2,359 research outputs found
Benchmarking inference methods for water quality monitoring and status classification
River water quality monitoring at limited temporal resolution can lead to imprecise and inaccurate classification of physicochemical status due to sampling error. Bayesian inference allows for the quantification of this uncertainty, which can assist decision-making. However, implicit assumptions of Bayesian methods can cause further uncertainty in the uncertainty quantification, so-called second-order uncertainty. In this study, and for the first time, we rigorously assessed this second-order uncertainty for inference of common water quality statistics (mean and 95th percentile) based on sub-sampling high-frequency (hourly) total reactive phosphorus (TRP) concentration data from three watersheds. The statistics were inferred with the low-resolution sub-samples using the Bayesian lognormal distribution and bootstrap, frequentist t test, and face-value approach and were compared with those of the high-frequency data as benchmarks. The t test exhibited a high risk of bias in estimating the water quality statistics of interest and corresponding physicochemical status (up to 99% of sub-samples). The Bayesian lognormal model provided a good fit to the high-frequency TRP concentration data and the least biased classification of physicochemical status (<â5% of sub-samples). Our results suggest wide applicability of Bayesian inference for water quality status classification, a new approach for regulatory practice that provides uncertainty information about water quality monitoring and regulatory classification with reduced bias compared to frequentist approaches. Furthermore, the study elucidates sizeable second-order uncertainty due to the choice of statistical model, which could be quantified based on the high-frequency data.Peer Reviewe
Decision making for two learning agents acting like human agents : A proof of concept for the application of a Learning Classifier Systems
The paper investigates the suitability of a Learning Classifier System implementation for mimicking human decision making in agent based social simulations incorporating network effects. Model behavior is studied for three distinct scenario settings. We provide proof of concept for the adequacy of LCA to tackle the task at hand. Specifically, it is found that the LCA provides the agents within the simulation model with the ability to learn and to react to environmental changes while accounting for bounded rational decision making and the presence of imperfect information, as well as network effects. Moreover it can be shown that the LCA-agents exhibit a habit like behavioural pattern
Recommended from our members
A Multidisciplinary Intubation Algorithm for Suspected COVID-19 Patients in the Emergency Department
Introduction: Intubation of patients suspected of having coronavirus disease 2019 (COVID-19) is considered to be a high-risk procedure due to the aerosolization of viral particles. In an effort to minimize the risk of exposure and optimize patient care, we sought to develop, test, provide training, and implement a standardized algorithm for intubating these high-risk patients at our institution.Methods: We developed an initial intubation algorithm, incorporating strategic use of equipment and incorporating emerging best practices. By combining simulation-based training sessions and rapid-cycle improvement methodology with physicians, nurses, and respiratory therapists, and incorporating their feedback into the development, we were able to optimize the process prior to implementation. Training sessions also enabled the participants to practice the algorithm as a team. Upon completion of each training session, participants were invited to complete a brief online survey about their overall experience.Results: An algorithm and training system vetted by simulation and actual practice were developed. A training video and dissemination package were made available for other emergency departments to adopt. Survey results were overall positive, with 97.92% of participants feeling confident in their role in the intubation process, and many participants citing the usefulness of the multidisciplinary approach to the training.Conclusion: A multidisciplinary, team-based approach to the development and training of a standardized intubation algorithm combining simulation and rapid-cycle improvement methodology is a useful, effective process to respond to rapidly evolving clinical information and experiences during a global pandemic
Coexistence versus extinction in the stochastic cyclic Lotka-Volterra model
Cyclic dominance of species has been identified as a potential mechanism to
maintain biodiversity, see e.g. B. Kerr, M. A. Riley, M. W. Feldman and B. J.
