scholarly journals Relationship Between Deceleration Morphology and Phase Rectified Signal Averaging-Based Parameters During Labor

2021 ◽  
Vol 8 ◽  
Author(s):  
Massimo W. Rivolta ◽  
Moira Barbieri ◽  
Tamara Stampalija ◽  
Roberto Sassi ◽  
Martin G. Frasch
Keyword(s):  
Animal Model ◽  
Response Time ◽  
Chronic Hypoxia ◽  
Fetal Heart ◽  
Time Interval ◽  
Morphological Parameters ◽  
Signal Averaging ◽  
Uterine Contractions ◽  
Wide Range ◽  
Robust To Noise

During labor, uterine contractions trigger the response of the autonomic nervous system (ANS) of the fetus, producing sawtooth-like decelerations in the fetal heart rate (FHR) series. Under chronic hypoxia, ANS is known to regulate FHR differently with respect to healthy fetuses. In this study, we hypothesized that such different ANS regulation might also lead to a change in the FHR deceleration morphology. The hypothesis was tested in an animal model comprising nine normoxic and five chronically hypoxic fetuses that underwent a protocol of umbilical cord occlusions (UCOs). Deceleration morphologies in the fetal inter-beat time interval (FRR) series were modeled using a trapezoid with four parameters, i.e., baseline b, deceleration depth a, UCO response time τu and recovery time τr. Comparing normoxic and hypoxic sheep, we found a clear difference for τu (24.8±9.4 vs. 39.8±9.7 s; p < 0.05), a (268.1±109.5 vs. 373.0±46.0 ms; p < 0.1) and Δτ = τu − τr (13.2±6.9 vs. 23.9±7.5 s; p < 0.05). Therefore, the animal model supported the hypothesis that hypoxic fetuses have a longer response time τu and larger asymmetry Δτ as a response to UCOs. Assessing these morphological parameters during labor is challenging due to non-stationarity, phase desynchronization and noise. For this reason, in the second part of the study, we quantified whether acceleration capacity (AC), deceleration capacity (DC), and deceleration reserve (DR), computed through Phase-Rectified Signal Averaging (PRSA, known to be robust to noise), were correlated with the morphological parameters. DC, AC and DR were correlated with τu, τr and Δτ for a wide range of the PRSA parameter T (Pearson's correlation ρ > 0.8, p < 0.05). In conclusion, deceleration morphologies have been found to differ between normoxic and hypoxic sheep fetuses during UCOs. The same difference can be assessed through PRSA based parameters, further motivating future investigations on the translational potential of this methodology on human data.

scholarly journals Relationship between Deceleration Morphology and Phase Rectified Signal Averaging-based Parameters during Labor

2021 ◽  
Author(s):  
Massimo W. Rivolta ◽  
Moira Barbieri ◽  
Tamara Stampalija ◽  
Roberto Sassi ◽  
Martin G. Frasch
Keyword(s):  
Animal Model ◽  
Response Time ◽  
Chronic Hypoxia ◽  
Fetal Heart ◽  
Time Interval ◽  
Morphological Parameters ◽  
Signal Averaging ◽  
Uterine Contractions ◽  
Wide Range ◽  
Robust To Noise

