An IoT-based energy management system for AC microgrids with grid and security constraints

This paper proposes an Internet-of-Things (IoT) based energy management system (EMS) for the optimal operation of unbalanced three-phase AC microgrids. The system utilizes a software architecture based on microservices, which includes a stochastic economic dispatch optimizer (EDO), a database, a web-based graphical user interface (GUI), and an application programming interface (API). The EDO uses a mixed-integer linear programming (MILP) model to ensure the day-ahead dispatch of the distributed energy resources (DERs) in the microgrid while adhering to grid constraints such as voltage, current, and power limits. Additionally, the optimization module takes into account security constraints for unplanned islanded operation, as well as stochastic scenarios of local demand and renewable generation. To assess the performance of the proposed IoT-based EMS, tests are conducted using a real-time simulator in a software-in-the-loop (SIL) experimental setup. Actual data from a microgrid located at the State University of Campinas (UNICAMP) in Brazil is utilized for the tests. The microgrid consisted of a photovoltaic (PV) system, a battery energy storage system (BESS), a thermal generation unit, and variable demands. Results indicated the effectiveness of the proposed IoT-based EMS in monitoring the operation of the microgrid and defining the optimal day-ahead dispatch of local DERs.</p

Alterations in vascular function in primary aldosteronism - a cardiovascular magnetic resonance imaging study

Introduction: Excess aldosterone is associated with increased cardiovascular risk. Aldosterone has a permissive effect on vascular fibrosis. Cardiovascular magnetic resonance imaging (CMR) allows study of vascular function by measuring aortic distensibility. We compared aortic distensibility in primary aldosteronism (PA), essential hypertension (EH) and normal controls and explored the relationship between aortic distensibility and pulse wave velocity (PWV).&lt;p&gt;&lt;/p&gt; Methods: We studied PA (n=14) and EH (n=33) subjects and age-matched healthy controls (n=17) with CMR, including measurement of aortic distensibility, and measured PWV using applanation tonometry. At recruitment, PA and EH patients had similar blood pressure and left ventricular mass.&lt;p&gt;&lt;/p&gt; Results: Subjects with PA had significantly lower aortic distensibilty and higher PWV compared to EH and healthy controls. These changes were independent of other factors associated with reduced aortic distensibility, including aging. There was a significant relationship between increasing aortic stiffness and age in keeping with physical and vascular aging. As expected, aortic distensibility and PWV were closely correlated.&lt;p&gt;&lt;/p&gt; Conclusion: These results demonstrate that PA patients display increased arterial stiffness compared to EH, independent of vascular aging. The implication is that aldosterone invokes functional impairment of arterial function. The long-term implications of arterial stiffening in aldosterone excess require further study.&lt;p&gt;&lt;/p&gt

Glycoprotein Ib activation by thrombin stimulates the energy metabolism in human platelets

<div><p>Thrombin-induced platelet activation requires substantial amounts of ATP. However, the specific contribution of each ATP-generating pathway <i>i</i>.<i>e</i>., oxidative phosphorylation (OxPhos) versus glycolysis and the biochemical mechanisms involved in the thrombin-induced activation of energy metabolism remain unclear. Here we report an integral analysis on the role of both energy pathways in human platelets activated by several agonists, and the signal transducing mechanisms associated with such activation. We found that thrombin, Trap-6, arachidonic acid, collagen, A23187, epinephrine and ADP significantly increased glycolytic flux (3–38 times <i>vs</i>. non-activated platelets) whereas ristocetin was ineffective. OxPhos (33 times) and mitochondrial transmembrane potential (88%) were increased only by thrombin. OxPhos was the main source of ATP in thrombin-activated platelets, whereas in platelets activated by any of the other agonists, glycolysis was the principal ATP supplier. In order to establish the biochemical mechanisms involved in the thrombin-induced OxPhos activation in platelets, several signaling pathways associated with mitochondrial activation were analyzed. Wortmannin and LY294002 (PI3K/Akt pathway inhibitors), ristocetin and heparin (GPIb inhibitors) as well as resveratrol, ATP (calcium-release inhibitors) and PP1 (Tyr-phosphorylation inhibitor) prevented the thrombin-induced platelet activation. These results suggest that thrombin activates OxPhos and glycolysis through GPIb-dependent signaling involving PI3K and Akt activation, calcium mobilization and protein phosphorylation.</p></div

