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To compare the perinatal outcomes of pregnancies complicated by chorioamniotic separation (CAS) vs septostomy following fetoscopic laser photocoagulation (FLP) for twin-twin transfusion syndrome (TTTS).This was a retrospective cohort analysis of monochorionic diamniotic twin pregnancies with TTTS that underwent FLP at one of two university-affiliated tertiary medical centers between January 2012 and December 2020. CAS and septostomy were diagnosed either during the procedure or by ultrasonography within 24-48 h after FLP. Data on procedure and postprocedure parameters, pregnancy outcomes and survival were collected from the patients' electronic medical records. Pregnancies were stratified according to the presence of CAS, septostomy or neither. Patients diagnosed with both CAS and septostomy were analyzed separately.Of the 522 women included in the cohort, 38 (7.3%) were diagnosed with CAS, 68 (13.0%) with septostomy and 23 (4.4%) with both CAS and septostomy. The remaining 393 (75.3%) women comprised the control group. Groups did not differ in demographic characteristics. The septostomy group had a lower rate of selective fetal growth restriction than did the CAS and control groups (24.2% vs 36.8% vs 42.7%, respectively; P = 0.017). Moreover, intertwin size discordance was lower in the septostomy group (15.1% vs 23.4% in the CAS group and 25.5% in the control group; P = 0.001). Median gestational age at FLP was significantly lower in the CAS group (19.3 weeks vs 20.4 weeks in controls and 20.9 weeks in the septostomy group; P = 0.049). The rate of delivery prior to 34 weeks was significantly higher in the CAS group (89.2%), followed by the septostomy group (80.9%), compared with the control group (69.0%) (P = 0.006). A secondary analysis demonstrated that patients with both CAS and septostomy presented the highest rates of delivery prior to 34 weeks (100%) and 32 weeks (68.2%).CAS and septostomy following laser surgery for TTTS are independently associated with higher rates of preterm delivery. The presence of these two findings in the same patient enhances the risk of prematurity. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Polymer flooding technology is widely used to enhance the oil recovery, but it increases the viscosity of the produced liquid, making the subsequent water treatment more challenging. Application of polymers impacts separation performance of hydrocyclone, which is an important equipment of produced liquid preseparation and sewage treatment in oil fields. In this work, the effect of polymer solution concentrations on the separation performance of hydrocyclone was studied by using sensitivity analysis. The sensitivity was calculated by numerical simulation, and the influence of polymer concentration on velocity field, pressure field, oil volume fraction, and separation efficiency of hydrocyclone was evaluated. The prototype was processed according to the similarity principle of fluid mechanics, and the relevant laboratory tests were carried out to verify the accuracy of simulation results. Within the tested range (100‐1000 mg/L), the increase of polymer solution concentrations caused adverse impacts on the velocity field, pressure field, and oil volume fraction of the hydrocyclone. When the concentrations of polymer solution reached 800 mg/L, the separation efficiency was reduced to less than 60%. The sensitivity sequence obtained by calculation is as follows: underflow outlet pressure drop > overflow outlet pressure drop > axial velocity > radial velocity > tangential velocity > pressure drop ratio. The change of pressure drop at underflow and overflow outlets was the primary cause for poor separation performance of hydrocyclone. The work can be used to guide the design and application of hydrocyclone for efficient treatment of polymer‐containing treatment liquid.

Summary The identification of the Hammerstein–Wiener (H‐W) systems based on the nonuniform input–output dataset remains a challenging problem. This article studies the identification problem of a p...

