6,802 research outputs found
Unbundling the Degree Effect in a Job Training Program for Disadvantaged Youth
Government-sponsored education and training programs have the goal to enhance participants' skills so as to become more employable, productive and dependable citizens and thus alleviate poverty and decrease public dependence. While most of the literature evaluating training programs concentrates on estimating their total average treatment effect, these programs offer a variety of services to participants. Estimating the effect of these components is of importance for the design and the evaluation of labor market programs. In this paper, we employ a recent nonparametric approach to estimate bounds on the "mechanism average treatment effect" to evaluate the causal effect of attaining a high school diploma, General Education Development or vocational certificate within a training program for disadvantaged youth 16-24 (Job Corps) relative to other services pffered, on two labor outcomes: employment probability and weekly earnings. We provide these estimates for different demographic groups by race, ethnicity, gender, and two age-risk groups (youth and young adults). Our analysis depicts a positive impact of a degree attainment within the training program on employment probability and weekly earnings for the majority of its participants which in general accounts for 55 - 63 percent of the effect of the program. The heterogeneity of the key demographic subgroups is documented in the relative importance of a degree attainment and of the other services provided in Job Corps.Causal Inference, Treatment Effects, Mechanism Average Effects, Nonparametric Bounds, Potential Outcomes, Principal Stratification, Training Programs, Job Corps, Active Labor Market Policies, Labor and Human Capital, Public Economics, C14, I20, J01,
Teaching and developing as a teacher in contradictory times
Teaching has become a more and more complex activity. Existing literature suggests, amongst other issues, fragmentation of teachers’ work, increasing accountability, bureaucracy and public scrutiny (Esteve, 2000; Estrela, 2001; Hargreaves, 2001). Over the last years, massive school reform initiatives to increase teaching standards and student attainment have been put into place in many countries setting more pressure on schools and teachers. However, if greater demands are placed upon schools and teachers to face the challenges of today’s society and the diversity of expectations of today’s students, in general, their working conditions and opportunities to learn and develop professionally have not been congruent with their needs. In the digital era, lack of resources and equipment, disparities in the access to education from the part of students and their families and different pathways and opportunities for (student) teachers to learn how to teach and to develop as professionals co-exist in various parts of the world. These scenarios present different kinds of challenges for teachers in different countries.National Funds through the FCT (Foundation for Science and Technology) and co-financed by European Regional Development Funds (FEDER) through the Competitiveness and Internationalization Operational Program (POCI) through CIEC (Research Centre on Child Studies, of the University of Minho) with the reference POCI-01-0145-FEDER-007562CIEC – Research Centre on Child Studies, IE, UMinho (FCT R&D unit 317), PortugalStrategic Project UID/CED/00317/2013info:eu-repo/semantics/publishedVersio
Avaliação da satisfação e importância atribuÃda aos serviços prestados na área da saúde mental
Com o objectivo de avaliar o grau de satisfação e importância atribuÃda aos serviços prestados
na consulta na área da saúde mental e identificar as relações entre as variáveis demográficas e o
grau de satisfação do utente foi realizado um estudo descritivo transversal, numa amostra de
305 utentes.
Com a aplicação do questionário verificamos que a satisfação conjugada com a importância
fornece-nos informação valiosa permitindo identificar pontos fortes, oportunidades ou
necessidades de melhoria dos serviços. Neste estudo verificamos que os utentes encontram-se
satisfeitos com os serviços prestados e consideram-nos importantes.
Na análise bivariada, encontramos relação entre a satisfação e escolaridade.In order to evaluate the degree of satisfaction and importance attached to services provided in
the consultation on mental health and identify relationships between demographic variables
and the degree of user satisfaction was conducted a cross-sectional survey in a sample of 305
users. With the application of the questionnaire we found that satisfaction coupled with the
importance provides us with valuable information allowing identifying strengths, opportunities
or needs for improved services. In this study we found that users are satisfied with the services
provided and consider them important.
