4,520 research outputs found
Maternal Employment and Overweight Children
This paper investigates whether children are more or less likely to be overweight if their mothers work. The prevalence of both overweight children and working mothers has risen dramatically over the past few decades, although these parallel trends may be coincidental. The goal of this paper is to help determine whether a causal relationship exists between maternal employment and childhood overweight. To accomplish this, we mainly utilize matched mother/child data from the National Longitudinal Survey of Youth and employ three main econometric techniques, probit models, sibling difference models, and instrumental variables models in this analysis. Our results indicate that a child is more likely to be overweight if his/her mother worked more intensively (in the form of greater hours per week) over the child's life. This effect is particularly evident for children of white mothers, of mothers with more education, and of mothers with a high income level. Applying our estimates to the trend towards greater maternal employment indicates that the increased hours worked per week among mothers between 1975 and 1999 led to about a 0.4 to 0.7 percentage point increase in overweight children, which represents a relatively small share of the overall increase.
Maternal employment and overweight children
This paper seeks to determine whether a causal relationship exists between maternal employment and childhood overweight. We use matched mother/child data from the National Longitudinal Survey of Youth and employ econometric techniques to control for observable and unobservable differences across individuals and families that may influence both children's weight and their mothers' work patterns. Our results indicate that a child is more likely to be overweight if his/her mother worked more hours per week over the child's life. Analyses by subgroups show that it is higher socioeconomic status mothers whose work intensity is particularly deleterious for their children's overweight status.Employment (Economic theory) ; Overweight children
Economic perspectives on childhood obesity
Obesity rates in the U.S. have skyrocketed in the last 30 years. Among adults, obesity rates more than doubled from the early 1970s to the late 1990s. Children obesity rates nearly tripled over the same period. This article discusses why obesity is of interest from an economic perspective. It them examines changes in children's lives, particularly the increase in maternal employment, that may have contributed to increases in children's weight.Overweight children
The effects of day care at the kindergarten level : day care centre versus in-home care
Two groups of nonmaternal day care providers, one made
up of in-horne caregivers, and the other of providers of day
care in centres, were asked to focus on their goals for the
children in their care. A group of kindergarten teachers
was asked to consider any differences they noticed in
children in· the two types of day care mentioned above. It
was found that in-horne caregivers, through flexibility, meet
the developmental goals of the children in their care.
Providers of tlay care in centres used a more structured and
social program in order to meet the overall developmental
goals for the children in their care. It was found that the
kindergarten teachers noticed differences in the children in
their classes in terms of their attitude and social
behaviour. The type and quality of care were seen as
possible influences on this outlook of young children in
kindergarten. The one common element that each group
highlighted with respect to the effects of day care at the
kindergarten level was the important role of the family in
the child's development not only in day care, but also in
kindergarten class. There is still a strong need to
determine the effects of various types of day care at all
levels, and specifically at the kindergarten level. The
more the kindergarten teacher is able to understand about
the child's day care experience, and his or her own life,the better off these children in day care will be. This
study confirmed both the importance of quality in child
care, and the important role of the family in the child care
decision
Linear response functions for a vibrational configuration interaction state
Linear response functions are implemented for a vibrational configuration interaction state allowing accurate analytical calculations of pure vibrational contributions to dynamical polarizabilities. Sample calculations are presented for the pure vibrational contributions to the polarizabilities of water and formaldehyde. We discuss the convergence of the results with respect to various details of the vibrational wave function description as well as the potential and property surfaces. We also analyze the frequency dependence of the linear response function and the effect of accounting phenomenologically for the finite lifetime of the excited vibrational states. Finally, we compare the analytical response approach to a sum-over-states approac
Distinct phosphorylation clusters determines the signalling outcome of the free fatty acid receptor FFA4/GPR120
