四川乐山市发现较大群的家燕及一例斑头雁留此越冬

2008年1月17日下午4时左右,笔者在四川乐山市水口镇大渡河边发现1只家燕正在河面低空飞行捕食.2008年1月25日西华师范大学杨志松博士在该市岷江边天池村及金灯村一带先后发现5小群家燕,分别为4只、1只、10只、1只和3只;同日,胡杰博士在该市青衣江边(金水湾至乐山高新区江段)也发现2小群家燕,分别为4只和6只.     

莴苣授粉前后中央细胞中钙的分布(简报)

Ca2 作为植物生长发育过程中的必需元素之一,通过特定的时、空分布参与调控植物生长发育的诸多发育过程[1].中央细胞是胚囊中体积最大的细胞,与卵器共同构成雌性生殖单位.在被子植物双受精作用中,卵细胞与一个精细胞融合形成胚,中央细胞与另一个精细胞融合并发育成胚乳,为胚的发育提供营养.     

水果湖湾蓝藻水华的形成及其对东湖影响的评价

东湖是武汉市最重要的湖泊,位于湖北省武汉市武昌区,属中型浅水湖泊,它集饮用水源、旅游、疗养、气候调节、水产养殖和水上运动等多功能于一体[1].因此,东湖水质的好坏与武汉人民的生活密切相关.     

Human Immunodeficiency Virus (HIV) infection model based on triangular neutrosophic cubic hesitant fuzzy number

In this paper,we define the basic concept of triangular neutrosophic cubic hesitant fuzzy number and their properties.We develop a triangular neutrosophic cubic hesitant fuzzy ordered weighted arithmetic averaging (TNCIIFOWAA) operator and a triangular neu-trosophic cubic hesitant fuzzy ordered weighted geometric averaging (TNCIIFOWGA) operator to aggregate triangular neutrosophic cubic hesitant fuzzy number (TNCHFN) information and investigate their properties.Furthermore,a multiple attribute decision-making method based on the TNCHFOWAA operator and triangular neutrosophic cubic hesitant fuzzy ordered weighted geometric (TNCHFOWG) operator and the score function of TNCHFN is established under a TNCHFN environment.Finally,an illustrative example of investment alternatives is given to demonstrate the application and effec-tiveness of the developed approach.     

椰子杂种优势及其利用研究进展(综述)

概述了国内外椰子杂交研究情况,并分析椰子杂交种在营养生长、产量、品质、抗性等方面的表现,认为椰子杂交种具有较强的杂种优势,利用前景广阔.     

我国农业微生物学的先驱——张宪武

张宪武(英文名Hsien Wu Chang,原籍河北献县)1905年8月6日生在吉林省吉林市一个比较富裕的商业资本家家庭,1920年毕业于吉林省立模范小学,1927年毕业于天津南开中学理科,1931年在燕京大学化学系毕业.     

A generalization of Poisson-Sujatha distribution and its applications to ecology

A generalization of Poisson Sujatha distribution(AGPSD),which includes Poisson-Lindley distribution(PLD)and Poisson-Sujatha distribution(PSD)as particular cases,has been proposed and studied.Its moments and moments-based measures including coefficient of variation,skewness,kurtosis and index of dispersion have been obtained and their behaviors have been discussed.The estimation of its parameters has been discussed with maximum likelihood estimation.The applications of the proposed distribution has been explained through two examples of count data from ecology and the goodness of fit of the distribution has been compared with Poisson distribution,PLD and PSD.     

微生物在水环境污染物降解中的应用

每年有大量来自工业、农业、养殖业和城市污水处理厂的废水被排入到水环境中,因此,地球上的水环境面临大量来自生活废水、工农业废水、非法排放的废水及其它废水的污染物质(如抗生素、杀虫剂,除草剂、烃等)的严重挑战,特别是近年来随着集约化养殖的发展,废水污染问题日益突出,并且随着分析手段的进步,能够检测到被排入水环境中的化学污染物质也越来越多,这些化学污染物对水环境中的生物产生有害影响.但是,微生物在污染控制上具有许多重要的作用.因此,本文对微生物在水环境污染物降解中的应用进行了评论.结果表明微生物主要是应用在水产养殖水中,而在其它的水体系(如河、湖、海)的应用较少.     

