We examine how interorganizational networks evolved after a disaster with an integrated approach that combines both social network perspectives and emergency management perspectives. This research ...describes changes in organizations that play a bridging role in interorganizational collaboration and examines endogenous and exogenous factors that lead organizations to be isolated during a disaster. Building from the Institutional Collective Action (ICA) framework, we argue that organizations that play the bridging role between two other organizations may fail to sustain their ties after a disaster. Because the bridging strategy involves risks, organizations are more likely to forge direct ties to other organizations that have resources they need rather than rely on bridges that they created before the disaster. We apply a stochastic actor-oriented model to show the dynamics of emergency management networks during the 2013 Seoul floods. This study contributes to understanding how the bridging strategy can be emasculated by endogenous and exogenous factors.
Joint modelling of genetic and environmental risk factors can provide important information to predict the risk of type 2 diabetes (T2D). Therefore, to predict the genetic risk of T2D, we constructed ...a polygenic risk score (PRS) using genotype data of one Korean cohort, KARE (745 cases and 2549 controls), and the genome-wide association study summary statistics of Biobank Japan. We evaluated the performance of PRS in an independent Korean cohort, HEXA (5684 cases and 35,703 controls). Individuals with T2D had a significantly higher mean PRS than controls (0.492 vs. - 0.078, p
). PRS predicted the risk of T2D with an AUC of 0.658 (95% CI 0.651-0.666). We also evaluated interaction between PRS and waist circumference (WC) in the HEXA cohort. PRS exhibited a significant sub-multiplicative interaction with WC (OR
0.991, 95% CI 0.987-0.995, p
= 4.93 × 10
) in T2D. The effect of WC on T2D decreased as PRS increased. The sex-specific analyses produced similar interaction results, revealing a decreased WC effect on T2D as the PRS increased. In conclusion, the risk of WC for T2D may differ depending on PRS and those with a high PRS might develop T2D with a lower WC threshold. Our findings are expected to improve risk prediction for T2D and facilitate the identification of individuals at an increased risk of T2D.
We present a new statistical test of association between a trait and genetic markers, which we theoretically and practically prove to be robust to arbitrarily complex population structure. The ...statistical test involves a set of parameters that can be directly estimated from large-scale genotyping data, such as those measured in genome-wide association studies (GWAS). We also derive a new set of methodologies, called a 'genotype-conditional association test' (GCAT), shown to provide accurate association tests in populations with complex structures, manifested in both the genetic and non-genetic contributions to the trait. We demonstrate the proposed method on a large simulation study and on the Northern Finland Birth Cohort study. In the Finland study, we identify several new significant loci that other methods do not detect. Our proposed framework provides a substantially different approach to the problem from existing methods, such as the linear mixed-model and principal-component approaches.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SBMB, UILJ, UKNU, UL, UM, UPUK
This paper elaborates the concept of collaboration risk and measures collaboration risk in an emergency management context to investigate the relations between perceived collaboration risks and ...network structure and to test a hypothesized non-linear form for this relation. Using an Institutional Collective Action (ICA) framework, the study discusses three dimensions of collaborative risk derived from coordination, division, and defection risk and measures these by means of a structured-survey of 69 organizations in the Seoul Metropolitan Area, South Korea. The results of a fractional polynomial regression model show that the perceived level of collaboration risk has an inverse U-curve relation with the number of collaborative ties forged by organizations. These findings imply that organizations' perceived collaboration risk beyond a threshold point motivates the termination of former ineffective arrangements. At the same time, the collaboration with other participants increases to a specific level of collaboration risk.
The study investigates the effect of embeddedness, defined as a property of interdependent relations in which organizations are integrated in a network, on collaboration risk emerging from relational ...uncertainty. Despite efforts to understand the structural effects of network governance, embedded relationships and their influence on collaboration remain relatively unexplored. A case of intergovernmental collaboration for emergency management is used as a test bed to examine the role of embeddedness in disaster networks and to extend the knowledge of collaboration risk within the institutional collective action framework. We hypothesize and test the effect of relational and structural embeddedness on the level of collaboration risk that an organization perceives. Our analysis of 69 organizations engaged in emergency management operations in the Seoul Metropolitan Area, South Korea reveals that both structural and relational embeddedness facilitate organizations to mitigate perceived collaboration risk. The results suggest that reachability secures relief of relational risk, and that commitment relationships bind participants.
