Critical Binder cumulant in two-dimensional anisotropic Ising models

The Binder cumulant at the phase transition of Ising models on square lattices with various ferromagnetic nearest and next-nearest neighbour couplings is determined using mainly Monte Carlo techniques. We discuss the possibility to relate the value of the critical cumulant in the isotropic, nearest neighbour and in the anisotropic cases to each other by means of a scale transformation in rectangular geometry, to pinpoint universal and nonuniversal features.Comment: 7 pages, 4 figures, submitted to J. Phys.

The effect of backing material on the transmitting response level and bandwidth of a wideband underwater transmitting transducer using 1-3 piezocomposite material

AbstractIncreasing operating depths of autonomous underwater vehicles have necessitated the development of underwater transducers that can operate at a greater depth. This paper investigates the possibility of incorporating rigid backing material into the transducer design to increase its stiffness and depth capability without adversely affecting its wide bandwidth and high transmitting levels. The transducer design under consideration uses 1-3 piezocomposite material, matching layer, coupling layer, stiff backing material (backing plates) and operates at 300 kHz with 200 kHz 6dB bandwidth

Routine first-trimester screening for fetal trisomies in twin pregnancy: cell-free DNA test contingent on results from combined test

Objective: To report on the routine clinical implementation of cell-free (cf)DNA analysis of maternal blood for trisomies 21, 18 and 13 contingent on the results of the first-trimester combined test in twin pregnancies. Methods: Screening for trisomies 21, 18 and 13 was carried out by a combination of maternal age, fetal nuchal translucency (NT) thickness, and serum free ß-hCG and PAPP-A at 11-13 weeks’ gestation in 959 twin pregnancies in two UK NHS hospitals. Women in the high-risk group (risk >1 in 100) were offered options of invasive testing, cfDNA testing or no further testing and those in the intermediate-risk group (risk 1 in 101 to 1 in 2500 in the first phase of the study and 1 in 101 to 1 in 500 in the second phase) were offered cfDNA or no further testing. The trisomic status of the pregnancies was determined by prenatal or postnatal karyotyping or examination of the neonates. Results: In 42 (4.4%) of the 959 pregnancies there was termination, miscarriage or stillbirth with no known karyotype or there was loss to follow up. The 917 pregnancies with known trisomic status of both twins, included 6 that were discordant for trisomy 21, 4 discordant for trisomy 18 and 896 with no trisomies 21, 18 or 13. Following combined screening, 47 (5.1%), 203 (22.2%) and 667 (72.7%) of the pregnancies were classified as high-risk, intermediate-risk and low-risk, respectively. The high-risk group included 5 (83.3%) cases of trisomy 21 and 3 (75.0%) of trisomy 18. The cfDNA test was carried out in 224 pregnancies and results were provided in 214 (95.5%); this group included 6 with trisomy 21, 3 with trisomy 18 and 206 with no trisomies 21, 18 or 13. The cfDNA test correctly classified as screen positive all 6 cases of trisomy 21 and 2 of the 3 with trisomy 18 and as screen negative for each of the trisomies all 206 unaffected pregnancies. Contingent screening, led to prenatal detection of all cases of trisomy 21 and 3 of 4 with trisomy 18. Conclusions: The study has demonstrated the feasibility of introducing cfDNA testing, contingent on the results of the first-trimester combined test for major trisomies, in a routine population of twin pregnancies

Interactions of the Human Papillomavirus E6 protein and their role in the persistence of viral episomes

