Bilateral Malignant Ovarian Teratoma With Peritoneal Metastasis in a Captive African Pygmy Hedgehog (Atelerix albiventris)

A 675-g, 1.4-year-old, female African pygmy hedgehog (Atelerix albiventris) was evaluated for progressive abdominal distension of 2 months duration. A large mass within the abdominal cavity was detected by radiography, ultrasonography, and computed tomography. The irregular, multilobulated mass, containing calcified, necrotic, and fatty areas was consistent with fused bilateral ovaries. Cytology of the mass suggested an ovarian adenoma or adenocarcinoma. The hedgehog died approximately 3 months after the initial presentation. Postmortem computed tomography and necropsy examination revealed a large bilaterally fused ovarian mass with peritoneal metastases. Histologically, the masses were composed of a variety of tissues from all 3 germ layers, including immature (embryonic) cells and neoplastic cells in the lymphatic system, which was consistent with malignant ovarian teratomas. This is the first report to describe malignant ovarian teratomas in a hedgehog.     

A feasible method for humane slaughter of eel (Anguilla anguilla L.): electrical stunning in fresh water prior to gutting

It was observed that farmed eels could be rendered unconscious and insensible instantaneously by passing an electrical current through fresh water. The general epileptiform insult on the EEG was characterized by a tonic/clonic and an exhaustion phase. After stunning, the ECG (electro‐cardiogram) revealed fibrillation. The electrical stunning parameters were on average 194 ± 4 V and 0.636 ± 0.040 A/dm² for 1.6 ± 0.4 s. Within a confidence level of 95%%, taking into account the number of animals with a reliable EEG (n = 29), at least 93% of all eels are effectively stunned in fresh water by an average current of 0.636 ± 0.040 A/dm². The behaviour of groups of five eels, which were able to move freely in the water was observed before and after stunning with 50 V and 0.17 A/dm². After 3‐s stunning, two eels were turned upside down. They changed to a normal position after 10 and 13 s respectively. Subsequently, all eels were very active in swimming behaviour and stopped swimming after 75 s. When stunned for a longer duration, all eels were turned upside down and stopped breathing for a limited period of time. In the last experiment the eels were stunned in fresh water (500 μS) with a voltage of 200 V for approximately 1 s, which was followed by 50 V for 5 min. As soon as the stunning started the water was de‐oxygenated by flushing nitrogen to kill the eels by suffocation during the period of unconsciousness and insensitivity. The oxygen saturation decreased from 74 ± 10 to 23 ± 11% at 22 °C. After stunning no brain activity and no responses to pain stimuli were observed on the EEG. The heart rate increased (P < 0.05) after stunning, which was followed by a significant decrease. Only 1 out of 18 eels returned partially from upside down to a normal position 2 h after stunning; however, the eel did not respond to pain stimuli in behaviour. The developed stunning procedure can be recommended for humane slaughter of 50‐kg batches of eels.     

中华蟾蜍胚后嗅球神经元自发电活动的发育变化

[目的]探讨中华蟾蜍(Bufo bufo gargarizans)胚后嗅球神经元自发电活的电生理学特性的发育变化。[方法]应用微电极电生理技术,对中华蟾蜍胚后嗅球神经元的自发放电活动进行在体胞外记录。[结果]随着嗅球的发育,其神经元的放电形式逐渐增多,单个放电振幅逐渐增大,且在变态期达最大;连续放电振幅在胚后发育的中期变化不大,但高于发育的早期和成体期;连续簇状放电频率随着发育时期而降低,但在成体期再次升高,而连续单个放电频率只在成体期增大。[结论]随着嗅球的发育,神经元的兴奋性逐步提高,神经元电活动形式逐渐呈现多样化。     