Our objective was to estimate the prevalence of depression and to determine whether high-risk health behaviors were associated with it among school-going adolescents, thereby assessing the need to integrate mental health services with the school health program. We conducted a cross-sectional study among 260 adolescents in schools of Bhavnagar city (western India) during January-October 2017. To assess depression, Beck Depression Inventory-II (BDI-II) was used and high-risk health behaviors were assessed by the Youth Risk Behavior Surveillance System (YRBSS) tool. Multivariable logistic regression analysis was performed to assess whether high-risk health behaviors were independent predictors of depression. The prevalence of depression was found to be 43%. Among high-risk health behaviors, adolescents carrying a sharp weapon to the school was the lowest (4%) and not eating breakfast was the highest (88%). On multiple logistic regression, feeling unsafe at school, self-perception regarding overweight, being a female, not living with both parents in the same house, being unhappy with school performance, having illness/seriously injured, and immediate family member being seriously ill/injured were found to be the significant predictors of depression among the adolescents. There is a need to address mental health issues like depression and high-risk health behaviors under the school health program through screening interventions.

Classification methods that leverage the strengths of data from multiple sources (multiview data) simultaneously have enormous potential to yield more powerful findings than two-step methods: association followed by classification. We propose two methods, sparse integrative discriminant analysis (SIDA), and SIDA with incorporation of network information (SIDANet), for joint association and classification studies. The methods consider the overall association between multiview data, and the separation within each view in choosing discriminant vectors that are associated and optimally separate subjects into different classes. SIDANet is among the first methods to incorporate prior structural information in joint association and classification studies. It uses the normalized Laplacian of a graph to smooth coefficients of predictor variables, thus encouraging selection of predictors that are connected. We demonstrate the effectiveness of our methods on a set of synthetic datasets and explore their use in identifying potential nontraditional risk factors that discriminate healthy patients at low versus high risk for developing atherosclerosis cardiovascular disease in 10 years. Our findings underscore the benefit of joint association and classification methods if the goal is to correlate multiview data and to perform classification.

The replacement of climatological background error covariance models with Hybrid error covariance models that linearly combine a localized ensemble covariance matrix and a climatological error covariance matrix has led to significant forecast improvements at several forecasting centres. To deepen understanding of why the Hybrid’s superficially ad-hoc mix of ensemble based covariances and climatological covariances yielded such significant improvements, we derive the linear state estimation equations that minimize analysis error variance given an imperfect ensemble covariance. For high dimensional models, the computational cost of the very large sample sizes required to empirically estimate the terms in these equations is prohibitive. However, a reasonable and computationally feasible approximation to these equations can be obtained from empirical estimates of the true error covariance between two model variables given an imperfect ensemble covariance between the same two variables. Here, using a Data Assimilation (DA) system featuring a simplified Global Circulation Model (SPEEDY), pseudo-observations of known error variance and an ensemble data assimilation scheme (LETKF), we quantitatively demonstrate that the traditional Hybrid used by many operational centres is a much better approximation to the true covariance given the ensemble covariance than either the static climatological covariance or the localized ensemble covariance. These quantitative findings help explain why operational centres have found such large forecast improvements when switching from a static error covariance model to a Hybrid forecast error covariance model. Another fascinating finding of our empirical study is that the form of current Hybrid error covariance models is fundamentally incorrect in that the weight given to the static covariance matrix is independent of the separation distance of model variables. Our results show that this weight should be an increasing function of variable separation distance. It is found that for ensemble covariances significantly different to zero, the true error covariance of spatially separated variables is an approximately linear function of the corresponding ensemble covariance, However, for small ensemble sizes and ensemble covariances near zero, the true covariance is an increasing function of the magnitude of the ensemble covariance and reaches a local minimum at the precise point where the ensemble covariance is equal to zero. It is hypothesized that this behaviour is a consequence of small ensemble size and, specifically, associated spurious fluctuations of the ensemble covariances and variances. Consistent with this hypothesis, this local minimum is almost eliminated by quadrupling the ensemble size.

When people experience major life changes, this often impacts their self‐presentation, networks, and online behavior in substantial ways. To effectively study major life transitions and ev...

