Disruptive Events Research Articles

A challenge to identity: Identity processing style and moral injury.

Moral injury is a potentially deleterious mental health outcome that can result from exposure to morally challenging events. Treatment of moral injury is currently hindered by incomplete understanding of its underlying mechanisms. Theories of adaptation posit that maintaining a coherent sense of self while realigning one's sense of self with reality aids in adaptation following a disruptive life event. Differences in identity processing style are thought to impact the extent to which an individual engages with the challenges of maintaining a coherent sense of self following identity-related challenges. However, little is known about how identity processing style relates to moral injury event-related distress. This study sought to investigate a hypothesized relationship between identity processing style and event-related distress as well as alternative outcomes including traumatic stress, depression and anxiety. Adults (N = 167) who had been exposed to a potentially morally injurious event were recruited online and completed validated measures of event-related distress, traumatic stress, depression, anxiety and identity processing style. There were significant positive associations between diffuse-avoidant processing and all mental health outcomes, no significant associations between informational processing and any mental health outcomes, and significant negative associations between normative processing and event-related distress and depression.

Network-based method for assessing multi-modal transportation network vulnerability to cascading failures

Transportation systems are vulnerable to disruptive events such as natural disasters, industrial accidents, terrorist attacks, and climate change. Vulnerability assessment is necessary to understand the impacts of these disruptive events, identify underlying deficiencies within the network, and improve transportation system resilience. Multi-modal transportation networks are often interdependent and form a “system of systems”, which creates a susceptibility to cascading indirect impacts within the integrated transportation network. Accurately modeling these interdependencies typically requires a large amount of data, such as traffic flow and travel demand information for transportation systems, which may not be available or accessible. This paper proposes a network topology-based framework to conduct an interdependent transportation network vulnerability analysis by introducing an algorithm to simulate cascading failures across transport systems. The proposed framework estimates the vulnerability of the network with respect to a specific hazard, combining the network topology and the functional attributes of the transportation infrastructure components. A case study with real-world data is conducted to demonstrate the applicability of the framework to the Houston freight transportation network, and to understand the network performance under different scenarios. This study presents an alternate method that stakeholders may use to assess interdependent transportation network vulnerability when more detailed flow-based data is not available.

(Post-)pandemic Somatechnics, Neoliberalism, and the Return to (Academic) Normalcy: Digital Conversations

This essay consists of a set of digital (post-)pandemic email correspondence held between a political sociologist and an interdisciplinary philosopher working at western European universities while the COVID-19 pandemic rapidly unfolded itself. Starting from an unsettling point in time in 2021, during which vaccination strategies and numerous eugenic pandemic containment measures were being discussed, the authors touch upon issues as diverse as the importance of embodied feminist theorising in pandemic crisis times; neoliberal extractive capitalism’s influence on society, pandemic (mis)management, and higher education; the problematic (post-)pandemic business-as-usual-narrative; grief, mourning, and trauma; the power of anger and protesting; and the forced return to normal(cy). These conversations are held together by an irruptions-based methodology based on Deleuze and Guattari (2000) . This methodology tries to make sense of the (post-)pandemic as a disruptive event while forming the backdrop for conversational and critical theoretical snippets, self-designed memes, and critical race, queer, disability, and feminist theoretical perspectives that all conceptualise (post-)pandemic somatechnics as a ‘form of ethico-political critical practice’ ( Sullivan and Murray 2011 : vii).

Mid-infrared Variability in Nearby Galaxies from the MaNGA Sample

We use mid-infrared variability in galaxies to search for active galactic nuclei (AGN) in the local universe. We use a sample of 10,220 galaxies from the Mapping Nearby Galaxies at Apache Point Observatory survey, part of the Sloan Digital Sky Survey. For each galaxy, we examine its mid-infrared variability in the W2 [4.6 μm] band over 13 years using data from the Wide Infrared Survey Explorer (WISE) All-Sky and Near Earth Objects WISE missions. We demonstrate that we can detect variability signatures as small as about 7% in the rms variation of W2 flux for the majority of cases. Using other AGN signatures of the variable galaxies, such as optical narrow lines, optical broad lines, and WISE W1 − W2 colors, we show that ∼75% of the variables show these additional AGN signatures, indicating that the bulk of these cases are likely to be AGN. We also identify seven galaxies that have light curves characteristic of tidal disruption events. We present here a publicly available catalog of the light-curve variability in W2 of these galaxies.

