logistic回归分析显示,不同职业对患者治疗意向有影响(P<0.05),与医务人员相比,从事教师(OR=10.81,95%CI:1.04~112.21)、个体户(OR=20.34,95%CI:3.46~119.43)及其他职业(OR=16.26,95%CI:4.05~65.29)的患者治疗意向更高;低尿失禁生活质量得分是患者治疗意向的促进因素(OR=0.96,95%CI:0.93~0.99)。结论盆底功能障碍患者对于接受生殖道激光微创治疗的意向较高,但对该治疗技术的整体认知不足。

生物反馈电刺激联合阴道哑铃凯格尔训练在产后盆底肌功能障碍患者盆底肌力康复中的应用

目的:探讨生物反馈电刺激联合阴道哑铃凯格尔训练在产后盆底肌功能障碍(PFD)患者盆底肌力康复中的应用效果。方法:选取70例PFD患者进行前瞻性研究,通过Excel生成随机数字将其分为对照组(n=34)和联合组(n=36)。对照组接受阴道哑铃凯格尔训练,联合组在对照组基础上增加生物反馈电刺激治疗,均持续治疗3个月。采用会阴肌力测试法(GRRUG)检测两组患者治疗后的盆底肌力,采用低频神经肌肉刺激治疗仪检测并对比两组患者盆底肌纤维肌电位均值及疲劳值的改善情况,采用女性性功能量表(FSFI)评定两组患者的性生活质量,同时记录并比较两组盆底功能受损情况。结果:治疗后,联合组患者Ⅰ类、Ⅱ类肌纤维Ⅲ级以上肌力占比均高于对照组(P<0.05);联合组Ⅰ类、Ⅱ类肌纤维盆底肌电均值高于对照组(P<0.05),盆底肌疲劳值低于对照组(P<0.05);联合组FSFI评分中性欲望、性唤起、阴道润滑度、性高潮、满意度、性交痛及总分高于对照组(P<0.05);联合组尿频尿急、腰骶酸痛、阴道松弛发生率低于对照组(P<0.05)。结论:生物反馈电刺激联合阴道哑铃凯格尔训练治疗产后PFD能显著提高盆底肌纤维肌力,改善尿频尿急、腰骶酸痛、阴道松弛等症状,提高患者性生活质量。

基于敏捷卫星平台的星载SAR Mosaic模式研究

Mosaic模式是聚束和ScanSAR的混合模式,能同时实现高分辨率、大场景成像。提出了一种易实现的Mosaic模式,它的距离向波束切换通过电扫描完成,方位向波束扫描通过机械扫描实现。敏捷卫星能通过控制俯仰机动,方便地实现方位向机械扫描,适于实施这种Mosaic模式。针对这种Mosaic模式的特点,提出了一种新的系统设计方法。该方法从零斜视角位置开始,递推求解一系列关于Burst斜视角和驻留时间的非线性方程组,得到系统参数和时间分配方案。此外,还提出了一种基于等效展宽天线方向图的Mosaic模式性能参数近似计算方法,它能直观、便利地得到Mosaic模式各种性能参数。

基于改进Mosaic数据增强和特征融合的Logo检测

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。

Mosaic方法在非均匀下垫面上的适用性研究

在非均匀下垫面情况下,Mosaic方法是目前国际上广泛运用于模式中计算地表通量的方法。大量的研究表明,下垫面的非均匀分布会引发局地环流,非均匀分布的空间尺度较大时,所引起的环流甚至可以达到海陆风的强度。这种环流的存在直接影响到次网格地表通量的计算。次网格地表非均匀分布,尤其是大尺度模式中的次网格非均匀分布,必将影响地表通量的计算。本文针对次网格地表非均匀问题,设计了高分辨率的Mosaic试验和非均匀试验,开展了不同背景风情况下的一系列数值试验,以探讨这种影响的程度。结果表明,在土壤湿度空间分布不均匀的情况下,运用Mosaic方法计算得到的地表潜热通量偏小,背景风较小的时候偏差较大,背景风增强时偏差减小。

Virus Movement Protein Gene Mediated Resistance Against Cucumber Mosaic Virus Infection

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.

