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Subjective time dilation is an effect discovered using the oddball paradigm, where expanding visual stimuli, but not shrinking ones, induce a prolongation of subjective temporal perception compared to static stimuli. This disparity is often seen as another demonstration of humans' evolved reaction to approaching threats, since visual expansion resembles approaching potential threats and warrants extra attention. In this study, we show that by manipulating the relative sizes of stimuli, both expanding and shrinking stimuli can induce prolongation of subjective time in an oddball paradigm. We propose an alternative explanation based on information theory, linking subjective temporal perception to entropy, an objective property of stimulus that is information uncertainty. Temporal function as a logistic function thus serves as the framework inside which content functions like information processing are able to operate coherently. [ABSTRACT FROM AUTHOR]

Recent research has indicated that attractive faces often cause a dilation of our time perception thus affecting physical and mental health, and speculates that this could be relevant to the fact that attractive faces capture people's attention. Nevertheless, there was no direct experimental data to support this speculation. The present work was designed to illustrate how attention affects time perception of facial attractiveness. It utilized two experiments to investigate this phenomenon. In Experiment 1, perception of timing and attention bias were assessed using a temporal reproduction task and a dot‐probe task. Increased attention bias was found to mediate the time dilation effect of facial attractiveness. Experiment 2 adopted dual‐task paradigm, combining a temporal reproduction task and attractiveness rating task, to manipulate attention allocation. The findings suggested that allocating more attention to the task requiring timing enhanced the time dilation effect caused by the faces. Results of Experiments 1 and 2 converge to show that attention plays an essential role in the effects of facial attractiveness on time perception. [ABSTRACT FROM AUTHOR]

Perception of time is not always veridical; rather, it is subjected to distortions. One such compelling distortion is that the duration of regularly spaced intervals is often overestimated. One account suggests that excitatory phases of neural entrainment concomitant with such stimuli play a major role. However, assessing the correlation between the power of entrained oscillations and time dilation has yielded inconclusive results. In this study, we evaluated whether phase characteristics of neural oscillations impact time dilation. For this purpose, we entrained 10‐Hz oscillations and experimentally manipulated the presentation of flickers so that they were presented either in‐phase or out‐of‐phase relative to the established rhythm. Simultaneous electroencephalography (EEG) recordings confirmed that in‐phase and out‐of‐phase flickers had landed on different inhibitory phases of high‐amplitude alpha oscillations. Moreover, to control for confounding factors of expectancy and masking, we created two additional conditions. Results, supplemented by the Bayesian analysis, indicated that the phase of entrained visual alpha oscillation does not differentially affect flicker‐induced time dilation. Repeating the same experiment with regularly spaced auditory stimuli replicated the null findings. Moreover, we found a robust enhancement of precision for the reproduction of flickers relative to static stimuli that were partially supported by entrainment models. We discussed our results within the framework of neural oscillations and time‐perception models, suggesting that inhibitory cycles of visual alpha may have little relevance to the overestimation of regularly spaced intervals. Moreover, based on our findings, we proposed that temporal oscillators, assumed in entrainment models, may act independently of excitatory phases in the brain's lower level sensory areas. [ABSTRACT FROM AUTHOR]

Three experiments are reviewed, performed (in 2014–2016) at ID18 of ESRF to measure the influence of acceleration on time dilation by measuring the relative shift between the absorption lines of two states of the same rotating absorber with accelerations anti‐parallel and parallel to the incident beam. Statistically significant data for rotation frequencies up to 510 Hz in both directions of rotation were collected. For each run with high rotation, a stable statistically significant 'vibration‐free' relative shift between the absorption lines of the two states was measured. This may indicate the influence of acceleration on time dilation. However, the measured relative shift was also affected by the use of a slit necessary to focus the beam to the axis of rotation to a focal spot of sub‐micrometre size. The introduction of the slit broke the symmetry in the absorption lines due to the nuclear lighthouse effect and affected the measured relative shift, preventing to claim conclusively the influence of acceleration on time dilation. Assuming that this loss of symmetry is of first order, the zero value of the relative shift, corrected for this loss, falls always within the experimental error limits, as predicted by Einstein's clock hypothesis. The requirements and an indispensable plan for a conclusive experiment, once the improved technology becomes available, is presented. This will be useful to future experimentalists wishing to pursue this experiment or a related rotor experiment involving a Mössbauer absorber and a synchrotron Mössbauer source. An indispensable plan, requirements and challenges to overcome for a conclusive experiment to test time dilation due to acceleration, based on three experiments at ESRF, is presented. [ABSTRACT FROM AUTHOR]

New results, additional techniques and know-how acquired, developed and employed in a recent HC-1898 experiment at the Nuclear Resonance Beamline ID18 of ESRF are presented, in the quest to explore the acceleration effect on time dilation. Using the specially modified Synchrotron Mössbauer Source and KB-optics together with a rotating single-line semicircular Mössbauer absorber on the rim of a specially designed rotating disk, the aim was to measure the relative spectral shift between the spectra of two states when the acceleration of the absorber is anti-parallel and parallel to the source. A control system was used for the first time and a method to quantify the effects of non-random vibrations on the spectral shift was developed. For several runs where the effect of these vibrations was negligible, a stable statistically significant non-zero relative shift was observed. This suggests the influence of acceleration on time. [ABSTRACT FROM AUTHOR]

We review a theorem of Gao‐Wald on a kind of a gravitational "time delay" effect in null geodesically complete spacetimes under NEC and NGC, and we observe that it is not valid anymore throughout its statement, as well as a conclusion that there is a class of cosmological models where particle horizons are absent, if one substituted the manifold topology with a finer (spacetime) topology. Since topologies of the Zeeman‐Göbel class incorporate the causal, differential, and conformal structure of a spacetime and there are serious mathematical arguments in favour of such topologies and against the manifold topology, there is a strong evidence that "time dilation" theorems of this kind are topological in nature rather than having a particular physical meaning. [ABSTRACT FROM AUTHOR]

