Epidemiology of drug abuse: an overview

Issues regarding the use of epidemiology in drug abuse research are discussed and systems for monitoring national trends and identifying risk factors are described. Data indicate a general decline in marijuana use among youth, a cohort aging effect among heroin and marijuana users, and increased prevalence and health consequences associated with cocaine use.     

Marijuana and driving in real-life situations

It is evident that the smoking of marijuana by human subjects does have a detrimental effect on their driving skills and performance in a restricted driving area, and that this effect is even greater under normal conditions of driving on city streets. The effect of marijuana on driving is not uniform for all subjects, however, but is in fact bidirectional; whether or not a significant decline occurs in driving ability is dependent both on the subject's capacity to compensate and on the dose of marijuana. For those subjects who improved their performance, the explanation may lie in overcompensation and possibly the sedative effect of the drug. Whereas the street portion of this study approximated normal driving conditions, it should be emphasized that the context of the driving experience een on city streets was experimental. the design of this study maximal safeguards in terms of a dual control vehicle and a driver observr; in addition, the subjects were proffessionally screened and, with rare exception, they were emotionally stable. Given the experimental setting and set, the safeguards, and the nature of the study sample, idiosyncratic behaviour that might occure under normal driving condition would be less likely to occur in a study such as this. Other identified factors might lead to more stringent conclussions regarding the effects of marijuana on driving.The first is night driving, which may be more stressful. But an even more important unanswered question is the cumulative effect of alcohol and marijuana on driving (64 percent of the study sample reported alcohol in combination with marihjuana before driving). Third, the doses of marijuana used in this study were within the range of social marijuana usage(1); more heroic doses might be taken before driving. Fourth, the effect of marijuana on reactions and decision during high speed is still another unknown. What are the recommendations that emarge from this study? Driving under the influence of marijuana should be avoided as much as should driving under the influence of alcohol. More investigation is urgently required-and high priority should be given to studies that approximate normal conditions of driving and in which alcohol and marijuana are administered to the same subjects.     

中国人均食物热值构成变化趋势

通过对美国、日本、中国（香港和台湾的资料另行统计）、中国香港特别行政区（以下简称香港）和新加坡的人均国内生产总值（ＧＤＰ）与食物热值构成变化情况比较，分析了中国未来人均食物热值构成的变化趋势，指出：随着人均ＧＤＰ的增长，中国人均食物热值摄入总量以及人均动物食品热值摄入比重都将有较大的增长，而人均谷物食品热值摄入比重逐渐下降。尽管食物热值构成变化取决于人均ＧＤＰ的增长速度和水平，但中国的人均食物热值     

DNA Complementary to Ribosomal RNA: Relation between Genomic Proportion and Ploidy

Ten Nicotiana species were assayed for the proportion of DNA that is complementary to ribosomal RNA. This proportion varies from 0.27 to 0.9 percent, with tetraploid species having lower values than the diploid species. The tetraploid species have about twice as much DNA per cell as do diploid species. Thus, the absolute number of genes for ribosomal RNA varies less than the proportion of complementary DNA. Further, the number of genes for the RNA in 80S ribosomes varies less among species than does that for the RNA in 70S ribosomes. The data indicate that loss of DNA complementary to ribosomal RNA is associated with tetraploidy in the genus Nicotiana.     

Normal skin test responses in chronic marijuana users

The cell-mediated immunity of 22 chronic marijuana smokers showed no difference from that of normal controls when evaluated by in vivo skin testing with 2,4-dinitrochlorobenzene. However, a significant difference was seen between these chronic marijuana users, all of whom could be sensitized to 2,4-dinitro-chlorobenzene, and age-matched cancer patients, who showed a decreased capacity to be sensitized.     

