Could mild hypoxia impair pilot decision making in emergencies?

The decreased pressure in the cabin of a pressurised aircraft (typically equivalent to ~8000 ft) reduces the oxygen level so that the blood oxygen saturation of all occupants falls from >97% (normoxia) at sea-level to below 92% (mild hypoxia). Although exposure to mild hypoxia does not affect well-learned cognitive and motor performance of aircrew, it has been proposed that it can affect the performance of some complex cognitive performance tasks involving multiple demands typical of emergency tasks that may have to be performed by pilots. In order to simulate some of these complex cognitive demands, 25 student volunteers participated in an experiment which assessed performance of complex logical reasoning and and multiple memory tasks before and after 2 hours of exposure to normoxia and mild hypoxia. Performance for the more difficult components of the complex reasoning task, especially involving conflict decisions, were marginally significantly degraded by mild hypoxia. Since the effects were only marginally significant future studies should investigate the effects of mild hypoxia on more subtle complex decision-making tasks.     

Exploitation Strategy and Performance of Contract Manufacturing Exporters: The Mediating Roles of Exploration Strategy and Marketing Capability

Contract manufacturing exporters (CMEs) receive a meagre share of global value chain returns, primarily because of the mundane and exploitative nature of the activities they perform in their dependency relationships with lead firms. We posit that CMEs can enhance their performance by capitalizing on their exploitation strategy. Exploitation strategy triggers exploration strategy which requires building marketing capabilities for enhanced performance. Based on data from 154 Vietnamese CMEs, we find significant indirect only mediation effects of: 1) exploration strategy between exploitation strategy and export performance; and 2) marketing capability between exploration strategy and export performance. Further, we find significant indirect only serial mediation of exploration strategy and marketing capability between exploitation strategy and export performance. The findings are also supported and contextualized based on illustrative quotes from face to face semi-structured interviews with senior managers of 10 Vietnamese CMEs. The findings suggest that CMEs' that consciously capitalize on the exploitation strategy by seeking exploration opportunities while building their marketing capability exhibit enhanced performance.     

Effects of Partnership Quality,Talent Management,and Global Mindset on Performance of Offshore IT Service Providers in India

This paper investigates the effects of partnership quality, talent management and global mindset on the performance of offshore service providers (OSPs) in the information technology sector in India. The findings show that partnership quality has partial and strong mediation effects on the impact of talent management and global mindset on performance of OSPs. We also find that talent management strongly mediates the effects of global mindset on partnership quality. Overall, the results confirm that global mindset, by itself, has limited direct influence on the performance of OSPs and that the full benefits of global mindset can only be enjoyed by OSPs which have well developed talent management and high quality partnerships with their clients. The implications and limitations of the study are also discussed.     

Calibration Approach-based Product Estimator of Finite Population Total with Subsampling of Nonrespondents under Single and Two-phase Sampling

Hansen and Hurwitz (1946) technique–based estimator of population total is proposed using the calibration approach under the assumption that the auxiliary variable is negatively correlated with the study variable. The variance estimation is also considered. The two-phase sampling case is also explored. The theoretical results are demonstrated through empirical studies using both generated and real population data. The proposed estimator of population total outperforms the existing estimators in terms of the criteria of relative bias and relative root mean square error.     

Less than Human? Diaspora,Disease and the Question of Citizenship

The aim of this special edition of International Migration is to bring about discussion between those conducting research in Diaspora Studies and the Anthropology of Public Health and Medicine. Historically, international migration has been associated with the transport of disease. Regardless of the evidence, metaphors of plague, and infection have circulated and been used to marginalise and keep out diaspora communities in host countries in an effort to ‘exclude filth’. Migrants have been referred to in terms such as the ‘Asiatic menace’ indicating a virus‐like threat to local populations. We look at the impact the traces of these images have on current host nations’ perceptions of diaspora communities and also ask what impact does this have on the diasporic communities’ self‐perceptions, if any? Does this affect conceptions of belonging, or feed into continuing dialogues of displacement? The movement of people has long been associated with the spread of disease and infections. In light of this, we are concerned with the role of medical knowledge and practices in relation to diaspora communities, and how these discourses have contributed to the perception of diaspora populations by host societies, and helped shape wider questions of belonging and citizenship. We aim to look at these questions in their historical context, both in their continuities and discontinuities, emphasising the importance of this to an understanding of current practices. Circuits of migration, and connected medical practices are taking new forms, where, on the one hand migrants are still associated with disease and pollution, but on the other migrants are also increasingly staffing the infrastructure of western public health services. At the same time, the west can no longer lay claim to ‘superior’ biomedical provision. These shifts signal new directions in the relationship between medical discourse and diasporic ‘others’, giving rise to a contradictory language of migrants being seen as both a threat, and a solution to the ‘health of the nation’.     

Natural cubic splines for the analysis of Alzheimer's clinical trials

Mixed model repeated measures (MMRM) is the most common analysis approach used in clinical trials for Alzheimer's disease and other progressive diseases measured with continuous outcomes over time. The model treats time as a categorical variable, which allows an unconstrained estimate of the mean for each study visit in each randomized group. Categorizing time in this way can be problematic when assessments occur off-schedule, as including off-schedule visits can induce bias, and excluding them ignores valuable information and violates the intention to treat principle. This problem has been exacerbated by clinical trial visits which have been delayed due to the COVID19 pandemic. As an alternative to MMRM, we propose a constrained longitudinal data analysis with natural cubic splines that treats time as continuous and uses test version effects to model the mean over time. Compared to categorical-time models like MMRM and models that assume a proportional treatment effect, the spline model is shown to be more parsimonious and precise in real clinical trial datasets, and has better power and Type I error in a variety of simulation scenarios.     

The Manufacturer's Incentive to Reduce Lead Times

Although, ceteris paribus, reducing lead times may be desirable from an overall system perspective, an upstream party (e.g., a manufacturer) may have strong disincentives to offer shorter lead times, even if this came at no cost. We consider a setting in which the downstream party has the ability to exert a costly effort to increase demand (e.g., through sales promotions, advertising, etc.) during the selling season, and compare two situations: one where there is zero lead time (i.e., all demand can be satisfied after observing the demand realization), and one where orders need to be made before demand is realized. We identify two interacting effects that may inhibit shorter lead times. A so‐called “safety stock effect” can be observed when a lower risk of stocking out under short lead times induces the downstream party to alter her order quantity. A second effect, termed as “effort effect,” arises if shorter lead times impact the downstream party's optimal sales effort, and, as a consequence, lead to different order quantities. We provide a formal characterization of both effects, insight into how these effects interact, and show under which conditions the manufacturer has an incentive to offer shorter lead times.