Purpose The purpose of this paper is to identify the negative impact of an incumbent supplier pushing out a buyer, the positive effect of an alternative supplier pulling a buyer, and the mooring impact that prevents a buyer from switching to a supplier in terms of the push-pull-mooring (PPM) model of migration theory. In this context, this study considers a buyer as the immigrant, an incumbent supplier as the origin, an alternative supplier as the destination, and inertia as the hesitance to migrate.
Design/methodology/approach This study collected survey data from 148 end-product manufacturers and first-tier suppliers. It tested whether the PPM model fit in a supply chain relationship (SCR) using the partial least squares structural equation modelling approach and SmartPLS package version 2.0.M3.
Findings The results support all hypotheses for causal relationships among factors of cognitive, affect, and behavioural intentions of each PPM effect. This study identifies the relative importance of each effect on a buyer's intention of switching an existing supplier.
Originality/value This study presents a new perspective that enhances the understanding of a buyer's behaviour towards a supplier by applying the PPM model of migration to a manufacturing SCR. It promotes interdisciplinary and integrated views as well as broadens the diversity of the results in the business-to-business context.
ABSTRACTThis study examines the interaction effect of foreign language and obedience pressure from superiors on the ethical judgment in an auditing context. We conducted a 2 × 2 between-participants experiment with language and obedience pressure as independent variables. Participants are accounting students from eight leading universities in Japan to proxy entry-level auditing professionals. They were asked to provide their judgments based on a consolidation reporting scenario. We found that, under obedience pressure, foreign language use makes one's judgment less aligned with the superior's preference (less compliant) than the use of the native language. These results provide new insights regarding the potential boundary of the foreign language effect in auditing issues.
With the circulation of wild poliovirus (WPV) types 1 and 3 continuing more than a decade after the original goal of eradicating all three types of WPVs by 2000, policymakers consider many immunization options as they strive to stop transmission in the remaining endemic and outbreak areas and prevent reintroductions of live polioviruses into nonendemic areas. While polio vaccination choices may appear simple, our analysis of current options shows remarkable complexity. We offer important context for current and future polio vaccine decisions and policy analyses by developing decision trees that clearly identify potential options currently used by countries as they evaluate national polio vaccine choices. Based on a comprehensive review of the literature we (1) identify the current vaccination options that national health leaders consider for polio vaccination, (2) characterize current practices and factors that appear to influence national and international choices, and (3) assess the evidence of vaccine effectiveness considering sources of variability between countries and uncertainties associated with limitations of the data. With low numbers of cases occurring globally, the management of polio risks might seem like a relatively low priority, but stopping live poliovirus circulation requires making proactive and intentional choices to manage population immunity in the remaining endemic areas and to prevent reestablishment in nonendemic areas. Our analysis shows remarkable variability in the current national polio vaccine product choices and schedules, with combination vaccine options containing inactivated poliovirus vaccine and different formulations of oral poliovirus vaccine making choices increasingly difficult for national health leaders.
We demonstrate enhanced differentiation of oligodendrocytes during neurogenesis of human embryonic stem cells (hESCs) using an extracellular matrix protein, vitronectin (VN). We show that VN is expressed in the ventral part of the developing human spinal cord. Combined treatment of retinoic acid, sonic hedgehog, and noggin in the presence of VN allows hESCs to differentiate into O4-positive oligodendrocytes. Particularly, VN profoundly promotes the derivation of oligodendrocyte progenitors that proliferate and differentiate into oligodendrocytes in response to mitogenic and survival factors. These results support the beneficial effect of VN on oligodendrocytic differentiation of hESCs. ; This research was supported by the Seoul Research and Business Development Program (10574) and by a Korea Science and Engineering Foundation (KOSEF) grant funded by the Korea Government(MOST) (R01-2006-000-11364-0).
