The consequences of dwarf galaxies colliding with the Milky Way

I simulate the collision of satellite galaxies with the Milky Way and observe the effects that this has on the orbits of the globular cluster populations within both the Milky Way and the satellite galaxies. This is done in order to investigate whether some of the Milky Way's globular clusters could have been donated from satellite galaxies which have been tidally stripped, since it is believed that the Sagittarius dwarf spheroidal galaxy is being tidally disrupted and that some of its globular clusters have been tidally stripped from it (such as Pal 12 and NGC 4147). It is also believed that there have been other Sagittarius-like satellite galaxies in the past which have donated globular clusters to the Milky Way. From a simulation of the 63 Casetti-Dinescu globular clusters orbiting in the Milky Way, I find that most of the encounters between the globular clusters occur at separations between 0.1 kpc and 10 kpc. I also find that there are approximately 24 (0.64%) collisions that may occur between the globular clusters in the next 10 Gyr. However some of these 24 collisions involve the same globular cluster (for example NGC 2808 which has 7 collisions). I vary the initial position values of the globular cluster pair which has the closest encounter, and I find that the collision is very dependant upon the initial conditions of the globular clusters. I then include the classical satellite galaxies in a simulation with the 63 globular clusters, and I find that most of the encounters between the satellite galaxies and the globular clusters occur at separations between 1 kpc and 10 kpc. However there is one encounter with a separation of 227 pc, this is between the SMC and NGC 7006, which has a probability of 1 for occurring in the next 10 Gyr. I also find that there are 10 (1.44%) collisions between the satellite galaxies and the globular clusters that may occur in the next 10 Gyr. The only satellite galaxies that are involved however are the Sagittarius dwarf galaxy, the LMC and the SMC. I generate 500 random Sagittarius-like satellite galaxies based upon the initial conditions of the Sagittarius dwarf galaxy, and I generate 500 random globular clusters. I simulate 10 randomly selected Sagittarius-like satellite galaxies, each containing 10 randomly selected globular clusters which are initially on circular orbits around their host galaxy, and the globular clusters have spacings from their host galaxy in steps of 0.45 kpc. The simulated dwarf galaxies use a decreasing mass function, and I find that after 1 Gyr they have lost all of their globular clusters to the Milky Way. I continue this simulation for a further 10 Gyr, and upon investigation of some of the globular clusters' properties (eccentricity, j_z, orbital energy, and pericentre-apocentre distances), and compare them to the globular clusters from the Casetti-Dinescu database. I find that there are 5 (8%) Casetti-Dinescu globular clusters which have similar properties to the accreted globular clusters from the Sagittarius-like satellite galaxies. These are NGC 1851, NGC 3201, NGC 4590, NGC 7006, and Pal 13. In appendix 3 I run a more realistic simulation and find that there are 6 (~10%) Casetti-Dinescu globular clusters which have similar properties to the accreted globular clusters from the Sagittarius-like satellite galaxies. These are NGC 1851, NGC 4147, NGC 4590, NGC 5024, NGC 6205, NGC 6284. I also calculate that if we have two Sagittarius-like satellite galaxies orbiting within the Milky Way every 5 Gyr and they each donate 9 globular clusters, then this means that 36 - 45 (23 - 29%) of the Milky Way's globular cluster population may have come from tidal stripping events (i.e. 4 - 5 Sagittarius-like satellite galaxies). This is in good agreement with Forbes et al., (2010), van den Bergh (2000), and Mackey & Gilmore (2004), who suggested that there were 27 - 47, 35, and 41 globular clusters which were accreted from satellite galaxies respectively. I believe that the 9 globular clusters previously mention are members of the 36 - 45 globular clusters that have been accreted in the Milky Way's history

Expanding the Gordon-Loeb Model to Cyber-Insurance

We present an economic model for decisions on competing cyber-security and cyber-insurance investment based on the Gordon-Loeb model for investment in information security. We consider a one-period scenario in which a firm may invest in information security measures to reduce the probability of a breach, in cyber-insurance or in a combination of both. The optimal combination of investment and insurance under the assumptions of the Gordon-Loeb model is investigated via consideration of the costs and benefits of investment in security alongside purchasing insurance at an independent premium rate. Under both exponential (constant absolute risk aversion) and logarithmic (constant relative risk aversion) utility functions it is found that when the insurance premium is below a certain value, utility is maximised with insurance and security investment. These results suggest that cyber-insurance is a worthwhile undertaking provided it is not overly costly. We believe this model to be the first attempt to integrate the Gordon-Loeb model into a classical microeconomic analysis of insurance, particularly using the Gordon-Loeb security breach functions to determine the probability of an insurance claim. The model follows the tradition of the Gordon-Loeb model in being accessible to practitioners and decision makers in information security

