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1.
The objective of this study was to evaluate the response of healthy housebound domestic cats to the simultaneous provision of 2 litterboxes of differing sizes by recording the average daily frequency of urination and defecation in each box. Forty-three households with 74 privately owned cats were each provided with 2 different-sized plastic containers, with the larger box being 86 cm in length, exceeding the size of commercially available litterboxes. Owners were also provided with an unlimited supply of clumping cat litter and a logbook to record daily urine and fecal deposits in the boxes as they were scooped over a 4-week period. The 2 litterboxes were initially placed at opposite sides of the same room in the owner's home. After 2 weeks, the boxes were emptied completely, refilled with clean clumping litter, and replaced in the opposite location. Results were recorded as simple counts of urine and fecal deposits for each day and each household. Over the 28-day period, there were a total of 5031 urine and fecal deposits in the larger boxes and 3239 urine and fecal deposits in the regular boxes. The effects of phase (days 1-14 vs. 15-28) and box size (regular vs. large) on the number of deposits per cat were evaluated using a linear mixed model. In addition to evaluating phase and box size, the effects of number of cats in the house, their average age, and gender were also evaluated. Urine deposits were significantly more frequent than fecal deposits. Large boxes were preferentially selected over regular boxes in both phases, but this difference was greater in phase 1 than phase 2. Further analysis indicated that there was a location preference during the first 2 days in phase 2, and this effect decreased as the study progressed. Results indicate that most cats show a definite preference for a larger litterbox than is typically available to them in homes and that other factors such as box cleanliness and location may have a compounding influence on this choice.  相似文献   
2.
草地地上生物量(Aboveground biomass,AGB)是衡量草地生产力的关键因素,准确测定草地AGB具有重要意义。高光谱因具有时效性强、不破坏草地等特点被广泛用于草地生理生态指标的测定。本研究提取和计算了海北试验站高寒草地冠层的原始光谱(Original spectrum,OR)反射率、一阶微分光谱(First derivative spectrum,FD)反射率、光谱位置面积参数(Spectral parameters of spectral position and area,PA)和植被指数(Vegetation indices,VI)4种不同类型的特征变量,使用连续投影算法(Successive projections algorithm,SPA)和递归特征消除算法(Recursive feature elimination,RFE)进行特征选择,采用随机森林算法(Random forest,RF)构建草地AGB估测模型。结果表明:在由4种特征变量分别构建的草地AGB估测模型中,基于VI的RF模型精度最高(测试集R2=0.70,RMSE=557.87 kg·ha-1),实测AGB与估测AGB的线性R2达到0.72;不同类型特征变量组合构建的草地AGB估测模型中,PA+VI组合的RF模型精度最高(R2=0.71,RMSE=548.97 kg·ha-1),实测AGB和估测AGB的线性R2达到0.73。  相似文献   
3.
The rank one updating formula and the parallel eliminating algorithm for linear recurrence systems ane combined fo form a MTMD parallel algorithm fo solve tridiagonal Toeplitz Cinear equations. This algorithm has a simple strictire and requires onlty a few storages as well as in-terprocessor communications. There is no special demand on the number of processors in the parallel system. The speedup can come dose to p12 comparing with the LU decomposition method (p is the number of processors). It is worth pointing out that it is proposed algcmthn that considels and organizes the parallel arithmetic in the first order linear ricurrence systems with constant coefficients.  相似文献   
4.
针对途安车怠速不稳等故障现象,介绍了故障排除过程,为专业及维修人员提供参考。  相似文献   
5.
The oral route is presently the preferred route of drug delivery. Poor oral bioavailability results in variable concentrations of drugs in the plasma and variable pharmacological responses, in addition to higher product costs. The unique canine physiology, anatomy and biochemistry makes designing canine dosage forms a challenging exercise. This article reviews the physicochemical, physiological, pharmacokinetic, pharmacological and formulation factors that can influence the drug availability of the oral formulations in dogs in an effort to provide a source of data to aid development of canine drug products with superior bioavailability.  相似文献   
6.
武威地区天然草地有毒植物及其防除   总被引:12,自引:2,他引:10  
对武威地区天然草地有毒植物的种类,分布及其对草地的危害情况进行了调查研究,结果表明,全区天然草地共有毒植物172号,分属31科84属,平均2.15种/m^2,盖度达4.41%地上部分生物量11.28g/m^2。对草地危害的主要黄花棘豆,甘肃棘豆,小花棘豆,狼毒和马草,受侵害的草地主要是山地草甸和山地草原,通过分析,提出了有毒植物防除和利用的建议。  相似文献   
7.
单宁是一种多酚化合物,广泛存在于各种植物中。本文对其性质、营养作用、对反刍动物的不利影响以及消除方法作了综述。  相似文献   
8.
本文对汉麻温水沤法脱胶过程中的水体pH值和果胶酶活性,以及汉麻韧皮纤维中各组成成分(果胶、半纤维素、纤维素、木质素)的动态变化进行了测定,探明了汉麻温水沤法脱胶过程中水体pH值、果胶酶活性和韧皮纤维脱胶状态的动态变化规律。  相似文献   
9.
为保证草坪绿化质量 ,延长其寿命 ,结合近年来在公路草坪施工与养护管理中积累的实践经验 ,对公路草坪的种类、生长习性 ,以及草坪建植后的浇水、除杂草、修剪、施肥、病虫害防治等养护管理技术进行了探讨与总结 ,以期为各地公路草坪绿化建设提供借鉴与参考。  相似文献   
10.
张培旗  李健  王群  刘淇  管斌 《水产科学》2005,24(11):17-20
在(20±2)℃水温条件下,研究磺胺甲基异唑在中国明对虾肌肉、血淋巴和肝胰脏3种组织中的残留及消除规律。药物在对虾肌肉、血淋巴、肝胰脏中的残留用二氯甲烷提取,反相高效液相色谱法检测,最低检测限可达0.01μg/mL,平均回收率为80%~90%。研究结果表明:磺胺甲基异唑在中国明对虾血淋巴中的残留量最小,在肝胰脏中的残留量最大且消除较慢,差异明显。建议把对虾的肝胰脏作为该药残留监控的靶组织,相应的休药期至少为20 d。  相似文献   
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