710 research outputs found

    Correlating Pressure‐Induced Emission Modulation with Linker Rotation in a Photoluminescent MOF

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    Conformational changes of linker units in metal‐organic frameworks (MOFs) are often responsible for gate‐opening phenomena in selective gas adsorption and stimuli‐responsive optical and electrical sensing behaviour. Herein, we show that pressure‐induced bathochromic shifts in both fluorescence emission and UV‐Vis absorption spectra of a two‐fold interpenetrated Hf MOF, linked by 1,4‐phenylene‐bis(4‐ethynylbenzoate) ligands ( Hf‐peb ), are induced by rotation of the central phenyl ring of the linker, from a coplanar arrangement to a twisted, previously unseen conformer. Single‐crystal X‐ray diffraction, alongside in situ fluorescence and UV‐Vis absorption spectroscopies, measured up to 2.1 GPa in a diamond anvil cell on single crystals, are in excellent agreement, correlating linker rotation with modulation of emission. Topologically isolating the 1,4‐phenylene‐bis(4‐ethynylbenzoate) units within a MOF facilitates concurrent structural and spectroscopic study in the absence of intermolecular perturbation, allowing characterisation of the luminescence properties of a high‐energy, twisted conformation of the previously well‐studied chromophore. We expect the unique environment provided by network solids, and the capability of combining crystallographic and spectroscopic analysis, will greatly enhance understanding of luminescent molecules and lead to the development of novel sensors and adsorbents

    An Assessment of How Australian Fisheries Management Plans Account for Climate Change Impacts

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    For Australian fisheries to remain productive and sustainable (environmentally and commercially), there is a need to incorporate climate change considerations into management and planning, and to implement planned climate adaptation options. Here, we determine the extent to which Australian state fisheries management documents consider issues relating to climate change, as well as how frequently climate change is considered a research funding priority within fisheries research in Australia. We conduct a content analysis of fisheries management documents investigating categories and themes relating to Australian state fisheries, climate, and environmental change. We also reviewed recent Research Priorities from the major fisheries research funding body for reference to climate change related themes, and the number of subsequently funded projects which considered climate change or related topics. Results show that commercial state fisheries management documents consider climate only to a limited degree in comparison to other topics, with less than one-quarter of all fisheries management documents having content relating to climate. However, we find that the south-east and south-west regions of the Australian coastline have the highest incorporation of “climate” and “environmental protection considerations” in their fisheries management documents, and that fisheries are more likely to have more “climate-related mentions” within their related management documents, if they (i) primarily target species with higher economic commercial catch values, (ii) commercial catch weights, or (iii) a greater number of commercial fish stocks existing. Only a small number of recently funded fisheries research projects considered climate change, representing only a small proportion of fisheries research investment. Given the extensive climate-driven impacts recently documented among key Australian fisheries species and associated ecosystems, we conclude that there is a clear need for fisheries management in Australia to consider longer-term climate adaptation strategies for Australian commercial state fisheries to remain sustainable into the future. We suggest that without additional climate-related fisheries research and funding, many Australian agencies and fisheries may not be prepared for the impacts and subsequent adaptation efforts required for sustainable fisheries under climate chang

    Seabird and marine mammal management options in the face of climate change

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    Climate change is already impacting Australia’s oceans. Responses by marine life to both climate variability and change have been documented for low trophic levels, however, responses for Australia’s iconic higher trophic level marine taxa are poorly understood, including for many conservation-dependent seabirds and marine mammals. We report initial results from a national study evaluating impacts an adaptation options. Individual time series and combined analyses show consistent responses to historical climate signals, however, improved monitoring protocols are needed to maximize detection of any climate-related demographic signals. Despite difference in sampling , the development of regional multi-species-indices of environmental change provides robust climate indicators over large regions

