Miracle-dz/UniFAR-FTUs huggingface dataset:
A Single Amino Acid Change in the Response Regulator PhoP, Acquired during Yersinia pestis Evolution, Affects PhoP Target Gene Transcription and Polymyxin B Susceptibility

ABSTRACT Yersinia pestis, the causative agent of plague, evolved from the closely related pathogen Yersinia pseudotuberculosis. During its emergence, Y. pestis is believed to have acquired its unique pathogenic characteristics through numerous gene gains/losses, genomic rearrangements, and single nucleotide polymorphism (SNP) changes. One such SNP creates a single amino acid variation in the DNA binding domain of PhoP, the response regulator in the PhoP/PhoQ two-component system. Y. pseudotuberculosis and the basal human-avirulent strains of Y. pestis harbor glycines at position 215 of PhoP, whereas the modern human-virulent strains (e.g., KIM and CO92) harbor serines at this residue. Since PhoP plays multiple roles in the adaptation of Y. pestis to stressful host conditions, we tested whether this amino acid substitution affects PhoP activity or the ability of Y. pestis to survive in host environments. Compared to the parental KIM6+ strain carrying the modern allele of phoP (phoP-S215), a derivative carrying the basal allele (phoP-G215) exhibited slightly defective growth under a low-Mg2+ condition and decreased transcription of a PhoP target gene, ugd, as well as an ∼8-fold increase in the susceptibility to the antimicrobial peptide polymyxin B. The phoP-G215 strain showed no apparent defect in flea colonization, although a phoP-null mutant showed decreased flea infectivity in competition experiments. Our results suggest that the amino acid variation at position 215 of PhoP causes subtle changes in the PhoP activity and raise the possibility that the change in this residue have contributed to the evolution of increased virulence in Y. pestis. IMPORTANCE Y. pestis acquired a single nucleotide polymorphism (SNP) in phoP when the highly human-virulent strains diverged from less virulent basal strains, resulting in an amino acid substitution in the DNA binding domain of the PhoP response regulator. We show that Y. pestis carrying the modern phoP allele has an increased ability to induce the PhoP-regulated ugd gene and resist antimicrobial peptides compared to an isogenic strain carrying the basal allele. Given the important roles PhoP plays in host adaptation, the results raise an intriguing possibility that this amino acid substitution contributed to the evolution of increased virulence in Y. pestis. Additionally, we present the first evidence that phoP confers a survival fitness advantage to Y. pestis inside the flea midgut.
An ABC‐transporter from Streptomyces longisporoflavus confers resistance to the polyether‐ionophore antibiotic tetronasin

Streptomyces longisporoflavus produces the poly‐ketide‐polyether antibiotic, tetronasin, which acts as an ionophore and depolarizes the membrane of bacteria sensitive to the drug. A genomic library of S. longisporoflavus DN A was cloned in Streptomyces Uvldans and screened to identify tetronasin‐resistance determinants. The inclusion of 0.2 M NaCl in the growth medium with tetronasin markedly improved the sensitivity of the screen. Two different resistance determinants, designated tnrB (ptetR51) and tnrA (ptetR11) respectively, were identified. The determinant tnrB (ptetR51) but not tnrA (ptetR11), also conferred resistance to tetronasin when cloned into Streptomyces albus. The tnrB determinant was further localized, by subcloning, to a 2.8 kb Kpnl fragment. DNA sequence analysis of this insert revealed one incomplete and two complete open reading frames (ORFs 1, 2 and 3). The deduced sequence of the gene product of ORF2 (TnrB2) revealed significant similarity to the ATP‐binding domains of the ABC (ATP binding cassette) superfamily of transport‐related proteins. The adjacent gene, ORF3, is translationally coupled to ORF2 and would encode a hydrophobic protein (TnrB3) with six transmembrane helices which probably constitutes the integral membrane component of the transporter. The mechanism of tetronasin resistance mediated by tnrB is probably an ATP‐dependent efflux system.
Evaluating hazards of lightning strike on stationary vehicles under overhead lines

