Phospholipase A2 is an "interfacial" enzyme and its binding to negatively charged surfaces is an important step during catalysis. The Gln48 phospholipase A2 from the venom of Vipera ammodytes ...meridionalis plays the role of chaperone and directs a toxic His48 PLA2 onto its acceptor. In the venom the two phospholipases A2 exist as a postsynaptic neurotoxic complex, Vipoxin. The X-ray structure of Gln48 PLA2, complexed to sulphate ions, which mimic the negatively charged groups of anionic membranes, has been determined by the molecular replacement method and refined to 1.9A resolution. The protein forms a homodimer stabilized by ionic, hydrophobic, and hydrogen-bond interactions. The structure reveals two anion-binding sites per subunit. These sites are probably involved in interactions with the negatively charged membrane surface and, in this way, in the "targeting" of the toxic component to the receptors of the postsynaptic membranes. In the absence of the chaperone subunit the toxin changes the target of the physiological attack. A comparison of the homodimeric Gln48 PLA2 structure with that of the heterodimeric Vipoxin reveals differences in regions involved in the pharmacological activity of the toxin. This fact, except the active site histidine substitution, can explain the absence of toxicity in the Gln48 protein in comparison to the His48 phospholipase A2.
We investigated the scale and characteristics of spring migration of soaring birds in Bourgas district, SE Bulgaria during three 5-day periods in March (27th-31st), April (20th-24th) and May ...(12th-16th) 2008. Simultaneous counts were carried out from six observation points in two separate areas (Karnobat and Sredets), located 24.5 km and 37.3 km inland from the Black Sea coast, respectively. In total, 31,049 soaring birds of at least 27 species were counted, by far the most numerous being the White Stork Ciconia ciconia (23,358 ind.), followed by the Lesser Spotted Eagle Aquila pomarina (3,112 ind.). In Karnobat area, situated farther from the Black Sea coast, the total number of soaring migrants (21,231) was more than two-fold higher than in Sredets area (9,818). Overall, there was a significant difference in flock size and flight altitude within separate area (i.e. among observation points) as well as between the two observation areas and the three 5-day periods. However, there was a substantial variance in factors significantly affecting the flock size and flight altitude among most numerous individual species. In general, birds passed at much higher altitude above Karnobat area (mean flight altitude 208.3 m ± 6.4) compared to Sredets area (mean flight altitude 130.5 m ± 4.4). In both observation areas, northern direction was the most commonly observed flight direction (46.3% of all recorded flight directions). The highest numbers of soaring migrants passed in the late afternoon, between 15.00 and 18.00 hrs - 11,554 individuals (43.0% of all birds counted). The study confirmed that the front of Western Black Sea migration route, or "Via Pontica" as part of the Mediterranean/Black Sea Flyway in SE Bulgaria, is rather wide, since the magnitude of inland migration in Bourgas district can be compared with that along the Black Sea coast, at least during spring migration. Both observation areas qualify as Important Bird Areas (IBA) of European importance according to the several BirdLife International criteria. We recommend that any new wind farms built should avoid the area of Hisar Hill south of Karnobat and the NW parts of Sredets Municipality.
Značilnosti spomladanske selitve jadrajočih ptic v notranjosti JV Bolgarije
Phospholipase A
2 is an “interfacial” enzyme and its binding to negatively charged surfaces is an important step during catalysis. The Gln48 phospholipase A
2 from the venom of
Vipera ammodytes ...meridionalis plays the role of chaperone and directs a toxic His48 PLA
2 onto its acceptor. In the venom the two phospholipases A
2 exist as a postsynaptic neurotoxic complex, Vipoxin. The X-ray structure of Gln48 PLA
2, complexed to sulphate ions, which mimic the negatively charged groups of anionic membranes, has been determined by the molecular replacement method and refined to 1.9
Å resolution. The protein forms a homodimer stabilized by ionic, hydrophobic, and hydrogen-bond interactions. The structure reveals two anion-binding sites per subunit. These sites are probably involved in interactions with the negatively charged membrane surface and, in this way, in the “targeting” of the toxic component to the receptors of the postsynaptic membranes. In the absence of the chaperone subunit the toxin changes the target of the physiological attack. A comparison of the homodimeric Gln48 PLA
2 structure with that of the heterodimeric Vipoxin reveals differences in regions involved in the pharmacological activity of the toxin. This fact, except the active site histidine substitution, can explain the absence of toxicity in the Gln48 protein in comparison to the His48 phospholipase A
2.
Background
This
article
elaborates on Horizon 2020 Smart5Grid Research and Innovation (R&I)
project
and reports the Smart5Grid Open Experimentation Platform (OEP), including its Open Service ...Repository (OSR), Verification and Validation (V&V), NetApp Controller (NAC), and Multi-access Edge Computing Orchestrator (MECO), as key results of this project. It then translates those results into energy vertical implications of the Smart5Grid for Transmission System Operators (TSOs), focusing on two particular Use Cases (UCs): UC3 Millisecond Level Precise Distribution Generation Control and UC4 Real-time Wide Area Monitoring pilot demonstrator of 5G virtual PDC capabilities for WAM of end-to-end electricity grids. More specifically, this work exhibits UC3 and UC4 NetApps developed as one of the key project deliverables. All use cases generate openly accessible data, except where specific security restrictions are applicable.
Methods
The Smart5Grid development methodology is based on the concept of Network Applications (NetApps). Their main mission is to hide the complexity of a 5G telco network for energy application developers in a way that empowers them to develop a NetApp without having to deal with the underlying network. A Virtual Infrastructure Manager (VIM) such as OpenStack or Kubernetes hosts every unit that composes a NetApp. The VIM provides monitoring data to a Network Function Vurtualisation Manager and Orchestrator (NFV MANO) framework, which airs information to the NAC that employs analysis algorithms to propose the optimal Virtual Network Function (VNF) and NetApp placing. A Slice Manager (SM) reserves resources for all these capabilities.
Results
The Smart5Grid architecture represents the main result that this work delineates in the context of its enhanced 5G telecommunication provider (telco) capabilities for transmission and distribution grids to face and manage more efficiently high Renewable Energy Sources (RES) penetration in a decarbonisation context.
This article presents the latency minimisation potential provided by the Smart5Grid Open Experimentation Platform (OEP) developed by the Horizon 2020 Smart5Grid Research and Innovation (R&I) project. ...It discusses the OEP performance and provides experimental data to substantiate its contribution to improving observability and manageability of distributed renewable generation in power grids. That experimental proof is delivered by two pilots running on the OEP: Demo 1 Millisecond Level Precise Distribution Generation Control, and Demo 2 Real-time Wide Area Monitoring (WAM) pilot of 5G virtual Phasor Data Concentrator v(PDC) capabilities for WAM of end-to-end electricity grids. This work reports two Network Applications (NetApps) created to support both demos and provides experimental evidence that the OEP offers latency of comparable measure to well-established wire-bound communications in addition to availability and reliability on top of by-design flexibility, scalability and modularity, which are especially relevant to power systems with high shares of Distributed Renewable Energy Recourses (DRERs). The software and methods used for the OEP development and experimental testbeds applied to measure its latency performance in both tailored pilot demos are explained at length. The test results are presented and interpreted with a view to discussing potential contributions of the presented 5G-enabled solutions for power grid smartification in conditions of high rollout of distributed renewable generation. All pilot demos generate openly accessible data, except where specific security restrictions are applicable.
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