Extrinsic and intrinsic regulation of axon regeneration at a crossroads

Repair of the injured spinal cord is a major challenge in medicine. The limited intrinsic regenerative response mounted by adult central nervous system (CNS) neurons is further hampered by astrogliosis, myelin debris and scar tissue that characterize the damaged CNS. Improved axon regeneration and recovery can be elicited by targeting extrinsic factors as well as by boosting neuron-intrinsic growth regulators. Our knowledge of the molecular basis of intrinsic and extrinsic regulators of regeneration has expanded rapidly, resulting in promising new targets to promote repair. Intriguingly certain neuron-intrinsic growth regulators are emerging as promising targets to both stimulate growth and relieve extrinsic inhibition of regeneration. This crossroads between the intrinsic and extrinsic aspects of spinal cord injury is a promising target for effective therapies for this unmet need

Hydrodynamics of bilayer membranes with diffusing transmembrane proteins

International audienceWe consider the hydrodynamics of lipid bilayers containing transmembrane proteins of arbitrary shape. This biologically-motivated problem is relevant to the cell membrane, whose fluctuating dynamics play a key role in phenomena ranging from cell migration, intercellular transport, and cell communication. Using Onsager's variational principle, we derive the equations that govern the relaxation dynamics of the membrane shape, of the mass densities of the bilayer leaflets, and of the diffusing proteins' concentration. With our generic formalism, we obtain several results on membrane dynamics. We find that proteins that span the bilayer increase the intermonolayer friction coefficient. The renormalization, which can be significant, is in inverse proportion to the protein's mobility. Second, we find that asymmetric proteins couple to the membrane curvature and to the difference in monolayer densities. For practically all accessible membrane tensions (σ > 10 −8 N/m) we show that the protein density is the slowest relaxing variable. Furthermore, its relaxation rate decreases at small wavelengths due to the coupling to curvature. We apply our formalism to the large-scale diffusion of a concentrated protein patch. We find that the diffusion profile is not self-similar, owing to the wavevector dependence of the effective diffusion coefficient

Forest defoliator outbreaks alter nutrient cycling in northern waters.

Insect defoliators alter biogeochemical cycles from land into receiving waters by consuming terrestrial biomass and releasing biolabile frass. Here, we related insect outbreaks to water chemistry across 12 boreal lake catchments over 32-years. We report, on average, 27% lower dissolved organic carbon (DOC) and 112% higher dissolved inorganic nitrogen (DIN) concentrations in lake waters when defoliators covered entire catchments and reduced leaf area. DOC reductions reached 32% when deciduous stands dominated. Within-year changes in DOC from insect outbreaks exceeded 86% of between-year trends across a larger dataset of 266 boreal and north temperate lakes from 1990 to 2016. Similarly, within-year increases in DIN from insect outbreaks exceeded local, between-year changes in DIN by 12-times, on average. As insect defoliator outbreaks occur at least every 5 years across a wider 439,661 km2 boreal ecozone of Ontario, we suggest they are an underappreciated driver of biogeochemical cycles in forest catchments of this region.Natural Environment Research Council (NE/L006561/1) Ontario Centres of Excellence (OCE/27649) Natural Sciences and Engineering Research Council of Canada (NSERC/509182-17

Controlled rotary motion of light-driven molecular motors assembled on a gold film

Using circular dichroism (CD) spectroscopy, we show that light-driven rotary molecular motors based on overcrowded alkenes can function in a self-assembled monolayer on semi-transparent gold films.

Condition of Natural Resources Conservation Service Wetland Easements in Illinois

During the 2019 fiscal year (1 October 2018 – 30 September 2019), the Illinois Natural History Survey (INHS) conducted wetland monitoring and wetland quality evaluations for the Natural Resources Conservation Service (NRCS) on Agriculture Conservation Easement Program - Wetland Reserve Easements (ACEP-WRE; n = 68). We visited each wetland easement twice; once in autumn/winter (November–January) and again during spring (February–March) totaling 136 easement visits. Easements were located in Fayette (n = 34), Alexander (n = 22), and Pulaski (n = 12) Counties. Monitored easements in Fayette County were all comprised of Wetland Reserve Program (WRP) easements. Monitored easements in Alexander County comprised 15 WRP easements, 8 Emergency Watershed Protection Program-Floodplain Easements (EWPP-FPE), and 1 ACEP-WRE easement. Monitored easements in Pulaski County were all comprised of WRP easements. The WRP and EWPP-FPE easements were enrolled in NRCS programs prior to 2014 Farm Bill restructuring of wetland easements that now fall into the ACEP-WRE program. We previously submitted easement monitoring worksheets and detailed photographs of easement conditions, and this report contains a summary, descriptive management plans (Appendix 1) that detail conditions of the easements, and give recommendations for improvements to vegetation communities and easement infrastructure for all 70 easements.Natural Resource Conservation Service (USDA)unpublishednot peer reviewedOpe

Zephyr: The Fourth Issue

This is the fourth issue of Zephyr, the University of New England\u27s journal of creative expression. Since 2000, Zephyr has published original drawings, paintings, photography, prose, and verse created by current and former members of the University community. Zephyr\u27s Editorial Board is made up exclusively of matriculating students.https://dune.une.edu/zephyr/1003/thumbnail.jp

Identification and relative quantification of tyrosine nitration in a model peptide using two-dimensional infrared spectroscopy

Nitration of tyrosine in proteins and peptides is a post-translational modification that occurs under conditions of oxidative stress. It is implicated in a variety of medical conditions, including neurodegenerative and cardiovascular diseases. However, monitoring tyrosine nitration and understanding its role in modifying biological function remains a major challenge. In this work, we investigate the use of electron-vibration-vibration (EVV) two-dimensional infrared (2DIR) spectroscopy for the study of tyrosine nitration in model peptides. We demonstrate the ability of EVV 2DIR spectroscopy to differentiate between the neutral and deprotonated states of 3-nitrotyrosine, and we characterize their spectral signatures using information obtained from quantum chemistry calculations and simulated EVV 2DIR spectra. To test the sensitivity of the technique, we use mixed-peptide samples containing various levels of tyrosine nitration, and we use mass spectrometry to independently verify the level of nitration. We conclude that EVV 2DIR spectroscopy is able to provide detailed spectroscopic information on peptide side-chain modifications and to detect nitration levels down to 1%. We further propose that lower nitration levels could be detected by introducing a resonant Raman probe step to increase the detection sensitivity of EVV 2DIR spectroscopy. (Graph Presented)

Genome analysis of the necrotrophic fungal pathogens Sclerotinia sclerotiorum and Botrytis cinerea

Sclerotinia sclerotiorum and Botrytis cinerea are closely related necrotrophic plant pathogenic fungi notable for their wide host ranges and environmental persistence. These attributes have made these species models for understanding the complexity of necrotrophic, broad host-range pathogenicity. Despite their similarities, the two species differ in mating behaviour and the ability to produce asexual spores. We have sequenced the genomes of one strain of S. sclerotiorum and two strains of B. cinerea. The comparative analysis of these genomes relative to one another and to other sequenced fungal genomes is provided here. Their 38–39 Mb genomes include 11,860–14,270 predicted genes, which share 83% amino acid identity on average between the two species. We have mapped the S. sclerotiorum assembly to 16 chromosomes and found large-scale co-linearity with the B. cinerea genomes. Seven percent of the S. sclerotiorum genome comprises transposable elements compared t