Search results for "Fisher"
showing 10 items of 1727 documents
High microbial diversity promotes soil ecosystem functioning
2018
ABSTRACT In soil, the link between microbial diversity and carbon transformations is challenged by the concept of functional redundancy. Here, we hypothesized that functional redundancy may decrease with increasing carbon source recalcitrance and that coupling of diversity with C cycling may change accordingly. We manipulated microbial diversity to examine how diversity decrease affects the decomposition of easily degradable (i.e., allochthonous plant residues) versus recalcitrant (i.e., autochthonous organic matter) C sources. We found that a decrease in microbial diversity (i) affected the decomposition of both autochthonous and allochthonous carbon sources, thereby reducing global CO 2 e…
Tillage Changes Vertical Distribution of Soil Bacterial and Fungal Communities.
2018
Tillage can strongly affect the long-term productivity of an agricultural system by altering the composition and spatial distribution of nutrients and microbial communities. The impact of tillage methods on the vertical distribution of soil microbial communities is not well understood, and the correlation between microbial communities and soil nutrients vertical distributions is also not clear. In the present study, we investigated the effects of conventional plowing tillage (CT: moldboard plowing), reduced tillage (RT: rotary tillage), and no tillage (NT) on the composition of bacterial and fungal communities within the soil profile (0-5, 5-10, 10-20, and 20-30 cm) using high-throughput se…
How do microbial communities in top-and subsoil respond to root litter addition under field conditions?
2016
Abstract Contrasting microbial community composition and activity at different soil depths may affect root litter decomposition. These effects have up to now been investigated mainly in laboratory studies, which may not be able to take into account complex in situ conditions. Our study aimed to analyze the composition and activity of microbial communities after addition of 13 C labeled wheat root litter to a loamy soil under grassland at 30, 60 and 90 cm depths, during a three-year field experiment. We investigated the dynamics of bacterial and fungal abundances and community structures by DNA genotyping and pyrosequencing of 16S and 18S rDNAs. The genetic structures of bacterial and fungal…
Inhibited fatty acid β-oxidation impairs stress resistance ability in Nile tilapia (Oreochromis niloticus)
2017
Energy metabolism plays important roles in stress resistance and immunity in mammals, however, such functions have not been established in fish. In the present study, Nile tilapia (Oreochromis niloticus) was fed with mildronate, an inhibitor of mitochondrial fatty acid (FA) β-oxidation, for six weeks subsequently challenged with Aeromonas hydrophila and ammonia nitrogen exposure. Mildronate treatment reduced significantly l-carnitine concentration and mitochondrial FA β-oxidation efficiency, while it increased lipid accumulation in liver. The fish with inhibited hepatic FA catabolism had lower survival rate when exposed to Aeromonas hydrophila and ammonia nitrogen. Moreover, fish fed mildro…
Immunity and inflammatory responses in gilthead sea bream (Sparus aurata L.) exposed to sub-lethal mixture of carbamazepine, cadmium chloride and pol…
2020
Chemical contaminants such as industrial and urban by-products, pharmaceuticals, drugs metabolites and, plastics, are continuously found in the oceans, affecting its quality and organism's welfare. Although these compounds are found at concentrations ranged ng L−1, there is an increasing concern about the potential adverse effects of the interactions among those substances present, simultaneously, in a mixture. In the present study, specimens of sea bream (Sparus aurata) were exposed, by food, to rising concentrations of a mixture of carbamazepine, polybrominated diphenyl ether-47 and cadmium chloride, for 15 days and then, maintained, with the same control diet, without contaminants, for o…
Dominant Tree Species and Soil Type Affect the Fungal Community Structure in a Boreal Peatland Forest
2016
ABSTRACT Boreal peatlands play a crucial role in global carbon cycling, acting as an important carbon reservoir. However, little information is available on how peatland microbial communities are influenced by natural variability or human-induced disturbances. In this study, we have investigated the fungal diversity and community structure of both the organic soil layer and buried wood in boreal forest soils using high-throughput sequencing of the internal transcribed spacer (ITS) region. We have also compared the fungal communities during the primary colonization of wood with those of the surrounding soils. A permutational multivariate analysis of variance (PERMANOVA) confirmed that the co…
Epigenetic mutations can both help and hinder adaptive evolution.
2015
Epigenetic variation is being integrated into our understanding of adaptation, yet we lack models on how epigenetic mutations affect evolution that includes de novo genetic change. We model the effects of epigenetic mutations on the dynamics and endpoints of adaptive walks—a process where a series of beneficial mutations move a population towards a fitness optimum. We use an individual-based model of an asexual population, where mutational effects are drawn from Fisher's geometric model. We find cases where epigenetic mutations speed adaptation or result in populations with higher fitness. However, we also find cases where they slow adaptation or result in populations with lower fitness. Th…
Under control: how a dietary additive can restore the gut microbiome and proteomic profile, and improve disease resilience in a marine teleostean fis…
2017
[Background]: The constant increase of aquaculture production and wealthy seafood consumption has forced the industry to explore alternative and more sustainable raw aquafeed materials, and plant ingredients have been used to replace marine feedstuffs in many farmed fish. The objective of the present study was to assess whether plant-based diets can induce changes in the intestinal mucus proteome, gut autochthonous microbiota and disease susceptibility of fish, and whether these changes could be reversed by the addition of sodium butyrate to the diets. Three different trials were performed using the teleostean gilthead sea bream (Sparus aurata) as model. In a first preliminary short-term tr…
Potential risk analysis of human anisakiasis through the consumption of mackerel, Scomber scombrus, sold at Spanish supermarkets
2016
Abstract Herein, the potential risk of human anisakiasis through the consumption of mackerel, Scomber scombrus , sold at nationwide Spanish supermarket chains is assessed, by means of the identification of anisakid and other nematode species found, and the analysis of intrinsic and extrinsic factors that may influence the prevalence and abundance of nematode worms, as well as their presence in the viscera or in the flesh. 231 fresh mackerel specimens caught between 2008 and 2014 (140 from the Atlantic and 91 from the Mediterranean), captured in autumn and spring and acquired at nationwide Spanish supermarket chains, were examined dissecting their viscera and submitting their flesh to artifi…
Ecological network analysis reveals the inter-connection between soil biodiversity and ecosystem function as affected by land use across Europe
2016
Soil organisms are considered drivers of soil ecosystem services (primary productivity, nutrient cycling, carbon cycling, water regulation) associated with sustainable agricultural production. Soil biodiversity was highlighted in the soil thematic strategy as a key component of soil quality. The lack of quantitative standardised data at a large scale has resulted in poor understanding of how soil biodiversity could be incorporated into legislation for the protection of soil quality. In 2011, the EcoFINDERS (FP7) project sampled 76 sites across 11 European countries, covering five biogeographical zones (Alpine, Atlantic, Boreal, Continental and Mediterranean) and three land-uses (arable, gra…