This article examines safety concerns concerning persons touching a vehicle located near an overhead line hit by lightning. Two models of lightning strikes are assumed for the analysis. The first model includes the entire lightning channel and current distribution along the channel while the second model is a short channel of surge current injected directly at the top of the struck tower. In order to evaluate the effects of the lightning model on the shock hazard level, the transient current passing through the body of a person touching the vehicle is evaluated and compared to the case of a person touching directly the struck tower. An integral formulation of Maxwell's equations is used to model the whole structure including the vehicle, power line, towers, grounding network, and lightning channel. The vehicle is modeled as an array of metallic plates, while the remainder of the system is modeled as an array of wire mesh conductors. Computations are carried out using the Method of Moments (MoM) for surface-wire integral equation in a stratified medium. Results show that safety is affected more by the indirect radiation and induction effects of the lightning channel for the case of a person touching the vehicle than for the case of a person touching the struck tower.
A Compact and Low-Power Fractionally Injection-Locked Quadrature Frequency Synthesizer Using a Self-Synchronized Gating Injection Technique for Software-Defined Radios

This paper describes a compact and low-power frequency synthesizer with quadrature phase output for software-defined radios (SDRs). The proposed synthesizer is constructed using a core phase-locked loop (PLL), which is coupled with a fractional-N injection-locked frequency divider (ILFD). The fractional-N injection-locking operation is achieved by the proposed self-synchronized gating injection technique. The principle of a fractional-N injection locking operation and the concept of the proposed circuits are described in detail. Analysis for predicting the locking range of the proposed fractional-N ILFD is investigated. A digital calibration scheme is adopted in order to compensate for process, voltage, and temperature (PVT) variations. Implemented in a 65 nm CMOS process, this work demonstrates continuous frequency coverage from 10 MHz to 6.6 GHz with quadrature phase output while occupying a small area of 0.38 mm2 and consuming 16 to 26 mW, depending on the output frequency. The normalized phase noise achieves -135.3 dBc/Hz at an offset of 3 MHz and -95.1 dBc/Hz at an offset of 10 kHz, both from a carrier frequency of 1.7 GHz.
Humanoid action imitation learning via boosting sample DQN in virtual demonstrator environment

With the growth of modern industrial automation, autonomous-learning applied in the field of robot has aroused considerable attentions of researchers. However, those existing learning methods typically require mass among of training set, increasing the difficulty of collecting samples which is time-consuming, while the validity of samples might be divergent greatly, and thus the training efficiency is limited. Simultaneously, the reinforcement learning used in the system was based on the hypothesis that each action in the sequence contribute equally to the consequence, which is not corresponding to the common rules. In this paper, we propose a method, boosting sample DQN, to optimize the validity of training sample set. Inspired by boosting method, by extracting samples from replay memory hierarchically based on statistical results, the efficiency of network training is improved. Our algorithm, which has a small count of parameters, has been transplanted to the dual-arm robot system successfully. This approach learns a set of trajectories for the action of reaching and grabbing target objects using real-time models obtained by interactively wearable sensing equipment. And also, solution was proposed to distinguish weights of different actions. Our method has proved to be adaptive in learning complicated tasks, including grabbing bottle within its scope, as we presented in the paper.
Interactions of a series of novel spiropyranocoumarin derivatives with reactive oxygen species

