Tundra soil carbon is vulnerable to rapid microbial decomposition under climate warming

Microbial decomposition of soil carbon in high-latitude tundra underlain with permafrost is one of the most important, but poorly understood, potential positive feedbacks of greenhouse gas emissions from terrestrial ecosystems into the atmosphere in a warmer world. Using integrated metagenomic technologies, we showed that the microbial functional community structure in the active layer of tundra soil was significantly altered after only 1.5 years of warming, a rapid response demonstrating the high sensitivity of this ecosystem to warming. The abundances of microbial functional genes involved in both aerobic and anaerobic carbon decomposition were also markedly increased by this short-term warming. Consistent with this, ecosystem respiration (R eco) increased up to 38%. In addition, warming enhanced genes involved in nutrient cycling, which very likely contributed to an observed increase (30%) in gross primary productivity (GPP). However, the GPP increase did not offset the extra R eco, resulting in significantly more net carbon loss in warmed plots compared with control plots. Altogether, our results demonstrate the vulnerability of active-layer soil carbon in this permafrost-based tundra ecosystem to climate warming and the importance of microbial communities in mediating such vulnerability

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

The effect of pond dyes on oviposition and survival in wild UK Culex mosquitoes

British Culex pipiens complex [Culex pipiens sensu lato) mosquito distribution, abundance, and potential for disease transmission are intimately linked to their environment. Pond and lake dyes that block light to restrict algal photosynthesis are a relatively new product assumed to be an environmentally friendly since they are based on food dyes. Their use in urban garden ponds raises questions linked to mosquito oviposition, since coloured water can be an attractant. Culex (mostly pipiens) is commonly found in UK gardens and is a potential vector of viruses including the West Nile Virus (WNV). Any factors that significantly change the distribution and population of Cx pipiens could impact future risks of disease transmission. A gravid trap was used to catch female Cx pipiens mosquitoes for use in oviposition choice tests in laboratory and semi-field conditions. Two types of pond dye, blue and shadow (which looks slightly red), were tested for their impact on oviposition and survival of wild caught Cx pipiens. There were no significant differences in the number of egg batches laid when gravid mosquitoes were given a choice between either blue dye and clear water or shadow dye and clear water indicating that these dyes are not attractants. Larvae hatched from egg batches laid by wild-caught gravid females were used to measure survival to adulthood with or without dye, , in a habitat controlled to prevent further colonisation. The experiment was run twice, once in the summer and again in the autumn, whereas the dyes had no impact on emergence in the summer, there were highly significant reductions in emergence of adults in both dye treated habitats in the autumn. Containers with or without shadow dye were placed outside to colonise naturally and were sampled weekly for larvae and pupae over a 6 month period through summer and autumn. There was a significant negative effect of shadow dye on pupal abundance in a three week period over the summer, but otherwise there was no effect. It is likely that population abundance and food was a more powerful factor for mosquito survival than the dye

The mechanisms of action of metformin

Metformin is a widely-used drug that results in clear benefits in relation to glucose metabolism and diabetes-related complications. The mechanisms underlying these benefits are complex and still not fully understood. Physiologically, metformin has been shown to reduce hepatic glucose production, yet not all of its effects can be explained by this mechanism and there is increasing evidence of a key role for the gut. At the molecular level the findings vary depending on the doses of metformin used and duration of treatment, with clear differences between acute and chronic administration. Metformin has been shown to act via both AMP-activated protein kinase (AMPK)-dependent and AMPK-independent mechanisms; by inhibition of mitochondrial respiration but also perhaps by inhibition of mitochondrial glycerophosphate dehydrogenase, and a mechanism involving the lysosome. In the last 10 years, we have moved from a simple picture, that metformin improves glycaemia by acting on the liver via AMPK activation, to a much more complex picture reflecting its multiple modes of action. More work is required to truly understand how this drug works in its target population: individuals with type 2 diabetes

Drivers of population structure of the bottlenose dolphin (Tursiops truncatus) in the Eastern Mediterranean Sea

The drivers of population differentiation in oceanic high dispersal organisms, have been crucial for research in evolutionary biology. Adaptation to different environments is commonly invoked as a driver of differentiation in the oceans, in alternative to geographic isolation. In this study, we investigate the population structure and phylogeography of the bottlenose dolphin (Tursiops truncatus) in the Mediterranean Sea, using microsatellite loci and the entire mtDNA control region. By further comparing the Mediterranean populations with the well described Atlantic populations, we addressed the following hypotheses: (1) bottlenose dolphins show population structure within the environmentally complex Eastern Mediterranean Sea; (2) population structure was gained locally or otherwise results from chance distribution of preexisting genetic structure; (3) strong demographic variations within the Mediterranean basin have affected genetic variation sufficiently to bias detected patterns of population structure. Our results suggest that bottlenose dolphin exhibits population structures that correspond well to the main Mediterranean oceanographic basins. Furthermore, we found evidence for fine scale population division within the Adriatic and the Levantine seas. We further describe for the first time, a distinction between populations inhabiting pelagic and coastal regions within the Mediterranean. Phylogeographic analysis suggests that current genetic structure, results mostly from stochastic distribution of Atlantic genetic variation, during a recent postglacial expansion. Comparison with Atlantic mtDNA haplotypes, further suggest the existence of a metapopulation across North Atlantic/Mediterranean, with pelagic regions acting as source for coastal environments

