24 research outputs found

    Real-Time Measurement of F-Actin Remodelling during Exocytosis Using Lifeact-EGFP Transgenic Animals

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    F-actin remodelling is essential for a wide variety of cell processes. It is important in exocytosis, where F-actin coats fusing exocytic granules. The purpose of these F-actin coats is unknown. They may be important in stabilizing the fused granules, they may play a contractile role and promote expulsion of granule content and finally may be important in endocytosis. To elucidate these functions of F-actin remodelling requires a reliable method to visualize F-actin dynamics in living cells. The recent development of Lifeact-EGFP transgenic animals offers such an opportunity. Here, we studied the characteristics of exocytosis in pancreatic acinar cells obtained from the Lifeact-EGFP transgenic mice. We show that the time-course of agonist-evoked exocytic events and the kinetics of each single exocytic event are the same for wild type and Lifeact-EGFP transgenic animals. We conclude that Lifeact-EGFP animals are a good model to study of exocytosis and reveal that F-actin coating is dependent on the de novo synthesis of F-actin and that development of actin polymerization occurs simultaneously in all regions of the granule. Our insights using the Lifeact-EGFP mice demonstrate that F-actin coating occurs after granule fusion and is a granule-wide event

    Ecological and Cultural Understanding as a Basis for Management of a Globally Significant Island Landscape

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    Islands provide the opportunity to explore management regimes and research issues related to the isolation, uniqueness, and integrity of ecological systems. K’gari (Fraser Island) is an Australian World Heritage property listed based on its outstanding natural value, specifically, the unique wilderness characteristics and the diversity of ecosystem types. Our goal was to draw on an understanding of the natural and cultural environment of K’gari as a foundation on which to build a management model that includes First Nations Peoples in future management and research. Our research involved an analysis of papers in the peer-reviewed scientific literature, original reports, letters, and other manuscripts now housed in the K’gari Fraser Island Research Archive. The objectives of the research were: (1) to review key historical events that form the cultural, social, and environmental narrative; (2) review the major natural features of the island and threats; (3) identify the gaps in research; (4) analyse the management and conservation challenges associated with tourism, biosecurity threats, vegetation management practices, and climate change and discuss whether the requirements for sustaining island ecological integrity can be met in the future; and (5) identify commonalities and general management principles that may apply globally to other island systems and other World Heritage sites listed on the basis of their unique natural and cultural features. We found that the characteristics that contribute to island uniqueness are also constraints for research funding and publication; however, they are important themes that warrant more investment. Our review suggests that K’gari is a contested space between tourist visitation and associated environmental impacts, with an island that has rich First Nations history, extraordinary ecological diversity, and breathtaking aesthetic beauty. This juxtaposition is reflected in disparate views of custodianship and use, and the management strategies are needed to achieve multiple objectives in an environmentally sustainable way whilst creating cultural equity in modern times. We offer a foundation on which to build a co-management model that includes First Nations Peoples in governance, management, research, and monitoring

    Generation of flavors and fragrances through biotransformation and de novo synthesis

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    Flavors and fragrances are the result of the presence of volatile and non-volatile compounds, appreciated mostly by the sense of smell once they usually have pleasant odors. They are used in perfumes and perfumed products, as well as for the flavoring of foods and beverages. In fact the ability of the microorganisms to produce flavors and fragrances has been described for a long time, but the relationship between the flavor formation and the microbial growth was only recently established. After that, efforts have been put in the analysis and optimization of food fermentations that led to the investigation of microorganisms and their capacity to produce flavors and fragrances, either by de novo synthesis or biotransformation. In this review, we aim to resume the recent achievements in the production of the most relevant flavors by bioconversion/biotransformation or de novo synthesis, its market value, prominent strains used, and their production rates/maximum concentrations.We would like to thank the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469 unit, COMPETE 2020 (POCI-01-0145FEDER-006684), and BiotecNorte operation (NORTE-01-0145FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

    Understanding conflict among experts working on controversial species : a case study on the Australian dingo

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    Expert elicitation can be valuable for informing decision-makers on conservation and wildlife management issues. To date, studies eliciting expert opinions have primarily focused on identifying and building consensus on key issues. Nonetheless, there are drawbacks of a strict focus on consensus, and it is important to understand and emphasize dissent, too. This study adopts a dissensus-based Delphi to understand conflict among dingo experts. Twenty-eight experts participated in three rounds of investigation. We highlight disagreement on most of the issues explored. In particular, we find that disagreement is underpinned by what we call “conflict over values” and “conflict over evidence.” We also note the broader role played by distrust in influencing such conflicts. Understanding and recognizing the different elements shaping disagreement is critical for informing and improving decision-making and can also enable critique of dominant paradigms in current practices. We encourage greater reflexivity and open deliberation on these aspects and hope our study will inform similar investigations in other contexts

    Glucose principally regulates insulin secretion in mouse islets by controlling the numbers of granule fusion events per cell

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    In dispersed single beta cells the response of each cell to glucose is heterogeneous. In contrast, within an islet, cell-to-cell communication leads to glucose inducing a more homogeneous response. For example, increases in NAD(P)H and calcium are relatively uniform across the cells of the islet. These data suggest that secretion of insulin from single beta cells within an islet should also be relatively homogeneous. The aim of this study was to test this hypothesis by determining the glucose dependence of single-cell insulin responses within an islet
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