1,878 research outputs found

    Essays on human capital investments in developing countries

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    This dissertation encompasses three chapters that explore determinants of parental investments in their children???s health and education in developing countries. Below are the individual abstracts for each chapter. Chapter 1: Child Ability, Parental Investments and Child Nutrition in Ecuador This paper investigates the role of family composition and child cognitive ability in explaining how resource-constrained households make nutritional investment decisions in their children. Parents have private information about their children???s abilities and health that is typically not available to researchers. I use a unique panel household dataset from Ecuador???s Bono de Desarrollo Humano that contains a measure of child cognitive ability and allows me to estimate its affect on resource allocation. I address reverse causality due to the effects of investments on ability and I use within household fixed effects to look at children to look at the intra-household investment decision. Findings point to the existence of sibling rivalry due to resource constraints; children with more siblings, and children in poor households, are less likely to eat high-quality food. Children with higher abilities are less likely to share a nutritional supplement with another family member, suggesting that parents must decide how to invest their limited resources, and child ability informs that decision. Within households of more than one child, children with higher abilities are more likely to eat higher quality foods than their siblings, even after controlling for child body size. Chapter 2: Child Ability and Household Human Capital Investment Decisions in Burkina Faso Using data we collected in rural Burkina Faso, we examine how children???s cognitive abilities influence resource constrained households??? decisions to invest in their education. We use a direct measure of child ability for all primary school-aged children, regardless of current school enrollment. We explicitly incorporate direct measures of the ability of each child???s siblings (both absolute and relative measures) to show how sibling rivalry exerts an impact on the parent???s decision of whether and how much to invest in their child???s education. We find children with one standard deviation higher own ability are 16 percent more likely to be currently enrolled, while having a higher ability sibling lowers current enrollment by 16 percent and having two higher ability siblings lowers enrollment by 30 percent. Results are robust to addressing the potential reverse causality of schooling influencing child ability measures and using alternative cognitive tests to measure ability. Chapter 3: Risk and Protective Factors for School Dropout in Mexico and Chile Fourteen percent of Chilean youth and 30 percent of Mexican youth have dropped out prior to completing secondary school. Of these youth, 90 to 97 percent are considered ???at risk,??? meaning that they engage in or are at risk of engaging in risky behaviors that are detrimental to their own development and to the well-being of their societies. This paper uses youth surveys from Chile and Mexico to demonstrate that early school dropout is strongly correlated with a range of risky behaviors as well as typically unobservable risk and protective factors. We test which of a large set of potential factors are correlated with dropping out of school early and other risky behaviors. These factors range from relationships with parents and institutions to household behaviors (abuse, discipline techniques) to social exclusion. We use stepwise regressions to sort out which variables best explain the observed variance in risky behaviors. We also use a non-parametric methodology to characterize different sub-groups of youth according to the amount of risk in their lives. We find that while higher socioeconomic status emerges as key explanatory factors for school dropout and six additional risky behaviors for boys and girls in both countries, it is not the only one. A good relationship with parents and peers, strong connection with local governmental institutions and schools, urban residence, younger age, and spirituality also emerge as being strongly correlated with school dropout and different risky behaviors. Similarly, young people that leave school early also engage in other risky behaviors. The variety of factors associated with leaving school early suggests that while poverty is important, it is not the only risk factor. This points to a wider range of policy entry points than currently used, including targeting parents and the relationship with schools

    p21 is decreased in polycystic kidney disease and leads to increased epithelial cell cycle progression: roscovitine augments p21 levels.

