Numerical solution of fractional Bratu–type BVPs: a generalized variational iteration approach

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Reem Assadi ◽  
Suheil Khuri ◽  
Issam Louhichi
Keyword(s):  
Numerical Solution ◽  
Variational Iteration Method ◽  
Original Research ◽  
Content Type ◽  
Variational Iteration ◽  
Starting Point ◽  
Type Boundary ◽  
Initial Starting ◽  
First Time ◽  
Proof Of Convergence

Purpose The purpose of this study is to implement a newly introduced numerical scheme for the numerical solution of a class of nonlinear fractional Bratu-type boundary value problems (BVPs). Design/methodology/approach This strategy is based on a generalization of the variational iteration method (VIM). This proposed generalized VIM (GVIM) is particularly suitable for tackling BVPs. Findings This scheme yields accurate solutions for a class of nonlinear fractional Bratu-type BVPs, for which the errors are uniformly distributed across a given domain. A proof of convergence is included. The numerical results confirm that this approach overcomes the deficiency of the VIM and other methods that exist in the literature in the sense that the solution does not deteriorate as the authors move away from the initial starting point. Originality/value The method introduced is based on original research that produces new knowledge. To the best of the authors’ knowledge, this is the first time that this GVIM is applied to fractional BVPs.

scholarly journals Scorpion Venom Antimicrobial Peptides Induce Siderophore Biosynthesis and Oxidative Stress Responses in Escherichia coli

mSphere ◽  
2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Mohamed M. Tawfik ◽  
Magnus Bertelsen ◽  
Mohamed A. Abdel-Rahman ◽  
Peter N. Strong ◽  
Keith Miller
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Peptides ◽  
Antimicrobial Agents ◽  
Venom Gland ◽  
Cation Transport ◽  
Content Type ◽  
Starting Point ◽  
Wide Range ◽  
Initial Starting ◽  
Increased Susceptibility

ABSTRACT The increasing development of microbial resistance to classical antimicrobial agents has led to the search for novel antimicrobials. Antimicrobial peptides (AMPs) derived from scorpion and snake venoms offer an attractive source for the development of novel therapeutics. Smp24 (24 amino acids [aa]) and Smp43 (43 aa) are broad-spectrum AMPs that have been identified from the venom gland of the Egyptian scorpion Scorpio maurus palmatus and subsequently characterized. Using a DNA microarray approach, we examined the transcriptomic responses of Escherichia coli to subinhibitory concentrations of Smp24 and Smp43 peptides following 5 h of incubation. Seventy-two genes were downregulated by Smp24, and 79 genes were downregulated by Smp43. Of these genes, 14 genes were downregulated in common and were associated with bacterial respiration. Fifty-two genes were specifically upregulated by Smp24. These genes were predominantly related to cation transport, particularly iron transport. Three diverse genes were independently upregulated by Smp43. Strains with knockouts of differentially regulated genes were screened to assess the effect on susceptibility to Smp peptides. Ten mutants in the knockout library had increased levels of resistance to Smp24. These genes were predominantly associated with cation transport and binding. Two mutants increased resistance to Smp43. There was no cross-resistance in mutants resistant to Smp24 or Smp43. Five mutants showed increased susceptibility to Smp24, and seven mutants showed increased susceptibility to Smp43. Of these mutants, formate dehydrogenase knockout (fdnG) resulted in increased susceptibility to both peptides. While the electrostatic association between pore-forming AMPs and bacterial membranes followed by integration of the peptide into the membrane is the initial starting point, it is clear that there are numerous subsequent additional intracellular mechanisms that contribute to their overall antimicrobial effect. IMPORTANCE The development of life-threatening resistance of pathogenic bacteria to the antibiotics typically in use in hospitals and the community today has led to an urgent need to discover novel antimicrobial agents with different mechanisms of action. As an ancient host defense mechanism of the innate immune system, antimicrobial peptides (AMPs) are attractive candidates to fill that role. Scorpion venoms have proven to be a rich source of AMPs. Smp24 and Smp43 are new AMPs that have been identified from the venom gland of the Egyptian scorpion Scorpio maurus palmatus, and these peptides can kill a wide range of bacterial pathogens. By better understanding how these AMPs affect bacterial cells, we can modify their structure to make better drugs in the future.