广藿香中挥发油的提取及β-环糊精的包合研究

应用水蒸气蒸馏法提取广藿香中挥发油,然后采用正交试验法,以β-CD和广藿香挥发油投料比、包合时间、包合温度为影响因素,以包合物收得率和挥发油包合率的综合评分为指标,选择广藿香挥发油的最佳提取条件及其β-环糊精(β-CD)包合工艺。结果表明,最佳工艺条件为挥发油与β-环糊精之比为1∶8,搅拌强度为600rpm,包含温度为50℃,包合时间为1h。     

三叶青地上部分显微结构多样性与总黄酮含量相关性

为揭示不同种源地三叶青(Tetrastigma hemsleyanum Diels & Gilg)茎、叶显微结构多样性,及其与地上部分总黄酮含量的相关性,以49个三叶青种质资源（简称“资源”）为研究对象,对各资源茎、叶的16个比例性状进行比较,采用相关性分析对茎叶比例性状及其与种源地位置和地上部分总黄酮含量关系进行统计分析。结果表明：茎维系数（NSB/LSL）、茎韧纤比（SPF/LSL）、茎维宽比（SXW/LSS）和茎木比（TSL/LSS）等,以及叶部的柄翅高比（PWL/PH）、柄翅宽比（DPW/PW）、柄皮层比（PCT/PH）和气孔密度（SD）等性状资源间变异系数较大,可作为资源间鉴别的解剖学依据。各资源比例性状与种源地地理位置相关性分析结果显示：随着种源地的南移,茎维管组织越来越发达,叶柄两翅逐渐变得不明显,皮层发达;随着种源地由东向西推移,叶气孔密度逐渐降低,叶柄两翅逐渐靠近,髓部变得发达。组织化学定位及相关性分析结果表明：三叶青地上部分黄酮类化合物主要分布于茎部薄壁组织中,地上部分总黄酮含量与茎长宽比（LSL/LSS）、茎皮层比（SCT/LSL）、茎韧纤比（SPF/LSL）和茎木比（TSL/LSS）存在极显著相关性,这些茎性状可作为高黄酮三叶青品种的形态学筛选依据。     

汶川震后滑坡体植被恢复不同阶段优势种种间关联研究——以银厂沟谢家店滑坡体为例

为探明震后滑坡体植被恢复过程中的群落种间关系的变化，基于2009-2018年对谢家店滑坡体植被恢复状况的持续监测数据，采用方差比率法、spearman秩相关分析法，从群落整体的关联状况及群落各垂直层次内主要物种间的关联状况两方面对滑坡体植被恢复的草本群落、灌草群落、乔灌草群落3个不同恢复阶段的种间关联动态进行研究。方差比率的检验结果表明，除灌草群落阶段群落整体关联情况为不显著的负关联外，其他各阶段均为不显著的正联结，且随恢复时间的增加群落正关联程度整体呈上升的趋势。spearman秩相关分析结果表明，草本层物种在灌草阶段，主要物种间正负联结种对之比小于1，其他各恢复阶段正负联结种对之比均大于1，正联结种对比例随恢复年限的增加整体呈上升趋势，负联结种对比例整体呈下降趋势；灌木层主要物种间正负联结种对之比随恢复年限的增加呈下降趋势，但下降趋势趋于缓和，说明灌木还处于演替的不稳定阶段；乔木层物种随恢复年限的增加正联结种对比例呈上升趋势，负联结种对比例呈下降趋势。方差比率与spearman秩相关分析的结果均表明，群落多数物种间还未达到显著相关，各物种相对独立。总的来说，震后滑坡体的植被恢复状况较好，群落物种间正联结程度不断增强，群落结构不断完善，物种逐渐趋于稳定共存。     

羽毛针禾种群遗传多样性分析

[目的]从分子水平对羽毛针禾居群内、居群间的遗传分化进行研究,揭示其遗传多样性水平。[方法]使用11条RAPD引物对生长于古尔班通古特沙漠的优良固沙植物羽毛针禾进行居群遗传变异分析。[结果]7个居群76个样品共检测到125个位点,总多态位点百分比为96.8%,居群内平均多态位点百分比为45.3%;羽毛针禾种群Shannon表型多样性指数（I）为0.5151,Nei’s基因多样度指数（h）为0.3471;居群间的基因分化系数为0.5284,即有52.84%的遗传多样性存在于居群间。[结论]羽毛针禾居群有较为丰富的遗传变异,且各居群间已有了明显分化。     

