Elevated asymmetric dimethylarginine (ADMA) and inverse correlation between circulating ADMA and glomerular filtration rate in children with sporadic focal segmental glomerulosclerosis (FSGS)

Background. Steroid-resistant nephrotic syndromes (NS) with focal and segmental glomerulosclerosis (FSGS) can be differentiated into sporadic and syndromic forms. In sporadic NS, a circulating FSGS-factor is discussed in the pathogenesis and is thought to inhibit the synthesis of nitric oxide (NO) from l-arginine by blocking the NO synthase (NOS). Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of all types of NOS. In a previous study we did not find an elevation of ADMA in a syndromic form of FSGS, the Schimke-immuno-osseous dysplasia. Here we report for the first time data on the l-arginine/NO pathway in sporadic FSGS of childhood. Methods. Nine children (5 to 18 years of age) suffering from sporadic FSGS and age-matched healthy controls were investigated. ADMA in plasma and urine as well as l-arginine in plasma were determined by gas chromatography-tandem mass spectrometry. The NO metabolites nitrate and nitrite were measured in plasma and urine by gas chromatography-mass spectrometry (GC-MS). The ADMA metabolite dimethylamine (DMA) was measured in urine by GC-MS. Results. We found elevated plasma levels of ADMA in children suffering from sporadic FSGS compared to healthy controls (851 nmol/L versus 684 nmol/L, P = 0.008). An inverse correlation between ADMA and glomerular filtration rate (GFR) was found in sporadic FSGS (Pearson's correlation coefficient −0.784, P = 0.012). Conclusion. Our study suggests that ADMA synthesis is elevated in sporadic FSGS. This finding argues for the involvement of ADMA in the pathogenesis of this disease in childhoo

Postglacial species arrival and diversity buildup of northern ecosystems took millennia

What drives ecosystem buildup, diversity, and stability? We assess species arrival and ecosystem changes across 16 millennia by combining regional-scale plant sedimentary ancient DNA from Fennoscandia with near-complete DNA and trait databases. We show that postglacial arrival time varies within and between plant growth forms. Further, arrival times were mainly predicted by adaptation to temperature, disturbance, and light. Major break points in ecological trait diversity were seen between 13.9 and 10.8 calibrated thousand years before the present (cal ka BP), as well as break point in functional diversity at 12.0 cal ka BP, shifting from a state of ecosystem buildup to a state where most habitat types and biotic ecosystem components were in place. Trait and functional diversity stabilized around 8 cal ka BP, after which both remained stable, although changes in climate took place and species inflow continued. Our ecosystem reconstruction indicates a millennial-scale time phase of formation to reach stable and resilient levels of diversity and functioning.publishedVersio

Past climate‐driven range shifts and population genetic diversity in arctic plants

High intra-specific genetic diversity is necessary for species adaptation to novel environments under climate change, but species tracking suitable conditions are losing alleles through successive founder events during range shift. Here, we investigated the relationship between range shift since the Last Glacial Maximum (LGM) and extant population genetic diversity across multiple plant species to understand variability in species responses.Location: The circumpolar Arctic and northern temperate alpine ranges.Methods: We estimated the climatic niches of 30 cold-adapted plant species using range maps coupled with species distribution models and hindcasted species suitable areas to reconstructions of the mid-Holocene and LGM climates. We computed the species-specific migration distances from the species glacial refugia to their current distribution and correlated distances to extant genetic diversity in 1295 populations. Differential responses among species were related to life-history traits.Results: We found a negative association between inferred migration distances from refugia and genetic diversities in 25 species, but only 11 had statistically significant negative slopes. The relationships between inferred distance and population genetic diversity were steeper for insect-pollinated species than wind-pollinated species, but the difference among pollination system was marginally independent from phylogenetic autocorrelation.Main conclusion: The relationships between inferred migration distances and genetic diversities in 11 species, independent from current isolation, indicate that past range shifts were associated with a genetic bottleneck effect with an average of 21% loss of genetic diversity per 1000 km−1. In contrast, the absence of relationship in many species also indicates that the response is species specific and may be modulated by plant pollination strategies or result from more complex historical contingencies than those modelled here

