scholarly journals ContrastingEx VivoEfficacies of “Reversed Chloroquine” Compounds in Chloroquine-Resistant Plasmodium falciparum and P. vivax Isolates

2015 ◽  
Vol 59 (9) ◽  
pp. 5721-5726 ◽  
Author(s):  
Grennady Wirjanata ◽  
Boni F. Sebayang ◽  
Ferryanto Chalfein ◽  
Prayoga ◽  
Irene Handayuni ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Ex Vivo ◽  
Rank Correlation ◽  
Multidrug Resistant ◽  
Content Type ◽  
Reversal Agents ◽  
Field Isolates ◽  
Spearman’S Rank Correlation ◽  
Spearman’S Rank Correlation Coefficient ◽  
Potential Use

ABSTRACTChloroquine (CQ) has been the mainstay of malaria treatment for more than 60 years. However, the emergence and spread of CQ resistance now restrict its use to only a few areas where malaria is endemic. The aim of the present study was to investigate whether a novel combination of a CQ-like moiety and an imipramine-like pharmacophore can reverse CQ resistanceex vivo. Between March to October 2011 and January to September 2013, two “reversed chloroquine” (RCQ) compounds (PL69 and PL106) were tested against multidrug-resistant field isolates ofPlasmodium falciparum(n= 41) andPlasmodium vivax(n= 45) in Papua, Indonesia, using a modifiedex vivoschizont maturation assay. The RCQ compounds showed high efficacy against both CQ-resistantP. falciparumandP. vivaxfield isolates. ForP. falciparum, the median 50% inhibitory concentrations (IC50s) were 23.2 nM for PL69 and 26.6 nM for PL106, compared to 79.4 nM for unmodified CQ (P< 0.001 andP= 0.036, respectively). The corresponding values forP. vivaxwere 19.0, 60.0, and 60.9 nM (P< 0.001 andP= 0.018, respectively). There was a significant correlation between IC50s of CQ and PL69 (Spearman's rank correlation coefficient [rs] = 0.727,P< 0.001) and PL106 (rs= 0.830,P< 0.001) inP. vivaxbut not inP. falciparum. Both RCQs were equally active against the ring and trophozoite stages ofP. falciparum, but inP. vivax, PL69 and PL106 showed less potent activity against trophozoite stages (median IC50s, 130.2 and 172.5 nM) compared to ring stages (median IC50s, 17.6 and 91.3 nM). RCQ compounds have enhancedex vivoactivity against CQ-resistant clinical isolates ofP. falciparumandP. vivax, suggesting the potential use of reversal agents in antimalarial drug development. Interspecies differences in RCQ compound activity may indicate differences in CQ pharmacokinetics between the twoPlasmodiumspecies.

Drivers of e-bidding implementation in the Saudi Arabian construction industry

2019 ◽  
Vol 10 (1) ◽  
pp. 16-27
Author(s):  
Ahmed M.Z. Sayed ◽  
Sadi Assaf ◽  
Adel S. Aldosary ◽  
Mohammad A. Hassanain ◽  
Abdullatif Abdallah
Keyword(s):  
Saudi Arabia ◽  
Construction Projects ◽  
Rank Correlation ◽  
Construction Costs ◽  
Content Type ◽  
Significance Level ◽  
Spearman’S Rank Correlation ◽  
Spearman’S Rank Correlation Coefficient ◽  
Key Drivers ◽  
Public Construction

