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11.
A 4-mo-old northern red-shouldered macaw (Diopsittaca nobilis) was admitted to the veterinary hospital of the Arruda Câmara Zoo, in the State of Paraiba, Brazil, for investigation of an orbital mass. Given rapid progression and lack of response to treatment, the bird was euthanized, and an autopsy was performed. Histologically, the mass consisted of a retrobulbar invasive tumor characterized by tubular and rosette-like structures, with interspersed heteroplastic tissues, such as aggregates of neuroglial cells and islands of hyaline cartilage. The tumor was immunopositive for pancytokeratin, GFAP, NSE, and S100. These findings were compatible with an ocular teratoid medulloepithelioma, a neoplasm best described in humans but also reported rarely in young cockatiels and African Grey parrots.  相似文献   
12.
ObjectiveTo analyse avian anaesthesia-related mortality in a UK zoological collection over a 5-year period and identify risk factors for mortality.Study designRetrospective cohort study.AnimalsA total of 135 individual birds across 37 species, anaesthetized during 206 events in a UK zoological collection between 1 January 2014 and 30 June 2019 (inclusive).MethodsAnaesthesia records were reviewed and variables such as age, body condition, weight, sex, duration of anaesthesia and health status were collated. Anaesthesia-related mortality was defined as those deaths occurring during anaesthesia and up to 7 days postanaesthesia. Outcome was analysed using multivariable conditional logistic regression. Overall mortality was defined and included birds euthanised during anaesthesia for non-anaesthesia related reasons. Data were summarised as median (range). A value of p < 0.05 was considered significant. Relative risks and 95% confidence intervals (95% CI) were calculated for the association between risk factors and anaesthetic death where a statistically significant difference was found.ResultsThe overall mortality rate was 10.19% (95% CI = 6.06–14.3%), while anaesthesia-related mortality was 3.88% (95% CI = 1.69–7.51%). Birds with an abnormal health status had a 15.53-fold (95% CI = 1.95–123.63) increased risk of death compared with those with a normal health status. The duration of anaesthesia was also a statistically significant risk factor (p = 0.021) in the univariable analysis, but not when combined with health status. No other variables were associated with anaesthesia-related mortality.Conclusions and clinical relevanceAbnormal health status and longer anaesthetic procedures were associated with a significantly increased risk of anaesthesia-related death in this population of birds. It is recommended that anaesthetic duration is minimized, and pre-existing diseases are diagnosed where possible prior to general anaesthesia of birds. Anaesthetizing healthy birds was associated with a low risk of mortality.  相似文献   
13.
Primary ovarian tumors are generally uncommon in rats used in toxicologic studies. A malignant Sertoli cell tumor was present in the ovary of a 19-week-old female Sprague Dawley rat. Macroscopically, the mass was white and firm, 10 × 13 × 17 mm in size, and located in the right ovary. Histopathologically, the mass was composed of nests of pleomorphic cells, which formed seminiferous-like tubules separated by a thin fibrovascular stroma. The tubules were lined by tumor cells, which had basally located nuclei and abundant eosinophilic and vacuolated cytoplasm. In some areas, the tumor cells were arranged in a retiform growth pattern, mimicking a rete testis/ovarii. Disseminated metastases to the surfaces of the mesentery, spleen and liver were also present. Immunohistochemically, many tumor cells were strongly positive for vimentin, estrogen receptor α and Ki 67. Some tumor cells were positive for pancytokeratin and inhibin α. These findings closely resemble those of an ovarian-derived human malignant Sertoli cell tumor. From our review of the literature, we believe this is the first report of a spontaneous malignant Sertoli cell tumor in the ovary of a young laboratory rat. This case might provide useful historical control information for rat toxicity studies.  相似文献   
14.