The E6 protein from high-risk Human Papillomaviruses (HPVs) has previously been shown to be necessary for the persistence of viral episomes in cells, however, the mechanism for this remains unclear. High-risk E6 proteins have many activities including the ability to degrade p53 and the ability to bind to and degrade PDZ proteins. In this study I aimed to further elucidate the role of E6 in the persistence of viral episomes. I used two HPV16 mutant genomes with mutations in the E6 open-reading frame; one that is unable to degrade p53 (16E6p53m), and one that lacks the PDZ-binding motif (16E6PDZ). I found that both are unable to persist episomally in cells thereby implicating these two activities of E6 in HPV episomal persistence. Upon closer investigation of the two mutant genomes, I found that the 16E6p53m genome does not replicate as efficiently as the wild-type genome. This result suggests a function for p53-degradation in genome replication, and consequently in genome persistence. Furthermore, by carrying out a more detailed analysis of the relationship between E6 and the PDZ protein hScrib, I showed that the wild-type E6 protein is stabilised by virtue of the PDZ-binding motif, present on its C-terminus. On the other hand, the mutant E6 protein that lacks the PDZ-binding motif (E6PDZ) is more susceptible to proteasomal degradation. These findings provide evidence for a previously unknown outcome of the E6-PDZ protein interaction, in stabilising wild-type E6 protein. In addition to the implications of this stabilisation in the persistence of viral episomes, it is also significant when considering the activities and properties of E6 that contribute to the development of neoplasia. Finally, I have also found that wild-type HPV16 genomes cannot persist in cells that constitutively express E6 protein, suggesting that the correct regulation of E6 expression is crucial

Mapping Intersects of Power and Reciprocity in Adult EducationDeliberative Civic Engagement and Leadership Development in Community-Engaged Scholarship

The purpose of this work is to assist in identifying and naming dynamic relational forces that shape the effectiveness of community engagement. Understanding power from the perspective of reciprocity supports adaptive and transformational learning necessary to increase the effectiveness of community-engaged partnerships and scholarship

Comparison of screening for pre-eclampsia at 31-34 weeks' gestation by sFlt-1/PlGF ratio and a method combining maternal factors with sFlt-1 and PlGF

Objective: To estimate the patient-specific risk of preeclampsia (PE) at 31-34 weeks’ gestation by a combination of maternal characteristics and medical history with multiple of the median (MoM) values of serum placental growth factor (PLGF) and serum soluble fms-like tyrosine kinase-1 (sFLT-1) and compare the performance of screening to that achieved by the sFLT-1 to PLGF ratio. Methods: This was a prospective observational study in women attending for a third-trimester ultrasound scan at 31-34 weeks as part of routine pregnancy care. We estimated the performance of screening of PE with delivery within four weeks of assessment (PE at <4 weeks) and PE from four weeks after assessment and up to 40 weeks’ gestation (PE at 4w-40GW) in screening by the sFLT-1 to PLGF ratio and by a to PLGF ratio and by a method utilizing Bayes theorem to combine maternal factors and MoM values of sFLT-1 and PLGF. The significance of difference in performance of screening between the method utilising Bayes theorem and that of the sFLT-1 to PLGF ratio was assessed by comparison of the areas under the receiver operating characteristic curves (AUROC). Results: The study population of 8,063 singleton pregnancies included 231 (2.9%) that subsequently developed PE. In the prediction of delivery with PE at <4 weeks the performance of the method utilising Bayes theorem was similar to that of the sFLT-1 to PLGF (AUROC: 0.987, 95%CI 0.979-0.995 vs. 0.988, 95%CI: 0.981-0.994; p=0.961). and at fixed fixed screen positive rate (SPR) of 3.9% the detection rate (DR) was 87.1% for both methods. In contrast, the performance of screening for delivery with PE at 4w-40GW was better with the method utilising Bayes theorem than with the sFLT-1 to PLGF ratio (AUROC: 0.884, 95%CI 0.854-0.914 vs. 0.818, 95%CI: 0.775--0.860 ; p<0.0001) and at total fixed SPR of 25.7% the DRs were 84.4% vs. 73.0%. Conclusion: At 31-34 weeks’ gestation the performance of screening for PE at <4 weeks from assessment by the method utilising Bayes theorem is similar to that of the sFLT-1 to PLGF ratio, but the former is superior to the latter in prediction of PE >>4 weeks

