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ConG is software for conducting economic experiments in continuous and discrete time. It allows experimenters with limited programming experience to create a variety of strategic environments featuring rich visual feedback in continuous time and over continuous action spaces, as well as in discrete time or over discrete action spaces. Simple, easily edited input files give the experimenter considerable flexibility in specifying the strategic environment and visual feedback. Source code is modular and allows researchers with programming skills to create novel strategic environments and displays.
We investigate experimentally the impact of continuous time on a four-player Hotelling location game. The static pure strategy Nash equilibrium (NE) consists of firms paired-up at the first and third quartiles of the linear city. In a repeated simultaneous move (discrete time) treatment, we largely replicate previous findings in which subjects fail to converge to the NE. However, in asynchronous move (continuous time) treatments we see clear convergence towards the NE.
We recently reported on the radio-frequency attenuation length of cold polar ice at Summit Station, Greenland, based on bi-static radar measurements of radio-frequency bedrock echo strengths taken during the summer of 2021. Those data also allow studies of (a) the relative contributions of coherent (such as discrete internal conducting layers with sub-centimeter transverse scale) vs incoherent (e.g. bulk volumetric) scattering, (b) the magnitude of internal layer reflection coefficients, (c) limits on signal propagation velocity asymmetries (‘birefringence’) and (d) limits on signal dispersion in-ice over a bandwidth of ~100 MHz. We find that (1) attenuation lengths approach 1 km in our band, (2) after averaging 10 000 echo triggers, reflected signals observable over the thermal floor (to depths of ~1500 m) are consistent with being entirely coherent, (3) internal layer reflectivities are ≈–60$\to$–70 dB, (4) birefringent effects for vertically propagating signals are smaller by an order of magnitude relative to South Pole and (5) within our experimental limits, glacial ice is non-dispersive over the frequency band relevant for neutrino detection experiments.
One of the largest contributors to uncertainty in predictions of sea-level rise from ice-sheet models is a lack of knowledge about the bed topography beneath ice sheets. Bed topography maps are normally made by interpolating between linear radar surveys using methods that include kriging, mass conservation and flowline diffusion, all of which may miss influential mesoscale (2–30 km) bedforms. Previous works have explored an Ice-Flow Perturbation Analysis (IFPA) approach for estimating bed topography using the surface expression of these mesoscale bedforms. Using regions of Pine Island Glacier that have been intensively surveyed by ice-penetrating radar as test sites, and a refined IFPA methodology, we find that IFPA detects bedforms capable of influencing ice flow which are not represented in Bedmachine Antarctica and other interpolated bed products. We further explore the ability of IFPA to estimate relative bed slipperiness, finding higher slipperiness in the main trunk and tributaries. Alongside other methods which estimate ice thickness, bed topography maps from IFPA have the potential to constrain projections of future sea-level rise, especially where radar data are sparse.
An outbreak surveillance system for Salmonella integrating whole genome sequencing (WGS) and epidemiological data was developed in South East and London in 2016–17 to assess local WGS clusters for triage and investigation. Cases genetically linked within a 5 single-nucleotide polymorphism (SNP) single linkage cluster were assessed using a set of locally agreed thresholds based on time, person and place, for reporting to local health protection teams (HPTs). Between September 2016 and September 2017, 230 unique 5-SNP clusters (442 weekly reports) of non-typhoidal Salmonella 5-SNP WGS clusters were identified, of which 208 unique 5-SNP clusters (316 weekly reports) were not reported to the HPTs. In the remaining 22 unique clusters (126 weekly clusters) reported to HPTs, nine were known active outbreak investigations, seven were below locally agreed thresholds and six exceeded local thresholds. A common source or vehicle was identified in four of six clusters that exceeded locally agreed thresholds. This work demonstrates that a threshold-based surveillance system, taking into account time, place and genetic relatedness, is feasible and effective in directing the use of local public health resources for risk assessment and investigation of non-typhoidal Salmonella clusters.