Making choices: developing digital research frameworks for information management

2018 ◽  
Vol 74 (1) ◽  
pp. 247-254 ◽  
Author(s):  
Maria Burke
Keyword(s):  
Information Management ◽  
Early Career ◽  
Future Research ◽  
Content Type ◽  
Starting Point ◽  
Making Choices ◽  
Three Stages ◽  
Research Frameworks ◽  
Initial Starting ◽  
Digital Research

Purpose The purpose of this paper is to suggest a digital research framework that can be applied to many of the areas that encompass the discipline of information management. Design/methodology/approach This communication proposes a new “Triple A” framework that allows the researcher to progress digital ideas by asking a series of staged questions. This is a progressive model consisting of three stages of acquaintance, adaption and application bounded by three major influencing issues of culture, communication and context. The Triple A framework is aimed to be flexible to apply to most styles of research yet robust enough to offer useful insights. Findings The model devised will assist (information management) researchers with choices of research approaches. It may be that early career researchers or those undertaking a postgraduate research will find this framework especially helpful to clarify thoughts and direction. The model aims to be useful and, whilst no doubt will be built on in future research, it is offered as foundation, an initial starting point, as those who work and study in information management fields endeavor to make new choices in our digitally managed information world. Originality/value The originality and value of this work is the proposition of a new model that will allow researchers to impose structure on ideas and encourage the viewing of work from a multi-disciplinary perspective within the growing and evolving digital areas.

scholarly journals Encountering UFOs and aliens in the tourism industry

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Daniel William Mackenzie Wright
Keyword(s):  
Supply And Demand ◽  
Secondary Data ◽  
Tourism Industry ◽  
Consumer Participation ◽  
Original Research ◽  
Philosophical Approach ◽  
Content Type ◽  
Starting Point ◽  
The Subject ◽  
Tourism Attractions

Purpose Human fascination in the unidentified flying objects (UFOs) and alien paranormal phenomenon is rich in history, explored widely in popular culture and many personal beliefs exist across society. The tourism industry offers a range of places where consumers can encounter such a phenomenon. Reports continue to highlight the growth in consumers participating at UFO and alien tourism attractions and locations. Significantly, the purpose of this paper is to shine a light on the relationship between UFOs, aliens and the tourism industry. Design/methodology/approach This paper takes a pragmatic philosophical approach by embracing a multi-disciplinary analysis. This study examines a range of secondary data information, statistics, reports and research studies. Findings By identifying the current impotence of the UFO and alien tourism markets and the growing consumer participation in it, this paper presents a theoretical starting point in the form of a model, which maps the current landscape of the industry from supply and demand perspectives. This study should be seen as a stepping stone towards further research into the UFO and alien tourism industry and provide researchers with a theoretical platform and novel ideas through which to explore the subject. Originality/value The phenomenon includes an established eclectic mix of attractions and likewise tourist motivations for visiting are wide and diverse. However, the subject lacks academic consideration. Thus, this paper presents original research and timely discussions on the topic.

The estimation of the length constant of a long cooling fin by variational iteration method

2015 ◽  
Vol 25 (4) ◽  
pp. 887-891 ◽  
Author(s):  
Yan Zhang ◽  
Qiaoling Chen ◽  
Fujuan Liu ◽  
Ping Wang
Keyword(s):  
Nonlinear Equation ◽  
Nonlinear Equations ◽  
Iteration Method ◽  
Design Methodology ◽  
Variational Iteration Method ◽  
Engineering Problem ◽  
Content Type ◽  
Variational Iteration ◽  
Length Constant ◽  
Good Agreement

Purpose – The purpose of this paper is to validate the variational iteration method (VIM) is suitable for various nonlinear equations. Design/methodology/approach – The He’s VIM is applied to solve nonlinear equation which is derived from actual engineering problem. The result was compared with other method. Findings – The result obtained from VIM shows good agreement with Xu’s result which provide a solid evidence that VIM is convenient and effective for solving nonlinear equation in the engineering. Originality/value – The VIM can be extended to many academic and engineering fields for nonlinear equations solving.

