基于体感交互的仿上肢采摘机器人系统设计与仿真

为提高农业自动化程度,保持农业机械化水平,提高农业生产效率,该文设计了一种基于仿生学,能够实时模仿人类上肢采摘行为的果实采摘机器人系统。该文首先分析了当操作者的采摘动作发生时,系统利用深度相机Kinect采集人体关节骨架信息,通过空间向量计算,计算出关节的位置偏移量和骨骼转动角度等信息,利用这些特征构建人体三维骨架模型;其次分析了人体上肢的生理学结构和自由度,依据仿生学的特点建立了人体上肢五自由度运动学模型。系统将识别到的动作指令发送到动作执行模块,带动机械臂的转动。最后,为了验证模型的有效性,进行了机器人动作模仿仿真试验,统计了系统对动作的识别率。分析结果表明,系统对采摘动作的平均识别率为90%以上,从而验证了原理设计的有效性。该系统设计可为五自由度机械臂模型的开发和控制提供参考。     

马骨硷性磷酸酶的提纯和性质的研究

用正丁醇抽提、DEAE纤维素(DE—52)和Con.A—Sepharose 4B柱层析等方法从马骨中分离提取硷性磷酸酶(ALP)同工酶。提纯倍数为24倍。从DE—52柱层析中得到两个有部分交叠的酶活性峰。经等电聚焦电泳鉴别其pI值分别为4.22(酶峰Ⅰ)和4.18(酶峰Ⅱ)。两酶峰的热稳定性较差,于56℃作用10min,活性降低60％以上。作用于磷酸苯二钠的km值分别为25mM(酶峰Ⅰ)和6.67mM(酶峰Ⅱ)。尿素对酶活性的影响随着浓度的增高而加强,3M尿素对酶峰Ⅰ抑制达86％,对酶峰Ⅱ达71％。一定浓度的Mg~(2+)对酶有显著激活作用。Zn~(2+),Ca~(2+)激活不明显,高浓度时却有抑制作用。两峰对Ca~(2+)浓度变化有明显的不同反应。EDTA对酶抑制作用显著,Zn~(2+)、Ca~(2+)在一定浓度下对此抑制有轻度逆转作用。上述结果表明,马骨ALP至少有两种同工酶成分。它们不同的等电点、热稳定性差及对尿素敏感等特性,为临床检测马血清中的骨ALP提供了实验依据。     

Inhibitory effects of septin 2 gene silencing induced by siRNA on migration of human colorectal cancer cell line LoVo

AIM:To investigate the expression of septin 2 in human colorectal cancer cell lines and the effect of septin 2 on the capacity of migration of human colorectal cancer cell line LoVo. METHODS:Real-time fluorescence quantitative RT-PCR and Western blotting analysis were used to determine the mRNA and protein levels of septin 2 in different metastatic potential cell lines, respectively. The expression of septin 2 in LoVo cells was silenced by siRNA. The efficacy of siRNA was confirmed by real-time fluorescence quantitative RT-PCR. Septin 2 and its co-localization with F-actin were measured by immunofluorescence method. The migration of transfected cells was analyzed by scratch test. RESULTS:The expression of septin 2 in LoVo cells was significantly higher than that in low metastatic potential cell lines such as SW480, HCT-116 and HT-29 at both mRNA and protein levels. The mRNA expression of septin 2was successfully silenced in LoVo cells by siRNA. Cell wound closure rate was also decreased in septin 2 siRNA group as compared with control group(both P<0.05). The co-expression of septin 2 and F-actin formed the typical filamentous-granular organization, and down-regulation of septin 2 resulted in cell skeleton disturbance with less or shorter pseudopodium and decreased stress fibers. CONCLUSION:Septin 2 is highly expressed in LoVo cells. Partial deletion of septin 2 represses the capability of tumor cell migration.     

