肠道病毒71型感染C57BL/6小鼠模型的初步建立

以1日龄C57BL/6乳鼠作为试验对象,分别通过颅内和腹腔注射肠道病毒71型(EV71)福建株感染,观察记录小鼠体重和体征,定期采集小鼠大脑、小肠、肺、肌肉4种组织,分析病毒载量,通过HE染色和免疫组化观察各种组织病理变化。结果:2种感染途径的C57BL/6乳鼠均于不同时间出现竖毛、弓背和消瘦症状。经腹腔注射感染的乳鼠能在肌肉组织中检测到病毒RNA,经颅内注射感染的乳鼠可在肌肉和肺组织中检测到病毒RNA。病理学及免疫组化结果显示:EV71福建株在骨骼肌中大量增殖,并可导致肌肉组织水肿和坏死、肺组织水肿充血以及神经元坏死等多种组织器官炎症反应。综上,初步建立通过颅内和腹腔注射感染EV71的C57BL/6乳鼠模型,为研究EV71病毒感染机制、建立更优的动物模型提供参考。     

高分辨四极杆飞行时间质谱仪判别复原乳和超高温灭菌乳

采用高分辨四极杆飞行时间质谱仪,结合化学计量学方法,利用非靶向代谢组学方法,对超高温灭菌乳和复原乳进行检测。牛乳样品经过前处理后,经过C18色谱柱分离,采用FullScan模式进行一级全扫描,扫描结果通过数据预处理后,导入SIMCA-P14.1软件中进行主成分分析和偏最小二乘方差判别分析。结果表明:正、负离子模式下共找到14种判别超高温灭菌乳和复原乳的表征因子,进一步通过这14种表征因子建立区分2种乳的判别模型,通过该判别模型能够准确地区分超高温灭菌乳和复原乳,为复原乳的判别提供理论依据。     

糖尿病大鼠皮肤溃疡阴证模型

糖尿病足溃疡在糖尿病并发症中较为常见且具有高的致死率,引起国内外专家关注。随着研究的深入,中西医在临床中发现一类症状相似糖尿病足溃疡久治难愈,符合中医学的阴证疮面,故称糖尿病足溃疡阴证。要想对糖尿病足溃疡阴证的发病机制,病理特点和干预治疗等多方面有深入的了解,动物模型的建立为其提供可靠有效的途径。论文概括了前人对于糖尿病大鼠皮肤溃疡模型的进展,同时总结其阴证模型的优缺点和自己的经验与认识,以期对临床具有指导意义的糖尿病大鼠皮肤溃疡阴证模型。     

未来气候变化条件下青藏高原多年冻土区潜在植被类型面积预估

在青藏高原多年冻土区根据490个植被调查样点数据和3种遥感数据集的27个变量,利用决策树分类模型,模拟出4种代表性浓度路径情景下10个气候系统模式在2050年和2070年的青藏高原高寒草地类型(高寒沼泽草甸、高寒草甸、高寒草原、高寒荒漠和裸地)潜在分布结果。同时为保证数据分析的一致性,利用数据对当前高原草地类型也进行了反演。结果表明:相比当前高寒草地分布面积,预计在2050年和2070年裸地和高寒草甸面积微弱减少,高寒草原和高寒荒漠面积在微弱增加,高寒沼泽草甸面积变化不明显。结果在4种代表性浓度路径情景下的表现基本一致,研究不仅可以为高寒草地气候变化研究提供植被类型相关的数据支持,还可以为青藏高原多年冻土区碳循环的探讨提供部分的方法和理论依据。     

Ultra‐frequent HRAS p.Q61R somatic mutation in canine acanthomatous ameloblastoma reveals pathogenic similarities with human ameloblastoma

Ameloblastoma is a locally aggressive odontogenic tumour that occurs in humans and dogs. Most ameloblastomas (AM) in humans harbour mutually‐exclusive driving mutations in BRAF, HRAS, KRAS, NRAS or FGFR2 that activate MAPK signalling, and in SMO that activates Hedgehog signalling. The remarkable clinical and histological similarities between canine acanthomatous ameloblastoma (CAA) and AM suggest they may harbour similar driving mutations. In this study, aimed at characterizing the mutational status of SMO, BRAF, HRAS, KRAS, NRAS and FGFR2 in CAA, we used RNA sequencing, Sanger sequencing and restriction fragment length polymorphism assays to demonstrate that 94% of CAA (n = 16) harbour a somatic HRAS p.Q61R mutation. The similarities in MAPK‐activating mutational profiles between CAA and AM implicate conserved molecular mechanisms of tumorigenesis, thus, qualifying the dog as a potentially useful model of disease. Given the relevance of RAS mutations in the pathogenesis of odontogenic tumours and other types of cancer, the results of this study are of comparative, translational, and veterinary value.     

