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The hidden hand of asymptomatic infection hinders control of neglected tropical diseases : a modeling analysis
Get PDFNeglected tropical diseases are responsible for considerable morbidity and mortality in low-income populations. International efforts have reduced their global burden, but transmission is persistent and case-finding-based interventions rarely target asymptomatic individuals.
Methods
We develop a generic mathematical modeling framework for analyzing the dynamics of visceral leishmaniasis in the Indian sub-continent (VL), gambiense sleeping sickness (gHAT), and Chagas disease and use it to assess the possible contribution of asymptomatics who later develop disease (pre-symptomatics) and those who do not (non-symptomatics) to the maintenance of infection. Plausible interventions, including active screening, vector control, and reduced time to detection, are simulated for the three diseases.
Results
We found that the high asymptomatic contribution to transmission for Chagas and gHAT and the apparently high basic reproductive number of VL may undermine long-term control. However, the ability to treat some asymptomatics for Chagas and gHAT should make them more controllable, albeit over relatively long time periods due to the slow dynamics of these diseases. For VL, the toxicity of available therapeutics means the asymptomatic population cannot currently be treated, but combining treatment of symptomatics and vector control could yield a quick reduction in transmission.
Conclusions
Despite the uncertainty in natural history, it appears there is already a relatively good toolbox of interventions to eliminate gHAT, and it is likely that Chagas will need improvements to diagnostics and their use to better target pre-symptomatics. The situation for VL is less clear, and model predictions could be improved by additional empirical data. However, interventions may have to improve to successfully eliminate this disease
The role of temperature and drying cycles on impurity deposition in drying porous media
Get PDFWe consider a liquid containing impurities saturating a porous material; when the liquid evaporates, the impurities are deposited within the material. Applications include filtration and waterproof textiles. We present a mathematical model incorporating coupling between evaporation, accumulation and transport of the impurities, and the impact of the deposited impurities on the transport of both the suspended impurities and the liquid vapour. By simulating our model numerically, we investigate the role of temperature and repeated drying cycles on the location of the deposited impurities. Higher temperatures increase the evaporation rate so that impurities are transported further into porous material before depositing than for lower temperatures. We quantify two distinct parameter regimes in which the material clogs: (i) the dry-clogging (high-temperature) regime, in which impurities are pushed far into the material before clogging, and (ii) the wet-clogging (high-impurity) regime, in which liquid becomes trapped by the clogging. Clogging restricts the extent to which drying time can be reduced by increasing the temperature
Everyday diagnostic work in the histopathology lab : CSCW perspectives on the utilization of data-driven clinical decision support systems
Get PDFIn this paper we present an ethnographic study of the work of histopathologists as they grapple with the twin innovations of transitioning to digital biopsy images and the prospective adoption of an AI-based clinical decision support system (CDSS). We explore how they are adapting to the former and their expectations of the latter. The study’s ethnomethodologically-informed ethnography approach brings to light some key issues regarding the nature of diagnostic work, and accountability and trust that are central to the successful adoption of technological innovations in clinical settings
Quantum key distribution for V2I communications with software‐defined networking
Get PDFThe evolution of Connected and Autonomous Vehicles (CAVs) promises improvements in our travel experience and the potential to enhance road safety and reduce environmental impact. This will be utilising highly diverse traffic environments that enable several advanced mobility applications. A secure, efficient, reliable, and resilient communications infrastructure is required to support developments in these CAV systems. Next generation of telecommunication networks will seamlessly integrate terrestrial, satellite, and airborne networks into a single wireless system satisfying the requirements of trustworthy future transport systems. Given the increasing importance of CAVs, coupled with their attractiveness as a cyber-attack for threat agents (e.g., disruption of transportation systems by nation states), security is paramount. Future communications systems offer an opportunity to integrate Quantum Key Distribution (QKD) into vehicular environments, protecting against advances in quantum computation that render many of the classical algorithms that underpin Public Key Infrastructure obsolete. This paper proposes a method for the integration of QKD in V2I networks to enable secure data communication. Quantum Key Distribution is used in the end-to-end path of vehicle-to-infrastructure (V2I) networks. Furthermore, an overarching Software-Defined Network, with integrated QKD, is introduced. We have investigated the security performance of QKD in a V2I network over an urban environment
Narrative alliances : the discursive foundations of international order