Purpose The purpose of this paper is to identify the key drivers for adopting electronic bidding (e-bidding) systems in public construction projects located in Saudi Arabia. Design/methodology/approach Literature review was undertaken to identify the drivers of e-bidding practices. Nine drivers, classified under four categories, were identified. A questionnaire survey was developed to assess the significance of the identified drivers. Responses were obtained from 20 large contractors, classified as Grade I and II contractors in Saudi Arabia, and 12 governmental authorities, representing owners of construction projects. The drivers were ranked according to their respective significance index (SI) values. Finally, a Spearman’s rank correlation coefficient was employed to ascertain the extent to which the two parties agreed on the significance level of the drivers. Findings Analysis of the identified drivers revealed that the most significant driver was “reduction in the physical storage requirements of bidding paperwork.” Further, a consensus was observed with regards to the significance of the drivers. The findings of the present study highlight the strong potential of widespread e-bidding adoption in Saudi Arabia. It demonstrates the key drivers for the implementation of e-bidding through the perspective of professionals within the context of Saudi Arabia. Originality/value Prior to this study, no previous research has endeavored to assess the drivers of e-bidding adoption in Saudi Arabia. The adoption of e-bidding will benefit organizations through improved efficiencies, which could potentially lower construction costs, thereby contributing to economic growth and benefitting the society at large.

Contractor prequalification for green buildings—evidence from Turkey

2020 ◽  
Vol 27 (6) ◽  
pp. 1377-1400 ◽  
Author(s):  
Asli Pelin Gurgun ◽  
Kerim Koc
Keyword(s):  
Life Cycle Cost ◽  
Legal Status ◽  
Rank Correlation ◽  
Green Building ◽  
Evaluation Tool ◽  
Content Type ◽  
Spearman’S Rank Correlation ◽  
Spearman’S Rank Correlation Coefficient ◽  
Practical Evaluation ◽  
Hierarchy Process

PurposeCompetent contractors are one of the critical stakeholders to achieve targeted sustainability objectives in green building (GB) projects. Prior to contractor selection, prequalification is an important step, which requires contractors with certain capabilities in addition to traditional features. This study aims to develop a systematic and practical model for prequalification in GB projects using a multi-criteria decision-making (MCDM) approach by adopting the analytical hierarchy process (AHP).Design/methodology/approachThe AHP model with 8 main criteria groups and 25 sub-criteria is structured based on literature review and professional opinions accompanied by a pilot study. Then, interviews with experts, who are experienced in the development and application phases of GB projects in Turkey, are arranged to collect judgements. The agreement levels between different groups of experts are analysed via Pearson's and Spearman's rank correlation coefficient. Model applicability is tested on six hypothetical contractors for practicality.FindingsThe results show that i) financial capabilities, ii) legal status and iii) sustainability groups are the top three main criteria, while i) compliance with schedule requirements of the client, ii) current legal status including suits, iii) negative litigation history records, iv) contractor's compliance capacity to client's sustainability checklist for the proposed project and v) sustainability with lower life cycle cost (durability, maintenance, constructability) are the top five sub-criteria.Originality/valueThere is a gap in the literature analysing contractor prequalification phase in GB projects. This study attempts to fill this lack provided with a practical evaluation tool.

scholarly journals Ex VivoDrug Susceptibility of Ferroquine against Chloroquine-Resistant Isolates of Plasmodium falciparum and P. vivax

2011 ◽  
Vol 55 (9) ◽  
pp. 4461-4464 ◽  
Author(s):  
Jutta Marfurt ◽  
Ferryanto Chalfein ◽  
Pak Prayoga ◽  
Frans Wabiser ◽  
Enny Kenangalem ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Combination Therapy ◽  
Drug Class ◽  
Ex Vivo ◽  
Multidrug Resistant ◽  
Drug Action ◽  
Drug Uptake ◽  
Content Type ◽  
Excellent Activity

ABSTRACTFerroquine (FQ; SSR97193), a ferrocene-containing 4-aminoquinoline derivate, has potentin vitroefficacy against chloroquine (CQ)-resistantPlasmodium falciparumand CQ-sensitiveP. vivax. In the current study,ex vivoFQ activity was tested in multidrug-resistantP. falciparumandP. vivaxfield isolates using a schizont maturation assay. Although FQ showed excellent activity against CQ-sensitive and -resistantP. falciparumandP. vivax(median 50% inhibitory concentrations [IC50s], 9.6 nM and 18.8 nM, respectively), there was significant cross-susceptibility with the quinoline-based drugs chloroquine, amodiaquine, and piperaquine (forP. falciparum,r= 0.546 to 0.700,P< 0.001; forP. vivax,r= 0.677 to 0.821,P< 0.001). The observedex vivocross-susceptibility is likely to reflect similar mechanisms of drug uptake/efflux and modes of drug action of this drug class. However, the potent activity of FQ against resistant isolates of bothP. falciparumandP. vivaxhighlights a promising role for FQ as a lead antimalarial against CQ-resistantPlasmodiumand a useful partner drug for artemisinin-based combination therapy.

