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Wound infections are often polymicrobial in nature, biofilm associated and therefore tolerant to antibiotic therapy, and associated with delayed healing. Escherichia coli and Staphylococcus aureus are among the most frequently cultured pathogens from wound infections. However, little is known about the frequency or consequence of E. coli and S. aureus polymicrobial interactions during wound infections. Here we show that E. coli kills Staphylococci, including S. aureus, both in vitro and in a mouse excisional wound model via the genotoxin, colibactin. Colibactin biosynthesis is encoded by the pks locus, which we identified in nearly 30% of human E. coli wound infection isolates. While it is not clear how colibactin is released from E. coli or how it penetrates target cells, we found that the colibactin intermediate N-myristoyl-D-Asn (NMDA) disrupts the S. aureus membrane. We also show that the BarA-UvrY two component system (TCS) senses the environment created during E. coli and S. aureus mixed species interaction, leading to upregulation of pks island genes. Further, we show that BarA-UvrY acts via the carbon storage global regulatory (Csr) system to control pks expression. Together, our data demonstrate the role of colibactin in interspecies competition and show that it is regulated by BarA-UvrY TCS during interspecies competition. Author summary: Wound infections are often polymicrobial in nature and are associated with poor disease prognoses. Escherichia coli and Staphylococcus aureus are among the top five most cultured pathogens from wound infections. However, little is known about the polymicrobial interactions between E. coli and S. aureus during wound infections. In this study, we show that E. coli kills S. aureus both in vitro and in a mouse excisional wound model via the genotoxin, colibactin. We also show that the BarA-UvrY two component system (TCS) regulates the pks island during this mixed species interaction, acting through the carbon storage global regulatory (Csr) system to control colibactin production. Together, our data demonstrate the role of colibactin in interspecies competition and show that it is regulated by BarA-UvrY TCS during interspecies competition. [ABSTRACT FROM AUTHOR]

Automatic Dependent Surveillance‐Broadcast (ADS‐B) system provides significant improvements in air traffic control system such as optimal routing in non‐radar environments with a new level of safety and efficiency. The ADS‐B system is being installed in many aircrafts in recent year. The ADS‐B equipped aircraft broadcasts the air traffic information to nearby aircraft and ground stations either once or twice per second. Because of the open channel communication atmosphere, the ADS‐B system is affected by many security attacks. Many authentication and batch verification schemes are available to provide data integrity and source authentication for the ADS‐B system. But they are suffering from computational overhead and communication overhead. Hence, an efficient anonymous authentication scheme is proposed for the ADS‐B system with batch verification based on Message Recovery Signature (MRS). The security and performance analysis section ensure that the proposed scheme provides essential security features with less computational and communication overhead comparison with the other existing schemes. [ABSTRACT FROM AUTHOR]

The electricity demand is increasing day by day. On the other side, fossil fuels are depleting at a higher rate. The abundantly available renewable energy sources like solar, wind, and fuel cells are becoming popular sources of energy. But due to the intermittent availability of these renewable energy sources, two or more energy sources are integrated together. Power electronic converters are used for integrating different energy sources. Various power electronic converter (PEC) topologies have been proposed and analyzed in detail to control maximum power point, voltage, frequency, and harmonic distortions. Each of these configurations will differ in its topology and operating principle. The objective of this paper is to present a comprehensive review of various aspects of PEC configurations available for integration of renewable energy sources by systematization into three groups (AC shunt coupled, DC shunt coupled, and hybrid coupled systems). Emphasis is also given to coordination power control, maximum power point, and grid integration challenges related to the hybrid energy system. Furthermore, a general, system modeling of solar, wind, and grid integration is presented here to give an overall picture of a hybrid renewable energy system. [ABSTRACT FROM AUTHOR]

Queuosine (Q) is a complex tRNA modification widespread in eukaryotes and bacteria that contributes to the efficiency and accuracy of protein synthesis. Eukaryotes are not capable of Q synthesis and rely on salvage of the queuine base (q) as a Q precursor. While many bacteria are capable of Q de novo synthesis, salvage of the prokaryotic Q precursors preQ0 and preQ1 also occurs. With the exception of Escherichia coli YhhQ, shown to transport preQ0 and preQ1, the enzymes and transporters involved in Q salvage and recycling have not been well described. We discovered and characterized 2 Q salvage pathways present in many pathogenic and commensal bacteria. The first, found in the intracellular pathogen Chlamydia trachomatis, uses YhhQ and tRNA guanine transglycosylase (TGT) homologs that have changed substrate specificities to directly salvage q, mimicking the eukaryotic pathway. The second, found in bacteria from the gut flora such as Clostridioides difficile, salvages preQ1 from q through an unprecedented reaction catalyzed by a newly defined subgroup of the radical-SAM enzyme family. The source of q can be external through transport by members of the energy-coupling factor (ECF) family or internal through hydrolysis of Q by a dedicated nucleosidase. This work reinforces the concept that hosts and members of their associated microbiota compete for the salvage of Q precursors micronutrients. [ABSTRACT FROM AUTHOR]

