Research summary: Researchers have increasingly emphasized the need to better understand how context affects the value of experiential learning. We address this gap by investigating when ...corporate-level experience ca be leveraged across borders and when experience needs to be country-specific to be valuable. We test our hypotheses using a unique multi-source panel dataset of 379 large MNCs from 29 home countries and their subsidiaries in 117 host countries over a 10-year period, 1999–2008. In contrast to prior research, we find that the ability of a firm to leverage its experience with political risk across borders is limited by the type of risk involved. Experience with nonstate violent conflicts may be transferrable, but only country-specific experience appears to yield measureable benefits for conflicts involving the host country government. Managerial summary: Violent conflicts not only increase social unrest but also impose added costs of doing business. For managers who find themselves in the midst of violent conflicts or who wish to survive and potentially gain a competitive advantage in operating in such challenging environments, is it possible to learn to manage such a seemingly "unmanageable" problem? In contrast to studies that have examined other types of political risk, we find that the ability of a firm to leverage its experience with violent conflict risk across borders is limited. Specifically, only country-specific experiential knowledge about how the host government prepares and manages such conflict risks yields measureable economic benefits for MNCs and their subsidiaries operating in countries during conflict.
Non-Darcy flows are a vital event leading to the inaccuracy in flow performance evaluation, particularly in the fractured wells in shale gas and tight oil deposits. The internal flow commonly ...indicates high flow rates at the early period of production, owing to the large geometric size of hydraulic fracture and high porosity in proppant packs. After that, the production flow rate decays steeply until the Darcy flow regime is attained. Therefore, accurate porous flow analyses from the Darcy to Forchheimer and then turbulent flow regimes are essential for optimal facility designs and economic productions in the unconventional deposits. The Comiti capillary model is recognised as the leading non-Darcy flow correlation for simple packed beds comprising mono-size grains. However, in actual hydraulic fractures, various types of proppants are used simultaneously and generally combined with numerous soil grains of different sizes and shapes. In this study, the Comiti model is modified by incorporating the effective diameters of the porous media and then examined for mixed complex multi-size packs. Subsequently, a novel type of non-Darcy flow equation is presented according to the logarithmic turbulent friction factor based on the physical variables determined only in the Darcy flow regime. The new equation presents accurate results for all the types of proppant packs under wide porosity and permeability ranges. The generalised non-Darcy flow correlation, which can be extensively employed from the Darcy to non-Darcy flow analyses, particularly beyond the Forchheimer regime, is presented for the accurate flow evaluation of the fractured reservoirs.
Retinoic acid (RA), a well-known vitamin A metabolite, mediates inhibition of the IL-6-driven induction of proinflammatory Th17 cells and promotes anti-inflammatory regulatory T cell generation in ...the presence of TGF-beta, which is mainly regulated by dendritic cells. To directly address the role of RA in Th17/regulatory T cell generation in vivo, we generated vitamin A-deficient (VAD) mice by continuous feeding of a VAD diet beginning in gestation. We found that a VAD diet resulted in significant inhibition of Th17 cell differentiation in the small intestine lamina propria by as early as age 5 wk. Furthermore, this diet resulted in low mRNA expression levels of IL-17, IFN regulatory factor 4, IL-21, IL-22, and IL-23 without alteration of other genes, such as RORgammat, TGF-beta, IL-6, IL-25, and IL-27 in the small intestine ileum. In vitro results of enhanced Th17 induction by VAD dendritic cells did not mirror in vivo results, suggesting the existence of other regulation factors. Interestingly, the VAD diet elicited high levels of mucin MUC2 by goblet cell hyperplasia and subsequently reduced gut microbiome, including segmented filamentous bacteria. Much like wild-type mice, the VAD diet-fed MyD88-/-TRIF-/- mice had significantly fewer IL-17-secreting CD4+ T cells than the control diet-fed MyD88-/-TRIF-/- mice. The results strongly suggest that RA deficiency altered gut microbiome, which in turn inhibited Th17 differentiation in the small intestine lamina propria.
