Is there evidence for an early start on renal replacement therapy in patients with higher glomerular filtration rate?

There is a trend in the last decade for an increase in early initiation in renal replacement therapy in the United States. In 1996 19% of patients initiated dialysis with an estimated glomerular fltration over 10 ml/min/1,73m2 percentage that actually has increase to 45%. This review will show the reasons and evidence behind the current tendencies. There is no factual evidence to support the claim of the benefcial effects in early dialysis starts. Data so far shows increase mortality in early dialysis, unrelated to the co-morbidities of patients with advanced chronic kidney disease. Residual renal function could also be affected by early initiation of dialysis, hampering survival in the long run. Finally will be showing the fnancial burden to the health system. Randomized clinical trials are needed to answer these questions.  Key words: Hemodialysis. Chronic renal failure. End stage kidney disease. Renal replacement therapy.      En los Estados Unidos se está notando un incremento del inicio precoz de terapias renales sustitutivas en esta última década. Del 19% de pacientes que iniciaron diálisis con fltrado glomerular por encima de 10 ml/min/1,73m2 en 1996 se ha pasado a un 45%. La presente revisión pretende hacer hincapié en este fenómeno, presentado evidencia referente a ello. No se conoce si existe benefcio alguno para el comienzo precoz de diálisis. Los datos demuestran un incremento de la mortalidad en diálisis precoz que no parece ser debido a las morbilidades de los pacientes con insufciencia renal crónica terminal. La función renal residual se puede afectar durante la diálisis de inicio comprometiendo la supervivencia del paciente a largo plazo. Finalmente, se expone el posible gasto fnanciero que esta tendencia acarrea a nuestro sistema de salud. Son necesarios estudios clínicos aleatorizados que den respuestas a estos dilemas. Palabras clave: Hemodiálisis. Insufciencia renal crónica. Insufciencia renal crónica terminal. Terapia renal sustitutiva

Socializaci?n de diferentes textos para la producci?n escrita en los estudiantes del grado octavo del Colegio San Paulo de Tocancipa S.A.S

104 p. Recurso Electr?nicoEste proyecto de investigaci?n presenta una propuesta did?ctica dirigida (a manejar la producci?n escrita de los estudiantes) que se desarroll? en el grado octavo de educaci?n secundaria en el Colegio San Paulo Tocancip? S.A.S, el cual se encuentra ubicado en Tocancip? (Cundinamarca). La necesidad de plantear y desarrollar este taller de escritura surge como resultado de las experiencias de las de los estudiantes al producir un texto en las diferentes actividades de sensibilizaci?n que realizamos como (leer un cuento y luego plasmar la idea de lo recuerdan del cuento.). Esto nos permiti? centrarnos en lo referente a la ausencia de h?bitos de escritura que presentan los estudiantes al estar expuestos a actividades rutinarias y repetitivas que vinculan el manejo de la lengua escrita. Teniendo en cuenta las necesidades de los estudiantes de grado octavo se procede a dise?ar y aplicar una propuesta pedag?gica que busque fortalecer el proceso de escritura de los estudiantes, de tal forma que en este ejercicio partamos de sus gustos e intereses, generando procesos de escritura libres y espont?neos mediados por su imaginaci?n, lo cual a su vez nos permiti? producir una amplia gama de textos, sin tener en cuenta la su naturaleza del mismo para ello utilizamos: cuentos, recetas, carta, micro relato, autobiograf?a entre otros. Que, a lo largo del proceso de investigaci?n, se pudo evidenciar que cambios surgen en la estructura de cada uno de los procesos que desarrollar?amos como: el pensamiento, la asociaci?n, el reconocimiento, la categorizaci?n, la segmentaci?n entre otros.This research project presents a didactic proposal directed (a maneuver of the written production of the students) that was developed in the eighth grade of the secondary education in the School San Pablo Tocancip? S.A.S, which is located in Tocancip? (Cundinamarca). The need to raise and develop this higher writing arises as a result of the students' experiences to produce a text in the various sensitization activities that are performed as (read a story and then translate the idea of the memory of the story). This allowed us to focus on the absence of writing habits that introduce students to being exposed to the routine and repetitive activities that link the management of written language. Taking into account the needs of eighth grade students in the process of designing and applying a pedagogical proposal that seeks to strengthen the writing process of students, so that in this exercise partial of their tastes and interests, generating processes of Free writing And spontaneous mediated by his imagination, which in turn allowed us to produce a wide range of texts, without taking into account the nature of the same used for it: stories, recipes, letter, micro story, autobiography among others. Throughout the research process, it was possible to show that changes arise in the structure of each of the processes that are achieved as: thought, association, recognition, categorization, segmentation among others. Keywords: writing, activities, texts, tools, stories, essay writing, grammar rules

Ice-nucleating particles in Canadian Arctic sea-surface microlayer and bulk seawater

The sea-surface microlayer and bulk seawater can contain ice-nucleating particles (INPs) and these INPs can be emitted into the atmosphere. Our current understanding of the properties, concentrations, and spatial and temporal distributions of INPs in the microlayer and bulk seawater is limited. In this study we investigate the concentrations and properties of INPs in microlayer and bulk seawater samples collected in the Canadian Arctic during the summer of 2014. INPs were ubiquitous in the microlayer and bulk seawater with freezing temperatures in the immersion mode as high as −14 °C. A strong negative correlation (R = −0. 7, p = 0. 02) was observed between salinity and freezing temperatures (after correction for freezing depression by the salts). One possible explanation is that INPs were associated with melting sea ice. Heat and filtration treatments of the samples show that the INPs were likely heat-labile biological materials with sizes between 0.02 and 0.2 µm in diameter, consistent with previous measurements off the coast of North America and near Greenland in the Arctic. The concentrations of INPs in the microlayer and bulk seawater were consistent with previous measurements at several other locations off the coast of North America. However, our average microlayer concentration was lower than previous observations made near Greenland in the Arctic. This difference could not be explained by chlorophyll a concentrations derived from satellite measurements. In addition, previous studies found significant INP enrichment in the microlayer, relative to bulk seawater, which we did not observe in this study. While further studies are needed to understand these differences, we confirm that there is a source of INP in the microlayer and bulk seawater in the Canadian Arctic that may be important for atmospheric INP concentrations

