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In this paper, we apply implicit functions to establish a general fixed point theorem in spherically complete ultrametric spaces which enable us to extend some known results. In particular, we will show that in a spherically complete space X a self-mapping T satisfies d(Tx, Ty) < max{d(x, Tx), d(y, Ty), d(x, Ty), d(y, Tx), d(x, y)} for each x, y ϵ X with x ≠ y, then T has a unique fixed point. This improves Gajic's fixed point theorem in spherically complete ultrametric spaces. [ABSTRACT FROM AUTHOR]

Our purpose in this work is to present several coupled fixed point results for different contraction mappings on cone metric spaces over Banach algebras by virtue of the properties of spectral radiuses. Also as an application, we give a simple example at the end of the paper. [ABSTRACT FROM AUTHOR]

Objective: To assess the association between myometrial electrical activity and time-to-delivery in preterm labor using uterine electromyography.Methods: Myometrial electrical activity was measured via the electrical uterine monitor (EUM) device. Data was prospectively collected among women admitted due to suspected preterm labor, prior to 34 weeks of gestation. EUM-Index was defined as the mean electrical activity of the uterine muscle over a period of 10 minutes measured in units of microjoule (μJ, microwatt second). The association between the EUM-Index at admission to time-to-delivery and delivery prior to 34 weeks of gestation was calculated.Results: Overall, 45 women were included in the study. EUM-Index combined with cervical dilatation, demonstrated significant correlation to time-to-delivery (R(2 )= 0.49, p = 0.005), which was strengthened for women presenting prior to 28 weeks of gestation. EUM-Index above the median (>3.05 MJ) was significantly associated with a shorter latency period for delivery (36.0 ± 19.4 vs. 50.2 ± 25.9 days, p = 0.04). For delivery prior to 34 weeks, the EUM-Index showed an AUC = 0.65 (95% CI 0.48-0.82), and a cutoff of 2.5 MJ provided 91.7% sensitivity and 93.3% negative predictive value.Conclusion: EUM-Index at time of admission due to suspected preterm labor is inversely correlated with time-to-delivery and may effectively rule out preterm delivery prior to 34 weeks. [ABSTRACT FROM AUTHOR]

It is well-known that application of invariant functions in various fields of pure or applied mathematics, physics and computer calculations is certainly of interest. In this paper, we study application of the invariant functions of Lie algebras, named $$\psi $$ and $$\varphi $$ function, respectively, to contractions of some lower-dimensional Lie algebras, with the goal of contributing to progress in any of these fields, particularly in physics and engineering. [ABSTRACT FROM AUTHOR]

In this paper, we first establish some user-friendly versions of fixed-point theorems for the sum of two operators in the setting that the involved operators are not necessarily compact and continuous. These fixed-point results generalize, encompass, and complement a number of previously known generalizations of the Krasnoselskii fixed-point theorem. Next, with these obtained fixed-point results, we study the existence of solutions for a class of transport equations, the existence of global solutions for a class of Darboux problems on the first quadrant, the existence and/or uniqueness of periodic solutions for a class of difference equations, and the existence and/or uniqueness of solutions for some kind of perturbed Volterra-type integral equations. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The objectives of these experiments were to characterize rumen motility patterns of cattle fed once daily using a real-time wireless telemetry system, determine when to measure rumen motility with this system, and determine the effect of ruminal dosing of ergot alkaloids on rumen motility. Ruminally cannulated Holstein steers (n = 8) were fed a basal diet of alfalfa cubes once daily. Rumen motility was measured by monitoring real-time pressure changes within the rumen using wireless telemetry and pressure transducers. Experiment 1 consisted of three 24-h rumen pressure collections beginning immediately after feeding. Data were recorded, stored, and analyzed using iox2 software and the rhythmic analyzer. All motility variables differed (P < 0.01) between hours and thirds (8-h periods) of the day. There were no differences between days for most variables. The variance of the second 8-h period of the day was less than (P < 0.01) the first for area and less than the third for amplitude, frequency, duration, and area (P < 0.05). These data demonstrated that the second 8-h period of the day was the least variable for many measures of motility and would provide the best opportunity for testing differences in motility due to treatments. In Exp. 2, the steers (n = 8) were pair-fed the basal diet of Exp. 1 and dosed with endophyte-free (E-) or endophyte-infected (E+; 0 or 10 μg ergovaline + ergovalinine / kg BW; respectively) tall fescue seed before feeding for 15 d. Rumen motility was measured for 8 h beginning 8 h after feeding for the first 14 d of seed dosing. Blood samples were taken on d 1, 7, and 15, and rumen content samples were taken on d 15. Baseline (P = 0.06) and peak (P = 0.04) pressure were lower for E+ steers. Water intake tended (P = 0.10) to be less for E+ steers the first 8 hour period after feeding. The E+ seed treatment at this dosage under thermoneutral conditions did not significantly affect rumen motility, ruminal fill, or dry matter of rumen contents.