Mother-child pairs may separate during early life, yet the health impacts thereof are unclear. We explored the patterns and impact of separation among women living with HIV (WLHIV) and their children in South Africa.WLHIV who had initiated antiretroviral therapy (ART) during pregnancy received HIV viral load (VL) testing and completed a timeline questionnaire of mother-child separation since delivery at 3-5 years post-partum. Health care usage was abstracted from routine medical records. We examined associations between separation and (a) maternal health outcomes (engagement in HIV care and HIV viral suppression, [VS]) and (b) child health outcomes (post-breastfeeding HIV testing and immunisation completion), using logistic regression.Of 346 mother-child pairs (median maternal age at antenatal ART initiation, 28 years), 24% were ever separated (median time to first separation 20 months, interquartile range [IQR] 9, 31). Most separated children were living with their grandmothers (65/83, 78%). Mothers who ever separated were younger, and more likely to be employed, and to reside in informal housing than those who never separated. Any separation reduced the odds of VS ≤ 50 copies/mL at four years post-partum (odds ratio 0.57; 95% CI 0.34-0.93); associations were similar for VL ≤ 1000 copies/mL and maternal engagement in care. No association was found between separation and child confirmatory HIV testing or immunisation completion.In this setting, mother-child separation is common in the first four years of life and appears associated with suboptimal maternal outcomes. Further research is required to understand the drivers and implications of mother-child separation.Les couples mère-enfant peuvent être séparés au début de la vie, mais les effets sur la santé ne sont pas clairs. Nous avons exploré les modèles et l'impact de la séparation chez les femmes vivant avec le VIH (PVVIH) et leurs enfants en Afrique du Sud. MÉTHODES: Les PVVIH qui avaient initié un traitement antirétroviral (ART) pendant la grossesse ont subi un test de charge virale du VIH (CV) et ont rempli un questionnaire chronologique sur la séparation mère-enfant depuis l'accouchement à 3-5 ans post-partum. L'utilisation des soins de santé a été extraite des dossiers médicaux de routine. Nous avons examiné les associations entre la séparation et (a) les résultats pour la santé maternelle (engagement dans les soins du VIH et la suppression virale du VIH [SV]) et (b) les résultats pour la santé de l'enfant (dépistage du VIH après l'allaitement et achèvement de la vaccination), en utilisant la régression logistique. RÉSULTATS: Sur 346 couples mère-enfant (âge maternel médian au début de l’ART prénatal, 28 ans), 24% ont été séparés (délai médian jusqu'à la première séparation 20 mois, intervalle interquartile [IQR] 9 à 31). La plupart des enfants séparés vivaient avec leurs grands-mères (65/83, 78%). Les mères qui ont vécu une telle séparation étaient plus jeunes et plus susceptibles d'avoir un emploi et de vivre dans un logement informel que celles qui ne l’ont jamais vécue. Toute séparation réduisait les chances de SV ≤50 copies/mL à quatre ans après l'accouchement (odds ratio 0,57; IC95%: 0,34-0,93); les associations étaient similaires pour la CV ≤1000 copies/mL et l'engagement de la mère dans les soins. Aucune association n'a été trouvée entre la séparation et le test de confirmation du VIH chez l'enfant ou l'achèvement de la vaccination.Dans ce contexte, la séparation mère-enfant est courante au cours des quatre premières années de la vie et semble associée à des résultats maternels sous-optimaux. Des recherches supplémentaires sont nécessaires pour comprendre les facteurs et les implications de la séparation mère-enfant.

Purpose To use a deep neural network (DNN) for solving the optimization problem of water/fat separation and to compare supervised and unsupervised training. Methods The current T 2 ∗ -IDEAL algorithm for solving water/fat separation is dependent on initialization. Recently, DNN has been proposed to solve water/fat separation without the need for suitable initialization. However, this approach requires supervised training of DNN using the reference water/fat separation images. Here we propose 2 novel DNN water/fat separation methods: 1) unsupervised training of DNN (UTD) using the physical forward problem as the cost function during training, and 2) no training of DNN using physical cost and backpropagation to directly reconstruct a single dataset. The supervised training of DNN, unsupervised training of DNN, and no training of DNN methods were compared with the reference T 2 ∗ -IDEAL. Results All DNN methods generated consistent water/fat separation results that agreed well with T 2 ∗ -IDEAL under proper initialization. Conclusion The water/fat separation problem can be solved using unsupervised deep neural networks.

