392 research outputs found
(S)norlaudanosoline synthase. the first enzyme in the benzylisoquinoline biosynthetic pathway
1. introduction Isoquinoline alkaloids form the largest group of alkaloids in the plant kingdom. Numerous publications deal with aspects of the biosynthesis of these compounds in vivo [ 11, while isoquinoline biosynthesis at the cell-free level had hardly been touched [Z]. The initial reaction in isoquinoline biosynthesis has long [3] been assumed to be a condensation of two aromatic units, both derived from tyrosine, namely dopamine and 3,4-d~ydroxyphenylacet~dehyde [4]. This scheme was later modified [5] where it was reported that condensation of dopamine with 3,4-dihydroxyphenylpyruvate would lead to an amino acid, norlaudanosoline-l-carboxylic acid, which in turn, by decarboxylation, would yield norlaudanosoline
Assessments of citizenship criteria:are immigrants more liberal?
The literature on citizenship policies is flourishing, yet we know little of which naturalisation requirements majorities and minorities find reasonable, and how they view existing citizenship regimes. Drawing on original survey data with young adults in Norway (N = 3535), comprising immigrants and descendants with origins from Iraq, Pakistan, Poland, Somalia and Turkey, as well as a nonimmigrant majority group, this article examines whether perceptions of ideal citizenship criteria and assessments of Norwayâs current rules differ between groups. In terms of ideal citizenship criteria, we find a striking similarity across groups when looking at six different dimensions of citizenship policy. When merged into an index and estimated in a multivariate regression model, we find that both immigrants and descendants are significantly more liberal than natives are, yet the differences are small. When assessing the semi-strict citizenship regime in Norway, we find that immigrants are significantly more positive towards the current rules than natives. The results lend little support to recent work on âstrategicâ and âinstrumentalâ citizenship and point instead to a close to universal conception of the terms of membership acquisition in Norway. This suggests that states may operate with moderate integration requirements while maintaining the legitimacy of the citizenship institution
Analysing diet of small herbivores: the efficiency of DNA barcoding coupled with high-throughput pyrosequencing for deciphering the composition of complex plant mixtures
Background
In order to understand the role of herbivores in trophic webs, it is essential to know what they feed on. Diet analysis is, however, a challenge in many small herbivores with a secretive life style. In this paper, we compare novel (high-throughput pyrosequencing) DNA barcoding technology for plant mixture with traditional microhistological method. We analysed stomach contents of two ecologically important subarctic vole species, Microtus oeconomus and Myodes rufocanus, with the two methods. DNA barcoding was conducted using the P6-loop of the chloroplast trnL (UAA) intron.
Results
Although the identified plant taxa in the diets matched relatively well between the two methods, DNA barcoding gave by far taxonomically more detailed results. Quantitative comparison of results was difficult, mainly due to low taxonomic resolution of the microhistological method, which also in part explained discrepancies between the methods. Other discrepancies were likely due to biases mostly in the microhistological analysis.
Conclusion
We conclude that DNA barcoding opens up for new possibilities in the study of plant-herbivore interactions, giving a detailed and relatively unbiased picture of food utilization of herbivores
Measurement of the top quark mass using the matrix element technique in dilepton final states
We present a measurement of the top quark mass in ppÂŻ collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. The data were collected by the D0 experiment corresponding to an integrated luminosity of 9.7ââfbâ1. The matrix element technique is applied to ttÂŻ events in the final state containing leptons (electrons or muons) with high transverse momenta and at least two jets. The calibration of the jet energy scale determined in the lepton+jets final state of ttÂŻ decays is applied to jet energies. This correction provides a substantial reduction in systematic uncertainties. We obtain a top quark mass of mt=173.93±1.84ââGeV
Kinned to be Norwegian : transnational adoptees' positioning in relation to whiteness and the negotiation of nationhood
Author's accepted version (postprint).This is an Accepted Manuscript of an article published by John Wiley & Sons Ltd in Nations and Nationalism on 13 April 2019.Available online: https://onlinelibrary.wiley.com/doi/full/10.1111/nana.12525acceptedVersio
Water scarcity hotspots travel downstream due to human interventions in the 20th and 21st century
Water scarcity is rapidly increasing in many regions. In a novel, multi-model assessment, we examine how human interventions (HI: land use and land cover change, man-made reservoirs and human water use) affected monthly river water availability and water scarcity over the period 1971â2010. Here we show that HI drastically change the critical dimensions of water scarcity, aggravating water scarcity for 8.8% (7.4â16.5%) of the global population but alleviating it for another 8.3% (6.4â15.8%). Positive impacts of HI mostly occur upstream, whereas HI aggravate water scarcity downstream; HI cause water scarcity to travel downstream. Attribution of water scarcity changes to HI components is complex and varies among the hydrological models. Seasonal variation in impacts and dominant HI components is also substantial. A thorough consideration of the spatially and temporally varying interactions among HI components and of uncertainties is therefore crucial for the success of water scarcity adaptation by HI
A national turn of local integration policy: multi-level governance dynamics in Denmark and Sweden
Underuse of medication for circulatory disorders among unmarried women and men in Norway?
