Initial Time Difference Research Articles

Variation of parameters and initial time difference Lipschitz stability of impulsive differential equations

In this paper, we investigate the Lipschitz stability of a perturbed impulsive differential system concerning the unperturbed system. We employ the variation of parameters or the constant of variation for impulsive differential systems with an initial time difference.

Retrospective analysis on the efficacy of epidural labor analgesia on early breast feeding after vaginal delivery

BackgroundBreastfeeding is essential for infants and mothers. Epidural labor analgesia is used frequently to alleviate pain during vaginal delivery. Studies have found that epidural labor analgesia potentially have negative effects on postpartum breastfeeding. However, the efficacy of epidural labor analgesia on early breastfeeding after vaginal delivery is unclear. Therefore, a retrospective analysis was performed to illuminate the efficacy of epidural labor analgesia on postpartum breast feeding.MethodsA total of 392 women who received vaginal delivery in the Second People’s Hospital of Foshan from July 2022 to June 2023 were selected for this study, and all women received epidural labor analgesia and were divided into three groups according to the efficacy of labor analgesia. There were three groups: parturients with VAS scores < 3 were divided into Group E (n = 192), parturients with VAS scores 4–6 were divided into Group M (n = 127), and parturients with VAS scores > 7 were divided into Group P (n = 73). The labor process, lactation initiation time, and incidence of delayed onset of lactation were analyzed. The lactation volume and time and LATCH score at 24, 48 and 72 h after vaginal delivery were also analyzed.ResultsThere was no significant difference in labor process times among the three groups (P > 0.05). The cases of prolactin use in Group M were less than those in Group E and Group P, with a significant difference (all P < 0.05). There was no significant difference in cases of prolactin use between Group E and Group P (P > 0.05). The lactation initiation time in Group M was significantly shorter than those in Group E and Group P (all P>0.05). There was no significant difference in lactation initiation time after vaginal delivery between Group E and Group P (P>0.05). The incidence of delayed onset of lactation in Group M was significantly lower those that in Group E and Group P (all P < 0.05). There was no statistically significant difference in the incidence of delayed onset of lactation between Group E and Group P (P > 0.05). The lactation volumes at 24, 48 and 72 h after vaginal delivery in Group M were significantly higher than those in Group E and Group P (all P < 0.05). There was no significant difference in lactation volume at 24, 48 and 72 h after vaginal delivery between Group E and Group P (P > 0.05). The lactation times at 24, 48 and 72 h after vaginal delivery in Group M were significantly higher than those in Group E and Group P (all P < 0.05). There was no significant difference in lactation times at 24, 48 and 72 h after vaginal delivery between Group E and Group P (P > 0.05). There was no significant difference in LATCH scores at 24, 48 and 72 h after vaginal delivery among the three groups (all P > 0.05).ConclusionsCompared with labor analgesia with excellent and poor analgesia efficacy, labor analgesia with moderate analgesia efficacy has fewer cases of prolactin use, more lactation volume and time, a shorter lactation initiation time, a lower incidence of delayed onset of lactation and no effect on the LATCH score of breastfeeding.

Lagrange stability in terms of two measures with initial time difference for set differential equations involving causal operators

In this paper, we investigate generalized variational comparison results aimed to study the stability properties in terms of two measures for solutions of Set Differential Equations (SDEs) involving causal operators, taking into consideration the difference in initial conditions. Next, we employ these comparison results in proving the theorems that give sufficient conditions for equi-boundedness, equi-attractiveness in the large, and Lagrange stability in terms of two measures with initial time difference for the solutions of perturbed SDEs involving causal operators in regard to their unperturbed ones.

