The SARS-CoV-2 virus emerged in December 2019 and has caused a worldwide pandemic due to the lack of any pre-existing immunity. Accurate serology testing is urgently needed to help diagnose ...infection, determine past exposure of populations and assess the response to a future vaccine. The landscape of antibody responses to SARS-CoV-2 is unknown. In this study, we utilized the luciferase immunoprecipitation system to assess the antibody responses to 15 different SARS-CoV-2 antigens in patients with COVID-19. We identified new targets of the immune response to SARS-CoV-2 and show that nucleocapsid, open reading frame (ORF)8 and ORF3b elicit the strongest specific antibody responses. ORF8 and ORF3b antibodies, taken together as a cluster of points, identified 96.5% of COVID-19 samples at early and late time points of disease with 99.5% specificity. Our findings could be used to develop second-generation diagnostic tests to improve serological assays for COVID-19 and are important in understanding pathogenicity.
We investigated 68 respiratory specimens from 35 coronavirus disease patients in Hong Kong, of whom 32 had mild disease. We found that severe acute respiratory syndrome coronavirus 2 and subgenomic ...RNA were rarely detectable beyond 8 days after onset of illness. However, virus RNA was detectable for many weeks by reverse transcription PCR.
This article reviews the rapidly growing domain of global value chain (GVC) research by analyzing several highly cited conceptual frameworks and then appraising GVC studies published in such ...disciplines as international business, general management, supply chain management, operations management, economic geography, regional and development studies, and international political economy. Building on GVC conceptual frameworks, we conducted the review based on a comparative institutional perspective that encompasses critical governance issues at the micro-, GVC, and macro-levels. Our results indicate that some of these issues have garnered significantly more scholarly attention than others. We suggest several future research topics such as microfoundations of GVC governance, GVC mapping, learning, impact of lead firm ownership and strategy, dynamics of GVC arrangements, value creation and distribution, financialization, digitization, the impact of renewed protectionism, the impact of GVCs on their macro-environment, and chain-level performance management.
The idea that entrepreneurial opportunities exist "out there" is increasingly under attack by scholars who argue that opportunities do not preexist objectively but are actively created through ...subjective processes of social construction. In this article we concede many of the criticisms pioneered by the creation approach but resist abandoning the preexisting reality of opportunities. Instead, we use realist philosophy of science to ontologically rehabilitate the objectivity of entrepreneurial opportunities by elucidating their propensity mode of existence. Our realist perspective offers an intuitive and paradox-free understanding of what it means for opportunities to exist objectively. This renewed understanding enables us to (1) explain that the subjectivities of the process of opportunity actualization do not contradict the objective existence of opportunities, (2) acknowledge the category of agency-intensive opportunites, (3) develop the notion of "nonopportunity," and (4) clarify the ways individuals might make cognitive contact with opportunities prior to their actualization. Our actualization approach serves as a refined metatheory for guiding future entrepreneurship research and facilitates the revisiting of subtle conceptual issues at the core of entrepreneurial theory, such as the nature of uncertainty and "nonentrepreneurs," as well as the role played by prediction in a scientific study of entrepreneurship.
The case study as a key research method has often been criticized for generating results that are less generalizable than those of large‐sample, quantitative methods. This paper clearly defines ...generalization and distinguishes it from other related concepts. Drawing on the literature, the author shows that case study results may be less generalizable than those of quantitative methods only in the case of within‐population generalization. The author argues that case studies have merits over quantitative methods in terms of theoretical generalization, identifying disconfirming cases and providing useful information for assessing the empirical generalizability of results.
Recent research suggests that the distance between countries in terms of culture, institutions, geographic proximity, and economic development matters in the foreign direct investment (FDI) decisions ...made by firms. This study focuses on the historical ties between countries as an additional factor affecting such decisions. In particular, it examines three major historical factors that affect cross-country ties with Vietnam, namely, Chinese occupation and conflict, French colonization, and socialist ideology, and examines the ways in which these historical ties have influenced FDI. The database consists of 631 wholly owned subsidiaries and 1215 joint ventures formed in Vietnam by multinational enterprises from 35 countries and regions between 1989 and 1999. The results indicate that firms from Hong Kong, Taiwan, France, and former and current socialist countries tended to be early movers in Vietnam, whereas firms from Mainland China tended to be late movers. Using the example of Vietnam, this study clearly shows that historical ties can provide additional explanatory power regarding FDI decisions beyond the conventional distance variables.
