Associations of prenatal maternal depressive symptoms with cord blood glucocorticoids and child hair cortisol levels in the project viva and the generation R cohorts:a prospective cohort study

Background: Prior studies have reported conflicting results regarding the association of prenatal maternal depression with offspring cortisol levels. We examined associations of high levels of prenatal depressive symptoms with child cortisol biomarkers. Methods:In Project Viva (n = 925, Massachusetts USA), mothers reported their depressive symptoms using the Edinburgh Postnatal Depression Scale (EPDS) during pregnancy, cord blood glucocorticoids were measured at delivery, and child hair cortisol levels were measured in mid-childhood (mean (SD) age: 7.8 (0.8) years) and early adolescence (mean (SD) age: 13.2 (0.9) years). In the Generation R Study (n = 1644, Rotterdam, The Netherlands), mothers reported depressive symptoms using the Brief Symptom Inventory (BSI) during pregnancy, and child hair cortisol was measured at a mean (SD) age of 6.0 (0.5) years. We used cutoffs of ≥ 13 for the EPDS and &gt; 0.75 for the BSI to indicate high levels of prenatal depressive symptoms. We used multivariable linear regression models adjusted for child sex and age (at outcome), and maternal pre-pregnancy BMI, education, social support from friends/family, pregnancy smoking status, marital status, and household income to assess associations separately in each cohort. We also meta-analyzed childhood hair cortisol results from both cohorts. Results: 8.0% and 5.1% of women respectively experienced high levels of prenatal depressive symptoms in Project Viva and the Generation R Study. We found no associations between high levels of maternal depressive symptoms during pregnancy and child cortisol biomarkers in either cohort. Conclusions: The present study does not find support for the direct link between high levels of maternal depressive symptoms and offspring cortisol levels.</p

Placental determinants of fetal growth: identification of key factors in the insulin-like growth factor and cytokine systems using artificial neural networks

<p>Abstract</p> <p>Background</p> <p>Changes and relationships of components of the cytokine and IGF systems have been shown in placenta and cord serum of fetal growth restricted (FGR) compared with normal newborns (AGA). This study aimed to analyse a data set of clinical and biochemical data in FGR and AGA newborns to assess if a mathematical model existed and was capable of identifying these two different conditions in order to identify the variables which had a mathematically consistent biological relevance to fetal growth.</p> <p>Methods</p> <p>Whole villous tissue was collected at birth from FGR (N = 20) and AGA neonates (N = 28). Total RNA was extracted, reverse transcribed and then real-time quantitative (TaqMan) RT-PCR was performed to quantify cDNA for IGF-I, IGF-II, IGFBP-1, IGFBP-2 and IL-6. The corresponding proteins with TNF-α in addition were assayed in placental lysates using specific kits. The data were analysed using Artificial Neural Networks (supervised networks), and principal component analysis and connectivity map.</p> <p>Results</p> <p>The IGF system and IL-6 allowed to predict FGR in approximately 92% of the cases and AGA in 85% of the cases with a low number of errors. IGF-II, IGFBP-2, and IL-6 content in the placental lysates were the most important factors connected with FGR. The condition of being FGR was connected mainly with the IGF-II placental content, and the latter with IL-6 and IGFBP-2 concentrations in placental lysates.</p> <p>Conclusion</p> <p>These results suggest that further research in humans should focus on these biochemical data. Furthermore, this study offered a critical revision of previous studies. The understanding of this system biology is relevant to the development of future therapeutical interventions possibly aiming at reducing IL-6 and IGFBP-2 concentrations preserving IGF bioactivity in both placenta and fetus.</p

Analytical Modelling of Transmission and Anchorage Length in Corroded Pre-Tensioned Concrete Elements

Pre-tensioned concrete (PC) elements are widely used in the construction industry, and the bond between strands and concrete is a key factor to evaluate their behavior. However, bond mechanisms are complex and existing design rules provide simplified formulations, which do not always ensure a good estimate of experimental evidence. Moreover, bond evolves during the service life of PC elements due to long term effects and external actions, that can lead to its deterioration. In this work, corrosion effects on bond of PC elements are analyzed through the development of analytical models, based on the Thick-Walled Cylinder (TWC) theory. New analytical models are presented, to estimate transmission and anchorage length in corroded PC elements

Novel reliability-based design formulation for evaluating transmission and anchorage lengths in prestressed concrete elements