Static recrystallization behavior of the cold-rolled Mg-1Al-1Zn-0.1Ca-0.2Y magnesium alloy sheet

In this study, we investigated the static recrystallization behavior and basal texture change from rolling direction (RD)-split (c-axes of grains toward the RD) to transverse direction (TD)-split (c-axes of grains toward the TD) of the cold-rolled Mg-1Al-1Zn-0.1Ca-0.2Y (AZXW1100) alloy during annealing. The cold-rolled AZXW1100 alloy sheet contained highly deformed shear bands (SBs), corresponding to 58 % of the total area, which caused rapid recrystallization at the beginning of annealing. The fine recrystallized grains nucleated in the SBs, and the intersection of the twins grew larger while consuming the deformed matrix grains, which did not recrystallize even at the late stage of annealing and were consumed by the surrounding recrystallized grains nucleated on the SBs. Owing to the difference in the recrystallization initiation time between the SB and deformed matrix grains, the recrystallized grains nucleated in the SBs guided the overall recrystallization behavior. Additionally, quasi-in-situ electron backscattered diffraction analyses clearly showed that among the recrystallized grains nucleated at the SBs, the grains with TD texture components became larger through preferential growth, whereas those with RD texture components did not grow and disappeared. Owing to this preferential grain growth, the texture intensity in the RD decreased and that in the TD was maintained, resulting in the formation of a diamond-like or TD-split texture. In this study, the co-segregation of Al, Zn, and Ca atoms along the grain boundaries and the formation of nanoscale Al8Mn5 particles were found to reduce boundary mobility and, consequently, hinder grain growth. These results can explain the texture change from a strong RD-split to a weak TD-split during annealing.

A fast TDOA and VDOA estimation method of the wideband frequency hopping signal

In the mobile multi-station passive positioning scenario, the carrier frequency hopping of the wideband frequency hopping communication signal will produce a changing Doppler frequency shift. Therefore, it is not possible to directly estimate the Doppler frequency difference of the observed signal containing multiple pulses. In this case, only the time difference and frequency difference of the single-hop signal can be estimated, but the accuracy is low. The existing methods often need the carrier frequency of each FH pulse signal as a priori information, and the high computational complexity of the two-dimensional search method of the time difference and frequency difference is difficult to overcome. Aiming at the above problems, a fast and high-precision estimation algorithm for the time difference of arrival and velocity difference of wideband frequency hopping signals is proposed in this paper. Firstly, the wideband frequency hopping signal is segmented in the time domain with multiple pulses as the unit, the signal model of time-varying time difference is established, and the time difference of each short-time segment is estimated by the generalized cross-correlation algorithm. The estimated values of the initial time difference and Doppler velocity difference can be worked out by least squares fitting of the time difference sequence obtained from the single pulse estimation. Finally, taking the Link16 data link signal as an example, the simulation experiment of the proposed method is conducted, which verifies the correctness and performance superiority of the algorithm.

Impacts of visual and cognitive distractions and time pressure on pedestrian crossing behaviour: A simulator study

Distractions have been recognised as one important factor associated with pedestrian injuries, as the increasing use of cell phones and personal devices. However, the situation is less clear regarding the differences in the effects of visual-manual and auditory-cognitive distractions. Here, we investigated distracted pedestrians in a one-lane road with continuous traffic using an immersive CAVE-based simulator. Sixty participants were recruited to complete a crossing task and perform one of two distractions, a visual-manual task and an auditory-cognitive task. Moreover, normal and time pressure crossing conditions were included as a baseline and comparison. For the first time, this study directly compared the impacts of visual-manual, auditory-cognitive distractions, and time pressure on pedestrian crossing behaviour and safety in a controlled environment. The results indicated that although pedestrian safety was compromised under both types of distraction, the effects of the applied distractions were different. When engaged in the visual-manual distraction, participants crossed the road slowly, but there was no significant difference in gap acceptance or initiation time compared to baseline. In contrast, participants walked slowly, crossed earlier, and accepted smaller gaps when performing the auditory-cognitive distraction. This has interesting parallels to existing findings on how these two types of distractions affect driver performance. Moreover, the effects of the visual-manual distraction were found to be dynamic, as these effects were affected by the gap size. Finally, compared to baseline, time pressure resulted in participants accepting smaller time gaps with shorter initiation times and crossing durations, leading to an increase in unsafe decisions and a decrease in near-collisions. These results provide new evidence that two types of distraction and time pressure impair pedestrian safety, but in different ways. Our findings may provide insights for further studies involving pedestrians with different distraction components.