AbstractDuring labor, uterine contractions trigger the response of the autonomic nervous system (ANS) of the fetus, producing sawtooth-like decelerations in the fetal heart rate (FHR) series. Under chronic hypoxia, ANS is known to regulate FHR differently with respect to healthy fetuses. In this study, we hypothesized that such different ANS regulation might also lead to a change in the FHR deceleration morphology. The hypothesis was tested in an animal model comprising 7 normoxic and 5 chronically hypoxic fetuses that underwent a protocol of umbilical cord occlusions (UCOs). Deceleration morphologies in the fetal inter-beat time interval (FRR) series were modeled using a trapezoid with four parameters, i.e., baseline b, deceleration depth a, UCO response time τu and recovery time τr. Comparing normoxic and hypoxic sheep, we found a clear difference for τu (24.8 ± 9.4 vs 39.8 ± 9.7 s; p < 0.05), a (268.1 ± 109.5 vs 373.0 ± 46.0 ms; p < 0.1) and Δτ = τu − τr (13.2 ± 6.9 vs 23.9 ± 7.5 s; p < 0.05). Therefore, the animal model supported the hypothesis that hypoxic fetuses have a longer response time τu and larger asymmetry Δτ as a response to UCOs. Assessing these morphological parameters during labor is challenging due to non-stationarity, phase desynchronization and noise. For this reason, in the second part of the study, we quantified whether acceleration capacity (AC), deceleration capacity (DC), and deceleration reserve (DR), computed through Phase-Rectified Signal Averaging (PRSA, known to be robust to noise), were correlated with the morphological parameters. DR and DC correlated with Δτ and τu for a wide range of the PRSA parameter T (max Pearson’s correlation ρ = 0.9, p < 0.05, and ρ = 0.6, p < 0.1, respectively). In conclusion, deceleration morphologies have been found to differ between normoxic and hypoxic sheep fetuses during UCOs. The same difference can be assessed through PRSA based parameters, further motivating future investigations on the translational potential of this methodology on human data.

scholarly journals Mathematical modeling shows that ball-rolling dung beetles can use dances to avoid competition

2021 ◽  
Author(s):  
Zhanyuan Yin ◽  
Leif Zinn-Brooks
Keyword(s):  
Mathematical Modeling ◽  
Optimal Strategy ◽  
Rolling Direction ◽  
Dung Beetles ◽  
Time Interval ◽  
Angular Deviation ◽  
Ball Rolling ◽  
Wide Range

Abstract Ball-rolling dung beetles shape a portion of dung into a ball and roll it away from the dung pile for later burial and consumption. These beetles perform dances (rotations and pauses) atop their dung balls in order to choose an initial rolling direction and to correct their rolling direction (reorient). Previous mathematical modeling showed that dung beetles can use reorientation to move away from the dung pile more efficiently. In this work, we study if reorientation can help beetles avoid competition (i.e., avoid having their dung balls captured), and if so, under what circumstances? This is investigated by implementing a model with two different type of beetles, a roller with a dung ball and a searcher which seeks to capture that dung ball. We show that reorientation can help rollers avoid searchers in a wide range of conditions, but that there are some circumstances in which rolling without reorienting can be a beetle's optimal strategy. We also show that rollers can minimize the probability that their dung ball is captured without making precise measurements of the time interval between dances or the angular deviation for dances.

scholarly journals Efficient and Cost-effective Service Broker Policy Based on User Priority in VIKOR for Cloud Computing

2021 ◽  
pp. 1-8
Author(s):  
Mohammed Radi ◽  
Ali Alwan ◽  
Abedallah Abualkishik ◽  
Adam Marks ◽  
Yonis Gulzar
Keyword(s):  
Cloud Computing ◽  
Response Time ◽  
Service Providers ◽  
Cost Effective ◽  
Cloud Service ◽  
User Preferences ◽  
Cloud Environment ◽  
Data Centre ◽  
Wide Range ◽  
Service Broker

Cloud computing has become a practical solution for processing big data. Cloud service providers have heterogeneous resources and offer a wide range of services with various processing capabilities. Typically, cloud users set preferences when working on a cloud platform. Some users tend to prefer the cheapest services for the given tasks, whereas other users prefer solutions that ensure the shortest response time or seek solutions that produce services ensuring an acceptable response time at a reasonable cost. The main responsibility of the cloud service broker is identifying the best data centre to be used for processing user requests. Therefore, to maintain a high level of quality of service, it is necessity to develop a service broker policy that is capable of selecting the best data centre, taking into consideration user preferences (e.g. cost, response time). This paper proposes an efficient and cost-effective plan for a service broker policy in a cloud environment based on the concept of VIKOR. The proposed solution relies on a multi-criteria decision-making technique aimed at generating an optimized solution that incorporates user preferences. The simulation results show that the proposed policy outperforms most recent policies designed for the cloud environment in many aspects, including processing time, response time, and processing cost. KEYWORDS Cloud computing, data centre selection, service broker, VIKOR, user priorities

scholarly journals Atrioventricular Conduction Time in Fetuses Assessed by Doppler Echocardiography