RADIOLOGIC ABNORMALITIES OF THE APPENDICULAR SKELETON OF THE LION (PANTHERA LEO): INCIDENTAL FINDINGS AND MYCOBACTERIUM BOVIS-INDUCED CHANGES

Thoracic and pelvic limbs from 15 euthanized free-ranging lions (Panthera leo), ranging in age from 16 to 144 months, underwent standard radiographic evaluation. All lions had tested positive for Mycobacterium bovis by means of a modified intradermal tuberculn test. The radiographs of six lions were normal and nine had incidental findings of which six had more than one lesion. Seven lions had lesions suspected to be associated with tuberculosis, which was confirmed in specific joints in two lions. Incidental pathology was classified as traumatic injuries and degenerative or trauma-associated joint disease. The traumatic lesions were fractures of which the most remarkable was a femur malunion. Four lions had fibula and another three lions had metacarpal/tarsal and phalangeal fractures. Joint lesions included glenoid, humeral head, and accessory carpal bone osteophytes. There was evidence of a cranial cruciate ligament rupture in an 8-year-old male. Trauma induced joint lesions were seen in four stifles (fragmented or displaced sesamoid bones, fragmented meniscal ossicle, or mineralized fragments). Radiological abnormalities believed to be caused by M. bovis were present in one stifle, one radiocarpal three tibiotarsal, and one tarsometatarsal joints. These had evidence of septic arthritis with extensive bone formation and capsular mineralization. In one 20-month-old lion, changes typical of a bone abscess were found in a proximal tibia. Radiologic evidence of elbow hygromas were seen in three elbows, all believed to be caused by M. bovis. Lions appeared to cope fairly well with a variety of traumatic injuries and were also susceptible to some of the aging/incidental radiologic findings seen in dogs and cats. The suspected M. bovis osseous lesions were more likely to involve the joints, particularly the tarsal joint and were mainly proliferative.     

北极狐骨骼的比较解剖研究

对北极狐骨骼系统进行解训观察,同时与革食动物马、牛及杂食动物猪的骨骼作形态学上的比较。由于生活习性所致,北极狐骨骼形态结构具有如下特征:北极狐的骨骼由头骨、躯干骨和四肢骨组成。头骨的主要特征是:枕骨的颈交不发达,眶上突不与颧弓相连,无眶上孔;颞骨岩部形成半球形鼓泡,鼻骨与颌前骨的鼻突之间不形成鼻颌切迹;泪骨几乎无颜面部;颌前骨的鼻突发达;上颌骨外面无面嵴;腭骨发达;犁骨腹缘后部不与鼻腔底壁接触;下颌骨支下缘无血管切迹、垂直部后下方有一角突。四肢骨的主要特征是:肩胛岗下端形成肩峰;臂骨未见三角肌结节和圆肌结节;尺骨比桡骨细长;腕骨7块;掌骨5块;指骨5指;左右髋骨几乎平行排列,坐骨弓宽平,荐结节高出荐骨;股骨有发达的大转子和较发达的小转子,缺第三转子;腓骨与胫骨等长;跗骨7块;躯干骨由7个颈椎、13个胸椎、7个腰椎、3个荐椎、15—17个尾椎组成;肋骨13对;胸骨由8个长柱状的胸骨节片和剑状软骨构成。     

Osteosarcoma in the proximal humerus of a mare

A 15‐year‐old Quarter Horse mare was examined for significant and progressive lameness in the right front limb. On physical examination, muscle atrophy over the scapular and pectoral regions were noted. A pain response was elicited on palpation of the scapulohumeral joint. No other abnormalities were noted on examination of the limb. Diagnostic nerve blocks ruled out a source of lameness in the distal limb. Arthrocentesis of the scapulohumeral joint was performed and results were within normal limits. Radiographs of the right scapulohumeral joint revealed an extensive, aggressive bone lesion in the proximal humerus, suspected to be an osteosarcoma. After a course of nonsteroidal anti‐inflammatory therapy, minimal improvement to the lameness was noted. The owner elected to subject the horse to euthanasia due to the lack of significant response to treatment. Post mortem radiographic and histological examinations determined a definitive diagnosis of an osteosarcoma in the proximal humerus.     

