250 research outputs found

    Cpx-dependent expression of YqjA requires cations at elevated pH

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    © FEMS 2017. All rights reserved. Under alkaline pH conditions, Escherichia coli must maintain a stable cytoplasmic pH of about 7.6 that is acidic relative to the environment. Bacteria employ various mechanisms to survive alkaline pH; however, membrane cation/H+ antiporters play a primary role by facilitating inward transport of protons. Escherichia coli YqjA belongs to the DedA/Tvp38 membrane protein family and, along with its paralog YghB, is required for growth at 42°C, proper cell division and antibiotic resistance. YqjA is required for viability at alkaline pH, requiring cations sodium or potassium to support growth under these conditions, suggesting it may be a transporter. We measured yqjA expression at different pHs and cation concentrations using a yqjA promoter-lacZ fusion. We found that yqjA promoter activity was highest at alkaline pH. Increased activity of the yqjA promoter required both the transcriptional regulator CpxR, in agreement with previous results, and sodium or potassium salts at alkaline pH. Extracellular cations are also required for activity of cpxP and degP promoters at alkaline pH, suggesting this is a general property of the Cpx regulon. To our knowledge, this is the first demonstration of cation-dependent expression of Cpx-regulated genes at alkaline pH

    Design Methodology of a New Wavelet Basis Function for Fetal Phonocardiographic Signals

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    Fetal phonocardiography (fPCG) based antenatal care system is economical and has a potential to use for long-term monitoring due to noninvasive nature of the system. The main limitation of this technique is that noise gets superimposed on the useful signal during its acquisition and transmission. Conventional filtering may result into loss of valuable diagnostic information from these signals. This calls for a robust, versatile, and adaptable denoising method applicable in different operative circumstances. In this work, a novel algorithm based on wavelet transform has been developed for denoising of fPCG signals. Successful implementation of wavelet theory in denoising is heavily dependent on selection of suitable wavelet basis function. This work introduces a new mother wavelet basis function for denoising of fPCG signals. The performance of newly developed wavelet is found to be better when compared with the existing wavelets. For this purpose, a two-channel filter bank, based on characteristics of fPCG signal, is designed. The resultant denoised fPCG signals retain the important diagnostic information contained in the original fPCG signal

    Methods of obtaining smooth surface in 2D/3D surface reconstruction

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    Surface reconstruction is an emergent research area in the field of computer aided design and manufacturing. There are various methods / algorithms which are working considerably well for surface reconstruction problem but we cannot say to the best of our knowledge that we got all the solutions. Missing surface can be repaired either by surface patch or by extending boundary curves. However, in both cases, surface smoothening problem arises in form of flat surface. The present paper has been tried to offer a solution to above problem which makes the curve smoother

    Ecological system with fear induced group defence and prey refuge

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    In this study, we investigate the dynamics of a spatial and non spatial prey-predator interaction model that includes the following: (i) fear effect incorporated in prey birth rate; (ii) group defence of prey against predators; and (iii) prey refuge. We provide comprehensive mathematical analysis of extinction and persistence scenarios for both prey and predator species. To better explore the dynamics of the system, a thorough investigation of bifurcation analysis has been performed using fear level, prey birth rate, and prey death rate caused by intra-prey competition as bifurcation parameter. All potential occurrences of bi-stability dynamics have also been investigated for some relevant sets of parametric values. Our numerical evaluations show that high levels of fear can stabilize the prey-predator system by ruling out the possibility of periodic solutions. Also, our model Hopf bifurcation is subcritical in contrast to traditional prey-predator models, which ignore the cost of fear and have supercritical Hopf bifurcations in general. In contrast to the general trend, predator species go extinct at higher values of prey birth rates. We have also found that, contrary to the typical tendency for prey species to go extinct, both prey and predator populations may coexist in the system as intra-prey competition level grows noticeably. The stability and Turing instability of associated spatial model have also been investigated analytically. We also perform the numerical simulation to observe the effect of different parameters on the density distribution of species. Different types of spatiotemporal patterns like spot, mixture of spots and stripes have been observed via variation of time evolution, diffusion coefficient of predator population, level of fear factor and prey refuge. The fear level parameter (k) has a great impact on the spatial dynamics of model system