BACKGROUND: It is well established that unmarried people have higher mortality from circulatory diseases and higher all-cause mortality than the married, and these marital status differences seem to be increasing. However, much remains to be known about the underlying mechanisms. Our objective was to examine marital status differences in the purchase of medication for circulatory diseases, and risk factors for them, which may indicate underuse of such medication by some marital status groups. METHODS: Using data from registers covering the entire Norwegian population, we analysed marital status differences in the purchase of medicine for eight circulatory disorders by people aged 50-79 in 2004-2008. These differences were compared with those in circulatory disease mortality during 2004-2007, considered as indicating probable differences in disease burden. RESULTS: The unmarried had 1.4-2.8 times higher mortality from the four types of circulatory diseases considered. However, the never-married in particular purchased less medicine for these diseases, or precursor risk factors of these diseases, primarily because of a low chance of making a first purchase. The picture was more mixed for the divorced and widowed. Both groups purchased less of some of these medicines than the married, but, especially in the case of the widowed, relatively more of other types of medicine. In contrast to the never-married, divorced and widowed people were as least as likely as the married to make a first purchase, but adherence rates thereafter, indicated by continuing purchases, were lower. CONCLUSION: The most plausible interpretation of the findings is that compared with married people, especially the never-married more often have circulatory disorders that are undiagnosed or for which they for other reasons underuse medication. Inadequate use of these potentially very efficient medicines in such a large population group is a serious public health challenge which needs further investigation. It is possible that marital status differences in use of medicines for circulatory disorders combined with an increasing importance of these medicines have contributed to the widening marital status gap in mortality observed in several countries. This also requires further investigation
Evolutionary winners are ecological losers among oceanic island plants
Aim
Adaptive radiation, in which successful lineages proliferate by exploiting untapped niche space, provides a popular but potentially misleading characterization of evolution on oceanic islands. Here we analyse the respective roles of members of in situ diversified vs. non-diversified lineages in shaping the main ecosystems of an archipelago to explore the relationship between evolutionary and ecological âsuccessâ.
Location
Canary Islands.
Taxon
Vascular plants.
Methods
We quantified the abundance/rarity of the native flora according to the geographical range (number of islands where present and geographical extent of the range), habitat breadth (climatic niche) and local abundance (cover) using species distribution data based on 500 Ă 500 m grid cells and 2000 vegetation inventories located all over the archipelago.
Results
Species of diversified lineages have significantly smaller geographic ranges, narrower climatic niches and lower local abundances than those of non-diversified lineages. Species rarity increased with the degree of diversification. The diversified Canarian flora is mainly comprised by shrubs. At both archipelagic and island level, the four core ecosystems (Euphorbia scrub, thermophilous woodlands, laurel forest and pine forest) were dominated by non-diversified lineages species, with diversified lineages species providing <25% cover. Species of diversified lineages, although constituting 54% of the archipelagic native flora, were only abundant in two rare ecosystems: high mountain scrub and rock communities.
Main conclusions
Radiated species, endemic products of in situ speciation, are mostly rare in all three rarity axes and typically do not play an important role in structuring plant communities on the Canaries. The vegetation of the major ecosystem types is dominated by plants representing non-diversified lineages (species that derive from immigration and accumulation), while species of evolutionarily successful lineages are abundant only in marginal habitats and could, therefore, be considered ecological losers. Within this particular oceanic archipelago, and we posit within at least some others, evolutionary success in plants is accomplished predominantly at the margins.publishedVersio
- âŠ