Get PDFAlliances are generally understood as groupings of states that combine to aggregate their physical capabilities against security threats. In this article we suggest transposing this well-established terminology of inter-state allegiance to the dimension of narrative. Focusing on the example of the ‘rules-based order’ (RBO), we provide a new conceptual entry point for understanding the complex relationship between order and discourse at the international level. Specifically, we examine how countries such as the United States, the United Kingdom, Australia, India and Japan—with varying degrees of consistency and coherence—go beyond merely proclaiming the existence of an established international system of cooperation, commitments and norms. They collectively tell a political story of the rules-based order—including its age, nature, purpose and sources of vulnerability—that rests on declaring some codes of conduct acceptable and appropriate while denouncing others as deviant. We argue that rallying behind a shared vision of international organization demarcates the boundaries of international legitimacy and establishes imperatives to act in defence of particular visions of international organization
Demonstrating software reliability using possibly correlated tests : insights from a conservative Bayesian approach
No full textThis paper presents Bayesian techniques for conservative claims about software reliability, particularly when evidence suggests the software’s executions are not statistically independent. We formalise informal notions of “doubting” that the executions are independent, and incorporate such doubts into reliability assessments. We develop techniques that reveal the extent to which independence assumptions can undermine conservatism in assessments, and identify conditions under which this impact is not significant. These techniques – novel extensions of conservative Bayesian inference (CBI) approaches – give conservative confidence bounds on the software’s failure probability per execution. With illustrations in two application areas – nuclear power-plant safety and autonomous vehicle (AV) safety – our analyses reveals: 1) the confidence an assessor should possess before subjecting a system to operational testing. Otherwise, such testing is futile – favourable operational testing evidence will eventually decrease one’s confidence in the system being sufficiently reliable; 2) the independence assumption supports conservative claims sometimes; 3) in some scenarios, observing a system operate without failure gives less confidence in the system than if some failures had been observed; 4) building confidence in a system is very sensitive to failures – each additional failure means significantly more operational testing is required, in order to support a reliability claim
The role of anxiety and depression in shaping the sleep–pain connection in patients with nonspecific chronic spinal pain and comorbid insomnia : a cross-sectional analysis
Get PDF(1) Background: This exploratory study aims to explore the relationship between nonspecific chronic spinal pain (nCSP) and insomnia symptoms, by examining the interconnections, strengths, and directional dependence of the symptoms. In addition, we aim to identify the key symptoms of the nCSP–insomnia relationship and shed light on the bidirectional nature of this relationship. (2) Methods: This study is a secondary analysis of the baseline data (cross-sectional) from a randomized controlled trial, which examined the added value of Cognitive Behavioral Therapy for Insomnia (CBT-I) combined with cognition-targeted exercise therapy, conducted in collaboration with the Universiteit Gent and Vrije Universiteit Brussel (Belgium). One hundred and twenty-three nCSP patients with comorbid insomnia were recruited through the participating hospitals, advertisements, announcements in local newspapers, pharmacies, publications from support groups, and primary care. To explore the interconnections and directionality between symptoms and the strengths of the relationships, we estimated a regularized Gaussian graphical model and a directed acyclic graph. (3) Results: We found only one direct, but weak, link between sleep and pain, namely, between average pain and difficulties maintaining sleep. (4) Conclusions: Despite the lack of strong direct links between sleep and pain, pain and sleep seem to be indirectly linked via anxiety and depression symptoms, acting as presumable mediators in the network of nCSP and comorbid insomnia. Furthermore, feeling slowed down and fatigue emerged as terminal nodes, implying their role as consequences of the network
Improved bounds for cross-Sperner systems
Get PDFA collection of families (F1,F2,⋯,Fk)∈P([n])k is cross-Sperner if there is no pair i≠j for which some Fi∈Fi is comparable to some Fj∈Fj. Two natural measures of the 'size' of such a family are the sum ∑ki=1|Fi| and the product ∏ki=1|Fi|. We prove new upper and lower bounds on both of these measures for general n and k≥2 which improve considerably on the previous best bounds. In particular, we construct a rich family of counterexamples to a conjecture of Gerbner, Lemons, Palmer, Patkós, and Szécsi from 2011
The Theresienstadt Family Camp in Auschwitz
No full textThe Theresienstadt Family Camp (BIIb) was, along with the “Gypsy” Camp, one of the two family camps in Auschwitz Birkenau. Everyone imprisoned there was sent from the Theresienstadt (Terezín) ghetto. This essay sketches its history, prisoner numbers, and offers an overview of why the SS decided to set it up. The history of BIIb is often told as one of conspiracies and contradictions; this essay attempts to place BIIb in the sphere of the known. The key aspects of the Terezín family camp were adaptation to Auschwitz and the violence encountered there, the barter economy that prominently featured sexuality, the children’s block, and the mass murder of the first prisoners on 8 March 1944. This essay also examines the interactions between rank-and-file prisoners, functionaries from within BIIb, and kapos, who were prisoners from outside BIIb