Simulations of the Collision between a Debris Stream and an Outer Dusty Torus: A Possible Channel for Forming a Fast-rise and Long-delay Radio Outburst in Tidal Disruption Events

A geometrically thick dusty torus structure is believed to exist in the nuclear regions of galaxies (especially in active galactic nuclei). The debris stream from a tidal disruption event (TDE) will possibly collide with the dusty torus and produce a transient flare. We perform three-dimensional hydrodynamic simulations to model the dynamical evolution of the interaction between unbound debris and a dusty torus. During the continuous interaction, shocked material will be spilled out from the interaction region and form an outflow. We calculate the temporal evolution of synchrotron emission by assuming that the shock accelerates a fraction of electrons in the outflow into a nonthermal distribution. We find that radio emission from the debris–torus collision generates a steep-rise and slow-decline radio light curve due to the sharp edge and dense gas of the dusty torus, where the radio outburst is delayed relative to the main optical/X-ray outburst by several years or even several tens of years. We apply our model to a TDE that happened in a narrow-line Seyfert I galaxy (PS16dtm), where both the radio spectrum and the light curve can be roughly reproduced. Future high-sensitivity, wide-field-of-view radio surveys have the opportunity to detect more such radio flares.

Managing sudden unexpected disruptions in complex projects: the antifragility hierarchy

Projects are prone to a variety of sudden unexpected disruptions across their development cycle, requiring that effective organizations develop strategies for proactively recognizing disruption likelihood and swiftly responding to these events. This paper explores a hierarchy of responses to disruption, based on Taleb’s theory of antifragile system behavior. Following this reasoning, we suggest that when faced with project disruptions, organizations need to investigate the means to trigger a ‘convex’ response that increases value through antifragile thinking. We propose an ‘antifragility hierarchy’ in which three key responses to project disruption are demonstrated, with a range of strategies available for addressing these disruptions. This hierarchy offers a novel conceptualization of responses to project disruption events, suggesting that the options available to organizations range from robust (the least effective) to antifragile (the most constructive). Finally, we offer a set of strategies for effectively responding to disruptions to promote antifragility in projects.

Adaptive communication power control for enhancing attack resilience in UAV networks

A swarm of Unmanned Aerial Vehicles (UAVs) comprises multiple UAVs that are capable of completing tasks beyond the capabilities of a single UAV. Due to the unique challenges of UAV missions, these vehicles often operate far from base stations, making network connectivity crucial for the successful completion of UAV swarm missions. However, existing methods do not account for strategies to maintain the overall connectivity of the UAV network when nodes are under attack. To address this issue, we propose a method named Adaptive Communication Power Control (ACPC) that dynamically adjusts UAV communication power to mitigate potential connectivity losses caused by node failures or malicious attacks. This adjustment ensures that the network can maintain information exchange among the remaining UAVs even in the event of disruptions. Additionally, we introduce a novel evaluation method to assess the overall connectivity of the network and validate ACPC through simulations of UAV swarm missions where some UAVs experience failures. Using this evaluation method, we measured the network’s state before and after attacks and recovery and calculated the additional energy consumption required by the UAVs. The results indicate that our method can increase the resilience of the UAV network by up to 5.36 times, while only raising the total communication energy consumption to 1.53 times.

