340 research outputs found

    How effective are food for education programs?: A critical assessment of the evidence from developing countries

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    "The economic motivations for investing in the education and nutritional status of primary-school-aged children are well established. Moreover, investments in both of these forms of human capital are likely to benefit from substantial complementarities. However, in developing countries, poor and creditconstrained households routinely invest less in education and nutrition than is privately or socially optimal. Food for education (FFE) programs, including meals served in school and take-home rations conditional on school attendance, attempt to improve these investments by subsidizing the cost of school participation through providing food that could improve nutrition and learning. This study examines the economic motivation for the use of FFE programs to increase investments in education and nutrition. The study then presents a critical review of the empirical evidence of the impact of FFE programs on education and nutrition outcomes for primary-school-aged children in developing countries. The main contribution of this study is to judge and summarize the strength of the evidence based on the extent to which existing studies have identified a causal effect of an FFE program, as opposed to finding an association between the program and key outcomes that may have been affected by other contextual factors. The economic rationale for FFE programs is to offer free food conditional on school attendance to increase the net benefits of schooling enough to change some households' decisions about their children's school participation. Although schoolaged children are past the critical window of opportunity during early childhood for the greatest gains from good nutrition, increasing food and nutrient consumption among school-aged children with low baseline food energy or micronutrient intake can improve weight, reduce susceptibility to infection, and increase cognitive function in the short run. Because school meals are usually fortified, a child's micronutrient intake can improve even if her total calorie consumption does not. These xi short-run gains may improve a child's educational attainment and academic achievement, which can improve future welfare. For logistical and political reasons, school meal programs are commonly provided to all children in a targeted school. This practice raises the cost of achieving program objectives, such as increased attendance rates, because it provides transfers to many children who would have attended school anyway. Take-home rations programs are less subject to this criticism, because they are more easily targeted to groups, such as poor or female children, who are in greater need or who may be more likely to change their human capital investment decisions as a result of the program. Even when provided at school, food transfers can be diverted to other household members by taking food away from the beneficiary child at other meals. This practice could diminish the size of the transfer received by the beneficiary child, resulting in only a small net gain in the child's daily consumption. However, empirical evidence suggests that a substantial share of the food provided through in-school meal programs is not redistributed away from the beneficiary child. The critical review examines the empirical literature on the impacts of FFE programs on education and nutrition outcomes. The education outcomes considered include school participation measured by enrollment and attendance, age at entry, drop-out status, learning achievement, and cognitive development. The nutrition outcomes reviewed include food energy consumption, anthropometry, and micronutrient status. The review focuses on the empirical literature with the strongest methodology for identifying causal impacts. This literature includes experimental studies, such as randomized controlled trials; experimental field trials; studies using quasi-experimental methods, such as natural or administrative experiments; and nonexperimental studies using careful evaluation designs. Although the literature on the impacts of FFE programs is vast, high-quality studies with evaluation designs that provide causal impact estimates are relatively few. The nutrition literature offers many more experimental studies on nutrition outcomes than is yet available in the economics literature on education outcomes, yet many of the nutrition studies are controlled trials in which many components of the intervention typically affected by behavior, such as amount of food available at a meal, are closely managed. The external validity of these studies for programs implemented in the field is often difficult to ascertain. The number of experimental field studies for any outcome is few, but growing. From the existing literature, it is possible to draw conclusions about the likely impact of FFE programs on some outcomes, whereas for other outcomes, the literature is inconclusive. The empirical evidence suggests that in-school feeding has a positive impact on school participation in areas where initial indicators of school participation are low. In-school meal programs have been shown to have small impacts on school xii summary attendance rates for children already enrolled in school. However, there is no causal evidence for an impact on net primary-school attendance rates for all school-aged children in the service area of a school because of limitations in study design. The only study we found with attendance data for a representative sample of primaryschool– aged children, including those enrolled in school at baseline and those not enrolled, found a strong association between participation in a school meal program and school attendance, but estimated impacts cannot be reliably attributed to causal effects of the program. For similar reasons, there is also scant evidence on the effects of school meals on primary-school enrollment rates. Two empirical studies find that school meal programs cause a significant increase in learning achievement, as measured by improvements in test scores. However, in each study, scores were significantly higher for school meal recipients on only one of three tests taken. The impact of in-school meals on learning appears to operate both through improvements in school attendance and through better learning efficiency while in school, though no study has separately identified the relative contribution of these effects. FFE programs may also have an impact on cognitive development, though the size and nature of the effect vary greatly by program, micronutrient content of the food, and the measure of cognitive development used. Empirical evidence on the effects of school meals on cognitive function is mixed and depends on the tests used, the content of the meals, and the initial nutritional status of the children. Most of the studies are conducted in a laboratory setting and look at the short-term impact of feeding on cognitive function. The aspects of cognitive ability tested differ by study, making it difficult to compare results. Nonetheless, there is evidence that school meals rich in animal-source foods improved cognitive function in Kenyan children. Another study demonstrates an effect of school breakfasts on cognitive function. Given the controlled setting that formed the basis for these experiments, it would be useful now to expand