An Experimental Investigation and Laboratory Simulation of Atmospheric Fading on a 900 MHz Transhorizon Radio-Link.

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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.

Prediction of stillbirth from maternal factors, fetal biometry and uterine artery Doppler at 19-24 weeks

Objectives: To evaluate the performance of screening for all stillbirths and those due to impaired placentation and unexplained or other causes by a combination of maternal factors, fetal biometry and uterine artery pulsatility index (UT-PI) at 19-24 weeks’ gestation and compare this performance to that of screening by UT-PI alone. Methods: This was a prospective screening study of 70,003 singleton pregnancies including 69,735 live births and 268 (0.38%) antepartum stillbirths; 159 (59%) were secondary to impaired placentation and 109 (41%) were due to other or unexplained causes. Multivariate logistic regression analysis was used to develop a model for prediction of stillbirth based on a combination of maternal factors, fetal biometry and UT-PI. Results: Combined screening predicted 55% of all stillbirths, including 75% of those due to impaired placentation and 23% of those that were due to other causes or unexplained, at false positive rate of 10%; within the impaired placentation group the detection rate of stillbirth at 37 weeks (88% vs 46%; p<0.001). The performance of screening by the combined test was superior to that of selecting the high-risk group on the basis of UT-PI being above the 90th percentile for gestational age, which predicted 48% of all stillbirths, 70% of those due to impaired placentation and 15% of those that were due to other causes or unexplained. Conclusions: Second-trimester screening by a combination of UT-PI with maternal factors and fetal biometry can predict a high proportion of stillbirths and in particular those due to impaired placentation

Prediction of large-for-gestational-age neonate by routine third-trimester ultrasound

Objectives: First, to evaluate and compare the performance of routine ultrasonographic estimated fetal weight (EFW) and fetal abdominal circumference (AC) at 31+0 - 33+6 and 35+0 - 36+6 weeks’ gestation in the prediction of large for gestational age (LGA) neonates born at ≥37 weeks’ gestation. Second, to assess the additive value of fetal growth velocity between 32 and 36 weeks’ gestation on the performance of EFW at 35+0 - 36+6 weeks’ gestation for prediction of LGA neonates. Third, to define the predictive performance for LGA neonates of different EFW cut-offs at routine ultrasound examination at 35+0 - 36+6 weeks’ gestation. Fourth, to propose a two-stage strategy for identifying pregnancies with LGA fetuses that may benefit from iatrogenic delivery during the 38th gestational week. Methods: First, data from 21,989 singleton pregnancies that had undergone routine ultrasound examination at 31+0 - 33+6 weeks’ gestation and 45,847 that had undergone routine ultrasound examination at 35+0 - 36+6 weeks were used to compare the predictive performance of EFW and AC for LGA neonates with birthweight >90th and >97th percentiles born at ≥37 weeks’ gestation. Second, data from 14,497 singleton pregnancies that had undergone routine ultrasound examination at 35+0 - 36+6 weeks’ gestation and had a previous scan at 30+0 – 34+6 weeks were used to determine, through multivariable logistic regression analysis, whether addition of growth velocity, defined by a difference in EFW and AC Z-scores between the early and late third trimester scans divided by the time interval between them, improved the performance of EFW at 35+0 - 36+6 weeks in the prediction of delivery of LGA neonates born at ≥37 weeks’ gestation. Third, in the database of the 45,847 pregnancies that had undergone routine ultrasound examination at 35+0 - 36+6 weeks’ gestation the screen positive and detection rate of LGA neonates born at ≥37 weeks’ gestation and at ≤10 days from the initial scan were calculated for different EFW percentile cut-offs between the 50th and 90th percentile. Results: First, the areas under the receiver operating characteristic curves (AUROC) of screening for LGA neonates were significantly higher with EFW Z-score than AC Z-score and at 35+0 - 36+6 than at 31+0 - 33+6 weeks’ gestation (p90th percentile at 35+0 - 36+6 weeks’ gestation the predictive performance for LGA neonates born at ≥37 weeks’ gestation was modest (65% and 46% for neonates with birthweight >97th and >90th percentiles, respectively, at screen positive rate of 10%), but the performance was better for prediction of LGA neonates born at ≤10 days from the scan (84% and 71% for neonates with birthweight >97th and >90th percentiles, respectively, at screen positive rate of 11%). Fourth, screening by EFW >70th percentile at 35+0 - 36+6 weeks’ gestation predicted 91% and 82% of LGA neonates with birthweight >97th and >90th percentiles born at ≥37 weeks’ gestation, at screen positive rate of 32%, and the respective values of screening by EFW >85th percentile for prediction of LGA neonates born at ≤10 days from the scan were 88%, 81% and 15%. On the basis of these results it was proposed that routine fetal biometry at 36 weeks’ gestation is a screening rather than diagnostic test for fetal macrosomia and that EFW >70th percentile should be used to identify pregnancies in need for another scan at 38 weeks and in the latter those with EFW >85th percentile should be considered for iatrogenic delivery during the 38th week. Conclusions: First, the predictive performance for LGA neonates by routine ultrasonographic examination during the third trimester is higher if the scan is carried out at 36 than at 32 weeks, the method of screening is EFW than fetal AC, the outcome measure is birthweight >97th than >90th percentile and if delivery occurs within 10 days than at any stage after assessment. Second, prediction of LGA neonates by EFW >90th percentile is modest and the study presents a two-stage strategy for maximizing the prenatal prediction of LGA neonates

