Mir-106b对阿尔茨海默病昼夜节律调控的初步研究

目的探讨mir-106b在阿尔茨海默病发病中的作用。方法取6月龄APPswe/PSΔE9小鼠脑组织,进行microRNA芯片的检测;利用real-time PCR对芯片检测结果进行验证;构建mir-106b表达载体,将其转染至SH-SY5Y细胞中构建mir-106b稳定转染的稳转细胞系。用Targetsan、Pictar、miRanda等靶基因预测软件,对mir-106b的靶基因进行预测,根据靶基因的功能选择可能与AD发病相关的靶基因,并用Western blot对所选择的靶基因在稳转细胞中的表达进行验证。用双荧光素酶报告检测系统检测mir-106b与其靶基因的结合位点。结果芯片结果显示,与野生型小鼠相比,6月龄APPswe/PSΔE9小鼠脑组织中mir-106b的表达下降,经real-time PCR验证,mir-106b的表达在APPswe/PSΔE9小鼠脑组织中的表达较野生型小鼠升高,差别具有统计学意义（P=0.03）。mir-106b稳转细胞系较对照mir-106b的表达升高2～5倍。神经PAS结构域蛋白2（neuronal PAS domain protein2,NPAS2）在mir-106b稳转细胞中的表达明显下降。双荧光素酶报告实验证实：与对照相比,带有NPAS2的3＇UTR的荧光素酶报告载体与mir-106b表达载体共转染,海肾荧光素酶/萤火虫荧光素酶的相对活性降低;荧光素酶报告载体的NPAS2-3＇UTR突变后与mir-106b表达载体共转染,海肾荧光素酶/萤火虫荧光素酶的相对活性升高。结论mir-106b可能通过调节机体生物钟基因NPAS2的表达,影响阿尔茨海默病人的生活节律,参与阿尔茨海默病的发生。     

用科学试验的原理和方法进行食用菌实验教学

分析原有食用菌实验教学中可能存在的问题,提出食用菌科学试验课程的任务,陈述在食用菌实验教学中进行科学试验的具体内容和方法,讨论实验教学中进行科学试验的目的意义。     

Grooming in desert bighorn sheep (Ovis canadensis mexicana) and the ghost of parasites past

Ectoparasites such as ticks have a negative effect on host fitness,whereas parasite-defense grooming is effective in removing ticks.The central control (programmed grooming) model proposes thatanimals engage in preventive tick-defense grooming in responseto an internal timing mechanism, even in the absence of peripheralstimulation from parasites. This model predicts that smalleranimals will groom more frequently than larger ones becauseof the higher cost of parasitism for a small animal (body sizeprinciple). The peripheral stimulation (stimulus driven) modelpredicts no size-related differences in grooming rate in theabsence of tick bite irritation. We observed grooming behaviorin a Chihuahuan desert population of bighorn sheep (Ovis canadensismexicana), where ticks have been absent for perhaps thousandsof years. Although not exposed to ticks, bighorns self groomedby means of oral and scratch grooming, albeit at very low ratescompared to size-matched ungulates in both tick-infested andtick-free environments. Logistic regression and general linearmodels revealed both the probability that grooming was performedduring a 10-min focal sample and the rate of grooming when itoccurred was greater for younger, smaller age/sex categoriesof less body mass. Oral and scratch grooming were negativelyassociated with body mass during both years, with juveniles(X = 15 kg) grooming the most frequently and the oldest males(X = 70–85 kg) grooming the least. Assuming that programmedgrooming evolved in a tick-infested environment, the currentgrooming behavior of this population is a relict of their ancestralenvironment, an adaptation to the "ghost of parasites past."     

