52 research outputs found

    Changes in microphytobenthos fluorescence over a tidal cycle: implications for sampling designs

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    Intertidal microphytobenthos (MPB) are important primary producers and provide food for herbivores in soft sediments and on rocky shores. Methods of measuring MPB biomass that do not depend on the time of collection relative to the time of day or tidal conditions are important in any studies that need to compare temporal or spatial variation, effects of abiotic factors or activity of grazers. Pulse amplitude modulated (PAM) fluorometry is often used to estimate biomass of MPB because it is a rapid, non-destructive method, but it is not known how measures of fluorescence are altered by changing conditions during a period of low tide. We investigated this experimentally using in situ changes in minimal fluorescence (F) on a rocky shore and on an estuarine mudflat around Sydney (Australia), during low tides. On rocky shores, the time when samples are taken during low tide had little direct influence on measures of fluorescence as long as the substratum is dry. Wetness from wave-splash, seepage from rock pools, run-off, rainfall, etc., had large consequences for any comparisons. On soft sediments, fluorescence was decreased if the sediment dried out, as happens during low-spring tides on particularly hot and dry days. Surface water affected the response of PAM and therefore measurements used to estimate MPB, emphasising the need for care to ensure that representative sampling is done during low tide

    Type 1 diabetes: translating mechanistic observations into effective clinical outcomes

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    Type 1 diabetes remains an important health problem, particularly in Western countries where the incidence has been increasing in younger children(1). In 1986, Eisenbarth described Type 1 diabetes as a chronic autoimmune disease. Work over the past 3 ½ decades has identified many of the genetic, immunologic, and environmental factors that are involved in the disease and have led to hypotheses concerning its pathogenesis. Based on these findings, clinical trials have been conducted to test these hypotheses but have had mixed results. In this review, we discuss the findings that have led to current concepts of the disease mechanisms, how this understanding has prompted clinical studies, and the results of these studies. The findings from preclinical and clinical studies support the original proposed model for how type 1 diabetes develops, but have also suggested that this disease is more complex than originally thought and will require broader treatment approaches

    Towards a global multidisciplinary consensus framework on haemophilia gene therapy: Report of the 2nd World Federation of Haemophilia Gene Therapy Round Table.

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    INTRODUCTION: With approval of gene therapy for haemophilia likely in the near future, policy frameworks are needed to guide the path forward for this disruptive and novel therapeutic advance. AIM: The WFH has initiated a series of multi-stakeholder Gene Therapy Round Tables (GTRT) to better understand where guidance is needed and develop initial consensus statements to inform policy. METHODS: The first day of the 2nd GTRT was devoted to didactic presentations on models of access to gene therapy, payment and health technology assessment considerations, regulatory issues and the generation of evidence on safety and durable efficacy of gene therapy products. On the second day, participants were tasked with developing and voting on consensus statements that reflected the information presented and multi-stakeholder views expressed during discussions in the 1st and 2nd WFH GTRTs. The statements covered global access to gene therapy for all people with haemophilia (PWH), collection of long-term safety and efficacy data, ensuring gene therapy is available for all subgroups of PWH including those who have been largely excluded from clinical trials and characterizing acceptable and ideal factor expression levels for gene therapy products. RESULTS: The first 3 statements achieved consensus (at least 80% agreement) by this group of experts. The statement on identifying an ideal and an acceptable factor level expression elicited a lively discussion but failed to achieve consensus by this group. CONCLUSIONS: This issue of ideal and acceptable factor level expression and other unresolved issues will be brought to the 3rd WFH GTRT in 2020
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