To assess the potential for contamination of personnel, patients, and the environment during use of contaminated N95 respirators and to compare the effectiveness of interventions to reduce contamination.
Design:
Simulation study of patient care interactions using N95 respirators contaminated with a higher and lower inocula of the benign virus bacteriophage MS2.
Methods:
In total, 12 healthcare personnel performed 3 standardized examinations of mannequins including (1) control with suboptimal respirator handling technique, (2) improved technique with glove change after each N95 contact, and (3) control with 1-minute ultraviolet-C light (UV-C) treatment prior to donning. The order of the examinations was randomized within each subject. The frequencies of contamination were compared among groups. Observations and simulations with fluorescent lotion were used to assess routes of transfer leading to contamination.
Results:
With suboptimal respirator handling technique, bacteriophage MS2 was frequently transferred to the participants, mannequin, and environmental surfaces and fomites. Improved technique resulted in significantly reduced transfer of MS2 in the higher inoculum simulations (P < .01), whereas UV-C treatment reduced transfer in both the higher- and lower-inoculum simulations (P < .01). Observations and simulations with fluorescent lotion demonstrated multiple potential routes of transfer to participants, mannequin, and surfaces, including both direct contact with the contaminated respirator and indirect contact via contaminated gloves.
Conclusion:
Reuse of contaminated N95 respirators can result in contamination of personnel and the environment even when correct technique is used. Decontamination technologies, such as UV-C, could reduce the risk for transmission.
This SHEA white paper identifies knowledge gaps and challenges in healthcare epidemiology research related to coronavirus disease 2019 (COVID-19) with a focus on core principles of healthcare epidemiology. These gaps, revealed during the worst phases of the COVID-19 pandemic, are described in 10 sections: epidemiology, outbreak investigation, surveillance, isolation precaution practices, personal protective equipment (PPE), environmental contamination and disinfection, drug and supply shortages, antimicrobial stewardship, healthcare personnel (HCP) occupational safety, and return to work policies. Each section highlights three critical healthcare epidemiology research questions with detailed description provided in supplementary materials. This research agenda calls for translational studies from laboratory-based basic science research to well-designed, large-scale studies and health outcomes research. Research gaps and challenges related to nursing homes and social disparities are included. Collaborations across various disciplines, expertise and across diverse geographic locations will be critical.
Chapter 3 introduces a range of multidisciplinary data sources available to study disasters and history and outlines some of the methodologies through which we can interpret and analyze these sources. The underpinning argument is that we can use history as a laboratory to better understand disasters – testing hypotheses rather than merely describing conspicuous phenomena, albeit with a recognition of what this also demands of us as historians. In particular, we discuss the production of suitable measures and methods to understand hazards and their effects, whilst also keeping in mind the limitations of the historical record and the need for a critical approach to sources. We consider, therefore, state-of-the-art challenges in historical disaster research such as how we can compensate for lacunae in the historical record by incorporating rapidly increasing volumes of data from the natural sciences, and the opportunities and pitfalls of historical ‘big data’. The chapter concludes by arguing for the importance of systematic comparative methodologies in moving beyond the descriptive and towards the analytical, which requires that we pay particular attention to scale and context.
Chapter 7 explores the links between disasters past and present. It first examines disaster history in the ‘Anthropocene’, considering how human–environment interactions – and hence the study of disasters – differ from the past. It then takes a twofold perspective, exploring the potential of historical research for better understanding disasters and, on the flipside, the potential of disasters for historical research. We review historical approaches that seek to improve our understanding of disaster management in the present – recognizing that most approaches have so far come from outside of the discipline of history. We then explore three areas where historical research can contribute: first, in analyzing the historical roots or path-dependent forces shaping present-day disasters; second, inanalyzing the evolution and functioning of institutions within certain social contexts; and third, in asking whether history can teach us how to ‘escape’ from disaster. The section on the potential of disasters for historical research considers how disasters – as tests at the extreme margin of society – can act as a window into aspects of society that may otherwise escape the eye. The chapter concludes by suggesting where disaster history may go in the coming years.
