13个药用石斛种质生物学特性比较研究

旨在减少药用石斛产业化发展中对野生中药材资源的依赖,筛选适合人工栽培的优良种质,实现中药产业持续发展与生态环境保护相协调。以湖北英山引种收集的13个药用石斛原生种质为试材,采用物候期观测、茎叶形态和花形态等生物学特性观测方法,同时进行生长适应性比较。结果表明：不同药用石斛种质的物候期不同,花期最早在3月底,多数集中在4—5月,最晚可到7—8月。不同种质间茎叶形态和花形态存在显著差异,可分为高大型、普通型和小型3个类型。不同药用石斛种质的花瓣和唇瓣颜色主要在白色到黄绿色之间变化。花瓣质地以革质为主,少数为厚革质、纸质或膜质。‘霍山石斛’、‘铁皮石斛’、‘铜皮石斛’和‘罗河石斛’的生长适应性较好。湖北省英山县地理气候条件优越,适合大多数药用石斛的生长。物候期、茎叶形态和花形态是区分药用石斛种质类别的重要指标。‘霍山石斛’、‘铁皮石斛’、‘铜皮石斛’（江西种源）是可以在湖北省推广发展的优质种质。     

筇竹与黄皮树人工混交林中筇竹地上部分生物量模型构建

本研究以筇竹与黄皮树人工混交林中筇竹地上部分为研究对象,测定分析了1~4年生分株地上部分各构件生物量及含水率,建立人工筇竹分株地上部分各构件的生物量及总生物量模型,以期为人工筇竹林的经营管理及其碳汇项目的开发提供科学依据。结果表明：随着筇竹分株年龄的增加,各构件含水率和生物量均逐渐减少,筇竹1~4年生分株地上部分平均含水率分别为57.62%、53.40%、50.01%、42.66%,平均生物量分别为133.99、123.31、109.76、85.39 g/m²;各年龄分株地上部分生物量的分配均呈现出秆＞枝＞叶的变化规律。不同年龄分株的胸径与秆、枝、叶生物量及地上部分总生物量均有极显著相关性(P＜0.01)。以胸径为自变量建立的各年龄筇竹分株地上部分总生物量模型的决定系数(R²)均在0.93以上,具有较高的可信度,也有着较强的适用性,可用于类似立地条件下的筇竹分株生物量估测。     

盐胁迫对三种盐生禾草种子萌发及其胚生长的影响

采用不同浓度的NaCl、Na₂CO₃和二者混合盐的胁迫,对羊草、野大麦和朝鲜碱茅种子的发芽率、发芽速度、胚根和胚芽的影响以及盐胁迫解除后的发芽率、胚根和胚芽的生长进行测定与分析。结果表明,随着Na₂CO₃和混合盐溶液浓度的增加,羊草和野大麦种子的发芽率、发芽速度、胚根和胚芽的相对生长均呈下降趋势;而12.5mmol/LNaCl和37.5mmol/LNa⁺混合盐的低浓度胁迫对朝鲜碱茅种子的萌发、胚根和胚芽的生长有促进作用,但发芽速度则随着盐浓度的升高而降低;Na₂CO₃溶液对3种禾草胚根和胚芽的生长均有明显的抑制作用;3种盐分胁迫对羊草和朝鲜碱茅胚根生长的影响均大于胚芽生长;朝鲜碱茅种子萌发时的耐盐性强于野大麦和羊草;盐胁迫解除后,3种禾草的发芽率随原胁迫盐浓度的增加呈升高趋势。     

