10 results
Search Results
2. Even a good influenza forecasting model can benefit from internet-based nowcasts, but those benefits are limited.
- Author
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Osthus, Dave, Daughton, Ashlynn R., and Priedhorsky, Reid
- Subjects
INFLUENZA ,RESPIRATORY infections ,PUBLIC health ,MATHEMATICAL models of forecasting - Abstract
The ability to produce timely and accurate flu forecasts in the United States can significantly impact public health. Augmenting forecasts with internet data has shown promise for improving forecast accuracy and timeliness in controlled settings, but results in practice are less convincing, as models augmented with internet data have not consistently outperformed models without internet data. In this paper, we perform a controlled experiment, taking into account data backfill, to improve clarity on the benefits and limitations of augmenting an already good flu forecasting model with internet-based nowcasts. Our results show that a good flu forecasting model can benefit from the augmentation of internet-based nowcasts in practice for all considered public health-relevant forecasting targets. The degree of forecast improvement due to nowcasting, however, is uneven across forecasting targets, with short-term forecasting targets seeing the largest improvements and seasonal targets such as the peak timing and intensity seeing relatively marginal improvements. The uneven forecasting improvements across targets hold even when “perfect” nowcasts are used. These findings suggest that further improvements to flu forecasting, particularly seasonal targets, will need to derive from other, non-nowcasting approaches. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
3. Estimating influenza incidence using search query deceptiveness and generalized ridge regression.
- Author
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Priedhorsky, Reid, Daughton, Ashlynn R., Barnard, Martha, O’Connell, Fiona, and Osthus, Dave
- Subjects
DISEASE incidence ,INFLUENZA ,SEASONAL influenza ,REGRESSION analysis ,INTERNET usage monitoring ,PHYSICAL sciences - Abstract
Seasonal influenza is a sometimes surprisingly impactful disease, causing thousands of deaths per year along with much additional morbidity. Timely knowledge of the outbreak state is valuable for managing an effective response. The current state of the art is to gather this knowledge using in-person patient contact. While accurate, this is time-consuming and expensive. This has motivated inquiry into new approaches using internet activity traces, based on the theory that lay observations of health status lead to informative features in internet data. These approaches risk being deceived by activity traces having a coincidental, rather than informative, relationship to disease incidence; to our knowledge, this risk has not yet been quantitatively explored. We evaluated both simulated and real activity traces of varying deceptiveness for influenza incidence estimation using linear regression. We found that deceptiveness knowledge does reduce error in such estimates, that it may help automatically-selected features perform as well or better than features that require human curation, and that a semantic distance measure derived from the Wikipedia article category tree serves as a useful proxy for deceptiveness. This suggests that disease incidence estimation models should incorporate not only data about how internet features map to incidence but also additional data to estimate feature deceptiveness. By doing so, we may gain one more step along the path to accurate, reliable disease incidence estimation using internet data. This capability would improve public health by decreasing the cost and increasing the timeliness of such estimates. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
4. Learning the structure of the world: The adaptive nature of state-space and action representations in multi-stage decision-making.
- Author
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Dezfouli, Amir and Balleine, Bernard W.
- Subjects
SMART structures ,ADAPTIVE natural resource management ,NATURE ,BRAIN mapping ,COGNITIVE psychology ,DECISION making - Abstract
State-space and action representations form the building blocks of decision-making processes in the brain; states map external cues to the current situation of the agent whereas actions provide the set of motor commands from which the agent can choose to achieve specific goals. Although these factors differ across environments, it is currently unknown whether or how accurately state and action representations are acquired by the agent because previous experiments have typically provided this information a priori through instruction or pre-training. Here we studied how state and action representations adapt to reflect the structure of the world when such a priori knowledge is not available. We used a sequential decision-making task in rats in which they were required to pass through multiple states before reaching the goal, and for which the number of states and how they map onto external cues were unknown a priori. We found that, early in training, animals selected actions as if the task was not sequential and outcomes were the immediate consequence of the most proximal action. During the course of training, however, rats recovered the true structure of the environment and made decisions based on the expanded state-space, reflecting the multiple stages of the task. Similarly, we found that the set of actions expanded with training, although the emergence of new action sequences was sensitive to the experimental parameters and specifics of the training procedure. We conclude that the profile of choices shows a gradual shift from simple representations to more complex structures compatible with the structure of the world. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