An appealing strategy for reconstructing the timing and tempo of paleoenvironmental change from sedimentary strata is to linearly interpolate between marker beds of known age. This method requires significant assumptions, but more advanced age modeling methods are usually not feasible. We used experiments to explore how changes in sedimentary processes invalidate these assumptions and affect estimates of time from the strata. When sedimentary processes changed to favor widespread deposition, we found that measuring time linearly systematically overestimated time duration from the resulting strata (time dilation) and misestimated the beginning and end of geologic intervals (phase shifting). When simple age models must be used for sedimentary strata, geologic evidence for transient changes in spatial sediment dispersal may help identify sections of dilated and shifted time, and better resolve time in sedimentary strata. Plain Language Summary: Sedimentary rocks can be used to measure the amount of time that passed between events in Earth history. Since it is rare to find layers of rock whose age can be measured, one needs a simplifying assumption: the thickness of sedimentary rocks is proportional to the amount of time that passed. In other words, the sediment accumulated relatively steadily, and gaps are short relative to the duration of interest. In this study, we show that this approach incorrectly dates events in the timeline, and erroneously inflates time durations. The bias is most significant when a change in environmental conditions causes sediment to spread more widely across the landscape than it did before. The bias is not as pronounced when sediment deposits are localized. Clues and context from sedimentary rocks may help reveal whether sediment was spreading widely or locally in the past. Using this evidence, geologists will be able to identify sections where simplifying assumptions will not hold, and can apply appropriate corrections. Key Points: If sediment dispersal changes through time and time is interpolated from long‐term rates, one will misestimate durations from strataMisestimation is not inevitable in the strata. Some changes in sediment dispersal result in distortion, while others do notGeologic clues that indicate the degree of sediment localization are key to diagnosing stratigraphic sections with substantial distortion [ABSTRACT FROM AUTHOR]

Tract dilation is one of the most difficult stages of endoscopic ultrasound‐guided hepaticogastrostomy (EUS‐HGS), especially for beginners. To overcome this problem, we applied a special dedicated dilator. Herein, we retrospectively evaluate the safety and usefulness of a novel drill dilator in EUS‐HGS. This single‐center retrospective study included 20 consecutive patients who underwent EUS‐HGS with a novel drill dilator. The tip is 0.77 mm, and it becomes 7F at 3 cm from tip. The track is dilated to 7F by simple clockwise rotation. The technical success rate of both initial tract dilation and stent placement was 20/20 (100%). No cases required additional dilation such as balloon or electric cautery. In 13/20 cases (65.0%), EUS‐HGS was performed by beginner endoscopists. Median time required for dilation was 62.5 s (range, 30–144 s). Median procedure time was 13 min (range, 7–25 min). Early adverse events were two cases of mild fever. There was no bile leakage or bleeding. The novel drill dilator appears to be safe and useful for EUS‐HGS. As it is not necessary to press the device strongly, there is no pushback during dilation and the scope position is stable. These characteristics facilitate EUS‐HGS even for beginners. This device may enable the further development and increased dissemination of EUS intervention. [ABSTRACT FROM AUTHOR]

Many Mössbauer spectroscopy (MS) experiments have used a rotating absorber in order to measure the second-order transverse Doppler (TD) shift, and to test the validity of the Einstein time dilation theory. From these experiments, one may also test the clock hypothesis (CH) and the time dilation caused by acceleration. In such experiments the absorption curves must be obtained, since it cannot be assumed that there is no broadening of the curve during the rotation. For technical reasons, it is very complicated to keep the balance of a fast rotating disk if there are moving parts on it. Thus, the Mössbauer source on a transducer should be outside the disk. Friedman and Nowik have already predicted that the X-ray beam finite size dramatically affects the MS absorption line and causes its broadening. We provide here explicit formulas to evaluate this broadening for a synchrotron Mössbauer source (SMS) beam. The broadening is linearly proportional to the rotation frequency and to the SMS beam width at the rotation axis. In addition, it is shown that the TD shift and the MS line broadening are affected by an additional factor assigned as the alignment shift which is proportional to the frequency of rotation and to the distance between the X-ray beam center and the rotation axis. This new shift helps to align the disk's axis of rotation to the X-ray beam's center. To minimize the broadening, one must focus the X-ray on the axis of the rotating disk and/or to add a slit positioned at the center, to block the rays distant from the rotation axis of the disk. Our experiment, using the 57Fe SMS, currently available at the Nuclear Resonance beamline (ID18) at the ESRF, with a rotating stainless steel foil, confirmed our predictions. With a slit installed at the rotation axis (reducing the effective beam width from 15.6 µm to 5.4 µm), one can measure a statistically meaningful absorption spectrum up to 300 Hz, while, without a slit, such spectra could be obtained up to 100 Hz only. Thus, both the broadening and the alignment shift are very significant and must be taken into consideration in any rotating absorber experiment. Here a method is offered to measure accurately the TD shift and to test the CH. [ABSTRACT FROM AUTHOR]

Real time dilation behaviors of a Si‐Ti‐Fe‐Al alloy electrode adopting a poly (amide‐imide) binder were investigated to understand the effects of thermal treatment temperature for PAI binder on the electrochemical performance of the Si‐alloy electrode using an in‐situ electrochemical dilatometer. In situ measurement of the electrode thickness showed that the changes in the volume of the Si electrode was suppressed by heat treatment greater than 300 °C, which well agreed with the improved cycle performance of the Si‐alloy electrode thermally treated at the same temperature. Differential dilation plots of the Si‐alloy electrodes were found to reveal more detailed changes in the volume of the Si‐alloy electrode, thus showing that the enhanced mechanical strength of thermally treated PAI effectively could control the expansion and contraction of the Si‐alloy electrode and ensuring a more stable cycle performance of the Si‐alloy electrode. [ABSTRACT FROM AUTHOR]

Introduction: In this feasibility study, we hypothesize that the evaluation of cervical biomechanical strength can be improved if cervical length measurement is supplemented with quantitative elastography, which is a technique based on conventional ultrasound elastography combined with a force‐measuring device. Our aims were to: (a) develop a force‐measuring device; (b) introduce a cervical elastography index (CEI) and a cervical strength index (CSI; defined as cervical length × CEI); (c) evaluate how these indexes assess the cervical softening that takes place during normal pregnancy; and (d) how these indexes predict the cervical dilatation time from 4 to 10 cm. Material and methods: An electronic force‐measuring device was mounted on the handle of the transvaginal probe, allowing for force measurement when conducting elastography. The study group concerned with normal cervical softening included 44 unselected pregnant women. Outcomes were CEI and CSI at different gestational ages. The study group for labor induction included 26 singleton term pregnant women admitted for labor induction. Outcome was defined as cervical dilatation time from 4 to 10 cm. Elastography measured the changes in mean gray value (intensity) during manual compressions. Region of interest was set within the anterior cervical lip. Results: We found that the mean of all variables regarding cervical softening decreased from early to late pregnancy: ie cervical length from 34 to 29 mm, CEI from 0.17 to 0.11 N, and CSI from 5.9 to 3.1 N mm. Moreover, the cervical dilatation time during labor induction was associated with CEI, although not statistically significantly (area under the ROC curve of 0.67), but not with the Bishop score, the cervical length, or the CSI. Conclusions: We propose that quantitative elastography based on changes in the intensity of the B‐mode ultrasound recording, in combination with a force‐measuring device on the handle of the vaginal probe, deserves further investigation as an approach for evaluation of cervical biomechanical strength. [ABSTRACT FROM AUTHOR]

The article focuses on the author's philosophical discussion on relativism, time dilation and context. He explains that truth is relative in virtue of his given examples and the admittance of relativistic semantics. He mentions a theory which will show on how to examine truth for assertions regarding temporal duration. He defends that his brand of relativism is different from others.