Near-Earth stream decoherence revisited: the limits of orbital similarity

Orbital similarity measures, such as the D values, have been extensively used in meteor science to identify meteoroid streams and associate meteorite falls with near-Earth objects (NEOs). However, the chaotic nature of near-Earth space challenges the long-term reliability of these measures for stream identification, and the increasing size of our fireball, meteorite fall, and NEO databases make random associations more common. Despite this, many researchers erroneously continue to use orbital similarity beyond its inherent limits. We aim to assess the statistical significance of using orbital similarity measures for identifying streams of meteoroids or asteroids and explore the implications of chaotic dynamics on the long-term coherence of these streams. We employed a kernel density estimation (KDE) based method to evaluate the statistical significance of orbital similarities within different datasets. Additionally, we conducted a Lyapunov characteristic lifetime analysis and simulated 300 fictitious meteoroid streams to estimate the decoherence lifetimes in near-Earth space. The orbital similarity was determined using the D$_ SH $, D', and D$_ H $ orbital similarity discriminants. Clustering analysis relied on a density-based spatial clustering of applications with noise (DBSCAN) algorithm. Our analysis found no statistically significant streams within the meteorite fall, fireball, or USG impact datasets, with orbital similarities consistent with random associations. Conversely, 12 statistically significant clusters were identified within the NEO population, likely resulting from tidal disruption events. The Lyapunov lifetime analysis revealed short characteristic lifetimes (60–200 years) for orbits in near-Earth space, emphasizing the rapid divergence of initially similar orbits. Meteoroid stream decoherence lifetimes ranged from $10^4$ to $10^5$ years, aligning with previous studies and underscoring the transient nature of such streams. The rapid decoherence of meteoroid streams and the chaotic dynamics of near-Earth orbits suggest that no reported stream or NEO associations of meteorites or fireballs are statistically significant according to orbital discriminates. Many are likely coincidental rather than indicative of a true physical link. However, several statistically significant clusters found within the NEO population are consistent with a tidal disruption formation. This contrast and lack of statistically significant associations amongst the impact datasets is likely due to the fireball databases being 2 orders of magnitude smaller than the NEO database and the higher intrinsic uncertainties of fireball observation derived orbits.

Ensuring continuity of care in times of crisis: A longitudinal analysis of dementia care delivery during armed conflict.

Individuals with dementia are particularly vulnerable during emergency situations due to challenges with cognition, mobility, and daily functioning. However, little is known about how disruptive events may specifically impact the health of those with dementia. To evaluate changes in health outcomes for individuals with and without dementia surrounding the Israel-Gaza war in October 2023. Specifically, we analyzed and compared changes in mental health status, medication adherence, healthcare service utilization, and associated costs between individuals with dementia (Study Group) and those without dementia (Control Group) during the period surrounding the Israel-Gaza war in October 2023. A prospective cohort study compared outcomes between individuals with dementia (Study Group, n = 24,178) and without (Control Group, n = 250,652) before and after the crisis onset. The conflict precipitously threw national systems into disarray, recruited healthcare personnel to the war effort, and disrupted supply chains. Compared to baseline, analysis revealed alterations in patterns of dementia diagnoses, healthcare service utilization, medication adherence, and associated costs during the crisis period for both groups. However, the Study Group experienced comparatively larger declines. Findings provide insights into how humanitarian emergencies, through disruption of health systems and care networks, differentially impact continuity of dementia care. This underscores the need for tailored crisis response strategies to address the heightened vulnerabilities of patients with dementia.

Environmental displacement and political instability: Evidence from Africa

Does environmental displacement provoke political instability? Though migration has long been considered an intermediary in the causal path between environmental change and political upheaval, the relationship remains theoretically underdeveloped and evidence has been limited. This article examines the impact of displacement caused by sudden-onset natural hazards on disruptive antigovernment events including armed conflict, protests and violent riots. It leverages the new Environmental Displacement Dataset (EnDis), an original dataset that identifies quantities of human movement in response to six types of sudden-onset natural hazards in Africa from 1990 to 2017, including floods, storms, wildfires, landslides, earthquakes and volcanic activity. The results of the analyses show that while environmental displacement is not associated with civil war onset or protests, it does increase the incidence of attacks by armed non-state actors and violent riots. Importantly, these destabilizing effects occurr primarily (1) in the context of displacement driven by floods and storms, and (2) when levels of displacement are well above average. Collectively, these findings portend deepening security crises and violent political upheaval as climate change drives more frequent episodes of extreme weather and excessive environmental displacement.

Understand your decision rather than your model prescription: Towards explainable deep learning approaches for commodity procurement

Hedging against price increases is particularly important in times of significant market uncertainty and price volatility. For commodity procuring firms, futures contracts are a widespread means of financially hedging price risks. Recently, digital data-driven decision-support approaches have been developed, with deep learning-based methods achieving outstanding results in capturing non-linear relationships between external features and price trends. Digital procurement systems leverage targeted purchasing decisions of these optimization models, yet the decision-mechanisms are opaque. We employ a prescriptive deep-learning approach modeling hedging decisions as a multi-label time series classification problem. We backtest the performance in two evaluation periods, i.e., 2018–2020 and 2021–2023, for natural gas, crude oil, nickel, and copper. The approach performs well in the first evaluation period of the testing framework yet fails to capture market disruptions (pandemic, geopolitical developments) in the second evaluation period, yielding significant hedging losses or degenerating into a simple hand-to-mouth procurement policy. We employ explainable artificial intelligence to analyze the performance for both periods. The results show that the models cannot handle market regime switches and disruptive events within the considered feature set.