Intelligent Noninvasive Diagnosis of Aneuploidy:Raw Values and Highly Imbalanced Dataset

The objective of this paper is to introduce a noninvasive diagnosis procedure for aneuploidy and to minimize the social and financial cost of prenatal diagnosis tests that are performed for fetal aneuploidies in an early stage of pregnancy. We propose a method by using artificial neural networks trained with data from singleton pregnancy cases, while undergoing first trimester screening. Three different datasets' with a total of 122 362 euploid and 967 aneuploid cases were used in this study. The data for each case contained markers collected from the mother and the fetus. This study, unlike previous studies published by the authors for a similar problem differs in three basic principles: 1) the training of the artificial neural networks is done by using the markers' values in their raw form (unprocessed), 2) a balanced training dataset is created and used by selecting only a representative number of euploids for the training phase, and 3) emphasis is given to the financials and suggest hierarchy and necessity of the available tests. The proposed artificial neural networks models were optimized in the sense of reaching a minimum false positive rate and at the same time securing a 100% detection rate for Trisomy 21. These systems correctly identify other aneuploidies (Trisomies 13&18, Turner, and Triploid syndromes) at a detection rate greater than 80%. In conclusion, we demonstrate that artificial neural network systems can contribute in providing noninvasive, effective early screening for fetal aneuploidies with results that compare favorably to other existing methods

Uterine artery pulsatility index at 30-34 weeks' gestation in the prediction of adverse perinatal outcome

Objective: To investigate the potential value of uterine artery Doppler at 30 34 weeks’ gestation in the prediction of adverse perinatal outcome. Methods: Screening study in 30,780 singleton pregnancies at 30 34 weeks. Uterine artery pulsatility index (PI) was measured and the values were converted to multiples of the median (MoM) after adjustment from variables in maternal characteristics and medical history that affect the measurements. Multivariable logistic regression analysis was used to determine if uterine artery PI had a significant additional contribution to maternal characteristics, medical history and obstetric factors in predicting adverse outcome. The detection rate (DR) and false positive rate (FPR) of screening by uterine artery PI were estimated for stillbirth, cesarean section for fetal distress, umbilical arter ial cord blood pH <7.0 or umbilical venous pH <7.1 and Apgar score <7 at 5 minutes. Results: The incidence of adverse perinatal outcome was higher in small for gestational age (SGA) than in non SGA fetuses, but the majority of cases for each adverse outcome were in the non SGA group, including about 70% of stillbirths and more than 80% of cases of cesarean section for fetal distress, low cord blood pH and low Apgar score. The performance of uterine artery PI >95 th percentile in screening for each adverse outcome was poor with DR of 6 16% and FPR of 5 6%. T he DR of high uterine artery PI for adverse outcome was higher in the SGA than non SGA groups, including 24% vs. 13% for stillbirth , 15% vs. 5% for cesarean section for fetal distress, 22% vs. 9% for low cord blood pH and 20% vs. 3% for low Apgar score. Conclusion: High uterine artery PI at 30 34 weeks’ gestation may be useful in the prediction of adverse perinatal outcome in pregnancies with SGA fetuses, but not in those with non SGA fetuses

Effect of Intermittent Pneumatic Foot Compression on Popliteal Artery Haemodynamics

AbstractPurpose: the aim was to investigate the effect of intermittent pneumatic foot compression (IPCfoot) on popliteal artery haemodynamics in normal individuals and in patients with intermittent claudication due to peripheral vascular disease (PVD) (Fontaine stage II). Material and methods: popliteal artery volume flow [vFl], pulsatility index [PI], mean velocity [mV], peak systolic [PSV] and end diastolic velocity [EDV], in 25 limbs of 20 normal subjects and 40 limbs of 32 stable claudicants were obtained in the sitting position before, during and within 30 seconds after the application of IPCfoot(applied pressure: 120 mmHg; inflation time: 3 seconds; deflation time: 17 seconds) using colour-flow duplex imaging (CFDI). The reproducibility of flow velocity estimations using CFDI in the horizontal [hor] (recovery) and sitting [sit] positions was evaluated in 20 limbs of normal controls and 20 limbs of claudicants. Results: popliteal artery vFl, mV, PSV and PI measurements were performed with a coefficient of variation (CV) of less than 14.6% among claudicants and of less than 13.3% in normal subjects. EDV is the least reproducible parameter with an overall CV range of 10.2–21.5% in normal controls and 9.1–18.6% in arteriopaths. On application of IPCfootpopliteal artery vFl increased by 111% in the control group (p<0.001) and by 51% in the claudicants (p<0.001). Within 30 seconds of the cessation of pump action flow decreased significantly in both groups (p<0.001), but maintained a significantly higher level than that at baseline (p<0.001, in both groups). The mV, PSV and EDV showed a similar pattern of significant changes. Both in normals and claudicants, the PI decreased with IPCfoot(p<0.001) and increased post-compression; however, it was significantly lower than baseline (p<0.005) within 30 seconds of impulse delivery. Conclusions: current CFDI technology enables a reproducible estimation of popliteal artery flow velocities. IPCfootcan significantly augment arterial calf inflow on an acute basis both in normals and claudicants. The increase of EDV and decrease of PI indicate that attenuation of peripheral resistance to flow is the main mechanism underlying the popliteal artery vFl enhancement on application of IPCfoot. Prospective trials on the long-term effect of IPCfootin the management of patients with PVD are indicated from the results of this study