Sex allocation and reproductive success in the andromonoecious perennial Solanum carolinense (Solanaceae). I. Female

Relative allocation of resources to growth vs. reproduction has long been known to be an important determinant of reproductive success. The importance of variation in allocation to different structures within reproductive allocation is somewhat less clear. This study was designed to elucidate the importance of allocation to vegetative vs. reproductive functions, and allocation within reproductive functions (sex allocation), to realized female success in an andromonoecious plant, Solanum carolinense. Allocation measurements were taken on plants in experimental arrays exposed to natural pollination conditions. These measurements included total flower number, the proportion of flowers that were male, flower size, and vegetative size. Flower number explained the majority of the variation among individuals in their success-that is, there was strong selection for increased flower production. There was also selection to decrease the proportion of flowers that were male, but neither flower size nor vegetative size (a measure of overall resource availability) were direct determinants of female success. After Bonferroni corrections for multiple comparisons, most phenotypic correlations among the traits measured were nonsignificant. Thus, in this andromonoecious species there is not a strong relationship between resource availability (vegetative size) and female success, and female success is instead determined by the relative production of the two different flower types.     

A simple permutation-type method for testing circular uniformity with correlated angular measurements

A simple method is provided for testing uniformity on the circle that allows dependence among repeated angular measurements on the same subject. Our null hypothesis is that the distribution of repeated angles is unaffected by rotation. This null can be evaluated with any test of uniformity by using a null reference distribution obtained by simulation, where each subject's vector of angles is rotated by a random amount. A new weighted version of the univariate Rayleigh test of circular uniformity is proposed.     

Difference in food selection between patas monkeys (Erythrocebus patas) and tantalus monkeys (<Emphasis Type="Italic">Cercopithecus aethiops tantalus</Emphasis>) in Kala Maloue National Park,Cameroon, in relation to nutrient content

Phytochemical or nutrient analyses of primate diets have revealed clues to their food selection in a single species. On the other hand, few interspecific comparisons of phytochemical or nutrient composition of primate diets have been made, although diets are considered to differ in phytochemical or nutrient content from primate species to species, since different species have different body weights and different morphological and physiological characteristics. I compared the nutrient content of diet between patas monkeys (Erythrocebus patas) and tantalus monkeys (Cercopithecus aethiops tantalus) living sympatrically in Cameroon. Patas subsisted on a smaller number of food items, most of which were also tantalus food items. Then, I compared the protein–fiber ratio and the available energy content of the food items eaten by patas (patas foods) with those items eaten only by tantalus (tantalus foods). Both variables were higher in patas than tantalus foods, although there was no significant difference in available energy of plant foods. Next, when I performed discriminant analysis for patas foods and tantalus foods, employing the above two variables, a discriminant function with positive coefficients for both variables was obtained. The mean discriminant-function score of patas foods was higher than that of tantalus foods. Despite being somewhat larger in weight, patas selectively fed on a smaller number of foods of higher quality than did tantalus. I discuss why the results are inconsistent with a well known body weight–diet relationship (Jarman–Bell principle). Energy-efficient locomotion enables patas to exploit not only small dispersed food items of high quality but also areas where high-quality foods are distributed in clumps. Electronic Publication     

On the pungent principle of Matricaria pubescens

The pungent principle of the aerial parts and roots of Matricaria pubescens has shown to be the known thienyl-hexadien-isobutylamide. The structure was confirmed by ¹³C NMR analysis. In addition, the roots afforded small amounts of decadien-isobutylamide, and the aerial parts afforded large amounts of herniarin. The chemosystematic significance of amide accumulation within the tribe Anthemideae is briefly discussed.     

皖南尖吻蝮蛇蛇毒中纤溶组分的荧光特性

用荧光光谱方法研究了皖南尖吻蝮蛇蛇毒中纤溶组分。研究了Ａｃｒ对ＦＰ内源发光的影响,结果表明,每个ＦＰ分子含有多个Ｔｒｐ残基,这些Ｔｒｐ残基约有８３％可被Ａｃｒ所淬灭,而且这些Ｔｒｐ残基位于ＦＰ分子的较疏水环境中。