1,367 research outputs found

    Investigating conflict between threatened marine megavertebrates and Mediterranean small-scale fisheries

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    Most fish stocks are being extracted at unsustainable rates and through bycatch, many marine megavertebrate species have unfavourable conservation status. The sheer number and diversity of small-scale fishing vessels worldwide presents a challenge to monitoring and research, therefore compared to industrialised fisheries, little is known about their activities or their sustainability. This thesis addresses this information gap by examining motorised polyvalent vessels <12 m length in the Mediterranean, which make up over 80 % of the fleet. We take North Cyprus as a case example to scrutinise interactions with marine turtles and dolphins. Marine turtle mortalities were found to be common (of the order of 1000 turtles caught annually; 60 % mortality), with trammel nets targeting Siganidae likely the greatest source of mortality. During the nesting season, breeding loggerhead turtles (Caretta caretta) were poorly protected from fishing pressure by a proposed Marine Protected Area, while both green (Chelonia mydas) and loggerhead turtles under-used areas within the reserve. After nesting in Cyprus, loggerhead turtles used foraging areas across the eastern Mediterranean, where they were impacted by a range of fisheries with small-scale fisheries likely leading to the mortality of three study animals. Dolphins frequented 28 % of set nets and small numbers were present in fishing areas year-round. Although infrequent, dolphin bycatch was considered to have population level impacts. A pinger was trialled but had no effect on interactions. Dolphin depredation cost fishers thousands of euro annually, while landings were estimated to be far beyond those previously reported. A tool was developed to provide spatiotemporal activity data on small-scale fisheries and this tool was used to demonstrate potential conflict between seabirds, sea turtles and protected habitats in MPAs and in a Marine IBA. The results presented using anthropological surveys, strand monitoring, onboard observation, telemetry, vessel tracking and acoustic monitoring, will be useful in developing fisheries policy for North Cyprus and in directing Marine Spatial Planning. Novel techniques developed will be relevant in addressing fisheries interactions with marine megavertebrates in small-scale fisheries globally

    The effect of biologging devices on reproduction, growth and survival of adult sea turtles

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    This is the final version. Available from BMC via the DOI in this record.The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.Background Telemetry and biologging systems, ā€˜trackingā€™ hereafter, have been instrumental in meeting the challenges associated with studying the ecology and behaviour of cryptic, wide-ranging marine mega-vertebrates. Over recent decades, globally, sea turtle tracking has increased exponentially, across species and life-stages, despite a paucity of studies investigating the effects of such devices on study animals. Indeed, such studies are key to informing whether data collected are unbiased and, whether derived estimates can be considered typical of the population at large. Methods Here, using a 26-year individual-based monitoring dataset on sympatric green (Chelonia mydas) and loggerhead (Caretta caretta) turtles, we provide the first analysis of the effects of device attachment on reproduction, growth and survival of nesting females. Results We found no significant difference in growth and reproductive correlates between tracked and non-tracked females in the years following device attachment. Similarly, when comparing pre- and post-tracking data, we found no significant difference in the reproductive correlates of tracked females for either species or significant carry-over effects of device attachment on reproductive correlates in green turtles. The latter was not investigated for loggerhead turtles due to small sample size. Finally, we found no significant effects of device attachment on return rates or survival of tracked females for either species. Conclusion While there were no significant detrimental effects of device attachment on adult sea turtles in this region, our study highlights the need for other similar studies elsewhere and the value of long-term individual-based monitoring

    The Practice and Potential of Renewable Energy Localisation: Results from a UK Field Trial

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    open access articleThe adaptation of electricity demand to match the non-despatchable nature of renewable generation is one of the key challenges of the energy transition. We describe a UK field trial in 48 homes of an approach to this problem aimed at directly matching local supply and demand. This combined a community-based business model with social engagement and demand response technology employing both thermal and electrical energy storage. A proportion of these homes (14) were equipped with rooftop photovoltaics (PV) amounting to a total of 45 kWp; the business model enabled the remaining 34 homes to consume the electricity exported from the PV-equipped dwellings at a favourably low tariff in the context of a time-of-day tariff scheme. We report on the useful financial return achieved by all participants, their overall experience of the trial, and the proportion of local generation consumed locally. The energy storage devices were controlled, with user oversight, to respond automatically to signals indicating the availability of low cost electricity either from the photovoltaics or the time of day grid tariff. A substantial response was observed in the resulting demand profile from these controls, less so from demand scheduling methods which required regular user configuration. Finally results are reported from a follow-up fully commercial implementation of the concept showing the viability of the business model. We conclude that the sustainability of the transition to renewable energy can be strengthened with a community-oriented approach as demonstrated in the trial that supports users through technological change and improves return on investment by matching local generation and consumption

    Anionic Host Defence Peptides from the Plant Kingdom: Their Anticancer Activity and Mechanisms of Action

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    It is becoming increasingly clear that plants, ranging from across the plant kingdom produce anionic host defence peptides (AHDPs) with potent activity against a wide variety of human cancers cells. In general, this activity involves membrane partitioning by AHDPs, which leads to membranolysis and / or internalization to attack intracellular targets such as DNA. Several models have been proposed to describe these events including: the toroidal pore and Shai-Matsuzaki-Huang mechanisms but, in general, the mechanisms underpinning the membrane interactions and anticancer activity of these peptides are poorly understood. Plant AHDPs with anticancer activity can be conveniently discussed with reference to two groups: cyclotides, which possess cyclic molecules stabilized by cysteine knot motifs, and other ADHPs that adopt extended and Ī±-helical conformations. Here, we review research into the anticancer action of these two groups of peptides along with current understanding of the mechanisms underpinning this action

    Managing complexity in the smart grid through a new approach to demand response

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    CASCADE was a consortium project with Cranfield UniversityAdoption of weather-dependent renewable generation of electricity has introduced additional complexity to the challenge of maintaining a dynamic equilibrium between generation and electricity demand. At the same time the need for electricity to power heating and transport in place of fossil fuels will lead to congestion in distribution networks. Part of the solution will be to manage domestic electricity demand using signals between the smart grid and smart home, but this must be done in a way that does not provoke further instability. We use an agent-based model of household electricity consumption and supply to show how the complexity of domestic demand can be shaped allowing it to make a contribution to system stability. A possible role for this method in balancing conflicting interests between electricity consumers, suppliers, and distribution network operators is discussedEPSRC under the CASCADE project (EP/GO59969/1

    Functionalising the azobenzene motif delivers a light-responsive membrane-interactive compound with the potential for photodynamic therapy applications

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    When adorned with n-octyl chains azobenzene is able to disrupt a variety of calcein-loaded phospholipid liposomes. The levels of lysis observed are dependent both on the lipid headgroup and the conformation of the azobenzene compound. In all cases studied, it has been shown that the cis-conformer is more membrane-interactive than the trans-conformer, suggesting that this class of molecule could be optimised for photo-dynamic therapy applications against infectious pathogens
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