中度石漠化小生境特征及分布格局研究

以贵州省毕节鸭池中度石漠化示范区为例,根据小生境的形成原因、外部形态特征、面积比例的量化指标等将中度石漠化生境划分成石面、石沟、石隙、台地、石洞、土面6种小生境类型。分别测定了各样地中各小生境的数量和面积比例,并绘制了小生境类型图。利用不同面积比例的样地,研究了不同小生境的分布格局、破碎化、多样性、均匀度、优势度、丰富度以及不同小生境之间的相关关系等;阐明了中度石漠化地区小生境的类型特征及空间格局分布情况。     

景东烟区烤烟新品种试验研究

为筛选出适宜普洱市景东烟区推广种植的烤烟新品种,采用大田试验,以云烟87为对照,对9个烤烟新品种的生育期、田间长势、抗性、经济性状以及外观质量进行了对比分析。结果表明,YN220、82-3041、云烟116以及云烟207四个品种的大田总生育期较短,可提早收获；YN220、云烟99以及云烟207在植物学特性和农艺性状上的表现优于或接近云烟87；YN220、云烟99、KRK26、云烟116以及云烟207的原烟外观质量表现与主栽品种云烟87一致；经济性状方面,新品种中KRK26在产量和产值上有优势,均价与级指方面则是YN220表现更优异,上等烟比例与上中等烟比例方面云烟99更突出。因此,YN220、KRK26以及云烟99可优先作为拟推广品种,云烟116和云烟207作为备选品种,进一步在景东烟区开展多点、多年试验,深入论证其推广的可行性。     

大豆、玉米和小米制备烘烤婴儿营养米粉的糊化特性研究

[目的]研究大豆、玉米和小米制备烘烤婴儿营养米粉的糊化特性.[方法]以大豆、玉米、小米为添加原料开发婴儿营养米粉,通过在米粉中添加大豆、玉米、小米进行两因素试验,与大米粉的碘蓝值进行对比分析.营养米粉以营养成分、色、香、味和冲调性的感官评定作为评价指标.[结果]试验得出,各处理间、原料添加比例、烘烤时间、原料添加比例×烘烤时间的差异极显著;添加10％的大豆粉烘烤3、5 rin与添加10％的小米粉烘烤15 min的碘蓝值高于大米粉.从营养米粉的营养性上说,加入20％的大豆粉营养最丰富,但豆腥味较大.[结论]研究可为新型婴儿营养米粉的制备提供参考依据.     

内陆河流域区域间水权初始配置探讨

水权的初始配置分为流域内行政区之间逐级配置和授予用水户水权2个阶段。内陆河流域区域之间的水权初始配置,以建立在多项配置指标基础上的混合配置模式为宜。利用AHP法与TOPSIS法相结合的水权初始配置模型得到的水权分配比例,可作为制定水权配置结果的协商依据。     

Influence of different nitrogen application on flour properties,gluten properties by HPLC and end-use quality of Korean wheat

This study was performed to identify how the different levels of nitrogen application affected the variances of gluten properties and end-use qualities and the differences of variances among Korean wheat cultivars. Protein and dry gluten content, SDS sedimentation volume and water absorption of Mixolab increased as nitrogen application increased. This ratio of the increase was higher in Korean wheat cultivars for bread than in Korean wheat cultivars for noodles and cookies. The proportion of(α+β)-gliadin measured by reversed-phase high-performance liquid chromatography(RP-HPLC) increased, but the proportion of ω-and γ-gliadin decreased as the protein content increased. The Korean wheat cultivars for bread showed a high proportion of(α+β)-gliadin increase, the Korean cultivars for noodles had a high proportion of γ-gliadin decrease and the Korean wheat cultivars for cookies had a high proportion of ω-gliadin decrease. However, there was no variation of the component in the proportion of glutenin component measured by RP-HPLC, even though the protein content was increased, but all of the protein fractions measured by size exclusion(SE)-HPLC were increased. The soluble monomeric protein showed a high proportion of Korean wheat cultivars for bread by the increase of protein content. Bread loaf volume increased by the increase of protein content but there were no variances in the ratio of increase among Korean wheat cultivars. The cookie diameter decreased with the increase of protein content, and this ratio of decrease was the highest in Korean wheat cultivars for cookies. The hardness of cooked noodles also increased by the increase of protein content but there were no variations in springiness and cohesiveness. The decrease proportion of ω-gliadin affected the increase of bread loaf volume, the hardness of cooked noodles, and the decrease of cookie diameter.     