The regional species richness and genetic diversity of Arctic vegetation reflect both past glaciations and current climate

AIM : The Arctic has experienced marked climatic differences between glacial and interglacial periods and is now subject to a rapidly warming climate. Knowledge of the effects of historical processes on current patterns of diversity may aid predictions of the responses of vegetation to future climate change. We aim to test whether plant species and genetic diversity patterns are correlated with time since deglaciation at regional and local scales. We also investigate whether species richness is correlated with genetic diversity in vascular plants. LOCATION : Circumarctic. METHODS : We investigated species richness of the vascular plant flora of 21 floristic provinces and examined local species richness in 6215 vegetation plots distributed across the Arctic. We assessed levels of genetic diversity inferred from amplified fragment length polymorphism variation across populations of 23 common Arctic species. Correlations between diversity measures and landscape age (time since deglaciation) as well as variables characterizing current climate were analysed using spatially explicit simultaneous autoregressive models. RESULTS : lts Regional species richness of vascular plants and genetic diversity were correlated with each other, and both showed a positive relationship with landscape age. Plot species richness showed differing responses for vascular plants, bryophytes and lichens. At this finer scale, the richness of vascular plants was not significantly related to landscape age, which had a small effect size compared to the models of bryophyte and lichen richness. MAIN CONCLUSION : Our study suggests that imprints of past glaciations in Arctic vegetation diversity patterns at the regional scale are still detectable today. Since Arctic vegetation is still limited by post-glacial migration lag, it will most probably also exhibit lags in response to current and future climate change. Our results also suggest that local species richness at the plot scale is more determined by local habitat factors.Compilation of the species richness data was made possible through the TFI Networks grant to CD, “Effect Studies and Adaptation to Climate Change,” under the Norforsk initiative (2011 – 2014) which supported two CBIONET-AVA workshops held in Denmark during 2013. The genetic studies were funded by the Research Council of Norway (grant nos. 150322/720 and 170952/V40 to CB).http://http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1466-82382017-04-30hb2016Plant Production and Soil Scienc

Willful ignorance: the avoidance of ethical attribute information

textProduct attribute information is not always readily available to consumers. This is especially true for ethical attributes such as labor practices, environmental friendliness, animal testing, etc. Normatively, consumers who would use an attribute in their decision making should seek that attribute information, especially if it is offered or is easily obtainable. Additionally, it seems clear-cut that if a consumer especially cares about an attribute, information about this attribute should be requested in order that it might be used in making a more well-informed decision. To avoid the attribute information would not be the obvious option. Yet, in a series of studies, I show that avoidance of ethical attribute information does occur, often when one would least expect it. In three studies I measure discrepancies between requests for available ethical attribute information and actual use of the same attribute information in a conjoint task. In both between-subject and within-subject designs I show that consumers (1) avoid ethical attribute information, and (2) counter-intuitively, are especially likely to avoid the information if they care about the underlying ethical issue. The avoidance of negative emotions, especially the avoidance of anger, appears to drive this patently nonnormative behavior. These findings add to the growing literature on avoidance and consumer decision making, and furthermore help to clarify why ethical attributes do not appear to play as strong a role in the marketplace as might be expected.Marketin

That’s Not How I Remember It: Willfully Ignorant Memory for Ethical Product Attribute Information

Abstract This research documents a systematic bias in memory for ethical attribute information: consumers have better memory for an ethical attribute when a product performs well on the attribute versus when a product performs poorly on the attribute. Because consumers want to avoid emotionally difficult ethical information (e.g., child labor) but believe they should remember it in order to do the right thing, the presence of negative ethical information in a choice or evaluation produces conflict between the want and should selves. Consumers resolve this conflict by letting the want self prevail and forgetting or misremembering the negative ethical information. A series of studies establishes the willfully ignorant memory effect, shows that it holds only for ethical attributes and not for other attributes, and provides process evidence that it is driven by consumers allowing the want self to prevail in order to avoid negative feelings associated with the conflict. We also ameliorate the effect by reducing the amount of pressure exerted by the should self. Lastly, we demonstrate that consumers judge forgetting negative ethical information as more morally acceptable than remembering but ignoring it, suggesting that willfully ignorant memory is a more morally acceptable form of coping with want/should conflict