Resource allocation based on overall equipment effectiveness using cooperative game

Kybernetes ◽  
2019 ◽  
Vol 49 (3) ◽  
pp. 819-834 ◽  
Author(s):  
Seyed Hadi Mousavi-Nasab ◽  
Jalal Safari ◽  
Ashkan Hafezalkotob
Keyword(s):  
Resource Allocation ◽  
Optimal Allocation ◽  
Rank Correlation ◽  
Nash Bargaining Solution ◽  
Nash Bargaining ◽  
Bargaining Solution ◽  
Content Type ◽  
Spearman’S Rank Correlation ◽  
Spearman’S Rank Correlation Coefficient ◽  
Topsis Technique

Purpose Resource allocation has always been a critical problem with significant economic relevance. Many industries allocate the resources based on classical methods such as overall equipment effectiveness (OEE) and data envelopment analysis (DEA). The lack of OEE factors’ weight, how it is defined, analyzed, interpreted and compared in OEE and selection of unrealistic weights, self-appraisal and disability of complete ranking in DEA are challenges that are possible to occur. These defects may result in unfair allocation of the resources. This study aims to overcome the mentioned weaknesses. Design/methodology/approach In this paper, an approach using a set of various DEA models and Nash bargaining solution (NBS) is designed to solve the resource allocation problem based on OEE, among a set of comparable and uniform DMUs (decision-making units) in a fair way. Findings The results show that a unique Pareto optimal allocation solution is obtained by the proposed DEA–NBS model among the DMUs. This allocation is more acceptable for players, because the allocation results are commonly determined by all DMUs rather than a specific one. Furthermore, the rankings achieved by the utilized methods and TOPSIS (technique for order preference by similarity to ideal solution) are compared by Spearman’s rank correlation coefficient to validate the resource allocation plan. The findings indicate that the DEA–NBS method has the best correlation with the TOPSIS approach. Originality/value To the best of authors’ knowledge, no research has considered the use of DEA and NBS with OEE.

Altmetrics and their relationship with citation counts: a case of journal articles in physics

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rishabh Shrivastava ◽  
Preeti Mahajan
Keyword(s):  
Design Methodology ◽  
Large Scale ◽  
Research Evaluation ◽  
Rank Correlation ◽  
Journal Articles ◽  
Content Type ◽  
Spearman’S Rank Correlation ◽  
Spearman’S Rank Correlation Coefficient ◽  
Low Coverage ◽  
The Relationship

Purpose The first purpose of the present study is to investigate the coverage of journal articles in Physics in various sources of altmetrics. Secondly, the study investigates the relationship between altmetrics and citations. Finally, the study also investigates whether the relationship between citations and altmetrics was stronger or weaker for those articles that had been mentioned at least once in the sources of altmetrics. Design/methodology/approach The journal articles in Physics having at least one author from an Indian Institution and published during 2014–2018 in sources of altmetrics have been investigated. Altmetric.com was used for collecting altmetrics data. Spearman’s rank correlation coefficient (ρ) has been used as the data found to be skewed. Findings The highest coverage was found on Twitter (22.68%), followed by Facebook (3.62%) and blogs (2.18%). The coverage in the rest of the sources was less than 1%. The average Twitter mentions for journal articles tweeted at least once was found to be 4 (3.99) and for Facebook mentions, it was found to be 1.48. Correlations between Twitter mentions–citations and Facebook mentions–citation were found to be statistically significant but low to weak positive. Research limitations/implications The study concludes that due to the low coverage of journal articles, altmetrics should be used cautiously for research evaluation keeping in mind the disciplinary differences. The study also suggests that altmetrics can function as complementary to citation-based metrics. Originality/value The study is one of the first large scale altmetrics studies dealing with research in Physics. Also, Indian research has not been attended to in the altmetrics literature and the present study shall fill that void.