Within the field of disaster studies there has always been the need to classify and label disasters. Researchers have distinguished between different types of disasters in terms of causes, outcomes, the element of surprise, scale, or scope. Chapter 2 discusses the pros and cons of the different classification systems, and also poses the question of whether it makes sense, in view of the large diversity of disasters, to study and compare these different types. Is it possible to move beyond the specificity of earthquakes or pandemics? We believe it does make sense. As historians, we can take a higher level of abstraction, revealing the similarities between different types of disasters. In order to understand why some societies coped more effectively with hazards and which characteristics were decisive in this, we can make use of various key concepts, namely disaster management, vulnerability, resilience, and risk. Overall, it is clear that hazards and disasters are not natural events but social processes.
Disasters break with normal routines and so the responses to disasters often require exceptional policies and unusual mobilization of people, know-how, capital, and goods. However, even exceptional interventions and measures are still conditioned by the institutional, social, and cultural layout of the society in question. Moreover, disaster responses are often – though not always – inspired by the memory of reacting to similar challenges in the past. Chapter 5 opens with a discussion of the coordination of disaster responses, with a particular emphasis on the role of ‘experts’ and ‘expertise’ and the importance of learning from disaster. Subsequently, the question is raised as to why responses were not always as effective as they could have been, and why societies do not automatically adapt their infrastructure or organization in appropriate ways to prevent the recurrence of disaster. In explaining the differing directions of disaster responses, we highlight two crucial variables revealed by history: social inequality and institutional rigidity.
Chapter 1 introduces the broad objective of the book. This is to show how history can be used to understand why biophysical shocks and hazards, sometimes leading to disasters, push societies in different directions – creating a diversity of possible social and economic outcomes. In order to understand this diversity, we need to look not only at institutional responses but also at the social actors behind these responses, who may have very different goals, not always equivalent to the ‘common good’. We illustrate how shocks and hazards, and the disasters that sometimes ensued, could thus have very diverse consequences not only between societies, but also within the same societies, between social groups, and across wealth, ethnic, and gender lines. In discussing these issues, the book goes back in time further than the modern period. Although the Industrial Revolution and associated new technologies brought momentous changes, these did not create a fundamental rift between the period before and after the Industrial Revolution, and we argue that the underlying mechanisms remained similar. After the outline of the intentions of this book, the chapter concludes with a survey of the fields of disaster studies, disaster history, and the relevant interpretative frameworks in historical research.
Hazards and disasters do not occur in a vacuum: they are guided by different preconditions and pressures, which can in turn shape responses in the immediate aftermath and over the long term. These pre-existing conditions and pressures may be basic environmental features of a region, well-established structural features of social organization or culture, or simply short-term processes occurring just before a hazard such as social revolt or migration. Chapter 4 makes an explicit distinction between pre-existing pressures connected to climate, environment, technology, and the economy and those connected to society such as institutions, poverty and inequality, and cultural values. Overall, we suggest that the diversity in pre-existing conditions and pressures seen across time and space played a significant role not only in the likelihood of hazards occurring throughout history, but also in the differing likelihood of hazards turning into disasters.
Chapter 6 discusses the effects of disasters. It distinguishes between effects in the immediate aftermath of the disaster – mortality and demographic recovery; land loss and capital destruction; economic crisis; and blame, scapegoating, and social unrest – and longer-term structural consequences – societal collapse; economic reconstruction; long-term demographic change; reconstruction, reform, and social changes; and redistribution of resources. This chapter argues that disasters, even similar ones, did not always produce homogeneous outcomes. Furthermore, rather than being totally damaging or even controversially regarded as a ‘force for good’, the effects of disasters are best assessed by making a basic distinction between the aggregate level and the distributive level: disasters could be instrumentalized to benefit a certain segment of a given population over others.