土壤微生物生物量熏蒸提取法中转换系数K_(EC)的测定研究

本文综述了熏蒸提取法中用于计算土壤微生物生物量时所需的转换系数KEC的测定方法 ,并对现有的各种方法的应用性作了简要的评价 ;同时指出了目前常采用的KEC值在使用上应注意的事项     

Dehorning and disbudding distress and its alleviation in calves

Dehorning and disbudding are routine painful procedures carried out on cattle to facilitate management. The pain caused by these procedures and its alleviation may be evaluated by monitoring behaviour and physiological responses, and by measuring their effects on weight gain. The cortisol response to cautery disbudding is significantly smaller than that to amputation dehorning which infers that the latter is more painful. Amputation dehorning stimulates a defined cortisol response with a rapid rise to a peak value within 30 min followed by a decline to a plateau which then declines to pre-treatment values after about 8 h. A cornual nerve blockade using lignocaine virtually eliminates the escape behaviour seen during disbudding and dehorning and reduces the plasma cortisol response to dehorning for about 2 h. Thereafter there is an increase in the plasma cortisol concentration, a delayed response, which lasts for about 6 h. A cornual nerve blockade, using lignocaine combined with cauterizing the wound caused by amputation dehorning, virtually eliminates the cortisol response as does combining a lignocaine blockade with the non-steroidal anti-inflammatory drug (NSAID) ketoprofen. When xylazine is combined with a cornual nerve blockade using lignocaine before dehorning, the cortisol response is virtually eliminated for about 3 h. When this regime is used before cautery disbudding and includes a NSAID given before and after disbudding the behaviour of calves so treated suggests that pain may be alleviated for 24 h. Cautery disbudding is preferable to amputation dehorning, but for optimal pain relief xylazine sedation, local anaesthesia and a NSAID should be used with both procedures.     

Evaluation of a citrate-based anticoagulant with platelet inhibitory activity for feline blood cell Counts

Abstract: Aggregation of feline platelets in vitro results in difficulty assessing platelet number. A citrate-based anticoagulant containing the platelet inhibitors theophylline, adenosine, and dipyridamole (CTAD; Diatube-H, Becton Dickinson, Oxford, UK) has been developed for use in human platelet studies and heparin assays. To evaluate the efficacy of CTAD in reducing platelet aggregation in feline blood samples, aliquots of blood from 51 cats were anticoagulated with EDTA, CTAD, and for 12 samples, citrate solution. Samples preserved in CTAD had significantly higher (P ≤ .001) platelet counts, as determined by an impedance counter, hemacy-tometer, and smear estimation, than samples preserved in EDTA. In addition, subjective assessment of blood smears showed significantly fewer platelet aggregates (P<.001) in CTAD-treated samples compared with EDTA samples. Although values were similar, automated platelet counts and smear estimates of platelet number were significantly higher (P < .05) and platelet aggregation was significantly less (P < .05) in CTAD samples than in citrate samples. These results suggest that the platelet inhibitory activity of CTAD reduced feline platelet aggregation. Automated total WBC counts in CTAD samples were significantly lower (P<.001) than automated counts in EDTA samples but were similar to manual WBC counts in EDTA samples. Differences in both platelet and WBC counts between CTAD and EDTA or citrate samples were clinically relevant. Mean platelet volume and MCV were significantly lower (P< .05) in CTAD samples than in EDTA samples. No effect was seen on cell morphology or staining characteristics. The anticoagulant CTAD offers an advantage over both EDTA and citrate for feline hematologic analysis, by decreasing pseudothrombocytopenia and pseudoleukocytosis.     

稻麦轮作条件下长期不同土壤管理对氮素肥力的影响

通过十二年的耕作和施肥长期定位试验研究表明,苏南太湖稻麦轮作地区,长期休闲的农田０～５ｃｍ土层最高含氮量可达２．８９％,休闲田结合结合每季耕翻,全氮含量下降,只及最高含氮量的７０％,保持在２％左右。无论免耕与否,不施肥土壤（０～５ｃｍ）全氮含量为最高含氮量的５０％左右,单施化肥时为５２％～５６％,猪粪＋化肥为６３％,秸秆＋化肥为６３％～７０％。不同耕作处理对土壤全氮、氮素矿化势、生物量氮和矿质氮在土层中的分布及含量有明显的影响。施肥,特别是配施有机肥对土壤全氮和土壤供氮容量的影响大于耕作对其的影响。固定态铵的含量不仅与土壤中的粘土矿物有关,施肥对其也有影响。     

