3,428 research outputs found

    The effect of child labor on mathematics and language achievement in Latin America

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    The authors use a unique data set on language, and mathematics test scores for third, and fourth graders in eleven different Latin American countries, to determine whether child labor raises or lowers school achievement. Their findings are amazingly consistent across countries. In every country, child labor lowers performance on tests of language and mathematics proficiency, even when controlling for school and household attributes. The magnitude of the effect is similar to the percentage reduction in adult wages from child labor reported by Ilahi, Sedlacek and Orazem. The adverse impact of child labor on test performance is larger when children work regularly, rather than occasionally. Even modest levels of child labor at early ages cause adverse consequences for the development of cognitive abilities. These findings strongly refute the presumptions that child labor may be neutral, or complementary to academic performance, provided that the child remains enrolled in school. Instead, child labor consistently makes a year of education less productive in the generation of human capital.

    Does Local School Control Raise Student Outcomes?: Evidence on the Roles of School Autonomy and Parental Participation

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    School autonomy and parental participation have been frequently proposed as ways of making schools more productive. Less clear is how governments can foster decentralized decision-making by local schools. This paper shows that across eight Latin-American countries, most of the variation in local control over school decisions exists within and not between countries. That implies that the exercise of local authority to manage schools is largely a local choice only modestly influenced by constitutional stipulations regarding jurisdiction over school personnel, curriculum and facilities. As a consequence, estimated impacts of local school autonomy, parental participation or school supplies on student performance must account for the endogeneity of local efforts to manage schools. Empirical tests confirm that local managerial effort by the principal and the parents and the adequacy of school supplies are strongly influenced by parental human capital and the size and remoteness of the community, and that these effects are only partially moderated by central policies regarding the locus of control over the schools. Correcting for endogeneity, parental participation and adequacy school supplies have strong positive effects on 4th grade test performance, but school autonomy has no discernable impact on school outcomes.autonomy; achievement; education; parental participaton; school inputs; test scores; Latin America

    Does Local School Control Raise Student Outcomes?: Theory and Evidence on the Roles of School Autonomy and Community Participation

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    School autonomy and parental participation have been frequently proposed as ways of making schools more productive. Less clear is how governments can foster decentralized decision-making by local schools. This paper shows that across eight Latin-American countries, most of the variation in local control over school decisions exists within and not between countries. That implies that the exercise of local authority to manage schools is largely a local choice only modestly influenced by constitutional stipulations regarding jurisdiction over school personnel, curriculum and facilities. As a consequence, estimated impacts of local school autonomy, parental participation or school supplies on student performance must account for the endogeneity of local efforts to manage schools. Empirical tests confirm that local managerial effort by the principal and the parents and the adequacy of school supplies are strongly influenced by parental human capital and the size and remoteness of the community, and that these effects are only partially moderated by central policies regarding the locus of control over the schools. Correcting for endogeneity, parental participation and adequacy school supplies have strong positive effects on 4th grade test performance, but school autonomy has no discernable impact on school outcomes.school; autonomy; performance; parental participation; management; local; central

    Una visión postestructuralista de la política exterior peronista: las fuentes internas de su identidad

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    Este trabajo tiene por objeto reflexionar sobre la existencia de una política exterior peronista e indagar sobre las fuerzas profundas que la han orientado y/o incidido en ella, con el fin de contribuir a realizar una aproximación al derrotero de la política exterior argentina. Ello desde una perspectiva post estructuralista, según la cual los discursos son productores de sentido y hacedores de las identidades. La hipótesis de este artículo entiende que las identidades en pugna resultan un factor clave para comprender el itinerario y sentido de la política exterior de los gobiernos peronistas y, en gran parte, de Argentina.This work aims to reflect on the existence of a Peronist foreign policy, investigate the deep forces that have guided and/or influenced in it to help understand the course of Argentina’s foreign policy. This from a post structuralist perspective, according to which discourses are producers of meaning and identities makers. The hypothesis of this article believes that conflicting identities are a key to understanding the direction of foreign policy and sense Peronist governments and, largely, to Argentina.Fil: Sanchez, Leandro Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones en Humanidades y Ciencias Sociales. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales; ArgentinaFil: Zapata, Victoria. Universidad Nacional de la Plata. Facultad de Ciencias Jurídicas y Sociales. Instituto de Relaciones Internacionales; Argentin

    Fouling assemblages associated with off-coast aquaculture facilities: an overall assessment of the Mediterranean Sea

