90 research outputs found
Constitutive expression and distinct properties of IFN-epsilon protect the female reproductive tract from Zika virus infection
The immunological surveillance factors controlling vulnerability of the female reproductive tract (FRT) to sexually transmitted viral infections are not well understood. Interferon-epsilon (IFNε) is a distinct, immunoregulatory type-I IFN that is constitutively expressed by FRT epithelium and is not induced by pathogens like other antiviral IFNs α, β and λ. We show the necessity of IFNε for Zika Virus (ZIKV) protection by: increased susceptibility of IFNε -/- mice; their “rescue” by intravaginal recombinant IFNε treatment and blockade of protective endogenous IFNε by neutralising antibody. Complementary studies in human FRT cell lines showed IFNε had potent anti-ZIKV activity, associated with transcriptome responses similar to IFNλ but lacking the proinflammatory gene signature of IFNα. IFNε activated STAT1/2 pathways similar to IFNα and λ that were inhibited by ZIKV-encoded non-structural (NS) proteins, but not if IFNε exposure preceded infection. This scenario is provided by the constitutive expression of endogenous IFNε. However, the IFNε expression was not inhibited by ZIKV NS proteins despite their ability to antagonise the expression of IFNβ or λ. Thus, the constitutive expression of IFNε provides cellular resistance to viral strategies of antagonism and maximises the antiviral activity of the FRT. These results show that the unique spatiotemporal properties of IFNε provides an innate immune surveillance network in the FRT that is a significant barrier to viral infection with important implications for prevention and therapy.Rosa C. Coldbeck-Shackley, Ornella Romeo, Sarah Rosli, Linden J. Gearing, Jodee A. Gould, San S. Lim, Kylie H. Van der Hoek, Nicholas S. Eyre, Byron Shue, Sarah A. Robertson, Sonja M. Best, Michelle D. Tate, Paul J. Hertzog, Michael R. Bear
Prediction of the in vivo mechanical behavior of biointegrable acrylic macroporous scaffolds
[EN] This study examines a biocompatible scaffold series of random copolymer networks P(EA-HEA) made of Ethyl Acrylate, EA, and 2-Hydroxyl Ethyl Acrylate, HEA. The P(EA-HEA) scaffolds have been synthesized with varying crosslinking density and filled with a Poly(Vinyl Alcohol), PVA, to mimic the growing cartilaginous tissue during tissue repair. In cartilage regeneration the scaffold needs to have sufficient mechanical properties to sustain the compression in the joint and, at the same time, transmit mechanical signals to the cells for chondrogenic differentiation. Mechanical tests show that the elastic modulus increases with increasing crosslinking density of P(EA-HEA) scaffolds. The water plays an important role in the mechanical behavior of the scaffold, but highly depends on the crosslinking density of the proper polymer. Furthermore, when the scaffold with hydrogel is tested it can be seen that the modulus increases with increasing hydrogel density. Even so, the mechanical properties are inferior than those of the scaffolds with water filling the pores. The hydrogel inside the pores of the scaffolds facilitates the expulsion of water during compression and lowers the mechanical modulus of the scaffold. The P(EA-HEA) with PVA shows to be a good artificial cartilage model with mechanical properties close to native articular cartilage.This work was funded by the Spanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2013-46467-C4-1-R (including the FEDER financial support). CIBER-BBN is an initiative funded by the VI National R&D&i Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program. CIBER actions are financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund. The authors acknowledge the assistance and advice of Electron Microscopy Service of the UPV.Vikingsson, L.; Antolinos Turpín, CM.; Gómez-Tejedor, JA.; Gallego Ferrer, G.; Gómez Ribelles, JL. (2016). Prediction of the in vivo mechanical behavior of biointegrable acrylic macroporous scaffolds. Materials Science and Engineering: C. 61:651-658. https://doi.org/10.1016/j.msec.2015.12.068S6516586
Co-limitation towards lower latitudes shapes global forest diversity gradients
The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers
Integrated global assessment of the natural forest carbon potential
Forests are a substantial terrestrial carbon sink, but anthropogenic changes in land use and climate have considerably reduced the scale of this system1. Remote-sensing estimates to quantify carbon losses from global forests2,3,4,5 are characterized by considerable uncertainty and we lack a comprehensive ground-sourced evaluation to benchmark these estimates. Here we combine several ground-sourced6 and satellite-derived approaches2,7,8 to evaluate the scale of the global forest carbon potential outside agricultural and urban lands. Despite regional variation, the predictions demonstrated remarkable consistency at a global scale, with only a 12% difference between the ground-sourced and satellite-derived estimates. At present, global forest carbon storage is markedly under the natural potential, with a total deficit of 226 Gt (model range = 151–363 Gt) in areas with low human footprint. Most (61%, 139 Gt C) of this potential is in areas with existing forests, in which ecosystem protection can allow forests to recover to maturity. The remaining 39% (87 Gt C) of potential lies in regions in which forests have been removed or fragmented. Although forests cannot be a substitute for emissions reductions, our results support the idea2,3,9 that the conservation, restoration and sustainable management of diverse forests offer valuable contributions to meeting global climate and biodiversity targets
The global distribution and drivers of wood density and their impact on forest carbon stocks.
