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1.
Jaakko Lumme Aila Oikarinen Seppo Lakovaara Risto Alatalo 《Journal of insect physiology》1974,20(10):2023-2033
Drosophila littoralis overwinters in the adult stage in a reproductive diapause. During the warm season there are one or two generations in Finland. The diapause appears to be a prolongation of the post-eclosion immaturity of young females. The termination of diapause is controlled by a combination of adequate temperature and sufficiently long photophases. The diapausing status of females is ascertained by inspecting the developmental stage of their ovaries. In laboratory experiments the maturity of ovaries is not closely correlated with the receptivity of females. 相似文献
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Karri Silventoinen Sampo Sammalisto Markus Perola Dorret I Boomsma Belinda K Cornes Chayna Davis Leo Dunkel Marlies De Lange Jennifer R Harris Jacob V B Hjelmborg Michelle Luciano Nicholas G Martin Jakob Mortensen Lorenza Nisticò Nancy L Pedersen Axel Skytthe Tim D Spector Maria Antonietta Stazi Gonneke Willemsen Jaakko Kaprio 《Twin research》2003,6(5):399-408
A major component of variation in body height is due to genetic differences, but environmental factors have a substantial contributory effect. In this study we aimed to analyse whether the genetic architecture of body height varies between affluent western societies. We analysed twin data from eight countries comprising 30,111 complete twin pairs by using the univariate genetic model of the Mx statistical package. Body height and zygosity were self-reported in seven populations and measured directly in one population. We found that there was substantial variation in mean body height between countries; body height was least in Italy (177 cm in men and 163 cm in women) and greatest in the Netherlands (184 cm and 171 cm, respectively). In men there was no corresponding variation in heritability of body height, heritability estimates ranging from 0.87 to 0.93 in populations under an additive genes/unique environment (AE) model. Among women the heritability estimates were generally lower than among men with greater variation between countries, ranging from 0.68 to 0.84 when an additive genes/shared environment/unique environment (ACE) model was used. In four populations where an AE model fit equally well or better, heritability ranged from 0.89 to 0.93. This difference between the sexes was mainly due to the effect of the shared environmental component of variance, which appears to be more important among women than among men in our study populations. Our results indicate that, in general, there are only minor differences in the genetic architecture of height between affluent Caucasian populations, especially among men. 相似文献
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The sediments and various organisms in Lake Päijänne were examined for contaminants. The average mercury content of water plants was 9, of plankton 14, of sediment 114, of zoobenthic predators 83, of fish 332–1510 and of birds 240–13685 μg kg−1 (wet weight). The average PCB content of plants was 3, of plankton 21, of the zoobenthos 44, of fish 36-117 and of birds 219–13490 μg kg−1 . The average ΔDDT content of plants was 0.5, of plankton 6, of the zoobenthos 14, of fish 7–42 and of birds 144-8262 μg kg−1 . Regional differences in mercury content were most pronounced in sediment and fish. PCB concentration was highest near a town. ΔDDT was quite evenly distributed. Water plant species did not differ from each other, nor did the plankton fractions. The zoobenthic predators contained more chlorinated hydrocarbons than did the herbivores. There were clear differences between most species of fish and the chlorinated hydrocarbon content was highest in vendace. In adult birds levels of all residues were significantly higher than in juveniles.
In most cases PCB content was positively correlated with ΔDDT and in birds PCB, ΔDDT and mercury levels were correlated. DDT residues occurred mostly as DDE, but in vendace the proportion of DDT was high. At most trophic levels, ΔDDT/PCB was 0.15-0.40 but in birds it reached 1–2. 相似文献
In most cases PCB content was positively correlated with ΔDDT and in birds PCB, ΔDDT and mercury levels were correlated. DDT residues occurred mostly as DDE, but in vendace the proportion of DDT was high. At most trophic levels, ΔDDT/PCB was 0.15-0.40 but in birds it reached 1–2. 相似文献
4.
Lahtinen SJ Ouwehand AC Reinikainen JP Korpela JM Sandholm J Salminen SJ 《Applied and environmental microbiology》2006,72(7):5132-5134
Plate counting and four culture-independent flow cytometric assays were used to determine the viability and intrinsic properties of three probiotic strains during storage. The strains showed reduction in plate counts but were able to maintain esterase activity, intact cytoplasmic membrane, and pH gradient. The apparently uncultivable probiotic cells were active and stress resistant. 相似文献
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Genetic and environmental influences on migraine: a twin study across six countries. 总被引:7,自引:0,他引:7
Elles J Mulder Caroline Van Baal David Gaist Mikko Kallela Jaakko Kaprio Dan A Svensson Dale R Nyholt Nicholas G Martin Alex J MacGregor Lynn F Cherkas Dorret I Boomsma Aarno Palotie 《Twin research》2003,6(5):422-431
Migraine is a common neurovascular brain disorder that is manifested in recurrent episodes of disabling headache. The aim of the present study was to compare the prevalence and heritability of migraine across six of the countries that participate in GenomEUtwin project including a total number of 29,717 twin pairs. Migraine was assessed by questionnaires that differed between most countries. It was most prevalent in Danish and Dutch females (32% and 34%, respectively), whereas the lowest prevalence was found in the younger and older Finnish cohorts (13% and 10%, respectively). The estimated genetic variance (heritability) was significant and the same between sexes in all countries. Heritability ranged from 34% to 57%, with lowest estimates in Australia, and highest estimates in the older cohort of Finland, the Netherlands, and Denmark. There was some indication that part of the genetic variance was non-additive, but this was significant in Sweden only. In addition to genetic factors, environmental effects that are non-shared between members of a twin pair contributed to the liability of migraine. After migraine definitions are homogenized among the participating countries, the GenomEUtwin project will provide a powerful resource to identify the genes involved in migraine. 相似文献
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Péter Poczai Jaakko Hyvönen János Taller Gizella Jahnke László Kocsis 《Plant Molecular Biology Reporter》2013,31(2):371-386
Teleki rootstocks are used in grapevine-producing countries all over the world. They represent one of the largest groups of available rootstocks but their origin is still in dispute although they have been regarded as Vitis berlandieri × V. riparia hybrids. To investigate their possible origin, we amplified and sequenced three chloroplast regions, two non-coding spacers (trnL-F, trnS-G) and the trnL group I intron in a core collection of Teleki rootstocks representing widespread accessions and related wild North American grape species (V. berlandieri, V. riparia and V. rupestris). Concatenated sequence data coupled with microstructural changes discovered in the chloroplast regions provided data to trace the maternal ancestry of the Teleki lines. All chloroplast regions showed both nucleotide and length variation. Length mutations in the non-coding regions represented mostly simple sequence repeats of poly-A and -T stretches. These indel characters exhibited additional diversity comparable with the nucleotide diversity and increased resolution of the phylogenetic trees. We found that a group of Teleki accessions position together with the wild grape species V. riparia. Another group of Teleki rootstocks formed a sister group to the other North American species V. berlandieri. These clades had moderate support values, and they do not share ancestry with other accessions of Teleki rootstocks resolved with high support value in the V. riparia clade. It seems that Teleki-Kober 5BB and 125 AA accessions might have a V. berlandieri maternal background. We also found great differences within putative clones of Teleki 5C and Teleki-Kober 5BB suggesting that the selection of these accessions was performed on heterogenous or mislabeled plant material collectively maintained under these names. 相似文献