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    Aquaculture facilities provide a suitable habitat for a wide group of marine species that are able to colonise and settle on artificial structures. This study aims to determine the composition of fouling communities in off-coast facilities, with special emphasis on motile epifauna and amphipods as a main group. Seventeen aquaculture sites were sampled along the Mediterranean coast, collecting samples by scraping fouling organisms directly from the ropes. Additionally, thirty publications were reviewed, in order to assess the similarity of aquaculture fouling with other fouling communities. Our results reflect that amphipods accounted for more than 80% of the epifauna associated with farms fouling communities. This characteristic epifauna was defined by seven amphipod species well-adapted to colonise and survive in these off-coast habitats. Most species common in farms have also been commonly found in harbours, marinas, and/or offshore on turtles, buoys or platforms etc., showing a great resistance to polluted areas but also to dispersal via rafting on floating objects. In this study, two exotic species were identified: Caprella scaura and Stenothoe georgiana, the latter being the first report from the Mediterranean Sea. The presence of Jassa slatteryi was also confirmed, underestimated until now in the Mediterranean

    Microglial response differences between amyloidogenic transgenic models and Alzheimer’s disease patients

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    Aims: The continuing failure to develop an effective treatment for Alzheimer’s disease (AD) reveals the complexity for AD pathology. Increasing evidence indicates that neuroinflammation involving particularly microglial cells contributes to disease pathogenesis. Here we analyze the differences in the microglial response between APP/PS1 model and human brains. Methods: RT-PCR, western blots, and immunostaining were performed in the hippocampus of human post mortem samples (from Braak II to Braak V-VI) and APP751SL/PS1M146L mice. In vitro studies to check the effect of S1 fractions on microglial cells were assayed. Results: In APP based models the high Abeta accumulation triggers a prominent microglial response. On the contrary, the microglial response detected in human samples is, at least, partial or really mild. This patent difference could simple reflect the lower and probably slower Abeta production observed in human hippocampal samples, in comparison with models or could reflect the consequence of a chronic long-standing microglial activation. However, beside this differential response, we also observed a prominent microglial degenerative process in Braak V-VI samples that, indeed, could compromise their normal role of surveying the brain environment and respond to the damage. This microglial degeneration, particularly relevant at the dentate gyrus of the hippocampal formation, might be mediated by the accumulation of toxic soluble phospho-tau species. Conclusions: These differences need to be considered when delineating animal models that better integrate the complexity of AD pathology and, therefore, guarantee clinical translation. Correcting dysregulated brain inflammatory responses might be a promising avenue to restore cognitive function. Supported by grants FIS PI15/00796 and FIS PI15/00957 co-financed by FEDER funds from European Union, and by Junta de Andalucia Proyecto de Excelencia CTS385 2035.Financiado por FIS PI15/00796 y FIS PI15/0095, cofinanciado por los fondos FEDER de la Unión Europea, y por Junta de Andalucia Proyecto de Excelencia CTS385 2035. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Microglial responses in the human Alzheimer’s disease frontal cortex

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    The continuing failure to develop an effective treatment for Alzheimer’s disease (AD) reveals the complexity for this pathology. Increasing evidence indicates that neuroinflammation involving particularly microglial cells contributes to AD pathogenesis. The actual view, based on the findings in APP based models, gives a cytotoxic/proinflammatory role to activated microglia. However, we have previously reported a limited activation and microglial degeneration in the hippocampus of AD patients in contrast with that observed in amyloidogenic models. Here, we evaluated the microglial response in a different region of AD brains, the frontal cortex. Post mortem tissue from controls (Braak 0-II) and AD patients (Braak V-VI) including familial cases, were obtained from Spain Neurological Tissue Banks. Cellular (immunohistochemistry and image analysis) and molecular (qPCR and western blots) approaches were performed. Frontal cortex of AD patients (Braak V-VI) showed strong microglial activation similar to that observed in amyloidogenic mice. These strongly activated microglial cells, predominantly located surrounding amyloid plaques, could drive the AD pathology and, in consequence, could be implicated in the pathology progression. Furthermore, different microglial responses were observed between sporadic and familial AD cases. These findings in the frontal cortex were highly in contrast to the attenuated activation and degenerative morphology displayed by microglial cells in the hippocampus of AD patients. Regional differences in the microglial response suggest different functional states of microglial cells in a region-specific manner. All together, these data provide a better understanding of the immunological mechanisms underlying AD progression and uncover new potential therapeutic targets to fight this devastating neurodegenerative disease.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Supported by PI18/01557 (AG) and PI18/01556 (JV) grants from ISCiii of Spain co-financed by FEDER funds from European Unio