BACKGROUND Quantitative muscle MRI is a robust tool to monitor intramuscular fatty replacement and disease activity in patients with neuromuscular disorders (NMDs). PURPOSE To implement a 3D sequence for quantifying simultaneously fat fraction (FF) and water T1 (T1,H2O ) in the skeletal muscle, evaluate regular undersampling in the partition-encoding direction, and compare it to a recently proposed 2D MR fingerprinting sequence with water and fat separation (MRF T1 -FF). STUDY TYPE Prospective. PHANTOM/SUBJECTS Seventeen-vial phantom at different FF and T1,H2O , 11 healthy volunteers, and 6 subjects with different NMDs. FIELD STRENGTH/SEQUENCE 3T/3D MRF T1 -FF, 2D MRF T1 -FF, STEAM MRS ASSESSMENT: FF and T1,H2O measured with the 2D and 3D sequences were compared in the phantom and in vivo at different undersampling factors (US). Data were acquired in healthy subjects before and after plantar dorsiflexions and at rest in patients. STATISTICAL TESTS Linear correlations, Bland-Altman analysis, two-way repeated measures analysis of variance (ANOVA), Student's t-test. RESULTS Up to a US factor of 3, the undersampled acquisitions were in good agreement with the fully sampled sequence (R2 ≥ 0.98, T1,H2O bias ≤10 msec, FF bias ≤4 × 10-4 ) both in phantom and in vivo. The 2D and 3D MRF T1 -FF sequences provided comparable T1,H2O and FF values (R2 ≥ 0.95, absolute T1,H2O bias ≤35 msec, and absolute FF bias ≤0.003). The plantar dorsiflexion induced a significant increase of T1,H2O in the tibialis anterior and extensor digitorum (relative increase of +10.8 ± 1.7% and + 7.7 ± 1.4%, respectively, P

In this study, we addressed the relevance of the state‐trait variance decomposition of global self‐esteem (GSE) in organizational research. We used a longitudinal sample of 393 military cadets followed for 2 years (n = 376) and adopted Latent Curve—Latent State‐Trait models for separating stable and transient factors in GSE and in three work‐related variables (e.g., work engagement, affective commitment, in‐role/extra‐role performance). Although literature often considered GSE a trait‐like variable, our results showed that it has a significant state variance that positively covaried with the state components of all three work‐related variables included in our study. Thus, we suggest rejecting the rigid separation between “state‐constructs” and “trait‐constructs”, and recommend a paradigm that focuses on the trait and state components of each psychological construct.

Objective: To study how divorce behavior in Denmark changed following a July 2013 reform that repealed mandatory separation periods for uncontested divorces, instead allowing for immediate administrative divorce.Background: Most countries have mandatory separation periods that couples undergo before they can divorce. Separation allows couples a grace-period, during which they may reconcile and stay together. Yet, the impact of separation periods on divorce risk remains understudied. Methods: Using monthly time series data on divorce rates from 2007-2018 (T=144), the research brief estimates the size and shape of the policy impact of the July 2013 reform. Using monthly administrative population data on all ever-married couples (N*T=40,431,848) the study further calculates the average characteristics of married couples in Denmark who would have remained together absent the reform.Results: After an initial spike in the divorce rate driven by couples divorcing earlier, the divorce rate settled at a 9.7 percent higher level compared to pre-reform. Couples who divorced because of the reform had been married for fewer years, were ethnic Danish, and had high school degree as highest educational level.Conclusion: Mandatory separation periods keep a minor, but substantial, share of potential divorcees together.

