铜污染土壤中不同多年生黑麦草品种富集效应的评价

采用盆栽试验,测定10个多年生黑麦草(Lolium perenne)品种在不同浓度铜污染土壤中的干生物量,以及植株根部、茎秆和叶片3个不同部位中的铜富集量,以期为铜污染土壤的恢复治理提供参考依据。结果表明:试验条件下,多年生黑麦草根部、茎秆和叶片3个不同部位中铜富集量随着土壤中Cu2+浓度的升高而升高;多年生黑麦草5(Harukaze)的铜富集能力较强,多年生黑麦草7和9的铜富集能力较差,其他介于两者之间。在铜胁迫下,多年生黑麦草根部是主要的铜富集器官,其次为茎秆,最后是叶片。采用隶属函数法铜富集特性进行综合评价,黑麦草5(Harukaze)具有较好铜富集能力,可优先考虑。     

《宠物外科手术学》教学模式改革与探讨

《宠物外科手术学》是一门实践性很强的学科,与其他专业相比,更强调能力的培养,强调实验技能和临床技能的训练,是宠物相关专业技能培养的重要组成部分。该课程对培养学生的临床思维能力、合理运用手术基本操作技术能力、学生对宠物外科手术技能综合运用能力、学生的社会就业方向等有着积极而重要的作用。为此,如何给学生更好地传授理论知识,提供更多临床实践和动手能力的机会,需要学校和教师在人才培养方面不断思索和改革。通过多年的临床教学经验,对该课程进行了一些教学改革尝试,旨在更好地培养学生宠物外科手术的实践能力,以适应社会的需要与发展。     

绵羊实验性硒过多症的研究Ⅰ.硒过多症动物模型的建立

对14只绵羊以0.1％亚硒酸钠液肌肉注射,逐渐增加剂量,历时3～4个月,复制出了慢性硒过多症动物模型。此动物模型是随着硒在体内的不断累积,呈现起病、中毒和致死三个不同的效应阶段,血硒水平在0.30、0.50、及1.00μg/ml以上,依次分别作为三个效应阶段的临界值。     

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.     

Plant Species Composition and Forage Production 14 Yr After Biosolids Application and Grazing Exclusion

This paper examines the effects of a single surface application of biosolids (at 20 dry Mg ha^{? 1}) on plant species composition, forage quality and quantity, and C stocks after 14 yr of rest in rangelands of the Central Interior of British Columbia. More than two times the aboveground biomass of grasses and the percent cover of plant litter were found in the biosolids treatment relative to the control, along with reductions in bare soil and microbiotic crust cover. Significantly greater plant uptake of all macronutrients (C, N, P, K, S, Ca, and Mg); most micronutrients (B, Cu, Mn, Mo, and Zn); and Al occurred in the biosolids treatment. P and Cu were the only two nutrients to be more concentrated in the biosolids-treated forage relative to the control forage, while N, Mg, and protein were more concentrated in the control forage. No significant difference in forage digestibility was found between biosolids and control treatments. Bluebunch wheatgrass, the late-seral native grass species, had significantly increased cover and aboveground biomass in the biosolids treatment relative to the control; however, between 2006 and 2016, non-native Kentucky bluegrass had reached > 25% cover in the biosolids plots, perhaps restricting the full recovery of bluebunch wheatgrass. Our findings indicate that biosolids application to ungrazed rangeland can increase long-term forage production and reduce bare soil. However, at our study site biosolids application also led to a long-term shift in the plant community composition away from the late-seral (i.e., bluebunch wheatgrass) trajectory, and the effects of this shift on rangeland health and productivity require further investigation.     