电刺激联合盆底肌肉训练辅以心理干预疗法对机器人辅助根治性前列腺切除术后患者尿失禁的影响

目的:探讨电刺激联合盆底肌肉训练辅以心理干预疗法对机器人辅助根治性前列腺切除术(RARP)后尿失禁患者的影响。方法:选取2020年7月—2021年12月南京医科大学第一附属医院收治的100例RARP后尿失禁患者作为研究对象,随机将其分为对照组和试验组,每组50例。对照组进行电刺激联合盆底肌肉训练,试验组在此基础上增加心理干预疗法,治疗时间均为两个月。使用国际尿失禁咨询委员会尿失禁问卷简表(ICIQ-UISF)、愈显率、1h尿垫试验、尿失禁生活质量问卷(I-QOL)、焦虑自评量表(SAS)和抑郁自评量表(SDS)评估两组的治疗效果。结果:与治疗前相比,治疗后两组患者的ICIQ-UI SF评分下降、1 h漏尿量减少、I-QOL评分升高、SAS评分和SDS评分均下降(P<0.001)。治疗后,试验组的ICIQ-UI SF评分、1 h漏尿量、I-QOL评分、SAS评分和SDS评分均优于对照组(P<0.001),且尿失禁的愈显率高于对照组(P<0.05)。结论:电刺激联合盆底肌肉训练辅以心理干预疗法能有效缓解RARP后患者的尿失禁,提高其生活质量和心理健康程度。

Molecular Tagging of a New Resistance Gene to Maize Dwarf Mosaic Virus Using Microsatellite Markers

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.

冲击荷载作用下井字梁楼盖的减振加固试验研究

针对大型动力设备运行时引起某工业厂房井字梁楼盖竖向振动的超限问题,采用增大刚度法(增加板厚和井字梁高度),通过缩尺模型试验研究了冲击荷载作用下井字梁楼盖结构的减振效果,推导出了局部井字梁楼盖结构的缩尺模型与原型结构物理量之间的相似关系,获得了试件的自振频率、动力响应等参数,并将试验结果与ABAQUS有限元模拟结果进行了对比分析。结果表明:适当增加板厚和井字梁高度均能有效降低井字梁楼盖的竖向振动加速度;相比于增加板厚的加固方法,增加井字梁高度的减振效果更佳;缩尺模型试件的实测与模拟竖向振动加速度的变化趋势基本一致,验证了缩尺模型与原型结构物理量之间相似关系的准确性和缩尺模型的有效性。

Agroinoculation as a Simple Way to Deliver a Tobacco Mosaic Virus- Based Expression Vector

烟草花叶病毒(TMV)表达载体30B是一个目前广泛应用的植物病毒表达载体,但用其生产外源蛋白时,必须先将它体外转录成RNA,才能被用来接种宿主植物。由于RNA体外转录费用昂贵、操作复杂,因此限制了30B表达载体的进一步应用。针对这一不足,我们用农杆菌接种法(agroinoculation)接种该病毒载体,即将30B cDNA置于花椰菜花叶病毒(CaMV)的35S启动子和终止子之间,再将整个表达框架插入到农杆菌T-DNA的左边界和右边界之内,构建成质粒p35S-30B,将转入该质粒的农杆菌注射到植物的叶片中,30B cDNA随T-DNA进入植物细胞后,被转录成可自我复制的RNA形式,进而发生系统侵染。为了检测此接种方式的可行性,绿色荧光蛋白(GFP)报告基因被克隆到p35S-30B中,构建成p35S-30B∶∶GFP,用含有该质粒的农杆菌进行注射操作。证实该病毒载体可通过简便的农杆菌接种法侵染Nicotiana benthamiana,在被接种植物的系统叶中,GFP的表达量可占植物总可溶蛋白的5.2％。