On Fuzzy Differential Inequalities with Upper and Lower Solutions

In this article, by using the technique of upper and lower solutions, some comparison results for first-order fuzzy differential equations are established. Hukuhara derivative, Hukuhara difference, and partial orderings are used for proving theorems. We extend our results to initial time difference case as well. Also, the practicality of these comparison results is demonstrated by giving an example.

Early warning of heavy rainfall event using time-lagged ensemble prediction system (case study February 15th 2019)

Convective clouds can be related to the development of intense storms that produce various extreme weather. The development of extreme weather could involve strong nonlinear interactions of many factors in the atmosphere, hence the ability to forecast extreme weather especially heavy rainfall and issued an early warning, becomes very important. BMKG has developed a time-lagged ensemble prediction system by utilizing the initial time difference, which is considered capable of providing data updates more closely to the forecasts final results. This study examines the percentile classification in the ensemble prediction system, to look for an extreme values distribution, then used it as extreme threshold. The extreme threshold was tested in a heavy rain case on February 15th 2019, on D-7, D-3, and D-1 of early warning dissemination. Based on this research, it was found that the use of the 90th and 95th percentile classification method was able to show a signal of extreme events on D-7 and D-3 events with a consistent probability pattern. In the D-1 prediction period, the probability value increases and the average precipitation value exceeds the extreme threshold.

Effect of 2,4-D and BAP on Morphological Characters and Genetic Stability of Kaffir Lime (Citrus hystrix DC.) Callus Cultures Among Generations

Kaffir lime has medicinal properties for the treatment of many diseases. We used in vitro culture techniques to maintain quality and increase the production of active compounds in kaffir lime. The objective of this study is to determine the phenotype and genotype of kaffir lime callus cultures grown on media with the addition of 2,4-Dichlorophenoxyacetic (2,4-D) and Benzylaminopurine (BAP) on three generations (G0, G1, and G2). The callus was induced and subcultured on Murashige and Skoog medium added with 2,4-D: BAP at concentrations of 1:0.5; 2:0 and 5:0. Results showed no significant difference in callus initiation time in all treatment groups. Morphological characteristics, including color, texture, and biomass, varied among growth regulator concentrations and generation level. A high level of callus generation corresponds to a more friable texture and a more yellowish callus. Callus grown with the addition of 2,4-D and BAP 2:0 and 5:0 showed a more friable structure and yellowish color than 1:0.5. Growth regulator concentrations in each generation did not affect the callus growth curves, but the length of each phase between generations was different. The exponential phases of G1 and G2 were faster than that of G0. Despite slight differences in phenotype, the DNA profiles of callus suggest the same pattern between treatment groups, thereby indicating that our kaffir lime callus has genetic stability and that the callus can be used as raw material for medicinal purposes. Keywords: ISSR markers, Kaffir lime callus, Generations, Genotype, Growth factor, Phenotype

Qualitative results for finite system of R-L fractional differential equations with initial time difference

Qualitative results such as existence and uniqueness of finite system of Riemann-Liouville (R-L) fractional differential equations with initial time difference are obtained. Monotone technique coupled with method of lower and upper solutions is developed to obtain existence and uniqueness of solutions of finite system of R-L fractional differential equations with initial time difference.

USER Protocol as a Guide to Resuscitation of the Patient with Septic Shock in the Emergency Department.

