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La tutoría entre iguales es una modalidad pedagógica en la que estudiantes, generalmente de semestres más avanzados, acompañan a sus pares en la orientación y el refuerzo de los procesos de aprendizaje dentro de un área disciplinar, el cual permite la promoción del aprendizaje cooperativo en el nivel de educación superior. Ante este planteamiento, el objetivo de este artículo se centró en evaluar la tutoría entre iguales como una modalidad para promover el aprendizaje cooperativo a nivel superior. El estudio siguió una metodología de tipo descriptiva con un diseño no experimental y de campo, puesto que fue necesario estudiar los hechos donde se originan para observarlo, describirlos y aplicar los instrumentos necesarios para la obtención de los resultados. El diseño de esta investigación se consideró no experimental y de campo. La población la constituyeron 14 estudiantes que ejercían el rol de tutores entre iguales. Se observaron y recolectaron los datos a través de la técnica de la observación participativa, para ello se utilizó como instrumentos una entrevista estructura y un cuestionario con una escala tipo Likert. Entre sus resultados, se destaca el hecho en la cual el porcentaje más alto con el 82% de los investigados, indican que la falta de profesores que les apoyen en su labor no les permite ayudar con más efectividad a sus pares estudiantes. Se pudo concluir que la tutoría entre iguales, como una modalidad para promover el aprendizaje cooperativo a nivel superior, no cumple su rol en los espacios universitarios investigados de Portoviejo.

La investigación-acción alude a una serie de estrategias metodológicas empleadas para el mejoramiento del sistema educativo y social, al pasar de lo mero social al compartir educacional. Atendiendo, esta posición en este artículo se presenta un estudio de la investigación - acción como una estrategia pedagógica de relación entre lo académico y social. La metodología fue de tipo descriptivo y documental. El corpus de la investigación la constituyó la revisión de fuentes bibliográficas y no bibliográficas La información se obtuvo a partir del registro, análisis e interpretación de las teorías relacionadas al tema en estudio. El enfoque epistémico fue de tipo hermenéutico, permitiendo el análisis de los contenidos de la información consultada de tipo académica o de divulgación, en formato físico o digital. Entre los resultados del análisis de la información, fue posible corroborar que las teorías relacionadas a la investigación acción dejo la exclusividad de uso para los temas sociales, convirtiéndose de gran importancia como estrategia pedagógica en la investigación académica.

El aprendizaje cooperativo, es una estrategia de gran motivación para lograr el aprendizaje de otro idioma. Bajo esta noción, se presenta este artículo cuyo objetivo es proponer actividades de aprendizaje cooperativo para los maestros que trabajan en las Escuelas Públicas Ecuatorianas en pro de motivar en los estudiantes el aprendizaje del inglés. Para ello, se utilizó un enfoque mixto cuali-cuantitativo. La población la constituyeron los estudiantes del octavo año de educación básica de las escuelas públicas ecuatorianas de la provincia de Tungurahua y cuya muestra fue de 32 estudiantes y 3 profesores de inglés. El instrumento aplicado fue una encuesta de 10 preguntas, cuyas alternativas de repuestas fueron Sí / No y opción múltiple, el análisis de la información obtenida permitió concluir que los profesores de inglés de las Escuelas Pública Ecuatoriana investigadas no aplicaban actividades de aprendizaje cooperativo en sus clases, preferían el trabajo individual para facilitar la evaluación y hacer comentarios individuales sobre la estructura de la gramática y el uso del vocabulario.

The frame and field rates that have been used for television since the 1930s cause problems for motion portrayal, which are increasingly evident on the large, high-resolution television displays that are now common. This paper reports on a program of experimental work that successfully demonstrated the advantages of higher frame rate capture and display as a means of improving the quality of television systems of all spatial resolutions. Additional benefits were identified from the use of high frame-rate capture for the production of programs to be viewed using conventional televisions. Ways to mitigate some of the production and distribution issues that high frame-rate television implies are suggested.