It is established that long-chain free fatty acids including ω-3 fatty acids mediate an array of biological responses through members of the free fatty acid receptor family, which includes FFA4. However, the signalling mechanisms and modes of regulation of this receptor class remain unclear. Here we employ mass spectrometry to determine that phosphorylation of mouse (m)FFAR4 occurs at five serine and threonine residues clustered in two separable regions of the C terminal tail, designated cluster 1 (Thr347, Thr349 and Ser350) and cluster 2 (Ser357 and Ser361). Mutation of these phospho-acceptor sites to alanine completely prevented phosphorylation of mFFA4 but did not limit receptor coupling to ERK1/2 activation. Rather an inhibitor of Gq/11 proteins completely prevented receptor signalling to ERK1/2. In contrast, the recruitment of arrestin 3, receptor internalization and activation of Akt were regulated by mFFA4 phosphorylation. The analysis of mFFA4 phosphorylation-dependent signalling was extended further by selective mutations of the phospho-acceptor sites. Mutations within cluster 2 did not affect agonist activation of Akt but instead significantly compromised receptor internalization and arrestin 3 recruitment. Distinctly, mutation of the phospho-acceptor sites within cluster 1 had no effect on receptor internalization and a less extensive effect on arrestin 3 recruitment, but significantly uncoupled the receptor from Akt activation. These unique observations define differential effects on signalling mediated by phosphorylation at distinct locations. This hallmark feature supports the possibility that the signalling outcome of mFFA4 activation can be determined by the pattern of phosphorylation (phosphorylation barcode) at the C-terminus of the receptor
The Influence of Environment on the Star Formation Rates of Galaxies
We have used a sample of 15749 galaxies taken from the Las Campanas Redshift
Survey to investigate the effects of environment on the rate of star formation
(SFR) in galaxies. The size and homogeneity of this data set allows us to
sample, for the first time, the entire range of galactic environment, from the
voids to the clusters, in a uniform manner, thus, we could decouple the local
galaxy density from the membership in associations. This decoupling is very
crucial for constraining the physical processes responsible for the
environmental dependencies of SFR. On the other hand, the use of an
automatically-measured concentration index (C), rather than Hubble type, allows
us to cleanly separate the morphological component from the SFR vs. environment
relationship. We find that cluster galaxies exhibit lower SFR for the same C
than field galaxies, while a further division of clusters by `richness' reveals
a new possible excitation of `starbursts' in poor clusters. Meanwhile, a more
general environmental investigation reveals that the SFR of a given C shows a
continuous correlation with the local density. Interestingly, this trend is
also observed both inside and outside of clusters, implying that physical
processes responsible for this correlation might not be intrinsic to the
cluster environment. On the other hand, galaxies with differing levels of SFR
appear to respond differently to the local density. Low levels of SFR are more
sensitive to environment inside than outside of clusters. In contrast, high
levels of SFR, identified as ``starbursts'', are as sensitive to local density
in the field as in clusters. We conclude that at least two separate processes
are responsible for the environmental sensitivity of the SFR.Comment: 25 pages, 10 figures, submitted to Ap
An Efficient Pseudospectral Method for the Computation of the Self-force on a Charged Particle: Circular Geodesics around a Schwarzschild Black Hole
The description of the inspiral of a stellar-mass compact object into a
massive black hole sitting at a galactic centre is a problem of major relevance
for the future space-based gravitational-wave observatory LISA (Laser
Interferometer Space Antenna), as the signals from these systems will be buried
in the data stream and accurate gravitational-wave templates will be needed to
extract them. The main difficulty in describing these systems lies in the
estimation of the gravitational effects of the stellar-mass compact object on
his own trajectory around the massive black hole, which can be modeled as the
action of a local force, the self-force. In this paper, we present a new
time-domain numerical method for the computation of the self-force in a
simplified model consisting of a charged scalar particle orbiting a nonrotating
black hole. We use a multi-domain framework in such a way that the particle is
located at the interface between two domains so that the presence of the
particle and its physical effects appear only through appropriate boundary
conditions. In this way we eliminate completely the presence of a small length
scale associated with the need of resolving the particle. This technique also
avoids the problems associated with the impact of a low differentiability of
the solution in the accuracy of the numerical computations. The spatial
discretization of the field equations is done by using the pseudospectral
collocation method and the time evolution, based on the method of lines, uses a
Runge-Kutta solver. We show how this special framework can provide very
efficient and accurate computations in the time domain, which makes the
technique amenable for the intensive computations required in the
astrophysically-relevant scenarios for LISA.Comment: 15 pages, 9 figures, Revtex 4. Minor changes to match published
versio
1-(2-Hydroxyethyl)-4-[3-(2-trifluoromethyl-9H-thioxanthen-9-ylidene)propyl]piperazine-1,4-diium dichloride: the dihydrochloride salt of flupentixol
In the title compound, C23H27F3N2OS+·2Cl−, the piperazinediium ring adopts a chair conformation. The dihedral angle between the two outer aromatic rings of the 9H-thioxanthene unit is 40.35 (18)°. The F atoms in the trifluoromethyl group are disordered over two sets of sites with occupancies of 0.803 (6) and 0.197 (6). In the crystal, molecules are connected by N—H⋯Cl, O—H⋯Cl C—H⋯O and C—H⋯Cl hydrogen bonds, forming chains propagating along [001]. There are also C—H⋯π interactions present in the crystal structure
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