scholarly journals Ex VivoActivity of Endoperoxide Antimalarials, Including Artemisone and Arterolane, against Multidrug-Resistant Plasmodium falciparum Isolates from Cambodia

2014 ◽  
Vol 58 (10) ◽  
pp. 5831-5840 ◽  
Author(s):  
Charlotte A. Lanteri ◽  
Suwanna Chaorattanakawee ◽  
Chanthap Lon ◽  
David L. Saunders ◽  
Wiriya Rutvisuttinunt ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Ex Vivo ◽  
Geometric Mean ◽  
Artemisinin Resistance ◽  
Multidrug Resistant ◽  
Chloroquine Resistance ◽  
Enzyme Linked Immunosorbent Assay ◽  
Multidrug Resistance Gene ◽  
Content Type ◽  
Clinical Resistance

ABSTRACTNovel synthetic endoperoxides are being evaluated as new components of artemisinin combination therapies (ACTs) to treat artemisinin-resistantPlasmodium falciparummalaria. We conducted blindedex vivoactivity testing of fully synthetic (OZ78 and OZ277) and semisynthetic (artemisone, artemiside, artesunate, and dihydroartemisinin) endoperoxides in the histidine-rich protein 2 enzyme-linked immunosorbent assay against 200P. falciparumisolates from areas of artemisinin-resistant malaria in western and northern Cambodia in 2009 and 2010. The order of potency and geometric mean (GM) 50% inhibitory concentrations (IC50s) were as follows: artemisone (2.40 nM) > artesunate (8.49 nM) > dihydroartemisinin (11.26 nM) > artemiside (15.28 nM) > OZ277 (31.25 nM) > OZ78 (755.27 nM).Ex vivoactivities of test endoperoxides positively correlated with dihydroartemisinin and artesunate. The isolates were over 2-fold less susceptible to dihydroartemisinin than the artemisinin-sensitiveP. falciparumW2 clone and showed sensitivity comparable to those with test endoperoxides and artesunate, with isolate/W2 IC50susceptibility ratios of <2.0. All isolates hadP. falciparumchloroquine resistance transporter mutations, with negative correlations in sensitivity to endoperoxides and chloroquine. The activities of endoperoxides (artesunate, dihydroartemisinin, OZ277, and artemisone) significantly correlated with that of the ACT partner drug, mefloquine. Isolates had mutations associated with clinical resistance to mefloquine, with 35% prevalence ofP. falciparummultidrug resistance gene 1 (pfmdr1) amplification and 84.5% occurrence of thepfmdr1Y184F mutation. GM IC50s for mefloquine, lumefantrine, and endoperoxides (artesunate, dihydroartemisinin, OZ277, OZ78, and artemisone) correlated withpfmdr1copy number. Given that current ACTs are failing potentially from reduced sensitivity to artemisinins and partner drugs, newly identified mutations associated with artemisinin resistance reported in the literature andpfmdr1mutations should be examined for their combined contributions to emerging ACT resistance.

scholarly journals ComparativeEx VivoActivity of Novel Endoperoxides in Multidrug-Resistant Plasmodium falciparum and P. vivax

2012 ◽  
Vol 56 (10) ◽  
pp. 5258-5263 ◽  
Author(s):  
Jutta Marfurt ◽  
Ferryanto Chalfein ◽  
Pak Prayoga ◽  
Frans Wabiser ◽  
Grennady Wirjanata ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Antimalarial Activity ◽  
Ex Vivo ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Intrinsic Activity ◽  
Drug Resistant ◽  
The Novel ◽  
Content Type ◽  
Artemisinin Derivatives