In France, 20% of breast cancers occur in women over the age of 70 and 10% in women over the age of 80. As these women are not included in screening programs, breast cancer is often diagnosed later, at the stage of a large tumor.To analyze clinical response, possibilities of conservative treatment and course of hormonal receptors in patients receiving neoadjuvant aromatase inhibitor (AI) therapy for at least 6 months.There were 75 patients, with a mean age of 75 +/- 8 years (range, 58-91 years) received AI for 6 months after the diagnosis of invasive breast cancer with positive hormonal receptors. Clinical and radiologic tumor reduction, the number of conservative treatments and the course of estrogens receptor-labeled cells were determined for each patient.All but 1 of these patients obtained clinical reduction of their tumor. Of these, 86% patients received conservative treatment. In the majority of patients, estrogen receptor (ER) level did not vary between the initial assay and analysis of the operative specimen.Aromatase inhibitors are effective as neoadjuvant therapy in ER positive elderly patients with large tumors, as is tamoxifen. Changes in hormone receptor expression during treatment do not predict clinical response. In our experience, neoadjuvant AI therapy should be administered for at least 6 months to optimize clinical response before deciding upon surgery. Discrepancy observed in the literature could be explained by the duration of the treatment.

This paper presents an experimental study that focuses on the formation of perfluoroisobutene (i-C4Fg). Experiments were carried out at atmospheric pressure in a quartz flow tube reactor over the temperature range of 823 to 1273K and an initial reactant feed concentration of 2% with the balance nitrogen. Reactants studied include chlorodifluoromethane (CHF2Cl), 1,1,1,2-tetrafluoro-2-chloroethane (CF3CHFCl), trifluoromethane (CHF3), perfluoropropene (C3F6), and mixtures of these species. Effluent gas concentrations were obtained using a water cooled gas sampling probe, and analysis of products was performed via on line gas chromatography with flame ionization detection and gas chromatography with mass selective detection. C3F6 pyrolysis produced more than 22% i-C.F, yield, while mixtures with CHF2Cl and CHF3 resulted in i-C4Fg yields of 14% and 28%, respectively. The pyrolysis of CF3CHFCI resulted in slightly greater than 6% i-C4Fg yield, and CHF2Cl decomposition produced up to 6% i-C4Fg yield, wh...

We have investigated the activation of the p38 mitogen-activated protein kinase (MAPK) in normal mouse T and B cells and its role in apoptosis. Cross-linking of the CD3 chains of the TCR complex on proliferating T cells resulted in activation of p38 MAPK and MAPKAP kinase-2. Cross-linking of CD28 failed to activate p38 MAPK or MAPKAP kinase-2, but synergized strongly with low doses of anti-CD3. Cross-linking of Fas on T cells also induced rapid activation of p38 MAPK and MAPKAP kinase-2. The in vivo activation of MAPKAP kinase-2 in response to cross-linking of CD3, Fas, or CD3 and CD28 was shown to be dependent on p38 MAPK activity using a specific inhibitor, SB 203580. SB 203580 did not inhibit activation-induced cell death in T cells when used at concentrations that suppressed activation of MAPKAP kinase-2 in vivo. Cross-linking of the B cell Ag receptor (BCR) or CD40 on freshly isolated or LPS-activated splenic B cells or the immature B lymphoma, WEHI 231, resulted in activation of p38 MAPK and MAPKAP kinase-2. In vivo inhibition of p38 MAPK activity in WEHI 231 cells by SB 203580 had no effect on either BCR-induced apoptosis or anti-CD40-mediated suppression of apoptosis. We conclude that the activation of p38 MAPK and MAPKAP kinase-2 by cross-linking of the TCR, BCR, Fas, or CD40 was not correlated with their roles in regulating lymphocyte survival, and that suppression of kinase activity did not inhibit the induction of apoptosis.

Les anti-angiogeniques sont maintenant de pratique courante dans l’arsenal therapeutique de la cancerologie. Leur mecanisme d’action les rend utiles dans de nombreuses localisations tumorales, que ce soit en traitement adjuvant ou en situation metastatique.