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    BackgroundAutosomal dominant polycystic kidney disease (ADPKD) is a common genetic disease with few treatment options other than renal replacement therapy. p21, a cyclin kinase inhibitor which has pleiotropic effects on the cell cycle, in many cases acts to suppress cell cycle progression and to prevent apoptosis. Because defects in cell cycle arrest and apoptosis of renal tubular epithelial cells occur in PKD, and in light of earlier reports that polycystin-1 upregulates p21 and that the cyclin-dependent kinase inhibitor roscovitine arrests progression in a mouse model, we asked whether (1) p21 deficiency might underlie ADPKD and (2) the mechanism of the salutary roscovitine effect on PKD involves p21.Methodsp21 levels in human and animal tissue samples as well as cell lines were examined by immunoblotting and/or immunohistochemisty. Apoptosis was assessed by PARP cleavage. p21 expression was attenuated in a renal tubular epithelial cell line by antisense methods, and proliferation in response to p21 attenuation and to roscovitine was assessed by the MTT assay.ResultsWe show that p21 is decreased in human as well as a non-transgenic rat model of ADPKD. In addition, hepatocyte growth factor, which induces transition from a cystic to a tubular phenotype, increases p21 levels. Furthermore, attenuation of p21 results in augmentation of cell cycle transit in vitro. Thus, levels of p21 are inversely correlated with renal tubular epithelial cell proliferation. Roscovitine, which has been shown to arrest progression in a murine model of PKD, increases p21 levels and decreases renal tubular epithelial cell proliferation, with no affect on apoptosis.ConclusionThe novelty of our study is the demonstration in vivo in humans and rat models of a decrement of p21 in cystic kidneys as compared to non-cystic kidneys. Validation of a potential pathogenetic model of increased cyst formation due to enhanced epithelial proliferation and apoptosis mediated by p21 suggests a mechanism for the salutary effect of roscovitine in ADPKD and supports further investigation of p21 as a target for future therapy

    A Spectral Method for Elliptic Equations: The Neumann Problem

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    Let Ω\Omega be an open, simply connected, and bounded region in Rd\mathbb{R}^{d}, d≥2d\geq2, and assume its boundary ∂Ω\partial\Omega is smooth. Consider solving an elliptic partial differential equation −Δu+γu=f-\Delta u+\gamma u=f over Ω\Omega with a Neumann boundary condition. The problem is converted to an equivalent elliptic problem over the unit ball BB, and then a spectral Galerkin method is used to create a convergent sequence of multivariate polynomials unu_{n} of degree ≤n\leq n that is convergent to uu. The transformation from Ω\Omega to BB requires a special analytical calculation for its implementation. With sufficiently smooth problem parameters, the method is shown to be rapidly convergent. For u∈C∞(Ω‾)u\in C^{\infty}(\overline{\Omega}) and assuming ∂Ω\partial\Omega is a C∞C^{\infty} boundary, the convergence of ∥u−un∥H1\Vert u-u_{n}\Vert_{H^{1}} to zero is faster than any power of 1/n1/n. Numerical examples in R2\mathbb{R}^{2} and R3\mathbb{R}^{3} show experimentally an exponential rate of convergence.Comment: 23 pages, 11 figure

    How Sensory Experiences of Children With and Without Autism Affect Family Occupations

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    We used a grounded theory approach to data analysis to discover what effect, if any, children's sensory experiences have on family occupations. We chose this approach because the existing literature does not provide a theory to account for the effect of children's sensory experiences on family occupations. Parents of six children who were typically developing and six children who had autism were interviewed. We analyzed the data using open, axial, and selective coding techniques. Children's sensory experiences affect family occupations in three ways: (1) what a family chooses to do or not do; (2) how the family prepares; and (3) the extent to which experiences, meaning, and feelings are shared

    The Layer 0 Inner Silicon Detector of the D0 Experiment

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    This paper describes the design, fabrication, installation and performance of the new inner layer called Layer 0 (L0) that was inserted in the existing Run IIa Silicon Micro-Strip Tracker (SMT) of the D0 experiment at the Fermilab Tevatron collider. L0 provides tracking information from two layers of sensors, which are mounted with center lines at a radial distance of 16.1 mm and 17.6 mm respectively from the beam axis. The sensors and readout electronics are mounted on a specially designed and fabricated carbon fiber structure that includes cooling for sensor and readout electronics. The structure has a thin polyimide circuit bonded to it so that the circuit couples electrically to the carbon fiber allowing the support structure to be used both for detector grounding and a low impedance connection between the remotely mounted hybrids and the sensors.Comment: 28 pages, 9 figure