the external validity of the evidence through field experiments. On other outcomes, the evidence of the impact of in-school feeding on primaryschool drop-out rates is inconclusive. We also found no study that examines the impact of school meals on age at school entry, probably because of the expense of collecting data on a representative sample of children around this age. Also, there is little conclusive evidence on the impact of take-home rations on education outcomes. For nutrition outcomes, most of the evidence comes from randomized trials in the nutrition literature. For food-energy (calorie) consumption, the evidence shows that in-school feeding programs show greater potential to improve children's total daily energy consumption when children's baseline consumption is well below their age- or weight-recommended consumption level. Differences in empirical strategy summary xiii may account for differences in findings across studies, as randomized experiments found a lower impact than did quasi-experimental studies. The diversity of program components and target populations in anthropometric studies, as well as the complexity of biological growth mechanisms, make it difficult to assess the effectiveness of FFE on anthropometric indicators. Overall, several studies showed gains in body size (for example, height, weight, body mass index) or composition (for example, mean upper-arm circumference) due to participation in FFE programs, with weight or body mass index appearing to respond most often. Improvements were typically small, though the effects of increased consumption may have been mitigated by increased activity levels in some cases. The micronutrient content of foods provided may contribute to gains in height (iron fortification) and mean upper-arm circumference (providing meat-based snacks). Deworming appears to have an interactive effect with FFE on height in one study. Turning to micronutrient status, iron fortification of FFE meals appears to improve iron status in nearly all studies reviewed. Evidence for other micronutrients is more sparse. One study found that meat-based meals improve plasma vitamin B12 concentrations but found no impact on other micronutrients. Two studies reviewed the impact of FFE on vitamin A status: one found a positive effect on plasma vitamin A status, whereas the other found no impact. Finally, one study found that iodine fortification reduced the prevalence of iodine deficiencies. The presence of malaria or other infections may impede detection of these benefits, particularly with respect to iron status. Combining the treatment with deworming can improve the effectiveness of iron supplementation, particularly in children with low baseline iron stores. Summarizing this evidence, FFE programs appear to have considerable impacts on primary-school participation, but the quality of this evidence is weak. Higher quality studies indicate some impacts on learning and cognitive development. There is evidence of effects on food consumption and micronutrient status, provided that initial consumption and nutrient deficiencies are identified and that programs are tailored to address these deficiencies. In many cases, the FFE programs appear to have little impact, because the levels of key outcome variables, such as school attendance or micronutrient status, are already high. Despite this evidence, significant research gaps remain. A surprising gap in this literature is the lack of convincing evidence of these programs' effect on school enrollment and attendance for a representative sample of school-aged children from the school's service area. There is also no conclusive empirical evidence on the impact of FFE programs on age at entry and grade repetition, and little on drop-out rates. In general, the impacts of take-home ration programs are poorly understood. Also, few studies identify the differential impacts of FFE on children by age or xiv summary gender. Finally, the impact of FFE programs on learning achievement has not been carefully analyzed by schooling inputs and class size. Perhaps the greatest omission in current research on FFE programs is the absence of well-designed cost-effectiveness studies. The policy decision on whether to undertake an FFE program or an alternative education or nutrition intervention should be based on relative differences in cost-effectiveness. However, most studies that measure program impact do not collect the additional data needed to obtain a measure of cost-effectiveness. Such studies would identify the cost from various interventions of achieving a certain percentage increase in primary-school attendance, for example. The most convincing approach would be to conduct sideby- side randomized field experiments of alternative programs. To our knowledge, only one study has done so, comparing in-school meals to programs that provide teachers with school supplies or foster parent–teacher communication. However, even these comparisons are complicated by the scarcity of programs likely to have the same kind of combined impacts on both education and nutrition outcomes. The most immediate policy implication of this review study is that more careful and systematic research is needed to find the most cost-effective combination of programs available. Without rigorous estimates of the impact of FFE programs on school participation, it is not possible to determine whether important secondary effects on learning achievement or cognitive development come primarily through school attendance or through joint effects of schooling and improved nutrition. It is these joint effects that are uniquely available through FFE programs. If the learning and cognitive benefits to school-aged children of simultaneous improvements in nutrition and schooling from FFE programs are small, cash-based programs may be more effective at increasing school participation. If there are no joint education and nutrition effects from FFE programs, it may be more cost-effective to replace these programs with specialized education and nutrition programs that are more narrowly targeted at specific objectives. More comprehensive and rigorous evaluation studies of FFE programs are needed to determine the full scope of the impacts of these programs and their relative cost-effectiveness. Our interpretation of the empirical evidence reviewed here leads to several recommendations on the design and use of FFE programs. Effects tend to be larger where schooling participation is low or where there are significant nutritional deficiencies. This fact argues for doing an assessment of school needs in target areas before starting an FFE program. Such an evaluation would improve targeting and allow FFE program components, such as the nutrient composition and quantity of food, to be tailored to local needs. Also, program administrators should be willing to consider complementary programs to improve school quality. Learning effects cannot be achieved if the instruction is of little value. Poor school quality lowers summary xv the benefits of participation and discourages attendance. Though much more evidence is needed, results from field experiments in the Philippines suggest that the cost of alternative programs to improve school quality may be only a fraction of the per child cost of an FFE program. Coordinated programs that combine FFE with improvements in school quality may be much more effective.." "Authors' AbstractPoverty reduction, Hunger, Food for education, School children, Education, Nutrition,