5. Efficient algorithms to discover alterations with complementary functional association in cancer.
- Author
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Sarto Basso, Rebecca, Hochbaum, Dorit S., and Vandin, Fabio
- Subjects
CANCER genetics ,PERTURBATION theory ,PHENOTYPES ,ALGORITHMS ,COMPUTATIONAL biology - Abstract
Recent large cancer studies have measured somatic alterations in an unprecedented number of tumours. These large datasets allow the identification of cancer-related sets of genetic alterations by identifying relevant combinatorial patterns. Among such patterns, mutual exclusivity has been employed by several recent methods that have shown its effectiveness in characterizing gene sets associated to cancer. Mutual exclusivity arises because of the complementarity, at the functional level, of alterations in genes which are part of a group (e.g., a pathway) performing a given function. The availability of quantitative target profiles, from genetic perturbations or from clinical phenotypes, provides additional information that can be leveraged to improve the identification of cancer related gene sets by discovering groups with complementary functional associations with such targets. In this work we study the problem of finding groups of mutually exclusive alterations associated with a quantitative (functional) target. We propose a combinatorial formulation for the problem, and prove that the associated computational problem is computationally hard. We design two algorithms to solve the problem and implement them in our tool UNCOVER. We provide analytic evidence of the effectiveness of UNCOVER in finding high-quality solutions and show experimentally that UNCOVER finds sets of alterations significantly associated with functional targets in a variety of scenarios. In particular, we show that our algorithms find sets which are better than the ones obtained by the state-of-the-art method, even when sets are evaluated using the statistical score employed by the latter. In addition, our algorithms are much faster than the state-of-the-art, allowing the analysis of large datasets of thousands of target profiles from cancer cell lines. We show that on two such datasets, one from project Achilles and one from the Genomics of Drug Sensitivity in Cancer project, UNCOVER identifies several significant gene sets with complementary functional associations with targets. Software available at: . [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
6. Ten simple rules for short and swift presentations.
- Author
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Lortie, Christopher J.
- Subjects
SCIENTIFIC communication ,SLIDES (Photography) ,GRAPHIC design ,SCIENCE ,COMMUNICATION - Abstract
The article offers tips on preparing short and swift scientific presentations. Since immediacy is important, preparing one primary message for the audience is suggested. Slides can be used to present a clear story by discussing one major point per slide. Using simple visuals is recommended. The style, graphical design, language and imagery of the presentation should be consistent.
- Published
- 2017
- Full Text
- View/download PDF
7. Entropy Transfer between Residue Pairs and Allostery in Proteins: Quantifying Allosteric Communication in Ubiquitin.
- Author
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Hacisuleyman, Aysima and Erman, Burak
- Subjects
ALLOSTERIC proteins ,ENTROPY ,UBIQUITIN ,POLYMERASE chain reaction ,COOPERATIVE binding (Biochemistry) - Abstract
It has recently been proposed by Gunasakaran et al. that allostery may be an intrinsic property of all proteins. Here, we develop a computational method that can determine and quantify allosteric activity in any given protein. Based on Schreiber's transfer entropy formulation, our approach leads to an information transfer landscape for the protein that shows the presence of entropy sinks and sources and explains how pairs of residues communicate with each other using entropy transfer. The model can identify the residues that drive the fluctuations of others. We apply the model to Ubiquitin, whose allosteric activity has not been emphasized until recently, and show that there are indeed systematic pathways of entropy and information transfer between residues that correlate well with the activities of the protein. We use 600 nanosecond molecular dynamics trajectories for Ubiquitin and its complex with human polymerase iota and evaluate entropy transfer between all pairs of residues of Ubiquitin and quantify the binding susceptibility changes upon complex formation. We explain the complex formation propensities of Ubiquitin in terms of entropy transfer. Important residues taking part in allosteric communication in Ubiquitin predicted by our approach are in agreement with results of NMR relaxation dispersion experiments. Finally, we show that time delayed correlation of fluctuations of two interacting residues possesses an intrinsic causality that tells which residue controls the interaction and which one is controlled. Our work shows that time delayed correlations, entropy transfer and causality are the required new concepts for explaining allosteric communication in proteins. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
8. Targeted pandemic containment through identifying local contact network bottlenecks
- Author
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Chris T. Bauch, Di Wang, Shenghao Yang, Priyabrata Senapati, and Kimon Fountoulakis
- Subjects
