167 research outputs found

    La educación en Colombia: análisis del marco normativo y de Los indicadores sectoriales.

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    En este documento se presenta una visión amplia de los problemas y del funcionamiento del sector educativo en Colombia, con énfasis en la educación pública. Inicialmente, se realiza una breve descripción de la política educativa durante las últimas décadas. Posteriormente, se realiza una evaluación detallada de las normas sobre descentralización educativa, así como de aquellas que rigen la carrera docente en el país. También se evalúa el comportamiento reciente de algunos indicadores sectoriales sobre gasto público, cobertura, eficiencia y calidad. Finalmente, se presentan algunas comparaciones internacionales y se analiza el esquema de remuneración e incentivos de los docentes. El comportamiento de los indicadores sectoriales, durante los últimos años, sugiere que el esfuerzo del Estado en materia de educación ha estado orientado principalmente a la ampliación de los niveles de cobertura

    Extracción de productos extracelulares de aeromonas hydrophila y sus efectos en tilapia roja (oreochromis spp.) y cachama blanca (piaractus brachypomus)

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    Se obtuvo un extracto crudo toxigénico (ECT) de A. hydrophila en diversos medios de cultivo como caldo BHI con extracto de levadura, soya tripticasa (TSB) y medio de sales mínimas (MSM). Además, se usaron diversas técnicas de concentración como la precipitación con solventes ácidos y concentración por deshidratación a 4 ºC; como técnica integrada de cultivo y concentración se usó el cultivo sobre papel celofán. Los extractos se pasaron por columna de cromatografía (QAE)-Sephadex A-50 y se les efectuó electroforesis en SDS-PAGE. Se midió la actividad biológica in vitro (actividad hemolítica y proteolítica) e in vivo (toxicidad en peces). Los resultados indican que para la cepa de trabajo utilizada y bajo nuestras condiciones de cultivo (28 ºC) el medio óptimo para la obtención de extracto es el MSM, y la técnica de concentración más adecuada es la deshidratación a 4 ºC. El extracto obtenido en TBS tuvo una actividad hemolítica de 128 UH/μL, proteolítica de 38,4 UP/μL, produjo alta mortalidad en peces y severas lesiones multiorgánicas. La electroforesis reveló bandas nítidas de 50 a 52 kDa y 63 a 68 kDa, que pueden corresponder a b hemolisina y a a hemolisina y otras tenues de 30 a 36 kDa que pueden corresponder a la metaloproteasa termoestable.A toxigenic raw extract of A. hydrophila was obtained from diverse culture medium (BHI with extract of yeast, (TSB) y minimum salt medium (MSM)) and diverse concentration techniques. Extracts were processed by Sephadex A-50 (QAE) and SDS-PAGE electrophoresis. Biological activity was measured in vitro (hemolytic and proteolitic activity) and in vivo (toxicity in fish). The results indicate that the optimal culture condition was 28 ºC and MSM was the optimum medium to extract. Dehydration at 4 ºC was the most adequate concentration technique. TBS extract obtained had an hemolytic activityof 128 UH/μL and a proteolitic activity of 38.4 UP/μL and produced high fish mortality and severe multiorganic lesions. Electrophoresis revealed bands from 50 to 52 kDa y 63 to 68 kDa, that could correspond to the b hemolisina or a hemolisina y other from 30 to 36 kDa that could correspond to the thermostable metalloprotease

    Proposal of a production and management index (PMI) for tilapia farms

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    Tilapia is one of the most important species in aquaculture; however, there is no available index to show the performance of a production unit. It is desirable to assess the productivity using indexes, such as the production and management index for shrimps and the European production efficacy factor for broilers. These indexes are based on data production: growth, survival, and feed conversion of a full production cycle. Taking into account these parameters, we propose a production and management index (PMI) for tilapia that is applicable for a specific period of the production cycle. For the construction and validation of the PMI we have used production data from 8, 614 monthly records of 2 tilapia farms in Huila Department (Colombia), and because of the complexity of tilapia management, different anomalous situations have been detected and then defined as exceptions. As a result, 419 records were considered extreme values because 1 or more exceptions were met. The value of the PMI varies from 0 (the worst situation) to 3.55, which reflects high variability. We have constructed a PMI for tilapia as the product of 3 elements to obtain a positive value index. Instead of classic parameters, we had to calculate an adapted version of them: the relative average daily growth, the survival (as a complementary value of the estimated monthly mortality), and a feed conversion ratio index. To assess the utility of the PMI, some comparisons were performed using records from black and red tilapia. We observed significant differences depending on tilapia strain (PMIblack = 1.0248 vs. PMIred = 1.1661; P < 0.001), age (better values for small fish), and season (PMIrainy = 1.0847 vs. PMIdry = 1.1011; P = 0.026). According to these results, we can conclude that the PMI could be a useful tool for tilapia farmers, despite the complexity of the calculation

    Summer dry-down modulates the isotopic composition of soil CO2 production in snow-dominated landscapes