Methods for specifying the target difference in a randomised controlled trial : the Difference ELicitation in TriAls (DELTA) systematic review

Peer reviewedPublisher PD

Sur la formation des prix dans l'économie du haut Moyen Âge

International audienceDuring the Early Middle Ages, market exchange coexists alongside non market exchange. The aim of this paper is to examine how possibly this two great modalities of exchange can be present at the same time in the economic life, in a period in which the existence of marketable surplus is a problem. The presumed deficiencies of the means of production, their presumed unsuitability with the economic development, the postulated incompetence of the élites, make the market exchange, and even the possibility that a profit sector exists in the economy, undervalued, or even denied. The social élites, just as the small scale actors, whatever their activity could be, farming or trading, have beside production, consumption and exchange, very subtle and complex attitudes. We shall see that some cognitive capacities exist within the groups of economic actors, that go far beyond an empirical knowledge and result from a reflection about the finalities of economics, the functions of wealth and about its use in a Christian society. Sixth century monks know how the prices are formed, as they know that there is a difference between price formation and price fixation, and also know how to manage with rules to ensure one's salvation. This knowledge also exists, within a very different framework, and the comparison between the practice of such men as Adalhard of Corbie and saint Benedict's Rule (or with the Master's Rule), give an explanation of their attitude toward prices: for them, things have a value and it is possible to measure it as well as modify it. The attitude of the Carolingian and post-carolingian élites during the famines allows us to understand how social and political authorities understood market exchange rules within a Christian society. At the end, there is a shared but tacit, as well, knowledge about the functioning of exchanges and a clear awareness about the fact that they can take several forms depending on the result aimed at.Durant le haut Moyen Âge, l'échange marchand coexiste avec l'échange non-marchand. Le but de cet article est d'examiner les conditions de possibilité de la présence de ces deux grandes modalités de l'échange au sein de la vie économique durant une période où l'existence même de surplus commerciaux fait question. Les déficiences supposées des moyens de production, leur éventuelle inadéquation avec le développement, l'incompétence elle aussi postulée des élites font que l'échange par le marché et la possibilité qu'il existe un secteur de profit sont le plus souvent sous-évalués voire niés. Les élites sociales tout comme les acteurs de petit niveau, qu'il s'agisse d'agriculteurs ou de commerçants, ont à l'égard de la production, de la consommation et de l'échange des attitudes très nuancées et complexes. On montre qu'il existe des capacités cognitives qui vont au-delà d'un savoir faire empirique mais relèvent d'une réflexion sur les finalités mêmes de la vie économique, sur les fonctions de la richesse et sur leur usage dans un monde chrétien. Les moines savent, au VIe siècle, comment se forment les prix et comprennent la différence entre formation et fixation des prix. Il savent aussi comment il faut jouer avec ces règles pour assurer son salut. Ce savoir existe aussi au IXe siècle, dans un monde très différent, et la comparaison entre les pratiques d'hommes comme Adalhard de Corbie et la règle de saint Benoît (ou celle du Maître) livre l'explication de leur attitude à l'égard des prix : pour eux les choses ont une valeur qu'il est possible de mesurer et de modifier. L'attitude des élites carolingiennes et post-carolingiennes lors des famines permet d'établir comment les autorités ont compris les règles de l'échange marchand à l'intérieur d'un monde chrétien. Il y a au bout du compte un savoir partagé mais tacite sur le fonctionnement des échanges et une conscience de ce que, en fonction des buts poursuivis, ceux-ci peuvent prendre plusieurs formes

Metaheuristics for Transmission Network Expansion Planning

This chapter presents the characteristics of the metaheuristic algorithms used to solve the transmission network expansion planning (TNEP) problem. The algorithms used to handle single or multiple objectives are discussed on the basis of selected literature contributions. Besides the main objective given by the costs of the transmission system infrastructure, various other objectives are taken into account, representing generation, demand, reliability and environmental aspects. In the single-objective case, many metaheuristics have been proposed, in general without making strong comparisons with other solution methods and without providing superior results with respect to classical mathematical programming. In the multi-objective case, there is a better convenience of using metaheuristics able to handle conflicting objectives, in particular with a Pareto front-based approach. In all cases, improvements are still expected in the definition of benchmark functions, benchmark networks and robust comparison criteria

6-Phosphofructo-2-kinase/fructose-2,6-biphosphatase 4 is essential for p53-null cancer cells.