A series of new spiro‐substituted pyranocoumarin derivatives have been synthesized starting from the commercially available 7‐hydroxycoumarin and the conformation of the pyran ring was investigated. The antioxidant activity of the compounds was evaluated in‐vitro, by means of three different tests: the interaction with the stable free radical 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH), the competition with DMSO for hydroxyl radicals scavenging ability and the quenching of superoxide anions generated by the enzymic xanthine–xanthine oxidase system. In the DPPH test the spiroadamantane derivative 13 was the most active and possessed a 40% inhibition at a concentration of 400 μm. All compounds successfully compete with DMSO for hydroxyl radicals generated by the Fe3+/ascorbic acid system. Compound 13 inhibited the oxidation of DMSO (3.125mm) by 93% at 2 mm and by 71% at 0.25 mm. The corresponding second‐order rate constants have been estimated and all compounds demonstrated higher rate constants compared with the reference compounds, 7‐hydroxycoumarin and mannitol. Derivatives possessing extended conjugation showed the highest inhibitory activity for superoxide anions generated by the xanthine–xanthine oxidase system, although the results of this experiment possessed partial parallelism with the results observed in the other two tests. The overall obtained data indicate that the size of the different spiro‐ substituents influence the degree of free radical scavenging and demonstrate the importance of extended conjugation for the anti‐oxidant activity. Due to its multiple mechanism of protective action, derivative 13 may serve as a lead for the development of analogues that could be useful for the treatment of pathophysiological processes dependent upon reactive oxygen species.
The Osteogenic Priming of Mesenchymal Stem Cells is Impaired in Experimental Diabetes

Diabetes mellitus encompasses a group of metabolic conditions embracing the dysfunction and failure of various tissues and organs, including bone. Sustained bone alterations seem to result from anabolic, rather than catabolic processes, and suggest a decreased osteoblastic recruitment and activity. Current knowledge on the cellular and molecular mechanisms were provided by studies performed with osteogenic populations cultured in diabetic‐simulated conditions, and osteogenic‐induced precursor populations harvested from diabetic animals, sustaining an impaired cellular behavior in terms of osteogenic responsiveness and function. However, the reasons leaning to this impairment remain essentially unknown, as the priming capability and functionality of undifferentiated precursors, developed within the diabetic environment, have not been addressed. Accordingly, this work aims to evaluate the functionality and osteogenic priming capability of bone marrow‐derived mesenchymal stem cells (MSCs), harvested from animals with experimental diabetes, and grown in the absence of any given differentiation factor. MSCs developed within a diabetic microenvironment displayed an impaired behavior, with diminished cell viability and proliferation, altered cytoskeleton organization, impaired osteogenic priming, and increased adipogenic activation. Further, the osteogenic induction of diabetic MSCs resulted in an impaired osteogenic commitment. The modified cell phenotype may be related, at least in part, with altered activity of ERK WNT and p38 signaling pathways in diabetic‐derived cultures. Specific strategies, aiming the modulation of the verified hindrances, may be of therapeutic value to enhance the functionality of diabetic MSCs and sustain an improved outcome in the metabolism and regeneration of the bone tissue in diabetic conditions. J. Cell. Biochem. 116: 1658–1667, 2015. © 2015 Wiley Periodicals, Inc.
Characterization of a Mammalian Peroxiredoxin That Contains One Conserved Cysteine*

A new type of peroxidase enzyme, named thioredoxin peroxidase (TPx), that reduces H2O2 with the use of electrons from thioredoxin and contains two essential cysteines was recently identified. TPx homologs, termed peroxiredoxin (Prx), have also been identified and include several proteins, designated 1-Cys Prx, that contain only one conserved cysteine. Recombinant human 1-Cys Prx expressed in and purified from Escherichia coli has now been shown to reduce H2O2 with electrons provided by dithiothreitol. Furthermore, human 1-Cys Prx transiently expressed in NIH 3T3 cells was able to remove intracellular H2O2 generated in response either to the addition of exogenous H2O2 or to treatment with platelet-derived growth factor. The conserved Cys47–SH group was shown to be the site of oxidation by H2O2. Thus, mutation of Cys47 to serine abolished peroxidase activity. Moreover, the oxidized intermediate appears to be Cys–SOH. In contrast to TPx, in which one of the two conserved cysteines is oxidized to Cys–SOH and then immediately reacts with the second conserved cysteine of the second subunit of the enzyme homodimer to form an intermolecular disulfide, the Cys–SOH of 1-Cys Prx does not form a disulfide. Neither thioredoxin, which reduces the disulfide of TPx, nor glutathione, which reduces the Cys–SeOH of oxidized glutathione peroxidase, was able to reduce the Cys–SOH of 1-Cys Prx and consequently could not support peroxidase activity. Human 1-Cys Prx was previously shown to exhibit a low level of phospholipase A2 activity at an acidic pH; the enzyme was thus proposed to be lysosomal, and Ser32 was proposed to be critical for lipase function. However, the mutation of Ser32 or Cys47 has now been shown to have no effect on the lipase activity of 1-Cys Prx, which was also shown to be a cytosolic protein. Thus, the primary cellular function of 1-Cys Prx appears to be to reduce peroxides with the use of electrons provided by an as yet unidentified source; the enzyme therefore represents a new type of peroxidase.
Human mobile inverted pendulum transporter — A mechatronic system case study