Evidence suggests that frequent and direct exposure to domestic animals has made farmers less susceptible to symptomatic Escherichia coli O157 infection than other members of the community. We have quantified the seroprevalence of antibodies to E. coli O157 lipopolysaccharide (LPS) from a representative cohort of farm workers in three geographically distinct regions of the United Kingdom during two sampling rounds over a 2-year period. All participants completed a questionnaire to determine the range and extent of recent animal contact alongside other potential occupational and environmental exposure routes. A total of 31/946 (3.3%) serum samples contained antibodies to E. coli O157 LPS (from both rounds combined). On the second sampling round, a significant difference in seropositivity was apparent between the three regions, with enhanced seroprevalence linked to recent contact with beef cattle, having a private water supply and contact with a child under 5 years old. Only five seropositive people reported symptoms of a gastrointestinal tract infection, although these symptoms were mild. These results further support the premise of acquired immunity to E. coli O157 associated with prolonged antigenic exposures within the farming environment.

In the United Kingdom, the influenza A(H1N1) 2009 pandemic had a distinct two-wave pattern of general practice consultations for influenza-like illness (ILI). We describe the epidemiology of the influenza pandemic in Wales between April and December 2009 using integrated data from a number of independent sources: GP surveillance, community virology surveillance, hospital admissions and deaths, and media enquiries monitoring. The first wave peaked in late July at 100 consultations per 100,000 general practice population and attracted intensive media coverage. The positivity rate for the A(H1N1)2009 influenza did not exceed 25% and only 44 hospitalisations and one death were recorded. By contrast, the second wave peaked in late October and although characterised by lower ILI consultation rates (65 consultations per 100,000 general practice population) and low profile media activity, was associated with much higher positivity rates for pandemic influenza A(H1N1)2009 (60%) and substantially more hospital admissions (n=379) and deaths (n=26). The large number of ILI-related consultations during the first wave in Wales probably reflected the intensive media activity rather than influenza virus circulating in the community. Data from community surveillance schemes may therefore have considerably overestimated the true incidence of influenza. This has implications for the future interpretation of ILI surveillance data and their use in policy making, and underlines the importance of using integrated epidemiological, virological and hospital surveillance data to monitor influenza activity.

A modelling study of radical chemistry in the coastal Antarctic boundary layer, based upon observations performed in the course of the CHABLIS (Chemistry of the Antarctic Boundary Layer and the Interface with Snow) campaign at Halley Research Station in coastal Antarctica during the austral summer 2004/2005, is described: a detailed zero-dimensional photochemical box model was used, employing inorganic and organic reaction schemes drawn from the Master Chemical Mechanism, with additional halogen (iodine and bromine) reactions added. The model was constrained to observations of long-lived chemical species, measured photolysis rates and meteorological parameters, and the simulated levels of HOx, NOx and XO compared with those observed. The model was able to replicate the mean levels and diurnal variation in the halogen oxides IO and BrO, and to reproduce NOx levels and speciation very well. The NOx source term implemented compared well with that directly measured in the course of the CHABLIS experiments. The model systematically overestimated OH and HO2 levels, likely a consequence of the combined effects of (a) estimated physical parameters and (b) uncertainties within the halogen, particularly iodine, chemical scheme. The principal sources of HOx radicals were the photolysis and bromine-initiated oxidation of HCHO, together with O(1D)+H2O. The main sinks for HOx were peroxy radical self- and cross-reactions, with the sum of all halogen-mediated HOx loss processes accounting for 40% of the total sink. Reactions with the halogen monoxides dominated CH3O2–HO2–OH interconversion, with associated local chemical ozone destruction in place of the ozone production which is associated with radical cycling driven by the analogous NO reactions. The analysis highlights the need for observations of physical parameters such as aerosol surface area and boundary layer structure to constrain such calculations, and the dependence of simulated radical levels and ozone loss rates upon a number of uncertain kinetic and photochemical parameters for iodine species.

Apres traitement conservateur, la survenue d’une recidive locale impose l’amputati du sein.

Canola meal was fed at 0, 10, 20, and 26 to 10% dietary levels to Large White turkey males during 0 to 19 wk of age. Feed was in meal and pelleted forms. Body weights were reduced at higher canola meal levels in mash and pelleted diets. When isocaloricity was maintained by addition of fat, 19-wk body weight was significantly greater with 20% canola meal than with the corn-soybean meal control. Differences in breast and leg yield were not significant statistically. Taste panel findings showed no preference among breast meat samples, but thigh meat from birds fed 20% canola meal was preferred over that of the control. Canola meal was an acceptable protein source in turkey diets in the present study.