牙鲆骨骼生长性状与微卫星标记的相关性分析

利用106对牙鲆微卫星标记,对62尾双单倍体牙鲆的基因组DNA进行检测;用X射线检测仪对其骨骼进行成像,以骨骼图片测量体高和体长;用SPSS 13.0软件对双单倍体牙鲆的体质量、体长、体高进行相关分析和回归分析;用最小二乘法对微卫星标记与体质量、体长、体高作相关性分析。结果获得17个与体质量、体长、体高显著相关的标记,其中,Poli162TUF与体质量、体长、体高显著相关(P0.05);Poli72HFSM、Poli106TUF与体质量、体高显著相关(P0.05);Poli2023TUF、Poli1013TUF与体长、体高显著相关(P0.05);Po-li2042TUF、Poli1980TUF、Poli2045TUF、Poli2039TUF、Poli34TUF、PoGT17、HLJYP45、HLJYP81与体长显著相关(P0.05);Poli102TUF、Poli136TUF、Poli62MHFS、6-G3与体高显著相关(P0.05)。这些标记反映了牙鲆的生长优势性状,可作为辅助育种的参考标记。     

施氏鲟仔稚幼鱼骨骼系统发育观察

为深入了解鲟形目鱼类骨骼生长发育过程,探究现存唯一的软骨硬鳞鱼骨骼适应性进化,采用软骨-硬骨双染色技术,对施氏鲟Acipenser schrenckii Brandt仔稚幼鱼的骨骼系统进行连续观察,总结出相应骨骼的生长发育规律及骨化时间.结果表明:施氏鲟初孵仔鱼观察不到明显的骨元件分化;仔鱼期的骨骼元件主要集中在头部,...     

Determination of sampling volumes needed for representative analysis of alpine soils

Alpine soils are characterized by a high variability of chemical and physical parameters. The spatial inhomogeneity of a specific parcel must be regarded as a nuisance factor for representative soil sampling. The only way to reduce the effect of the variation between the samples is to combine several samples taken within an area of a few square meters. The presented approach shows how much soil material has to be taken in order to obtain representative values of soil properties such as soil density, the proportion of soil skeleton and fine earth, organic C, N, and the root content. Bulk density can be determined with an error ≤ 10% by sampling c. 6300 cm³ of soil within an area of 6 × 4.5 m for 0—20 cm sampling depth. With the same volume, the accuracy of soil skeleton measurement is ≤ 20%. In our case study, the determination of organic C in the fine earth of the whole soil profile needs a sample volume of 15,800 cm³ in order to reduce the error tolerance below ± 10%. In 0—20 cm soil depth, the error tolerance of ± 10% is achieved with c. 4000 cm³ for N and c. 6300 cm³ for organic C. Nearly 16,000 cm³ were needed to determine the soil root mass in the top 20 cm of a soil with an accuracy of ± 10%. In order to yield reasonable results, large sampling volumes are needed for soils in alpine areas. These volumes depend on the parameters to be investigated. Our investigation makes an initial attempt at optimizing the sampling strategy within an area of a few square meters in order to overcome this nuisance factor variation.     

基于YOLOv5m和CBAM-CPN的单分蘖水稻植株表型参数提取

为快速获取单分蘖水稻植株的形态结构和表型参数,该研究提出了一种基于目标检测和关键点检测模型相结合的骨架提取和表型参数获取方法。该方法基于目标检测模型生成穗、茎秆、叶片的边界框和类别,将所得数据分别输入到关键点检测模型检测各部位关键点,按照语义信息依次连接关键点形成植株骨架,依据关键点坐标计算穗长度、茎秆长度、叶片长度、叶片-茎秆夹角4种表型参数。首先,构建单分蘖水稻的关键点检测和目标检测数据集;其次,训练Faster R-CNN、YOLOv3、YOLOv5s、YOLOv5m目标检测模型,经过对比,YOLOv5m的检测效果最好,平均精度均值（mean average precision,mAP）达到91.17%;然后,应用人体姿态估计的级联金字塔网络（cascaded pyramid network,CPN）提取植株骨架,并引入注意力机制CBAM（convolutional block attention module）进行改进,与沙漏网络（hourglass networks,HN）、堆叠沙漏网络模型（stacked hourglass networks,SHN）和CPN模型相比,CBAM-CPN模型的预测准确率分别提高了9.68、8.83和0.5个百分点,达到94.75%,4种表型参数的均方根误差分别为1.06、0.81、1.25 cm和2.94°。最后,结合YOLOv5m和CBAM-CPN进行预测,4种表型参数的均方根误差分别为1.48 、1.05 、1.74 cm和2.39°,与SHN模型相比,误差分别减小1.65、3.43、2.65 cm和4.75°,生成的骨架基本能够拟合单分蘖水稻植株的形态结构。所提方法可以提高单分蘖水稻植株的关键点检测准确率,更准确地获取植株骨架和表型参数,有助于加快水稻的育种和改良。