Massive inclusion of digital technologies in schools : Argentinian young adolescents' appropriation of computers and the Internet in popular and middle classes

Since the implementation of the Programa Conectar Igualdad (PCI) (Connecting Equality Program) in 2010 in Argentina, numerous Social Science specialists started to research how massive ICT introduction in schools would radically affect teaching and learning processes, knowledge building and youth behaviour. Nevertheless, there is still not much empirical evidence showing the ways in which these technologies are appropriated. This situation discloses the need of placing research questions locally situated with regard to those potential changes. What existing access methods does PCI encounter? And how does its implementation participate in the design of personal and family heterogeneous trajectories of ICTs appropriation? How do the students themselves perceive the infl uence of PCI on their own technologic abilities and competence? How do knowledge and aptitudes associated to new digital media articulate with the knowledge manners promoted by the school format and institutionalism? How does the massive introduction of netbooks affect the interaction among different school actors (students-teachers)? What happens in other sociability and socialization spaces, such as the house and cybercafé?Facultad de Humanidades y Ciencias de la Educació

Massive inclusion of digital technologies in schools : Argentinian young adolescents' appropriation of computers and the Internet in popular and middle classes

Since the implementation of the Programa Conectar Igualdad (PCI) (Connecting Equality Program) in 2010 in Argentina, numerous Social Science specialists started to research how massive ICT introduction in schools would radically affect teaching and learning processes, knowledge building and youth behaviour. Nevertheless, there is still not much empirical evidence showing the ways in which these technologies are appropriated. This situation discloses the need of placing research questions locally situated with regard to those potential changes. What existing access methods does PCI encounter? And how does its implementation participate in the design of personal and family heterogeneous trajectories of ICTs appropriation? How do the students themselves perceive the infl uence of PCI on their own technologic abilities and competence? How do knowledge and aptitudes associated to new digital media articulate with the knowledge manners promoted by the school format and institutionalism? How does the massive introduction of netbooks affect the interaction among different school actors (students-teachers)? What happens in other sociability and socialization spaces, such as the house and cybercafé?Facultad de Humanidades y Ciencias de la Educació

Massive inclusion of digital technologies in schools : Argentinian young adolescents' appropriation of computers and the Internet in popular and middle classes

Since the implementation of the Programa Conectar Igualdad (PCI) (Connecting Equality Program) in 2010 in Argentina, numerous Social Science specialists started to research how massive ICT introduction in schools would radically affect teaching and learning processes, knowledge building and youth behaviour. Nevertheless, there is still not much empirical evidence showing the ways in which these technologies are appropriated. This situation discloses the need of placing research questions locally situated with regard to those potential changes. What existing access methods does PCI encounter? And how does its implementation participate in the design of personal and family heterogeneous trajectories of ICTs appropriation? How do the students themselves perceive the infl uence of PCI on their own technologic abilities and competence? How do knowledge and aptitudes associated to new digital media articulate with the knowledge manners promoted by the school format and institutionalism? How does the massive introduction of netbooks affect the interaction among different school actors (students-teachers)? What happens in other sociability and socialization spaces, such as the house and cybercafé?Facultad de Humanidades y Ciencias de la Educació

Detecting bacterial endophytes in tropical grasses of the Brachiaria genus and determining their role in improving plant growth

Plant-growth-promoting (PGP) bacteria include a diverse group of soil bacteria thought to stimulate plant growth by various mechanisms. Brachiaria forage grasses, of African origin, are perennials that often grow under low-input conditions and are likely to harbour unique populations of PGP bacteria. Three bacterial strains that tested positive for nitrogenase reductase gene sequences (nifH) were isolated from Brachiaria hybrid CIAT 36062 and introduced into Brachiaria hybrid cv. Mulato, which also had indigenous endophytic bacteria testing positive for nifH gene sequences. Under conditions of nutrient deficiency, inoculated Mulato plants had significantly higher biomass production, chlorophyll and total nitrogen contents in leaves than do control plants and were darker green. Strains ofendophytic bacteria were then artificially introduced into Brachiaria  brizantha CIAT 6294, which does not have indigenous endophytic bacteria. Results were consistent with those obtained with artificially inoculated Mulato plants, suggesting that these endophytic bacteria do benefit plant growth. DNA sequence analysis demonstrated that the nifH gene sequences were highly similar to those from Klebsiella pneumoniae and other N2-fixing organisms and that the nif genes had consensus  sequences identical to those of other N2-fixing bacteria.Key words: Bacterial endophytes, green fluorescent protein, nitrogenase reductase, plant growth-promoting bacteria, Brachiaria

Screening unsaturated fat sources included to low and high forage diets with different fat dietary concentration using an in vitro gas production system