IntroductionSepsis is a disease that is still associated with high mortality, in which timely interventions are related to better results.ObjectiveTo determine if there is a difference in in-hospital mortality, fluid balances, norepinephrine initiation and recovery time of blood pressure, when comparing the resuscitation of the patient who is admitted to the emergency room in septic shock by applying the ultrasound protocol (USER) versus the standard of care.Patients and MethodsThis is a prospective, cohort study conducted in the emergency room of a highly complex hospital of patients with septic shock.Results83 patients recruited in total. The groups were comparable in demographics, mean baseline blood pressure, disease severity given by the SOFA value, and arterial lactate. A statistically significant difference was documented in the fluid balances at 4 hours, median 1325mL (IQR:451–2455mL) in Group C versus 900mL (IQR:440–1292) in Group U (p=0.048) and at 6 hours, median 1658mL (IQR:610–2925mL) versus 1107mL (IQR:600–1500mL), p=0.026, as well as in the total fluid balance of hospital stay, median 14,564mL (IQR:8660–18,705mL) versus 8660mL (IQR:5309–16,974mL), p=0.049. On the other hand, in the USER Group, the mean blood pressure ≥ 65mmHg was achieved in 97.4% of the patients 4 hours after the start of the protocol versus 50% in Group C (p=<0.001). Mortality with the use of the protocol compared with conventional therapy was (56.4% vs 61.36%, p=0.647).ConclusionThe use of the USER protocol in patients with septic shock in the emergency room showed lower fluid balances at 4 and 6 hours, and of the total hospital stay, as well as earlier initiation of norepinephrine and statistically significant faster improvement in blood pressure. Although a statistically significant difference was not found in the days of ICU stay, hospitalization and in-hospital mortality, a trend was observed in the reduction of these parameters.

Qualitative results for finite system of R-L fractional differential equations with initial time difference

Qualitative results for finite system of R-L fractional differential equations with initial time difference

Effect of complementary feeding behavior change communication delivered through community-level actors on the time of initiation of complementary foods in rural communities of West Gojjam zone, Northwest Ethiopia: a cluster-randomized controlled trial

BackgroundAttaining the recommended level of complementary feeding practices remains a serious challenge in many developing countries. Complementary foods are usually untimely initiated, which has adverse consequences on the growth, development, and survival of infants. The focus of most studies conducted worldwide seemed to be on the effect of behavior change interventions on the adequacy of complementary diets; but not on the timing of initiations. Moreover, many of the interventions targeted only mothers/caregivers of infants, and studies that engaged the family members are scarce. This study aimed to evaluate the effectiveness of complementary feeding behavior change communication delivered through women development army leaderson the time of initiation of complementary foods.MethodsWe conducted a cluster-randomized controlled trial in rural communities of West Gojjam Zone, Northwest Ethiopia from February 2017 to March 2018. A total of 16 geographic clusters were selected. Trial participants in the intervention group received complementary feeding behavior change intervention for 9 months whereas those in the control group received only the usual health care. Trained women development army leaders delivered the intervention. A pre-tested, structured interviewer-administered questionnaire was used for data collection. Generalized estimated equation (GEE) regression and survival analyses were used to test differences in time of initiation of complementary food between the study groups.ResultsThe intervention significantly improved the likelihood of timely initiation of complementary food by 22 percentage points [RR: 2.6; 95% CI: 1.78–5.86], and reduced the risk of late initiations by 19 percentage points [RR: 2.8; 95% CI: 1.83–4.37]. The complementary food initiation survival curve for the control group after 6 months was constantly above the curve than for the intervention group. The median age at the introduction of complementary food for infants was 6 months in the intervention group, and 6.7 months in the control group and the difference was statistically significant (P-value < 0.001).ConclusionsComplementary feeding behavior change communication improved the rate of timely initiation of complementary foods and reduced the risk of late initiations.Trial registrationClinicalTrials.gov, NCT03488680. Registered 5 April 2018-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03488680.

Diagnostic Value of Quantitative Analysis by Contrast-Enhanced Ultrasound of Endometrial Lesions.

To explore the diagnostic value of time-intensity curve parameters from contrast-enhanced ultrasound (CEUS) examinations of endometrial lesions. Fifty-two patients with suspected endometrial lesions who received vaginal CEUS examinations were divided into a polyp group (n = 36), a malignant group (n = 11), and a normal control group (n = 5) based on the pathologic diagnosis. The midpoint of the myometrium at the same depth as the endometrial lesion was used as the reference point. The initial increase time, time to peak, area under the curve, and peak intensity were determined by the time-intensity curve. The relative parameters, namely, the initial increase time difference, peak time difference, area ratio, and peak intensity ratio, were also calculated and analyzed statistically. The comparison results of the relative parameters among the groups showed that the differences in the time difference, intensity ratio, and area ratio were statistically significant. The differences in the intensity ratio and time difference between the malignant and normal groups were statistically significant (P < .001). The differences in the intensity ratio, area ratio, and time difference between the malignant and polyp groups were statistically significant (P < .001). The diagnostic value of the intensity ratio and area ratio was confirmed by a receiver operating characteristic curve. The sensitivity and specificity of the intensity ratio and area ratio in the groups were 100% and 77.5% and 85.7% and 85.0%, respectively. The relative CEUS parameters in endometrial lesions provide more diagnostic value in differential diagnosis of benign and malignant lesions than the absolute parameters.