    Biological Impacts of Marine Heatwaves

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    Climatic extremes are becoming increasingly common against a background trend of global warming. In the oceans, marine heatwaves (MHWs)—discrete periods of anomalously warm water—have intensified and become more frequent over the past century, impacting the integrity of marine ecosystems globally. We review and synthesize current understanding of MHW impacts at the individual, population, and community levels. We then examine how these impacts affect broader ecosystem services and discuss the current state of research on biological impacts of MHWs. Finally, we explore current and emergent approaches to predicting the occurrence andimpacts of future events, along with adaptation and management approaches. With further increases in intensity and frequency projected for coming decades, MHWs are emerging as pervasive stressors to marine ecosystems globally. A deeper mechanistic understanding of their biological impacts is needed to better predict and adapt to increased MHW activity in the Anthropocene.publishedVersio

    Phase 3 Trial of 177Lu-Dotatate for Midgut Neuroendocrine Tumors

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    Background Patients with advanced midgut neuroendocrine tumors who have had disease progression during first-line somatostatin analogue therapy have limited therapeutic options. This randomized, controlled trial evaluated the efficacy and safety of lutetium-177 (177Lu)-Dotatate in patients with advanced, progressive, somatostatin-receptor-positive midgut neuroendocrine tumors. Methods We randomly assigned 229 patients who had well-differentiated, metastatic midgut neuroendocrine tumors to receive either 177Lu-Dotatate (116 patients) at a dose of 7.4 GBq every 8 weeks (four intravenous infusions, plus best supportive care including octreotide long-acting repeatable [LAR] administered intramuscularly at a dose of 30 mg) (177Lu-Dotatate group) or octreotide LAR alone (113 patients) administered intramuscularly at a dose of 60 mg every 4 weeks (control group). The primary end point was progression-free survival. Secondary end points included the objective response rate, overall survival, safety, and the side-effect profile. The final analysis of overall survival will be conducted in the future as specified in the protocol; a prespecified interim analysis of overall survival was conducted and is reported here. Results At the data-cutoff date for the primary analysis, the estimated rate of progression-free survival at month 20 was 65.2% (95% confidence interval [CI], 50.0 to 76.8) in the 177Lu-Dotatate group and 10.8% (95% CI, 3.5 to 23.0) in the control group. The response rate was 18% in the 177Lu-Dotatate group versus 3% in the control group (P<0.001). In the planned interim analysis of overall survival, 14 deaths occurred in the 177Lu-Dotatate group and 26 in the control group (P=0.004). Grade 3 or 4 neutropenia, thrombocytopenia, and lymphopenia occurred in 1%, 2%, and 9%, respectively, of patients in the 177Lu-Dotatate group as compared with no patients in the control group, with no evidence of renal toxic effects during the observed time frame. Conclusions Treatment with 177Lu-Dotatate resulted in markedly longer progression-free survival and a significantly higher response rate than high-dose octreotide LAR among patients with advanced midgut neuroendocrine tumors. Preliminary evidence of an overall survival benefit was seen in an interim analysis; confirmation will be required in the planned final analysis. Clinically significant myelosuppression occurred in less than 10% of patients in the 177Lu-Dotatate group. (Funded by Advanced Accelerator Applications; NETTER-1 ClinicalTrials.gov number, NCT01578239 ; EudraCT number 2011-005049-11

    Stakeholder influence and relationships informengagement strategies in marine conservation

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    Many current marine conservation approaches do not adequately consider the diverse social elements and human aspects necessary to achieve conservation outcomes. The results of conservation research are therefore not always useful for conservation managers to apply in practice. To address this gap, this study combines qualitative methods and quantitative social network analysis to help conservation managers gain in-depth insight into social elements of marine conservation and opportunities that can help achieve conservation outcomes. Specifically, using the North West Shelf Flatback Turtle Conservation Program as a case study, our analysis shows that 1) a stakeholder’s position in the turtle conservation network is not the sole or best indicator of their leadership potential to achieve conservation outcomes, 2) peripheral stakeholders are also important for trust, decision-making, and future success, 3) mixed-methods can identify additional opportunities to maintain and further build trust and influence between diverse stakeholders 4) building relationships to support conservation outcomes is accomplished by leveraging stakeholders’ roles in the conservation program. By identifying who has influence and who needs to be involved in marine conservation to achieve success, this study demonstrates the value of mixed-methods research approaches. Specifically, our findings show how social network approaches can help conservation managers and stakeholders strategically build communication and engagement strategies that can be used to achieve conservation outcomes.This work was supported by the North West Shelf Flatback Turtle Conservation program; GTP was supported by an Australian Research Council Future Fellowship; and the Commonwealth Scientific and Industrial Research Organisation