The bifunctional enzyme 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase-4 (PFKFB4) controls metabolic flux through allosteric regulation of glycolysis. Here we show that p53 regulates the expression of PFKFB4 and that p53-deficient cancer cells are highly dependent on the function of this enzyme. We found that p53 downregulates PFKFB4 expression by binding to its promoter and mediating transcriptional repression via histone deacetylases. Depletion of PFKFB4 from p53-deficient cancer cells increased levels of the allosteric regulator fructose-2,6-bisphosphate, leading to increased glycolytic activity but decreased routing of metabolites through the oxidative arm of the pentose-phosphate pathway. PFKFB4 was also required to support the synthesis and regeneration of nicotinamide adenine dinucleotide phosphate (NADPH) in p53-deficient cancer cells. Moreover, depletion of PFKFB4-attenuated cellular biosynthetic activity and resulted in the accumulation of reactive oxygen species and cell death in the absence of p53. Finally, silencing of PFKFB4-induced apoptosis in p53-deficient cancer cells in vivo and interfered with tumour growth. These results demonstrate that PFKFB4 is essential to support anabolic metabolism in p53-deficient cancer cells and suggest that inhibition of PFKFB4 could be an effective strategy for cancer treatment.Cancer Research UK; German Cancer Aid (grant 111917); German Research Foundation (FOR 2314); CRUK-EPSRC Imaging Centre in Cambridge and Manchester (grant 16465

Structure-Based Development of Small Molecule PFKFB3 Inhibitors: A Framework for Potential Cancer Therapeutic Agents Targeting the Warburg Effect

Cancer cells adopt glycolysis as the major source of metabolic energy production for fast cell growth. The HIF-1-induced PFKFB3 plays a key role in this adaptation by elevating the concentration of Fru-2,6-BP, the most potent glycolysis stimulator. As this metabolic conversion has been suggested to be a hallmark of cancer, PFKFB3 has emerged as a novel target for cancer chemotherapy. Here, we report that a small molecular inhibitor, N4A, was identified as an initial lead compound for PFKFB3 inhibitor with therapeutic potential. In an attempt to improve its potency, we determined the crystal structure of the PFKFB3•N4A complex to 2.4 Å resolution and, exploiting the resulting molecular information, attained the more potent YN1. When tested on cultured cancer cells, both N4A and YN1 inhibited PFKFB3, suppressing the Fru-2,6-BP level, which in turn suppressed glycolysis and, ultimately, led to cell death. This study validates PFKFB3 as a target for new cancer therapies and provides a framework for future development efforts

Time to focus on outcome assessment tools for childhood vasculitis

Childhood systemic vasculitides are a group of rare diseases with multi-organ involvement and potentially devastating consequences. After establishment of new classification criteria (Ankara consensus conference in 2008), it is now time to establish measures for proper definition of activity and damage in childhood primary vasculitis. By comparison to adult vasculitis, there is no consensus for indices of activity and damage assessment in childhood vasculitis. Assessment of disease activity is likely to become a major area of interest in pediatric rheumatology in the near future. After defining the classification criteria for primary systemic childhood vasculitis, the next step was to perform a validation study using the original Birmingham vasculitis activity score as well as the disease extent index to measure disease activity in childhood vasculitis. Presently, there are efforts in place to develop a pediatric vasculitis activity score. This paper reviews the current understanding about the assessment tools (i.e., clinical features, laboratory tests, radiologic assessments, etc.) widely used for evaluation of the disease activity and damage status of the children with vasculitis