Fat inclusion can increase energy density of diets fed to ruminants, but detrimental effects to nutrient digestion have been reported. There is evidence that not all fat sources have this negative response and this effect can vary depending on the forage concentration in the diet. The objective of this experiment was to determine the effects of including different types of unsaturated fats to high and low forage diets in vitro digestibility and fermentation. An experiment was conducted using an in vitro gas production (GP) system. Treatments included either low forage (LF; 35%) or high forage (HF; 70%) with 2 dietary fat concentrations (6 or 9%) and of 7 different fat source treatments (control + 6 different types of unsaturated fat sources). The control diet had a basal level of fat in the diet [3% fat (0% fat inclusion); and fat sources were added to attain 6% or 9% fat and consisted of (Coconut oil, CO; Poultry fat, PF; Palm oil, PO; Palm kernel oil, PKO; Ca Salts, MEG; Soybean oil, SOY)]. Modules (GP) were randomly assigned to treatments in a 2×2×7 factorial design and incubated for two 24 h runs. A randomized complete block design with 4 replicates per treatment and 2 runs was used. Run was the blocking factor. Data were analyzed using the MIXED procedure of SAS. Apparent digestibility (AD) for DM, OM, NDF, ADF and true dry matter digestibility (TDMD) were higher in LF-treatment. Cumulative gas produced in mL was greater in LF (P = 0.01). Fat concentration had no effect on AD, but the 6% fat had a higher gas production (P = 0.03; 109.6 vs. 103.5 mL ± 2.44). The CO had the highest DM AD followed by SOY and PF (54.5, 51.8, and 50.6% ± 0.48) and cumulative gas production followed same pattern. The TDMD and OM AD were higher in CO, however the NDF and ADF AD were higher in MEG-fed modules. Final pH was not affected by treatments. Final NH3N concentration was greater in HF and 9% fat. These results suggest that LF diets with high dietary fat concentration can be utilized and different types of fat sources may improve DM and fiber rumen digestibility

The Effects of Cultivation Site on Forage Quality of Calliandra calothyrsus var. Patulul

An in vitro experiment was performed to compare the forage quality of foliage of Calliandra (Calliandra calothyrsus Meissner var. Patulul) cultivated on either low or medium-fertility soils in Colombia and Kenya, respectively. A grass-alone diet, with and without urea supplementation, and five legume-supplemented diets (1/3 of dietary dry matter) were tested with the rumen simulation technique (Rusitec) (n=4). The legume supplements consisted of Cratylia (Cratylia argentea), Calliandra from Colombia or Kenya, or 1:1 mixtures of Cratylia with Calliandra Colombia or Kenya. The tannin content of Calliandra Colombia was almost twice as high as that of Calliandra Kenya. Supplementation with urea or Cratylia alone, but not with Calliandra alone, increased ammonia concentration in the fermenter fluid. Unlike Calliandra Colombia, Calliandra Kenya in mixture with Cratylia increased ammonia concentration. The apparent degradation of organic matter increased with all types of supplementation, except with Calliandra Colombia alone. Although the foliage of Calliandra from the two cultivation sites had similar contents of organic matter, crude protein and neutral detergent fibre, they differed in␣nearly all fermentation properties. The material from Kenya showed a higher apparent nutrient degradability. These results indicate that C. calothyrsus var. Patulul cultivated at the Kenyan site had a clearly higher forage quality than foliage from the same variety cultivated in Colombia. However, both materials had a much lower forage quality than Cratylia. The Cratylia-related effects on ruminal fermentation were mainly the results of an increased supply of fermentable nitrogenous compounds as was obvious from the comparison with the urea-supplemented gras

Identificação e composição química de espécies de invasoras consumidas por bovinos em pastagens cultivadas em Paragominas, Pará.

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Hot-Pressing of (Ti, Mt)(C, N)-Co-Mo2C (Mt=Ta, Nb) powdered cermets synthesized by a mechanically induced self-sustaining reaction

A mechanically induced self-sustaining reaction (MSR) has been successfully employed for manufacturing powdered cermets based on Ti, Ti–Ta and Ti–Nb carbonitrides using Co as the binder phase and Mo2C as the sintering additive. The powders were sintered by hot-pressing, and complete chemical, microstructural and mechanical characterizations were performed on the densified cermets. When elemental Ta, Nb and/or Mo2C were added to the initial raw mixture submitted to the MSR process, smaller ceramic grains were observed after sintering, which suggested that ceramic particle growth was hindered by the presence of Ta, Nb and/or Mo in the host titanium carbonitride structure. Nanoindentation measurements enabled the determination of the hardness of the ceramic and binder phases, and values in the range of 26–29 GPa and 14–16 GPa were found, respectively. The high hardness values of the binder were related to the formation of intermetallic phases.Gobierno de España European Regional Development No. MAT2011- 2298

To how many?

Determinar a cuantos pacientes le realizamos prácticas recomendadas en promoción de la salud y prevención o pesquisa de enfermedades prevalentes en atención primaria

Screening: knowledge on evidence levels and healthy medical recommendations

El desarrollo de una Guía de Práctica Clínica (GPC), se basa en las definiciones de calidad, nivel de evidencia y grado de recomendación. Actualmente hay más de 100 sistemas de clasificación de evidencia. El empleo de la evidencia en las ciencias, se atribuye a la medicina tradicional china. Pero sus inicios datan del año 1976, cuando se creó la Canadian Task Force on Preventive Health Care (CTFPHC). En ella, se gestaron y estructuraron los niveles de evidencia y grados de recomendación para pacientes asintomáticos, apuntando cuáles procedimientos eran adecuados y cuáles deberían ser evitados. Este sistema, permitió tomar conciencia y establecer un orden jerárquico de ciertas prácticas, teniendo en cuenta la evidencia de las investigaciones clínicas. En el último tiempo, los sistemas de salud han integrado, conceptos de medicina basada en la evidencia en áreas como la elaboración de GPC; las que contribuyen a la toma de decisiones de los profesionales del equipo de salud