Critical Binder cumulant for isotropic Ising models on square and triangular lattices

Using Monte Carlo techniques, the critical Binder cumulant U* of isotropic nearest-neighbour Ising models on square and triangular lattices is studied. For rectangular shapes, employing periodic boundary conditions, U* is found to show the same dependence on the aspect ratio for both lattice types. Similarly, applying free boundary conditions for systems with square as well as circular shapes for both lattices, the simulational findings are also consistent with the suggestion that, for isotropic Ising models with short-range interactions, U* depends on the shape and the boundary condition, but not on the lattice structure.Comment: 7 pages, 4 figures, submitted to J. Stat. Mec

Fetal middle cerebral artery and umbilical artery pulsatility index: effects of maternal characteristics and medical history

To define the contribution of maternal variables which influence the measured fetal middle cerebral artery (MCA) and umbilical artery (UA) pulsatility index (PI) in the assessment of fetal wellbeing

The various power decays of the survival probability at long times for free quantum particle

The long time behaviour of the survival probability of initial state and its dependence on the initial states are considered, for the one dimensional free quantum particle. We derive the asymptotic expansion of the time evolution operator at long times, in terms of the integral operators. This enables us to obtain the asymptotic formula for the survival probability of the initial state $\psi (x)$, which is assumed to decrease sufficiently rapidly at large $|x|$. We then show that the behaviour of the survival probability at long times is determined by that of the initial state $\psi$ at zero momentum $k=0$. Indeed, it is proved that the survival probability can exhibit the various power-decays like $t^{-2m-1}$ for an arbitrary non-negative integers $m$ as $t \to \infty$, corresponding to the initial states with the condition $\hat{\psi} (k) = O(k^m)$ as $k\to 0$.Comment: 15 pages, to appear in J. Phys.

Biomarkers of impaired placentation at 35-37 weeks' gestation in the prediction of adverse perinatal outcome

Objective: This screening study at 35-37 weeks’ gestation investigates the potential value of uterine artery pulsatility index (UtA-PI) and serum levels of the angiogenic placental growth factor (PlGF) and antiangiogenic factor soluble fms-like tyrosine kinase-1 (sFLT-1) in the prediction of adverse perinatal outcome in small for gestational age (SGA) and non-SGA neonates. Methods: This was a prospective observational study in 19,209 singleton pregnancies attending for a routine hospital visit at 35+0 - 36+6 weeks’ gestation. This visit included recording of maternal demographic characteristics and medical history, sonographic estimation of fetal weight (EFW), color Doppler ultrasound for measurement of the mean UtA-PI, and measurement of serum concentration of PlGF and sFLT. Multivariable logistic regression analysis was carried out to determine which of the factors from maternal or pregnancy characteristics and measurements of UtA-PI, PlGF and sFLT-1, provided a significant contribution in the prediction of each of four adverse outcome measures: first, stillbirth, second, cesarean section for presumed fetal compromise in labor, third, neonatal death or hypoxic ischemic encephalopathy grades 2 and 3, and fourth, admission to the neonatal unit (NNU) for ≥48 hours. Predicted probabilities from logistic regression analysis were used to construct receiver operating characteristic (ROC) curves to assess performance of screening for these adverse outcomes. Results: First, 83% of stillbirths, 82% of cesarean sections for presumed fetal compromise in labor, 91% of cases of neonatal death or hypoxic ischemic encephalopathy and 86% of NNU admissions for ≥48 hours occurred in pregnancies with non-SGA babies. Second, UtA-PI >95th percentile, sFLT-1 >95th percentile and PLGF 95th, sFLT-1 >95th and PLGF <5th percentiles for most adverse outcomes was <2.5 in both SGA and non-SGA neonates. Conclusions: In pregnancies undergoing routine antenatal assessment at 35-37 weeks’ gestation measurements of UtA-PI, sFLT-1 or PlGF provide poor prediction of adverse perinatal outcome in both SGA and non-SGA fetuses