We present a hypothesis for a mechanism involving self-organization of small functional units that leads to organ-level synchronization of uterine contractions in human labor. This view is in contrast to the long-held presumption that the synchronized behavior of the uterus is subject to well-defined internal organization (as is found in the heart) that exists prior to the onset of labor. The contractile units of the uterus are myocytes, which contract in response to both mechanical stretch and electrical stimulation. Throughout pregnancy progesterone maintains quiescence by suppression of "contraction-associated proteins" (CAPs). At the end of pregnancy a functional withdrawal of progesterone and an increasingly estrogenic environment leads to an increase in the production of CAPs. One CAP of particular importance is connexin 43, which creates gap junctions between the myocytes that cause them to become electrically coupled. The electrical connectivity between myocytes, combined with an increase in intrauterine pressure at the end of pregnancy shifts the uterus towards an increasingly unstable critical point, characterized by irregular, uncoordinated contractions. We propose that synchronous, coordinated contractions emerge from this critical point through a process of self-organization, and that the search for a uterine pacemaker has been unfruitful for the sole reason that it is non-existent. [ABSTRACT FROM AUTHOR]

Structure-prone DNA repeats are common components of genomic DNA in all kingdoms of life. In humans, these repeats are linked to genomic instabilities that result in various hereditary disorders, including many cancers. It has long been known that DNA repeats are not only highly polymorphic in length but can also cause chromosomal fragility and stimulate gross chromosomal rearrangements, i.e., deletions, duplications, inversions, translocations and more complex shuffles. More recently, it has become clear that inherently unstable DNA repeats dramatically elevate mutation rates in surrounding DNA segments and that these mutations can occur up to ten kilobases away from the repetitive tract, a phenomenon we call repeat-induced mutagenesis (RIM). This review describes experimental data that led to the discovery and characterization of RIM and discusses the molecular mechanisms that could account for this phenomenon. [ABSTRACT FROM AUTHOR]

In this paper we generalize the notion of $C^{*}$-valued contraction mappings, recently introduced by Ma et al., by weakening the contractive condition introduced by them. Using the new notion of $C^{*}$-valued contractive type mappings, we establish a fixed point theorem for such mappings. Our result generalizes the result by Ma et al. and those contained therein except for the uniqueness. [ABSTRACT FROM AUTHOR]

Objective: We aimed to evaluate the performance of a non-invasive EMG electrical uterine monitor (EUM) versus tocodynamometry (TOCO) by comparing both to internal uterine pressure catheter (IUPC). Study design: Prospective observational trial. Uterine activity was recorded continuously and simultaneously, in women during active term labor, with TOCO, EUM and IUPC. Uterine activity tracings were analyzed by three blinded physicians. Results: Overall, 385 tracings from 43 women were analyzed. A similar rate of interpretable tracings between physicians was demonstrated for EUM (87%; 95% CI 80.9–92.7%) and IUPC (94.8%; 95% CI 83.4–96.3%), with a significantly lower rate for TOCO (67.5%; 95% CI 59.4–76.8%,p < 0.001). There is a significant difference in the contraction frequency for EUM versus IUPC (0.77 ± 2.3) compared to TOCO versus IUPC (−3.34 ± 4.97). There is a high variability between the timing of TOCO contractions as compared to IUPC (4.74 ± 10.03 seconds), while a gap of 8.46 ± 4.24 seconds was detected for EUM. The sensitivity, positive predictive value and false positive rate for individual contraction identification by TOCO and EUM are 54.0%, 84.4%, 15.6% and 94.2%, 87.6%, 12.4%, respectively. Conclusion: EUM is efficient as IUPC for uterine activity assessment and both techniques are superior in comparison to external tocodynamometry. Our results support the use of non-invasive EMG technology to monitor uterine activity. [ABSTRACT FROM AUTHOR]