Objective: Abnormal placental invasion is more common after an elective Cesarean delivery, suggesting that prelabor Cesarean section (CS) increases the likelihood of the CS scar being above the internal cervical os and predisposing to a scar pregnancy in the future. The aim of this study was to assess the location and integrity of the CS scar in postpartum women delivered by CS at different stages of labor.Methods: This was a prospective cohort study of women at term who underwent a CS for the first time. In all women, cervical dilatation was determined by digital examination at the time of the CS. All patients had a transvaginal ultrasound examination to assess the location of the CS scar in relation to the internal cervical os, as well as the presence of a scar niche.Results: A total of 407 pregnant women were recruited into the study: 103 with cervical dilatation ≤ 2 cm, 261 with cervical dilatation 3-7 cm and 43 with cervical dilatation ≥ 8 cm at the time of the CS. A statistically significant correlation was observed between cervical dilatation at the time of the CS and the position of the CS scar. The scar was positioned in the uterus above the internal cervical os in 97.1% (100/103) of women delivered at a cervical dilatation of 0-2 cm, whereas the scar was located at or below the internal cervical os in 97.7% (42/43) of cases delivered at a cervical dilatation of 8-10 cm (P < 0.001). A uterine-scar defect (niche) was observed in 38.1% (64/168) of women with the scar located above, compared with 18.0% (43/239) of those with the scar situated at or below, the internal cervical os (P < 0.001).Conclusions: Prelabor and early-labor Cesarean delivery are associated with an increased prevalence of a scar in the uterine cavity as well as a scar niche. CS in late labor is associated with the uterine scar being situated in the endocervical canal and with a lower incidence of a niche. The position and integrity of the CS scar after prelabor and early-labor Cesarean delivery explain the predisposition to abnormal placental invasion in subsequent pregnancy. © 2020 International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

Introduction: Epidural analgesia (EA) is an established option for efficient intrapartum analgesia. Meta-analyses have shown that EA differentially affects the first stage of labor but prolongs the second. The question of EA timing remains open. We aimed to investigate whether EA prolongs delivery in total and whether the EA administration timing vis-à-vis cervical dilation at catheter insertion is associated with a modulation of its effects on the duration of the first and second stages, as well as the rate of instrumental vaginal delivery in primiparas and multiparas.Material and Methods: A retrospective electronic medical records-based study of 18 870 singleton term deliveries occurring in our institution from 2003 to 2015. Cervical dilation was determined within a half-hour of EA administration. We examined whether cervical dilation at EA administration correlated with the duration of the first and/or second stage, with the rate of prolonged second stage, and with the rate of interventional delivery. The study group was stratified to 10 subgroups defined by 1-cm intervals of cervical dilation at EA administration. Logistic regression modeling was applied to analyze the association between EA timing and rate of instrumental delivery while controlling for possible confounders.Results: In primiparas, receiving EA correlated with longer medians of active first stage (+51 minutes; P < .001) and second stage (+55 minutes; P < .001). In multiparas, median increases in active first stage (+43 minutes; P < .001) and second stage (+8 minutes; P < .001) were noted. The timing of EA, vis-à-vis cervical dilation (1-10 cm) was not associated with a substantial modulation of these effects. Logistic regression showed that cervical dilation at EA was not associated with a higher instrumental vaginal delivery rate.Conclusions: Epidural analgesia prolonged the first and second stages of labor vs no epidural. Having EA was associated with a higher instrumental delivery rate but not with higher rates of maternal or neonatal complications, in primi- and multiparas. Importantly, the timing of EA, vis-à-vis cervical dilation, was not associated with substantial changes in the duration of labor stages or the instrumental delivery rate. Thus, EA may be offered early in the first stage of labor. [ABSTRACT FROM AUTHOR]

The article discusses the simultaneous simulation method employed by clinical educators to improve the fidelity of simulation, which is used to train medical trainees in situations that resemble real-world patient encounters. According to the author, simultaneous simulation method produces time dilation. This time dilation occurs through multitasking, an increase in cognitive loads and intentional binding.

The prediction of time to onset of parturition in a preparturient bitch is of great clinical value, particularly for bitches at high risk of dystocia and those lacking relevant clinical data from the time of breeding. In a previous study, four cut‐offs for plasma progesterone levels, measured by radioimmunoassay, were shown to be useful for predicting the likelihood of a bitch entering stage one of parturition within defined time intervals. The first aim of the current study was to evaluate these cut‐offs in a clinical setting, using serum progesterone samples drawn from preparturient bitches 12‐hourly instead of 6‐hourly and assessed using chemiluminescence immunoassay. Furthermore, the use of 13,14‐dihydro‐15‐keto‐prostaglandin F2α, (PGFM), a metabolite of prostaglandin F2α, in predicting the time to onset of parturition was evaluated. Forty bitches carrying two or more foetuses were admitted to a specialist veterinary reproduction hospital 53 d after the onset of cytological dioestrus when that date was known, or 57 d after the last mating. Vaginal speculum examinations were performed every 6 hr until cervical dilatation was visualized (time of cervical dilatation; TCD). Serum samples were collected at 08h00 and 18h00 daily until TCD. All bitches underwent elective caesarean section at TCD. Results of this study show that approximately 5% and 10% of preparturient bitches will reach TCD within 12 hr despite a serum progesterone level of at least 15.8 nmol/L and 8.7 nmol/L respectively. In addition, there is a 95% probability that a preparturient bitch will reach TCD within 48 hr if her serum progesterone level is below 8.7 nmol/L, and a 91% probability of her reaching TCD within 24 hr if her serum progesterone level is below 3.18 nmol/L. Approximately 90% of bitches that demonstrate a 20% increase in PGFM over a 12‐hr period are likely to be within 36 hr of TCD. These results provide useful benchmarks for the management of canine parturition. [ABSTRACT FROM AUTHOR]

Special relativity (SR) determines the properties of synchrotron radiation, but the corresponding mechanisms are frequently misunderstood. Time dilation is often invoked among the causes, whereas its role would violate the principles of SR. Here it is shown that the correct explanation of the synchrotron radiation properties is provided by a combination of the Doppler shift, not dependent on time dilation effects, contrary to a common belief, and of the Lorentz transformation into the particle reference frame of the electromagnetic field of the emission-inducing device, also with no contribution from time dilation. Concluding, the reader is reminded that much, if not all, of our argument has been available since the inception of SR, a research discipline of its own standing. [ABSTRACT FROM AUTHOR]