融合2D-3D卷积特征识别哺乳母猪姿态转换

母猪姿态转换影响仔猪存活率,且动作幅度与持续时间存在差异,准确识别难度大。该研究提出一种融合2D-3D卷积特征的卷积网络（2D+3D-CNet,2D+3D Convolutional Network）识别深度图像母猪姿态转换。以视频段为输入,引入注意力机制SE模块和3D空洞卷积,以提升3D卷积网络姿态转换的时空特征提取能力,用2D卷积提取母猪的空间特征;经特征融合后,动作识别分支输出母猪转换概率,姿态分类分支输出4类姿态概率,结合这两个输出结果识别8类姿态转换,减少了人工标注数据集的工作量;最后设计动作分数,优化母猪姿态转换的时间定位。在测试集上,2D+3D-CNet姿态转换识别精度为97.95%、召回率为91.67%、测试速度为14.39帧/s,精度、召回率和时间定位精度均高于YOWO、FRCNN-HMM和MOC-D方法。该研究结果实现了母猪姿态转换高精度识别。     

A typology of agricultural production systems: Capability building trajectories of three Asian economies

Analysing the agricultural sectors of Taiwan, Malaysia and Singapore, this paper examines the capability‐building process that encourages productivity and innovation. It describes and explains the origins and subsequent evolution of three forms of agricultural production system, each generating different farming capabilities and distinct forms of competitive advantages. The paper argues that Taiwan's rice‐oriented agricultural production system stimulates both productivity and innovation, helping Taiwanese farmers raise their income level and living standards. The active deployment of state institutions and a malleable labour force, evidenced in the Malaysian palm oil industry, is effective in raising farming productivity but not the ability to innovate. Singapore's aquaculture‐oriented agricultural production system is somewhat useful in stimulating productivity and innovation. Yet the city‐state's inherent lack of space and open international trade regime have circumscribed the potential of its aquaculture industry. It now relies on the regional ethnic Chinese business networks to expand the aquaculture industry's knowledge base and its industrial commons. The principles discussed in this paper provide policy lessons, or at least some initial guidance, for other developing economies aspiring to modernise their agricultural sector.     

Gene Expression in Black Tiger Prawns Following Intramuscular Injection of β-gal Plasmid

Gene expression in black tiger prawns (Penaeus monodon) was studied following intra-muscular injection of CMVGal plasmid into the second abdominal segment. We used an in situ staining technique to detect -gal expression in one- and three-month-old injected prawns. We found that only one of the three-month-old prawns expressed the marker gene (2 days after injection), and the site of expression was confined to the sixth abdominal segment away from the injection site. We repeated the experiment on a new batch of three-month-old prawns, but using fluorometric determination technique. This time we found that -gal expression was detected (6/42) at the site of injection after 2, 7, and 14 days. In two other test samples, transgene expression was detected in the sixth abdominal segment only, further confirming the possibility of injected DNA dispersal. The results of the study also suggest that direct gene transfer is a feasible technique in black tiger prawns.     

新生代员工企业文化内部整合感知对工作满意度的影响研究——基于汽车整车制造业的实证数据

企业文化内部整合两个特质“参与性”与“一致性”对于工作满意度存在积极影响。相比传统员工,新生代员工对于企业文化的内部整合感知对于工作满意度表现出更强的预测作用。管理者应注重新生代员工的参与性激励、团队凝聚力塑造,与其建立民主沟通模式。     

Pyruvate kinase is necessary for Brucella abortus full virulence in BALB/c mouse

Brucellosis, caused by a facultative intracellular pathogen Brucella, is one of the most prevalent zoonosis worldwide. Host infection relies on several uncanonical virulence factors. A recent research hotpot is the links between carbon metabolism and bacterial virulence. In this study, we found that a carbon metabolism-related pyruvate kinase (Pyk) encoded by pyk gene (locus tag BAB_RS24320) was associated with Brucella virulence. Determination of bacterial growth curves and resistance to environmental stress factors showed that Pyk plays an important role in B. abortus growth, especially under the conditions of nutrition deprivation, and resistance to oxidative stress. Additionally, cell infection assay showed that Pyk is necessary for B. abortus survival and evading fusion with lysosomes within RAW264.7 cells. Moreover, animal experiments exhibited that the Pyk deletion significantly reduced B. abortus virulence in a mouse infection model. Our results elucidated the role of the Pyk in B. abortus virulence and provided information for further investigation of Brucella virulence associated carbon metabolism.