Superoxide and nitric oxide are generated by skeletal muscle, and these species are increased by contractile activity. Mitochondria have long been assumed to play the primary role in generation of superoxide in muscle, but recent studies indicate that, during contractile activity, membrane-localized NADPH oxidase(s) rapidly generate(s) superoxide that plays a role in redox signaling. This process is important in upregulation of rapid and specific cytoprotective responses that aid maintenance of cell viability following contractile activity, but the overall extent to which redox signaling contributes to regulation of muscle metabolism and homeostasis following contractile activity is currently unclear, as is identification of key redox-sensitive protein targets involved in these processes. Reactive oxygen and nitrogen species have also been implicated in the loss of muscle mass and function that occurs with aging, although recent work has questioned whether oxidative damage plays a key role in these processes. A failure of redox signaling occurs in muscle during aging and may contribute to the age-related loss of muscle fibers. Whether such changes in redox signaling reflect primary age-related changes or are secondary to the fundamental mechanisms is unclear. For instance, denervated muscle fibers within muscles from aged rodents or humans appear to generate large amounts of mitochondrial hydrogen peroxide that could influence adjacent innervated fibers. Thus, in this instance, a "secondary" source of reactive oxygen species may be potentially generated as a result of a primary age-related pathology (loss of neurons), but, nevertheless, may contribute to loss of muscle mass and function during aging. [ABSTRACT FROM AUTHOR]

Aldrin and dieldrin are chloroorganic insecticides which are recognised as endocrine disruptors. The aim of the study was to investigate their effect on the secretory functions of the uterus and ovary and on myometrial contractions. Myometrial strips and uterine and ovarian cells from nonpregnant cows were incubated with the xenobiotics (0.1, 1 or 10 ng/ml) for 24 or 72 h. Next, their effect on viability of myometrial, endometrial, granulosa and luteal cells, myometrial strip contractions, the synthesis and secretion of prostaglandins (PGs: PGF2α and PGE2) from uterine cells, the secretion of oestradiol (E2), testosterone (T) and oxytocin (OT) from granulosa cells and the secretion of progesterone (P4) and OT from luteal cells were determined. Neither of the xenobiotics (10 ng/ml) affected ( P > 0.05) the viability of the ovarian and uterine cells, while both (0.1–10 ng/ml) decreased ( P < 0.05) the basal and OT-stimulated myometrial contractions. In spite of these effects, neither of the insecticides affected ( P > 0.05) the synthesis and the secretion of PGs from the myometrial cells. Although they also did not impair the secretion of the PGs from the endometrial cells, they abolished ( P < 0.05) the stimulatory effect of OT ( P < 0.05) on the secretion of the PGs and stimulated ( P < 0.05) the secretion of OT from the granulosa and luteal cells. Moreover, aldrin and dieldrin stimulated secretion of E2 and T from the granulosa cells, while only dieldrin increased ( P < 0.05) the secretion of P4 from luteal cells. The data show that aldrin and dieldrin stimulated the secretory function of the cultured granulosa and luteal cells and inhibited the myometrial contractions of cows in vitro, which may affect on natural parturition. [ABSTRACT FROM AUTHOR]

Aim This experimental in vitro study examined differences in the expression and activity of calcium release-activated calcium ( CRAC) channels of human term-pregnant and non-pregnant myometrium. Material and Methods The tissue samples were obtained from term-pregnant myometrium in labor of women undergoing cesarean section and from non-pregnant myometrium of women undergoing total hysterectomy due to uterine myoma. The expression of Orai1 protein, a pore-forming subunit of CRAC channels, in human myometrium was examined using immunohistochemistry. CRAC channel involvement in the amplitude and frequency of myometrial contractions was evaluated in vitro using a tissue bath method with a CRAC ion channel blocker 3-fluropyridine-4-carboxylic acid ( FPCA). Results Decreased Orai1 expression was observed in human term-pregnant laboring myometrium compared with non-pregnant myometrium. However, the initial oxytocin-induced contraction of myometrium was significantly suppressed at different doses of FPCA in both non-pregnant human isolated myometrium and non-pregnant myometrium. The frequency of contractions was the most significantly reduced at the lowest dose of FPCA in non-pregnant myometrium and remained suppressed at all doses of FPCA in term-pregnant myometrium. Salbutamol was shown as more effective in suppression of amplitude in term-pregnant isolated myometrium. Conclusion Our results provide the first information about the changes in the Orai1 protein expression and activity of human myometrial CRAC channels in term-pregnant laboring myometrium. [ABSTRACT FROM AUTHOR]