In bivariate analysis, we found the relationship between satisfaction and education level
Synthesis and Characterization of functional ceramic materials at the nano- and microscale with enhanced properties
Semiconductor nanoparticles (NPs) and nanowires (NWs) of doped ZnO system have been synthesised at low temperature (190 °C) by a novel Polyol-Mediated Thermolysis (PMT) process and Vapour-Solid (VS) reaction. Ce/Ru doped ZnO NPs with different molar content (1-3--5-10%) have been synthesised by both experimental processes. The crystallite size, morphology, specific surface area and band gap have been evaluated. Also, the structural and functional characteristics were carried out by X-ray diffraction technique (XRD), high resolution transmission electron microscopy (HRTEM), Brunauer, Emmett and Teller (BET) method, UV-Vis diffuse reflectance spectra (DRS), UV-Vis spectroscopy and photoluminescence measurements (PL). Also, the photocatalytic activities of ZnO nanoparticles were evaluated by removal rate of methyleneblue (MB) under UV irradiation (365 nm) at RT. XRD patterns revealed a hexagonal ZnO wurtzite-type crystalline structure with a preferred orientation of(101) plane. Any secondary phases have been identified such as Ce02, Ce203, ee, Ru02, Ru304, Ru. HRTEM showed NPs in shape from spherical/ellipsoidal to hexagonal, that does not change significantly with the increasing of precursor solution concentration and kind of dopant element in the samples obtained from PMTprocess. The size of NPs was observed in the range from 16 to 23 run. Using the Kubelka-Munk treatment on the diffuse reflectance spectra, the direct band energy has been estimated at <3.0 eV in the Ru-doped samples. The PL spectra mainly consist of four emission bands: (i) a strong UV emission band, (ii) a weak blue band, (iii) a blue-green band and (iv) a green-yellow band, respectively. The reported results showed the photocatalytic efficiency of doped ZnO nanoparticles was always enhanced
Phenolic profile and physicochemical characterization of quince (Cydonia oblonga Mill) fruits at different maturity index
The ripening of fruits is a determinant factor on the composition of phytochemical compounds such as phenolic compounds. In this study the phenolic profile of quince fruits was determined as a function of its maturity index. Based on the total soluble solids (TSS) and the acidity (TA) of the fruits, four maturity indexes were established (12.55, 14.56, 21.86 and 24.77), using the ratio of TSS/TA. The phenolic profile of quince fruits with different maturity indexes were obtained by a reversed-phase HPLC-DAD and HPLC-DAD/MS. A PCA loading plot was generated to explain the relationship between physicochemical parameters and the phenolic compounds. The phenolic compounds identified in the quince fruits were 3-0-caffeoylquinic acid, catechin, 4-0-caffeoylquinic acid, 5-0-caffeoylquinic acid, coumaric acid, quercetin-3-0-rutinoside and quercetin-3-0-glycosides. The maturity index increase caused in general a reduction of phenolic compounds, these compounds were also influenced by pH and acidity of fruits. Quince is a valuable source of natural phenolic antioxidants, and can be used as raw material to elaborate diverse food products, providing important functional properties
Islet Cannabinoid Receptors Cellular Distribution and Biological Function
Objectives: To determine the cellular distribution of islet cannabinoid receptors (CBs) and their involvement in the development of metabolic and hormonal changes in rats fed a fructose-rich diet (F). Methods: In normal rat islets, we determined CBs (immunofluorescence and RT-PCR) and glucose-stimulated insulin secretion (GSIS) of isolated islets incubated with the CB1 antagonist rimonabant (R) and/or different CBs agonists. In 3-week F-fed rats, we determined the in vivo effect of R upon serum glucose, triglyceride and insulin levels, HOMA-IR, GSIS and CBs and IRS gene expression levels (real-time PCR). Results: CBs appeared exclusively in islet α-cells. Whereas different CBs agonists enhanced GSIS in normal rat islets, R did not affect it. F rats had higher serum triglyceride and insulin levels and HOMA-IR than control rats; these alterations were prevented by R coadministration. Although R did not correct the increased GSIS observed in F islets, it modulated CBs and IRS gene expression. Conclusion: Islet CBs would exert an important modulatory role in metabolic homeostasis. Administration of R and F affected islet CBs expression and prevented the development of Finduced metabolic impairment. Selective islet CB1 blockers could be useful to prevent/treat the alterations induced by the intake of unbalanced/unhealthy diets.Fil: Gagliardino, Juan Jose. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro Cientifico Tecnológico La Plata; ArgentinaFil: Flores, Luis Emilio. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro Cientifico Tecnológico La Plata. Centro de Endocrinologia Experimental y Aplicada (i); ArgentinaFil: Alzugaray, Maria Eugenia. