989 research outputs found

    Molecular basis of APC/C regulation by the spindle assembly checkpoint.

    Full text link
    In the dividing eukaryotic cell, the spindle assembly checkpoint (SAC) ensures that each daughter cell inherits an identical set of chromosomes. The SAC coordinates the correct attachment of sister chromatid kinetochores to the mitotic spindle with activation of the anaphase-promoting complex (APC/C), the E3 ubiquitin ligase responsible for initiating chromosome separation. In response to unattached kinetochores, the SAC generates the mitotic checkpoint complex (MCC), which inhibits the APC/C and delays chromosome segregation. By cryo-electron microscopy, here we determine the near-atomic resolution structure of a human APC/C–MCC complex (APC/C(MCC)). Degron-like sequences of the MCC subunit BubR1 block degron recognition sites on Cdc20, the APC/C coactivator subunit responsible for substrate interactions. BubR1 also obstructs binding of the initiating E2 enzyme UbcH10 to repress APC/C ubiquitination activity. Conformational variability of the complex enables UbcH10 association, and structural analysis shows how the Cdc20 subunit intrinsic to the MCC (Cdc20(MCC)) is ubiquitinated, a process that results in APC/C reactivation when the SAC is silenced

    Serological survey for mycoplasma hyopneumoniae in free-living wild boars from Campos Gerais region, Paraná, Brasil.

    Get PDF
    The south region of Brazil was responsible for 80.3% of total pork meat export in the country in 2015 (2), with the state of Paraná accountable for 21% of the total pork meat production in that year. Pig farming represented 5.7% of the agricultural gross income of the state in 2016, and the Campos Gerais region accounted for 13.2% of that amount (2). Wild boars are the result of crossbreeding between boars (Sus scrofa scrofa) and domestic pigs (Sus scrofa domesticus). The total population of free-living wild boars in Brazil is unknown (11), but sightings are common in the crop fields and near livestock farms of different regions of Paraná state, including in Campos Gerais (9). The health status of pig herds is important in terms of maintenance and growth of pork production and exports and there are evidences that domestic pigs and wild boars share vulnerabilities in certain viral and bacterial pathogen infections (12). Mycoplasma hyopneumoniae (Mhyo) is a bacterial pathogen that causes porcine enzootic pneumonia, an economically important disease that affects both domestic pigs and wild boars. Mhyo was first isolated in 1965, simultaneously in the United Kingdom (UK) and in the United States of America (USA) (3; 7). Economic losses related to this pathogen and mycoplasmal pneumonia in pig herds are associated with decreased feed efficiency, reduced average of the daily weight gain, and increased medication costs. Thus, knowing the health status of free-living wild boars in the regards of this pathogen is important for the biosecurity of the pork production. The aim of this study was to investigate antibodies against Mhyo in serum samples of free-living wild boars in Campos Gerais region

    Nox2 underpins microvascular inflammation and vascular contributions to cognitive decline

    Get PDF
    \ua9 The Author(s) 2022. Chronic microvascular inflammation and oxidative stress are inter-related mechanisms underpinning white matter disease and vascular cognitive impairment (VCI). A proposed mediator is nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (Nox2), a major source of reactive oxygen species (ROS) in the brain. To assess the role of Nox2 in VCI, we studied a tractable model with white matter pathology and cognitive impairment induced by bilateral carotid artery stenosis (BCAS). Mice with genetic deletion of Nox2 (Nox2 KO) were compared to wild-type (WT) following BCAS. Sustained BCAS over 12 weeks in WT mice induced Nox2 expression, indices of microvascular inflammation and oxidative damage, along with white matter pathology culminating in a marked cognitive impairment, which were all protected by Nox2 genetic deletion. Neurovascular coupling was impaired in WT mice post-BCAS and restored in Nox2 KO mice. Increased vascular expression of chemoattractant mediators, cell-adhesion molecules and endothelial activation factors in WT mice post-BCAS were ameliorated by Nox2 deficiency. The clinical relevance was confirmed by increased vascular Nox2 and indices of microvascular inflammation in human post-mortem subjects with cerebral vascular disease. Our results support Nox2 activity as a critical determinant of VCI, whose targeting may be of therapeutic benefit in cerebral vascular disease

    Phylogenetic position of an uncharacterized Brazilian strain of bovine papillomavirus in the genus Xipapillomavirus based on sequencing of the L1 open reading frame