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    In mountainous landscapes, soil moisture is highly dynamic due to the effects of topography and the temporal variability imposed by seasonal precipitation, including rainfall and snow. Soil moisture is known to affect ecosystem carbon exchange both aboveground and belowground, as well as the stable isotopic composition of exchanged CO 2 . In this study we used an extensive suite of measurements to examine the effects of seasonal changes in soil moisture on the isotopic composition of soil CO 2 production at the landscape level. We show that the seasonal decline in soil moisture (i.e., summer dry-down) appeared to impose a trend in the δ 13 C of soil CO 2 production (δ P ) with more negative δ P early in the growing season when soils were wet, and more positive δ P as the growing season progressed and soils dried out. This seemingly generalizable pattern for a snow-dominated watershed is likely to represent the variability of recently assimilated C, tracked through the plant-soil system and imprinted in the respired CO 2 . Thus, our observations suggest that, at least for mountainous environments, seasonal changes in δ P are largely mediated by soil moisture and their spatial variability is partially organized by topography

    Is Pretenure Interdisciplinary Research a Career Risk?

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    Despite initiatives to promote interdisciplinary research, early-career academics continue to perceive professional risks to working at the interface between traditional disciplines. Unexpectedly, the inherent practical challenges of interdisciplinary scholarship, such as new methodologies and lexicons, are not the chief source of the perceived risk. The perception of risk is pervasive across disciplines, and it persists despite efforts to support career development for individuals with common interests [Mitchell and Weiler, 2011]. Suggestions that interdisciplinary work can go unrewarded in academia [Clark et al., 2011] foster a concern that targeting interdisciplinary questions, such as those presented by climate change, will pose problems for acquiring and succeeding in a tenure-track position. If self-preservation limits the questions posed by early-career academics, a perceived career risk is as damaging as a real one to new transdisciplinary initiatives. Thus, institutions should address the source of this perception whether real or specious

    Comparative Analysis of Cervical Spine Management in a Subset of Severe Traumatic Brain Injury Cases Using Computer Simulation

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    BACKGROUND: No randomized control trial to date has studied the use of cervical spine management strategies in cases of severe traumatic brain injury (TBI) at risk for cervical spine instability solely due to damaged ligaments. A computer algorithm is used to decide between four cervical spine management strategies. A model assumption is that the emergency room evaluation shows no spinal deficit and a computerized tomogram of the cervical spine excludes the possibility of fracture of cervical vertebrae. The study's goal is to determine cervical spine management strategies that maximize brain injury functional survival while minimizing quadriplegia. METHODS/FINDINGS: The severity of TBI is categorized as unstable, high risk and stable based on intracranial hypertension, hypoxemia, hypotension, early ventilator associated pneumonia, admission Glasgow Coma Scale (GCS) and age. Complications resulting from cervical spine management are simulated using three decision trees. Each case starts with an amount of primary and secondary brain injury and ends as a functional survivor, severely brain injured, quadriplegic or dead. Cervical spine instability is studied with one-way and two-way sensitivity analyses providing rankings of cervical spine management strategies for probabilities of management complications based on QALYs. Early collar removal received more QALYs than the alternative strategies in most arrangements of these comparisons. A limitation of the model is the absence of testing against an independent data set. CONCLUSIONS: When clinical logic and components of cervical spine management are systematically altered, changes that improve health outcomes are identified. In the absence of controlled clinical studies, the results of this comparative computer assessment show that early collar removal is preferred over a wide range of realistic inputs for this subset of traumatic brain injury. Future research is needed on identifying factors in projecting awakening from coma and the role of delirium in these cases

    Multi-drug resistance, inappropriate initial antibiotic therapy and mortality in Gram-negative severe sepsis and septic shock: A retrospective cohort study

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    INTRODUCTION: The impact of in vitro resistance on initially appropriate antibiotic therapy (IAAT) remains unclear. We elucidated the relationship between non-IAAT and mortality, and between IAAT and multi-drug resistance (MDR) in sepsis due to Gram-negative bacteremia (GNS). METHODS: We conducted a single-center retrospective cohort study of adult intensive care unit patients with bacteremia and severe sepsis/septic shock caused by a gram-negative (GN) organism. We identified the following MDR pathogens: MDR P. aeruginosa, extended spectrum beta-lactamase and carbapenemase-producing organisms. IAAT was defined as exposure within 24 hours of infection onset to antibiotics active against identified pathogens based on in vitro susceptibility testing. We derived logistic regression models to examine a) predictors of hospital mortality and b) impact of MDR on non-IAAT. Proportions are presented for categorical variables, and median values with interquartile ranges (IQR) for continuous. RESULTS: Out of 1,064 patients with GNS, 351 (29.2%) did not survive hospitalization. Non-survivors were older (66.5 (55, 73.5) versus 63 (53, 72) years, P = 0.036), sicker (Acute Physiology and Chronic Health Evaluation II (19 (15, 25) versus 16 (12, 19), P <0.001), and more likely to be on pressors (odds ratio (OR) 2.79, 95% confidence interval (CI) 2.12 to 3.68), mechanically ventilated (OR 3.06, 95% CI 2.29 to 4.10) have MDR (10.0% versus 4.0%, P <0.001) and receive non-IAAT (43.4% versus 14.6%, P <0.001). In a logistic regression model, non-IAAT was an independent predictor of hospital mortality (adjusted OR 3.87, 95% CI 2.77 to 5.41). In a separate model, MDR was strongly associated with the receipt of non-IAAT (adjusted OR 13.05, 95% CI 7.00 to 24.31). CONCLUSIONS: MDR, an important determinant of non-IAAT, is associated with a three-fold increase in the risk of hospital mortality. Given the paucity of therapies to cover GN MDRs, prevention and development of new agents are critical