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro Cientifico Tecnológico la Plata; ArgentinaFil: Cubilla, Marisa Angelica. Universidad Austral. Facultad de Ciencias Biomédicas; ArgentinaFil: Raschia, Maria A.. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro Cientifico Tecnológico La Plata; ArgentinaFil: del Zotto, Hector Herminio. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro Cientifico Tecnológico La Plata; ArgentinaFil: Román, Carolina Lisi. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro Cientifico Tecnológico La Plata. Centro de Endocrinologia Experimental y Aplicada (i); ArgentinaFil: Suburo, Angela Maria. Universidad Austral. Facultad de Ciencias Biomedicas; Argentin
Synthesis of Ce/Ru Doped ZnO photocatalysts to the degradation of emerging pollutants in wastewater
Semiconductor nanoparticles (NPs) and nanowires (NWs) of doped ZnO system with different dopant content have been synthesized by Polyol-Mediated Thermolysis (PMT) process and Vapour-Solid (VS) reaction. The average crystallite size, morphology, specific surface area, and direct band gap have been evaluated. The structural and functional characteristics have been studied by X-Ray Diffraction techniques (XRD), Field Emission Scanning Electron Microscope (FESEM), High Resolution Transmission Electron Microscopy (HRTEM), Brunauer, Emmett and Teller (BET) method, UV-Vis Diffuse Reflectance Spectra (DRS), UV-Vis Spectroscopy, and Photoluminescence measurements (PL). Also, the photocatalytic activities of pure and doped ZnONPs were evaluated by removal rate of Methylene Blue (MB) under UV irradiation (365 nm) at room temperature. XRD patterns revealed the common hexagonal ZnO Wurtzite-type structures with a preferred orientation of (101) plane. Secondary phases as CeO2, Ce2O3, Ce, RuO2, Ru3O4, Ruhave been identified. For both dopant, Ceand Ru, and for all the concentrations in the precursor solution, FESEM and HRTEM showed NPswith morphologies ranging from spherical/ellipsoidal to hexagonal. The size of NPs was observed to decrease (from ~30 to ~16 nm) with increasing doping concentration due to the interaction between the Ce-O-Zn or Ru-O-Zn ions. EDS results confirmed the incorporation of Ce or Ru ions into ZnO lattice.Using the Kubelka-Munk treatment on the diffuse reflectance spectra, the direct band gap energy has been estimated to be slightly lower than 3.0 eV in both, the Ce and Ru-doped samples. Compared with pure ZnO NPs, the PL spectra of the doped NPs showed red-shifted UV emission and an enhanced blue emission with the typical broad green-yellow emission. The results showed that photocatalytic efficiency of doped ZnO NPs was always enhanced
Effect of chitosan-Aloe vera coating on postharvest quality of blueberry (Vaccinium corymbosum) fruit
The present study was carried out to evaluate the effect of chitosan-based edible coatings with Aloe vera extract on the postharvest blueberry fruit quality during storage at 5 °C. Firstly, A. vera fractions (pulp and liquid) were extracted from leaves and evaluated in terms of antifungal and antioxidant capacities. The choice of the most adequate chitosan and A. vera fraction concentrations to be incorporated in coating formulation was made based on the wettability of the corresponding coating solutions. Coatings with 0.5% (w/v) chitosan + 0.5% (w/v) glycerol + 0.1% (w/v) Tween 80 + 0.5% (v/v) A. vera liquid fraction presented the best characteristics to uniformly coat blueberry surface. Physico-chemical (i.e., titratable acidity, pH, weight loss) and microbiological analyses of coated blueberries (non-inoculated or artificially inoculated with Botrytis cinerea) were performed during 25 d. Microbiological growth and water loss levels were approximately reduced by 50% and 42%, respectively, in coated blueberries after 25 d compared to uncoated blueberries. After 15 d, weight loss values were 6.2% and 3.7% for uncoated and chitosanA. vera coated blueberries, respectively. Uncoated fruits presented mold contamination after 2 d of storage (2.0 ± 0.32 log CFU g1), whilst fruits with chitosan-based coatings with A. vera presented mold contamination only after 9 d of storage (1.3 ± 0.35 log CFU g1). Overall, coatings developed in this study extend blueberries shelf-life for about 5 d, demonstrating for the first time that the combination of chitosan and A. vera liquid fraction as edible coating materials has great potential in expanding the shelf-life of fruits.Joana T. Martins (SFRH/BPD/89992/2012) is the recipient of a
fellowship from the Fundação para a Ciência e Tecnologia (FCT,
Portugal). MarÃa L. Flores-López thanks Mexican Science and
Technology Council(CONACYT, Mexico) for PhD fellowship support
(CONACYT Grant number: 215499/310847). The authors thank the
FCT the strategic funding of UID/BIO/04469/2013 unit and the
project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-
027462)
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