    Decoding damage-associated microglia in post mortem hippocampus of Alzheimer’s disease patients

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    The relationship between Alzheimer’s disease (AD) and neuroinflammation has become stronger since the identification of several genetic risk factors related to microglial function. Though the role of microglial cells in the development/progression of AD is still unknown, a dysfunctional response has recently gained support. In this sense, we have reported an attenuated microglial activation associated to amyloid plaques in the hippocampus of AD patients, including a prominent degenerative process of the microglial population in the dentate gyrus, which was in contrast to the exacerbated microglial response in amyloidogenic models. This microglial degeneration could compromise their normal role of surveying the brain environment and respond to the damage. Here, we have further analyzed the phenotypic profile displayed by the damage-associated microglial cells by immunostaining and qPCR in the hippocampus of postmortem samples of AD patients (Braak V-VI) and control cases (Braak 0-II). Damage-associated microglial cells of Braak V-VI individuals were clustered around amyloid plaques and expressed Iba1, CD68, Trem2, TMEM119 and CD45high. A subset of these cells also expressed ferritin. On the contrary, these microglia down-regulated homeostatic markers, such as Cx3cr1 and P2ry12. The homeostatic and ramified microglial cells of non-demented Braak II cases were characterized by Iba1, CX3CR1, P2ry12, TMEM119 and CD45low expression. The dynamic of the microglial molecular phenotypes associated to AD pathology needs to be considered for better understand the disease complexity and, therefore, guarantee clinical success. Correcting dysregulated brain inflammatory responses might be a promising avenue to prevent/slow cognitive decline.Universidad de Málaga. Campus de excelencia Internacional-Andalucía Tech. Supported by PI18/01557 (AG) and PI18/01556 (JV) grants from ISCiii of Spain co-financed by FEDER funds from European Union

    Child Labor and School Achievement in Latin America

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    Child labor’s effect on academic achievement is estimated using unique data on third and fourth graders in nine Latin-American countries. Cross-country variation in truancy regulations provides an exogenous shift in the ages of children normally in these grades, providing exogenous variation in the opportunity cost of children’s time. Least squares estimates suggest that child labor lowers test scores, but those estimates are biased toward zero. Corrected estimates are still negative and statistically significant. Children working 1 standard deviation above the mean have average scores that are 16 percent lower on mathematics examinations and 11 percent lower on language examinations, consistent with the estimates of the adverse impact of child labor on returns to schooling

    Dissecting the microglial response in transgenic models of amyloidogenesis and tauopathy

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    Amyloid-beta (Abeta) peptide deposits and hyperphosphorylated tau protein (phospho-tau) accumulate in Alzheimer’s disease (AD) brains. These abnormal protein aggregates leads to glial activation, synaptic dysfunction, neuronal loss and cognitive decline. While microglial response has mostly been analyzed in relation to Abeta accumulation, little is still known about inflammatory processes associated with tau pathology. Microglial reactivity and defective glial responses have been involved in these proteinopathies. Our aim is to clarify the effects of Abeta and tau separately, in order to improve the comprehension of their differential contribution to neuroinflammation and neurodegeneration. We compared the progression of these processes in an amyloidogenic AD model (APPSL/PS1M146L) and two different models of tauopathy (ThyTau22 and hP301S) from 2 to 18 months of age. Accumulation of aggregated proteins was assessed using specific anti- Abeta and phospho-tau antibodies. Inflammatory response was studied using a battery of microglial markers (Iba1, CD45, CD68, Trem2 and Gal-3). In the hippocampus of these models, Tau and Abeta pathologies initiated as early as 2 months of age and increased progressively with aging. Neuritic plaques induced a strong microglial activation associated to plaques in APP/PS1 mice. Interestingly, inflammatory markers and microglial reactivity were barely increased in the hippocampus of ThyTau mice in contrast to not only APP/PS1, but also to P301S mice, which displayed a prominent microglial response. Deciphering the specific effects of Abeta, tau and their different toxic species, would indeed enable the development of novel therapeutic strategies and drugs targeting neuroinflammatory pathways related to these proteinopathies.Universidad de Málaga. Campus de excelencia Andalucía-Tech. Supported by PI18/01557 (AG) and PI18/01556 (JV) grants from ISCiii of Spain co-financed by FEDER funds from European Union, and by grant PPIT.UMA.B1.2017/26 (RS-V)
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