Interactions among biotic and abiotic controls of carbon dynamics in a global change field experiment

Climate warming and increased atmospheric nitrogen deposition may substantially influence biosphere C cycling over the next century by altering ecosystem processes such as productivity and decomposition. Field studies are commonly used to explore plant responses to global change, although the underlying mechanisms can be difficult to isolate owing to the lack of control of factors such as plant-animal interactions. Ultimately, indirect effects via herbivore and detritivore responses may feedback to influence plant responses to the experimental treatments. The goal of this thesis was to explore interactions among biotic and abiotic drivers of carbon dynamics within the context of experimental warming and nitrogen addition in the field. Evidence from a herbivore exclusion experiment revealed that mollusc effects on net primary productivity were more pronounced in warmed plots than in ambient temperature plots, likely as a result of temperature-related increases in mollusc metabolic activity and plant consumption rate. Furthermore, the effects of rodent exclusion on grass biomass were significantly greater in N-fertilized plots than non-fertilized plots. Feeding experiments suggested that this finding is likely attributed to increased grass palatability in response to N addition. Results from a litter decomposition experiment indicated that warming impeded the contribution of detritivores to carbon turnover, though this effect was transient. Increased precipitation over the course of the experiment may have promoted recovery of the detritivore community, and could also account for the significant detritivore effects observed following one year of incubation. Reciprocal litter transplants between the treatments plots and untreated areas of the field indicated that the observed responses from the main experiment were unlikely to be accounted for by the individual effects of litter quality or microenvironment alone. Overall, the influence of global change factors such as warming and increased atmospheric nitrogen deposition on carbon-related processes such as productivity can be substantially modified by indirect effects on herbivore dynamics, with consumer-specific treatment effects suggesting that this relationship is complex and can depend on both diet quality and microclimate. Though detritivores were relatively insensitive to warming and N addition as decomposition progressed, they likely play an important role in the overall magnitude of ecosystem C turnover

Analysis of alpha defensin variation in samples from periodontitis patients

Background: In recent years, many studies have found positive associations between copy number variants and predisposition to human complex disease. On chromosome 8p23.1, a copy number variation locus, named DEFA1A3 is associated with susceptibility to IgA nephropathy, and is more generally thought to be involved in the host immune response in people with periodontitis. Objective: The main objective of this study was to undertake DEFA1A3 copy number measurement in 744 European samples with periodontitis and also to determine if there is an association between the copy numbers and periodontitis. Results and Conclusions: In this study we have used the Paralogue Ratio Tests to type 741 DNA samples from individuals with periodontitis and assessed the accuracy in typing copy number. As a second part of our work, we have found that there is an association between copy number distribution and periodontitis, but further work needs to be done in order to fully confirm and explore this conclusion

Trailing-edge dynamics of a morphing NACA0012 aileron at high Reynolds number by high-speed PIV

Particle image velocimetry (piv) measurements are made at the trailing edge of a piezoelectric actuated aileron in order to investigate the physical effect on the flow via high-frequency low-amplitude actuation at high Reynolds numbers. The measurements at different actuation frequencies show the modification of the primary frequency components of the flow with the actuation frequency. A statistical analysis reveals the reduction of the Reynolds stress components which increases with the actuation frequency. Proper orthogonal decomposition (pod) analysis shows the modification of the spatial modes illustrating the vortex breakdown in the shear-layer and the reduction of the temporal mode spectral energy depending on the actuation. It has been shown that a specific low amplitude actuation frequency produces a significant reduction of the predominant shear-layer frequency

Trailing-edge dynamics and morphing of a deformable flat plate at high Reynolds number by time-resolved PIV