机电设备安装工程造价的有效控制与管理措施分析探讨

文章通过对建筑工程造价的分析,介绍了机电工程安装的特点,并分析了影响机电设备安装工程造价的因素,总结出相对的控制方法和管理措施。     

生物质燃气冷热电联供系统性能分析

为提高能源的利用效率,缓解传统能源短缺及其利用过程中带来的环境问题,设计了一种以内燃机为驱动装置的生物质燃气冷热电联供系统,对其能量流程进行了分析,并以北京市某面积为10 000 m2的宾馆为例,对该系统在热跟随和电跟随两种运行模式下的设备选型、燃料消耗量和补电量以及能效、经济和排放性能进行了分析比较。通过比较可知,联供系统在电跟随模式下比在热跟随模式下的一次能源利用率高4.3%,缩短投资回收期1.4年,但少减排254.9 t CO2。因此,该生物质气冷热电联供系统在热跟随模式下的环境效益较好,在电跟随模式下的能源效益和经济效益更佳。     

基于电磁感应的典型干旱区土壤盐分空间异质性

为研究干旱区土壤盐分空间异质性,指导农业生产实践,运用大地电导率仪（EM38、EM31）对研究区域进行移动式磁感调查,获取表观电导率（ECa）。同时,通过27个校准点的采样和ECa测量,建立土壤盐分的电磁感应解译模型。干旱区土壤盐分质量分数与EM38、EM31水平模式读数（H38、H31）显示出良好的相关性（R=0.935）,可以利用ECa结合GIS和地统计学知识研究土壤盐分的空间分布。采用两种方法进行研究：一种是先利用解译模型获取磁感调查点的土壤盐分质量分数,然后进行地统计分析研究其空间分布;另一种是先利用地统计分析研究H38和H31的空间分布,然后利用解译模型通过栅格运算计算盐分质量分数,精度检验显示前者预测值与实测值之间的相关性更好（R2, 0.888＞0.873）;标准差较低（std. 0.414＜0.426）,具有更高的预测精度。研究结果表明,基于电磁感应研究干旱区土壤盐分空间异质性是切实可行的,这对于土壤盐渍化的快速诊断,指导农业生产和促进精准农业的发展具有重要的意义。     

电工电子技术课程在设施农业与科学专业教学改革中的实践

分析了设施农业与科学专业学生的学习特点,结合本专业情况对如何提高教学质量提出了教学内容重组、改革教学手段、采取多种教学形式、重视能力的测试、提高教师自身素质等进行教学的思路。     

电力工程管理中的安全问题

一些电力施工现场存在事故隐患,不能及时发现和消除,导致发生人员伤亡、电网破坏和设备损失的安全事故。下面就如何搞好电力工程施工安全管理提出对策意见。     

建筑电气现场施工问题与应对措施探讨

建筑电气现场施工是建筑工程项目重要的环节,关系到整个工程的质量。由于电气安装等问题引发的灾难和事故不在少数,对电气施工问题的处理方式影响着整个建筑工程。由此可见,加强对建筑电气现场施工环节的控制是非常重要的。文章主要就建筑电气现场施工问题及应对措施进行了探讨。     

基于ERT技术反演红壤剖面水分入渗过程

水分运动是土壤中物质和能量传输的主要驱动力，但是水分在土壤中的运动轨迹复杂多变，难以直接捕捉。本研究以第四纪红黏土发育的红壤为研究对象，借助电阻率成像技术（ERT），反演水分在林地和农地土壤中的入渗过程。研究发现，ERT技术能够实现水分在红壤包气带入渗过程的可视化，ERT测定的表观电阻率的变化量与烘干法测定的土壤水分之间呈极显著正相关关系（P<0.01），林地的决定系数为0.72，农地为0.53。土地利用类型影响水分入渗的范围和方式，在2 cm水头高度注水100 L的情况下，林地的入渗深度大于80 cm，而农地约为50 cm，在此基础上，继续注水200 min，林地和农地均出现明显的优先流现象。但是，林地的优先流比农地更为发育，林地是通过根系等大孔隙快速向下传输，而农地则以“指流”的方式，间断性向深层运动。在土壤层次复杂、背景含水量高、土壤黏重等不利因素的影响下，ERT技术依然能捕捉优先流在红壤中发生和发育的过程。