以乌苏1号无芒雀麦为材料,设置2个生长环境(荒漠绿洲区、高海拔地带),通过观测幼穗分化进程及开花习性,探究生境对无芒雀麦幼穗分化及生殖格局的影响。结果表明,无芒雀麦幼穗分化从分蘖期开始至抽穗期结束,分为初生期、伸长期、结节期、小穗原基分化期、小花原基分化期、雌雄蕊原基分化期、雌雄蕊形成期和完穗期8个时期。幼穗分化是从生长锥顶端第1枝梗原基与小花原基开始分化,相同小枝梗上原基与小花原基均是自下逐渐向上发育;整穗是从顶部向下逐渐开花,下部枝梗开花时间小于上部枝梗;小穗上的小花由下向上逐步开花。与荒漠绿洲区相比,高海拔地带的无芒雀麦幼穗分化时间晚,周期缩短,穗部赤霉素(GA)、脱落酸(ABA)及叶片可溶性蛋白含量相对较高,细胞分裂素(CTK)含量和种子千粒重较低,但高海拔地带单穗成熟种子粒数与单位面积内种子产量高,更适合无芒雀麦种子生产。  相似文献   
15.
果实表型数据高通量、自动获取是果树新品种育种研究的基础,实现幼果精准检测是获取生长数据的关键。幼果期果实微小且与叶片颜色相近,检测难度大。为了实现自然环境下苹果幼果的高效检测,采用融合挤压激发块(Squeeze-and-Excitation block, SE block)和非局部块(Non-Local block, NL block)两种视觉注意机制,提出了一种改进的YOLOv4网络模型(YOLOv4-SENL)。YOLOv4模型的骨干网络提取高级视觉特征后,利用SE block在通道维度整合高级特征,实现通道信息的加强。在模型改进路径聚合网络(Path Aggregation Network, PAN)的3个路径中加入NL block,结合非局部信息与局部信息增强特征。SE block和NL block两种视觉注意机制从通道和非局部两个方面重新整合高级特征,强调特征中的通道信息和长程依赖,提高网络对背景与果实的特征捕捉能力。最后由不同尺寸的特征图实现不同大小幼果的坐标和类别计算。经过1 920幅训练集图像训练,网络在600幅测试集上的平均精度为96.9%,分别比SSD、Faster R-CNN和YOLOv4模型的平均精度提高了6.9百分点、1.5百分点和0.2百分点,表明该算法可准确地实现幼果期苹果目标检测。模型在480幅验证集的消融试验结果表明,仅保留YOLOv4-SENL中的SE block比YOLOv4模型精度提高了3.8百分点;仅保留YOLOv4-SENL中3个NL block视觉注意模块比YOLOv4模型的精度提高了2.7百分点;将YOLOv4-SENL中SE block与NL blocks相换,比YOLOv4模型的精度提高了4.1百分点,表明两种视觉注意机制可在增加少量参数的基础上显著提升网络对苹果幼果的感知能力。该研究结果可为果树育种研究获取果实信息提供参考。  相似文献   
16.
采用L9(34)正交设计,探讨氮、磷、钾肥配施对幼龄腰果植株生长和结果的影响.试验结果表明,对于2龄腰果植株,最佳施肥组合为N1P1K1,年施氮(N)150 g/株、磷(P2O5) 50 g/株和钾(K2O) 50 g/株处理,可以促进植株生长;对于3龄腰果植株,年施氮250~450 g/株处理,植株的冠幅、株高增量随着氮施用量增加而增大,磷、钾影响不显著;现蕾期和初花期,P2O5 90 g/株和K2O 200 g/株处理的植株现蕾、开花枝梢比例最高,施氮影响不显著;盛花坐果期,施N 350 g/株、P2O5 150 g/株和K2O 150 g/株处理的植株现蕾开花枝梢比例最高.氮和钾对3龄植株结果影响较大,年施N 250~450 g/株处理,平均株产量随着氮施用量的增加而增加,最佳施肥组合为N3P1K2,施N 450 g/株、P2O5 90 g/株和K2O 150 g/株处理,可以促进3龄腰果植株结果.3龄植株腰果产量与初花期叶片钾(K)含量(0.43%~0.47%)和盛花坐果期叶片N含量(1.89%~2.20%)呈直线显著正相关.  相似文献   
17.