The barriers to sustainable risk transfer in the cyber-insurance market

Efficient risk transfer is an important condition for ensuring the sustainability of a market according to the established economics literature. In an inefficient market, significant financial imbalances may develop and potentially jeopardise the solvency of some market participants. The constantly evolving nature of cyber-threats and lack of public data sharing mean that the economic conditions required for quoted cyber-insurance premiums to be considered efficient are highly unlikely to be met. This paper develops Monte Carlo simulations of an artificial cyber-insurance market and compares the efficient and inefficient outcomes based on the informational setup between the market participants. The existence of diverse loss distributions is justified by the dynamic nature of cyber-threats and the absence of any reliable and centralised incident reporting. It is shown that the limited involvement of reinsurers when loss expectations are not shared leads to increased premiums and lower overall capacity. This suggests that the sustainability of the cyber-insurance market requires both better data sharing and external sources of risk tolerant capital.Comment: 32 pages, 9 figures, 17 table

Pricing cyber-insurance for systems via maturity models

Pricing insurance for risks associated with information technology systems presents a complex modelling challenge, combining the disciplines of operations management, security, and economics. This work proposes a socioeconomic model for cyber-insurance decisions compromised of entity relationship diagrams, security maturity models, and economic models, addressing a long-standing research challenge of capturing organizational structure in the design and pricing of cyber-insurance policies. Insurance pricing is usually informed by the long experience insurance companies have of the magnitude and frequency of losses that arise in organizations based on their size, industry sector, and location. Consequently, their calculations of premia will start from a baseline determined by these considerations. A unique challenge of cyber-insurance is that data history is limited and not necessarily informative of future loss risk meaning that established actuarial methodology for other lines of insurance may not be the optimal pricing strategy. The model proposed in this paper provides a vehicle for agreement between practitioners in the cyber-insurance ecosystem on cyber-security risks and allows for the users to choose their desired level of abstraction in the description of a system.Comment: 31 pages, 12 figures, 11 table

Help-seeking attitudes and behaviours among humanitarian aid workers

Due to the nature of their work and operating environments, humanitarian aid workers experience higher rates of psychological distress, burnout and mental health conditions than other emergency service worker populations. Fourteen international humanitarian workers were interviewed to examine whether they seek help from others in the context of work-related distress, specifically, their attitudes and behaviors regarding personal help-seeking at such times, their preferred sources of support and factors that enable or constrain effective help-seeking. Thematic analysis of the data derived five superordinate themes: (1) cultural aspects of help-seeking; (2) risks with formal, internal support; (3) lack of shared understanding of humanitarian context; (4) self-censoring and withdrawal; and (5) role maturity. There is high, in principle, support for personal help-seeking but its use is highly selective. Work colleagues are regarded as the most trusted and effective source of help in high stress periods, while barriers that exist with family and friends mean they are rarely sought out at such times. Trust and confidentiality concerns limit the use of internal agency supports and psychosocial services. External psychological services are preferred but are often found to be unsatisfactory. These findings can support aid organisations to address stigma perceptions that are commonly associated with personal help-seeking, particularly among early career practitioners, and normalise its use as a form of occupational self-care

How consistently do physicians diagnose and manage drug-induced interstitial lung disease? Two surveys of European ILD specialist physicians