Tropospheric ozone sources and wave activity over Mexico City and Houston during MILAGRO/Intercontinental Transport Experiment (INTEX-B) Ozonesonde Network Study, 2006 (IONS-06)

During the INTEX-B (Intercontinental Chemical Transport Experiment)/ MILAGRO (Megacities Initiative: Local and Global Research Observations) experiments in March 2006 and the associated IONS-06 (INTEX Ozonesonde Network Study; <a href="http://croc.gsfc.nasa.gov/intexb/ions06.html" target="_blank">http://croc.gsfc.nasa.gov/intexb/ions06.html</a>), regular ozonesonde launches were made over 15 North American sites. The soundings were strategically positioned to study inter-regional flows and meteorological interactions with a mixture of tropospheric O<sub>3</sub> sources: local pollution; O<sub>3</sub> associated with convection and lightning; stratosphere-troposphere exchange. The variability of tropospheric O<sub>3</sub> over the Mexico City Basin (MCB; 19° N, 99° W) and Houston (30° N, 95° W) is reported here. MCB and Houston profiles displayed a double tropopause in most soundings and a subtropical tropopause layer with frequent wave disturbances, identified through O<sub>3</sub> laminae as gravity-wave induced. Ozonesondes launched over both cities in August and September 2006 (IONS-06, Phase 3) displayed a thicker tropospheric column O<sub>3</sub> (~7 DU or 15–20%) than in March 2006; nearly all of the increase was in the free troposphere. In spring and summer, O<sub>3</sub> laminar structure manifested mixed influences from the stratosphere, convective redistribution of O<sub>3</sub> and precursors, and O<sub>3</sub> from lightning NO. Stratospheric O<sub>3</sub> origins were present in 39% (MCB) and 60% (Houston) of the summer sondes. Comparison of summer 2006 O<sub>3</sub> structure with summer 2004 sondes (IONS-04) over Houston showed 7% less tropospheric O<sub>3</sub> in 2006. This may reflect a sampling contrast, August to mid-September 2006 instead of July-mid August 2004

Dynamics of the Electro-Optic response of Blue Bronze

We have studied the charge density wave (CDW) repolarization dynamics in blue bronze by applying square-wave voltages of different frequencies to the sample and measuring the changes in infrared transmittance, proportional to CDW strain. The frequency dependence of the electro-transmittance was fit to a modified harmonic oscillator response and the evolution of the parameters as functions of voltage, position, and temperature are discussed. Resonant frequencies decrease with distance from the current contacts, indicating that the resulting delays are intrinsic to the CDW with the strain effectively flowing from the contact. For a fixed position, the average relaxation time has a voltage dependence given by tau_0~V^-p, with 1<p<2. The temperature dependence of the fitting parameters shows that the dynamics are governed by both the force on the CDW and the CDW current: for a given force and position, both the relaxation and delay times are inversely proportional to the CDW current as temperature is varied. The long relaxation and delay times (~ 1 ms) suggest that the strain response involves the motion of macroscopic objects, presumably CDW phase dislocation lines.Comment: 36 pages, including 12 figures, submitted to Phys. Rev.

La factura de agua como estrategia para trabajar con habilidades de pensamiento y cuidado del ambiente

El aprendizaje en los niños está mediado por su cotidianidad (familia, amigos, medios de comunicación, y la vida escolar), es decir, existe una constante interacción entre el conocimiento común y el científico en donde este último es sometido a prueba por medio de la experimentación, bien sea en el aula como en otros espacios académicos, los cuales permiten el desarrollo del crecimiento de la cultura

Ice-nucleating ability of aerosol particles and possible sources at three coastal marine sites

Despite the importance of ice-nucleating particles (INPs) for climate and precipitation, our understanding of these particles is far from complete. Here, we investigated INPs at three coastal marine sites in Canada, two at mid-latitude (Amphitrite Point and Labrador Sea) and one in the Arctic (Lancaster Sound). For Amphitrite Point, 23 sets of samples were analyzed, and for Labrador Sea and Lancaster Sound, one set of samples was analyzed for each location. At all three sites, the ice-nucleating ability on a per number basis (expressed as the fraction of aerosol particles acting as an INP) was strongly dependent on the particle size. For example, at diameters of around 0.2µm, approximately 1 in 106 particles acted as an INP at −25°C, while at diameters of around 8µm, approximately 1 in 10 particles acted as an INP at −25°C. The ice-nucleating ability on a per surface-area basis (expressed as the surface active site density, ns) was also dependent on the particle size, with larger particles being more efficient at nucleating ice. The ns values of supermicron particles at Amphitrite Point and Labrador Sea were larger than previously measured ns values of sea spray aerosols, suggesting that sea spray aerosols were not a major contributor to the supermicron INP population at these two sites. Consistent with this observation, a global model of INP concentrations under-predicted the INP concentrations when assuming only marine organics as INPs. On the other hand, assuming only K-feldspar as INPs, the same model was able to reproduce the measurements at a freezing temperature of −25°C, but under-predicted INP concentrations at −15°C, suggesting that the model is missing a source of INPs active at a freezing temperature of −15°C

Reply to: Caution over the use of ecological big data for conservation

info:eu-repo/semantics/publishedVersio