Our understanding of the regulation of appetite has improved considerably over the last few decades. Recent work, stimulated by efforts aimed at curbing the current obesity epidemic, has unravelled ...some of the complex pathways regulating energy homeostasis. Key factors to this progress have been the discovery of leptin and the neuronal circuitry involved in mediating its effects, as well as the identification of gut hormones that have important physiological roles relating to energy homeostasis. Despite these advances in research, there are currently no effective treatments for the growing problem of obesity. In this article, we summarise the regulatory pathways controlling appetite with a special focus on gut hormones. We detail how recent findings have contributed to our knowledge regarding the pathogenesis and treatment of common obesity. A number of barriers still need to be overcome to develop safe and effective anti-obesity treatments. We outline problems highlighted by historical failures and discuss the potential of augmenting natural satiety signals, such as gut hormones, to treat obesity.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Smart grid is the nexus of advanced information and communication technologies and legacy power systems. With increasing awareness on the vulnerabilities of smart grids to cyberattacks, cybersecurity ...is becoming a prime concern. Earlier, it was assumed that the power system communication protocols are very specialized and different, so the "security by obscurity" approach would be sufficient. However, with the standardization of communication protocols for power utilities and the emergence of the power market, this approach is no longer valid. IEC 62351 Standard has been published to provide security recommendations for different power system communication protocols including IEC 61850. IEC 61850 is emerging as the most promising and popular power system communication standard. Therefore, in this article, a detailed analysis of security threats, possible attacks, and security requirements for IEC 61850 communication is presented. Building on this, the security considerations presented in IEC 62351 for securing different IEC 61850 messages, such as generic object-oriented substation events (GOOSE), sampled values (SV), routable-GOOSE, routable-SV, and manufacturing message specification messages have been presented in great detail.
It is an exciting time for power systems as there are many ground-breaking changes happening simultaneously. There is a global consensus in increasing the share of renewable energy-based generation ...in the overall mix, transitioning to a more environmental-friendly transportation with electric vehicles as well as liberalizing the electricity markets, much to the distaste of traditional utility companies. All of these changes are against the status quo and introduce new paradigms in the way the power systems operate. The generation penetrates distribution networks, renewables introduce intermittency, and liberalized markets need more competitive operation with the existing assets. All of these challenges require using some sort of storage device to develop viable power system operation solutions. There are different types of storage systems with different costs, operation characteristics, and potential applications. Understanding these is vital for the future design of power systems whether it be for short-term transient operation or long-term generation planning. In this paper, the state-of-the-art storage systems and their characteristics are thoroughly reviewed along with the cutting edge research prototypes. Based on their architectures, capacities, and operation characteristics, the potential application fields are identified. Finally, the research fields that are related to energy storage systems are studied with their impacts on the future of power systems.
Due to environmental concerns, power system generation is shifting from traditional fossil-fuel resources to renewable energy such as wind, solar and geothermal. Some of these technologies are very ...location specific while others require high upfront costs. Photovoltaic (PV) generation has become the rising star of this pack, thanks to its versatility. It can be implemented with very little upfront costs, e.g., small solar home systems, or large solar power plants can be developed to generate MWs of power. In contrast with wind or tidal generation, PV can be deployed all around the globe, albeit with varying potentials. These merits have made PV the renewable energy technology with highest installed capacity around the globe. However, PV penetration into the grid comes with its drawbacks. The inverter-interfaced nature of the PV systems significantly impacts the power system operation from protection, power flow and stability perspectives. There must be strategies to mitigate these negative impacts so that PV penetration into the grid can continue. This paper gives a thorough overview of such strategies from different research fields: such as communication, artificial intelligence, power electronics and electric vehicle charging coordination. In addition, possible research directions are given for future work.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
•An increase in Ha causes the decreases of average Nu, SHT and ST.•An increase in Ri increases the mixed convection modes as well as the rate of heat transfer.•An increase in the Re and ϕ causes an ...enhancement in Nu and entropy generation tools.•Heat transfer irreversibility is dominating than the fluid friction irreversibility for low Ha.
