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3. Supply chain collaboration of Ghana's gold mining industry

Author

Arhin, Francis Kow

Abstract

The gold mining industry contributes about 41% of Ghana's export earnings, generating about 14% as tax revenue and a total of 5.5% gross domestic product (GDP). It is essential to salvage the industry's image. Employees of the industry can be laid off and made redundant because the industry's financial position is almost always affected during critical moments. This in most cases result in the holding up of suppliers' payments and operations grinding to a halt due to procurement, logistics and inventory issues. In light of this, an empirical study is being conducted with the aim of identifying the factors of supply chain collaboration in Ghana's mining industry. Mixed methods were used including a purposive sampling method which was used with survey questionnaires administered on eleven operational mining companies in Ghana. SPSS tool was used in the analysis of data. Semi-structured interviews were conducted at the mines site (company premises) in September 2019 in Ghana. The results identified some factors that affect the collaborative supply chain. These are the pricing of products and service, variable payment systems, open book, the share of company values, and consolidation of orders. Identifying these factors contribute to existing literature which makes this study unique as they have not been discovered in any of the supply chain literature in the context of gold mining. A framework in supply chain collaboration was developed, which is unique to the gold mining sector in Ghana. The result will have managerial implications to drive the gold mining industry's performance forward. Mining organisations will benefit from this study as this can be replicated in other gold mining sectors in Africa and across the globe's mining industry.

Published
2021

11. Critical Factors of Digital Supply Chains for Organizational Performance Improvement

Author

Khan, Sharfuddin Ahmed, Kusi-Sarpong, Simonov, Gupta, Himanshu, Arhin, Francis Kow, Lawal, Jennifer Nguseer, and Hassan, Syed Mehmood

Abstract

Technological advancement is redefining supply chains (SCs) processes and soon traditional ways of managing SCs will no more be feasible and effective. Due to recent advancement in technology, digitalization has become an emerging topic among decision-makers and researchers. To cope-up with this emerging trend in customer behavior and remain competitive, organizations must move from their traditional ways of managing their SCs to digital supply chains (DSCs) for improved organizational performance. Therefore, the purpose of this article is in two folds: First, to identify critical factors of DSCs that are essential for transitioning traditional SCs to DSCs to improve organizational performance. Second, interpretive structural modeling is used to establish the relationship among critical factors and (matriced’ impacts croise´s multiplication applique´e a´un classement used to identify the driving and dependency power of the critical factors. Thus, this article identified fifteen DSC critical factors and established their direct and indirect effect on DSCs. The results show that “SC resilience”, and “proactive prevention” have the highest dependency power factors whilst “integration” and “advanced operational models” have the highest driving power factors. This article can help SC managers and decision-makers to understand the critical factors essential in adopting DSCs for improving organizational performance.

Published
2024
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22. Inhibition of transcription in Staphylococcus aureus by a primary sigma factor-binding polypeptide from phage G1

Author

Dehbi, Mohammed, Moeck, Gregory, Arhin, Francis F., Bauda, Pascale, Bergeron, Dominique, Kwan, Tony, Liu, Jing, McCarty, John, DuBow, Michael, and Pelletier, Jerry

Subjects
Staphylococcus aureus -- Genetic aspects, Staphylococcus aureus -- Research, Genetic transcription -- Research, Polypeptides -- Physiological aspects, Polypeptides -- Genetic aspects, Polypeptides -- Research, RNA polymerases -- Research, Bacteriophages -- Genetic aspects, Bacteriophages -- Research, Bacterial genetics -- Reports, Biological sciences
Abstract