    Mechanism of high-mobility group protein B enhancement of progesterone receptor sequence-specific DNA binding

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    The DNA-binding domain (DBD) of progesterone receptor (PR) is bipartite containing a zinc module core that interacts with progesterone response elements (PRE), and a short flexible carboxyl terminal extension (CTE) that interacts with the minor groove flanking the PRE. The chromosomal high-mobility group B proteins (HMGB), defined as DNA architectural proteins capable of bending DNA, also function as auxiliary factors that increase the DNA-binding affinity of PR and other steroid receptors by mechanisms that are not well defined. Here we show that the CTE of PR contains a specific binding site for HMGB that is required for stimulation of PR-PRE binding, whereas the DNA architectural properties of HMGB are dispensable. Specific PRE DNA inhibited HMGB binding to the CTE, indicating that DNA and HMGB–CTE interactions are mutually exclusive. Exogenous CTE peptide increased PR-binding affinity for PRE as did deletion of the CTE. In a PR-binding site selection assay, A/T sequences flanking the PRE were enriched by HMGB, indicating that PR DNA-binding specificity is also altered by HMGB. We conclude that a transient HMGB–CTE interaction alters a repressive conformation of the flexible CTE enabling it to bind to preferred sequences flanking the PRE

    Infant Formula Trade and Food Safety

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    Beginning in 2004, the Chinese formula market suffered from a string of contamination events from counterfeit formula in 2004, melamine in 2008 to mercury and aflatoxin (a human carcinogen) in 2012. In this paper, we seek to understand the effects of these safety concerns in a market which lacks product substitutes. Whereas the literature shows international flows for produce, beef, and poultry are changed by persistent contaminations, the international infant formula market is less responsive to repeated health concerns

    A Survey of CN and CH Variations in Galactic Globular Clusters from SDSS Spectroscopy

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    We present a homogeneous survey of the CN and CH bandstrengths in eight Galactic globular clusters observed during the course of the Sloan Extension for Galactic Understanding and Exploration (SEGUE) sub-survey of the SDSS. We confirm the existence of a bimodal CN distribution among RGB stars in all of the clusters with metallicity greater than [Fe/H] = -1.7; the lowest metallicity cluster with an observed CN bimodality is M53, with [Fe/H] ~ -2.1. There is also some evidence for individual CN groups on the subgiant branches of M92, M2, and M13, and on the red giant branches of M92 and NGC 5053. Finally, we quantify the correlation between overall cluster metallicity and the slope of the CN bandstrength-luminosity plot as a means of further demonstrating the level of CN-enrichment in cluster giants. Our results agree well with previous studies reported in the literature.Comment: AJ submitted; 80 pages, 22 figure