A computational analysis has been performed in a horizontal channel with an open cavity filled with hybrid nanofluid of Al2O3-Cu-water having an adiabatic square obstacle inside. The bottom wall of the cavity is taken as hot while all the rest walls of the channel and cavity are adiabatic except the left end of the channel which is taken as cold. Three different vertical locations of the obstacle are considered. The governing partial differentials equations are solved via Galerkin finite element method in space and the Crank-Nicolson in time. Newton method is utilized to cope with discretized nonlinear systems of equations and the Gaussian elimination method has been applied to solve the associated linear subproblems in each nonlinear iteration. The emerging parameters are Richardson number (0.01⩽Ri⩽20), nanoparticle volume fraction (0.0⩽ϕ⩽0.04),(1⩽Re⩽200) and Hartmann number (0⩽Ha⩽100). Calculations of the streamlines, isotherms, average Nusselt number and entropy generation will be the main focus of interest in this study.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
To identify metabolic pathways that are perturbed in pancreatic ductal adenocarcinoma (PDAC), we investigated gene-metabolite networks with integration of metabolomics and transcriptomics.
We ...conducted global metabolite profiling analysis on two independent cohorts of resected PDAC cases to identify critical metabolites alteration that may contribute to the progression of pancreatic cancer. We then searched for gene surrogates that were significantly correlated with the key metabolites, by integrating metabolite and gene expression profiles.
Fifty-five metabolites were consistently altered in tumors as compared with adjacent nontumor tissues in a test cohort (N = 33) and an independent validation cohort (N = 31). Weighted network analysis revealed a unique set of free fatty acids (FFA) that were highly coregulated and decreased in PDAC. Pathway analysis of 157 differentially expressed gene surrogates revealed a significantly altered lipid metabolism network, including key lipolytic enzymes PNLIP, CLPS, PNLIPRP1, and PNLIPRP2. Gene expressions of these lipases were significantly decreased in pancreatic tumors as compared with nontumor tissues, leading to reduced FFAs. More importantly, a lower gene expression of PNLIP in tumors was associated with poorer survival in two independent cohorts. We further showed that two saturated FFAs, palmitate and stearate, significantly induced TRAIL expression, triggered apoptosis, and inhibited proliferation in pancreatic cancer cells.
Our results suggest that impairment in a lipolytic pathway involving lipases, and a unique set of FFAs, may play an important role in the development and progression of pancreatic cancer and provide potential targets for therapeutic intervention.
Real-time energy management automation in microgrid can improve energy security, reliability, efficiency, and power quality but is a challenging issue as it requires a robust, deterministic, and ...interoperable communication architecture. IEC 61850-based communication architecture has the potential to be the promising solution for microgrid automation. Hence, this paper addresses this challenge by proposing IEC 61850-based design and modeling of IEDs for different types of distributed energy resources and a new logical node for controllable loads along with the design of structure and size of communication messages required for energy management automation in microgrid for the first time. This paper demonstrates the validation and implementation of the proposed design and modeling through a real-time system-in-the-loop simulation for a test microgrid. Finally, to justify the feasibility of the proposed design and modeling, dynamic performance of the microgrid communication architecture is evaluated in terms of end-to-end delay and throughput for different network topological configurations. This paper intends to provide a platform to model, configure, and evaluate a promising future standards-based communication for microgrid automation.
The integrity and authenticity of message exchanges in IEC 61850 based automated substations is critical. IEC 62351-6 recommends Message Authentication Code (MAC) based cybersecurity scheme for ...securing IEC 61850 Sampled Value (SV) and GOOSE messages. This IEC 62351-6 standard-based approach is effective for an Intelligent Electronic Device (IED) that subscribes to a single SV stream. However, for applications where an IED needs to subscribe to multiple SV streams, IEC 62351-6 MAC based technique results in significant computational time overhead. This letter proposes a lightweight optimized security scheme based on quantum secure Blake-2s algorithm for IEC 61850 SV stream. Experimental results show that the proposed scheme improves the computational overhead latency by 56.03% compared to the scheme recommended in IEC 62351-6 standards.
The ecosystem services concept provides both an analytical and communicative tool to identify and quantify the link between human welfare and the environment, and thus to evaluate the ramifications ...of management interventions. Marine spatial planning (MSP) and Ecosystem-based Management (EBM) are a form of management intervention that has become increasingly popular and important globally. The ecosystem service concept is rarely applied in marine planning and management to date which we argue is due to the lack of a well-structured, systematic classification and assessment of marine ecosystem services. In this paper we not only develop such a typology but also provide guidance to select appropriate indicators for all relevant ecosystem services. We apply this marine-specific ecosystem service typology to MSP and EBM. We thus provide not only a novel theoretical construct but also show how the ecosystem services concept can be used in marine planning and management.
•An application-oriented marine ecosystem service (ES) typology is developed.•It meets the requirements for an application in EBM and marine spatial planning.•It facilitates the implementation of the EU Marine Strategy Framework Directive.•It includes detailed definitions, examples, indicators to facilitate its utilization.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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