    Get PDF
    The use of PCR assays with degenerate primers has suggested the existence of numerous as yet uncharacterized bovine papillomaviruses (BPV). Despite the endemic nature of BPV infections, the identification of BPV types in Brazilian cattle is still only sporadic. However, in a recent analysis of a partial segment of the L1 gene, we observed notable diversity among the BPV types detected. The aim of this study was to determine the phylogenetic position of the previously identified wild strain BPV/BR-UEL2 detected in the state of Paraná in Brazil. Since previous analysis of the partial L1 sequence had shown that this strain was most closely related to BPV type 4, genus-specific primers were designed. Phylogenetic analysis using complete L1 ORF sequences revealed that BPV/BR-UEL2 was related to BPV types classified in the genus Xipapillomavirus and shared the highest L1 nucleotide sequence similarity with BPV type 4 (78%). This finding suggests that BPV/BR-UEL2 should be classified as a potential new type of BPV in the genus Xipapillomavirus

    Why Social Enterprises Are Asking to Be Multi-stakeholder and Deliberative: An Explanation around the Costs of Exclusion.

    Get PDF
    The study of multi-stakeholdership (and multi-stakeholder social enterprises in particular) is only at the start. Entrepreneurial choices which have emerged spontaneously, as well as the first legal frameworks approved in this direction, lack an adequate theoretical support. The debate itself is underdeveloped, as the existing understanding of organisations and their aims resist an inclusive, public interest view of enterprise. Our contribution aims at enriching the thin theoretical reflections on multi-stakeholdership, in a context where they are already established, i.e. that of social and personal services. The aim is to provide an economic justification on why the governance structure and decision-making praxis of the firm needs to account for multiple stakeholders. In particular with our analysis we want: a) to consider production and the role of firms in the context of the “public interest” which may or may not coincide with the non-profit objective; b) to ground the explanation of firm governance and processes upon the nature of production and the interconnections between demand and supply side; c) to explain that the costs associated with multi-stakeholder governance and deliberation in decision-making can increase internal efficiency and be “productive” since they lower internal costs and utilise resources that otherwise would go astray. The key insight of this work is that, differently from major interpretations, property costs should be compared with a more comprehensive range of costs, such as the social costs that emerge when the supply of social and personal services is insufficient or when the identification of aims and means is not shared amongst stakeholders. Our model highlights that when social costs derived from exclusion are high, even an enterprise with costly decisional processes, such as the multistakeholder, can be the most efficient solution amongst other possible alternatives

    Aspectos sanitários dos núcleos de conservação in situ de bovinos pantaneiros.

    Get PDF
    Este trabalho teve como objetivo a avaliação sorológica dos rebanhos de dois núcleos de conservação de bovinos Pantaneiros existentes na região do Pantanal (C1 em Corumbá-MS e C2 em Poconé-MT), para as seguintes enfermidades: brucelose, tuberculose, leptospirose, neosporose, toxoplasmose, leucose, rinotraqueíte infecciosa bovina (IBR) e diarréia viral bovina (BVD).bitstream/item/79834/1/BP103.pd

    Nature-based solutions efficiency evaluation against natural hazards: Modelling methods, advantages and limitations

    Get PDF
    Nature-based solutions (NBS) for hydro-meteorological risks (HMRs) reduction and management are becoming increasingly popular, but challenges such as the lack of well-recognised standard methodologies to evaluate their performance and upscale their implementation remain. We systematically evaluate the current state-of-the art on the models and tools that are utilised for the optimum allocation, design and efficiency evaluation of NBS for five HMRs (flooding, droughts, heatwaves, landslides, and storm surges and coastal erosion). We found that methods to assess the complex issue of NBS efficiency and cost-benefits analysis are still in the development stage and they have only been implemented through the methodologies developed for other purposes such as fluid dynamics models in micro and catchment scale contexts. Of the reviewed numerical models and tools MIKE-SHE, SWMM (for floods), ParFlow-TREES, ACRU, SIMGRO (for droughts), WRF, ENVI-met (for heatwaves), FUNWAVE-TVD, BROOK90 (for landslides), TELEMAC and ADCIRC (for storm surges) are more flexible to evaluate the performance and effectiveness of specific NBS such as wetlands, ponds, trees, parks, grass, green roof/walls, tree roots, vegetations, coral reefs, mangroves, sea grasses, oyster reefs, sea salt marshes, sandy beaches and dunes. We conclude that the models and tools that are capable of assessing the multiple benefits, particularly the performance and cost-effectiveness of NBS for HMR reduction and management are not readily available. Thus, our synthesis of modelling methods can facilitate their selection that can maximise opportunities and refute the current political hesitation of NBS deployment compared with grey solutions for HMR management but also for the provision of a wide range of social and economic co-benefits. However, there is still a need for bespoke modelling tools that can holistically assess the various components of NBS from an HMR reduction and management perspective. Such tools can facilitate impact assessment modelling under different NBS scenarios to build a solid evidence base for upscaling and replicating the implementation of NBS
    corecore