切花月季生物学特性的研究

对江苏常州引进的 2 6个切花月季品种的物候期、花枝生长、开花特性及适应性等作了详细的观测记录 ,为今后切花月季的引种栽培提供科学的依据     

四种鲜切花保鲜剂的筛选

本文研究了四种鲜切花(唐菖蒲、月季、康乃馨和鹤望兰)的保鲜剂配方,观测各种保鲜剂对切花外观品质和瓶插寿命的影响,从中筛选出各种鲜切花的较佳保鲜剂,并讨论了组成保鲜剂配方的各种成分(糖、杀菌剂、有机酸、无机盐、乙烯抑制剂和拮抗剂以及植物生长调节剂)的作用。     

不同保鲜剂对非洲菊切花的保鲜效应

探讨不同保鲜剂对非洲菊切花的瓶插寿命、观赏品质以及生理生化指标的影响。结果表明,在供试7组保鲜剂中,以处理7(T₇):20g/L Suc+200mg/L 8-HQC+150mg/L CA+75 mg/L KH₂PO₄·3H₂O+1g/L CaCl₂的保鲜效果最佳,可显著延长非洲菊切花瓶插寿命;T₇处理有利于减缓花瓣组织pH上升、花青素含量下降及花瓣细胞膜相对透性的上升,从而延长瓶插寿命。     

Effect of exogenous hormones on leaf yellowing in cut flowering branches of Alstroemeria pelegrina L.

Inclusion of IAA in the vase water had little effect on leaf yellowing in cut flowering branches of Alstroemeria pelegrina L. while kinetin delayed leaf yellowing at 10^–4M (continuous treatment). Chlorophyll was effectively retained by 10^–7M gibberellic acid (GA) in the vase water or by a 20h pulse at 5°C with 10^–5/10^–4M GA. After 16h of ¹⁴C-GA₃ uptake at 20°C relatively high levels of ¹⁴C were found in leaves and low levels in stems and flowers. After this treatment about half of the ¹⁴C-GA₃ in leaves was metabolized into unknown compounds.     

含矮壮素的保鲜剂对非洲菊切花衰老的影响

含矮壮素的保鲜剂能增加非洲菊切花瓶插衰老过程中SOD、CAT、POD的活性,削弱MDA含量的增加和的O-2生成速率,减少蛋白质的降解,降低脯氨酸含量和水分散失,维持膜结构的相对稳定性,延长切花瓶插寿命4 d左右.     

Defining Health‐Related Obesity in Prepubertal Children

Objective: The purpose of this study was to develop percentage of fat and waist circumference cut‐points in prepubertal children with the intention of defining obesity associated with cardiovascular disease (CVD) risk. Research Methods and Procedures: A cross‐sectional analysis of 87 prepubertal children aged 4 to 11 years was used. Percentage of body fat was determined by DXA. Waist circumference was measured to the nearest millimeter. Receiver Operating Characteristic analyses of percentage of fat and waist circumference were used to develop cut‐points for individuals with adverse levels of CVD risk factors. Results: The risk factors selected for analyses (i.e., fasting insulin, high‐density lipoprotein cholesterol, low‐density lipoprotein cholesterol, triglycerides, and total cholesterol/high‐density lipoprotein cholesterol) were significantly related to percentage of body fat and waist circumference. Likelihood ratios were used to identify percentage of fat and waist circumference cut‐points associated with adverse cardiovascular risk profiles. Two cut‐points, an upper cut‐point of 33% body fat and a lower cut‐point of 20% body fat, were derived. Waist circumference cut‐points indicative of adverse and normal risk‐factor profiles were 71 cm and 61 cm, respectively. Discussion: The data indicate that children with ≥33% body fat and children with a waist circumference ≥71 cm were more likely to possess an adverse CVD risk‐factor profile than a normal risk‐factor profile. The likelihood of children with <20% body fat or a waist circumference <61 cm possessing an adverse CVD risk‐factor profile as opposed to a normal risk‐factor profile was small. The cut‐points describe an adequate health‐related definition of childhood obesity.     

Sensitivity and Specificity of Anthropometrics for the Prediction of Diabetes in a Biracial Cohort

Objective: To evaluate the ability of body mass index, waist circumference, waist‐to‐hip ratio, and combinations of these variables to discriminate individuals who will develop diabetes in adulthood. Research Methods and Procedures: Data were from 45‐ to 64‐year‐old men and women who were members of the Atherosclerosis Risk in Communities cohort. The analysis sample consisted of 12,814 African American and white participants who were free of diabetes at baseline. Body mass index, waist circumference, waist‐to‐hip ratio, and diabetes incidence (defined as one glucose measure ≥126 mg/dL after fasting for at least 8 hours, one nonfasting glucose measure ≥200 mg/dL, and self‐report of diabetes or report of taking medication for diabetes). Results: 1515 new cases of diabetes were identified over the 9‐year follow‐up. Areas under receiver operating characteristic curves ranged from 0.66 to 0.73 for single measures. The curves were smooth, with no indication of a threshold. Waist tended to have the highest receiver operating characteristic statistic in all groups, but differences were small. Discussion: The three anthropometric indices tested were approximately equivalent in their ability to predict diabetes. Sensitivity and specificities differed among ethnic and gender groups.     

Enhancements, easy shortcuts, and the richness of human activities

One argument that is frequently invoked against the technological enhancement of human functioning is that it is morally suspect, or even wrong, to take an easy shortcut. Some things that usually take effort, endurance or struggle can come easily with the use of an enhancer. This paper analyses the various arguments that circle round the idea that enhancement of human functioning is problematic because of the 'easy shortcut' that it offers. It discusses the concern that quick fixes lead to corrosion of character and the idea that suffering, pain, hard work and effort are essential for real and worthy achievements, and argues that these views are largely mistaken. Next, the paper argues that the core worry about taking an easy shortcut is that it makes us lose sight of the complexities of our means and ends; in other words, the argument warns against reducing the richness of human activities. A vocabulary of 'practices', 'internal goods' and 'focal engagement' will be used to articulate this argument further. The conclusion is that the easy shortcut argument has no general validity as an argument against enhancement 'as such'. The paper urges us, however, to evaluate enhancement technologies not only in terms of their efficiency in reaching certain goals but also in terms of their contribution to intrinsically worthwhile human activities. It can point out some of the caveats, as well as the opportunities, of the use of enhancement technologies.     

The Youden Index and the optimal cut-point corrected for measurement error

Random measurement error can attenuate a biomarker's ability to discriminate between diseased and non-diseased populations. A global measure of biomarker effectiveness is the Youden index, the maximum difference between sensitivity, the probability of correctly classifying diseased individuals, and 1-specificity, the probability of incorrectly classifying health individuals. We present an approach for estimating the Youden index and associated optimal cut-point for a normally distributed biomarker that corrects for normally distributed random measurement error. We also provide confidence intervals for these corrected estimates using the delta method and coverage probability through simulation over a variety of situations. Applying these techniques to the biomarker thiobarbituric acid reaction substance (TBARS), a measure of sub-products of lipid peroxidation that has been proposed as a discriminating measurement for cardiovascular disease, yields a 50% increase in diagnostic effectiveness at the optimal cut-point. This result may lead to biomarkers that were once naively considered ineffective becoming useful diagnostic devices.