Machine learning in fermentative biohydrogen production: Advantages, challenges, and applications.

Hydrogen can be produced in an environmentally friendly manner through biological processes using a variety of organic waste and biomass as feedstock. However, the complexity of biological processes limits their predictability and reliability, which hinders the scale-up and dissemination. This article reviews contemporary research and perspectives on the application of machine learning in biohydrogen production technology. Several machine learning algorithems have recently been implemented for modeling the nonlinear and complex relationships among operational and performance parameters in biohydrogen production as well as predicting the process performance and microbial population dynamics. Reinforced machine learning methods exhibited precise state prediction and retrieved the underlying kinetics effectively. Machine-learning based prediction was also improved by using microbial sequencing data as input parameters. Further research on machine learning could be instrumental in designing a process control tool to maintain reliable hydrogen production performance and identify connection between the process performance and the microbial population.

An integrated approach of designing functionality with security for distributed cyber-physical systems.

In this work, we propose a multi-tier architectural model to separate functionality and security concerns for distributed cyber-physical systems. On the line of distributed computing, such systems require the identification of leaders for distribution of work, aggregation of results, etc. Further, we propose a fault-tolerant leader election algorithm that can independently elect the functionality and security leaders. The proposed election algorithm identifies a list of potential leader capable nodes to reduce the leader election overhead. It keeps identifying the highest potential node as the leader, whenever needed, including the situation when one has failed. We also explain the proposed architecture and its management method through a case study. Further, we perform several experiments to evaluate the system performance. The experimental results show that the proposed architectural model improves the system performance in terms of latency, average response time, and the number of real-time tasks completed within the deadline.

Excellent Combination of Tensile ductility and strength due to nanotwinning and a biamodal structure in cryorolled austenitic stainless steel.

Austenitic stainless steels are prominent materials for their superior corrosion resistance and a combination of strength and ductility. However, the relatively low yield strength limits its application in high strength structural applications. Cryorolling is one of the promising methods of enhancing the mechanical properties of sheet metals. In the present work, Cryorolling of UNS S31000 stainless steel resulted in five-fold enhancement in yield strength with a significant loss in ductility. However, flash annealing at 800 °C for 120 s could restore its ductility up to 50% of its original ductility. The enhancement in strength is attributed to the formation of deformation nano-twins during flash annealing along with a bimodal grain structure.

Preexisting variation in DNA damage response predicts the fate of single mycobacteria under stress.

Clonal microbial populations are inherently heterogeneous, and this diversification is often considered as an adaptation strategy. In clinical infections, phenotypic diversity is found to be associated with drug tolerance, which in turn could evolve into genetic resistance. Mycobacterium tuberculosis, which ranks among the top ten causes of mortality with high incidence of drug-resistant infections, exhibits considerable phenotypic diversity. In this study, we quantitatively analyze the cellular dynamics of DNA damage responses in mycobacteria using microfluidics and live-cell fluorescence imaging. We show that individual cells growing under optimal conditions experience sporadic DNA-damaging events manifested by RecA expression pulses. Single-cell responses to these events occur as transient pulses of fluorescence expression, which are dependent on the gene-network structure but are triggered by extrinsic signals. We demonstrate that preexisting subpopulations, with discrete levels of DNA damage response, are associated with differential susceptibility to fluoroquinolones. Our findings reveal that the extent of DNA integrity prior to drug exposure impacts the drug activity against mycobacteria, with conceivable therapeutic implications.

