174 research outputs found

    A phenomenological model of weakly damped Faraday waves and the associated mean flow

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    A phenomenological model of parametric surface waves (Faraday waves) is introduced in the limit of small viscous dissipation that accounts for the coupling between surface motion and slowly varying streaming and large scale flows (mean flow). The primary bifurcation of the model is to a set of standing waves (stripes, given the functional form of the model nonlinearities chosen here). Our results for the secondary instabilities of the primary wave show that the mean flow leads to a weak destabilization of the base state against Eckhaus and Transverse Amplitude Modulation instabilities, and introduces a new longitudinal oscillatory instability which is absent without the coupling. We compare our results with recent one dimensional amplitude equations for this system systematically derived from the governing hydrodynamic equations.Comment: Complete paper with embedded figures (PostScript, 3 Mb) http://www.csit.fsu.edu/~vinals/mss/jmv1.p

    Preeclampsia and COVID-19: results from the INTERCOVID prospective longitudinal study

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    Background: It is unclear whether the suggested link between COVID-19 during pregnancy and preeclampsia is an independent association or if these are caused by common risk factors. Objective: This study aimed to quantify any independent association between COVID-19 during pregnancy and preeclampsia and to determine the effect of these variables on maternal and neonatal morbidity and mortality. Study Design: This was a large, longitudinal, prospective, unmatched diagnosed and not-diagnosed observational study assessing the effect of COVID-19 during pregnancy on mothers and neonates. Two consecutive not-diagnosed women were concomitantly enrolled immediately after each diagnosed woman was identified, at any stage during pregnancy or delivery, and at the same level of care to minimize bias. Women and neonates were followed until hospital discharge using the standardized INTERGROWTH-21st protocols and electronic data management system. A total of 43 institutions in 18 countries contributed to the study sample. The independent association between the 2 entities was quantified with the risk factors known to be associated with preeclampsia analyzed in each group. The outcomes were compared among women with COVID-19 alone, preeclampsia alone, both conditions, and those without either of the 2 conditions. Results: We enrolled 2184 pregnant women; of these, 725 (33.2%) were enrolled in the COVID-19 diagnosed and 1459 (66.8%) in the COVID-19 not-diagnosed groups. Of these women, 123 had preeclampsia of which 59 of 725 (8.1%) were in the COVID-19 diagnosed group and 64 of 1459 (4.4%) were in the not-diagnosed group (risk ratio, 1.86; 95% confidence interval, 1.32–2.61). After adjustment for sociodemographic factors and conditions associated with both COVID-19 and preeclampsia, the risk ratio for preeclampsia remained significant among all women (risk ratio, 1.77; 95% confidence interval, 1.25–2.52) and nulliparous women specifically (risk ratio, 1.89; 95% confidence interval, 1.17–3.05). There was a trend but no statistical significance among parous women (risk ratio, 1.64; 95% confidence interval, 0.99–2.73). The risk ratio for preterm birth for all women diagnosed with COVID-19 and preeclampsia was 4.05 (95% confidence interval, 2.99–5.49) and 6.26 (95% confidence interval, 4.35–9.00) for nulliparous women. Compared with women with neither condition diagnosed, the composite adverse perinatal outcome showed a stepwise increase in the risk ratio for COVID-19 without preeclampsia, preeclampsia without COVID-19, and COVID-19 with preeclampsia (risk ratio, 2.16; 95% confidence interval, 1.63–2.86; risk ratio, 2.53; 95% confidence interval, 1.44–4.45; and risk ratio, 2.84; 95% confidence interval, 1.67–4.82, respectively). Similar findings were found for the composite adverse maternal outcome with risk ratios of 1.76 (95% confidence interval, 1.32–2.35), 2.07 (95% confidence interval, 1.20–3.57), and 2.77 (95% confidence interval, 1.66–4.63). The association between COVID-19 and gestational hypertension and the direction of the effects on preterm birth and adverse perinatal and maternal outcomes, were similar to preeclampsia, but confined to nulliparous women with lower risk ratios. Conclusion: COVID-19 during pregnancy is strongly associated with preeclampsia, especially among nulliparous women. This association is independent of any risk factors and preexisting conditions. COVID-19 severity does not seem to be a factor in this association. Both conditions are associated independently of and in an additive fashion with preterm birth, severe perinatal morbidity and mortality, and adverse maternal outcomes. Women with preeclampsia should be considered a particularly vulnerable group with regard to the risks posed by COVID-19