广东发现细裂玉凤花

2007年9月,对广东省惠州市新墟镇白云嶂进行植物学考察时,在一个斜坡上的一片次生阔叶林的潮湿林缘,发现了兰科植物细裂玉凤花Habenaria leptoloba Benth。此植物的模式产地为香港,第一次采集时间为1857年,后来虽在香港仍有发现,但事隔150年后才在广东发现。     

空桐树的化学成分研究(英文)

从空桐树(Paulownia kawakamii)首次提取分离出7个化合物,经波谱分析和化学反应,分别鉴定为α-lapachone(1)、9-hydroxy-α-lapachone(2)、黄钟花醌(3)、芝麻素(4)、泡桐素(5)、谷甾醇棕榈酸脂(6)和β-谷甾醇(7).     

低温环境中乳酸菌的开发利用

乳酸菌作为一种益生资源,越来越为人们所重视.在自然界存在的乳酸菌中,有一类虽然人们一直在利用,但是还没有充分的研究和开发,这类乳酸菌就是低温环境中生长的乳酸菌.国外目前所见有关低温乳酸菌的报道多集中于低温冷藏肉、鱼制品及泡菜中的乳酸菌,集中研究和应用的菌属主要包括Leuconostoc和Lactobacillus,而国内这方面的研究并不多见.笔者根据目前国内外低温乳酸菌的研究现状,阐述了其存在环境、种类及相应作用,并对其研究涉及的领域、趋势及应用前景进行了探讨和展望,以期为国内这类乳酸菌资源的研究开发提供参考和依据.     

川西古尔沟农耕区冬季小型兽类的初步研究

将冬季川西古尔沟农耕区小型兽类生境划分为河岸灌丛、农田、山地灌丛3个生境,利用Shannon-Winer指数计算各群落的多样性和均匀性,发现各生境的冬季小型兽类群落都以社鼠为主要群落组成物种,其中河岸灌丛生境的物种多样性指数(H)和均匀性指数(E)分别是0.9219和0.5817;农田生境的H=0.6144,E=0.3876;山地灌丛生境的H=0.7959,E=0.3427.同时对各群落的优势种社鼠按臼齿磨损度划分年龄组,发现冬季只有成年Ⅰ组、成年Ⅱ组、近老体组、老年组4个年龄阶段的个体,没有幼体组和亚成体组的个体.可以认为种群来年的繁殖力较稳定,不存在爆发的可能性.     

一种改进的平板影印工具及其应用

[目的]建立一种简便高效的平板影印工具,克服传统影印工具的缺陷.[方法]将大量竹签按照一定方法捆扎成与平皿内盖直径相近的捆,将单根牙签转移菌落的效果进行扩大,从而实现菌落的大规模转移.[结果]本实验室使用上述工具成功地进行了平板影印和传代,并进行转化子大规模筛选.[结论]与传统工具相比,该影印工具更为经济简便,而且效果清晰,为微生物平板筛选提供新的方法和思路.国家发明专利申请号:2007100291331.     

穿越时空的手迹

现代的人们迄今还没有弄明白,远古人类为什么要在许多岩石上留下各种各样的岩画或者人类自己的手印,而且,随着这些印记不断增加的发现,人们对它们的好奇心也就越重。在我国的历史记载中,最早是在公元5世纪北魏地理学家郦道元在《水经注》里著录黄河自宁夏流入内蒙古途中的岩画:“河水又东北。历石岩山西,尽着虎马之状,粲然成群,类似图马。故亦谓之画石山也”,这应该是世界上最早记录岩画的著作。人类童年的遗物人类自从出现在地球上以来,已经走过了几十万年的发展史,目前正处在一个人生的“青壮年”时期。岩画是刻绘、凿刻在岩崖或石块上的…     

玛丽·安宁与她的化石发现

玛丽·安宁是十九世纪英国著名的化石收藏与发现家,当时许多重要的古生物研究都源于她的化石发现。1799年玛丽·安宁出生于英国南部多而特海岸的一个贫苦家庭,从小就在家附近的一个叫来姆利吉的悬崖边采拾被海浪冲刷出来的贝壳化石,收集并买给当地的富人和收藏家以补贴家中的生     

关于生物学研究模型教学的一点思考

如何利用现有的资源提高生物学教学效果.应该补充现代生物学发展历史和生物研究多样化模型两方面的知识.提供了学生应该掌握的研究历史和研究模型方面的基本脉络.     