    The WiggleZ Dark Energy Survey: Direct constraints on blue galaxy intrinsic alignments at intermediate redshifts

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    Correlations between the intrinsic shapes of galaxy pairs, and between the intrinsic shapes of galaxies and the large-scale density field, may be induced by tidal fields. These correlations, which have been detected at low redshifts (z<0.35) for bright red galaxies in the Sloan Digital Sky Survey (SDSS), and for which upper limits exist for blue galaxies at z~0.1, provide a window into galaxy formation and evolution, and are also an important contaminant for current and future weak lensing surveys. Measurements of these alignments at intermediate redshifts (z~0.6) that are more relevant for cosmic shear observations are very important for understanding the origin and redshift evolution of these alignments, and for minimising their impact on weak lensing measurements. We present the first such intermediate-redshift measurement for blue galaxies, using galaxy shape measurements from SDSS and spectroscopic redshifts from the WiggleZ Dark Energy Survey. Our null detection allows us to place upper limits on the contamination of weak lensing measurements by blue galaxy intrinsic alignments that, for the first time, do not require significant model-dependent extrapolation from the z~0.1 SDSS observations. Also, combining the SDSS and WiggleZ constraints gives us a long redshift baseline with which to constrain intrinsic alignment models and contamination of the cosmic shear power spectrum. Assuming that the alignments can be explained by linear alignment with the smoothed local density field, we find that a measurement of \sigma_8 in a blue-galaxy dominated, CFHTLS-like survey would be contaminated by at most +/-0.02 (95% confidence level, SDSS and WiggleZ) or +/-0.03 (WiggleZ alone) due to intrinsic alignments. [Abridged]Comment: 18 pages, 12 figures, accepted to MNRAS; v2 has correction to one author's name, NO other changes; v3 has minor changes in explanation and calculations, no significant difference in results or conclusions; v4 has an additional footnote about model interpretation, no changes to data/calculations/result

    Constraining the Scatter in the Mass-Richness Relation of maxBCG Clusters With Weak Lensing and X-ray Data

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    We measure the logarithmic scatter in mass at fixed richness for clusters in the maxBCG cluster catalog, an optically selected cluster sample drawn from SDSS imaging data. Our measurement is achieved by demanding consistency between available weak lensing and X-ray measurements of the maxBCG clusters, and the X-ray luminosity--mass relation inferred from the 400d X-ray cluster survey, a flux limited X-ray cluster survey. We find \sigma_{\ln M|N_{200}}=0.45^{+0.20}_{-0.18} (95% CL) at N_{200} ~ 40, where N_{200} is the number of red sequence galaxies in a cluster. As a byproduct of our analysis, we also obtain a constraint on the correlation coefficient between \ln Lx and \ln M at fixed richness, which is best expressed as a lower limit, r_{L,M|N} >= 0.85 (95% CL). This is the first observational constraint placed on a correlation coefficient involving two different cluster mass tracers. We use our results to produce a state of the art estimate of the halo mass function at z=0.23 -- the median redshift of the maxBCG cluster sample -- and find that it is consistent with the WMAP5 cosmology. Both the mass function data and its covariance matrix are presented.Comment: 14 pages, 6 figures, submitted to Ap

    Production and perception of speaker-specific phonetic detail at word boundaries

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    Experiments show that learning about familiar voices affects speech processing in many tasks. However, most studies focus on isolated phonemes or words and do not explore which phonetic properties are learned about or retained in memory. This work investigated inter-speaker phonetic variation involving word boundaries, and its perceptual consequences. A production experiment found significant variation in the extent to which speakers used a number of acoustic properties to distinguish junctural minimal pairs e.g. 'So he diced them'—'So he'd iced them'. A perception experiment then tested intelligibility in noise of the junctural minimal pairs before and after familiarisation with a particular voice. Subjects who heard the same voice during testing as during the familiarisation period showed significantly more improvement in identification of words and syllable constituents around word boundaries than those who heard different voices. These data support the view that perceptual learning about the particular pronunciations associated with individual speakers helps listeners to identify syllabic structure and the location of word boundaries

