共查询到8条相似文献,搜索用时 15 毫秒
1.
Prof. Dr. Hans Joachim Gross 《当今生物学》2014,44(4):268-270
A revolution: the Clever Hans Phenomenon Verbal communication with animals or understanding animal language is an age old desire present in all human cultures. This dream seemed to come true 110 years ago, when a horse was presented which commmunicated with everybody and which was able to express human thoughts and ideas. The surprising solution of this miraculous phenomenon opened completely new and revolutionary insights into the possibilities and mechanisms of non‐verbal communication between humans and animals. This fundamental lesson has later often been neglected or even commpletely forgotten with the consequence that many animal experiments yielded questionable results. 相似文献
2.
Prof. Dr. Michael Wink 《当今生物学》2015,45(4):225-235
Secondary metabolites Already 400 million years ago when land plants evolved, they probably produced secondary metabolites as means of defence against herbivores, microbes and competing plants. Secondary metabolites usually are bioactive agents, which can interfere with molecular targets in animals and microbes. Therefore, many plants and substances isolated from them can serve as valuable drugs in medicine and pharmacy. Some secondary metabolites also serve as signal compounds to attract pollinating animals and seed‐dispersing animals, but also for UV protection, as antioxidants or mobile nitrogen stores. Biology and evolution but also physiological and genetic bases of secondary metabolism are discussed in this overview. 相似文献
3.
Eckart Voland Prof. Dr. 《当今生物学》2010,40(1):29-35
In this essay the author combines research findings and hypotheses to reach the conclusion that human religiousness may well arise from a variety of evolutionary adaptations. Though religions cannot be put to the test of hard science, religious customs and behaviour appear to be linked to adaptive advantages. These include improved ability to deal with crises and to overcome the temptation to benefit from the fruits of others' labours without paying, hence strengthening cooperation and moral solidarity, whilst improving competitiveness of the group with others. These behavioural traits fit well with the observation that human cognitive strategies are highly pre‐programmed to generate religious convictions. 相似文献
4.
《当今生物学》2018,48(1):45-53
The Cell Nucleus – A Town in the Cell. Part II: Chromatin Nanoarchitecture and Gene Regulation In the second part of this article on nuclear architecture we describe the ground‐breaking potential of super‐resolution fluorescence microscopy (nanoscopy) and new molecular approaches to study the structure of chromatin domains at the nanometer scale and explore their 3D positions in larger chromatin domain clusters. New results and models argue for a decisive role of these structures in nuclear functions, such as gene regulation. 相似文献
5.
Prof. Dr. Andreas Bürkert Sulaiman Al Khanjari Nadiya A. Al‐Saady Edmond De Langhe Dirk Hölscher Jens Gebauer Stephan Behrendt Stefan Happe Katja Brinkmann Eva Schlecht 《当今生物学》2010,40(5):334-341
Until recently little was known about the crop diversity in the Sultanate of Oman, situated at the NE tip of the Arabian Peninsula. Interdisciplinary research in the often millenia‐old oases provide evidence for their role as reservoirs for plant genetic resources of ancient varieties of wheat and banana. Two newly discovered banana clones show a highly efficient biochemical defense mechanisms against some of the most devastating pests and diseases of banana. If these mechanisms can be properly understood and exploited in breeding programs, may have major impact on the commercial production of edible banana. 相似文献
6.
Diethelm Kleiner 《当今生物学》2016,46(2):96-104
From bacterium to collective nets Many, possibly the majority of bacterial species can exhibit an individual (planctonic) or collective life style. Transition to collectivity is generally stimulated by external factors. Swarms enable more effective colonization of new niches, construction of biofilms provides protection from toxins and predators. Lack of specific nutrients forces use of collective survival strategies like formation of spores, fruiting bodies or heterocysts. Pathogens can overcome the defence mechanisms of the host by synchronized excretion of virulence factors. Transition to collective life styles is irreversible beyond a certain ”point of no return\". This irreversibility is due to the action of autocatalytic regulatory cycles. 相似文献
7.
Enthalpy change on the mixing of R- and S-enantiomers of chiral liquid compounds such as dimethyl malate (1), methyl 3-hydroxylbutanoate (2), 2-butanol (3), ethyl 4-chloro-3-hydroxylbutanoate (4), 1,3,3-trimethylbicycle-[2.2.1]heptan-2-one (5), 3,7-dimethyl-6-octenal (6), and 8-bromo-2,6-dimethyl-2-octene (7) is measured over the entire range of mole fractions at 298.15 K, albeit very small values. The mixing of chiral liquids of R-1 + S-1, R-2 + S-2, R-3 + S-3, R-6 + S-6, and R-7 + S-7 produces enthalpic destabilization over the entire range of mole fractions, while that of R-4 + S-4 and R-5 + S-5 shows enthalpic stabilization over entire compositions. Enthalpy change on mixing at an equimolar concentration and the intermolecular interaction obtained by the molecular mechanics calculations show a linear correlation, except for a few compounds measured. 相似文献
8.
Abstract. The fragmentation and deterioration of old‐growth forest habitat by modern forestry have become a major threat to species diversity in Fennoscandia. In order to develop a conservation strategy for the remaining diversity it is essential to identify the existing diversity and to develop appropriate conservation and monitoring programs. For these purposes indicators of conservation value for administrative prioritization are required. This study examines the predictability of plant and fungal species richness on two spatial scales on 46 isolated old‐growth forest islands (0.17 ‐ 12 ha) in a forest‐wetland mosaic. We explore (1) to what extent area, isolation and stand structure variables can explain the variation in species richness and (2) if richness patterns of individual species groups correlate. Isolation showed no relation to species richness. Area explained 50 ‐ 70% of the variation in total species richness and was positively related to the density of crustose lichens and Red‐list species in island interiors. Stand structure variables explained 28 ‐ 66% of the residual variation in total species richness after controlling for island size, and 15 ‐ 73% of the variation in density of species in island interiors. The highest predictability of species richness was found among substrate‐specific fungi and Red‐list species. Different stand structure variables were found to explain richness in the different species groups, and only among a few species groups species richness correlated. Thus, species richness of one single species group is unlikely to be a good indicator for total biodiversity. The results show that measurements of stand size and stand structure variables may be a strong complementary tool, and sometimes a substitute to extensive species inventories when one aims to estimate and monitor plant and fungal species diversity in old‐growth Picea abies forests. 相似文献