Time needed to intubate and suction a manikin prior to instituting positive pressure ventilation: a simulation trial

Tracheal suctioning in non-vigorous newborn delivered through meconium-stained amniotic fluid (MSAF) is supposed to delay initiation of positive pressure ventilation (PPV), but the magnitude of such delay is unknown. To compare the time of PPV initiation when performing immediate laryngoscopy with intubation and suctioning vs. performing immediate PPV without intubation in a manikin model. Randomized controlled crossover (AB/BA) trial comparing PPV initiation with or without endotracheal suctioning in a manikin model of non-vigorous neonates born through MSAF. Participants were 20 neonatologists and 20 pediatric residents trained in advanced airway management. Timing of PPV initiation was longer with vs. without endotracheal suctioning in both pediatric residents (mean difference 13 s, 95% confidence interval 8 to 18 s; p < 0.0001) and neonatologists (mean difference 12 s, 95% confidence interval 8 to 16 s; p < 0.0001). The difference in timing of PPV initiation was similar between pediatric residents and neonatologists (mean difference − 1 s, 95% confidence interval − 7 to 6 s; p = 0.85).Conclusions: Performing immediate laryngoscopy with intubation and suctioning was associated with longer—but not clinically relevant—time of initiation of PPV compared with immediate PPV without intubation in a manikin model. While suggesting negligible delay in starting PPV, further studies in a clinical setting are warranted.Registration: clinicaltrial.gov NCT04076189.What is Known:• Management of the non-vigorous newborn delivered through meconium-stained amniotic fluid remains still controversial.• Tracheal suctioning in non-vigorous newborn delivered through meconium-stained amniotic fluid is supposed to delay initiation of positive pressure ventilation, but the magnitude of such delay is unknown.What is New:• Performing immediate ventilation without intubation was associated with shorter—but not clinically relevant—time of initiation of ventilation compared to immediate laryngoscopy with intubation and suctioning in a manikin model.• Further studies in a clinical setting are warranted.

Lateral Perturbation-Induced and Voluntary Stepping in Fallers and Nonfallers After Stroke.

A loss of balance poststroke from externally induced perturbations or during voluntary movements is often recovered by stepping. The purpose of this study was to characterize stepping behavior during lateral induced waist-pull perturbations and voluntary steps in community-dwelling fallers and nonfallers with chronic stroke. This study used a cohort design. Thirty participants >6months poststroke were exposed to 24 externally triggered lateral waist-pull perturbations and 20 voluntary steps. Balance tolerance limit (BTL) (transition from single to multiple steps) and first step type were determined for the waist-pull perturbations. Step parameters of initiation time, velocity, first step length, and clearance were calculated at and above BTL and for the voluntary steps. Hip abductor/adductor torque, foot cutaneous sensation, and self-reported falls that occurred 6months prior were evaluated. Twelve participants were classified retrospectively as fallers and 18 as nonfallers. Fallers had a reduced BTL and took more medial first steps than nonfallers. Above BTL, no between-group differences were found in medial steps. At BTL, the nonparetic step clearance was reduced in fallers. Above BTL, fallers took longer to initiate a paretic and nonparetic step and had a reduced nonparetic step length and clearance compared with nonfallers. There was a between-group difference in step initiation time for voluntary stepping with the paretic leg (P<.05). Fallers had a reduced paretic abductor torque and impaired paretic foot cutaneous sensation. A high fall rate poststroke necessitates effective fall prevention strategies. Given that more differences were found during perturbation-induced stepping between fallers and nonfallers, further research assessing perturbation-induced training on reducing falls is needed. Falls assessments should include both externally induced perturbations along with voluntary movements in determining the fall risk.