红豆杉细胞悬浮培养系统激素优化的研究

采用均匀设计安排预试验以确定进一步优化研究的范围,在此基础上采用响应面一阶模型的设计方法,获得关于悬浮培养的红豆杉细胞生长与激素浓度之间的回归方程,表明ＮＡＡ、６－ＢＡ是影响细胞生长的关键因素,２,４－Ｄ、ＮＡＡ、６－ＢＡ以０．２３：１：０．６２比例在现有配方基础上递增有利于接近最优目标。     

Morphological Classification of Traditional Philippine Upland Rice Cultivars in Upland Nurseries Using Cluster Analysis Methods for Recommendation, Breeding and Selection Purposes

Using eight morphological parameters with six cluster analysis methods, a set of 21 traditional and four improved Philippine upland rice cultivars (cvs) could be separated into five groups: (1) improved semi-dwarf plant type, (2) improved or 'moderately modified' (short) Indica plant type, (3) traditional tall Indica plant type, (4) traditional tall Japonica plant type and (5) traditional short Japonica plant type. The results emphasized the importance of the separation into Indica and Japonica plant types, but the cultivars could be classified more accurately using growth characteristics such as tillering ability, followed by plant height and leaf area parameters. The clusters containing Indica cvs consistently showed a higher tiller number per plant, a higher growth stage (DC classification) and narrower leaves than clusters with Japonica cvs. The parameters culm length, plant height, leaf area, leaf length and width were represented in subgroups with both long and short expression of the respective characteristic. Use of the existing variability of morphological traits within the group of traditional upland rice cvs should be beneficial in recommendation, breeding, selection and development of upland rice cvs for the different rice ecosystems as well as for the upland rice/rice blast pathosystem.     

禄劝板栗矢尖蚧梨圆蚧发生规律及防治研究

板栗矢尖蚧、梨圆蚧在禄劝县海拔1500～2000m的板栗种植园内混合发生,两种虫害1年均发生3代,其中较低海拔栗林梨圆蚧发生严重,矢尖蚧发生较轻;阳坡栗林矢尖蚧危害严重,阴坡栗林梨圆蚧危害严重.对板栗物候和两种蚧虫生活史的观察得出,药物防治的最佳时间为板栗抽梢现蕾期(4月上旬)及落叶期(11月上旬).防治试验表明利用速扑杀和氧化乐果喷雾防治两种蚧虫效果良好,其中速扑杀1000倍液防治这两种蚧虫效果最佳,矢尖蚧的虫口减退率达99%,梨圆蚧的虫口减退率达95%.     

Sensory evaluation as a selection tool in apple breeding

Several conventional sensory methods were adapted to provide aprocedure that is suitable for screening apple (Malus × domestica) breeding selections for dessert quality. Trained judges were presented with randomized coded samples (apple slices) and asked to rate them on 0 to 9 bipolar hedonic (liking) scales for texture and flavour, and 0 to 9 unipolar intensity scales for skin toughness, crispness, hardness, juiciness, aroma, sweetness and sourness. Appearance liking was rated on coded samples of five whole apples, using the 0 to 9 hedonic scale. A minimum panel size of eleven judges was generally sufficient to obtain statistical discrimination of one point on the 0 to 9 scales. Panel mean scores for breeding selections relative to standards have been consistent from panel to panel and year to year. A subset of selections and cultivars was rated for appearance and taste by consumers in blind taste tests. In-house panel findings were comparable to consumer ratings for taste and appearance liking, with a few exceptions in appearance. Panel mean scores for texture and flavour liking were regressed on texture and flavour components. Crispness accounted for about 90% of the variation in texture liking. Juiciness, aroma, sweetness and sourness were all important to flavour liking, but their relative importance changed from year to year and in total accounted for only about 60% of variation in flavour liking. Perceived sweetness and sourness were better predictors of liking than analytical measurements of soluble solids and titratable acidity. Formal sensory evaluation can be used successfully for screening breeding selections, and may provide more reliable data than the opinions of only one or two people.     

辛氯乳油中辛硫磷不同分析方法的比较研究

采用高压液相色谱法、气相色谱法及薄层－紫外法３种方法,对辛氯乳油中的辛硫磷进行分析测定,并对这３种分析方法进行系统比较,结果表明：液相色谱法是其中的最佳方法。