A graph-empowered agent-based simulation: Impacts of coordination schemes on critical infrastructures resilience

Critical infrastructure systems are governed by several sectors working together to maintain social, economic, and environmental well-being. Their cyber–physical interdependencies influence their performance and resilience to routine failures and extreme events. To balance investment and restoration decisions in the face of disruptive events, mostly centralized mathematical formulations and solutions were presented in the literature. However, not all physical and dynamic characteristics of infrastructure systems and their decision makers can be modeled via mathematical models. In this study, we take a different approach and utilize agent-based modeling to simulate city-scale interdependent infrastructure networks as a complex adaptive system. In specific, we design a flexible modular (object-oriented) simulation tool capable of capturing the dynamic behaviors of various networks. We first model each infrastructure as a weighted graph with relevant geospatial attributes. Decision makers for each infrastructure sector are represented by intelligent agents. We then define three information and coordination schemes among agents, including no communication, leader–follower, and decentralized coalitions. To show the applicability of the approach, we use publicly available interdependent water distribution and road networks for the City of Tampa, FL, which is prone to hurricanes. We simulate different magnitudes of physical, cyber, and cyber–physical failures, evaluate resource allocation decisions, made by agents under each coordination scheme, and quantify the aggregated resilience. The simulation platform will help municipalities in various cities to quantify the impact of their collective decision making and identify the best coordination structures when interdependencies are modeled in infrastructure systems.

Recurring tidal disruption events a decade apart in IRAS F01004-2237

In theory, recurring tidal disruption events (TDEs) may occur when a close stellar binary encounters a supermassive black hole, if one star is captured and undergoes repeating partial TDEs, or if both stars are tidally disrupted (double TDEs). In addition, independent TDEs may be observed over decades in some special galaxies where the TDE rate is extremely high. Exploring the diversity of recurring TDEs and probing their natures with rich observational data helps us to understand these mechanisms. We report the discovery of a second optical flare that occurred in September 2021 in IRAS F01004-2237, where a first flare that occurred in 2010 had already been reported. We also present a detailed analysis of multi-band data. We aim to understand the nature of the flare and explore the possible causes of the recurring flares. We describe our analysis of the position of the flare, the multi-band light curves (LCs), the optical and ultraviolet (UV) spectra, and the X-ray LC and spectra. The position of the flare coincides with the galaxy centre with a precision of 650 pc. The flare peaks in $ days with an absolute magnitude of $ and fades in two years, roughly following $L $. It maintains a nearly constant blackbody temperature of sim 22,000 K in later stages. Its optical and UV spectra show hydrogen and helium broad emission lines with full width at half maxima of 7,000--21,000 km s$^ $ and a He II/Halpha ratio of 0.3--2.3. It shows weak X-ray emission relative to UV emission, with X-ray flares lasting for $<2-3$ weeks, during which the spectrum is soft with a power-law index of $ $. These characters are consistent with a TDE, ruling out the possibilities of a supernova or an active galactic nucleus flare. With a TDE model, we infer a peak UV luminosity of $3.3 $ erg s$^ $ and an energy budget of $4.5 $ erg. A TDE caused the flare that occurred in 2021. The two optical flares separated by $10.3 years can be interpreted as repeating partial TDEs, double TDEs, or two independent TDEs. Although no definitive conclusion can be drawn, the partial TDEs interpretation predicts a third flare around 2033, and the independent TDEs interpretation predicts a high TDE rate of $ $ yr$^ $ in F01004-2237, both of which can be tested by future observations.

