Trips-in-Motion Time Matrix to Identify Time Windows as an Input for Time-of-Day Modelling

Background: Prior studies have assessed the effect of time of day and day of week on stroke code frequency. Observations that early evening times might result in more treatable stroke cases have been noted. Experiential data raise the question as to whether 7pm codes are often “real” and “intervenable”. Understanding treatment patterns can help allocate resources. We assessed whether 7am early morning stroke code activation resulted in higher yield of acute treatment compared to 7pm evening stroke codes. Methods: A retrospective analysis of prospectively collected data from an IRB approved stroke registry, from 7/2004-7/2020, was performed. All patients presenting as a stroke code to our comprehensive stroke center (CSC) or covered hospitals were included. Subjects were divided into 2 groups: (7ASC): Stroke code called 06:00-08:00 and (7PSC) Stroke code called 18:00-20:00. Treatment was defined as receiving any thrombolytic or endovascular intervention. Chi-squared was used for categorical and 2-proportion Z-Test was used for proportional data. Results: A total of 988 subjects were identified with stroke codes in these time epochs. Total number of code activations (including mimics) was higher in 7PSC group [277(28.0%) 7ASC, 711(72.0%) 7PSC; p<0.0001] compared to 7ASC group. For patient with final diagnosis of stroke, number of code activations remained higher in 7PSC group [134(28.3%) 7ASC, 340(71.7%) 7PSC; p<0.0001]. Acute treatment rates did not differ between groups [22.7% 7ASC, 22.5% 7PSC; p=0.62]. Conclusions: We noted more 7PSC stroke codes even when not adjusting for the extended stroke code time windows in later years of the database. We hypothesize that this may be due to more witnesses being available in the early evening. In spite of this finding, acute treatment rates did not differ between times. This data does not support provider perception that early morning codes are unlikely to be “true or treatable” and early evening codes are often “true and treatable”. Irrespective of perception, stroke providers in a CSC must be immediately and equally available in both early morning and evening. This also has ramifications for interventional procedure staffing and clinical trial enrollments. Further analyses in a larger dataset are warranted.

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Faecal corticosterone and immunoglobulin A in young adult rats

Laboratory Animals ◽

10.1258/00236770360563822 ◽

2003 ◽

Vol 37 (2) ◽

pp. 166-171 ◽

Cited By ~ 34

Author(s):

Liselotte Pihl ◽

Jann Hau

Keyword(s):

Body Weight ◽

Young Adult ◽

Time Windows ◽

Immunoglobulin A ◽

Time Of Day ◽

Female Rats ◽

Male Rats ◽

Adult Rats ◽

Faecal Pellets ◽

Non Invasive

Quantitative analyses of relevant molecules in faeces may have potential as future non-invasive measures of stress. This study examined levels of faecal corticosterone and immunoglobulin A (IgA) in young adult rats and how these levels varied according to age, gender and time of day. Faecal samples were collected from 40 young adult rats (7 weeks old, n = 20 and 10 weeks old, n = 20) of both sexes from two time windows: day and night. The concentrations of corticosterone and IgA were measured by ELISAs following organic solvent extraction and aqueous extraction, respectively, of the molecules from faecal pellets. The production of faeces per time unit was higher in males than in females, and linear correlations were found between the faecal concentrations of corticosterone and IgA and total amounts of the respective molecules excreted in faeces per kg body weight per hour. In all further analyses the levels of the two molecules were calculated as amounts secreted per kg of body weight per hour. There was no gender difference between females and males in the production of corticosterone and IgA, but 7-week-old animals excreted significantly higher amounts of both molecules than did 10-week-old rats. The levels of IgA excreted by female rats were higher in the evening than in the morning, and male rats excreted higher concentrations of corticosterone in the morning than in the evening.

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Context-Aware Link Embedding with Reachability and Flow Centrality Analysis for Accurate Speed Prediction for Large-Scale Traffic Networks

Electronics ◽

10.3390/electronics9111800 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1800

Author(s):

Chanjae Lee ◽

Young Yoon

Keyword(s):

Traffic Flow ◽

Large Scale ◽

Time Windows ◽

Time Of Day ◽

Feature Representation ◽

Traffic Networks ◽

Speed Prediction ◽

External Conditions ◽

Traffic Speed ◽

Spatio Temporal

This paper presents a novel method for predicting the traffic speed of the links on large-scale traffic networks. We first analyze how traffic flows in and out of every link through the lowest cost reachable paths. We aggregate the traffic flow conditions of the links on every hop of the inbound and outbound reachable paths to represent the traffic flow dynamics. We compute a new measure called traffic flow centrality (i.e., the Z value) for every link to capture the inherently complex mechanism of the traffic links influencing each other in terms of traffic speed. We combine the features regarding the traffic flow centrality with the external conditions around the links, such as climate and time of day information. We model how these features change over time with recurrent neural networks and infer traffic speed at the subsequent time windows. Our feature representation of the traffic flow for every link remains invariant even when the traffic network changes. Furthermore, we can handle traffic networks with thousands of links. The experiments with the traffic networks in the Seoul metropolitan area in South Korea reveal that our unique ways of embedding the comprehensive spatio-temporal features of links outperform existing solutions.

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