Deciphering past and present atmospheric metal pollution of urban environments: The role of black crusts formed on historical constructions

Construction materials affected by black crusts (BCs) can be subjected to restoration, demolition, recycling or even to their management as waste products. Therefore, the determination of their chemical features should be considered a crucial step before undertaking any action. In this work, we present the development of an analytical methodology useful to be implemented as a routine screening tool to detect recent and past atmospheric emissions of heavy metals, nowadays superficially deposited or even encapsulated in BCs. For its development, BCs together with the underneath original substrate/construction material were sampled from the historical construction Punta Begona Galleries (Getxo, Basque Country, North of Spain). In order to detect quickly and in a cost-effective way the stratification of the metallic deposits in the BCs over time (surface or external/recent and internal/past), thin sections were analyzed by elemental spectroscopic imaging techniques (SEM-EDS and mu-ED-XRF). In the external part of the BCs, iron particles were mainly identified, whereas in the inner areas (past deposition events) of the most exposed BCs to the atmosphere, lead accumulations together with zinc and copper were identified. Additional Raman imaging studies allowed to perform the molecular speciation study of lead, identifying mainly laurionite (PbClOH) together with hydrocerussite (Pb-3(CO3)(2)(OH)(2)). The presence of the mentioned lead chloride hydroxide confirms the role of the marine aerosol (chloride input) in the formation of the metallic compounds. These experimental evidences were used to assist the chemical equilibrium models developed to explain the reactivity pathway, which lead to the formation of the identified compounds. Through ICP-MS and lead isotopic ratio analysis, more than 3000 mg kg(-1) of lead were quantified in the BCs, probably coming from the old emissions conducted by the old power station close to the construction,. That lead content can be high enough to consider those crusts as a source of metallic contamination and a possible risk to the environment and human health

Identification and Filtering of Uncharacteristic Noise in the CMS Hadron Calorimeter

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Flexible, actin-based ridges colocalise with the β1 integrin on the surface of melanoma cells

Using a combination of laser-scanning confocal microscopy and atomic force microscopy, we have identified flexible, actin-based structures on the surface of cells derived from the vertical growth phase of melanoma progression. These flexible structures, lacking on the surface of mature melanocytes, were observed on the surface of all four melanoma cell lines tested. Further investigation revealed that the β1 integrin colocalises with these actin-based ridges on the cell surface, whereas β1 integrin distribution in melanocytes did not correlate with actin-based structures. Fibronectin staining on the surface of melanoma cells was partially codistributed with the ridges. The combination of structural information derived from atomic force microscopy images and fluorescent imaging of the distribution of labelled proteins involved in invasion and metastasis has allowed us to identify a common feature that may be involved in disease progression, at the surface of vertical growth phase melanoma cells, despite the known variation in genetic composition of melanoma

Performance of CMS hadron calorimeter timing and synchronization using test beam, cosmic ray, and LHC beam data

This paper discusses the design and performance of the time measurement technique and of the synchronization systems of the CMS hadron calorimeter. Time measurement performance results are presented from test beam data taken in the years 2004 and 2006. For hadronic showers of energy greater than 100 GeV, the timing resolution is measured to be about 1.2 ns. Time synchronization and out-of-time background rejection results are presented from the Cosmic Run At Four Tesla and LHC beam runs taken in the Autumn of 2008. The inter-channel synchronization is measured to be within ±2 ns

Metabolic changes of salicylic acid-elicited Catharanthus roseus cell suspension cultures monitored by NMR-based metabolomics

The effect of salicylic acid (SA) on the metabolic profile of Catharanthus roseus suspension cells throughout a time course (0, 6, 12, 24, 48 and 72 h after treatment) was investigated using NMR spectroscopy and multivariate data analysis. When compared to control cell lines, SA-treated cells showed a high level of sugars (glucose and sucrose) up to 48 h after treatment, followed by a dynamic change in amino acids, phenylpropanoids, and tryptamine. Additionally, one compound—2,5-dihydroxybenzoic-5-O-glucoside—was detected solely in SA-treated cells