Adaptación de los recursos hídricos al cambio climático: aplicación de modelos hidrológicos al caso de la cuenca del río Babahoyo-Ecuador

La presente tesis doctoral es una contribución metodológica para la incorporación de criterios de cambio climático, en la planificación integral de los recursos hídricos de cuencas hidrográficas, basada en la comparación del cambio de volumen de agua, en los componentes del balance hídrico (BH) entre el periodo base (1986-2005) y los escenarios del IPCC (RCP2.6, RCP4.5, RCP6.0 y RCP8.5) para el periodo (2081-2100), donde la variable cambiante es la temperatura media, que incrementa en 1,00oC, 1,85oC, 2,25oC, y 3,70oC, respectivamente.Sobre la metodología, la complejidad radica en la recopilación, validación y estructuración de información base para hacer correr de los modelos hidrológicos, y los mapas de los componentes del BH e índice de aridez (IDA). La investigación permitió la implementación del desarrollo de una metodología, que probó ser funcional y adecuada para su replicación en otras cuencas hidrográficas de Ecuador, con la flexibilidad de ser perfectible, debido a su funcionalidad como módulo abierto y escalable.Los resultados obtenidos de los componentes del BH para el periodo base y futuros para los diferentes escenarios de cambio climático de trayectoria de concentración representativa (RCP), fueron producto del modelamiento hidrológico con la herramienta ArcSWAT sobre la plataforma de sistemas de información geográfica (SIG). Con el módulo interno de programación orientada a objetos del SIG, fueron elaborados de forma semiautomática, los mapas del balance hídrico (BH), como base para la construcción de índice de aridez (IDA).El IDA permite cuantificar y cualificar zonas climáticas, si bien no es específicamente un índice de cambio climático (modelos de clima para atmósfera), el IDA permite la comparación entre resultados del BH (base y proyección), enmarcado en los escenarios RCP.La presente investigación es una aportación en la contribución metodológica en Ecuador, para la incorporación de criterios de cambio climático en la formulación y actualización de planes de gestión integrada de los recursos hídricos, que permitiría a las autoridades, contar con información en la toma de decisiones a corto, mediano y largo plazo, para garantizar el uso y aprovechamiento del agua, mediante la mitigación de impactos, control de exposición y reducción de vulnerabilidad de los recursos hídricos, que por efecto del cambio climático, son susceptibles de reducción volumétrica del agua útil en la cuenca hidrográfica.<br /

Effect of the carbon nanotube surface characteristics on the conductivity and dielectric constant of carbon nanotube/poly(vinylidene fluoride) composites

Commercial multi-walled carbon nanotubes (CNT) were functionalized by oxidation with HNO3, to introduce oxygen-containing surface groups, and by thermal treatments at different temperatures for their selective removal. The obtained samples were characterized by adsorption of N2 at -196°C, temperature-programmed desorption and determination of pH at the point of zero charge. CNT/poly(vinylidene fluoride) composites were prepared using the above CNT samples, with different filler fractions up to 1 wt%. It was found that oxidation reduced composite conductivity for a given concentration, shifted the percolation threshold to higher concentrations, and had no significant effect in the dielectric response

Protocol for the detection and nutritional management of high-output stomas

Introduction: An issue of recent research interest is excessive stoma output and its relation to electrolyte abnormalities. Some studies have identified this as a precursor of dehydration and renal dysfunction. A prospective study was performed of the complications associated with high-output stomas, to identify their causes, consequences and management.Materials and methods: This study was carried out by a multidisciplinary team of surgeons, gastroenterologists, nutritionists and hospital pharmacists. High-output stoma (HOS) was defined as output ≥1500 ml for two consecutive days. The subjects included in the study population, 43 patients with a new permanent or temporary stoma, were classified according to the time of HOS onset as early HOS (<3 weeks after initial surgery) or late HOS (≥3 weeks after surgery). Circumstances permitting, a specific protocol for response to HOS was applied. Each patient was followed up until the fourth month after surgery.Results: Early HOS was observed in 7 (16 %) of the sample population of 43 hospital patients, and late HOS, in 6 of the 37 (16 %) non-early HOS population. By type of stoma, nearly all HOS cases affected ileostomy, rather than colostomy, patients. The patients with early HOS remained in hospital for 18 days post surgery, significantly longer than those with no HOS (12 days). The protocol was applied to the majority of EHOS patients and achieved 100 % effectiveness. 50 % of readmissions were due to altered electrolyte balance. Hypomagnesaemia was observed in 33 % of the late HOS patients.Conclusion: The protocol developed at our hospital for the detection and management of HOS effectively addresses possible long-term complications arising from poor nutritional status and chronic electrolyte alteration

<i>Gaia</i> Data Release 1. Summary of the astrometric, photometric, and survey properties

Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. Aims. A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release. Methods. The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue. Results. Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the HIPPARCOS and Tycho-2 catalogues – a realisation of the Tycho-Gaia Astrometric Solution (TGAS) – and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of ∼3000 Cepheid and RR-Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yr−1 for the proper motions. A systematic component of ∼0.3 mas should be added to the parallax uncertainties. For the subset of ∼94 000 HIPPARCOS stars in the primary data set, the proper motions are much more precise at about 0.06 mas yr−1. For the secondary astrometric data set, the typical uncertainty of the positions is ∼10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to ∼0.03 mag over the magnitude range 5 to 20.7. Conclusions. Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data

