Scheduling Medical Procedures: How One Single Delay Begets Multiple Subsequent Delays

Background: Delay is a common feature of medical disease management. Delays occur because schedules are filled, patients forget their appointment, equipment is unavailable, or because medical and non-medical complications interfere with the planned procedure. The aim of the present analysis is to model how one single delay can lead to multiple subsequent delays.Methods: The consecutive stream of delays is analyzed in terms of a stochastic process comprising of a random sum of random time periods. Any untoward event causes a procedural delay, which provides a time window of opportunity for yet another delaying event to occur.Results: The stochastic model explains why even a single initial delay can easily lead to a multitude of subsequent delays. The expected overall delay is always longer than the initial delay caused by the deferment of the initial procedure. The analysis demonstrates how in individual patients an initially short delay may subsequently expand into days or weeks.Conclusion: Because a single delay can easily burgeon into a lengthy series of multiple delays, the primary goal should be to avoid the precipitating delay at the onset.

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Conversion of Anergic T Cells Into Foxp3- IL-10+ Regulatory T Cells by a Second Antigen Stimulus In Vivo

Frontiers in Immunology ◽

10.3389/fimmu.2021.704578 ◽

2021 ◽

Vol 12 ◽

Author(s):

Anna Sophie Thomann ◽

Theresa Schneider ◽

Laura Cyran ◽

Ina Nathalie Eckert ◽

Andreas Kerstan ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Time Window ◽

Common Mechanism ◽

Short Term ◽

Subsequent Conversion ◽

Time Periods ◽

Anergic T Cells ◽

Tr1 Cells

T cell anergy is a common mechanism of T cell tolerance. However, although anergic T cells are retained for longer time periods in their hosts, they remain functionally passive. Here, we describe the induction of anergic CD4+ T cells in vivo by intravenous application of high doses of antigen and their subsequent conversion into suppressive Foxp3- IL-10+ Tr1 cells but not Foxp3+ Tregs. We describe the kinetics of up-regulation of several memory-, anergy- and suppression-related markers such as CD44, CD73, FR4, CD25, CD28, PD-1, Egr-2, Foxp3 and CTLA-4 in this process. The conversion into suppressive Tr1 cells correlates with the transient intracellular CTLA-4 expression and required the restimulation of anergic cells in a short-term time window. Restimulation after longer time periods, when CTLA-4 is down-regulated again retains the anergic state but does not lead to the induction of suppressor function. Our data require further functional investigations but at this stage may suggest a role for anergic T cells as a circulating pool of passive cells that may be re-activated into Tr1 cells upon short-term restimulation with high and systemic doses of antigen. It is tentative to speculate that such a scenario may represent cases of allergen responses in non-allergic individuals.

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Sequential Metabolic Changes in Rat Brain following Middle Cerebral Artery Occlusion: A 2-Deoxyglucose Study

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1989.110 ◽

1989 ◽

Vol 9 (6) ◽

pp. 765-773 ◽

Cited By ~ 84

Author(s):

Kazuya Shiraishi ◽

Frank R. Sharp ◽

Roger P. Simon

Keyword(s):

Amino Acid ◽

Time Course ◽

Time Window ◽

Excitatory Amino Acid ◽

Cerebral Metabolism ◽

Focal Ischemia ◽

Artery Occlusion ◽

Window Of Opportunity ◽

Cerebral Artery Occlusion ◽

Permanent Focal Ischemia

The distribution and time course of altered cerebral metabolism following permanent focal ischemia was studied in rat using the 2-deoxyglucose (2DG) technique. Increased 2DG uptake preceded decreased 2DG uptake and infarction in the caudate putamen and cortex. Decreased 2DG uptake without infarction was observed for 72 h in thalamus and for 24 h in hippocampus (areas remote from the ischemic zones). This study supports the concept of cell excitation as a pathophysiologic process in permanent focal ischemia. The time course of increased metabolism may demarcate the time window of opportunity for the previously demonstrated attenuation of stroke size with inhibition of cell excitation by pharmacologic blockade of excitatory amino acid neurotransmission.