Validating a Time Series of Annual Grass Percent Cover in the Sagebrush Ecosystem

We mapped yearly (2000–2016) estimates of annual grass percent cover for much of the sagebrush ecosystem of the western United States using remotely sensed, climate, and geophysical data in regression-tree models. Annual grasses senesce and cure by early summer and then become beds of fine fuel that easily ignite and spread fire through rangeland systems. Our annual maps estimate the extent of these fuels and can serve as a tool to assist land managers and scientists in understanding the ecosystem’s response to weather variations, disturbances, and management. Validating the time series of annual maps is important for determining the usefulness of the data. To validate these maps, we compare Bureau of Land Management Assessment Inventory and Monitoring (AIM) data to mapped estimates and use a leave-one-out spatial assessment technique that is effective for validating maps that cover broad geographical extents. We hypothesize that the time series of annual maps exhibits high spatiotemporal variability because precipitation is highly variable in arid and semiarid environments where sagebrush is native, and invasive annual grasses respond to precipitation. The remotely sensed data that help drive our regression-tree model effectively measures annual grasses’ response to precipitation. The mean absolute error (MAE) rate varied depending on the validation data and technique used for comparison. The AIM plot data and our maps had substantial spatial incongruence, but despite this, the MAE rate for the assessment equaled 12.62%. The leave-one-out accuracy assessment had an MAE of 8.43%. We quantified bias, and bias was more substantial at higher percent cover. These annual maps can help management identify actions that may alleviate the current cycle of invasive grasses because it enables the assessment of the variability of annual grass ? percent cover distribution through space and time, as part of dynamic systems rather than static systems.     

兽医临床实例训练课程教学与考核模式的探索

兽医临床实例训练是安徽农业大学动物医学专业近几年新开设的一门实践课程。该课程以学校动物医院为实践平台,以提高学生的动手操作技能,增强临床实践能力,培养学生的临床思维能力和初步职业素质为目标,通过在教学过程中不断地实践和完善,探索出一套合理的、先进的教学与考核模式。该模式取得了明显的教学效果,为兽医临床实践教学改革提供了新思维和新方法。     

基于翻转课堂的项目式实验教学探索与实践——以《生物学综合实验》课程为例

项目驱动式教学方法注重培养学生自主学习能力及实践创新能力。翻转课堂能够利用网络资源将知识传授和知识内化合理安排以增加学生参与项目实践的时间和效率。生物学综合实验具有较强的实践性和操作性,文章在生物学综合实验教学中引入了基于翻转课堂的项目驱动式教学方法,探索和建立了以培养自主学习能力及实践创新能力为主导的教学模式,提升了学生实践能力,并有效提高了教学质量,取得了较好的教学效果。     

Bright artificial light at night is associated with increased body mass,poor reproductive success and compromised disease tolerance in Australian budgerigars (Melopsittacus undulatus)

Artificial light at night (ALAN) can cause circadian disruption and result in adverse behavioral and ecological effects in free‐living birds, but studies on captive pet birds as companion animals have been infrequent. We studied the effects of exposure to bright ALAN on body mass, melatonin sulfate levels, reproduction and disease severity in Australian budgerigars (Melopsittacus undulatus) kept in captivity. During the experiment, birds were kept under outdoor temperature, humidity and natural photoperiod from September to December. A total of 48 birds were equally split into 4 groups (6 mating pairs each) and concurrently exposed to ALAN of 200 lux with different duration (0, 30, 60 and 90 min). Monthly observations were recorded for all dependent parameters. ALAN exposure increased mass gain and suppressed melatonin levels in a dose‐dependent manner, especially during December. In addition, ALAN exposure in all duration groups decreased egg production and reduced hatchability from 61% ± 14% in the ALAN‐unexposed control group to 0% in the ALAN‐exposed birds. Disease severity was also found to increase in line with the duration of ALAN exposure. In captive M. undulatus, ALAN exposure was demonstrated to affect photoperiodic regulation with subsequent excess mass gain and reproduction impairment, and increased susceptibility to infections plausibly through duration dose‐dependent suppression of melatonin. To the best of our knowledge, this is the first study to demonstrate a possible association between acute bright ALAN of increasing duration and both natural development of infections as well as reproductive cessation in captive birds. Our findings could be used to improve breeding conditions of captive birds.     

A comparably high virulence strain of porcine reproductive and respiratory syndrome virus isolated in Taiwan

Porcine reproductive and respiratory syndrome virus (PRRSV) has been endemic in Taiwan since 1991. This study aimed to present a highly virulent PRRSV in Taiwan based on farm data collection and both in vitro and in vivo evaluations in virus challenge studies. This virulent PRRSV strain was first noticed on Farm TSYM due to continuously high nursery mortality rate and severe PRRSV-associated pneumonia. In phylogenetic surveillance, the PRRSV TSYM-strain remained in the predominant position for years, even with several other PRRSV strain invasions. In laboratory challenge trials, the TSYM-strain led to prolonged pyrexia, growth retardation, high mortality rates and high viremia titer that similar to the highly pathogenic PRRSV. The TSYM-strain isolate also triggered early interleukin-10 up-regulation and significantly higher infection rates under in vitro experiments. This study provides information of a comparably virulent strain in Taiwan and its appearance in both farm and laboratory levels.