星星草对碱化土壤物理性质的影响

研究不同生长年限的星星草对碱化土壤及对应碱斑土壤的机械组成、土壤孔隙度、容重和含水量的影响。结果表明,星星草生长1、2和3年后,粘粒和细砂所占比例减小,而粗粉和细粉所占比例增大。土壤总孔隙度、毛管孔隙度和非毛管孔隙度随着生长年数的增加呈不同程度的增加,而土壤容重则越来越小,>0.25mm的水稳定性团聚体随之增加。星星草地土壤含水量和田间持水量均高于碱斑土壤。星星草改善了碱化土壤结构、通透性、保水性和土壤物理环境。     

黄河源区“黑土滩”混播草地牧草植物量及营养动态初探

黄河源区的极度退化草地——"黑土滩",改建成人工草地是一种恢复退化草地的重要途径,同时可以收获大量饲草。对"黑土滩"混播草地(垂穗披碱草Elymus nutans+中华羊茅Festuca sinensis+碱茅Puc-cinellia distans+冷地早熟禾Poa crymophila+赖草Leymus secalinus)的生产力和营养价值动态进行了研究,分析了放牧对草地生产力的影响。结果表明,从生长高峰期8月到翌年4月,草地生产力自然损失量为144.3 g/m2,损失率为34.9%。这期间放牧利用导致牧草被采食187.2 g/m2。传统的放牧利用,使该类人工草地利用率为45.2%。冷季草地牧草营养价值全都下降,粗蛋白含量降低了69.86%,粗脂肪降低了65.85%。该"黑土滩"混播草地在夏季属碳氮营养型(CN),冬季属碳营养型(C)。因此建议,"黑土滩"混播草地在夏季生长高峰期适度进行人工割草,冬季进行适度放牧利用。     

甘肃省坡耕地利用状况与退耕还林还草技术对策研究

对甘肃省坡耕地的利用状况及其退耕的可行性进行了较为全面的分析,按照因地制宜的原则,将退耕区域划分为陇中黄土丘陵沟壑区、陇东黄土台塬区、山高坡陡的陇南山区与河西防风固沙区四大区,并就各区退耕后的还林还草方式进行了具体的论证,提出了15°～25°和25°以上坡耕地退耕还林还草的具体技术对策。     

Genetic parameters for abnormal sucking traits in Austrian Fleckvieh heifers

Cross‐sucking and intersucking are considered abnormal behaviours in cattle and constitute a common problem in dairy farming. Cross‐sucking in calves is defined as sucking any body parts of another calf whereas intersucking in heifers and cows is defined as sucking the udder or udder area. The aim of this study was to determine the genetic variability for abnormal sucking behaviour by estimating genetic parameters and examining individual differences between sires with large progeny groups. By means of a questionnaire, cattle breeders in the federal state Lower Austria were requested to identify all currently kept animals which are known of either inter‐ or cross‐sucking (both defined as the same binary trait ‘sucking’ with 0 and 1 referring to the absence and presence of this abnormal behaviour) or allowing sucking (also treated as a binary trait, scored as 1 if an animal was known of allowing herd mates to suck and 0 otherwise). Records of 1222 farms and 13 332 dual purpose Simmental females aged between 21 and 700 days were investigated applying a linear animal model with fixed herd × year × season and random genetic animal effect and a threshold sire model with the herd × year × season effect being treated as random. In total, 8.6% and 4.1% of all calves/heifers were observed sucking and allowing sucking, respectively. Heritabilities of 0.040 ± 0.014 and 0.007 ± 0.006 (linear animal model) and 0.116 ± 0.041 and 0.026 ± 0.024 (threshold model) were found for the traits sucking and allowing sucking, respectively. Breeding values were estimated applying the same models for the trait sucking. Taking all 254 sires into account, the Pearson and Spearman correlation coefficients between breeding values estimated by linear animal and sire threshold model were 0.86 and 0.80. Thus, little difference was observed between the two methods.     

鲁梅克斯对草甸盐土的改土效应研究

在草甸盐土上种植鲁梅克斯Rumex patientia×R.tianschanicus cv.Rumex K-1,脱盐改土效果十分明显.种植鲁梅克斯3～4年,鲜草产量达100.51 t/hm2,pH值由8.43降为7.99,耕作层土壤总孔隙度增加5.29%～7.06%,土壤容重降低0.14～0.21 g/cm3,水稳性团粒结构增加23.14%～32.34%,自然含水量增加72.12～89.44 g/kg,土壤有机质、速效氮、磷、钾亦随之增加.