La Participación Eje de la Investigación en el Área de Ciencias Naturales en el Grado 6° B del Colegio Gabriela Mistral N°. 2

La sociedad actual está viviendo cambios muy profundos, Los avances en el campo de la educación exigen habilidades y la implementación de estrategias que generen espacios de participación e interacción en el aula de clase y en los ambientes complejos en que se desenvuelve nuestros educandos. Como educadores estamos obligados a reconceptualizar la visión de la participación en el proceso pedagógico, pues posibilita la dinamización y la interacción social dentro del aula de clase: además promueve el desarrollo de la autonomía, generando espacios de intercambio de ideas y de reflexiones que posibiliten la investigación de los fenómenos que los participantes tienen la oportunidad de conocer y valorar.Por lo anterior, el proyecto pedagógico se ha concebido como elemento que me brinda, como maestra, la oportunidad de buscar herramientas pedagógicas participativas integradoras, como la lúdica y el pensamiento crítico que posibiliten el desarrollo de los procesos investigativos encaminados a generar espacios de reflexión, de interpretación y de formulación de hipótesis para que se produzcan inferencias, se hagan deducciones, se descubran los conocimientos de manera autónoma y responsable y se creen satisfacciones individuales y colectivas. De hecho, el proyecto pedagógico tiene como motivación fundamental la construcción de espacios de interacción social y cultural, orientados a facilitar el aprendizaje bajo un enfoque constructivista que edifique los saberes, los valores y creencias, dándole un nuevo significado a la enseñanza de las ciencias naturales

Efeito da redução do tempo de aplicação na permeabilidade dentinária de um adesivo universal em modo etch-and-rinse vs self-etch

Objetivo: Analisar a influência na permeabilidade dentinária da redução do tempo de aplicação do adesivo universal OptiBond Universal® (Kerr), aplicado pela técnica etch-and-rinse e self- etch. Método: Foram selecionados e distribuídos 20 espécimes em dois grupos de estudo: Grupo I – aplicação do adesivo universal durante 5 segundos, pela técnica self-etch; Grupo II – aplicação do adesivo universal durante 5 segundos pela técnica etch-and-rinse. A permeabilidade máxima foi medida após o condicionamento ácido de cada espécime com ácido ortofosfórico durante 15 segundos. De seguida foi aplicado e polimerizado o adesivo, e medida novamente a permeabilidade do espécime. As diferenças na redução da permeabilidade após a aplicação do adesivo foram analisadas com o t-test. Resultados: Verificou-se redução da permeabilidade dentinária após a aplicação do adesivo em ambos os grupos de estudo. A redução do Grupo II (81.7±11.43%) foi superior, comparativamente ao Grupo I (71.8±18.07%). No entanto não se verificaram diferenças estatisticamente significativas entre os grupos estudados (p=0.160). Conclusão: A permeabilidade dentinária não é influenciada pela aplicação de um sistema universal pela técnica etch-and-rinse ou pela técnica self-etch, com a redução do tempo de aplicação para 5 segundos.Aim: To analyze the influence in dentin permeability of the 5-second appliance of OptiBond Universal® (Kerr Corp., Orange, EUA), comparing modes of application, etch-and-rinse and self-etch. Methods: 20 specimes were randomly assigned to 2 study groups: group I – application of the adhesive during 5 seconds by self-etch mode; group II – application of the adhesive during 5 seconds by etch-na-rinse mode. The maximum permeability was measured in each specimen after the application of 37.5% phosphoric acid for 15 seconds. The adhesive was then applied and light-cured, and the permeability measured once more. The differences in permeability reduction after adhesive application were analyzed with the Kolmogorov-Smirnov test, the Levene test and the t-test. Results: Both study groups showed a reduction of permeability after the application of the adhesive. The reduction in Group II (81.7±11.43%) was higher when compared to Group I (71.8±18.07%), although there were no statistical differences between groups (p=0.160). Conclusion: Dentin permeability does not seem to be influenced by the mode of application of the adhesive, whether it is etch-and-rinse or self-etch, when the time of the adhesive application is reduced to 5 seconds

Accelerated inbreeding depression suggests synergistic epistasis for deleterious mutations in Drosophila melanogaster

Epistasis may have important consequences for a number of issues in quantitative genetics and evolutionary biology. In particular, synergistic epistasis for deleterious alleles is relevant to the mutation load paradox and the evolution of sex and recombination. Some studies have shown evidence of synergistic epistasis for spontaneous or induced deleterious mutations appearing in mutation-accumulation experiments. However, many newly arising mutations may not actually be segregating in natural populations because of the erasing action of natural selection. A demonstration of synergistic epistasis for naturally segregating alleles can be achieved by means of inbreeding depression studies, as deleterious recessive allelic effects are exposed in inbred lines. Nevertheless, evidence of epistasis from these studies is scarce and controversial. In this paper, we report the results of two independent inbreeding experiments carried out with two different populations of Drosophila melanogaster. The results show a consistent accelerated inbreeding depression for fitness, suggesting synergistic epistasis among deleterious alleles. We also performed computer simulations assuming different possible models of epistasis and mutational parameters for fitness, finding some of them to be compatible with the results observed. Our results suggest that synergistic epistasis for deleterious mutations not only occurs among newly arisen spontaneous or induced mutations, but also among segregating alleles in natural populationsXunta de Galicia | Ref. ED431C 2016-037Ministerio de Economía y Competitividad | Ref. CGL2016-75904-C2-1-