FOS: Computer and information sciences ,Viral Diseases ,Facebook ,Computer science ,Epidemiology ,Distributed computing ,Social Sciences ,01 natural sciences ,Systems Science ,Oregon ,Medical Conditions ,Sociology ,Agent-Based Modeling ,Medicine and Health Sciences ,Centrality ,Biology (General) ,Computer Networks ,0303 health sciences ,education.field_of_study ,Ecology ,Simulation and Modeling ,Quebec ,Social Communication ,Computer Science - Social and Information Networks ,Infectious Diseases ,Computational Theory and Mathematics ,Social Networks ,Modeling and Simulation ,Convex optimization ,Physical Sciences ,Network Analysis ,Algorithms ,Research Article ,Physics - Physics and Society ,Computer and Information Sciences ,QH301-705.5 ,Population ,FOS: Physical sciences ,Physics and Society (physics.soc-ph) ,Research and Analysis Methods ,Models, Biological ,Bottleneck ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0103 physical sciences ,Genetics ,Humans ,Computer Simulation ,Quantitative Biology - Populations and Evolution ,010306 general physics ,education ,Molecular Biology ,Pandemics ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology ,Social and Information Networks (cs.SI) ,Simulation modeling ,Populations and Evolution (q-bio.PE) ,COVID-19 ,Covid 19 ,Flow network ,Communications ,Transmission (telecommunications) ,Flow (mathematics) ,FOS: Biological sciences ,Social Media ,Mathematics - Abstract
Decision-making about pandemic mitigation often relies upon simulation modelling. Models of disease transmission through networks of contacts--between individuals or between population centres--are increasingly used for these purposes. Real-world contact networks are rich in structural features that influence infection transmission, such as tightly-knit local communities that are weakly connected to one another. In this paper, we propose a new flow-based edge-betweenness centrality method for detecting bottleneck edges that connect nodes in contact networks. In particular, we utilize convex optimization formulations based on the idea of diffusion with p-norm network flow. Using simulation models of COVID-19 transmission through real network data at both individual and county levels, we demonstrate that targeting bottleneck edges identified by the proposed method reduces the number of infected cases by up to 10% more than state-of-the-art edge-betweenness methods. Furthermore, the proposed method is orders of magnitude faster than existing methods., Comment: 38 pages, 21 figures
- Published
- 2021
9. Ten Simple Rules for Curating and Facilitating Small Workshops.
- Author
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McInerny, Greg J.
- Subjects
FORUMS ,WORKSHOPS (Facilities) -- Design & construction ,RESEARCH ,TOPIC & comment (Grammar) ,DISCUSSION ,TIME perspective ,INTERACTION model (Communication) - Abstract
The article discusses the creation of good workshops which could be in a diverse form and fit different goals. This is needed for exploring a single research topic, initiation of working group, and interdisciplinary collaborations. It requires attendees, timetables, and interactions. Topics discussed processes in facilitating workshops including assessment on past success and failures, developing of workshop name, and preparing for speakers speech.
- Published
- 2016
- Full Text
- View/download PDF
10. High-Degree Neurons Feed Cortical Computations.
- Author
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Timme, Nicholas M., Ito, Shinya, Myroshnychenko, Maxym, Nigam, Sunny, Shimono, Masanori, Yeh, Fang-Chin, Hottowy, Pawel, Litke, Alan M., and Beggs, John M.
- Subjects
NEURONS ,HIGHER nervous activity ,INFORMATION resources ,COMPUTATIONAL mechanics ,MULTIVARIATE analysis - Abstract
Recent work has shown that functional connectivity among cortical neurons is highly varied, with a small percentage of neurons having many more connections than others. Also, recent theoretical developments now make it possible to quantify how neurons modify information from the connections they receive. Therefore, it is now possible to investigate how information modification, or computation, depends on the number of connections a neuron receives (in-degree) or sends out (out-degree). To do this, we recorded the simultaneous spiking activity of hundreds of neurons in cortico-hippocampal slice cultures using a high-density 512-electrode array. This preparation and recording method combination produced large numbers of neurons recorded at temporal and spatial resolutions that are not currently available in any in vivo recording system. We utilized transfer entropy (a well-established method for detecting linear and nonlinear interactions in time series) and the partial information decomposition (a powerful, recently developed tool for dissecting multivariate information processing into distinct parts) to quantify computation between neurons where information flows converged. We found that computations did not occur equally in all neurons throughout the networks. Surprisingly, neurons that computed large amounts of information tended to receive connections from high out-degree neurons. However, the in-degree of a neuron was not related to the amount of information it computed. To gain insight into these findings, we developed a simple feedforward network model. We found that a degree-modified Hebbian wiring rule best reproduced the pattern of computation and degree correlation results seen in the real data. Interestingly, this rule also maximized signal propagation in the presence of network-wide correlations, suggesting a mechanism by which cortex could deal with common random background input. These are the first results to show that the extent to which a neuron modifies incoming information streams depends on its topological location in the surrounding functional network. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
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