An amylase gene was identified in a Streptococcus bovis 033 lambda gtWES lambda B genomic library. Using a starch overlay and a Congo red-iodine staining procedure, amylase positive clones could be identified by zones of clearing. Ten amylase positive clones were identified using this procedure. The clone chosen for further study, lambda SBA105, contained an insert of approximately 7.5 kb. The insert was mapped, and subcloning localized the amylase gene to a region of approximately 3.1 kb. Cloning of the 3.1 kb amylase fragment into pUC18 in both orientations revealed that the amylase gene was transcribed from its own promoter. Amylase activity was expressed by the Escherichia coli subclones and was found to be largely associated with the cytoplasmic fraction. Southern hybridization of genomic DNA from the amylolytic strains, S. bovis 033, S. bovis 077, Butyrivibrio fibrisolvens 194 and 195 revealed a single hybridizing band in S. bovis 033 DNA only. This indicates that the amylase gene from S. bovis may differ from the amylases of these other amylolytic bacteria.

NOx measurements were conducted at the Halley Research Station, Antarctica, during the austral summer period 1 January–10 February 2005. A clear NOx diurnal cycle was observed with minimum concentrations close to instrumental detection limit (5 pptv) measured between 04:00–05:00 GMT. NOx concentrations peaked (24 pptv) between 19:00–20:00 GMT, approximately 5 h after local solar noon. An optimised box model of NOx concentrations based on production from in-snow nitrate photolysis and chemical loss derives a mean noon emission rate of 3.48×108 molecules cm−2 s−1, assuming a 100 m boundary layer mixing height, and a relatively short NOx lifetime of ~6.4 h. This emission rate compares to directly measured values ranging from 1.7 to 3.4×108 molecules cm−2 s−1 made on 3 days at the end of the study period. Calculations of the maximum rate of NO2 loss via a variety of conventional HOx and halogen oxidation processes show that the lifetime of NOx is predominantly controlled by halogen processing, namely BrNO3 and INO3 gas-phase formation and their subsequent heterogeneous uptake, with a potential smaller contribution from HNO4 formation and uptake. Furthermore the presence of halogen oxides is shown to significantly perturb NOx concentrations by decreasing the NO/NO2 ratio. We conclude that in coastal Antarctica, the potential ozone production efficiency of NOx emitted from the snowpack is mitigated by the more rapid NOx loss due to halogen nitrate hydrolysis. These results suggest that the role of halogen oxides need to be considered when interpreting the isotopic signature of nitrate impurities held within snow and ice.

Our objective was to study the prognostic value of stoutness in non-metastatic breast cancer, from a population of French women.We constituted a large observational cohort of patients followed since a first unilateral breast cancer without distant dissemination. Stoutness was assessed using the body mass index (BMI, in kg/m(2)) at the time of diagnosis. Patients were classified into the four main categories of BMI, defined according to the World Health Organization recommendations. The risk of prognosis events was analyzed according to the BMI categories. To this end, survival analyses were achieved.The patients having a BMI value of at least 25 kg/m(2) presented significantly higher risks of death and metastasis recurrences when they were compared to the patients having a normal value of BMI. The multivariate analyses found a modest increase of risk, about 10 to 20%, depending on the degree of fatness. It reached about 20 to 50% according to the univariate analyses. The obese patients (BMIor= 30 kg/m(2)) had an increase of 50% of the risk of second primary cancers, comparatively to the patients having a normal value of BMI. Regarding contralateral, nodal and local recurrences, the survival analyses did not achieve any significant relationship with stoutness.A poorer prognosis is observed when breast cancer patients have a value of BMI that matches at least with overweight. Contrary to the results of few recent surveys, underweight patients do not present a poorer prognosis than normal weight patients. Excess of weight represents a modifiable factor in order to improve female breast cancer prognosis.

