535 research outputs found

    The Glial Regenerative Response to Central Nervous System Injury Is Enabled by Pros-Notch and Pros-NFΞΊB Feedback

    Get PDF
    Organisms are structurally robust, as cells accommodate changes preserving structural integrity and function. The molecular mechanisms underlying structural robustness and plasticity are poorly understood, but can be investigated by probing how cells respond to injury. Injury to the CNS induces proliferation of enwrapping glia, leading to axonal re-enwrapment and partial functional recovery. This glial regenerative response is found across species, and may reflect a common underlying genetic mechanism. Here, we show that injury to the Drosophila larval CNS induces glial proliferation, and we uncover a gene network controlling this response. It consists of the mutual maintenance between the cell cycle inhibitor Prospero (Pros) and the cell cycle activators Notch and NFΞΊB. Together they maintain glia in the brink of dividing, they enable glial proliferation following injury, and subsequently they exert negative feedback on cell division restoring cell cycle arrest. Pros also promotes glial differentiation, resolving vacuolization, enabling debris clearance and axonal enwrapment. Disruption of this gene network prevents repair and induces tumourigenesis. Using wound area measurements across genotypes and time-lapse recordings we show that when glial proliferation and glial differentiation are abolished, both the size of the glial wound and neuropile vacuolization increase. When glial proliferation and differentiation are enabled, glial wound size decreases and injury-induced apoptosis and vacuolization are prevented. The uncovered gene network promotes regeneration of the glial lesion and neuropile repair. In the unharmed animal, it is most likely a homeostatic mechanism for structural robustness. This gene network may be of relevance to mammalian glia to promote repair upon CNS injury or disease

    Towards the environmental sustainability assessment for the viticulture

    Get PDF
    During the last decades in Italy the wine sector focused on the environmental sustainability of the production processes, including the agricultural, the agro-industrial and the packaging phases. Recent surveys highlighted that the wine consumers are interested in the environmental certifications, even if they are not familiar with them. Several environmental pressures can be evaluated in the viticulture phase, but an elevated number of the analysed impacts require the collection of a large set of input data and significant efforts during the elaboration phase. Therefore, the aim of the present work was the identification of the inventory data and impacts, which mainly describe the environmental pressures associated with the viticulture phase. Particularly, the results of the life cycle assessment (LCA) were integrated with those of a model and a simplified approach for evaluating the risks due to the pesticides use. The LCA identified three phases, which are responsible of 70-80% of the CO2eq (CO2 equivalent), the cumulated energy utilisation, the acidification potential (expressed in SO2 equivalent) and the eutrophication (expressed in PO4 equivalent), i.e. the harvesting, the crop protection and the ligature. The phase of the pesticides use was analysed also through the pesticides risk indicator (PERI) model and a simplified approach elaborated by the Regional Agency for the Environment Protection in Tuscany, Italy. Results concerning the environmental risk showed that the PERI model, the Arpat approach and the LCA were coherent for the pesticide mix highlighting that the associated environmental risk is more than doubled from 2004 to 2010. Finally, some operative indications were elaborated in order to reduce the impacts and improve the local and global environmental sustainability of the viticulture phase

    Endocytic trafficking is required for neuron cell death through regulating TGF-beta signaling in \u3ci\u3eDrosophila melanogaster\u3c/i\u3e

    Get PDF
    Programmed cell death (PCD) is an essential feature during the development of the central nervous system in Drosophila as well as in mammals. During metamorphosis, a group of peptidergic neurons (vCrz) are eliminated from the larval central nervous system (CNS) via PCD within 6-7 h after puparium formation. To better understand this process, we first characterized the development of the vCrz neurons including their lineages and birth windows using the MARCM (Mosaic Analysis with a Repressible Cell Marker) assay. Further genetic and MARCM analyses showed that not only Myoglianin (Myo) and its type I receptor Baboon is required for neuron cell death, but also this death signal is extensively regulated by endocytic trafficking in Drosophila melanogaster. We found that clathrin-mediated membrane receptor internalization and subsequent endocytic events involved in Rab5-dependent early endosome and Rab11-dependent recycling endosome differentially participate in TGF-Ξ² [beta] signaling. Two early endosome-enriched proteins, SARA and Hrs, are found to act as a cytosolic retention factor of Smad2, indicating that endocytosis mediates TGF-Ξ² [beta] signaling through regulating the dissociation of Smad2 and its cytosolic retention factor

    The Relationship Among HFACS Levels and Analysis of Human Factors in Unmanned and Manned Air Vehicles

    Get PDF
    This dissertation analyzes the structural relationships among the Human Factors Accident Classification System levels for unmanned air vehicle and manned air vehicle accidents and the common relationships between unmanned air vehicle and manned air vehicle accident causes. The study acquired DOD HFACS accident classification data from 347 United States Air Force Class A accident reports for the years between 2000 and 2013. The dissertation utilized a set of analysis that is considered to contribute substantially to the respective domain of the study. The correlations found among categorical levels were applied to HFACS taxonomy based on the Reason Model via path analysis – structural equation modeling. The study concluded the presence of statistically significant paths at both UAV and MAV accidents and common partial paths of those aircraft types within the framework of DOD HFACS taxonomy. The study also suggests that accident data can be utilized to test and improve the failure model of an organization through identification of significant effects such as technology and structural changes in the organization

    Identification of genes influencing dendrite morphogenesis in developing peripheral sensory and central motor neurons.

    Get PDF
    BACKGROUND: Developing neurons form dendritic trees with cell type-specific patterns of growth, branching and targeting. Dendrites of Drosophila peripheral sensory neurons have emerged as a premier genetic model, though the molecular mechanisms that underlie and regulate their morphogenesis remain incompletely understood. Still less is known about this process in central neurons and the extent to which central and peripheral dendrites share common organisational principles and molecular features. To address these issues, we have carried out two comparable gain-of-function screens for genes that influence dendrite morphologies in peripheral dendritic arborisation (da) neurons and central RP2 motor neurons. RESULTS: We found 35 unique loci that influenced da neuron dendrites, including five previously shown as required for da dendrite patterning. Several phenotypes were class-specific and many resembled those of known mutants, suggesting that genes identified in this study may converge with and extend known molecular pathways for dendrite development in da neurons. The second screen used a novel technique for cell-autonomous gene misexpression in RP2 motor neurons. We found 51 unique loci affecting RP2 dendrite morphology, 84% expressed in the central nervous system. The phenotypic classes from both screens demonstrate that gene misexpression can affect specific aspects of dendritic development, such as growth, branching and targeting. We demonstrate that these processes are genetically separable. Targeting phenotypes were specific to the RP2 screen, and we propose that dendrites in the central nervous system are targeted to territories defined by Cartesian co-ordinates along the antero-posterior and the medio-lateral axes of the central neuropile. Comparisons between the screens suggest that the dendrites of peripheral da and central RP2 neurons are shaped by regulatory programs that only partially overlap. We focused on one common candidate pathway controlled by the ecdysone receptor, and found that it promotes branching and growth of developing da neuron dendrites, but a role in RP2 dendrite development during embryonic and early larval stages was not apparent. CONCLUSION: We identified commonalities (for example, growth and branching) and distinctions (for example, targeting and ecdysone response) in the molecular and organizational framework that underlies dendrite development of peripheral and central neurons.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
    • …
    corecore