Lipid Composition of Comedones Compared With That of Human Skin Surface in Acne Patients

TLC† analysis of comedo lipids from the face, neck, chest and back of acne patients of both sexes, ages 12 to 26 years, (some 65 specimens) gave the same gross composition except for hydrocarbons more saturated than squalene and lipids more polar than free cholesterol. Quantitative data (chromatography plus GLC of isolated fractions) on both comedo and surface lipids from each of 3 acne patients revealed the following. Free fatty acids plus triglycerides comprised ∼63% of both comedo and skin surface lipids. However, for the comedo, 90% of this sum was free fatty acids compared with only 25% for surface lipid. This implies that triglycerides in comedo lipids are nearly completely hydrolyzed but only 25% hydrolyzed in surface lipids. GLC patterns of the free fatty acids were almost identical for both surface and comedo lipids in all 3 subjects except for slightly more unsaturated acids in surface lipids. For comedo and surface lipids respectively, wax esters were 14% and 24%, sterol esters 4% and 2%, free cholesterol 12% and 2%, and squalene 8% and 9%. Absence of free alcohols and constancy of GLC composition of the entire wax ester fraction indicated it was not hydrolyzed in either surface or comedo lipids. GLC composition of the entire sterol ester fraction from comedones indicated that the fatty acids were derived from epidermis and sebum

Comparative HPLC-MSn analysis of canine and human meibomian lipidomes: many similarities, a few differences

The aim of this study was to evaluate the lipidome of meibomian gland secretions in canines (cMGS) – a common pet and laboratory animal – and to compare it with that of human MGS (hMGS), to determine whether canines could be used as a valid experimental animal model in studies of the biochemistry and physiology of the human ocular surface in general, and of the Meibomian glands in particular. The MGS of both species were evaluated using HPLC in combination with atmospheric pressure chemical ionization ion trap mass spectrometry. The main lipid classes found in cMGS were very long chain cholesteryl esters, wax esters, (O-acyl)-omega-hydroxy fatty acids (OAHFA), and cholesteryl esters of OAHFA. The lipidomes of cMGS and hMGS were found to be qualitatively similar, which implies similar biosynthetic and biodegradation pathways in canines and humans. However, some quantitative differences between the two were observed

Study protocol for the randomised controlled trial: combined multimarker screening and randomised patient treatment with ASpirin for evidence-based PREeclampsia prevention (ASPRE)

This is the final version of the article. Available from BMJ Publishing Group via the DOI in this record.INTRODUCTION: Pre-eclampsia (PE) affects 2-3% of all pregnancies and is a major cause of maternal and perinatal morbidity and mortality. Prophylactic use of low-dose aspirin in women at risk for PE may substantially reduce the prevalence of the disease. Effective screening for PE requiring delivery before 37 weeks (preterm PE) can be provided by a combination of maternal factors, uterine artery Doppler, mean arterial pressure, maternal serum pregnancy-associated plasma protein A and placental growth factor at 11-13 weeks' gestation, with a detection rate of 75% at a false-positive rate of 10%. We present a protocol (V.6, date 25 January 2016) for the ASpirin for evidence-based PREeclampsia prevention (ASPRE) trial, which is a double-blinded, placebo-controlled, randomised controlled trial (RCT) that uses an effective PE screening programme to determine whether low-dose aspirin given to women from 11 to 13 weeks' gestation will reduce the incidence of preterm PE. METHODS AND ANALYSIS: All eligible women attending for their first trimester scan will be invited to participate in the screening study for preterm PE. Those found to be at high risk of developing preterm PE will be invited to participate in the RCT. Further scans will be conducted for assessment of fetal growth and biomarkers. Pregnancy and neonatal outcomes will be collected and analysed. The first enrolment for the pilot study was in April 2014. As of April 2016, 26 670 women have been screened and 1760 recruited to the RCT. The study is registered on the International Standard Randomised Controlled Trial Number (ISRCTN) registry. TRIAL REGISTRATION NUMBER: ISRCTN13633058.This study is supported by grants from the European Union 7th Framework Programme—FP7-HEALTH-2013-INNOVATION-2 (ASPRE Project # 601852) and the Fetal Medicine Foundation (FMF) (Charity No: 1037116)