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A novel and highly efficient procedure in preparing different cyclic phosphinates using ring-closing metathesis (RCM) was described. The results suggested that the efficiency of the catalyic RCM combined with the ease of preparation of the dienes contributes to the methodology's attractiveness as an alternative to the formation of differently substitued five-, six- and seven-membered phosphinates. Moreover, the methodology shows potential for the synthesis of more functionalized and biologically active phosphorus containing heterocycles.

Examines the reality of the kink pair formation model as an explanation for the Bordoni relaxation in aluminum. Use of two-wave acoustic coupling method; Discussion of the discrepancy observed in face-centered-cubic metals between the Peierls stress values deduced from the measurements of the internal friction spectrum; Determination of the kink mobility.

Presents information on a study which discussed the use of a two-wave acoustic method called the coupling technique, in dislocation dynamics. Interaction mechanisms controlling the dynamics of dislocation displacement; Discussion on the nonlinear characteristics of a relaxation mechanism; Information on ultrasonic bias stress experiments; Concept of signature.

Proximate determinants theory considers infertility rates a risk factor for lower fertility rates, but the assumption that people who perceive infertility will have fewer children has not been tested. This study investigates the association of self-perceived infertility with the number of children people have had after 11 years. Infertility implies reduced chances of conception (rather than sterility), but people do not always consistently perceive infertility over time. If people who think they are infertile at one time can later report no infertility, then does self-perceived infertility necessarily lead to having fewer children? We answer this question by analyzing 11 waves of the German family panel (pairfam) data using negative binomial growth curve models for eight core demographic subgroups created by combinations of gender (men/women), parity (0/1+children), and initial age groups (25-27 and 35-37). Those who repeatedly perceived themselves to be infertile (three times or more) had fewer children than those who perceived themselves to be infertile once or twice in only four of eight gender by initial parity by age groups. Only in four groups did people who perceived themselves to be infertile once or twice have fewer children than those who never perceived themselves to be infertile in both the unadjusted and adjusted models. Thus, self-perceived infertility does not necessarily result in fewer children. Rather, the association depends upon life course context and gender., (© 2024. The Author(s).)

Following the onset of the COVID-19 pandemic, many countries faced short-term fertility declines in 2020-2021, a development which did not materialize in the majority of German-speaking and Nordic countries. However, more recent birth statistics show a steep fertility decline in 2022. We aim to provide empirical evidence on the unexpected birth decline in 2022 in Germany and Sweden. We rely on monthly birth statistics and present seasonally adjusted monthly Total Fertility Rates (TFR) for Germany and Sweden. We relate the nine-month lagged fertility rates to contextual developments regarding COVID-19. The seasonally adjusted monthly TFR of Germany dropped from 1.5-1.6 in 2021 to 1.4 in early 2022 and again in autumn 2022, a decline of about 10% in several months. In Sweden, the corresponding TFR dropped from about 1.7 in 2021 to 1.5-1.6 in 2022, a decline of almost 10%. There is no association of the fertility trends with changes in unemployment, infection rates, or COVID-19 deaths, but a strong association with the onset of vaccination programmes and the weakening of pandemic-related restrictions. The fertility decline in 2022 in Germany and Sweden is remarkable. Common explanations of fertility change during the pandemic do not apply. The association between the onset of mass vaccinations and subsequent fertility decline indicates that women adjusted their behaviour to get vaccinated before becoming pregnant. Fertility decreased as societies were opening up with more normalized life conditions. We provide novel information on fertility declines and the COVID-19-fertility nexus during and in the immediate aftermath of the pandemic., (© 2024. The Author(s).)