Few reliable predictors of postarrival psychological adjustment have been identified with regard to refugees once they arrive in their host country. We investigated the association between family separation and psychological symptoms in refugees resettled in Australia from 2013 to 2016. Participants were 1,495 adult refugees (M = 38.9 years, SD = 12.7) who participated in the Building a New Life in Australia population-based study across 4 years. Participants were assessed for psychological distress and posttraumatic stress symptoms (PTSS) using the Kessler Psychological Distress Scale (K6) and Posttraumatic Stress Disorder-8 (PTSD-8), respectively. We used latent class growth analysis (LCGA) to identify latent longitudinal trajectories and binary logistic regression to assess the contribution of family predictor variables toward PTSD-8 and K6 symptom trajectory class membership. The LCGA supported a four-class solution for PTSS, categorized as improving PTSS (18.4%), persistently high PTSS (11.5%), resilient PTSS (57.3%), and deteriorating PTSS (12.6%). For the K6, LCGA supported a four-class solution comprising classes categorized as persistently high psychological distress (PD; 7.0%), improving PD (17.3%), resilient PD (61.1%), and deteriorating PD (14.6%). Separation from family members did not independently predict the course of psychological symptoms; however, worry about family and friends contributed to the persistence of high PTSD-8 scores, OR = 1.75, and deteriorating K6 scores, OR = 1.57. The current findings suggest persistently high or worsening psychological symptom trajectories during the postsettlement phase may be marked by worry about family and friends, in addition to older age and female gender, rather than separation alone.

We investigate whether paying fathers to stay at home with their newborn child affects marital stability. Our empirical analysis is based on a reform in Iceland that offered one month of parental leave earmarked to fathers with a child born on or after January 2001. This reform created substantial economic incentives for fathers to be more involved in caring for their children during their first months of life, and the take-up rate in the first year was 82.4%. We apply a regression discontinuity framework to assess the effect of this reform on the probability of separation among couples and find that parents who are entitled to paternity leave are less likely to separate. The effect persists throughout the first 15 years after the child is born. Interestingly, paternity leave has the strongest impact among couples where the mother has higher, or equal, educational attainment to that of the father.

AIM: Predictions from statistical models may be uncalibrated, meaning that the predicted values do not have the nominal coverage probability. This is easiest seen with probability predictions in machine‐learning classification, including the common species occurrence probabilities. Here, a predicted probability of, say, .7 should indicate that out of 100 cases with these environmental conditions, and hence the same predicted probability, the species should be present in 70 and absent in 30. INNOVATION: A simple calibration plot shows that this is not necessarily the case, particularly not for overfitted models or algorithms that use non‐likelihood target functions. As a consequence, ‘raw’ predictions from such a model could easily be off by .2, are unsuitable for averaging across model types, and resulting maps hence be substantially distorted. The solution, a flexible calibration regression, is simple and can be applied whenever deviations are observed. MAIN CONCLUSIONS: ‘Raw’, uncalibrated probability predictions should be calibrated before interpreting or averaging them in a probabilistic way.

Purpose To develop a new water-fat separation and B-0 estimation algorithm to effectively suppress the multiple resonances of fat signal in EPI. This is especially relevant for DWI where fat is often a confounding factor. Methods Water-fat separation based on chemical-shift encoding enables robust fat suppression in routine MRI. However, for EPI the different chemical-shift displacements of the multiple fat resonances along the phase-encoding direction can be problematic for conventional separation algorithms. This work proposes a suitable model approximation for EPI under B-0 and fat off-resonance effects, providing a feasible multi-peak water-fat separation algorithm. Simulations were performed to validate the algorithm. In vivo validation was performed in 6 volunteers, acquiring spin-echo EPI images in the leg (B-0 homogeneous) and head-neck (B-0 inhomogeneous) regions, using a TE-shifted interleaved EPI sequence with/without diffusion sensitization. The results are numerically and statistically compared with voxel-independent water-fat separation and fat saturation techniques to demonstrate the performance of the proposed algorithm. Results The reference separation algorithm without the proposed spatial shift correction caused water-fat ambiguities in simulations and in vivo experiments. Some spectrally selective fat saturation approaches also failed to suppress fat in regions with severe B-0 inhomogeneities. The proposed algorithm was able to achieve improved fat suppression for DWI data and ADC maps in the head-neck and leg regions. Conclusion The proposed algorithm shows improved suppression of the multi-peak fat components in multi-shot interleaved EPI applications compared to the conventional fat saturation approaches and separation algorithms.