First, the traditional debates on time: In 1927, J. M. E. McTaggart notably defended a "static time" interpretation of SR by pointing to what he considered as a fundamental paradox in any flowing time rendition: Past, present and future are incompatible determinations. Prof. Saulson begins with the fact that the light cone in SR that accompanies an event P in spacetime divides the world into the causal future, the causal past, and the acausal elsewhere. A FLOWING TIME INTERPRETATION OF SPECIAL RELATIVITY VIA AN INHOMOGENEOUS TENSE-AS-RELATIONAL ONTOLOGY: A COMMENT ON SAULSON. [Extracted from the article]

Introduction: Childbirth experience is an increasingly recognized and important measure of quality of obstetric care. Previous research has shown that it can be affected by intrapartum care and how labor is followed. A partograph is recommended to follow labor progression by recording cervical dilation over time. There are currently different guidelines in use worldwide to follow labor progression. The two main ones are the partograph recommended by the World Health Organization (WHO) based on the work of Friedman and Philpott and a guideline based on Zhang's research. In our study we assessed the effect of adhering to Zhang's guideline or the WHO partograph on childbirth experience. Zhang's guideline describes expected normal labor progression based on data from contemporary obstetric populations, resulting in an exponential progression curve, compared with the linear WHO partograph. The choice of labor curve affects the intrapartum follow‐up of women and this could potentially affect childbirth experience. Material and methods: The Labor Progression Study (LaPS) study was a prospective, cluster randomized controlled trial conducted at 14 birth centers in Norway. Birth centers were randomized to either follow Zhang's guideline or the WHO partograph. Nulliparous women in active labor, with one fetus in cephalic presentation at term and spontaneous labor onset were included. At 4 weeks postpartum, included women received an online login to complete the Childbirth Experience Questionnaire (CEQ). Total score on the CEQ, the four domain scores on the CEQ, and scores on the individual items on the CEQ were compared between the two groups. Results: There were 1855 women in the Zhang group and 1749 women in the WHO partograph group. There was no difference in the total or domain CEQ scores between the two groups. We found statistically significant differences for two individual items; women in the Zhang group scored lower on positive memories and feeling of control. Conclusions: Based on our findings on childbirth experience there is no reason to prefer Zhang's guideline over the WHO partograph. [ABSTRACT FROM AUTHOR]

Background and Aim: Endoscopic papillary balloon dilation (EPBD) has been advocated as an alternative therapy to endoscopic sphincterotomy for bile duct stones. However, studies have shown that EPBD may increase the risk for pancreatitis. Pancreatitis after EPBD is believed to be related to papillary damage after balloon dilation. We changed the dilation method to a theoretically less hazardous one. This modified dilation method was compared with the initial method. Methods: A total of 324 patients with bile duct stones underwent EPBD by the modified method between June 1999 and June 2003. Three hundred and twenty-four patients undergoing EPBD by the initial method served as a historical control group. The success rate of stone removal and the incidence of procedure-related pancreatitis were compared between the two groups. In the modified method, the balloon was inflated until disappearance of the balloon waist, and the pressure was then maintained for 15 s. In the initial method, the balloon was inflated at 8 atmospheres for 2 min. Results: Bile duct stones were successfully removed in 313 of 324 patients (96.6%) in the modified group and in 314 of 324 patients (96.9%) in the initial group (not significant). The incidence of postprocedure pancreatitis showed a lower tendency in the modified group (4.0%, 13/324) than in the initial group (7.4%, 24/324) ( P-value = 0.0626). The severity of pancreatitis was significantly reduced in the modified group. Conclusion: The modified method of EPBD is feasible for extraction of bile duct stones, and may potentially decrease the incidence of severe post-EPBD pancreatitis. [ABSTRACT FROM AUTHOR]

Objective: Documentation of middle ear pressure at different stages of balloon Eustachian tuboplasty and assessing risk of barotrauma with this procedure. Main outcome measures: Middle ear pressure measurements in patients undergoing balloon Eustachian tuboplasty at the time of pre‐insertion, catheter insertion, inflation, one minute post inflation, deflation, and catheter withdrawal, as well as documentation of pressure change in the middle ear between different stages. Results: A total of 24 patients and 45 Eustachian tubes, 11 females and 13 males, with an average age of 55.6 years were included in this study. Middle ear pressure values during the active stages of the procedure varied from −356 to +159 daPa. The overall greatest negative pressure change measured was −515 daPa from catheter insertion to immediately post balloon inflation. The overall greatest positive pressure change measured was +418 daPa from immediate catheter inflation to one minute post inflation. Conclusions: There was no consistent pattern of middle ear pressure change noted during the different stages of balloon Eustachian tuboplasty as both positive and negative middle ear pressure changes were noted at the time of balloon dilation. Dangerous levels of middle ear pressure raising concern for barotrauma were not identified during the procedure. Level of evidence: Level IV. [ABSTRACT FROM AUTHOR]

Objective: To determine the risk of spontaneous and medically indicated preterm birth associated with mode of birth in previous term‐born pregnancy. Design: Retrospective cohort study. Setting: Two UK maternity units. Population or sample: A total of 16 340 women with first two consecutive singleton births and the first birth at term. Methods: Retrospective cohort study using routinely collected clinical data. Main outcome measures: Incidence of spontaneous preterm birth and medically indicated preterm birth at less than 37 weeks of gestation after term birth, in relation to mode of birth in first pregnancy. Subgroup analysis on cervical dilatation at the time of first caesarean birth. Results: Compared with vaginal birth, emergency caesarean birth at full dilatation was associated with an increase in spontaneous preterm birth (2.3% vaginal birth versus 4.5% full dilatation caesarean; adjusted odds ratio [aOR] 3.29, 95% CI 2.02–5.13, P < 0.001). Elective caesarean, emergency caesarean at <4 cm dilatation, and emergency caesarean at 4–9 cm dilatation were associated with increased medically indicated preterm birth (0.8% vaginal births versus 1.9% elective caesarean, 3.3% <4 cm caesarean, 1.3% 4–9 cm caesarean; aOR 2.30, 95% CI 1.19–4.15, P = 0.009; aOR 4.68, 95% CI 2.98–7.24, P < 0.001; and aOR 2.43, 95% CI 1.43–4.00, P = 0.001, respectively). Conclusions: Term caesarean in the first stage of labour or performed prelabour is associated with medically indicated preterm birth. Term caesarean in the second stage of labour is associated with spontaneous preterm birth. Caesarean in the second stage of labour is associated with spontaneous preterm birth. Caesarean in the second stage of labour is associated with spontaneous preterm birth. [ABSTRACT FROM AUTHOR]

