186 research outputs found

    When does female multiple mating evolve to adjust inbreeding? : Effects of inbreeding depression, direct costs, mating constraints, and polyandry as a threshold trait

    Get PDF
    Ackowledgements: This work was funded by a European Research Council Starting Grant to JMR. All simulations were performed using the Maxwell computing cluster at the University of AberdeenPeer reviewedPublisher PD

    Evolution of precopulatory and post-copulatory strategies of inbreeding avoidance and associated polyandry

    Get PDF
    Acknowledgments This work was funded by a European Research Council Starting Grant to JMR. Computer simulations were performed using the Maxwell Computing Cluster at the University of Aberdeen. We thank Matthew E. Wolak and two anonymous reviewers for very helpful comments.Peer reviewedPublisher PD

    New factors enhancing the reactivity of cysteines in molten globule-like structures

    Get PDF
    Protein cysteines often play crucial functional and structural roles, so they are emerging targets to design covalent thiol ligands that are able to modulate enzyme or protein functions. Some of these residues, especially those involved in enzyme mechanisms-including nucleophilic and reductive catalysis and thiol-disulfide exchange-display unusual hyper-reactivity; such a property is expected to result from a low pK(a)and from a great accessibility to a given reagent. New findings and previous evidence clearly indicate that pK(a)perturbations can only produce two-four-times increased reactivity at physiological pH values, far from the hundred and even thousand-times kinetic enhancements observed for some protein cysteines. The data from the molten globule-like structures of ribonuclease, lysozyme, bovine serum albumin and chymotrypsinogen identified new speeding agents, i.e., hydrophobic/electrostatic interactions and productive complex formations involving the protein and thiol reagent, which were able to confer exceptional reactivity to structural cysteines which were only intended to form disulfides. This study, for the first time, evaluates quantitatively the different contributions of pK(a)and other factors to the overall reactivity. These findings may help to clarify the mechanisms that allow a rapid disulfide formation during the oxidative folding of many proteins

    Proton momentum distribution in a protein hydration shell

    Get PDF
    The momentum distribution of protons in the hydration shell of a globular protein has been measured through deep inelastic neutron scattering at 180 and 290 K, below and above the crossover temperature T-c=1.23T(g), where T-g=219 K is the glass transition temperature. It is found that the mean kinetic energy of the water hydrogens shows no temperature dependence, but the measurements are accurate enough to indicate a sensible change of momentum distribution and effective potential felt by protons, compatible with the transition from a single to a double potential well. This could support the presence of tunneling effects even at room temperature, playing an important role in biological function

    LCA to Estimate the Environmental Impact of Dairy Farms: A Case Study

    Get PDF
    Intensive farming is responsible for extreme environmental impacts under different aspects, among which global warming represents a major reason of concern. This is a quantitative problem linked to the farm size and a qualitative one, depending on farming methods and land management. The dairy sector is particularly relevant in terms of environmental impact, and new approaches to meeting sustainability goals at a global scale while meeting society's needs are necessary. The present study was carried out to assess the environmental impact of dairy cattle farms based on a life cycle assessment (LCA) model applied to a case study. These preliminary results show the possibility of identifying the most relevant impacts in terms of supplied products, such as animal feed and plastic packaging, accounting for 19% and 15% of impacts, respectively, and processes, in terms of energy and fuel consumption, accounting for 53% of impacts overall. In particular, the local consumption of fossil fuels for operations within the farm represents the most relevant item of impact, with a small margin for improvement. On the other hand, remarkable opportunities to reduce the impact can be outlined from the perspective of stronger partnerships with suppliers to promote the circularity of packaging and the sourcing of animal feed. Future studies may include the impact of drug administration and the analysis of social aspects of LCA

    A trait-based approach for predicting species responses to environmental change from sparse data : how well might terrestrial mammals track climate change?