幼树靶标探测器设计与试验   总被引:1,自引:11,他引:1  
针对果园对靶喷药中幼树靶标难以精准探测的难题,该文基于红外传感器设计了幼树靶标探测器,该探测器能同时探测喷药机两侧果树树干,根据用户设置的喷雾宽度和延迟距离等参数计算出靶标喷雾位置,并准确控制电磁阀开闭以进行对靶喷药。实验室试验表明,在传感器探测范围内探测距离和树干直径对探测器探测准确性几乎没有影响,速度对探测准确性有微小量影响,速度不大于1m/s时喷雾总宽度计算精度不小于96.1%。果园试验表明,行走速度不大于0.94m/s时,幼树靶标探测器能100%探测到树干并准确计算出喷雾位置和喷雾宽度。  相似文献   
18.
  • 1. To assess the efficacy of environmental management policies and practices, there is a progressive transition from monitoring of activities towards assessment of their outcomes for the environment.
  • 2. Population trends of key taxonomic groups can serve as useful indicators of broader environmental integrity and health. Several necessary and desirable criteria for selecting meaningful and suitable indicators are discussed. The attributes of a range of taxa and survey methods used for their assessment are discussed with reference to these criteria.
  • 3. Survey methods, data holdings and analytical methods for populations of wild birds at present provide a good basis for developing indicators of the quality of fresh waters at a landscape scale. Other taxa are not necessarily any less appropriate; however, survey design and data representativeness are often limiting factors to the use of other taxa for assessing geographic and temporal trends.
  • 4. Taxonomic science and ecological monitoring are necessary for determining society' progress with sustainable development and for informing appropriate enhancements to policy and management practice, particularly so for fresh waters.
Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
19.
Abstract –  Estuarine migration in Allis shad ( Alosa alosa ) usually does not take place before mid-summer, but exposure to salinity in brackish water may occur earlier as many spawning areas are of necessity located in upper estuarine zones due to the placement of dams. Therefore, Allis shad conservation programmes need to consider the risk of mortality due to the ability of young Allis shad to tolerate salinity. To evaluate larval mortality due to the inability of larvae to withstand salinity during early ontogeny, we exposed larvae of different ages (from few days old to 27 days old) to salinities ranging from 0 to 30 g·l−1. Results indicate that direct seawater exposure induces high mortality in young larvae whatever the ontogenetic stage. However, young larvae can easily deal with upper estuary salinity conditions.  相似文献   
20.
以3~4年生5个不同砧穗组合富士苹果幼树为材料,研究植物内源激素含量与早花性和易成形性间的关系。结果表明:乔化砧组合树体高大、生长旺盛,短枝比例和花序数量均显著低于矮化砧组合。矮化砧木组合中,M26组合虽然短枝比例很高,但单株成花量低,树体长势弱;SH16组合次之;T337组合长势中庸、单株成花量大。一年中,春、秋梢开始生长期,幼叶IAA、ZR含量出现高峰,根系第2次生长高峰期,细根IAA、ZR、GA_3含量出现高峰。幼叶ZR和细根IAA含量呈负相关,IAA、GA_3分别在地上部和地下部之间存在正相关。5月5日,幼叶IAA和ZR含量分别与当年生枝量呈正相关;5月20日,ZR、ZR/GA_3分别与短枝比例呈正相关,GA_3与花序数量呈负相关;根系第2次生长高峰期,苹果幼树开花相关指标分别与细根中的IAA、ZR、GA_3、IAA/ZR呈正相关,说明内源激素在地上部成花与地下部根系生长过程中具有重要调节作用。渭北地区,T337自根砧木富士苹果组合体现了早花性和树体易成形性的统一。  相似文献   
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