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卡拉麦里山是我多年魂牵梦萦之地。它起始了我野生动物摄影之路,让我流连忘返,如同患上“相思病”,总感到最好的片子还在下一次。虽然它也让我有过失望、痛苦,甚至是生命的代价,可还是无法阻止我迈向它的脚步。再去,再去…… 这是我第21次走进它,但决不是最后一次。 荒野“探戈” 2001年7月17日,我和弟弟冯强、老友孟宪新清晨6时离乌市第21次去卡拉麦里山。本想寻一条近路,结果却适得其反,多绕了近130公里路,跑坏了一条轮胎,午夜12点半才抵达卡拉麦里的拍摄地点。第  相似文献   

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Background

To convert deserts into arable, green landscapes is a global vision, and desert farming is a strong growing area of agriculture world-wide. However, its effect on diversity of soil microbial communities, which are responsible for important ecosystem services like plant health, is still not known.

Methodology/Principal Findings

We studied the impact of long-term agriculture on desert soil in one of the most prominent examples for organic desert farming in Sekem (Egypt). Using a polyphasic methodological approach to analyse microbial communities in soil as well as associated with cultivated plants, drastic effects caused by 30 years of agriculture were detected. Analysing bacterial fingerprints, we found statistically significant differences between agricultural and native desert soil of about 60%. A pyrosequencing-based analysis of the 16S rRNA gene regions showed higher diversity in agricultural than in desert soil (Shannon diversity indices: 11.21/7.90), and displayed structural differences. The proportion of Firmicutes in field soil was significantly higher (37%) than in the desert (11%). Bacillus and Paenibacillus play the key role: they represented 96% of the antagonists towards phytopathogens, and identical 16S rRNA sequences in the amplicon library and for isolates were detected. The proportion of antagonistic strains was doubled in field in comparison to desert soil (21.6%/12.4%); disease-suppressive bacteria were especially enriched in plant roots. On the opposite, several extremophilic bacterial groups, e.g., Acidimicrobium, Rubellimicrobium and Deinococcus-Thermus, disappeared from soil after agricultural use. The N-fixing Herbaspirillum group only occurred in desert soil. Soil bacterial communities were strongly driven by the a-biotic factors water supply and pH.

Conclusions/Significance

After long-term farming, a drastic shift in the bacterial communities in desert soil was observed. Bacterial communities in agricultural soil showed a higher diversity and a better ecosystem function for plant health but a loss of extremophilic bacteria. Interestingly, we detected that indigenous desert microorganisms promoted plant health in desert agro-ecosystems.  相似文献   

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Love is a complex neurobiological phenomenon, relying on trust, belief, pleasure and reward activities within the brain, i.e., limbic processes. These processes critically involve oxytocin, vasopressin, dopamine, and serotonergic signaling. Moreover, endorphin and endogenous morphinergic mechanisms, coupled to nitric oxide autoregulatory pathways, play a role. Naturally rewarding or pleasurable activities are necessary for survival and appetitive motivation, usually governing beneficial biological behaviors like eating, sex, and reproduction. Yet, a broad basis of common signaling and beneficial neurobiological features exists with connection to the love concept, thereby combining physiological aspects related to maternal, romantic or sexual love and attachment with other healthy activities or neurobiological states. Medical practice can make use of this concept, i.e., mind/body or integrative medicine. Thus, love, pleasure, and lust have a stress-reducing and health-promoting potential, since they carry the ability to heal or facilitate beneficial motivation and behavior. In addition, love and pleasure ensure the survival of individuals and their species. After all, love is a joyful and useful activity that encompasses wellness and feelings of well-being.  相似文献   

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Love does not necessarily benefit its object, and cost-free love may damage both object and subject. Our love of animals mobilises several distinct human concerns and should not be considered always as a virtue or always as a benefit to the animals themselves. We need to place this love in its full psychological, cultural, and moral context in order to assess what form it ought to take if animals are to benefit from it.  相似文献   

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Self-protection tendencies allowed our human ancestors to survive and thrive. In three experiments, we find that individuals who have a salient self-protection motive are more altruistic to others, such as by helping them out or offering them more money in the dictator game paradigm. Self-protecting individuals desire to “bind together” as there is “safety in numbers”, and being altruistic to others should be one (but not the only) way to achieve this goal. Consistent with this reasoning, we find across three behavioral experiments using both non-monetary (Experiment 1) and monetary altruistic contexts (Experiments 2–3) that self-protecting individuals are more altruistic when the altruism is not anonymous (Experiment 1) and when they have the reasonable expectation of future interaction with the recipient (Experiment 2), both of which are situations that should increase affiliation. The effect attenuates when altruism does not help self-protecting individuals, such as when money is donated to impersonal organizations rather than individuals (Experiment 3). We finally discuss the theoretical contributions as well as limitations of our work.  相似文献   

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