Robust Modifications to Model Reference Adaptive Control for Reference Voltage Tracking in a Dual Active Bridge Dc-Dc Converter

Model Reference Adaptive Control (MRAC) is useful for achieving a desired dynamic response with no prior knowledge of system parameters. Traditional MRAC is sensitive to noise in the state variables, leading to adaptation parametric drift. The drift in parameters, if left unchecked, leads to loss of closed loop stability. In power electronic systems, the ripple in the output voltage serves as a bounded noise, which leads to MRAC instability. This drift phenomenon is observed through the simulation and hardware experimentation of a Dual Active Bridge (DAB) converter and mitigated using deadzone modification and σ modification approaches. These two methods are then compared to evaluate their respective strengths and weaknesses for practical hardware implementation of power electronics using MRAC

Physical Processes in Star Formation

© 2020 Springer-Verlag. The final publication is available at Springer via https://doi.org/10.1007/s11214-020-00693-8.Star formation is a complex multi-scale phenomenon that is of significant importance for astrophysics in general. Stars and star formation are key pillars in observational astronomy from local star forming regions in the Milky Way up to high-redshift galaxies. From a theoretical perspective, star formation and feedback processes (radiation, winds, and supernovae) play a pivotal role in advancing our understanding of the physical processes at work, both individually and of their interactions. In this review we will give an overview of the main processes that are important for the understanding of star formation. We start with an observationally motivated view on star formation from a global perspective and outline the general paradigm of the life-cycle of molecular clouds, in which star formation is the key process to close the cycle. After that we focus on the thermal and chemical aspects in star forming regions, discuss turbulence and magnetic fields as well as gravitational forces. Finally, we review the most important stellar feedback mechanisms.Peer reviewedFinal Accepted Versio

Electrochemical assay of the nitrate and nitrite reductase activities of Rhizobium japonicum

Thiswork describes an electrochemical method for the determination of the nitrate and nitrite reductase activities of Rhizobium japonicum. The advantage of themethod lies in the use of whole cells for the analysis and we earlier developed this protocol for the assay of NO. The results obtained are comparable to the spectrophotometric Griess assay. As the method is based on electrochemical reduction, the commonly interfering biological components like ascorbic acid, uric acid, dopamine, etc., will not interfere with the analysis. This method can be extended to the fabrication of biosensors for nitrate and nitrite using the same principle

In vivo proton magnetic resonance spectroscopy (MRS) and single photon emission computerized tomography (SPECT) in systemic lupus erythematosus (SLE)

Neuropsychiatric involvement in SLE (NP-SLE) may not be picked up by routine neuroimaging procedures like computerized tomography (CT) or magnetic resonance imaging (MRI). We prospectively studied the role of single photon emission computerized tomography (SPECT) and magnetic resonance spectroscopy (MRS) in detection of NP-SLE in 20 patients with lupus (10 with clinical NP involvement and 10 without) and 9 healthy controls. MRI abnormalities were seen in 5/10 patients with NP-SLE while the MRI was normal in all the lupus patients without clinical NP involvement. Perfusion defects on SPECT were seen in as many as 8/10 patients with NP-SLE while only 1/10 lupus patients without clinical NP involvement and none of the healthy controls demonstrated perfusion defects. MRS revealed abnormal metabolite ratios in all patients with NP-SLE and as many as 8 lupus patients without clinical NP features. Normal metabolite ratios were observed in healthy controls. SPECT and MRS can help detect changes not evident on MRI and may serve as useful supplements to existing neuroimaging techniques in the diagnosis of NP-SLE. The precise significance of alterations in regional cerebral blood flow on SPECT and neurometabolite ratios on MRS needs larger, longitudinal studies

Discovery, timing, and multiwavelength observations of the black widow millisecond pulsar PSR J1555-2908

Galaxie

Potent transmission-blocking monoclonal antibodies from naturally exposed individuals target a conserved epitope on Plasmodium falciparum Pfs230.

Pfs230 is essential for Plasmodium falciparum transmission to mosquitoes and is the protein targeted by the most advanced malaria-transmission-blocking vaccine candidate. Prior understanding of functional epitopes on Pfs230 is based on two monoclonal antibodies (mAbs) with moderate transmission-reducing activity (TRA), elicited from subunit immunization. Here, we screened the B cell repertoire of two naturally exposed individuals possessing serum TRA and identified five potent mAbs from sixteen Pfs230 domain-1-specific mAbs. Structures of three potent and three low-activity antibodies bound to Pfs230 domain 1 revealed four distinct epitopes. Highly potent mAbs from natural infection recognized a common conformational epitope that is highly conserved across P. falciparum field isolates, while antibodies with negligible TRA derived from natural infection or immunization recognized three distinct sites. Our study provides molecular blueprints describing P. falciparum TRA, informed by contrasting potent and non-functional epitopes elicited by natural exposure and vaccination

Highly potent, naturally acquired human monoclonal antibodies against Pfs48/45 block Plasmodium falciparum transmission to mosquitoes.

Malaria transmission-blocking vaccines (TBVs) aim to induce antibodies that interrupt malaria parasite development in the mosquito, thereby blocking onward transmission, and provide a much-needed tool for malaria control and elimination. The parasite surface protein Pfs48/45 is a leading TBV candidate. Here, we isolated and characterized a panel of 81 human Pfs48/45-specific monoclonal antibodies (mAbs) from donors naturally exposed to Plasmodium parasites. Genetically diverse mAbs against each of the three domains (D1-D3) of Pfs48/45 were identified. The most potent mAbs targeted D1 and D3 and achieved >80% transmission-reducing activity in standard membrane-feeding assays, at 10 and 2 μg/mL, respectively. Co-crystal structures of D3 in complex with four different mAbs delineated two conserved protective epitopes. Altogether, these Pfs48/45-specific human mAbs provide important insight into protective and non-protective epitopes that can further our understanding of transmission and inform the design of refined malaria transmission-blocking vaccine candidates