This paper proposes an artificial neural network (ANN) based maximum power point tracking (MPPT) control strategy for wind energy conversion system (WECS) implemented with a DC/DC converter. The proposed topology utilizes a radial basis function network (RBFN) based neural network control strategy to extract the maximum available power from the wind velocity. The results are compared with a classical Perturb and Observe (P&O) method and Back propagation network (BPN) method. In order to achieve a high voltage rating, the system is implemented with a quadratic boost converter and the performance of the converter is validated with a boost and single ended primary inductance converter (SEPIC). The performance of the MPPT technique along with a DC/DC converter is demonstrated using MATLAB/Simulink. [ABSTRACT FROM AUTHOR]

In this paper, a novel co-ordinated hybrid maximum power point tracking (MPPT)-pitch angle based on a radial basis function network (RBFN) is proposed for a variable speed variable pitch wind turbine. The proposed controller is used to maximise output power when the wind speed is low and optimise the power when the wind speed is high. The proposed controller provides robustness to the nonlinear characteristic of wind speed. It uses wind speed, generator speed, and generator power as input variables and utilises the duty cycle and the reference pitch angle as the output control variables. The duty cycle is used to control the converter so as to maximise the power output and the reference pitch angle is used to control the generator speed in order to control the generator output power in the above rated wind speed region. The effectiveness of the proposed controller was verified using MATLAB/Simulink software. [ABSTRACT FROM AUTHOR]

This paper presents the design and analytical modeling of the proposed solar photovoltaic standalone system under varying environmental conditions. The proposed system consists of a unique structure of a solar PV-tree, maximum power point tracking (MPPT) technique, and DC–DC converter. The output voltage acquired from the solar PV tree is low. A DC–DC boost converter is utilized to step-up the required amount of voltage level. In this paper, the appropriate duty cycle is obtained for extracting the optimum power from the solar PV tree by using various MPPT mechanisms such as perturb and observe (P&O), incremental conductance (INC), and a radial basis function network (RBFN)-based neural network (NN). The proposed solar photovoltaic tree-based energy harvesting system is designed and validated by using MATLAB/SIMULINK software and real-time application. The simulation results of the above-mentioned three techniques are compared with each other in order to show the effectiveness of the proposed system with RBFN. The RBFN-MPPT provides a significant improvement in tracking efficiency of 6.0% and 5.72% as compared with the P&O method and the INC method at 1000 W/m2 irradiance condition. From the simulation and real-time results, it is concluded that the RBFN-based NN provides better tracking efficiency and less oscillation as compared with the other two algorithms. [ABSTRACT FROM AUTHOR]

In this study, a modified non-uniform adiabatic section in a Two-Phase Closed Thermosiphon (TPCT) is proposed where the uniform section was replaced by convergent and divergent (C-D) sections. The heat transfer analysis was performed on the modified TPCT and their findings were compared with standard TPCT. The deionized water (DI) in the proportion of 30 vol% is filled in both the TPCTs. Further, the heat transfer performance analysis was carried out for three different orientations, such as 0°, 45° and 90°, and heat input was varied from 50 to 250 W. The effect of these geometrical changes and inclination angles on the heat transfer performance of both the TPCT were evaluated to compare the thermal resistance, wall temperature variation and heat transfer coefficient. The non-dimensional numbers such as Weber (WE), Bond (BO), Condensation (CO) and Kutateladze (KU) were investigated based on heat fluxes for both TPCTs. By introducing the convergent-divergent section nearer to the condenser, the pressure before and after the C-D section was increased and decreased. This enhances the heat transfer in the evaporator slightly up to 2% and 1.4% at horizontal and 45° orientation, respectively, in Non-Uniformed Adiabatic Section (NUAS) TPCT when compared to Uniformed Adiabatic Section (UAS) TPCT. The thermal resistance of NUAS TPCT was reduced by up to 4.5% relative to UAS TPCT in horizontal and 45°. The results of the non-dimensional number also confirmed that NUAS TPCT provided better performance by enhancing 2% more pool boiling characteristics, interaction forces and condensate returns. Several factors such as gravity assistance, fluid accumulation, pressure drop and thermal resistance exert an influence on the heat transfer performance of the proposed NUAS TPCT at various orientation angles. However, different type of cross-sectional variations subjected to orientation changes may also get influenced by several other parameters that in turn affect the heat transfer performance distinctly. [ABSTRACT FROM AUTHOR]