The primary sigma factor of Staphylococcus aureus, [[sigma].sup.SA], regulates the transcription of many genes, including several essential genes, in this bacterium via specific recognition of exponential growth phase promoters. In this study, we report the existence of a novel staphylococcal phage G1-derived growth inhibitory polypeptide, referred to as G1ORF67, that interacts with [[sigma].sup.SA] both in vivo and in vitro and regulates its activity. Delineation of the minimal domain of [[sigma].sup.SA] that is required for its interaction with G1ORF67 as amino acids 294 to 360 near the carboxy terminus suggests that the G1 phage-encoded anti-[sigma] factor may occlude the -35 element recognition domain of [[sigma].sup.SA]. AS would be predicted by this hypothesis, the G1ORF67 polypeptide abolished both RNA polymerase core-dependent binding of [[sigma].sup.SA] to DNA and [[sigma].sup.SA]-dependent transcription in vitro. While G1ORF67 profoundly inhibits transcription when expressed in S. aureus cells in mode of action studies, our finding that G1ORF67 was unable to inhibit transcription when expressed in Escherichia coli concurs with its inability to inhibit transcription by the E. coli holoenzyme in vitro. These features demonstrate the selectivity of G1ORF67 for S. aureus RNA polymerase. We predict that G1ORF67 is one of the central polypeptides in the phage G1 strategy to appropriate host RNA polymerase and redirect it to phage reproduction.

Published
2009

25. Effects of disruption of xylanase-encoding genes on the xylanolytic system of Streptomyces lividans

Author

Arhin, Francis F., Shareck, Francois, Kluepfel, Dieter, and Morosoli, Rolf

Subjects
Streptomyces -- Genetic aspects, Biological sciences
Abstract

Disruption of xylanase-encoding genes on the xylanolytic system of wild-type Streptomyces lividans using vectors that integrate into respective genes shows that it decreases the growth rate and xylanase activities. Disruption of xlnA did not affect xlnB and xlnC expression while xlnB and xlnC disruptions did not affect xlnA expression but affected the expressions of each other. XlnB or xlnC hydrolytic product fractions influence xlnB and xlnC expressions in the disrupted strain while the small xylo-oligosaccharides do not affect the expressions.

Published
1994

26. Cloning, nucleotide sequence and expression in Streptomyces lividans and Escherichia coli of pabB from Lactococcus lactis subsp. lactis NCDO 496

Author

Arhin, Francis F. and Vining, Leo C.

Subjects
Streptomyces -- Research, Escherichia coli -- Research, Nucleotide sequence -- Analysis, Cloning -- Analysis, Biological sciences
Abstract

The cloning of the gene pabB encoding the aminase activity of p-aminobenzoate (PABA) synthase in Lactococcus lactis subsp. lactis in pIJ41 was undertaken. These genes are usually expressed in Streptomyces lividans strains, which are inefficient in PABA biosynthesis. The 1.2 kb deletion in the region between the aph promoter and the cloning site in the PIJ41 was associated with the expression of the gene. The localization of the pabB complementing gene in the 1.9 kb segment was induced by the subcloning of the pBR322 and the expression of the cloned L. lactis DNA fragment in Escherichia Coli AB3295.

Published
1993

45. Antimicrobial drug discovery through bacteriophage genomics

Author

Liu, Jing, primary, Dehbi, Mohammed, additional, Moeck, Greg, additional, Arhin, Francis, additional, Bauda, Pascale, additional, Bergeron, Dominique, additional, Callejo, Mario, additional, Ferretti, Vincent, additional, Ha, Nhuan, additional, Kwan, Tony, additional, McCarty, John, additional, Srikumar, Ramakrishnan, additional, Williams, Dan, additional, Wu, Jinzi J, additional, Gros, Philippe, additional, Pelletier, Jerry, additional, and DuBow, Michael, additional

Published
2004
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46. Comparative In VitroActivities of Oritavancin, Dalbavancin, and Vancomycin against Methicillin-Resistant Staphylococcus aureusIsolates in a Nondividing State

Author

Belley, Adam, Lalonde Seguin, David, Arhin, Francis, and Moeck, Greg

Abstract

ABSTRACTAntibacterial agents that kill nondividing bacteria may be of utility in treating persistent infections. Oritavancin and dalbavancin are bactericidal lipoglycopeptides that are approved for acute bacterial skin and skin structure infections in adults caused by susceptible Gram-positive pathogens. Using time-kill methodology, we demonstrate that oritavancin exerts bactericidal activity against methicillin-resistant Staphylococcus aureus(MRSA) isolates that are maintained in a nondividing state in vitro, whereas dalbavancin and the glycopeptide vancomycin do not.