Identification of autoantibodies against transthyretin for the screening and diagnosis of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic, autoimmune, systemic and inflammatory rheumatic disease that leads to inflammation of the joints and surrounding tissues. Identification of novel protein(s) associated with severity of RA is a prerequisite for better understanding of pathogenesis of this disease that may also have potential to serve as novel biomarkers in the diagnosis of RA. Present study was undertaken to compare the amount of autoantigens and autoantibodies in the plasma of RA patients in comparison to healthy controls. Plasma samples were collected from the patients suffering from RA, Osteoarthritis (OA), Systemic lupus erythematosus (SLE) and healthy volunteers. The screening of plasma proteins were carried out using 2-dimensional gel electrophoresis followed by identification of differentially expressed protein by MALDI-TOF MS/MS. Among several differentially expressed proteins, transthyretin (TTR) has been identified as one of the protein that showed significantly up regulated expression in the plasma of RA patients. The results were further validated by Western blot analysis and ELISA. In comparison to OA synovium, an exclusive significantly high expression of TTR in RA has been validated through IHC, Western blotting and IEM studies. Most importantly, the increase in expression of TTR with the progression of severity of RA condition has been observed. The autoantibodies against TTR present in the RA plasma were identified using immunoprecipitation-Western methods. The significant production of autoantibodies was validated by ELISA and Western blot analysis using recombinant pure protein of TTR. Hence, these novel observations on increase in TTR expression with the increase in severity of RA conditions and significant production of autoantibodies against TTR clearly suggest that a systematic studies on the role TTR in the pathogenesis of RA is immediately required and TTR may be used as a serum diagnostic marker together with other biochemical parameters and clinical symptoms for RA screening and diagnosis.

Mycobacterium tuberculosis cyclophilin A uses novel signal sequence for secretion and mimics eukaryotic cyclophilins for interaction with host protein repertoire.

Cyclophilins are prolyl isomerases with multitude of functions in different cellular processes and pathological conditions. Cyclophilin A (PpiA) of Mycobacterium tuberculosis is secreted during infection in intraphagosomal niche. However, our understanding about the evolutionary origin, secretory mechanism or the interactome of M. tuberculosis PpiA is limited. This study demonstrates through phylogenetic and structural analyses that PpiA has more proximity to human cyclophilins than the prokaryotic counterparts. We report a unique N-terminal sequence (MADCDSVTNSP) present in pathogenic mycobacterial PpiA and absent in non-pathogenic strains. This sequence stretch was shown to be essential for PpiA secretion. The overexpression of full-length PpiA from M. tuberculosis in non-pathogenic Mycobacterium smegmatis resulted in PpiA secretion while truncation of the N-terminal stretch obstructed the secretion. In addition, presence of an ESX pathway substrate motif in M. tuberculosis PpiA suggested possible involvement of Type VII secretion system. Site-directed mutagenesis of key residues in this motif in full-length PpiA also hindered the secretion in M. smegmatis. Bacterial two-hybrid screens with human lung cDNA library as target were utilized to identify interaction partners of PpiA from host repertoire, and a number of substrates with functional representation in iron storage, signal transduction and immune responses were detected. The extensive host interactome coupled with the sequence and structural similarity to human cyclophilins is strongly suggestive of PpiA being deployed by M. tuberculosis as an effector mimic against the host cyclophilins.

Alkaline pretreatment methods followed by acid hydrolysis of Saccharum spontaneum for bioethanol production.

Different alkaline pretreatment methods (NaOH, NaOH+10% urea and aqueous ammonia) were optimized for maximum delignification of Saccharum spontaneum at 30°C. Maximum delignification were obtained as 47.8%, 51% and 48% from NaOH (7% NaOH, 48h, and 10% biomass loading), NaOH+urea (7% NaOH+10% urea, 48 h and 10% biomass loading) and 30% ammonia (40 days and 10% biomass loading) respectively. H(2)SO(4) 60% (v/v), 10% biomass loading at 30°C for 4h, were optimized conditions to solubilize the cellulose and hemicellulose from solid residue obtained after different optimized alkaline pretreatments. Slurry thus obtained was diluted to obtain final acid concentration of 10% (v/v) for real hydrolysis of cellulose and hemicellulose at 100°C for 1h. Among all pretreatment methods applied, the best result 0.58 g (85%) reducing sugars/g of initial biomass after acid hydrolysis was obtained from aqueous ammonia pretreated biomass. Scheffersomyces stipitis CBS6054 was used to ferment the hydrolysate; ethanol yield (Y(p/s)) and productivity (r(p)) were found to be 0.35 g/g and 0.22 g/L/h respectively.