Method of lower - upper solutions of fractional differential equations with initial time difference and applications

Method of lower - upper solutions of fractional differential equations with initial time difference and applications

Initial time difference quasilinearization method for fractional differential equations involving generalized Hilfer fractional derivative

We build the quasilinearization method with initial time difference for nonlinear fractional differential equations (FDEs) involving generalized Hilfer fractional derivative under various conditions on the nonlinear function involved in the right hand side of the equation. An essential comparison result concerning lower and upper solutions is obtained for this generalized FDEs without demanding the Holder continuity assumption.

Cirrhotic Nodule Transformation to Hepatocellular Carcinoma: Natural History and Predictive Biomarkers on Contrast-Enhanced Ultrasound.

OBJECTIVE. The objective of our study was to identify sonographic biomarkers predicting or indicating eventual malignant transformation of pathologically confirmed cirrhotic nodules. MATERIALS AND METHODS. Thirty-nine consecutive patients with 44 pathologically confirmed cirrhotic nodules (mean size, 17.5 ± 8.5 [SD] mm) who initially underwent contrast-enhanced ultrasound examination at detection and then underwent follow-up conventional ultrasound every 3-4 months thereafter were retrospectively included. Malignant transformation was identified on the basis of noninvasive diagnostic criteria for hepatocellular carcinoma or rebiopsy. Malignant transformation biomarkers were identified from clinical and sonographic variables and the performance thereof was evaluated using ROC curves. RESULTS. Fourteen nodules (31.8%) had eventual malignant transformation after a median follow-up time of 26.7 months. At initial detection, nodule size (hazard ratio [HR], 1.07; p = 0.019) and a contrast arrival time difference between the nodule and liver of more than 0.5 second (HR, 4.35; p = 0.011) were independent predictors for malignant transformation. The area under the ROC curve (Az) of initial nodule size (Az = 0.64, p = 0.131) and contrast arrival time difference between the nodule and liver (Az = 0.66, p = 0.029) improved after combining the two (Az = 0.75, p = 0.002). During follow-up, echogenicity change (p = 0.044), absolute growth rate (p < 0.001), and relative growth rate (p < 0.001) correlated with malignant transformation. Sensitivity analysis revealed that an absolute growth rate of 5 mm or greater in 6 months or a relative growth rate of 30% or greater in 6 months could be considered as threshold growth for identifying malignant transformation (specificity, 100.0%; positive predictive value, 100.0%). The absence of both echogenicity change and threshold growth was highly accurate in excluding malignant transformation (sensitivity, 100.0%; negative predictive value, 100.0%). CONCLUSION. The contrast arrival time difference between the nodule and liver at initial detection was useful in stratifying eventual malignant transformation risk for cirrhotic nodules. During follow-up, growth rate and echogenicity change correlated with malignant transformation; threshold growth on ultrasound may be considered a potential major feature in noninvasive diagnostic criteria of hepatocellular carcinoma.

Analysis and automatic detection of potential Omura’s whale signals in the Indian Ocean

The north Indian Ocean is a rich environment for passive acoustic monitoring of baleen whales including fin and blue whales, with several different populations of blue whales having been identified by recordings of their song type. A signal known as the Diego Garcia Croak (DGC) has been recorded on two hydrophone triads near Diego Garcia that make up part of the International Monitoring System of the Comprehensive Nuclear Test Ban Treaty Organization. The DGC signal was tentatively attributed to a blue whale (Sousa and Harris, 2015) but has recently been linked to the Omura’s whale (Cerchio et al., 2019). In previous work, the DGC has been observed visually on spectrograms and initial time and frequency statistics obtained. In this work, a least squares detector is constructed for the signals and applied to long term recordings from 2002 and 2003. The resulting detections are used to extend previous measurements of the DGC signal, generating a robust characterization of the DGC, including frequency statistics, inter-call intervals, and call lengths. Further, localization methods will be applied to initial time-difference of arrival results and used to explore source level estimation of the DGC signal.