Aims The purpose of this study was to investigate the effect of visfatin on in vitro myometrial contractility in human and rat, and compare it to leptin. Main methods Myometrial strips from term pregnant women having a caesarean section or rats were dissected, superfused with physiological saline and the effects of visfatin (500pM–25nM) or leptin (1nM–1μM), on spontaneous and oxytocin-induced contractions were studied. After establishment of regular contractions, tissues were incubated for control and test response at 37 °C for 20 min, and then contractility was assayed. Key findings In human and rat myometrium, visfatin had similar dose dependent effects on contractility. In the human myometrium, compared with that of controls (100%), 10 nM produced a significant (paired t-test) decrease in the 20 min integral of spontaneous (64 ± 8%, n = 13) and oxytocin-induced contractions (55 ± 9%, n = 5), mean ± SEM. In rat tissue the decrease was also significant (spontaneous, 76 ± 7%, n = 7; oxytocin-induced 68 ± 6%, n = 3). Leptin at this concentration (10 nM) had no effect in rat or human, and even at a higher concentration (1 μM) produced only a small inhibitory effect (~ 80%) on contractions. Significance These data are the first to show that visfatin inhibits myometrial contractility and does so more potently than leptin. Our data suggest that increased output of visfatin and leptin in obese pregnant women may impair uterine contractility resulting in an unplanned Caesarean delivery. [ABSTRACT FROM AUTHOR]

Curcumin is a naturally occurring compound which has been used in traditional medicine in India for a long time. This study investigated the ability of curcumin to inhibit the contractility of isolated caprine (goat) detrusor muscle. The ability of three concentrations of curcumin (30, 100 and 300 µM) to inhibit the 100 µM acetylcholine-induced contractility of the isolated caprine urinary bladder detrusor muscle was investigated. The effect of raising the concentration of acetylcholine from 100, 200 and 400 µM to overcome the curcumin-induced inhibition of detrusor contractility and the effects of the reversal agents tetraethylammonium, a potassium channel blocker (100 µM), glibenclamide, an ATP-sensitive potassium channel blocker (10 µM), and propranolol, a beta adrenergic receptor blocker (1 µM), on the inhibitory effect of detrusor contractility was also studied. Curcumin caused a concentration-dependent inhibition of acetylcholine-induced contractility of the isolated detrusor muscle which was statistically significant at all three concentrations of curcumin used. This inhibition was partially overcome by raising the concentration of ACh to 200 and 400 µM. The inhibition was overcome by the concurrent administration of tetraethylammonium. Glibenclamide reversed the inhibitory effect of 100 µM curcumin, but not that of 300 µM curcumin. Propranolol reversed the inhibitory effect of 100 µM curcumin but not that of 300 µM curcumin. These results suggest that curcumin inhibited the contractions of the isolated detrusor muscle. The results further suggest that the inhibitory effect is mediated by various mechanisms: stimulation of beta adrenergic receptors; an anticholinergic effect; and the opening of ATP-sensitive potassium channels. [ABSTRACT FROM AUTHOR]

Aims: Premature ventricular contractions (PVCs) are a common form of arrhythmia associated with an unfavourable prognosis in patients with structural heart disease. However, the prognostic significance in absence of heart disease is debated. With this study, we aim to investigate whether subjects with PVC, without structural heart disease, have a worse prognosis than the general population., Methods and Results: Patients evaluated for PVC at a secondary care centre in Stockholm County from January 2010 to December 2016 were identified. We included patients without history of previous heart disease who had undergone echocardiography and exercise test with normal findings. Based on sex and age, we matched the PVC cohort to a four times bigger control group from the general population and compared the outcome in terms of mortality and cardiovascular morbidity during a median follow-up time of 5.2 years. We included 820 patients and 3,264 controls. Based on a non-inferiority analysis, the PVC group did not have a higher mortality than the control group (0.44, CI 0.27-0.72). Sensitivity analysis with propensity score matching confirmed this result., Conclusions: PVC patients, who after thorough evaluation showed no signs of structural heart disease, did not have a worse prognosis when compared to an age- and sex- control group based on the general population., Competing Interests: Conflict of interest: RS and MJ have no conflict of interest to declare. LF has received consultancy fees from Bayer and Sanofi. MR has received consultancy fees from Pfizer, Roche, Zenicor, Medtronic and Janssen. VF has received consultancy fees from Medtronic., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Society of Cardiology.)