This work proposes two new formulations for designing both transmission and anchorage lengths in prestressed reinforced concrete members. Such two length values represent, respectively, the distance required to transmit completely the prestressing force in the concrete, and the overall distance needed to fully anchor the tendon force in the concrete at the ultimate limit state. The two formulations proposed here are based on a reliability-based design, starting from the equations discussed within the fib TG2.5 “Bond and Material Models” and from the current approach present in the fib MC2010. For such scope, two datasets were collected, one for each investigated variable, which comprise more than 1000 experimental evidences from literature. The collected results were used to carry out a probabilistic calibration of the two formulations, and to evaluate the model uncertainty for both the investigated cases. Lastly, suitable coefficients are proposed to compute the two lengths, targeting to the required reliability level

Mechanical behavior of corroded strands: a review of constitutive models

Chloride-induced pitting corrosion of prestressing strands is one of the main causes of degradation and collapse of existing pre-tensioned and post-tensioned bridges and viaducts. To assess the residual performance of these structures and plan effective maintenance, a complete understanding of this phenomenon is necessary. In fact, pitting corrosion reduces strands cross-sectional area and affects steel properties, like ultimate strength or strain. For this reason, a review of five different constitutive models found in literature has been carried out. A comparison between the different experimental procedures and hypotheses has been made. Due to the complexity of the problem and the different assumptions made by authors, models results exhibit significant differences, particularly in predicting ultimate strength

Probabilistic investigation of transmission length formulations considering model uncertainties

Transmission length is a key parameter for detailing and assessing shear and anchorage resistance of pre -tensioned concrete members, and according to the main design codes, semi-empirical models are adopted to estimate its value. In these approaches, model uncertainty may affect the results and often plays an important role in achieving the desired reliability. The purpose of this study is to investigate the current code design formulations for the transmission length described in the upcoming Eurocode 2:2020 and fib Model Code 2020, and to propose new coefficients to consider the model uncertainties. To this end, a database with 951 experi-mental measures of transmission length was collected from the existing literature and properly filtered to obtain a homogeneous sample of 561 experimental observations on which model formulations were applied. The un-certainties of the two models were estimated and suitable probability models were derived. Results show that the prestress force release methodology strongly affects the uncertainties, both in terms of mean value and dispersion of the prediction. Finally, new probabilistic coefficients were proposed to adjust the formulations and ensure the achievement of the target reliability length to be adopted in each design situation, both at the serviceability and ultimate limit states

Reliability-based design of transmission and anchorage lengths in prestressed concrete elements

This work proposes new reliability-based formulations for the design of trans-mission and anchorage lengths in prestressed reinforced concrete, starting fromthe equations discussed and proposed byfibTG2.5“Bond and Material Models.”To this end, an extensive experimental dataset with more than 900 results wascollected from the scientific literature. Then, two deterministic models were pro-posed, one for the transmission and one for the anchorage length. For each,model uncertainty was evaluated, and then a probabilistic calibration of theirdistributions was carried out, separating the cases when sudden or gradual pre-stress release was applied. Then, probabilistic models were developed for trans-mission and anchorage length evaluation, depending on the prestress releasemethod: from them, it was possible to evaluate suitable coefficients to targetvarying reliability indexes. Particularly, two design situations were considered,for transverse stresses verification at the Serviceability Limit State (SLS) andshear and anchorage verification at the Ultimate Limit State (ULS). Lastly, thereliability of current deterministic models was verifie

Development of a Bridge Management System (BMS) Based on the New Guidelines of the Italian Ministry of Transport

Among all components of the road network, the most vulnerable are connected elements such as bridges, viaducts and tunnels. All public or private entities dealing with infrastructures need a management system. A Bridge Management System (BMS) is an informative tool for storing, analyzing and managing data on the bridge status and organizing inspection and maintenance activities. It can include deterioration models and cost and optimization analysis tools. In Europe, the first Bridge Management System was the BRIME project, developed in the early 2000s. BRIME’s main purposes were to create a unique standard for the European area and monitoring the most important bridges. Worldwide BMS research began in the 1990s. Due to certain dramatic events in the last few years, like the collapse of Morandi’s Bridge (GE, Italy), the Italian Ministry of Transport published new guidelines in 2020. This work explains the method used to create a Bridge Management System, based on these Guidelines, and used to plan maintenance activities for the bridges owned by the Administration of the Noncello territory, in northeastern Italy