    Health status and labor force participation : evidence for urban low and middle income individuals in Colombia

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    This paper analyzes the relationship between individual health status and labor force participation using the first wave of the Colombian Longitudinal Survey. The empirical modeling strategy accounts for the presence of potential endogeneity between these two variables. The results show that there is a positive relationship between health and labor force participation in both directions, indicating that better health is likely to lead to a higher probability of participation in the labor market, but also that individuals who participate in the labor market are more likely to report better health. Interesting differences are uncovered when comparing the results by gender and/or age groups. For instance, for younger females, health status and higher education positively affect the probability of labor participation, whereas having children under the age of 5 and being married reduce their probability of participation. Our findings also highlight the importance of public policy to guarantee good health conditions of the population which could also have a positive impact on labor productivity and consequently on long-run economic growth.info:eu-repo/semantics/publishedVersio

    Extended Field Laser Confocal Microscopy (EFLCM): Combining automated Gigapixel image capture with in silico virtual microscopy

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    <p>Abstract</p> <p>Background</p> <p>Confocal laser scanning microscopy has revolutionized cell biology. However, the technique has major limitations in speed and sensitivity due to the fact that a single laser beam scans the sample, allowing only a few microseconds signal collection for each pixel. This limitation has been overcome by the introduction of parallel beam illumination techniques in combination with cold CCD camera based image capture.</p> <p>Methods</p> <p>Using the combination of microlens enhanced Nipkow spinning disc confocal illumination together with fully automated image capture and large scale <it>in silico </it>image processing we have developed a system allowing the acquisition, presentation and analysis of maximum resolution confocal panorama images of several Gigapixel size. We call the method Extended Field Laser Confocal Microscopy (EFLCM).</p> <p>Results</p> <p>We show using the EFLCM technique that it is possible to create a continuous confocal multi-colour mosaic from thousands of individually captured images. EFLCM can digitize and analyze histological slides, sections of entire rodent organ and full size embryos. It can also record hundreds of thousands cultured cells at multiple wavelength in single event or time-lapse fashion on fixed slides, in live cell imaging chambers or microtiter plates.</p> <p>Conclusion</p> <p>The observer independent image capture of EFLCM allows quantitative measurements of fluorescence intensities and morphological parameters on a large number of cells. EFLCM therefore bridges the gap between the mainly illustrative fluorescence microscopy and purely quantitative flow cytometry. EFLCM can also be used as high content analysis (HCA) instrument for automated screening processes.</p

    Predictors of hospital mortality among septic ICU patients with Acinetobacter spp. bacteremia: A cohort study

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    BACKGROUND: We hypothesized that among septic ICU patients with Acinetobacter spp. bacteremia (Ac-BSI), carbapenem-resistant Acinetobacter spp. (CRAc) increase risk for inappropriate initial antibiotic therapy (non-IAAT), and non-IAAT is a predictor of hospital death. METHODS: We conducted a retrospective cohort study of adult septic ICU patients with Ac-BSI. Non-IAAT was defined as exposure to initially prescribed antibiotics not active against the pathogen based on in vitro susceptibility testing, and having no exposure to appropriate antimicrobial treatment within 24 hours of drawing positive culture. We compared patients who died to those who survived, and derived regression models to identify predictors of hospital mortality and of non-IAAT. RESULTS: Out of 131 patients with Ac-BSI, 65 (49.6%) died (non-survivors, NS). NS were older (63 [51, 76] vs. 56 [45, 66] years, p = 0.014), and sicker than survivors (S): APACHE II (24 [19, 31] vs. 18 [13, 22], p < 0.001) and Charlson (5 [2, 8] vs. 3 [1, 6], p = 0.009) scores. NS were also more likely than S to require pressors (75.4% vs. 42.4%, p < 0.001) and mechanical ventilation (75.4% vs. 53.0%, p = 0.008). Both CRAc (69.2% vs. 47.0%, p = 0.010) and non-IAAT (83.1% vs. 59.1%, p = 0.002) were more frequent among NS than S. In multivariate analyses, non-IAAT emerged as an independent predictor of hospital death (risk ratio [RR] 1.42, 95% confidence interval [CI] 1.10-1.58), while CRAc was the single strongest predictor of non-IAAT (RR 2.66, 95% CI 2.43-2.72). CONCLUSIONS: Among septic ICU patients with Ac-BSI, non-IAAT predicts mortality. Carbapenem resistance appears to mediate the relationship between non-IAAT and mortality
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