First, we will see that if T is a contraction of the k-quasi-∗-class A operator, then the nonnegative operator D = T∗k(∣T²∣ - ∣T∗∣²)Tk is a contraction whose power sequence {Dn}n=1∞ converges strongly to a projection P and TT∗kP = 0. Second, it will be proved that if T is a contraction of the k-quasi-∗-class A operator, then either T has a non-trivial invariant subspace or T is a proper contraction. Finally it will be proved that if T belongs to the k-quasi-∗-class A and is a contraction, then T has a Wold-type decomposition and T has the PF property. [ABSTRACT FROM AUTHOR]

Quinine, chloroquine and mefloquine are commonly used to treat malaria, however, with associated gastrointestinal (GI) side-effects. These drugs act as antagonists at recombinant 5-HT3 receptors and modulate gut peristalsis. These gastrointestinal side effects may be the result of antagonism at intestinal 5-HT3 receptors. Ileum from male C57BL/6 mice and guinea pigs was mounted longitudinally in organ baths. The concentration--response curves for 5-HT and the selective 5-HT3 agonist 2-Me-5-HT were obtained with 5-HT (pEC50=7.57±0.33, 12) more potent (P=0.004) than 2-Me-5-HT (pEC50=5.45±0.58, n=5) in mouse ileum. There was no difference in potency of 5-HT (pEC50=5.42±0.15, n=8) and 2-Me-5-HT (pIC50=5.01±0.55, n=11) in guinea pig ileum (P>0.05). Quinine, chloroquine or mefloquine was applied for 10 min and inhibitions prior to submaximal agonist application. In mouse ileum, quinine, chloroquine and mefloquine antagonised 5-HT-induced contractions (pIC50=4.9±0.17, n=7; 4.76±0.14, n=5; 6.21±0.2, n=4, correspondingly) with mefloquine most potent (P<0.05). Quinine, chloroquine and mefloquine antagonised 2-me-5-HT-induced contractions (pIC50=6.35±0.11, n=8; 4.64±0.2, n=7; 5.11±0.22, n=6, correspondingly) with quinine most potent (P<0.05). In guinea-pig ileum, quinine, chloroquine and mefloquine antagonised 5-HT-induced contractions (pIC50=5.02±0.15, n=6; 4.54±0.1, n=7; 5.32±0.13, n=5) and 2-me-5-HT-induced contractions (pIC50=4.62±0.25, n=5; 4.56±0.14, n=6; 5.67±0.12, n=4) with chloroquine least potent against 5-HT and mefloquine most potent against 2-me-5-HT (P<0.05). These results support previous studies identifying anti-malarial drugs as antagonists at recombinant 5-HT3 receptors and may also demonstrate the ability of these drugs to influence native 5-HT3 receptor-evoked contractile responses which may account for their associated GI side-effects. [ABSTRACT FROM AUTHOR]

Quadratic algebras are generalizations of Lie algebras; they include the symmetry algebras of second-order superintegrable systems in two dimensions as special cases. The superintegrable systems are exactly solvable physical systems in classical and quantum mechanics. For constant curvature spaces, we show that the free quadratic algebras generated by the first- and second-order elements in the enveloping algebras of their Euclidean and orthogonal symmetry algebras correspond one-to-one with the possible superintegrable systems with potential defined on these spaces. We describe a contraction theory for quadratic algebras and show that for constant curvature superintegrable systems, ordinary Lie algebra contractions induce contractions of the quadratic algebras of the superintegrable systems that correspond to geometrical pointwise limits of the physical systems. One consequence is that by contracting function space realizations of representations of the generic superintegrable quantum system on the 2-sphere (which give the structure equations for Racah/Wilson polynomials) to the other superintegrable systems one obtains the full Askey scheme of orthogonal hypergeometric polynomials. [ABSTRACT FROM AUTHOR]