Erratum

The proportion of dogs among animals used in research was incorrectly reported in Constance Holden's article "Billion dollar price tag for new animal rules" (News & Comment, 4 Nov., p. 662). Dogs make up about 1% of research animals, according to the Office of Technology Assessment. Primates make up about 0.05%.     

新疆石油产业与区内其他产业的关联分析

本研究运用灰关联分析原理,逐层推进分析了新疆石油产业及石油产业上中下游的新疆石油开采业、石油加工业、石油化工业与新疆三次产业及新疆主要工业发展的关联程度。新疆石油产业对新疆工业的带动力与其本身所具有的经济总量很不匹配,需对新疆石油产业进行结构调整,加大对石油加工业和石油化工业的投入,提高石油加工业与石油化工业在新疆石油产业中的比重。     

菠菜挂面护绿工艺研究

以小麦面粉为主料、菠菜为辅料 ,食盐、碳酸钠、醋酸锌为添加剂 ,研究生产品质良好的菠菜挂面的最佳工艺。结果表明 :最佳的工艺参数为 ,菠菜为面粉质量的 30 % ,食盐为面粉的 2 .0 % ,碳酸钠为菠菜的 0 .2 % ,醋酸锌为菠菜的 0 .0 2 %。     

A link between virulence and ecological abundance in natural populations of Staphylococcus aureus

Staphylococcus aureus is a major cause of severe infection in humans and yet is carried without symptoms by a large proportion of the population. We used multilocus sequence typing to characterize isolates of S. aureus recovered from asymptomatic nasal carriage and from episodes of severe disease within a defined population. We identified a number of frequently carried genotypes that were disproportionately common as causes of disease, even taking into account their relative abundance among carriage isolates. The existence of these ecologically abundant hypervirulent clones suggests that factors promoting the ecological fitness of this important pathogen also increase its virulence.     

农科大学生吸烟现状调查分析

对在校1～4年级本科生采用“国际防痨和呼吸病联盟烟草与健康委员会”设计的调查表为基础,根据甘肃农业大学的生源实际情况,自行设计自填式问题调查表进行调查,共调查565人,对553份有效答卷进行统计分析。结果表明:大学生总吸烟率为63.8 %,其中每日吸烟者占18.8 %,偶尔吸烟者占45.0 %;烟卷种类有普通型和过滤嘴型,其中以过滤嘴烟卷为主,占74.2 %;每日吸烟10支以上占53.8 %;大学生对控制全社会吸烟的态度较积极。不吸烟的原因,60.6 % 的学生认为是“保护自己的身体健康”;30.4 % 的学生是“为了不使周围人感到讨厌”;34.5 % 的学生不吸烟是为了“省钱”。大学生对吸烟危害认识不清,不吸烟并不是源于自身健康的要求,而是屈从于外界条件,控制大学生吸烟需要全社会与学校的密切配合。     

EMS诱变对不同基因型胡麻种子萌发及M3农艺性状和品质性状的影响

以5个不同基因型胡麻品种为供试材料,用甲基磺酸乙酯（EMS）作诱变剂,设置5个诱变浓度和4个处理时间,探讨EMS诱变对不同基因型胡麻品种的诱变效应。结果表明,在不同品种间,尤其在不同颜色籽粒的品种间,EMS诱变对种子发芽率、田间相对出苗率的影响存在显著差异。EMS诱变对M3农艺和品质性状的诱变效应有正有负,不同品种和不同处理间存在差异。利用线性回归方程计算最佳EMS诱变条件,统计M3代不同处理品质性状高于对照的突变株数的比例,综合得到不同籽粒颜色胡麻品种的最佳诱变条件：褐色籽粒胡麻品种为（0.6%,4 h或2 h）,浅黄色籽粒品种为（0.3%,4 h）。通过EMS诱变创制高粗脂肪材料155份、高木酚素含量材料45份、高亚麻酸含量的材料26份,为胡麻品种品质改良提供了新的优异资源。