Long-distance plant dispersal to North Atlantic islands: colonization routes and founder effect

Long-distance dispersal (LDD) processes influence the founder effect on islands.We use genetic data for 25 Atlantic species and similarities among regional floras to analyse colonization, and test whether the genetic founder effect on five islands is associated with dispersal distance, island size and species traits. Most species colonized postglacially via multiple dispersal events from several source regions situated 280 to .3000 km away, and often not from the closest ones. A strong founder effect was observed for insect-pollinated mixed maters, and it increased with dispersal distance and decreased with island size in accordance with the theory of island biogeography. Only a minor founder effect was observed for wind-pollinated outcrossing species. Colonization patterns were largely congruent, indicating that despite the importance of stochasticity, LDD is mainly determined by common factors, probably dispersal vectors. Our findings caution against a priori assuming a single, close source region in biogeographic analyses. Amplified fragment length polymorphism (AFLP); dispersal vector; founder effect; genetic diversity; islands; long-distance dispersal (LDD); postglacial; species traits

Spatiotemporal distribution of Arctic herbivores in spring: Potential for competition?

Biotic interactions are important to the structure and dynamics of food webs and may affect the spatial and temporal distribution of species. In the Arctic, spring snow-cover limits food availability at a critical time for herbivores, potentially leading to resource competition. This study investigates the potential for competition over forage resources during spring in a high-Arctic herbivore community comprising the resident, endemic Svalbard reindeer (Rangifer tarandus platyrhynchus) and Svalbard rock ptarmigan (Lagopus muta hyperborea), and the migratory pink-footed goose (Anser brachyrhynchus) and barnacle goose (Branta leucopsis). First, we investigated herbivore behaviour that could indicate the potential for competition by conducting a field study, and second, we quantified the effects of snow-cover extent, vegetation type and presence of potential herbivore competitors on the spatiotemporal distributions of herbivores using camera-traps in one early and one late snow melt year. Only reindeer and geese appeared with sufficient sample sizes for analysis. The field study revealed that reindeer and geese foraged in the same areas, particularly moss tundra habitats. Although geese were regularly alerted by reindeer, no direct aggressive interactions were observed. The camera-trap study showed that neither of the herbivores significantly affected the spatiotemporal distribution of its potential competitor, but reindeer and goose distribution was instead driven by snow-cover extent and vegetation type. However, the shared space use by these species may lead to different types of interactions, such as facilitation or exploitative competition, which require further assessment, including dietary overlap studies, particularly in the context of climate change-induced shifts in snow melt timing and herbivore abundances

Long-distance plant dispersal to North Atlantic islands: colonization routes and founder effect

Long-distance dispersal (LDD) processes influence the founder effect on islands.We use genetic data for 25 Atlantic species and similarities among regional floras to analyse colonization, and test whether the genetic founder effect on five islands is associated with dispersal distance, island size and species traits. Most species colonized postglacially via multiple dispersal events from several source regions situated 280 to .3000 km away, and often not from the closest ones. A strong founder effect was observed for insect-pollinated mixed maters, and it increased with dispersal distance and decreased with island size in accordance with the theory of island biogeography. Only a minor founder effect was observed for wind-pollinated outcrossing species. Colonization patterns were largely congruent, indicating that despite the importance of stochasticity, LDD is mainly determined by common factors, probably dispersal vectors. Our findings caution against a priori assuming a single, close source region in biogeographic analyses. Amplified fragment length polymorphism (AFLP); dispersal vector; founder effect; genetic diversity; islands; long-distance dispersal (LDD); postglacial; species traits