基于高光谱图像的龙眼叶片叶绿素含量分布模型

针对传统高光谱单点法检测叶绿素含量效率低、精度不足等问题,提出一种基于高光谱图像和卷积神经网络(CNN)多特征融合的深度学习龙眼叶片叶绿素含量分布预测模型。首先进行Savitzky-Golay光谱去噪,然后通过奇异值分解(SVD)和独立成分分析(ICA)提取特征光谱,再对特征光谱图像提取灰度共生矩阵(GLCM)和CNN纹理特征,最后建立粒子群优化(PSO)支持向量回归(SVR)、深度神经网络(DNNs)分布模型。结果表明,基于特征光谱建模的PSO-SVR预测效果最佳,全期的校正集和验证集模型决定系数R2为0.822 0和0.815 2。对比多种主流模型,基于特征光谱、GLCM纹理、CNN纹理特征的ICA-DNNs模型预测精度最高,校正集和验证集R2分别为0.835 8和0.821 0。试验结果表明,高光谱图像可快速无损地对龙眼叶片叶绿素含量分布进行检测,可为龙眼树实时营养监测和病害早期防治提供理论依据。     

农村妇女营养健康水平形成机理实证研究——以河北涉县为例

为了解农村妇女营养健康水平形成机理,本研究依照随机抽样原则,对河北省涉县农村妇女进行随机抽样调查分析。通过对河北省涉县251份农村妇女调查问卷分析,运用AMOS16对农村妇女营养健康水平形成机理进行实证研究,结果表明:农村妇女的膳食营养、生活方式和饮食习惯正向影响其营养健康水平,而身体素质则产生负向影响;健康素养则通过生活方式、身体素质和饮食习惯对其营养健康水平产生间接的影响;卫生习惯对其营养健康水平没有直接的影响,而是通过膳食营养对其营养健康水平产生间接的影响。针对上述结论,本研究对政府提出了加强农村妇女营养健康危害因素分析、确定针对性的防治方案等政策性建议,希望通过采取相关措施进一步提升我国农村妇女健康水平,改善我国农村地区医疗卫生服务现状,加强农村地区重大疾病防控。     

Accuracy of open magnetic resonance imaging for guiding injection of the equine deep digital flexor tendon within the hoof

Lesions of the distal deep digital flexor tendon (DDFT) are frequently diagnosed using MRI in horses with foot pain. Intralesional injection of biologic therapeutics shows promise in tendon healing; however, accurate injection of distal deep digital flexor tendon lesions within the hoof is difficult. The aim of this experimental study was to evaluate accuracy of a technique for injection of the deep digital flexor tendon within the hoof using MRI‐guidance, which could be performed in standing patients. We hypothesized that injection of the distal deep digital flexor tendon within the hoof could be accurately guided using open low‐field MRI to target either the lateral or medial lobe at a specific location. Ten cadaver limbs were positioned in an open, low‐field MRI unit. Each distal deep digital flexor tendon lobe was assigned to have a proximal (adjacent to the proximal aspect of the navicular bursa) or distal (adjacent to the navicular bone) injection. A titanium needle was inserted into each tendon lobe, guided by T1‐weighted transverse images acquired simultaneously during injection. Colored dye was injected as a marker and postinjection MRI and gross sections were assessed. The success of injection as evaluated on gross section was 85% (70% proximal, 100% distal). The success of injection as evaluated by MRI was 65% (60% proximal, 70% distal). There was no significant difference between the success of injecting the medial versus lateral lobe. The major limitation of this study was the use of cadaver limbs with normal tendons. The authors conclude that injection of the distal deep digital flexor tendon within the hoof is possible using MRI guidance.     

Effect of cleaning status on accuracy and precision of oxygen flowmeters of various ages

Objective

To evaluate oxygen flowmeters for accuracy and precision, assess the effects of cleaning and assess conformity to the American Society for Testing Materials (ASTM) standards.

Clinical and computed tomography tumour dimension assessments for planning wide excision of injection site sarcomas in cats: how strong is the agreement?

In injection site sarcoma (ISS) in cats lateral as well as deep margins should be correctly planned for a successful surgical outcome. The discrepancy between clinical and computed tomography (CT) measurements of dimension in resectable tumour has led to possible bias that affects the subsequent surgical dose. The aim of this study was to prospectively investigate the agreement between clinical and CT measurements of dimension in newly diagnosed ISS in cats. Fifty‐three client‐owned cats that underwent both clinical and CT measurements of the length and width of ISS were included. CT measurements showed a tendency towards being larger than clinical dimensions, and this difference increased with increasing tumour size. Based on our results, in further studies focusing on ISS in cats, the kind of assessment used to define tumour dimensions (CT versus clinic) should be declared and specified to properly consider surgical results and prognostic impact of this variable.     

Detection of synchronous primary tumours and previously undetected metastases in 736 dogs with neoplasia undergoing CT scans for diagnostic,staging and/or radiation treatment planning purposes

The purpose of our study was to describe synchronous primary tumours and previously undetected metastases in 736 dogs with confirmed neoplasia in which computed tomography (CT) scans were performed for diagnostic, staging and/or radiation treatment planning purposes. All CTs were reviewed by a radiologist. Tumour‐associated CT abnormalities were detected in 38/736 (5%), including confirmed or suspected synchronous primary neoplasms (n = 24), metastases of the primary tumour (n = 9) or both (n = 3). In lymph nodes (LN) that were considered abnormal on CT scan and were aspirated, 23% contained metastasis, and 6% of ‘normal’ appearing LN that were aspirated contained metastasis. Thorough evaluation of CTs and routine aspiration of regional LN are critical because results affect recommendations to perform additional staging tests and treatment for the primary and secondary tumour(s).     

广西石灰岩特有珍稀药用植物类群的基本特征研究

报道广西石灰岩特有珍稀药用植物的环境背景和类群组成,重点分析了该植物类群的基本特征。由于岩溶地区特殊的自然环境,广西石灰岩特有珍稀药用植物达133种,隶属于53科81属,区系成分复杂多样,热带性质明显,古老和进化成分并存,单种属、寡种属多,喜钙植物及近新分类群所占比重较大。     

基于深度学习的农作物病害图像识别技术进展

农作物病害的无损检测和早期识别是精准农业和生态农业发展的关键。随着图像采集和图像处理技术的进步,高光谱成像等先进成像探测技术和基于深度学习的图像分析技术越来越多地应用于农作物病虫害的无损检测中。本文首先简单介绍了以深度学习为代表的图像识别技术的基本原理,然后系统地阐述了基于深度学习的先进成像技术和先进图像识别分析技术在农作物病害检测识别中的国内外研究现状,分析了其在农作物病害检测识别上存在的优缺点,如具有快速、准确率高等优点以及数据量过大处理不便等缺点,并进一步指出,利用高光谱成像和热红外成像与深度学习相结合,将成为今后研究农作物病虫害早期检测的主要发展方向。