3066 consecutive Gamma Nails. 12 years experience at a single centre

<p>Abstract</p> <p>Background</p> <p>Fixation of trochanteric hip fractures using the Gamma Nail has been performed since 1988 and is today well established and wide-spread. However, a number of reports have raised serious concerns about the implant's complication rate. The main focus has been the increased risk of a subsequent femoral shaft fracture and some authors have argued against its use despite other obvious advantages, when this implant is employed.</p> <p>Through access to a uniquely large patient data base available, which is available for analysis of trochanteric fractures; we have been able to evaluate the performance of the Gamma Nail over a twelve year period.</p> <p>Methods</p> <p>3066 consecutive patients were treated for trochanteric fractures using Gamma Nails between 1990 and 2002 at the Centre de Traumatologie et de l'Orthopedie (CTO), Strasbourg, France. These patients were retrospectively analysed. Information on epidemiological data, intra- and postoperative complications and patients' outcome was retrieved from patient notes. All available radiographs were assessed by a single reviewer (AJB).</p> <p>Results</p> <p>The results showed a low complication rate with the use of the Gamma Nail. There were 137 (4.5%) intraoperative fracture-related complications. Moreover 189 (6.2%) complications were detected postoperatively and during follow-up. Cut-out of the lag screw from the femoral head was the most frequent mechanical complication (57 patients, 1.85%), whereas a postoperative femoral shaft fracture occurred in 19 patients (0.6%). Other complications, such as infection, delayed healing/non-union, avascular femoral head necrosis and distal locking problems occurred in 113 patients (3.7%).</p> <p>Conclusions</p> <p>The use of the Gamma Nail in trochanteric hip fractures is a safe method with a low complication rate. In particular, a low rate of femoral shaft fractures was reported. The low complication rate reported in this series can probably be explained by strict adherence to a proper surgical technique.</p

Evaluating hospital websites in Kuwait to improve consumer engagement and access to health information:a cross-sectional analytical study

Abstract Background Current advances in information and communication technology have made accessing and obtaining health-related information easier than ever before. Today, many hospital websites use a patient-centric approach to promote engagement and encourage learning for better health-related decision making. However, little is known about the current state of hospital websites in the State of Kuwait. This study aims to evaluate hospital websites in Kuwait and offer recommendations to improve patient engagement and access to health information. Methods This study employs a cross-sectional analytical approach to evaluate hospital websites in Kuwait in 2017. The websites of hospitals that provide in-patient services were identified through a structured search. Only active websites that were available in either English or Arabic were considered. The evaluation of the websites involved a combination of automated and expert- based evaluation methods and was performed across four dimensions: Accessibility, Usability, Presence, and Content. Results Nine hospitals met the inclusion criteria. Most of the websites fell short in all four dimensions. None of the websites passed the accessibility guidelines. The usability of websites varied between hospitals. Overall, the majority of hospitals in Kuwait have rudimentary online presence and their websites require careful reassessment with respect to design, content, and user experience. The websites focus primarily on promoting services provided by the hospital rather than engaging and communicating with patients or providing evidence-based information. Conclusions Healthcare organization and website developers should follow best-practices to improve their websites taking into consideration the quality, readability, objectivity, coverage and currency of the information as well as the design of their websites. Hospitals should leverage social media to gain outreach and better engagement with consumers. The websites should be offered in additional languages commonly spoken by people living in Kuwait. Efforts should be made to ensure that health information on hospital websites are evidence-based and checked by healthcare professionals

Internal fixation treatments for intertrochanteric fracture: A systematic review and meta-Analysis of randomized evidence

The relative effects of internal fixation strategies for intertrochanteric fracture after operation remain uncertain. We conducted a systematic review and meta-Analysis of randomized controlled trials (RCTs) to address this important issue. We searched PubMed, EMBASE and CENTRAL for RCTs that compared different internal fixation implants in patients with intertrochanteric fracture at 6-month follow-up or longer. We ultimately included 43 trials enrolling 6911 patients; most trials were small in sample sizes and events. Their risk of bias was generally unclear due to insufficient reporting. Because of these, no statistically significant differences were present from most of the comparisons across all the outcomes, and no definitive conclusions can be made. However, a number of trials compared two commonly used internal fixation strategies, gamma nail (GN) and sliding hip screw (SHS). There is good evidence suggesting that, compared to SHS, GN may increase the risk of cut out (OR = 1.87, 95% CI, 1.08 to 3.21), re-operation (OR = 1.61, 95% CI, 1.02 to 2.53), intra-operative (OR = 3.14, 95% CI, 1.34 to 7.35) and later fractures (OR = 3.67, 95% CI, 1.37 to 9.83). Future randomized trials or observational studies that are carefully designed and conducted are warranted to establish the effects of alternative internal fixation strategies for intertrochanteric fracture