Background: Pancreatitis is a common cause of extrahepatic bile duct obstruction (EHBDO) in dogs. Information describing the clinical course of dogs with pancreatitis associated bile duct obstruction (PABDO) is limited. Objectives: To describe the clinical course of PABDO in dogs and determine if presumed markers of disease severity are predictors of survival. Animals Forty‐six client‐owned dogs with PABDO. Methods: A retrospective review of medical records from dogs diagnosed with PABDO was performed. Data, including clinical signs and biochemical changes, were collected 6 times throughout the course of disease. Outcome was defined as either survival (discharge from the hospital) or death. Results: Thirty‐three (79%) out of 42 dogs with PABDO survived. Thirty‐one (94%) of the 33 dogs that survived received medical management alone. Time from onset of clinical signs to initial documented increase in serum bilirubin concentration, peak bilirubin elevation, and initial decline in serum bilirubin concentration were 7 (median), 8, and 15 days, respectively. The median number of days from onset of clinical signs to outcome date was 13. Clinical signs of fever, vomiting, and anorexia were decreased in frequency from the onset of clinical signs to the time of peak bilirubin. Median bile duct dilatation at the time of ultrasonographic diagnosis of PABDO and peak bilirubin were not different between survivors (7.6 mm, 11.7 mg/dL) and nonsurvivors (6 mm, 10.6 mg/dL, P =.12, P =.8). Conclusions: Dogs with PABDO often have a prolonged course of illness and improve clinically despite biochemical evidence of progression of EHBDO. [ABSTRACT FROM AUTHOR]

Elective caesarean section (CS) is the safest means of delivering the litter in bitches in specific situations. Timeously performing elective pre‐parturient CSs at a fixed time would be convenient and prevent emergency CSs and foetal demise. This review proposes a method of performing elective pre‐parturient CSs which is safe for both the bitch and puppies. Brachycephaly, small litters and large litters, preceding litter delivered by CS and trial of labour after a preceding CS are identified as factors increasing the need for CS whereas emergency CS is identified as factor increasing foetal demise. The first day of cytological dioestrus more precisely predicts the day of onset of spontaneous parturition than the first day of the LH surge or the dates during oestrus on which progesterone (P4) first exceeds 6 nM or 16 nM. Foetal biparietal diameter at the time of onset of spontaneous parturition varies too much to accurately predict readiness for CS. During the last few days of gestation, P4 with cut‐off concentrations at 15.8, 8.7 and 3.18 nM, but not plasma cortisol concentrations, hold promise as predictors of onset of parturition and when to perform pre‐parturient CSs. A protocol associating medetomidine hydrochloride as premedicant with propofol as induction agent and sevoflurane as maintenance is safe for scheduled CS and yields good maternal and puppy survival rates at delivery, 2 hr and 7 days after CSs. Clinicians have to pay attention to the haematocrit of bitches at the time of cervical dilatation which is at the lower end of the normal reference ranges for non‐pregnant dogs and to the decline in haematocrit during CS (as a proxy for blood loss) which is approximately 7% for both parturient (open cervix) and pre‐parturient (closed cervix) CSs. Pre‐parturient CSs can be scheduled and performed 57 days after onset of cytological dioestrus with puppy survival rates of 99%. Collectively, these studies provide a protocol to safely perform elective CSs in a large proportion of the obstetric population at a convenient time of the day but more research is required with larger numbers to establish whether this practice is routinely safe and safe in all breeds. [ABSTRACT FROM AUTHOR]

Background: There are questions about the use of the 'one-centimetre per hour rule' as a valid benchmark for assessing the adequacy of labour progress.Objectives: To determine the accuracy of the alert (1-cm/hour) and action lines of the cervicograph in the partograph to predict adverse birth outcomes among women in first stage of labour.Search Strategy: PubMed, EMBASE, CINAHL, POPLINE, Global Health Library, and reference lists of eligible studies.Selection Criteria: Observational studies and other study designs reporting data on the correlation between the alert line status of women in labour and the occurrence of adverse birth outcomes.Data Collection and Analysis: Two reviewers at a time independently identified eligible studies and independently abstracted data including population characteristics and maternal and perinatal outcomes.Main Results: Thirteen studies in which 20 471 women participated were included in the review. The percentage of women crossing the alert line varied from 8 to 76% for all maternal or perinatal outcomes. No study showed a robust diagnostic test accuracy profile for any of the selected outcomes.Conclusions: This systematic review does not support the use of the cervical dilatation over time (at a threshold of 1 cm/h during active first stage) to identify women at risk of adverse birth outcomes.Tweetable Abstract: Alert line of partograph does not identify women at risk of adverse birth outcomes. [ABSTRACT FROM AUTHOR]

Introduction Inconsistent evidences of the metabolic syndrome (MetS) impact on vascular reactivity raise questions on flow-mediated dilation ( FMD) discriminatory power for disturbances induced by this clustering of risk factors. Previous reports, however, suggest that covariates such as the follow-up of the artery diameter changes, the arterial size and shear stress affect FMD responses and consequently its discriminatory power for distinctive clinical profiles. Objective To determine the impact of Met S on traditional, arterial size- and shear-rate-adjusted FMD, the follow-up-derived time-to-peak diameter ( TP), as well as their power for discriminating subjects with this clustering of risk factors from a sample of healthy individuals. Methods Twenty-one Met S and ten healthy subjects underwent an assessment of endothelial function via FMD. Results Traditional and allometrically scaled FMD did not differ between groups ( P>0·05) as well as the approach in which the covariate was the peak diameter shear rate. In the existence of Met S, TP was longer (67·7 ± 16·4 s versus healthy 42·1 ± 16·3 s, P = 0·001). ROC curve analysis indicated that TP ( AUC = 0·871 [95% CI, 0·718-1·000]) had greater power of discrimination for Met S than FMD approaches. In addition, TP presented a moderate and significant association with sE-selectin ( r = 0·458, P = 0·048). Conclusion Time-to-peak diameter (TP) rather than FMD distinguished Met S from a healthy profile. Therefore, at least in subjects with Met S, TP may provide insights into the impact of this clustering of risk factors on the vascular phenotype. [ABSTRACT FROM AUTHOR]

The article focuses on artificial intelligence (AI). It states that psychological view would ground moral status in the psychological properties of entity whose status is being appraised and duplicability and fragility would influence our moral obligations to AI. It mentions that if artificial intelligence research continues to progress, intuitive ethics encounter a range of cases for which it is as ill-prepared as intuitive physics was for quantum entanglement and relativistic time dilation.