CSR Authenticity During Disruptive Events: Exploring Social Media Evaluations of Tesla's Ventilator Initiative in Response to COVID‐19

ABSTRACTCorporate social responsibility (CSR) initiatives have increasingly become subject to authenticity evaluations on social media. Whilst CSR initiatives are evaluated as authentic if they were perceived to genuinely address societal issues and needs, it is unclear, however, how a disruptive event would change the way stakeholders perceive a company's CSR authenticity. Disruptive events have unique features of urgency, scarcity and uncertainty, which may make stakeholders expect companies to organize their CSR initiatives in different ways in order to be perceived as authentic. Hence, this study aims to explore the conceptualization of CSR authenticity during a disruptive event by analyzing social media evaluations of CSR initiatives. This paper presents the outcomes of an abductive analysis of Twitter evaluations about a respiratory‐ventilator production initiative of Tesla in response to the COVID‐19 crisis. Our findings suggest that three dimensions constitute CSR authenticity during a disruptive event: responsiveness, reliability and motivation. Disruptive events direct the attention of social media users to certain dimensions of CSR authenticity. We discuss the meaning and salience of these dimensions and conclude by implications for theory and practice.

Strengthening food supply resilience: Lean and Lean Six Sigma strategies for disruptions

ABSTRACT Recognizing that the food industry faces a myriad of challenges, ranging from natural disasters to geopolitical conflicts and pandemics, this study explores how Lean, and Lean Six Sigma (L&LSS) can fortify supply chains against such diverse disruptions. While the COVID-19 pandemic serves as a contextual backdrop, our focus is on the broader application of L&LSS methodologies in navigating disruptive events. This study analyzes responses from 120 food firms, utilising structural equation modelling to correlate L&LSS practices with adaptive performance during crises. Our findings indicate that L&LSS not only equip firms to maintain operational continuity amidst disruptions but also positions them to anticipate and adapt to future systemic shocks. By elucidating the positive correlation between L&LSS engagement and crisis resilience, this research contributes a strategic framework to the literature, advocating for a pre-emptive embrace of L&LSS practices as essential to navigating the unpredictable nature of global crises.

Does the Innovative City Pilot Policy Improve Urban Resilience? Evidence from China

The assessment of the relationship between the innovative city pilot policy (ICPP) and urban resilience is crucial for enhancing cities’ ability to foresee, endure, and recover from various disruptive events. Despite the widespread implementation of the ICPP in China, it remains uncertain if this strategy will contribute to the development of urban resilience. Starting with data collected from 245 prefecture-level cities in China from 2004 to 2020, this paper initially evaluates the causal effect of the policy intervention using the difference-in-differences (DID) model and the propensity score matching-difference-in-differences (PSM-DID) method. A multi-dimensional urban resilience measurement index and a mediating effect model were constructed. The empirical results show that (1) the ICPP has a significant effect on urban resilience, which remains in force after a series of robustness tests, such as a placebo test and difference-in-differences machine learning (DML) approach; (2) regional R&D investment, technological talent attraction, green innovation capability enhancement, and information infrastructure development are identified as the mediating variable for the ICPP’s impact on urban resilience dimensions; and (3) heterogeneity study results show that the ICPP has a significantly greater impact on medium-sized cities, attributed to their capacity to enhance the resilience of cities with more growing space. Furthermore, cities with lower economic agglomeration saw a greater increase in urban resilience due to the ICPP. Accordingly, it is recommended to prioritize the allocation of innovative resources to non-coastal regions, cities with low economic agglomeration, and medium-sized cities. This study provides crucial recommendations for the enlargement of the ICPP’s scale and coordinated progress of China’s urban resilience.

Assessing the Moisture Resilience of Wood Frame Wall Assemblies

Resilience has been used as a building performance metric that measures the building’s capability of absorption, response, and recovery from one or a series of disruptive events, e.g., extreme weather events or power outage events. With respect to resilience, in relation to the moisture performance of the building envelope (moisture resilience), this aspect has not yet been thoroughly explored nor defined. Given the expected increase in annual precipitation in certain regions of Canada as induced by climate change effects occurring both currently and in the future, the moisture resilience of building envelops will require immediate attention given that wall assemblies of buildings are predicted to be subjected to excessive moisture loads in the coming years. In this study, the moisture resilience of wood frame wall assemblies to mould growth was described from three aspects: (i) absorption—the ability of the wall to maintain a low level of relative humidity on the OSB; (ii) response—the fluctuation of the relative humidity on the OSB; and (iii) recovery—the rate at which the relative humidity recovers to an acceptable level. The metrics used to demonstrate the relative impact of these factors on moisture performance were also developed. The results have revealed a robust correlation between moisture performance and the relative influence of various newly defined aspects of moisture resilience.