自贡恐龙博物馆巡礼

2007年元旦假期细雨沥沥,我还是兴致勃勃,去参观了自贡恐龙博物馆。我从怀化火车站出发,坐了一昼夜火车到达重庆,再转坐大巴车到达自贡汽车总站。随便找一家招待所住下,就打听怎样去自贡恐龙博物馆的公交线路。我是元月5日坐15路公交车前往自贡恐龙博物馆的,该馆离我住处大约有10公里,路况较好,不一会儿就到达了目的地,当我走进博物馆广场时,被眼前的场景吸引住了,首先进入眼帘是“恐龙群窟,世界奇观”横匾立在进口处,使人为之一振,遐想联翩。游人广场中央“大地留痕”和“生命之泉”雕塑格外显眼,示意着地球的产生和生命的诞生,追根求源,世…     

The fly factor phenomenon is mediated by interkingdom signaling between bacterial symbionts and their blow fly hosts

We tested the recent hypothesis that the"fly factor"phenomenon(food cur-rently or previously fed on by flies attracts more flies than the same type of food kept inccessible to flies)is mediated by bacterial symbionts deposited with feees or regur-gitated by feeding flies.We allowed laboratory-reared black blow flies,Phormia regina(Meigen),to feed and de fecate on bacterial Luria-Bertani medium solidified with agar,and isolated seven morphologically distinct bacterial colonies.We identified these us-ing matrix-assisted laser desorption/ionization mass spectrometry and sequencing of the 165 rRNA gene.In two-choice laboratory experiments,traps baited with cultures of Pro-teus mirabilis Hauser,Morganella morganii subsp.sibonii Jensen,or Serratia marcescens Bizio,captured significantly more flies than corresponding control jars baited with tryptic soy agar only.A mixture of seven bacterial strains as a trap bait was more attractive to flies than a single bacterial isolate(M.m.siboni).In a field experiment,traps baited with agar cultures of P:mirabilis and M.m siboni in combination captured significantly more flies than lraps baited with either bacterial isolate alone or the agar control.As evident by gas chromatography-mass spectrometry,the odor profiles of bacterial isolates differ,which may explain the additive effect of bacteria to the attractiveness of bacterial trap baits.As"generalist bacteria,"P mirabilis and M.m.sibonii growing on animal protein(beef liver)or plant protein(tofu)are similarly effective in attracting flies.Bacteria-derived airborne semiochemicals appear to mediate foraging by flies and to inform their feeding and oviposition decisions.     

A conformable mathematical model for alcohol consumption in Spain

A study on the conformable model of alcohol consumption in Spain has been presented.For the proposed model,the existence as well as the uniqueness of the solution has been discussed with the help of fixed-point theory.An analytical technique,Variational Iteration Method (VIM),has been used to obtain the solution to the governing system of differential equations.With the help of suitable plots,the role of fractional order derivative has been highlighted.For decreasing values of fractional order derivative,decrease in the number of non-consumers and non-risk consumers has been observed.By increasing the value of fractional order derivative,a sharp decrease can be seen in the compartment of risk-consumers.The agreement between the current study and the already existing studies,with ordinary derivatives,has also been pointed out.     

cGAS guards against chromosome endto-end fusions during mitosis and facilitates replicative senescence

As a sensor of cytosolic DNA, the role of cyclic GMP-AMP synthase (cGAS) in innate immune response is well established, yet how its functions in different biological conditions remain to be elucidated. Here, we identify cGAS as an essential regulator in inhibiting mitotic DNA double-strand break (DSB) repair and protecting short telomeres from end-to-end fusion independent of the canonical cGAS-STING pathway. cGAS associates with telomeric/subtelomeric DNA during mitosis when TRF1/TRF2/POT1 are deficient on telomeres. Depletion of cGAS leads to mitotic chromosome end-to-end fusions predominantly occurring between short telomeres. Mechanistically, cGAS interacts with CDK1 and positions them to chromosome ends. Thus, CDK1 inhibits mitotic non-homologous end joining (NHEJ) by blocking the recruitment of RNF8. cGAS-deficient human primary cells are defective in entering replicative senescence and display chromosome end-to-end fusions, genome instability and prolonged growth arrest. Altogether, cGAS safeguards genome stability by controlling mitotic DSB repair to inhibit mitotic chromosome end-to-end fusions, thus facilitating replicative senescence.