Published
2016
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48. Use of In VitroVancomycin Testing Results To Predict Susceptibility to Oritavancin, a New Long-Acting Lipoglycopeptide

Author

Jones, Ronald N., Turnidge, John D., Moeck, Greg, Arhin, Francis F., and Mendes, Rodrigo E.

Abstract

ABSTRACTOritavancin is a recently approved lipoglycopeptide antimicrobial agent with activity against Gram-positive pathogens. Its extended serum elimination half-life and concentration-dependent killing enable single-dose treatment of acute bacterial skin and skin structure infections. At the time of regulatory approval, new agents, including oritavancin, are not offered in the most widely used susceptibility testing devices and therefore may require application of surrogate testing using a related antimicrobial to infer susceptibility. To evaluate vancomycin as a predictive susceptibility marker for oritavancin, 26,993 recent Gram-positive organisms from U.S. and European hospitals were tested using reference MIC methods. Organisms included Staphylococcus aureus, coagulase-negative staphylococci (CoNS), beta-hemolytic streptococci (BHS), viridans group streptococci (VGS), and enterococci (ENT). These five major pathogen groups were analyzed by comparing results with FDA-approved susceptible breakpoints for both drugs, as well as those suggested by epidemiological cutoff values and supported by pharmacokinetic/pharmacodynamic analyses. Vancomycin susceptibility was highly accurate (98.1 to 100.0%) as a surrogate for oritavancin susceptibility among the indicated pathogen species. Furthermore, direct MIC comparisons showed high oritavancin potencies, with vancomycin/oritavancin MIC90results of 1/0.06, 2/0.06, 0.5/0.12,1/0.06, and >16/0.06 μg/ml for S. aureus, CoNS, BHS, VGS, and ENT, respectively. In conclusion, vancomycin demonstrated acceptable accuracy as a surrogate marker for predicting oritavancin susceptibility when tested against the indicated pathogens. In contrast, 93.3% of vancomycin-nonsusceptible enterococci had oritavancin MIC values of ≤0.12 μg/ml, indicating a poor predictive value of vancomycin for oritavancin resistance against these organisms. Until commercial oritavancin susceptibility testing devices are readily available, isolates that when tested show vancomycin susceptibility can be inferred to be susceptible to oritavancin by using FDA-approved breakpoints.

Published
2015
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50. Antimicrobial drug discovery through bacteriophage genomics.

Author

Arhin, Francis, Bauda, Pascale, Bergeron, Dominique, Callejo, Mario, Ferretti, Vincent, Nhuan Ha, Vincent, Kwan, Tony, McCarty, John, Srikumar, Ramakrishnan, Williams, Dan, Jinzi J. Wu, Dan, Gros, Philippe, Pelletier, Jerry, DuBow, Michael, Jing Liu, Dehbi, Mohammed, and Moeck, Greg

Subjects
*ANTI-infective agents, *BACTERIOPHAGE genetics, *ANTIBIOTICS, *GENETICS of staphylococcus aureus infections, *DNA replication, *COMMUNICABLE diseases
Abstract

Over evolutionary time bacteriophages have developed unique proteins that arrest critical cellular processes to commit bacterial host metabolism to phage reproduction. Here, we apply this concept of phage-mediated bacterial growth inhibition to antibiotic discovery. We sequenced 26 Staphylococcus aureus phages and identified 31 novel polypeptide families that inhibited growth upon expression in S. aureus. The cellular targets for some of these polypeptides were identified and several were shown to be essential components of the host DNA replication and transcription machineries. The interaction between a prototypic pair, ORF104 of phage 77 and DnaI, the putative helicase loader of S. aureus, was then used to screen for small molecule inhibitors. Several compounds were subsequently found to inhibit both bacterial growth and DNA synthesis. Our results suggest that mimicking the growth-inhibitory effect of phage polypeptides by a chemical compound, coupled with the plethora of phages on earth, will yield new antibiotics to combat infectious diseases. [ABSTRACT FROM AUTHOR]

Published
2004
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