The live, attenuated oral poliovirus vaccine (OPV) provides a powerful tool for controlling and stopping the transmission of wild polioviruses (WPVs), although the risks of vaccine‐associated paralytic polio (VAPP) and circulating vaccine‐derived poliovirus (cVDPV) outbreaks exist as long as OPV remains in use. Understanding the dynamics of cVDPV emergence and outbreaks as a function of population immunity and other risk factors may help to improve risk management and the development of strategies to respond to possible outbreaks. We performed a comprehensive review of the literature related to the process of OPV evolution and information available from actual experiences with cVDPV outbreaks. Only a relatively small fraction of poliovirus infections cause symptoms, which makes direct observation of the trajectory of OPV evolution within a population impractical and leads to significant uncertainty. Despite a large global surveillance system, the existing genetic sequence data largely provide information about transmitted virulent polioviruses that caused acute flaccid paralysis, and essentially no data track the changes that occur in OPV sequences as the viruses transmit largely asymptomatically through real populations with suboptimal immunity. We updated estimates of cVDPV risks based on actual experiences and identified the many limitations in the existing data on poliovirus transmission and immunity and OPV virus evolution that complicate modeling. Modelers should explore the space of potential model formulations and inputs consistent with the available evidence and future studies should seek to improve our understanding of the OPV virus evolution process to provide better information for policymakers working to manage cVDPV risks.
With the intensifying global efforts to eradicate wild polioviruses, policymakers face complex decisions related to achieving eradication and managing posteradication risks. These decisions and the expanding use of inactivated poliovirus vaccine (IPV) trigger renewed interest in poliovirus immunity, particularly the role of mucosal immunity in the transmission of polioviruses. Sustained high population immunity to poliovirus transmission represents a key prerequisite to eradication, but poliovirus immunity and transmission remain poorly understood despite decades of studies. In April 2010, the U.S. Centers for Disease Control and Prevention convened an international group of experts on poliovirus immunology and virology to review the literature relevant for modeling poliovirus transmission, develop a consensus about related uncertainties, and identify research needs. This article synthesizes the quantitative assessments and research needs identified during the process. Limitations in the evidence from oral poliovirus vaccine (OPV) challenge studies and other relevant data led to differences in expert assessments, indicating the need for additional data, particularly in several priority areas for research: (1) the ability of IPV‐induced immunity to prevent or reduce excretion and affect transmission, (2) the impact of waning immunity on the probability and extent of poliovirus excretion, (3) the relationship between the concentration of poliovirus excreted and infectiousness to others in different settings, and (4) the relative role of fecal‐oral versus oropharyngeal transmission. This assessment of current knowledge supports the immediate conduct of additional studies to address the gaps.
Successfully managing risks to achieve wild polioviruses (WPVs) eradication and address the complexities of oral poliovirus vaccine (OPV) cessation to stop all cases of paralytic poliomyelitis depends strongly on our collective understanding of poliovirus immunity and transmission. With increased shifting from OPV to inactivated poliovirus vaccine (IPV), numerous risk management choices motivate the need to understand the tradeoffs and uncertainties and to develop models to help inform decisions. The U.S. Centers for Disease Control and Prevention hosted a meeting of international experts in April 2010 to review the available literature relevant to poliovirus immunity and transmission. This expert review evaluates 66 OPV challenge studies and other evidence to support the development of quantitative models of poliovirus transmission and potential outbreaks. This review focuses on characterization of immunity as a function of exposure history in terms of susceptibility to excretion, duration of excretion, and concentration of excreted virus. We also discuss the evidence of waning of host immunity to poliovirus transmission, the relationship between the concentration of poliovirus excreted and infectiousness, the importance of different transmission routes, and the differences in transmissibility between OPV and WPV. We discuss the limitations of the available evidence for use in polio risk models, and conclude that despite the relatively large number of studies on immunity, very limited data exist to directly support quantification of model inputs related to transmission. Given the limitations in the evidence, we identify the need for expert input to derive quantitative model inputs from the existing data.