    Re-structuring of marine communities exposed to environmental change

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    Species richness is the most commonly used but controversial biodiversity metric in studies on aspects of community stability such as structural composition or productivity. The apparent ambiguity of theoretical and experimental findings may in part be due to experimental shortcomings and/or heterogeneity of scales and methods in earlier studies. This has led to an urgent call for improved and more realistic experiments. In a series of experiments replicated at a global scale we translocated several hundred marine hard bottom communities to new environments simulating a rapid but moderate environmental change. Subsequently, we measured their rate of compositional change (re-structuring) which in the great majority of cases represented a compositional convergence towards local communities. Re-structuring is driven by mortality of community components (original species) and establishment of new species in the changed environmental context. The rate of this re-structuring was then related to various system properties. We show that availability of free substratum relates negatively while taxon richness relates positively to structural persistence (i.e., no or slow re-structuring). Thus, when faced with environmental change, taxon-rich communities retain their original composition longer than taxon-poor communities. The effect of taxon richness, however, interacts with another aspect of diversity, functional richness. Indeed, taxon richness relates positively to persistence in functionally depauperate communities, but not in functionally diverse communities. The interaction between taxonomic and functional diversity with regard to the behaviour of communities exposed to environmental stress may help understand some of the seemingly contrasting findings of past research

    Optimising fisheries management in relation to tuna catches in the western central Pacific Ocean: A review of research priorities and opportunities

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    Some of the most important development goals for the countries and territories of the Western and Central Pacific Ocean (WCPO) involve the sustainable management of their fisheries in light of environmental, economic and social uncertainties. The responses of fish populations to variability in the marine environment have implications for decision making processes associated with resource management. There is still considerable uncertainty in estimating the responses of tuna populations to short-to-medium-term variability and longer-term change in the oceanic environment. A workshop was organised to examine how advances in oceanography, fisheries science and fisheries economics could be applied to the tuna fisheries of the WCPO and in doing so identify research priorities to improve understanding relevant to progressing management. Research priorities identified included: (i) improved parameterisation of end to end ecosystem model components, processes and feedbacks through expanded biological observations and incorporation of higher resolution climate models; (ii) development of seasonal and inter-annual forecasting tools enabling management responses to short-term variability in tuna distributions and abundances; (iii) improved understanding of the population dynamics of and the energy transfer efficiencies between food web components; (iv) assessment of the optimal value of access rights and overall fishery value under multiple scenarios of tuna distribution and abundance and influences on decision making by fisheries managers and fleets and (v) development of management strategy evaluation frameworks for utilisation in the implementing and testing of fishery management procedures and to help prioritise research directions and investment. Issues discussed and research priorities identified during the workshop have synergies with other internationally managed fisheries and therefore are applicable to many other fisheries

    A global assessment of marine heatwaves and their drivers

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    Marine heatwaves (MHWs) can cause devastating impacts to marine life. Despite the serious consequences of MHWs, our understanding of their drivers is largely based on isolated case studies rather than any systematic unifying assessment. Here we provide the first global assessment under a consistent framework by combining a confidence assessment of the historical refereed literature from 1950 to February 2016, together with the analysis of MHWs determined from daily satellite sea surface temperatures from 1982–2016, to identify the important local processes, large-scale climate modes and teleconnections that are associated with MHWs regionally. Clear patterns emerge, including coherent relationships between enhanced or suppressed MHW occurrences with the dominant climate modes across most regions of the globe – an important exception being western boundary current regions where reports of MHW events are few and ocean-climate relationships are complex. These results provide a global baseline for future MHW process and prediction studies
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