Reversible circuits with testability using quantum controlled NOT and swap gates

A new method of designing reversible circuits with inbuilt testability is presented by exploiting the properties of quantum controlled NOT and Swap gates. The design process is based on the methodology of placement of gates in such a manner that it produces parity preserving circuits. The testability of these circuits can be achieved by comparing the input and output parity under single bit fault detection. Experiments are conducted on a set of benchmark circuits which show an average reduction up to 51% in operating costs, when compared to existing work

Diet-dependent depletion of queuosine in tRNAs in Caenorhabditis elegans does not lead to a developmental block

Queuosine (Q), a hypermodified nucleoside, occurs at the wobble position of transfer RNAs (tRNAs) with GUN anticodons. In eubacteria, absence of Q affects messenger RNA (mRNA) translation and reduces the virulence of certain pathogenic strains. In animal cells, changes in the abundance of Q have been shown to correlate with diverse phenomena including stress tolerance, cell proliferation and tumour growth but the function of Q in animals is poorly understood. Animals are thought to obtain Q (or its analogues) as a micronutrient from dietary sources such as gut microflora. However, the difficulty of maintaining animals under bacteria-free conditions on Q-deficient diets has severely hampered the study of Q metabolism and function in animals. In this study, we show that as in higher animals, tRNAs in the nematode Caenorhabditis elegans are modified by Q and its sugar derivatives. When the worms were fed on Q-deficient Escherichia coli, Q modification was absent from the worm tRNAs suggesting that C. elegans lacks a de novo pathway of Q biosynthesis. The inherent advantages of C. elegans as a model organism, and the simplicity of conferring a Q-deficient phenotype on it make it an ideal system to investigate the function of Q modification in tRNA

A Single Mammalian Mitochondrial Translation Initiation Factor Functionally Replaces Two Bacterial Factors

The mechanism of translation in eubacteria and organelles is thought to be similar. In eubacteria, the three initiation factors IF1, IF2, and IF3 are vital. Although the homologs of IF2 and IF3 are found in mammalian mitochondria, an IF1 homolog has never been detected. Here, we show that bovine mitochondrial IF2 (IF2mt) complements E. coli containing a deletion of the IF2 gene (E. coli ΔinfB). We find that IF1 is no longer essential in an IF2mt-supported E. coli ΔinfB strain. Furthermore, biochemical and molecular modeling data show that a conserved insertion of 37 amino acids in the IF2mt substitutes for the function of IF1. Deletion of this insertion from IF2mt supports E. coli for the essential function of IF2. However, in this background, IF1 remains essential. These observations provide strong evidence that a single factor (IF2mt) in mammalian mitochondria performs the functions of two eubacterial factors, IF1 and IF2

Genetic Analysis Identifies a Function for the queC (ybaX) Gene Product at an Initial Step in the Queuosine Biosynthetic Pathway in Escherichia coli

Queuosine (Q), one of the most complex modifications occurring at the wobble position of tRNAs with GUN anticodons, is implicated in a number of biological activities, including accuracy of decoding, virulence, and cellular differentiation. Despite these important implications, its biosynthetic pathway has remained unresolved. Earlier, we observed that a naturally occurring strain of Escherichia coli B105 lacked Q modification in the tRNAs. In the present study, we developed a genetic screen to map the defect in E. coli B105 to a single gene, queC (renamed from ybaX), predicted to code for a 231-amino-acid-long protein with a pI of 5.6. As analyzed by mobility of tRNA(Tyr) on acid urea gels and two-dimensional thin-layer chromatography of the modified nucleosides, expression of QueC from a plasmid-borne copy confers a Q(+) phenotype to E. coli B105. Further, analyses of tRNA(Tyr) from E. coli JE10651 (queA mutant), its derivative generated by deletion of chromosomal queC (queA ΔqueC), and E. coli JE7325, deficient in converting preQ(0) to preQ(1), have provided the first genetic evidence for the involvement of QueC at a step leading to production of preQ(0), the first known intermediate in the generally accepted pathway that utilizes GTP as the starting molecule. In addition, we discuss the possibilities of collaboration of QueC with other cellular proteins in the production of preQ(0)