The present paper investigates the turbulent wake structure in the near-region past the trailing edge of a deformable inclined plate. The plate is actuated by shape memory alloys. Using these actuators a significant deformation (bending) can be achieved (≈10%≈10% of the chord) under the aerodynamic loads corresponding to a Reynolds number of 200 000. The shear-layer dynamics as well as the mean velocity and turbulent stresses have been quantified for a reference case (flat plate inclined at 10°). The present study investigates the modification of the shear-layer and near-wake dynamics achieved by means of the dynamic deformation of the plate compared with static cases that include three intermediate positions of the deformed plate. The comparison of the static cases with the dynamic regime discusses the validity of the quasi-static hypothesis for the present low frequency actuation. It is found that the present actuation enhances the shearing mechanisms past the trailing-edge and modifies the von-Kármán mode as well as the structure of the shear-layer, Kelvin–Helmholtz eddies. Moreover, the increase of the bending enhances the appearance of the pairing mechanism between successive shear-layer eddies and the interaction between the von-Kármán and shear-layer instability modes. Furthermore, it has been found that the increase of the plate׳s curvature leads to an attenuation of the shear-layer amplitude and of the overall spectral energy, concerning the most deformed positio

Immunogenic Consensus Sequence T Helper Epitopes for a Pan-Burkholderia Biodefense Vaccine

Background: Biodefense vaccines against Category B bioterror agents Burkholderia pseudomallei (BPM) and Burkholderia mallei (BM) are needed, as they are both easily accessible to terrorists and have strong weaponization potential. Burkholderia cepaciae (BC), a related pathogen, causes chronic lung infections in cystic fibrosis patients. Since BPM, BM and BC are all intracellular bacteria, they are excellent targets for T cell-based vaccines. However, the sheer volume of available genomic data requires the aid of immunoinformatics for vaccine design. Using EpiMatrix, ClustiMer and EpiAssembler, a set of immunoinformatic vac-cine design tools, we screened the 31 available Burkholderia genomes and performed initial tests of our selections that are candidates for an epitope-based multi-pathogen vaccine against Burkholderia species. Results: Immunoinformatics analysis of 31 Burkholderia genomes yielded 350,004 9-mer candidate vaccine peptides of which 133,469 had perfect conservation across the 10 BM genomes, 175,722 had per-fect conservation across the 11 BPM genomes and 40,813 had perfect conservation across the 10 BC genomes. Further screening with EpiMatrix yielded 54,010 high-scoring Class II epitopes; these were assembled into 2,880 longer highly conserved ‘immunogenic consensus sequence’ T helper epitopes. 100% of the peptides bound to at least one HLA class II allele in vitro, 92.7% bound to at least two alleles, 82.9% to three, and 75.6% of the binding results were consistent with the immunoinformatics analysis. Conclusions: Our results show it is possible to rapidly identify promiscuous T helper epitopes conserved across multiple Burkholderia species and test their binding to HLA ligands in vitro. The next step in our process will be to test the epitopes ex vivo using peripheral leukocytes from BC, BPM infected humans and for immunogenicity in human HLA transgenic mice. We expect that this approach will lead to development of a licensable, pan-Burkholderia biodefense vaccine

Segregation analysis identifies specific alpha-defensin (DEFA1A3) SNP–CNV haplotypes in predisposition to IgA nephropathy

BACKGROUND: Immunoglobulin A (IgA) nephropathy is a disorder of the immune system affecting kidney function, and genome-wide association studies (GWAS) have defined numerous loci with associated variation, all implicating components of innate or adaptive immunity. Among these, single nucleotide polymorphisms (SNPs) in a region including the multiallelic copy number variation (CNV) of DEFA1A3 are associated with IgA nephropathy in both European and Asian populations. At present, the precise factors underlying the observed associations at DEFA1A3 have not been defined, although the key alleles differ between Asian and European populations, and multiple independent factors may be involved even within a single population. METHODS: In this study, we measured DEFA1A3 copy number in UK family trios with an offspring affected by IgA nephropathy, used the population distributions of joint SNP-CNV haplotypes to infer the likely segregation in trios, and applied transmission disequilibrium tests (TDT) to examine joint SNP-CNV haplotypes for over- or undertransmission into affected offspring from heterozygous parents. RESULTS AND CONCLUSIONS: We observed overtransmission of 3-copy class 2 haplotypes (raw p = 0.029) and some evidence for under-transmission of 3-copy class 1 haplotypes (raw p = 0.051), although these apparent effects were not statistically significant after correction for testing of multiple haplotypes