The density of wood is a key indicator of the carbon investment strategies of trees, impacting productivity and carbon storage. Despite its importance, the global variation in wood density and its environmental controls remain poorly understood, preventing accurate predictions of global forest carbon stocks. Here we analyse information from 1.1 million forest inventory plots alongside wood density data from 10,703 tree species to create a spatially explicit understanding of the global wood density distribution and its drivers. Our findings reveal a pronounced latitudinal gradient, with wood in tropical forests being up to 30% denser than that in boreal forests. In both angiosperms and gymnosperms, hydrothermal conditions represented by annual mean temperature and soil moisture emerged as the primary factors influencing the variation in wood density globally. This indicates similar environmental filters and evolutionary adaptations among distinct plant groups, underscoring the essential role of abiotic factors in determining wood density in forest ecosystems. Additionally, our study highlights the prominent role of disturbance, such as human modification and fire risk, in influencing wood density at more local scales. Factoring in the spatial variation of wood density notably changes the estimates of forest carbon stocks, leading to differences of up to 21% within biomes. Therefore, our research contributes to a deeper understanding of terrestrial biomass distribution and how environmental changes and disturbances impact forest ecosystems
Motor planning ability is not related to lesion side or functional manual ability in children with hemiplegic cerebral palsy
Optimal task performance requires anticipatory planning to select the most appropriate movement strategy. There is conflicting evidence for hemispheric specialisation of motor planning, with some suggesting left hemisphere dominance, claiming that children with right hemiplegic cerebral palsy (HCP) are therefore disproportionally affected. An alternative view is that there is a positive relationship between functional ability (rather than side of lesion) and motor planning skill. We aimed to compare children with right and left HCP on motor planning ability and to explore its relationship with functional manual ability. Participants were 76 children with HCP (40 left HCP; 30 female), aged 4–15 years (Mean 9.09, SD 2.94). Motor planning was assessed using a measure of end-state comfort, which involved turning a hexagonal handle 180° without readjusting grasp. This is difficult, or in some cases impossible, to achieve unless an appropriate initial grasp is adopted. Children completed 24 turns (12 clockwise), which were video recorded for offline scoring. Functional manual ability was assessed with the ABILHAND-Kids questionnaire, completed by parents. Contrary to the existing literature, no differences were observed between right and left HCP. However, a significant interaction between direction of turn and side of hemiplegia indicated a preferential bias for turns in the medial direction, consistent with the “medial over lateral advantage”. There was no relationship between functional ability and motor planning. Therefore, motor planning may not be a priority for therapeutic intervention to improve functional ability in HCP
Developmental plasticity connects visual cortex to motoneurons after stroke
We report motor cortical function in the left occipital cortex of a subject who
suffered a left middle cerebral artery stroke early in development. Transcranial
magnetic stimulation of the left occipital cortex evoked contraction of right
hand muscles. Electroencephalogram recorded over the left occipital cortex
showed: 1) coherence with electromyogram from a right hand muscle; 2) a typical
sensorimotor Mu rhythm at rest that was suppressed during contraction of right
hand muscles. This is the first evidence that cortical plasticity extends beyond
reshaping of primary sensory cortical fields to respecification of the cortical
origin of subcortically projecting pathways
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