Objective To review and update the research on melatonin receptor expression in the human myometrium, in particular as it pertains to uterine contractility at labor. Design Summary of previous studies with the addition of new data on the transcriptional regulation of melatonin receptor expression in human myometrial cells. Setting Not applicable. Patient(s) Late-term pregnant volunteers. Intervention(s) Biopsy collection for in vitro analyses provided the original data. More recently, uterine contractions in late-term pregnant volunteers were assessed before, during, and after acute white-light exposure. Main Outcome Measure(s) Melatonin receptor signaling in myometrial cells and uterine contractions in late-term pregnant volunteers. Result(s) Melatonin acts through the MTNR1B melatonin receptor that is expressed in the myometrium at late term to synergistically enhance oxytocin-dependent signaling and contractions. Acute inhibition of endogenous melatonin levels with light reversibly suppresses uterine contractions. Conclusion(s) These results point to a significant role for circulating melatonin in the timing and degree of uterine contractions in late-term pregnancy. Understanding the regulation of melatonin receptors remains a future objective. [ABSTRACT FROM AUTHOR]

The main goal of the present paper is to introduce certain duals and transpositions of a high-order tensor playing an important role in continuum mechanics. Emphasis is also placed on the comparison of the duals and the transpositions. In contrast to the duals, the transpositions depend on a metric of an underlying metric space. A high-order tensor is itself a representation of a multilinear function on a tensor space, obtained by means of the multilinear extension. The duals and the transpositions of a high-order tensor are identified as multilinear maps defined by the generalized scalar and the inner product, respectively. Consequently, the duals and the transpositions distinguish and define symmetries and symmetry-preserving transformation rules of a co-, contra- and mixed-variant tensor, respectively. As an application in continuum mechanics, the duals and the transpositions of a usual fourth-order tensor are defined and are employed to the determination of symmetries involved. [ABSTRACT FROM PUBLISHER]

For decades, it was believed that the diameter of gastrointestinal smooth muscle cells is sufficiently narrow, and that the diffusion of calcium across the plasma membrane is sufficient, to support contractile activity. Thus, depolarization-triggered release of intracellular calcium was not believed to be operative in gastrointestinal smooth muscle. However, after the incubation of muscle segments in solutions devoid of calcium and containing the calcium chelator ethylene glycol tetraacetic acid, an alternative electrical event occurred that was distinct from normal slow waves and spikes. Subsequently, it was demonstrated in gastrointestinal smooth muscle segments that membrane depolarization associated with this alternative electrical event triggered rhythmic contractions by release of intracellular calcium. Although this concept of depolarization-triggered calcium release was iconoclastic, it has now been demonstrated in multiple gastrointestinal smooth muscle preparations. On the basis of these observations, we investigated whether a rhythmic electrical and mechanical event would occur in aortic smooth muscle under the same calcium-free conditions. The incubation of aortic segments in a solution with no added calcium plus ethylene glycol tetraacetic acid induced a fast electrical event without corresponding tension changes. On the basis of the frequency of these fast electrical events, we pursued, contrary to what has been established dogma for more than three centuries, the question of whether the smooth muscle wall of the aorta undergoes rhythmic activation during the cardiac cycle. As with depolarization-triggered contractile activity in gastrointestinal smooth muscle, it was "well known" that rhythmic activation of the aorta does not occur in synchrony with the heartbeat. In a series of experiments, however, it was demonstrated that rhythmic contractions occur in the aortic wall in synchrony with the heartbeat and share a common pacemaker with the heart. We conclude that important observations in the vascular system became derivative from those in the gastrointestinal system. The challenging of scientific dogma potentially leads to the expansion of our fundamental knowledge base [ABSTRACT FROM AUTHOR]