    Educação e produção de moda na Segunda Guerra Mundial: as voluntárias da Legião Brasileira de Assistência Education and fashion production during the Second World War: the volunteers of Brazilian Legion of Assistance

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    As transformações observadas na educação e na moda durante os anos de 1942-1945, da participação do Brasil na Segunda Guerra mundial, são analisadas por intermédio dos estilos e perfis criados pela Legião Brasileira de Assistência para as voluntárias. Examino os cursos, os serviços e as atividades criadas pela instituição a fim de envolver e preparar as voluntárias para revelar os estilos e perfis femininos que emergem no cenário nacional e mostrar como a guerra refletiu e influenciou o comportamento e o vestuário femininos.<br>The transformations observed in education and in fashion between 1942-1945, the years in which Brazil took part in Second World War, are analyzed through styles and profiles created by Brazilian Legion of Assistance for the volunteers. The courses, the services and the activities created by the institution with the aim of involving and preparing the volunteers will be analyzed so as to reveal the styles and female profiles that emerge from the national scenario and show how the war reflected and influenced female behavior and clothing

    Lebenswerte von Studienanfaengern Studenten-Intervallstudie Leistung (SIL) ; Teil des Maximalberichtes SIL A

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    UuStB Koeln(38)-940106348 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

    Diabetes mellitus, maternal adiposity, and insulin-dependent gestational diabetes are associated with COVID-19 in pregnancy: the INTERCOVID study

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    Background Among nonpregnant individuals, diabetes mellitus and high body mass index increase the risk of COVID-19 and its severity. Objective This study aimed to determine whether diabetes mellitus and high body mass index are risk factors for COVID-19 in pregnancy and whether gestational diabetes mellitus is associated with COVID-19 diagnosis. Study Design INTERCOVID was a multinational study conducted between March 2020 and February 2021 in 43 institutions from 18 countries, enrolling 2184 pregnant women aged ≥18 years; a total of 2071 women were included in the analyses. For each woman diagnosed with COVID-19, 2 nondiagnosed women delivering or initiating antenatal care at the same institution were also enrolled. The main exposures were preexisting diabetes mellitus, high body mass index (overweight or obesity was defined as a body mass index ≥25 kg/m2), and gestational diabetes mellitus in pregnancy. The main outcome was a confirmed diagnosis of COVID-19 based on a real-time polymerase chain reaction test, antigen test, antibody test, radiological pulmonary findings, or ≥2 predefined COVID-19 symptoms at any time during pregnancy or delivery. Relationships of exposures and COVID-19 diagnosis were assessed using generalized linear models with a Poisson distribution and log link function, with robust standard errors to account for model misspecification. Furthermore, we conducted sensitivity analyses: (1) restricted to those with a real-time polymerase chain reaction test or an antigen test in the last week of pregnancy, (2) restricted to those with a real-time polymerase chain reaction test or an antigen test during the entire pregnancy, (3) generating values for missing data using multiple imputation, and (4) analyses controlling for month of enrollment. In addition, among women who were diagnosed with COVID-19, we examined whether having gestational diabetes mellitus, diabetes mellitus, or high body mass index increased the risk of having symptomatic vs asymptomatic COVID-19. Results COVID-19 was associated with preexisting diabetes mellitus (risk ratio, 1.94; 95% confidence interval, 1.55–2.42), overweight or obesity (risk ratio, 1.20; 95% confidence interval, 1.06–1.37), and gestational diabetes mellitus (risk ratio, 1.21; 95% confidence interval, 0.99–1.46). The gestational diabetes mellitus association was specifically among women requiring insulin, whether they were of normal weight (risk ratio, 1.79; 95% confidence interval, 1.06–3.01) or overweight or obese (risk ratio, 1.77; 95% confidence interval, 1.28–2.45). A somewhat stronger association with COVID-19 diagnosis was observed among women with preexisting diabetes mellitus, whether they were of normal weight (risk ratio, 1.93; 95% confidence interval, 1.18–3.17) or overweight or obese (risk ratio, 2.32; 95% confidence interval, 1.82–2.97). When the sample was restricted to those with a real-time polymerase chain reaction test or an antigen test in the week before delivery or during the entire pregnancy, including missing variables using imputation or controlling for month of enrollment, the observed associations were comparable. Conclusion Diabetes mellitus and overweight or obesity were risk factors for COVID-19 diagnosis in pregnancy, and insulin-dependent gestational diabetes mellitus was associated with the disease. Therefore, it is essential that women with these comorbidities are vaccinated
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