Summary: Introduction: Endothelial dysfunction is considered the first step in the development of atherosclerosis. Flow‐mediated dilation (FMD) has been the most common assessment of endothelial function in research but it has failed in obtaining a widespread use in clinical settings due to a lack of standardization and a large inter‐subject variability. Normalization of FMD to endothelial shear stress (ESS) has been proposed to solve its technical limitations. However, studies have not considered the characteristic of the blood flow during FMD under pulsatile conditions in their ESS estimations. Methods: A total of 26 young healthy subjects (15 females and 11 males) underwent FMD testing. Microhematocrit measurement was used to determine blood viscosity (μ). ESS was calculated by Womersley's approximation, ESS = μ*2K*Velocity/Diameter, where K is a function of Womersley's parameter (α). Blood flow patterns were determined by critical Reynolds number. Statistical analysis included repeated measures ANOVA to detect ESS differences during FMD until peak dilation. Significance was established at P≤0.05. Results: The mean (SD) FMD% and time to peak dilation were 7·4 (3·1) % and 35 (9·3) seconds, respectively. ESS was significantly reduced during FMD until peak dilation (P<0·001). Turbulent blood flow was the only pattern observed until peak dilation in 96·15% of the sample. Conclusion: Peak FMD dilation in a young healthy population is triggered mostly by high‐ESS under turbulent flow conditions. Due to the pulsatile nature of blood flow and the appearance of a turbulent pattern during FMD, ESS should be estimated by Womersley's approximation rather than Poiseuille's law. [ABSTRACT FROM AUTHOR]

We investigate seismic velocity changes in response to the tidal strain at Izu‐Oshima volcano, Japan, by analyzing the data of permanent seismic stations and a small seismic array to evaluate the characteristics of strain sensitivity of velocity changes. We estimate the seismic velocity changes by phase differences between cross‐correlations functions of ambient noises at the frequency of 2–4 Hz stacked for time periods with different tidal strain amplitudes. The seismic velocity changes decrease and increase during dilatation and contraction periods, respectively, when analyzing the cross‐correlations functions at early lapse times ranging from 2 to 7 s. The strain sensitivity of seismic velocity changes is estimated to be −2.1±0.2×104 at the early lapse times. However, we find that strain sensitivity of the seismic velocity changes decreases when analyzing the cross‐correlation functions at later lapse times from 7 s to 35 s. Applying an array analysis to the cross‐correlation functions, we observe apparent velocities of about 1 km/s at the early lapse times and those of higher than 1 km/s at the late lapse times. Since the group velocity of Rayleigh waves is 1.1 km/s at Izu‐Oshima volcano, the apparent velocities at the late lapse times may indicate the scattered or reflected body waves incident from a deeper region. Decrease of strain sensitivity with the lapse times therefore results from the emergence of body waves on the late lapse times. These results highlight the need to pay attention to wave types of cross‐correlation functions and their paths to interpret seismic velocity changes. Key Points: Seismic velocity decreases and increases during dilatation and contraction periods, respectively, at lapse times from 2 to 7 sArray analysis enables us to understand wave properties of cross‐correlations functions accuratelyStrain sensitivity of seismic velocity changes decreases with lapse times because scattered body waves contaminate the cross‐correlation functions [ABSTRACT FROM AUTHOR]

We prove a new lower bound for the dilatation of an arbitrary pseudo-Anosov map on a surface of genus g with n punctures. Our bound improves the former super-exponential dependence on the genus by a polynomial dependence. [ABSTRACT FROM AUTHOR]

Time duration is perceived to be longer when accompanied by dynamic sensory stimulation than when accompanied by static stimulation. This distortion of time perception is thought to be due to the acceleration of an internal pacemaker that has been assumed to be the main component of temporal judgments. In order to investigate whether the function of the internal pacemaker is modality dependent or independent, we examined the correlation of visual flicker and auditory flutter effects on a temporal production task. While seeing a 10-Hz visual flicker or hearing a 10-Hz auditory flutter, participants estimated a duration of 2500 ms as accurately as possible by pressing a button. The results showed a significant within-individual correlation between the time distortion due to visual flicker and that due to auditory flutter. Additionally, we found that time distortion due to auditory flutter tended to be larger in female participants than in male participants. These results suggest that the mechanisms underlying subjective time dilation are similar between vision and audition within individuals, but that they vary across individuals. [ABSTRACT FROM AUTHOR]

Abstract: We consider the class of all sense‐preserving harmonic mappings f = h + g ¯ of the unit disk D, where h and g are analytic with g ( 0 ) = 0, and determine the Bohr radius if any one of the following conditions holds: 1.h is bounded in D. 2.h satisfies the condition Re h ( z ) ≤ 1 in D with h ( 0 ) > 0. 3.both h and g are bounded in D. 4.h is bounded and g ′ ( 0 ) = 0. We also consider the problem of determining the Bohr radius when the supremum of the modulus of the dilatation of f in D is strictly less than 1. In addition, we determine the Bohr radius for the space B of analytic Bloch functions and the space B H of harmonic Bloch functions. The paper concludes with two conjectures. [ABSTRACT FROM AUTHOR]

Presents information on experiments conducted on an on-line method, which can be used to measure residence time distribution (RTD) in a twin-screw extruder. Rate and extent of physical or chemical reaction governed by time-temperature effects; Application of the stimulus-response technique; Use of radioactive, dielectric and optical properties for on-line measurement.

Continuous data can be summarised by their location and spread. Histograms are a useful way of displaying patterns in the data because they group similar values in a range together. [Extracted from the article]

Background Single dilator technique ( SDT) and guide wire dilating forceps ( GWDF) are the two most commonly used techniques of percutaneous dilatational tracheostomy ( PDT) in critically ill adult patients. We performed a meta-analysis of randomised, controlled trials comparing intraoperative, mid-term and late complications of these two techniques. Methods Pertinent studies were searched in BioMedCentral, PubMed, Embase and the Cochrane Central Register of clinical trials. We selected all randomised studies comparing SDT and GWDF techniques in adult critically ill patients published in a peer-reviewed journal. Results Among 1040 retrieved studies, five eligible studies randomising 363 patients (181 to GWDF, 182 to SDT) were identified. The incidence of the composite outcome difficult cannula insertion/difficult dilation or failure was higher with the GWDF technique (15.5% vs. 4.9 %, P = 0.02). Moreover, intraprocedural bleeding was more common in the GWDF group (19.3% vs. 7.6% in SDT group, P = 0.018). A trend towards an increased incidence of fracture of tracheal rings was noted in the SDT group (6.5% vs. 0.5% in the GWDF group, P = 0.13). No difference in mid-term or long-term complications was observed. Conclusion GWDF technique is associated with a higher incidence of intraprocedural bleeding and of technical difficulties in completing the procedure (difficult cannula insertions/difficult dilations or failures) compared with the SDT technique. No differences were identified in mid-term and long-term complications. Further studies comparing SDT and GWDF in the general population and in subgroups of high-risk patients (like obese or hypoxaemic patients) are warranted. [ABSTRACT FROM AUTHOR]