2011 ◽  
pp. 611-616 ◽  
Author(s):  
V. TOMEK ◽  
J. JANOUŠEK ◽  
O. REICH ◽  
J. GILÍK ◽  
R. A. GEBAUER ◽  
...  
Keyword(s):  
Heart Rate ◽  
Reference Values ◽  
Gestational Age ◽  
Doppler Echocardiography ◽  
Fetal Heart ◽  
Atrioventricular Conduction ◽  
Time Interval ◽  
Conduction Time ◽  
Time Intervals ◽  
Normal Limits

We performed measurement of mechanical atrioventricular conduction time intervals in human fetuses assessed by Doppler echocardiography and provided reference values. We found that atrioventricular conduction time interval was prolonged with gestational age and decreased with increasing fetal heart rate. No correlation between gestational age and heart rate was found. Using normal limits established by this study, mechanical atrioventricular interval >135 ms in the 20th week and/or >145 ms in the 26th week of gestation could be suspected of having the first-degree AV block. We compared reference values with fetuses of mothers with anti-SSA Ro/SSB La autoantibodies, being in risk of isolated congenital heart block development. One of 21 fetuses of mothers with positive autoantibodies was affected by prolonged atrioventricular interval according to the established limits, with sinus rhythm after the birth.

Psychiatric side effects induced by supraphysiological doses of combinations of anabolic steroids correlate to the severity of abuse

2006 ◽  
Vol 21 (8) ◽  
pp. 551-562 ◽  
Author(s):  
Thomas A. Pagonis ◽  
Nikiforos V. Angelopoulos ◽  
George N. Koukoulis ◽  
Christos S. Hadjichristodoulou
Keyword(s):  
Side Effects ◽  
Anabolic Steroids ◽  
Linear Regression Analysis ◽  
Control Group ◽  
Time Interval ◽  
Psychological Consequences ◽  
Psychometric Instruments ◽  
Wide Range ◽  
Significant Difference ◽  
Psychiatric Side Effects

AbstractObjectiveThe objective of our study was to evaluate the psychological consequences of real-world AAS use in athletes abusing such agents, in comparison with a placebo and control group of comparable athletes, while correlating the severity of abuse with the side effects observed. The hypothesis tested by the study was that the use of AAS induces a wide range of psychological side effects whose impact and emergence is dependent upon the severity of the abuse.DesignThe study includes a substantial group of AAS abusing athletes and two more groups demographically similar to the first, one composed of athletes not using any substance and a placebo group. All athletes were stratified according to the severity of AAS abuse. Psychometric instruments were applied to all athletes in specific time intervals, dependent to the AAS abusers' regimens, providing us with a final psychological profile that was to be compared to the pre-study profile. All results were comparable (within and between groups) for statistically significant differences and correlated to the severity of the abuse. Homogeneity of all groups was safeguarded by random doping controls, monitoring of drug levels and analysis of all self obtained drugs by method of liquid chromatography/mass spectrometry. All athletes were provided with a common exercise and dietary regime, so common training and nutritional conditions were achieved.MethodsWe studied a cohort of 320 body-building, amateur and recreational athletes, of whom 160 were active users of AAS (group C), 80 users administering placebo drugs (group B) and 80 not abusing any substance (Group A). Group C athletes were stratified according to AAS abuse parameters, thus providing us with three subgroups of “light, medium and heavy abuse”. Athletes of groups A and B were included in a “no abuse” subgroup. The psychometric instruments used were the Symptoms Check List-90 (SCL-90) and the Hostility and Direction of Hostility Questionnaire (HDHQ). The psychometric evaluations took place within a time interval of 13 months. Statistical analysis was performed by using the Mann–Whitney/Wilcoxon two-sample non-parametric test (Kruskal–Wallis test for two groups) for data that were not normally distributed and Linear regression analysis was used to ascertain the correlation between severity of use and escalation of side effects.ResultsThe study showed a statistically significant increase in all psychometric subscales recorded in group C, and no statistically significant difference in group C and A. There was a significant increase in the scorings of group C for all subscales of SCL-90 and HDHQ. Correlation of abuse severity and side effects showed that there was a statistical significant increase in Δ values of all SCL-90 and HDHQ subscales that escalated from light abuse to medium and heavy abuse/consumption patterns.ConclusionsThe results of the study suggest that the wide range of psychiatric side effects induced by the use of AAS is correlated to the severity of abuse and the force of these side effects intensifies as the abuse escalates.