Exploring the fate of cattle herds with inconclusive reactors to the tuberculin skin test

Bovine tuberculosis (TB) is an important animal health issue in many parts of the world. In England and Wales, the primary test to detect infected animals is the single intradermal comparative cervical tuberculin test, which compares immunological responses to bovine and avian tuberculins. Inconclusive test reactors (IRs) are animals that demonstrate a positive reaction to the bovine tuberculin only marginally greater than the avian reaction, so are not classified as reactors and immediately removed. In the absence of reactors in the herd, IRs are isolated, placed under movement restrictions and re-tested after 60 days. Other animals in these herds at the time of the IR result are not usually subject to movement restrictions. This could affect efforts to control TB if undetected infected cattle move out of those herds before the next TB test. To improve our understanding of the importance of IRs, this study aimed to assess whether median survival time and the hazard of a subsequent TB incident differs in herds with only IRs detected compared with negative-testing herds. Survival analysis and extended Cox regression were used, with herds entering the study on the date of the first whole herd test in 2012. An additional analysis was performed using an alternative entry date to try to remove the impact of IR retesting and is presented in the Supplementary Material. Survival analysis showed that the median survival time among IR only herds was half that observed for clear herds (2.1 years and 4.2 years respectively; p < 0.001). Extended Cox regression analysis showed that IR-only herds had 2.7 times the hazard of a subsequent incident compared with negative-testing herds in year one (hazard ratio: 2.69; 95% CI: 2.54, 2.84; p < 0.001), and that this difference in the hazard reduced by 63% per year. After 2.7 years the difference had disappeared. The supplementary analysis supported these findings showing that IR only herds still had a greater hazard of a subsequent incident after the IR re-test, but that the effect was reduced. This emphasizes the importance of careful decision making around the management of IR animals and indicates that re-testing alone may not be sufficient to reduce the risk posed by IR only herds in England and Wales

Main findings and diagnostic yield of bronchoalveolar lavage, bronchial brushing and transbronchial biopsy in HIV-positive patients

HIVBronchoalveolar lavage, bronchial brushing and transbronchial biopsy are of fundamental importance in the diagnosis of pathologies affecting the lungs of immunosuppressed patients, especially those infected with HIV. This was a descriptive and retrospective study, in which the results of bronchoalveolar lavages, bronchial brushings and transbronchial biopsies of HIV-positive patients attended at the Clinical Hospital of the Federal University of Triangulo Mineiro from 1999 to 2015 were reviewed to determine the most frequent findings in these patients, to evaluate the diagnostic accuracy of these procedures and to correlate bronchoscopy results with clinical and radiological findings. Serological tests for HIV were confirmed and cases with negative or unverified serology were excluded. Medical records were reviewed for correlation with clinical and radiological findings. A total of 1,423 patients with a mean age of 50 years were initially selected; 727 cases had no serology for HIV; 696 had serology for HIV and 64 were positive. Of these, 47 were men, aged 24 to 84 years, and 17 women, aged 31 to 69 years. Biopsies and cytological tests were positive in 20 (31.25%) of the 64 patients and the most frequent diagnosis was pneumocystosis, found in 8 cases (12.5%). Of the 20 bronchofibroscopy-positive patients, only 2 did not show agreement between histopathological and clinical-radiological diagnoses. The analysis of the cytological tests and biopsy specimens obtained by bronchofibroscopy seems to be valuable for the etiological diagnosis of pulmonary infections in HIV- positive patients; however, negative results do not always exclude the diagnosis. In these cases, clinical symptoms and imaging findings may help to guide the best therapy

Case Study area: Leiria National Forest, Portugal

info:eu-repo/semantics/draf

Association of the microsatellite in the 3' untranslated region of the CD154 gene with rheumatoid arthritis in females from a Spanish cohort: a case-control study

CD40–CD154 interaction is an important mediator of inflammation and has been implicated in T helper type 1-mediated autoimmune diseases including rheumatoid arthritis (RA). Linkage studies have shown association of markers in the proximity of the CD154 gene. In the present work we investigated whether specific allele variants of the microsatellite in the 3' UTR of the CD154 gene might modulate the risk of RA. The study, in a case-control setting, included 189 patients and 150 healthy controls from the Canary Islands, Spain. The 24CAs allele was less represented in female patients than in controls (0.444 in controls versus 0.307 in patients, P = 0.006, odds ratio (OR) 0.556, 95% confidence interval (CI) 0.372 to 0.831) but not in males (0.414 versus 0.408), and only when homozygous (P = 0.012; OR 0.35, 95% CI 0.16 to 0.77). We also verified that CD154 association with RA was independent of human leukocyte antigen (HLA) phenotype. A further functional study showed that after stimulation anti-CD3, CD154 mRNA was more stable in CD4+ T lymphocytes from patients with RA bearing the 24CAs allele (mRNA half-life 208 minutes) than in patients without the 24CAs allele (109 minutes, P = 0.009). However, a lower percentage of CD154+CD4+ T lymphocytes was seen in freshly isolated peripheral blood mononuclear cells from patients carrying 24CAs alleles (mean 4.28 versus 8.12; P = 0.033), and also in CD4+ T lymphocytes stimulated with anti-CD3 (median 29.40 versus 47.60; P = 0.025). These results were concordant with the smaller amounts of CD154 mRNA isolated from stimulated T lymphocytes with 24CAs alleles. The CD154 microsatellite therefore seems to affect the expression of the gene in a complex manner that implies not only mRNA stability. These data suggest that the CD154 microsatellite contributes to the regulation of mRNA and protein expression, although further studies will be necessary to elucidate its role in disease predisposition