Error management: implications for construction

2016 ◽  
Vol 16 (4) ◽  
pp. 418-424 ◽  
Author(s):  
Peter E.D. Love ◽  
Jim Smith
Keyword(s):  
Design Methodology ◽  
Shared Responsibility ◽  
Error Reporting ◽  
Future Research ◽  
Error Management ◽  
Learning From Errors ◽  
Content Type ◽  
Alternative Approach ◽  
Starting Point ◽  
Initial Starting

Purpose Conventional “wisdom” in construction has placed emphasis on error prevention and is often aligned with the concept of “Zero Vision”; improvements to safety and quality have been minimal. An alternative approach is needed to ensure significant improvements in safety and quality; thus, this paper aims to introduce the concept of error management. Design/methodology/approach The paper reviews the extant literature and draws upon the phenomenological research and observations experienced by the authors. Findings It is promulgated that if quality and safety performance within projects is to improve, then construction organisations and their management need to openly acknowledge their presence so that “learning from errors” can form an integral part of an organisation’s fabric. This will require the institutionalisation of error reporting and an organisational (shared) responsibility for their occurrence. Originality/value The concept of error management has not been addressed previously in the construction literature. The authors introduce the concept and provide implications for management. The observations and experiences presented in this paper provide an initial starting point for future research to explore “how” construction organisations and projects can avoid the negative error consequences and learn to prevent them in the future.

Convergent optimal variational iteration method and applications to heat and fluid flow problems

2016 ◽  
Vol 26 (3/4) ◽  
pp. 790-804 ◽  
Author(s):  
Mustafa Turkyilmazoglu
Keyword(s):  
Fluid Flow ◽  
Iteration Method ◽  
Sufficient Conditions ◽  
Variational Iteration Method ◽  
Content Type ◽  
Flow Problems ◽  
Variational Iteration ◽  
Physical Problems ◽  
Novel Approach ◽  
Heat And Fluid Flow

Purpose – In an earlier paper (Turkyilmazoglu, 2011a), the author introduced a new optimal variational iteration method. The idea was to insert a parameter into the classical variational iteration formula in an aim to prevent divergence or to accelerate the slow convergence property of the classical approach. The purpose of this paper is to approve the superiority of the proposed method over the traditional one on several physical problems treated before by the classical variational iteration method. Design/methodology/approach – A sufficient condition theorem with an upper bound for the error is also presented to further justify the convergence of the new variational iteration method. Findings – The optimal variational iteration method is found to be useful for heat and fluid flow problems. Originality/value – The optimal variational iteration method is shown to be convergent under sufficient conditions. A novel approach to obtain the optimal convergence parameter is introduced.

Numerical solution of the general Volterra nth-order integro-differential equations via variational iteration method

2018 ◽  
Vol 13 (02) ◽  
pp. 2050042
Author(s):  
Fernane Khaireddine
Keyword(s):  
Differential Equations ◽  
Exact Solutions ◽  
Numerical Solution ◽  
General Formula ◽  
Iteration Method ◽  
Variational Iteration Method ◽  
Approximate Solutions ◽  
Numerical Examples ◽  
Variational Iteration ◽  
Linear And Nonlinear

In this paper, we use the variational iteration method (VIM) to construct approximate solutions for the general [Formula: see text]th-order integro-differential equations. We show that his method can be effectively and easily used to solve some classes of linear and nonlinear Volterra integro-differential equations. Finally, some numerical examples with exact solutions are given.

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