Network analysis to examine infectious contact relations provides an important means to uncover the topologies of individual infectious contact networks. This study aims to investigate the spread of ...diseases among individuals over contact networks by exploring the 2015 Middle East Respiratory Syndrome (MERS) outbreak in Korea. We present several distinct features of MERS transmission by employing a comprehensive approach in network research to examine both the traced relationship matrix of infected individuals and their bipartite transmission routes among healthcare facilities visited for treatment. The results indicate that a few super-spreaders were more likely to hold certain structural advantages by linking to an exceptional number of other individuals, causing several ongoing transmission events in neighbourhoods without the aid of any intermediary. Thus, the infectious contact network exhibited small-world dynamics characterised by locally clustered contacts exposed to transmission paths via short path lengths. In addition, nosocomial infection analysis shows the pattern of a common-source outbreak followed by secondary person-to-person transmission of the disease. Based on the results, we suggest policy implications related to the redesign of prevention and control strategies against the spread of epidemics.
Nanocrystalline Pb films prepared by reducing PbO2 precursors have up to 700-fold lower H+ reduction activity than polycrystalline Pb foil electrodes but maintain the ability to reduce CO2. As a ...result, these “oxide-derived” Pb (OD–Pb) electrodes have higher Faradaic efficiency for CO2 reduction to HCO2 – in aqueous solutions with almost no competitive H+ reduction. Even with very low CO2 concentrations in N2-saturated NaHCO3 solution, OD–Pb converts CO2 derived from HCO3 – decomposition to HCO2 – with almost quantitative Faradaic efficiency while Pb foil has less than 10% efficiency. Electrokinetic data suggest that the difference in selectivity between the two electrodes is caused by a difference in the coverage of a surface layerlikely a metastable Pb oxidethat is passivating for H+ reduction but active for CO2 reduction.
Background. The advent of macrolides has led to therapeutic advances in the treatment of Mycobacterium avium complex lung disease (MAC-LD). The aim of this study was to elucidate the treatment ...outcomes of macrolide-containing regimens. Methods. We performed a systematic review and meta-analysis of published studies reporting treatment outcomes of macrolide-containing regimens for MAC-LD using the Medline, Embase, and Cochrane Library databases through 31 July 2016. The rates of treatment success, default from treatment, and adverse events of macrolide-containing regimens were assessed. Treatment success was defined as either 12 months of sustained culture negativity while on therapy or achievement of culture conversion and completion of the planned treatment without relapse. Results. In total, 16 studies involving 1462 patients were included. The rate of treatment success was 60.0% (95% confidence interval CI, 55.1%–64.8%). The proportion of patients who defaulted from the treatment was 16.0% (95% CI, 12.3%–19.7%). When a thrice-weekly dosing schedule was available, the default rate was 12.0% (95% CI, 8.9%–15.0%). Adverse events necessitating treatment discontinuation or dosage modification of macrolides were observed in 6.4% of patients (95%, CI, 3.2%–9.5%), and decreased auditory acuity was the most common adverse event. Conclusions. Treatment outcomes of macrolide-containing regimens are relatively poor in terms of both the treatment success and default rates. The default rate could be reduced if a thrice-weekly dosing schedule is available. Clinicians should be aware of decreased auditory function as the most common adverse event associated with macrolide-containing regimens.
With an increasingly assertive China and the intensifying influence of the Sinocentre, Chinese overseas who have access to Chineseness can exercise their agentic power in using their cultural capital ...for economic gains. Beijing has recognised the potential for diasporic Chinese entrepreneurs to contribute to the Belt and Road Initiative (BRI) given their influence in Southeast Asia's economy. Correspondingly, these entrepreneurs hail the BRI as a strategic opportunity for them to turn their cultural capital into fiscal capital. Considering the increased global connectivity and new Chinese migration geographies led by the BRI, this article examines the case of Chinese business associations in Brunei Darussalam. The heterogenous responses of these ethnic Chinese and their associations to China and the BRI attest to the multiplicity and contestations of Chineseness based on different migration histories and sentiments to their ancestral land. We focus on the dynamics between the old Chinese Bruneian business elites and the more recent Chinese business migrants from Malaysia and China. An investigation of the cultural and economic politics within the Chinese Bruneian business community will provide insights into the modality of Chineseness as an economic asset that can be tactically used by diasporic Chinese entrepreneurs to maintain their social position and to respond to China's economic rise.