International audience; The demand for large and reliable datasets on isotopic composition has increased ingeochemistry and environmental sciences over recent years. We present an automated ionchromatographic separation method using a robotic pipetting arm, termed “ChemCobOne”, toreduce the time of sample separation. Its performance was tested for lithium isotope separationin geological reference materials using a single-step separation with HCl (0.2 mol l-1) and a 2-mlresin volume. This refined lithium purification method does not forfeit precision, accuracy orpurity compared with manual sample processing. In addition, a 7Li value for NASS-6 of 30.99 ±0.50‰ (2s) (95%CI = 0.14‰, n = 44) was determined and the first 7Li values for the granite rock

A key issue when using Bayesian variable selection for logistic regression is choosing an appropriate prior distribution. This can be particularly difficult for high-dimensional data where complete separation will naturally occur in the high-dimensional space. We propose the use of the Normal-Gamma prior with recommendations on calibration of the hyper-parameters. We couple this choice with the use of joint credible sets to avoid performing a search over the high-dimensional model space. The approach is shown to outperform other methods in high-dimensional settings, especially with highly correlated data. The Bayesian approach allows for a natural specification of the hyper-parameters.

Purpose Effective removal of chemical-shift artifacts in echo-planar imaging (EPI) is a challenging problem especially with severe field inhomogeneity. This study aims to develop a reliable water/fat separation technique for point spread function (PSF) encoded EPI (PSF-EPI) by using its intrinsic multiple echo-shifted images. Theory and methods EPI with PSF encoding can achieve distortion-free imaging and can be highly accelerated using the tilted-CAIPI technique. In this study, the chemical-shift encoding existing in the intermediate images with different time shifts of PSF-EPI is used for water/fat separation, which is conducted with latest water/fat separation algorithms. The method was tested in T1-weighted, T2-weighted, and diffusion weighted imaging in healthy volunteers. Results The ability of the proposed method to separate water/fat using intrinsic PSF-EPI signals without extra scans was demonstrated through in vivo T1-weighted, T2-weighted, and diffusion weighted imaging experiments. By exploring different imaging contrasts and regions, the results show that this PSF-EPI based method can separate water/fat and remove fat residues robustly. Conclusion By using the intrinsic signals of PSF-EPI for water/fat separation, fat signals can be effectively suppressed in EPI even with severe field inhomogeneity. This water/fat separation method for EPI can be extended to multiple image contrasts. The distortion-free PSF-EPI technique, thus, has the potential to provide anatomical and functional images with high-fidelity and practical acquisition efficiency.

As an attractive alternative technology for the separation of long chain olefin and paraffin, a novel silver-based deep eutectic solvent (Ag-DES) was prepared and utilized for 1-octene/n-octane separations. Comprehensive reactive extraction separation experiments were performed to highlight the Ag-DES concentration and operating temperature discriminations using compounds with different ratio of 1-octene/n-octane. The novel Ag-DES showed optimal separation performance regarding 1-octene/n-octane and possessed the highest levels separation selectivity in the range 3.75-16.74 with excellent circulation stability in our best knowledge. Furthermore, FT-Raman measurements and quantum chemistry calculation were performed to elucidate the interaction mechanism of Ag-DES in the separation of 1-octene and n-octane, which revealed that both chemical complexation and strong physical attraction existed in the complex of Ag-DES with 1-octene rather than n-octane. This study lends important insight for the development of Ag-DES reactive extraction separation process for the energy-efficient long chain α-olefin purification from F-T synthesis products.