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1.
Martyn Rix 《Curtis's Botanical Magazine》2010,27(3):290-295
Tropaeolum speciosum Poepp. & Endl. is described and illustrated. Its habitat in the wild, and its pollination are discussed, and instructions for its successful cultivation are given. 相似文献
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Household‐level correlates of children's physical activity levels in and across 12 countries 下载免费PDF全文
Deirdre M. Harrington Fiona Gillison Stephanie T. Broyles Jean‐Philippe Chaput Mikael Fogelholm Gang Hu Rebecca Kuriyan Anura Kurpad Allana G. LeBlanc Carol Maher Jose Maia Victor Matsudo Timothy Olds Vincent Onywera Olga L. Sarmiento Martyn Standage Mark S. Tremblay Catrine Tudor‐Locke Pei Zhao Peter T. Katzmarzyk for the ISCOLE Research Group 《Obesity (Silver Spring, Md.)》2016,24(10):2150-2157
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Pair-formation behaviour among the Eiders began after the annual moult, in late September. There was a small peak of display in October and November and a large one in the following April and May. As a result, the female population became paired in two phases, up to 50% in the autumn and the remainder in the following spring. The seasonal cycle of the abundance of Leydig cells was bimodal, with a peak in October and a large one in April-May. That the peaks represent increased androgen production was supported by the cycles of Leydig cell enzyme activity and lipid content and of penis weight. The monthly means of Leydig cell abundance and of the rate of display were statistically correlated. Experiments with sexually quiescent males in eclipse plumage demonstrated that testosterone was capable of inducing pair-formation behaviour. Relatively advanced stages of spermatogenesis were found in autumn, and were maintained through the winter, complete development occurring in the spring. Seasonal changes in the production of pituitary gonadotropin followed a bimodal pattern with peaks in autumn and in the spring. Field evidence is presented which suggests that Follicle Stimulating Hormone and Luteinizing Hormone were produced at different phases of a circadian rhythm of photosensitivity. 相似文献
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Genetics of NAD metabolism in Salmonella typhimurium and cloning of the nadA and pnuC loci. 总被引:3,自引:2,他引:1 下载免费PDF全文
The nadA and pnuC loci of S. typhimurium were cloned and found to reside within a 2.2-kilobase region. Two-dimensional O'Farrell gel electrophoresis of the proteins produced after chloramphenicol amplification and subsequent release from chloramphenicol inhibition revealed NadA and PnuC to be 43,000- and 25,000-molecular-weight proteins, respectively. The data indicated that nadA and pnuC represent two distinct genes. 相似文献
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Martyn Kelly 《Ecological Indicators》2011,11(5):1492-1494
Many diatom-based methods have been proposed in recent years. Besse-Lototskaya et al. (2011) compare some of those developed for assessing inorganic nutrients. However, they fail to address the two questions of greatest interest to those who wish to use such metrics to inform decision-making. These questions are: what is the role of diatom-based trophic metrics in environmental management in Europe in the twenty-first century and do these indices represent causal relationships with underlying pressure gradients? The present economic climate means that Member States of the European Union will look more critically at all methods for assessing freshwater quality and developers need to ensure that their methods are “fit-for-purpose”. 相似文献