    Get PDF
    Acknowledgements LS was supported by two STSMs by the COST Action ES1101 ”Harmonising Global Biodiversity Modelling“ (Harmbio), supported by COST (European Cooperation in Science and Technology). JMB and SMW were funded by CEH projects NEC05264 and NEC05100. JMJT and SCFP are grateful for the support of the Natural Environment Research Council UK (NE/J008001/1). LS, JAH and JMJT conceived the original idea. LS, JAH, JMB, TC & JMJT designed the study; LS collected the data; LS and TC performed the statistical analyses; LS conducted the integrodifference modelling assisted by JMB and SMW. LS conducted the individual-based modelling assisted by SCFP. LS led the writing supported by JMJT, JMB, SCFP, SMW, TC, JAH and GB.Peer reviewedPublisher PD

    Ebolavirus and Marburgvirus: insight the Filoviridae family

    Get PDF
    Ebolavirus and Marburgvirus (belonging to the Filoviridae family) emerged four decades ago and cause epidemics of haemorrhagic fever with high case-fatality rates. The genome of filoviruses encodes seven proteins. No significant homology is observed between filovirus proteins and any known macromolecule. Moreover, Marburgvirus and Ebolavirus show significant differences in protein homology. The natural maintenance cycle of filoviruses is unknown, the natural reservoir, the mode of transmission, the epidemic disease generation, and temporal dynamics are unclear. Lastly, Ebolavirus and Marburgvirus are considered as potential biological weapons. Vaccine appears the unique therapeutic frontier. Here, molecular and clinical aspects of filoviral haemorrhagic fevers are summarized

    Variation in parent-offspring kinship in socially monogamous systems with extra-pair reproduction and inbreeding

    Get PDF
    ACKNOWLEDGMENTS We thank the Tsawout and Tseycum First Nations bands for allowing access to Mandarte; everyone who contributed to long-term data collection; Lukas Keller and Ryan Germain for helpful discussions; and the European Research Council, UK Royal Society, National Sciences and Engineering Research Council of Canada and Swiss National Science Foundation for their invaluable support. DATA ARCHIVING Data are available from the Dryad Digital Repository: http://dx.doi.org/10.5061/dryad.4r383.Peer reviewedPublisher PD

    Multi-criterion trade-offs and synergies for spatial conservation planning

    Get PDF
    1. Nature conservation policies need to deliver on multiple criteria, including genetic diversity, population viability and species richness as well as ecosystem services. The challenge of integrating these may be addressed by simulation modelling. 2. We used four models (MetaConnect, SPOMSIM, a community model and InVEST) to assess a variety of spatial habitat patterns with two levels of total habitat cover and realised at two spatial scales, exploring which landscape structures performed best according to five different criteria assessed for four functional types of organisms (approximately representing trees, butterflies, small mammals and birds). 3. The results display both synergies and trade-offs: population size and pollination services generally benefitted more from fragmentation than did genetic heterozygosity, and species richness more than allelic richness, although the latter two varied considerably among the functional types. 4. No single landscape performed best across all criteria, but averaging over criteria and functional types, overall performance improved with greater levels of habitat cover and intermediate fragmentation (or less fragmentation in cases with lower habitat cover). 5. Synthesis and applications. Different conservation objectives must be traded off, and considering only a single taxon or criterion may result in sub-optimal choices when planning reserve networks. Nevertheless, heterogeneous spatial patterns of habitat can provide reasonable compromises for multiple criteria

    Ultra-rapid glutathionylation of chymotrypsinogen in its molten globule-like conformation: a comparison to archaeal proteins

    Get PDF
    Chymotrypsinogen, when reduced and taken to its molten globule-like conformation, displays a single cysteine with an unusual kinetic propensity toward oxidized glutathione (GSSG) and other organic thiol reagents. A single residue, identified by mass spectrometry like Cys1, reacts with GSSG about 1400 times faster than an unperturbed protein cysteine. A reversible protein-GSSG complex and a low pK(a) (8.1 +/- 0.1) make possible such astonishing kinetic property which is absent toward other natural disulfides like cystine, homocystine and cystamine. An evident hyper-reactivity toward 5,5 ' -dithiobis-(2-nitrobenzoic acid) (DTNB) and 1-chloro-2,4-dinitrobenzene (CDNB) was also found for this specific residue. The extraordinary reactivity toward GSSG is absent in two proteins of the thermophilic archaeon Sulfolobus solfataricus, an organism lacking glutathione: the Protein Disulphide Oxidoreductase (SsPDO) and the Bacterioferritin Comigratory Protein 1 (Bcp1) that displays Cys residues with an even lower pK(a) value (7.5 +/- 0.1) compared to chymotrypsinogen. This study, which also uses single mutants in Cys residues for Bcp1, proposes that this hyper-reactivity of a single cysteine, similar to that found in serum albumin, lysozyme, ribonuclease, may have relevance to drive the "incipit" of the oxidative folding of proteins from organisms where the glutathione/oxidized glutathione (GSH/GSSG) system is present
    • 

    corecore