Introduction Currently there are no general guidelines for diagnosis or management of suspected drug-induced (DI) interstitial lung disease (ILD). The objective was to survey a sample of current European practice in the diagnosis and management of DI-ILD, in the context of the prescribing information approved by regulatory authorities for 28 licenced drugs with a recognised risk of DI-ILD. Methods Consultant physicians working in specialist ILD centres across Europe were emailed two surveys via a website link. Initially, opinion was sought regarding various diagnostic and management options based on seven clinical ILD case vignettes and five general questions regarding DI-ILD. The second survey involved 29 statements regarding the diagnosis and management of DI-ILD, derived from the results of the first survey. Consensus agreement was defined as 75% or greater. Results When making a diagnosis of DI-ILD, the favoured investigations used (other than computed tomography) included pulmonary function tests, bronchoscopy and blood tests. The preferred method used to decide when to stop treatment was a pulmonary function test. In the second survey, the majority of the statements were accepted by the 33 respondents, with only four of 29 statements not achieving consensus when the responses “agree” and “strongly agree” were combined as one answer. Conclusion The two surveys provide guidance for clinicians regarding an approach to the diagnosis and management of DI-ILD in which the current evidence base is severely lacking, as demonstrated by the limited information provided by the manufacturers of the drugs associated with a high risk of DI-ILD that we reviewed

The barriers to sustainable risk transfer in the cyber-insurance market

Efficient risk transfer is an important condition for ensuring the sustainability of a market according to the established economics literature. In an inefficient market, significant financial imbalances may develop and potentially jeopardize the solvency of some market participants. The constantly evolving nature of cyber-threats and lack of public data sharing mean that the economic conditions required for quoted cyber-insurance premiums to be considered efficient are highly unlikely to be met. This paper develops Monte Carlo simulations of an artificial cyber-insurance market and compares the efficient and inefficient outcomes based on the informational setup between the market participants. The existence of diverse loss distributions is justified by the dynamic nature of cyber-threats and the absence of any reliable and centralized incident reporting. It is shown that the limited involvement of reinsurers when loss expectations are not shared leads to increased premiums and lower overall capacity. This suggests that the sustainability of the cyber-insurance market requires both better data sharing and external sources of risk tolerant capital

"I'm still here, but no one hears you" : a qualitative study of young women's experiences of persistent distress post family-based treatment for adolescent anorexia nervosa

Background: Family-based treatment (FBT) is the current treatment of choice for adolescent AN based on positive outcomes that include weight restoration in around two-thirds of adolescents. Nevertheless around a quarter dropout from treatment, particularly in the earlier phases, and a notable proportion of treated adolescents are reported to experience ongoing psychological distress during and post-treatment. This study explores the under-researched experiences of these adolescents. Method: Fourteen participants from Australia, New Zealand and the United Kingdom were interviewed about their experiences of FBT. An inductive thematic analysis of interview transcript data generated key themes related to their experiences, identity negotiations and the discursive materials these used to construct these. Results: The participants identified working as a family unit as key to their recovery, highlighting the importance of family therapy interventions for adolescent AN. However, they perceived an almost exclusive focus on weight restoration in the first phase of FBT was associated with experiences that included a relative neglect of their psychological distress and a loss of voice. Key within these experiences were processes whereby the adolescent engaged in identity negotiation and (re)claiming of their voice and implicit in their family standing with them in the treatment was that their life was worth saving. What was noted as most helpful was when therapists advocated and took into consideration their unique needs and preferences and tailored treatment interventions to these. Conclusions: There is a need to develop and research treatments that address, from the outset of treatment, the adolescents’ psychological distress (including as experienced in the context of their weight restoration). This should be with priority accorded to the adolescent’s voice and identity negotiations, as they and their families take steps to address the physical crisis of AN and in doing so, support more holistic and durable recovery

Positioning Dispositions in Initial Teacher Education: An Action Research Approach

In spite of debate, ambiguity, and tension around teacher dispositions, in the past over two decades, the place of dispositions in initial teacher education (ITE) has been widely supported among policy makers and researchers. Specifically, debate on whether dispositions are teachable has largely given way to action to foster dispositions. Adopting a two-cycle participatory action research design, this study explored ways to teach the first-year teacher candidates’ dispositions in an early childhood ITE programme in New Zealand. The intervention included eight focus dispositions and corresponding strategies to teach each focus disposition. Data collection methods included student self-assessment surveys, individual and focus group interviews with students and teaching staff, team meetings, and a variety of pedagogical documentation. Ethnographic content analysis generated three themes: legitimacy of the intervention, experiential orientation of the intervention, and effect of the intervention. The study exemplifies how dispositions intervention can be incorporated in ITE programmes