The cyclin-dependent kinase (CDK) inhibitor p27 level is associated with progression of renal damage. We previously reported that mRNA of Skp2, a component of Skp/Cullin/F-box (SCF)-ubiquitin ligase which targets to p27, was increased in unilateral ureteral obstructive kidneys in mice and that the nephritis was attenuated in Skp2-deficient mice. However, the details have not been fully clarified. Here, we found that not only Skp2 but also cdc kinase subunit 1 (Cks1), an essential cofactor for the SCF-Skp2 ubiquitin ligase in targeting p27, was increased in another chronic progressive model, anti-thymocyte serum (ATS) rat nephropathy. After induction of ATS nephropathy, Skp2+/Cks1+/Ki67+ tubular epithelial cell numbers increased, and p27+ tubular epithelial cells decreased transiently. Moreover, we found that TNFα was involved in expression of both Skp2 and Cks1 in NRK cell line as well as the in ATS nephropathy. Nuclear accumulations of NF-κB subunits RelB and p52 were increased in the tubular epithelial cells of the nephritic kidney. Both Skp2 and Cks1 were colocalized with RelB in these cells. These data suggest that both Skp2 and Cks1 are up-regulated by the TNFα-RelB/p52 pathway in the early stages of renal damage and are collaboratively involved in down-regulation of p27 in proliferative tubular dilation and the progression of chronic nephropathy. [ABSTRACT FROM AUTHOR]

Objective To study the effects of early versus delayed oxytocin augmentation on the obstetrical and neonatal outcome in nulliparous women with spontaneous but prolonged labour. Design Randomised controlled study. Setting Two delivery units in Sweden. Population Healthy nulliparous women with normal pregnancies, spontaneous onset of active labour, a cervical dilatation of 4–9 cm and no progress in cervical dilatation for 2 hours and for an additional hour if amniotomy was performed due to slow progress. Methods Women ( n = 630) were randomly allocated either to labour augmentation by oxytocin infusion (early oxytocin group) or to postponement of oxytocin augmentation for another 3 hours (expectant group). Main outcome measure Mode of delivery (spontaneous vaginal or instrumental vaginal delivery or caesarean section) and time from randomisation to delivery. Results The caesarean section rate was 29 of 314 (9%) in the early oxytocin group and 34 of 316 (11%) in the expectant group (OR 0.8, 95% CI 0.5–1.4), and instrumental vaginal delivery 54 of 314 (17%) in the early oxytocin versus 38 of 316 (12%) in the expectant group (OR 1.5, 95% CI 0.97–2.4). Early initiation of oxytocin resulted in a mean decrease of 85 minutes in the randomisation to delivery interval. Conclusion Early administration of oxytocin did not change the rate of caesarean section or instrumental vaginal delivery but shortened labour duration significantly in women with a 2-hour arrest in cervical dilatation. No other clear benefits or harms were seen between early and delayed administration of oxytocin. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to develop and validate a prediction model of vaginal birth after cesarean delivery (VBAC) in China. Methods: A nomogram for effective prediction of VBAC of singleton, cephalic and one previous low‐transverse cesarean section deliveries was created by comparing the combinations of ultrasonographic and non‐ultrasonographic factors from five hospitals between 2018 and 2019. Results: A total of 1066 women were included. Of the women who underwent trial of labor after cesarean (TOLAC), 854 (80.1%) had a VBAC. Ultrasound factors included reached a higher area under the curve (AUC) combined with non‐ultrasonographic factors. Of the three ultrasonographic factors analyzed, the best predictive factor for successful TOLAC was fetal abdominal circumference. A nomogram was generated with eight validated factors, including maternal age, gestational week, height, previous vaginal delivery, Bishop score, dilatation of the cervix at the time of admission, body mass index at delivery, and fetal abdominal circumference by ultrasound. The trained and validated AUC were 0.719 (95% confident interval 0.674–0.764) and 0.774 (95% confident interval 0.712–0.837), respectively. Conclusion: Our VBAC nomogram based on obstetric factors and fetal abdominal circumference obtained by ultrasound could be used to counsel women who are considering TOLAC. Synopsis: Our VBAC nomogram based on obstetric factors and fetal abdominal circumference determined by ultrasound could be used to counsel women who are considering TOLAC. [ABSTRACT FROM AUTHOR]

The article by Bonet (BJOG 2019;126:1524-33) is not the first paper to challenge the benefit of the partogram and the 1 cm/hour rate of progress. The graphical representation of labour using the partogram and normal progress of labour at >=1 cm/hour are an integral part of the philosophy of Active Management of Labour (AML), which has been practiced at the National Maternity Hospital, Dublin for the last 55 years. This philosophy, which at best is often misunderstood and ignored and at worst misrepresented and misused, has been shown to be associated with low caesarean section rates in nulliparous spontaneous labour and also reduce caesarean section rates when studied in randomised trials (Brown et al. I Cochrane Database Syst Rev i 2013;4:CD004907). [Extracted from the article]

The literature points to a large distributed brain network involved in the estimation of time. Among these regions, the role of the insular cortex is still poorly understood. At the confluence of emotional, interoceptive, and environmental signals, this brain structure has been proposed to underlie awareness of the passage of time and emotion related time dilation. Yet, this assumption has not been tested so far. This study aimed at exploring how a lesion of the insula affects subjective duration, either in an emotional context or in a non‐emotional context. Twenty‐one patients with a stroke affecting the insula, either left or right, were studied for their perception of sub and supra second durations. A verbal estimation task and a temporal bisection task were used with either pure tones or neutral and emotional sounds lasting between 300 and 1500 ms and presented monaurally. Results revealed that patients with a right insular lesion, showed less temporal sensitivity than both control participants and patients with a left insular lesion. Unexpectedly, emotional effects were similar in patients and control participants. Altogether, these results suggest a specific role of the right insula in the discrimination of durations, but not in emotion related temporal distortion. In addition, an ear × emotion interaction in control participants suggests that temporal processing of positive and negative sounds may be lateralized in the brain. [ABSTRACT FROM AUTHOR]