Background: Preterm birth is the largest single cause of infant death in the United States. A cervical length of <2.5 cm, measured in the mid-trimester, has been shown to identify individuals at increased risk. Uterine electromyography is an emerging technology for noninvasively assessing uterine bioelectrical activity. With its ability to characterize nuanced differences in myometrial signals, uterine electromyography assessments during the mid-trimester may provide insight into the mechanisms of cervical shortening.Objective: This study aimed to characterize uterine bioelectrical activity in pregnant individuals with short cervices in the mid-trimester compared with that of pregnant individuals of the same gestational age with normal cervical lengths.Study Design: This is a prospective cohort study of subjects with singleton, nonanomalous pregnancies between 16 weeks and 0 days and 22 weeks and 6 days of gestational age. Subjects with normal cervical length (≥3.0 cm) were compared with subjects with short cervical length (<2.5 cm). The short-cervical-length cohort was further stratified by history of preterm birth. Multichannel uterine electromyography recordings were obtained for ∼60 minutes using proprietary, directional electromyography sensors on the abdomen. Uterine electromyography signals were observed and classified in groups as spikes, short bursts, and bursts. Primary outcomes were relative expression of spike, short-burst, and burst uterine electromyography signals. Subgroup analyses assessed each signal percentage by cervical length, history of preterm birth, and gestational age at delivery. Differences in percentage of uterine electromyography signals according to cervical length were analyzed using nonparametric tests of significance.Results: Of the 28 included subjects, 10 had normal and 18 had short cervical length. There were 9 subjects with short cervical length and a history of preterm birth. Spikes were the most commonly recorded signals and were higher in the normal-cervical-length cohort (96.3% [interquartile range, 93.1%-100.0%]) than the short-cervical-length cohort (75.2% [interquartile range, 66.7%-92.0%], P=.001). In contrast, median percentages of short-bursts and bursts were significantly higher in subjects with a short cervical length (17.3% [interquartile range, 13.6%-23.9%] vs 2.5% for normal cervical length [interquartile range, 0%-5.5%], P=.001 and 6.6% [interquartile range, 0%-13.4%] vs 0% for normal cervical length [interquartile range, 0%-2.8%], P=.014, respectively). Within subgroup analyses, cervical length was inversely proportional to percentage of observed short-bursts (P=.013) and bursts (P=.014). Subjects with short cervical length and history of preterm birth had higher burst percentages (12.8% [interquartile range, 9.0%-15.7%]) than those with short cervical length and no history of preterm birth (3.3% [interquartile range, 0%-5.0%], P=.003).Conclusion: Short-burst and burst uterine electromyography signals are observed more frequently in mid-trimester patients with short cervical lengths. This relationship provides insight into abnormal myometrial activation in the mid-trimester and offers a plausible biophysiological link to cervical shortening. [ABSTRACT FROM AUTHOR]

Abstract: Continuing the analysis initiated by Lachièze-Rey and Peccati (2013), we use contraction operators to study the normal approximation of random variables having the form of a -statistic written on the points in the support of a random Poisson measure. Applications are provided to subgraph counting, boolean models and coverage of random networks. [Copyright &y& Elsevier]

The study was conducted to evaluate the incidence of subacute rumen acidosis in cattle and impact of this situation (SARA) in the pH of the urine, in rumen contractions and faecal physical qualities. In four cows farms were checked 87 samples from rumen content sample through the nasoesophagal probe and equally urine samples at the cows in start of lactation and in middle lactation. All animals were checked clinically for rumen contractions and faecal physical qualities. Esteemed affected by SARA condition, cows which had pH of rumen content 5.5 and less. From the total heads in the experiment were found 24 cows (27.58 %) with SARA condition. Of these, 15 heads (32.6 %) were at the beginning of lactation and 9 heads (21.95%) in mid-lactation. pH of the urine seems influenced by the pH value of the rumen contentst. Among these indicators related to positive character dependency (r = 0403). pH of the rumen contents affects the number of its contractions. The results showed poor korelative and negative character (r = - 0329). Physical qualities and faecal structure were also affected by the pH values of rumen contents. pH of the urine, the number and strength of ruminal movements and with them the changes in the physical structure of faecal can be used for early diagnosis of SARA condition in cows. [ABSTRACT FROM AUTHOR]

Abstract: We show that the only indecomposable solvable Leibniz non-Lie algebra with nilradical of maximal nilpotence index is rigid in any dimension, and moreover that it is complete, i.e., only possesses inner derivations. The possible contractions of onto Lie algebras are obtained. [Copyright &y& Elsevier]

The business cycles literature shows that the likelihood of an expansion or contraction ending increases with its age, i.e. they exhibit positive duration dependence. This evidence rests on the assumption that the magnitude of duration dependence is the same over time. However, we assume that the degree of likeliness of an expansion or contraction ending as it gets older might indeed change after a specific duration. Estimating a continuous-time Weibull model for a group of 13 industrial countries over the period 1948-2009 and allowing for the presence of a change-point in the duration-dependence parameter; we conclude that the evidence of positive duration dependence is no longer present when an expansion surpasses 10 years of duration. [ABSTRACT FROM AUTHOR]

Abstract: Hypoxia, or the lack of oxygen, has multiple impacts on the vascular system. The major molecular sensors for hypoxia at the cellular level are hypoxia inducible factor and heme oxygenase. Hypoxia also acts on the vasculature directly conveying its damaging effects through disruption of the control of vascular tone, particularly in the coronary circulation, enhancement of inflammatory responses and activation of coagulation pathways. These effects could be particularly detrimental under pathological conditions such as obstructive sleep apnea and other breathing disorders. [Copyright &y& Elsevier]