Confounding caused by latent population structure in genome‐wide association studies has been a big concern despite the success of genome‐wide association studies at identifying genetic variants ...associated with complex diseases. In particular, because of the growing interest in association mapping using count phenotype data, it would be interesting to develop a testing framework for genetic associations that is immune to population structure when phenotype data consist of count measurements. Here, I propose a solution for testing associations between single nucleotide polymorphisms and a count phenotype in the presence of an arbitrary population structure. I consider a classical range of models for count phenotype data. Under these models, a unified test for genetic associations that protects against confounding was derived. An algorithm was developed to efficiently estimate the parameters that are required to fit the proposed model. I illustrate the proposed approach using simulation studies and an empirical study. Both simulated and real‐data examples suggest that the proposed method successfully corrects population structure.
Disaster scholars have investigated the nature of organizational resilience, but extant research has not examined various network strategies within hierarchical and horizontal collaboration ...structures. The question of how the structural arrangements for collaboration within emergency management networks influence disaster resilience remains unanswered. This study begins to fill this lacuna by analyzing a bonding and bridging strategy for interorganizational collaboration to determine how these patterns of organizational relations might enhance the level of organizational resilience in each hierarchical and horizontal emergency management network. Bonding strategies highlight the importance of trust and information redundancy to emergency preparedness and response. Bridging strategies capture the tendency for local actors to seek partners to obtain crucial information and resources across the region. The results support the study hypothesis that bridging strategies in hierarchical emergency management networks have a positive effect on the level of organizational resilience. Neither type of network strategy influenced resilience in horizontal network structures. The findings confirm that the coordinating role of the national and provincial governments is critical to the building of a resilient community in terms of interorganizational collaboration, and demonstrate the steering role of the national and provincial governments with regard to resilience.
This paper examines the actions and the factors driving those actions to reduce energy consumption and enhance energy efficiency taken by United States cities. While not much empirical evidence is ...available on why governments pursue practical sustainability actions, we attempt to shed more light on this important topic by empirically identifying factors that contribute to concrete actions toward sustainability policies. We adopt political market theory as a basic theoretical framework with policy-making applied to city energy consumption. Using the 2010 ICMA (local government sustainability policies and program) data, this study expands the focus of analyses to evaluate the effect of the form of government on energy consumption and energy efficiency by using multiple regression analysis. The findings show that at the city level, the mayor- council form of government are negatively associated with governments’ efforts to reduce energy consumption. However, cities with at-large elections and municipal ownership are more likely to adopt sustainability actions. We also find that a large-scale economy has significant effects on the effort to reduce city energy consumption and improve energy efficiency. This shows that environmental policies are directly connected to locally relevant affairs, including housing, energy use, green transportation, and water. Thus, local level administrators could take an executive role to protect the environment, encourage the development of alternative energy, and reduce the use of fossil fuel and coal energy. These efforts can lead to important environmental ramifications and relevant actions by municipal governments.
The selective cell separation is a critical step in fundamental life sciences, translational medicine, biotechnology, and energy harvesting. Conventional cell separation methods are fluorescent ...activated cell sorting and magnetic-activated cell sorting based on fluorescent probes and magnetic particles on cell surfaces. Label-free cell separation methods such as Raman-activated cell sorting, electro-physiologically activated cell sorting, dielectric-activated cell sorting, or inertial microfluidic cell sorting are, however, limited when separating cells of the same kind or cells with similar sizes and dielectric properties, as well as similar electrophysiological phenotypes. Here we report a label-free density difference amplification-based cell sorting (dDACS) without using any external optical, magnetic, electrical forces, or fluidic activations. The conceptual microfluidic design consists of an inlet, hydraulic jump cavity, and multiple outlets. Incoming particles experience gravity, buoyancy, and drag forces in the separation chamber. The height and distance that each particle can reach in the chamber are different and depend on its density, thus allowing for the separation of particles into multiple outlets. The separation behavior of the particles, based on the ratio of the channel heights of the inlet and chamber and Reynolds number has been systematically studied. Numerical simulation reveals that the difference between the heights of only lighter particles with densities close to that of water increases with increasing the ratio of the channel heights, while decreasing Reynolds number can amplify the difference in the heights between the particles considered irrespective of their densities.
Unpredicted disasters obstruct the operation of a well-functioning network, but such a network should be resistant to the challenges of such disasters to provide successful responses. This study aims ...to investigate the effect of a strong commitment driven by drills on building sustainable emergency management networks during disasters. The logic of collaboration risk is embedded in the collective action dilemma; therefore, building a strong commitment is important. On the basis of an Emergency Medicine survey done in 2012 and 2013 in the Southeastern Economic Regions of Korea, the relation between strong commitment and network arrangements was examined using the Logistic Regression Quadratic Assignment Procedure analysis. The results of this study show that higher levels of strong commitment driven by exercises are more likely to result in sustainable ties. This implies that beyond the interest of creating planning networks, the means of reinforcing the degree of commitment among members of networks, such as drills, must be developed.
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