The recent resurgence of interest in the stereoscopic cinema and the increasing availability to the consumer of stereoscopic televisions and computer displays are leading broadcasters to consider, once again, the feasibility of stereoscopic broadcasting. High Definition Television is now widely deployed, and the R&D departments of broadcasters and consumer electronics manufacturers are starting to plan future enhancements to the experience of television. Improving the perception of depth via stereoscopy is a strong candidate technology. In this paper we will consider the challenges associated with the production, transmission and display of different forms of "three-dimensional" television. We will explore options available to a broadcaster wishing to start a 3D service using the technologies available at the present time, and consider how they could be improved to enable many more television programmes to be recorded and transmitted in a 3D-compatible form, paying particular attention to scenarios such as live broadcasting, where the workflows developed for the stereoscopic cinema are inapplicable. We will also consider the opportunities available for broadcasters to reach audiences with "three-dimensional" content via other media in the near future: for example, distributing content via the existing stereoscopic cinema network, or over the Internet to owners of stereoscopic computer displays.

To evaluate the genetic relationship within and between wood and plains bison of Elk Island National Park, genomic DNA samples were screened for restriction fragment length polymorphisms (RFLP) with cDNA probes for growth hormone, growth hormone releasing factor, somatostatin, and insulin-like growth factor-1. Of the 28 fragments identified, two revealed RFLPs, both of which were associated with the growth hormone releasing factor locus. The observed frequencies of the polymorphic sites did not differ from a Hardy–Weinberg distribution in either population, which is indicative of random mating populations. The contingency χ2 tests for homogeneity indicate that the fragment frequencies of the polymorphic restriction sites differ significantly (P = 0.00) between the wood and plains bison. The number of net nucleotide substitutions between the two populations was 0.0007, indicative of a recent divergence. Conversion of the bison nucleotide divergence results in a relative protein divergence of 0.007 to 0.018. This converted divergence corresponds closely to the divergence reported for other geographically isolated populations; thus, this preliminary analysis suggests the bison have at least reached the stage of geographic isolation in their evolutionary divergence.

This study presents information on the course and rates of weight gain and the associations among weight gain, prepregnancy weight-for-height, and infant birth weight, based on a total sample of 1419 uncomplicated term deliveries to adolescents. The distribution of cumulative weight gain indicates that for adolescents not only is the median gain at term (14.2-15.5 kg) significantly in excess of that reported for adults, but also weight-gain velocity is greater from the beginning of pregnancy. Although the contributions of prepregnancy weight-for-height and weight gain to birth weight may be independent, they are not necessarily additive. Birth weight does not appear improved for the infants of overweight adolescents except when weight gain is low (less than 11.1-12.3 kg at term), and, for Puerto Rican and black adolescents, birth weight is not further improved at any maternal prepregnancy body mass index (weight-for-height) with excessive weight gains (greater than 17.9-19.3 kg at term).

Diets containing 0 or 22 mg of virginiamycin per kilogram were fed to 448 Nicholas Large White turkeys from day-old to slaughter at 16 (females) or 20 wk of age (males). Weight gain of males, but not females, fed treated diets increased significantly from 0 to 4 and 4 to 8 wk of age, but not in later periods. However, final weights of both sexes were increased by treatment with virginiamycin. Feed efficiency of treated birds increased to 8 wk of age but not overall. Mortality and carcass finish and fleshing scores were unaffected by the antibiotic treatment.

Two experiments were conducted to investigate the response of turkeys to graded levels of bambermycins in wheat-based diets. In one, 960 Medium White poults were fed 0, 2, 3, or 4 mg bambermycins per kg from day-old to 12 wk of age. In the other, 264 male and 408 female Large White poults were fed 0, 2, 5, or 10 mg bambermycins per kg from day-old to 15 (females) or 18 (males) wk of age. Response of Medium White poults increased with age, with significantly greater weight gain from 8 to 12 wk of age as well as final weights when the diet was supplemented with bambermycins. Large White poults responded with highly significant increases in gains from 0 to 4 and 4 to 8 wk of age, and a highly significant linear response to bambermycins in final weights. Although feed efficiency of Large White poults from 0 to 4 wk of age increased with bambermycins, overall efficiency in both trials decreased when the diets were supplemented. The earlier and greater response of Large White poults in comparison with birds of a Medium White strain may be related to the differing growth characteristics of those strains. The difference may also be related to the re-use of litter in the former trial. However, the effect of neither strain nor litter was determined within the same experiment.