M. Bohannan [Nature {\bf 418}, 171 (2002)] and B. Kirkup and M. A. Riley
[Nature {\bf 428}, 412 (2004)]. Through analytical methods supported by
numerical simulations, we address this issue by studying the properties of a
paradigmatic non-spatial three-species stochastic system, namely the
`rock-paper-scissors' or cyclic Lotka-Volterra model. While the deterministic
approach (rate equations) predicts the coexistence of the species resulting in
regular (yet neutrally stable) oscillations of the population densities, we
demonstrate that fluctuations arising in the system with a \emph{finite number
of agents} drastically alter this picture and are responsible for extinction:
After long enough time, two of the three species die out. As main findings we
provide analytic estimates and numerical computation of the extinction
probability at a given time. We also discuss the implications of our results
for a broad class of competing population systems.Comment: 12 pages, 9 figures, minor correction
Perceived responsiveness in suicidal ideation: An experience sampling study in psychiatric patients
Introduction: Perceived responsiveness, or the extent to which one feels understood, validated and cared for by close others, plays a crucial role in people's wellâbeing. Can this interpersonal process also protect people at risk? We assessed whether fluctuations in suicidal ideation were associated with fluctuations in the degree of perceived responsiveness that psychiatric patients (admitted in the context of suicide or indicating suicidal ideation) experienced in daily interactions immediately after discharge.
Methods: Fiftyâseven patients reported on suicidal ideation (5 times a day) and perceived responsiveness (daily) for four consecutive weeks. The effects of established risk factorsâthwarted belongingness, perceived burdensomeness, and hopelessnessâwere assessed as well.
Results: The more patients felt that close others had been responsive to them, the less suicidal ideation they reported. At low levels of thwarted belongingness, perceived burdensomeness, or hopelessness, perceived responsiveness seemed to play a protective role, negatively coâoccurring with suicidal ideation. When thwarted belongingness, perceived burdensomeness, and hopelessness were high, perceived responsiveness did not have an effect.
Conclusion: Perceived responsiveness could be a protective factor for suicidal ideation for people at risk only when they are experiencing low levels of negative perceptions. When experiencing highly negative perceptions, however, perceived responsiveness seems to matter less
Respiration-Locking of Olfactory Receptor and Projection Neurons in the Mouse Olfactory Bulb and Its Modulation by Brain State
For sensory systems of the brain, the dynamics of an animalâs own sampling behavior has a direct consequence on ensuing computations. This is particularly the case for mammalian olfaction, where a rhythmic flow of air over the nasal epithelium entrains activity in olfactory system neurons in a phenomenon known as sniff-locking. Parameters of sniffing can, however, change drastically with brain states. Coupled to the fact that different observation methods have different kinetics, consensus on the sniff-locking properties of neurons is lacking. To address this, we investigated the sniff-related activity of olfactory sensory neurons (OSNs), as well as the principal neurons of the olfactory bulb (OB), using 2-photon calcium imaging and intracellular whole-cell patch-clamp recordings in vivo, both in anesthetized and awake mice. Our results indicate that OSNs and OB output neurons lock robustly to the sniff rhythm, but with a slight temporal shift between behavioral states. We also observed a slight delay between methods. Further, the divergent sniff-locking by tufted cells (TCs) and mitral cells (MCs) in the absence of odor can be used to determine the cell type reliably using a simple linear classifier. Using this classification on datasets where morphological identification is unavailable, we find that MCs use a wider range of temporal shifts to encode odors than previously thought, while TCs have a constrained timing of activation due to an early-onset hyperpolarization. We conclude that the sniff rhythm serves as a fundamental rhythm but its impact on odor encoding depends on cell type, and this difference is accentuated in awake mice
Modeling Contagion of Behavior in Friendship Networks as Coordination Games
It has been shown that humans are heavily influenced by peers when it comes to choice of behavior, norms or opinions. In order to better understand and help to predict societyâs behavior, it is therefore desirable to design social simulations that incorporate representations of those network aspects. We address this topic, by investigating the performance of a coordination game mechanism in representing the diffusion of behavior for distinct data sets and diverse behaviors in children and adolescent social networks. We introduce a set of quality measurements in order to assess the adequacy of our simulations and find evidence that a coordination game environment could underlie some of the diffusion processes, while other processes may not be modeled coherently as a coordination game
Do resource bases enable social inclusion of students with Asperger syndrome in a mainstream secondary school?
This research identifies the way in which one secondary school with a resourced provision for students with Asperger syndrome promotes the social inclusion for them, and the perceptions of staff members and parents on the social experience of schooling for these children. Interviews were conducted with five teachers, two learning support assistants and the head of the resourced provision. Questionnaires were completed by eight parents of students with Asperger syndrome. The research found that a positive social experience of schooling was perceived by members of staff and parents due to the additional support of the resource in teaching social skills, providing a safe place and the support from learning support assistants. Some negative perceptions of social experience were also reported, which highlighted the need for educational provision for students on the autism spectrum to be considered at an individual level
- âŠ