Background
The coronavirus disease 2019 (COVID-19) pandemic is having a profound impact on the health and development of children worldwide. There is limited evidence on the impact of COVID-19 and ...its related school closures and disease-containment measures on the psychosocial wellbeing of children; little research has been done on the characteristics of vulnerable groups and factors that promote resilience.
Methods
We conducted a large-scale cross-sectional population study of Hong Kong families with children aged 2–12 years. Parents completed an online survey on family demographics, child psychosocial wellbeing, functioning and lifestyle habits, parent–child interactions, and parental stress during school closures due to COVID-19. We used simple and multiple linear regression analyses to explore factors associated with child psychosocial problems and parental stress during the pandemic.
Results
The study included 29,202 individual families; of which 12,163 had children aged 2–5 years and 17,029 had children aged 6–12 years. The risk of child psychosocial problems was higher in children with special educational needs, and/or acute or chronic disease, mothers with mental illness, single-parent families, and low-income families. Delayed bedtime and/or inadequate sleep or exercise duration, extended use of electronic devices were associated with significantly higher parental stress and more psychosocial problems among pre-schoolers.
Conclusions
This study identifies vulnerable groups of children and highlights the importance of strengthening family coherence, adequate sleep and exercise, and responsible use of electronic devices in promoting psychosocial wellbeing during the COVID-19 pandemic.
Many papers have been published recently in the fields of strategy and international business research incorporating the role of organizational knowledge as a basis of firm competitive advantage. ...While such knowledge is normally developed within the firm, it is important that firms possess the ability to learn from others in order to meet the increasing pace of competition. Knowledge transfer, defined here as an event through which one organization learns from the experience of another, has thus become an important research area within the broader domain of organizational learning and knowledge management. This paper presents a theoretical framework, identifies key themes covered by the six articles included in the Special Issue on Inter‐Organizational Knowledge Transfer, and then discusses priorities for future research.
The human placenta is a dynamic and heterogeneous organ critical in the establishment of the fetomaternal interface and the maintenance of gestational well-being. It is also the major source of ...cell-free fetal nucleic acids in the maternal circulation. Placental dysfunction contributes to significant complications, such as preeclampsia, a potentially lethal hypertensive disorder during pregnancy. Previous studies have identified significant changes in the expression profiles of preeclamptic placentas using whole-tissue analysis. Moreover, studies have shown increased levels of targeted RNA transcripts, overall and placental contributions in maternal cell-free nucleic acids during pregnancy progression and gestational complications, but it remains infeasible to noninvasively delineate placental cellular dynamics and dysfunction at the cellular level using maternal cell-free nucleic acid analysis. In this study, we addressed this issue by first dissecting the cellular heterogeneity of the human placenta and defined individual cell-type–specific gene signatures by analyzing more than 24,000 nonmarker selected cells from full-term and early preeclamptic placentas using large-scale microfluidic single-cell transcriptomic technology. Our dataset identified diverse cellular subtypes in the human placenta and enabled reconstruction of the trophoblast differentiation trajectory. Through integrative analysis with maternal plasma cell-free RNA, we resolved the longitudinal cellular dynamics of hematopoietic and placental cells in pregnancy progression. Furthermore, we were able to noninvasively uncover the cellular dysfunction of extravillous trophoblasts in early preeclamptic placentas. Our work showed the potential of integrating transcriptomic information derived from single cells into the interpretation of cell-free plasma RNA, enabling the noninvasive elucidation of cellular dynamics in complex pathological conditions.
The challenges firms face increase with their product diversification levels because different product markets possess different sociopolitical issues. We argue that secondary stakeholders, as ...represented by various nonprofit or non-governmental organizations, serve as agents mitigating the external constraints embedded within sociopolitical environments. Firms should therefore maintain relationships with different secondary stakeholder scopes commensurate with their product diversification levels in order to enhance financial performance. Analyzing a sample of U.S. Fortune 500 firms during the period from 1996 to 2003, we found that secondary stakeholders play a positive moderating role in the relationship between product diversification and financial performance. Furthermore, this moderating effect was stronger in the case of unrelated diversification than in related diversification.
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