It is an inherent property of a mechatronic system that it involves several interacting sub-systems and the design process for such systems involves an in-depth understanding of a number of engineering disciplines. A truly mechatronic design requires use of advanced models during the design procedure combined with the formulation and the solution of an optimization problem involving a number of constraints related to performance, costs, geometry, availability of components etc. In this paper, we present a case-study of a more traditional design procedure for a highly multi-disciplinary device, which nevertheless illustrates the potentials of unifying classical engineering technologies (mechanics, electronics, control systems) with modern high-efficient inverter-fed permanent-magnet AC motors and the latest MEMS sensor technology. A full-scale fully operational prototype of a two-wheel mobile inverted pendulum has been built based on the presented design.
Does the is Artifact Matter in Sociomateriality Research? A Literature Review of Empirical Studies

A fundamental objective of IS research is the investigation of the dynamic interplay between the social and the material. As a consequence, the concept of sociomateriality has evolved to depict the interaction of the social and material in different environments, such as organizations. Although various definitions have emerged, sociomateriality remains a buzzword, however, its application in real world settings often remains unclear. Our study's objective is to assess the IS artifact in sociomaterial research and to clarify the intertwining of the social and material agencies. On the basis of the conceptualization of the IS artifact and the dominances of the agencies, we suggest a framework to systematically evaluate the artifact's role in sociomaterial research settings, and derive opportunities and potentials for future research on sociomateriality. Our approach will be helpful to focus greater attention on the dynamic interplay and the role of the IS artifact in sociomaterial inquiries.
Ticarcillin and ticarcillin-clavulanic acid susceptibility tests: error rates for disk tests with consecutively isolated members of the family Enterobacteriaceae

A five-laboratory coordinated study was undertaken to determine whether ticarcillin and ticarcillin-clavulanic acid disk susceptibility tests could accurately detect resistance among enteric bacilli. Each facility performed disk tests and broth microdilution susceptibility tests with reagents distributed from a common source, and appropriate controls were included in order to ensure methodologic uniformity. Each institution tested 500 consecutively isolated enteric bacilli against ticarcillin and ticarcillin-clavulanic acid. The prevalence of discrepancies between disk tests and dilution tests with 2,435 unselected enteric bacilli provided a valid estimate of the true error rate for tests with the two disks. The current interpretive criteria for susceptibility tests with ticarcillin and ticarcillin-clavulanic acid disks were found to be reliable; i.e., there were major or very major discrepancies between MIC categories and disk test results for less than 1% of all strains and minor discrepancies for only 5 to 10%. Even lower error rates would occur if the zone size-interpretive criteria were modified, but at this time it is difficult to determine whether the practical problems created by making such changes can be justified by the magnitude of the problem that is being resolved.
Helicobacter pylori infection induces hyperammonaemia in Mongolian gerbils with liver cirrhosis