ABSTRACTThe declining efficacy of artemisinin derivatives againstPlasmodium falciparumhighlights the urgent need to identify alternative highly potent compounds for the treatment of malaria. In Papua Indonesia, where multidrug resistance has been documented against bothP. falciparumandP. vivaxmalaria, comparativeex vivoantimalarial activity againstPlasmodiumisolates was assessed for the artemisinin derivatives artesunate (AS) and dihydroartemisinin (DHA), the synthetic peroxides OZ277 and OZ439, the semisynthetic 10-alkylaminoartemisinin derivatives artemisone and artemiside, and the conventional antimalarial drugs chloroquine (CQ), amodiaquine (AQ), and piperaquine (PIP).Ex vivodrug susceptibility was assessed in 46 field isolates (25P. falciparumand 21P. vivax). The novel endoperoxide compounds exhibited potentex vivoactivity against both species, but significant differences in intrinsic activity were observed. Compared to AS and its active metabolite DHA, all the novel compounds showed lower or equal 50% inhibitory concentrations (IC50s) in both species (median IC50s between 1.9 and 3.6 nM inP. falciparumand 0.7 and 4.6 nM inP. vivax). The antiplasmodial activity of novel endoperoxides showed different cross-susceptibility patterns in the twoPlasmodiumspecies: whereas theirex vivoactivity correlated positively with CQ, PIP, AS, and DHA inP. falciparum, the same was not apparent inP. vivax. The current study demonstrates for the first time potent activity of novel endoperoxides against drug-resistantP. vivax. The high activity against drug-resistant strains of bothPlasmodiumspecies confirms these compounds to be promising candidates for future artemisinin-based combination therapy (ACT) regimens in regions of coendemicity.

The reliability, use and evaluation of sources of information on foodstuffs

2017 ◽  
Vol 119 (3) ◽  
pp. 442-452 ◽  
Author(s):  
Julita Szlachciuk ◽  
Irena Ozimek
Keyword(s):  
Food Packaging ◽  
Family Members ◽  
Rank Correlation ◽  
Sources Of Information ◽  
Content Type ◽  
Spearman’S Rank Correlation ◽  
Spearman’S Rank Correlation Coefficient ◽  
Frequency Of Use ◽  
Research Findings ◽  
The Impact

Purpose The purpose of this paper is to investigate how young Polish consumers perceive the selected sources of information on foodstuffs. The authors have also taken into account the consumers’ comprehension, hierarchy of importance and use of labels on food products. Design/methodology/approach The survey sample consisted of a group of respondents aged 16-24. The participants were students of secondary schools and universities located in Poland, on the territory of Mazovian Voivodeship. The questionnaires were distributed among the respondents: the χ2 test was used to show the impact of demographic variables, while the Spearman’s rank correlation coefficient was applied to examine the relationship between the respondents’ attentiveness to the information contained on the food packaging and its legibility and comprehensibility. Findings The study ascertained the existence of differences in the perception of the reliability of sources of information on foodstuffs and the declared frequency of using them. In the respondents’ opinion, the most reliable information can be obtained from nutrition consultants, family members, physicians or pharmacists. Furthermore, the analysis of the frequency of use of individual sources of information by the respondents proved that most often they relied on the recommendations from their family members, the information contained in the label and advice offered by their acquaintances. Originality/value The research findings indicate that the key action should be to carry out further educational activities aimed at young consumers in order to enable them to execute their rights to fair information and education, in the foodstuffs market, as well as to increase their consumer activity.

scholarly journals PotentEx VivoActivity of Naphthoquine and Methylene Blue against Drug-Resistant Clinical Isolates of Plasmodium falciparum and Plasmodium vivax

2015 ◽  
Vol 59 (10) ◽  
pp. 6117-6124 ◽  
Author(s):  
Grennady Wirjanata ◽  
Boni F. Sebayang ◽  
Ferryanto Chalfein ◽  
Prayoga ◽  
Irene Handayuni ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Plasmodium Falciparum ◽  
Ex Vivo ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Trophozoite Stage ◽  
Content Type ◽  
Susceptibility Data ◽  
Highly Active