Typhoid fever is an acute systemic infectious disease responsible for an estimated 12-20 million illnesses and over 150 000 deaths annually. In March, 2018, a new recommendation was issued by WHO for the programmatic use of typhoid conjugate vaccines in endemic countries. Health economic analyses of typhoid vaccines have informed funding decisions and national policies regarding vaccine rollout. However, by focusing only on averted typhoid cases and their associated costs, traditional cost-effectiveness analyses might underestimate crucial benefits of typhoid vaccination programmes, because the potential effect of typhoid vaccines on the treatment of patients with non-specific acute febrile illnesses is not considered. For every true case of typhoid fever, three to 25 patients without typhoid disease are treated with antimicrobials unnecessarily, conservatively amounting to more than 50 million prescriptions per year. Antimicrobials for suspected typhoid might therefore be an important selective pressure for the emergence and spread of antimicrobial resistance globally. We propose that large-scale, more aggressive typhoid vaccination programmes-including catch-up campaigns in children up to 15 years of age, and vaccination in lower incidence settings-have the potential to reduce the overuse of antimicrobials and thereby reduce antimicrobial resistance in many bacterial pathogens. Funding bodies and national governments must therefore consider the potential for broad reductions in antimicrobial use and resistance in decisions related to the rollout of typhoid conjugate vaccines.
In: Park, Se Eun, Toy, Trevor, Espinoza, Ligia Maria Cruz, Panzner, Ursula, Mogeni, Ondari D., Im, Justin, Poudyal, Nimesh, Pak, Gi Deok, Seo, Hyeongwon, Chon, Yun, Schutt-Gerowitt, Heidi, Mogasale, Vittal orcid:0000-0003-0596-8072 , Ramani, Enusa, Dey, Ayan orcid:0000-0002-0718-7336 , Park, Ju Yeong, Kim, Jong-Hoon, Seo, Hye Jin, Jeon, Hyon Jin, Haselbeck, Andrea, Conway Roy, Keriann, MacWright, William, Adu-Sarkodie, Yaw, Owusu-Dabo, Ellis, Osei, Isaac, Owusu, Michael, Rakotozandrindrainy, Raphael, Soura, Abdramane Bassiahi, Kabore, Leon Parfait, Teferi, Mekonnen, Okeke, Iruka N., Kehinde, Aderemi, Popoola, Oluwafemi, Jacobs, Jan, Metila, Octavie Lunguya, Meyer, Christian G., Crump, John A., Elias, Sean, Maclennan, Calman A., Parry, Christopher M., Baker, Stephen, Mintz, Eric D., Breiman, Robert F., Clemens, John D. and Marks, Florian (2019). The Severe Typhoid Fever in Africa Program: Study Design and Methodology to Assess Disease Severity, Host Immunity, and Carriage Associated With Invasive Salmonellosis. Clin. Infect. Dis., 69. S. S422 - 13. CARY: OXFORD UNIV PRESS INC. ISSN 1537-6591
Background. Invasive salmonellosis is a common community-acquired bacteremia in persons residing in sub-Saharan Africa. However, there is a paucity of data on severe typhoid fever and its associated acute and chronic host immune response and carriage. The Severe Typhoid Fever in Africa (SETA) program, a multicountry surveillance study, aimed to address these research gaps and contribute to the control and prevention of invasive salmonellosis. Methods. A prospective healthcare facility-based surveillance with active screening of enteric fever and clinically suspected severe typhoid fever with complications was performed using a standardized protocol across the study sites in Burkina Faso, the Democratic Republic of Congo (DRC), Ethiopia, Ghana, Madagascar, and Nigeria. Defined inclusion criteria were used for screening of eligible patients for enrollment into the study. Enrolled patients with confirmed invasive salmonellosis by blood culture or patients with clinically suspected severe typhoid fever with perforation were eligible for clinical follow-up. Asymptomatic neighborhood controls and immediate household contacts of each case were enrolled as a comparison group to assess the level of Salmonella-specific antibodies and shedding patterns. Healthcare utilization surveys were performed to permit adjustment of incidence estimations. Postmortem questionnaires were conducted in medically underserved areas to assess death attributed to invasive Salmonella infections in selected sites. Results. Research data generated through SETA aimed to address scientific knowledge gaps concerning the severe typhoid fever and mortality, long-term host immune responses, and bacterial shedding and carriage associated with natural infection by invasive salmonellae. Conclusions. SETA supports public health policy on typhoid immunization strategy in Africa.