    Correlates of Social, Demographic and Behavioral Factors affecting Adolescent Sexuality in a Traditional Society in India: Perspectives and Challenges

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    Background: Adolescent risk behavior is a major concern.Objectives: The study assessed the effect of school background, personal, social and other deviant behavior on school going adolescent sexual behavior. Material and Methods: The sample covered 3069 randomly selected adolescents (students) from 9th to 12th standard in various governments, private and missionary run schools from two districts namely; Aizawl being state capital and Champhai being distant under developed district.Summary: School background, leisure and entertainment practices, influence of taking alcohol, tobacco, drug, peer influence were found to be the major risk factor for indulgence in unsafe sex practices among adolescents. About 10% accepted involvement in premarital sex and majority of them (70%) of them had premarital sex between age group 15-19 years. The schools lacked in organizing awareness program and counseling activities on consequences of adolescent sex. The ARSH Program needs to synergize with school health program for desired results. Conclusions: Adolescent sexual risk behavior is a part of overall deviant behavior and can be managed in holistic manner

    Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis: A Glimpse into The Future

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    Background: A class of uncommon IgG4-related systemic diseases known as vasculitis caused by antineutrophil cytosolic antibodies (ANCA) is distinguished by the enlargement of small to large blood vessels. Objective: This review article offers an in-depth analysis of the most recent developments in ANCA-associated vasculitis, covering a range of topics from pathophysiology and diagnostics to treatment and long-term results.   Methods: In this review we investigated the existing work on ANCA associated vasculitis by different sources such as Science Direct, Scopus, Pubmed, Web of Science, Google scholar and SciHub. Results: A number of diseases, including eosinophilic granulomatosis with polyangiitis (EGPA), microscopic polyangiitis (MPA), and granulomatosis with polyangiitis (GPA), can have significant morbidity and mortality if they are not appropriately diagnosed and treated. Understanding the pathophysiology, clinical presentation, and curative options for ANCA-associated vasculitis have advanced significantly during the past ten years. The development of specific immunosuppressive medications has been largely responsible for the remarkable evolution in recent years in the treatment of ANCA-associated vasculitis. Conclusion: This review article has provided a detailed examination of the therapy for AAV, alternatives available, including induction and maintenance regimens, as well as the accompanying advantages and disadvantages. Additionally, the growing importance of biologic drugs like rituximab was examined, emphasizing its potential as supplements or replacements for traditional medical treatments

    In-Vitro Evidences for the Formulation, Development, and Evaluation of Budesonide Oral Nano-sponges

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    Idiopathic inflammatory bowel disease is quite common, with ulcerative colitis and Crohn's disease being the most common forms. Due to its high receptor affinity and quick diversion, the anti-inflammatory effects of the glucocorticoid budesonide are limited, but it is nevertheless useful in some situations. A unique BUD nano-sponges was developed by employing quasi-solvent diffusion and Eudragit S-100 as the polymer to address the problem of low efficacy and accessibility. Material and Methods: Drug release profile and percentage of drug entrapment in BUD Nano sponges were also measured and analyzed. Clinical activity score, colon/body weight ratio, and macroscopic ulceration activity were among the criteria used in an in vivo investigation of the formulation in male Wistar rats. Finally, histological investigation was done on colon tissue samples. Results: When compared to other BUD formulations on the market, this one performed exceptionally well, suggesting that the designed nanosponges are highly effective. The Wistar rats' clinical activity score was reduced when treated with the formed nanosponges. When compared to the placebo group, those who took this supplement saw a dramatic decrease in their colon weight ratio. Nanosponge colon histology revealed healthy colon anatomy and architecture. Conclusion: The findings of this study have substantiated the efficacy of BUD nano-sponges as innovative carriers in the treatment of inflammatory bowel diseas
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