ABSTRACTThe 4-aminoquinoline naphthoquine (NQ) and the thiazine dye methylene blue (MB) have potentin vitroefficacies againstPlasmodium falciparum, but susceptibility data forP. vivaxare limited. The species- and stage-specificex vivoactivities of NQ and MB were assessed using a modified schizont maturation assay on clinical field isolates from Papua, Indonesia, where multidrug-resistantP. falciparumandP. vivaxare prevalent. Both compounds were highly active againstP. falciparum(median [range] 50% inhibitory concentration [IC50]: NQ, 8.0 nM [2.6 to 71.8 nM]; and MB, 1.6 nM [0.2 to 7.0 nM]) andP. vivax(NQ, 7.8 nM [1.5 to 34.2 nM]; and MB, 1.2 nM [0.4 to 4.3 nM]). Stage-specific drug susceptibility assays revealed significantly greater IC50s in parasites exposed at the trophozoite stage than at the ring stage for NQ inP. falciparum(26.5 versus 5.1 nM,P= 0.021) andP. vivax(341.6 versus 6.5 nM,P= 0.021) and for MB inP. vivax(10.1 versus 1.6 nM,P= 0.010). The excellentex vivoactivities of NQ and MB against bothP. falciparumandP. vivaxhighlight their potential utility for the treatment of multidrug-resistant malaria in areas where both species are endemic.

scholarly journals Ex VivoSusceptibility of Plasmodium falciparum to Antimalarial Drugs in Western, Northern, and Eastern Cambodia, 2011-2012: Association with Molecular Markers

2013 ◽  
Vol 57 (11) ◽  
pp. 5277-5283 ◽  
Author(s):  
Pharath Lim ◽  
Dalin Dek ◽  
Vorleak Try ◽  
Richard T. Eastman ◽  
Sophy Chy ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Copy Number ◽  
Ex Vivo ◽  
Geometric Mean ◽  
Multidrug Resistant ◽  
Parasite Resistance ◽  
Resistance Marker ◽  
First Line ◽  
Content Type ◽  
Preah Vihear

ABSTRACTIn 2008, dihydroartemisinin (DHA)-piperaquine (PPQ) became the first-line treatment for uncomplicatedPlasmodium falciparummalaria in western Cambodia. Recent reports of increased treatment failure rates after DHA-PPQ therapy in this region suggest that parasite resistance to DHA, PPQ, or both is now adversely affecting treatment. While artemisinin (ART) resistance is established in western Cambodia, there is no evidence of PPQ resistance. To monitor for resistance to PPQ and other antimalarials, we measured drug susceptibilities for parasites collected in 2011 and 2012 from Pursat, Preah Vihear, and Ratanakiri, in western, northern, and eastern Cambodia, respectively. Using a SYBR green I fluorescence assay, we calculated theex vivo50% inhibitory concentrations (IC50s) of 310 parasites to six antimalarials: chloroquine (CQ), mefloquine (MQ), quinine (QN), PPQ, artesunate (ATS), and DHA. Geometric mean IC50s (GMIC50s) for all drugs (except PPQ) were significantly higher in Pursat and Preah Vihear than in Ratanakiri (P≤ 0.001). An increased copy number ofP. falciparummdr1(pfmdr1), an MQ resistance marker, was more prevalent in Pursat and Preah Vihear than in Ratanakiri and was associated with higher GMIC50s for MQ, QN, ATS, and DHA. An increased copy number of a chromosome 5 region (X5r), a candidate PPQ resistance marker, was detected in Pursat but was not associated with reduced susceptibility to PPQ. Theex vivoIC50andpfmdr1copy number are important tools in the surveillance of multidrug-resistant (MDR) parasites in Cambodia. While MDRP. falciparumis prevalent in western and northern Cambodia, there is no evidence for PPQ resistance, suggesting that DHA-PPQ treatment failures result mainly from ART resistance.

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