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Congestion and Pollution, Vehicle Routing Problem of a Logistics Provider in Thailand

The Open Transportation Journal ◽

10.2174/1874447801913010203 ◽

2019 ◽

Vol 13 (1) ◽

pp. 203-212

Author(s):

Chanicha Moryadee ◽

Wissawa Aunyawong ◽

Mohd Rizaimy Shaharudin

Keyword(s):

Time Window ◽

Optimal Solution ◽

Computation Time ◽

Future Research ◽

Multiple Time ◽

Emission Model ◽

Time Dependency ◽

Routing Problem ◽

Original Solution ◽

Time Periods

Aim and Objective: This study aims to minimise the travelling distance, operation cost in terms of fuel consumption, and CO2 emissions. It introduces the Time-Dependency Pollution-Routing Problem (TDPRP) with the implementation of the time-dependency and emission model, including constraints such as the limitation of vehicle capacity and vehicle’s speed during different time periods in Thailand. Furthermore, the time window constraint is applied for representing a more realistic model. The main objective is to minimise the total pollution generated because of transportation. Methods: The Genetic Algorithm (GA) and Tabu Search (TS) methods have been used to generate the optimal solution with a variety of experiments. The best solutions from all the experiments have been compared to the original solution in terms of the quality of the solution and the computation time. Results: The best solution was generated by using the TS method with 30,000 trials. The minimum of the total CO2 emissions was 183.9846 kilograms produced from all of the vehicles during transportation, nearly half from the current transportation plan, which produced 320.94 kilograms of CO2 emissions. Conclusion: The proposed model optimised both the route and schedules (multiple time periods) for a number of vehicles, for which the transportation during a fixed congestion period could be predicted to avoid traffic congestion and reduce the CO2 emission. Future research is suggested to add other specific algorithms as well as constraints in order to make the model more realistic.

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Abstract 17168: Stroke Stabilization Following Repetitive Xenon Liposomal Delivery

Circulation ◽

10.1161/circ.138.suppl_1.17168 ◽

2018 ◽

Vol 138 (Suppl_1) ◽

Author(s):

Xing Yin ◽

Manoj P Dandekar ◽

Tao Peng ◽

Melvin E Klegerman ◽

Melanie R Moody ◽

...

Keyword(s):

Time Window ◽

Single Injection ◽

Infarct Volume ◽

Artery Occlusion ◽

Brain Protection ◽

Stroke Treatment ◽

Novel Method ◽

Time Periods ◽

Cerebral Artery Occlusion

Introduction: Stroke is a leading cause of brain injury. Most stroke survival has long-term disability due to cerebral damage. We have demonstrated that xenon(Xe) liposomal injection provides novel neuroprotection. Hypothesis: Repetitive Xe-liposomal administration over a longer period post stroke results in brain protection. Methods: Stroke was induced by middle cerebral artery occlusion(MCAO) for 6 hours. Xe-liposomes were intravenously administrated for varying duration and time periods to investigate the administration frequency and administration duration. Infarct size was evaluated by TTC staining. Forelimb placing/Grid walking were conducted to evaluate neurological function. Results: MCA occlusion for 6 hours generated a 23%±2.8% infarct volume. Repetitive injections at every one hour for 5 injections effectively reduced infract volume(3.8%±0.2%,p<0.05) than a single injection(11%±2.3). Extending Xe liposomal treatment to 3 days further decreased infarct volume to 1.9%%±0.7 (p<0.01,Fig.1A). Behavior tests results are correlated with TTC staining(Fig. 1B). Conclusions: Repetitive Xe-liposomal administration over the first 6 hours following MCAO and extending daily administration results in brain stabilization.This novel method may help may help extend the time window for stroke treatment.

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Window of opportunity

Therapeutische Umschau ◽

10.1024/0040-5930/a000814 ◽

2016 ◽

Vol 73 (7) ◽

pp. 431-435

Author(s):

Markus G. Mohaupt

Keyword(s):