A Dynamic Data Fragmentation and Distribution Strategy for Main-Memory Database Cluster

2012 ◽  
Vol 490-495 ◽  
pp. 1231-1236 ◽  
Author(s):  
Tran Van Hung ◽  
Chuan He Huang
Keyword(s):  
Response Time ◽  
Cluster Computing ◽  
Data Access ◽  
Fast Response ◽  
Main Memory ◽  
Relation Database ◽  
Computing Platform ◽  
Wide Range ◽  
Cluster Environment ◽  
Remote Sites

MMDB cluster system is a memory optimized relation database that implements on cluster computing platform, provides applications with extremely fast response time and very high throughput as required by many applications in a wide range of industries. Here, a new dynamic fragment allocation algorithm (DFAPR) in Partially Replicated allocation scenario is proposed. This algorithm reallocates data with respect to changing data access pattern for each fragment in which data is maintained in current site, migrated or created new replicas on remote sites depend on accessing frequency and average response time. At last, the simulation results show that the DFAPR is suitable for MMDB cluster because it provides a better response time and maximize the locality of processing so it could be developed parallel processing of MMDB in cluster environment.

Abstract 249: The Effect of Response Time on Out-Of-Hospital Cardiac Arrest Survival Varies by Patient Subpopulation

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Clara Stoesser ◽  
Justin Boutilier ◽  
Christopher L Sun ◽  
Katie N Dainty ◽  
Steve Lin ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Regression Analysis ◽  
Response Time ◽  
Time Interval ◽  
Probability Of Survival ◽  
Subgroup Analyses ◽  
Impact On Survival ◽  
The Impact ◽  
Cardiac Arrest Survival ◽  
Hospital Cardiac Arrest

Itroduction: Previous research has quantified the impact of EMS response time on the probability of survival from OHCA, but the impact on different subpopulations is currently unknown. Aim: To investigate how response time affects OHCA survival for different patient subpopulations. Methods: We conducted a logistic regression analysis on non-EMS witnessed OHCAs of presumed cardiac etiology from the Toronto Regional RescuNet between January 1, 2007 and December 31, 2016. We predicted survival using age, sex, public location, presenting rhythm, bystander witnessed, bystander resuscitation, and response time, defined as the time interval from 911 call to EMS arrival at the patient. We conducted subgroup analyses to quantify the effect of response time on survival for eight different subpopulations: public, private, bystander resuscitation, no bystander resuscitation, patients ≥65, patients <65, witnessed, and unwitnessed OHCA. We also quantified the effect of response time on survival for pairwise intersections of the subpopulations. We compared our results to Valenzuela et al. (1997), which suggests survival odds decrease by 10% for each minute delay in response time. Results: We identified 22,988 OHCAs. Overall, a one-minute delay in EMS response time was associated with a 13.2% reduction in the odds of survival. The reduction varied by subpopulation, ranging from a 7.2% reduction in survival odds for unwitnessed arrests to a 16.4% reduction in survival odds for arrests with bystander resuscitation. Response time had the largest impact on survival for the subpopulation of OHCAs that were both witnessed and received bystander resuscitation (17.4% reduction in survival odds). Conclusion: The effect of a one-minute delay in EMS response on the odds of survival from OHCA can be as low as a 7.2% reduction and as high as a 17.4% reduction. This variability contrasts with the currently accepted 10% rule that is assumed across the entire population.