BACKGROUND AND AIMS We previously reported the effect of Helicobacter pylori eradication on hyperammonaemia in patients with liver cirrhosis. However, the role of H pylori as a cause of hyperammonaemia is controversial. We developed an animal model with liver cirrhosis and investigated the effect ofH pylori infection on hyperammonaemia. MATERIALS AND METHODS Five week old male Mongolian gerbils were inoculated orally with broth culture of H pylori. Forty eight gerbils were divided into four groups. Gerbils not inoculated with H pylori were fed a commercial rodent diet (group A) or a choline deficient diet (group C). Gerbils inoculated with H pyloriwere fed the commercial rodent diet (group B) or the choline deficient diet (group D). Blood ammonia levels of the femoral vein and portal vein were measured 30 weeks later. RESULTS All gerbils fed the choline deficient diet developed liver cirrhosis with fatty metamorphosis. The survival rate of group D was significantly lower than that of the other groups. Systemic and portal blood ammonia levels in group D were significantly higher than those in the other groups. CONCLUSIONS H pylori infection induces hyperammonaemia in gerbils with liver cirrhosis.
Xis and Fis proteins prevent site-specific DNA inversion in lysogens of phage HK022

HK022, a temperate coliphage related to lambda, forms lysogens by inserting its DNA into the bacterial chromosome through site-specific recombination. The Escherichia coli Fis and phage Xis proteins promote excision of HK022 DNA from the bacterial chromosome. These two proteins also act during lysogenization to prevent a prophage rearrangement: lysogens formed in the absence of either Fis or Xis frequently carried a prophage that had suffered a site-specific internal DNA inversion. The inversion is a product of recombination between the phage attachment site and a secondary attachment site located within the HK022 left operon. In the absence of both Fis and Xis, the majority of lysogens carried a prophage with an inversion. Inversion occurs during lysogenization at about the same time as prophage insertion but is rare during lytic phage growth. Phages carrying the inverted segment are viable but have a defect in lysogenization, and we therefore suggest that prevention of this rearrangement is an important biological role of Xis and Fis for HK022. Although Fis and Xis are known to promote excision of lambda prophage, they had no detectable effect on lambda recombination at secondary attachment sites. HK022 cIts lysogens that were blocked in excisive recombination because of mutation in fis or xis typically produced high yields of phage after thermal induction, regardless of whether they carried an inverted prophage. The usual requirement for prophage excision was bypassed in these lysogens because they carried two or more prophages inserted in tandem at the bacterial attachment site; in such lysogens, viable phage particles can be formed by in situ packaging of unexcised chromosomes.
1200V, 25A bi-directional Si DMOS IGBT fabricated with fusion wafer bonding

A 1200V, 25A bi-directional silicon DMOS-IGBT has been successfully fabricated using a hydrophobic bonding process at low temperature (400°C). With the aid of a glass carrier approach, a flat and clean bonding surface for producing an electrically stable and transparent junction was achieved. The static and dynamic performance with and without back-side gate control are presented and compared.
Expression of IGF‐I and insulin receptor genes in the rat central nervous system: A developmental, regional, and cellular analysis

Using a solution‐hybridization assay and specific oligonucleotidic probes, we have studied IGF‐I and insulin receptor mRNAs in the rat central nervous system during development. The expression of mRNAs was maximal at embryonic day 15 and 20 for IGF‐I receptors, and at embryonic day 20 and the day of birth for insulin receptors. After birth, the expression of both receptor transcripts decreased and reached minimal levels in the adult. At the time at which these transcripts were maximally expressed (embryonic day 20), the regional analysis indicated that IGF‐I receptor transcripts were widely distributed in the brain. In contrast, insulin receptor transcripts were restricted to certain areas in which they were coexpressed with the IGF‐I receptor transcripts. We next analyzed which cells at embryonic day 20 expressed those receptor transcripts. Late embryonic neurons, astrocytes, and neonatal progenitors of oligodendrocytes synthesized both IGF‐I and insulin receptor mRNAs after a short time in culture. However, astrocytes expressed preferentially IGF‐I receptor transcripts, while young progenitors for oligodendrocytes expressed high levels of insulin receptor transcripts. As a whole, our data indicate that during rat CNS development expression of IGF‐I and insulin receptors appears to be stage‐and cell‐specific. The differences observed between the expression of both receptors might point to a specific, but coordinative role of IGF‐I and insulin and their receptors during that time.