    The MINERν\nuA Data Acquisition System and Infrastructure

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    MINERν\nuA (Main INjector ExpeRiment ν\nu-A) is a new few-GeV neutrino cross section experiment that began taking data in the FNAL NuMI (Fermi National Accelerator Laboratory Neutrinos at the Main Injector) beam-line in March of 2010. MINERν\nuA employs a fine-grained scintillator detector capable of complete kinematic characterization of neutrino interactions. This paper describes the MINERν\nuA data acquisition system (DAQ) including the read-out electronics, software, and computing architecture.Comment: 34 pages, 16 figure

    Alexithymia and its association with burnout, depression and family support among Greek nursing staff

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    <p>Abstract</p> <p>Background</p> <p>Few studies have examined the relation between alexithymia (i.e. the inability to recognize and verbalize emotions) and professional burnout. Considering the absence of relevant studies in the Greek scientific literature, the aim of this work was to examine the associations of alexithymia with the three facets of professional burnout, the perception of family support and depression in nursing personnel.</p> <p>Methods</p> <p>The study was performed in one of the largest hospitals in Greece and included 95 nurses. Assessments of alexithymia, burnout, depression and family support were made by means of the Toronto Alexithymia Scale, the Maslach Burnout Inventory, the Beck Depression Inventory and the Julkunen Family Support Scale, respectively. Student's t-test, Pearson's correlation and stepwise linear regression were used for the evaluation of data.</p> <p>Results</p> <p>Alexithymia was correlated positively with depression, emotional exhaustion and depersonalization, and negatively with sense of family support and personal achievement. Additionally, family support was correlated positively with personal achievement and negatively with depression.</p> <p>Conclusion</p> <p>In the scientific literature there is a debate as to whether alexithymia is a stable personality characteristic or if it is dependent on symptoms of mental disorders. We tried to interpret the associations of alexithymia with professional burnout, depressive symptoms and family support. From this study it appears very likely that alexithymia is directly associated with depression and personal achievement, but also indirectly with the sense of family support.</p

    Hearing Feelings: Affective Categorization of Music and Speech in Alexithymia, an ERP Study

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    Background: Alexithymia, a condition characterized by deficits in interpreting and regulating feelings, is a risk factor for a variety of psychiatric conditions. Little is known about how alexithymia influences the processing of emotions in music and speech. Appreciation of such emotional qualities in auditory material is fundamental to human experience and has profound consequences for functioning in daily life. We investigated the neural signature of such emotional processing in alexithymia by means of event-related potentials. Methodology: Affective music and speech prosody were presented as targets following affectively congruent or incongruent visual word primes in two conditions. In two further conditions, affective music and speech prosody served as primes and visually presented words with affective connotations were presented as targets. Thirty-two participants (16 male) judged the affective valence of the targets. We tested the influence of alexithymia on cross-modal affective priming and on N400 amplitudes, indicative of individual sensitivity to an affective mismatch between words, prosody, and music. Our results indicate that the affective priming effect for prosody targets tended to be reduced with increasing scores on alexithymia, while no behavioral differences were observed for music and word targets. At the electrophysiological level, alexithymia was associated with significantly smaller N400 amplitudes in response to affectively incongruent music and speech targets, but not to incongruent word targets. Conclusions: Our results suggest a reduced sensitivity for the emotional qualities of speech and music in alexithymia during affective categorization. This deficit becomes evident primarily in situations in which a verbalization of emotional information is required

    Search for associated Higgs boson production using like charge dilepton events in p(p)over-bar collisions at root s=1.96 TeV

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    We present a search for associated Higgs boson production in the process p (p) over bar -> W/ZH -> l(+/-)l'(+/-) + X in ee, e mu, and mu mu final states. The search is based on data collected by the D0 experiment at the Fermilab Tevatron Collider at root s = 1.96 TeV corresponding to 5.3 fb(-1) of integrated luminosity. We require two isolated leptons (electrons or muons) with the same electric charge and additional kinematic requirements. No significant excess above background is observed, and we set 95% C. L. observed (expected) upper limits on ratio of the production cross section to the standard model prediction of 6.4 (7.3) for a Higgs boson mass of 165 GeV and 13.5 (19.8) for a mass of 115 GeV
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