A room of one’s own? The consequences of living density on individual well-being and social anomie

Abstract The global housing affordability crisis and COVID shutdowns have put living space inequality back on the political agenda. Drawing on Durkheim’s theory of anomie and density, this paper argues that on how many square meters a society lives matters for how stable or anomic it develops. Using data from the Swiss Household Panel, we examine the selection, short-term, and dynamic effects associated with transitions to overcrowded and under-occupied dwellings. We conceptualize these transitions as disruptive events that require a reconfiguration of personal and social equilibria in individuals’ lives. While overcrowded housing leads to a heightening of emotional states and more tense internal household dynamics, people respond by adjusting their leisure activities and restructuring their support networks from strong to weak ties. Conversely, moving to an under-occupied dwelling is associated with melancholic emotional stabilization, but improves household balance and leads to consolidation of the core network of relatives at the expense of outer social circles. We conclude that the classical characterization of anomie as a mismatch between personal means and societal ends should be understood as a multifaceted phenomenon in which meso-level social networks can be a crucial means to cope with disruptions that arise at other levels.

AT 2021hdr: A candidate tidal disruption of a gas cloud by a binary super massive black hole system

With a growing number of facilities able to monitor the entire sky and produce light curves with a cadence of days, in recent years there has been an increased rate of detection of sources whose variability deviates from standard behavior, revealing a variety of exotic nuclear transients. The aim of the present study is to disentangle the nature of the transient AT\,2021hdr, whose optical light curve used to be consistent with a classic Seyfert 1 nucleus, which was also confirmed by its optical spectrum and high-energy properties. From late 2021, AT\,2021hdr started to present sudden brightening episodes in the form of oscillating peaks in the Zwicky Transient Facility (ZTF) alert stream, and the same shape is observed in X-rays and UV from Swift data. The oscillations occur every sim 60-90 days with amplitudes of sim 0.2 mag in the g and r bands. Very Long Baseline Array (VLBA) observations show no radio emission at milliarcseconds scale. It is argued that these findings are inconsistent with a standard tidal disruption event (TDE), a binary supermassive black hole (BSMBH), or a changing-look active galactic nucleus (AGN); neither does this object resemble previous observed AGN flares, and disk or jet instabilities are an unlikely scenario. Here, we propose that the behavior of AT\,2021hdr might be due to the tidal disruption of a gas cloud by a BSMBH. In this scenario, we estimate that the putative binary has a separation of sim 0.83 mpc and would merge in sim 7times 10$^4$ years. This galaxy is located at 9 kpc from a companion galaxy, and in this work we report this merger for the first time. The oscillations are not related to the companion galaxy.

Sources and Radiations of the Fermi Bubbles

Two enigmatic gamma-ray features in the galactic central region, known as Fermi Bubbles (FBs), were found from Fermi-LAT data. An energy release, (e.g., by tidal disruption events in the Galactic Center, GC), generates a cavity with a shock that expands into the local ambient medium of the galactic halo. A decade or so ago, a phenomenological model of the FBs was suggested as a result of routine star disruptions by the supermassive black hole in the GC which might provide enough energy for large-scale structures, like the FBs. In 2020, analytical and numerical models of the FBs as a process of routine tidal disruption of stars near the GC were developed; these disruption events can provide enough cumulative energy to form and maintain large-scale structures like the FBs. The disruption events are expected to be 10−4∼10−5yr−1, providing an average power of energy release from the GC into the halo of E˙∼3×1041 erg s−1, which is needed to support the FBs. Analysis of the evolution of superbubbles in exponentially stratified disks concluded that the FB envelope would be destroyed by the Rayleigh–Taylor (RT) instabilities at late stages. The shell is composed of swept-up gas of the bubble, whose thickness is much thinner in comparison to the size of the envelope. We assume that hydrodynamic turbulence is excited in the FB envelope by the RT instability. In this case, the universal energy spectrum of turbulence may be developed in the inertial range of wavenumbers of fluctuations (the Kolmogorov–Obukhov spectrum). From our model we suppose the power of the FBs is transformed partly into the energy of hydrodynamic turbulence in the envelope. If so, hydrodynamic turbulence may generate MHD fluctuations, which accelerate cosmic rays there and generate gamma-ray and radio emission from the FBs. We hope that this model may interpret the observed nonthermal emission from the bubbles.