    The Galaxy Content of SDSS Clusters and Groups

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    Imaging data from the Sloan Digital Sky Survey are used to characterize the population of galaxies in groups and clusters detected with the MaxBCG algorithm. We investigate the dependence of Brightest Cluster Galaxy (BCG) luminosity, and the distributions of satellite galaxy luminosity and satellite color, on cluster properties over the redshift range 0.1 < z < 0.3. The size of the dataset allows us to make measurements in many bins of cluster richness, radius and redshift. We find that, within r_200 of clusters with mass above 3e13 h-1 M_sun, the luminosity function of both red and blue satellites is only weakly dependent on richness. We further find that the shape of the satellite luminosity function does not depend on cluster-centric distance for magnitudes brighter than ^{0.25}M_i - 5log(h) < -19. However, the mix of faint red and blue galaxies changes dramatically. The satellite red fraction is dependent on cluster-centric distance, galaxy luminosity and cluster mass, and also increases by ~5% between redshifts 0.28 and 0.2, independent of richness. We find that BCG luminosity is tightly correlated with cluster richness, scaling as L_{BCG} ~ M_{200}^{0.3}, and has a Gaussian distribution at fixed richness, with sigma_{log L} ~ 0.17 for massive clusters. The ratios of BCG luminosity to total cluster luminosity and characteristic satellite luminosity scale strongly with cluster richness: in richer systems, BCGs contribute a smaller fraction of the total light, but are brighter compared to typical satellites. This study demonstrates the power of cross-correlation techniques for measuring galaxy populations in purely photometric data.Comment: 22 pages, 14 figures, submitted to Ap

    A Quasar Catalog with Simultaneous UV, Optical and X-ray Observations by Swift

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    We have compiled a catalog of optically-selected quasars with simultaneous observations in UV/optical and X-ray bands by the Swift Gamma Ray Burst Explorer. Objects in this catalog are identified by matching the Swift pointings with the Sloan Digital Sky Survey Data Release 5 quasar catalog. The final catalog contains 843 objects, among which 637 have both UVOT and XRT observations and 354 of which are detected by both instruments. The overall X-ray detection rate is ~60% which rises to ~85% among sources with at least 10 ks of XRT exposure time. We construct the time-averaged spectral energy distribution for each of the 354 quasars using UVOT photometric measurements and XRT spectra. From model fits to these SEDs, we find that the big blue bump contributes about 0.3 dex to the quasar luminosity. We re-visit the alpha_ox-L_uv relation by selecting a clean sample with only type 1 radio-quiet quasars; the dispersion of this relation is reduced by at least 15% compared to studies that use non-simultaneous UV/optical and X-ray data. We only found a weak correlation between L/L_Edd and alpha_uv. We do not find significant correlations between alpha_x and alpha_ox, alpha_ox and alpha_uv, and alpha_x and Log L(0.3-10 keV). The correlations between alpha_uv and alpha_x, alpha_ox and alpha_x, alpha_ox and alpha_uv, L/L_Edd and alpha_x, and L/L_Edd and alpha_ox are stronger amongst low-redshift quasars, indicating that these correlations are likely driven by the changes of SED shape with accretion state.Comment: 63 pages, 22 figures, accepted by ApJ

    The Milky Way Tomography with SDSS: III. Stellar Kinematics

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    We study Milky Way kinematics using a sample of 18.8 million main-sequence stars with r<20 and proper-motion measurements derived from SDSS and POSS astrometry, including ~170,000 stars with radial-velocity measurements from the SDSS spectroscopic survey. Distances to stars are determined using a photometric parallax relation, covering a distance range from ~100 pc to 10 kpc over a quarter of the sky at high Galactic latitudes (|b|>20 degrees). We find that in the region defined by 1 kpc <Z< 5 kpc and 3 kpc <R< 13 kpc, the rotational velocity for disk stars smoothly decreases, and all three components of the velocity dispersion increase, with distance from the Galactic plane. In contrast, the velocity ellipsoid for halo stars is aligned with a spherical coordinate system and appears to be spatially invariant within the probed volume. The velocity distribution of nearby (Z<1Z<1 kpc) K/M stars is complex, and cannot be described by a standard Schwarzschild ellipsoid. For stars in a distance-limited subsample of stars (<100 pc), we detect a multimodal velocity distribution consistent with that seen by HIPPARCOS. This strong non-Gaussianity significantly affects the measurements of the velocity ellipsoid tilt and vertex deviation when using the Schwarzschild approximation. We develop and test a simple descriptive model for the overall kinematic behavior that captures these features over most of the probed volume, and can be used to search for substructure in kinematic and metallicity space. We use this model to predict further improvements in kinematic mapping of the Galaxy expected from Gaia and LSST.Comment: 90 pages, 26 figures, submitted to Ap
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