2,774 research outputs found
Lactate signalling regulates fungal β-glucan masking and immune evasion
AJPB: This work was supported by the European Research Council (STRIFE, ERC- 2009-AdG-249793), The UK Medical Research Council (MR/M026663/1), the UK Biotechnology and Biological Research Council (BB/K017365/1), the Wellcome Trust (080088; 097377). ERB: This work was supported by the UK Biotechnology and Biological Research Council (BB/M014525/1). GMA: Supported by the CNPq-Brazil (Science without Borders fellowship 202976/2014-9). GDB: Wellcome Trust (102705). CAM: This work was supported by the UK Medical Research Council (G0400284). DMM: This work was supported by UK National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC/K000306/1). NARG/JW: Wellcome Trust (086827, 075470,101873) and Wellcome Trust Strategic Award in Medical Mycology and Fungal Immunology (097377). ALL: This work was supported by the MRC Centre for Medical Mycology and the University of Aberdeen (MR/N006364/1).Peer reviewedPostprin
Early star-forming galaxies and the reionization of the Universe
Star forming galaxies represent a valuable tracer of cosmic history. Recent
observational progress with Hubble Space Telescope has led to the discovery and
study of the earliest-known galaxies corresponding to a period when the
Universe was only ~800 million years old. Intense ultraviolet radiation from
these early galaxies probably induced a major event in cosmic history: the
reionization of intergalactic hydrogen. New techniques are being developed to
understand the properties of these most distant galaxies and determine their
influence on the evolution of the universe.Comment: Review article appearing in Nature. This posting reflects a submitted
version of the review formatted by the authors, in accordance with Nature
publication policies. For the official, published version of the review,
please see http://www.nature.com/nature/archive/index.htm
Bacteria-Killing Type IV Secretion Systems
Bacteria have been constantly competing for nutrients and space for billions of years.
During this time, they have evolved many different molecular mechanisms by which
to secrete proteinaceous effectors in order to manipulate and often kill rival bacterial
and eukaryotic cells. These processes often employ large multimeric transmembrane
nanomachines that have been classified as types I–IX secretion systems. One of the
most evolutionarily versatile are the Type IV secretion systems (T4SSs), which have
been shown to be able to secrete macromolecules directly into both eukaryotic and
prokaryotic cells. Until recently, examples of T4SS-mediated macromolecule transfer
from one bacterium to another was restricted to protein-DNA complexes during
bacterial conjugation. This view changed when it was shown by our group that many
Xanthomonas species carry a T4SS that is specialized to transfer toxic bacterial effectors
into rival bacterial cells, resulting in cell death. This review will focus on this special
subtype of T4SS by describing its distinguishing features, similar systems in other
proteobacterial genomes, and the nature of the effectors secreted by these systems
and their cognate inhibitor
Wind speed variability over the Canary Islands, 1948-2014: focusing on trend differences at the land-ocean interface and below-above the trade-wind inversion layer
This study simultaneously examines wind speed trends at the land?ocean interface, and below?above the trade-wind inversion layer in the Canary Islands and the surrounding Eastern North Atlantic Ocean: a key region for quantifying the variability of trade-winds and its response to large-scale atmospheric circulation changes. Two homogenized data sources are used: (1) observed wind speed from nine land-based stations (1981?2014), including one mountain weather station (Izaña) located above the trade-wind inversion layer; and (2) simulated wind speed from two atmospheric hindcasts over ocean (i.e., SeaWind I at 30 km for 1948?2014; and SeaWind II at 15 km for 1989?2014). The results revealed a widespread significant negative trend of trade-winds over ocean for 1948?2014, whereas no significant trends were detected for 1989?2014. For this recent period wind speed over land and ocean displayed the same multi-decadal variability and a distinct seasonal trend pattern with a strengthening (late spring and summer; significant in May and August) and weakening (winter?spring?autumn; significant in April and September) of trade-winds. Above the inversion layer at Izaña, we found a predominance of significant positive trends, indicating a decoupled variability and opposite wind speed trends when compared to those reported in boundary layer. The analysis of the Trade Wind Index (TWI), the North Atlantic Oscillation Index (NAOI) and the Eastern Atlantic Index (EAI) demonstrated significant correlations with the wind speed variability, revealing that the correlation patterns of the three indices showed a spatio-temporal complementarity in shaping wind speed trends across the Eastern North Atlantic.C. A. -M. has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 703733 (STILLING project). This research was also supported by the Research Projects: Swedish BECC, MERGE, VR (2014–5320), PCIN-2015-220, CGL2014-52135-C03-01 and Red de variabilidad y cambio climático RECLIM (CGL2014-517221-REDT). M.M is indebted to the Spanish Government for funding through the “Ramón y Cajal” program and supported by Grant PORTIO (BIA2015-70644-R
A methodology for parameter estimation in seaweed productivity modelling
This paper presents a combined approach for parameter estimation in models of primary production.
The focus is on gross primary production and nutrient assimilation by seaweeds.
A database of productivity determinations, biomass and mortality measurements and nutrient uptake
rates obtained over one year for Gelidium sesquipedale in the Atlantic Ocean off Portugal has been used.
Annual productivity was estimated by harvesting methods, and empirical relationships using mortality/
wave energy and respiration rates have been derived to correct for losses and to convert the estimates
to gross production.
In situ determinations of productivity have been combined with data on the light climate (radiation
periods, intensity, mean turbidity) to give daily and annual productivity estimates. The theoretical nutrient
uptake calculated using a 'Redfield ratio' approach and determinations of in situ N and P consumption
by the algae during incubation periods have also been compared.
The results of the biomass difference and incubation approaches are discussed in order to assess the
utility of coefficients determined in situ for parameter estimation in seaweed production models
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