Southern Africa occupies a critical position within the southern hemisphere for the study of broadscale global change and the three oceans around South Africa (the Atlantic, Indian and Southern ...Oceans) play a vital role in determining local and regional climate and weather patterns. Oceans and coasts also provide various resources and services (e.g. food and carbon sequestration), but these services are threatened by human activities. Uncertainty of the impact and consequences of these anthropogenic activities makes it problematic to manage marine resources. Given the recent global emphasis on the development of ‘ocean economies’, the exploitation of living (fisheries, aquaculture and tourism) and non-living (oil and gas, minerals, energy) marine resources should be on a scale that is socially and economically justifiable and ecologically sustainable. In 2014, ‘Operation Phakisa’ was launched in South Africa as an initiative to accelerate execution of the National Development Plan. The primary focus of Phakisa is to unlock the economic potential of South Africa’s oceans. This will be achieved through the ‘implementation of an overarching, integrated ocean governance framework for sustainable growth of the ocean economy that will maximise socio-economic benefits while ensuring adequate ocean environmental protection’ by 2019. Marine spatial planning (MSP) is a key component of this integrated governance framework, and the development of MSP legislation during 2016 was prioritised as ‘critical’ to achieving the Operation Phakisa objectives. Accordingly, the Department of Environmental Affairs (DEA) published the Marine Spatial Planning Bill (2017) ‘to provide a framework for marine spatial planning in South Africa’s waters; to provide for the development of the marine spatial plan; to provide for institutional arrangements for the implementation of the marine spatial plan and governance of the use of the ocean by multiple sectors; and to provide for matters connected therewith’.
Marine legislation is becoming more complex and marine ecosystem-based management is specified in national and regional legislative frameworks. Shelf-seas community and ecosystem models (hereafter ...termed ecosystem models) are central to the delivery of ecosystem-based management, but there is limited uptake and use of model products by decision makers in Europe and the UK in comparison with other countries. In this study, the challenges to the uptake and use of ecosystem models in support of marine environmental management are assessed using the UK capability as an example. The UK has a broad capability in marine ecosystem modelling, with at least 14 different models that support management, but few examples exist of ecosystem modelling that underpin policy or management decisions. To improve understanding of policy and management issues that can be addressed using ecosystem models, a workshop was convened that brought together advisors, assessors, biologists, social scientists, economists, modellers, statisticians, policy makers, and funders. Some policy requirements were identified that can be addressed without further model development including: attribution of environmental change to underlying drivers, integration of models and observations to develop more efficient monitoring programmes, assessment of indicator performance for different management goals, and the costs and benefit of legislation. Multi-model ensembles are being developed in cases where many models exist, but model structures are very diverse making a standardised approach of combining outputs a significant challenge, and there is a need for new methodologies for describing, analysing, and visualising uncertainties. A stronger link to social and economic systems is needed to increase the range of policy-related questions that can be addressed. It is also important to improve communication between policy and modelling communities so that there is a shared understanding of the strengths and limitations of ecosystem models.
•Ecosystem models have great potential to support decision-making, but UK examples are limited.•Ecosystem models would be more widely used with better awareness of capability, quality assurance, and uncertainty.•UK ecosystem modelling with immediate value to policy and capability gaps are identified.•Communities of policy makers and scientists are needed to co-develop ecosystem models.
Antarctica, the sub-Antarctic islands and surrounding Southern Ocean are regarded as one of the planet’s last remaining wildernesses, ‘insulated from threat by their remoteness and protection under ...the Antarctic Treaty System’. Antarctica encompasses some of the coldest, windiest and driest habitats on earth. Within the Southern Ocean, sub-Antarctic islands are found between the Sub-Antarctic Front to the north and the Polar Front to the south. Lying in a transition zone between warmer subtropical and cooler Antarctic waters, these islands are important sentinels from which to study climate change. A growing body of evidence now suggests that climatically driven changes in the latitudinal boundaries of these two fronts define the islands’ short- and long-term atmospheric and oceanic circulation patterns. Consequently, sub-Antarctic islands and their associated terrestrial and marine ecosystems offer ideal natural laboratories for studying ecosystem response to change. For example, a recent study indicates that the shift in the geographical position of the oceanic fronts has disrupted inshore marine ecosystems, with a possible impact on top predators. Importantly, biotic responses are variable as indicated by different population trends of these top predators. When studied collectively, these variations in species’ demographic patterns point to complex spatial and temporal changes within the broader sub-Antarctic ecosystem, and invite further examination of the interplay between extrinsic and intrinsic drivers.
Ten dogs were subjected to defibrinogenation with an intravenous perfusion of ancrod (1 unit/kg) (Arvin, Knoll AG, Ludwigshafen, Federal Republic of Germany) over a 2 1/2 hour period. Six of them ...were subjected to extracorporeal elimination of carbon dioxide with a polypropylene membrane lung by means of veno-venous bypass. The remaining four dogs did not undergo extracorporeal circulation and served as control subjects. In both groups, ancrod administration itself resulted in a marked drop in alpha 2-antiplasmin (33% and 67%, respectively, of the baseline values) and in slight but significant decreases in factor II and plasminogen activities of 25% and 20%, respectively (p less than 0.05), in the group subjected to carbon dioxide removal. There were no significant changes in platelet number or factor V and antithrombin III activities. During the 6-hour bypass period, platelet count and antithrombin III and factor II and V levels decreased significantly. No bleeding was observed. Histologic examination of lung biopsy tissue showed no pathologic features. Analysis of the membrane of the artificial lungs revealed no fibrin deposits. In the control group, except for a drop in alpha 2-antiplasmin levels (54%), no significant changes in hemostatic parameters occurred during the corresponding 6 hours. We conclude that, despite the drop in coagulation factors and in alpha 2-antiplasmin activity during bypass, ancrod can be considered as a valuable alternative anticoagulant for extracorporeal carbon dioxide removal.
The effects of cholera toxin on the responses of cultured Sertoli cells were compared with those elicited by follicle-stimulating hormone (FSH), and N6O2'-dibutyryl-3',5'-cyclic AMP (bu2cAMP). ...Addition of FSH or cholera toxin increased cAMP levels. Subsequently there was greater rates of conversion of testosterone to 17beta-estradiol, formation of androgen-binding protein (ABP), and incorporation of 3Hthymidine into DNA by Sertoli cells prepared from testes of immature rats and cultured in the presence of either FSH or cholera toxin. Addition of bu2-cAMP also resulted in enhanced rates of formation of ABP, synthesis of 17beta-estradiol and synthesis of DNA. Cholera toxin and bu2-cAMP elicited changes in morphology of cultured Sertoli cells indistinguishable from those following FSH addition. It is concluded that elevated intracellular cAMP levels can duplicate known actions of FSH on cultured Sertoli cells, but the possible obligatory role of cAMP in mediating FSH actions remains to be evaluated.
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