The effect of breastfeeding on children's cognitive and noncognitive development

This paper uses propensity score matching methods to investigate the relationship between breastfeeding and children's cognitive and noncognitive development. We find that breastfeeding for four weeks is positively and statistically significantly associated with higher cognitive test scores, by around one tenth of a standard deviation. The association between breastfeeding and noncognitive development is weaker, and is restricted to children of less educated mothers. We conclude that interventions which increase breastfeeding rates would improve not only children's health, but also their cognitive skills, and possibly also their noncognitive development

Marriage and Housework

This paper provides insights into the welfare gains of forming a couple by estimating how much of the difference in housework time between single and married individuals is causal and how much is due to selection. Using longitudinal data from Australia, UK and US, we find that selection into marriage by individuals with a higher taste for home-produced goods can explain about half of the observed differences in housework documented in the cross-sectional data. There remains a genuine two-hour increase in housework time for each partner upon marriage, with women specializing in routine, and men specializing in non-routine housework tasks

Marriage and housework

This article provides insights into the gains of forming a couple by estimating how much of the difference in housework between single and married individuals is causal and how much is due to selection. Time-varying observed variables and time-invariant heterogeneity explains about half of the observed differences in housework documented in the cross-sectional data. There remains a genuine one-and-a-half-hour increase per week in housework time for each partner, with women specializing in routine and men in non-routine housework tasks

COVID-19 School Closures and Parental Labor Supply in the United States

We examine the role of school closures in contributing to the negative labor market impacts of the COVID-19 pandemic. We collect detailed daily information on school closures at the school-district level, which we merge to individual level data on various employment and socio- demographic characteristics from the monthly Current Population Survey from January 2019 through May 2020. Using a difference-in-differences estimation approach, we gauge how the intensity of school closures affects the labor supply of mothers and fathers of young school-age children. We find evidence of non-negligible labor supply reductions, particularly among mothers. These impacts prove robust to endogeneity checks and persist after accounting for other social-distancing measures in place

Finite element modelling of braided fibres subject to large deformations

This paper presents a numerical methodology to model elastic braided fibres. Elastic transversely isotropic material was used due to the anisotropy of the strands. Large deformation finite analysis based on large rotations / small strains total Lagrangian formulation was used to account for geometrical nonlinearities. Pre-processing was necessary to insert interface elements where strands are in self contact and with other materials, followed by a potential flow analysis that was undertaken to evaluate the fibre directions for every individual strand. An FE model of a knot demonstrates the important of defining interface elements, while a three plait braided model shows the importance of using a transversely isotropic model compared to an isotropic model. A twelve strand sinnet rope (T12) was also modelled using the proposed methodology and highlights new challenges when using dierent types of braiding

Multi-filter transit observations of WASP-39b and WASP-43b with three San Pedro M\'artir telescopes

Three optical telescopes located at the San Pedro M\'artir National Observatory were used for the first time to obtain multi-filter defocused photometry of the transiting extrasolar planets WASP-39b and WASP-43b. We observed WASP-39b with the 2.12m telescope in the U filter for the first time, and additional observations were carried out in the R and I filters using the 0.84m telescope. WASP-43b was observed in VRI with the same instrument, and in the i filter with the robotic 1.50m telescope. We reduced the data using different pipelines and performed aperture photometry with the help of custom routines, in order to obtain the light curves. The fit of the light curves (1.5--2.5mmag rms), and of the period analysis, allowed a revision of the orbital and physical parameters, revealing for WASP-39b a period ($4.0552947 \pm 9.65 \times 10^{-7}$ days) which is $3.084 \pm 0.774$ seconds larger than previously reported. Moreover, we find for WASP-43b a planet/star radius ($0.1738 \pm 0.0033$) which is $0.01637 \pm 0.00371$ larger in the i filter with respect to previous works, and that should be confirmed with additional observations. Finally, we confirm no evidence of constant period variations in WASP-43b.Comment: 13 pages, 7 figures, accepted in PASP, scheduled for the February 1, 2015 issu

Contributions on lindane degradation by Microcystis aeruginosa PCC 7806

Cyanobacteria are able to tolerate, and even metabolize, moderate doses of organochlorine pesticides, such as lindane (¿-hexachlorocyclohexane), one of the most persistent and widely used in recent decades. Previous work showed that Microcystis aeruginosa PCC 7806 degrades lindane and that, in the presence of the pesticide, microcystin synthesis is enhanced. In this work, using in silico approaches, we have identified in M. aeruginosa putative homologues of the lin genes, involved in lindane degradation in Sphingobium japonicum UT26S. Real-time RT-PCR assays showed that the putative linC gene was induced in the presence of 7 mg/L of lindane. Additionally, prxA, encoding a peroxiredoxin, and involved in oxidative stress response, was also induced when lindane was present. Taking into account these results, M. aeruginosa PCC 7806 may degrade lindane through a metabolic pathway involving a putative 2, 5-dichloro-2, 5-cyclohexadiene-1, 4-diol dehydrogenase encoded by a linC homologue. However, the low similarity of the other potential lin homologues suggest the existence of an alternative pathway different to that of heterotrophic microorganisms such as S. japonicum