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AimThe aim of our paper was to explore expressions of life choices and life chances (aspects of agency within structures) related to power and experiences of health among early unemployed adolescent young men during the transition period to adulthood. These expressions of agency within structure were interpreted in the light of Cockerham’s Health Lifestyles Theory. Furthermore, social constructions of masculinities were addressed in our analysis.MethodsRepeated interviews with ten young men in a cohort of school leavers were analyzed with qualitative content analysis.ConclusionsQualitative research could contribute to develop the understanding of the agency within structure relationships. Future studies need to pay attention to experiences of health among young people at the margin of the labor market in various milieus – and to analyze these in relation to gender constructions and within the frame-work of agency within structure. 相似文献
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Herbert Braunschmid Bernadette Mükisch Thomas Rupp Irmgard Schäffler Pietro Zito Daniele Birtele Stefan Dötterl 《Arthropod-Plant Interactions》2017,11(3):363-379
Floral scent is a key mediator in many plant–pollinator interactions. It is known to vary not only among plant species, but also within species among populations. However, there is a big gap in our knowledge of whether such variability is the result of divergent selective pressures exerted by a variable pollinator climate or alternative scenarios (e.g., genetic drift). Cypripedium calceolus is a Eurasian deceptive lady’s-slipper orchid pollinated by bees. It is found from near sea level to altitudes of 2500 m. We asked whether pollinator climate and floral scents vary in a concerted manner among different altitudes. Floral scents of four populations in the Limestone Alps were collected by dynamic headspace and analyzed by gas chromatography coupled to mass spectrometry (GC/MS). Flower visitors and pollinators (the subset of visitors with pollen loads) were collected and identified. Preliminary coupled gas chromatographic and electroantennographic measurements with floral scents and pollinators revealed biologically active components. More than 70 compounds were detected in the scent samples, mainly aliphatics, terpenoids, and aromatics. Although several compounds were found in all samples, and all samples were dominated by linalool and octyl acetate, scents differed among populations. Similarly, there were strong differences in flower visitor spectra among populations with most abundant flower visitors being bees and syrphid flies at low and high altitudes, respectively. Pollinator climate differed also among populations; however, independent of altitude, most pollinators were bees of Lasioglossum, Andrena, and Nomada. Only few syrphids acted as pollinators and this is the first record of flies as pollinators in C. calceolus. The electrophysiological tests showed that bees and syrphid flies sensed many of the compounds released by the flowers, among them linalool and octyl acetate. Overall, we found that both floral scent and visitor/pollinator climate differ among populations. We discuss whether interpopulation variation in scent is a result of pollinator-mediated selection. 相似文献
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Phylogenetic signals in thermal traits remain stronger in the tropics if we can believe published physiological data. A reply to McKechnie et al., “Data quality problems undermine analyses of endotherm upper critical temperatures” 下载免费PDF全文
Christian Hof Susanne A. Fritz Roland Prinzinger Markus Pfenninger Katrin Böhning‐Gaese Imran Khaliq 《Journal of Biogeography》2017,44(10):2427-2431
Due to concerns about data quality, McKechnie, Coe, Gerson, and Wolf ( 2016 ) questioned the conclusions of our study (Khaliq et al., 2015 ) published in this journal. Here, we argue that most of the questioned data points are in fact useful for macrophysiological analyses, mostly because the vast majority of data are explicitly reported in the peer‐reviewed physiological literature. Furthermore, we show that our conclusions remain largely robust irrespective of the data inclusion criterion. While we think that constructive debates about the adequate use of primary data in meta‐studies as well as more transparency in data inclusion criteria are indeed useful, we also emphasize that data suitability should be evaluated in the light of the scope and scale of the study in which they are used. We hope that this discussion will not discourage the exchange between disciplines such as biogeography and physiology, as this integration is needed to address some of the most urgent scientific challenges. 相似文献
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Christoph Syldatk Vera Lehmensiek Gaby Ulrichs Ulrich Bilitewski Karsten Krohn Hartmut Höke Fritz Wagner 《Biotechnology letters》1992,14(2):99-104
Summary Resting cells of a mutant ofArthrobacter sp. (DSM 3747) were used for the bioconversion of D,L-5-benzylhydantoin and related compounds to the corresponding L-amino acids. After optimization of the reaction conditions in shake flask experiments, bioconversions were performed in a preparative scale in a 2-l-bioreactor under nitrogen atmosphere. Specific productivities of 0.4 (p-NO2-L-phenylalanine) up to 3.9 mM amino acid x g cell dry mass–1 x h–1 (p-Cl-L-phenylalanine) were obtained. D,L-5-p-COOH-Benzylhydantoin, D,L-5-phenylhydantoin and D,L-5-p-OH-phenylhydantoin were not accepted as substrates. 相似文献
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F Gümü?el R H Cool A Weijland P H Anborgh A Parmeggiani 《Biochimica et biophysica acta》1990,1050(1-3):215-221
Mutagenesis was carried out in the N-terminal domain of elongation factor Tu (EF-Tu) to characterize the structure-function relationships of this model GTP binding protein with respect to stability, the interaction with GTP and GDP, and the catalytic activity. The substitutions were introduced in elements around the guanine nucleotide binding site or in the loops defining this site, in the intact molecule or in the isolated N-terminal domain (G domain). The double substitution Val88----Asp and Leu121----Lys, two residues situated on two vicinal alpha-helices, influences the basic activities of the truncated factor to a limited extent, probably via long-range interactions, and induces a destabilisation of the G domain structure. The functional alterations brought about by substitutions on the consensus sequences 18-24 and 80-83 highlight the importance of these residues for the interaction with GTP/GDP and the GTPase activity. Mutations concerning residues interacting with the guanine base lead to proteins in large part insoluble and inactive. In one case, the mutated protein (EF-TuAsn135----Asp) inhibited the growth of the host cell. This demonstrates the crucial role of the base specificity for the active conformation of EF-Tu. The obtained results are discussed in the light of the three-dimensional structure of EF-Tu. 相似文献
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