Abstract: For semigroups and , we show that if is a representation of by contractions on a Hilbert space then , where and is the unitary spectrum of with respect to . For a representation of a suitable semigroup by contractions on a Banach space, we give sharp conditions on which guarantee that the equality above holds. These conditions concern the thinness of in the harmonic analysis sense. These results are related to theorems of Katznelson–Tzafriri type, which give conditions guaranteeing that vanishes. [Copyright &y& Elsevier]

Abstract: The group classification of a class of variable coefficient reaction–diffusion equations with exponential nonlinearities is carried out up to both the equivalence generated by the corresponding generalized equivalence group and the general point equivalence. The set of admissible transformations of this class is exhaustively described via finding the complete family of maximal normalized subclasses and associated conditional equivalence groups. Limit processes between variable coefficient reaction–diffusion equations with power nonlinearities and those with exponential nonlinearities are simultaneously studied with limit processes between objects related to these equations (including Lie symmetries, exact solutions and conservation laws). [Copyright &y& Elsevier]

The article tests the hypothesis that prolonged, controlled mechanical ventilation results in a time-dependent reduction in rat diaphragmatic blood flow and oxidative phosphorylation resulting in muscle fatigue. It explains that mechanical ventilation is a life-saving intervention in respiratory failure but when prolonged, it is associated with numerous complications. Findings reveal that it reduces rat diaphragm blood flow, impairing oxygen delivery and uptake leading to difficult weaning.

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The active transport of sperm through the female genital tract is a very important factor in the fertilisation process. There is conflicting evidence as to whether seminal plasma has a positive or a negative effect on reproductive performance regarding the sperm transport in the female genital tract. In this study, we investigated if the perfused swine uterus is an appropriate model to study the effect of human seminal plasma on uterine contractility. It was found that repeated application of human seminal plasma caused a significantly higher rise in pressure and frequency of contractions in perfused swine uteri compared to buffer [a 1.8-fold and 1.5-fold pressure rise (Δ t1SP, P = 0.025; Δ t2SP, P = 0.004)] after the first and second application of seminal plasma respectively, and even a 2-fold pressure rise after the third application with a statistical significance of P = 0.007. The pressure rise caused by the seminal plasma over the entire period of application was calculated using a mathematical programme and was represented by the integral of the pressure curve over time. This perfusion model as well as the use of pressure-time integrals is suitable for patho-physiological studies of the uterus. [ABSTRACT FROM AUTHOR]

Objective. To analyze typical maternal heart rate (MHR) patterns in the first and second stages of labor. Design. Observational study. Setting. Tertiary care community hospital. Population. Normal term parturients with epidural anesthesia. Methods. Confirmed MHR and uterine activity were simultaneously recorded. The average MHR was analyzed 10 seconds before, as well as at the peak of, each contraction and/or pushing effort. Each woman contributed one datapoint at each time point to the analysis. Main outcome measure. Change in MHR during contractions. Results. First stage: 7.6±2.1 contractions per woman ( n=18) were analyzed. Average MHR decreased during contractions: from 83±13 to 74±10bpm; p<0.001). In 56% (10/18) of the women, 'early' type decelerations were seen in at least 50% of contractions. Second stage: 3.5±1.5 contractions per woman. All women ( n=15) showed MHR accelerations during every pushing effort (ΔMHR: +35±13bpm; 88±14 to 123±17bpm; p<0.001). MHR was persistently >100bpm in three women (17%) in the first stage, and in four women (27%) in the second stage. Peak MHR >140bpm occurred during pushing in 20%. Conclusion. Decreases in MHR during contractions in the first stage of labor can mimic fetal heart rate (FHR) accelerations as well as early type decelerations. Thus, first stage tracings with a low baseline and early type decelerations may be maternal in origin and FHR should be independently confirmed in such tracings. Because second stage MHR accelerations generally show greater amplitude than FHR accelerations, tracings with repetitive accelerations during contractions (especially when Δ >20bpm) should be considered MHR until proven otherwise. [ABSTRACT FROM AUTHOR]

The pathogenesis of preterm birth (PTB) is largely unknown and the endocrine stress pathway is likely to participate in the mechanisms allowing onset of labor. However, the vast majority of the studies evaluating psychosocial distress denied an association with PTB. Uterine contractility rather than PTB seems associated with distress in pregnancy. [ABSTRACT FROM AUTHOR]