Beiträge zur Flora der Mark Brandenburg

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Beiträge zur Flora der Mark Brandenburg

Ohne Zusammenfassung     

Beiträge zur Flora der Mark Brandenburg

Ohne Zusammenfassung     

Beiträge zur Flora der Mark Brandenburg

Ohne Zusammenfassung     

Beiträge zur Flora der Mark Brandenburg

Ohne Zusammenfassung     

Versuch einer Uebersicht der V?gel der Mark

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Versuch einer Uebersicht der V?gel der Mark

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Mark—Recapture Accurately Estimates Census for Tuatara,a Burrowing Reptile

Abstract: Estimates of population size are necessary for effective management of threatened and endangered species, but accurate estimation is often difficult when species are cryptic. We evaluated effectiveness of mark–recapture techniques using the Lincoln–Peterson estimator for predicting true census size of a population of tuatara (Sphenodon punctatus), a burrowing reptile that is a conservation priority in New Zealand. We found that Lincoln–Peterson estimates (NŇ = 85) were accurate for predicting the census size (N = 87) after only a 3-day mark–recapture survey. We recommend this method as a cost-effective way to accurately estimate population size for isolated, inaccessible tuatara populations, because it requires limited personnel, expertise, and time, and has low environmental impact on fragile sites.     

Who is Who? Non-invasive Methods to Individually Sex and Mark Altricial Chicks

Many experiments require early determination of offspring''s sex as well as early marking of newborns for individual recognition. According to animal welfare guidelines, non-invasive techniques should be preferred whenever applicable. In our group, we work on different species of song birds in the lab and in the field, and we successfully apply non-invasive methods to sex and individually mark chicks. This paper presents a comprehensive non-invasive tool-box. Sexing birds prior to the expression of secondary sexual traits requires the collection of DNA-bearing material for PCR. We established a quick and easy method to sex birds of any age (post hatching) by extracting DNA from buccal swabs. Results can be obtained within 3 hours. For individual marking chick''s down feathers are trimmed in specific patterns allowing fast identification within the hatching order. This set of methods is easily applicable in a standard equipped lab and especially suitable for working in the field as no special equipment is required for sampling and storage. Handling of chicks is minimized and marking and sexing techniques are non-invasive thereby supporting the RRR-principle of animal welfare guidelines.     

Roles of electrostatic interaction and dispersion in CH···CH,CH···π, and π···π ethylene dimers

The structural, mechanical, electronic, and optical properties of orthorhombic Bi₂S₃ and Bi₂Se₃ compounds have been investigated by means of first principles calculations. The calculated lattice parameters and internal coordinates are in very good agreement with the experimental findings. The elastic constants are obtained, then the secondary results such as bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio, anisotropy factor, and Debye temperature of polycrystalline aggregates are derived, and the relevant mechanical properties are also discussed. Furthermore, the band structures and optical properties such as real and imaginary parts of dielectric functions, energy-loss function, the effective number of valance electrons, and the effective optical dielectric constant have been computed. We also calculated some nonlinearities for Bi₂S₃ and Bi₂Se₃ (tensors of elasto-optical coefficients) under pressure.

问·题·解·答

问:假根与真根有什么区别?答:假根,一般为低等植物所特有,是具有吸收和固着作用的丝状结构,分枝或不分枝,仅由伸长的单细胞或单列的多细胞所构成,无组织分化。如藻类、真菌就具有这种假根。但是现存的高等植物中,苔藓植物以及蕨类植物的原叶体上也具有假根。真根较之于假根,主要在于有机械、输导等组织的分化。真根植物可以说是由仅有假根的无根类型逐渐进化而来的。一般来说,蕨类的孢子体世代以及种子植物都具有。不过,在某些如水生或腐生的种子植物中,由于其生存环境的特殊性,     

自学·质疑·精讲·练习

自学·质疑·精讲·练习”课堂教学方法,简易可行,便于推广,适宜不同年级、不同教学内容,便于穿插演示实验、讲解法等其他教学方法,使学生的主体作用、教师的主导作用得以充分发挥,有利于增强学生的集体主义精神,有利于培养学生的自学能力,提高分析问题、解决问题...     

·科研快讯·

《科学-转化医学》:按摩或可加速受损肌肉康复按摩疗法近年来被越来越多的人所接受。一项新研究也显示,按摩疗法可通过与大多数镇痛药相同的生物学机制来减轻肌肉疼痛,可能有助于受损肌肉     

Effect of stepwise microhydration on the methylammonium···phenol and ammonium···phenol interaction

A computational study has been performed for studying the characteristics of the interaction of phenol with ammonium and methylammonium cations. The effect of the presence of water molecules has also been considered by microhydrating the clusters with up to three water molecules. Clusters of phenol with ammonium and methylammonium cations present similar characteristics, though ammonium complexes have been found to be more stable than the methylammonium ones. The first water molecule included in the complexes interacts with a N-H group of ammoniun cations and simultaneously with the hydroxyl oxygen atom of phenol (or the aromatic ring). This first water molecule is more tightly bound in the complex, so the stability gain as more water molecules are included drops significantly by 2-3 kcal?mol^?1 with respect to the first one. As more water molecules are included, the differences between favorable coordination sites (the cation, the hydroxyl group or a previous water molecule) decrease. As a consequence, several of the most stable complexes located including three water molecules already exhibit hydrogen bonds between the hydroxyl group and one water molecule. The results indicate that a cyclic pattern formed by a series of hydrogen bonds: π···H-N-H···O-H···O-?, is characteristic of the most stable minima, being kept as more water molecules are included in the system. Therefore, this pattern can be expected to be crucial in ammonium cations···phenol interaction if exposed to the solvent to any degree.     

爱鸟·观鸟·赏鸟·护鸟

<正>"春眠不觉晓,处处闻啼鸟",唐代诗人孟浩然的诗句是我们儿时便能诵读的。春天代表着希望,鸟类寓意着新生。在这样一个春光明媚的时刻,我们怎能忘怀"自在娇莺恰恰啼"的美丽画卷呢?说到鸟类,我们总有无限的美好遐思——它们自由奔放,翱翔长空。它们婀娜多姿,步态轻盈。它们歌喉动听,嘤嘤啼啭……鸟类是自     

读者·作者·审者·编者

《中国生物化学与分子生物学报》自2006年1月起改为月刊为缩短出版周期,提高期刊学术水平和刊印质量,经《中国生物化学与分子生物学报》编委会讨论决定,上报中国生物化学与分子生物学会同意,获得中国科协和北京市新闻出版局批准,本刊自2006年1月起改为月刊,每月20日出版.每期96