Background: Emerging research suggests that physical activity among children and adolescents decreased during the COVID-19 pandemic. However, a differentiated overview of European youth is lacking. In particular, no systematic analysis has been conducted to date on the impact of heterogeneous pandemic restrictions and school closures within European countries, and with regard to potentially vulnerable groups., Methods: We searched seven databases and included studies for children and adolescents (≤ 19 years) of the WHO European Region that compared physical activity during the COVID-19 pandemic with a pre-pandemic baseline using validated measurement instruments. We used the Oxford Stringency Index and School Closure Index as indicators of restriction stringency. Screening for eligibility, data extraction, assessment of the study risk of bias (using the 'Risk of Bias in Non-randomized Studies - of Exposure' [ROBINS-E]) and certainty grading of evidence (using the GRADE approach), were all done in duplicate. Unpublished data was requested from study authors. Data were pooled in random effects models. An a priori protocol was published, reporting is carried out in accordance with the 'Preferred Reporting Items for Systematic Review and Meta-Analyses' (PRISMA) statement., Results: Of 14,897 non-duplicate records, 26 publications (n = 15,038 pre-pandemic, n = 13,041 during pandemic) met full inclusion criteria. Comparison before and during the COVID-19 pandemic revealed a significant reduction in total physical activity (standardized mean difference [SMD], -0.57 [95%CI, -0.95; -0.20]) and moderate-to-vigorous physical activity (SMD, -0.43 [95% CI, -0.75; -0.10]), corresponding to a decrease of 12 min per day (a 20% reduction of the WHO recommendation). A decrease in sporting activity was also recorded. Subgroup analyses suggested that middle childhood (aged 8-12) and adolescents were particularly affected by the decline. School closures were associated with a reduction in physical activity. The certainty of evidence for all outcomes was low., Conclusions: A sharp decline in all forms of physical activity was recorded among European children and adolescents during the COVID-19 pandemic. This decline was higher during periods of school closure and mainly affected younger schoolchildren and adolescents. Immediate action by policy-makers and practitioners, as well as evidence-based public health strategies, are imperative in reversing this trend., Trial Registration: PROSPERO: CRD42023395871., (© 2023. The Author(s).)

Much of the literature on fertility intentions has shown that they are broadly predictive of fertility behaviour. Fertility intentions tend to change over a person's life. How religiosity affects these changes over time has rarely been the subject of investigation. In this paper, we focus on whether and how religiosity affects trajectories of lifetime fertility intentions. Specifically, we examine whether highly religious people start with higher fertility intentions and are more likely to sustain them during their life course compared to their less religious counterparts. We apply random and fixed effects growth curve models to data from the German family panel pairfam, using a sample of 6214 women and 5802 men aged 14-46. We find that religiosity mainly contributes to explain the starting level at teenage years but not the trajectories of lifetime fertility intentions as people get older. Highly religious people start with higher intentions than less religious people. However, similarly to less religious people they experience a decline in their fertility intentions with age. This study demonstrates that religiosity is an important variable in research on fertility intentions but with changing relevance over the life course., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Introduction: The implementation of COVID-19 pandemic-related restrictions resulted in limitations for physical activity (PA) opportunities, which may have initiated a longer-term behavioural change. The protocol describes the methodology for a planned systematic review that aims to summarise changes in PA and physical fitness (PF) in children and adolescents in the WHO European Region after the onset of the COVID-19 pandemic., Methods and Analysis: The protocol adheres to the 'Preferred Reporting Items for Systematic Review and Meta-Analysis for Protocols' (PRISMA-P) statement. Using a peer-reviewed search strategy according to the evidence-based checklist 'Peer Review of Electronic Search Strategies' (PRESS), we will perform a systematic literature search in seven databases. Inclusion criteria are all primary studies that gathered data on children and adolescents ≤19 years living in the WHO European Region and made a comparison to pre-pandemic data. Primary outcomes are PA and PF. We will assess the risk of bias with the 'Risk of Bias Instrument for Non-Randomized Studies of Exposures' (ROBINS-E). The 'Grading of Recommendations Assessment, Development and Evaluation' (GRADE) approach will be used for the evaluation of the certainty of evidence. Also, subgroup analyses will be performed (eg, for gender, age, stringency of pandemic restrictions)., Ethics and Dissemination: Ethical approval is not required, as primary data will not be collected in this study. The results will be presented in a peer-reviewed publication and at congresses relevant to the research field., Prospero Registration Number: CRD42023395871., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)