Evaluation of the methodological quality of studies of the performance of diagnostic tests for bovine tuberculosis using QUADAS

There has been little assessment of the methodological quality of studies measuring the performance (sensitivity and/or specificity) of diagnostic tests for animal diseases. In a systematic review, 190 studies of tests for bovine tuberculosis (bTB) in cattle (published 1934-2009) were assessed by at least one of 18 reviewers using the QUADAS (Quality Assessment of Diagnostic Accuracy Studies) checklist adapted for animal disease tests. VETQUADAS (VQ) included items measuring clarity in reporting (n = 3), internal validity (n = 9) and external validity (n = 2). A similar pattern for compliance was observed in studies of different diagnostic test types. Compliance significantly improved with year of publication for all items measuring clarity in reporting and external validity but only improved in four of the nine items measuring internal validity (p < 0.05). 107 references, of which 83 had performance data eligible for inclusion in a meta-analysis were reviewed by two reviewers. In these references, agreement between reviewers' responses was 71% for compliance, 32% for unsure and 29% for non-compliance. Mean compliance with reporting items was 2, 5.2 for internal validity and 1.5 for external validity. The index test result was described in sufficient detail in 80.1% of studies and was interpreted without knowledge of the reference standard test result in only 33.1%. Loss to follow-up was adequately explained in only 31.1% of studies. The prevalence of deficiencies observed may be due to inadequate reporting but may also reflect lack of attention to methodological issues that could bias the results of diagnostic test performance estimates. QUADAS was a useful tool for assessing and comparing the quality of studies measuring the performance of diagnostic tests but might be improved further by including explicit assessment of population sampling strategy.The SE3238 project “Meta-analysis of diagnostic tests and modelling to identify appropriate testing strategies to reduce M. bovis infection in GB herds” was funded by the UK Department for Environment, Food and Rural Affairs (Defra).http://www.elsevier.com/locate/prevetmedam2018Veterinary Tropical Disease

Meta-analyses of the sensitivity and specificity of ante-mortem and post-mortem diagnostic tests for bovine tuberculosis in the UK and Ireland

Publication history: Accepted - 26 February 2017; Published online - 6th March 2017.Bovine Tuberculosis (bTB) in cattle is a global health problem and eradication of the disease requires accu-rate estimates of diagnostic test performance to optimize their efficiency. The objective of this study was,through statistical meta-analyses, to obtain estimates of sensitivity (Se) and specificity (Sp), for 14 differ-ent ante-mortem and post-mortem diagnostic tests for bTB in cattle. Using data from a systematic reviewof the scientific literature (published 1934–2009) diagnostic Se and Sp were estimated using Bayesianlogistic regression models adjusting for confounding factors. Random effect terms were used to accountfor unexplained heterogeneity. Parameters in the models were implemented using Markov Chain MonteCarlo (MCMC), and posterior distributions for the diagnostic parameters with adjustment for covariates(confounding factors) were obtained using the inverse logit function. Estimates for Se and/or Sp of thetuberculin skin tests and the IFN- blood test were compared with estimates published 2010–2015.Median Se for the single intradermal comparative cervical tuberculin skin (SICCT) test (standard inter-pretation) was 0.50 and Bayesian credible intervals (CrI) were wide (95% CrI 0.26, 0.78). Median Sp forthe SICCT test was 1.00 (95% CrI 0.99, 1.00). Estimates for the IFN- blood test Bovine Purified ProteinDerivative (PPD)-Avian PPD and Early Secreted Antigen target 6 and Culture Filtrate Protein 10 (ESAT-6/CFP10) ESAT6/CFP10 were 0.67 (95% CrI 0.49, 0.82) and 0.78 (95% CrI 0.60, 0.90) respectively for Se,and 0.98 (95% CrI 0.96, 0.99) and 0.99 (95% CrI 0.99, 1.00) for Sp. The study provides an overview of theaccuracy of a range of contemporary diagnostic tests for bTB in cattle. Better understanding of diagnostictest performance is essential for the design of effective control strategies and their evaluation.The SE3238 project “Meta-analysis of diagnostic tests and modelling to identify appropriate testing strategies to reduce M. bovis infection in GB herds” was funded by the UK Department for Envi-ronment, Food and Rural Affairs (Defra)