VaxCelerate II: Rapid development of a self-assembling vaccine for Lassa fever

Development of effective vaccines against emerging infectious diseases (EID) can take as much or more than a decade to progress from pathogen isolation/identification to clinical approval. As a result, conventional approaches fail to produce field-ready vaccines before the EID has spread extensively. Lassa is a prototypical emerging infectious disease endemic to West Africa for which no successful vaccine is available. We established the VaxCelerate Consortium to address the need for more rapid vaccine development by creating a platform capable of generating and pre-clinically testing a new vaccine against specific pathogen targets in less than 120 d. A self-assembling vaccine is at the core of the approach. It consists of a fusion protein composed of the immunostimulatory Mycobacterium tuberculosis heat shock protein 70 (MtbHSP70) and the biotin binding protein, avidin. Mixing the resulting protein (MAV) with biotinylated pathogen-specific immunogenic peptides yields a self-assembled vaccine (SAV). To meet the time constraint imposed on this project, we used a distributed R&D model involving experts in the fields of protein engineering and production, bioinformatics, peptide synthesis/design and GMP/GLP manufacturing and testing standards. SAV immunogenicity was first tested using H1N1 influenza specific peptides and the entire VaxCelerate process was then tested in a mock live-fire exercise targeting Lassa fever virus. We demonstrated that the Lassa fever vaccine induced significantly increased class II peptide specific interferon-γ CD4+ T cell responses in HLA-DR3 transgenic mice compared to peptide or MAV alone controls. We thereby demonstrated that our SAV in combination with a distributed development model may facilitate accelerated regulatory review by using an identical design for each vaccine and by applying safety and efficacy assessment tools that are more relevant to human vaccine responses than current animal models

Corn-Soybean Intercropping Improved the Nutritional Quality of Forage Cultivated on Podzols in Boreal Climate

Intercropping systems could be a potential source of nutrient-rich forage production in cool climates on podzolic soils common in boreal ecosystems. In this study, we evaluated the effects of corn–soybean intercropping (IC) on the nutritional quality of forage. Two silage corn varieties were cultivated as monocropping (MC) or were intercropped with three forage soybean varieties using a randomized complete block design. IC significantly increased the crude protein (22%) and decreased the acid detergent (14%) and neutral detergent (6%) fibers. Forage net energy, total digestible nutrients, ash, dry matter intake, digestible dry matter and relative feed value were also significantly increased (p ≤ 0.05) in the IC treatments compared to corn MC. The macro and micro nutrients were higher in IC than corn MC. Intercropping increased the omega 3 fatty acid (FA) contents (67%) compared to corn MC. IC also increased the active microbial community in the plant root zone, which may contribute to the improvement in forage nutritional quality because the active soil microbial community composition showed significant correlations with soluble sugars, soluble proteins and potassium contents of the forage. These results demonstrate that corn–soybean IC could be a suitable cropping system to increase the nutritional quality of forage cultivated on podzols in boreal climates. The resultant forage has the potential to be a source of high-value animal feed for livestock production in cool climate regions of the world

Conversion of t11t13 CLA into c9t11 CLA in Caco-2 Cells and Inhibition by Sterculic Oil

Background : Conjugated linoleic acids (CLA), and principally c9t11 CLA, are suspected to have numerous preventive properties regarding non-infectious pathologies such as inflammatory diseases, atherosclerosis and several types of cancer. C9t11 CLA is produced in the rumen during biohydrogenation of linoleic acid, but can also be synthesized in mammalian tissues from trans-vaccenic acid (C18:1 t11) through the action of delta-9 desaturase (D9D). For several years, it is also known that c9t11 CLA can be synthesized from conjugated linolenic acids (CLnA), i.e. c9t11c13 CLnA and c9t11t13 CLnA. This study aimed at investigating to which extent and by which route c9t11 CLA can be produced from another isomer of CLA, the t11t13 CLA that is structurally very similar to c9t11t13 CLnA, in Caco-2 cells