To gain the fundamental understanding of deformation mechanisms in an aluminum-containing austenitic high-Mn steel (Fe-32Mn-8.9Al-0.78 C (wt.%)), in-situ straining transmission electron microscopy ...(TEM) analysis is conducted. The in-situ observation during the deformation demonstrates that the plastic deformation is accommodated by the pronounced planar dislocation gliding followed by the formation of slip bands (SBs) and highly dense dislocation walls (HDDWs). Experimental evidences of the glide plane softening can be obtained from the interaction between the gliding perfect dislocations and the L'1
ordered precipitates in the austenite matrix. Furthermore, the observation of the localized cross-slip of dislocations at the slip band intersections enables to understand why slip bands are extensively developed without mutual obstructions between the slip bands. The enhanced strain hardening rate of the aluminum-containing austenitic high-Mn steels can be attributed to the pronounced planar dislocation glides followed by formation of extensive slip band which prevent premature failure by suppressing strain localization.
A large body of molecular and neurophysiological evidence connects synaptic plasticity to specific functions and energy metabolism in particular areas of the brain. Furthermore, altered plasticity ...and energy regulation has been associated with a number of neuropsychiatric disorders. A favourable approach enabling the modulation of neuronal excitability and energy in humans is to stimulate the brain using transcranial direct current stimulation (tDCS) and then to observe the effect on neurometabolites using magnetic resonance spectroscopy (MRS). In this way, a well‐defined modulation of brain energy and excitability can be achieved using a dedicated tDCS protocol to a predetermined brain region. This systematic review was guided by the preferred reporting items for systematic reviews and meta‐analysis and summarises recent literature studying the effect of tDCS on neurometabolites in the human brain as measured by proton or phosphorus MRS. Limitations and recommendations are discussed for future research. The findings of this review provide clear evidence for the potential of using tDCS and MRS to examine and understand the effect of neurometabolites in the in vivo human brain.
This review aims to provide useful guidance for potential investigators. Based on the studies identified, we explore previous efforts to unravel the transcranial direct current stimulation (tDCS) action mechanisms on the central nervous system. The findings are highlighted, along with the limitations and proposed recommendations for future research.
A series of Fe-30 wt%Mn-10.5 wt%Al-1.1 wt%C steels with Mo addition from 0 to 5 wt% were prepared to investigate the effect of Mo on the microstructure and tensile deformation behavior of austenitic ...lightweight steel. When the Mo content was below 4 wt%, the microstructure of solution-treated samples consisted of austenite and κ–carbide, while Mo-enriched M6C and M23C6 carbides were additionally precipitated in samples containing Mo more than 4 wt% during a solution treatment at 1050 °C. These carbides inhibited austenite grain growth during the solution treatment, resulting in significant grain refinement in the samples containing more that 4 wt% of Mo. Tensile test results showed that the yield strength gradually decreased with an increase in the Mo content up to 3 wt% due to the suppression of κ–carbide precipitation, whereas it significantly increased when the Mo content exceeded 4 wt% due to grain refinement and precipitation strengthening caused by Mo-enriched carbides. During the tensile deformation, the strain hardening rates of all alloys increased and then the deformation mode subsequently changed with an increase in the Mo content from shearband-induced plasticity (SIP) to microband-induced plasticity (MBIP). Finally, the change in the κ-carbide precipitation behavior upon the addition of Mo and its effect on the deformation behavior were carefully analyzed and discussed through nanoindentation experiments, first-principles calculations and atom probe tomography analyses.
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