Multiferroicity in Ba0.97La0.03Ti1-xNixO3 (0.03 <= x <= 0.07) ceramics

Pure and doped BaTiO3 (BTO) with different doping concentrations e.g. Ba0.97La0.03Ti1-xNixO3 (x = 0.03, 0.05, 0.07) were synthesized via sol-gel method. X-ray diffraction (XRD) patterns confirm the single phase formation for all samples. Polarization versus Electric field (P-E) loops for pure BTO shows non linear ferroelectric loop which tends towards lossy capacitor behavior as Ni doping concentration increases from x = 0.03 to 0.07. Moreover, it is observed that the value of dielectric constant and dielectric loss increases with Ni doping concentration and found maximum for x = 0.07 sample. Room temperature magnetization versus magnetic field CM-H) loops indicate the existence of ferromagnetism in x = 0.03 sample. However, x = 0.07 sample shows the presence of diamagnetic phase in this sample. Magnetoelectric study reveals the presence of magnetoelectric coupling only for pure and x = 0.03 and 0.05 sample. However, the value of quadratic magnetoelectric coefficient (beta) is maximum for x = 0.03 sample, which is 3.34 x 10(-4) mu V/cm Oe(2)

Observation of magnetoelectric coupling in (1-x) BaTiO3/(x) La0.7Sr0.3MnO3 composites

In the present work, we have synthesized BaTiO3 (BTO) and La0.7Sr0.3MnO3 (LSMO) composites, (1 - x) BTO/(x) LSMO with x = 0.05, 0.10, 0.15 and 0.20. X-ray diffraction (XRD) patterns show the peaks corresponding to both BTO and LSMO phase, which indicates the successful formation of composites. Polarization versus electric field (P-E) loops of sample with x = 0.05 shows feeble ferroelectric behaviour which tends towards lossy capacitor behaviour for x = 0.10. Further, no ferroelectric loop is observed for composites x = 0.15 and 0.20. It is observed that the value of dielectric constant and dielectric loss is maximum for x = 0.05 which decreases with the increment of LSMO content above x = 0.05. Furthermore, room temperature magnetization versus magnetic field (M-H) loops shows the saturation magnetization enhances from 0.063 to 0.218 emu/g for the sample x = 0.05-0.20, respectively. Magnetoelectric study reveals that the value of quadratic magnetoelectric coefficient beta decreases from 1.64 x 10 (4) to 3.75 x 10 (5) mv/cm Oe(2) for the composites x = 0.05 to x = 0.10, which indicates that maximum magnetoelectric coupling is present in the sample x = 0.05. Further, no magnetoelectric coupling is observed for the sample x = 0.15 and 0.20

Design for Stuck-at Fault Testability in MCT based Reversible Circuits

Testability leads to a large increment in operating costs from their original circuits which drastically increases the power consumption in logic circuits. This paper presents a new design for testability methodology for the detection of stuck-at faults in multiple controlled Toffoli based reversible circuits. The circuit is modified in such a manner that the applied test vector reaches all the levels without any change in values on the wires of the circuit. An (n+1) dimensional general test set containing only two test vectors is presented, which provide full coverage of single and multiple stuck-at faults in the circuit. The work is further extended to locate the occurrence of stuck-at faults in the circuit. Deterministic approaches are described and the modification methodology is experimented on a set of benchmarks. The present work achieved a reduction up to $50.58\%$ in operating costs as compared to the existing work implemented on the same platform

Reversible circuits with testability using quantum controlled NOT and swap gates

529-532A new method of designing reversible circuits with inbuilt testability is presented by exploiting the properties of quantum controlled NOT and Swap gates. The design process is based on the methodology of placement of gates in such a manner that it produces parity preserving circuits. The testability of these circuits can be achieved by comparing the input and output parity under single bit fault detection. Experiments are conducted on a set of benchmark circuits which show an average reduction up to 51% in operating costs, when compared to existing work