Kardiovaskuläre Erkrankungen ◽

Window Of Opportunity ◽

Präventive Maßnahmen ◽

Kardiovaskuläre Komplikationen ◽

Sind Eine ◽

Hypertensive Schwangerschaftserkrankungen

Zusammenfassung. Kardiovaskuläre Erkrankungen sind eine Hauptursache für Morbidität und Mortalität. Es ist vordringlich, diese Bedrohung zu minimieren. Hypertensive Schwangerschaften treten einerseits bevorzugt bei Frauen auf, die zu kardiovaskulären Erkrankungen tendieren, andererseits prädisponieren hypertensive Schwangerschaftserkrankungen, z.B. eine Präeklampsie, für spätere kardiovaskuläre Komplikationen. So sollten präventive Massnahmen schon früh nach der akuten Erkrankungen dieses Risiko reduzieren. Dazu gehört die Information bezüglich eines gesunden Lebensstil und zukünftige hausärztliche Kontrolluntersuchungen der kardiovaskulären Risikoindikatoren. In ähnlicher Weise sind Kinder mit einem erniedrigten Geburtsgewicht bzw. Mangelgeburtlichkeit für ein gegebenes Gestationsalter betroffen. Da diese Geburtskomplikationen häufiger bei hypertensiven Schwangerschaftserkrankungen auftreten, sollten den Müttern vergleichbare langfristige präventive Massnahmen getroffen werden. Zusammenfassend benötigen Mutter und häufig auch die Kinder aus hypertensiven Schwangerschaften geeignete kardiovaskuläre langfristige Präventionsmassnahmen. Frauen mit einem bislang nicht erkannten metabolischen bzw. Herz-Kreislauferkrankungsrisiko können damit einem sorgfältigen Follow-up zugeführt werden. Somit kann die hypertensive Schwangerschaft als Risikoindikator die Basis für eine frühzeitige Risikoprävention und ein gesundes Leben legen.

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Feel Thine Own Self – Mood Congruency Evaluation of Emotional State Adjectives

Journal of Psychophysiology ◽

10.1027/0269-8803/a000272 ◽

2020 ◽

pp. 1-17

Author(s):

Szczepan J. Grzybowski ◽

Miroslaw Wyczesany ◽

Jan Kaiser

Keyword(s):

Mood Induction ◽

Semantic Analysis ◽

Emotional State ◽

Time Window ◽

Event Related Potential ◽

Negativity Bias ◽

Positive Potential ◽

Semantic Access ◽

Current Mood ◽

Component Time

Abstract. The goal of the study was to explore event-related potential (ERP) differences during the processing of emotional adjectives that were evaluated as congruent or incongruent with the current mood. We hypothesized that the first effects of congruence evaluation would be evidenced during the earliest stages of semantic analysis. Sixty mood adjectives were presented separately for 1,000 ms each during two sessions of mood induction. After each presentation, participants evaluated to what extent the word described their mood. The results pointed to incongruence marking of adjective’s meaning with current mood during early attention orientation and semantic access stages (the P150 component time window). This was followed by enhanced processing of congruent words at later stages. As a secondary goal the study also explored word valence effects and their relation to congruence evaluation. In this regard, no significant effects were observed on the ERPs; however, a negativity bias (enhanced responses to negative adjectives) was noted on the behavioral data (RTs), which could correspond to the small differences traced on the late positive potential.

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Time Window from Visual Images to Visual Short-Term Memory: Consolidation or Integration?

Experimental Psychology (formerly Zeitschrift für Experimentelle Psychologie) ◽

10.1027/1618-3169.51.1.45 ◽

2004 ◽

Vol 51 (1) ◽

pp. 45-51 ◽

Cited By ~ 21

Author(s):

Yuhong Jiang

Keyword(s):

Short Term Memory ◽

Time Window ◽

Short Interval ◽

Visual Images ◽

Short Term ◽

Temporal Window ◽

Term Memory ◽

Visual Short Term Memory ◽

Probe Task ◽

Long Time

Abstract. When two dot arrays are briefly presented, separated by a short interval of time, visual short-term memory of the first array is disrupted if the interval between arrays is shorter than 1300-1500 ms ( Brockmole, Wang, & Irwin, 2002 ). Here we investigated whether such a time window was triggered by the necessity to integrate arrays. Using a probe task we removed the need for integration but retained the requirement to represent the images. We found that a long time window was needed for performance to reach asymptote even when integration across images was not required. Furthermore, such window was lengthened if subjects had to remember the locations of the second array, but not if they only conducted a visual search among it. We suggest that a temporal window is required for consolidation of the first array, which is vulnerable to disruption by subsequent images that also need to be memorized.

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