Prometheus

2018 ◽  
Author(s):  
Andrew C. Scott
Keyword(s):  
Volcanic Activity ◽  
Human Interaction ◽  
Time Interval ◽  
C4 Grasses ◽  
Fossil Plants ◽  
Natural Fire ◽  
Lightning Strikes ◽  
Wide Range ◽  
Cooked Meat ◽  
Vegetation And Climate

It is sometimes said that humans were born of fire. While a wide range of animal species interact with fire, we appear to be the only species to have learned to tame it, and more importantly to make it. There is evidence that early humans were aware of fire and may have exploited naturally occurring fire, but only later did they control and manage it. Human interaction with fire must have proceeded through various levels, the first of which can be described as the opportunistic phase. In this phase, natural fire may have been exploited to help in hunting, for example. When, how, and why did this happen? It is widely agreed that our story begins in Africa. It is here that we see the evolution of hominins, a group of related genera that include the Australopithecines and later the genus Homo. How common would fire have been in the environments in which they lived? We already know from the study of fossil plants, as well as isotope data, that there were important changes in both the vegetation and climate over the past 10 million years. It is also during this time interval that hominins emerged from apes. Through the Oligocene and Miocene (30–8 million years ago), Africa was largely covered by tropical rainforest, where fire was present but infrequent, started both by lightning strikes and volcanic activity. As the climate began to dry and C4 grasses spread at the end of the Miocene Epoch, around 8 million years ago, habitats became more open. Fire became more frequent, and from an animal perspective would have become more visible, not just from flames but also smoke. Frequent fire in the landscape would have had many consequences for the early hominins, not just because game was more easily killed, but burned animals (naturally cooked meat) would have made a useful addition to the diet, and the new flush of growth following fire would also have attracted large herds of herbivores. Fire may have been conserved through adding fuel, including dung, which is slow burning.

scholarly journals Design and Evaluation of LYSO/SiPM LIGHTENING PET Detector with DTI Sampling Method

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5820
Author(s):  
Zhenzhou Deng ◽  
Yushan Deng ◽  
Guandong Chen
Keyword(s):  
High Performance ◽  
Sampling Method ◽  
Average Energy ◽  
High Sensitivity ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Time Interval ◽  
Silicon Photomultiplier ◽  
Experimental Conditions ◽  
Wide Range

Positron emission tomography (PET) has a wide range of applications in the treatment and prevention of major diseases owing to its high sensitivity and excellent resolution. However, there is still much room for optimization in the readout circuit and fast pulse sampling to further improve the performance of the PET scanner. In this work, a LIGHTENING® PET detector using a 13 × 13 lutetium-yttrium oxyorthosilicate (LYSO) crystal array read out by a 6 × 6 silicon photomultiplier (SiPM) array was developed. A novel sampling method, referred to as the dual time interval (DTI) method, is therefore proposed to realize digital acquisition of fast scintillation pulse. A semi-cut light guide was designed, which greatly improves the resolution of the edge region of the crystal array. The obtained flood histogram shown that all the 13 × 13 crystal pixels can be clearly discriminated. The optimum operating conditions for the detector were obtained by comparing the flood histogram quality under different experimental conditions. An average energy resolution (FWHM) of 14.3% and coincidence timing resolution (FWHM) of 972 ps were measured. The experimental results demonstrated that the LIGHTENING® PET detector achieves extremely high resolution which is suitable for the development of a high performance time-of-flight PET scanner.

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