An intention to move distorts the perception of time. For example, a visual stimulus presented during the preparation of manual movements is perceived longer than actual. Although neural mechanisms underlying this action‐induced time distortion have been unclear, here we propose a new model in which the distortion is caused by a sensory–motor interaction mediated by alpha rhythm. It is generally known that viewing a stimulus induces a reduction in amplitude of occipital 10‐Hz wave ("alpha‐blocking"). Preparing manual movements are also known to reduce alpha power in the motor cortex ("mu‐suppression"). When human participants prepared movements while viewing a stimulus, we found that those two types of classical alpha suppression interacted in the third (time‐processing) region in the brain, inducing a prominent decrease in alpha power in the supplementary motor cortex (SMA). Interestingly, this alpha suppression in the SMA occurred in an asymmetric manner (such that troughs of alpha rhythm was more strongly suppressed than peaks), which can produce a gradual increase (slow shift of baseline) in neural activity. Since the neural processing in the SMA encodes a subjective time length for a sensory event, the increased activity in this region (by the asymmetric alpha suppression) would cause an overestimation of elapsed time, resulting in the action‐induced time distortion. Those results showed a unique role of alpha wave enabling communications across distant (visual, motor, and time‐processing) regions in the brain and further suggested a new type of sensory–motor interaction based on neural desynchronization (rather than synchronization). [ABSTRACT FROM AUTHOR]

Quantum entanglement and relativistic causality are key concepts in theoretical works seeking to unify quantum mechanics and gravity. In this article, a gedanken experiment that couples the spin to spacetime is proposed, and is then analyzed in the context of quantum information by using different approaches to quantum gravity. Both classical gravity theory and certain quantum theories predict that around a spin‐half particle, the spherical symmetry of spacetime is broken by its magnetic field or merely by its intrinsic angular momentum. It is asserted that any spin‐related deviation from spherical symmetry, upon appropriate measurement, can violate relativistic causality and quantum no‐cloning. To avoid these violations, the measurable spacetime around the particle's rest frame shall typically remain spherically symmetric, potentially as a back‐action by the act of a covariant measurement, or due to a quantized spin‐dependence of the magnetic field. This way, this gedanken experiment suggests a censorship mechanism preventing the possibility of spacetime‐based spin detection, which can shed light on the interface between quantum mechanics and gravity. Since this proposed gedanken experiment is independent of any specific theory, it is suitable for testing the coupling of quantum matter and spacetime in present and future candidate theories of quantum gravity. [ABSTRACT FROM AUTHOR]

Purpose To propose new frequency offset corrected inversion (FOCI) pulses with significantly reduced radiofrequency (RF) power deposition for spin echo imaging by incorporating the variable-rate selective excitation (VERSE) schemes into the pulse design. Materials and Methods Two schemes are proposed to design the new FOCI pulses with dramatically reduced peak RF power requirements. In scheme A, the time-dilation function is derived from a predefined adiabaticity factor modulation function. In scheme B, the time-dilation function is predefined, while the adiabaticity factor is conserved. Results The new FOCI pulses are shown to be able to operate at reduced specific absorption rate (SAR), specifically at the same peak RF power as that of a five- or seven-lobe sinc inversion pulse of the same duration. Using the new FOCI pulse, significant gain in sensitivity was observed in in vivo spin-echo echo-planar imaging, which was attributed to the improved refocusing slice profile. Conclusion The new FOCI pulses can replace the 180° five- or seven-lobe sinc pulses in spin-echo imaging with the same peak RF power requirement and significantly improved slice profile. J. Magn. Reson. Imaging 2004;20:531-537. © 2004 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Time perception is a fundamental component of everyday life. Although time can be measured using standard units, the relationship between an individual's experience of perceived time and a standard unit is highly sensitive to context. Stressful and threatening stimuli have been previously shown to produce time distortion effects, such that individuals perceive the stimuli as lasting for different amounts of time as compared to a standard unit. As a highly social species, humans are acutely sensitive to social stressors; however, time distortion effects have not been studied in the context of social stress. We collected psychophysiological (electrocardiogram and impedance cardiography) and time perception data before, during, and after a modified version of the Trier Social Stress Test for 42 participants. Based on prior theories and evidence from the time perception literature, we hypothesized that experiencing a stressful event would result in time distortion. This hypothesis was supported by the data, with individuals on average reproducing short and long duration negative and positive stimuli as lasting longer after experiencing social stress, t(41) = −3.55, p = .001, and t(41) = −4.12, p < .001 for negative stimuli, and t(41) = −2.43, p = .02, and t(41) = −3.07, p = .004 for positive stimuli. However, changes in time perception were largely unrelated to psychophysiological reactivity to social stress. These findings are in line with some other studies of time distortion, and provide evidence for the interoceptive salience model of time perception. Implications for mechanisms of time distortion are discussed. [ABSTRACT FROM AUTHOR]

We present a real-time framework which allows interactive visualization of relativistic effects for time-resolved light transport. We leverage data from two different sources: real-world data acquired with an effective exposure time of less than 2 picoseconds, using an ultra-fast imaging technique termed femtophotography, and a transient renderer based on ray-tracing. We explore the effects of time dilation, light aberration, frequency shift and radiance accumulation by modifying existing models of these relativistic effects to take into account the time-resolved nature of light propagation. Unlike previous works, we do not impose limiting constraints in the visualization, allowing the virtual camera to explore freely a reconstructed 3D scene depicting dynamic illumination. Moreover, we consider not only linear motion, but also acceleration and rotation of the camera. We further introduce, for the first time, a pinhole camera model into our relativistic rendering framework, and account for subsequent changes in focal length and field of view as the camera moves through the scene. [ABSTRACT FROM AUTHOR]

A local system of bodies in General Relativity whose exterior metric field asymptotically approaches the Minkowski metric effaces any effects of the matter distribution exterior to its Minkowski boundary condition. To enforce to all orders this property of gravity which appears to hold in nature, a method using linear algebraic scaling equations is developed which generates by an iterative process an N-body Lagrangian expansion for gravity's motion-independent potentials which fulfills exterior effacement along with needed metric potential expansions. Then additional properties of gravity - interior effacement and Lorentz time dilation and spatial contraction - produce additional iterative, linear algebraic equations for obtaining the full non-linear and motion-dependent N-body gravity Lagrangian potentials as well. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Time duration is perceived to be longer when accompanied by dynamic sensory stimulation than when accompanied by static stimulation. This distortion of time perception is thought to be due to the acceleration of an internal pacemaker that has been assumed to be the main component of temporal judgments. In order to investigate whether the function of the internal pacemaker is modality dependent or independent, we examined the correlation of visual flicker and auditory flutter effects on a temporal production task. While seeing a 10-Hz visual flicker or hearing a 10-Hz auditory flutter, participants estimated a duration of 2500 ms as accurately as possible by pressing a button. The results showed a significant within-individual correlation between the time distortion due to visual flicker and that due to auditory flutter. Additionally, we found that time distortion due to auditory flutter tended to be larger in female participants than in male participants. These results suggest that the mechanisms underlying subjective time dilation are similar between vision and audition within individuals, but that they vary across individuals. [ABSTRACT FROM AUTHOR]